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Sample records for analog chihuahua mexico

  1. Amphibians and reptiles of the state of Chihuahua, Mexico, with comparisons with adjoining states.

    Science.gov (United States)

    Lemos-Espinal, Julio A; Smith, Geoffrey R; Woolrich-Piña, Guillermo A; Cruz, Alexander

    2017-01-01

    Chihuahua is Mexico's largest state, and its physiographic complexity affects the distribution of its herpetofauna. We list amphibians and reptiles for the state of Chihuahua, with their conservation status. We also compare this list to those of six adjoining states in the United States and Mexico (New Mexico, Texas, Coahuila, Durango, Sinaloa, and Sonora). A total of 175 species of amphibians and reptiles is found in Chihuahua. Thirty-eight are amphibians, and 137 reptiles. Chihuahuan amphibians and reptiles represent just over 37% of such species from Chihuahua and neighboring states. Chihuahua shares the highest proportion of its herpetofauna with Sonora and Durango. Most of the herpetofauna of Chihuahua falls in IUCNs least concern category and is not listed by SEMARNAT. However, turtles in Chihuahua are a group of particular conservation concern.

  2. Amphibians and reptiles of the state of Chihuahua, Mexico, with comparisons with adjoining states

    Directory of Open Access Journals (Sweden)

    Julio A. Lemos-Espinal

    2017-02-01

    Full Text Available Chihuahua is Mexico’s largest state, and its physiographic complexity affects the distribution of its herpetofauna. We list amphibians and reptiles for the state of Chihuahua, with their conservation status. We also compare this list to those of six adjoining states in the United States and Mexico (New Mexico, Texas, Coahuila, Durango, Sinaloa, and Sonora. A total of 175 species of amphibians and reptiles is found in Chihuahua. Thirty-eight are amphibians, and 137 reptiles. Chihuahuan amphibians and reptiles represent just over 37% of such species from Chihuahua and neighboring states. Chihuahua shares the highest proportion of its herpetofauna with Sonora and Durango. Most of the herpetofauna of Chihuahua falls in IUCNs least concern category and is not listed by SEMARNAT. However, turtles in Chihuahua are a group of particular conservation concern.

  3. Diversity of amphibians and reptiles associated with grasslands of Janos-Casas Grandes, Chihuahua, Mexico (La diversidad de anfibios y reptiles asociada a los pastizales de Janos-Casas Grandes, Chihuahua, Mexico)

    Science.gov (United States)

    Georgina Santos-Barrera; Jesus Pacheco-Rodriguez

    2006-01-01

    Prairie-dog (Cynomys ludovicianus) colonies in northwest Chihuahua, Mexico, have been of great significance not only in initiating protection programs for the species but also in learning about the biological diversity (flora and fauna) of the natural grasslands of Janos-Casas Grandes, Chihuahua. Therefore a study of the herpetological fauna within the prairie-dog...

  4. Wind Transport of Radionuclide- Bearing Dust, Peña Blanca, Chihuahua, Mexico

    Science.gov (United States)

    Velarde, R.; Goodell, P. C.; Gill, T. E.; Arimoto, R.

    2007-05-01

    This investigation evaluates radionuclide fractionation during wind erosion of high-grade uranium ore storage piles at Peña Blanca (50km north of Chihuahua City), Chihuahua, Mexico. The aridity of the local environment promotes dust resuspension by high winds. Although active operations ceased in 1983, the Peña Blanca mining district is one of Mexico`s most important uranium ore reserves. The study site contains piles of high grade ore, left loose on the surface, and separated by the specific deposits from which they were derived (Margaritas, Nopal I, and Puerto I). Similar locations do not exist in the United States, since uranium mining sites in the USA have been reclaimed. The Peña Blanca site serves as an analog for the Yucca Mountain project. Dust deposition is collected at Peña Blanca with BSNE sediment catchers (Fryrear, 1986) and marble dust traps (Reheis, 1999). These devices capture windblown sediment; subsequently, the sample data will help quantify potentially radioactive short term field sediment loss from the repository surface and determine sediment flux. Aerosols and surface materials will be analyzed and radioactivity levels established utilizing techniques such as gamma spectroscopy. As a result, we will be able to estimate how much radionuclide contaminated dust is being transported or attached geochemically to fine grain soils or minerals (e.g., clays or iron oxides). The high-grade uranium-bearing material is at secular equilibrium, thus the entire decay series is present. Of resulting interest is not only the aeolian transport of uranium, but also of the other daughter products. These studies will improve our understanding of geochemical cycling of radionuclides with respect to sources, transport, and deposition. The results may also have important implications for the geosciences and homeland security, and potential applications to public health. Funding for this project is provided in part via a NSF grant to Arimoto.

  5. Energy saving programs and renewable energies in Chihuahua, Mexico; Programas de ahorro de energia y energias renovables en Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ibarra Noris, Jose Luis [Gobierno del Estado de Chihuahua (Mexico)

    2005-07-01

    The high index of economic and technological growth registered in the border zone of northern Mexico in the last years, has simultaneously caused an annual growth in the electrical energy demand in a percentage higher than 6%. In this document are included the economic and environmental impacts caused by the projects developed in the Chihuahua State on energy efficiency and on the available potential of renewable energies. In order to evaluate the environmental impact that is caused when saving electrical energy in the diverse projects in process, the emission of CO{sub 2} is the only emission taken into account (even though also emissions of SO{sub 2}, NO{sub 2} and Hg exist) for being this polluting agent the one that contributes in greater amount to the global warming and the greenhouse effect. The emission index of CO{sub 2} that we considered in this presentation is of 600 kg/mwh, on the basis of the type of fuel and volume of generation of the plants in operation of the Comision Federal de Electricidad (CFE) in the Chihuahua State. [Spanish] El alto indice de crecimiento economico y tecnologico registrado en la zona fronteriza del norte de Mexico en los ultimos anos, ha ocasionado paralelamente un crecimiento en la demanda de energia electrica superior al 6% anual. En este documento se incluyen los impactos economicos y ambientales de los proyectos que se desarrollan en el estado de Chihuahua en eficiencia energetica y en el potencial que se tiene de energias renovables. Para evaluar el impacto ambiental que se obtiene al ahorrar energia electrica en los diversos proyectos en proceso, se toma en cuenta unicamente emisiones de CO{sub 2} (aun cuando tambien existen emisiones de SO{sub 2}, NO{sub 2} y Hg) por ser este el contaminante que en mayor cantidad afecta al calentamiento global y al efecto invernadero. El indice de emisiones de CO{sub 2} que consideramos en esta presentacion es de 600 kg/mwh, en base al tipo de combustible y volumen de generacion de las

  6. Guarijio de Arechuyvo, Chihuahua (Guarijio of Arechuyvo, Chihuahua).

    Science.gov (United States)

    Miller, Wick R.

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Guarijio, an indigenous language of Mexico spoken in Arechuyvo, Chihuahua. The objective of collecting such a representative sampling of the linguistic…

  7. GAMMA-RAY CHARACTERIZATION OF THE U-SERIES INTERMEDIATE DAUGHTERS FROM SOIL SAMPLES AT THE PENA BLANCA NATURAL ANALOG, CHIHUAHUA, MEXICO

    International Nuclear Information System (INIS)

    French, D.C.; Anthony, E.Y.; Goodell, P.C.

    2005-01-01

    The Pena Blanca natural analog is located in the Sierra Pena Blanca, approximately 50 miles north of Chihuahua City, Mexico. The Sierra Pena Blanca is composed mainly of ash-flow tuffs, and the uranium in the region is contained in the brecciated zones of these tuffs. The Pena Blanca site is considered a natural analog to the proposed Yucca Mountain Nuclear Waste Repository because they share similar characteristics of structure, volcanic lithology, tectonic activity, and hydrologic regime. One of the mineralized zones, the Nopal I deposit, was mined in the early 1980s and the ore was stockpiled close to the mine. This stockpile area has subsequently been cleared and is referred to as the prior high-grade stockpile (PHGS) site. Soil surrounding boulders of high-grade ore associated with the PHGS site have been sampled. The purpose of this study is to characterize the transport of uranium series radioisotopes from the boulder to the soil during the past 25 years. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. The daughter to parent ratios are used to establish whether the samples are in secular equilibrium. Activities are determined using gamma-ray spectroscopy. Isotopes of the uranium series decay chain detected by gamma-ray spectroscopy include 210 Pb, 234 U, 234 Th, 230 Th, 226 Ra, 214 Pb, 214 Bi, and 234 Pa. Preliminary results indicate that some daughter to parent pairs appear to be in secular disequilibrium. Thorium is in excess relative to uranium, and radium is in excess relative to thorium. A deficiency appears to exist for 210 Pb relative to 214 Bi and 214 Pb. If these results are borne out by further analysis, they would suggest transport of nuclides from the high-grade boulder into its surroundings, followed by continued leaching of uranium and lead from the environment

  8. Alternative perspectives of quality of prenatal care in Chihuahua, Mexico

    OpenAIRE

    Lourdes Camarena O; Christine von Glascoe

    2007-01-01

    Objective: this article describes the process and results of a research on the quality of prenatal care from the perspective of pregnant women who use the principal subsystems of the Mexican healthcare system in the city of Chihuahua, Mexico. Methodology: the field of cognitive anthropology was adopted using techniques that reveal the organization of concepts of quality in prenatal care based on pregnant women’s knowledge and experience, in terms of where they decided to seek care. Results: a...

  9. Spatial analysis techniques applied to uranium prospecting in Chihuahua State, Mexico

    Science.gov (United States)

    Hinojosa de la Garza, Octavio R.; Montero Cabrera, María Elena; Sanín, Luz H.; Reyes Cortés, Manuel; Martínez Meyer, Enrique

    2014-07-01

    To estimate the distribution of uranium minerals in Chihuahua, the advanced statistical model "Maximun Entropy Method" (MaxEnt) was applied. A distinguishing feature of this method is that it can fit more complex models in case of small datasets (x and y data), as is the location of uranium ores in the State of Chihuahua. For georeferencing uranium ores, a database from the United States Geological Survey and workgroup of experts in Mexico was used. The main contribution of this paper is the proposal of maximum entropy techniques to obtain the mineral's potential distribution. For this model were used 24 environmental layers like topography, gravimetry, climate (worldclim), soil properties and others that were useful to project the uranium's distribution across the study area. For the validation of the places predicted by the model, comparisons were done with other research of the Mexican Service of Geological Survey, with direct exploration of specific areas and by talks with former exploration workers of the enterprise "Uranio de Mexico". Results. New uranium areas predicted by the model were validated, finding some relationship between the model predictions and geological faults. Conclusions. Modeling by spatial analysis provides additional information to the energy and mineral resources sectors.

  10. Democratic Leadership in Middle Schools of Chihuahua Mexico: Improving Middle Schools through Democracy

    Science.gov (United States)

    Delgado, Manuel Lopez

    2014-01-01

    The purpose of this study was to analyse the effects of the implementation of a democratic approach to lead and manage middle schools in Chihuahua, Mexico. This research was based on a Likert questionnaire and semistructured interviews to explore the level of involvement of students, teachers, and parents in schools participating in a programme…

  11. Natural Analog Studies at Pena Blanca, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    A.M. Simmons

    2005-07-11

    The significance of the Pena Blanca uranium deposits in the State of Chihuahua, Mexico as potential natural analogs for a nuclear waste repository in unsaturated welded tuff was first recognized in the 1980s. In the 1970s, the Pena Blanca region was a major target of uranium exploration and exploitation by the Mexican government. Since then the Nopal I uranium deposit has been studied extensively by researchers in the U.S., Mexico, and Europe. The Nopal I deposit represents an environment similar to that of the proposed high-level radioactive waste repository at Yucca Mountain in many ways. Both are located in semi-arid regions. Both are located in Tertiary rhyolitic tuffs overlying carbonate rocks that have been subjected to basin and range-style tectonic deformation. Both are located in a chemically oxidizing, unsaturated zone 200 m or more above the water table. The alteration of uraninite to secondary minerals at Nopal I may be similar to the alteration of uranium fuel rods in this type of setting. Investigations at Nopal I and in the surrounding Sierra Pena Blanca have included detailed outcrop mapping, hydrologic and isotopic studies of flow and transport, studies of mineral alteration, modeling, and performance assessment.

  12. Natural Analog Studies at Pena Blanca, Mexico

    International Nuclear Information System (INIS)

    A.M. Simmons

    2005-01-01

    The significance of the Pena Blanca uranium deposits in the State of Chihuahua, Mexico as potential natural analogs for a nuclear waste repository in unsaturated welded tuff was first recognized in the 1980s. In the 1970s, the Pena Blanca region was a major target of uranium exploration and exploitation by the Mexican government. Since then the Nopal I uranium deposit has been studied extensively by researchers in the U.S., Mexico, and Europe. The Nopal I deposit represents an environment similar to that of the proposed high-level radioactive waste repository at Yucca Mountain in many ways. Both are located in semi-arid regions. Both are located in Tertiary rhyolitic tuffs overlying carbonate rocks that have been subjected to basin and range-style tectonic deformation. Both are located in a chemically oxidizing, unsaturated zone 200 m or more above the water table. The alteration of uraninite to secondary minerals at Nopal I may be similar to the alteration of uranium fuel rods in this type of setting. Investigations at Nopal I and in the surrounding Sierra Pena Blanca have included detailed outcrop mapping, hydrologic and isotopic studies of flow and transport, studies of mineral alteration, modeling, and performance assessment

  13. GAMMA-RAY CHARACTERIZATION OF THE U-SERIES INTERMEDIATE DAUGHTERS FROM SOIL SAMPLES AT THE PENA BLANCA NATURAL ANALOG, CHIHUAHUA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    D.C. French; E.Y. Anthony; P.C. Goodell

    2005-07-18

    The Pena Blanca natural analog is located in the Sierra Pena Blanca, approximately 50 miles north of Chihuahua City, Mexico. The Sierra Pena Blanca is composed mainly of ash-flow tuffs, and the uranium in the region is contained in the brecciated zones of these tuffs. The Pena Blanca site is considered a natural analog to the proposed Yucca Mountain Nuclear Waste Repository because they share similar characteristics of structure, volcanic lithology, tectonic activity, and hydrologic regime. One of the mineralized zones, the Nopal I deposit, was mined in the early 1980s and the ore was stockpiled close to the mine. This stockpile area has subsequently been cleared and is referred to as the prior high-grade stockpile (PHGS) site. Soil surrounding boulders of high-grade ore associated with the PHGS site have been sampled. The purpose of this study is to characterize the transport of uranium series radioisotopes from the boulder to the soil during the past 25 years. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. The daughter to parent ratios are used to establish whether the samples are in secular equilibrium. Activities are determined using gamma-ray spectroscopy. Isotopes of the uranium series decay chain detected by gamma-ray spectroscopy include {sup 210}Pb, {sup 234}U, {sup 234}Th, {sup 230}Th, {sup 226}Ra, {sup 214}Pb, {sup 214}Bi, and {sup 234}Pa. Preliminary results indicate that some daughter to parent pairs appear to be in secular disequilibrium. Thorium is in excess relative to uranium, and radium is in excess relative to thorium. A deficiency appears to exist for {sup 210}Pb relative to {sup 214}Bi and {sup 214}Pb. If these results are borne out by further analysis, they would suggest transport of nuclides from the high-grade boulder into its surroundings, followed by continued leaching of uranium and lead from the environment.

  14. PBDEs, PCBs, and DDE in eggs and their impacts on aplomado falcons (Falco femoralis) from Chihuahua and Veracruz, Mexico.

    Science.gov (United States)

    Mora, M A; Baxter, C; Sericano, J L; Montoya, A B; Gallardo, J C; Rodríguez-Salazar, J R

    2011-12-01

    Eggs from aplomado falcons (Falco femoralis septentrionalis) nesting in Chihuahua and Veracruz, Mexico, were analyzed for organochlorine pesticides, PCBs, and PBDEs. p,p'-DDE was the only organochlorine found in all eggs at concentrations ranging from 0.13 to 7.85 μg/g wet weight. PCBs ranged from 0.04 to 2.80 μg/g wet weight and PBDEs from 62 to 798 ng/g lipid weight. DDE concentrations in eggs were not significantly different among regions; however, PCBs were significantly greater (P = 0.015) in Tinaja Verde, Chihuahua than in the other three regions. Also, PBDEs were significantly higher (P Mexico. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. PBDEs, PCBs, and DDE in eggs and their impacts on aplomado falcons (Falco femoralis) from Chihuahua and Veracruz, Mexico

    International Nuclear Information System (INIS)

    Mora, M.A.; Baxter, C.; Sericano, J.L.; Montoya, A.B.; Gallardo, J.C.; Rodriguez-Salazar, J.R.

    2011-01-01

    Eggs from aplomado falcons (Falco femoralis septentrionalis) nesting in Chihuahua and Veracruz, Mexico, were analyzed for organochlorine pesticides, PCBs, and PBDEs. p,p'-DDE was the only organochlorine found in all eggs at concentrations ranging from 0.13 to 7.85 μg/g wet weight. PCBs ranged from 0.04 to 2.80 μg/g wet weight and PBDEs from 62 to 798 ng/g lipid weight. DDE concentrations in eggs were not significantly different among regions; however, PCBs were significantly greater (P = 0.015) in Tinaja Verde, Chihuahua than in the other three regions. Also, PBDEs were significantly higher (P < 0.0001) in eggs from Veracruz than in those from Chihuahua. DDE concentrations in eggs were much lower than those associated with eggshell thinning. PBDEs and PCBs were lower than those reported in raptors from industrialized countries. Overall, contaminant concentrations observed suggest no likely impact on hatching success. The PBDE concentrations are among the first to be reported in raptor species in Mexico. - Highlights: → We analyzed environmental contaminants in eggs of aplomado falcons from Mexico. → Of all the organochlorine pesticides, only p,p'-DDE was detected in all the eggs. → Eggshell thickness was 20% thicker than the reported in eggshells from the 1970s. → Total PCBs and PBDEs were lower than those reported in industrialized countries. → Aplomado falcons in Mexico are currently not affected by DDE, PCBs, or PBDEs. - PBDEs, PCBs, and p,p'-DDE were not elevated in eggs and not likely to impact aplomado falcons in eastern and northern Mexico.

  16. PBDEs, PCBs, and DDE in eggs and their impacts on aplomado falcons (Falco femoralis) from Chihuahua and Veracruz, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Mora, M.A., E-mail: mmora@tamu.edu [Department of Wildlife and Fisheries Sciences, Texas A and M University, College Station, TX 77843-2258 (United States); Baxter, C. [Department of Wildlife and Fisheries Sciences, Texas A and M University, College Station, TX 77843-2258 (United States); Sericano, J.L. [Geochemical and Environmental Research Group, Texas A and M University, College Station, TX 77845 (United States); Montoya, A.B. [The Peregrine Fund, Inc, Boise, ID 83709 (United States); Gallardo, J.C. [Instituto de Neuroetologia, Universidad Veracruzana, Xalapa, Veracruz 91190 (Mexico); Rodriguez-Salazar, J.R. [The Peregrine Fund, Inc, Boise, ID 83709 (United States)

    2011-12-15

    Eggs from aplomado falcons (Falco femoralis septentrionalis) nesting in Chihuahua and Veracruz, Mexico, were analyzed for organochlorine pesticides, PCBs, and PBDEs. p,p'-DDE was the only organochlorine found in all eggs at concentrations ranging from 0.13 to 7.85 {mu}g/g wet weight. PCBs ranged from 0.04 to 2.80 {mu}g/g wet weight and PBDEs from 62 to 798 ng/g lipid weight. DDE concentrations in eggs were not significantly different among regions; however, PCBs were significantly greater (P = 0.015) in Tinaja Verde, Chihuahua than in the other three regions. Also, PBDEs were significantly higher (P < 0.0001) in eggs from Veracruz than in those from Chihuahua. DDE concentrations in eggs were much lower than those associated with eggshell thinning. PBDEs and PCBs were lower than those reported in raptors from industrialized countries. Overall, contaminant concentrations observed suggest no likely impact on hatching success. The PBDE concentrations are among the first to be reported in raptor species in Mexico. - Highlights: > We analyzed environmental contaminants in eggs of aplomado falcons from Mexico. > Of all the organochlorine pesticides, only p,p'-DDE was detected in all the eggs. > Eggshell thickness was 20% thicker than the reported in eggshells from the 1970s. > Total PCBs and PBDEs were lower than those reported in industrialized countries. > Aplomado falcons in Mexico are currently not affected by DDE, PCBs, or PBDEs. - PBDEs, PCBs, and p,p'-DDE were not elevated in eggs and not likely to impact aplomado falcons in eastern and northern Mexico.

  17. Prevalence of rheumatic diseases in Raramuri people in Chihuahua, Mexico: a community-based study.

    Science.gov (United States)

    Del Río Nájera, Danyella; Santana, Natalia; Peláez-Ballestas, Ingris; González-Chávez, Susana A; Quiñonez-Flores, Celia M; Pacheco-Tena, César

    2016-07-01

    This study aimed to determine the prevalence of musculoskeletal (MSK) pain and rheumatic diseases in the Raramuri population (also known as Tarahumaras) who are an indigenous group in the northern state of Chihuahua in Mexico. We used the Community-Oriented Program for Control of Rheumatic Diseases (COPCORD) methodology. An analytical cross-sectional study was conducted including indigenous Raramuri aged ≥18 years from communities settled in Chihuahua City. Subjects with positive MSK pain were evaluated by primary care physicians and rheumatologists. Demographic and occupational factors such as gender and job type associated with rheumatic disease were investigated. A total of 380 indigenous Raramuri (mean age 33.6 ± 13.1 years; 37.9 % male) were interviewed. Seventy-six individuals (20 %) reported MSK pain in the last 7 days. Pain intensity was reported as "severe" and "the most severe" in 30 % of the cases. Fifty-six individuals (14.7 %) reported pain in the past and 86 (22.6 %) had either past or current pain. The prevalence of rheumatic diseases was 10.5 %. Diagnosed diseases were osteoarthritis (6.6 %), low back pain (1.6 %), spondyloarthritis (0.8 %), rheumatoid arthritis (0.5 %), non-specific arthritis (0.5 %), rheumatic regional pain syndromes (0.3 %), and fibromyalgia (0.3 %). Rheumatic disease was associated with the following variables: age (odds ratio (OR) 1.04, 95 % confidence interval (CI) 1.02-1.08; p = 0.006), family history of rheumatic symptoms (OR 6.9; 95 % CI 2.6-18.7; p rheumatic disease prevention program in the Raramuri people in Chihuahua, Mexico.

  18. Comparison of Oil Content and Fatty Acids Profile of Western Schley, Wichita, and Native Pecan Nuts Cultured in Chihuahua, Mexico.

    Science.gov (United States)

    Rivera-Rangel, L R; Aguilera-Campos, K I; García-Triana, A; Ayala-Soto, J G; Chavez-Flores, D; Hernández-Ochoa, L

    2018-01-01

    Two different extraction processes, Soxhlet and ultrasound, were used to obtain the oil extracts of Western Schley, Wichita, and Native pecan nuts cultured in Chihuahua, Mexico. The aspects evaluated in this study were the extraction yield of the processes and fatty acids' profile of the resulting extracts. Gas chromatography coupled with mass spectrometry (GC-MS) was used to identify and determine the composition percentage of fatty acids present in pecan nuts oils extracted. The results obtained show that higher oil extraction yields were obtained by Soxhlet method with hexane (69.90%) in Wichita varieties. Wichita, Western Schley, and Native pecan nuts from Chihuahua are rich in PUFA (polyunsaturated fatty acids) and MUFA (monounsaturated fatty acids) and have low levels of SFA (saturated fatty acids). The predominant fatty acid present in all pecan nuts oils was linoleic acid followed by oleic acid. Myristic acid, palmitic acid, and linolenic acid were also identified in representative quantities. The results from this study suggest that there are statistically significant differences in the chemical composition of the pecan nuts oils extracted from the varieties cultured in Chihuahua, Mexico, and those cultivated in other regions of the world.

  19. Comparison of Oil Content and Fatty Acids Profile of Western Schley, Wichita, and Native Pecan Nuts Cultured in Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    L. R. Rivera-Rangel

    2018-01-01

    Full Text Available Two different extraction processes, Soxhlet and ultrasound, were used to obtain the oil extracts of Western Schley, Wichita, and Native pecan nuts cultured in Chihuahua, Mexico. The aspects evaluated in this study were the extraction yield of the processes and fatty acids’ profile of the resulting extracts. Gas chromatography coupled with mass spectrometry (GC-MS was used to identify and determine the composition percentage of fatty acids present in pecan nuts oils extracted. The results obtained show that higher oil extraction yields were obtained by Soxhlet method with hexane (69.90% in Wichita varieties. Wichita, Western Schley, and Native pecan nuts from Chihuahua are rich in PUFA (polyunsaturated fatty acids and MUFA (monounsaturated fatty acids and have low levels of SFA (saturated fatty acids. The predominant fatty acid present in all pecan nuts oils was linoleic acid followed by oleic acid. Myristic acid, palmitic acid, and linolenic acid were also identified in representative quantities. The results from this study suggest that there are statistically significant differences in the chemical composition of the pecan nuts oils extracted from the varieties cultured in Chihuahua, Mexico, and those cultivated in other regions of the world.

  20. Comparison of Oil Content and Fatty Acids Profile of Western Schley, Wichita, and Native Pecan Nuts Cultured in Chihuahua, Mexico

    Science.gov (United States)

    Rivera-Rangel, L. R.; Aguilera-Campos, K. I.; García-Triana, A.; Ayala-Soto, J. G.; Chavez-Flores, D.

    2018-01-01

    Two different extraction processes, Soxhlet and ultrasound, were used to obtain the oil extracts of Western Schley, Wichita, and Native pecan nuts cultured in Chihuahua, Mexico. The aspects evaluated in this study were the extraction yield of the processes and fatty acids' profile of the resulting extracts. Gas chromatography coupled with mass spectrometry (GC-MS) was used to identify and determine the composition percentage of fatty acids present in pecan nuts oils extracted. The results obtained show that higher oil extraction yields were obtained by Soxhlet method with hexane (69.90%) in Wichita varieties. Wichita, Western Schley, and Native pecan nuts from Chihuahua are rich in PUFA (polyunsaturated fatty acids) and MUFA (monounsaturated fatty acids) and have low levels of SFA (saturated fatty acids). The predominant fatty acid present in all pecan nuts oils was linoleic acid followed by oleic acid. Myristic acid, palmitic acid, and linolenic acid were also identified in representative quantities. The results from this study suggest that there are statistically significant differences in the chemical composition of the pecan nuts oils extracted from the varieties cultured in Chihuahua, Mexico, and those cultivated in other regions of the world. PMID:29610686

  1. Uranium-series isotopes transport in surface, vadose and ground waters at San Marcos uranium bearing basin, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Burillo Montúfar, Juan Carlos; Reyes Cortés, Manuel; Reyes Cortés, Ignacio Alfonso; Espino Valdez, Ma. Socorro; Hinojosa de la Garza, Octavio Raúl; Nevárez Ronquillo, Diana Pamela; Herrera Peraza, Eduardo; Rentería Villalobos, Marusia; Montero Cabrera, María Elena

    2012-01-01

    In the U deposit area at San Marcos in Chihuahua, Mexico, hydrogeological and climatic conditions are very similar to the Nopal I, Peña Blanca U deposit, 50 km away. The physicochemical parameters and activity concentrations of several 238 U-series isotopes have been determined in surface, vadose and ground waters at San Marcos. The application of some published models to activity ratios of these isotopes has allowed assessing the order of magnitude of transport parameters in the area. Resulting retardation factors in San Marcos area are R f238 ≈ 250–14,000 for the unsaturated zone and ≈110–1100 for the saturated zone. The results confirm that the mobility of U in San Marcos is also similar to that of the Nopal I U deposit and this area can be considered as a natural analog of areas suitable for geologic repositories of high-level nuclear waste.

  2. Exposure Assessment to Environmental Chemicals in Children from Ciudad Juarez, Chihuahua, Mexico.

    Science.gov (United States)

    Ochoa-Martinez, Angeles C; Orta-Garcia, Sandra T; Rico-Escobar, Edna M; Carrizales-Yañez, Leticia; Del Campo, Jorge D Martin; Pruneda-Alvarez, Lucia G; Ruiz-Vera, Tania; Gonzalez-Palomo, Ana K; Piña-Lopez, Iris G; Torres-Dosal, Arturo; Pérez-Maldonado, Ivan N

    2016-05-01

    It has been demonstrated that the human biomonitoring of susceptible populations is a valuable method for the identification of critical contaminants. Therefore, the purpose of this study was to assess the exposure profile for arsenic (As), lead (Pb), mercury (Hg), 1-hydroxypyrene (1-OHP), 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in children living in Ciudad Juarez, Chihuahua, Mexico (a major manufacturing center in Mexico). In 2012, we evaluated a total of 135 healthy children living in Ciudad Juarez since birth. The total PBDEs levels ranged from nondetectable (exposure levels to chemicals analyzed in the children living in the study community. Therefore, a biomonitoring program for the surveillance of the child population in Ciudad Juarez is necessary.

  3. A concurrent exposure to arsenic and fluoride from drinking water in Chihuahua, Mexico.

    Science.gov (United States)

    González-Horta, Carmen; Ballinas-Casarrubias, Lourdes; Sánchez-Ramírez, Blanca; Ishida, María C; Barrera-Hernández, Angel; Gutiérrez-Torres, Daniela; Zacarias, Olga L; Saunders, R Jesse; Drobná, Zuzana; Mendez, Michelle A; García-Vargas, Gonzalo; Loomis, Dana; Stýblo, Miroslav; Del Razo, Luz M

    2015-04-24

    Inorganic arsenic (iAs) and fluoride (F-) are naturally occurring drinking water contaminants. However, co-exposure to these contaminants and its effects on human health are understudied. The goal of this study was examined exposures to iAs and F- in Chihuahua, Mexico, where exposure to iAs in drinking water has been associated with adverse health effects. All 1119 eligible Chihuahua residents (>18 years) provided a sample of drinking water and spot urine samples. iAs and F- concentrations in water samples ranged from 0.1 to 419.8 µg As/L and from 0.05 to 11.8 mg F-/L. Urinary arsenic (U-tAs) and urinary F- (U-F-) levels ranged from 0.5 to 467.9 ng As/mL and from 0.1 to 14.4 µg F-/mL. A strong positive correlation was found between iAs and F- concentrations in drinking water (rs = 0.741). Similarly, U-tAs levels correlated positively with U-F- concentrations (rs = 0.633). These results show that Chihuahua residents exposed to high iAs concentrations in drinking water are also exposed to high levels of F-, raising questions about possible contribution of F- exposure to the adverse effects that have so far been attributed only to iAs exposure. Thus, investigation of possible interactions between iAs and F- exposures and its related health risks deserves immediate attention.

  4. Radon concentrations in ground and drinking water in the state of Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Villalba, L.; Colmenero Sujo, L.; Montero Cabrera, M.E.; Cano Jimenez, A.; Renteria Villalobos, M.; Delgado Mendoza, C.J.; Jurado Tenorio, L.A.; Davila Rangel, I.; Herrera Peraza, E.F.

    2005-01-01

    This paper reports 222 Rn concentrations in ground and drinking water of nine cities of Chihuahua State, Mexico. Fifty percent of the 114 sampled wells exhibited 222 Rn concentrations exceeding 11 Bq/L, the maximum contaminant level (MCL) recommended by the USEPA. Furthermore, around 48% (123 samples) of the tap-water samples taken from 255 dwellings showed radon concentrations over the MCL. There is an apparent correlation between total dissolved solids and radon concentration in ground-water. The high levels of 222 Rn found may be entirely attributed to the nature of aquifer rocks

  5. Radon concentrations in ground and drinking water in the state of Chihuahua, Mexico.

    Science.gov (United States)

    Villalba, L; Colmenero Sujo, L; Montero Cabrera, M E; Cano Jiménez, A; Rentería Villalobos, M; Delgado Mendoza, C J; Jurado Tenorio, L A; Dávila Rangel, I; Herrera Peraza, E F

    2005-01-01

    This paper reports (222)Rn concentrations in ground and drinking water of nine cities of Chihuahua State, Mexico. Fifty percent of the 114 sampled wells exhibited (222)Rn concentrations exceeding 11Bq/L, the maximum contaminant level (MCL) recommended by the USEPA. Furthermore, around 48% (123 samples) of the tap-water samples taken from 255 dwellings showed radon concentrations over the MCL. There is an apparent correlation between total dissolved solids and radon concentration in ground-water. The high levels of (222)Rn found may be entirely attributed to the nature of aquifer rocks.

  6. Characterization of urban solid waste in Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Gomez, Guadalupe; Meneses, Montserrat; Ballinas, Lourdes; Castells, Francesc

    2008-01-01

    The characterization of urban solid waste generation is fundamental for adequate decision making in the management strategy of urban solid waste in a city. The objective of this study is to characterize the waste generated in the households of Chihuahua city, and to compare the results obtained in areas of the city with three different socioeconomic levels. In order to identify the different socioeconomic trends in waste generation and characterization, 560 samples of solid waste were collected during 1 week from 80 households in Chihuahua and were hand sorted and classified into 15 weighted fractions. The average waste generation in Chihuahua calculated in this study was 0.676 kg per capita per day in April 2006. The main fractions were: organic (48%), paper (16%) and plastic (12%). Results show an increased waste generation associated with the socioeconomic level. The characterization in amount and composition of urban waste is the first step needed for the successful implementation of an integral waste management system

  7. Characterization of urban solid waste in Chihuahua, Mexico.

    Science.gov (United States)

    Gomez, Guadalupe; Meneses, Montserrat; Ballinas, Lourdes; Castells, Francesc

    2008-12-01

    The characterization of urban solid waste generation is fundamental for adequate decision making in the management strategy of urban solid waste in a city. The objective of this study is to characterize the waste generated in the households of Chihuahua city, and to compare the results obtained in areas of the city with three different socioeconomic levels. In order to identify the different socioeconomic trends in waste generation and characterization, 560 samples of solid waste were collected during 1 week from 80 households in Chihuahua and were hand sorted and classified into 15 weighted fractions. The average waste generation in Chihuahua calculated in this study was 0.676 kg per capita per day in April 2006. The main fractions were: organic (48%), paper (16%) and plastic (12%). Results show an increased waste generation associated with the socioeconomic level. The characterization in amount and composition of urban waste is the first step needed for the successful implementation of an integral waste management system.

  8. Radioactive hydrogeochemical processes in the Chihuahua-Sacramento Basin, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Burillo, J. C.; Reyes C, M.; Montero C, M. E.; Renteria V, M.; Herrera P, E. F. [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes No. 120, Complejo Industrial Chihuahua, 31109 Chihuahua (Mexico); Reyes, I.; Espino, M. S., E-mail: elena.montero@cimav.edu.mx [Universidad Autonoma de Chihuahua, Facultad de Ingenieria, Nuevo Campus Universitario, Chihuahua (Mexico)

    2012-06-15

    The Chihuahua Basin is divided by its morphology into three main sub basins: Chihuahua-Sacramento sub basin, Chihuahua Dam sub basin and Chuviscar River sub basin. In the aquifers at the Sacramento sub basin, specific concentrations of uranium in groundwater range from 460 to 1260 Bq / m{sup 3}. The presence of strata and sandy clay lenses with radiometric anomalies in the N W of Chihuahua Valley was confirmed by a litostatigraphic study and gamma spectrometry measurements of drill cuttings. High uranium activity values found in the water of some deep wells may correspond to the presence of fine material bodies of carbonaceous material, possible forming pa leo-sediment of flooding or pa leo-soils. It is suggested that these clay horizons are uranyl ion collectors. Uranyl may suffer a reduction process by organic material. Furthermore the groundwater, depending on its ph and Eh, oxidizes and re-dissolves uranium. The hydrogeochemical behavior of San Marcos dam and the N W Valley area is the subject of studies that should help to clarify the origin of the radioactive elements and their relationships with other pollutants in the watershed. (Author)

  9. Radioactive hydrogeochemical processes in the Chihuahua-Sacramento Basin, Mexico

    International Nuclear Information System (INIS)

    Burillo, J. C.; Reyes C, M.; Montero C, M. E.; Renteria V, M.; Herrera P, E. F.; Reyes, I.; Espino, M. S.

    2012-01-01

    The Chihuahua Basin is divided by its morphology into three main sub basins: Chihuahua-Sacramento sub basin, Chihuahua Dam sub basin and Chuviscar River sub basin. In the aquifers at the Sacramento sub basin, specific concentrations of uranium in groundwater range from 460 to 1260 Bq / m 3 . The presence of strata and sandy clay lenses with radiometric anomalies in the N W of Chihuahua Valley was confirmed by a litostatigraphic study and gamma spectrometry measurements of drill cuttings. High uranium activity values found in the water of some deep wells may correspond to the presence of fine material bodies of carbonaceous material, possible forming pa leo-sediment of flooding or pa leo-soils. It is suggested that these clay horizons are uranyl ion collectors. Uranyl may suffer a reduction process by organic material. Furthermore the groundwater, depending on its ph and Eh, oxidizes and re-dissolves uranium. The hydrogeochemical behavior of San Marcos dam and the N W Valley area is the subject of studies that should help to clarify the origin of the radioactive elements and their relationships with other pollutants in the watershed. (Author)

  10. Arsenic in freshwater fish in the Chihuahua County water reservoirs (Mexico).

    Science.gov (United States)

    Nevárez, Myrna; Moreno, Myriam Verónica; Sosa, Manuel; Bundschuh, Jochen

    2011-01-01

    Water reservoirs in Chihuahua County, Mexico, are affected by some punctual and non-punctual geogenic and anthropogenic pollution sources; fish are located at the top of the food chain and are good indicators for the ecosystems pollution. The study goal was to: (i) determine arsenic concentration in fish collected from the Chuviscar, Chihuahua, San Marcos and El Rejon water reservoirs; (ii) to assess if the fishes are suitable for human consumption and (iii) link the arsenic contents in fish with those in sediment and water reported in studies made the same year for these water reservoirs. Sampling was done in summer, fall and winter. The highest arsenic concentration in the species varied through the sampling periods: Channel catfish (Ictalurus punctatus) with 0.22 ± 0.15 mg/kg dw in winter and Green sunfish (Lepomis cyanellus) with 2.00 ± 0.15 mg/kg dw in summer in El Rejon water reservoir. A positive correlation of arsenic contents was found through all sampling seasons in fish samples and the samples of sediment and water. The contribution of the weekly intake of inorganic arsenic, based on the consumption of 0.245 kg fish muscles/body weight/week was found lower than the acceptable weekly intake of 0.015 mg/kg/body weight for inorganic arsenic suggested by FAO/WHO.

  11. Radon concentrations in ground and drinking water in the state of Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Villalba, L. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico); Colmenero Sujo, L. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico); Instituto Tecnologico de Chihuahua II, Ave. de las Industrias 11101, Chihuahua, Chih. (Mexico); Montero Cabrera, M.E. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico)]. E-mail: elena.montero@cimav.edu.mx; Cano Jimenez, A. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico); Renteria Villalobos, M. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico); Delgado Mendoza, C.J. [Facultad de Ciencias Quimicas, Universidad Autonoma de Chihuahua, Ciudad Universitaria S/N, Chihuahua, Chih. (Mexico); Jurado Tenorio, L.A. [Facultad de Ciencias Quimicas, Universidad Autonoma de Chihuahua, Ciudad Universitaria S/N, Chihuahua, Chih. (Mexico); Davila Rangel, I. [Centro Regional de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 20, Zacatecas, Zac. (Mexico); Herrera Peraza, E.F. [Centro de Investigacion en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, CP 31109 Chihuahua, Chih. (Mexico)

    2005-07-01

    This paper reports {sup 222}Rn concentrations in ground and drinking water of nine cities of Chihuahua State, Mexico. Fifty percent of the 114 sampled wells exhibited {sup 222}Rn concentrations exceeding 11 Bq/L, the maximum contaminant level (MCL) recommended by the USEPA. Furthermore, around 48% (123 samples) of the tap-water samples taken from 255 dwellings showed radon concentrations over the MCL. There is an apparent correlation between total dissolved solids and radon concentration in ground-water. The high levels of {sup 222}Rn found may be entirely attributed to the nature of aquifer rocks.

  12. Persistent environmental pollutants in eggs of aplomado falcons from Northern Chihuahua, Mexico, and South Texas, USA

    Science.gov (United States)

    Mora, M.A.; Montoya, A.B.; Lee, M.C.; Macias-Duarte, Alberto; Rodriguez-Salazar, R.; Juergens, P.W.; Lafon-Terrazas, A.

    2008-01-01

    The northern aplomado falcon (Falco femoralis septentrionalis) disappeared from south Texas in the 1940s. Due to great success in the release of captive-reared aplomado falcons in south Texas, there are currently more than 40 established nesting pairs in the region. Addled eggs from aplomado falcons nesting in northern Chihuahua and south Texas were analyzed to determine organochlorine (OC) and inorganic element contaminant burdens and their potential association with egg failures and effects on reproduction. Among the OCs, DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] was present at the highest concentrations (range 262-21487??ng/g wet weight) followed by polychlorinated biphenyls (PCBs, range 88-3274??ng/g ww). DDE was greater (P = 0.03) in eggs from El Sueco (Chihuahua, Mexico) than in those from Matagorda Island (Texas, USA). DDE concentrations in eggs of aplomado falcons from El Sueco were elevated; however, reproductive success in the two Chihuahuan populations did not seem to be affected by DDE. DDE and metals in potential avian prey of the aplomado falcon from Matagorda Island were very low and below levels in the diet at which some negative effects might be expected. Except for mercury (Hg), metal concentrations in eggs were fairly low and were not different among locations in Chihuahua and south Texas. Hg was somewhat elevated and was greater (P Chihuahua locations. Periodic monitoring of Hg concentrations in addled eggs of aplomado falcons in south Texas is recommended to continue evaluating potential negative effects on their recovery. ?? 2007 Elsevier Ltd. All rights reserved.

  13. "The State of Chihuahua", Lesson Plan for "Cultural Unit: Focus on Mexico."

    Science.gov (United States)

    Llewellyn, Marianne

    This lesson plan was designed for students in Montana schools. The objectives for this culture unit are having: (1) students recognize the similarities between their home stat of Montana and the Mexican state of Chihuahua; (2) students learn about features unique to Chihuahua; and (3) students create an advertising brochure marketing Chihuahua to…

  14. Federalization of Education in Chihuahua

    Science.gov (United States)

    Marak, Andrae M.

    2005-01-01

    This article examines the politics behind the initial centralization of primary education in Chihuahua, Mexico during the 1920s and 1930s. The article argues that the centralization of primary education was one of many tools used by the federal government to consolidate its power in the wake of the Mexican Revolution (1910-1917) and create a…

  15. Crustal deformation and seismic measurements in the region of McDonald Observatory, West Texas. [Texas and Northern Chihuahua, Mexico

    Science.gov (United States)

    Dorman, H. J.

    1981-01-01

    The arrival times of regional and local earthquakes and located earthquakes in the Basin and Range province of Texas and in the adjacent areas of Chihuahua, Mexico from January 1976 to August 1980 at the UT'NASA seismic array are summarized. The August 1931 Texas earthquake is reevaluated and the seismicity and crustal structure of West Texas is examined. A table of seismic stations is included.

  16. Sails: a new gypsum speleothem from Naica, Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Forti Paolo

    2007-01-01

    Full Text Available The caves of Naica (Chihuahua, Mexico are perhaps the most famous mine caves of the world due to the presence of giganticgypsum crystals. Nevertheless, very little research has been carried out on this karst area until now. A multidisciplinary investigationstarted in 2006 with the aim not only to define the genesis and the age of the Naica gypsum crystals, but also on other scientificaspects of these caves.This paper describes a completely new type of gypsum speleothem: the “sails”, observed only inside the Cueva de las Velas, one ofthe caves of the Naica system. This speleothem consists of extremely thin, elongated skeleton crystals that have grown epitaxiallyonly on the tips of the gypsum crystals pointing upward. The genesis of sails is strictly related to the environmental conditions setup inside the cave just after the artificial lowering of the groundwater by mine dewatering (less than 20 yr ago. In a few years sail speleothems will disappear entirely and therefore this study is fundamental to preserve at least the memory of them.

  17. Knowledge and use of edible mushrooms in two municipalities of the Sierra Tarahumara, Chihuahua, Mexico.

    Science.gov (United States)

    Quiñónez-Martínez, Miroslava; Ruan-Soto, Felipe; Aguilar-Moreno, Ivonne Estela; Garza-Ocañas, Fortunato; Lebgue-Keleng, Toutcha; Lavín-Murcio, Pablo Antonio; Enríquez-Anchondo, Irma Delia

    2014-09-17

    The Sierra Madre Occidental of Chihuahua in Northern Mexico is inhabited by indigenous Raramuris, mestizos, and other ethnic groups. The territory consists of canyons and ravines with pine, oak and pine-oak forests in the higher plateaus. A great diversity of potentially edible mushrooms is found in forests of the Municipalities of Bocoyna and Urique. Their residents are the only consumers of wild mushrooms in the Northern Mexico; they have a long tradition of collecting and eating these during the "rainy season." However, despite the wide diversity of edible mushrooms that grow in these areas, residents have a selective preference. This paper aims to record evidence of the knowledge and use of wild potentially edible mushroom species by inhabitants of towns in the Sierra Tarahumara of Chihuahua, Mexico. Using a semi-structured technique, we surveyed 197 habitants from seven locations in Urique, Bocoyna, and the Cusarare area from 2010 to 2012. Known fungi, local nomenclature, species consumed, preparation methods, appreciation of taste, forms of preservation, criteria for differentiating toxic and edible fungi, other uses, economic aspects, and traditional teaching were recorded. To identify the recognized species, photographic stimuli of 22 local edible species and two toxic species were used. The respondents reported preference for five species: Amanita rubescens, Agaricus campestris, Ustilago maydis, Hypomyces lactifluorum, and the Amanita caesarea complex. No apparent differences were found between ethnic groups in terms of preference, although mestizos used other species in Bocoyna (Boletus edulis and B. pinophilus). Some different uses of fungi are recognized by respondents, i.e. home decorations, medicine, as food in breeding rams, etc. The studied population shows a great appreciation towards five species, mainly the A. caesarea complex, and an apparent lack of knowledge of nearly 20 species which are used as food in other areas of Mexico. There are no

  18. First-year performance of the Chorreras pv-hybrid ice-making system in Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, Luis; Foster, Robert; Cota, Alma D [Southwest Technology Development Institute, Las Cruces, New Mexico (United States)

    2000-07-01

    This paper describes the reliability and performance of the Chorreras photovoltaic (PV) hybrid ice-making system. The system is a first of its kind in the world and is located near the fishing village of Chorreras, which is located along a man-made lake in a remote desert area of the State of Chihuahua in northern Mexico. The information gathered from technical field visits and a GOES satellite-based data collection system are reviewed to discuss system design and operation. The system has been working well in producing ice on a daily basis with only some minor control problems and water line calcification that reduced ice production until the line was cleaned. The hybrid system provides a daily average of 8.9 kWh at 240 volts to the ice-maker. The system Coefficient of Performance (COP) is about 0.65 and a total of 97 percent of the energy has been supplied by the PV array, while only 3 percent has been supplied by the back-up propane-fueled generator. Production of ice varies slightly each month due to changes in insolation and ambient temperatures. Overall ice production averages about 85 kg of ice per day. This project and this paper are dedicated to the memory of Ing. Juan Jose Onate Rodriguez from the Direccion General de Desarrollo Rural, who was the original project developer for the State of Chihuahua. [Spanish] Este articulo describe la confiabilidad y el rendimiento del sistema hibrido fotovoltaico (PV) de Chorreras para produccion de hielo. El sistema es el primero en su tipo en el mundo y esta localizado cerca del pueblo de pescadores de Chorreras, a la orilla de un lago artificial en un area desertica remota en el estado de Chihuahua, al norte de Mexico. Se esta revisando la informacion recopilada por las visitas tecnicas de campo y por el sistema de recoleccion de datos satelital GOES para analizar el diseno y operacion del sistema, que ha estado funcionando con buenos resultados en la produccion diaria de hielo, teniendo solo problemas menores de

  19. Uranium in the Surrounding of San Marcos-Sacramento River Environment (Chihuahua, Mexico)

    Science.gov (United States)

    Rentería-Villalobos, Marusia; Cortés, Manuel Reyes; Mantero, Juan; Manjón, Guillermo; García-Tenorio, Rafael; Herrera, Eduardo; Montero-Cabrera, Maria Elena

    2012-01-01

    The main interest of this study is to assess whether uranium deposits located in the San Marcos outcrops (NW of Chihuahua City, Mexico) could be considered as a source of U-isotopes in its surrounding environment. Uranium activity concentrations were determined in biota, ground, and surface water by either alpha or liquid scintillation spectrometries. Major ions were analyzed by ICP-OES in surface water and its suspended matter. For determining uranium activity in biota, samples were divided in parts. The results have shown a possible lixiviation and infiltration of uranium from geological substrate into the ground and surface water, and consequently, a transfer to biota. Calculated annual effective doses by ingestion suggest that U-isotopes in biota could not negligibly contribute to the neighboring population dose. By all these considerations, it is concluded that in this zone there is natural enhancement of uranium in all environmental samples analyzed in the present work. PMID:22536148

  20. Coliform and Metal Contamination in Lago de Colina, a Recreational Water Body in Chihuahua State, Mexico

    Science.gov (United States)

    Rubio-Arias, Hector; Rey, Nora I.; Quintana, Rey M.; Nevarez, G. Virginia; Palacios, Oskar

    2011-01-01

    Lago de Colina (Colina Lake) is located about 180 km south of the city of Chihuahua (Mexico), and during the Semana Santa (Holy Week) vacation period its recreational use is high. The objective of this study was to quantify coliform and heavy metal levels in this water body before and after the Holy Week vacation period in 2010. Twenty sampling points were randomly selected and two water samples were collected at each point near the surface (0.30 m) and at 1 m depth. After the Holy Week vacation the same twenty points were sampled at the same depths. Therefore, a total 80 water samples were analyzed for fecal and total coliforms and levels of the following metals: Al, As, B, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Se, Si and Zn. It was hypothesized that domestic tourism contaminated this water body, and as a consequence, could have a negative impact on visitor health. An analysis of variance (ANOVA) study was performed for each element and its interactions considering a factorial design where factor A was sample date and factor B was sample depth. Fecal coliforms were only detected at eight sampling points in the first week, but after Holy Week, both fecal and total coliforms were detected at most sampling points. The concentrations of Al, B, Na, Ni and Se were only statistically different for factor A. The levels of Cr, Cu, K and Mg was different for both date and depth, but the dual factor interaction was not significant. The amount of Ca and Zn was statistically different due to date, depth and their interaction. No significant differences were found for any factor or the interaction for the elements As, Fe and Mn. Because of the consistent results, it is concluded that local tourism is contaminating the recreational area of Colina Lake, Chihuahua, Mexico. PMID:21776236

  1. Coliform and metal contamination in Lago de Colina, a recreational water body in Chihuahua State, Mexico.

    Science.gov (United States)

    Rubio-Arias, Hector; Rey, Nora I; Quintana, Rey M; Nevarez, G Virginia; Palacios, Oskar

    2011-06-01

    Lago de Colina (Colina Lake) is located about 180 km south of the city of Chihuahua (Mexico), and during the Semana Santa (Holy Week) vacation period its recreational use is high. The objective of this study was to quantify coliform and heavy metal levels in this water body before and after the Holy Week vacation period in 2010. Twenty sampling points were randomly selected and two water samples were collected at each point near the surface (0.30 m) and at 1 m depth. After the Holy Week vacation the same twenty points were sampled at the same depths. Therefore, a total 80 water samples were analyzed for fecal and total coliforms and levels of the following metals: Al, As, B, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Se, Si and Zn. It was hypothesized that domestic tourism contaminated this water body, and as a consequence, could have a negative impact on visitor health. An analysis of variance (ANOVA) study was performed for each element and its interactions considering a factorial design where factor A was sample date and factor B was sample depth. Fecal coliforms were only detected at eight sampling points in the first week, but after Holy Week, both fecal and total coliforms were detected at most sampling points. The concentrations of Al, B, Na, Ni and Se were only statistically different for factor A. The levels of Cr, Cu, K and Mg was different for both date and depth, but the dual factor interaction was not significant. The amount of Ca and Zn was statistically different due to date, depth and their interaction. No significant differences were found for any factor or the interaction for the elements As, Fe and Mn. Because of the consistent results, it is concluded that local tourism is contaminating the recreational area of Colina Lake, Chihuahua, Mexico.

  2. Boer Colonization in Chihuahua and the American Southwest, 1903-1917

    Directory of Open Access Journals (Sweden)

    Lawrence Douglas Taylor Hansen

    2002-10-01

    Full Text Available The colonizing efforts of some groups of Boer exiled from Southafrica in Chihuahua and the American  southwest, a few years after the second anglo-boer war from 1899 to 1902, are analysed in this article. The study focuses, mainly, on the circumstances that originated this proyect  and the reasons  for the nonefulfillment of the colony settled in Chihuahua, which provoked the dissemination of most of the settlers into other regions.  On a comparative basis, two more  proyects  are analysed: the establishment of foreign Mormon and Mennonite settlers, who shared some of the Boer migrant characteristics, in Mexico.

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

    Science.gov (United States)

    2012-06-08

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

  4. Characterization of uranium minerals from Chihuahua using synchrotron radiation

    International Nuclear Information System (INIS)

    Burciaga V, D. C.; Reyes C, M.; Reyes R, A.; Renteria V, M.; Esparza P, H.; Fuentes C, L.; Fuentes M, L; Silva S, M.; Herrera P, E.; Munoz, A.; Montero C, M. E.

    2010-01-01

    Uranium mineral deposits in the vicinity of Chihuahua City (northern Mexico) have motivated a multidisciplinary investigation due to their tech no-environmental importance. It provides a broad scope study of representative mineral samples extracted from the San Marcos deposit, located northwest of Chihuahua City. The zone of interest is the source of the Sacramento River, which runs at Chihuahua City. The high uranium content of the San Marcos deposit, which was formed by hydrothermal mineralization, has resulted in elevated levels of uranium in surface and ground water, fish, plants and sediments in this region. Mineral identification of the uranium-bearing phases was accomplished with a suite of techniques. Among these phases are those called meta tyuyamunite (Ca(UO 2 ) 2 (VO 4 ) 2 ·3-5 H 2 O) and becquerelite [Ca(UO 2 ) 6 O 4 (OH) 6 ·8(H 2 O)]. It was decided to study an almost pure meta tyuyamunite sample extracted from Pena Blanca, Chihuahua uranium ore and to synthesize the becquerelite, using a modified procedure from a published one. In the current work the crystal structure of meta tyuyamunite is presented, resolved by the Rietveld refinement. Both samples were studied by X-ray absorption fine structure at beamline 2-3, Stanford Synchrotron Radiation Light source. In the present work both the spectra and extended X-ray absorption fine structure parameters are presented. (Author)

  5. Soft-sediment deformation structures interpreted as seismites in the uppermost Aptian to lowermost Albian transgressive deposits of the Chihuahua basin (Mexico)

    Science.gov (United States)

    Blanc, E.J.-P.; Blanc-Aletru, M. -C.; Mojon, P.-O.

    1998-01-01

    Several levels of soft-sediment deformation structures (s.-s.d.s.) cut by synsedimentary normal faults have been observed in the transition beds between the "Las Vigas" and "La Virgen" formations (Cretaceous) in the northeastern part of the Chihuahua basin in Mexico. These structures consisted of four kinds of motifs (floating breccias, flame-like structures, large pillow structures, and wavy structures). They are restricted to five "stratigraphie" levels (Z1-Z5) and surrounded by undeformed beds in fluvio-lacustrine and tidal deposits and can be traced over a distance of several hundred meters. This deformation is interpreted to have resulted from the combined effects of liquidization and shear stress in soft-sediments due to local earthquakes in the area which could have been generated during the rifting stage of the Chihuahua basin. New constraints placed on the age of the "Las Vigas" Formation (bracketed by Late Aptian charophytes at the bottom and colomiellids of late Aptian to earliest Albian age at the top) suggest that this synrift tectonism lasted at least until the end of the Aptian. ?? Springer-Verlag 1998.

  6. Coliform and Metal Contamination in Lago de Colina, a Recreational Water Body in Chihuahua State, Mexico

    Directory of Open Access Journals (Sweden)

    Hector Rubio-Arias

    2011-06-01

    Full Text Available Lago de Colina (Colina Lake is located about 180 km south of the city of Chihuahua (Mexico, and during the Semana Santa (Holy Week vacation period its recreational use is high. The objective of this study was to quantify coliform and heavy metal levels in this water body before and after the Holy Week vacation period in 2010. Twenty sampling points were randomly selected and two water samples were collected at each point near the surface (0.30 m and at 1 m depth. After the Holy Week vacation the same twenty points were sampled at the same depths. Therefore, a total 80 water samples were analyzed for fecal and total coliforms and levels of the following metals: Al, As, B, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Se, Si and Zn. It was hypothesized that domestic tourism contaminated this water body, and as a consequence, could have a negative impact on visitor health. An analysis of variance (ANOVA study was performed for each element and its interactions considering a factorial design where factor A was sample date and factor B was sample depth. Fecal coliforms were only detected at eight sampling points in the first week, but after Holy Week, both fecal and total coliforms were detected at most sampling points. The concentrations of Al, B, Na, Ni and Se were only statistically different for factor A. The levels of Cr, Cu, K and Mg was different for both date and depth, but the dual factor interaction was not significant. The amount of Ca and Zn was statistically different due to date, depth and their interaction. No significant differences were found for any factor or the interaction for the elements As, Fe and Mn. Because of the consistent results, it is concluded that local tourism is contaminating the recreational area of Colina Lake, Chihuahua, Mexico.

  7. Heterogeneous seepage at the Nopal I natural analogue site, Chihuahua, Mexico

    Science.gov (United States)

    Dobson, Patrick F.; Ghezzehei, Teamrat A.; Cook, Paul J.; Rodríguez-Pineda, J. Alfredo; Villalba, Lourdes; de La Garza, Rodrigo

    2012-02-01

    A study of seepage occurring in an adit at the Nopal I uranium mine in Chihuahua, Mexico, was conducted as part of an integrated natural analogue study to evaluate the effects of infiltration and seepage on the mobilization and transport of radionuclides. An instrumented seepage collection system and local automated weather station permit direct correlation between local precipitation events and seepage. Field observations recorded between April 2005 and December 2006 indicate that seepage is highly heterogeneous with respect to time, location, and quantity. Seepage, precipitation, and fracture data were used to test two hypotheses: (1) that fast flow seepage is triggered by large precipitation events, and (2) that an increased abundance of fractures and/or fracture intersections leads to higher seepage volumes. A few zones in the back adit recorded elevated seepage volumes immediately following large (>20 mm/day) precipitation events, with transit times of less than 4 h through the 8-m thick rock mass. In most locations, there is a 1-6 month time lag between the onset of the rainy season and seepage, with longer times observed for the front adit. There is a less clear-cut relation between fracture abundance and seepage volume; processes such as evaporation and surface flow along the ceiling may also influence seepage.

  8. Characterization of uranium minerals from Chihuahua using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Burciaga V, D. C.; Reyes C, M.; Reyes R, A.; Renteria V, M.; Esparza P, H.; Fuentes C, L.; Fuentes M, L; Silva S, M.; Herrera P, E.; Munoz, A.; Montero C, M. E. [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua (Mexico)

    2010-02-15

    Uranium mineral deposits in the vicinity of Chihuahua City (northern Mexico) have motivated a multidisciplinary investigation due to their tech no-environmental importance. It provides a broad scope study of representative mineral samples extracted from the San Marcos deposit, located northwest of Chihuahua City. The zone of interest is the source of the Sacramento River, which runs at Chihuahua City. The high uranium content of the San Marcos deposit, which was formed by hydrothermal mineralization, has resulted in elevated levels of uranium in surface and ground water, fish, plants and sediments in this region. Mineral identification of the uranium-bearing phases was accomplished with a suite of techniques. Among these phases are those called meta tyuyamunite (Ca(UO{sub 2}){sub 2}(VO{sub 4}){sub 2{center_dot}}3-5 H{sub 2}O) and becquerelite [Ca(UO{sub 2}){sub 6}O{sub 4}(OH){sub 6{center_dot}}8(H{sub 2}O)]. It was decided to study an almost pure meta tyuyamunite sample extracted from Pena Blanca, Chihuahua uranium ore and to synthesize the becquerelite, using a modified procedure from a published one. In the current work the crystal structure of meta tyuyamunite is presented, resolved by the Rietveld refinement. Both samples were studied by X-ray absorption fine structure at beamline 2-3, Stanford Synchrotron Radiation Light source. In the present work both the spectra and extended X-ray absorption fine structure parameters are presented. (Author)

  9. Committed dose assessment based on background outdoor gamma exposure in Chihuahua City, Mexico

    International Nuclear Information System (INIS)

    Luevano G, S.; Perez T, A.; Pinedo A, C.; Renteria V, M.; Carrillo F, J.; Montero C, M. E.

    2015-10-01

    Full text: Determining ionizing radiation in a geographic area serves to assess its effects on populations health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the committed dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, annual effective dose, and the lifetime cancer risk, 48 sampling points were randomly selected along the Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Muller counter. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226 Ra, 232 Th, 40 K and their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Outdoor gamma dose rates ranged from 56 to 193 n Gy h -1 . Results indicated that lifetime effective dose to inhabitants of Chihuahua City is in average of 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of activity concentrations in soil were 51.8, 73.1, and 1096.5 Bq kg -1 , of 226 Ra, 232 Th and 40 K, respectively. From the analysis of the spatial distribution of 232 Th, 226 Ra, and 40 K is to north, to north-center, and to south of city, respectively. In conclusion, natural background gamma dose received by inhabitants of Chihuahua City is high and mainly due to geological characteristics of the zone. (Author)

  10. Committed dose assessment based on background outdoor gamma exposure in Chihuahua City, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Luevano G, S.; Perez T, A.; Pinedo A, C.; Renteria V, M. [Universidad Autonoma de Chihuahua, Facultad de Zootecnia y Ecologia, Perif. Francisco R. Almada Km 1, 31415 Chihuahua, Chih. (Mexico); Carrillo F, J.; Montero C, M. E., E-mail: mrenteria@uach.mx [Centro de Investigacion en Materiales Avanzados, Miguel de Cervantes 120, 31136 Chihuahua, Chih. (Mexico)

    2015-10-15

    Full text: Determining ionizing radiation in a geographic area serves to assess its effects on populations health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the committed dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, annual effective dose, and the lifetime cancer risk, 48 sampling points were randomly selected along the Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Muller counter. At the same sites, 48 soil samples were taken to obtain the activity concentrations of {sup 226}Ra, {sup 232}Th, {sup 40}K and their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Outdoor gamma dose rates ranged from 56 to 193 n Gy h{sup -1}. Results indicated that lifetime effective dose to inhabitants of Chihuahua City is in average of 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of activity concentrations in soil were 51.8, 73.1, and 1096.5 Bq kg{sup -1}, of {sup 226}Ra, {sup 232}Th and {sup 40}K, respectively. From the analysis of the spatial distribution of {sup 232}Th, {sup 226}Ra, and {sup 40}K is to north, to north-center, and to south of city, respectively. In conclusion, natural background gamma dose received by inhabitants of Chihuahua City is high and mainly due to geological characteristics of the zone. (Author)

  11. Migration behavior of naturally occurring radionuclides at the Nopal I uranium deposit, Chihuahua, Mexico

    Science.gov (United States)

    Prikryl, James D.; Pickett, David A.; Murphy, William M.; Pearcy, English C.

    1997-04-01

    Oxidation of pyrite at the Nopal I uranium deposit, Peña Blanca district, Chihuahua, Mexico has resulted in the formation of Fe-oxides/hydroxides. Anomalous U concentrations (i.e. several hundred to several thousand ppm) measured in goethite, hematite, and amorphous Fe-oxyhydroxides in a major fracture that crosscuts the deposit and the absence of U minerals in the fracture suggest that U was retained during secondary mineral growth or sorbed on mineral surfaces. Mobilization and transport of U away from the deposit is suggested by decreasing U concentrations in fracture-infilling materials and in goethite and hematite with distance from the deposit. Greater than unity {234U}/{238U} activity ratios measured in fracture-infilling materials indicate relatively recent ( < 1 Ma) U uptake from fluids that carried excess 234U. Systematic decreases in {234U}/{238U} activity ratios of fracture materials with distance from the deposit suggest a multistage mobilization process, such as remobilization of U from 234U-enriched infill minerals or differential or diminished transport of U-bearing solutions containing excess 234U.

  12. Geochemistry of the thermal springs from Piedras de Lumbre Zone, Chihuahua, Mexico; Geoquimica de los manantiales termales de la zona de Piedras de Lumbre, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Tello Hinojosa, Enrique [Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)

    1996-01-01

    Chemical analysis of water produced by 12 hot springs in the geothermal areas of Recubichi and Piedras de Lumbre, Chihuahua, Mexico were carried out in order to establish the geochemical characteristic of the groundwater and to know their interaction with deeper geothermal fluids. We made two sampling of water and gases in 1984 and 1995. The chemical composition of waters produced by the springs is of sulfate alkaline type. It was found, according to the Na:K:Mg relative content that most hot springs are located in the partial equilibrium zone, whereas the lowest temperature hot springs shift toward the groundwaters domain. The temperature estimated from gas geothermometry was 187 degrees celsius. It was found that the He has a deep origin, whereas the N{sub 2} is of atmospheric origin. Methane was not detected, suggesting that equilibria between gases and the liquid phase was reached at temperatures over 150 degrees celsius. The chemical compositions for the springs at Recubichi and Piedras de Lumbre zones are similar, so, it suggests that they have the same origin. The water quality of the springs for agricultural use, is classified between C2-S2 and C2-S3 types, that suggest that this water can be used for irrigation. The arsenic element was not detected and the concentration for the boron element is lower that 0.175 ppm. [Espanol] Los analisis quimicos de agua de 12 manantiales y 4 fumarolas de las zonas de Recubichi y Piedras de Lumbre, Chihuahua, Mexico fueron estudiados con el fin de conocer las caracteristicas geoquimicas del acuifero somero y su interaccion con fluidos geotermicos. Se realizaron 2 muestreos tanto de agua como de gases en 1984 y 1995. En ambos muestreos se encontro que la composicioon quimica del agua de todos los manantiales es del tipo sulfatado-sodico. De acuerdo con el contenido relativo de Na:K:Mg el agua de los manantiales mas calientes (93 grados celsius), se ubica en la zona de equilibrio parcial, mientras que en los de menor

  13. 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

  14. Heterogeneous seepage at the Nopal I natural analogue site, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, Patrick F.; Cook, Paul J.; Ghezzehei, Teamrat A.; Rodriguez, J. Alfredo; Villalba, Lourdes; de la Garza, Rodrigo

    2008-10-25

    An integrated field, laboratory, and modeling study of the Pena Blanca (Chihuahua, Mexico) natural analogue site is being conducted to evaluate processes that control the mobilization and transport of radionuclides from a uranium ore deposit. One component of this study is an evaluation of the potential for radionuclide transport through the unsaturated zone (UZ) via a seepage study in an adit at the Nopal I uranium mine, excavated 10 m below a mined level surface. Seasonal rainfall on the exposed level surface infiltrates into the fractured rhyolitic ash-flow tuff and seeps into the adit. An instrumented seepage collection system and local automated weather station permit direct correlation between local precipitation events and seepage within the Nopal I +00 adit. Monitoring of seepage within the adit between April 2005 and December 2006 indicates that seepage is highly heterogeneous with respect to time, location, and quantity. Within the back adit area, a few zones where large volumes of water have been collected are linked to fast flow path fractures (0-4 h transit times) presumably associated with focused flow. In most locations, however, there is a 1-6 month time lag between major precipitation events and seepage within the adit, with longer residence times observed for the front adit area. Seepage data obtained from this study will be used to provide input to flow and transport models being developed for the Nopal I hydrogeologic system.

  15. Heterogeneous seepage at the Nopal I natural analogue site, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Dobson, Patrick F.; Cook, Paul J.; Ghezzehei, Teamrat A.; Rodriguez, J. Alfredo; Villalba, Lourdes; de la Garza, Rodrigo

    2008-01-01

    An integrated field, laboratory, and modeling study of the Pena Blanca (Chihuahua, Mexico) natural analogue site is being conducted to evaluate processes that control the mobilization and transport of radionuclides from a uranium ore deposit. One component of this study is an evaluation of the potential for radionuclide transport through the unsaturated zone (UZ) via a seepage study in an adit at the Nopal I uranium mine, excavated 10 m below a mined level surface. Seasonal rainfall on the exposed level surface infiltrates into the fractured rhyolitic ash-flow tuff and seeps into the adit. An instrumented seepage collection system and local automated weather station permit direct correlation between local precipitation events and seepage within the Nopal I +00 adit. Monitoring of seepage within the adit between April 2005 and December 2006 indicates that seepage is highly heterogeneous with respect to time, location, and quantity. Within the back adit area, a few zones where large volumes of water have been collected are linked to fast flow path fractures (0-4 h transit times) presumably associated with focused flow. In most locations, however, there is a 1-6 month time lag between major precipitation events and seepage within the adit, with longer residence times observed for the front adit area. Seepage data obtained from this study will be used to provide input to flow and transport models being developed for the Nopal I hydrogeologic system.

  16. Three-dimensional hydrogeologic framework model of the Rio Grande transboundary region of New Mexico and Texas, USA, and northern Chihuahua, Mexico

    Science.gov (United States)

    Sweetkind, Donald S.

    2017-09-08

    As part of a U.S. Geological Survey study in cooperation with the Bureau of Reclamation, a digital three-dimensional hydrogeologic framework model was constructed for the Rio Grande transboundary region of New Mexico and Texas, USA, and northern Chihuahua, Mexico. This model was constructed to define the aquifer system geometry and subsurface lithologic characteristics and distribution for use in a regional numerical hydrologic model. The model includes five hydrostratigraphic units: river channel alluvium, three informal subdivisions of Santa Fe Group basin fill, and an undivided pre-Santa Fe Group bedrock unit. Model input data were compiled from published cross sections, well data, structure contour maps, selected geophysical data, and contiguous compilations of surficial geology and structural features in the study area. These data were used to construct faulted surfaces that represent the upper and lower subsurface hydrostratigraphic unit boundaries. The digital three-dimensional hydrogeologic framework model is constructed through combining faults, the elevation of the tops of each hydrostratigraphic unit, and boundary lines depicting the subsurface extent of each hydrostratigraphic unit. The framework also compiles a digital representation of the distribution of sedimentary facies within each hydrostratigraphic unit. The digital three-dimensional hydrogeologic model reproduces with reasonable accuracy the previously published subsurface hydrogeologic conceptualization of the aquifer system and represents the large-scale geometry of the subsurface aquifers. The model is at a scale and resolution appropriate for use as the foundation for a numerical hydrologic model of the study area.

  17. Establishment of Native Grasses with Biosolids on Abandoned Croplands in Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Pedro Jurado-Guerra

    2013-01-01

    Full Text Available The objective of the work was to evaluate establishment and forage production of native grasses with application of biosolids, a byproduct of waste-water treatment, at an abandoned field, in Ejido Nuevo Delicias, Chihuahua, Mexico. Four biosolids rates from 0 (control to 30 dry Mg ha−1 and two methods of application, surface applied (BioSur and soil incorporated (BioInc, were evaluated. Seedbed preparation included plowing and harrowing before rainfall. Field plots of 5 × 5 m were manually sown with a mix of blue grama (Bouteloua gracilis (50% and green sprangletop (Leptochloa dubia (50% in early August 2005. Experimental design was a randomized block with a split plot arrangement. Grass density, height, and forage production were estimated for three years. Data were analyzed with mixed linear models and repeated measures. Green sprangletop density increased under all biosolids rates regardless of method of application, while blue grama density slightly decreased. Biosolids were more beneficial for green sprangletop height than for blue grama height. Blue grama forage production slightly increased, while green sprangletop forage production increased the most at 10 Mg ha−1 biosolids rate under BioSur method. It was concluded that BioSur application at 10 and 20 Mg ha−1 rates had positive effects on the establishment and forage production of native grasses, especially green sprangletop.

  18. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

    Directory of Open Access Journals (Sweden)

    Sergio Luevano-Gurrola

    2015-09-01

    Full Text Available Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

  19. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico.

    Science.gov (United States)

    Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

    2015-09-30

    Determining ionizing radiation in a geographic area serves to assess its effects on a population's health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h(-1). At the same sites, 48 soil samples were taken to obtain the activity concentrations of (226)Ra, (232)Th and (40)K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h(-1). Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg(-1), for (226)Ra, (232)Th and (40)K, respectively. From the analysis, the spatial distribution of (232)Th, (226)Ra and (40)K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

  20. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

    Science.gov (United States)

    Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

    2015-01-01

    Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize. PMID:26437425

  1. Seasonal characterization of municipal solid waste (MSW) in the city of Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Gomez, Guadalupe; Meneses, Montserrat; Ballinas, Lourdes; Castells, Francesc

    2009-01-01

    Management of municipal solid waste (MSW) has become a significant environmental problem, especially in fast-growing cities. The amount of waste generated increases each year and this makes it difficult to create solutions which due to the increase in waste generation year after year and having to identify a solution that will have minimum impact on the environment. To determine the most sustainable waste management strategy for Chihuahua, it is first necessary to identify the nature and composition of the city's urban waste. The MSW composition varied considerably depending on many factors, the time of year is one of them. Therefore, as part of our attempt to implement an integral waste management system in the city of Chihuahua, we conducted a study of the characteristics of MSW composition for the different seasons. This paper analyzes and compares the findings of the study of the characterization and the generation of solid waste from households at three different socio-economic levels in the city over three periods (April and August, 2006 and January, 2007). The average weight of waste generated in Chihuahua, taking into account all three seasons, was 0.592 kg capita -1 day -1 . Our results show that the lowest income groups generated the least amount of waste. We also found that less waste was generated during the winter season. The breakdown for the composition of the waste shows that organic waste accounts for the largest proportion (45%), followed by paper (17%) and others (16%).

  2. Seasonal characterization of municipal solid waste (MSW) in the city of Chihuahua, Mexico.

    Science.gov (United States)

    Gómez, Guadalupe; Meneses, Montserrat; Ballinas, Lourdes; Castells, Francesc

    2009-07-01

    Management of municipal solid waste (MSW) has become a significant environmental problem, especially in fast-growing cities. The amount of waste generated increases each year and this makes it difficult to create solutions which due to the increase in waste generation year after year and having to identify a solution that will have minimum impact on the environment. To determine the most sustainable waste management strategy for Chihuahua, it is first necessary to identify the nature and composition of the city's urban waste. The MSW composition varied considerably depending on many factors, the time of year is one of them. Therefore, as part of our attempt to implement an integral waste management system in the city of Chihuahua, we conducted a study of the characteristics of MSW composition for the different seasons. This paper analyzes and compares the findings of the study of the characterization and the generation of solid waste from households at three different socio-economic levels in the city over three periods (April and August, 2006 and January, 2007). The average weight of waste generated in Chihuahua, taking into account all three seasons, was 0.592 kg capita(-1) day(-1). Our results show that the lowest income groups generated the least amount of waste. We also found that less waste was generated during the winter season. The breakdown for the composition of the waste shows that organic waste accounts for the largest proportion (45%), followed by paper (17%) and others (16%).

  3. Uranium deposits associated to tertiary acid volcanism of the Pena Blanca Sierra (Chihuahua, Mexico)

    International Nuclear Information System (INIS)

    Aniel, B.

    1986-12-01

    The uraniferous deposits located in the Sierra de Pena Blanca (Chihuahua, Mexico) are the consequence of successive events that modified acid volcanic rocks. The devitrification of the Nopal Formation, vitroclastic tuffs, is esential in the cooling history because it releases uranium that becomes available. The uranium present in fluids as uranylcarbonate complexes, precipitate along the lamellea of hematite (exsolutions of the ilmenites). The presence of sulfur causes the destabilization of the ilmenites with uranium oxide (pitchblende - titanium oxide - pyrite), the pseudomorph of magnetites (pitchblende - pyrite) and the transformation of hematite into pyrite. The silice coming from the kaolinization of feldspars recristallizes as microcristalline quartz so that the rock appears compact. Fractures cause the uplifting of the lower unit of Nopal formation. It has been altered to montmorillonite. A carbonatation of this tuff has been observed and these two types of alteration occur after kaolinization. The Escuadra formation overlies the Nopal formation. The deposition takes place on an eroded basement where a soil developed. The two formations will together undergo transformations due to the saturation level and the primary ore will be only oxidized or oxidized, transported and reconcentrated. Late and localized thermal activities have been observed and may be the result of tectonic movements occurring after the supergene modification [fr

  4. Determination of Rn{sup 222} in samples of well water and domicile of the cities of Chihuahua and Aldama, Mexico; Determinacion de Rn{sup 222} en muestras de agua de pozos y domicilio de las ciudades de Chihuahua y Aldama, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Villalba, L.; Colmenero S, L.; Montero C, M.E. [Centro de Investigacion en Materiales Avanzados (CIMAV), Av. Miguel de Cervantes Saavedra 120, 31109 Chihuahua (Mexico)]. e-mail: lourdes.villalba@cimav. edu. mx

    2004-07-01

    The study of the content of dissolved Rn{sup 222} is presented in underground water and of domicile of the cities of Chihuahua and Aldama of the State of Chihuahua. The existence of the Rn{sup 222} in the underground waters comes from its constant production in the rocks of the terrestrial bark. It has been determined that the radon is a noble gas of more solubility in the water, this solubility induces high concentrations in underground water, as well as bigger risk to the health in the human body once ingested or inhaled. Of the 32 wells studied in the cities of Chihuahua and Aldama, the content of dissolved Rn{sup 222} in the water of 22 of them is bigger than 11 Bq/l and of 73 studied samples of water of domiciles 47 show bigger values that 11 Bq/l. These radon contents are attributable to the uraniferous rocks present in the aquifers. (Author)

  5. Geochemistry of the thermal springs from San Antonio El Bravo zone, Chihuahua, Mexico; Geoquimica de manantiales termales de la zona de San Antonio El Bravo, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Tello Hinojosa, Enrique [Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)

    1996-05-01

    Isotopic and chemical analysis o water produced by 14 springs in the San Antonio El Bravo, Chihuahua, Mexico geothermal area, were carried out in order to establish the geochemical characteristics of the groundwater and to know their interaction with deeper geothermal fluids. We made two samplings of water and gases in 1984 and 1995. The chemical composition of waters produced by the springs in of sodium-bicarbonate-chloride type. It was found, according to the Na:K:Mg relative content, that most hot springs are located in the partial equilibrium zone, whereas the lowest temperature hot springs shift toward the groundwaters domain. The temperature estimated from gas geothermometry was 129 degrees celsius. The isotopic composition at Ojo Caliente and Infiernito springs presents enrichment in {delta}{sup 18}O, product rock-water interaction at high temperature. The Agua Roque spring is located in the line of meteoric waters. Analysis of metals was carried out too, the concentration of gold element is 0.09 mg/l in Ojo Caliente and Infiernito springs, whereas silver, aluminum and iron elements were not detected. The water quality of the springs for agricultural use, is classified between C2-S1, C3-S1, C3- S2, C4-S3 and C4-S4 types, that suggests that only the water from Agua Roque can be used for irrigation. The arsenic element was not detected but the concentration of the boron element is high for irrigation use (2.39 ppm). [Espanol] Los analisis quimicos e isotopicos de agua de 14 manantiales de la zona de San Antonio El Bravo. Chihuahua, Mexico, fueron realizados con el fin de conocer las caracteristicas geoquimicas del acuifero somero y su interaccion con fluidos geotermicos. Se realizaron 2 muestreos tanto de agua como de gases en 1984 y 1995. En ambos muestreos se encontro que la composicion quimica del agua de todos los manantiales es del tipo bicarbonatado-clorurado-sodico. De acuerdo con el contenido relativo de Na:K:Mg el agua de los manantiales mas calientes

  6. Use of deuterium and oxygen-18 in hydrological problems at Delicias Valley, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Castillo C, R.; Morales, P.; Cortes, A.

    1983-01-01

    An initial study using stable isotopes at Delicias Valley, Chihuahua, is presented, where we found an aquifer with two kinds of waters, one of recent infiltration (highly fractionated) and another of more depleted isotope concentration representing precipitation before the construction of the dam and distribution channels. (author)

  7. U-Series Disequilibria in Soils, Pena Blanca Natural Analog, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    D. French; E. Anthony; P. Goodell

    2006-01-01

    The Nopal I uranium deposit located in the Sierra Pena Blanca, Mexico. The deposit was mined in the early 1980s, and ore was stockpiled close by. This stockpile area was cleared and is now referred to as the Prior High Grade Stockpile (PHGS). Some of the high-grade boulders from the site rolled downhill when it was cleared in the 1990s. For this study soil samples were collected from the alluvium surrounding and underlying one of these boulders. A bulk sample of the boulder was also collected. Because the Prior High Grade Stockpile had no ore prior to the 1980s a maximum residence time for the boulder is about 25 years, this also means that the soil was at background as well. The purpose of this study is to characterize the transport of uranium series radionuclides from ore to the soil. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. Isotopes of the uranium series decay chain detected include 210 Pb, 234 U, 230 Th, 226 Ra, 214 Pb, and 214 Bi. Peak areas for each isotope are determined using gamma-ray spectroscopy with a Canberra Ge (Li) detector and GENIE 2000 software. The boulder sample is close to secular equilibrium when compared to the standard BL-5 (Beaver Lodge Uraninite from Canada). Results for the soils, however, indicate that some daughter/parent pairs are in secular disequilibrium. These daughter/parent (D/P) ratios include 230 Th/ 234 U, which is greater than unity, 226 Ra/ 230 Th, which is also greater than unity, and 210 Pb/ 214 Bi, which is less than unity. The gamma-ray spectrum for organic material lacks 230 Th peaks, but contains 234 U and 226 Ra, indicating that plants preferentially incorporate 226 Ra. Our results, combined with previous studies require multistage history of mobilization of the uranium series radionuclides. Earlier studies at the ore zone could limit the time span for mobilization only to a few thousand years. The contribution of this study is that the short

  8. Determination of Rn222 in samples of well water and domicile of the cities of Chihuahua and Aldama, Mexico

    International Nuclear Information System (INIS)

    Villalba, L.; Colmenero S, L.; Montero C, M.E.

    2004-01-01

    The study of the content of dissolved Rn 222 is presented in underground water and of domicile of the cities of Chihuahua and Aldama of the State of Chihuahua. The existence of the Rn 222 in the underground waters comes from its constant production in the rocks of the terrestrial bark. It has been determined that the radon is a noble gas of more solubility in the water, this solubility induces high concentrations in underground water, as well as bigger risk to the health in the human body once ingested or inhaled. Of the 32 wells studied in the cities of Chihuahua and Aldama, the content of dissolved Rn 222 in the water of 22 of them is bigger than 11 Bq/l and of 73 studied samples of water of domiciles 47 show bigger values that 11 Bq/l. These radon contents are attributable to the uraniferous rocks present in the aquifers. (Author)

  9. U-Sries Disequilibra in Soils, Pena Blanca Natural Analog, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    D. French; E. Anthony; P. Goodell

    2006-03-16

    The Nopal I uranium deposit located in the Sierra Pena Blanca, Mexico. The deposit was mined in the early 1980s, and ore was stockpiled close by. This stockpile area was cleared and is now referred to as the Prior High Grade Stockpile (PHGS). Some of the high-grade boulders from the site rolled downhill when it was cleared in the 1990s. For this study soil samples were collected from the alluvium surrounding and underlying one of these boulders. A bulk sample of the boulder was also collected. Because the Prior High Grade Stockpile had no ore prior to the 1980s a maximum residence time for the boulder is about 25 years, this also means that the soil was at background as well. The purpose of this study is to characterize the transport of uranium series radionuclides from ore to the soil. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. Isotopes of the uranium series decay chain detected include {sup 210}Pb, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 214}Pb, and {sup 214}Bi. Peak areas for each isotope are determined using gamma-ray spectroscopy with a Canberra Ge (Li) detector and GENIE 2000 software. The boulder sample is close to secular equilibrium when compared to the standard BL-5 (Beaver Lodge Uraninite from Canada). Results for the soils, however, indicate that some daughter/parent pairs are in secular disequilibrium. These daughter/parent (D/P) ratios include {sup 230}Th/{sup 234}U, which is greater than unity, {sup 226}Ra/{sup 230}Th, which is also greater than unity, and {sup 210}Pb/{sup 214}Bi, which is less than unity. The gamma-ray spectrum for organic material lacks {sup 230}Th peaks, but contains {sup 234}U and {sup 226}Ra, indicating that plants preferentially incorporate {sup 226}Ra. Our results, combined with previous studies require multistage history of mobilization of the uranium series radionuclides. Earlier studies at the ore zone could limit the time span for mobilization only

  10. Unsaturated zone waters from the Nopal I natural analog, Chihuahua, Mexico -- Implications for radionuclide mobility at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Pickett, D.A.; Murphy, W.M.

    1999-07-01

    Chemical and U-Th isotopic data on unsaturated zone waters from the Nopal I natural analog reveal effects of water-rock interaction and help constrain models of radionuclide release and transport at the site and, by analogy, at the proposed nuclear waste repository at Yucca Mountain. Geochemical reaction-path modeling indicates that, under oxidizing conditions, dissolution of uraninite (spent fuel analog) by these waters will lead to eventual schoepite precipitation regardless of initial silica concentration provided that groundwater is not continuously replenished. Thus, less soluble uranyl silicates may not dominate the initial alteration assemblage and keep dissolved U concentrations low. Uranium-series activity ratios are consistent with models of U transport at the site and display varying degrees of leaching versus recoil mobilization. Thorium concentrations may reflect the importance of colloidal transport of low-solubility radionuclides in the unsaturated zone.

  11. Unsaturated zone waters from the Nopal I natural analog, Chihuahua, Mexico -- Implications for radionuclide mobility at Yucca Mountain

    International Nuclear Information System (INIS)

    Pickett, D.A.; Murphy, W.M.

    1999-01-01

    Chemical and U-Th isotopic data on unsaturated zone waters from the Nopal I natural analog reveal effects of water-rock interaction and help constrain models of radionuclide release and transport at the site and, by analogy, at the proposed nuclear waste repository at Yucca Mountain. Geochemical reaction-path modeling indicates that, under oxidizing conditions, dissolution of uraninite (spent fuel analog) by these waters will lead to eventual schoepite precipitation regardless of initial silica concentration provided that groundwater is not continuously replenished. Thus, less soluble uranyl silicates may not dominate the initial alteration assemblage and keep dissolved U concentrations low. Uranium-series activity ratios are consistent with models of U transport at the site and display varying degrees of leaching versus recoil mobilization. Thorium concentrations may reflect the importance of colloidal transport of low-solubility radionuclides in the unsaturated zone

  12. Natural radioactivity in groundwater and estimates of committed effective dose due to water ingestion in the state of Chihuahua (Mexico)

    International Nuclear Information System (INIS)

    Villalba, L.; Montero-Cabrera, M. E.; Manjon-Collado, G.; Colmenero-Sujo, L.; Renteria-Villalobos, M.; Cano-Jimenez, A.; Rodriguez-Pineda, A.; Davila-Rangel, I.; Quirino-Torres, L.; Herrera-Peraza, E. F.

    2006-01-01

    The activity concentration of 222 Rn, 226 Ra and total uranium in groundwater samples collected from wells distributed throughout the state of Chihuahua has been measured. The values obtained of total uranium activity concentration in groundwater throughout the state run from -1 . Generally, radium activity concentration was -1 , with some exceptions; in spring water of San Diego de Alcala, in contrast, the value reached ∼5.3 Bq l -1 . Radon activity concentration obtained throughout the state was from 1.0 to 39.8 Bq l -1 . A linear correlation between uranium and radon dissolved in groundwater of individual wells was observed near Chihuahua City. Committed effective dose estimates for reference individuals were performed, with results as high as 134 μSv for infants in Aldama city. In Aldama and Chihuahua cities the average and many individual wells showed activity concentration values of uranium exceeding the Mexican norm of drinking water quality. (authors)

  13. Experience in the transport and disposal of uranium mill tailings from Aldama City to Sierra Pena Blanca in Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Ruiz, M.; Molina, G.; Angeles C, A.; Cruz G, S.; Lizacano C, D.; Reyes, J.; Rojas, V.

    1996-01-01

    In the process of decontamination, transport and disposal of uranium mill tailings, in the state of Chihuahua, Mexico, was necessary the multidisciplinary and multi institutional task to select mainly the site for the final disposal. The uranium mill tailings content Ra-226 which half live time is 1600 years, therefore the site should be adequately stable, a remote place of population, and which containment will survive for thousand of years. The decontamination of site where the uranium mill tailings were 25 years ago, required the application of norms from regulator organism. For the transport of uranium mill tailings was necessary that the vehicles had devices to reduce the dispersion of material in the road. The selection of the site was product of balance between the cost of transport and the final disposal. To typify the site, studies of hydrology, meteorology, ecology, geology and seismology were performed. On the other hand, the decision to locate the deposit in the site was due to dispersion of material by the rain, wind and bowls. (authors). 3 refs., 1 fig., 1 tab

  14. Radioactive mineral samples from the northwest of Chihuahua City, Mexico

    International Nuclear Information System (INIS)

    Reyes C, M.; Montero C, M.E.; Renteria V, M.; Fuentes M, L.; Fuentes C, L.; Herrera P, E.F.; Esparza P, H.; Rodriguez P, A.

    2007-01-01

    The Chihuahua-Sacramento valley is an area of 6 km wide by about 32 km in length, it is located from north to south. In the area, at least two zones exist that may have rocks with radioactive minerals: The Pastorias zone at the SW and the Majalca-San Marcos zone to the NW. The latter, was the object of the present investigation. By studying the geologic conditions and the processes of alteration in the San Marcos deposits, its hydrothermal origin and the different (at least two) alteration stages that has transformed the alkaline rhyolitic rock into per-alkaline were determined, to do more favorable the conditions for the hexavalent uranium minerals deposits. In the mineralogical characterization the following radioactive species were identified: uranofane, meta tyuyamunite and uraninite. These minerals were found also with secondary quartz-feldspar mineralization, with abundant hematization and an advanced process of argillization. The XRD, SEM and optical microscopy analyses of samples were very important for the accomplishment of the present investigation. (Author)

  15. Radioactive mineral samples from the northwest of Chihuahua City, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Reyes C, M.; Montero C, M.E.; Renteria V, M.; Fuentes M, L.; Fuentes C, L.; Herrera P, E.F.; Esparza P, H. [Facultad de Ingenieria, Universidad Autonoma de Chihuahua, Nuevo Campus Universitario s/n, Chihuahua, Mexico y Centro de Investigacion en Materiales Avanzados, Miguel de Cervantes 120, 31109 Chihuahua (Mexico); Rodriguez P, A. [World Wildlife Fund (WWF), Chihuahuan Desert Program, Coronado 1005, 31000 Chihuahua (Mexico)]. e-mail: elena.montero@cimav.edu.mx

    2007-07-01

    The Chihuahua-Sacramento valley is an area of 6 km wide by about 32 km in length, it is located from north to south. In the area, at least two zones exist that may have rocks with radioactive minerals: The Pastorias zone at the SW and the Majalca-San Marcos zone to the NW. The latter, was the object of the present investigation. By studying the geologic conditions and the processes of alteration in the San Marcos deposits, its hydrothermal origin and the different (at least two) alteration stages that has transformed the alkaline rhyolitic rock into per-alkaline were determined, to do more favorable the conditions for the hexavalent uranium minerals deposits. In the mineralogical characterization the following radioactive species were identified: uranofane, meta tyuyamunite and uraninite. These minerals were found also with secondary quartz-feldspar mineralization, with abundant hematization and an advanced process of argillization. The XRD, SEM and optical microscopy analyses of samples were very important for the accomplishment of the present investigation. (Author)

  16. Radiologic inspection in an office built rod contaminated with radioactive material, in Tiaquepaque, Jalisco, Mexico; Inspeccion radiologica en una oficina construida con varilla contaminada con material radiactivo, en Tlaquepaque, Jalisco, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Salas Mar, B.

    2011-07-01

    Note that in 1983 took place {sup T}he most important radiological accident occurred in Mexico in recent years occurred in Ciudad Juarez, Chihuahua, consisting ea involuntary casting a source of Cobalt-60 (originally intended for medical use in teletherapy) and manufacture of rods for the construction and steel bases for tables, in the smelter {sup S}teel de Chihuahua{sup ,} so presumably, that the rods of the office of Tlaquepaque, come from the radiological accident.

  17. Syringomyelia and Craniocervical Junction Abnormalities in Chihuahuas

    OpenAIRE

    Kiviranta, A.‐M.; Rusbridge, C.; Laitinen‐Vapaavuori, O.; Hielm‐Björkman, A.; Lappalainen, A.K.; Knowler, S.P.; Jokinen, T.S.

    2017-01-01

    Background: Chiari-like malformation (CM) and syringomyelia (SM) are widely reported in Cavalier King Charles Spaniels and Griffon Bruxellois dogs. Increasing evidence indicates that CM and SM also occur in other small and toy breed dogs, such as Chihuahuas. Objectives: To describe the presence of SM and craniocervical junction (CCJ) abnormalities in Chihuahuas and to evaluate the possible association of CCJ abnormalities with SM. To describe CM/SM-related clinical signs and neuro...

  18. Effects of thinnings on growth and yield in natural Pinus arizonica and Pinus durangensis stands in the El Largo-Madera region in Chihuahua State

    Science.gov (United States)

    Oscar Estrada Murrieta; Luis A. Dominguez Pereda; Marcelo Zepeda Bautista

    1995-01-01

    This paper presents the result of the first dasometric analysis made with the data of some permanent thinning plots established at different times since 1964 in the Unit of Conservation and Forest Development #2 in Chihuahua State, Mexico. The results show the benefits of thinnings on the growth rates of residual stands, the increment's redistribution, and the...

  19. Syringomyelia and Craniocervical Junction Abnormalities in Chihuahuas.

    Science.gov (United States)

    Kiviranta, A-M; Rusbridge, C; Laitinen-Vapaavuori, O; Hielm-Björkman, A; Lappalainen, A K; Knowler, S P; Jokinen, T S

    2017-11-01

    Chiari-like malformation (CM) and syringomyelia (SM) are widely reported in Cavalier King Charles Spaniels and Griffon Bruxellois dogs. Increasing evidence indicates that CM and SM also occur in other small and toy breed dogs, such as Chihuahuas. To describe the presence of SM and craniocervical junction (CCJ) abnormalities in Chihuahuas and to evaluate the possible association of CCJ abnormalities with SM. To describe CM/SM-related clinical signs and neurologic deficits and to investigate the association of CM/SM-related clinical signs with signalment, SM, or CCJ abnormalities. Fifty-three client-owned Chihuahuas. Prospective study. Questionnaire analyses and physical and neurologic examinations were obtained before magnetic resonance and computed tomography imaging. Images were evaluated for the presence of SM, CM, and atlantooccipital overlapping. Additionally, medullary kinking, dorsal spinal cord compression, and their sum indices were calculated. Scratching was the most common CM/SM-related clinical sign and decreased postural reaction the most common neurologic deficit in 73 and 87% of dogs, respectively. Chiari-like malformation and SM were present in 100 and 38% of dogs, respectively. Syringomyelia was associated with the presence of CM/SM-related clinical signs (P = 0.034), and medullary kinking and sum indices were higher in dogs with clinical signs (P = 0.016 and P = 0.007, respectively). Syringomyelia and CCJ abnormalities are prevalent in Chihuahuas. Syringomyelia was an important factor for the presence of CM/SM-related clinical signs, but many dogs suffered from similar clinical signs without being affected by SM, highlighting the clinical importance of CCJ abnormalities in Chihuahuas. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  20. Primer registro de la cotorra argentina (Myiopsitta monachus en Chihuahua, México

    Directory of Open Access Journals (Sweden)

    Ricardo Abel Soto-Cruz

    2015-06-01

    Full Text Available Reportamos el primer registro de la cotorra argentina (Myiopsitta monachus en las ciudades de Chihuahua y Delicias en Chihuahua, México. Observamos cinco individuos de esta especie de junio a diciembre de 2011 en las instalaciones de la Facultad de Zootecnia y Ecología de la Universidad Autónoma de Chihuahua; grupos de 2 a 12 individuos en el área urbana de la ciudad de Chihuahua durante 2012, y cuatro individuos en ciudad Delicias, a 80 km al sureste de la ciudad de Chihuahua, en el 2013. Previamente, en enero de 2011, se reportó, en el portal electrónico de aVerAves, el avistamiento de un individuo en el noroeste del estado. Dada la presencia de nidos activos en las ciudades de Chihuahua y Delicias, la especie podría estar ya establecida en esta parte del país. Recomendamos dar seguimiento a las poblaciones existentes de esta especie a fin de documentar los posibles riesgos a los ecosistemas en la región.

  1. Four centuries of reconstructed hydroclimatic variability for Northwestern Chihuahua, Mexico, based on tree rings

    Directory of Open Access Journals (Sweden)

    José Villanueva Díaz

    2015-03-01

    Full Text Available A Douglas-fir chronology with a length of 409 years (1600-2008 was developed for northwestern Chihuahua in Mesa de las Guacamayas, a “Natural Protected Area” known as an important nesting habitat for the thickbilled parrot (Rhynchopsitta pachyrhyncha an endangered neotropical bird. Increment cores and cross-sections from selected Douglas-fir trees (Pseudotsuga menziesii in a mixed conifer forest were obtained with an increment borer and a chain-saw. Standard dendrochronological techniques were used to process and date each one of the rings to their exact year of formation. The quality of dating of the measured series was analyzed with the COFECHA program, while biological trends not related to climate (age differences, stem-size increases, and disturbances were removed by standardization procedures in the ARSTAN program. Tree ring series of earlywood, latewood and total ring width were developed for the last four centuries. The total ring-width chronology was significantly associated (r>0.40, p=0.000 with nearby chronologies, particularly those located <200 km apart along the western slopes of the Sierra Madre Occidental (SMO observing correlations as high as 0.69 (p<0.001. Association between chronologies decreased for those sites in the state of Durango along the SMO but separated more than 200 km in straight line and also for sites in nearby borderline in the USA side. The similar climatic response among distant chronologies implies the influence of common atmospheric circulatory patterns affecting a large portion of land simultaneously. ENSO is one of the most important factors in determining inter-annual and multiannual hydroclimatic variability in northern Mexico, increasing winter-spring precipitation in its warm phase and causing extreme droughts in its cold phase.

  2. Uranium series isotopes concentration in sediments at San Marcos and Luis L. Leon reservoirs, Chihuahua, Mexico

    Science.gov (United States)

    Méndez-García, C.; Renteria-Villalobos, M.; García-Tenorio, R.; Montero-Cabrera, M. E.

    2014-07-01

    Spatial and temporal distribution of the radioisotopes concentrations were determined in sediments near the surface and core samples extracted from two reservoirs located in an arid region close to Chihuahua City, Mexico. At San Marcos reservoir one core was studied, while from Luis L. Leon reservoir one core from the entrance and another one close to the wall were investigated. 232Th-series, 238U-series, 40K and 137Cs activity concentrations (AC, Bq kg-1) were determined by gamma spectrometry with a high purity Ge detector. 238U and 234U ACs were obtained by liquid scintillation and alpha spectrometry with a surface barrier detector. Dating of core sediments was performed applying CRS method to 210Pb activities. Results were verified by 137Cs AC. Resulting activity concentrations were compared among corresponding surface and core sediments. High 238U-series AC values were found in sediments from San Marcos reservoir, because this site is located close to the Victorino uranium deposit. Low AC values found in Luis L. Leon reservoir suggest that the uranium present in the source of the Sacramento - Chuviscar Rivers is not transported up to the Conchos River. Activity ratios (AR) 234U/overflow="scroll">238U and 238U/overflow="scroll">226Ra in sediments have values between 0.9-1.2, showing a behavior close to radioactive equilibrium in the entire basin. 232Th/overflow="scroll">238U, 228Ra/overflow="scroll">226Ra ARs are witnesses of the different geological origin of sediments from San Marcos and Luis L. Leon reservoirs.

  3. Uranium series isotopes concentration in sediments at San Marcos and Luis L. Leon reservoirs, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Méndez-García, C.; Montero-Cabrera, M. E.; Renteria-Villalobos, M.; García-Tenorio, R.

    2014-01-01

    Spatial and temporal distribution of the radioisotopes concentrations were determined in sediments near the surface and core samples extracted from two reservoirs located in an arid region close to Chihuahua City, Mexico. At San Marcos reservoir one core was studied, while from Luis L. Leon reservoir one core from the entrance and another one close to the wall were investigated. 232 Th-series, 238 U-series, 40 K and 137 Cs activity concentrations (AC, Bq kg −1 ) were determined by gamma spectrometry with a high purity Ge detector. 238 U and 234 U ACs were obtained by liquid scintillation and alpha spectrometry with a surface barrier detector. Dating of core sediments was performed applying CRS method to 210 Pb activities. Results were verified by 137 Cs AC. Resulting activity concentrations were compared among corresponding surface and core sediments. High 238 U-series AC values were found in sediments from San Marcos reservoir, because this site is located close to the Victorino uranium deposit. Low AC values found in Luis L. Leon reservoir suggest that the uranium present in the source of the Sacramento – Chuviscar Rivers is not transported up to the Conchos River. Activity ratios (AR) 234 U/ 238 U and 238 U/ 226 Ra in sediments have values between 0.9–1.2, showing a behavior close to radioactive equilibrium in the entire basin. 232 Th/ 238 U, 228 Ra/ 226 Ra ARs are witnesses of the different geological origin of sediments from San Marcos and Luis L. Leon reservoirs

  4. REGIONAL HYDROLOGY OF THE NOPAL I SITE, SIERRA DE PENA BLANCA, CHIHUAHUA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    J.A. Rodriguez-Pineda; P. Goodell; P.F. Dobson; J. Walton; R. Oliver; De La Garza; S. Harder

    2005-07-11

    The U.S. Department of Energy sponsored the drilling of three wells in 2003 near the Nopal I uranium deposit at the Sierra Pena Blanca, Chihuahua, Mexico. Piezometric information is being collected to understand groundwater flow at local and regional levels as part of an ongoing natural analogue study of radionuclide migration. Water level monitoring reported at these and other wells in the region is combined with archival data to provide a better understanding of the hydrology at Nopal I. Initial results suggest that the local hydrology is dependent on the regional hydrologic setting and that this groundwater system behaves as an unconfined aquifer. The region is dominated by an alternating sequence of highlands and basins that step down from west to east. The Sierra de Pena Blanca was downdropped from the cratonic block to the west during Cenozoic extension. The Nopal I area is near the intersection of two large listric faults, and the questa of ash flow tuffs that hosts the deposit has been subjected to complex structural events. The Pena Blanca Uranium District was originally characterized by 105 airborne radiometric anomalies, indicating widespread uranium mineralization. The Nopal I uranium deposit is located in the Sierra del Pena Blanca between the Encinillas Basin to the west, with a mean elevation of 1560 m, and the El Cuervo Basin to the east, with a mean elevation of 1230 m. The Nopal I + 10 level is at an intermediate elevation of 1463 m, with a corresponding groundwater elevation of approximately 1240 m. The regional potentiometric surface indicates flow from west to east, with the El Cuervo Basin being the discharge zone for the regional flow system. However, it appears that the local groundwater potential beneath the Nopal I site is more in accordance with the water table of the El Cuervo Basin than with that of the Encinillas Basin. This might indicate that there is limited groundwater flow between the Encinillas Basin and the Nopal I area.

  5. REGIONAL HYDROLOGY OF THE NOPAL I SITE, SIERRA DE PENA BLANCA, CHIHUAHUA, MEXICO

    International Nuclear Information System (INIS)

    Rodriguez-Pineda, J.A.; Goodell, P.; Dobson, P.F.; Walton, J.; Oliver, R.; De La Garza; Harder, S.

    2005-01-01

    The U.S. Department of Energy sponsored the drilling of three wells in 2003 near the Nopal I uranium deposit at the Sierra Pena Blanca, Chihuahua, Mexico. Piezometric information is being collected to understand groundwater flow at local and regional levels as part of an ongoing natural analogue study of radionuclide migration. Water level monitoring reported at these and other wells in the region is combined with archival data to provide a better understanding of the hydrology at Nopal I. Initial results suggest that the local hydrology is dependent on the regional hydrologic setting and that this groundwater system behaves as an unconfined aquifer. The region is dominated by an alternating sequence of highlands and basins that step down from west to east. The Sierra de Pena Blanca was downdropped from the cratonic block to the west during Cenozoic extension. The Nopal I area is near the intersection of two large listric faults, and the questa of ash flow tuffs that hosts the deposit has been subjected to complex structural events. The Pena Blanca Uranium District was originally characterized by 105 airborne radiometric anomalies, indicating widespread uranium mineralization. The Nopal I uranium deposit is located in the Sierra del Pena Blanca between the Encinillas Basin to the west, with a mean elevation of 1560 m, and the El Cuervo Basin to the east, with a mean elevation of 1230 m. The Nopal I + 10 level is at an intermediate elevation of 1463 m, with a corresponding groundwater elevation of approximately 1240 m. The regional potentiometric surface indicates flow from west to east, with the El Cuervo Basin being the discharge zone for the regional flow system. However, it appears that the local groundwater potential beneath the Nopal I site is more in accordance with the water table of the El Cuervo Basin than with that of the Encinillas Basin. This might indicate that there is limited groundwater flow between the Encinillas Basin and the Nopal I area

  6. Neuronal ceroid lipofuscinosis associated with an MFSD8 mutation in Chihuahuas.

    Science.gov (United States)

    Ashwini, Akanksha; D'Angelo, Antonio; Yamato, Osamu; Giordano, Cristina; Cagnotti, Giulia; Harcourt-Brown, Tom; Mhlanga-Mutangadura, Tendai; Guo, Juyuan; Johnson, Gary S; Katz, Martin L

    2016-08-01

    The neuronal ceroid lipofuscinoses (NCLs) are hereditary neurodegenerative disorders characterized by progressive declines in neurological functions, seizures, and premature death. NCLs result from mutations in at least 13 different genes. Canine versions of the NCLs can serve as important models in developing effective therapeutic interventions for these diseases. NCLs have been described in a number of dog breeds, including Chihuahuas. Studies were undertaken to further characterize the pathology of Chihuahua NCL and to verify its molecular genetic basis. Four unrelated client owned Chihuahuas from Japan, Italy and England that exhibited progressive neurological signs consistent with a diagnosis of NCL underwent neurological examinations. Brain and in some cases also retinal and heart tissues were examined postmortem for the presence of lysosomal storage bodies characteristic of NCL. The affected dogs exhibited massive accumulation of autofluorescent lysosomal storage bodies in the brain, retina and heart accompanied by brain atrophy and retinal degeneration. The dogs were screened for known canine NCL mutations previously reported in a variety of dog breeds. All 4 dogs were homozygous for the MFSD8 single base pair deletion (MFSD8:c.843delT) previously associated with NCL in a Chinese Crested dog and in 2 affected littermate Chihuahuas from Scotland. The dogs were all homozygous for the normal alleles at the other genetic loci known to cause different forms of canine NCL. The MFSD8:c.843delT mutation was not present in 57 Chihuahuas that were either clinically normal or suffered from unrelated diseases or in 1761 unaffected dogs representing 186 other breeds. Based on these data it is almost certain that the MFSD8:c.843delT mutation is the cause of NCL in Chihuahuas. Because the disorder occurred in widely separated geographic locations or in unrelated dogs from the same country, it is likely that the mutant allele is widespread among Chihuahuas. Genetic testing

  7. [Depression in older adults with extreme poverty belonging to Social Program in City Juarez, Chihuahua, Mexico].

    Science.gov (United States)

    Flores-Padilla, Luis; Ramírez-Martínez, Flor Rocío; Trueba-Gómez, Rocío

    2016-01-01

    To identify depression in older adults living in extreme poverty beneficiaries of social program in City Juarez, Chihuahua. Analytical study in 941 adults > 60 years, studied variables: age, sex, marital status, education and work, extreme poverty, place of residence, asylum. Yesavage Geriatric scale was used. X², IC poverty depression is greater than that reported in the literature. The support granted by the Mexican Government to social programs that benefit older adults should be planned strategically with aims on improving the long-term health.

  8. Uranium series isotopes concentration in sediments at San Marcos and Luis L. Leon reservoirs, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Méndez-García, C.; Montero-Cabrera, M. E., E-mail: elena.montero@cimav.edu.mx [Centro de Investigación en Materiales Avanzados, CIMAV, Miguel de Cervantes 120, 31109, Chihuahua, Chihuahua (Mexico); Renteria-Villalobos, M. [Facultad de Zootecnia y Ecología Universidad Autónoma de Chihuahua, Periferico Francisco R. Almada Km 1, 31410, Chihuahua (Mexico); García-Tenorio, R. [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Avda. Reina Mercedes s/n, 41012 Seville (Spain)

    2008-01-01

    Spatial and temporal distribution of the radioisotopes concentrations were determined in sediments near the surface and core samples extracted from two reservoirs located in an arid region close to Chihuahua City, Mexico. At San Marcos reservoir one core was studied, while from Luis L. Leon reservoir one core from the entrance and another one close to the wall were investigated. ²³²Th-series, ²³⁸U-series, ⁴⁰K and ¹³⁷Cs activity concentrations (AC, Bq kg⁻¹) were determined by gamma spectrometry with a high purity Ge detector. ²³⁸U and ²³⁴U ACs were obtained by liquid scintillation and alpha spectrometry with a surface barrier detector. Dating of core sediments was performed applying CRS method to ²¹⁰Pb activities. Results were verified by ¹³⁷Cs AC. Resulting activity concentrations were compared among corresponding surface and core sediments. High ²³⁸U-series AC values were found in sediments from San Marcos reservoir, because this site is located close to the Victorino uranium deposit. Low AC values found in Luis L. Leon reservoir suggest that the uranium present in the source of the Sacramento – Chuviscar Rivers is not transported up to the Conchos River. Activity ratios (AR) ²³⁴U/²³⁸U and ²³⁸U/²²⁶Ra in sediments have values between 0.9–1.2, showing a behavior close to radioactive equilibrium in the entire basin. ²³²Th/²³⁸U, ²²⁸Ra/²²⁶Ra ARs are witnesses of the different geological origin of sediments from San Marcos and Luis L. Leon reservoirs.

  9. U-Series Transport Studies at the Pena Blanca, Mexico Natural Analog Site

    Energy Technology Data Exchange (ETDEWEB)

    A. M. Simmons; M. T. Murrell

    2001-05-31

    Natural analogs provide a line of evidence that supports the understanding of how natural and engineered processes would occur over long time frames and large spatial scales at a potential nuclear waste repository at Yucca Mountain, Nevada. Studies of U-series disequilibria within and around uranium deposits can provide valuable information on the timing of actinide mobility and hence the stability of a potential repository over geologic time scales. The Nopal I uranium deposit at Pena Blanca, Mexico, is situated in unsaturated tuff that is similar in composition to the Topopah Spring Tuff of Yucca Mountain and closely matches other evaluation criteria for suitable natural analogs. By modeling the observed radioactive isotope disequilibria at Nopal I, we can estimate the rates of sorption-desorption and dissolution-precipitation of the radionuclides over time. Such information is vital to the testing or validation of performance assessment models for geologic nuclear waste disposal.

  10. U-Series Transport Studies at the Pena Blanca, Mexico Natural Analog Site

    International Nuclear Information System (INIS)

    Simmons, A. M.; Murrell, M. T.

    2001-01-01

    Natural analogs provide a line of evidence that supports the understanding of how natural and engineered processes would occur over long time frames and large spatial scales at a potential nuclear waste repository at Yucca Mountain, Nevada. Studies of U-series disequilibria within and around uranium deposits can provide valuable information on the timing of actinide mobility and hence the stability of a potential repository over geologic time scales. The Nopal I uranium deposit at Pena Blanca, Mexico, is situated in unsaturated tuff that is similar in composition to the Topopah Spring Tuff of Yucca Mountain and closely matches other evaluation criteria for suitable natural analogs. By modeling the observed radioactive isotope disequilibria at Nopal I, we can estimate the rates of sorption-desorption and dissolution-precipitation of the radionuclides over time. Such information is vital to the testing or validation of performance assessment models for geologic nuclear waste disposal

  11. Characterization of source rocks and groundwater radioactivity at the Chihuahua valley

    Energy Technology Data Exchange (ETDEWEB)

    Renteria V, M.; Montero C, M.E.; Reyes C, M.; Herrera P, E.F.; Valenzuela H, M. [Centro de lnvestigacion en Materiales Avanzados, Miguel de Cervantes 120, 31109 Chihuahua, (Mexico); Rodriguez P, A. [World Wildlife Fund (WWF), Chihuahuan Desert Program, Coronado 1005, 31000 Chihuahua (Mexico); Manjon C, G.; Garcia T, R. [Universidad de Sevilla, Departamento de Fisica Aplicada 11, ETS Arquitectura, Av. Reina Mercedes 2, 41012 Sevilla, (Spain); Crespo, T. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Av. Complutense 22, 28040 Madrid, (Spain)]. e-mail: elena.montero@cimav.edu.mx

    2007-07-01

    As part of a scientific research project about alpha radioactivity in groundwater for human consumption at the Chihuahua City, the characterization of rock sources of radioactivity around de Chihuahua valley was developed. The radioactivity of groundwater and sediments was determined, too. The radioactivity of uranium- and thorium- series isotopes contained in rocks was obtained by high resolution gamma-ray spectroscopy. Some representative values are 50 Bq/kg for the mean value of Bi-214 activity, and 121.5 Bq/kg for the highest value at West of the city. The activity of sediments, extracted during wells perforation, was determined using a Nal(TI) detector. A non-reported before uranium ore was localized at the San Marcos range formation. Its outcrops are inside the Chihuahua-Sacramento valley basin and its activity characterization was performed. Unusually high specific uranium activities, determined by alpha spectrometry, were obtained in water, plants, sediments and fish extracted at locations close to outcrops of uranium minerals. The activity of water of the San Marcos dam reached 7.7 Bq/L. The activity of fish, trapped at San Marcos dam, is 0.99 Bq/kg. Conclusions about the contamination of groundwater at North of Chihuahua City were obtained. (Author)

  12. Characterization of source rocks and groundwater radioactivity at the Chihuahua valley

    International Nuclear Information System (INIS)

    Renteria V, M.; Montero C, M.E.; Reyes C, M.; Herrera P, E.F.; Valenzuela H, M.; Rodriguez P, A.; Manjon C, G.; Garcia T, R.; Crespo, T.

    2007-01-01

    As part of a scientific research project about alpha radioactivity in groundwater for human consumption at the Chihuahua City, the characterization of rock sources of radioactivity around de Chihuahua valley was developed. The radioactivity of groundwater and sediments was determined, too. The radioactivity of uranium- and thorium- series isotopes contained in rocks was obtained by high resolution gamma-ray spectroscopy. Some representative values are 50 Bq/kg for the mean value of Bi-214 activity, and 121.5 Bq/kg for the highest value at West of the city. The activity of sediments, extracted during wells perforation, was determined using a Nal(TI) detector. A non-reported before uranium ore was localized at the San Marcos range formation. Its outcrops are inside the Chihuahua-Sacramento valley basin and its activity characterization was performed. Unusually high specific uranium activities, determined by alpha spectrometry, were obtained in water, plants, sediments and fish extracted at locations close to outcrops of uranium minerals. The activity of water of the San Marcos dam reached 7.7 Bq/L. The activity of fish, trapped at San Marcos dam, is 0.99 Bq/kg. Conclusions about the contamination of groundwater at North of Chihuahua City were obtained. (Author)

  13. 77 FR 36569 - Endangered and Threatened Wildlife and Plants; Thick-Billed Parrot Draft Recovery Plan Addendum

    Science.gov (United States)

    2012-06-19

    ...). In Mexico, this species occurs in the States of Chihuahua, Sonora, Durango, Jalisco, Colima, and... elevations of the Sierra Madre Occidental of Mexico, extending from northwestern Chihuahua and northeastern.... Thick-billed parrots migrate seasonally from their primary breeding (summering) grounds in Chihuahua to...

  14. The T wave in the V10 precordial electrocardiographic lead is negative in healthy Chihuahua dogs.

    Science.gov (United States)

    Dijkstra, Marieke; Szatmári, Viktor

    2009-12-01

    The T wave polarity in the V10 precordial electrocardiographic (ECG) lead in Chihuahuas is described as positive in the veterinary literature. The aim of this study was to investigate the polarity of the T wave in the V10 precordial ECG lead in clinically healthy Chihuahuas. Our null hypothesis was that healthy Chihuahuas have a negative T wave in V10. In this prospective study, 67 healthy breeder-owned Chihuahuas were used. A physical examination, 10-lead ECG and an echocardiogram were performed on each dog. No cardio-respiratory abnormalities were revealed in any of the otherwise healthy dogs. Three out of 67 ECGs were of insufficient quality because of baseline artifacts due to movement of the animal. Two other ECGs showed a nearly iso-electric T wave in the V10 lead. The remaining 62 ECGs showed negative T waves in the V10 lead. Right ventricular hypertrophy was excluded with echocardiography in all dogs. In contrast to previous reports, we found that healthy Chihuahuas have negative T wave in the V10 precordial ECG lead.

  15. Geologic studies in the Sierra de Pena Blanca, Chihuahua, Mexico

    Science.gov (United States)

    Reyes-Cortes, Ignacio Alfonso

    The Sierra del Cuervo has been endowed with uranium mineralization, which has attracted many geological studies, and recently the author was part of a team with the goal of selecting a site of a radioactive waste repository. The first part of the work adds to the regional framework of stratigraphy and tectonics of the area. It includes the idea of a pull apart basin development, which justifies the local great thickness of the Cuervo Formation. It includes the regional structural frame work and the composite stratigraphic column of the Chihuahua Trough and the equivalent Cretaceous Mexican Sea. The general geologic features of the NE part of the Sierra del Cuervo are described, which include the folded ignimbrites and limestones in that area; the irregular large thicknesses of the Cuervo Formation; and the western vergence of the main folding within the area. Sanidine phenocrystals gave ages of 54.2 Ma and 51.8 Ma ± 2.3 Ma. This is the first time these dates have been reported in print. This age indicates a time before the folded structures which outcrop in the area, and 44 Ma is a date after the Cuervo Formation was folded. The Hidalgoan orogeny cycle affected the rocks between this lapse of time. Since then the area has been partially affected by three tensional overlapped stages, which resulted in the actual Basin and Range physiography. The jarosite related to the tectonic activity mineralization has been dated by the Ar-Ar method and yields an age of 9.8 Ma. This is the first report of a date of mineralization timing at Pena Blanca Uranium District in the Sierra del Cuervo. These are some of the frame work features that justify the allocation of a radioactive waste repository in the Sierra del Cuervo. An alluvial fan system within the Boquilla Colorada microbasin was selected as the best target for more detailed site assessment. The study also included the measurement of the alluvium thicknesses by geoelectric soundings; studies of petrography and weathered

  16. Dose by {sup 222} Rn in houses of the Chihuahua city; Dosis por {sup 222} Rn en casas-habitacion de la ciudad de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Colmenero S, L.H.; Talamantes F, C. [ITCH II, Ave. de las Industrias 11101, Chihuahua (Mexico); Villalba, M.L. [UACH, Facultad de Ingenieria, Chihuahua (Mexico); Dobson, P.F. [Laboratorio Nacional Lawrence Berkeley, California (United States); Ortalejo M, B. [UACH, Facultad de Enfermeria y Nutriologia, Chihuahua (Mexico)]. e-mail: luis.colmenero@cimav.edu.mx

    2007-07-01

    Full text: The dose equivalent that the population of the Chihuahua city receives due to the radon in air that joined to values of uranium, thorium and potassium due to the floor and radon in water was determined, they give values very above the international and national norms. The state of Chihuahua contains near 56 locations distributed by the whole state. The city of Chihuahua, capital of the state, is surrounded of rocks with great content of uranium, for what their floor also contains to the {sup 226} Ra that generates to the {sup 222} Rn. The construction of the housings of the city of Chihuahua is mainly of brick, block and adobe; the material to elaborate them is take from the rocks and floor of the surroundings, this makes that the radon is presented in a great quantity of houses of this city. As the floor and water they also contain those natural radionuclides, the total dose equivalent that the inhabitants receive is bigger to other cities of the country. Diverse international organizations dedicated to the radioactivity, indicate that the level of the {sup 222} Rn should not surpass the 148 Bq/m{sup 3}, since this gas produces lung cancer. The state of Chihuahua has an index of deaths on the average by lung cancer of double the national average, the capital of the state also has a high index. The radon concentration in a house depends on the construction material with which was made, as well as of the existent climatic conditions. During the day, this concentration depends mainly on the interior temperature, so during the night and dawn increases the radon concentration. The radon is the biggest source of radioactive dose received by the human being and it can generate a problem of public health if the concentration is high during enough time, for what the city of Chihuahua has the geologic and climatic characteristics to have it. This study was carried out in 50 house-room of the city of Chihuahua. Built houses with brick, block and adobe were

  17. Heavy metals in water of the San Pedro River in Chihuahua, Mexico and its potential health risk

    Directory of Open Access Journals (Sweden)

    Melida Gutierrez

    2008-06-01

    Full Text Available The objective of this study was to determine the seasonal and downstream water quality variations of the San Pedro River in Chihuahua, Mexico. Water samples were collected monthly from October 2005 to August 2006 in triplicate, totaling 165 water samples. The five sampling locations were: below the Francisco I. Madero dam (LP; between Rosales and Delicias (RD; Meoqui (M; El Torreon (ET, and Julimes (LJ. The levels of As, Be, Ca, Cd, Co, Cu, Cr, Fe, Li, Mg, Mn, Mo, Ni, Pb, Sb, Se, Sr, Ti, Ta, V and Zn were measured using an Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES Perkin Elmer 2100. In addition, temperature, pH, electrical conductivity and total and fecal coliformes were determined. The statistical analysis considered a factorial treatment design; where factor A was the location point and factor B was sampling date. In addition, a multivariate technique looking for principal components was performed. The results indicated that some samples exceeded Mexican standards for As, Be, Ca, Cd, Co, Cr, Fe, Mn, Ni, Pb, Sb, Se, Sr and Zn. The As level must be considered for a red flag to the communities along the Rio San Pedro because both the monthly average level (0.10 mg L-1 and location (0.10 mg L-1 exceeded the Mexican and International norms. The multivariate analysis showed a predominant aggregation at the LP location, meaning that there was a predominance of As, Sr, Fe and Li. At the rest of the locations the elements did not present a tendency for aggregation. Statistics applied to sampling month showed that December, January, March and April were aggregated in a negative quadrant of component 1 indicating a predominance of V, Ni, Be, Fe and As. Overall, the results confirmed that this stretch of the San Pedro River is contaminated with heavy metals and other contaminants that might affect human health as well as the health of the ecosystem.

  18. Heavy metals in water of the San Pedro River in Chihuahua, Mexico and its potential health risk

    Science.gov (United States)

    Gutiérrez, Roberto L.; Rubio-Arias, Hector; Quintana, Ray; Ortega, Juan Angel; Gutierrez, Melida

    2008-01-01

    The objective of this study was to determine the seasonal and downstream water quality variations of the San Pedro River in Chihuahua, Mexico. Water samples were collected monthly from October 2005 to August 2006 in triplicate, totaling 165 water samples. The five sampling locations were: below the Francisco I. Madero dam (LP); between Rosales and Delicias (RD); Meoqui (M); El Torreon (ET), and Julimes (LJ). The levels of As, Be, Ca, Cd, Co, Cu, Cr, Fe, Li, Mg, Mn, Mo, Ni, Pb, Sb, Se, Sr, Ti, Ta, V and Zn were measured using an Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) Perkin Elmer 2100. In addition, temperature, pH, electrical conductivity and total and fecal coliformes were determined. The statistical analysis considered a factorial treatment design; where factor A was the location point and factor B was sampling date. In addition, a multivariate technique looking for principal components was performed. The results indicated that some samples exceeded Mexican standards for As, Be, Ca, Cd, Co, Cr, Fe, Mn, Ni, Pb, Sb, Se, Sr and Zn. The As level must be considered for a red flag to the communities along the Rio San Pedro because both the monthly average level (0.10 mg L−1) and location (0.10 mg L−1) exceeded the Mexican and International norms. The multivariate analysis showed a predominant aggregation at the LP location, meaning that there was a predominance of As, Sr, Fe and Li. At the rest of the locations the elements did not present a tendency for aggregation. Statistics applied to sampling month showed that December, January, March and April were aggregated in a negative quadrant of component 1 indicating a predominance of V, Ni, Be, Fe and As. Overall, the results confirmed that this stretch of the San Pedro River is contaminated with heavy metals and other contaminants that might affect human health as well as the health of the ecosystem. PMID:18678922

  19. Dose by 222 Rn in houses of the Chihuahua city

    International Nuclear Information System (INIS)

    Colmenero S, L.H.; Talamantes F, C.; Villalba, M.L.; Dobson, P.F.; Ortalejo M, B.

    2007-01-01

    Full text: The dose equivalent that the population of the Chihuahua city receives due to the radon in air that joined to values of uranium, thorium and potassium due to the floor and radon in water was determined, they give values very above the international and national norms. The state of Chihuahua contains near 56 locations distributed by the whole state. The city of Chihuahua, capital of the state, is surrounded of rocks with great content of uranium, for what their floor also contains to the 226 Ra that generates to the 222 Rn. The construction of the housings of the city of Chihuahua is mainly of brick, block and adobe; the material to elaborate them is take from the rocks and floor of the surroundings, this makes that the radon is presented in a great quantity of houses of this city. As the floor and water they also contain those natural radionuclides, the total dose equivalent that the inhabitants receive is bigger to other cities of the country. Diverse international organizations dedicated to the radioactivity, indicate that the level of the 222 Rn should not surpass the 148 Bq/m 3 , since this gas produces lung cancer. The state of Chihuahua has an index of deaths on the average by lung cancer of double the national average, the capital of the state also has a high index. The radon concentration in a house depends on the construction material with which was made, as well as of the existent climatic conditions. During the day, this concentration depends mainly on the interior temperature, so during the night and dawn increases the radon concentration. The radon is the biggest source of radioactive dose received by the human being and it can generate a problem of public health if the concentration is high during enough time, for what the city of Chihuahua has the geologic and climatic characteristics to have it. This study was carried out in 50 house-room of the city of Chihuahua. Built houses with brick, block and adobe were selected. The quantification

  20. Natural radioactivity in soils of the main cities of the State of Chihuahua; Radiactividad natural en suelos de las principales ciudades del Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Colmenero S, L.; Montero C, M.E.; Villalba, L. [CIMAV, Av. Miguel de Cervantes Saavedra 120, 31109 Chihuahua (Mexico)]. e-mail: luis.colmenero@cimav.edu.mx

    2003-07-01

    The state of Chihuahua counts with at least 56 uranium zones or of minerals associated to this, being Pena Blanca the greatest and more important deposit of the country. Some of the main cities of the state are near to these deposits, as Aldama and Chihuahua. Its were took samples of soil of 11 cities of the state to determine the natural activity of radionuclides. It was determined the specific activity attributable to the parents of the series of {sup 238} U, {sup 232} Th, and of the {sup 40} K isotopes, as well as effective dose rate H{sub E} in the soil samples. It was used the high resolution gamma spectrometry of a high purity Ge detector in the laboratory of Environmental Radiological Surveillance of the CIMAV. The measure of the activity of the uranium series carries out by means of the lines of 351 KeV of the {sup 214} Pb and of 609 keV of the {sup 214} Bi, while the thorium series it was deduced of the lines of 238 keV of the {sup 212} Pb and of 912 keV of the {sup 228} Ac. Its were carried out copies and replies for the quality control. Its were found high values of specific activity of some radionuclides, in the near cities to uranium deposits like Aldama and Chihuahua. For the cities that are not near to deposits, as Ciudad Juarez and Ojinaga, the found values were normal. Also the effective dose rate was high for the near cities to deposits like Aldama, Bocoyna, Chihuahua, Jimenez and Nuevo Casas Grandes, it is also necessary to determine, the radon in air levels and of radionuclides in consumption water to obtain the dose that the population of those populations receives. (Author)

  1. Gallbladder agenesis in a Chihuahua.

    Science.gov (United States)

    Kamishina, Hiroaki; Katayama, Masaaki; Okamura, Yasuhiko; Sasaki, Jun; Chiba, Satoshi; Goryo, Masanobu; Sato, Reeko; Yasuda, Jun

    2010-07-01

    A 4-year-old neutered male Chihuahua was presented with a history of anorexia and vomiting. Continuous elevation of liver enzymes was found on repeated blood examinations and the dog was referred to us for further evaluation. The absence of gallbladder was suspected on ultrasonography. Exploratory laparotomy and retrograde cholangiography confirmed gallbladder agenesis and a possible hypoplasia of the right medial and lateral liver lobes. Histologically, proliferation of bile ductules associated with portal fibrosis and pseudolobular formation were apparent in the liver lobes.

  2. Modeling of U-series Radionuclide Transport Through Soil at Pena Blanca, Chihuahua, Mexico

    Science.gov (United States)

    Pekar, K. E.; Goodell, P. C.; Walton, J. C.; Anthony, E. Y.; Ren, M.

    2007-05-01

    The Nopal I uranium deposit is located at Pena Blanca in Chihuahua, Mexico. Mining of high-grade uranium ore occurred in the early 1980s, with the ore stockpiled nearby. The stockpile was mostly cleared in the 1990s; however, some of the high-grade boulders have remained there, creating localized sources of radioactivity for a period of 25-30 years. This provides a unique opportunity to study radionuclide transport, because the study area did not have any uranium contamination predating the stockpile in the 1980s. One high-grade boulder was selected for study based upon its shape, location, and high activity. The presumed drip-line off of the boulder was marked, samples from the boulder surface were taken, and then the boulder was moved several feet away. Soil samples were taken from directly beneath the boulder, around the drip-line, and down slope. Eight of these samples were collected in a vertical profile directly beneath the boulder. Visible flakes of boulder material were removed from the surficial soil samples, because they would have higher concentrations of U-series radionuclides and cause the activities in the soil samples to be excessively high. The vertical sampling profile used 2-inch thicknesses for each sample. The soil samples were packaged into thin plastic containers to minimize the attenuation and to standardize sample geometry, and then they were analyzed by gamma-ray spectroscopy with a Ge(Li) detector for Th-234, Pa-234, U-234, Th-230, Ra-226, Pb-214, Bi-214, and Pb-210. The raw counts were corrected for self-attenuation and normalized using BL-5, a uranium standard from Beaverlodge, Saskatchewan. BL-5 allowed the counts obtained on the Ge(Li) to be referenced to a known concentration or activity, which was then applied to the soil unknowns for a reliable calculation of their concentrations. Gamma ray spectra of five soil samples from the vertical profile exhibit decreasing activities with increasing depth for the selected radionuclides

  3. 78 FR 72751 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to the Foreign...

    Science.gov (United States)

    2013-12-03

    ... State, and the Secretary of Homeland Security when designating and blocking the property or interests in... providing financial or technological support for or to, or providing goods or services in support of, the..., Chihuahua 31240, Mexico; DOB 04 Nov 1945; POB Aquiles Serdan, Chihuahua, Mexico; nationality Mexico; citizen...

  4. PROTEIN & SENSORY ANALYSIS TO CHARACTERIZE MEXICAN CHIHUAHUA CHEESES

    Science.gov (United States)

    It has been established that native microflora in raw milk cheeses, including Queso Chihuahua, a Mexican cheese variety, contributes to the development of unique flavors through degradation of milk proteins resulting in the release of free amino acids and short peptides that influence the taste and ...

  5. Neuroaxonal Dystrophy and Cavitating Leukoencephalopathy of Chihuahua Dogs.

    Science.gov (United States)

    Degl'Innocenti, Sara; Asiag, Nimrod; Zeira, Offer; Falzone, Cristian; Cantile, Carlo

    2017-09-01

    A novel form of neuroaxonal dystrophy is described in 3 Chihuahua pups, 2 of which were from the same litter. It was characterized not only by accumulation of numerous and widely distributed axonal swellings (spheroids) but also by a severe cavitating leukoencephalopathy. The dogs presented with progressive neurological signs, including gait abnormalities and postural reaction deficits. Magnetic resonance images and gross examination at necropsy revealed dilation of lateral ventricles and cerebral atrophy, accompanied by cavitation of the subcortical white matter. Histopathologically, severe axonal degeneration with formation of large spheroids was found in the cerebral and cerebellar white matter, thalamus, and brainstem nuclei. Small-caliber spheroids were observed in the cerebral and cerebellar gray matter. The telencephalic white matter had severe myelin loss and cavitation with relative sparing of the U-fibers. Different from previously reported cases of canine neuroaxonal dystrophy, in these Chihuahuas the spheroid distribution predominantly involved the white matter with secondary severe leukoencephalopathy.

  6. Management Proposals of the Sabinas Reynosa Aquifer in Northeast Mexico, and Implications in the Development of Main Towns in Chihuahua

    Science.gov (United States)

    Sanchez, E. E.

    2008-12-01

    The Sabinas Reynosa water table aquifer is located in northeast Mexico in the state of Chihuahua, where this hydrologic unit is controlled by Laramide structures. The hydrostratigraphy consists of three units. At the base is a slightly compacted conglomerate HU1. The middle unit HU2 consists of clay materials packed with a carbonate cement. The upper unit is constituted by a sandy caliche with a calcareous matrix with secondary porosity, which allows it to store and transmit large volumes of water. The three units are of Paleogene age. Recently, the towns near the Sabinas Reynosa aquifer have presented supply problems, thus, this project will determine the hydrologic characterization using the groundwater budget method in order to establish the volume of water that the aquifer will yield per unit of time. The first phase consisted of defining the balance equation, by establishing the terms involved in the budget and calculating their respective values. Two different factors were defined: the inflows and outflows. In the first case, underground inflow with 225.68 Mm3 in the last five years, recharge by irrigation with 32.08 Mm3 and anthropogenic recharge with 270.50 Mm3 were considered. In the second case, the factors include underground outflow with 359.55 Mm3, pumping with 561.43 Mm3 and evapotranspiration from the water table with 130.61 Mm3. Although this last variable was calculated on a preliminary basis, a more accurate estimate requires additional studies (in process), with the aim of obtaining a more representative value. In this work is considered that evapotranspiration takes a decisive role in the analysis of the budget and hence, in the decisions that have to be taken for the proper management of the hydrological system.

  7. Radiation accident of 60Co contamination. Mexico 1984

    International Nuclear Information System (INIS)

    1985-01-01

    The action taken to mitigate the consequences of a radiation accident occuring in the State of Chihuahua, Mexico, is described, when a no longer in use cobalt-60 teletherapy unit, with radioactive pellets still inside, was sold, unwittingly as ordinary scrap to be finally made into reinforced steel rods. The finished metallic items, unknowingly contaminated with cobalt-60, were subsequently sold in central and northern Mexico and in the United States of America. The junkyard, transport vehicle, several foundries and some streets of two cities and the road between them were also made radioactive by the accident. The discovery of and search for the radioactive metallic products is described as is their final disposal and the decontamination of the affected sites. Individual and collective radiation doses is estimated. (author)

  8. Influence of climate and land use on historical surface fires in pine-oak forests, Sierra Madre Occidental, Mexico

    Science.gov (United States)

    Emily K. Heyerdahl; Ernesto Alvarado

    2003-01-01

    The rugged mountains of the Sierra Madre Occidental, in north-central Mexico, support a mosaic of diverse ecosystems. Of these, the high-elevation, temperate pine-oak forests are ecologically significant for their extensiveness and biodiversity. They cover nearly half the land area in the states of Durango and Chihuahua (42%), and comprise a similar percentage of the...

  9. The Social Construction of Transgenic Corn: Relevant Social Actors in Chihuahua

    Directory of Open Access Journals (Sweden)

    Marco Antonio Fernández Nava

    2016-01-01

    Full Text Available According to the socio-technical perspective, the meaning of a technological artefact does not lie within the artefact itself. Analyzing transgenic corn from a socio-technical perspective means taking one’s research beyond the artefact itself. To do this, it is necessary to overcome and avoid determinist positions, be they social or technological. This work takes as it point of departure the Social Construction of Technology Focus (SCOT. In this sense, transgenic corn is an unfinished object that is affected by an onslaught of struggles, opinions, agreements, disagreements, designs and redefinitions of the relevant social actors. These groups, the Democratic Campesino Front, El Barzón, National Agro-dynamic and Regional Agricultural Union of Yellow Corn Producers (UNIPRO, demonstrate how technological development is a social process. The deconstruction of transgenic corn according to the perspectives of these different social actors is key to the process of constructivist analysis: to take the artefacts just as each social actor views them. The objective of this study then is to describe how the different social groups, through their actions, construct and deconstruct the meaning of transgenic corn in Chihuahua, Mexico.

  10. Prevalencia de displasia y cáncer cervicouterino y factores asociados en el Hospital Central de Chihuahua, México

    OpenAIRE

    Ivonne Salas-Urrutia; Eyra Alejandra Villalobos; Brenda Lizeth Ramírez-Vega

    2006-01-01

    Objetivos: Los objetivos del presente estudio fueron determinar la prevalencia y los factores de riesgo asociados a cáncer cervicouterino en; las mujeres que acuden al Hospital Central de Chihuahua en el 2004 ya que no se cuenta registros de esta entidad en la ciudad de Chihuahua.; Material y Métodos: Se realizó un estudio observacional, transversal, donde se incluyó a mujeres que demandaron realizarse la citología; cervical en el Hospital Central del Estado de Chihuahua, en el año 2...

  11. Uncomfortable Experience: Lessons Lost in the Apache War

    Science.gov (United States)

    2015-03-01

    the Apache War gripped the focus of American and Mexican citizens throughout Arizona, New Mexico, Chihuahua , and Sonora for a period greater than...Arizona and portions of New Mexico, and Northern Sonora and Chihuahua .5 Although confusion exists as to their true subdivisions, the Chokonen led by...contributed directly to the Victorio War, the Loco and Geronimo campaigns, and the Nana and Chatto- Chihuahua raids that followed.38 Once again, failure to

  12. Qualitative evidence on abortion stigma from Mexico City and five states in Mexico.

    Science.gov (United States)

    Sorhaindo, Annik M; Juárez-Ramírez, Clara; Díaz Olavarrieta, Claudia; Aldaz, Evelyn; Mejía Piñeros, María Consuelo; Garcia, Sandra

    2014-01-01

    Social manifestations of abortion stigma depend upon cultural, legal, and religious context. Abortion stigma in Mexico is under-researched. This study explored the sources, experiences, and consequences of stigma from the perspectives of women who had had an abortion, male partners, and members of the general population in different regional and legal contexts. We explored abortion stigma in Mexico City where abortion is legal in the first trimester and five states-Chihuahua, Chiapas, Jalisco, Oaxaca, and Yucatán-where abortion remains restricted. In each state, we conducted three focus groups-men ages 24-40 years (n = 36), women 25-40 years (n = 37), and young women ages 18-24 years (n = 27)-and four in-depth face-to-face interviews in total; two with women (n = 12) and two with the male partners of women who had had an abortion (n = 12). For 4 of the 12 women, this was their second abortion. This exploratory study suggests that abortion stigma was influenced by norms that placed a high value on motherhood and a conservative Catholic discourse. Some participants in this study described abortion as an "indelible mark" on a woman's identity and "divine punishment" as a consequence. Perspectives encountered in Mexico City often differed from the conservative postures in the states.

  13. Nationwide survey of radon levels in indoor workplaces in Mexico using Nuclear Track Methodology

    International Nuclear Information System (INIS)

    Espinosa, G.; Golzarri, J.I.; Angeles, A.; Griffith, R.V.

    2009-01-01

    This report presents the preliminary results of an indoor workplace radon survey conducted during 2006-2007. Monitoring was carried out in 24 of the 32 federal entities of Mexico, incorporating 26 cities and 288 locations. The area monitored was divided into 8 regions for the purposes of the study: Chihuahua (a state with uranium mines), North-Central, South-Central, Southeast, South, Northeast, Northwest, and West. These regions differ in terms of geographic and geological characteristics, climate, altitude, and building materials and architectonic styles. Nuclear Track Methodology (NTM) was employed for the survey, using a passive closed-end cup device with Poly Allyl Diglycol Carbonate (PADC), known by its trade name CR-39 (Lantrack), as detector material. Well-established protocols for making continuous indoor radon measurements were followed, including one-step chemical etching in a 6.25 M KOH solution at 60 ± 1 deg. C with an etching time of 18 h. The track densities were determined with an automatic digital system at the Instituto de Fisica de la Universidad Nacional Autonoma de Mexico (IFUNAM) (Physics Institute of the National Autonomous University of Mexico), and calibrated in facilities at the Oak Ridge National Laboratory (ORNL). The importance of this survey lies in the fact that it represents the first time a nationwide survey of radon levels in indoor workplaces has been carried out in Mexico. Mean indoor radon levels from continuous measurements taken during and after working hours ranged from 13 Bq m -3 (the lower limit of detection) to 196 Bq m -3 . Analogous official controls or regulations for radon levels in indoor workplaces do not exist in Mexico. The survey described here contributes to knowledge of the natural radiological environment in workplaces, and will aid the relevant authorities in establishing appropriate regulations. The survey was made possible by the efforts of both a private institutions and the Dosimeter Application Project

  14. Integrated petrographic and geochemical study of coal and gas shales from the Sabinas and Chihuahua basins, North of Mexico: estimation of methane gas resources

    International Nuclear Information System (INIS)

    De La O Burrola, Francisco

    2013-01-01

    This comprehensive characterization study was performed using organic petrology and geochemistry conducted in the Sabinas basin and Chihuahua in northern Mexico. This information allowed a numerical modeling of gas formation, considering the thermal subsidence of coal and carbonaceous shales. The objectives of this thesis are: - Establish a characterization methodology for the studied rocks - Estimate potential gas generator and its regional distribution - Estimate the methane gas resources For the development of this project, we conducted an intensive campaign representative sampling of coal, carbonaceous shales and coal gas 'in situ'. For the Sabinas basin were studied 97 samples and 114 samples in the basin of Chihuahua. The analyses carried out that were used on the samples analyzed allowed to characterize the kerogen and gas. The methodology used to cross petrographic and geochemical information to analyze the petroleum system by numerical modeling. Analyses were: Petrographic, reflectance %Ro, elemental analysis and immediate, Rock Eval6 R (Bulk rock), isotopic analysis, δ 13 C, δD, (coal gas), scanning electron microscopy, image analysis and analysis of macerals fluid inclusions. The analyzes that were used on the samples allowed to characterize the sample, the kerogen and gas. The methodology used to cross petrographic and geochemical information for analyze the oil system by numerical modeling. Analyses were: Petrographic, reflectance %Ro, elemental analysis and immediate, Rock Eval6 R (Bulk rock), isotopic analysis, δ 13 C, δD, (coal gas), scanning electron microscopy, image analysis and analysis of macerals fluid inclusions A computer program was constructed to cross the information with the analysis of samples of artificial maturation experiments in the laboratory. This approach allowed estimation of methane gas resources generated by coal and carbonaceous shales. The main results obtained for Sabinas Basin were: - The kerogen of the

  15. Lung Cancer Mortality and Radon Concentration in a Chronically Exposed Neighborhood in Chihuahua, Mexico: A Geospatial Analysis

    Science.gov (United States)

    Hinojosa de la Garza, Octavio R.; Sanín, Luz H.; Montero Cabrera, María Elena; Serrano Ramirez, Korina Ivette; Martínez Meyer, Enrique; Reyes Cortés, Manuel

    2014-01-01

    This study correlated lung cancer (LC) mortality with statistical data obtained from government public databases. In order to asses a relationship between LC deaths and radon accumulation in dwellings, indoor radon concentrations were measured with passive detectors randomly distributed in Chihuahua City. Kriging (K) and Inverse-Distance Weighting (IDW) spatial interpolations were carried out. Deaths were georeferenced and Moran's I correlation coefficients were calculated. The mean values (over n = 171) of the interpolation of radon concentrations of deceased's dwellings were 247.8 and 217.1 Bq/m3, for K and IDW, respectively. Through the Moran's I values obtained, correspondingly equal to 0.56 and 0.61, it was evident that LC mortality was directly associated with locations with high levels of radon, considering a stable population for more than 25 years, suggesting spatial clustering of LC deaths due to indoor radon concentrations. PMID:25165752

  16. Aspects of radiological safety and protection in the decontamination of the Benefit plant of uranium in Ciudad Aldama and in the storage of its residues in Pena Blanca, Chihuahua, Mexico; Aspectos de seguridad y proteccion radiologica en la descontaminacion de la planta de beneficio de uranio en Ciudad Aldama y en el almacenamiento de sus residuos en Pena Blanca, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz C, M A [Facultad de Quimica, UNAM (Mexico)

    1998-07-01

    Between 1969 and 1971 the National Commission of Nuclear Energy and the Mining Fostering Commission operated coordinately a production plant of uranium and molybdenum concentrates (Benefit plant) at Ciudad Aldama, Chihuahua, Mexico. During two years of operation some 45 tonnes of uranium concentrate and approximately 35,000 tonnes of uranium wetlands were produced. These last were stored in a dam to 120 m. toward West of the plant. Due to the nearness of the population with respect to what was the Benefit plant and over all to the wetland dam, the objective of this work had two main aspects: On the one hand, to carry out the works of radiological decontamination of the benefit plant of uranium, according to the established normative by the Regulatory organization in matter of radiological safety and protection (CNSNS) for the population and the hard workers. After that the works mentioned were realized it was considered that the estate which comprises what was the Benefit plant did not reach the established criteria by the CNSNS for being considered of unrestricted use such estate and it was not allowed any type of construction in the zone which could be showed the residual contamination which remains there. On the other hand, to determine the site where could be stored the radioactive wastes generated by the radiological decontamination and the wetland mobilization for its definitive storage in benefit of the present population and of the future generations due to the radionuclides which are in a such material. The site more adequate technical and economically to storage the wastes generated by this activity was evaluated. Whereby studies about demography, use of soil and water, meteorology, hydrology and ecology were realized. The site selected being in the Pena Blanca mountains, Chihuahua, place where is located one of the uranium zones and the most important of the country. In this work, specific objectives also were treated such as: knowing the radiological

  17. y gestión de la política regional. El caso de Chihuahua

    Directory of Open Access Journals (Sweden)

    Luis Enrique Gutiérrez Casas

    2007-01-01

    Full Text Available This essay describes the regional development potential model and proposes a reviewed version of Biehl approach. Based on this model it is introduced a classification system capable of characterizing different regional contexts and anticipate public policies for specific territorial problems. The case of study is the mexican northern state of Chihuahua. The findings of this study validates the model as an analytical tool—non-substitute but complementary to the set of models and instruments used by regional economics—, and gives practical information in order to planning development policies for the municipalities of Chihuahua.

  18. Spatial Analysis of the National Evaluation of Scholastic Achievement (ENLACE in Schools of the Municipality of Juarez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Luis Ernesto Cervera Gómez

    2008-05-01

    Full Text Available This research was focused on analyzing the results of the first National Assessment of Academic Achievement for Scholar Centers (ENLACE; acronym in Spanish applied during the year 2006 in the Municipality of Juarez (State of Chihuahua, Mexico. In order to conduct the spatial analysis a geographical information system (GIS was used to make a georeferenced database were all variables were connected to a point representing a school. Results of the examinations expressed as deficient, elemental, good en excellent were spatially distributed over the urban area of Ciudad Juárez. Apparently there is a high spatial correlation between ENLACE’s results with the socioeconomic level of people. In this way results going from good to excellent were spatially located over the sectors more developed of the city. Poor results going from Insufficient to Elemental were spatially located at places with higher deficits of infrastructure and low socioeconomic levels.

  19. Natural radioactivity in soils of the main cities of the State of Chihuahua

    International Nuclear Information System (INIS)

    Colmenero S, L.; Montero C, M.E.; Villalba, L.

    2003-01-01

    The state of Chihuahua counts with at least 56 uranium zones or of minerals associated to this, being Pena Blanca the greatest and more important deposit of the country. Some of the main cities of the state are near to these deposits, as Aldama and Chihuahua. Its were took samples of soil of 11 cities of the state to determine the natural activity of radionuclides. It was determined the specific activity attributable to the parents of the series of 238 U, 232 Th, and of the 40 K isotopes, as well as effective dose rate H E in the soil samples. It was used the high resolution gamma spectrometry of a high purity Ge detector in the laboratory of Environmental Radiological Surveillance of the CIMAV. The measure of the activity of the uranium series carries out by means of the lines of 351 KeV of the 214 Pb and of 609 keV of the 214 Bi, while the thorium series it was deduced of the lines of 238 keV of the 212 Pb and of 912 keV of the 228 Ac. Its were carried out copies and replies for the quality control. Its were found high values of specific activity of some radionuclides, in the near cities to uranium deposits like Aldama and Chihuahua. For the cities that are not near to deposits, as Ciudad Juarez and Ojinaga, the found values were normal. Also the effective dose rate was high for the near cities to deposits like Aldama, Bocoyna, Chihuahua, Jimenez and Nuevo Casas Grandes, it is also necessary to determine, the radon in air levels and of radionuclides in consumption water to obtain the dose that the population of those populations receives. (Author)

  20. A case of factor X deficiency in a Chihuahua dog.

    Science.gov (United States)

    Heuss, Jessica; Weatherton, Linda

    2016-08-01

    A juvenile Chihuahua dog developed hemoperitoneum after routine ovariohysterectomy. She was managed with packed red blood cell and fresh frozen plasma transfusions as well as an exploratory laparotomy to verify ligature sites. No recurrence of hemorrhage occurred. Factor X deficiency was diagnosed and confirmed with repeat analysis including during times of health.

  1. Aspects of radiological safety and protection in the decontamination of the Benefit plant of uranium in Ciudad Aldama and in the storage of its residues in Pena Blanca, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Ruiz C, M.A.

    1998-01-01

    Between 1969 and 1971 the National Commission of Nuclear Energy and the Mining Fostering Commission operated coordinately a production plant of uranium and molybdenum concentrates (Benefit plant) at Ciudad Aldama, Chihuahua, Mexico. During two years of operation some 45 tonnes of uranium concentrate and approximately 35,000 tonnes of uranium wetlands were produced. These last were stored in a dam to 120 m. toward West of the plant. Due to the nearness of the population with respect to what was the Benefit plant and over all to the wetland dam, the objective of this work had two main aspects: On the one hand, to carry out the works of radiological decontamination of the benefit plant of uranium, according to the established normative by the Regulatory organization in matter of radiological safety and protection (CNSNS) for the population and the hard workers. After that the works mentioned were realized it was considered that the estate which comprises what was the Benefit plant did not reach the established criteria by the CNSNS for being considered of unrestricted use such estate and it was not allowed any type of construction in the zone which could be showed the residual contamination which remains there. On the other hand, to determine the site where could be stored the radioactive wastes generated by the radiological decontamination and the wetland mobilization for its definitive storage in benefit of the present population and of the future generations due to the radionuclides which are in a such material. The site more adequate technical and economically to storage the wastes generated by this activity was evaluated. Whereby studies about demography, use of soil and water, meteorology, hydrology and ecology were realized. The site selected being in the Pena Blanca mountains, Chihuahua, place where is located one of the uranium zones and the most important of the country. In this work, specific objectives also were treated such as: knowing the radiological

  2. Success in Mexico Requires a Military Solution

    Science.gov (United States)

    2011-10-27

    conditions, law enforcement at the state and local levels need standardization of procedures and training. Success has been shown in Chihuahua City...accreditation.86 The results in Chihuahua City were increased professionalization and one where the police had a basis of knowledge to fall back...5, 2009, http://www.economist.com/node/13234157. 12 Daniel M. Sabet, "Two Steps Forward: Lessons from Chihuahua ," in Police and Public Security in

  3. La vivienda nueva en la ciudad de Chihuahua: oferta y demanda

    Directory of Open Access Journals (Sweden)

    María de Lourdes Romo-Aguilar

    2012-01-01

    Full Text Available El objetivo del presente artículo es analizar el papel del gobierno y del mercado inmobiliario en relación con la disponibilidad de vivienda nueva en la ciudad de Chihuahua en el periodo 2000-2005, no sólo en términos cuantitativos sino también en calidad en cuanto a que tenga las características que le permitan satisfacer las necesidades básicas de las familias, como lo define la agenda internacional denominada Habitat, éstas son: espacio suficiente, seguridad y disponibilidad de servicios, entre otros. Para ello, este trabajo se divide en seis apartados: 1 apuntes teórico-conceptuales sobre la vivienda; 2 desarrollo institucional de atención a la vivienda en México; 3 dinámica de crecimiento de la ciudad de Chihuahua; 4 características de la vivienda tradicional y nueva; 5 oferta de vivienda nueva para el caso particular, y 6 demanda de vivienda. Finalmente se presentan las conclusiones sobre el tema.

  4. Examiner's finger-mounted near-infrared spectroscopy is feasible to analyze cerebral and skeletal muscle oxygenation in conscious Chihuahuas

    Science.gov (United States)

    Hiwatashi, Keisuke; Doi, Kimiaki; Mizuno, Risuke; Yokosuka, Makoto

    2017-02-01

    To measure regional saturation of oxygen (rSO2) of hemoglobin and total hemoglobin index (HbI) in the brain (through the molera of the head) and skeletal muscle (musculus gracilis) of conscious Chihuahua dogs using an examiner's finger-mounted near-infrared spectroscopy (NIRS) device, Toccare, we investigated brain and skeletal muscle NIRS in 48 Chihuahuas without severe disease. To measure rSO2 and total HbI, a Toccare probe was placed on the molera of the head and musculus gracilis of each dog for real-time recording. Stable NIRS values were obtained within 10 s. We also examined the effect of anesthesia on rSO2 and total HbI of a Chihuahua. Cerebral rSO2 values (59%±7%) were significantly lower than those obtained at femoral regions (67%±6%), whereas total HbI values in the brain (0.38±0.09) were significantly higher than those of the musculus gracilis (0.20±0.05). Sedation with a combination of medetomidine and ketamine decreased cerebral rSO2 along with a corresponding reduction in heart rate. Sevoflurane anesthesia with 100% O2 maintained rSO2 in the brain with an even lower heart rate. In conclusions, we measured brain and skeletal muscle rSO2 of hemoglobin in conscious Chihuahuas using a newly developed NIRS device, Toccare, and found that changes in cerebral oxygenation levels were associated with administration of anesthetics.

  5. y Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Socorro Arzaluz Solano

    2006-01-01

    Full Text Available El artículo aborda la aplicación del Programa Hábitat, diseñado por el Gobierno de Vicente Fox en 2002, en dos ciudades fronterizas: Nogales, Sonora, y Ciudad Juárez, Chihuahua. Se analiza la implantación del programa atendiendo sus particularidades, entre otros aspectos, se señalan los diferentes agentes que intervinieron en la ejecución de Hábitat, que pese a la claridad de las reglas, fueron diferentes en cada caso. También, las forma s de participación ciudadana promovidas por los gobiernos locales en ambos casos. Se presentan una reflexión final sobre el desarrollo de Hábitat en la frontera norte, y algunas recomendaciones.

  6. Intelligence Fusion Paradigm: Understanding Complex Operational Environments Implementing the Institutional Analysis and Development Framework

    Science.gov (United States)

    2012-12-14

    Originally spanning from West Texas into Central Arizona and South into Mexico encompassing Chihuahua , the Apache territory was expansive. The...northern parts of the Mexican states of Sonora and Chihuahua . The Rio Grande acted as the eastern boundary. Occasional journeys and raids brought them as... Chihuahua , Naiche Tribal Leaders Followed to ensure no treachery Vast information on the customs, limited information on arrest Control over tribal

  7. THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL

    Energy Technology Data Exchange (ETDEWEB)

    G. Saulnier and W. Statham

    2006-04-16

    The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. The Pena Blanca Natural Analogue Performance Assessment Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash-flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following analogous characteristics as compared to the Yucca Mountain repository site: (1) Analogous source--UO{sub 2} uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geology--(i.e. fractured, welded, and altered rhyolitic ash-flow tuffs); (3) Analogous climate--Semiarid to arid; (4) Analogous setting--Volcanic tuffs overlie carbonate rocks; and (5) Analogous geochemistry--Oxidizing conditions Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table.

  8. THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL

    International Nuclear Information System (INIS)

    G. Saulnier; W. Statham

    2006-01-01

    The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. The Pena Blanca Natural Analogue Performance Assessment Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash-flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following analogous characteristics as compared to the Yucca Mountain repository site: (1) Analogous source--UO 2 uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geology--(i.e. fractured, welded, and altered rhyolitic ash-flow tuffs); (3) Analogous climate--Semiarid to arid; (4) Analogous setting--Volcanic tuffs overlie carbonate rocks; and (5) Analogous geochemistry--Oxidizing conditions Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table

  9. Natural analogs for Yucca Mountain

    International Nuclear Information System (INIS)

    Murphy, W.M.

    1995-01-01

    High-level radioactive waste in the US, spent fuels from commercial reactors and nuclear materials generated by defense activities, will remain potentially hazardous for thousands of years. Demonstrable long-term stability of certain geologic and geochemical systems motivates and sustains the concept that high-level waste can be safely isolated in geologic repositories for requisite periods of time. Each geologic repository is unique in its properties and performance with reguard to isolation of nuclear wastes. Studies of processes analogous to waste-form alteration and radioelement transport in environments analogous to Yucca Mountain are being conducted at two sites, described in this article to illustrate uses of natural analog data: the Nopal I uranium deposit in the Sierra Pena Blanca, Mexico, and the Akrotiri archaeological site on the island of Santorini, Greece

  10. Drinking water intake and source patterns within a US-Mexico border population.

    Science.gov (United States)

    Regnier, Adam; Gurian, Patrick; Mena, Kristina D

    2015-01-01

    This study was undertaken to identify water intake and source patterns among a population that resides in a hot, arid region on the US-Mexico border. A cross-sectional community-based survey was conducted among households in the neighbouring cities of El Paso, TX, USA and Ciudad Juárez, Chihuahua, Mexico to obtain data on the quantity and source of water consumed. The study was also designed to identify factors that impact water consumption patterns, including gender, demographics, socio-economic status, cultural characteristics, health status, types of occupations and residences, available water sources and outdoor temperature, among many others. Of all factors studied, outdoor air temperature was found to have the strongest impact upon water intake quantity. Specifically, among the survey participants, when the outdoor air temperature exceeded 90 °F, water consumption increased by 28 %. Additionally, it was found that participants in this region consumed approximately 50 % more water than the values reported in previous studies.

  11. Oral folic acid supplementation decreases palate and/or lip cleft occurrence in Pug and Chihuahua puppies and elevates folic acid blood levels in pregnant bitches.

    Science.gov (United States)

    Domosławska, A; Jurczak, A; Janowski, T

    2013-01-01

    The aim of this study was to compare the frequency of the occurrence of lip and/or palate cleft (CL/CP) in new-borns of two breeds, Pugs and Chihuahuas, and to measure the folic acid blood levels in bitches during gestations both with and without folic acid oral supplementation. Bitches of 13 Pugs and 17 Chihuahuas with CL/CP cases were used in the study. In trial 1, the animals of the experimental group (n=25) were given additional folic acid from the onset of heat till the 40th day of gestation. The females of the control group (n=12) were fed a traditional diet. From all the animals blood was collected at the onset of heat, 14 days later and on the 30th day of the gestation to estimate folic acid concentration. In trial 2, the prevalence of CP/CL cases in litters from pregnancies before and after supplementation was compared. The percentage of puppies with CL/CP after supplementation decreased in both Pugs and Chihuahua puppies (10.86% and 15.78% vs. 4.76% and 4.8% respectively). On Day 0, the concentrations of folic acid were at a low physiological level (around 8 ng/ml) in all the animals. In bitches of the experimental group the blood level of folic acid on day 14th and 30th of the treatment showed an increase in both breeds (13.65 +/- 4.27 ng/ml in Pugs, 10.79 +/- 2.84 ng/ml in Chihuahuas, and 14.94 +/- 3.22 ng/ml in Pugs, 12.95 +/- 3.58 in Chihuahuas, respectively) while in the control group, this level decreased with time of gestation both in Pugs and in Chihuahuas (around 6 ng/ml). Folic acid supplementation seems to be a simple, effective preventive method to reduce the risk of CL/CP, especially in the predisposed breeds.

  12. [Epidemiology of gunshot wounds at Ciudad Juárez, Chihuahua General Hospital].

    Science.gov (United States)

    Moye-Elizalde, G A; Ruiz-Martínez, F; Suarez-Santamaría, J J; Ruiz-Ramírez, M; Reyes-Gallardo, A; Díaz-Apodaca, B A

    2013-01-01

    Since 2007, Ciudad Juárez, Chihuahua has been considered as one of the most violent cities in the world. The General Hospital in this city is the main facility where patients with gunshot wounds are taken. The increased number of admissions of patients with these injuries to many hospitals in the country deserves special attention, as it has an impact on hospital resources and management protocols. To disseminate the epidemiology of fractures caused by gunshot wounds and the hospital care of these patients. A retrospective, observational cohort study was conducted of patients admitted to the Traumatology and Orthopedics Service, Cd. Juárez General Hospital, in Chihuahua, Mexico, from January 2008 to December 2010. All of them sustained fractures resulting from gunshot wounds. A total of 1281 patients with a diagnosis of gunshot wounds were admitted to the hospital; 402 of them were included in this study with 559 fractures; 329 were males and 73 females. Of the 559 fractures, 257 involved the upper limb, 294 the lower limb, and 8 the pelvis. Gunshot wounds-related fractures were classified according to the Gustilo classification. Seventy-nine patients had grade I fractures, 302 grade III, and 21 patients had both grades. Conservative treatment was used in 44.3% of fractures and osteosynthesis in 55%. One patient underwent amputation upon admission. The most widely used osteosynthesis methods were external fixator (37%), straight plates (21%) and intramedullary nail (17%). Five patients (1.3%) underwent amputation: two with femur fracture and 3 with humeral fracture. There were 27 deep infections (6%); one of them resulted in late amputation of the pelvic limb. The most common associated injuries included: chest injuries in 20 patients and abdominal injuries in 17. The range of hospital stay was 1-18 days, with a mean stay of 11 days. The overall mortality rate considering the total number of patients admitted (1,281) was 99 patients (7.72%). From 2006 to 2010 the

  13. Effect of Atmospheric Conditions on Coverage of Fogger Applications in a Desert Surface Boundary Layer

    Science.gov (United States)

    2012-01-01

    Salyani, T. W. Walker, M. Farooq ABSTRACT. Near-ground aerosol fogs were applied in the Chihuahua Desert of New Mexico, which has widely spaced, low...Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Near-ground aerosol fogs were applied in the Chihuahua Desert of...1.6° surrounded by sparse Chihuahua De- sert vegetation approximately 2 m tall (fig. 1). The vegeta- tion was primarily mesquite and creosote bushes

  14. Proceedings of the National Conference on Climate Change and Water Resources Management (1st) Held in Albuquerque, New Mexico on November 4-7, 1991

    Science.gov (United States)

    1993-12-01

    of Albuquerque, New Mexico (pop. 500,000), and El Paso, Texas- Ciudad Juarez, Chihuahua (pop. 1 million), as well as in four sister cities near the... Ciudad Juarez area. The latter twin cities currently withdraw groundwater at the highest rate anywhere in the lower Rio Grande basin (Eaton and Anderson...kcal m 2day-1), H,. is net solar (short wave) radiation, H, is atmospheric long-wave radiation, H, is conductive loss ( sensible heat), H. is

  15. The Role of Science in Advising the Decision Making Process: A Pathway for Building Effective Climate Change Mitigation Policies in Mexico at the Local Level.

    Science.gov (United States)

    Barraza, Roberto; Velazquez-Angulo, Gilberto; Flores-Tavizón, Edith; Romero-González, Jaime; Huertas-Cardozo, José Ignacio

    2016-04-27

    This study examines a pathway for building urban climate change mitigation policies by presenting a multi-dimensional and transdisciplinary approach in which technical, economic, environmental, social, and political dimensions interact. Now, more than ever, the gap between science and policymaking needs to be bridged; this will enable judicious choices to be made in regarding energy and climate change mitigation strategies, leading to positive social impacts, in particular for the populations at-risk at the local level. Through a case study in Juarez, Chihuahua, Mexico, we propose a multidimensional and transdisciplinary approach with the role of scientist as policy advisers to improve the role of science in decision-making on mitigation policies at the local level in Mexico.

  16. Volcanic settings and their reservoir potential: An outcrop analog study on the Miocene Tepoztlán Formation, Central Mexico

    Science.gov (United States)

    Lenhardt, Nils; Götz, Annette E.

    2011-07-01

    The reservoir potential of volcanic and associated sedimentary rocks is less documented in regard to groundwater resources, and oil and gas storage compared to siliciclastic and carbonate systems. Outcrop analog studies within a volcanic setting enable to identify spatio-temporal architectural elements and geometric features of different rock units and their petrophysical properties such as porosity and permeability, which are important information for reservoir characterization. Despite the wide distribution of volcanic rocks in Mexico, their reservoir potential has been little studied in the past. In the Valley of Mexico, situated 4000 m above the Neogene volcanic rocks, groundwater is a matter of major importance as more than 20 million people and 42% of the industrial capacity of the Mexican nation depend on it for most of their water supply. Here, we present porosity and permeability data of 108 rock samples representing five different lithofacies types of the Miocene Tepoztlán Formation. This 800 m thick formation mainly consists of pyroclastic rocks, mass flow and fluvial deposits and is part of the southern Transmexican Volcanic Belt, cropping out south of the Valley of Mexico and within the two states of Morelos and Mexico State. Porosities range from 1.4% to 56.7%; average porosity is 24.8%. Generally, permeabilities are low to median (0.2-933.3 mD) with an average permeability of 88.5 mD. The lavas are characterized by the highest porosity values followed by tuffs, conglomerates, sandstones and tuffaceous breccias. On the contrary, the highest permeabilities can be found in the conglomerates, followed by tuffs, tuffaceous breccias, sandstones and lavas. The knowledge of these petrophysical rock properties provides important information on the reservoir potential of volcanic settings to be integrated to 3D subsurface models.

  17. 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).

  18. Conmemoraciones históricas, activación y posicionamiento turístico: Centenario, Bicentenario y Tricentenario en Chihuahua

    Directory of Open Access Journals (Sweden)

    Anna María Fernández Poncela

    2011-01-01

    Full Text Available Este texto es una revisión y reflexión sobre algunos conceptos y fenómenos sociales con relación al patrimonio cultural, las conmemoraciones históricas y el turismo cultural. El estudio de caso es la triple celebración en Chihuahua, Centenario de la Revolución Mexicana, Bicentenario de la Independencia de México y Tricentenario de la fundación de la ciudad capital del estado de Chihuahua. Con este ejemplo, se observa cómo se reproduce y consume la identidad nacional, el patrimonio histórico y cultural -tangible e intangible- y cómo el turismo consume identidad y patrimonio. Desde el presente exaltamos el pasado y proyectamos expectativas hacia el futuro.

  19. Numerical analysis of a proposed percolation experiment at the Pena Blanca natural analog site

    International Nuclear Information System (INIS)

    Green, R.T.; Rice, G.

    1995-01-01

    A field-scale percolation test is proposed for the Pena Blanca natural analog site near Chihuahua, MX. To aid in design of the field test, the V-TOUGH two-phase flow simulator was applied to model percolation of water through 8 to 10 m of partially saturated fractured tuff. The rock was characterized as a composite medium using measured hydraulic properties for the rock matrix and estimated values for the fractures. Measured matrix permeability varied over four orders of magnitude and fracture apertures were estimated to range from 10 to 1,000 μm. Water arrival times were predicted to vary between one day to 10,000 yr. The utility of the composite model and other representations of flow through fractured porous media can be tested using results from the field scale infiltration test data

  20. The Role of Science in Advising the Decision Making Process: A Pathway for Building Effective Climate Change Mitigation Policies in Mexico at the Local Level

    Directory of Open Access Journals (Sweden)

    Roberto Barraza

    2016-04-01

    Full Text Available This study examines a pathway for building urban climate change mitigation policies by presenting a multi-dimensional and transdisciplinary approach in which technical, economic, environmental, social, and political dimensions interact. Now, more than ever, the gap between science and policymaking needs to be bridged; this will enable judicious choices to be made in regarding energy and climate change mitigation strategies, leading to positive social impacts, in particular for the populations at-risk at the local level. Through a case study in Juarez, Chihuahua, Mexico, we propose a multidimensional and transdisciplinary approach with the role of scientist as policy advisers to improve the role of science in decision-making on mitigation policies at the local level in Mexico.

  1. Uranium and radium activities in samples of aquifers of the main cities of the Estado de Chihuahua; Actividades de uranio y radio en muestras de agua subterranea de las principales ciudades del Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Villalba, L.; Colmenero S, L.; Montero C, M.E. [CIMAV, Av. Miguel de Cervantes Saavedra 120, 31109 Chihuahua (Mexico)]. e-mail: lourdes.villalba@cimav.edu.mx

    2003-07-01

    The natural uranium is in four valence states +3, +4, +5 and +6 being the hexavalent state the more soluble, which plays an important role in the transport of the uranium in the environment. The high concentrations of uranium in water not only in near waters to uranium mines, but also are in some mineral waters or in waters that are extracted of deep wells as it happens in the State of Chihuahua, where the underground waters are the fundamental source of consumption. The radium is a disintegration product of the uranium, the radio content in water is considered the second source of natural radioactivity. The distribution of radium in water is in function of the uranium content present in the aquifer. It was determined the uranium and radium content in samples of underground water of the main cities of the State of Chihuahua according to their number of inhabitants. The extraction methods for uranium and sulfates precipitation of Ba-Ra by means of the addition of barium carriers for the radium were used. The measures of the activities of uranium and radium were carried out by means of a portable liquid scintillation detector trade mark Thiathler-OY HIDEX. The obtained results have demonstrated that the content of uranium and radium in dissolution are in most of the sampling wells above the permissible maximum levels that manage the Mexican regulations. The high contents of uranium and radio can be attributed since to the influence of the geologic substrate characteristic of the zone in the State of Chihuahua they exist but of 50 uranium deposits. (Author)

  2. Relación entre consultas a urgencias por enfermedad respiratoria y contaminación atmosférica en Ciudad Juárez, Chihuahua Relationship between emergency room visits for respiratory disease and atmospheric pollution in Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Leticia Hernández-Cadena

    2000-08-01

    Full Text Available OBJETIVO: Analizar la relación entre las concentraciones ambientales de partículas de diámetro OBJECTIVE: To assess the relationship of <=10 µm particles (PM10 and atmospheric ozone concentrations, with the daily number of emergency visits due to asthma and acute respiratory diseases, among children aged under 15, living in Ciudad Juarez, Chihuahua, Mexico. MATERIAL AND METHODS: Between 1998 and 1999, an ecologic study was conducted. Atmospheric data were obtained from the Environmental Protection Agency (EPA, from eight monitoring stations located in Ciudad Juarez, Chihuahua, and El Paso, Texas. From July 1997 to December 1998, data from emergency room visits for respiratory illness were abstracted from existing medical records of two Mexican Institute of Social Security (IMSS hospitals in Ciudad Juarez. Diagnoses were classified into two groups: a asthma, and b upper respiratory infections (URI, according to the International Classification of Diseases (ICD-9 and/or IDC-10. Statistical analysis was carried out using the Poisson regression time series method. RESULTS: During the study period, the mean 24-hour PM10 level was 34.46 µg/m³ (SD=17.99 and the mean ozone level was 51.60 ppb (SD=20.70. The model shows that an increase of 20 µg/m³ in the mean 24-hour exposure to PM10 was related to an increase of 4.97% (95% CI 0.97-9.13 in emergency visits for asthma, with a 5-day lag, as well as to an increase of 9% (95% CI 1.8-16.8 when a cumulative 5-day exposure was considered. URI increased 2.95% as a cause of emergency room visits, for each 20 µg/m³ increase in the mean 24-hour exposure to PM10. The impact of PM10 on emergency visits for asthma was greater on days with ozone ambient levels exceeded 49 ppb (median value. CONCLUSIONS: A positive association was found between environmental PM10 and ozone concentrations and the daily number of emergency room visits due to asthma and acute respiratory diseases, even with levels lower than the

  3. 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

  4. The fuel consumption increase in Ciudad Juarez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Thomas M. Fullerton Jr

    2012-07-01

    Full Text Available This research analyzes short–run gasoline consumption dynamics in Ciudad Juárez, Chihuahua, México. Parameter estimation is carried out using linear transfer function arima analysis. This market is of interest because it is influenced by regional, national, and international economic conditions due to its location on the border with the United States. Explanatory variables that satisfy the significance criterion include the real price of gasoline in Ciudad Juárez, the price of gasoline in Ciudad Juárez relative to that charged across the border in el Paso, Texas, USA, and formal sector employment in Ciudad Juárez. Out–of–sample simulations indicate that the model is relatively accurate for forecasts of to 1 to 24 months into the future.

  5. [Child abuse: its knowledge, attention and diffusion in three pediatric hospitals in Mexico].

    Science.gov (United States)

    Loredo-Abdalá, Arturo; Villanueva-Clift, Héctor; Aguilar-Ceniceros, Angélica María; Casas-Muñoz, Abigail

    Child abuse (CA) was observed in Mexico since the early 60's through isolated publications from clinical cases and where manifestations of physical injury or sexual abuse predominated. Since the 90's, the Clinic for Integral Care of the Abused Child was established at the National Institute of Pediatrics (CAINM-INP, for its Spanish acronym), which actions were addressed to the care, teaching and research on this topic. This approach was replicated in two hospital centers in the country: the Clinic for Integral Care of the Abused Children at Children's Specialty Care Hospital of Chihuahua and the Pediatric Service of the General Hospital of Mexicali. The main objective of this work was to present to the medical community, paramedics, and other professionals who interact with the pediatric population and society, the efforts that have been made in Mexico to address this legal, medical, and social pathology in a logical manner, and always aimed at protecting victims and their families. Copyright © 2016 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

  6. A predictable suite of helminth parasites in the long-billed dowitcher, Limnodromus scolopaceus, from the Chihuahua desert in Texas and Mexico.

    Science.gov (United States)

    Canaris, Albert G; Ortiz, Rafael; Canaris, Gay J

    2010-12-01

    Eighty-eight long-billed dowitchers, Limnodromus scolopaceus, were examined for helminth parasites, 62 from Texas and 26 from Mexico. In total, 3,558 helminth parasites were obtained from this host, 2,273 from Texas birds and 1,285 from birds from Mexico. The component communities consisted of 22 species of helminths in Texas, and 19 in Mexico. Of a total of 26 helminth species recorded from the 2 localities, 15 were common to both, 7 found only in Texas, and 4 only in Mexico. Fifty-nine of 62 Texas birds and 25 of 26 birds from Mexico were infected. The most prevalent helminth for Texas was the cestode Shipleya inermis. The cestode Aploparaksis retroversa was the most abundant, accounting for 37% of the total abundance, and was second highest in prevalence. Five species of cestodes, A. retroversa, Aploparaksis diagonalis, Aploparaksis occidentalis, Aploparaksis rissae, and Shipleya inermis accounted for 79% of total abundance. In the sample from Mexico, S. inermis was also highest in prevalence, followed by the nematode Hystrichis tricolor. The cestode A. retroversa was highest in abundance at 50% of the total, and was third highest in prevalence. Mean species richness, diversity, and evenness were similar among the component communities of Texas and Mexico. A predictable suite of aploparaksid cestodes, together with the cestode S. inermis, constituted 79%, and 61%, of total abundance for the component communities of Texas and Mexico, respectively, and were present in all component communities for locality, season, and year. The cestodes, A. retroversa and S. inermis, were the dominant species in all component communities. Differences among component communities and low similarities for all other comparisons were largely caused by less predictable suites of helminth species. A checklist of helminth parasites reported for long-billed dowitchers is included.

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

    Directory of Open Access Journals (Sweden)

    Enderson, E. F.

    2009-01-01

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

  8. Immigrant children and school interculturality in northern Chihuahua

    Directory of Open Access Journals (Sweden)

    Tamara Segura Herrera

    2018-09-01

    Full Text Available In the Mexican context, interculturality represents a discourse of recognition and respect for cultural diversity, in particular of indigenous peoples. The purpose of this article is to explore how interculturality among immigrant children of indigenous and mixed-race origins is constructed. The starting premise is that interculturality is also an interactive process of communication between individuals of different cultures. The methodology is based on the results of an anthropological study carried out at the Center for Comprehensive Attention to Migrant Children, in Ascension, Chihuahua. Based on observations and interviews, it was found that immigrant children construct interculturality in the classrooms, in the recreation areas, and during the journey to school. Therefore, the conclusion is that they do so in these school spaces, through relationships and meanings, sometimes in dispute, which they establish among themselves and with the teaching staff.

  9. Uranium and radium activities in samples of aquifers of the main cities of the Estado de Chihuahua

    International Nuclear Information System (INIS)

    Villalba, L.; Colmenero S, L.; Montero C, M.E.

    2003-01-01

    The natural uranium is in four valence states +3, +4, +5 and +6 being the hexavalent state the more soluble, which plays an important role in the transport of the uranium in the environment. The high concentrations of uranium in water not only in near waters to uranium mines, but also are in some mineral waters or in waters that are extracted of deep wells as it happens in the State of Chihuahua, where the underground waters are the fundamental source of consumption. The radium is a disintegration product of the uranium, the radio content in water is considered the second source of natural radioactivity. The distribution of radium in water is in function of the uranium content present in the aquifer. It was determined the uranium and radium content in samples of underground water of the main cities of the State of Chihuahua according to their number of inhabitants. The extraction methods for uranium and sulfates precipitation of Ba-Ra by means of the addition of barium carriers for the radium were used. The measures of the activities of uranium and radium were carried out by means of a portable liquid scintillation detector trade mark Thiathler-OY HIDEX. The obtained results have demonstrated that the content of uranium and radium in dissolution are in most of the sampling wells above the permissible maximum levels that manage the Mexican regulations. The high contents of uranium and radio can be attributed since to the influence of the geologic substrate characteristic of the zone in the State of Chihuahua they exist but of 50 uranium deposits. (Author)

  10. Prevalence and genetic diversity of Bartonella strains in rodents from northwestern Mexico.

    Science.gov (United States)

    Rubio, André V; Ávila-Flores, Rafael; Osikowicz, Lynn M; Bai, Ying; Suzán, Gerardo; Kosoy, Michael Y

    2014-12-01

    Bartonella infections were investigated in wild rodents from northwestern Chihuahua, Mexico. A total of 489 rodents belonging to 14 species were surveyed in four areas. Bartonella bacteria were cultured from 50.1% of rodent samples (245/489). Infection rates ranged from 0% to 83.3% per rodent species, with no significant difference between sites except for Cynomys ludovicianus. Phylogenetic analyses of the citrate synthase gene (gltA) of the Bartonella isolates revealed 23 genetic variants (15 novel and 8 previously described), clustering into five phylogroups. Three phylogroups were associated with Bartonella vinsonii subsp. vinsonii, B. vinsonii subsp. arupensis, and B. washoensis, respectively. The other two phylogroups were not genetically related to any known Bartonella species. The genetic variants and phylogenetic groups exhibited a high degree of host specificity, mainly at the genus and family levels. This is the first study that describes the genetic diversity of Bartonella strains in wild rodents from Mexico. Considering that some variants found in this study are associated with Bartonella species that have been reported as zoonotic, more investigations are needed to further understand the ecology of Bartonella species in Mexican wildlife and their implications for human health.

  11. Rural electrification in Chihuahua, Mexico at one third of the cost vs a conventional substation

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, Omar; Gomez, Rolando; Solano, Arturo; Acosta, Eduardo

    2010-09-15

    This paper and presentation describes technical details about a successful experience in a unique project in Mexico for making possible the rural electrification at one third of the total cost vs a traditional substation. This alternate solution for electrification of rural communities where construction of distribution lines or traditional substations are not economically possible due to local government's budget limits or because the electrical companies are looking for the ROI Return Over Investment in poverty communities.

  12. Recent evolution and divergence among populations of a rare Mexican endemic, Chihuahua spruce, following holocene climatic warming

    Science.gov (United States)

    F. Thomas Ledig; Virginia Jacob-Cervantes; Paul D. Hodgskiss

    1997-01-01

    Fragmentation and reduction in population size are expected to reduce genetic diversity. However, examples from natural populations of forest trees are scarce. The range of Chihuahua spruce retreated northward and fragmented coincident with the warming climate that marked the early Holocene. The isolated populations vary from 15 to 2441 trees, which provided an...

  13. Survival and sprouting responses of Chihuahua Pine after the Rodeo-Chediski Fire on the Mogollon Rim, Arizona

    Science.gov (United States)

    Kenneth H. Baumgartner; Peter Z. Fule

    2007-01-01

    Chihuahua pines (Pinus leiophylla Schiede and Deppe var. chihuahuana Engelmann) were surveyed on 11 study plots on the Mogollon Rim in east central Arizona to compare characteristics of trees that sprouted from the base or root collar after the Rodeo-Chediski fire with those of trees that did not sprout. The differences in trees...

  14. Study of the total uranium in underground water in the city of Jimenez, Chihuahua; Estudio del uranio total en agua subterranea en la Ciudad de Jimenez, Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Renteria V, M. [Centro de Investigacion de Materiales Avanzados (CIMAV), Av. Miguel de Cervantes Saavedra 120, 31109 Chihuahua (Mexico)]. e-mail: marusia.renteria@cimav.edu.mx

    2004-07-01

    Samples of water of wells in the city of Jimenez, Chihuahua were analyzed, and its were determined the content of total uranium. It was used the technique of extraction of uranium from water adding Bis ( 2- ethylexyl) phosphate and scintillating Beta plate Hi safe, and the measures of the activities were carried out in the portable scintillation detector Thiathler- O Y HIDEX. The obtained interval of concentrations was 0.12 to 0.26 Bq/l that it is finds below the maximum permissible limits that it manages the Mexican regulation. It was found a significant correlation among the concentration of uranium and those total solid dissolved present in the samples. (Author)

  15. Verterbrate diversity in northwestern Chihuahua, Mexico (Diversidad de vertebrados del noroeste de Chihuahua, Mexico)

    Science.gov (United States)

    Jesus Pacheco; Gerardo Ceballos; Georgina Santos; Rurik List; Patricia Manzano; Juan Cruzado

    2006-01-01

    Biodiversity loss is one of the most severe global environmental problems. Among other factors, it is fostered by the destruction and fragmentation of natural ecosystems. The Chihuahuan prairies merit no exception; a great number of its associated species are endangered by habitat fragmentation or deterioration. The prairie dog (Cynomys spp) illustrates this situation...

  16. La investigación educativa en Chihuahua, campo de oportunidades

    Directory of Open Access Journals (Sweden)

    Jesús Adolfo Trujillo Holguín

    2016-10-01

    Full Text Available El crecimiento que experimenta el campo de la investigación educativa en el estado de Chihuahua, durante los últimos años, es notorio. Las y los investigadores locales ocupan espacios académicos en redes y grupos de investigación nacionales e internacionales, se incorporan al Sistema Nacional de Investigadores (SNI, compiten por recursos en programas públicos de apoyo a la investigación científica, participan en congresos y encuentros de investigación más allá de las fronteras estatales, organizan y promueven congresos para atraer investigadores de distintas latitudes, publican libros y artículos y –en suma– son protagonistas del quehacer investigativo del país.

  17. NaturAnalogs for the Unsaturated Zone

    Energy Technology Data Exchange (ETDEWEB)

    A. Simmons; A. Unger; M. Murrell

    2000-03-08

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model.

  18. Natural Analogs for the Unsaturated Zone

    International Nuclear Information System (INIS)

    Simmons, A.; Unger, A.; Murrell, M.

    2000-01-01

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model

  19. Movement and spatial proximity patterns of rangeland-raised Raramuri Criollo cow-calf pairs

    Science.gov (United States)

    The objective of this study was to compare movement patterns of nursing vs. nonnursing mature cows and to characterize cow-calf proximity patterns in two herds of Raramuri Criollo cattle. Herds grazed rangeland pastures in southern New Mexico (4355 ha) and west-central Chihuahua, Mexico (633 ha)'' A...

  20. Polymorphism of locus DRB3.2 in populations of Creole Cattle from Northern Mexico

    Directory of Open Access Journals (Sweden)

    Ilda G. Fernández

    2008-01-01

    Full Text Available The polymorphism of locus BoLA-DRB3.2 of the Major Histocompatibility Complex was evaluated in two northern Mexican Creole cattle populations, Chihuahua (n = 47 and Tamaulipas (n = 51. The BoLA-DRB3.2 locus was typed by amplification and digestion with restriction endonuclease enzymes (PCR-RFLP. Fifty-two alleles were detected (28 previously reported and 24 new ones. In the Chihuahua population, 18 alleles and 5.5 effective alleles were found, while in the Tamaulipas population there were 34 and 10.8, respectively. The allele frequencies ranged from 0.011 to 0.383 in Chihuahua and from 0.010 to 0.206 in Tamaulipas. The frequencies of the new alleles in both cattle populations were low (0.010 to 0.053. The expected heterozygosity was 0.827 and 0.916, respectively, for the Chihuahua and Tamaulipas populations. Both populations presented a heterozygote deficit: [Chihuahua F IS = 0.1 (p = 0.019 and Tamaulipas F IS = 0.317 (p < 0.001]. In conclusion, this study showed that the Mexican Creole cattle have many low-frequency alleles, several of which are exclusive to these populations. Genetic distances obtained show that the Mexican Creole cattle population is composed of independent populations, far apart from other South American Creole populations.

  1. Microenvironmental air and soil monitoring of contaminants: An evaluation of indoor and outdoor levels in Chihuahua City

    Science.gov (United States)

    Delgado-Rios, Marcos

    Like most of the cities around the world Chihuahua City suffers atmospheric and soil pollution. This is a problem that requires immediate attention from both public authorities and the scientific community. Although it is known that high levels of heavy metals are present in the airborne particulate matter, soil and dust in many urban regions, the information about personal exposure to these pollutants in Chihuahua City is nonexistent. This study focuses on the analysis and characterization of lead and arsenic in the airborne and soil particulate matter present in the interiors of households and their surrounding outdoor environments in the southern part of Chihuahua City. The sampling area chosen for this study was located in the southern part of Chihuahua City. An atmospheric sampling point selected by the Centro de Investigacion en Materiales Avanzados (CIMAV) was selected as a geographical center, with a 2 km radius forming the sampling area. The households selected for analyses were located on Lombardo Toledano Street, a high-traffic street. The main objectives of this study were to establish the maximum exposure level in outdoor and indoor environments for particulate matter less than 10 mum (PM 10), Pb, and As, to determine the background level of Chihuahua City for these same elements, to determine the isotopic ratios of Pb206 and Pb207 in the indoor and outdoor atmospheric samples, and to verify if the source of the pollution is from anthropogenic and/or natural sources. Additionally, a comparison of the analytical data from X-ray fluorescence (XRF) versus the analytical data from inductively coupled plasma with optical emission spectroscopy (ICP-OES) was conducted. The comparison of these techniques was based on sample preparation, speed of analysis, and accuracy of results. In the case of sample preparation, two extraction techniques were performed for a comparison of the extraction/leaching of Pb and As from the samples. These microwave

  2. A Comparison of Angular Values of the Pelvic Limb with Normal and Medial Patellar Luxation Stifles in Chihuahua Dogs Using Radiography and Computed Tomography.

    Science.gov (United States)

    Phetkaew, Thitaporn; Kalpravidh, Marissak; Penchome, Rampaipat; Wangdee, Chalika

    2018-02-01

     This article aimed to determine and compare the angular values of the pelvic limb in normal and medial patellar luxation (MPL) stifles in Chihuahuas using radiography and computed tomographic (CT) scan, to identify the relationship between pelvic limb angles and severity of MPL. In addition, radiographic and CT images were compared to determine the more suitable method of limb deformity assessment.  Sixty hindlimbs of Chihuahuas were divided into normal and grade 1, 2, 3 and 4 MPL groups. The pelvic limb angles in frontal and sagittal planes were evaluated on radiography and CT scan. Femoral and tibial torsion angles (FTA and TTA) were evaluated only by CT scan. All angles were compared among normal and MPL stifles and between radiography and CT scan.  Based on the CT scan, the mechanical lateral distal femoral angle (mLDFA), anatomical caudal proximal femoral angle (aCdPFA), and TTA were related to the severity of MPL. The mLDFA and TTA were significantly increased ( p  Chihuahuas are aLDFA, mLDFA, aCdPFA and TTA. Radiography had some limitations for evaluating pelvic limb angles. The caudocranial radiograph is recommended for the assessment of the distal femoral angles, while the craniocaudal radiograph is for the tibial angles. Schattauer GmbH Stuttgart.

  3. Real-time PCR genotyping assay for canine progressive rod-cone degeneration and mutant allele frequency in Toy Poodles, Chihuahuas and Miniature Dachshunds in Japan.

    Science.gov (United States)

    Kohyama, Moeko; Tada, Naomi; Mitsui, Hiroko; Tomioka, Hitomi; Tsutsui, Toshihiko; Yabuki, Akira; Rahman, Mohammad Mahbubur; Kushida, Kazuya; Mizukami, Keijiro; Yamato, Osamu

    2016-03-01

    Canine progressive rod-cone degeneration (PRCD) is a middle- to late-onset, autosomal recessive, inherited retinal disorder caused by a substitution (c.5G>A) in the canine PRCD gene that has been identified in 29 or more purebred dogs. In the present study, a TaqMan probe-based real-time PCR assay was developed and evaluated for rapid genotyping and large-scale screening of the mutation. Furthermore, a genotyping survey was carried out in a population of the three most popular breeds in Japan (Toy Poodles, Chihuahuas and Miniature Dachshunds) to determine the current mutant allele frequency. The assay separated all the genotypes of canine PRCD rapidly, indicating its suitability for large-scale surveys. The results of the survey showed that the mutant allele frequency in Toy Poodles was high enough (approximately 0.09) to allow the establishment of measures for the prevention and control of this disorder in breeding kennels. The mutant allele was detected in Chihuahuas for the first time, but the frequency was lower (approximately 0.02) than that in Toy Poodles. The mutant allele was not detected in Miniature Dachshunds. This assay will allow the selective breeding of dogs from the two most popular breeds (Toy Poodle and Chihuahua) in Japan and effective prevention or control of the disorder.

  4. Impacto de la violencia homicida en la esperanza de vida masculina de México Impact of homicide on male life expectancy in Mexico

    Directory of Open Access Journals (Sweden)

    Guillermo Julián González-Pérez

    2012-11-01

    Full Text Available OBJETIVO: Determinar el impacto de la violencia homicida en la esperanza de vida masculina (EVM de México y sus 32 estados durante los trienios 1998-2000 y 2008-2010, así como el grado de participación de los diferentes grupos etarios en la pérdida de años de EVM por esta causa. MÉTODOS: A partir de datos oficiales sobre defunciones y población, se construyeron tablas abreviadas de mortalidad masculina para México y sus estados en los trienios estudiados. Se calcularon la esperanza de vida temporaria masculina y los años de esperanza de vida perdidos (AEVP en el grupo etario de 15 a 75 años, por causas seleccionadas (homicidios, diabetes mellitus y accidentes de transporte y por grupos de edad en cada trienio. RESULTADOS: Entre 1998-2000 y 2008-2010 se incrementaron los AEVP por homicidio a nivel nacional y en 19 estados; en cuatro de ellos, la cifra de AEVP en 2008-2010 superó los dos años, destacándose el caso de Chihuahua, con 5,2 años. De 18 estados donde la esperanza de vida temporaria masculina disminuyó entre los dos trienios, en 14 aumentaron los AEVP por homicidio. En 2008-2010 los homicidios fueron responsables del mayor porcentaje de AEVP masculinos en el grupo etario de 20 a 44 años. Los AEVP por homicidio en el grupo de 15 a 44 años de edad se incrementaron entre ambos trienios. CONCLUSIONES: El aumento de la violencia homicida, especialmente entre los jóvenes, es un freno para el incremento de la esperanza de vida masculina en México. En varios estados, como Chihuahua y Durango, esta violencia parece ser la principal responsable del descenso de la esperanza de vida masculina entre los 15 y 75 años de edad.OBJECTIVE: To determine the impact of homicide on male life expectancy in Mexico and its 32 states during the three-year periods 1998-2000 and 2008-2010 and the weight of the different age groups in years of life expectancy lost (YLEL due to this cause. METHODS: Based on official death and population data

  5. Clinical and neuropathological findings of acute carbon monoxide toxicity in chihuahuas following smoke inhalation.

    Science.gov (United States)

    Kent, Marc; Creevy, Kate E; Delahunta, Alexander

    2010-01-01

    Three adult Chihuahuas were presented for evaluation after smoke inhalation during a house fire. All three dogs received supportive care and supplemental oxygen. After initial improvement, the dogs developed seizures. Despite anticonvulsant therapy and supportive care, the dogs died. The brains of two dogs were examined. Lesions were identified that were compatible with acute carbon monoxide (CO) toxicity. Lesions were confined to the caudate nucleus, the globus pallidus, and the substantia nigra bilaterally, as well as the cerebellum, cerebral cortex, and dorsal thalamus. This case report describes the clinicopathological sequelae in acute CO toxicity.

  6. Investigación educativa: la experiencia en el estado de Chihuahua

    Directory of Open Access Journals (Sweden)

    Evangelina Cervantes Holguín

    2016-04-01

    Full Text Available Este ensayo tiene como propósito recuperar las experiencias de investigación de los académicos e instituciones superiores establecidas en la región. Asimismo, permite conocer el estado que guarda esta actividad intelectual y el desarrollo que ha tenido el campo de la educación en el estado de Chihuahua. De manera concreta se establecen cuatro etapas: antecedentes, primeras experiencias de investigación (1984 a 1990; cambios y desafíos (1990 al 2000; crecimiento (2000 al 2009 y apertura y expansión (2009. En esta última fase, se destaca la pertinencia de la Rediech como espacio para generar, desarrollar, fortalecer y difundir la actividad investigativa en esta entidad.

  7. Diferencias en la recaudación del impuesto predial en la zona fronteriza: evidencia en los municipios de Chihuahua

    Directory of Open Access Journals (Sweden)

    Jorge Ibarra Salazar

    2014-01-01

    Full Text Available Basándonos en el estudio de Ibarra y Sotres (2009, en este artículo aportamos evidencia adicional que relaciona las características de la región frontera norte y el marco institucional con la recaudación del impuesto predial. Estimamos una serie de especificaciones econométricas usando una base de datos de panel para los 67 municipios de Chihuahua correspondiente a 2002-2006. Nuestra hipótesis central es que la dinámica económica y demográfica en la zona fronteriza de Chihuahua ha originado una mayor demanda de servicios e infraestructura en los municipios fronterizos de ese estado, lo que los ha motivado a diferenciar su marco institucional para obtener mayores recursos por concepto de impuesto predial en comparación con los municipios no fronterizos. Esto es posible dado que la reforma constitucional de 1999 al Artículo 115 posibilita a los municipios modificar el marco institucional fiscal para enfrentar sus propias peculiaridades.

  8. Patent ductus arteriosus in a family of Chihuahuas.

    Science.gov (United States)

    Bomassi, E; Libermann, S; Bille, C; Rattez, E

    2011-04-01

    This report describes a patent ductus arteriosus (PDA) in four puppies from the same family of Chihuahuas, bred from the same mother and from two different litters. Identification of this congenital anomaly relies on clinical examination, radiography and ultrasonography. Three of these puppies were female, and had a type-1 PDA. A conventional surgical ligation was performed on one of them, whilst the others underwent no treatment. One puppy was male, and presented with a type-4 PDA, requiring euthanasia. Post-mortem examination and histopathological examination of the PDA allowed characterisation of the histological anomalies, which were identical to those described in other breeds. The mother and the two stud dogs were not affected. Even though the mode of transmission has not been fully identified, it is evident that this PDA is hereditary in nature. To the authors' knowledge this is the first description of this congenital cardiopathy in a family of this breed, and in a significant number of first-generation individuals. © 2011 British Small Animal Veterinary Association.

  9. Dust Bowl migration as an analog for possible global warming-induced migration from Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.H.; Longstreth, J.D.; Johnson, A.K.; Rosenberg, N.J.

    1994-06-01

    As a result of increases in CO{sub 2} and other radiatively important trace gases, scientists have predicted increases in mean worldwide temperatures of 2--5 degrees C over the next 50 to 100 years. Such temperature increases may result in climate modifications that would in turn be associated with increases in drought and desertification and could even change the patterns of the monsoons and tropical rains, which are important to agriculture throughout the world. They predicted that the rise in sea level caused by melting and thermal expansion of glaciers and polar icecaps could flood large population centers, destroying habitation and displacing populations. This will result in approximately 50 million ``environmental refugees`` worldwide, triple the number of today. The expected shifts in precipitation are also likely to result in (1) increased runoff contaminated with pesticides, salts, garbage, sewage, and eroded soil, and (2) drought also leading to increased soil erosion and salinization, as well as depletion of limited water resources. The total impact of global warming on agriculture and human habitation could considerably slow the economic development of some nations and would particularly affect agricultural production. Loss of homes, the inability to raise food, an increased prevalence of disease and worsened economic conditions may drive people to leave their homelands, seeking entry into countries which have more resources and greater resistance to the economic consequences of climatic change. This report looks at the possible environmental impacts and economic impacts of the greenhouse effect on Mexico while using the American Dust Bowl event as an analog.

  10. Border Pedagogy as a Conduit to Greater Understanding

    Science.gov (United States)

    Cashman, Timothy G.

    2013-01-01

    The article describes a study that was conducted in Malaysia, and at the borders of Chihuahua, Mexico, and Ontario, Canada, to compare the reactions of social studies teachers from Canada, Malaysia, and Mexico to the bombing of Iraq by the U.S. on March 20, 2003. The key objective of the investigations in all three countries was to uncover…

  11. The Knowledge, Perception, and Attitude of Patients Living with ...

    African Journals Online (AJOL)

    planning eye health education programs. Subjects and .... from this study can be utilized in planning eye health education ..... awareness and knowledge in urban Chennai. ... impairment and eyecare services in the State of Chihuahua, Mexico.

  12. Multidrug-Resistant Bacteria Isolated from Surface Water in Bassaseachic Falls National Park, Mexico.

    Science.gov (United States)

    Delgado-Gardea, Ma Carmen E; Tamez-Guerra, Patricia; Gomez-Flores, Ricardo; Zavala-Díaz de la Serna, Francisco Javier; Eroza-de la Vega, Gilberto; Nevárez-Moorillón, Guadalupe Virginia; Pérez-Recoder, María Concepción; Sánchez-Ramírez, Blanca; González-Horta, María Del Carmen; Infante-Ramírez, Rocío

    2016-06-16

    Bacterial pathogens are a leading cause of waterborne disease, and may result in gastrointestinal outbreaks worldwide. Inhabitants of the Bassaseachic Falls National Park in Chihuahua, Mexico show seasonal gastroenteritis problems. This aim of this study was to detect enteropathogenic microorganisms responsible for diarrheal outbreaks in this area. In 2013, 49 surface water samples from 13 selected sampling sites along the Basaseachi waterfall and its main rivers, were collected during the spring, summer, autumn, and winter seasons. Fecal and total coliform counts were determined using standard methods; the AutoScan-4 system was used for identification of isolates and the antibiotic resistance profile by challenging each organism using 21 antibiotics. Significant differences among seasons were detected, where autumn samples resulted in the highest total (p water-borne microorganisms exhibited resistance to cefazoline, cefuroxime, ampicillin, and ampicillin-sulbactam. The presence of these microorganisms near rural settlements suggests that wastewater is the contamination source, providing one possible transmission mechanism for diarrheal outbreaks.

  13. Uranium-238 and thorium-232 series concentrations in soil, radon-222 indoor and drinking water concentrations and dose assessment in the city of Alameda, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Colmenero Sujo, L.; Montero Cabrera, M.E. E-mail: elena.montero@cimav.edu.mx; Villalba, L.; Renteria Villalobos, M.; Torres Moye, E.; Garcia Leon, M.; Garcia-Tenorio, R.; Mireles Garcia, F.; Herrera Peraza, E.F.; Sanchez Aroche, D

    2004-07-01

    High-resolution gamma spectrometry was used to determine the concentration of {sup 40}K, {sup 238}U and {sup 232}Th series in soil samples taken from areas surrounding the city of Aldama, in Chihuahua. Results of indoor air short-time sampling, with diffusion barrier charcoal detectors, revealed relatively high indoor radon levels, ranging from 29 to 422 Bq/m{sup 3}; the radon concentrations detected exceeded 148 Bq/m{sup 3} in 76% of the homes tested. Additionally, liquid scintillation counting showed concentrations of radon in drinking water ranging from 4.3 to 42 kBq/m{sup 3}. The high activity of {sup 238}U in soil found in some places may be a result of the uranium milling process performed 20 years ago in the area. High radon concentrations indoor and in water may be explained by assuming the presence of uranium-bearing rocks underneath of the city, similar to a felsic dike located near Aldama. The estimated annual effective dose of gamma radiation from the soil and radon inhalation was 3.83 mSv.

  14. Uranium-238 and thorium-232 series concentrations in soil, radon-222 indoor and drinking water concentrations and dose assessment in the city of Aldama, Chihuahua, Mexico.

    Science.gov (United States)

    Colmenero Sujo, L; Montero Cabrera, M E; Villalba, L; Rentería Villalobos, M; Torres Moye, E; García León, M; García-Tenorio, R; Mireles García, F; Herrera Peraza, E F; Sánchez Aroche, D

    2004-01-01

    High-resolution gamma spectrometry was used to determine the concentration of 40K, 238U and 232Th series in soil samples taken from areas surrounding the city of Aldama, in Chihuahua. Results of indoor air short-time sampling, with diffusion barrier charcoal detectors, revealed relatively high indoor radon levels, ranging from 29 to 422 Bq/m3; the radon concentrations detected exceeded 148 Bq/m3 in 76% of the homes tested. Additionally, liquid scintillation counting showed concentrations of radon in drinking water ranging from 4.3 to 42 kBq/m3. The high activity of 238U in soil found in some places may be a result of the uranium milling process performed 20 years ago in the area. High radon concentrations indoor and in water may be explained by assuming the presence of uranium-bearing rocks underneath of the city, similar to a felsic dike located near Aldama. The estimated annual effective dose of gamma radiation from the soil and radon inhalation was 3.83 mSv.

  15. Overweight and aerobic fitness in children in the United States/Mexico border region El sobrepeso y el acondicionamiento aeróbico en niños de la frontera mexicanoestadounidense

    Directory of Open Access Journals (Sweden)

    Karen J. Coleman

    2004-04-01

    Full Text Available OBJECTIVE: To study overweight and aerobic fitness among children in the third and fourth grades of elementary schools in a city in the United States of America (El Paso, Texas and a city in Mexico (Chihuahua, Chihuahua that are on or near the border between those two countries, and to compare the results from those two cities with earlier findings for other children in the United States. METHODS: We followed the El Paso children (427 boys and 385 girls, 93% of them of Mexican descent from third to fourth grade and assessed the change in their body mass index (BMI. In the city of Chihuahua we cross-sectionally measured the BMI of a sample of third grade children (221 boys and 237 girls and a sample of fourth grade children (268 boys and 215 girls. BMI and triceps skinfolds were measured for all the children studied in the two cities. BMI was used to assess risk for overweight (at least the 85th percentile BMI for age and gender and overweight (at least the 95th percentile BMI for age and gender in all the children. The distance that El Paso children ran in nine minutes was used to assess their aerobic fitness (aerobic fitness was not measured in the Chihuahua children. The data from El Paso were collected in 1999, 2000, and 2001, and the Chihuahua data were collected in 2000 and 2001. RESULTS: In the El Paso boys, overweight significantly increased in the one year from third grade to fourth grade, from 22% to 28%, while risk for overweight significantly increased, from 37% to 44%. In the El Paso girls, risk for overweight significantly increased over the same one-year period, from 29% to 37%. The El Paso boys and girls were significantly less fit when compared to samples of children from throughout the United States. Third and fourth grade children from Chihuahua had similar rates of risk for overweight and of overweight when compared to the children from the same grades in El Paso. CONCLUSIONS: Children in both El Paso and Chihuahua were more

  16. Microbial indicators of fecal contamination in soils under different wastewater irrigation patterns

    International Nuclear Information System (INIS)

    Contreras-Godinez, C. A.; Palacios-Lopez, O. A.; Munoz-Castellanos, L. N.; Saucedo-Teran, R.; Rubio-Arias, H.; Nevarez-Moorillon, G. V.

    2009-01-01

    The use of wastewater to irrigate produce was a common practice in some suburban areas in Mexico. The continuous use of wastewater can increase the chance of fecal soil contamination, which can percolate in soil and finally cause groundwater contamination. A suburban area in Chihuahua, mexico, has been traditionally irradiated with wastewater for production of agriculture goods, including produce and animal foodstuffs. (Author)

  17. Pena Blanca Natural Analogue Project: Summary of activities

    International Nuclear Information System (INIS)

    Levy, S.; Goldstein, S.; Dobson, P.F.; Goodell, P.; Ku, T.-L.; Abdel-Fattah, A.; Saulnier, G.; Fayek, M.; de la Garza, R.

    2011-01-01

    The inactive Nopal I uranium mine in silicic tuff north of Chihuahua City, Chihuahua, Mexico, was studied as a natural analogue for an underground nuclear-waste repository in the unsaturated zone. Site stratigraphy was confirmed from new drill cores. Data from site studies include chemical and isotopic compositions of saturated- and unsaturated-zone waters. A partial geochronology of uranium enrichment and mineralization was established. Evidence pertinent to uranium-series transport in the soil zone and changing redox conditions was collected. The investigations contributed to preliminary, scoping-level performance assessment modeling.

  18. Pena Blanca Natural Analogue Project: Summary of activities

    Energy Technology Data Exchange (ETDEWEB)

    Levy, S.; Goldstein, S.; Dobson, P.F.; Goodell, P.; Ku, T.-L.; Abdel-Fattah, A.; Saulnier, G.; Fayek, M.; de la Garza, R.

    2011-02-01

    The inactive Nopal I uranium mine in silicic tuff north of Chihuahua City, Chihuahua, Mexico, was studied as a natural analogue for an underground nuclear-waste repository in the unsaturated zone. Site stratigraphy was confirmed from new drill cores. Data from site studies include chemical and isotopic compositions of saturated- and unsaturated-zone waters. A partial geochronology of uranium enrichment and mineralization was established. Evidence pertinent to uranium-series transport in the soil zone and changing redox conditions was collected. The investigations contributed to preliminary, scoping-level performance assessment modeling.

  19. Pena blanca natural analogue project: summary of activities

    International Nuclear Information System (INIS)

    Levy, Schon S.; Goldstein, Steven J.; Abdel-Fattah, Amr I.

    2010-01-01

    The inactive Nopal I uranium mine in silicic tuff north of Chihuahua City, Chihuahua, Mexico, was studied as a natural analogue for an underground nuclear-waste repository in the unsaturated zone. Site stratigraphy was confirmed from new drill core. Datafrom site studies include chemical and isotopic compositions of saturated- and unsaturated-zone waters. A partial geochronology of uranium enrichment and mineralization was established. Evidence pertinent to uranium-series transport in the soil zone and changing redox conditions was collected. The investigations contributed to preliminary, scoping-level performance assessment modeling.

  20. Pena blanca natural analogue project: summary of activities

    Energy Technology Data Exchange (ETDEWEB)

    Levy, Schon S [Los Alamos National Laboratory; Goldstein, Steven J [Los Alamos National Laboratory; Abdel - Fattah, Amr I [Los Alamos National Laboratory

    2010-12-08

    The inactive Nopal I uranium mine in silicic tuff north of Chihuahua City, Chihuahua, Mexico, was studied as a natural analogue for an underground nuclear-waste repository in the unsaturated zone. Site stratigraphy was confirmed from new drill core. Datafrom site studies include chemical and isotopic compositions of saturated- and unsaturated-zone waters. A partial geochronology of uranium enrichment and mineralization was established. Evidence pertinent to uranium-series transport in the soil zone and changing redox conditions was collected. The investigations contributed to preliminary, scoping-level performance assessment modeling.

  1. EVALUACIÓN DE LA PROPUESTA DE INTERVENCIÓN PARA ESTUDIANTES SOBRESALIENTES: CASO CHIHUAHUA, MÉXICO

    Directory of Open Access Journals (Sweden)

    Pedro Covarrubias Pizarro

    2015-01-01

    Full Text Available Este artículo tiene como propósito exponer los resultados de un trabajo de investigación evaluativa realizado para valorar la implementación de la Propuesta de Intervención Educativa para alumnos y alumnas con Aptitudes Sobresalientes, puesta en marcha por la Secretaría de Educación Pública de México durante el ciclo escolar 2007-2008. Para evaluar dicha propuesta, se diseñó y aplicó un modelo conformado por cuatro componentes, cuatro criterios y trece descriptores. Para la recuperación de los datos y su análisis correspondiente, se empleó una metodología de corte mixto que consideró diferentes momentos, actores e instrumentos. En este documento se presenta el trabajo realizado mediante el enfoque cualitativo, destacando los resultados obtenidos en los grupos de discusión y las entrevistas semiestructuradas. El estudio se llevó a cabo en el estado de Chihuahua, México y participaron como informantes significativos el personal de educación especial del subsistema estatal del estado de Chihuahua, padres y madres de familia de estudiantes sobresalientes, maestras de grupo regular, alumnado identificado como sobresaliente y personas expertas en el tema de las altas capacidades. Los resultados apuntan que la propuesta de intervención valorada cuenta con cualidades relacionadas con su fundamento teórico y metodológico, sin embargo, la mayor debilidad se ubica en la operatividad, aspecto que puede ser sujeto a mejorar para la obtención de mayores resultados en la intervención.

  2. Estimating maquiladora hazardous waste generation on the U.S./Mexico border

    Science.gov (United States)

    Bowen, Mace M.; Kontuly, Thomas; Hepner, George F.

    1995-03-01

    Maquiladoras, manufacturing plants that primarily assemble foreign components for reexport, are located in concentrations along the northern frontier of the US/Mexico border. These plants process a wide variety of materials using modern industrial technologies within the context of developing world institutions and infrastructure. Hazardous waste generation by maquiladoras represents a critical environmental management issue because of the spatial concentration of these plants in border municipalities where the infrastructure for waste management is nonexistent or poor. These border municipalities contain rapidly increasing populations, which further stress their waste handling infrastructure capacities while exposing their populations to greater contaminant risks. Limited empirical knowledge exists concerning hazardous waste types and generation rates from maquiladorsas. There is no standard reporting method for waste generation or methodology for estimating generation rates at this time. This paper presents a method that can be used for the rapid assessment of hazardous waste generation. A first approximation of hazardous waste generation is produced for maquiladoras in the three municipalities of Nogales, Sonora, Mexicali, Baja California, and Cd. Juarez, Chihuahua, using the INVENT model developed by the World Bank. In addition, our intent is to evaluate the potential of the INVENT model for adaptation to the US/Mexico border industrial situation. The press of border industrial development, especially with the recent adoption of the NAFTA, make such assessments necessary as a basis for the environmental policy formulation and management needed in the immediate future.

  3. TLALOCNet continuous GPS-Met Array in Mexico supporting the 2017 NAM GPS Hydrometeorological Network.

    Science.gov (United States)

    Cabral-Cano, E.; Salazar-Tlaczani, L.; Adams, D. K.; Vivoni, E. R.; Grutter, M.; Serra, Y. L.; DeMets, C.; Galetzka, J.; Feaux, K.; Mattioli, G. S.; Miller, M. M.

    2017-12-01

    TLALOCNet is a network of continuous GPS and meteorology stations in Mexico to study atmospheric and solid earth processes. This recently completed network spans most of Mexico with a strong coverage emphasis on southern and western Mexico. This network, funded by NSF, CONACyT and UNAM, recently built 40 cGPS-Met sites to EarthScope Plate Boundary Observatory standards and upgraded 25 additional GPS stations. TLALOCNet provides open and freely available raw GPS data, and high frequency surface meteorology measurements, and time series of daily positions. This is accomplished through the development of the TLALOCNet data center (http://tlalocnet.udg.mx) that serves as a collection and distribution point. This data center is based on UNAVCO's Dataworks-GSAC software and also works as part of UNAVCO's seamless archive for discovery, sharing, and access to GPS data. The TLALOCNet data center also contains contributed data from several regional GPS networks in Mexico for a total of 100+ stations. By using the same protocols and structure as the UNAVCO and other COCONet regional data centers, the scientific community has the capability of accessing data from the largest Mexican GPS network. This archive provides a fully queryable and scriptable GPS and Meteorological data retrieval point. In addition, real-time 1Hz streams from selected TLALOCNet stations are available in BINEX, RTCM 2.3 and RTCM 3.1 formats via the Networked Transport of RTCM via Internet Protocol (NTRIP) for real-time seismic and weather forecasting applications. TLALOCNet served as a GPS-Met backbone for the binational Mexico-US North American Monsoon GPS Hydrometeorological Network 2017 campaign experiment. This innovative experiment attempts to address water vapor source regions and land-surface water vapor flux contributions to precipitation (i.e., moisture recycling) during the 2017 North American Monsoon in Baja California, Sonora, Chihuahua, and Arizona. Models suggest that moisture recycling is

  4. Study of the total uranium in underground water in the city of Jimenez, Chihuahua

    International Nuclear Information System (INIS)

    Renteria V, M.

    2004-01-01

    Samples of water of wells in the city of Jimenez, Chihuahua were analyzed, and its were determined the content of total uranium. It was used the technique of extraction of uranium from water adding Bis ( 2- ethylexyl) phosphate and scintillating Beta plate Hi safe, and the measures of the activities were carried out in the portable scintillation detector Thiathler- O Y HIDEX. The obtained interval of concentrations was 0.12 to 0.26 Bq/l that it is finds below the maximum permissible limits that it manages the Mexican regulation. It was found a significant correlation among the concentration of uranium and those total solid dissolved present in the samples. (Author)

  5. Homozygosity of single nucleotide polymorphisms in the 3' region of the canine estrogen receptor 1 gene is greater in Toy Poodles than in Miniature Dachshunds and Chihuahuas.

    Science.gov (United States)

    Pathirana, Indunil N; Tanaka, Kakeru; Kawate, Noritoshi; Tsuji, Makoto; Hatoya, Shingo; Inaba, Toshio; Tamada, Hiromichi

    2011-06-01

    Differences in the distribution of single nucleotide polymorphisms (SNPs) and haplotypes in the estrogen receptor α gene (ESR1) were examined in Miniature Dachshunds (n = 48), Chihuahuas (n = 20) and Toy Poodles (n = 18). Five DNA fragments located in the 40-kb region at the 3' end of ESR1 were amplified by polymerase chain reaction and were directly sequenced. We compared allele, genotype and estimated haplotype frequencies at each SNP in the 3' end of ESR1 for these three breeds of small dog. The frequency of the major allele and the genotype frequency of the major allele homozygotes, were significantly higher in Toy Poodles for five SNPs (SNP #5, #14-17) than in Miniature Dachshunds, and significantly higher in Toy Poodles than Chihuahuas for three SNPs (SNP #15-17). A common haplotype block was identified in an approximately 20-kb region encompassing four SNPs (SNPs # 14-17). The frequencies of the most abundant estimated haplotype (GTTG) and GTTG homozygotes were significantly higher in Toy Poodles than in the other two breeds. These results imply that homozygosity for the allele, genotype and haplotype distribution within the block at the 3' end of ESR1 is greater in Toy Poodles than in Miniature Dachshunds and Chihuahuas. © 2011 The Authors; Animal Science Journal © 2011 Japanese Society of Animal Science.

  6. Children's mental health and collective violence: a binational study on the United States-Mexico border.

    Science.gov (United States)

    Leiner, Marie; Puertas, Hector; Caratachea, Raúl; Avila, Carmen; Atluru, Aparna; Briones, David; Vargas, Cecilia de

    2012-05-01

    To investigate the risk effects of poverty and exposure to collective violence attributed to organized crime on the mental health of children living on the United States-Mexico border. A repeated, cross-sectional study measured risk effects by comparing scores of psychosocial and behavioral problems among children and adolescents living on the border in the United States or Mexico in 2007 and 2010. Patients living in poverty who responded once to the Pictorial Child Behavior Checklist (P+CBCL) in Spanish were randomly selected from clinics in El Paso, Texas, United States (poverty alone group), and Ciudad Juarez, Chihuahua, Mexico (poverty plus violence group). Only children of Hispanic origin (Mexican-American or Mexican) living below the poverty level and presenting at the clinic for nonemergency visits with no history of diagnosed mental, neurological, or life-threatening disease or disability were included. Exposure to collective violence and poverty seemed to have an additive effect on children's mental health. Children exposed to both poverty and collective violence had higher problem scores, as measured by the P+CBCL, than those exposed to poverty alone. It is important to consider that children and adolescents exposed to collective violence and poverty also have fewer chances to receive treatment. Untreated mental health problems predict violence, antisocial behaviors, and delinquency and affect families, communities, and individuals. It is crucial to address the mental health of children on the border to counteract the devastating effects this setting will have in the short term and the near future.

  7. Leaching Behavior of Slags from AN Old Lead Smelter in Chihuahua, Mexico: Metals, Chlorides, Nitrates, Sulfates and Tds Analyses

    Science.gov (United States)

    Espejel-Garcia, D.; Wenglas-Lara, G.; Villalobos-Aragon, A.; Espejel-Garcia, V. V.

    2013-05-01

    Waste materials (such as, smelter slags, waste glass, tires, plastics, rubbish, ashes, etc.), have a large potential to substitute natural materials, reducing costs, especially for the construction industry. Smelter slags are resistant and have better compression strength values in comparison to natural aggregates, and generally are far beyond of what the standard ratios need to qualify a material as a good one for construction. But this material has a big problem within it: the existence of toxic elements and compounds in high concentrations, which means that water and soil contamination can be present after water infiltrates through this material; so we perform leaching experiments to characterize and measure the possible contamination under controlled conditions. To perform the slags-leaching experiments, we used an EA-NEN-7375-2004 tank test standard from Netherlands. This test was selected because to our knowledge it is the only one which allows the use of coarse material, as the one utilized in construction. The leaching experiments sampling was performed at different times: 6, 24, 168 and 360 hours, to compare the leachate concentration at the two different pH's values (5 and 8) selected to simulate real conditions. For the leaching experiments, the slags were mixed with natural road base material (gravel-sands from volcanic rocks) at different proportions of 30% and 50%. In order to understand the slags' leaching behavior, other experiments were carried out with the pure material, for both (slags and natural aggregates). After analyses by ICP-OES , the slags from this smelter in Chihuahua contain Pb (0.5 - 4 wt.%), Zn (15-35 wt.%) and As (0.6 wt.%), as well such as: bicarbonates, chlorides, nitrates, sulfates, Mg, K, Na, Ca and TDS. Based on the results of the leaching analyses, via atomic absorption technique, we conclude that Pb and As concentrations are provided by the slags, meanwhile, the bicarbonates, chlorides, Na and Ca are contributed by the road

  8. Chihuahua: a water reuse case in the desert.

    Science.gov (United States)

    Espino, M S; Navarro, C J; Pérez, J M

    2004-01-01

    Water supply for all kind of uses in Chihuahua is mainly groundwater. During the last decade this city has been damaged with a heavy hydrologic crisis because of a persistent drought. This came up with the overexploitation of groundwater aquifers; therefore a deficit between demand and offer was done. To minimize this problem the government authorities have started an integral plan of optimizing hydrologic resources which considers the treatment of wastewater and the use of reclaimed water. The secondary wastewater treatment facility of the city treats about 30,000 m3/d of a wastewater with high organic contents, and produces an effluent with low concentration of suspended solids, organic matter, fats, detergents, and metals. Reclaimed water is conveyed toward strategic sites for the irrigation of great green areas in sport clubs, educational institutions and industrial zones, besides of its utilization on some manufacturing processes, road service, and also over construction industry. The potential reuse of this water goes farther from those activities; the treatment of the secondary effluent until the required levels of the water-bearing recharge criteria are met for drinking water supply is considered as the next step to achieve through a suitable planning strategy for the best integral resource advantage.

  9. Morbilidad infantil por causas respiratorias y su relación con la contaminación atmosférica en Ciudad Juárez, Chihuahua, México Infant morbidity caused by respiratory diseases and its relation with the air pollution in Juarez City, Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Leticia Hernández-Cadena

    2007-02-01

    de control de la contaminación atmosférica para evitar que empeore la situación actual.OBJECTIVE: To assess the impact of atmospheric pollutants on the respiratory health of children of different age groups in Juarez City, Chihuahua, Mexico. MATERIAL AND METHODS: Data on emergency room visits between 1997 and 2001 for respiratory diseases in children less than 17 years old were obtained from hospitals in the Juarez City belonging to the Mexican Social Security Institute (IMSS. Diseases were classified into three groups according to ICD 9th and 10th codes: a upper respiratory diseases, b lower respiratory diseases, and c asthma attacks. This information was stratified by age group (5 years. Daily air pollution data (ozone and PM10 and weather conditions were obtained from the Monitoring Network System in Juarez City. Statistical analysis was carried out using a Generalized Additive Model assuming a Poisson distribution. RESULTS: Ozone concentrations, but not PM10, were statistically associated with emergency room visits for respiratory diseases, mainly among children 5 years old or younger. In this group, an increase of 20 ppb 1-hr maximum for ozone was associated with an increase of 8.3% in the number of emergency room visits for upper respiratory diseases, with a 3-day exposure lag; and an increase of 12.7% in the number of emergency room visits for lower respiratory diseases when considering a 4-day exposure lag in a maximum 8-hr mobile average. The largest effect for the complete sample and for the group 6 to 16 years of age was observed for 3-day lag (5.1% for an increase of 20 ppb 1-hr maximum for ozone. For the 6 to16 year old group we did not find a significant effect. CONCLUSION: The wide range of risk is quite important and might represent a substantial cost for the health system as well as for the society. Our results emphasize the need to implement preventive and control measures for air pollution and avoid the worsening of the present situation.

  10. La violencia en la región noroeste de Chihuahua. Experiencias e impactos desde la comunidad educativa

    OpenAIRE

    Marcos J. Estrada Ruiz; Adán Cano Aguilar

    2013-01-01

    La violencia escolar ha sido un tema explorado de manera importante en los últimos años desde la investigación educativa en México, sin embargo, en contextos de alta violencia no se han mostrado los impactos de la violencia extraescolar y estructural, en la escuela y en otros espacios comunitarios. El artículo presenta resultados de una investigación que tuvo por objetivo reconstruir el impacto de la violencia en la región noroeste de Chihuahua, desde la comunidad educativa (docentes, padres,...

  11. Desarrollo forestal sustentable en Chihuahua, México: una estrategia multidimensional

    Directory of Open Access Journals (Sweden)

    Concepción Luján Álvarez

    2008-01-01

    Full Text Available Establecer una estrategia multidimensional para lograr el desarrollo forestal sustentable en la región de clima templado frío en Chihuahua, México, fue el objetivo del presente estudio, que se obtuvo con la aplicación del modelo Multiconferencia de Búsqueda (MCB, basado en el sistema de organización por asociaciones de productores forestales (ejidatarios, comuneros y pequeños propietarios, incluidos indígenas y mestizos. La metodología participativa aplicada consideró el carácter social de la propiedad de los recursos forestales en México, y se apoyó en la colaboración activa de ejidos y comunidades y demás actores relacionados. La estrategia multidimensional establecida está integrada por las dimensiones ecológicas ambientales, socioculturales, económicas, político-institucionales y científico-tecnológicas, que incluye objetivos y acciones estratégicas que consideran las necesidades e intereses comunes de los involucrados en la búsqueda del desarrollo forestal regional, con visión de sustentabilidad.

  12. Potential human health risk by 234,238U and 210Po due to consumption of fish from the "Luis L. Leon" reservoir (Northern Mexico)

    Science.gov (United States)

    Luna-Porres, M. Y.; Rodríguez-Villa, M. A.; Herrera-Peraza, E.; Cabral-Lares, M.; Renteria-Villalobos, M.; Montero-Cabrera, M. E.

    2014-07-01

    The Conchos River is one of the most important in northern Mexico and the main surface waterway in the arid state of Chihuahua. The Luis L. Leon dam produces the Luis L. Leon Reservoir, which is the last major reservoir before the Conchos River enters the Rio Grande at the Texas-Chihuahua border. Activity concentrations (AC) of 234,238U and 210Po in fillet and liver of three stocked fish species (Lepomis cyanellus, Cyprinus carpio and Ictalurus furcatus), as well as in water from the Luis L. Leon reservoir were determined. 238U and 234U ACs in fillet samples showed values of 0.007-0.014 and 0.01-0.02 Bq kg-1 wet weight (ww), respectively. Liver samples for Lepomis cyanellus, Cyprinus carpio and Ictalurus furcatus species, present 210Po AC of 1.16-3.26 0.70-1.13 and 0.93-1.37 Bqṡkg-1 ww. The elemental Bioaccumulation Factor (BAF) for fish tissues respect to their concentrations in water was determined. Lepomis cyanellus species showed the highest BAF for total uranium in fillet, with value 1.5. The annual effective dose for uranium in adults by fish consumption in this work ranged from 4.46×10-3 to 3.68×10-2 μSvṡyear-1. The difference in concentrations of uranium in fillet among the studied species is likely primarily due to their differences in diet and habitat.

  13. Craniometric Analysis of the Hindbrain and Craniocervical Junction of Chihuahua, Affenpinscher and Cavalier King Charles Spaniel Dogs With and Without Syringomyelia Secondary to Chiari-Like Malformation.

    Science.gov (United States)

    Knowler, Susan P; Kiviranta, Anna-Mariam; McFadyen, Angus K; Jokinen, Tarja S; La Ragione, Roberto M; Rusbridge, Clare

    2017-01-01

    To characterize and compare the phenotypic variables of the hindbrain and craniocervical junction associated with syringomyelia (SM) in the Chihuahua, Affenpinscher and Cavalier King Charles Spaniel (CKCS). Analysis of 273 T1-weighted mid-sagittal DICOM sequences of the hindbrain and craniocervical junction from 99 Chihuahuas, 42 Affenpinschers and 132 CKCSs. The study compared 22 morphometric features (11 lines, eight angles and three ratios) of dogs with and without SM using refined techniques based on previous studies of the Griffon Bruxellois (GB) using Discriminant Function Analysis and ANOVA with post-hoc corrections. The analysis identified 14/22 significant traits for SM in the three dog breeds, five of which were identical to those reported for the GB and suggest inclusion of a common aetiology. One ratio, caudal fossa height to the length of the skull base extended to an imaginary point of alignment between the atlas and supraoccipital bones, was common to all three breeds (p values 0.029 to Chihuahua had a smaller angle between the dens, atlas and basioccipital bone (p value < 0.001); Affenpinschers had a smaller distance from atlas to dens (p value 0.009); CKCS had a shorter distance between the spheno-occipital synchondrosis and atlas (p value 0.007). The selected morphometries successfully characterised conformational changes in the brain and craniocervical junction that might form the basis of a diagnostic tool for all breeds. The severity of SM involved a spectrum of abnormalities, incurred by changes in both angulation and size that could alter neural parenchyma compliance and/or impede cerebrospinal fluid channels.

  14. Vegetation-derived insights on the mobilization and potential transport of radionuclides from the Nopal I natural analog site, Mexico

    International Nuclear Information System (INIS)

    Leslie, B.W.; Pickett, D.A.; Pearcy, E.C.

    1999-01-01

    The Nopal I uranium (U) deposit, Pena Blanca, Mexico is a source term and contaminant transport natural analog to the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. In an attempt to characterize the mobilization and potential transport of radionuclides in the unsaturated zone at the Nopal I deposit, vegetation growing on ore piles was analyzed for 238 U, 235 U, and 232 Th decay-series isotopes. Specimens of Phacelia robusta growing on high-grade piles of U ore were collected and analyzed by alpha autoradiography, and by alpha and gamma spectrometry. Activities for U, thorium (Th), and radium (Ra) isotopes (Bq/kg dried plant) were 300, 1,000, and 7,000 for 238 U, 230 Th, and 226 Ra, respectively. The 226 Ra activities in these specimens are among the highest ever measured for plants; furthermore, the plant-to-soil 226 Ra concentration ratio is higher than expected. These results demonstrate the large mobility and bio-availability of Ra in the Nopal I environment, and support previous indications of recent loss of 226 Ra from the ore body. Comparison between the activities of 238 U and 232 Th decay-chain Th isotopes in the plants and in the ore substrate indicate that relative mobilization into pore solutions of 228 Th > 230 Th > 232 Th, in a ratio of about 50--25:4:1, respectively. The similarity of the plant's 234 U/ 238 U activity ratio (∼1.2) to that of a caliche deposit that formed adjacent to the Nopal ore body around 54 ka suggests the 234 U/ 238 U activity ratio of U released from the ore is approximately 1.2. The U and 226 Ra isotope activities of the plants and ore substrate, and solubility considerations, are used to assess a source term model of the potential Yucca Mountain repository. These results suggest the use of a natural analog source term model in performance assessments may be non-conservative

  15. Correlation of the activity of the {sup 238} U in soil and {sup 222} Rn in domiciles, with the rocks of cities of the Estado de Chihuahua; Correlacion de la actividad del {sup 238} U en suelo y {sup 222} Rn en domicilios, con las rocas de ciudades del Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Colmenero S, L.; Villalba, L.; Montero C, M.E. [Centro de Investigacion en Materiales Avanzados (CIMAV), Av. Miguel de Cervantes 120 C.P. 31109 Chihuahua (Mexico)]. e-mail: luis.colmenero@cimav.edu.mx

    2004-07-01

    The state of Chihuahua has numerous locations of uranium, being Pena Blanca the great and more important location of the country. Diverse rock types with important quantities of uranium are distributed by the whole state. The igneous extrusive acid rocks are those that have bigger quantity of uranium, like they are the rhyolites and dacites and these rocks are located in enough proportion by the whole state. Some of the main cities of the state are near to locations or uraniferous rocks, as Aldama, Nuevo Casas Grandes, Chihuahua, Jimenez and Bocoyna, other important cities are not near important locations. It was determined specific activity by gamma spectroscopy of the series of the {sup 238} U in soils and determination of the radon concentration in domiciles of the main cities of the state. They were found high specific activity values in soil in eight of the thirteen analyzed cities and important radon concentrations in three cities. It was found relationship among the specific activity in soil in near cities to uraniferous locations. (Author)

  16. Mujeres indígenas, gobierno y comunidad: El caso de mujeres tarahumaras en Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Martha Estela Pérez García

    2016-01-01

    Full Text Available La situación de las mujeres indígenas en Chihuahua se caracteriza por la marginación, pobreza y desigualdad. Por esta razón, algunos(as miembros de la etnia rarámuri obligados por las necesidades más elementales, emigran con sus familias a las principales ciudades de la entidad. En el caso específico de la comunidad indígena asentada en Ciudad Juárez, Chihuahua, encontramos que son mujeres quienes dirigen las tareas de gobierno, rol tradicionalmente asignados a los hombres. El objetivo de este artículo es realizar un acercamiento de la participación femenina en el gobierno de la colonia tarahumara, con el propósito de conocer cómo se genera esta participación, sus liderazgos y las formas de resolución de sus problemas al interior de la comunidad. Para este propósito se realizaron entrevista con representantes de la comunidad y sus dos gobernadoras, además de un grupo focal con la presidenta y un grupo de mujeres. Los resultados de esta investigación mostraron dos cuestiones significativas: la situación de extrema vulnerabilidad en que viven las indígenas en el entorno urbano y que el gobierno femenino usa estrategias apegadas al rol de género para mantener el orden, el liderazgo y mejorar la calidad de vida de su comunidad.

  17. Criollo cattle: Heritage genetics for arid landscapes

    Science.gov (United States)

    Thirty cows and three bulls from the Chinipas region in the state of Chihuahua, Mexico, were introduced onto the US Department of Agriculture – Agricultural Research Service’s Jornada Experimental Range (JER) in 2005. Since then behavioral research has revealed these cattle, most accurately referre...

  18. Evaluación de la propuesta de intervención para estudiantes sobresalientes: caso Chihuahua, México

    Directory of Open Access Journals (Sweden)

    Covarrubias Pizarro, Pedro

    2015-09-01

    Full Text Available Este artículo tiene como propósito exponer los resultados de un trabajo de investigación evaluativa realizado para valorar la implementación de la Propuesta de Intervención Educativa para alumnos y alumnas con Aptitudes Sobresalientes, puesta en marcha por la Secretaría de Educación Pública de México durante el ciclo escolar 2007-2008. Para evaluar dicha propuesta, se diseñó y aplicó un modelo conformado por cuatro componentes, cuatro criterios y trece descriptores. Para la recuperación de los datos y su análisis correspondiente, se empleó una metodología de corte mixto que consideró diferentes momentos, actores e instrumentos. En este documento se presenta el trabajo realizado mediante el enfoque cualitativo, destacando los resultados obtenidos en los grupos de discusión y las entrevistas semiestructuradas. El estudio se llevó a cabo en el estado de Chihuahua, México y participaron como informantes significativos el personal de educación especial del subsistema estatal del estado de Chihuahua, padres y madres de familia de estudiantes sobresalientes, maestras de grupo regular, alumnado identificado como sobresaliente y personas expertas en el tema de las altas capacidades. Los resultados apuntan que la propuesta de intervención valorada cuenta con cualidades relacionadas con su fundamento teórico y metodológico, sin embargo, la mayor debilidad se ubica en la operatividad, aspecto que puede ser sujeto a mejorar para la obtención de mayores resultados en la intervención.

  19. Geochemical and isotopic determination of deep groundwater contributions and salinity to the shallow groundwater and surface water systems, Mesilla Basin, New Mexico, Texas, and Mexico

    Science.gov (United States)

    Robertson, A.; Carroll, K. C.; Kubicki, C.; Purtshert, R.

    2017-12-01

    The Mesilla Basin/Conejos-Médanos aquifer system, extending from southern New Mexico to Chihuahua, Mexico, is a priority transboundary aquifer under the 2006 United States­-Mexico Transboundary Aquifer Assessment Act. Declining water levels, deteriorating water quality, and increasing groundwater use by municipal, industrial, and agricultural users on both sides of the international border raise concerns about long-term aquifer sustainability. Relative contributions of present-day and "paleo" recharge to sustainable fresh groundwater yields has not been determined and evidence suggests that a large source of salinity at the distal end of the Mesilla Basin is saline discharge from deep groundwater flow. The magnitude and distribution of those deep saline flow paths are not determined. The contribution of deep groundwater to discharge and salinity in the shallow groundwater and surface water of the Mesilla Basin will be determined by collecting discrete groundwater samples and analyzing for aqueous geochemical and isotopic tracers, as well as the radioisotopes of argon and krypton. Analytes include major ions, trace elements, the stable isotopes of water, strontium and boron isotopes, uranium isotopes, the carbon isotopes of dissolved inorganic carbon, noble gas concentrations and helium isotope ratios. Dissolved gases are extracted and captured from groundwater wells using membrane contactors in a process known as ultra-trace sampling. Gas samples are analyzed for radioisotope ratios of krypton by the ATTA method and argon by low-level counting. Effectiveness of the ultra-trace sampling device and method was evaluated by comparing results of tritium concentrations to the krypton-85 content. Good agreement between the analyses, especially in samples with undetectable tritium, indicates that the ultra-trace procedure is effective and confirms that introduction of atmospheric air has not occurred. The geochemistry data indicate a complex system of geochemical

  20. Social acceptability urban form and sustainability in urban neighborhoods in Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Claudia Gabriela Vargas Fernández

    2016-11-01

    Full Text Available In the field of urban planning, questioning around sustainability and the possibility of sustainable urban planning has led to a new set of approaches and discussions that impact studies on urban form and sustainable livelihoods. This approach characterized the work presented by Mike Jenks and Colin Jones (2010, Dimensions of the Sustainable City, where a set of variables are presented about urban sustainability from the neighbourhood level of analysis. In that sense, this article proposes the analysis of three social housing neighborhoods in Ciudad Juárez, Chihuahua, México, integrating aspects of urban form and social acceptability, in order to understand the relationship between the physical and sociocultural dimensions of the concept of urban sustainability.

  1. DEL NEOCORPORATIVISMO A NIVEL FABRIL MAQUILADORAS Y SINDICATOS EN LA CIUDAD DE CHIHUAHUA, MÉXICO

    Directory of Open Access Journals (Sweden)

    Patricia Ravelo

    2000-01-01

    Full Text Available En este ensayo buscamos responder una pregunta: ¿Existe en las maquiladoras de exportación de la ciudad de Chihuahua, en el norte industrializado de México, una nueva relación entre el trabajo y el capital, un vínculo neocorporativo? Para dilucidar esta cuestión abordamos varias dimensiones de tal relación entre trabajo y capital: organización del trabajo y empleo; proceso de trabajo; salario; prestaciones sindicales y regresión de derechos. Es una visión pesimista sobre estas relaciones en los "nuevos" contextos de industrialización, pero que, con todo, alcanza a ver un futuro más promisorio para el trabajo.

  2. Del neocorporativismo a nivel fabril maquiladoras y sindicatos en la ciudad de chihuahua, México

    Directory of Open Access Journals (Sweden)

    Sergio Sánchez

    2000-04-01

    Full Text Available En este ensayo buscamos responder una pregunta: ¿Existe en las maquiladoras de exportación de la ciudad de Chihuahua, en el norte industrializado de México, una nueva relación entre el trabajo y el capital, un vínculo neocorporativo? Para dilucidar esta cuestión abordamos varias dimensiones de tal relación entre trabajo y capital: organización del trabajo y empleo; proceso de trabajo; salario; prestaciones sindicales y regresión de derechos. Es una visión pesimista sobre estas relaciones en los “nuevos” contextos de industrialización, pero que, con todo, alcanza a ver un futuro más promisorio para el trabajo.

  3. The Analogy as a Cognitive Strategy that Encourages Reading Comprehension in Expository Texts

    Directory of Open Access Journals (Sweden)

    José Viveros-Márquez

    2010-12-01

    Full Text Available This research arises from the current state of reading in Mexico, because the contextual situation to local and national level has become critical on this issue. Results on standardized tests such as ENLACE (National Assessment of Academic Achievement in Schools and PISA (Program for International Student Assessment have shown that Mexican basic level students have text comprehension problems. Given this reality, this is a qualitative descriptive study on the use of analogies in reading as a strategy for reading comprehension, through application of an ethnographic survey, a questionnaire and the application of a pedagogical model for the use of analogies in reading. The study incorporates the theoretical tenets of Constructivism, referring to Piaget (1969, Vygotsky (1997 and Ausubel (2002. The results show that the use of analogies promotes reading comprehension in 4th grade students, from an expository text that compares the evolution of man and the metamorphosis of a butterfly.

  4. Correlation of the activity of the 238 U in soil and 222 Rn in domiciles, with the rocks of cities of the Estado de Chihuahua

    International Nuclear Information System (INIS)

    Colmenero S, L.; Villalba, L.; Montero C, M.E.

    2004-01-01

    The state of Chihuahua has numerous locations of uranium, being Pena Blanca the great and more important location of the country. Diverse rock types with important quantities of uranium are distributed by the whole state. The igneous extrusive acid rocks are those that have bigger quantity of uranium, like they are the rhyolites and dacites and these rocks are located in enough proportion by the whole state. Some of the main cities of the state are near to locations or uraniferous rocks, as Aldama, Nuevo Casas Grandes, Chihuahua, Jimenez and Bocoyna, other important cities are not near important locations. It was determined specific activity by gamma spectroscopy of the series of the 238 U in soils and determination of the radon concentration in domiciles of the main cities of the state. They were found high specific activity values in soil in eight of the thirteen analyzed cities and important radon concentrations in three cities. It was found relationship among the specific activity in soil in near cities to uraniferous locations. (Author)

  5. Detecting analogical resemblance without retrieving the source analogy.

    Science.gov (United States)

    Kostic, Bogdan; Cleary, Anne M; Severin, Kaye; Miller, Samuel W

    2010-06-01

    We examined whether people can detect analogical resemblance to an earlier experimental episode without being able to recall the experimental source of the analogical resemblance. We used four-word analogies (e.g., robin-nest/beaver-dam), in a variation of the recognition-without-cued-recall method (Cleary, 2004). Participants studied word pairs (e.g., robin-nest) and were shown new word pairs at test, half of which analogically related to studied word pairs (e.g., beaver-dam) and half of which did not. For each test pair, participants first attempted to recall an analogically similar pair from the study list. Then, regardless of whether successful recall occurred, participants were prompted to rate the familiarity of the test pair, which was said to indicate the likelihood that a pair that was analogically similar to the test pair had been studied. Across three experiments, participants demonstrated an ability to detect analogical resemblance without recalling the source analogy. Findings are discussed in terms of their potential relevance to the study of analogical reasoning and insight, as well as to the study of familiarity and recognition memory.

  6. Border Environmental Education Resource Guide: Southern New Mexico, South Texas, Northern Chihuahua, Northern Coahuila, Northern Nuevo Leon, Northern Tamaulipas = Guia de Recursos de Educacion Ambiental en la Frontera: Sur de Nuevo Mexico, Sur de Texas, Norte de Chihuahua, Norte de Coahuila, Norte de Nuevo Leon, Norte de Tamaulipas.

    Science.gov (United States)

    Meissner, David, Comp.

    This guide provides educators and residents of the border with useful information about environmental education program offerings along the eastern half of the United States-Mexico border. The programs listed in the guide represent a broad range of educational efforts focused on understanding the environment and solving environmental problems in…

  7. Vegetation-derived insights on the mobilization and potential transport of radionuclides from the Nopal I natural analog site, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Leslie, B.W.; Pickett, D.A.; Pearcy, E.C.

    1999-07-01

    The Nopal I uranium (U) deposit, Pena Blanca, Mexico is a source term and contaminant transport natural analog to the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. In an attempt to characterize the mobilization and potential transport of radionuclides in the unsaturated zone at the Nopal I deposit, vegetation growing on ore piles was analyzed for {sup 238}U, {sup 235}U, and {sup 232}Th decay-series isotopes. Specimens of Phacelia robusta growing on high-grade piles of U ore were collected and analyzed by alpha autoradiography, and by alpha and gamma spectrometry. Activities for U, thorium (Th), and radium (Ra) isotopes (Bq/kg dried plant) were 300, 1,000, and 7,000 for {sup 238}U, {sup 230}Th, and {sup 226}Ra, respectively. The {sup 226}Ra activities in these specimens are among the highest ever measured for plants; furthermore, the plant-to-soil {sup 226}Ra concentration ratio is higher than expected. These results demonstrate the large mobility and bio-availability of Ra in the Nopal I environment, and support previous indications of recent loss of {sup 226}Ra from the ore body. Comparison between the activities of {sup 238}U and {sup 232}Th decay-chain Th isotopes in the plants and in the ore substrate indicate that relative mobilization into pore solutions of {sup 228}Th > {sup 230}Th > {sup 232}Th, in a ratio of about 50--25:4:1, respectively. The similarity of the plant's {sup 234}U/{sup 238}U activity ratio ({approximately}1.2) to that of a caliche deposit that formed adjacent to the Nopal ore body around 54 ka suggests the {sup 234}U/{sup 238}U activity ratio of U released from the ore is approximately 1.2. The U and {sup 226}Ra isotope activities of the plants and ore substrate, and solubility considerations, are used to assess a source term model of the potential Yucca Mountain repository. These results suggest the use of a natural analog source term model in performance assessments may be non-conservative.

  8. Craniometric Analysis of the Hindbrain and Craniocervical Junction of Chihuahua, Affenpinscher and Cavalier King Charles Spaniel Dogs With and Without Syringomyelia Secondary to Chiari-Like Malformation.

    Directory of Open Access Journals (Sweden)

    Susan P Knowler

    Full Text Available To characterize and compare the phenotypic variables of the hindbrain and craniocervical junction associated with syringomyelia (SM in the Chihuahua, Affenpinscher and Cavalier King Charles Spaniel (CKCS.Analysis of 273 T1-weighted mid-sagittal DICOM sequences of the hindbrain and craniocervical junction from 99 Chihuahuas, 42 Affenpinschers and 132 CKCSs. The study compared 22 morphometric features (11 lines, eight angles and three ratios of dogs with and without SM using refined techniques based on previous studies of the Griffon Bruxellois (GB using Discriminant Function Analysis and ANOVA with post-hoc corrections.The analysis identified 14/22 significant traits for SM in the three dog breeds, five of which were identical to those reported for the GB and suggest inclusion of a common aetiology. One ratio, caudal fossa height to the length of the skull base extended to an imaginary point of alignment between the atlas and supraoccipital bones, was common to all three breeds (p values 0.029 to <0.001. Associated with SM were a reduced occipital crest and two acute changes in angulation i 'sphenoid flexure' at the spheno-occipital synchondrosis ii 'cervical flexure' at the foramen magnum allied with medulla oblongata elevation. Comparing dogs with and without SM, each breed had a unique trait: Chihuahua had a smaller angle between the dens, atlas and basioccipital bone (p value < 0.001; Affenpinschers had a smaller distance from atlas to dens (p value 0.009; CKCS had a shorter distance between the spheno-occipital synchondrosis and atlas (p value 0.007.The selected morphometries successfully characterised conformational changes in the brain and craniocervical junction that might form the basis of a diagnostic tool for all breeds. The severity of SM involved a spectrum of abnormalities, incurred by changes in both angulation and size that could alter neural parenchyma compliance and/or impede cerebrospinal fluid channels.

  9. Analysis of Institutional Competitiveness of Junior High Schools through the Admission Test to High School Education

    Science.gov (United States)

    Armendáriz, Joyzukey; Tarango, Javier; Machin-Mastromatteo, Juan Daniel

    2018-01-01

    This descriptive and correlational research studies 15,658 students from 335 secondary schools in the state of Chihuahua, Mexico, through the results of the examination of admission to high school education (National High School Admission Test--EXANI I from the National Assessment Center for Education--CENEVAL) on logical-mathematical and verbal…

  10. Lessons Learned from Two Neighbors: How Educators Teach of United States Policies

    Science.gov (United States)

    Cashman, Timothy G.

    2013-01-01

    This study provides an analysis of data collected from Chihuahua, Mexico, and Ontario, Canada, educators on how United States (U. S.) policies are taught and discussed in their classrooms. Teachers and administrators were interviewed with regard to their respective curricula and classroom discussions. The researcher sought to gain insight on how…

  11. Investigation of the radioactivity in air, water and soil in the Estado de Chihuahua; Investigacion de la radiactividad en aire, agua y suelo en el Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Montero C, M.E.; Renteria V, M.; Herrera P, E.F.; Villalba, M.L. [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, C.P. 31109, Chihuahua (Mexico); Colmenero S, L.H. [CIMAV e Instituto Tecnologico de Chihuahua, Av. de las Industrias 11101, Chihuahua (Mexico)]. e-mail: elena.montero@cimav.edu.mx

    2004-07-01

    The results of the determinations of activities of the series of U-238, Th-232 and the K-40 in soils, of the Rn-222 in the air of the domiciles, and in underground water are presented, as well as the total uranium activity in underground water, product of an extensive sampling in the state of Chihuahua. In two of the aquifers a positive correlation was obtained among the concentration of total uranium and the Rn-222 dissolved in the water of each well. Also it was finds a positive tendency among the averages of the concentration of U-238 in the soil and of the concentration of Rn-222 in the air of the domiciles in different towns, and among the averages of the concentration of U-238 in the floor and of the concentration of the Rn-222 dissolved in the well water in different aquifer. It is suggested that the constitution for rocks more or less uraniferous of the alluvial valleys gives explanation to the observed correlations. (Author)

  12. The USAID/DOE Mexico Renewable Energy Program: Using technology to build new markets

    Science.gov (United States)

    Hanley, Charles J.

    1997-02-01

    Under the Mexico Renewable Energy Program, managed by Sandia National Laboratories, sustainable markets for renewable energy technologies are developed through the implementation of pilot projects. Sandia provides technical assistance to several Mexican rural development organizations so they can gain the technical and institutional capability to appropriately utilize renewables within their ongoing programs. Activities in the area of water pumping have shown great replication potential, where the tremendous rural demand for water represents a potential renewable market of over 2 billion. Thirty-six photovoltaic water pumping projects have been installed thus far in the Mexican states of Chihuahua, Sonora, Baja California Sur, and Quintana Roo, and 60 more will be implemented this year. The majority of these projects are in partnership with the Mexican Trust for Shared Risk (FIRCO), which has asked Sandia for assistance in extending the program nationwide. This replication is beginning in five new states, and will continue to grow. Sandia is keeping the U.S. renewable energy industry involved in the program through facilitating partnerships between U.S. and Mexican vendors, and through commercialization assistance with new systems technologies. The program is sponsored by the Department of Energy and the U.S. Agency for International Development.

  13. La organización de las escuelas secundarias del estado de Chihuahua, en el marco de la reforma educativa

    Directory of Open Access Journals (Sweden)

    David Manuel Arzola Franco

    2010-10-01

    Full Text Available El presente artículo se deriva de un proyecto de investigación apoyado por el Fondo Mixto CONACYT-Gobierno del Estado de Chihuahua, cuyo propósito consiste en indagar sobre la visión que tienen los actores involucrados en la Reforma de la Educación Secundaria (RS, con respecto a los procesos de transformación que se pretenden operar en el ámbito organizativo. El trabajo se llevó a cabo a través de la aplicación de una encuesta, a una muestra representativa de docentes, directivos, alumnos y padres/madres de familia, de escuelas secundarias, generales y técnicas, del estado de Chihuahua. El análisis está centrado en algunos aspectos relacionados con la organización de los 43 centros educativos: el funcionamiento institucional, los procesos comunicativos, las acciones de orientación y tutoría, el trabajo colaborativo; la información sobre la dinámica para la implementación de la Reforma de la Educación Secundaria (RS, y las perspectivas de los sujetos con respecto al manejo de los indicadores educativos a nivel institucional. Los datos recabados ponen de relieve que la RS se limita al cambio del plan y los programas de estudio; no se advierten transformaciones en la estructura organizativa de las escuelas de este nivel: formas de gobierno, aspectos normativos, procesos de comunicación y participación, toma de decisiones, etc.

  14. Sustaining the grassland sea: Regional perspectives on identifying, protecting and restoring the Sky Island region's most intact grassland valley landscapes

    Science.gov (United States)

    Gitanjali S. Bodner; Peter Warren; David Gori; Karla Sartor; Steven Bassett

    2013-01-01

    Grasslands of the Sky Islands region once covered over 13 million acres in southeastern Arizona and adjacent portions of New Mexico, Sonora, and Chihuahua. Attempts to evaluate current ecological conditions suggest that approximately two thirds of these remain as intact or restorable grassland habitat. These grasslands provide watershed services such as flood control...

  15. Jaime Urrutia Fucugauchi Receives 2013 International Award: Citation

    Science.gov (United States)

    Lomnitz, Cinna

    2014-01-01

    Jaime Urrutia Fucugauchi was born in Chihuahua, Mexico. His surname Urrutia means "distant" in Basque, and Fucugauchi means roughly "Good luck—come in!" in Japanese. And Jaime, of course, is "James" in Spanish. Thus, Jaime was international from birth. There could hardly have been a better candidate for the AGU International Award.

  16. The involvement of citizens and water management: Neighborhood committees leaders in Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Gustavo Córdova Bojórquez

    2005-07-01

    Full Text Available This paper seeks to analyze public participation in water management through a survey applied to the leaders of neighborhood committees in Ciudad Juarez, Chihuahua. As part of the methodology, two variables —external and internal influences— and fourteen indicators were utilized. Results show that neighborhood committees, as a public participation structure, are in crisis. The structure shows both internal and external signs of breaking up: there are no clear mechanisms of summons or participation, nor are there any adecuate mechanisms capable of articulating demands and government authority, insofar as external political agents have been allowed to participate in internal management and committee issues. For this reason, the capacity of local neighborhood committees to make decisions regarding city water management is placed in doubt.

  17. Analogical scaffolding: Making meaning in physics through representation and analogy

    Science.gov (United States)

    Podolefsky, Noah Solomon

    This work reviews the literature on analogy, introduces a new model of analogy, and presents a series of experiments that test and confirm the utility of this model to describe and predict student learning in physics with analogy. Pilot studies demonstrate that representations (e.g., diagrams) can play a key role in students' use of analogy. A new model of analogy, Analogical Scaffolding, is developed to explain these initial empirical results. This model will be described in detail, and then applied to describe and predict the outcomes of further experiments. Two large-scale (N>100) studies will demonstrate that: (1) students taught with analogies, according to the Analogical Scaffolding model, outperform students taught without analogies on pre-post assessments focused on electromagnetic waves; (2) the representational forms used to teach with analogy can play a significant role in student learning, with students in one treatment group outperforming students in other treatment groups by factors of two or three. It will be demonstrated that Analogical Scaffolding can be used to predict these results, as well as finer-grained results such as the types of distracters students choose in different treatment groups, and to describe and analyze student reasoning in interviews. Abstraction in physics is reconsidered using Analogical Scaffolding. An operational definition of abstraction is developed within the Analogical Scaffolding framework and employed to explain (a) why physicists consider some ideas more abstract than others in physics, and (b) how students conceptions of these ideas can be modeled. This new approach to abstraction suggests novel approaches to curriculum design in physics using Analogical Scaffolding.

  18. Integrated geographic information systems (IGIS) analysis and definition of the tectonic framework of northern Mexico

    Science.gov (United States)

    Martinez Pina, Carlos Manuel

    Crustal rupture structures reactivated in the course of the tectonic history of northern Mexico are the surface expressions of planes of weakness, in the form of simple or composite rectilinear features or slightly curved, defined as lineaments. Unless otherwise defined as strike-slip faults, lineaments are part of parallel and sub-parallel oblique convergent or oblique divergent tectonic zones cross cutting the Sierra Madre Occidental and northern Mexico, in a NW trend. These shear zones are the response to the oblique subduction of the Farallon plate beneath North America. Kinematic analysis of five selected sites in northern Mexico, three basins and two compressional shear zones, proved possible a combination of shear mechanism diagram and models from analogue materials, with satellite imagery and geographic information systems, as an aid to define strike-slip fault motion. This was done using a reverse engineering process by comparing geometries. One of the sites assessed, involving the Parras Basin, Coahuila Block (CB), San Marcos fault, a postulated PBF-1 fault, allowed for palinpastic reconstruction of the CB that corroborated the results of the vector motion defined, in addition to an extension of ˜25% in a northwest southeast direction. A GIS-based compilation and georeferenced regional structural studies by several researchers were used as ground control areas (GCA); their interpolation and interpretation, resulted in a tectonic framework map of northern Mexico. In addition, shaded relief models overlaid by the lineaments / fault layer allowed structural analyses of basins related to these major structures. Two important results were obtained from this study: the Tepehuanes-San Luis-fault (TSL) and the Guadalupe fault, named herein, displaces the Villa de Reyes graben, and the Aguascalientes graben, respectively, to the SE, confirming their left lateral vector motion; afterwards TSL was displaced south by the right lateral strike slip Taxco-San Miguel de

  19. Binational school-based monitoring of traffic-related air pollutants in El Paso, Texas (USA) and Ciudad Juarez, Chihuahua (Mexico)

    International Nuclear Information System (INIS)

    Raysoni, Amit U.; Sarnat, Jeremy A.; Sarnat, Stefanie Ebelt; Garcia, Jose Humberto; Holguin, Fernando; Flores Luevano, Silvia; Li, Wen-Whai

    2011-01-01

    Paired indoor and outdoor concentrations of fine and coarse particulate matter (PM), PM2.5 reflectance [black carbon(BC)], and nitrogen dioxide (NO 2 ) were determined for sixteen weeks in 2008 at four elementary schools (two in high and two in low traffic density zones) in a U.S.-Mexico border community to aid a binational health effects study. Strong spatial heterogeneity was observed for all outdoor pollutant concentrations. Concentrations of all pollutants, except coarse PM, were higher in high traffic zones than in the respective low traffic zones. Black carbon and NO 2 appear to be better traffic indicators than fine PM. Indoor air pollution was found to be well associated with outdoor air pollution, although differences existed due to uncontrollable factors involving student activities and building/ventilation configurations. Results of this study indicate substantial spatial variability of pollutants in the region, suggesting that children's exposures to these pollutants vary based on the location of their school. - Highlights: → First binational investigation characterizing traffic air pollutants at four schools in El Paso, USA and Cd. Juarez, Mexico. → Paired in-outdoor sampling of PM 2.5 , PM 10-2.5 , reflectance [black carbon(BC)], and NO 2 for 16 weeks in 2008 at each school. → Two schools (one in each city) were located in high traffic density areas and the other two in areas of low traffic density. → Usage of spatially resolved environmental indictors of traffic pollutants in a range of exposure settings. → Substantial intra-urban spatial variability in pollutant concentrations observed between and within the two cities. - Spatial variability in traffic-mediated pollutant concentrations can exist at the intra-urban level and ambient monitoring sites may not accurately represent these concentration gradients.

  20. Characterization of Mexican zeolite minerals; Caracterizacion de minerales zeoliticos mexicanos

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez C, M.J

    2005-07-01

    50% of the Mexican territory is formed by volcanic sequences of the Pliocene type, which appear extensively in the northwest states (Sonora, Sinaloa, Chihuahua, Durango) and west of Mexico (Jalisco and Nayarit), in central Mexico (Zacatecas, Guanajuato, San Luis Potosi, Queretaro, Hidalgo) and south of Mexico (Guerrero, Oaxaca); therefore, it is to be expected that in our country big locations of natural zeolites exist in its majority of the clinoptilolite type. The present study was focused toward the characterization of two Mexican natural zeolite rocks presumably of the clinoptilolite and filipsite types, one of them comes from the state of Chihuahua and the other of a trader company of non metallic minerals, due that these materials are not characterized, its are not known their properties completely and therefore, the uses that can be given to these materials. In this investigation work it was carried out the characterization of two Mexican zeolite rocks, one coming from the Arroyo zone, municipality of La Haciendita, in the state of Chihuahua; and the other one was bought to a trader company of non metallic minerals. The two zeolites so much in their natural form as conditioned with sodium; they were characterized by means of X-ray diffraction, scanning electron microscopy of high vacuum and elementary microanalysis (EDS), surface area analysis (BET), thermal gravimetric analysis. To differentiate the heulandite crystalline phase of the other clinoptilolite rock, its were carried out thermal treatments. The quantification of Al, Na, Ca, K, Mg, Fe was carried out in solution, by means of atomic absorption spectroscopy and the quantity of Si was determined by gravimetry. The zeolite rocks presented for the major part the crystalline heulandite and clinoptilolite phases for the most part, and it was found that the zeolite coming from the state of Chihuahua possesses a bigger content of heulandite and the denominated filipsite it is really a zeolite

  1. Characterization of Mexican zeolite minerals

    International Nuclear Information System (INIS)

    Jimenez C, M.J.

    2005-01-01

    50% of the Mexican territory is formed by volcanic sequences of the Pliocene type, which appear extensively in the northwest states (Sonora, Sinaloa, Chihuahua, Durango) and west of Mexico (Jalisco and Nayarit), in central Mexico (Zacatecas, Guanajuato, San Luis Potosi, Queretaro, Hidalgo) and south of Mexico (Guerrero, Oaxaca); therefore, it is to be expected that in our country big locations of natural zeolites exist in its majority of the clinoptilolite type. The present study was focused toward the characterization of two Mexican natural zeolite rocks presumably of the clinoptilolite and filipsite types, one of them comes from the state of Chihuahua and the other of a trader company of non metallic minerals, due that these materials are not characterized, its are not known their properties completely and therefore, the uses that can be given to these materials. In this investigation work it was carried out the characterization of two Mexican zeolite rocks, one coming from the Arroyo zone, municipality of La Haciendita, in the state of Chihuahua; and the other one was bought to a trader company of non metallic minerals. The two zeolites so much in their natural form as conditioned with sodium; they were characterized by means of X-ray diffraction, scanning electron microscopy of high vacuum and elementary microanalysis (EDS), surface area analysis (BET), thermal gravimetric analysis. To differentiate the heulandite crystalline phase of the other clinoptilolite rock, its were carried out thermal treatments. The quantification of Al, Na, Ca, K, Mg, Fe was carried out in solution, by means of atomic absorption spectroscopy and the quantity of Si was determined by gravimetry. The zeolite rocks presented for the major part the crystalline heulandite and clinoptilolite phases for the most part, and it was found that the zeolite coming from the state of Chihuahua possesses a bigger content of heulandite and the denominated filipsite it is really a zeolite

  2. Documenting the biodiversity of the Madrean Archipelago: An analysis of a virtual flora and fauna

    Science.gov (United States)

    Nicholas S. Deyo; Thomas R. Van Devender; Alex Smith; Edward. Gilbert

    2013-01-01

    The Madrean Archipelago Biodiversity Assessment (MABA) of Sky Island Alliance is an ambitious project to document the distributions of all species of animals and plants in the Madrean Archipelago, focusing particularly on northeastern Sonora and northwestern Chihuahua, Mexico. The information is made available through MABA’s online database (madrean.org). The sources...

  3. Conservation implications of spur length variation in long-spur columbines (Aquilegia longissima)

    Science.gov (United States)

    Christopher J. Stubben; Brook G. Milligan

    2007-01-01

    Populations of long-spur columbine (Aquilegia longissima) with spurs 10-16 cm long are known only from a few populations in Texas, a historical collection near Baboquivari Peak, Arizona, and scattered populations in Coahuila, Chihuahua, and Nuevo Leon, Mexico. Populations of yellow columbine with spurs 7-10 cm long are also found in Arizona, Texas,...

  4. Detecting analogies unconsciously

    Directory of Open Access Journals (Sweden)

    Thomas Peter Reber

    2014-01-01

    Full Text Available Analogies may arise from the conscious detection of similarities between a present and a past situation. In this functional magnetic resonance imaging study, we tested whether young volunteers would detect analogies unconsciously between a current supraliminal (visible and a past subliminal (invisible situation. The subliminal encoding of the past situation precludes awareness of analogy detection in the current situation. First, participants encoded subliminal pairs of unrelated words in either one or nine encoding trials. Later, they judged the semantic fit of supraliminally presented new words that either retained a previously encoded semantic relation (‘analog’ or not (‘broken analog’. Words in analogs versus broken analogs were judged closer semantically, which reflects unconscious analogy detection. Hippocampal activity associated with subliminal encoding correlated with the behavioral measure of unconscious analogy detection. Analogs versus broken analogs were processed with reduced prefrontal but enhanced medial temporal activity. We conclude that analogous episodes can be detected even unconsciously drawing on the episodic memory network.

  5. Automatic activation of categorical and abstract analogical relations in analogical reasoning.

    Science.gov (United States)

    Green, Adam E; Fugelsang, Jonathan A; Dunbar, Kevin N

    2006-10-01

    We examined activation of concepts during analogical reasoning. Subjects made either analogical judgments or categorical judgments about four-word sets. After each four-word set, they named the ink color of a single word in a modified Stroop task. Words that referred to category relations were primed (as indicated by longer response times on Stroop color naming) subsequent to analogical judgments and categorical judgments. This finding suggests that activation of category concepts plays a fundamental role in analogical thinking. When colored words referred to analogical relations, priming occurred subsequent to analogical judgments, but not to categorical judgments, even though identical four-word stimuli were used for both types of judgments. This finding lends empirical support to the hypothesis that, when people comprehend the analogy between two items, they activate an abstract analogical relation that is distinct from the specific content items that compose the analogy.

  6. Analog computing

    CERN Document Server

    Ulmann, Bernd

    2013-01-01

    This book is a comprehensive introduction to analog computing. As most textbooks about this powerful computing paradigm date back to the 1960s and 1970s, it fills a void and forges a bridge from the early days of analog computing to future applications. The idea of analog computing is not new. In fact, this computing paradigm is nearly forgotten, although it offers a path to both high-speed and low-power computing, which are in even more demand now than they were back in the heyday of electronic analog computers.

  7. The USAID/DOE Mexico Renewable Energy Program: Using technology to build new markets

    International Nuclear Information System (INIS)

    Hanley, C.J.

    1997-01-01

    Under the Mexico Renewable Energy Program, managed by Sandia National Laboratories, sustainable markets for renewable energy technologies are developed through the implementation of pilot projects. Sandia provides technical assistance to several Mexican rural development organizations so they can gain the technical and institutional capability to appropriately utilize renewables within their ongoing programs. Activities in the area of water pumping have shown great replication potential, where the tremendous rural demand for water represents a potential renewable market of over $2 billion. Thirty-six photovoltaic water pumping projects have been installed thus far in the Mexican states of Chihuahua, Sonora, Baja California Sur, and Quintana Roo, and 60 more will be implemented this year. The majority of these projects are in partnership with the Mexican Trust for Shared Risk (FIRCO), which has asked Sandia for assistance in extending the program nationwide. This replication is beginning in five new states, and will continue to grow. Sandia is keeping the U.S. renewable energy industry involved in the program through facilitating partnerships between U.S. and Mexican vendors, and through commercialization assistance with new systems technologies. The program is sponsored by the Department of Energy and the U.S. Agency for International Development. copyright 1997 American Institute of Physics

  8. Science Teachers' Analogical Reasoning

    Science.gov (United States)

    Mozzer, Nilmara Braga; Justi, Rosária

    2013-08-01

    Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to introduce analogies in their lessons. Both aspects have been discussed in the literature in the last few decades. However, almost nothing is known about how teachers draw their own analogies for instructional purposes or, in other words, about how they reason analogically when planning and conducting teaching. This is the focus of this paper. Six secondary teachers were individually interviewed; the aim was to characterize how they perform each of the analogical reasoning subprocesses, as well as to identify their views on analogies and their use in science teaching. The results were analyzed by considering elements of both theories about analogical reasoning: the structural mapping proposed by Gentner and the analogical mechanism described by Vosniadou. A comprehensive discussion of our results makes it evident that teachers' content knowledge on scientific topics and on analogies as well as their pedagogical content knowledge on the use of analogies influence all their analogical reasoning subprocesses. Our results also point to the need for improving teachers' knowledge about analogies and their ability to perform analogical reasoning.

  9. Percepción de estudiantes de educación superior sobre sus competencias en las TIC en las universidades Autónoma de Chihuahua y Veracruzana

    Directory of Open Access Journals (Sweden)

    Carlos Arturo Torres Gastelú

    2011-10-01

    Full Text Available Las universidades públicas mexicanas están enfrentando el reto de incorporar las TIC como un recurso valioso en el proceso integral de desarrollo de habilidades, conocimientos y competencias en el alumnado. En este sentido, se presentan los resultados de un estudio cuyo objetivo fue contrastar los niveles de competencias en TIC del alumnado entre la Universidad Autónoma de Chihuahua y la Universidad Veracruzana. El criterio de selección de la muestra fue tomar una licenciatura afín sobre sistemas computacionales. El estudio fue cuantitativo y de carácter exploratorio. Se alcanzó una muestra de 240 alumnos en ambas universidades, de los cuales 134 pertenecen a la Universidad Veracruzana y 106 a la Universidad Autónoma de Chihuahua. En ambas universidades se aplicó el mismo instrumento cuantitativo. El análisis de los resultados se hizo por frecuencia y se empleó un procesamiento cuantitativo (porcentajes, frecuencias, medias, Chi cuadrado. Los resultados muestran confianza de los estudiantes en sus competencias en TIC para interactuar en ambientes de enseñanza mediados por tecnología. Además, no se encontraron diferencias significativas por género entre los niveles de competencias estudiados en ambas universidades.

  10. SITUACIÓN ECONÓMICA DE LA PRODUCCIÓN DE BOVINOS DE CARNE EN EL ESTADO DE CHIHUAHUA, MÉXICO

    Directory of Open Access Journals (Sweden)

    Nicol\\u00E1s Callejas-Ju\\u00E1rez

    2014-01-01

    Full Text Available El objetivo del presente estudio fue analizar la situación microeconómica de Unidades Representativas de Producción (URP del sistema de producción vaca-becerro en el estado de Chihuahua, Mé - xico. Se analizaron cuatro escalas de producción (20, 40, 200 y 500 vientres en edad productiva en cuatro regiones del es - tado de Chihuahua, México. Con la metodología de panel se obtuvieron costos e ingresos en 2009, con la participación de cinco a diez productores por panel. Se utiliz ó el modelo de simulación económica MEXSIM de la Universidad de Texas A&M, adaptado para México por la Red Nacional de Inves - tigación en Política Pública. La viabilidad económica medi - da a través de la probabilidad de obtener reservas finales de efectivo negativas y perder capital, fue buena para CHBC20, CHBC200 y CHBC500 y moderada para CHBC40. La uti - lidad neta más baja por vientre fue para CHBC40 ($ 27,76 dólares y la más alta para CHBC20 ($ 403,42 dólares. La relación beneficio-costo fue de 2,16 y 1,78 para CHBC500 y CHBC200, respectivamente. Todas las URP obtuvieron el ingreso neto suficiente para cubrir sus gastos familiares, ex - cepto CHBC20 que generó 70%. Las URP con mayor escala fueron más rentables que las pequeñas y todas trabajaron so - bre su punto de equilibrio. El margen de ganancia fue mayor cuanto más grande fue la escala de producción, con lo que se mostró evidencia de economía de escala.

  11. Analog synthetic biology.

    Science.gov (United States)

    Sarpeshkar, R

    2014-03-28

    We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations.

  12. 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,…

  13. Binational digital soils map of the Ambos Nogales watershed, southern Arizona and northern Sonora, Mexico

    Science.gov (United States)

    Norman, Laura

    2004-01-01

    We have prepared a digital map of soil parameters for the international Ambos Nogales watershed to use as input for selected soils-erosion models. The Ambos Nogales watershed in southern Arizona and northern Sonora, Mexico, contains the Nogales wash, a tributary of the Upper Santa Cruz River. The watershed covers an area of 235 km2, just under half of which is in Mexico. Preliminary investigations of potential erosion revealed a discrepancy in soils data and mapping across the United States-Mexican border due to issues including different mapping resolutions, incompatible formatting, and varying nomenclature and classification systems. To prepare a digital soils map appropriate for input to a soils-erosion model, the historical analog soils maps for Nogales, Ariz., were scanned and merged with the larger-scale digital soils data available for Nogales, Sonora, Mexico using a geographic information system.

  14. Pathogenic landscape of transboundary zoonotic diseases in the Mexico-US border along the Rio Grande

    Directory of Open Access Journals (Sweden)

    Maria Dolores Esteve-Gasent

    2014-11-01

    Full Text Available Transboundary zoonotic diseases, several of which are vector borne, can maintain a dynamic focus, and have pathogens circulating in geographic regions encircling multiple geopolitical boundaries. Global change is intensifying transboundary problems including the spatial variation of the risk and incidence of zoonotic diseases. The complexity of these challenges can be greater in areas where rivers delineate international boundaries and encompass transitions between ecozones. The Rio Grande serves as a natural border between the US State of Texas and the Mexican States of Chihuahua, Coahuila, Nuevo León, and Tamaulipas. Not only millions of people live in this transboundary region but also a substantial movement of goods and people pass through it everyday. Moreover, it occurs over a region that functions as a corridor for animal migrations, and thus links the Neotropic and Nearctic biogeographic zones, with the latter being a known foci of zoonotic diseases. However, the pathogenic landscape of important zoonotic diseases in the south Texas-Mexico transboundary region remains to be fully understood. An international perspective on the interplay between disease systems, ecosystem processes, land use, and human behaviors is applied here to analyze landscape and spatial features of Venezuelan equine encephalitis, Hantavirus disease, Lyme Borreliosis, Leptospirosis, Bartonellosis, Chagas disease, human Babesiosis, and Leishmaniasis. Surveillance systems following the One Health approach with a regional perspective will help identifying opportunities to mitigate the health burden of those diseases on human and animal populations. It is proposed that the Mexico-US border, along the Rio Grande region be viewed as a continuum landscape where zoonotic pathogens circulate regardless of national borders.

  15. Preliminary flora of the Sierra Bacadehuachi, Sonora, Mexico

    Science.gov (United States)

    Thomas R. Van Devender; Ana Lilia Reina-Guerrero; George M. Ferguson; George Yatskievych; Beatriz E. Loyola-Reina; Gertrudis Yanes-Arvayo; Maria de la Paz Montanez-Armenta; John L. Anderson; Stephen F. Hale; Sky Jacobs

    2013-01-01

    The Sierra Bacadéhuachi in east-central Sonora is the westernmost mountain range in the Sierra Madre Occidental (SMO), located east of Bacadéhuachi, Municipio de Bacadéhuachi, 34 km east of the Chihuahua border, and 165 km south of the Arizona border. The vegetation ranges from lowland foothills thornscrub up through desert grassland to oak woodland and pine-oak forest...

  16. Health impacts of air pollution on morbidity and mortality among children of Ciudad Juarez, Chihuahua, Mexico : working paper

    International Nuclear Information System (INIS)

    Romieu, I.; Aguilar, M.R.; Macias, H.M.; Villarreal, A.B.; Cadena, L.H.; Arroyo, L.C.

    2003-01-01

    This study evaluated the impact of air pollution on a group of children in Ciudad Juarez, Mexico where a large urban population of children live in poor conditions. In particular, the study examined the associations between ozone ambient levels and respiratory-related emergency visits to hospitals by children. The impact of PM10 on respiratory health was also examined. Upper respiratory infections and asthma were found to be associated with ozone ambient levels for all age groups. In children aged 5 or less, ozone exposure was related to lower respiratory infections as well. Ambient air pollutants were not related to respiratory deaths in the population of children involved in this study, but data suggests that that PM10 ambient levels might increase the risk of respiratory mortality in infants less than one year old. An increase in respiratory mortality was noted among infants from the lowest socio-economic status (SES) group. This report emphasizes the need for implementing cost effective interventions to control existing air pollution problems and to prevent the situation from worsening. 22 refs., 27 tabs., 5 figs

  17. THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL

    Energy Technology Data Exchange (ETDEWEB)

    G.J. Saulnier Jr; W. Statham

    2006-03-10

    The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. the Pena Blanca Natural Analogue Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following characteristics as compared to the Yucca Mountain repository site. (1) Analogous source: UO{sub 2} uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geologic setting: fractured, welded, and altered rhyolitic ash flow tuffs overlying carbonate rocks; (3) Analogous climate: Semiarid to arid; (4) Analogous geochemistry: Oxidizing conditions; and (5) Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table. The Nopal I deposit is approximately 8 {+-} 0.5 million years old and has been exposed to oxidizing conditions during the last 3.2 to 3.4 million years. The Pena Blanca Natural Analogue Model considers that the uranium oxide and uranium silicates in the ore deposit were originally analogous to uranium-oxide spent nuclear fuel. The Pena Blanca site has been characterized using field and laboratory investigations of its fault and fracture distribution, mineralogy, fracture fillings, seepage into the mine adits, regional hydrology, and mineralization that shows the extent of radionuclide migration. Three boreholes were drilled at the Nopal I mine site in 2003 and these boreholes have provided samples for lithologic characterization, water-level measurements, and water samples for laboratory

  18. THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL

    International Nuclear Information System (INIS)

    G.J. Saulnier Jr; W. Statham

    2006-01-01

    The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. the Pena Blanca Natural Analogue Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following characteristics as compared to the Yucca Mountain repository site. (1) Analogous source: UO 2 uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geologic setting: fractured, welded, and altered rhyolitic ash flow tuffs overlying carbonate rocks; (3) Analogous climate: Semiarid to arid; (4) Analogous geochemistry: Oxidizing conditions; and (5) Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table. The Nopal I deposit is approximately 8 ± 0.5 million years old and has been exposed to oxidizing conditions during the last 3.2 to 3.4 million years. The Pena Blanca Natural Analogue Model considers that the uranium oxide and uranium silicates in the ore deposit were originally analogous to uranium-oxide spent nuclear fuel. The Pena Blanca site has been characterized using field and laboratory investigations of its fault and fracture distribution, mineralogy, fracture fillings, seepage into the mine adits, regional hydrology, and mineralization that shows the extent of radionuclide migration. Three boreholes were drilled at the Nopal I mine site in 2003 and these boreholes have provided samples for lithologic characterization, water-level measurements, and water samples for laboratory analysis

  19. COMPUTATION IN CLOUD; A COMPETITIVE STRATEGY FOR THE SMALL AND MEDIUM COMPANIES IN MEXICO

    Directory of Open Access Journals (Sweden)

    Alma Lilia Sapién Aguilar

    2014-05-01

    Full Text Available Cloud  computing  is  a  technology  that  provides  services  via  the  Internet.  With  this technology, companies can gain a competitive advantage, provide better customer service and reduce  costs. The objective of this research  was to analyze  the Cloud computing  service of companies  in the  city of ChihuahuaMexico.  This  was  a non-experimental,  descriptive  and empirical study with a quantitative approach, which was based on a survey conducted in the months  of  January  2012  through  April  2013.  The  study’s  purpose  was  small  and  medium enterprises (SMEs in the industrial, commercial and service sectors which represent the study population. Finite population formula was used to obtain the sample size, which were selected in a random manner. The results showed that 93 % of companies obtain reduced costs using cloud computing. Storage and sharing information was detected as some of the most used services. Companies want to have savings in technology infrastructure in order to increase the life cycle of the equipment, in addition to provide a higher quality service to customers.

  20. Margaritasite: a new mineral of hydrothermal origin from the Pena Blanca uranium district, Mexico.

    Science.gov (United States)

    Wenrich, K.J.; Modreski, P.J.; Zielinski, R.A.; Seeley, J.L.

    1982-01-01

    Margaritasite, (Cs,K,H3O)2(UO2)2V2O8.nH2O (where Cs > K, H3O and n approx 1), a 10.514, b 8.425, c 7.25 A, beta 106.01o, P21/a, Z = 2, is a newly recognized uranium ore mineral named for the Margaritas deposit, Pena Blanca uranium district, Chihuahua, Mexico, at which it was discovered. A Cs-rich analogue of carnotite, margaritasite is the natural equivalent of synthetic Cs-uranyl vanadate (A.M. 43- 799, 50-825). A fine-grained yellow mineral, it is most easily distinguished from carnotite by XRD; X-ray powder patterns (CuKalpha radiation) show that the (001) reflection of margaritasite lies at 12.7o (2theta ), while that of carnotite is found at 13.8o (2theta ). The shift of the (001) reflection in margaritasite reflects the structural changes caused when Cs occupies the sites filled by K in carnotite. Synthesis experiments indicate that margaritasite also differs from carnotite in a higher-T hydrothermal origin. Chemical analyses and XRD data for margaritasite and synthetic Cs- carnotite, and chemical analyses for rocks from Sierra Pena Blanca and vicinity, are tabulated.-J.A.Z.

  1. Investigation of the radioactivity in air, water and soil in the Estado de Chihuahua

    International Nuclear Information System (INIS)

    Montero C, M.E.; Renteria V, M.; Herrera P, E.F.; Villalba, M.L.; Colmenero S, L.H.

    2004-01-01

    The results of the determinations of activities of the series of U-238, Th-232 and the K-40 in soils, of the Rn-222 in the air of the domiciles, and in underground water are presented, as well as the total uranium activity in underground water, product of an extensive sampling in the state of Chihuahua. In two of the aquifers a positive correlation was obtained among the concentration of total uranium and the Rn-222 dissolved in the water of each well. Also it was finds a positive tendency among the averages of the concentration of U-238 in the soil and of the concentration of Rn-222 in the air of the domiciles in different towns, and among the averages of the concentration of U-238 in the floor and of the concentration of the Rn-222 dissolved in the well water in different aquifer. It is suggested that the constitution for rocks more or less uraniferous of the alluvial valleys gives explanation to the observed correlations. (Author)

  2. La vegetación como sistema de control para las Islas de Calor Urbano en Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Maria Goretti Salas Esparza

    2017-06-01

    Full Text Available A nivel mundial, el territorio ha experimentado un proceso de urbanización, el cual ha modificado las condiciones físicas y climatológicas como consecuencia de la densificación y construcción de las zonas urbanas, sobre todo a partir de la utilización de materiales que retienen el calor y que propician el fenómeno de isla de calor urbano (ICU, término establecido por Gordon Manley en 1958 (Fernández, 1996. Este trabajo evalúa el impacto que tienen las áreas verdes para actuar como sistema de control de isla de calor sobre Ciudad Juárez, Chihuahua, durante el verano del 2016. La metodología consistió en analizar cuatro áreas verdes para determinar la diferencia de temperatura que existe entre las zonas arboladas y las no arboladas, registrando temperaturas con sensores Hobo®, cada 15 minutos. Los resultados obtenidos demostraron que existe una diferencia de temperatura de 3,82 °C entre los lugares arbolados y no arbolados en el área verde con mayor nivel de vegetación, mientras que el área verde con menor nivel de vegetación se encontró una diferencia de 0,53 °C. Sin embargo, el impacto que tendrán sobre la zona urbana dependerá de la configuración y características de la misma área verde.   Documeto fianciado bajo el marco Tesis de Maestría en Planificación y Desarrollo Urbano " Áreas verdes como sistema de control para las Islas de Calor Urbano en Ciudad Juárez, Chihuahua".Universidad Autónoma de Ciudad Juárez

  3. Rhetoric and analogies

    OpenAIRE

    Aragonès, Enriqueta; Gilboa, Itzhak; Postlewaite, Andrew; Schmeidler, David; Universitat Autònoma de Barcelona. Unitat de Fonaments de l'Anàlisi Econòmica; Universitat Autònoma de Barcelona. Institut d'Anàlisi Econòmica

    2013-01-01

    The art of rhetoric may be defined as changing other people's minds (opinions, beliefs) without providing them new information. One tech- nique heavily used by rhetoric employs analogies. Using analogies, one may draw the listener's attention to similarities between cases and to re-organize existing information in a way that highlights certain reg- ularities. In this paper we offer two models of analogies, discuss their theoretical equivalence, and show that finding good analogies is a com- p...

  4. Un acercamiento al concepto de representación: el caso de las mujeres políticas en el estado de Chihuahua

    Directory of Open Access Journals (Sweden)

    Martha Estela Pérez

    2013-01-01

    Full Text Available En este documento se reflexiona sobre el fenómeno de la representación simbólica y política de las mujeres en el estado de Chihuahua. Este caso se centra en la escasa representación del sexo femenino en la política institucional y, de igual forma, se hace un acercamiento a los esquemas culturales que siguen vigentes en la esfera pública, los cuales no sólo inciden en el quehacer político femenino y masculino, sino que también conllevan a generar espacios de discriminación e inequidad y obstaculizan el empoderamiento femenino.

  5. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  6. EL PROCESO DE TRABAJO PARTICIPATIVO EN LA EVALUACIÓN DE BIBLIOTECAS UNIVERSITARIAS: CASO UNIVERSIDAD AUTÓNOMA DE CHIHUAHUA

    Directory of Open Access Journals (Sweden)

    Javier Tarango Ortiz

    2009-01-01

    Full Text Available Se describe la experiencia obtenida en el sistema de bibliotecas de la Universidad Autónoma de Chihuahua durante el diseño y validación de un plan de evaluación a partir del empleo de un modelo de trabajo participativo. El modelo propuesto es sustentado en una revisión de la literatura de los trabajos relacionados al tema de la evaluación de las bibliotecas universitarias en México, así como los principios generales de la metaevaluación y evaluación. El trabajo concluye analizando las condiciones que propician desarrollar evaluaciones bibliotecarias a través de la participación e identifica los retos que debe enfrentar el profesional de la in-formación al desarrollar procesos evaluatorios no convencionales.

  7. Participación ciudadana en las colonias sin agua potable y alcantarillado de Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Gustavo Córdova Bojórquez

    2007-01-01

    Full Text Available En este artículo se presenta un análisis de la participación ciudadana en la gestión del agua en 14 colonias que carecen del servicio de agua potable y alcantarillado en Ciudad Juárez, Chihuahua. La metodología consistió en analizar y relacionar las influencias externas e internas de los ciudadanos resultando una participación ciudadana muy baja en la gestión del agua determinada en gran medida por el poco conocimiento sobre el tema, la poca confianza en las instituciones públicas, la mínima disposición de participar en proyectos comunitarios y por la gran influencia que tiene el sistema político en la gestión del servicio.

  8. Sexual differentiation in the distribution potential of northern jaguars (Panthera onca)

    Science.gov (United States)

    Boydston, Erin E.; Lopez Gonzalez, Carlos A.

    2005-01-01

    We estimated the potential geographic distribution of jaguars in the southwestern United States and northwestern Mexico by modeling the jaguar ecological niche from occurrence records. We modeled separately the distribution of males and females, assuming records of females probably represented established home ranges while male records likely included dispersal movements. The predicted distribution for males was larger than that for females. Eastern Sonora appeared capable for supporting male and female jaguars with potential range expansion into southeastern Arizona. New Mexico and Chihuahua contained environmental characteristics primarily limited to the male niche and thus may be areas into which males occasionally disperse.

  9. Study of the absorbed dose in small fields with absence of lateral electronic balance in stereotactic radiosurgery and radiotherapy with modulated intensity; Estudio de la dosis absorbida en campos pequenos con ausencia de equilibrio electronico lateral en radiocirugia estereotaxica y radioterapia con intensidad modulada

    Energy Technology Data Exchange (ETDEWEB)

    Vargas V, M. X.

    2013-07-01

    In this thesis we develop and experimental and theoretical study, using semi analytical techniques of the physical dosimetry for small and nonstandard fields for stereotactic radiosurgery (Srs) and intensity modulated radiation therapy (IMRT), with high energy photon beams from a BrainLAB system with cones at Instituto del Cancer SOLCA (Ecuador) and a Tomo Therapy Hi-Art system at Centro Oncologico de Chihuahua (Mexico). (Author)

  10. Study of the absorbed dose in small fields with absence of lateral electronic balance in stereotactic radiosurgery and radiotherapy with modulated intensity

    International Nuclear Information System (INIS)

    Vargas V, M. X.

    2013-01-01

    In this thesis we develop and experimental and theoretical study, using semi analytical techniques of the physical dosimetry for small and nonstandard fields for stereotactic radiosurgery (Srs) and intensity modulated radiation therapy (IMRT), with high energy photon beams from a BrainLAB system with cones at Instituto del Cancer SOLCA (Ecuador) and a Tomo Therapy Hi-Art system at Centro Oncologico de Chihuahua (Mexico). (Author)

  11. Flora of Chihuahuan desertscrub on limestone in northeastern Sonora, Mexico

    Science.gov (United States)

    Thomas R. Van Devender; Ana Lilia Reina-Guerrero; J. Jesus. Sanchez-Escalante

    2013-01-01

    Transects were done in desertscrub on limestone to characterize the flora of the westernmost Chihuahuan Desert. Most of the sites (15) were in the Municipios of Agua Prieta and Naco in northeastern Sonora, with single sites near Ascensión, northwestern Chihuahua and east of Douglas in southeastern Arizona. A total of 236 taxa were recorded on transects. Dicot perennial...

  12. High-speed and high-resolution analog-to-digital and digital-to-analog converters

    NARCIS (Netherlands)

    van de Plassche, R.J.

    1989-01-01

    Analog-to-digital and digital-to-analog converters are important building blocks connecting the analog world of transducers with the digital world of computing, signal processing and data acquisition systems. In chapter two the converter as part of a system is described. Requirements of analog

  13. Estimating natural background groundwater chemistry, Questa molybdenum mine, New Mexico

    Science.gov (United States)

    Verplanck, Phillip L.; Nordstrom, D. Kirk; Plumlee, Geoffrey S.; Walker, Bruce M.; Morgan, Lisa A.; Quane, Steven L.

    2010-01-01

    This 2 1/2 day field trip will present an overview of a U.S. Geological Survey (USGS) project whose objective was to estimate pre-mining groundwater chemistry at the Questa molybdenum mine, New Mexico. Because of intense debate among stakeholders regarding pre-mining groundwater chemistry standards, the New Mexico Environment Department and Chevron Mining Inc. (formerly Molycorp) agreed that the USGS should determine pre-mining groundwater quality at the site. In 2001, the USGS began a 5-year, multidisciplinary investigation to estimate pre-mining groundwater chemistry utilizing a detailed assessment of a proximal natural analog site and applied an interdisciplinary approach to infer pre-mining conditions. The trip will include a surface tour of the Questa mine and key locations in the erosion scar areas and along the Red River. The trip will provide participants with a detailed understanding of geochemical processes that influence pre-mining environmental baselines in mineralized areas and estimation techniques for determining pre-mining baseline conditions.

  14. La tecnificación del riego ante la escasez del agua para la generación de alimentos. Estudio de caso en Chihuahua, México

    OpenAIRE

    Olvera-Salgado, Maria Dolores; Investigadora del Instituto Mexicano de Tecnología del Agua, México.; Bahena-Delgado, Gregorio; Profesor de la Universidad Autónoma del Estado de Morelos-ipro. México.; Alpuche Garcés, Óscar; Profesor investigador de la Universidad Autónoma del Estado de Morelos; García Matías, Francisco; Profesor de la Universidad Autónoma del Estado de Morelos

    2014-01-01

    La investigación tuvo como objetivo analizar la productividad del agua y el impactode la tecnificación del riego sobre ella y el rendimiento de los cultivos comoprincipales aportadores de alimentos. Se realizó en el Distrito de Riego 005, Delicias,Chihuahua. Se usó el método comparativo para dos escenarios: el antes, como lacondición previa a la tecnificación del riego en el año 2003, caracterizada por unasuperficie con riego por gravedad, y el después en 2012-2013, en la superficie conriego ...

  15. Neuronal ceroid-lipofuscinosis in longhaired Chihuahuas: clinical, pathologic, and MRI findings.

    Science.gov (United States)

    Nakamoto, Yuya; Yamato, Osamu; Uchida, Kazuyuki; Nibe, Kazumi; Tamura, Shinji; Ozawa, Tsuyoshi; Ueoka, Naotami; Nukaya, Aya; Yabuki, Akira; Nakaichi, Munekazu

    2011-01-01

    Neuronal ceroid-lipofuscinosis (NCL) is a rare group of inherited neurodegenerative lysosomal storage diseases characterized histopathologically by the abnormal accumulation of ceroid- or lipofuscin-like lipopigments in neurons and other cells throughout the body. The present article describes the clinical, pathologic, and magnetic resonance imaging (MRI) findings of the NCL in three longhaired Chihuahuas between 16 mo and 24 mo of age. Clinical signs, including visual defects and behavioral abnormalities, started between 16 mo and 18 mo of age. Cranial MRI findings in all the dogs were characterized by diffuse severe dilation of the cerebral sulci, dilated fissures of diencephalons, midbrain, and cerebellum, and lateral ventricular enlargement, suggesting atrophy of the forebrain. As the most unusual feature, diffuse meningeal thickening was observed over the entire cerebrum, which was strongly enhanced on contrast T1-weighted images. The dogs' conditions progressed until they each died subsequent to continued neurologic deterioration between 23 mo and 24 mo of age. Histopathologically, there was severe to moderate neuronal cell loss with diffuse astrogliosis throughout the brain. The remaining neuronal cells showed intracytoplasmic accumulation of pale to slightly yellow lipopigments mimicking ceroid or lipofuscin. The thickened meninges consisted of the proliferation of connective tissues with abundant collagen fibers and mild infiltration of inflammatory cells suggesting neuroimmune hyperactivity. Although the etiology of this neuroimmune hyperactivity is not currently known, MRI findings such as meningeal thickening may be a useful diagnostic marker of this variant form of canine NCL.

  16. Structured Analog CMOS Design

    CERN Document Server

    Stefanovic, Danica

    2008-01-01

    Structured Analog CMOS Design describes a structured analog design approach that makes it possible to simplify complex analog design problems and develop a design strategy that can be used for the design of large number of analog cells. It intentionally avoids treating the analog design as a mathematical problem, developing a design procedure based on the understanding of device physics and approximations that give insight into parameter interdependences. The proposed transistor-level design procedure is based on the EKV modeling approach and relies on the device inversion level as a fundament

  17. Analog and hybrid computing

    CERN Document Server

    Hyndman, D E

    2013-01-01

    Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl

  18. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J M

    2010-01-01

    The design of an analog-to-digital converter or digital-to-analog converter is one of the most fascinating tasks in micro-electronics. In a converter the analog world with all its intricacies meets the realm of the formal digital abstraction. Both disciplines must be understood for an optimum conversion solution. In a converter also system challenges meet technology opportunities. Modern systems rely on analog-to-digital converters as an essential part of the complex chain to access the physical world. And processors need the ultimate performance of digital-to-analog converters to present the results of their complex algorithms. The same progress in CMOS technology that enables these VLSI digital systems creates new challenges for analog-to-digital converters: lower signal swings, less power and variability issues. Last but not least, the analog-to-digital converter must follow the cost reduction trend. These changing boundary conditions require micro-electronics engineers to consider their design choices for...

  19. Mexico’s National Security Challenges and the Military Endeavor

    Science.gov (United States)

    2013-03-01

    10 highlighted major challenges for nations in the region and their armies, such as poverty and lack of social development, massive migration ...31 15 2006 2007-2009 2010 2011 Sinaloa cartel Sinaloa cartel Sinaloa cartel Sinaloa cartel Beltran Leyva cartel South pacific cartel...Mexican population in many states, such as Tamaulipas, Coahuila, Chihuahua, Sinaloa , and Durango, is fearful of organized crime. The majority of the

  20. Experiments in Total Quality Management at the Autonomous University of Chihuahua’s School of Animal Husbandry. A Case Study

    OpenAIRE

    Heriberto Aranda Gutiérrez

    2006-01-01

    Presented here are experiments and results obtained by the School of Animal Husbandry of the Autonomous University of Chihuahua (UACH), Mexico, after implementing a quality-management system. The methodology was based on a process of strategic planning, with the use of models for the quality of official state, national, and international organizations. There was improvement in the performance of 25 indicators related with teaching, research, extension and administrative activities. It...

  1. Corima: A Bilingual Experiment in the Tarahumara Region in the State of Chihuahua, Mexico. How Does It Measure against Transitional Bilingual Programs in the United States?

    Science.gov (United States)

    Nunez, Mario A.

    This report explores two bilingual educational approaches currently in use in Mexico and the United States. The study pursues a limited comparison between two modalities of bilingual instruction, as observed and reported in the consulted literature. The U.S. model featured is known as the two-way bilingual model, an additive approach to…

  2. Analysis of single nucleotide polymorphisms in the 3' region of the estrogen receptor 1 gene in normal and cryptorchid Miniature Dachshunds and Chihuahuas.

    Science.gov (United States)

    Pathirana, Indunil Nishantha; Tanaka, Kakeru; Kawate, Noritoshi; Tsuji, Makoto; Kida, Kayoko; Hatoya, Shingo; Inaba, Toshio; Tamada, Hiromichi

    2010-08-01

    This study was performed to examine the distribution of single nucleotide polymorphisms (SNPs) and estimated haplotypes in the canine estrogen receptor (ER) alpha gene (ESR1) and the association of them with different phenotypes of cryptorchidism (CO) in Miniature Dachshunds and Chihuahuas. Forty CO and 68 normal dogs were used, and CO was classified into unilateral (UCO; n=33) and bilateral CO (BCO; n=5) or into abdominal (ACO; n=16) and inguinal CO (ICO; n=22). Thirteen DNA fragments located in the 70-kb region at the 3' end of ESR1 were amplified by PCR and sequenced to examine 13 SNPs (#1-#13) reported in a canine SNP database. Ten SNPs (#1-#4, #7, #8, #10-#13) were not polymorphic, and 5 new SNPs (#14-#18) were discovered. A common haplotype block in normal, CO and CO phenotypes was identified for an approximately 20-kb region encompassing 4 SNPs (#14-#17). Allele, genotype and haplotype frequencies in CO without classification by phenotype and also in UCO, ACO and ICO phenotypes were not statistically different from the normal group. Significant differences in genotype frequencies and homozygosity for the estimated GTTG haplotype within the block were observed in BCO compared with the normal group, although the number of BCO animals was small. Our results demonstrate that the examined SNPs and haplotypes in the 3' end of canine ESR1 are not associated with unilateral, abdominal and inguinal CO phenotypes and CO per se in Miniature Dachshunds and Chihuahuas. Further studies are necessary to suggest a clear association between the ESR1 SNPs and bilateral CO in dogs.

  3. Mineralogical composition of the meteorite El Pozo (Mexico): a Raman, infrared and XRD study.

    Science.gov (United States)

    Ostrooumov, Mikhail; Hernández-Bernal, Maria del Sol

    2011-12-01

    The Raman (RMP), infrared (IR) and XRD analysis have been applied to the examination of mineralogical composition of El Pozo meteorite (an ordinary chondrite L5 type; village Valle of Allende, founded in State of Chihuahua, Mexico: 26°56'N and 105°24'W, 1998). RMP measurements in the range of 100-3500 cm(-1) revealed principal characteristic bands of the major minerals: olivine, two polymorph modifications of pyroxene (OPx and CPx) and plagioclase. Some bands of the minor minerals (hematite and goethite) were also identified. All these minerals were clearly distinguished using IR and XRD techniques. XRD technique has shown the presence of some metallic phases such as kamacite and taenite as well as troilite and chromite. These minerals do not have characteristic Raman spectra because Fe-Ni metals have no active modes for Raman spectroscopy and troilite is a weak Raman scatterer. Raman mapping microspectroscopy was a key part in the investigation of El Pozo meteorite's spatial distribution of the main minerals because these samples are structurally and chemically complex and heterogeneous. The mineral mapping by Raman spectroscopy has provided information for a certain spatial region on which a spatial distribution coexists of the three typical mineral assemblages: olivine; olivine+orthopyroxene; and orthopyroxene. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. An overall Water Quality Index (WQI) for a man-made aquatic reservoir in Mexico.

    Science.gov (United States)

    Rubio-Arias, Hector; Contreras-Caraveo, Manuel; Quintana, Rey Manuel; Saucedo-Teran, Ruben Alfonso; Pinales-Munguia, Adan

    2012-05-01

    A Water Quality Index (WQI) is a useful statistical tool for simplifying, reporting and interpreting complex information obtained from any body of water. A simple number given by any WQI model explains the level of water contamination. The objective was to develop a WQI for the water of the Luis L. Leon dam located in the state of Chihuahua, Mexico. Monthly water samples were obtained in 2009; January 10, February 12, March 8, May 20, June 10, July 9, August 12, September 10, October 11, November 15 and December 13. Ten sampling sites were randomly selected after dividing the study area using a geographic package. In each site, two samples at the top depth of 0.20 m and 1.0 m were obtained to quantify physical-chemical parameters. The following 11 parameters were considered to calculate the WQI; pH, Electrical Conductivity (EC), Dissolved Oxygen (DO), color, turbidity, ammonia nitrogen, fluorides, chlorides, sulfates, Total Solids (TS) and phosphorous (P). The data analysis involved two steps; a single analysis for each parameter and the WQI calculation. The resulted WQI value classified the water quality according to the following ranges: 2.8 excellent water. The results showed that the WQI values changed from low levels (WQI 2.8) most of the year and the variation was due to time of sampling generally rainy season.

  5. 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.

  6. Analog earthquakes

    International Nuclear Information System (INIS)

    Hofmann, R.B.

    1995-01-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository

  7. Poverty, population density, and the epidemiology of burns in young children from Mexico treated at a U.S. pediatric burn facility.

    Science.gov (United States)

    Patel, Dipen D; Rosenberg, Marta; Rosenberg, Laura; Foncerrada, Guillermo; Andersen, Clark R; Capek, Karel D; Leal, Jesus; Lee, Jong O; Jimenez, Carlos; Branski, Ludwik; Meyer, Walter J; Herndon, David N

    2018-03-07

    Children 5 and younger are at risk for sustaining serious burn injuries. The causes of burns vary depending on demographic, cultural and socioeconomic variables. At this pediatric burn center we provided medical care to children from Mexico with severe injuries. The purpose of this study was to understand the impact of demographic distribution and modifiable risk factors of burns in young children to help guide prevention. A retrospective chart review was performed with children 5 and younger from Mexico who were injured from 2000-2013. The medical records of 447 acute patients were reviewed. Frequency counts and percentages were used to identify geographic distribution and calculate incidence of burns. Microsoft Powermap software was used to create a geographical map of Mexico based on types of burns. A binomial logistic regression was used to model the incidence of flame burns as opposed to scald burns in each state with relation to population density and poverty percentage. In all statistical tests, alpha=0.05 for a 95% level of confidence. Burns were primarily caused by flame and scald injuries. Admissions from flame injuries were mainly from explosions of propane tanks and gas lines and house fires. Flame injuries were predominantly from the states of Jalisco, Chihuahua, and Distrito Federal. Scalds were attributed to falling in large containers of hot water or food on the ground, and spills of hot liquids. Scald injuries were largely from the states of Oaxaca, Distrito Federal, and Hidalgo. The odds of a patient having flame burns were significantly associated with poverty percentage (ppoverty led to decrease in odds of a flame burn, but an increase in the odds of scald burns. Similarly, we found that increasing population density led to a decrease in the odds of a flame burn, but an increase in the odds of a scald burn. Burns in young children from Mexico who received medical care at this pediatric burn center were attributed to flame and scalds. Potential

  8. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  9. 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...

  10. Optical analogy. Synthesis report

    International Nuclear Information System (INIS)

    1965-01-01

    The authors report the study of conditions under which light attenuation (reflection, diffusion, absorption) and the attenuation of some radiations (notably thermal neutrons) can be described with analogical calculations. The analogy between light physical properties and neutron properties is not searched for, but the analogy between their attenuation characteristics. After having discussed this possible analogy, they propose a mathematical formulation of neutron and optical phenomena which could theoretically justify the optical analogy. The second part reports a more practical study of optics problems such as the study of simple optics materials and illumination measurements, or more precisely the study of angular distributions of optical reflections, a determination of such angular distributions, and an experimental determination of the albedo

  11. [Reference values for cholesterol, triglycerides and glucose in a population of Hispanic children from 6 to 11 y, in the northern border of Mexico and the United States of America].

    Science.gov (United States)

    Arenas Berumen, Ever; Gómez Miranda, Luis Mario; Torres Balcázar, Elías; Padilla Alvarado, Victor Hugo; Renteria, Ivan

    2014-10-31

    Overweight and obesity in children in the Mexico-USA border have evolved differently to the rest of their respective countries. New reference values of cholesterol, triglycerides and glucose are required to treatment. To determine the reference values of cholesterol, triglycerides and glucose in Hispanic children between 6 and 11 years in the Mexico-USA border. A prospective, cross-sectional, descriptive and observational study. A population of Hispanic children between 6 and 11 years of both boys and girls, belonging to three public institutions in the cities of Ensenada and Chihuahua, randomly selected, were studied. The study variables were the levels of total cholesterol (TC), triglycerides (TG) and glucose (G). From 300 subjects studied just 54 children completed the study. Higher average values of TC (168.7 ± 27.2 mg / dl), TG (80.6 ± 48.4 mg / dl) and G (88.3 ± 8.9 mg / dl) were observed. An additional behavior was founded, never reported previously to the limit of the knowledge of the authors; glucose levels of the children studied decreased with increased of cholesterol and triglycerides. To discard a random relationship between the variables, the Pearson correlation coefficient was determined between waist circumference and BMI, verifying an inverse association with G and direct with the TG. The reference values for Hispanic children between 6 and 11 years living on the northern border of Mexico-USA differ with respect to the national average values of the countries studied. Further studies are needed in larger populations to confirm the trend ob served in glucose levels of normal children, overweight and obese. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  12. Are all analogies created equal? Prefrontal cortical functioning may predict types of analogical reasoning.

    Science.gov (United States)

    Chrysikou, Evangelia G; Thompson-Schill, Sharon L

    2010-06-01

    Abstract The proposed theory can account for analogies based on learned relationships between elements in the source and target domains. However, its explanatory power regarding the discovery of new relationships during analogical reasoning is limited. We offer an alternative perspective for the role of PFC in analogical thought that may better address different types of analogical mappings.

  13. Niveles de contaminación del agua potable en la cabecera municipal de Ascención, Chihuahua, México

    Directory of Open Access Journals (Sweden)

    Héctor Osbaldo Rubio Arias

    2015-01-01

    Full Text Available Introducción: El agua es una sustancia indispensable para la vida por lo que se considera como el recurso natural más apreciado en el planeta. En el norte de México existe el “Programa ambiental México-Estados Unidos: Frontera 2020”; en el cual participan instituciones mexicanas como la Junta Municipal de Aguas y Saneamiento (JMAS mientras que por parte de los Estados Unidos de Norteamérica participan el Taskforce U.S., la Agencia Ambiental (USEPA y la Universidad Estatal de Nuevo Mexico, entre otras (PAMEUF, 2013. En dicho programa ambiental el municipio de Ascensión está contemplado dentro de los planes de acción, por ser una región fronteriza, en especial en lo relacionado a la meta 2, la cual especifica el suministro de agua limpia y segura. Es importante mencionar que, a la fecha, no se conoce información que permita evaluar el nivel de calidad que aportan los cinco pozos que surten de agua a la cabecera municipal de Ascención, Chihuahua. El objetivo fue evaluar la calidad del agua potable que utiliza la comunidad de Ascensión, Chihuahua, mediante análisis físico-químico-metales y microbiológicos. Método: Las muestras de agua se obtuvieron de cinco pozos y de cinco hogares seleccionados al azar en cuatro temporadas. Se realizaron cuatro muestreos; julio de 2011, septiembre de 2011, diciembre de 2011 y mayo de 2012. Por lo tanto, se analizaron un total de 40 muestras a las que se les cuantificó el potencial de hidrógeno (pH, conductividad eléctrica (CE, temperatura (T, oxígeno disuelto (OD, turbidez (Tur, sólidos totales (SDT, coliformes totales (CT, coliformes fecales (CF y los siguientes metales; Al, As, B, Cd, Ca, Cu, Cr, Fe, Mg, Mn, Ni, Ag, Pb, K, Na, Se, Si y Zn. Se aplicó un ANOVA para buscar diferencias por estación (Factor A, por fuente (Factor B y su interacción (AxB. Para la variable de coliformes se aplicó la prueba noparamétrica de Kruskal-Wallis. En todos los casos se consideró un nivel de

  14. Estimation of Seasonal Risk Caused by the Intake of Lead, Mercury and Cadmium through Freshwater Fish Consumption from Urban Water Reservoirs in Arid Areas of Northern Mexico

    Directory of Open Access Journals (Sweden)

    Myrna Nevárez

    2015-02-01

    Full Text Available Bioavailability and hence bioaccumulation of heavy metals in fish species depends on seasonal conditions causing different risks levels to human health during the lifetime. Mercury, cadmium and lead contents in fish from Chihuahua (Mexico water reservoirs have been investigated to assess contamination levels and safety for consumers. Muscle samples of fish were collected across the seasons. Lead and cadmium were analyzed by inductively coupled plasma-optical emission spectrometry, and mercury by cold-vapor atomic absorption spectrometry. The highest concentrations of cadmium (0.235 mg/kg, mercury (0.744 mg/kg and lead (4.298 mg/kg exceeded the maximum levels set by European regulations and Codex Alimentarius. Lead concentrations found in fish from three water reservoirs also surpassed the limit of 1 mg/kg established by Mexican regulations. The provisional tolerable weekly intake (PTWI suggested by the World Health Organization for methyl mercury (1.6 µg/kg bw per week was exceeded in the spring season (1.94 µg/kg bw per week. This might put consumers at risk of mercury poisoning.

  15. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  16. Analogical Reasoning in Geometry Education

    Science.gov (United States)

    Magdas, Ioana

    2015-01-01

    The analogical reasoning isn't used only in mathematics but also in everyday life. In this article we approach the analogical reasoning in Geometry Education. The novelty of this article is a classification of geometrical analogies by reasoning type and their exemplification. Our classification includes: analogies for understanding and setting a…

  17. Analog and mixed-signal electronics

    CERN Document Server

    Stephan, Karl

    2015-01-01

    A practical guide to analog and mixed-signal electronics, with an emphasis on design problems and applications This book provides an in-depth coverage of essential analog and mixed-signal topics such as power amplifiers, active filters, noise and dynamic range, analog-to-digital and digital-to-analog conversion techniques, phase-locked loops, and switching power supplies. Readers will learn the basics of linear systems, types of nonlinearities and their effects, op-amp circuits, the high-gain analog filter-amplifier, and signal generation. The author uses system design examples to motivate

  18. Meat analog: a review.

    Science.gov (United States)

    Malav, O P; Talukder, S; Gokulakrishnan, P; Chand, S

    2015-01-01

    The health-conscious consumers are in search of nutritious and convenient food item which can be best suited in their busy life. The vegetarianism is the key for the search of such food which resembles the meat in respect of nutrition and sensory characters, but not of animal origin and contains vegetable or its modified form, this is the point when meat analog evolved out and gets shape. The consumers gets full satisfaction by consumption of meat analog due to its typical meaty texture, appearance and the flavor which are being imparted during the skilled production of meat analog. The supplement of protein in vegetarian diet through meat alike food can be fulfilled by incorporating protein-rich vegetative food grade materials in meat analog and by adopting proper technological process which can promote the proper fabrication of meat analog with acceptable meat like texture, appearance, flavor, etc. The easily available vegetables, cereals, and pulses in India have great advantages and prospects to be used in food products and it can improve the nutritional and functional characters of the food items. The various form and functional characters of food items are available world over and attracts the meat technologists and the food processors to bring some innovativeness in meat analog and its presentation and marketability so that the acceptability of meat analog can be overgrown by the consumers.

  19. Digital and analog communication systems

    Science.gov (United States)

    Shanmugam, K. S.

    1979-01-01

    The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

  20. Propuesta de Rehabilitación Urbana para la Colonia Tarahumara en Ciudad Cuauhtémoc, Chihuahua, México.

    Directory of Open Access Journals (Sweden)

    Leticia Peña Barrera

    2014-12-01

    El gobierno del Estado de Chihuahua, interesado en apoyar a comunidades tarahumaras o rarámuris, promueve la creación de la Colonia Tarahumara en la ciudad de Cuauhtémoc, donando en 2001 el terreno y el financiamiento para las primeras 50 viviendas en propiedad común, y así lograr su arraigo. En este trabajo se presenta la propuesta de reequipamiento urbano-ecológico de la Colonia Tarahumara, la cual fue presentada a la Fundación Tarahumara para la construcción de otras 50 unidades de vivienda, teniendo en cuenta factores determinantes de localización e identificación de las costumbres de la comunidad rarámuri, como también soluciones urbano-bioclimáticas, con el fin de que ésta pueda tener acceso a la financiación federal de la Sedesol y, por último, de contribuir al desarrollo sostenible de la comunidad tarahumara.

  1. Mexico Is Not Colombia: Alternative Historical Analogies for Responding to the Challenge of Violent Drug-Trafficking Organizations

    Science.gov (United States)

    2014-01-01

    The most glaring omission is an explicit mention of violence. Elsewhere in the world (and in different historical periods in Mexico) the presence of...Hobbesian world in which violence is met with violence, force with force. Part of this opportunity structure is the presence of a sur- plus of...police and judiciary; overpopulated , violent prisons High costs of security with rise of private security rms Reduced support for government

  2. Children's Development of Analogical Reasoning: Insights from Scene Analogy Problems

    Science.gov (United States)

    Richland, Lindsey E.; Morrison, Robert G.; Holyoak, Keith J.

    2006-01-01

    We explored how relational complexity and featural distraction, as varied in scene analogy problems, affect children's analogical reasoning performance. Results with 3- and 4-year-olds, 6- and 7-year-olds, 9- to 11-year-olds, and 13- and 14-year-olds indicate that when children can identify the critical structural relations in a scene analogy…

  3. PHASE ANALYSES OF URANIUM BEARING MINERALS FROM THE HIGH GRADE ORE, NOPAL I, PENA BLANCA, MEXICO

    International Nuclear Information System (INIS)

    Ren, M.; Goodell, P.; Kelts, A.; Anthony, E.Y.; Fayek, M.; Fan, C.; Beshears, C.

    2005-01-01

    The Nopal I uranium deposit is located in the Pena Blanca district, approximately 40 miles north of Chihuahua City, Mexico. The deposit was formed by hydrothermal processes within the fracture zone of welded silicic volcanic tuff. The ages of volcanic formations are between 35 to 44 m.y. and there was secondary silicification of most of the formations. After the formation of at least part of the uranium deposit, the ore body was uplifted above the water table and is presently exposed at the surface. Detailed petrographic characterization, electron microprobe backscatter electron (BSE) imagery, and selected x-ray maps for the samples from Nopal I high-grade ore document different uranium phases in the ore. There are at least two stages of uranium precipitation. A small amount of uraninite is encapsulated in silica. Hexavalent uranium may also have been a primary precipitant. The uranium phases were precipitated along cleavages of feldspars, and along fractures in the tuff. Energy dispersive spectrometer data and x-ray maps suggest that the major uranium phases are uranophane and weeksite. Substitutions of Ca and K occur in both phases, implying that conditions were variable during the mineralization/alteration process, and that compositions of the original minerals have a major influence on later stage alteration. Continued study is needed to fully characterize uranium behavior in these semi-arid to arid conditions

  4. PHASE ANALYSES OF URANIUM-BEARING MINERALS FROM THE HIGH GRADE ORE, NOPAL I, PENA BLANCA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    M. Ren; P. Goodell; A. Kelts; E.Y. Anthony; M. Fayek; C. Fan; C. Beshears

    2005-07-11

    The Nopal I uranium deposit is located in the Pena Blanca district, approximately 40 miles north of Chihuahua City, Mexico. The deposit was formed by hydrothermal processes within the fracture zone of welded silicic volcanic tuff. The ages of volcanic formations are between 35 to 44 m.y. and there was secondary silicification of most of the formations. After the formation of at least part of the uranium deposit, the ore body was uplifted above the water table and is presently exposed at the surface. Detailed petrographic characterization, electron microprobe backscatter electron (BSE) imagery, and selected x-ray maps for the samples from Nopal I high-grade ore document different uranium phases in the ore. There are at least two stages of uranium precipitation. A small amount of uraninite is encapsulated in silica. Hexavalent uranium may also have been a primary precipitant. The uranium phases were precipitated along cleavages of feldspars, and along fractures in the tuff. Energy dispersive spectrometer data and x-ray maps suggest that the major uranium phases are uranophane and weeksite. Substitutions of Ca and K occur in both phases, implying that conditions were variable during the mineralization/alteration process, and that compositions of the original minerals have a major influence on later stage alteration. Continued study is needed to fully characterize uranium behavior in these semi-arid to arid conditions.

  5. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  6. 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.

  7. 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....

  8. Hydraulic Capacitor Analogy

    Science.gov (United States)

    Baser, Mustafa

    2007-01-01

    Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…

  9. Analog fourier transform channelizer and OFDM receiver

    OpenAIRE

    2007-01-01

    An OFDM receiver having an analog multiplier based I-Q channelizing filter, samples and holds consecutive analog I-Q samples of an I-Q baseband, the I-Q basebands having OFDM sub-channels. A lattice of analog I-Q multipliers and analog I-Q summers concurrently receives the held analog I-Q samples, performs analog I-Q multiplications and analog I-Q additions to concurrently generate a plurality of analog I-Q output signals, representing an N-point discrete Fourier transform of the held analog ...

  10. Burnout syndrome in teachers of a professional institution in Mexico

    OpenAIRE

    Alma Lilia Sapién Aguilar; Laura Cristina Piñón Howlet; María del Carmen Gutiérrez Diez; Hector Rubio Arias

    2015-01-01

    Burnout syndrome, or burning for work syndrome, is a long-term effect of chronic stress and occurs in jobs that have direct contact with people. The aim was to determine the existence of Burnout in professors of the Faculty of Accounting and Administration (FCA) of the Autonomous University of Chihuahua (UACH) and its relation with emotional factors such as depression, anxiety and insomnia, job satisfaction, and socio-demographic and labor indicators. The research design had a quantitative ap...

  11. La violencia en la región noroeste de Chihuahua. Experiencias e impactos desde la comunidad educativa

    Directory of Open Access Journals (Sweden)

    Marcos J. Estrada Ruiz

    2013-01-01

    Full Text Available La violencia escolar ha sido un tema explorado de manera importante en los últimos años desde la investigación educativa en México, sin embargo, en contextos de alta violencia no se han mostrado los impactos de la violencia extraescolar y estructural, en la escuela y en otros espacios comunitarios. El artículo presenta resultados de una investigación que tuvo por objetivo reconstruir el impacto de la violencia en la región noroeste de Chihuahua, desde la comunidad educativa (docentes, padres, estudiantes de dos municipios en particular. A la manera de estudios en caso y recurriendo al análisis de contenido, se analizanlos impactos en la percepción del incremento de la violencia a partir de la experiencia directa; la modificación de la dinámica de las escuelas; el abandono de los espacios públicos y el señalamiento de “nuevos” actores, aparentemente ajenos a la comunidad, que aparecen a priori por su condición social, como los responsables de la violencia.

  12. Borderplex Economic Growth: Chicken, Egg, or Scrambled?

    OpenAIRE

    Fullerton, Thomas; Molina, Angel; Ibarreche, Santiago

    2007-01-01

    Regional debates over which metropoitan economy is the dominant growth pole in multi-city areas can be intense. Such discourse is frequently voiced with regard to economic expansion in the El Paso, Texas, USA - Ciudad Juarez, Chihuahua, Mexico borderplex economy. To date, no empirical analyses have been carried out to address that question. Granger causality tests are applied to various cross-border data to shed light on that question and others regarding the nature of regional growth in t...

  13. Natural CO2 Analogs for Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Scott H. Stevens; B. Scott Tye

    2005-07-31

    The report summarizes research conducted at three naturally occurring geologic CO{sub 2} fields in the US. The fields are natural analogs useful for the design of engineered long-term storage of anthropogenic CO{sub 2} in geologic formations. Geologic, engineering, and operational databases were developed for McElmo Dome in Colorado; St. Johns Dome in Arizona and New Mexico; and Jackson Dome in Mississippi. The three study sites stored a total of 2.4 billion t (46 Tcf) of CO{sub 2} equivalent to 1.5 years of power plant emissions in the US and comparable in size with the largest proposed sequestration projects. The three CO{sub 2} fields offer a scientifically useful range of contrasting geologic settings (carbonate vs. sandstone reservoir; supercritical vs. free gas state; normally pressured vs. overpressured), as well as different stages of commercial development (mostly undeveloped to mature). The current study relied mainly on existing data provided by the CO{sub 2} field operator partners, augmented with new geochemical data. Additional study at these unique natural CO{sub 2} accumulations could further help guide the development of safe and cost-effective design and operation methods for engineered CO{sub 2} storage sites.

  14. An Overall Water Quality Index (WQI) for a Man-Made Aquatic Reservoir in Mexico

    Science.gov (United States)

    Rubio-Arias, Hector; Contreras-Caraveo, Manuel; Quintana, Rey Manuel; Saucedo-Teran, Ruben Alfonso; Pinales-Munguia, Adan

    2012-01-01

    A Water Quality Index (WQI) is a useful statistical tool for simplifying, reporting and interpreting complex information obtained from any body of water. A simple number given by any WQI model explains the level of water contamination. The objective was to develop a WQI for the water of the Luis L. Leon dam located in the state of Chihuahua, Mexico. Monthly water samples were obtained in 2009; January 10, February 12, March 8, May 20, June 10, July 9, August 12, September 10, October 11, November 15 and December 13. Ten sampling sites were randomly selected after dividing the study area using a geographic package. In each site, two samples at the top depth of 0.20 m and 1.0 m were obtained to quantify physical-chemical parameters. The following 11 parameters were considered to calculate the WQI; pH, Electrical Conductivity (EC), Dissolved Oxygen (DO), color, turbidity, ammonia nitrogen, fluorides, chlorides, sulfates, Total Solids (TS) and phosphorous (P). The data analysis involved two steps; a single analysis for each parameter and the WQI calculation. The resulted WQI value classified the water quality according to the following ranges: water; from 2.3 to 2.8 good water; and >2.8 excellent water. The results showed that the WQI values changed from low levels (WQI 2.8) most of the year and the variation was due to time of sampling generally rainy season. PMID:22754466

  15. An Overall Water Quality Index (WQI for a Man-Made Aquatic Reservoir in Mexico

    Directory of Open Access Journals (Sweden)

    Hector Rubio-Arias

    2012-05-01

    Full Text Available A Water Quality Index (WQI is a useful statistical tool for simplifying, reporting and interpreting complex information obtained from any body of water. A simple number given by any WQI model explains the level of water contamination. The objective was to develop a WQI for the water of the Luis L. Leon dam located in the state of Chihuahua, Mexico. Monthly water samples were obtained in 2009; January 10, February 12, March 8, May 20, June 10, July 9, August 12, September 10, October 11, November 15 and December 13. Ten sampling sites were randomly selected after dividing the study area using a geographic package. In each site, two samples at the top depth of 0.20 m and 1.0 m were obtained to quantify physical-chemical parameters. The following 11 parameters were considered to calculate the WQI; pH, Electrical Conductivity (EC, Dissolved Oxygen (DO, color, turbidity, ammonia nitrogen, fluorides, chlorides, sulfates, Total Solids (TS and phosphorous (P. The data analysis involved two steps; a single analysis for each parameter and the WQI calculation. The resulted WQI value classified the water quality according to the following ranges: 2.8 excellent water. The results showed that the WQI values changed from low levels (WQI < 2.3 in some points during autumn time to high levels (WQI > 2.8 most of the year and the variation was due to time of sampling generally rainy season.

  16. Inductive, Analogical, and Communicative Generalization

    Directory of Open Access Journals (Sweden)

    Adri Smaling

    2003-03-01

    Full Text Available Three forms of inductive generalization - statistical generalization, variation-based generalization and theory-carried generalization - are insufficient concerning case-to-case generalization, which is a form of analogical generalization. The quality of case-to-case generalization needs to be reinforced by setting up explicit analogical argumentation. To evaluate analogical argumentation six criteria are discussed. Good analogical reasoning is an indispensable support to forms of communicative generalization - receptive and responsive (participative generalization — as well as exemplary generalization.

  17. Aquifer recharge estimation at the Mesilla Bolson and Guaymas aquifer systems, Mexico

    International Nuclear Information System (INIS)

    Ojeda, C.G.

    2001-01-01

    Three unsaturated profiles were obtained from Mesilla Bolson and Guaymas aquifer systems, northern Mexico. About 500 mL of undisturbed soil from depths between 1 m and 58 m below the surface were obtained every meter by dry percussion from a borehole located near Cd Juarez, Chihuahua state. The other two boreholes were located in the southwestern portion of Sonora state; about 500 mL of undisturbed soil from depths 0-5.50 and 0- 8.50 m were obtained every 0.25 m by dry drilling at Narciso Mendoza and Guaymas sites, respectively. Samples were contained in sealed glass jars and analyzed for moisture content, chloride, deuterium and nitrate (NO 3 -N). The interstitial water was extracted by elution; chloride and nitrate were determined by automated colorimetry while deuterium by direct reduction. Considering an average precipitation at Mesilla Bolson area of 230 mm/year, a chloride rain content of 1 mg/L and a mean Cl content on the unsaturated profile of 977 mg/L below the zero flux plane, we estimated by the Cl mass balance approach a net palaeorecharge in the area of about 0.24 mm/year with a probable time scale profile of 11,000 years. For the Guaymas area the net recharge is in the range 0.11-0.16 mm/year, assuming an average rainfall of 320 mm/year, Cl rainfall content of 3.4 mg/L and mean Cl concentrations on the profiles of 6,939 and 9,470 mg/L below the zero flux plane, respectively. (author)

  18. Using evidence on violence and injury prevention for policy development and decision making in Ciudad Juarez, Mexico.

    Science.gov (United States)

    Gutiérrez, Luis Alberto; Pacheco, Sergio; Juárez, Alethia Yurithzi; Palacios, Luis Alexandro; Cerqueira, Maria Teresa

    2012-05-01

    This report describes the implementation process and functional structure of the Observatory of Security and Citizen Conviviality of the Juarez Municipality (Observatorio de Seguridad y Convivencia Ciudadanas del Municipio de Juárez) in Chihuahua, Mexico, and discusses the most relevant lessons learned and main challenges in the near future. The Observatory, created in 2008, is a joint effort of the Juarez Municipal Government, Autonomous University of Ciudad Juarez (Universidad Autónoma de Ciudad Juárez), and the Pan American Health Organization. The Observatory's main objective is to propose strategies and public policy recommendations to prevent and control violence and injuries in the Juarez Municipality. Most key federal, state, and local agencies have joined this independent autonomous citizen-based initiative, feed the databases, and benefit from the information produced by a multisectoral, multidisciplinary approach. The Observatory contributes far more than the technical data provided and its facilitating functions. The clear results obtained in such a short time-as seen in the preliminary results of the case study on road injuries from January 2009 to July 2011-demonstrate the appropriateness of this course of action and should stimulate the creation of new observatories whenever and wherever needed. Lessons learned, as discussed here, can open the way to new endeavors, and current challenges show how much work remains to be done.

  19. ANÁLISIS DE LA CALIDAD DEL AGUA EN LAS LAGUNAS DE BUSTILLOS Y DE LOS MEXICANOS (CHIHUAHUA, MÉXICO

    Directory of Open Access Journals (Sweden)

    Jesús Pilar Amado Álvarez

    2016-01-01

    Full Text Available En la parte central del estado de Chihuahua (México se encuentra la cuenca de drenaje que alimenta las lagunas endorreicas de Bustillos, y de los Mexicanos. Estos humedales de especial interés ambiental, se encuentran amenazados por una fuerte presión de actividades humanas. Para este trabajo se han planteado una serie de análisis químicos, físicos y microbiológicos, que determinan unos elevados índices de contaminación en estos hábitats acuáticos. Los resultados han mostrado bajos índices de oxígeno disuelto y elevadas concentraciones en nitratos y bacterias coliformes en el agua. Se ha detectado que las principales fuentes de contaminación de estos recursos hídricos son las actividades agropecuarias, los vertidos de aguas residuales de las áreas urbanas y, en mayor medida, por los desechos de los tratamientos industriales.

  20. Analogical Reasoning and Computer Programming.

    Science.gov (United States)

    Clement, Catherine A.; And Others

    1986-01-01

    A study of correlations between analogical reasoning and Logo programming mastery among female high school students related the results of pretests of analogical reasoning to posttests of programming mastery. A significant correlation was found between analogical reasoning and the ability to write subprocedures for use in several different…

  1. Resources of thermal control in vernacular houses of North of Mexico and Peru. A comparative analysis; Recursos de control termico en viviendas vernaculas del Norte de Mexico y Peru. Un analisis comparativo

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, Luis F. [Universidad Autonoma Metropolitana Azcapotzalco, Mexico, D.F.(Mexico)

    2000-07-01

    In this paper results of a comparative analysis made between prehispanic houses and vernacular houses at the environs of the city of Trujillo, Peru and of Casas Grandes in Chihuahua, Mexico, are presented, with the purpose of identifying the formal, functional and material characteristics that allowed their thermal adaptation to geographic environments with hostile climates, resulting from their location in desert zones. Without having existed any contact between the historical and vernacular cultures that were developed almost two thousand years ago in the Valley of Moche and the Valley of Casas Grandes, a series of architectonic answers with remarkable coincidences has been generated in their effectiveness to be integrated to the extreme prevailing climatic conditions. Among these answers it is possible to emphasize the use of soil as construction material, the structure massiveness, geographic orientation, roof slopes, dimensions of their premises, grouping forms, window types, open spaces, sunshades, rooftop gardens and lattice windows, among other design resources. Nevertheless, with the passage of time an important part of the knowledge that based these forms of adaptation to the environment were being lost and the architecture transformed to give way to a vernacular tradition whose characteristics have turned out to be less and less efficient. Most serious of this tendency is that in recent years, as a result of the incorporation of other people's construction systems, the local architecture has been degenerating until almost totally loose the traits that supported their integration to the surrounding environment transforming itself into spaces with a null thermal comfort. The analysis not only allows to evaluate the architectonic elements identified to promote their conservation as an historical testimony but fundamentally, as a source for designing housing solutions that at present and in the future will recover the ancestral wisdom. [Spanish] En esta

  2. 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

  3. Proceedings of the 24. National seminar on the rational use of energy and exposition of equipment and services and 7. Binational seminar on energy saving [Selected Papers]; 24. Seminario nacional sobre el uso racional de energia y exposicion de equipos y servicios y 7. Seminario binacional de ahorro de energia. Memoria Tecnica. [Ponencias seleccionadas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This document contains the technical briefings of the 24. National Seminar on the rational use of energy, and exhibition of the equipment and services and the 7. Binational seminar on energy saving, organized by the Asociacion de Profesionistas y Tecnicos en Aplicacion Energetica (ATPAE), in Ciudad Juarez, Chihuahua, Mexico, from November 9 to 11, 2005. This seminar dealt with subjects such as: electrical energy saving, energy distribution, solar energy, energy saving in compressed air, biomass, administration and control of the demand of the electrical energy, bioclimatic architecture, use of the compressed natural gas, renewable energy, co-generation, qualification and consultancy for the intelligent use of the energy in PyMES. [Spanish] Este documento contiene la memoria tecnica del 24 Seminario Nacional sobre el uso racional de energia, y exposicion de los equipos y servicios y el 7 Seminario binacional de ahorro de energia, organizado por la Asociacion de Tecnicos y Profesionistas en Aplicacion Energetica (ATPAE), en Ciudad Juarez, Chihuahua, Mexico, del 9 al 11 de noviembre del 2005. Este seminario trato temas tales como: ahorro de energia electrica, distribucion de la energia, energia solar, ahorro de energia en aire comprimido, biomasa, administracion y control de la demanda de la energia electrica, arquitectura bioclimatica, uso del gas natural comprimido, energia renovable, cogeneracion, capacitacion y consultoria para el uso inteligente de la energia en las Pymes.

  4. Analogical reasoning in children with specific language impairment: Evidence from a scene analogy task.

    Science.gov (United States)

    Krzemien, Magali; Jemel, Boutheina; Maillart, Christelle

    2017-01-01

    Analogical reasoning is a human ability that maps systems of relations. It develops along with relational knowledge, working memory and executive functions such as inhibition. It also maintains a mutual influence on language development. Some authors have taken a greater interest in the analogical reasoning ability of children with language disorders, specifically those with specific language impairment (SLI). These children apparently have weaker analogical reasoning abilities than their aged-matched peers without language disorders. Following cognitive theories of language acquisition, this deficit could be one of the causes of language disorders in SLI, especially those concerning productivity. To confirm this deficit and its link to language disorders, we use a scene analogy task to evaluate the analogical performance of SLI children and compare them to controls of the same age and linguistic abilities. Results show that children with SLI perform worse than age-matched peers, but similar to language-matched peers. They are more influenced by increased task difficulty. The association between language disorders and analogical reasoning in SLI can be confirmed. The hypothesis of limited processing capacity in SLI is also being considered.

  5. PEMETAAN ANALOGI PADA KONSEP ABSTRAK FISIKA

    Directory of Open Access Journals (Sweden)

    Nyoto Suseno

    2014-11-01

    Full Text Available The research of any where founded majority students have common difficulties in abstract physics concept. The result of observation, lecturers have problem  in teaching implementation of abstract concepts on physics learning. The objective of this research is to find out the ways how to overcome this problem. The research place of  physics education programs and senior high school. The data are colected by quetionere, observation and interview. The lecturer behavior to making out this case is use of analogy to make concrete a abstract concept. This action is true, because the analogies are dynamic tools that facilitate understanding, rather than representations of the correct and static explanations. Using analogies not only promoted profound understanding of abstract concept, but also helped students overcome their misconceptions. However used analogy in teaching not yet planed with seriousness, analogy used spontanously with the result that less optimal. By planing and selecting right analogy, the role of analogy can be achieved the optimal result. Therefore, it is important to maping analogies of abstract consepts on physics learning.

  6. Science Teachers' Analogical Reasoning

    Science.gov (United States)

    Mozzer, Nilmara Braga; Justi, Rosária

    2013-01-01

    Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to…

  7. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  8. Detrital zircon U-Pb geochronology of Cambrian to Triassic miogeoclinal and eugeoclinal strata of Sonora, Mexico

    Science.gov (United States)

    Gehrels, G.E.; Stewart, John H.

    1998-01-01

    One hundred and eighty two individual detrital zircon grains from Cambrian through Permian miogeoclinal strata, Ordovician eugeoclinal rocks, and Triassic post-orogenic sediments in northwestern Sonora have been analyzed. During Cambrian, Devonian, Permian, and Triassic time, most zircons accumulating along this part of the Cordilleran margin were shed from 1.40-1.45 and 1.62-1.78 Ga igneous rocks that are widespread in the southwestern United States and northwestern Mexico. Zircons with ages of approximately 1.11 Ga are common in Cambrian strata and were apparently shed from granite bodies near the sample site. The sources of 225-280 Ma zircons in our Triassic sample are more problematic, as few igneous rocks of these ages are recognized in northwestern Mexico. Such sources may be present but unrecognized, or the grains could have been derived from igneous rocks of the appropriate ages to the northwest in the Mojave Desert region, to the east in Chihuahua and Coahuila, or to the south in accreted(?) arc-type terranes. Because the zircon grains in our Cambrian and Devonian to Triassic samples could have accumulated in proximity to basement rocks near their present position or in the Death Valley region of southern California, our data do not support or refute the existence of the Mojave-Sonora megashear. Ordovician strata of both miogeoclinal and eugeoclinal affinity are dominated by >1.77 Ga detrital zircons, which are considerably older than most basement rocks in the region. Zircon grains in the miogeoclinal sample were apparently derived from the Peace River arch area of northwestern Canada and transported southward by longshore currents. The eugeoclinal grains may also have come from the Peace River arch region, with southward transport by either sedimentary or tectonic processes, or they may have been shed from off-shelf slivers of continents (perhaps Antarctica?) removed from the Cordilleran margin during Neoproterozoic rifting. It is also possible that the

  9. Implications of Earth analogs to Martian sulfate-filled Fractures

    Science.gov (United States)

    Holt, R. M.; Powers, D. W.

    2017-12-01

    Sulfate-filled fractures in fine-grained sediments on Mars are interpreted to be the result of fluid movement during deep burial. Fractures in the Dewey Lake (aka Quartermaster) Formation of southeastern New Mexico and west Texas are filled with gypsum that is at least partially synsedimentary. Sulfate in the Dewey Lake takes two principal forms: gypsum cement and gypsum (mainly fibrous) that fills fractures ranging from horizontal to vertical. Apertures are mainly mm-scale, though some are > 1 cm. The gypsum is antitaxial, fibrous, commonly approximately perpendicular to the wall rock, and displays suture lines and relics of the wall rock. Direct evidence of synsedimentary, near-surface origin includes gypsum intraclasts, intraclasts that include smaller intraclasts that contain gypsum clasts, intraclasts of gypsum with suture lines, gypsum concentrated in small desiccation cracks, and intraclasts that include fibrous gypsum-filled fractures that terminate at the eroded clast boundary. Dewey Lake fracture fillings suggest that their Martian analogs may also have originated in the shallow subsurface, shortly following the deposition of Martian sediments, in the presence of shallow aquifers.

  10. Advances in Analog Circuit Design 2015

    CERN Document Server

    Baschirotto, Andrea; Harpe, Pieter

    2016-01-01

    This book is based on the 18 tutorials presented during the 24th workshop on Advances in Analog Circuit Design. Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, including low-power and energy-efficient analog electronics, with specific contributions focusing on the design of efficient sensor interfaces and low-power RF systems. This book serves as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development. ·         Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; ·         Presents material in a tutorial-based format; ·         Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing.

  11. A new species of Trachymyrmex (Hymenoptera, Formicidae) fungus-growing ant from the Sierra Madre Oriental of northeastern Mexico

    Science.gov (United States)

    Sánchez-Peña, Sergio R.; Chacón-Cardosa, Manuela Citlali; Canales-del-Castillo, Ricardo; Ward, Lauren; Resendez-Pérez, Diana

    2017-01-01

    been driven by the Pliocene-Holocene desertification of southwestern North America. This process resulted in isolated mesic refugia and forests in the Madrean ranges and piedmonts of northeastern Mexico (the current habitat of T. pakawa) while T. smithi adapted to the deeper, often sandy soils on the drier desert plains of Coahuila and Chihuahua states in Mexico, and New Mexico and Texas in the USA. Within the Nearctic species of the Trachymyrmex septentrionalis species group, T. pakawa is the species that is closest (by geographical distribution) to Neotropical species of Trachymyrmex like T. saussurei. PMID:29118621

  12. A new species of Trachymyrmex (Hymenoptera, Formicidae fungus-growing ant from the Sierra Madre Oriental of northeastern Mexico

    Directory of Open Access Journals (Sweden)

    Sergio R. Sánchez-Peña

    2017-10-01

    have been driven by the Pliocene-Holocene desertification of southwestern North America. This process resulted in isolated mesic refugia and forests in the Madrean ranges and piedmonts of northeastern Mexico (the current habitat of T. pakawa while T. smithi adapted to the deeper, often sandy soils on the drier desert plains of Coahuila and Chihuahua states in Mexico, and New Mexico and Texas in the USA. Within the Nearctic species of the Trachymyrmex septentrionalis species group, T. pakawa is the species that is closest (by geographical distribution to Neotropical species of Trachymyrmex like T. saussurei.

  13. Students' Pre- and Post-Teaching Analogical Reasoning when They Draw Their Analogies

    Science.gov (United States)

    Mozzer, Nilmara Braga; Justi, Rosaria

    2012-01-01

    Analogies are parts of human thought. From them, we can acquire new knowledge or change that which already exists in our cognitive structure. In this sense, understanding the analogical reasoning process becomes an essential condition to understand how we learn. Despite the importance of such an understanding, there is no general agreement in…

  14. Analogical proportions: another logical view

    Science.gov (United States)

    Prade, Henri; Richard, Gilles

    This paper investigates the logical formalization of a restricted form of analogical reasoning based on analogical proportions, i.e. statements of the form a is to b as c is to d. Starting from a naive set theoretic interpretation, we highlight the existence of two noticeable companion proportions: one states that a is to b the converse of what c is to d (reverse analogy), while the other called paralogical proportion expresses that what a and b have in common, c and d have it also. We identify the characteristic postulates of the three types of proportions and examine their consequences from an abstract viewpoint. We further study the properties of the set theoretic interpretation and of the Boolean logic interpretation, and we provide another light on the understanding of the role of permutations in the modeling of the three types of proportions. Finally, we address the use of these proportions as a basis for inference in a propositional setting, and relate it to more general schemes of analogical reasoning. The differences between analogy, reverse-analogy, and paralogy is still emphasized in a three-valued setting, which is also briefly presented.

  15. Medición de la vulnerabilidad: el caso de la adicción a drogas ilícitas en Chihuahua, México

    Directory of Open Access Journals (Sweden)

    Roberto J. Córdova-Contreras

    2010-01-01

    Full Text Available En el presente estudio se explora el modelo de Rogers para cuantificar la vulnerabilidad, pero sin pruebas empíricas de su utilidad. Éste usa un triángulo equilátero cuyos lados representan los recursos personales y el apoyo ambiental, y la base el grado de vulnerabilidad. Se comparan los datos de la Encuesta estatal de adicciones del estado de Chihuahua, del año 2000, con los resultados obtenidos con la visión tradicional de la epidemiología. El enfoque de la vulnerabilidad identificó a la población analizada como muy sensible. La comparación entre los métodos mostró diferencias importantes, pero no permiten inferir cuál es mejor. Estudios futuros podrán examinar la utilidad del modelo abordado aquí, en diversos contextos.

  16. Genetic structure of Mexican Mestizo women with breast cancer based on three STR loci.

    Science.gov (United States)

    Calderón-Garcidueñas, Ana L; Rivera-Prieto, Roxana A; Ortíz-Lopez, Rocio; Rivas, Fernando; Barrera-Saldaña, Hugo A; Peñaloza-Espinosa, Rosenda I; Cerda-Flores, Ricardo M

    2008-01-01

    The aim of this population genetics study was to compare the genetic structure of Mexican women with breast cancer (BrCa) with previously reported data of four random populations (Nuevo León, Hispanics, Chihuahua, and Central Region of Mexico). A sample of 115 unrelated women with BrCa and whose four grandparents were born in five zones of Mexico were interviewed at a reference hospital in Northeastern Mexico. Noncodifying STRs D7S820, D13S317, and D16S39 were analyzed; genotype distribution was in agreement with Hardy-Weinberg expectations for all three markers. Similar allele frequencies among four random populations and this selected population were found. According with this and previous studies using molecular and nonmolecular nuclear DNA markers not associated with any disease, Mexican Mestizo population is genetically homogeneous and therefore, genetic causes of BrCa are less heterogeneous, simplifying genetic epidemiologic studies.

  17. Desarrollo de un destino de turismo médico en el contexto de la frontera México-Estados Unidos: el caso de Ciudad Juárez, Chihuahua, México

    OpenAIRE

    Martínez Almanza, María Teresa

    2016-01-01

    La asistencia sanitaria es uno de los temas primordiales del siglo XXI. Los problemas relacionados con la atención médica contemporánea han generado una creciente demanda de servicios de pacientes extranjeros. En el marco de la teoría fundamentada, mediante 69 entrevistas en profundidad, realizadas de 2013 a 2015, se analiza el proceso de desarrollo de Ciudad Juárez, Chihuahua, México como un destino turístico médico de frontera. Se presenta una narrativa de la génesis y evolución del caso d...

  18. Analog circuit design art, science and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    This book is far more than just another tutorial or reference guide - it's a tour through the world of analog design, combining theory and applications with the philosophies behind the design process. Readers will learn how leading analog circuit designers approach problems and how they think about solutions to those problems. They'll also learn about the `analog way' - a broad, flexible method of thinking about analog design tasks.A comprehensive and useful guide to analog theory and applications. Covers visualizing the operation of analog circuits. Looks at how to rap

  19. Resistive RAMs as analog trimming elements

    Science.gov (United States)

    Aziza, H.; Perez, A.; Portal, J. M.

    2018-04-01

    This work investigates the use of Resistive Random Access Memory (RRAM) as an analog trimming device. The analog storage feature of the RRAM cell is evaluated and the ability of the RRAM to hold several resistance states is exploited to propose analog trim elements. To modulate the memory cell resistance, a series of short programming pulses are applied across the RRAM cell allowing a fine calibration of the RRAM resistance. The RRAM non volatility feature makes the analog device powers up already calibrated for the system in which the analog trimmed structure is embedded. To validate the concept, a test structure consisting of a voltage reference is evaluated.

  20. Fast multichannel analog storage system

    International Nuclear Information System (INIS)

    Freytag, D.R.

    1982-11-01

    A Multichannel Analog Storage System based on a commercial 32-channel parallel in/serial out (PISO) analog shift register is described. The basic unit is a single width CAMAC module containing 512 analog cells and the associated logic for data storage and subsequent readout. At sampling rates of up to 30 MHz the signals are strobed directly into the PISO. At higher rates signals are strobed into a fast presampling stage and subsequently transferred in block form into an array of PISO's. Sampling rates of 300 MHz have been achieved with the present device and 1000 MHz are possible with improved signal drivers. The system is well suited for simultaneous handling of many signal channels with moderate numbers of samples in each channel. RMS noise over full scale signal has been measured as 1:3000 (approx. = 11 bit). However, nonlinearities in the response and differences in sensitivity of the analog cells require an elaborate calibration system in order to realize 11 bit accuracy for the analog information

  1. Rio Grande transboundary integrated hydrologic model and water-availability analysis, New Mexico and Texas, United States, and Northern Chihuahua, Mexico

    Science.gov (United States)

    Hanson, Randall T.; Ritchie, Andre; Boyce, Scott E.; Ferguson, Ian; Galanter, Amy; Flint, Lorraine E.; Henson, Wesley

    2018-05-31

    Changes in population, agricultural development and practices (including shifts to more water-intensive crops), and climate variability are increasing demands on available water resources, particularly groundwater, in one of the most productive agricultural regions in the Southwest—the Rincon and Mesilla Valley parts of Rio Grande Valley, Doña Ana and Sierra Counties, New Mexico, and El Paso County, Texas. The goal of this study was to produce an integrated hydrological simulation model to help evaluate water-management strategies, including conjunctive use of surface water and groundwater for historical conditions, and to support long-term planning for the Rio Grande Project. This report describes model construction and applications by the U.S. Geological Survey, working in cooperation and collaboration with the Bureau of Reclamation.This model, the Rio Grande Transboundary Integrated Hydrologic Model, simulates the most important natural and human components of the hydrologic system, including selected components related to variations in climate, thereby providing a reliable assessment of surface-water and groundwater conditions and processes that can inform water users and help improve planning for future conditions and sustained operations of the Rio Grande Project (RGP) by the Bureau of Reclamation. Model development included a revision of the conceptual model of the flow system, construction of a Transboundary Rio Grande Watershed Model (TRGWM) water-balance model using the Basin Characterization Model (BCM), and construction of an integrated hydrologic flow model with MODFLOW-One-Water Hydrologic Flow Model (referred to as One Water). The hydrologic models were developed for and calibrated to historical conditions of water and land use, and parameters were adjusted so that simulated values closely matched available measurements (calibration). The calibrated model was then used to assess the use and movement of water in the Rincon Valley, Mesilla Basin

  2. Long-term infrastructure forecasting in the Gulf of Mexico: a decision- and resource-based approach

    International Nuclear Information System (INIS)

    Kaiser, M.J.; Mesyanzhinov, D.V.; Pulsipher, A.G.

    2004-01-01

    A long-term infrastructure forecast in the Gulf of Mexico is developed in a disaggregated decision- and resource-based environment. Models for the installation and removal rates of structures are performed across five water depth categories for the Western and Central Gulf of Mexico planning areas for structures grouped according to a major and nonmajor classification. Master hydrocarbon production schedules are constructed per water depth and planning area using a two-parameter decision model, where 'bundled' resources are recoverable at a given time and at a specific rate. The infrastructure requirements to support the expected production is determined by extrapolating historical data. The analytic forecasting framework allows for subjective judgement, technological change, analogy, and historical trends to be employed in a user-defined manner. Special attention to the aggregation procedures employed and the general methodological framework are highlighted, including a candid discussion of the limitations of analysis and suggestions for further research

  3. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  4. Producing and Recognizing Analogical Relations

    Science.gov (United States)

    Lipkens, Regina; Hayes, Steven C

    2009-01-01

    Analogical reasoning is an important component of intelligent behavior, and a key test of any approach to human language and cognition. Only a limited amount of empirical work has been conducted from a behavior analytic point of view, most of that within Relational Frame Theory (RFT), which views analogy as a matter of deriving relations among relations. The present series of four studies expands previous work by exploring the applicability of this model of analogy to topography-based rather than merely selection-based responses and by extending the work into additional relations, including nonsymmetrical ones. In each of the four studies participants pretrained in contextual control over nonarbitrary stimulus relations of sameness and opposition, or of sameness, smaller than, and larger than, learned arbitrary stimulus relations in the presence of these relational cues and derived analogies involving directly trained relations and derived relations of mutual and combinatorial entailment, measured using a variety of productive and selection-based measures. In Experiment 1 participants successfully recognized analogies among stimulus networks containing same and opposite relations; in Experiment 2 analogy was successfully used to extend derived relations to pairs of novel stimuli; in Experiment 3 the procedure used in Experiment 1 was extended to nonsymmetrical comparative relations; in Experiment 4 the procedure used in Experiment 2 was extended to nonsymmetrical comparative relations. Although not every participant showed the effects predicted, overall the procedures occasioned relational responses consistent with an RFT account that have not yet been demonstrated in a behavior-analytic laboratory setting, including productive responding on the basis of analogies. PMID:19230515

  5. Calculation of the structural shielding of the radiotherapy treatment room equipped with a linear accelerator type Tomo therapy Hi-Art in the Oncology Center of Chihuahua, Mexico; Calculo del blindaje estructural de la sala de tratamiento de radioterapia equipada con un acelerador lineal del tipo Tomotherapy Hi-Art en el Centro Oncologico de Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Caballero G, C. A. [Southwest Oncology Centers, North Civic Center Plaza No. 2926, Scottsdale, Arizona (United States); Plascencia, J. C. [Centro Oncologico Louis and Lucille Grado, Republica del Peru No. 102-5, Col. Americas, Aguascalientes (Mexico); Vargas V, M. X.; Toledo J, P., E-mail: cabshm@msn.co [Centro Oncologico de Chihuahua, Hacienda de la Esperanza No. 6304, Fracc. Cima Comercial, Chihuahua (Mexico)

    2010-09-15

    therapy. In this work these specific methodologies are used for the structural shielding calculations of the tomo therapy equipment installed in the Oncology Center of Chihuahua. These calculation methodologies consider the primary radiation, of leakage, disperse, second dispersion and leakage dispersion. The obtained results indicate that due to the lead barrier of the primary beam, the main component that contributes to the shielding requirements of the installation is the leakage radiation. On the other hand, the component that more affects of the door shielding is the dispersion component in the patient. (Author)

  6. Mother-Offspring Interactions in Raramuri Criollo Cattle on New Mexico and Chihuahua (Mexico) Rangelands

    Science.gov (United States)

    Rangeland beef cows spend approximately six months of a typical year raising their calf. This endeavor is known to significantly alter a dam’s grazing behavior and spatial distribution patterns. The objective of this study was to characterize cow-calf contact events in two herds of Raramuri Criollo ...

  7. Challenges in Using Analogies

    Science.gov (United States)

    Lin, Shih-Yin; Singh, Chandralekha

    2011-01-01

    Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features. One way to help students learn physics is via analogical reasoning. Students can be taught to make an analogy between situations that are more familiar or easier to understand and another situation where the same…

  8. The Micro-Category Account of Analogy

    Science.gov (United States)

    Green, Adam E.; Fugelsang, Jonathan A.; Kraemer, David J. M.; Dunbar, Kevin N.

    2008-01-01

    Here, we investigate how activation of mental representations of categories during analogical reasoning influences subsequent cognitive processing. Specifically, we present and test the central predictions of the "Micro-Category" account of analogy. This account emphasizes the role of categories in aligning terms for analogical mapping. In a…

  9. Priming analogical reasoning with false memories.

    Science.gov (United States)

    Howe, Mark L; Garner, Sarah R; Threadgold, Emma; Ball, Linden J

    2015-08-01

    Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false memory priming of complex analogical reasoning tasks in the absence of simple semantic associations. In Experiment 1, we demonstrated the robustness of false memory priming in analogical reasoning when backward associative strength among the problem terms was eliminated. In Experiments 2a and 2b, we extended these findings by demonstrating priming on newly created homonym analogies that can only be solved by inhibiting semantic associations within the analogy. Overall, the findings of the present experiments provide evidence that the efficacy of false memory priming extends to complex analogical reasoning problems.

  10. An emergent approach to analogical inference

    Science.gov (United States)

    Thibodeau, Paul H.; Flusberg, Stephen J.; Glick, Jeremy J.; Sternberg, Daniel A.

    2013-03-01

    In recent years, a growing number of researchers have proposed that analogy is a core component of human cognition. According to the dominant theoretical viewpoint, analogical reasoning requires a specific suite of cognitive machinery, including explicitly coded symbolic representations and a mapping or binding mechanism that operates over these representations. Here we offer an alternative approach: we find that analogical inference can emerge naturally and spontaneously from a relatively simple, error-driven learning mechanism without the need to posit any additional analogy-specific machinery. The results also parallel findings from the developmental literature on analogy, demonstrating a shift from an initial reliance on surface feature similarity to the use of relational similarity later in training. Variants of the model allow us to consider and rule out alternative accounts of its performance. We conclude by discussing how these findings can potentially refine our understanding of the processes that are required to perform analogical inference.

  11. Children's analogical reasoning about natural phenomena.

    Science.gov (United States)

    Pauen, S; Wilkening, F

    1997-10-01

    This report investigates children's analogical reasoning in a physics task, using an analogy generated by the children rather than by the experimenter. A total of 127 elementary school children took part in three related studies. Children learned to predict the behavior of a balance scale. Later, they were asked to solve a force interaction problem. Two versions of the balance scale training were devised: version A suggested an incorrect solution to the target problem (negative analogy), and version B suggested a correct solution to the target problem (positive analogy). In Study 1, 9- to 10-year-olds showed spontaneous transfer in both training conditions. In Study 2, 7-year-olds did not show any transfer in the positive analogy condition. Study 3 revealed that the lack of transfer in younger children was not due to a failure either to notice the analogy or to perform the mapping. Instead, 7-year-olds transferred only selected aspects of the correct solution. Copyright 1997 Academic Press.

  12. Working memory predicts children's analogical reasoning.

    Science.gov (United States)

    Simms, Nina K; Frausel, Rebecca R; Richland, Lindsey E

    2018-02-01

    Analogical reasoning is the cognitive skill of drawing relationships between representations, often between prior knowledge and new representations, that allows for bootstrapping cognitive and language development. Analogical reasoning proficiency develops substantially during childhood, although the mechanisms underlying this development have been debated, with developing cognitive resources as one proposed mechanism. We explored the role of executive function (EF) in supporting children's analogical reasoning development, with the goal of determining whether predicted aspects of EF were related to analogical development at the level of individual differences. We assessed 5- to 11-year-old children's working memory, inhibitory control, and cognitive flexibility using measures from the National Institutes of Health Toolbox Cognition battery. Individual differences in children's working memory best predicted performance on an analogical mapping task, even when controlling for age, suggesting a fundamental interrelationship between analogical reasoning and working memory development. These findings underscore the need to consider cognitive capacities in comprehensive theories of children's reasoning development. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Process and circuiting arrangement for the conversion of analog signals to digital signals and digital signals to analog signals

    International Nuclear Information System (INIS)

    Wintzer, K.

    1977-01-01

    Process for analog-to-digital and digital-to-analog conversion in telecommunication systems whose outstations each have an analog transmitter and an analog receiver. The invention illustrates a method of reducing the power demand of the converters at times when no conversion processes take place. (RW) [de

  14. Analogies and the 5E Model

    Science.gov (United States)

    Orgill, Mary Kay; Thomas, Megan

    2007-01-01

    Science classes are full of abstract or challenging concepts that are easier to understand if an analogy is used to illustrate the points. Effective analogies motivate students, clarify students' thinking, help students overcome misconceptions, and give students ways to visualize abstract concepts. When they are used appropriately, analogies can…

  15. How Analogy Drives Physics

    International Nuclear Information System (INIS)

    Hofstadter, Doug

    2004-01-01

    Many new ideas in theoretical physics come from analogies to older ideas in physics. For instance, the abstract notion of 'isospin' (or isotopic spin) originated in the prior concept of 'spin' (quantized angular momentum); likewise, the concept of 'phonon' (quantum of sound, or quantized collective excitation of a crystal) was based on the prior concept of 'photon' (quantum of light, or quantized element of the electromagnetic field). But these two examples, far from being exceptions, in fact represent the bread and butter of inventive thinking in physics. In a nutshell, intraphysics analogy-making -- borrowing by analogy with something already known in another area of physics -- is central to the progress of physics. The aim of this talk is to reveal the pervasiveness -- indeed, the indispensability -- of this kind of semi-irrational, wholly intuitive type of thinking (as opposed to more deductive mathematical inference) in the mental activity known as 'doing physics'. Speculations as to why wild analogical leaps are so crucial to the act of discovery in physics (as opposed to other disciplines) will be offered.

  16. Elaboración del duelo de una madre cuyo hijo trabajaba como sicario en Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    Rosalía Delgado Durán

    2014-01-01

    Full Text Available El presente trabajo es parte de una investigación cualitativa sobre el proceso de ela - boración de duelo de la madre de un sicario en el contexto de una terapia Gestalt. Se utilizó para su análisis la perspectiva de las etapas del duelo de Kübler-Ross (2006:59- 119. La exacerbación de la violencia generada en buena medida por pugnas entre gru - pos del crimen organizado en Ciudad Juárez, Chihuahua (Martínez, 2008, ha dado como resultado una gran cantidad de muertes, una de ellas es el caso que nos ocupa. Si bien uno de los objetivos iniciales de la investigación era documentar y analizar las etapas en el desarrollo del duelo de una madre a partir del fallecimiento de su hijo, este se replanteó durante el transcurso de la misma, ya que una de las características del duelo de esta madre es que inició justo cuando se enteró del trabajo que él realizaba.

  17. Component Processes in Analogical Reasoning

    Science.gov (United States)

    Sternberg, Robert J.

    1977-01-01

    Describes alternative theoretical positions regarding (a) the component information processes used in analogical reasoning and (b) strategies for combining these processes. Also presents results from three experiments on analogical reasoning. (Author/RK)

  18. 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…

  19. Is the link from working memory to analogy causal? No analogy improvements following working memory training gains.

    Directory of Open Access Journals (Sweden)

    J Elizabeth Richey

    Full Text Available Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data, but less work has tested this relationship through experimental manipulation. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants' performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks. Participants' improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning.

  20. Is the link from working memory to analogy causal? No analogy improvements following working memory training gains.

    Science.gov (United States)

    Richey, J Elizabeth; Phillips, Jeffrey S; Schunn, Christian D; Schneider, Walter

    2014-01-01

    Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data, but less work has tested this relationship through experimental manipulation. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants' performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks. Participants' improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning.

  1. Is the Link from Working Memory to Analogy Causal? No Analogy Improvements following Working Memory Training Gains

    Science.gov (United States)

    Richey, J. Elizabeth; Phillips, Jeffrey S.; Schunn, Christian D.; Schneider, Walter

    2014-01-01

    Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data [1], but less work has tested this relationship through experimental manipulation [2]. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants’ performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks [3], [4]. Participants’ improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning. PMID:25188356

  2. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew

    2001-01-01

    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

  3. Heterogeneous Seepage at the Nopal I Uranium Mine, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Dobson, Patrick; Dobson, Patrick F.; Cook, Paul J.; Ghezzehei, Teamrat; Rodriguez, J. Alfredo; Garza, Rodrigo de la

    2008-01-01

    The primary objective of this analogue study is to evaluate flow and transport processes of relevance to the proposed Yucca Mountain repository. Seepage data obtained from this study will be used to constrain flow and transport models being developed for the Nopal I system

  4. Analog circuit design art, science, and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    Analog Circuit Design: Art, Science, and Personalities discusses the many approaches and styles in the practice of analog circuit design. The book is written in an informal yet informative manner, making it easily understandable to those new in the field. The selection covers the definition, history, current practice, and future direction of analog design; the practice proper; and the styles in analog circuit design. The book also includes the problems usually encountered in analog circuit design; approach to feedback loop design; and other different techniques and applications. The text is

  5. Synthetic Analogs of Phospholipid Metabolites as Antimalarials.

    Science.gov (United States)

    1979-07-01

    phosphatidic acid analogs containing ether and phosphonate groups; completely non- hydrolyzable lecithin analogs containing phosphinate and ether groups...substance is a completely non- hydrolyzable analog of lecithin containing ether and phosphonate moieties instead of the normally labile carboxylic and...and also ant-i-phospholipase C (clostridial enzyme) activity. This substance Is a completely non- hydrolyzable analog of lecithin containing ether

  6. FGF growth factor analogs

    Science.gov (United States)

    Zamora, Paul O [Gaithersburg, MD; Pena, Louis A [Poquott, NY; Lin, Xinhua [Plainview, NY; Takahashi, Kazuyuki [Germantown, MD

    2012-07-24

    The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

  7. 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...

  8. 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.

  9. Structure problems in the analog computation

    International Nuclear Information System (INIS)

    Braffort, P.L.

    1957-01-01

    The recent mathematical development showed the importance of elementary structures (algebraic, topological, etc.) in abeyance under the great domains of classical analysis. Such structures in analog computation are put in evidence and possible development of applied mathematics are discussed. It also studied the topological structures of the standard representation of analog schemes such as additional triangles, integrators, phase inverters and functions generators. The analog method gives only the function of the variable: time, as results of its computations. But the course of computation, for systems including reactive circuits, introduces order structures which are called 'chronological'. Finally, it showed that the approximation methods of ordinary numerical and digital computation present the same structure as these analog computation. The structure analysis permits fruitful comparisons between the several domains of applied mathematics and suggests new important domains of application for analog method. (M.P.)

  10. Molecular modeling of fentanyl analogs

    Directory of Open Access Journals (Sweden)

    LJILJANA DOSEN-MICOVIC

    2004-11-01

    Full Text Available Fentanyl is a highly potent and clinically widely used narcotic analgesic. A large number of its analogs have been synthesized, some of which (sufentanil and alfentanyl are also in clinical use. Theoretical studies, in recent years, afforded a better understanding of the structure-activity relationships of this class of opiates and allowed insight into the molecular mechanism of the interactions of fentanyl analogs with their receptors. An overview of the current computational techniques for modeling fentanyl analogs, their receptors and ligand-receptor interactions is presented in this paper.

  11. Terrestrial Analogs to Mars

    Science.gov (United States)

    Farr, T. G.; Arcone, S.; Arvidson, R. W.; Baker, V.; Barlow, N. G.; Beaty, D.; Bell, M. S.; Blankenship, D. D.; Bridges, N.; Briggs, G.; Bulmer, M.; Carsey, F.; Clifford, S. M.; Craddock, R. A.; Dickerson, P. W.; Duxbury, N.; Galford, G. L.; Garvin, J.; Grant, J.; Green, J. R.; Gregg, T. K. P.; Guinness, E.; Hansen, V. L.; Hecht, M. H.; Holt, J.; Howard, A.; Keszthelyi, L. P.; Lee, P.; Lanagan, P. D.; Lentz, R. C. F.; Leverington, D. W.; Marinangeli, L.; Moersch, J. E.; Morris-Smith, P. A.; Mouginis-Mark, P.; Olhoeft, G. R.; Ori, G. G.; Paillou, P.; Reilly, J. F., II; Rice, J. W., Jr.; Robinson, C. A.; Sheridan, M.; Snook, K.; Thomson, B. J.; Watson, K.; Williams, K.; Yoshikawa, K.

    2002-08-01

    It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites, instrument tests, laboratory measurements (including analysis of Martian meteorites), and computer and laboratory modeling. The combination of all these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel has considered the following two key questions: (1) How do terrestrial analog studies tie in to the Mars Exploration Payload Assessment Group science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel has considered the issues of data collection, value of field workshops, data archiving, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities.

  12. Expert analogy use in a naturalistic setting

    Science.gov (United States)

    Kretz, Donald R.; Krawczyk, Daniel C.

    2014-01-01

    The use of analogy is an important component of human cognition. The type of analogy we produce and communicate depends heavily on a number of factors, such as the setting, the level of domain expertise present, and the speaker's goal or intent. In this observational study, we recorded economics experts during scientific discussion and examined the categorical distance and structural depth of the analogies they produced. We also sought to characterize the purpose of the analogies that were generated. Our results supported previous conclusions about the infrequency of superficial similarity in subject-generated analogs, but also showed that distance and depth characteristics were more evenly balanced than in previous observational studies. This finding was likely due to the nature of the goals of the participants, as well as the broader nature of their expertise. An analysis of analogical purpose indicated that the generation of concrete source examples of more general target concepts was most prevalent. We also noted frequent instances of analogies intended to form visual images of source concepts. Other common purposes for analogies were the addition of colorful speech, inclusion (i.e., subsumption) of a target into a source concept, or differentiation between source and target concepts. We found no association between depth and either of the other two characteristics, but our findings suggest a relationship between purpose and distance; i.e., that visual imagery typically entailed an outside-domain source whereas exemplification was most frequently accomplished using within-domain analogies. Overall, we observed a rich and diverse set of spontaneously produced analogical comparisons. The high degree of expertise within the observed group along with the richly comparative nature of the economics discipline likely contributed to this analogical abundance. PMID:25505437

  13. Expert Analogy Use in a Naturalistic Setting

    Directory of Open Access Journals (Sweden)

    Donald R Kretz

    2014-11-01

    Full Text Available The use of analogy is an important component of human cognition. The type of analogy we produce and communicate depends heavily on a number of factors, such as the setting, the level of domain expertise present, and the speaker’s goal or intent. In this observational study, we recorded economics experts during scientific discussion and examined the categorical distance and structural depth of the analogies they produced. We also sought to characterize the purpose of the analogies that were generated. Our results supported previous conclusions about the infrequency of superficial similarity in subject-generated analogs, but also showed that distance and depth characteristics were more evenly balanced than in previous observational studies. This finding was likely due to the nature of the goals of the participants, as well as the broader nature of their expertise. An analysis of analogical purpose indicated that the generation of concrete source examples of more general target concepts was most prevalent. We also noted frequent instances of analogies intended to form visual images of source concepts. Other common purposes for analogies were the addition of colorful speech, inclusion (i.e., subsumption of a target into a source concept, or differentiation between source and target concepts. We found no association between depth and either of the other two characteristics, but our findings suggest a relationship between purpose and distance; i.e., that visual imagery typically entailed an outside-domain source whereas exemplification was most frequently accomplished using within-domain analogies. Overall, we observed a rich and diverse set of spontaneously produced analogical comparisons. The high degree of expertise within the observed group along with the richly comparative nature of the economics discipline likely contributed to this analogical abundance.

  14. A bilateral frontoparietal network underlies visuospatial analogical reasoning.

    Science.gov (United States)

    Watson, Christine E; Chatterjee, Anjan

    2012-02-01

    Our ability to reason by analogy facilitates problem solving and allows us to communicate ideas efficiently. In this study, we examined the neural correlates of analogical reasoning and, more specifically, the contribution of rostrolateral prefrontal cortex (RLPFC) to reasoning. This area of the brain has been hypothesized to integrate relational information, as in analogy, or the outcomes of subgoals, as in multi-tasking and complex problem solving. Using fMRI, we compared visuospatial analogical reasoning to a control task that was as complex and difficult as the analogies and required the coordination of subgoals but not the integration of relations. We found that analogical reasoning more strongly activated bilateral RLPFC, suggesting that anterior prefrontal cortex is preferentially recruited by the integration of relational knowledge. Consistent with the need for inhibition during analogy, bilateral, and particularly right, inferior frontal gyri were also more active during analogy. Finally, greater activity in bilateral inferior parietal cortex during the analogy task is consistent with recent evidence for the neural basis of spatial relation knowledge. Together, these findings indicate that a network of frontoparietal areas underlies analogical reasoning; we also suggest that hemispheric differences may emerge depending on the visuospatial or verbal/semantic nature of the analogies. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Neural correlates of creativity in analogical reasoning.

    Science.gov (United States)

    Green, Adam E; Kraemer, David J M; Fugelsang, Jonathan A; Gray, Jeremy R; Dunbar, Kevin N

    2012-03-01

    Brain-based evidence has implicated the frontal pole of the brain as important for analogical mapping. Separately, cognitive research has identified semantic distance as a key determinant of the creativity of analogical mapping (i.e., more distant analogies are generally more creative). Here, we used functional magnetic resonance imaging to assess brain activity during an analogy generation task in which we varied the semantic distance of analogical mapping (as derived quantitatively from a latent semantic analysis). Data indicated that activity within an a priori region of interest in left frontopolar cortex covaried parametrically with increasing semantic distance, even after removing effects of task difficulty. Results implicate increased recruitment of frontopolar cortex as a mechanism for integrating semantically distant information to generate solutions in creative analogical reasoning. 2012 APA, all rights reserved

  16. Using Visual Analogies To Teach Introductory Statistical Concepts

    Directory of Open Access Journals (Sweden)

    Jessica S. Ancker

    2017-07-01

    Full Text Available Introductory statistical concepts are some of the most challenging to convey in quantitative literacy courses. Analogies supplemented by visual illustrations can be highly effective teaching tools. This literature review shows that to exploit the power of analogies, teachers must select analogies familiar to the audience, explicitly link the analog with the target concept, and avert misconceptions by explaining where the analogy fails. We provide guidance for instructors and a series of visual analogies for use in teaching medical and health statistics.

  17. Multidrug-Resistant Bacteria Isolated from Surface Water in Bassaseachic Falls National Park, Mexico

    Directory of Open Access Journals (Sweden)

    Ma. Carmen E. Delgado-Gardea

    2016-06-01

    Full Text Available Bacterial pathogens are a leading cause of waterborne disease, and may result in gastrointestinal outbreaks worldwide. Inhabitants of the Bassaseachic Falls National Park in Chihuahua, Mexico show seasonal gastroenteritis problems. This aim of this study was to detect enteropathogenic microorganisms responsible for diarrheal outbreaks in this area. In 2013, 49 surface water samples from 13 selected sampling sites along the Basaseachi waterfall and its main rivers, were collected during the spring, summer, autumn, and winter seasons. Fecal and total coliform counts were determined using standard methods; the AutoScan-4 system was used for identification of isolates and the antibiotic resistance profile by challenging each organism using 21 antibiotics. Significant differences among seasons were detected, where autumn samples resulted in the highest total (p < 0.05 and fecal (p < 0.001 coliform counts, whereas the lowest total coliform counts were recorded in spring. Significant differences between sampling sites were observed, where samples from sites 6, 8, and 11 had the highest total coliform counts (p < 0.009, whereas samples from site 9 exhibited the lowest one. From the microbiological analysis, 33 bacterial isolates from 13 different sites and four sampling seasons were selected; 53% of isolates were resistant to at least one antibiotic, and 15% exhibited a multidrug resistance (MDB phenotype. MDB were identified as Klebsiella oxytoca (two out of four identified isolates, Escherichia coli (2/7, and Enterobacter cloacae (1/3. In addition, some water-borne microorganisms exhibited resistance to cefazoline, cefuroxime, ampicillin, and ampicillin-sulbactam. The presence of these microorganisms near rural settlements suggests that wastewater is the contamination source, providing one possible transmission mechanism for diarrheal outbreaks.

  18. CMOS analog circuit design

    CERN Document Server

    Allen, Phillip E

    1987-01-01

    This text presents the principles and techniques for designing analog circuits to be implemented in a CMOS technology. The level is appropriate for seniors and graduate students familiar with basic electronics, including biasing, modeling, circuit analysis, and some familiarity with frequency response. Students learn the methodology of analog integrated circuit design through a hierarchically-oriented approach to the subject that provides thorough background and practical guidance for designing CMOS analog circuits, including modeling, simulation, and testing. The authors' vast industrial experience and knowledge is reflected in the circuits, techniques, and principles presented. They even identify the many common pitfalls that lie in the path of the beginning designer--expert advice from veteran designers. The text mixes the academic and practical viewpoints in a treatment that is neither superficial nor overly detailed, providing the perfect balance.

  19. Frontopolar cortex mediates abstract integration in analogy.

    Science.gov (United States)

    Green, Adam E; Fugelsang, Jonathan A; Kraemer, David J M; Shamosh, Noah A; Dunbar, Kevin N

    2006-06-22

    Integration of abstractly similar relations during analogical reasoning was investigated using functional magnetic resonance imaging. Activation elicited by an analogical reasoning task that required both complex working memory and integration of abstractly similar relations was compared to activation elicited by a non-analogical task that required complex working memory in the absence of abstract relational integration. A left-sided region of the frontal pole of the brain (BA 9/10) was selectively active for the abstract relational integration component of analogical reasoning. Analogical reasoning also engaged a left-sided network of parieto-frontal regions. Activity in this network during analogical reasoning is hypothesized to reflect categorical alignment of individual component terms that make up analogies. This parieto-frontal network was also engaged by the complex control task, which involved explicit categorization, but not by a simpler control task, which did not involve categorization. We hypothesize that frontopolar cortex mediates abstract relational integration in complex reasoning while parieto-frontal regions mediate working memory processes, including manipulation of terms for the purpose of categorical alignment, that facilitate this integration.

  20. The force of dissimilar analogies in bioethics.

    Science.gov (United States)

    Mertes, Heidi; Pennings, Guido

    2011-04-01

    Although analogical reasoning has long been a popular method of reasoning in bioethics, current literature does not sufficiently grasp its variety. We assert that the main shortcoming is the fact that an analogy's value is often judged on the extent of similarity between the source situation and the target situation, while in (bio)ethics, analogies are often used because of certain dissimilarities rather than in spite of them. We make a clear distinction between dissimilarities that aim to reinforce a similar approach in the source situation and the target situation and dissimilarities that aim to undermine or denounce a similar approach. The former kind of dissimilarity offers the analogy more normative force than if there were no dissimilarities present; this is often overlooked by authors who regard all relevant dissimilarities as detrimental to the analogy's strength. Another observation is that an evaluation of the normative force of an analogy cannot be made independently of moral principles or theories. Without these, one cannot select which elements in an analogy are morally relevant nor determine how they should be interpreted.

  1. Anti-Plasmodium activity of ceramide analogs

    Directory of Open Access Journals (Sweden)

    Gatt Shimon

    2004-12-01

    Full Text Available Abstract Background Sphingolipids are key molecules regulating many essential functions in eukaryotic cells and ceramide plays a central role in sphingolipid metabolism. A sphingolipid metabolism occurs in the intraerythrocytic stages of Plasmodium falciparum and is associated with essential biological processes. It constitutes an attractive and potential target for the development of new antimalarial drugs. Methods The anti-Plasmodium activity of a series of ceramide analogs containing different linkages (amide, methylene or thiourea linkages between the fatty acid part of ceramide and the sphingoid core was investigated in culture and compared to the sphingolipid analog PPMP (d,1-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol. This analog is known to inhibit the parasite sphingomyelin synthase activity and block parasite development by preventing the formation of the tubovesicular network that extends from the parasitophorous vacuole to the red cell membrane and delivers essential extracellular nutrients to the parasite. Results Analogs containing methylene linkage showed a considerably higher anti-Plasmodium activity (IC50 in the low nanomolar range than PPMP and their counterparts with a natural amide linkage (IC50 in the micromolar range. The methylene analogs blocked irreversibly P. falciparum development leading to parasite eradication in contrast to PPMP whose effect is cytostatic. A high sensitivity of action towards the parasite was observed when compared to their effect on the human MRC-5 cell growth. The toxicity towards parasites did not correlate with the inhibition by methylene analogs of the parasite sphingomyelin synthase activity and the tubovesicular network formation, indicating that this enzyme is not their primary target. Conclusions It has been shown that ceramide analogs were potent inhibitors of P. falciparum growth in culture. Interestingly, the nature of the linkage between the fatty acid part and the

  2. The future of vitamin D analogs

    Directory of Open Access Journals (Sweden)

    Carlien eLeyssens

    2014-04-01

    Full Text Available The active form of vitamin D3, 1,25-dihydroxyvitamin D3, is a major regulator of bone and calcium homeostasis. In addition, this hormone also inhibits the proliferation and stimulates the differentiation of normal as well as malignant cells. Supraphysiological doses of 1,25-dihydroxyvitamin D3 are required to reduce cancer cell proliferation. However, these doses will lead in vivo to calcemic side effects such as hypercalcemia and hypercalciuria. During the last 25 years, many structural analogs of 1,25-dihydroxyvitamin D3 have been synthesized by the introduction of chemical modifications in the A-ring, central CD-ring region or side chain of 1,25-dihydroxyvitamin D3 in the hope to find molecules with a clear dissociation between the beneficial antiproliferative effects and adverse calcemic side effects. One example of such an analog with a good dissociation ratio is calcipotriol (DaivonexR, which is clinically used to treat the hyperproliferative skin disease psoriasis. Other vitamin D analogs were clinically approved for the treatment of osteoporosis or secondary hyperparathyroidism. No vitamin D analog is currently used in the clinic for the treatment of cancer although several analogs have been shown to be potent drugs in animal models of cancer. Omics studies as well as in vitro cell biological experiments unraveled basic mechanisms involved in the antineoplastic effects of vitamin D and its analogs. 1,25-dihydroxyvitamin D3 and analogs act in a cell type- and tissue-specific manner. Moreover, a blockade in the transition of the G0/1 towards S phase of the cell cycle, induction of apoptosis, inhibition of migration and invasion of tumor cells together with effects on angiogenesis and inflammation have been implicated in the pleiotropic effects of 1,25-dihydroxyvitamin D3 and its analogs. In this review we will give an overview of the action of vitamin D analogs in tumor cells and look forward how these compounds could be introduced in the

  3. Enhancing programming logic thinking using analogy mapping

    Science.gov (United States)

    Sukamto, R. A.; Megasari, R.

    2018-05-01

    Programming logic thinking is the most important competence for computer science students. However, programming is one of the difficult subject in computer science program. This paper reports our work about enhancing students' programming logic thinking using Analogy Mapping for basic programming subject. Analogy Mapping is a computer application which converts source code into analogies images. This research used time series evaluation and the result showed that Analogy Mapping can enhance students' programming logic thinking.

  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. Gemini analogs of vitamin D.

    Science.gov (United States)

    Pazos, Gonzalo; Rivadulla, Marcos L; Pérez-García, Xenxo; Gandara, Zoila; Pérez, Manuel

    2014-01-01

    The Gemini analogs are the last significant contribution to the family of vitamin D derivatives in medicine, for the treatment of cancer. The first Gemini analog was characterized by two symmetric side chains at C-20. Following numerous modifications, the most active analog bears a C-23-triple bond, C-26, 27- hexafluoro substituents on one side chain and a terminal trideuteromethylhydroxy group on the other side chain. This progression was possible due to improvements in the synthetic methods for the preparation of these derivatives, which allowed for increasing molecular complexity and complete diastereoselective control at C-20 and the substituted sidechains.

  6. Gestión de conocimiento en PyME del sector servicios en la ciudad de Chihuahua

    Directory of Open Access Journals (Sweden)

    María del Carmen Gutiérrez-Diez

    2015-01-01

    Full Text Available La gestión de conocimiento es fundamental en la sobrevivencia de las PyME. Este trabajo describe los resultados, obtenidos hasta mayo del 2013, donde en particular se estudian los procesos de gestión de conocimiento, en treinta PyME del sector de servicios, ubicadas en la ciudad de Chihuahua. Se usó como marco de referencia el modelo de espiral de creación de conocimiento organizacional de Nonaka y Takeuchi., a partir del cual de evaluaron las dimensiones de Socialización, Interiorización, Exteriorización y Combinación. Se desarrolló y aplicó un instrumento, dirigido a los empleadores. Los resultados fueron analizados a través de una estadistica descriptiva, correlacional y regresión lineal. En los resultados obtenidos, se describen los valores asignados por los empleadores a estas diferentes categorías. Se obtuvo que las categorías de Socialización y Combinación muestran aportaciones más bajas, mientras que Exteriorización, Interiorización y Combinación aportan más al proceso de gestión de conocimiento. Lo anterior permite concluir una clara falta de estrategias y procesos que favorezcan la generación del conocimiento organizacional para estas PyME, en particular en las actividades de Socialización y Combinación.

  7. A fast multichannel analog storage system

    International Nuclear Information System (INIS)

    Freytag, D.R.

    1983-01-01

    A Multichannel Analog Storage System based on a commercial 32-channel parallel in/serial out (PISO) analog shift register is described. The basic unit is a single width CAMAC module containing 512 analog cells and the associated logic for data storage and subsequent readout. At sampling rates of up to 30 MHz the signals are strobed directly into the PISO. At higher rates signals are strobed into a fast presampling stage and subsequently transferred in block form into an array of PISO's. Sampling rates of 300 MHz have been achieved with the present device and 1000 MHz are possible with improved signal drivers. The system is well suited for simultaneous handling of many signal channels with moderate numbers of samples in each channel. RMS noise over full scale signal has been measured as 1:3000 (approx. =11 bit). However, nonlinearities in the response and differences in sensitivity of the analog cells require an elaborate calibration system in order to realize 11 bit accuracy for the analog information

  8. 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.

  9. Atheism and Analogy: Aquinas Against the Atheists

    OpenAIRE

    Linford, Daniel J.

    2014-01-01

    In the 13th century, Thomas Aquinas developed two models for how humans may speak of God - either by the analogy of proportion or by the analogy of proportionality. Aquinas's doctrines initiated a theological debate concerning analogy that spanned several centuries. In the 18th century, there appeared two closely related arguments for atheism which both utilized analogy for their own purposes. In this thesis, I show that one argument, articulated by the French materialist Paul-Henri Thiry Bar...

  10. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  11. Scientific Analogies and Their Use in Teaching Science

    Science.gov (United States)

    Kipnis, Nahum

    Analogy in science knew its successes and failures, as illustrated by examples from the eighteenth-century physics. At times, some scientists abstained from using a certain analogy on the ground that it had not yet been demonstrated. Several false discoveries in the 18th and early 19th centuries appeared to support their caution. It is now clear that such a position reflected a methodological confusion that resulted from a failure to distinguish between particular and general analogies. Considering analogy as a hierarchical structure provides a new insight into "testing an analogy". While warning science teachers of dangers associated with use of analogy, historical cases and their analysis provided here may encourage them to use analogy more extensively while avoiding misconceptions. An argument is made that the history of science may be a better guide than philosophy of science and cognitive psychology when it concerns the role of analogy in science and in teaching science for understanding.

  12. Drawing Analogies in Environmental Education

    Science.gov (United States)

    Affifi, Ramsey

    2014-01-01

    Reconsidering the origin, process, and outcomes of analogy-making suggests practices for environmental educators who strive to disengage humans from the isolating illusions of dichotomizing frameworks. We can view analogies as outcomes of developmental processes within which human subjectivity is but an element, threading our sense of self back…

  13. 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…

  14. Conjecturing via Reconceived Classical Analogy

    Science.gov (United States)

    Lee, Kyeong-Hwa; Sriraman, Bharath

    2011-01-01

    Analogical reasoning is believed to be an efficient means of problem solving and construction of knowledge during the search for and the analysis of new mathematical objects. However, there is growing concern that despite everyday usage, learners are unable to transfer analogical reasoning to learning situations. This study aims at facilitating…

  15. 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…

  16. Spectrometric analog-to-digital converter

    International Nuclear Information System (INIS)

    Ormandzhiev, S.I.; Jordanov, V.T.

    1988-01-01

    Converter of digit-by-digit counterbalancing with slipping dial with number of channels equal to total number of states of the main digital-to-analog converter of digit-by-digit counterbalancing systems is presented. Algorithm for selection of digital-to-analog converters, which must be used by means of computer is suggested

  17. Relations as transformations: implications for analogical reasoning.

    Science.gov (United States)

    Leech, Robert; Mareschal, Denis; Cooper, Richard P

    2007-07-01

    We present two experiments assessing whether the size of a transformation instantiating a relation between two states of the world (e.g., shrinks) is a performance factor affecting analogical reasoning. The first experiment finds evidence of transformation size as a significant factor in adolescent analogical problem solving while the second experiment finds a similar effect on adult analogical reasoning using a markedly different analogical completion paradigm. The results are interpreted as providing evidence for the more general framework that cognitive representations of relations are best understood as mental transformations.

  18. Fermilab accelerator control system: Analog monitoring facilities

    International Nuclear Information System (INIS)

    Seino, K.; Anderson, L.; Smedinghoff, J.

    1987-10-01

    Thousands of analog signals are monitored in different areas of the Fermilab accelerator complex. For general purposes, analog signals are sent over coaxial or twinaxial cables with varying lengths, collected at fan-in boxes and digitized with 12 bit multiplexed ADCs. For higher resolution requirements, analog signals are digitized at sources and are serially sent to the control system. This paper surveys ADC subsystems that are used with the accelerator control systems and discusses practical problems and solutions, and it describes how analog data are presented on the console system

  19. 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...

  20. Environmental Impact Analysis Process. Final Environmental Impact Statement. Supersonic Flight Operations in the Reserve Military Operations Area, Holloman, New Mexico

    Science.gov (United States)

    1983-01-01

    Juniper, one-seed Juniperus monosperma Juniper, rocky mountain Juniperus scopulorum Oak, Gambel Querqus gambeli Oak, gray Quercus grisea Oak, silverleaf... Quercus hypoleucoides Pine, Chihuahua (localized) Pinus leiophylla Pine, pinyon Pinus edulis Pine, ponderosa Pinus ponderosa Pine, southwestern white...stansburiana Currant, Golden Ribes aureum Grape, Canyon Vitis Arizonica Groundsel, Ragwort Senecio multicapitatus Morning Glory, Red Starflower Ipomea

  1. Musik som analogi og metafor

    DEFF Research Database (Denmark)

    Bonde, Lars Ole

    2014-01-01

    Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser......Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser...

  2. Non-analog Monte Carlo estimators for radiation momentum deposition

    International Nuclear Information System (INIS)

    Hykes, Joshua M.; Densmore, Jeffery D.

    2009-01-01

    The standard method for calculating radiation momentum deposition in Monte Carlo simulations is the analog estimator, which tallies the change in a particle's momentum at each interaction with the matter. Unfortunately, the analog estimator can suffer from large amounts of statistical error. In this paper, we present three new non-analog techniques for estimating momentum deposition. Specifically, we use absorption, collision, and track-length estimators to evaluate a simple integral expression for momentum deposition that does not contain terms that can cause large amounts of statistical error in the analog scheme. We compare our new non-analog estimators to the analog estimator with a set of test problems that encompass a wide range of material properties and both isotropic and anisotropic scattering. In nearly all cases, the new non-analog estimators outperform the analog estimator. The track-length estimator consistently yields the highest performance gains, improving upon the analog-estimator figure of merit by factors of up to two orders of magnitude.

  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. Analog-to-digital conversion using custom CMOS analog memory for the EOS time projection chamber

    International Nuclear Information System (INIS)

    Lee, K.L.; Arthur, A.A.; Jones, R.W.; Matis, H.S.; Nakamura, M.; Kleinfelder, S.A.; Ritter, H.G.; Wienman, H.H.

    1990-01-01

    This paper describes the multiplexing scheme of custom CMOS analog memory integrated circuits, 16 channels x 256 cells, into analog to digital converters (ADC's) to handle 15,360 signal channels of a time projection, chamber detector system. Primary requirements of this system are high density, low power and large dynamic range. The analog memory device multiplexing scheme was designed to digitize the information stored in the memory cells. The digitization time of the ADC's and the settling times for the memory unit were carefully interleaved to optimize the performance and timing during the multiplexing operation. This kept the total number of ADC's, a costly and power dissipative component, to an acceptable minimum

  5. 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)

  6. NASA HRP Immunology Discipline - Use of Terrestrial Analogs

    Science.gov (United States)

    Crucian, Brian

    2014-01-01

    Due to the cost and operational constraints, as well as technical implementation limitations, it is desirous to perform relevant space physiology investigations first in terrestrial 'space analogs'. This is particularly true for initial investigations, which may then provide appropriate focus for subsequent flight investigations, or for mechanistic investigations that simply cannot be performed during spaceflight. Appropriate analog choice is extremely important. There are a wide variety of terrestrial space analogs, each relevant to a particular physiological discipline (or disciplines) and each with a particular fidelity (or lack thereof) to spaceflight, and each with unique operational constraints. The HRP Immunology Discipline is tasked with managing the HRP Risk concerning clinical risk for Astronaut crews related to spaceflight-associated immune dysregulation. Such dysregulation has been documented to occur during spaceflight, and found to persist for the duration of a 6-month ISS mission. Studies continue to characterize the onorbit phenomenon, but it generally consists of diminished immunocyte function, dysregulated cytokine profiles, and persistent herpesvirus reactivation. Causes are thought to synergistically include microgravity, psychological or physiological stress, radiation, and/or circadian misalignment. An appropriate terrestrial analog for immune dysregulation would replicate as many of these influences as possible. Such analogs may include clinostat or bioreactor cell culture (microgravity), hindlimb suspension (stress, fluid shifts, hypokinesis), or human deployment to remote or extreme environments (isolation, stress, circadian). Also, the laboratory setting may be used as an analog, or to augment analogs, such as sleep deprivation/misalignment or human centrifugation to replicate gravitational stress. As an appropriate example of a NASA Disciplines use of Terrestrial space analogs, this talk will discuss spaceflight associated immune

  7. The Development of Analogical Reasoning Processes.

    Science.gov (United States)

    Sternberg, Robert J.; Rifkin, Bathsheva

    1979-01-01

    Two experiments were conducted to test the generalizability to children of a theory of analogical reasoning processes, originally proposed for adults, and to examine the development of analogical reasoning processes in terms of five proposed sources of cognitive development. (MP)

  8. 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…

  9. Computational approaches to analogical reasoning current trends

    CERN Document Server

    Richard, Gilles

    2014-01-01

    Analogical reasoning is known as a powerful mode for drawing plausible conclusions and solving problems. It has been the topic of a huge number of works by philosophers, anthropologists, linguists, psychologists, and computer scientists. As such, it has been early studied in artificial intelligence, with a particular renewal of interest in the last decade. The present volume provides a structured view of current research trends on computational approaches to analogical reasoning. It starts with an overview of the field, with an extensive bibliography. The 14 collected contributions cover a large scope of issues. First, the use of analogical proportions and analogies is explained and discussed in various natural language processing problems, as well as in automated deduction. Then, different formal frameworks for handling analogies are presented, dealing with case-based reasoning, heuristic-driven theory projection, commonsense reasoning about incomplete rule bases, logical proportions induced by similarity an...

  10. Design and Analysis of Reconfigurable Analog System

    Science.gov (United States)

    2011-02-01

    34010010" �" �" �" �" �" �" �±" N3 N2 N± P1 P2 P3 * Current sources $RR = 1; *Ramp Rate (slope of the...2008/12/12/31e83bac-500f-4182- acca -4d360295fd9c.pdf, Analog Devices, Analog Dialogue 39-06, June 2005. [15] D. A. Johns, K. Martin "Analog Integrated

  11. 78 FR 14983 - Fisheries of the Gulf of Mexico; Gulf of Mexico Fishery Management Council; Public Meeting

    Science.gov (United States)

    2013-03-08

    ... the Gulf of Mexico; Gulf of Mexico Fishery Management Council; Public Meeting AGENCY: National Marine... of Gulf of Mexico Fishery Management Council Spanish Mackerel and Cobia Stock Assessment Review Workshop. SUMMARY: Independent peer review of Gulf of Mexico Spanish Mackerel and Cobia stocks will be...

  12. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Perceptions of Rebuttal Analogy: Politeness and Implications for Persuasion.

    Science.gov (United States)

    Whaley, Bryan B.

    1997-01-01

    States that recent theorizing about the role of analogy in persuasion suggests that "rebuttal" analogy addresses two communicative functions by serving as argument and a method of social attack. Examines message receivers' perceptions of rebuttal analogy and rebuttal analogy users. Finds that participants perceived the communicator using…

  14. Elucidating the neurotoxic effects of MDMA and its analogs.

    Science.gov (United States)

    Karuppagounder, Senthilkumar S; Bhattacharya, Dwipayan; Ahuja, Manuj; Suppiramaniam, Vishnu; Deruiter, Jack; Clark, Randall; Dhanasekaran, Muralikrishnan

    2014-04-17

    There is a rapid increase in the use of methylenedioxymethamphetamine (MDMA) and its structural congeners/analogs globally. MDMA and MDMA-analogs have been synthesized illegally in furtive dwellings and are abused due to its addictive potential. Furthermore, MDMA and MDMA-analogs have shown to have induced several adverse effects. Hence, understanding the mechanisms mediating this neurotoxic insult of MDMA-analogs is of immense importance for the public health in the world. We synthesized and investigated the neurotoxic effects of MDMA and its analogs [4-methylenedioxyamphetamine (MDA), 2, 6-methylenedioxyamphetamine (MDMA), and N-ethyl-3, 4-methylenedioxyamphetamine (MDEA)]. The stimulatory or the dopaminergic agonist effects of MDMA and MDMA-analogs were elucidated using the established 6-hydroxydopamine lesioned animal model. Additionally, we also investigated the neurotoxic mechanisms of MDMA and MDMA-analogs on mitochondrial complex-I activity and reactive oxygen species generation. MDMA and MDMA-analogs exhibited stimulatory activity as compared to amphetamines and also induced several behavioral changes in the rodents. MDMA and MDMA-analogs enhanced the reactive oxygen generation and inhibited mitochondrial complex-I activity which can lead to neurodegeneration. Hence the mechanism of neurotoxicity, MDMA and MDMA-analogs can enhance the release of monoamines, alter the monoaminergic neurotransmission, and augment oxidative stress and mitochondrial abnormalities leading to neurotoxicity. Thus, our study will help in developing effective pharmacological and therapeutic approaches for the treatment of MDMA and MDMA-analog abuse. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Binational Teacher Development: Teacher Ambassador Exchange Program, New Mexico, USA and Nuevo Leon, Mexico.

    Science.gov (United States)

    Habermann, Mary Jean

    The report describes the rationale for and history of an exchange program for Nuevo Leon (Mexico) and New Mexico bilingual education teachers. The program evolved from the need to help Spanish-speaking students maintain their own language and culture while in the United States. New Mexico's state policy concerning language-minority children and…

  16. Calculation of the structural shielding of the radiotherapy treatment room equipped with a linear accelerator type Tomo therapy Hi-Art in the Oncology Center of Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Caballero G, C. A.; Plascencia, J. C.; Vargas V, M. X.; Toledo J, P.

    2010-09-01

    . In this work these specific methodologies are used for the structural shielding calculations of the tomo therapy equipment installed in the Oncology Center of Chihuahua. These calculation methodologies consider the primary radiation, of leakage, disperse, second dispersion and leakage dispersion. The obtained results indicate that due to the lead barrier of the primary beam, the main component that contributes to the shielding requirements of the installation is the leakage radiation. On the other hand, the component that more affects of the door shielding is the dispersion component in the patient. (Author)

  17. Los cambios en la estructura intraurbana de Ciudad Juárez, Chihuahua, de monocéntrica a multicéntrica

    Directory of Open Access Journals (Sweden)

    César M. Flores Fuentes

    2001-01-01

    Full Text Available El artículo tiene como objetivo analizar los cambios en la estructura intraurbana de Ciudad Juárez, Chihuahua, durante el periodo 1989-1993. Para ello se usaron los censos económicos de comercio y servicios de 1989 y 1994, el censo de población de 1990 y el conteo de población de1995, ambos a nivel de AGEB. Lo anterior fue posible mediante la construcción del índice de centralidad. En 1989 la estructura intraurbana de Ciudad Juárez mostró la presencia de dos centros principales. Dichos centros, aunque con la misma jerarquía urbana, tienen distintas funciones, como resultado de contar con ramas económicas que tienen diferentes áreas de mercado, desigual densidad poblacional y distinta capacidad de compra de sus principales consumidores. Para 1994 la ciudad siguió teniendo esos dos centros principales, aunque se crearon tres nuevos subcentros que se localizan fuera de las tradicionales áreas centrales, en zonas de fácil acceso y buena infraestructura. En este contexto, la estructura intraurbana se encuentra en proceso de convertirse de monocéntrica en multicéntrica

  18. Learning Plate Tectonics Using a Pre-Analogy Step

    Science.gov (United States)

    Glesener, G. B.; Sandoval, W. A.

    2011-12-01

    Previous research has shown that children tend to demonstrate lower performance on analogical reasoning tasks at a causal relations level compared to most adults (Gentner & Toupin, 1986). This tendency is an obstacle that geoscience educators must overcome because of the high frequency of analogies used in geoscience pedagogy. In particular, analog models are used to convey complex systems of non-everyday/non-observable events found in nature, such as plate tectonics. Key factors in successful analogical reasoning that have been suggested by researchers include knowledge of the causal relations in the base analog (Brown & Kane, 1988; Gentner, 1988; Gentner & Toupin, 1986), and development of learning strategies and metaconceptual competence(Brown & Kane, 1988). External factors, such as guiding cues and hints have been useful cognitive supports that help students reason through analogical problems (Gick & Holyoak, 1980). Cognitive supports have been seen by researchers to decrease processing demands on retrieval and working memory (Richland, Zur, & Holyoak, 2007). We observed third and fourth graders learning about plate tectonics beginning with a pre-analogy step-a cognitive support activity a student can do before working with an analogy to understand the target. This activity was designed to aid students in developing their understanding of object attributes and relations within an analog model so that more focus can be placed on mapping the corresponding higher-order relations between the base and target. Students learned targeted concepts of plate tectonics, as measured by pre to post gains on items adapted from the Geosciences Concept Inventory. Analyses of classroom interaction showed that students used the object attributes and higher-order relations highlighted in the pre-analogy activity as resources to reason about plate boundaries and plate movement during earthquakes.

  19. 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.

  20. Analogy-Enhanced Instruction: Effects on Reasoning Skills in Science

    Science.gov (United States)

    Remigio, Krisette B.; Yangco, Rosanelia T.; Espinosa, Allen A.

    2014-01-01

    The study examined the reasoning skills of first year high school students after learning general science concepts through analogies. Two intact heterogeneous sections were randomly assigned to Analogy-Enhanced Instruction (AEI) group and Non Analogy-Enhanced (NAEI) group. Various analogies were incorporated in the lessons of the AEI group for…

  1. Epistemology of analogy: Knowledge, society and expression

    Directory of Open Access Journals (Sweden)

    Mauricio Beuchot

    2017-06-01

    Full Text Available In this article we expose the bases of analog epistemology. This theory of knowledge is between an extreme subjectivism and an extreme objectivism. Analog hermeneutics is a realistic hermeneutics. She seeks the truth, but incorporates the meaning and emotion. We have separated the reason from the experience, the praxis theory, the mind or the soul of the body. We have to get them back together, if we do not get lost in the rational (which says little of the human being, or we lose ourselves in the emotional (without logical consistency. The analogical hermeneutic realism is able, thanks to the analogy itself, to mediate in this way of union.

  2. Geospatial analysis of land use and water interaction in the peri-urban area of Cuauhtémoc, Chihuahua. A socio-environmental study in northern Mexico

    Directory of Open Access Journals (Sweden)

    Rolando Enrique Díaz Caravantes

    2013-07-01

    Full Text Available For decades, city growth has been considered only in terms of land availability. In cities of northern Mexico, usually located in arid or semi-arid regions, there is a high dependence on groundwater. For this reason, comprehensive planning urban must consider the peri-urban area not only in terms of soil, but also groundwater. Water transfer for urban use produces severe alterations to the natural environment as aquifer depletion and drastic changes in land use/cover. This paper presents a spatial analysis of land use and water in the peri-urban area of Ciudad Cuauhtémoc. Using geographic modeling and remote sensing we assessed the dynamics of land use/cover. The results indicate that land change processes occur in a context of high competition for water between different users. This process is not usually considered in studies measuring urban spatial expansion, but should be considered to fully understand the effects of urban growth in the territory.

  3. Nopal I uranium deposit: A study of radionuclide migration

    International Nuclear Information System (INIS)

    Wong, V.; Anthony, E.; Goodell, P.

    1996-01-01

    This summary reports on activities of naturally-occurring radionuclides for the Nopal I uranium deposit located in the Pena Blanca Uranium District, Chihuahua, Mexico. Activities were determined using gamma-ray spectroscopy. In addition, data reduction procedures and sample preparation (for Rn retention) will be discussed here. Nopal I uranium deposit has been identified as one of the most promising sites for analogue studies to the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. The objective of this research is to study the potential for radionuclide migration by testing whether any portion of the deposit is in secular equilibrium

  4. RADIONUCLIDE DISPERSION RATES BY AEOLIAN, FLUVIAL, AND POROUS MEDIA TRANSPORT

    International Nuclear Information System (INIS)

    Walton, J.; Goodell, P.; Brashears, C.; French, D.; Kelts, A.

    2005-01-01

    Radionuclide transport was measured from high grade uranium ore boulders near the Nopal I Site, Chihuahua, Mexico. High grade uranium ore boulders were left behind after removal of a uranium ore stockpile at the Prior High Grade Stockpile (PHGS). During the 25 years when the boulder was present, radionuclides were released and transported by sheetflow during precipitation events, wind blown resuspension, and infiltration into the unsaturated zone. In this study, one of the boulders was removed, followed by grid sampling of the surrounding area. Measured gamma radiation levels in three dimensions were used to derive separate dispersion rates by the three transport mechanisms

  5. RADIONUCLIDE DISPERSION RATES BY AEOLIAN, FLUVIAL, AND POROUS MEDIA TRANSPORT

    Energy Technology Data Exchange (ETDEWEB)

    J. Walton; P. Goodell; C. Brashears; D. French; A. Kelts

    2005-07-11

    Radionuclide transport was measured from high grade uranium ore boulders near the Nopal I Site, Chihuahua, Mexico. High grade uranium ore boulders were left behind after removal of a uranium ore stockpile at the Prior High Grade Stockpile (PHGS). During the 25 years when the boulder was present, radionuclides were released and transported by sheetflow during precipitation events, wind blown resuspension, and infiltration into the unsaturated zone. In this study, one of the boulders was removed, followed by grid sampling of the surrounding area. Measured gamma radiation levels in three dimensions were used to derive separate dispersion rates by the three transport mechanisms.

  6. Nopal I uranium deposit: A study of radionuclide migration

    Energy Technology Data Exchange (ETDEWEB)

    Wong, V.; Anthony, E.; Goodell, P. [Univ. of Texas, El Paso, TX (United States)

    1996-12-01

    This summary reports on activities of naturally-occurring radionuclides for the Nopal I uranium deposit located in the Pena Blanca Uranium District, Chihuahua, Mexico. Activities were determined using gamma-ray spectroscopy. In addition, data reduction procedures and sample preparation (for Rn retention) will be discussed here. Nopal I uranium deposit has been identified as one of the most promising sites for analogue studies to the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. The objective of this research is to study the potential for radionuclide migration by testing whether any portion of the deposit is in secular equilibrium.

  7. Analog elements for transuranic chemistries

    International Nuclear Information System (INIS)

    Weimer, W.C.

    1982-01-01

    The analytical technique for measuring trace concentrations of the analog rare earth elements has been refined for optimal detection. The technique has been used to determine the rare earth concentrations in a series of geological and biological materials, including samples harvested from controlled lysimeter investigations. These studies have demonstrated that any of the trivalent rare earth elements may be used as analog elements for the trivalent transuranics, americium and curium

  8. Analogy, explanation, and proof

    Science.gov (United States)

    Hummel, John E.; Licato, John; Bringsjord, Selmer

    2014-01-01

    People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic) whose truth was not even known prior to the existence of the explanation (proof). What do the cognitive operations underlying the inference that the milk is sour have in common with the proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This seemingly small difference poses a challenge to the task of marshaling our understanding of analogical reasoning to understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence. PMID:25414655

  9. Analogy, Explanation, and Proof

    Directory of Open Access Journals (Sweden)

    John eHummel

    2014-11-01

    Full Text Available People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic whose truth was not even known prior to the existence of the explanation (proof. What do the cognitive operations underlying the (inductive inference that the milk is sour have in common with the (deductive proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This small-seeming difference poses a challenge to the task of marshaling our understanding of analogical reasoning in the service of understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence.

  10. Insulin analogs with improved pharmacokinetic profiles.

    Science.gov (United States)

    Brange; Vølund

    1999-02-01

    The aim of insulin replacement therapy is to normalize blood glucose in order to reduce the complications of diabetes. The pharmacokinetics of the traditional insulin preparations, however, do not match the profiles of physiological insulin secretion. The introduction of the rDNA technology 20 years ago opened new ways to create insulin analogs with altered properties. Fast-acting analogs are based on the idea that an insulin with less tendency to self-association than human insulin would be more readily absorbed into the systemic circulation. Protracted-acting analogs have been created to mimic the slow, steady rate of insulin secretion in the fasting state. The present paper provides a historical review of the efforts to change the physicochemical and pharmacological properties of insulin in order to improve insulin therapy. The available clinical studies of the new insulins are surveyed and show, together with modeling results, that new strategies for optimal basal-bolus treatment are required for utilization of the new fast-acting analogs.

  11. 9 CFR 93.427 - Cattle from Mexico.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cattle from Mexico. 93.427 Section 93... CONVEYANCE AND SHIPPING CONTAINERS Ruminants Mexico 10 § 93.427 Cattle from Mexico. (a) Cattle and other ruminants imported from Mexico, except animals being transported in bond for immediate return to Mexico or...

  12. Los pasiegos. La analogía salvaje y lo salvaje de la analogía

    Directory of Open Access Journals (Sweden)

    JAIME DE LA CALLE VALVERDE

    2007-01-01

    -entendiendo salvaje como un pensamiento humano prístino-: por un lado en sus relaciones con el racionalismo (¿emerge la analogía desde el racionalismo?, ¿qué relación guarda con éste?, ¿su nacimiento es resultado de una función «natural»? y por otro sobre la naturaleza social de lo salvaje a partir de las bases sociales que lo producen. Es decir, se rastrea lo que de salvaje tiene la analogía, si la analogía es o no una función ahistórica y asocial del intelecto humano. No se examina todo el complejo analógico de los pasiegos, únicamente aquél que establece relaciones homólogas entre las vacas y el entorno.

  13. How the creative use of analogies can shape medical practice.

    Science.gov (United States)

    Prasad, G V Ramesh

    2015-06-01

    Analogical reasoning is central to medical progress, and is either creative or conservative. According to Hofmann et al., conservative analogy relates concepts from old technology to new technologies with emphasis on preservation of comprehension and conduct. Creative analogy however brings new understanding to new technology, brings similarities existing in the source domain to a target domain where they previously had no bearing, and imports something entirely different from the content of the analogy itself. I defend the claim that while conservative analogies are useful by virtue of being comfortable to use from familiarity and experience, and are more easily accepted by society, they only lead to incremental advances in medicine. However, creative analogies are more exciting and productive because they generate previously unexpected associations across widely separated domains, emphasize relations over physical similarities, and structure over superficiality. I use kidney transplantation and anti-rejection medication development as an exemplar of analogical reasoning used to improve medical practice. Anti-rejection medication has not helped highly sensitized patients because of their propensity to rejecting most organs. I outline how conservative analogical reasoning led to anti-rejection medication development, but creative analogical reasoning helped highly sensitized and blood type incompatible patients through domino transplants, by which they obtain a kidney to which they are not sensitized. Creative analogical reasoning is more likely than conservative analogical reasoning to lead to revolutionary progress. While these analogies overlap and creative analogies eventually become conservative, progress is best facilitated by combining conservative and creative analogical reasoning. © 2015 John Wiley & Sons, Ltd.

  14. 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...

  15. Analogs for transuranic elements

    International Nuclear Information System (INIS)

    Weimer, W.C.; Laul, J.C.; Kutt, J.C.

    1981-01-01

    A combined theoretical and experimental approach is being used to estimate the long-term environmental and biogeochemical behaviors of selected transuranic elements. The objective of this research is to estimate the effect that long-term (hundreds of years) environmental weathering has on the behavior of the transuranic elements americium and curium. This is achieved by investigating the actual behavior of naturally occurring rare earth elements, especially neodymium, that serve as transuranic analogs. Determination of the analog element behavior provides data that can be used to estimate the ultimate availability to man of transuranic materials released into the environment

  16. 23rd workshop on Advances in Analog Circuit Design

    CERN Document Server

    Baschirotto, Andrea; Makinwa, Kofi

    2015-01-01

    This book is based on the 18 tutorials presented during the 23rd workshop on Advances in Analog Circuit Design.  Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, serving as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.    • Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing; • Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; • Presents material in a tutorial-based format.

  17. Bayesian analogy with relational transformations.

    Science.gov (United States)

    Lu, Hongjing; Chen, Dawn; Holyoak, Keith J

    2012-07-01

    How can humans acquire relational representations that enable analogical inference and other forms of high-level reasoning? Using comparative relations as a model domain, we explore the possibility that bottom-up learning mechanisms applied to objects coded as feature vectors can yield representations of relations sufficient to solve analogy problems. We introduce Bayesian analogy with relational transformations (BART) and apply the model to the task of learning first-order comparative relations (e.g., larger, smaller, fiercer, meeker) from a set of animal pairs. Inputs are coded by vectors of continuous-valued features, based either on human magnitude ratings, normed feature ratings (De Deyne et al., 2008), or outputs of the topics model (Griffiths, Steyvers, & Tenenbaum, 2007). Bootstrapping from empirical priors, the model is able to induce first-order relations represented as probabilistic weight distributions, even when given positive examples only. These learned representations allow classification of novel instantiations of the relations and yield a symbolic distance effect of the sort obtained with both humans and other primates. BART then transforms its learned weight distributions by importance-guided mapping, thereby placing distinct dimensions into correspondence. These transformed representations allow BART to reliably solve 4-term analogies (e.g., larger:smaller::fiercer:meeker), a type of reasoning that is arguably specific to humans. Our results provide a proof-of-concept that structured analogies can be solved with representations induced from unstructured feature vectors by mechanisms that operate in a largely bottom-up fashion. We discuss potential implications for algorithmic and neural models of relational thinking, as well as for the evolution of abstract thought. Copyright 2012 APA, all rights reserved.

  18. Analogical reasoning for reliability analysis based on generic data

    Energy Technology Data Exchange (ETDEWEB)

    Kozin, Igor O

    1996-10-01

    The paper suggests using the systemic concept 'analogy' for the foundation of an approach to analyze system reliability on the basis of generic data, describing the method of structuring the set that defines analogical models, an approach of transition from the analogical model to a reliability model and a way of obtaining reliability intervals of analogous objects.

  19. Analogical reasoning for reliability analysis based on generic data

    International Nuclear Information System (INIS)

    Kozin, Igor O.

    1996-01-01

    The paper suggests using the systemic concept 'analogy' for the foundation of an approach to analyze system reliability on the basis of generic data, describing the method of structuring the set that defines analogical models, an approach of transition from the analogical model to a reliability model and a way of obtaining reliability intervals of analogous objects

  20. [Prevalence of irritable bowel syndrome in Veracruz City, Mexico: a community-based survey].

    Science.gov (United States)

    Valerio-Ureña, J; Vásquez-Fernández, F; Jiménez-Pineda, A; Cortázar-Benítez, L F; Azamar-Jácome, A A; Duarte-Velázquez, M E; Torres-Medina, V

    2010-01-01

    Irritable bowel syndrome (IBS) is recognized as the most frequent functional digestive disorder around the world. In Latin America and Mexico there are few studies in order to demonstrate its real prevalence in general population. To determine the prevalence of IBS in general population from Veracruz City Mexico, using the Rome II criteria. Using basic information given by bureau for planning urban services from Veracruz country, a 10% random population sample was obtained. Subjects between 16-80 years old were interviewed using a questionnaire based on Rome II criteria and a visual analogous scale in order to estimate the negative effect of IBS symptoms on daily activities. We interviewed 459 subjects with a median age of 31.2 +/- 13.6 years old detecting 78 subjects (16.9%) with IBS symptoms: 25 males and 53 females (gender prevalence of 11.3% and 22.1%, respectively). 28.2% of them had IBS with diarrhea, 50% had IBS with constipation and 21.8% alternating bowel movements, diarrhea and constipation. Negative effect of IBS symptoms on daily activities was significant. The prevalence of IBS in open population was 16.9% according to Rome II criteria, being higher in those older than 35 years old. Constipation was the predominant pattern. Further studies should evaluate associated factors of these findings.

  1. Analog electronics for radiation detection

    CERN Document Server

    2016-01-01

    Analog Electronics for Radiation Detection showcases the latest advances in readout electronics for particle, or radiation, detectors. Featuring chapters written by international experts in their respective fields, this authoritative text: Defines the main design parameters of front-end circuitry developed in microelectronics technologies Explains the basis for the use of complementary metal oxide semiconductor (CMOS) image sensors for the detection of charged particles and other non-consumer applications Delivers an in-depth review of analog-to-digital converters (ADCs), evaluating the pros and cons of ADCs integrated at the pixel, column, and per-chip levels Describes incremental sigma delta ADCs, time-to-digital converter (TDC) architectures, and digital pulse-processing techniques complementary to analog processing Examines the fundamental parameters and front-end types associated with silicon photomultipliers used for single visible-light photon detection Discusses pixel sensors ...

  2. Evolution of the Late Cretaceous-Paleogene Cordilleran arc magmatism in NW Mexico: a review from updated geochronological studies.

    Science.gov (United States)

    Valencia-Moreno, M.; Iriondo, A.; Perez-Segura, E.; Noguez-Alcantara, B.

    2007-05-01

    During most of the Mesozoic and Cenozoic, the locus of subduction related arc magmatism in northwestern Mexico was relatively mobile, probably due to changes in the mechanical conditions of the Farallon-North America plate convergence. The older Mesozoic events recognized in this region occurred in the Late Triassic and Jurassic, but the associated rocks are poorly preserved. However, a belt of Late Cretaceous through Paleogene magmatic rocks is well exposed along Baja California, Sonora and Sinaloa. Since the late 70's, it was noted that during the Early Cretaceous the igneous activity along this belt remained relatively static in the westernmost part, but migrated eastward in the Late Cretaceous, penetrating more than 1000 km into the continent. The arc magmatism reached western Sonora at about 90 Ma, and then it started to move faster inland, presumably due to flattening of the subducted oceanic slab. Recent U-Pb zircon data revealed unexpected old ages (89-95 Ma) near the eastern edge of Sonora, which are difficult to explain on the basis of the classic tectonic interpretations. A model based on two synchronic sites for magma emplacement may explain the age overlapping observed along the belt; however, a profound re-evaluation a proper geodynamic scenario to support this model is required. Even if restoration of the large Neogene crustal extension is made, particularly for central and northern Sonora, the relatively flat-subduction regime commonly accepted for the Laramide event appears unable to explain the anomalously broad expression of the magmatic belt in northwestern Mexico. An alternative model based on two synchronic sites of magma emplacement, as suggested by the new age data, may better explain the large volume of igneous rocks produced during this time in Sonora and most of Chihuahua. This mechanism may differ southwards in Sinaloa, where the magmatic belt becomes considerably narrower. Moreover, the possible existence of two spatially distinct sites

  3. Analogical Matrices in Young Children and Students with Intellectual Disability: Reasoning by Analogy or Reasoning by Association?

    Science.gov (United States)

    Denaes, Caroline

    2012-01-01

    Background: Analogical reasoning (AR) is renowned for being a complex activity. Young children tend to reason by association, rather by analogy, and people with intellectual disability present problems of memorization. Both these populations usually show low performances in AR. The present author investigated whether familiar material and external…

  4. 76 FR 64248 - Gulf of Mexico Reef Fish Fishery; Closure of the 2011 Gulf of Mexico Commercial Sector for...

    Science.gov (United States)

    2011-10-18

    .... 040205043-4043-01] RIN 0648-XA766 Gulf of Mexico Reef Fish Fishery; Closure of the 2011 Gulf of Mexico... the commercial sector for greater amberjack in the exclusive economic zone (EEZ) of the Gulf of Mexico... Reef Fish Resources of the Gulf of Mexico (FMP). The FMP was prepared by the Gulf of Mexico Fishery...

  5. Severely impaired bone material quality in Chihuahua zebrafish resembles classical dominant human osteogenesis imperfecta.

    Science.gov (United States)

    Fiedler, Imke A K; Schmidt, Felix N; Wölfel, Eva M; Plumeyer, Christine; Milovanovic, Petar; Gioia, Roberta; Tonelli, Francesca; Bale, Hrishikesh A; Jähn, Katharina; Besio, Roberta; Forlino, Antonella; Busse, Björn

    2018-04-17

    Excessive skeletal deformations and brittle fractures in the vast majority of patients suffering from osteogenesis imperfecta (OI) are a result of substantially reduced bone quality. Since the mechanical competence of bone is dependent on the tissue characteristics at small length scales, it is of crucial importance to assess how osteogenesis imperfecta manifests at the micro- and nanoscale of bone. In this context, the Chihuahua (Chi/ +) zebrafish, carrying a heterozygous glycine substitution in the α1 chain of collagen type I, has recently been proposed as suitable animal model of classical dominant OI, showing skeletal deformities, altered mineralization patterns and a smaller body size. This study assessed the bone quality properties of Chi/+ at multiple length scales using micro-computed tomography (micro-CT), histomorphometry, quantitative back-scattered electron imaging, Fourier transform infrared spectroscopy, nanoindentation and X-ray microscopy. At the skeletal level, Chi/+ display smaller body size, deformities and fracture calli in the ribs. Morphological changes at the whole bone level showed that the vertebrae in Chi/+ had a smaller size, smaller thickness and distorted shape. At the tissue level, Chi/+ displayed a higher degree of mineralization, lower collagen maturity, lower mineral maturity, altered osteoblast morphology, and lower osteocyte lacunar density compared to WT. The alterations in the cellular, compositional and structural properties of Chi/+ bones bear an explanation for the impaired local mechanical properties, which promote an increase in overall bone fragility in Chi/ +. The quantitative assessment of bone quality in Chi/+ thus further validates this mutant as an important model reflecting osseous characteristics associated with human classical dominant osteogenesis imperfecta. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  6. Neurotoxic Alkaloids: Saxitoxin and Its Analogs

    Directory of Open Access Journals (Sweden)

    Troco K. Mihali

    2010-07-01

    Full Text Available Saxitoxin (STX and its 57 analogs are a broad group of natural neurotoxic alkaloids, commonly known as the paralytic shellfish toxins (PSTs. PSTs are the causative agents of paralytic shellfish poisoning (PSP and are mostly associated with marine dinoflagellates (eukaryotes and freshwater cyanobacteria (prokaryotes, which form extensive blooms around the world. PST producing dinoflagellates belong to the genera Alexandrium, Gymnodinium and Pyrodinium whilst production has been identified in several cyanobacterial genera including Anabaena, Cylindrospermopsis, Aphanizomenon Planktothrix and Lyngbya. STX and its analogs can be structurally classified into several classes such as non-sulfated, mono-sulfated, di-sulfated, decarbamoylated and the recently discovered hydrophobic analogs—each with varying levels of toxicity. Biotransformation of the PSTs into other PST analogs has been identified within marine invertebrates, humans and bacteria. An improved understanding of PST transformation into less toxic analogs and degradation, both chemically or enzymatically, will be important for the development of methods for the detoxification of contaminated water supplies and of shellfish destined for consumption. Some PSTs also have demonstrated pharmaceutical potential as a long-term anesthetic in the treatment of anal fissures and for chronic tension-type headache. The recent elucidation of the saxitoxin biosynthetic gene cluster in cyanobacteria and the identification of new PST analogs will present opportunities to further explore the pharmaceutical potential of these intriguing alkaloids.

  7. 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...

  8. A hierarchical spatiotemporal analog forecasting model for count data.

    Science.gov (United States)

    McDermott, Patrick L; Wikle, Christopher K; Millspaugh, Joshua

    2018-01-01

    Analog forecasting is a mechanism-free nonlinear method that forecasts a system forward in time by examining how past states deemed similar to the current state moved forward. Previous applications of analog forecasting has been successful at producing robust forecasts for a variety of ecological and physical processes, but it has typically been presented in an empirical or heuristic procedure, rather than as a formal statistical model. The methodology presented here extends the model-based analog method of McDermott and Wikle (Environmetrics, 27, 2016, 70) by placing analog forecasting within a fully hierarchical statistical framework that can accommodate count observations. Using a Bayesian approach, the hierarchical analog model is able to quantify rigorously the uncertainty associated with forecasts. Forecasting waterfowl settling patterns in the northwestern United States and Canada is conducted by applying the hierarchical analog model to a breeding population survey dataset. Sea surface temperature (SST) in the Pacific Ocean is used to help identify potential analogs for the waterfowl settling patterns.

  9. Molecular interactions between (--epigallocatechin gallate analogs and pancreatic lipase.

    Directory of Open Access Journals (Sweden)

    Shihui Wang

    Full Text Available The molecular interactions between pancreatic lipase (PL and four tea polyphenols (EGCG analogs, like (--epigallocatechin gallate (EGCG, (--gallocatechin gallate (GCG, (--epicatechin gallate (ECG, and (--epigallocatechin (EC, were studied from PL activity, conformation, kinetics and thermodynamics. It was observed that EGCG analogs inhibited PL activity, and their inhibitory rates decreased by the order of EGCG>GCG>ECG>EC. PL activity at first decreased rapidly and then slowly with the increase of EGCG analogs concentrations. α-Helix content of PL secondary structure decreased dependent on EGCG analogs concentration by the order of EGCG>GCG>ECG>EC. EGCG, ECG, and EC could quench PL fluorescence both dynamically and statically, while GCG only quenched statically. EGCG analogs would induce PL self-assembly into complexes and the hydrodynamic radii of the complexes possessed a close relationship with the inhibitory rates. Kinetics analysis showed that EGCG analogs non-competitively inhibited PL activity and did not bind to PL catalytic site. DSC measurement revealed that EGCG analogs decreased the transition midpoint temperature of PL enzyme, suggesting that these compounds reduced PL enzyme thermostability. In vitro renaturation through urea solution indicated that interactions between PL and EGCG analogs were weak and non-covalent.

  10. Functional DNA: Teaching Infinite Series through Genetic Analogy

    Science.gov (United States)

    Kowalski, R. Travis

    2011-01-01

    This article presents an extended analogy that connects infinite sequences and series to the science of genetics, by identifying power series as "DNA for a function." This analogy allows standard topics such as convergence tests or Taylor approximations to be recast in a "forensic" light as mathematical analogs of genetic concepts such as DNA…

  11. 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...

  12. Analog techniques in CEBAF's RF control system

    International Nuclear Information System (INIS)

    Hovater, C.; Fugitt, J.

    1989-01-01

    Recent developments in high-speed analog technology have progressed into the areas of traditional RF technology. Diode related devices are being replaced by analog IC's in the CEBAF RF control system. Complex phase modulators and attenuators have been successfully tested at 70 MHz. They have three advantages over existing technology: lower cost, less temperature sensitivity, and more linearity. RF signal conditioning components and how to implement the new analog IC's will be covered in this paper. 4 refs., 5 figs

  13. Analog techniques in CEBAF'S RF control system

    International Nuclear Information System (INIS)

    Hovater, C.; Fugitt, J.

    1989-01-01

    Recent developments in high-speed analog technology have progressed into the areas of traditional rf technology. Diode-related devices are being replaced by analog IC's in the CEBAF rf control system. Complex phase modulators and attenuators have been successfully tested at 70 MHz. They have three advantages over existing technology: lower cost, less temperature sensitivity, and more linearity. Rf signal conditioning components and how to implement the new analog IC's will be covered in this paper. 4 refs., 5 figs

  14. Effect of the temperature on the sorption of cadmium in natural clinoptilolite from the State of Chihuahua; Efecto de la temperatura sobre la sorcion de cadmio en clinoptilolita natural del Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Arambula V, V

    2004-07-01

    The investigation works related with the removal of cadmium of aqueous solutions, they make emphasis in a great number of materials that were used for this end, as well as in the parameters that influence, such as the temperature and the pH. In this work it was investigated the effect of the temperature on the removal of cadmium, using a zeolitic mineral native of the State of Chihuahua for they were determined it kinetic parameters, those diffusivity coefficients and the retention mechanisms (adsorption or ion exchange) involved. The clinoptilolite samples were characterized by means of scanning electron microscopy in high vacuum (MEB), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part consisted on putting in contact solutions of cadmium with the mineral, varying the temperature, the time of contact or the concentration; the quantification of sodium and cadmium in the liquid phase was carried out by means of atomic absorption spectroscopy (EAA). It was determined the time of equilibrium for the removal process. The temperature and the concentration influence on the process of sorption of cadmium in the zeolitic mineral (kinetics and isotherms). The kinetic model that describes better the sorption process of cadmium in the clinoptilolite was the pseudo-2 order. The apparent coefficient of diffusivity presented a greater value conforms to increment the temperature. The results of the isotherm of adsorption of cadmium presented a better adjustment to the Freundlich model. The quantity of cadmium retained by the mineral it was greater than the quantity of sodium found in the solution after the contact between the solution of cadmium and the zeolitic mineral and in accordance with the obtained separation factors, the natural zeolite shows a greater affinity for the cadmium that for the sodium ({alpha} > 1). (Author)

  15. Electric power and environment in Mexico; Energia electrica y medio ambiente en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Quintanilla, J. [ed.] [UNAM IIE-PUE, Ciudad Universitaria (Mexico)

    1997-07-01

    This volume is one of the three resulting volumes about the project named Document analysis and prospective organized by the National Autonomous University of Mexico (UNAM) through it University Energy Program (PUE). It is a non-periodical publication collection of the variable content and extent that as a whole constitutes an information heritage and an original contribution about the energy problematic as International level as at the country context and the University activities. In this book the manners of producing electrical energy are discussed, so how satisfying the growing necessities of this energy in Mexico without contaminating environment and how doing rational and efficient use of energy. The content of each document of this book is however exclusive responsibility of authors, as in the information as in their told opinions. The following papers were presented: 1) Hydroelectricity, soils use and water management. 2) The electric generation in Mexico and its environmental impacts: Past, present and future. 3) The nucleo electricity and the radioactive materials management. 4) Exposure to electromagnetic fields and its association with leukemia in children. 5) The electric power in Mexico and the supportable development. 6) Potential of electric generation at great scale with eolic energy in Mexico. 7) Toward an electric generation scheme distributed with non-conventional energies. 8) Renewable sources of energy in Mexico at the Century 21. (Author)

  16. Benefit of Analog, Programmable and Digital Hearing Aids

    Directory of Open Access Journals (Sweden)

    Jamileh Fatahi

    2006-12-01

    Full Text Available Background and Aims: As the hearing aid technology progressively promotes toward replacing analog hearing aids with digital and programmable ones, comparison of the patient satisfaction of those kinds of hearing aids by means of a valuable tool seems so necessary. So, the aim of this study was to compare self-reported benefit of analog, digitally controlled programmable and digital hearing aids for reducing disability caused by hearing impairment in mild to severe sensorineural hearing impaired persons. Materials and Methods: This cross-sectional study was performed on 90 persons with mild to severe sensorineural hearing loss dividing into three groups: 43 subjects were fitted with digital, 15 with programmable, 32 with analog hearing aids. After pure tone audiometry, Abbreviated profile of hearing aid benefit (APHAB was completed before and one month after using hearing aids to determine the benefit of them. Results: Global APHAB mean scores for digital, programmable and analog hearing aids were 49.05, 33.19 and 39.53, respectively. Ease of Communication subscale mean scores were 53.46 for digitals, 37.66 for programmables and 39.09 for analogs. Background noise subscale mean scores for digital programmable and analog hearing aids were 46.36, 25.53 and 35.31, respectively. Global and also both subscale mean scores showed significant difference between digital hearing aids and programmable and analog ones. There was no significant difference between reverberation subscale mean scores of three groups. Conclusion: It seems digital hearing aids may be more beneficial to reduce disability caused by hearing loss than analog and programmable hearing aids are.

  17. ANALOGICAL REASONING USING TRANSFORMATIONS OF RULES

    OpenAIRE

    Haraguchi, Makoto; 原口, 誠

    1986-01-01

    A formalism of analogical reasoning is presented. The analogical reasoning can be considered as a deduction with a function of transforming logical rules. From this viewpoint, the reasoning is defined in terms of deduction, and is therefore realized in a logic programming system. The reasoning system is described as an extension of Prolog interpreter.

  18. Georeferenced Population Datasets of Mexico (GEO-MEX): Urban Place GIS Coverage of Mexico

    Data.gov (United States)

    National Aeronautics and Space Administration — The Urban Place GIS Coverage of Mexico is a vector based point Geographic Information System (GIS) coverage of 696 urban places in Mexico. Each Urban Place is...

  19. La estructura espacial urbana y accesibilidad diferenciada a centros de empleo en Ciudad Juárez, Chihuahua

    Directory of Open Access Journals (Sweden)

    César M. Fuentes Flores

    2009-01-01

    Full Text Available Existen disparidades intraurbanas en los tiempos de traslado del viaje al trabajo en transporte público y privado, producto de una accesibilidad diferenciada a los centros de empleo en Ciudad Juárez, Chihuahua; el objetivo del artículo es explicarlas. La metodología empleada es el análisis espacial, además se elaboraron cuatro modelos de regresión simple estimados mediante la técnica de mínimos cuadrados ordinarios (MCO. Las variables se construyeron con información de la Encuesta de origen-destino de 1997, el XII Censo general de población y vivienda de 2000 y el XIII Censo económico de 1999, a nivel del área geográfica básica (AGEB. Los resultados de los modelos de regresión indican que el índice de accesibilidad, el balance entre empleos y viviendas, el valor del suelo y las variables aproximadas de uso del suelo (proporción de trabajadores en el sector secundario y terciario muestran efectos estadísticamente significativos al explicar diferencias en los tiempos de traslado al trabajo en transporte público. Así mismo, el índice de accesibilidad, valor del suelo y la proporción de trabajadores en el sector secundario incrementan dichos tiempos en transporte privado. Los resultados tienen implicaciones en términos de políticas de usos del suelo y planeación del transporte.

  20. Josephson junction analog and quasiparticle-pair current

    DEFF Research Database (Denmark)

    Bak, Christen Kjeldahl; Pedersen, Niels Falsig

    1973-01-01

    A close analogy exists between a Josephson junction and a phase-locked loop. A new type of electrical analog based on this principle is presented. It is shown that the inclusion in this analog of a low-pass filter gives rise to a current of the same form as the Josephson quasiparticle-pair current....... A simple picture of the quasiparticle-pair current, which gives the right dependences, is obtained by assuming a junction cutoff frequency to be at the energy gap. ©1973 American Institute of Physics...

  1. Fast parallel-series analog-to-digital converter

    International Nuclear Information System (INIS)

    Pogosov, A.Yu.

    1987-01-01

    Fast analog-to-digital converters are used in systems for detection of rapid processes, nuclear spectroscopy. A 12-digit analog-to-digital converter with conversion time of 160 ns and conversion frequency of 8.3 MHz is described; a segmented digital-to-analog converter with differential non-linearity of < 0.01% and a differential amplifier-limiter with setting time of 80 ns at the error of 0.2% are utilized in the converter; a control device is based on the chain of flip-flop circuit

  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. 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.

  4. CMOS Analog IC Design: Fundamentals

    OpenAIRE

    Bruun, Erik

    2018-01-01

    This book is intended for use as the main textbook for an introductory course in CMOS analog integrated circuit design. It is aimed at electronics engineering students who have followed basic courses in mathematics, physics, circuit theory, electronics and signal processing. It takes the students directly from a basic level to a level where they can start working on simple analog IC design projects or continue their studies using more advanced textbooks in the field. A distinct feature of thi...

  5. Cyclopentanoid analogs of phosphatidylcholine: susceptibility to phospholipase A2.

    Science.gov (United States)

    Lister, M D; Hancock, A J

    1988-10-01

    Six isomers of dipalmitoylcyclopentanetriol phosphocholine (cyclopentano-lecithin) were tested as potential substrates for phospholipase A2. Since each of these analogs possesses a configuration that mimics a narrow range of conformations of a glycerophospholipid molecule, the analogs were used to assess the enzyme's conformational requirements. Studies showed that all of the analogs containing the phosphocholine at the C-1 (or C-3) position could be hydrolyzed, while only one of the three analogs that contains the polar head group at the C-2 position was susceptible. Kinetic studies, however, revealed that only the all-trans-(1,3/2-1P)-cyclopentano-lecithin gave initial rates of hydrolysis that were measurable by pH-stat. Acyl group specificity of the enzyme towards the all-trans isomer was determined with an analog was acyl groups were distinguishable. The synthesis of this mixed-acid-cyclopentano-PC is described herein. When this analog was enzymatically assayed, results unequivocally showed the enzyme to be specific for C-2 acyl hydrolysis. This specificity, and data showing that the all-trans analog is stereospecifically hydrolyzed, indicate that it is acted on in an analogous manner to dipalmitoylphosphatidylcholine. These studies indicate that although the configuration of the analog is not necessarily a prerequisite for hydrolysis, there does appear to be an optimal spatial orientation for enzymatic activity. The analogy between the susceptibilities of all-trans-(1,3/2-1P)-cyclopentano-lecithin and glycero-lecithin suggests that the conformation of the glycero-lecithin during phospholipase A2-mediated hydrolysis may be best simulated by the all-trans orientation of C-O bonds in the artificial substrate.

  6. The environmental policy in Mexico: Crisis and perspectives; La politica ambiental en Mexico: Crisis y perspectivas

    Energy Technology Data Exchange (ETDEWEB)

    Urquidi, Victor [Colegio de Mexico, Mexico, D. F. (Mexico)

    1997-12-31

    In this paper some aspects of the environmental situation in Mexico are condensed. The main roll performed by the modality of the energy resources consumption and the evolution of the environmental policy in Mexico from 1971 to 1996 is analyzed. It is concluded that in Mexico it has not been able to define the environmental policy in all its extension requiring, therefore, a greater participation of all the sectors to protect Nature and fight against the industrial and municipal pollution [Espanol] En esta ponencia se resumen algunos aspectos de la situacion ambiental actual de Mexico. Se analiza el papel central desempenado por la modalidad del consumo de energeticos y la evolucion de la politica ambiental en Mexico desde 1971 hasta 1996. Se concluye en que la politica ambiental en Mexico no se ha podido definir todavia en todos sus alcances por lo que se requiere una mayor participacion de todos los sectores para proteger la naturaleza y combatir la contaminacion industrial y municipal

  7. The environmental policy in Mexico: Crisis and perspectives; La politica ambiental en Mexico: Crisis y perspectivas

    Energy Technology Data Exchange (ETDEWEB)

    Urquidi, Victor [Colegio de Mexico, Mexico, D. F. (Mexico)

    1996-12-31

    In this paper some aspects of the environmental situation in Mexico are condensed. The main roll performed by the modality of the energy resources consumption and the evolution of the environmental policy in Mexico from 1971 to 1996 is analyzed. It is concluded that in Mexico it has not been able to define the environmental policy in all its extension requiring, therefore, a greater participation of all the sectors to protect Nature and fight against the industrial and municipal pollution [Espanol] En esta ponencia se resumen algunos aspectos de la situacion ambiental actual de Mexico. Se analiza el papel central desempenado por la modalidad del consumo de energeticos y la evolucion de la politica ambiental en Mexico desde 1971 hasta 1996. Se concluye en que la politica ambiental en Mexico no se ha podido definir todavia en todos sus alcances por lo que se requiere una mayor participacion de todos los sectores para proteger la naturaleza y combatir la contaminacion industrial y municipal

  8. Analogy, higher order thinking, and education.

    Science.gov (United States)

    Richland, Lindsey Engle; Simms, Nina

    2015-01-01

    Analogical reasoning, the ability to understand phenomena as systems of structured relationships that can be aligned, compared, and mapped together, plays a fundamental role in the technology rich, increasingly globalized educational climate of the 21st century. Flexible, conceptual thinking is prioritized in this view of education, and schools are emphasizing 'higher order thinking', rather than memorization of a cannon of key topics. The lack of a cognitively grounded definition for higher order thinking, however, has led to a field of research and practice with little coherence across domains or connection to the large body of cognitive science research on thinking. We review literature on analogy and disciplinary higher order thinking to propose that relational reasoning can be productively considered the cognitive underpinning of higher order thinking. We highlight the utility of this framework for developing insights into practice through a review of mathematics, science, and history educational contexts. In these disciplines, analogy is essential to developing expert-like disciplinary knowledge in which concepts are understood to be systems of relationships that can be connected and flexibly manipulated. At the same time, analogies in education require explicit support to ensure that learners notice the relevance of relational thinking, have adequate processing resources available to mentally hold and manipulate relations, and are able to recognize both the similarities and differences when drawing analogies between systems of relationships. © 2015 John Wiley & Sons, Ltd.

  9. Analog forecasting with dynamics-adapted kernels

    Science.gov (United States)

    Zhao, Zhizhen; Giannakis, Dimitrios

    2016-09-01

    Analog forecasting is a nonparametric technique introduced by Lorenz in 1969 which predicts the evolution of states of a dynamical system (or observables defined on the states) by following the evolution of the sample in a historical record of observations which most closely resembles the current initial data. Here, we introduce a suite of forecasting methods which improve traditional analog forecasting by combining ideas from kernel methods developed in harmonic analysis and machine learning and state-space reconstruction for dynamical systems. A key ingredient of our approach is to replace single-analog forecasting with weighted ensembles of analogs constructed using local similarity kernels. The kernels used here employ a number of dynamics-dependent features designed to improve forecast skill, including Takens’ delay-coordinate maps (to recover information in the initial data lost through partial observations) and a directional dependence on the dynamical vector field generating the data. Mathematically, our approach is closely related to kernel methods for out-of-sample extension of functions, and we discuss alternative strategies based on the Nyström method and the multiscale Laplacian pyramids technique. We illustrate these techniques in applications to forecasting in a low-order deterministic model for atmospheric dynamics with chaotic metastability, and interannual-scale forecasting in the North Pacific sector of a comprehensive climate model. We find that forecasts based on kernel-weighted ensembles have significantly higher skill than the conventional approach following a single analog.

  10. 77 FR 56168 - Reef Fish Fishery of the Gulf of Mexico; Gulf of Mexico Individual Fishing Quota Programs

    Science.gov (United States)

    2012-09-12

    .... 090206140-91081-03] RIN 0648-XC227 Reef Fish Fishery of the Gulf of Mexico; Gulf of Mexico Individual... red snapper and grouper/tilefish components of the reef fish fishery in the Gulf of Mexico (Gulf), the... INFORMATION: The reef fish fishery of the Gulf of Mexico is managed under the Fishery Management Plan for Reef...

  11. Circuit with a successive approximation analog to digital converter

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2011-01-01

    During successive approximation analog to digital conversion a series of successive digital reference values is selected that converges towards a digital representation of an analog input signal. An analog reference signal is generated dependent on the successive digital reference values and

  12. Circuit with a successive approximation analog to digital converter

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2010-01-01

    During successive approximation analog to digital conversion a series of successive digital reference values is selected that converges towards a digital representation of an analog input signal. An analog reference signal is generated dependent on the successive digital reference values and

  13. 16-channel analog store and multiplexer unit

    Energy Technology Data Exchange (ETDEWEB)

    Brossard, M; Kulka, Z [Clermont-Ferrand-2 Univ., 63 - Aubiere (France). Lab. de Physique Corpusculaire

    1979-03-15

    A 16-channel analog store and multiplexer unit is described. The unit enables storing and selection of analog information which is then digitally encoded by single ADC. This solution becomes economically attractive particularly in multidetector pulse height analysis systems.

  14. [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.

  15. Mexico and the CTBT; Mexico y el CTBT

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre G, J.; Martinez L, J.; Ruiz E, L. J.; Aragon M, I. B., E-mail: jaguirre@cnsns.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Barragan 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

    2013-10-15

    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)

  16. Analogical Reasoning in the Engineering Design Process and Technology Education Applications

    OpenAIRE

    2008-01-01

    This synthesis paper discusses the research exploring analogical reasoning, the role of analogies in the engineering design process, and educational applications for analogical reasoning. Researchers have discovered that analogical reasoning is often a fundamental cognitive tool in design problem solving. Regarding the possible role of analogical reasoning in the context of technology education; analogies may be a useful tool to develop student’s design skills, teach abstract or complex conce...

  17. Geothermal energy from deep sedimentary basins: The Valley of Mexico (Central Mexico)

    Science.gov (United States)

    Lenhardt, Nils; Götz, Annette E.

    2015-04-01

    The geothermal potential of the Valley of Mexico has not been addressed in the past, although volcaniclastic settings in other parts of the world contain promising target reservoir formations. A first assessment of the geothermal potential of the Valley of Mexico is based on thermophysical data gained from outcrop analogues, covering all lithofacies types, and evaluation of groundwater temperature and heat flow values from literature. Furthermore, the volumetric approach of Muffler and Cataldi (1978) leads to a first estimation of ca. 4000 TWh (14.4 EJ) of power generation from Neogene volcanic rocks within the Valley of Mexico. Comparison with data from other sedimentary basins where deep geothermal reservoirs are identified shows the high potential of the Valley of Mexico for future geothermal reservoir utilization. The mainly low permeable lithotypes may be operated as stimulated systems, depending on the fracture porosity in the deeper subsurface. In some areas also auto-convective thermal water circulation might be expected and direct heat use without artificial stimulation becomes reasonable. Thermophysical properties of tuffs and siliciclastic rocks qualify them as promising target horizons (Lenhardt and Götz, 2015). The here presented data serve to identify exploration areas and are valuable attributes for reservoir modelling, contributing to (1) a reliable reservoir prognosis, (2) the decision of potential reservoir stimulation, and (3) the planning of long-term efficient reservoir utilization. References Lenhardt, N., Götz, A.E., 2015. Geothermal reservoir potential of volcaniclastic settings: The Valley of Mexico, Central Mexico. Renewable Energy. [in press] Muffler, P., Cataldi, R., 1978. Methods for regional assessment of geothermal resources. Geothermics, 7, 53-89.

  18. Eye Movements Reveal Optimal Strategies for Analogical Reasoning.

    Science.gov (United States)

    Vendetti, Michael S; Starr, Ariel; Johnson, Elizabeth L; Modavi, Kiana; Bunge, Silvia A

    2017-01-01

    Analogical reasoning refers to the process of drawing inferences on the basis of the relational similarity between two domains. Although this complex cognitive ability has been the focus of inquiry for many years, most models rely on measures that cannot capture individuals' thought processes moment by moment. In the present study, we used participants' eye movements to investigate reasoning strategies in real time while solving visual propositional analogy problems (A:B::C:D). We included both a semantic and a perceptual lure on every trial to determine how these types of distracting information influence reasoning strategies. Participants spent more time fixating the analogy terms and the target relative to the other response choices, and made more saccades between the A and B items than between any other items. Participants' eyes were initially drawn to perceptual lures when looking at response choices, but they nonetheless performed the task accurately. We used participants' gaze sequences to classify each trial as representing one of three classic analogy problem solving strategies and related strategy usage to analogical reasoning performance. A project-first strategy, in which participants first extrapolate the relation between the AB pair and then generalize that relation for the C item, was both the most commonly used strategy as well as the optimal strategy for solving visual analogy problems. These findings provide new insight into the role of strategic processing in analogical problem solving.

  19. Eye Movements Reveal Optimal Strategies for Analogical Reasoning

    Directory of Open Access Journals (Sweden)

    Michael S. Vendetti

    2017-06-01

    Full Text Available Analogical reasoning refers to the process of drawing inferences on the basis of the relational similarity between two domains. Although this complex cognitive ability has been the focus of inquiry for many years, most models rely on measures that cannot capture individuals' thought processes moment by moment. In the present study, we used participants' eye movements to investigate reasoning strategies in real time while solving visual propositional analogy problems (A:B::C:D. We included both a semantic and a perceptual lure on every trial to determine how these types of distracting information influence reasoning strategies. Participants spent more time fixating the analogy terms and the target relative to the other response choices, and made more saccades between the A and B items than between any other items. Participants' eyes were initially drawn to perceptual lures when looking at response choices, but they nonetheless performed the task accurately. We used participants' gaze sequences to classify each trial as representing one of three classic analogy problem solving strategies and related strategy usage to analogical reasoning performance. A project-first strategy, in which participants first extrapolate the relation between the AB pair and then generalize that relation for the C item, was both the most commonly used strategy as well as the optimal strategy for solving visual analogy problems. These findings provide new insight into the role of strategic processing in analogical problem solving.

  20. An Analog Computer for Electronic Engineering Education

    Science.gov (United States)

    Fitch, A. L.; Iu, H. H. C.; Lu, D. D. C.

    2011-01-01

    This paper describes a compact analog computer and proposes its use in electronic engineering teaching laboratories to develop student understanding of applications in analog electronics, electronic components, engineering mathematics, control engineering, safe laboratory and workshop practices, circuit construction, testing, and maintenance. The…

  1. The interplay of conflict and analogy in multidisciplinary teams.

    Science.gov (United States)

    Paletz, Susannah B F; Schunn, Christian D; Kim, Kevin H

    2013-01-01

    Creative teamwork in multidisciplinary teams is a topic of interest to cognitive psychologists on the one hand, and to both social and organizational psychologists on the other. However, the interconnections between cognitive and social layers have been rarely explored. Drawing on mental models and dissonance theories, the current study takes a central variable studied by cognitive psychologists-analogy-and examines its relationship to a central variable examined by social psychologists-conflict. In an observational, field study, over 11h of audio-video data from conversations of the Mars Exploration Rover scientists were coded for different types of analogy and micro-conflicts that reveal the character of underlying psychological mechanisms. Two different types of time-lagged logistic models applied to these data revealed asymmetric patterns of associations between analogy and conflict. Within-domain analogies, but not within-discipline or outside-discipline analogies, preceded science and work process conflicts, suggesting that in multidisciplinary teams, representational gaps in very close domains will be more likely to spark conflict. But analogies also occurred in reaction to conflict: Process and negative conflicts, but not task conflicts, preceded within-discipline analogies, but not to within-domain or outside-discipline analogies. This study demonstrates ways in which cognition can be bidirectionally tied to social processes and discourse. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. 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

  3. Fluorinated analogs of malachite green: synthesis and toxicity.

    Science.gov (United States)

    Kraus, George A; Jeon, Insik; Nilsen-Hamilton, Marit; Awad, Ahmed M; Banerjee, Jayeeta; Parvin, Bahram

    2008-04-27

    A series of fluorinated analogs of malachite green (MG) have been synthesized and their toxicity to Saccharomyces cerevisiae and a human ovarian epithelial cell line examined. The toxicity profiles were found to be different for these two species. Two analogs, one with 2,4-difluoro substitution and the other with 2-fluoro substitution seem to be the most promising analogs because they showed the lowest toxicity to the human cells.

  4. Analogies between classical statistical mechanics and quantum mechanics

    International Nuclear Information System (INIS)

    Uehara, M.

    1986-01-01

    Some analogies between nonequilibrium classical statistical mechanics and quantum mechanics, at the level of the Liouville equation and at the kinetic level, are commented on. A theorem, related to the Vlasov equation applied to a plasma, is proved. The theorem presents an analogy with Ehrenfest's theorem of quantum mechanics. An analogy between the plasma kinetic theory and Bohm's quantum theory with 'hidden variables' is also shown. (Author) [pt

  5. Pulmonary effects of active smoking and secondhand smoke exposure among adolescent students in Juárez, Mexico

    Directory of Open Access Journals (Sweden)

    Bird Y

    2016-06-01

    Full Text Available Yelena Bird,1 Hugo Staines-Orozco2 1School of Public Health, University of Saskatchewan, Saskatoon, SK, Canada; 2Institute of Biomedical Sciences, Universidad Autónoma de Ciudad Juárez, Anillo Envolvente del PRONAF y Calle Estocolmo, Ciudad Juárez, Chihuahua, Mexico Background: Youth smoking trends among Latin American countries, including Mexico, are on the rise. Notably, although the high prevalence of smoking in teens has been well documented in the literature, few studies have evaluated the impact of smoking and secondhand smoke (SHS exposure on their respiratory system.  Objective: To investigate the effects of smoking and SHS exposure on the respiratory health and lung function among eighth-grade students in Juárez, Mexico. Methods: A cross-sectional study was undertaken on a sample of convenience. The study outcomes centered on evaluating 300 students’ lung function by spirometry (forced expiratory volume in 1 second [FEV1], forced expiratory volume in 1 second/forced vital capacity ratio [FEV1/FVC], and forced mid-expiratory flow rate [FEF25%–75%] and their respiratory health (smoking behavior and SHS exposure by their self-reported responses to a standardized respiratory questionnaire. The study outcomes were compared among three distinct groups: 1 nonsmokers/nonexposed to SHS; 2 nonsmokers/exposed to SHS; and 3 smokers. Results: The majority of the study participants were 14 years old (85%, females (54%, who attended eighth grade in a public school setting (56%. Approximately, half reported being of low socioeconomic status (49% and nonsmokers/exposed to SHS (49%. The lung function parameters of smokers were found to be lower (FEV1 =62.88±10.25; FEV1/FVC =83.50±14.15; and FEF25%–75% =66.35±12.55 than those recorded for the nonsmokers/exposed to SHS (FEV1 =69.41±11.35; FEV1/FVC =88.75±15.75; and FEF25%–75% =78.90±14.65 and significantly reduced when compared to the nonsmokers/nonexposed to SHS (FEV1 =79.14±13

  6. Tracking cognitive phases in analogical reasoning with event-related potentials.

    Science.gov (United States)

    Maguire, Mandy J; McClelland, M Michelle; Donovan, Colin M; Tillman, Gail D; Krawczyk, Daniel C

    2012-03-01

    Analogical reasoning consists of multiple phases. Four-term analogies (A:B::C:D) have an encoding period in which the A:B pair is evaluated prior to a mapping phase. The electrophysiological timing associated with analogical reasoning has remained unclear. We used event-related potentials to identify neural timing related to analogical reasoning relative to perceptual and semantic control conditions. Spatiotemporal principal-components analyses revealed differences primarily in left frontal electrodes during encoding and mapping phases of analogies relative to the other conditions. The timing of the activity differed depending upon the phase of the problem. During the encoding of A:B terms, analogies elicited a positive deflection compared to the control conditions between 400 and 1,200 ms, but for the mapping phase analogical processing elicited a negative deflection that occurred earlier and for a shorter time period, between 350 and 625 ms. These results provide neural and behavioral evidence that 4-term analogy problems involve a highly active evaluation phase of the A:B pair. 2012 APA, all rights reserved

  7. Subsidence Induced Faulting Hazard risk maps in Mexico City and Morelia, central Mexico

    Science.gov (United States)

    Cabral-Cano, E.; Solano-Rojas, D.; Hernández-Espriu, J.; Cigna, F.; Wdowinski, S.; Osmanoglu, B.; Falorni, G.; Bohane, A.; Colombo, D.

    2012-12-01

    Subsidence and surface faulting have affected urban areas in Central Mexico for decades and the process has intensified as a consequence of urban sprawl and economic growth. This process causes substantial damages to the urban infrastructure and housing structures and in several cities it is becoming a major factor to be considered when planning urban development, land use zoning and hazard mitigation strategies in the next decades. Subsidence is usually associated with aggressive groundwater extraction rates and a general decrease of aquifer static level that promotes soil consolidation, deformation and ultimately, surface faulting. However, local stratigraphic and structural conditions also play an important role in the development and extension of faults. Despite its potential for damaging housing, and other urban infrastructure, the economic impact of this phenomena is poorly known, in part because detailed, city-wide subsidence induced faulting risk maps have not been published before. Nevertheless, modern remote sensing techniques are most suitable for this task. We present the results of a risk analysis for subsidence induced surface faulting in two cities in central Mexico: Morelia and Mexico City. Our analysis in Mexico City and Morelia is based on a risk matrix using the horizontal subsidence gradient from a Persistent Scatterer InSAR (Morelia) and SqueeSAR (Mexico City) analysis and 2010 census population distribution data from Mexico's National Institute of Statistics and Geography. Defining subsidence induced surface faulting vulnerability within these urbanized areas is best determined using both magnitude and horizontal subsidence gradient. Our Morelia analysis (597,000 inhabitants with localized subsidence rates up to 80 mm/yr) shows that 7% of the urbanized area is under a high to very high risk level, and 14% of its population (11.7% and 2.3% respectively) lives within these areas. In the case of the Mexico City (15'490,000 inhabitants for the

  8. High-frequency analog integrated circuit design

    CERN Document Server

    1995-01-01

    To learn more about designing analog integrated circuits (ICs) at microwave frequencies using GaAs materials, turn to this text and reference. It addresses GaAs MESFET-based IC processing. Describes the newfound ability to apply silicon analog design techniques to reliable GaAs materials and devices which, until now, was only available through technical papers scattered throughout hundred of articles in dozens of professional journals.

  9. HAPS, a Handy Analog Programming System

    DEFF Research Database (Denmark)

    Højberg, Kristian Søe

    1975-01-01

    HAPS (Hybrid Analog Programming System) is an analog compiler that can be run on a minicomputer in an interactive mode. Essentially HAPS is written in FORTRAN. The equations to be programmed for an ana log computer are read in by using a FORTRAN-like notation. The input must contain maximum...... and emphasizes the limitations HAPS puts on equation structure, types of computing circuit, scaling, and static testing....

  10. The use of analogy in pro-life argumentation

    Directory of Open Access Journals (Sweden)

    Simona Mazilu

    2012-11-01

    Full Text Available The paper is concerned with how analogy is strategically used in pro-life argumentation on abortion. Pragma-dialectics (van Eemeren and Grootendorst 1992 offers a set of critical questions by means of which I will evaluate the use of the argumentation based on a relation of analogy in terms of dialectical soundness. Examining various pro-life texts, I have noticed that the analogies employed remain unexplained. Therefore, despite the apparent similarities between abortion and the German holocaust or slavery, for instance, there are essential differences which are not mentioned. I claim that these analogies mainly have a rhetorical function, to operate what has been called by Micheli (2007: 960 “a transfer of emotional consensus”.

  11. Patterns of Analogical Reasoning among Beginning Readers

    Science.gov (United States)

    Farrington-Flint, Lee; Wood, Clare; Canobi, Katherine H.; Faulkner, Dorothy

    2004-01-01

    Despite compelling evidence that analogy skills are available to beginning readers, few studies have actually explored the possibility of identifying individual differences in young children's analogy skills in early reading. The present study examined individual differences in children's use of orthographic and phonological relations between…

  12. 9 CFR 93.325 - Horses from Mexico.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Horses from Mexico. 93.325 Section 93... CONVEYANCE AND SHIPPING CONTAINERS Horses Mexico 18 § 93.325 Horses from Mexico. Horses offered for entry from Mexico shall be inspected as provided in §§ 93.306 and 93.323; shall be accompanied by a...

  13. Single-event transients (SET) in analog circuits

    International Nuclear Information System (INIS)

    Chen Panxun; Zhou Kaiming

    2006-01-01

    A new phenomenon of single- event upset is introduced. The transient signal is produced in the output of analog circuits after a heavy ion strikes. The transient upset can influence the circuit connected with the output of analog circuits. For example, the output of operational amplifier can be connected with the input of a digital counter, and the pulse of sufficiently high transient output induced by an ion can increase counts of the counter. On the other hand, the transient voltage signal at the output of analog circuits can change the stage of other circuits. (authors)

  14. An analog silicon retina with multichip configuration.

    Science.gov (United States)

    Kameda, Seiji; Yagi, Tetsuya

    2006-01-01

    The neuromorphic silicon retina is a novel analog very large scale integrated circuit that emulates the structure and the function of the retinal neuronal circuit. We fabricated a neuromorphic silicon retina, in which sample/hold circuits were embedded to generate fluctuation-suppressed outputs in the previous study [1]. The applications of this silicon retina, however, are limited because of a low spatial resolution and computational variability. In this paper, we have fabricated a multichip silicon retina in which the functional network circuits are divided into two chips: the photoreceptor network chip (P chip) and the horizontal cell network chip (H chip). The output images of the P chip are transferred to the H chip with analog voltages through the line-parallel transfer bus. The sample/hold circuits embedded in the P and H chips compensate for the pattern noise generated on the circuits, including the analog communication pathway. Using the multichip silicon retina together with an off-chip differential amplifier, spatial filtering of the image with an odd- and an even-symmetric orientation selective receptive fields was carried out in real time. The analog data transfer method in the present multichip silicon retina is useful to design analog neuromorphic multichip systems that mimic the hierarchical structure of neuronal networks in the visual system.

  15. 7 CFR 319.8-13 - From Northwest Mexico.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false From Northwest Mexico. 319.8-13 Section 319.8-13... for the Entry of Cotton and Covers from Mexico § 319.8-13 From Northwest Mexico. Contingent upon continued freedom of Northwest Mexico and of the West Coast of Mexico from infestations of the pink bollworm...

  16. Reynolds analogy for the Rayleigh problem at various flow modes.

    Science.gov (United States)

    Abramov, A A; Butkovskii, A V

    2016-07-01

    The Reynolds analogy and the extended Reynolds analogy for the Rayleigh problem are considered. For a viscous incompressible fluid we derive the Reynolds analogy as a function of the Prandtl number and the Eckert number. We show that for any positive Eckert number, the Reynolds analogy as a function of the Prandtl number has a maximum. For a monatomic gas in the transitional flow regime, using the direct simulation Monte Carlo method, we investigate the extended Reynolds analogy, i.e., the relation between the shear stress and the energy flux transferred to the boundary surface, at different velocities and temperatures. We find that the extended Reynolds analogy for a rarefied monatomic gas flow with the temperature of the undisturbed gas equal to the surface temperature depends weakly on time and is close to 0.5. We show that at any fixed dimensionless time the extended Reynolds analogy depends on the plate velocity and temperature and undisturbed gas temperature mainly via the Eckert number. For Eckert numbers of the order of unity or less we generalize an extended Reynolds analogy. The generalized Reynolds analogy depends mainly only on dimensionless time for all considered Eckert numbers of the order of unity or less.

  17. Two analogy strategies: the cases of mind metaphors and introspection

    Science.gov (United States)

    Fischer, Eugen

    2018-04-01

    Analogical reasoning is often employed in problem-solving and metaphor interpretation. This paper submits that, as a default, analogical reasoning addressing these different tasks employs different mapping strategies. In problem-solving, it employs analogy-maximising strategies (like structure mapping, Gentner, D., & Markman, A. B. (1997). Structure mapping in analogy and similarity. American Psychologist, 52, 45-56); in metaphor interpretation, analogy-minimising strategies (like ATT-Meta, Barnden, J. A. (2015). Open-ended elaborations in creative metaphor. In T. R. Besold, M. Schorlemmer, & A. Smaill (Eds.), Computational creativity research: Towards creative machines (pp. 217-242). Berlin: Springer). The two strategies interact in analogical reasoning with conceptual metaphors. This interaction leads to predictable fallacies. The paper supports these hypotheses through case-studies on "mind" metaphors from ordinary discourse, and abstract problem-solving in the philosophy of mind, respectively. It shows that (1) default metaphorical interpretations for vision- and space-cognition metaphors can be derived with a variant of the analogy-minimising ATT-Meta approach, (2) philosophically influential introspective conceptions of the mind can be derived with conceptual metaphors only through an analogy-maximising strategy, and (3) the interaction of these strategies leads to hitherto unrecognised fallacies in analogical reasoning with metaphors. This yields a debunking explanation of introspective conceptions.

  18. 25th workshop on Advances in Analog Circuit Design

    CERN Document Server

    Harpe, Pieter; Makinwa, Kofi

    2017-01-01

    This book is based on the 18 tutorials presented during the 25th workshop on Advances in Analog Circuit Design. Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, including low-power and energy-efficient analog electronics, with specific contributions focusing on the design of continuous-time sigma-delta modulators, automotive electronics, and power management. This book serves as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.

  19. Is the Link from Working Memory to Analogy Causal? No Analogy Improvements following Working Memory Training Gains

    OpenAIRE

    Richey, J. Elizabeth; Phillips, Jeffrey S.; Schunn, Christian D.; Schneider, Walter

    2014-01-01

    Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data [1], but less work has tested this relationship through experimental manipulation [2]. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working mem...

  20. Selective termination, fetal reduction and analogical reasoning.

    Science.gov (United States)

    Pennings, G

    2013-06-01

    Analogical reasoning is a basic method in bioethics. Its main purpose is to transfer the rule from an existing or known situation to a new and problematic situation. This commentary applies the lifeboat analogy to the context of selective termination and fetal reduction. It turns out that the analogy is only partially helpful as the main principle in the case of selective termination is the procreative beneficence principle. However, the wide person-affecting form of this principle doubly justifies selective termination: i.e. one prevents the harm caused by the birth of an affected child and one increases the life chances of the remaining fetuses. I conclude, however, that all analogies are basically flawed since they assume that fetuses as such have interests. I argue that fetuses only have interests to the extent that they are potential future persons. Copyright © 2013 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  1. Epithermal uranium deposits in a volcanogenic context: the example of Nopal 1 deposit, Sierra de Pena Blanca, Mexico

    Science.gov (United States)

    Calas, G.; Angiboust, S.; Fayek, M.; Camacho, A.; Allard, T.; Agrinier, P.

    2009-12-01

    The Peña Blanca molybdenum-uranium field (Chihuahua, Mexico) exhibits over 100 airborne anomalies hosted in tertiary ignimbritic ash-flow tuffs (44 Ma) overlying the Pozos conglomerate and a sequence of Cretaceous carbonate rocks. Uranium occurrences are associated with breccia zones at the intersection of two or more fault systems. Periodic reactivation of these structures associated with Basin and Range and Rio Grande tectonic events resulted in the mobilization of U and other elements by meteoric fluids heated by geothermal activity. Trace element geochemistry (U, Th, REE) provides evidence for local mobilization of uranium under oxidizing conditions. In addition, O- and H-isotope geochemistry of kaolinite, smectite, opal and calcite suggests that argillic alteration proceeded at shallow depth with meteoric water at 25-75 °C. Focussed along breccia zones, fluids precipitated several generations of pyrite and uraninite together with kaolinite, as in the Nopal 1 mine, indicating that mineralization and hydrothermal alteration of volcanic tuffs are contemporaneous. Low δ34S values (~ -24.5 ‰) of pyrites intimately associated with uraninite suggest that the reducing conditions at the origin of the U-mineralization arise from biological activity. Later, the uplift of Sierra Pena Blanca resulted in oxidation and remobilization of uranium, as confirmed by the spatial distribution of radiation-induced defect centers in kaolinites. These data show that tectonism and biogenic reducing conditions can play a major role in the formation and remobilization of uranium in epithermal deposits. By comparison with the other uranium deposits at Sierra Pena Blanca and nearby Sierra de Gomez, Nopal 1 deposit is one of the few deposits having retained a reduced uranium mineralization.

  2. The design analogy : a model for moral problem solving

    NARCIS (Netherlands)

    Dorst, C.H.; Royakkers, L.M.M.

    2006-01-01

    In this paper we explore an analogy between design and ethics, first drawn by Whitbeck. We investigate her claim that such an analogy can help to understand moral problems and aid us in dealing with them by suggesting strategies for addressing moral problems. We explore the nature of analogies, and

  3. 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.

  4. Baccharis Salicifolia development in the presence of high concentrations of uranium in the arid environment of San Marcos, Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Luna P, M. Y.; Alarcon H, M. T.; Silva S, M.; Renteria V, M; Rodriguez V, M. A.; Herrera P, E.; Reyes C, M.; Montero C, M. E., E-mail: elena.montero@cimav.edu.m [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, 31109 Chihuahua (Mexico)

    2011-02-15

    In humid zones and marine environments the bio indicator contaminants by trace elements are well established. However, in arid zones it is more difficult to find these tools because there is less biodiversity. The objective of this paper was to analyze the behavior of the Baccharis salicifolia plant in areas with high uranium concentration in arid zones, to determine the characteristics of tolerance and possible use as a bio monitor for the presence of such contaminants. For this project a uraniferous zone was selected in San Marcos, located northwest of the City of Chihuahua. A total of 8 sampling points of the plant and soil were located here. Each sample was divided into the root and the stem and leaves to determine the specific activity of the uranium in both parts of the plant and its sediments. The determination of the specific activities of the total uranium in the samples was obtained by liquid scintillation with alpha-beta separation. The results indicate a tendency for the plant to accumulate the uranium in its different parts, and to trans locate it to its stem and leaves. The plant is resistant to high concentrations of uranium, not showing any specific changes in relation to non contaminated areas that might indicate the presence of the contaminant. Therefore, its use as a bio monitor species is limited. (Author)

  5. Baccharis Salicifolia development in the presence of high concentrations of uranium in the arid environment of San Marcos, Chihuahua

    International Nuclear Information System (INIS)

    Luna P, M. Y.; Alarcon H, M. T.; Silva S, M.; Renteria V, M; Rodriguez V, M. A.; Herrera P, E.; Reyes C, M.; Montero C, M. E.

    2011-01-01

    In humid zones and marine environments the bio indicator contaminants by trace elements are well established. However, in arid zones it is more difficult to find these tools because there is less biodiversity. The objective of this paper was to analyze the behavior of the Baccharis salicifolia plant in areas with high uranium concentration in arid zones, to determine the characteristics of tolerance and possible use as a bio monitor for the presence of such contaminants. For this project a uraniferous zone was selected in San Marcos, located northwest of the City of Chihuahua. A total of 8 sampling points of the plant and soil were located here. Each sample was divided into the root and the stem and leaves to determine the specific activity of the uranium in both parts of the plant and its sediments. The determination of the specific activities of the total uranium in the samples was obtained by liquid scintillation with alpha-beta separation. The results indicate a tendency for the plant to accumulate the uranium in its different parts, and to trans locate it to its stem and leaves. The plant is resistant to high concentrations of uranium, not showing any specific changes in relation to non contaminated areas that might indicate the presence of the contaminant. Therefore, its use as a bio monitor species is limited. (Author)

  6. 9 CFR 94.15 - Animal products and materials; movement and handling.

    Science.gov (United States)

    2010-01-01

    ... California, Baja California Sur, Campeche, Chihuahua, Coahuila, Nuevo Leon, Quintana Roo, Sinaloa, Sonora... Inspección Federal plant in Baja California, Baja California Sur, Campeche, Chihuahua, Coahuila, Nuevo Leon...) from Baja California, Baja California Sur, Campeche, Chihuahua, Nuevo Leon, Quintana Roo, Sinaloa...

  7. Yes… Mexico is a racist country

    DEFF Research Database (Denmark)

    Carrales, Juan Carlos Finck

    2017-01-01

    According to recent official statistics, in Mexico there is a relation between people’s privileges and their skin color: The lighter, the more privilege. However, social exclusion by racist practices in Mexico has been common practically since its Spanish conquest between 1519 and 1521, in which...... privileges where absorbed and monopolized by European settlers in Mexico (Spanish people: peninsulares) and their descendants (creole: criollos). As a consequence, currently in Mexico, the color of skin affects people’s economic and political privileges and powers in individual and social levels related...

  8. Wafer-level chip-scale packaging analog and power semiconductor applications

    CERN Document Server

    Qu, Shichun

    2015-01-01

    This book presents a state-of-art and in-depth overview in analog and power WLCSP design, material characterization, reliability, and modeling. Recent advances in analog and power electronic WLCSP packaging are presented based on the development of analog technology and power device integration. The book covers in detail how advances in semiconductor content, analog and power advanced WLCSP design, assembly, materials, and reliability have co-enabled significant advances in fan-in and fan-out with redistributed layer (RDL) of analog and power device capability during recent years. Along with new analog and power WLCSP development, the role of modeling is a key to assure successful package design. An overview of the analog and power WLCSP modeling and typical thermal, electrical, and stress modeling methodologies is also provided. This book also: ·         Covers the development of wafer-level power discrete packaging with regular wafer-level design concepts and directly bumping technology ·    �...

  9. Modern Communication: Exploring Physiological Transmission through Tech-Savvy Analogies

    Science.gov (United States)

    Hollabaugh, Christopher R.; Milanick, Mark A.

    2014-01-01

    Analogies are often helpful for students to grasp key physiological concepts; sometimes the technical jargon makes the concept seem more complex than it actually is. In this article the authors provide several analogies for information transfer processes that sometimes confuse students. For an analogy to be useful, of course, it needs to be…

  10. AnalogRF and mixed-signal circuit systematic design

    CERN Document Server

    Tlelo-Cuautle, Esteban; Castro-Lopez, Rafael

    2013-01-01

    Despite the fact that in the digital domain, designers can take full benefits of IPs and design automation tools to synthesize and design very complex systems, the analog designers’ task is still considered as a ‘handcraft’, cumbersome and very time consuming process. Thus, tremendous efforts are being deployed  to develop new design methodologies in the analog/RF and mixed-signal domains. This book collects 16 state-of-the-art contributions devoted to the topic of systematic design of analog, RF and mixed signal circuits. Divided in the two parts Methodologies and Techniques recent theories, synthesis techniques and design methodologies, as well as new sizing approaches in the field of robust analog and mixed signal design automation are presented for researchers and R/D engineers.  

  11. Proportional and functional analogical reasoning in normal and language-impaired children.

    Science.gov (United States)

    Nippold, M A; Erskine, B J; Freed, D B

    1988-11-01

    Teachers often use analogies in classroom settings to clarify new concepts for their students. However, analogies may inadvertently confuse the youngster who has difficulty identifying the one-to-one comparisons underlying them. Although analogical reasoning has been studied extensively in normal children, no information was available concerning this construct in children having a specific language impairment. Thus, it was unknown to what extent they might be deficient in analogical reasoning. Therefore, in the present study, 20 children ages 6-8 years (mean age = 7:6) having normal nonverbal intelligence but deficits in language comprehension were administered tasks of verbal and perceptual proportional analogical reasoning and a problem-solving task of functional analogical reasoning. Compared to a normal-language control group matched on the basis of chronological age and sex, the language-impaired group was deficient in all three tasks of analogical reasoning. However, when the factor of nonverbal intelligence was controlled statistically, the differences between the groups on each of the tasks were removed. Additional findings were that verbal proportional analogical reasoning was significantly correlated to perceptual proportional analogical reasoning and to functional analogical reasoning. Implications for assessment and intervention with young school-age language-impaired children are discussed.

  12. Analogical reasoning and aging: the processing speed and inhibition hypothesis.

    Science.gov (United States)

    Bugaiska, Aurélia; Thibaut, Jean-Pierre

    2015-01-01

    This study was designed to investigate the effect of aging on analogical reasoning by manipulating the strength of semantic association (LowAssoc or HighAssoc) and the number of distracters' semantic analogies of the A:B::C:D type and to determine which factors might be responsible for the age-related differences on analogical reasoning by testing two different theoretical frameworks: the inhibition hypothesis and the speed mediation hypothesis. We compared young adults and two groups of aging people (old and old-old) with word analogies of the A:B::C:D format. Results indicate an age-related effect on analogical reasoning, this effect being greatest with LowAssoc analogies. It was not associated with the presence of semantic distractors. Moreover, the results show that the variance part of the analogy task due to age was mainly explained by processing speed (rather than by inhibition) in the case of old participants and by both processing speed and inhibition in the old-old group. These results are discussed in relation to current models of aging and their interaction with the processes involved in analogical reasoning.

  13. Analogy as a means of theoretical adoption of pedagogical disciplines

    Directory of Open Access Journals (Sweden)

    Solovcova Irina A.

    2006-01-01

    Full Text Available The paper considers an application of analogy in the initial-teacher training as a tool of approaching pedagogical disciplines. The author proposes a classification of pedagogical analogies which provides choices of the most efficient model for a specific didactic situation. The article clarifies the model of the theoretical approach to pedagogical disciplines through active use of analogy, which contributes to a higher efficiency in a teacher and student interaction. The model consists of three stages: training (the stage of acquiring analogy model, the analytical stage (acquisition of pedagogical concepts, phenomena and systems through the application of analogy, and the stage of self-realization (the application of analogy method in students’ scientific-research activities considering external and internal didactic conditions which transform analogy from a teaching method into a tool for the acquisition of pedagogical disciplines. The author demonstrates that the application of analogy has a positive effect not only on the acquisition of pedagogical knowledge (especially methodic and the development of heuristic skills in students, but also on motivation for the study of pedagogical disciplines (cognitive aspect and professional pedagogical activity (formation of an individual-pedagogical attitude. .

  14. Synthetic Biology: A Unifying View and Review Using Analog Circuits.

    Science.gov (United States)

    Teo, Jonathan J Y; Woo, Sung Sik; Sarpeshkar, Rahul

    2015-08-01

    We review the field of synthetic biology from an analog circuits and analog computation perspective, focusing on circuits that have been built in living cells. This perspective is well suited to pictorially, symbolically, and quantitatively representing the nonlinear, dynamic, and stochastic (noisy) ordinary and partial differential equations that rigorously describe the molecular circuits of synthetic biology. This perspective enables us to construct a canonical analog circuit schematic that helps unify and review the operation of many fundamental circuits that have been built in synthetic biology at the DNA, RNA, protein, and small-molecule levels over nearly two decades. We review 17 circuits in the literature as particular examples of feedforward and feedback analog circuits that arise from special topological cases of the canonical analog circuit schematic. Digital circuit operation of these circuits represents a special case of saturated analog circuit behavior and is automatically incorporated as well. Many issues that have prevented synthetic biology from scaling are naturally represented in analog circuit schematics. Furthermore, the deep similarity between the Boltzmann thermodynamic equations that describe noisy electronic current flow in subthreshold transistors and noisy molecular flux in biochemical reactions has helped map analog circuit motifs in electronics to analog circuit motifs in cells and vice versa via a `cytomorphic' approach. Thus, a body of knowledge in analog electronic circuit design, analysis, simulation, and implementation may also be useful in the robust and efficient design of molecular circuits in synthetic biology, helping it to scale to more complex circuits in the future.

  15. History of nonnative Monk Parakeets in Mexico.

    Science.gov (United States)

    Hobson, Elizabeth A; Smith-Vidaurre, Grace; Salinas-Melgoza, Alejandro

    2017-01-01

    Nonnative Monk Parakeets have been reported in increasing numbers across many cities in Mexico, and were formally classified as an invasive species in Mexico in late 2016. However, there has not been a large-scale attempt to determine how international pet trade and national and international governmental regulations have played a part in colonization, and when the species appeared in different areas. We describe the changes in regulations that led the international pet trade market to shift to Mexico, then used international trade data to determine how many parakeets were commercially imported each year and where those individuals originated. We also quantified the recent increases in Monk Parakeet (Myiopsitta monachus) sightings in Mexico in both the scientific literature and in citizen science reports. We describe the timeline of increased reports to understand the history of nonnative Monk Parakeets in Mexico. As in other areas where the species has colonized, the main mode of transport is through the international pet trade. Over half a million Monk Parakeets were commercially imported to Mexico during 2000-2015, with the majority of importation (90%) occurring in 2008-2014, and almost all (98%) were imported from Uruguay. The earliest record of a free-flying Monk Parakeet was observed during 1994-1995 in Mexico City, but sightings of the parakeets did not become geographically widespread in either the scientific literature or citizen science databases until 2012-2015. By 2015, parakeets had been reported in 97 cities in Mexico. Mexico City has consistently seen steep increases in reporting since this species was first reported in Mexico. Here we find that both national and international legal regulations and health concerns drove a rise and fall in Monk Parakeet pet trade importations, shortly followed by widespread sightings of feral parakeets across Mexico. Further monitoring of introduced Monk Parakeet populations in Mexico is needed to understand the

  16. Abstract analogical reasoning in high-functioning children with autism spectrum disorders.

    Science.gov (United States)

    Green, Adam E; Kenworthy, Lauren; Mosner, Maya G; Gallagher, Natalie M; Fearon, Edward W; Balhana, Carlos D; Yerys, Benjamin E

    2014-12-01

    Children with autism spectrum disorders (ASD) exhibit a deficit in spontaneously recognizing abstract similarities that are crucial for generalizing learning to new situations. This may contribute to deficits in the development of appropriate schemas for navigating novel situations, including social interactions. Analogical reasoning is the central cognitive mechanism that enables typically developing children to understand abstract similarities between different situations. Intriguingly, studies of high-functioning children with ASD point to a relative cognitive strength in basic, nonabstract forms of analogical reasoning. If this analogical reasoning ability extends to abstract analogical reasoning (i.e., between superficially dissimilar situations), it may provide a bridge between a cognitive capability and core ASD deficits in areas such as generalization and categorization. This study tested whether preserved analogical reasoning abilities in ASD can be extended to abstract analogical reasoning, using photographs of real-world items and situations. Abstractness of the analogies was determined via a quantitative measure of semantic distance derived from latent semantic analysis. Children with ASD performed as well as typically developing children at identifying abstract analogical similarities when explicitly instructed to apply analogical reasoning. Individual differences in abstract analogical reasoning ability predicted individual differences in a measure of social function in the ASD group. Preliminary analyses indicated that children with ASD, but not typically developing children, showed an effect of age on abstract analogical reasoning. These results provide new evidence that children with ASD are capable of identifying abstract similarities through analogical reasoning, pointing to abstract analogical reasoning as a potential lever for improving generalization skills and social function in ASD. © 2014 International Society for Autism Research, Wiley

  17. Quantum Analog Computing

    Science.gov (United States)

    Zak, M.

    1998-01-01

    Quantum analog computing is based upon similarity between mathematical formalism of quantum mechanics and phenomena to be computed. It exploits a dynamical convergence of several competing phenomena to an attractor which can represent an externum of a function, an image, a solution to a system of ODE, or a stochastic process.

  18. 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...

  19. Fast event recorder utilizing a CCD analog shift register

    International Nuclear Information System (INIS)

    Ducar, R.J.; McIntyre, P.M.

    1978-01-01

    A system of electronics has been developed to allow the capture and recording of relatively fast, low-amplitude analog events. The heart of the system is a dual 455-cell analog shift register charge-coupled device, Fairchild CCD321ADC-3. The CCD is operated in a dual clock mode. The input is sampled at a selectable clock rate of .25-20 MHz. The stored analog data is then clocked out at a slower rate, typically about .25 MHz. The time base expansion of the analog data allows for analog-to-digital conversion and memory storage using conventional medium-speed devices. The digital data is sequentially loaded into a static RAM and may then be block transferred to a computer. The analog electronics are housed in a single-width NIM module, and the RAM memory in a single-width CAMAC module. Each pair of modules provides six parallel channels. Cost is about $200.00 per channel. Applications are described for ionization imaging (TPC, IRC) and long-drift calorimetry in liquid argon

  20. Changes in analogical reasoning in adulthood.

    Science.gov (United States)

    Clark, E; Gardner, M K; Brown, G; Howell, R J

    1990-01-01

    This study sought to investigate adult intellectual development through an analysis of a particular type of cognitive ability, verbal analogical reasoning. The performance of 60 individuals between the ages of 20 and 79 was compared on 100 verbal analogies. The subjects consisted of six groups of ten individuals each (five males and five females), matched as a group for education and gender. Solution times and error rates served as the dependent measures. Results showed that there was a significant trend for the older subjects (60- and 70-year-olds) to be slower than the young subjects (20-, 30-, 40-, and 50-year-olds), but not necessarily more error prone. These data suggest that verbal analogical reasoning changes with age. Supplemental data demonstrated a change in other abilities as well (i.e., decline in perceptual-motor speed and spatial skill).