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Sample records for unit maya clay

  1. Plasticity, political economy, and physical growth status of Guatemala Maya children living in the United States.

    Science.gov (United States)

    Bogin, B; Loucky, J

    1997-01-01

    Migration of Maya refugees to the United States since the late 1970s affords the opportunity to study the consequences of life in a new environment on the growth of Maya children. The children of this study live in Indiantown, Florida, and Los Angeles, California. Maya children between 4 and 14 years old (n = 240) were measured for height, weight, fatness, and muscularity. Overall, compared with reference data for the United States, the Maya children are, on average, healthy and well nourished. They are taller and heavier and carry more fat and muscle mass than Maya children living in a village in Guatemala. However, they are shorter, on average, than children of black, Mexican-American, and white ethnicity living in Indiantown. Children of Maya immigrants born in the United States tend to be taller than immigrant children born in Guatemala or Mexico. Families that invest economic and social resources in their children have taller children. More economic successful families have taller children. Migration theory and political economy theory from the social sciences are combined with plasticity theory and life history theory (parental investment) from biology to interpret these data.

  2. Acculturation stress among Maya in the United States.

    Science.gov (United States)

    Millender, Eugenia

    2012-01-01

    Abstract: As health care disparities become more evident in our multicultural nation, culture sensitive health research needs to be a priority in order for good health care to take place. This article will explore the literature related to acculturation stress and mental health disparities among the Mayan population. Literatures of similar but distinct groups are included due to the limited amount of research of the Mayan population. Using Leiniger's Transcultural nursing theory, these findings suggest that nurses have a large gap to fill to address the mental health disparities of specific cultural groups like the indigenous Maya, thereby satisfying their nursing obligations.

  3. Mathematical Contributions of the Mayas, Aztecs & Incas: A Native American Curriculum Unit for Middle and High School. NATAM XIX.

    Science.gov (United States)

    Stodola, Janet

    Written to fulfill the requirements for a University of Minnesota College of Education off-campus Indian education course for public school teachers, this Native American curriculum unit for middle and high school reflects the mathematical achievements of the Maya, Aztec, and Inca Indians. The number systems, notation, and calendar techniques of…

  4. Maya-American Children: A Biocultural View.

    Science.gov (United States)

    Bogin, Barry

    2002-01-01

    Discusses social, economic, and political conditions that influence the growth and health of children of Guatemalan Maya immigrants to the United States. As of 2000, Maya-American children age 6-12 years were, on average, 11 centimeters taller, and also heavier, than their Guatemalan peers. The heaviness is probably due to sedentary lifestyles.…

  5. Maya-American Children: A Biocultural View.

    Science.gov (United States)

    Bogin, Barry

    2002-01-01

    Discusses social, economic, and political conditions that influence the growth and health of children of Guatemalan Maya immigrants to the United States. As of 2000, Maya-American children age 6-12 years were, on average, 11 centimeters taller, and also heavier, than their Guatemalan peers. The heaviness is probably due to sedentary lifestyles.…

  6. Rafael Maya

    Directory of Open Access Journals (Sweden)

    Jaime Duarte French

    1982-01-01

    Full Text Available Con la generosidad ilimitada que le es propia, me ha solicitado el maestro Rafael Maya que escriba, a manera de introducción de estas páginas, algunas palabras relativas a su obra. Es difícil imaginar un compromiso de mayor responsabilidad. Cuando el maestro se fijó en mí para tan ponderoso y noble encargo, es seguro que tuvo presente, tan solo, mi antigua e inextinguible devoción por su labor intelectual, y dentro de ella, por su poesia, que es, en el conjunto de su producción literaria, la parte de excepción donde el hombre ha volcado, con asombrosa esplendidez, todos los frutos sazonados de sus huertos interiores.

  7. Maya chemistry of organic inorganic hybrid materials: isomerization, cyclicization and redox tuning of organic dyes attached to porous silicates

    OpenAIRE

    ANTONIO DOMÉNECH CARBÓ; Valle-Algarra, Francisco M.; Domenech Carbo, Mª Teresa; Osete Cortina, Laura; Domine ., Marcelo Eduardo

    2013-01-01

    [EN] Association of indigo and lapachol dyes to aluminosilicate clays yields polyfunctional organic – inorganic hybrid materials forming Maya Blue-like systems. Upon partial removing of clay's zeolitic water by moderate thermal treatment, abundant isomerization, cyclicization and oxidation reactions occur defining a‘ Maya chemistry whose complexity could explain the versatile use of such materials in the pre-Columbian cultures and permits the...

  8. Autodesk Maya 2014 essentials

    CERN Document Server

    Naas, Paul

    2013-01-01

    The premiere book on getting started with Maya 2014 Whether you're just beginning, or migrating from another 3D application, this step-by-step guide is what you need to get a good working knowledge of Autodesk Maya 2014. Beautifully illustrated with full-color examples and screenshots, Autodesk Maya 2014 Essentials explains the basics of Maya as well as modeling, texturing, animating, setting a scene, and creating visual effects. You'll absorb important concepts and techniques, and learn how to confidently use Maya tools the way professionals do. Each chapter includes fun and cha

  9. Extending the roads for survival: An ethnography of the ongoing Maya Diaspora

    OpenAIRE

    Bazua Morales, Carlos Miguel

    2013-01-01

    The present ethnographic research examines a diverse group of migrants from the Macro- Maya culture, originally from Yucatan, Chiapas and Guatemala. Findings confirm that there is a longstanding migration pattern in which the Maya have engaged in order to survive, and, now, the Maya have extended these roads of survival to the California Bay Area in the United States. This research aims to address the cultural, political and social migration conditions Maya from Guatemala and Mexico have face...

  10. Mastering Autodesk Maya 2013

    CERN Document Server

    Palamar, Todd

    2012-01-01

    Provides hands-on intermediate-to-advanced coverage of the leading 3D software Maya is the industry-leading 3D animation and effects software used in movies, visual effects, games, and other genres. For intermediate and advanced users who already know Maya basics, this official Maya guide provides the detailed coverage you need to unlock the software's more complex features. Elevate your skills in modeling, texturing, animation, and visual effects, and gain proficiency in high-level techniques for film, television, game development, and more. Artists who are already proficient in Maya basics

  11. Mastering Autodesk Maya 2012

    CERN Document Server

    Palamar, Todd

    2011-01-01

    The exclusive, official guide to the very latest version of Maya Get extensive, hands-on, intermediate to advanced coverage of Autodesk Maya 2012, the top-selling 3D software on the market. If you already know Maya basics, this authoritative book takes you to the next level. From modeling, texturing, animation, and visual effects to high-level techniques for film, television, games, and more, this book provides professional-level Maya instruction. With pages of scenarios and examples from some of the leading professionals in the industry, author Todd Palamar will help you master the entire CG

  12. Introducing Maya 2011

    CERN Document Server

    Derakhshani, Dariush

    2010-01-01

    A practical, step-by-step guide to Maya 2011. Four previous editions can't be wrong: this book is the perfect introduction to 3D and Maya. Learn to build and animate your own digital models and scenes with step-by-step instruction and fun and practical examples, while you draw inspiration from the striking examples included from talented Maya users. You'll create a simple animation of the planets in the solar system, learn to model a human hand and a decorative box?among other projects?and master all essential tools.: Provides a thorough, step-by-step introduction to Maya 2011; Explains the co

  13. Mastering Autodesk Maya 2011

    CERN Document Server

    Keller, Eric

    2010-01-01

    A beautifully-packaged, advanced reference on the very latest version of Maya. If you already know the basics of Maya, the latest version of this authoritative book takes you to the next level. From modeling, texturing, animation, and visual effects to high-level techniques for film, television, games, and more, this book provides professional-level Maya instruction. With pages of scenarios and examples from some of the leading professionals in the industry, this book will help you master the entire CG production pipeline.: Provides professional-level instruction on Maya, the industry-leading

  14. The Maya of Florida.

    Science.gov (United States)

    Burns, Allan F.

    1989-01-01

    Discusses the Maya people who fled Guatemala due to a civil war and illegally entered the U.S. and settled in Florida. Presents a picture of their living conditions, employment opportunities, cultural traditions, community development, and family organization. Discusses a Kanjobal Association and the CORN-MAYA program, and explains immigration…

  15. The Maya of Florida.

    Science.gov (United States)

    Burns, Allan F.

    1989-01-01

    Discusses the Maya people who fled Guatemala due to a civil war and illegally entered the U.S. and settled in Florida. Presents a picture of their living conditions, employment opportunities, cultural traditions, community development, and family organization. Discusses a Kanjobal Association and the CORN-MAYA program, and explains immigration…

  16. Mastering Autodesk Maya 2014

    CERN Document Server

    Palamar, Todd

    2013-01-01

    Hands-on intermediate-to-advanced coverage of the leading 3D software Autodesk Maya is the industry-leading 3D animation and effects software used in movies, visual effects, games, and other genres. If you already know the basics of Maya and are ready to elevate your skills, then this book is for you. Nearly 1,000 pages are packed with organized, professional, and valuable insight on the leading 3D application on the market, enabling you to unlock the software's more complex features. Ideal as both a tutorial and study guide for the Autodesk Maya exam, this Autodesk Official Press

  17. Introducing Autodesk Maya 2012

    CERN Document Server

    Derakhshani, Dariush

    2011-01-01

    A practical, step-by-step guide to Maya 2012 This book is the ideal primer to getting started with Maya, the premier 3D animation and effects software used in movies, visual effects, games, cartoons, short films, and commercials. You'll learn the Maya interface and the basics of modeling, texturing, animating, and visual effects. Professional visual effects artist and instructor Dariush Derakhshani explains the nuances of the complex software, while creative tutorials offer realistic, professional challenges for those new to 3D. You'll be up and running in no time with the world's most popular

  18. Maya Studio Projects Dynamics

    CERN Document Server

    Palamar, Todd

    2009-01-01

    The only hands-on book devoted to mastering Maya's dynamics tools for water, wind, and fire. In the world of animation, the ability to create realistic water, wind, and fire effects is key. Autodesk Maya software includes powerful dynamics tools that have been used to design breathtaking effects for movies, games, commercials, and short films. This professional guide teaches you the primary techniques you need to make the most of Maya's toolkit, so you'll soon be creating water that ripples, gusting winds and gentle breezes, and flickering fires the way Hollywood pros do. The one-of-a-kind boo

  19. Maya Education and Pan Maya Ideology in the Yucatan.

    Science.gov (United States)

    Burns, Allan

    1998-01-01

    A University of Yucatan (Mexico) professor who taught a Mayan linguistics course to indigenous teachers in Mayan discusses three issues that are central to understanding how indigenous education interacts with pan-Maya identity: the importance of locally developed Maya literature, the symbols used to define Maya culture, and a conflict over Maya…

  20. Maya Education and Pan Maya Ideology in the Yucatan.

    Science.gov (United States)

    Burns, Allan

    1998-01-01

    A University of Yucatan (Mexico) professor who taught a Mayan linguistics course to indigenous teachers in Mayan discusses three issues that are central to understanding how indigenous education interacts with pan-Maya identity: the importance of locally developed Maya literature, the symbols used to define Maya culture, and a conflict over Maya…

  1. Practical Maya programming with Python

    CERN Document Server

    Galanakis, Robert

    2014-01-01

    ""Practical Maya Programming with Python"" is a practical tutorial packed with plenty of examples and sample projects which guides you through building reusable, independent modules and handling unexpected errors. If you are a developer looking to build a powerful system using Python and Maya's capabilities, then this book is for you. Practical Maya Programming with Python is perfect for intermediate users with basic experience in Python and Maya who want to better their knowledge and skills.

  2. "I am Maya, not Guatemalan, nor Hispanic"—the Belongingness of Mayas in Southern Florida

    Directory of Open Access Journals (Sweden)

    Patrick T. Hiller

    2009-09-01

    Full Text Available This article explores the personal meanings and public expressions of home, ethnicity and belonging among Maya/Guatemalan immigrants living in South Florida, specifically from the viewpoints of seven biographies of first and second-generation Maya immigrants. Our examination of their narratives suggests why these immigrants actively resist a public mis-categorization of being part of the Hispanic community by emphasizing their indigenous heritage. As such, this study provides a new type of research regarding Maya immigrants and their "positioning" or their "self-localization" as indigenous peoples seeking refuge in the United States. These are narratives of Maya lives, most of them child survivors, who fled the genocide in Guatemala with their families and who have faced discrimination while living in the United States. What is unique about our study is its emphasis upon biography for portraying particular facets of ethnicity and indigeneity and the difficult processes of transnational migration faced by Maya peoples now living in Florida. URN: urn:nbn:de:0114-fqs0903106

  3. Autodesk Maya 2013 Essentials

    CERN Document Server

    Naas, Paul

    2012-01-01

    Recommnded text for those preparing for the Maya Associate exam Maya, the industry-leading 3D animation and effects software used in movies, games, cartoons, and commercials, is challenging to learn. This full-color guide features approachable, hands-on exercises and additional task-based tutorials that allow new users to quickly become productive with the program and familiar with its workflow in a professional environment. You'll learn the basics of modeling, texturing, animating, and lighting; explore different parts of the production pipeline; and practice on some real-world projects. Ma

  4. Fault imprint in clay units: magnetic fabric, structural and mineralogical signature

    Science.gov (United States)

    Moreno, Eva; Homberg, Catherine; Schnyder, Johann; Person, Alain; du Peloux1, Arthur; Dick, Pierre

    2014-05-01

    Fault-induced deformations in clay units can be difficult to decipher because strain markers are not always visible at outcrop scale or using geophysical methods. Previous studies have indicated that the anisotropy of magnetic susceptibility (ASM) provides a powerful and rapid technique to investigate tectonic deformation in clay units even when they appear quite homogenous and undeformed at the outcrop scale (Lee et al. 1990, Mattei et al. 1997). We report here a study based on ASM, structural analysis and magnetic and clay mineralogy from two boreholes (TF1 and ASM1)drilled horizontally in the Experimental Station of Tournemire of the Institute for Radiological Protection and Nuclear Safety (IRSN) in Aveyron (France). The boreholes intersect a N-S trending strike-slip fault from west to east. The ASM study indicates the evolution of the magnetic fabric from the undeformed host rock to the fault core. Also, all the fractures cutting the studied interval of the core have been measured as well as the slip vectors which are generally well preserved. In the two boreholes, the undeformed sediments outside the fault zone are characterized by an oblate fabric, a sub-vertical minimum susceptibility axis (k3) perpendicular to the bedding plane and without magnetic lineation. Within the fault zone, a tilt in the bedding plane has been observed in two boreholes TF1 and ASM1. In addition, in the TF1 core, the fault area presents a tectonic fabric characterized by a triaxial AMS ellipsoid. Moreover, the magnetic lineation increases and k3 switches from a vertical to a sub-horizontal plane. This kind of fabric has not been observed in borehole ASM1. The structural analysis of the individual fractures making the fault zone indicates a complex tectonic history with different imprint in the two fault segments cut by the two boreholes. The large majority of fractures correspond to dextral strike-slip faults but normal and reverse movements were observed and are more or less

  5. Ball clay and bentonite deposits of the central and western Gulf of Mexico Coastal Plain, United States

    Science.gov (United States)

    Hosterman, John W.

    1984-01-01

    The Gulf of Mexico Coastal Plain produces approximately 85 percent of the ball clay used in the United States. The best commercial-grade clay deposits are composed of poorly crystalline kaolinite and small amounts of Md illite and (or) smectite. Sand and silt and iron oxide minerals are virtually absent, but quartz is present in the clay-size fraction. The best grade ball clays are found as lenses limited to the Wilcox Group (Paleocene and lower Eocene) and Claiborne Group (middle Eocene). Reserves of ball clay are sufficient for the present, but because of the lenticular nature of the clay bodies, close-spaced drilling, detailed sampling, mineralogic analyses, and ceramic testing are needed to prove future reserves.Approximately 11 percent of the total bentonite produced in the United States comes from the Gulf Coast region. The commercial-grade bentonites are composed primarily of smectite with little or no Md illite and kaolinite. The nonclay impurities are quartz, feldspar, muscovite, biotite, calcite, dolomite, gypsum, and heulandite. Commercial bentonites occur in the Upper Cretaceous formations in Alabama and Mississippi, in Paleocene formations in Mississippi and Tennessee, and in Eocene and Miocene formations in Texas. The demand for low-swelling bentonite of the Gulf Coastal Plain has not increased along with the demand for swelling bentonite; therefore the reserves are adequate.

  6. An assessment of dioxin levels in processed ball clay from the United States

    Energy Technology Data Exchange (ETDEWEB)

    Ferrario, J.; Byrne, C. [USEPA, Stennis Space Ctr. Mississippi (United States); Schaum, J. [USEPA, Washington, DC (United States)

    2004-09-15

    Introduction The presence of dioxin-like compounds in ball clay was discovered in 1996 as a result of an investigation to determine the sources of elevated levels of dioxin found in two chicken fat samples from a national survey of poultry. The investigation indicated that soybean meal added to chicken feed was the source of dioxin contamination. Further investigation showed that the dioxin contamination came from the mixing of a natural clay known as ''ball clay'' with the soybean meal as an anti-caking agent. The FDA subsequently discontinued the use of contaminated ball clay as an anti-caking agent in animal feeds. The source of the dioxins found in ball clay has yet to be established. A comparison of the characteristic dioxin profile found in ball clay to those of known anthropogenic sources from the U.S.EPA Source Inventory has been undertaken, and none of those examined match the features found in the clays. These characteristic features together with the fact that the geologic formations in which the clays are found are ancient suggest a natural origin for the dioxins. The plasticity of ball clays makes them an important commercial resource for a variety of commercial uses. The percentage of commercial uses of ball clay in 2000 included: 29% for floor and wall tile, 24% for sanitary ware, 10% pottery, and 37% for other industrial and commercial uses. The total mining of ball clay in the U.S. for 2003 was 1.12 million metric tons. EPA is examining the potential for the environmental release of dioxins from the processing/use of ball clays and evaluating potential exposure pathways. Part of this overall effort and the subject of this study includes the analysis of dioxin levels found in commercially available ball clays commonly used in ceramic art studios.

  7. Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in shallow, recently recharged ground water -- Input data set for clay sediment (gwava-s_clay)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the amount of clay sediment in the soil, in percent times 1000, in the conterminous United States. The data set was used as an input data...

  8. Fe K-edge XANES of Maya blue pigment

    Energy Technology Data Exchange (ETDEWEB)

    Rio, M. Sanchez del [ESRF, Experiments Division, B.P. 220, F-38043, Grenoble Cedex (France)]. E-mail: srio@esrf.fr; Sodo, A. [ESRF, Experiments Division, B.P. 220, F-38043, Grenoble Cedex (France); Eeckhout, S.G. [ESRF, Experiments Division, B.P. 220, F-38043, Grenoble Cedex (France); Neisius, T. [ESRF, Experiments Division, B.P. 220, F-38043, Grenoble Cedex (France); Martinetto, P. [Laboratoire de Cristallographie, CNRS, Grenoble B.P. 166, F-38042, Grenoble Cedex 09 (France); Dooryhee, E. [Laboratoire de Cristallographie, CNRS, Grenoble B.P. 166, F-38042, Grenoble Cedex 09 (France); Reyes-Valerio, C. [INAH, Mexico DF (Mexico)

    2005-08-15

    The utilization of techniques used in Materials Science for the characterization of artefacts of interest for cultural heritage is getting more and more attention nowadays. One of the products of the ancient Maya chemistry is the 'Maya blue' pigment, made with natural indigo and palygorskite. This pigment is different from any other pigment used in other parts of the world. It is durable and acid-resistant, and still keeps many secrets to scientists even though it has been studied for more than 50 years. Although the pigment is basically made of palygorskite Si{sub 8}(Mg{sub 2}Al{sub 2})O{sub 20}(OH){sub 2}(OH{sub 2}){sub 4}.4H{sub 2}O and an organic colourant (indigo: C{sub 16}H{sub 10}N{sub 2}O{sub 2}), a number of other compounds have been found in previous studies on archaeological samples, like other clays and minerals, iron nanoparticles, iron oxides, impurities of transition metals (Cr, Mn, Ti, V), etc. We measured at the ESRF ID26 beamline the Fe K-edge XANES spectra of the blue pigment in ancient samples. They are compared to XANES spectra of Maya blue samples synthesized under controlled conditions, and iron oxides usually employed as pigments (hematite and goethite). Our results show that the iron found in ancient Maya blue pigment is related to the Fe exchanged in the palygorskite clay. We did not find iron in metallic form or goethite in archaeological Maya blue.

  9. Organic/Inorganic Complex Pigments: Ancient Colors Maya Blue

    Energy Technology Data Exchange (ETDEWEB)

    Polette-Niewold, L.A.; Manciu, F.S.; Torres, B.; Alvarado, M.; Jr.; Chianelli, R.R.

    2009-06-04

    Maya Blue is an ancient blue pigment composed of palygorskite clay and indigo. It was used by the ancient Maya and provides a dramatic background for some of the most impressive murals throughout Mesoamerica. Despite exposure to acids, alkalis, and chemical solvents, the color of the Maya Blue pigment remains unaltered. The chemical interaction between palygorskite and indigo form an organic/inorganic complex with the carbonyl oxygen of the indigo bound to a surface Al{sup 3+} in the Si-O lattice. In addition indigo will undergo an oxidation to dehydroindigo during preparation. The dehydro-indigo molecule forms a similar but stronger complex with the Al{sup 3+}. Thus, Maya Blue varies in color due to the mixed indigo/dehydroindigo complex. The above conclusions are the result of application of multiple techniques (X-ray diffraction, differential thermal analysis/thermal gravimetric analysis, high resolution transmission electron microscopy, scanning electron microscopy, infrared and Raman spectroscopy) to the characterization of the organic/inorganic complex. A picture of the bonding of the organic molecule to the palygorskite surface forming a surface complex is developed and supported by the results of density functional theory calculations. We also report that other organic molecules such as thioindigo form similar organic/inorganic complexes thus, opening an entirely new class of complex materials for future applications.

  10. Transdiciplina y sustentabilidad maya

    OpenAIRE

    Eduardo Bello; Erin I. J. Estrada; Pedro Macario Mendoza; Axayacatl Segundo; Luis Sánchez

    2002-01-01

    A través de un enfoque transdiciplinario se realizó una investigación acerca de la sustentabilidad como opción a la conservación de la biodiversidad y a la creciente necesidad regional por aumentar la producción de alimentos. Este estudio se realizó específicamente en las comunidades mayas de Xhazil, Chancah Veracruz y Uh May, pertenecientes al ejido Xhazil y anexos en el centro de Quintana Roo.

  11. Transdiciplina y sustentabilidad maya

    Directory of Open Access Journals (Sweden)

    Eduardo Bello

    2002-01-01

    Full Text Available A través de un enfoque transdiciplinario se realizó una investigación acerca de la sustentabilidad como opción a la conservación de la biodiversidad y a la creciente necesidad regional por aumentar la producción de alimentos. Este estudio se realizó específicamente en las comunidades mayas de Xhazil, Chancah Veracruz y Uh May, pertenecientes al ejido Xhazil y anexos en el centro de Quintana Roo.

  12. En recuerdo de Maya

    Directory of Open Access Journals (Sweden)

    Carlos Arturo Caparroso

    1982-01-01

    Full Text Available Uno de los más grandes poetas de Colombia, de este siglo, Rafael Maya (1897-1980, ha fallecido en Bogotá en los últimos dias del pasado julio. Fue, además, un brillante orador académico, un crítico literario de valía y autoridad que estudió en numerosos ensayos y discursos una porción muy copiosa de nuestras letras, un eminente profesor de literatura patria y de cultura griega. Decano de la Escuela Nacional de Bellas Artes.

  13. Maya Studio Projects Photorealistic Characters

    CERN Document Server

    Palamar, Todd

    2011-01-01

    Create realistic characters with Maya tools and this project-based book Maya character generation tools are extremely sophisticated, and there's no better way to learn all their capabilities than by working through the projects in this hands-on book. This official guide focuses on understanding and implementing Maya's powerful tools for creating realistic characters for film, games, and TV. Use a variety of tools to create characters from skeleton to clothing, including hairstyles and facial hair, and learn how to use Performance Capture. A DVD includes supplementary videos, project support fi

  14. Microanalysis study of archaeological mural samples containing Maya blue pigment

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez del Rio, M. [ESRF, BP220, F-38043 Grenoble (France)]. E-mail: srio@esrf.fr; Martinetto, P. [Laboratoire de Cristallographie, CNRS, BP166 F-30842 Grenoble (France); Somogyi, A. [ESRF, BP220, F-38043 Grenoble (France); Reyes-Valerio, C. [INAH, Mexico DF (Mexico); Dooryhee, E. [Laboratoire de Cristallographie, CNRS, BP166 F-30842 Grenoble (France); Peltier, N. [Laboratoire de Cristallographie, CNRS, BP166 F-30842 Grenoble (France); Alianelli, L. [INFM-OGG c/o ESRF, BP220, F-38043 Grenoble Cedex (France); Moignard, B. [C2RMF, 6 Rue des Pyramides, F-75041 Paris Cedex 01 (France); Pichon, L. [C2RMF, 6 Rue des Pyramides, F-75041 Paris Cedex 01 (France); Calligaro, T. [C2RMF, 6 Rue des Pyramides, F-75041 Paris Cedex 01 (France); Dran, J.-C. [C2RMF, 6 Rue des Pyramides, F-75041 Paris Cedex 01 (France)

    2004-10-08

    Elemental analysis by X-ray fluorescence and particle induced X-ray emission is applied to the study of several Mesoamerican mural samples containing blue pigments. The most characteristic blue pigment is Maya blue, a very stable organo-clay complex original from Maya culture and widely used in murals, pottery and sculptures in a vast region of Mesoamerica during the pre-hispanic time (from VIII century) and during the colonization until 1580. The mural samples come from six different archaeological sites (four pre-hispanic and two from XVI century colonial convents). The correlation between the presence of some elements and the pigment colour is discussed. From the comparative study of the elemental concentration, some conclusions are drawn on the nature of the pigments and the technology used.

  15. Entre velos: Maya para contrabajo

    Directory of Open Access Journals (Sweden)

    Rosa María Rodríguez Hernández

    2014-01-01

    Full Text Available Maya para contrabajo se materializa a partir de una imagen de Pepe Romero, cuyo texto interpreta a La decadencia de la mentira de Oscar Wilde. La estructura de Maya es binaria, especular y asimétrica; su poética obedece al juego verdad/mentira que subyace en la obra artística y en la vivencia del artista. Maya trae a la memoria las voces de los Upanishad, Schopenhauer, Shakespeare y Beethoven, influencias éstas en la obra de Wagner y, todas ellas, en la de Eliot. Los aspectos gestuales y visuales de Maya entrelazan con la danza de Pina Bausch y con la retórica (hypotiposis.

  16. Layout of Ancient Maya Cities

    Science.gov (United States)

    Aylesworth, Grant R.

    Although there is little doubt that the ancient Maya of Mesoamerica laid their cities out based, in part, on astronomical considerations, the proliferation of "cosmograms" in contemporary scholarly discourse has complicated matters for the acceptance of rigorous archaeoastronomical research.

  17. Dimensiones culturales e identidades situadas: la herencia maya en migrantes yucatecos a Estados Unidos Cultural Dimensions and Situated Identities: Mayan Inheritance in Yucatec Migrants to the United States

    Directory of Open Access Journals (Sweden)

    Pedro Antonio Be Ramírez

    2011-01-01

    Full Text Available Este artículo trata sobre la conformación identitaria de los migrantes de Telchac Pueblo a partir de algunos elementos culturales vinculados con su herencia maya ancestral. Las dimensiones culturales que aquí se presentan no son únicas ni mucho menos absolutas para explicar el pasado maya en Yucatán; más bien corresponden a ciertos aspectos que permiten comprender la manera en cómo los migrantes yucatecos se conciben a sí mismos desde discursos y prácticas situados en contextos sociales reales. Las bases o dimensiones culturales consideradas emblemas que otorgan carácter distintivo a la identidad son el eje central y admiten dar cuenta del mantenimiento, la reelaboración y lo situacional de las costumbres y tradiciones en esta región del sureste mexicano.This article focuses on the conformation of identity of migrants from Telchac Pueblo, Yucatan, viewed initially as cultural elements that play out Mayan ancient heritage. The cultural dimensions presented here are not unique, and much less absolute in explaining Yucatan's Mayan past. Rather they correspond to certain aspects that allow us to understand the ways in which yucatecan migrants conceive themselves within current situated discourse practices. The bases or cultural dimensions considered are emblematic and grant distinctive character to local identity: they are seen as a central axis that allows for comprehension of cultural persistence (or resistance, the (re elaboration of customs and the situational features of traditions within this Mexican southeast region.

  18. Territorial organization of the lowland classic maya.

    Science.gov (United States)

    Marcus, J

    1973-06-01

    Thus far I have discussed ancient Maya sociopolitical structure from the upper levels of the hierarchy downward. Let me now summarize their territorial organization from the bottom upward, starting at the hamlet level (Fig. 8). The smallest unit of settlement-one usually overlooked by archeological surveys in the lowland rain forest-was probably a cluster of thatched huts occupied by a group of related families; larger clusters may have been divided into four quadrants along the lines suggested by Coe (26). Because of the long fallow period (6 to 8 years) characteristic of slash-and-burn agriculture in the Petén, these small hamlets are presumed to have changed location over the years, although they probably shifted in a somewhat circular fashion around a tertiary ceremonial-civic center for whose maintenance they were partly responsible. These tertiary centers were spaced at fairly regular intervals around secondary ceremonial-civic centers with pyramids, carved monuments, and palace-like residences. In turn, the secondary centers occurred at such regular intervals as to form hexagonal patterns around primary centers, which were still larger, with acropolises, multiple ceremonial plazas, and greater numbers of monuments. In some cases, the distance between secondary centers was roughly twice the distance between secondary and tertiary centers, creating a lattice of nested hexagonal cells. This pattern, which conforms to a Western theoretical construct, was presumably caused by factors of service function, travel, and transport. The pattern was not recognized by the Maya at all. They simply recognized that a whole series of smaller centers were dependent on a primary center and therefore mentioned its emblem glyph. Linking the centers of the various hexagons were marriage alliances between members of royal dynasties, who had no kinship ties with the farmers in the hamlets. Out of the large number of primary centers available to them, the Maya selected four as

  19. Becoming Maya? Appropriation of the White Shaman.

    Science.gov (United States)

    Montejo, Victor D.

    1999-01-01

    The history of anthropology among the Maya consists of both the literal exploitation of archaeological finds and the appropriation of Maya culture and history by the Western academic world to construct distorted theories of the Maya past. In the ultimate disgrace, some Mayan priests are training White anthropologists to become shamans themselves…

  20. Becoming Maya? Appropriation of the White Shaman.

    Science.gov (United States)

    Montejo, Victor D.

    1999-01-01

    The history of anthropology among the Maya consists of both the literal exploitation of archaeological finds and the appropriation of Maya culture and history by the Western academic world to construct distorted theories of the Maya past. In the ultimate disgrace, some Mayan priests are training White anthropologists to become shamans themselves…

  1. Ancient Maya impacts on the Earth's surface: An Early Anthropocene analog?

    Science.gov (United States)

    Beach, Tim; Luzzadder-Beach, Sheryl; Cook, Duncan; Dunning, Nicholas; Kennett, Douglas J.; Krause, Samantha; Terry, Richard; Trein, Debora; Valdez, Fred

    2015-09-01

    The measure of the "Mayacene," a microcosm of the Early Anthropocene that occurred from c. 3000 to 1000 BP, comes from multiple Late Quaternary paleoenvironmental records. We synthesized the evidence for Maya impacts on climate, vegetation, hydrology and the lithosphere, from studies of soils, lakes, floodplains, wetlands and other ecosystems. Maya civilization had likely altered local to regional ecosystems and hydrology by the Preclassic Period (3000-1700 BP), but these impacts waned by 1000 BP. They altered ecosystems with vast urban and rural infrastructure that included thousands of reservoirs, wetland fields and canals, terraces, field ridges, and temples. Although there is abundant evidence that indicates the Maya altered their forests, even at the large urban complex of Tikal as much as 40% of the forest remained intact through the Classic period. Existing forests are still influenced by ancient Maya forest gardening, particularly by the large expanses of ancient stone structures, terraces, and wetland fields that form their substrates. A few studies suggest deforestation and other land uses probably also warmed and dried regional climate by the Classic Period (1700-1100 BP). A much larger body of research documents the Maya impacts on hydrology, in the form of dams, reservoirs, canals, eroded soils and urban design for runoff. Another metric of the "Mayacene" are paleosols, which contain chemical evidence for human occupation, revealed by high phosphorus concentrations and carbon isotope ratios of C4 species like maize in the C3-dominated tropical forest ecosystem. Paleosol sequences exhibit "Maya Clays," a facies that reflects a glut of rapidly eroded sediments that overlie pre-Maya paleosols. This stratigraphy is conspicuous in many dated soil profiles and marks the large-scale Maya transformation of the landscape in the Preclassic and Classic periods. Some of these also have increased phosphorous and carbon isotope evidence of C4 species. We synthesize

  2. Dioxin congener patterns in commercial catfish from the United States and the indication of mineral clays as the potential source.

    Science.gov (United States)

    Huwe, J K; Archer, J C

    2013-01-01

    Since 1991 the US Department of Agriculture (USDA) has conducted annual surveys of pesticide residues in foods under the Agricultural Marketing Service's Pesticide Data Program (PDP). To assess chemical residues in domestically marketed catfish products, 1479 catfish samples were collected during the 2008-2010 PDPs. A subset of 202 samples was analysed for 17 toxic polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs). The average pattern of the individual PCDD/F congener concentrations in the catfish was rather unique in that it had almost no measurable amounts of polychlorinated dibenzofurans (PCDFs), but all PCDDs were present. This pattern was more dominant in the domestically produced catfish products than in the imported products (China/Taiwan). Comparison of the pattern to known sources of PCDD/Fs showed strong similarities to the pattern of PCDD/Fs found in kaolin clays which have often been used as anti-caking agents in animal feeds. To investigate whether catfish feeds may be the source of the PCDD/Fs found in the catfish, archived catfish feed data from a US Food and Drug Administration (USFDA) database were examined. In 61 out of 112 feed samples, the PCDD concentrations were 50 times higher than the PCDF concentrations and resembled the pattern found in the catfish products and in clays mined in the south-eastern United States. Although the source of PCDD/Fs in domestically marketed catfish products cannot be definitively established, mined clay products used in feeds should be considered a likely source and, given the wide concentration range of PCDD/Fs that has been found in clays, a critical control point for PCDD/Fs entrance to the food supply.

  3. Ball clay

    Science.gov (United States)

    Virta, Robert L.

    2010-01-01

    The article reports on the global market performance of ball clay in 2009 and presents an outlook for its 2010 performance. Several companies mined ball call in the country including Old Hickey Clay Co., Kentucky-Tennessee Clay Co., and H.C. Spinks Clay Co. Information on the decline in ball clay imports and exports is also presented.

  4. Maya Calendars in the Classroom

    Science.gov (United States)

    Taylor, Cynthia E.; Rehm, Megan A.; Catepillán, Ximena

    2015-01-01

    This article presents a lesson in which least common multiples helps students not only develop a perspective on an ancient culture but also draw on the cultural background of classmates. The Maya calendar received a lot of attention in the years leading up to December 21, 2012, because of the mythological end of "creation." Co-author…

  5. Maya Calendars in the Classroom

    Science.gov (United States)

    Taylor, Cynthia E.; Rehm, Megan A.; Catepillán, Ximena

    2015-01-01

    This article presents a lesson in which least common multiples helps students not only develop a perspective on an ancient culture but also draw on the cultural background of classmates. The Maya calendar received a lot of attention in the years leading up to December 21, 2012, because of the mythological end of "creation." Co-author…

  6. Deep data science to prevent and treat growth faltering in Maya children.

    Science.gov (United States)

    Varela-Silva, M I; Bogin, B; Sobral, J A G; Dickinson, F; Monserrat-Revillo, S

    2016-06-01

    The Maya people are descended from the indigenous inhabitants of southern Mexico, Guatemala and adjacent regions of Central America. In Guatemala, 50% of infants and children are stunted (very low height-for-age), and some rural Maya regions have >70% children stunted. A large, longitudinal, intergenerational database was created to (1) provide deep data to prevent and treat somatic growth faltering and impaired neurocognitive development, (2) detect key dependencies and predictive relations between highly complex, time-varying, and interacting biological and cultural variables and (3) identify targeted multifactorial intervention strategies for field testing and validation. Contributions to this database included data from the Universidad del Valle de Guatemala Longitudinal Study of Child and Adolescent Development, child growth and intergenerational studies among the Maya in Mexico and studies about Maya migrants in the United States.

  7. Clay Play

    Science.gov (United States)

    Rogers, Liz; Steffan, Dana

    2009-01-01

    This article describes how to use clay as a potential material for young children to explore. As teachers, the authors find that their dialogue about the potential of clay as a learning medium raises many questions: (1) What makes clay so enticing? (2) Why are teachers noticing different play and conversation around the clay table as compared to…

  8. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2011-01-01

    The article discusses the latest developments in the global ball clay mining industry, particularly in the U.S., as of June 2011. It cites several firms that are involved in ball clay mining in the U.S., including HC Spins Clay Co. Inc., the Imerys Group and Old Hickory Clay Co. Among the products made from ball clay are ceramic tiles, sanitaryware, as well as fillers, extenders and binders.

  9. Population structure of the Classic period Maya.

    Science.gov (United States)

    Scherer, Andrew K

    2007-03-01

    This study examines the population structure of Classic period (A.D. 250-900) Maya populations through analysis of odontometric variation of 827 skeletons from 12 archaeological sites in Mexico, Guatemala, Belize, and Honduras. The hypothesis that isolation by distance characterized Classic period Maya population structure is tested using Relethford and Blangero's (Hum Biol 62 (1990) 5-25) approach to R matrix analysis for quantitative traits. These results provide important biological data for understanding ancient Maya population history, particularly the effects of the competing Tikal and Calakmul hegemonies on patterns of lowland Maya site interaction. An overall F(ST) of 0.018 is found for the Maya area, indicating little among-group variation for the Classic Maya sites tested. Principal coordinates plots derived from the R matrix analysis show little regional patterning in the data, though the geographic outliers of Kaminaljuyu and a pooled Pacific Coast sample did not cluster with the lowland Maya sites. Mantel tests comparing the biological distance matrix to a geographic distance matrix found no association between genetic and geographic distance. In the Relethford-Blangero analysis, most sites possess negative or near-zero residuals, indicating minimal extraregional gene flow. The exceptions were Barton Ramie, Kaminaljuyu, and Seibal. A scaled R matrix analysis clarifies that genetic drift is a consideration for understanding Classic Maya population structure. All results indicate that isolation by distance does not describe Classic period Maya population structure. (c) 2006 Wiley-Liss, Inc.

  10. Cumulative Trauma Among Mayas Living in Southeast Florida.

    Science.gov (United States)

    Millender, Eugenia I; Lowe, John

    2016-01-04

    Mayas, having experienced genocide, exile, and severe poverty, are at high risk for the consequences of cumulative trauma that continually resurfaces through current fear of an uncertain future. Little is known about the mental health and alcohol use status of this population. This correlational study explored t/he relationship of cumulative trauma as it relates to social determinants of health (years in the United States, education, health insurance status, marital status, and employment), psychological health (depression symptoms), and health behaviors (alcohol use) of 102 Guatemalan Mayas living in Southeast Florida. The results of this study indicated that, as specific social determinants of health and cumulative trauma increased, depression symptoms (particularly among women) and the risk for harmful alcohol use (particularly among men) increased. Identifying risk factors at an early stage before serious disease or problems are manifest provides room for early screening leading to early identification, early treatment, and better outcomes.

  11. Amazing Maya Inventions You Can Build Yourself: New Book Designed to Help Kids Learn History of the Ancient Maya Civilization

    Science.gov (United States)

    Bell-Rehwoldt, Sheri

    2007-01-01

    In this article, the author describes her book, "Amazing Maya Inventions You Can Build Yourself," a new book designed to help kids learn the history of the ancient Maya civilization. "Amazing Maya Inventions You Can Build Yourself" offers the reader an engaging exploration of the history and culture of the Maya through building and crafts projects…

  12. Amazing Maya Inventions You Can Build Yourself: New Book Designed to Help Kids Learn History of the Ancient Maya Civilization

    Science.gov (United States)

    Bell-Rehwoldt, Sheri

    2007-01-01

    In this article, the author describes her book, "Amazing Maya Inventions You Can Build Yourself," a new book designed to help kids learn the history of the ancient Maya civilization. "Amazing Maya Inventions You Can Build Yourself" offers the reader an engaging exploration of the history and culture of the Maya through building and crafts projects…

  13. Clay Houses

    Science.gov (United States)

    Pedro, Cathy

    2011-01-01

    In this article, the author describes a project designed for fourth-graders that involves making clay relief sculptures of houses. Knowing the clay houses will become a family heirloom makes this lesson even more worth the time. It takes three classes to plan and form the clay, and another two to underglaze and glaze the final products.

  14. Clay and Anxiety Reduction: A One-Group, Pretest/Posttest Design with Patients on a Psychiatric Unit

    Science.gov (United States)

    Kimport, Elizabeth R.; Hartzell, Elizabeth

    2015-01-01

    Little research exists on using clay as an anxiety-reducing intervention with patients in psychiatric hospitals. This article reports on a study that used a one-group, pretest/posttest design with 49 adults in a psychiatric facility who created a clay pinch pot. The State-Trait Anxiety Inventory (STAI) was used as a pre- and posttest measure.…

  15. Clay and Anxiety Reduction: A One-Group, Pretest/Posttest Design with Patients on a Psychiatric Unit

    Science.gov (United States)

    Kimport, Elizabeth R.; Hartzell, Elizabeth

    2015-01-01

    Little research exists on using clay as an anxiety-reducing intervention with patients in psychiatric hospitals. This article reports on a study that used a one-group, pretest/posttest design with 49 adults in a psychiatric facility who created a clay pinch pot. The State-Trait Anxiety Inventory (STAI) was used as a pre- and posttest measure.…

  16. Algunas consideraciones sobre la arquitectura maya

    OpenAIRE

    Cejudo Collera, Mónica; DEPFA UNAM

    2013-01-01

    Con la finalidad de definir las variantes regionales y estilísticas que utilizaron los cons- tructores de la sociedad maya a lo largo de las varias etapas de su desarrollo, se estu- dian, en este artículo, los elementos que conforman las estructuras de la arquitectura maya. El resultado de este proceso de análisis permite ver cómo, a partir de una con- cepción global de la arquitectura y el urbanismo mayas, cada sitio se desarrolló sobre la base de su singularidad.

  17. Early Maya writing at San Bartolo, Guatemala.

    Science.gov (United States)

    Saturno, William A; Stuart, David; Beltrán, Boris

    2006-03-03

    The ruins of San Bartolo, Guatemala, contain a sample of Maya hieroglyphic writing dating to the Late Preclassic period (400 B.C. to 200 A.D.). The writing appears on preserved painted walls and plaster fragments buried within the pyramidal structure known as "Las Pinturas," which was constructed in discrete phases over several centuries. Samples of carbonized wood that are closely associated with the writing have calibrated radiocarbon dates of 200 to 300 B.C. This early Maya writing implies that a developed Maya writing system was in use centuries earlier than previously thought, approximating a time when we see the earliest scripts elsewhere in Mesoamerica.

  18. Tracking algorithms for the active target MAYA

    CERN Document Server

    Roger, T; Demonchy, C E; Mittig, W; Savajols, H; Tanihata, I

    2010-01-01

    The MAYA detector is a Time-Charge Projection Chamber based on the concept of active target. These type of devices use a part of the detection system, the filling gas in this case, in the role of reaction target. The MAYA detector performs three-dimensional tracking, in order to determine physical observables of the reactions occurring inside the detector. The reconstruction algorithms of the tracking use the information from a two-dimensional projection on the segmented cathode, and, in general, they need to be adapted for the different experimental settings of the detector. This work presents some of the most relevant solutions developed for the MAYA detector.

  19. Maya Studio Projects Game Environments and Props

    CERN Document Server

    McKinley, Michael

    2010-01-01

    Use Maya to create realistic environments and props for digital games. Weapons, vehicles, tools, buildings, trees, plants, walls, ceilings, and floors-these items may seem secondary to the game environment, but they are integral parts of the game and they all need to be created. Maya Studio Projects: Game Environments and Props is a step-by-step project guide to creating some of the most popular game art. Author Michael McKinley shares techniques for getting the most out of Maya to create realistic, vivid, and compelling worlds and otherworldly props. Along the way, he provides notes and FYIs

  20. Getting started in 3D with Maya

    CERN Document Server

    Watkins, Adam

    2012-01-01

    Deliver professional-level 3D content in no time with this comprehensive guide to 3D animation with Maya. With over 12 years of training experience, plus several award winning students under his belt, author Adam Watkins is the ideal mentor to get you up to speed with 3D in Maya. Using a structured and pragmatic approach Getting Started in 3D with Maya begins with basic theory of fundamental techniques, then builds on this knowledge using practical examples and projects to put your new skills to the test. Prepared so that you can learn in an organic fashion, each chapter builds on the know

  1. Directional layouts in central lowland Maya settlement

    DEFF Research Database (Denmark)

    Bevan, Andrew; Jobbová, Eva; Helmke, Christophe

    2013-01-01

    This paper suggests the existence of non-random, directional patterns in the location of housemounds across the Late Classic Maya settlement landscape at Baking Pot, Belize, and then explores the wider implications of this patterning in the central Maya lowlands. It introduces an anisotropic method......, by implication, also a set of routes running throughout the housemound landscape and local Maya neighbourhoods during the site’s Late and Terminal Classic history. Furthermore, different possible alignments in different parts of the site are tentatively regarded as an indication of shifting orientations...... to localised grids, following the shift in alignment of monumental architecture, as the settlement landscape expanded over time. Finally, we discuss the implications of these findings with respect to the broader interpretation of Maya settlement patterns....

  2. Climate and the Collapse of Maya Civilization

    National Research Council Canada - National Science Library

    Gerald H. Haug; Detlef Günther; Larry C. Peterson; Daniel M. Sigman; Konrad A. Hughen; Beat Aeschlimann

    2003-01-01

    .... A seasonally resolved record of titanium shows that the collapse of Maya civilization in the Terminal Classic Period occurred during an extended regional dry period, punctuated by more intense...

  3. Maya Angelou's Children's Books: Inspiration for Turning Poetry into Music

    Science.gov (United States)

    Beegle, Amy C.

    2014-01-01

    This column presents books for children penned by Maya Angelou. These poems and stories, based on her experiences as an African American woman living in the United States, Egypt, Ghana, and South Africa, include extraordinary photography and artwork. Suggestions for inclusion in the general music classroom are provided.

  4. Maya Angelou's Children's Books: Inspiration for Turning Poetry into Music

    Science.gov (United States)

    Beegle, Amy C.

    2014-01-01

    This column presents books for children penned by Maya Angelou. These poems and stories, based on her experiences as an African American woman living in the United States, Egypt, Ghana, and South Africa, include extraordinary photography and artwork. Suggestions for inclusion in the general music classroom are provided.

  5. Dibenzo-p-dioxins in the environment from ceramics and pottery produced from ball clay mined in the United States

    Science.gov (United States)

    Ferrario, Joseph; Byrne, Christian

    2002-01-01

    Processed ball clay samples used in the production of ceramics and samples of the ceramic products were collected and analyzed for the presence and concentration of the 2,3,7,8-Cl substituted polychlorinated dibenzo-p-dioxins and -furans (PCDDs/PCDFs). The processed ball clay had average PCDD concentrations of 3.2 ng/g toxic equivalents, a congener profile, and isomer distribution consistent with those found previously in raw ball clay. The PCDF concentrations were below the average limit of detection (LOD) of 0.5 pg/g. The final fired ceramic products were found to be free of PCDDs/PCDFs at the LODs. A consideration of the conditions involved in the firing process suggests that the PCDDs, if not destroyed, may be released to the atmosphere and could represent an as yet unidentified source of dioxins to the environment. In addition, the PCDDs in clay dust generated during manufacturing operations may represent a potential occupational exposure.

  6. Mapping the Ancient Maya Landscape from Space

    Science.gov (United States)

    Sever, Tom

    2003-01-01

    This project uses new satellite and airborne imagery in combination with remote sensing, GIS, and GPS technology to understand the dynamics of how the Maya successfully interacted with their karst topographic landscape for several centuries in the northern Peten region of Guatemala. The ancient Maya attained one of the greatest population densities in human history in the tropical forest of the Peten, Guatemala, and it was in this region that the Maya civilization began, flourished, and abruptly disappeared for unknown reasons around AD 800. How the Maya were able to successfully manage water and feed this dense population is not known at this time. However, a recent NASA-funded project was the first to investigate large seasonal swamps (bajos) that make up 40 percent of the landscape. Through the use of remote sensing, ancient Maya features such as cities, roadways, canals and water reservoirs have been detected and verified through ground reconnaissance. The results of this research cast new light on the adaptation of the ancient Maya to their environment. Micro-environmental variation within the wetlands was elucidated and the different vegetational associations identified in the satellite imagery. More than 70 new archeological sites within and at the edges of the bajo were mapped and tested. Modification of the landscape by the Maya in the form of dams and reservoirs in the Holmul River and its tributaries and possible drainage canals in bajos was demonstrated. The recent acquisition of one-meter IKONOS imagery and high resolution STAR-3i radar imagery (2.5m backscatter/ 10m DEM), opens new possibilities for understanding how a civilization was able to survive for centuries upon a karst topographic landscape and their human-induced effects upon the local climate. This understanding is critical for the current population that is presently experiencing rapid population growth and destroying the landscape through non-traditional farming and grazing techniques

  7. The small Maya AUV – Initial field results

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.; Madhan, R.; Maurya, P.; Navelkar, G.; Mascarenhas, A.A.M.Q.; Prabhudesai, S.; Afzulpurkar, S.; Bandodkar, S.N.

    sensors used here are placed within or external to the nose volume. Table 2 below lists the sensor payloads that have been used on the Maya AUV TABLE 2: Scientific sensor payloads used on Maya AUV Sensor used on Maya Manufacturer Range...

  8. Ownership of Language in Yucatec Maya Revitalization Pedagogy

    Science.gov (United States)

    Guerrettaz, Anne Marie

    2015-01-01

    This classroom-based study examined a Yucatec Maya language course for teachers and the pedagogical implementation of national language policy in Mexico. Analysis of this teacher education program focused on various dimensions of teachers' Maya-language expertise, the teaching of the emergent standard Maya, and hegemonic constructions of…

  9. Ownership of Language in Yucatec Maya Revitalization Pedagogy

    Science.gov (United States)

    Guerrettaz, Anne Marie

    2015-01-01

    This classroom-based study examined a Yucatec Maya language course for teachers and the pedagogical implementation of national language policy in Mexico. Analysis of this teacher education program focused on various dimensions of teachers' Maya-language expertise, the teaching of the emergent standard Maya, and hegemonic constructions of…

  10. Role of water on formation and structural features of Maya blue

    Science.gov (United States)

    Mondelli, C.; Sánchez del Río, M.; González, M. A.; Magazzú, A.; Cavallari, C.; Suárez, M.; García-Romero, E.; Romano, P.

    2012-02-01

    The Maya blue (MB) is an artificial pigment created between 500-800 A.D. and used in murals, pottery and sculptures by Mayas and other people in Mesoamerica. MB is resistant to age, acid, weathering, biodegradation and even modern chemical solvents, but the chemical reasons behind the resistance to chemical aggressions are still under debate. Water plays a fundamental role in the interactions between indigo and clay. The dynamics of the clay's zeolitic and structural water molecules during the formation of MB, usually stabilized by moderate heating, has been monitored by means of neutron inelastic scattering. Neutron incoherent scattering in these samples is only due to the hydrogen atoms, so the signal is very sensitive to the amount of released water, providing detailed information on the dehydration process. A simultaneous analysis of the coherent elastic scattering and the incoherent scattering allows observing and quantifying how the structure of the clay is affected by dehydration. Here we show that a quite resistant pigment can be obtained at room temperature simply by dehydrating a palygorskite-indigo mixture employing only vacuum, without any thermal treatment.

  11. Soil and Human Interactions in Maya Wetlands

    Science.gov (United States)

    Beach, Timothy; Luzzadder-Beach, Sheryl

    2013-04-01

    Since the early 1990s, we have studied Maya interaction with soils in Mexico, Belize, Guatemala, and elsewhere. We studied upland and lowland soils, but here we focus on seasonal or 'Bajo' wetlands and perennial wetlands for different reasons. Around the bajos, the ancient Maya focused on intensive agriculture and habitation despite the difficulties their Vertisol soils posed. For the perennial wetlands, small populations spread diffusely through Mollisol and Histisol landscapes with large scale, intensive agro-ecosystems. These wetlands also represent important repositories for both environmental change and how humans responded in situ to environmental changes. Work analyzing bajo soils has recorded significant diversity but the soil and sediment record shows two main eras of soil instability: the Pleistocene-Holocene transition as rainfall fluctuated and increased and tropical forest pulsed through the region, and the Maya Preclassic to Classic 3000 to 1000 BP as deforestation, land use intensity, and drying waxed and waned. The ancient Maya adapted their bajo soil ecosystems successfully through agro-engineering but they also withdrew in many important places in the Late Preclassic about 2000 BP and Terminal Classic about 1200 BP. We continue to study and debate the importance of perennial wetland agro-ecosystems, but it is now clear that Maya interaction with these soil landscapes was significant and multifaceted. Based on soil excavation and coring with a broad toolkit of soil stratigraphy, chemistry, and paleoecology from 2001 to 2013, our results show the ancient Maya interacted with their wetland soils to maintain cropland for maize, tree crops, arrow root, and cassava against relative sea level rise, increased flooding, and aggradation by gypsum precipitation and sedimentation. We have studied these interactions across an area of 2000 km2 in Northern Belize to understand how Maya response varied and how these soil environments varied over time and distance

  12. Paralelismo, ciclicidad y creatividad en el arte verbal maya yucateco

    Directory of Open Access Journals (Sweden)

    Valentina Vapnarsky

    2008-01-01

    Full Text Available Este artículo contribuye a demostrar que el recurso discursivo del paralelismo en la tradición maya juega un papel esencial en diferentes niveles de organización discursiva, y no sólo en cuanto al verso y unidades contiguas como se ha señalado generalmente. Analizamos la variedad de niveles en los cuales se pueden desarrollar los paralelismos, así como la relación con otras figuras retóricas, en especial la ciclicidad, que se destaca como un recurso importante para el despliegue de paralelismos entre unidades distanciadas. El análisis se hace mediante el estudio detallado de un diálogo ritual de la peregrinación de San Juan Bautista entre los mayas macehuales (cruso'ob de Quintana Roo (México. Confirma que los paralelismos discursivos se deben considerar no sólo como elementos estéticos o poéticos, con sus efectos emocionales y enfáticos, sino también como procesos de organización macrodiscursiva, con funciones temáticas, semánticas y pragmáticas.In this paper we argue that parallelism as a discursive recourse in the Maya oral tradition plays a crucial role at different levels of discursive organization, and not only at the level of the verse and contiguous units as is generally assumed. We analyze the variety of levels at which parallelisms are at play, as well as the relation of parallelism with other rhetorical figures, in particular cyclicity which stands out as an important recourse for the deployment of parallelisms through distant units. The analysis is based on a detailed study of a ritual dialogue of San Juan Bautista's peregrination among the Maya Macehuales (cruso'ob from Quintana Roo (Mexico. it confirms that discursive parallelisms must be considered not only as esthetical or poetical elements, with their emotional and emphatic effects, but also as procedures of macro-discursive organization, with thematic, semantic and pragmatic functions.

  13. The nature of porosity in organic-rich mudstones of the Upper Jurassic Kimmeridge Clay Formation, North Sea, offshore United Kingdom

    Science.gov (United States)

    Fishman, Neil S.; Hackley, Paul C.; Lowers, Heather; Hill, Ronald J.; Egenhoff, Sven O.; Eberl, Dennis D.; Blum, Alex E.

    2012-01-01

    Analyses of organic-rich mudstones from wells that penetrated the Upper Jurassic Kimmeridge Clay Formation, offshore United Kingdom, were performed to evaluate the nature of both organic and inorganic rock constituents and their relation to porosity in this world-class source rock. The formation is at varying levels of thermal maturity, ranging from immature in the shallowest core samples to mature in the deepest core samples. The intent of this study was to evaluate porosity as a function of both organic macerals and thermal maturity. At least four distinct types of organic macerals were observed in petrographic and SEM analyses and they all were present across the study area. The macerals include, in decreasing abundance: 1) bituminite admixed with clays; 2) elongate lamellar masses (alginite or bituminite) with small quartz, feldspar, and clay entrained within it; 3) terrestrial (vitrinite, fusinite, semifusinite) grains; and 4) Tasmanites microfossils. Although pores in all maceral types were observed on ion-milled surfaces of all samples, the pores (largely nanopores with some micropores) vary as a function of maceral type. Importantly, pores in the macerals do not vary systematically as a function of thermal maturity, insofar as organic pores are of similar size and shape in both the immature and mature Kimmeridge rocks. If any organic pores developed during the generation of hydrocarbons, they were apparently not preserved, possibly because of the highly ductile nature of much of the rock constituents of Kimmeridge mudstones (clays and organic material). Inorganic pores (largely micropores with some nanopores) have been observed in all Kimmeridge mudstones. These pores, particularly interparticle (i.e., between clay platelets), and intraparticle (i.e., in framboidal pyrite, in partially dissolved detrital K-feldspar, and in both detrital and authigenic dolomite) are noteworthy because they compose much of the observable porosity in the shales in both

  14. The Ancient Maya Landscape from Space

    Science.gov (United States)

    Sever, T.; Arnold, James E. (Technical Monitor)

    1999-01-01

    The Peten, once inhabited by a population of several million before the collapse of the ancient Maya in the 10th and 11th centuries, is being repopulated toward its former demographic peak. Environmental dynamics, however, impose severe constraints to further development. Current practices in subsistence, commercial agriculture, and cattle raising are causing rapid deforestation resulting in the destruction of environmental and archeological resources. The use of remote sensing and Geographic Information Systems (GIS) technology is a cost-effective methodology for addressing issues in Maya archeology as well as monitoring the environmental impacts being experienced by the current population.

  15. The Ancient Maya Landscape from Space

    Science.gov (United States)

    Sever, T.; Arnold, James E. (Technical Monitor)

    1999-01-01

    The Peten, once inhabited by a population of several million before the collapse of the ancient Maya in the 10th and 11th centuries, is being repopulated toward its former demographic peak. Environmental dynamics, however, impose severe constraints to further development. Current practices in subsistence, commercial agriculture, and cattle raising are causing rapid deforestation resulting in the destruction of environmental and archeological resources. The use of remote sensing and Geographic Information Systems (GIS) technology is a cost-effective methodology for addressing issues in Maya archeology as well as monitoring the environmental impacts being experienced by the current population.

  16. Mythological Emblem Glyphs of Ancient Maya Kings

    DEFF Research Database (Denmark)

    Helmke, Christophe

    2012-01-01

    Heinrich Berlin’s identification of Emblem Glyphs in 1958 has rightly been hailed as one of the major breakthroughs in the decipherment of ancient Maya writing. Although their exact function and meaning was unclear at the time, these are now recognized to serve as exalted regal titles that incorp......Heinrich Berlin’s identification of Emblem Glyphs in 1958 has rightly been hailed as one of the major breakthroughs in the decipherment of ancient Maya writing. Although their exact function and meaning was unclear at the time, these are now recognized to serve as exalted regal titles...

  17. Mapping The Ancient Maya Landscape From Space

    Science.gov (United States)

    Sever, Tom; Arnold, James E. (Technical Monitor)

    2002-01-01

    The Peten region of northern Guatemala is one of the last places on earth where major archeological sites remain to be discovered. It was in this region that the Maya civilization began, flourished, and abruptly disappeared. Remote sensing technology is helping to locate and map ancient Maya sites that are threatened today by accelerating deforestation and looting. Thematic Mapper and IKONOS satellite and airborne Star3-I radar data, combined with Global Positioning System (GPS) technology, are successfully detecting ancient Maya features such as cities, roadways, canals, and water reservoirs. Satellite imagery is also being used to map the bajos, which are seasonally flooded swamps that cover over 40% of the land surface. The use of bajos for farming has been a source of debate within the professional community for many years. But the recent detection and verification of cultural features within the bajo system by our research team are providing conclusive evidence that the ancient Maya had adapted well to wetland environments from the earliest times and utilized them until the time of the Maya collapse. The use of the bajos for farming is also an important resource for the future of the current inhabitants who are experiencing rapid population growth. Remote sensing imagery is also demonstrating that in the Preclassic period (600 BC- AD 250), the Maya had already achieved a high organizational level as evidenced by the construction of massive temples and an elaborate inter-connecting roadway system. Although they experienced several setbacks such as droughts and hurricanes, the Maya nevertheless managed the delicate forest ecosystem successfully for several centuries. However, around AD 800, something happened to the Maya to cause their rapid decline and eventual disappearance from the region. The evidence indicates that at this time there was increased climatic dryness, extensive deforestation, overpopulation, and widespread warfare. This raises a question that

  18. Maya Studio Projects Texturing and Lighting

    CERN Document Server

    Lanier, Lee

    2011-01-01

    Learn to create realistic digital assets for film and games with this project-based guide Focused entirely on practical projects, this hands-on guide shows you how to use Maya's texturing and lighting tools in real-world situations. Whether you need to sharpen your skills or you're looking to break into the field for the first time, you'll learn top industry techniques for this important skill as you follow the instructions for several specific projects. You can even create your own version, using final Maya scene files to validate results. The companion DVD includes supplemental videos, proje

  19. The Language of Classic Maya Inscriptions1.

    Science.gov (United States)

    Houston; Robertson; Stuart

    2000-06-01

    Recent decipherments of Classic Maya hieroglyphs (ca. a.d. 250 to 850) reveal phonological and morphological patterns that, through epigraphic and historical analyses, isolate a single, coherent prestige language with unique and widespread features in script. We term this language "Classic Ch'olti'an" and present the evidence for its explicable historical configuration and ancestral affiliation with Eastern Ch'olan languages (Ch'olti' and its still-viable descendant, Ch'orti'). We conclude by exploring the possibility that Ch'olti'an was a prestige language that was shared by elites, literati, and priests and had a profound effect on personal and group status in ancient Maya kingdoms.

  20. The 'End' of the Maya Long Count? 2012 and the Classic Maya

    National Research Council Canada - National Science Library

    Boot, Erik

    2013-01-01

    .... In the year of 2012 this particular subject was chosen as various non- and pseudo-scientific and New Age publications hold that the Maya Long Count ends in 2012, more specifically on December 21...

  1. The Source of Volcanic Ash in Late Classic Maya Pottery at El Pilar, Belize

    Science.gov (United States)

    Catlin, B. L.; Ford, A.; Spera, F. J.

    2007-12-01

    The presence of volcanic ash used as temper in Late Classic Maya pottery (AD 600-900) at El Pilar has been long known although the volcano(s) contributing ash have not been identified. We use geochemical fingerprinting, comparing compositions of glass shards in potsherds with volcanic sources to identify the source(s). El Pilar is located in the Maya carbonate lowlands distant from volcanic sources. It is unlikely Maya transported ash from distant sites: ash volumes are too large, the terrain too rugged, and no draft animals were available. Ash layer mining is unlikely because mine sites have not been found despite intensive surveys. Nearest volcanic sources to El Pilar, Belize and Guatemala, are roughly 450 km to the south and east. The ash found in potsherds has a cuspate morphology. This suggests ash was collected during, or shortly after, an ash airfall event following eruption. Analyses of n=333 ash shards from 20 ceramic (pottery) sherds was conducted by electron microprobe for major elements, and LA-ICPMS for trace elements and Pb isotopes. These analyses can be compared to volcanic materials from candidate volcanoes in the region. The 1982 El Chichon eruption caused airfall deposition (pot firing on glass compositional changes, experiments were conducted in which high silica volcanic glass was fired with clay according to heating schedules used by Maya potters. Two important changes are that Na is rapidly lost preferentially to K and that the Si/Ca ratio decreases due to Ca diffusion from matrix into glass during firing. One expects that ratios of the refractory trace elements such as La/Yb and Zr/Hf are less susceptible to modification. Further experiments of trace element mobility during firing are underway.

  2. Discovering the Ancient Maya from Space

    Science.gov (United States)

    Sever, T. L.

    2008-01-01

    The Pet6n region of northern Guatemala contains some of the most significant Mayan archeological sites in Latin America. It was in this region that the Maya civilization began, flourished, and abruptly disappeared. Remote sensing technology is helping to locate and map ancient Maya sites that are threatened today by accelerating deforestation and looting. Thematic Mapper, IKONOS, and QuickBird satellite, and airborne STAR-3i and AIRSAR radar data, combined with Global Positioning System (GPS) technology, are successfully detecting ancient Maya features such as sites, roadways, canals, and water reservoirs. Satellite imagery is also being used to map the bajos, which are seasonally flooded swamps that cover over 40% of the land surface. Through the use of various airborne and satellite sensor systems we have been able to detect and map ancient causeways, temples, reservoirs, and land forms, and locate these features on the ground through GPS technology. Recently, we have discovered that there is a strong relationship between a tropical forest vegetation signature in satellite imagery and the location of archeological sites. We believe that the use of limestone and lime plasters in ancient Maya construction affects the moisture, nutrition, and plant species of the surface vegetation. We have mapped these vegetation signatures in the imagery and verified through field survey that they are indicative of archeological sites. Through the use of remote sensing and GIS technology it is possible to identify unrecorded archeological features in a dense tropical forest environment and monitor these cultural features for their protection.

  3. Maya Angelou's "Letter to My Daughter"

    Science.gov (United States)

    Grady, Marilyn L.

    2008-01-01

    This article highlights the works of two prolific authors: James Bryant Conant and Maya Angelou. Among the books Conant wrote were: "The American High School Today" (1959), "Slums and Suburbs" (1961), "The Education of American Teachers" (1963), and "The Comprehensive High School" (1967). On the other hand, Angelou's series of autobiographical…

  4. Maya Divination: Ritual Techniques of Distributed Cognition

    DEFF Research Database (Denmark)

    McGraw, John J.

    2016-01-01

    Based on more than 24 months of ethnographic research among Maya ritualists in the western highlands of Guatemala, this article examines how pajooneem, or tz’ite’ seed divination, facilitates decision-making and distributes cognition between client, diviner, and ritual techniques. Tz’ite’ seed...

  5. Personhood in Maya Art : a theoretical perspective

    NARCIS (Netherlands)

    Osorio, Laura Ann

    2015-01-01

    In contrast to a traditional ethno-archaeological approach, in which contemporary communities are mined for information that can be applied to the past, this study considers that the interpretation of Maya material culture belongs to the people whose identity has been formed within the natural and m

  6. Maya Angelou's "Letter to My Daughter"

    Science.gov (United States)

    Grady, Marilyn L.

    2008-01-01

    This article highlights the works of two prolific authors: James Bryant Conant and Maya Angelou. Among the books Conant wrote were: "The American High School Today" (1959), "Slums and Suburbs" (1961), "The Education of American Teachers" (1963), and "The Comprehensive High School" (1967). On the other hand, Angelou's series of autobiographical…

  7. Personhood in Maya Art : a theoretical perspective

    NARCIS (Netherlands)

    Osorio, Laura Ann

    2015-01-01

    In contrast to a traditional ethno-archaeological approach, in which contemporary communities are mined for information that can be applied to the past, this study considers that the interpretation of Maya material culture belongs to the people whose identity has been formed within the natural and

  8. Discovering the Ancient Maya from Space

    Science.gov (United States)

    Sever, T. L.

    2008-01-01

    The Pet6n region of northern Guatemala contains some of the most significant Mayan archeological sites in Latin America. It was in this region that the Maya civilization began, flourished, and abruptly disappeared. Remote sensing technology is helping to locate and map ancient Maya sites that are threatened today by accelerating deforestation and looting. Thematic Mapper, IKONOS, and QuickBird satellite, and airborne STAR-3i and AIRSAR radar data, combined with Global Positioning System (GPS) technology, are successfully detecting ancient Maya features such as sites, roadways, canals, and water reservoirs. Satellite imagery is also being used to map the bajos, which are seasonally flooded swamps that cover over 40% of the land surface. Through the use of various airborne and satellite sensor systems we have been able to detect and map ancient causeways, temples, reservoirs, and land forms, and locate these features on the ground through GPS technology. Recently, we have discovered that there is a strong relationship between a tropical forest vegetation signature in satellite imagery and the location of archeological sites. We believe that the use of limestone and lime plasters in ancient Maya construction affects the moisture, nutrition, and plant species of the surface vegetation. We have mapped these vegetation signatures in the imagery and verified through field survey that they are indicative of archeological sites. Through the use of remote sensing and GIS technology it is possible to identify unrecorded archeological features in a dense tropical forest environment and monitor these cultural features for their protection.

  9. Climate Change and Classic Maya Water Management

    National Research Council Canada - National Science Library

    Lucero, Lisa J; Gunn, Joel D; Scarborough, Vernon L

    2011-01-01

    .... We show not only how Classic Maya (ca. A.D. 250-950) society dealt with the annual seasonal extremes, but also how kings and farmers responded differently in the face of a series of droughts in the Terminal Classic period (ca. A.D. 800-950...

  10. Algunas consideraciones sobre los numerales mayas

    Directory of Open Access Journals (Sweden)

    Oscar Fernández Sánchez

    2014-09-01

    Full Text Available Para los mayas, a diferencia de Occidente, la matemática tiene un significado que sobrepasa los numerales y las operaciones entre ellos. Según su cosmovisión, la Deidad, la creadora del universo, es soberana en cuanto al cálculo matemático (Cabrera, 1992. La matemática maya ofrece la posibilidad de realizar las operaciones aritméticas de suma, resta, multiplicación, división y cálculo de raíces de forma sencilla, dado que la cultura maya logró sintetizar la cantidad mediante tres símbolos y logró sintetizar el valor con el sistema posicional en base veinte (Calderón, 1966. Se pretende en este artículo hacer un reconocimiento de los numerales mayas, su concepción metafórica y algunas operaciones aritméticas.

  11. Egyptians, Maya, Minoans. Learning Works Enrichment Series.

    Science.gov (United States)

    Matthies, Susanna

    The activities in this instructional resource book are designed to be used by gifted 4-8th grade students as independent research guides or in guided or cooperative learning environments. The activities are organized in three sections which focus the ancient civilizations of Egypt, Maya, and Minoa. The activities presented encourage development of…

  12. Does the Maya Forest Need More Roads?

    DEFF Research Database (Denmark)

    Conde, Dalia Amor; Ramos, Victor Hugo; Burgués, Irene

    , habitat fragmentation and forest fire were projected for a larger set of projects. We used two separate models to predict these impacts, one focused on just Guatemala's Maya Biosphere Reserve, and the other looking at a larger, three-country area. Our projections indicate that if all the projects...

  13. Earth. Water. Sky. The Liminal Landscape of the Maya Sweatbath

    OpenAIRE

    Miller, Catherine Annalisa

    2013-01-01

    This dissertation investigates the ancient healing tradition of the Maya sweatbath, its landscape, and rituals, which after three millennia is still practiced today among the contemporary Maya. Frequently overlooked because of its size, the ancient Maya sweatbath's location in ancient ceremonial cores, royal courts, and near important ritual structures and sacred water features accentuates its importance and need to understand its role, siting, and connection with the landscape. A three ste...

  14. Des quartiers chez les Mayas à l’époque classique ?

    OpenAIRE

    Lemonnier, Éva

    2014-01-01

    Des quartiers chez les Mayas à l’époque classique ? En dépit de la richesse des données archéologiques, ethnographiques et ethnohistoriques sur la question des quartiers (ou unités définies comme telles) dans les sociétés mayas postclassiques, historiques et contemporaines, pour la période classique, ce type d’unité de regroupement, intermédiaire entre l’habitat élémentaire (la famille étendue) et l’établissement (la communauté), est loin d’être avéré. Depuis trente ans, ce modèle d’organisat...

  15. Stars Influence on the Earth in Maya Culture: Stars and Planets in Maya Culture

    Directory of Open Access Journals (Sweden)

    Emanuel George Oprea

    2015-11-01

    Full Text Available The Mesoamerican Culture of Maya’s was one of the ancient and advanced cultures of the American continent and they influenced other Amerindian peoples. The life of Maya people, of the Earth itself and of the Universe is set and constructed around Maya Calendar and has a cyclic character as a direct influence of the stars. Many centuries the Western civilization with the its linear Calendar had not accepted the ideas of the possible influence of the stars and planets to peoples lives. The end of the last century and the beginning of XXI’s had started to demonstrate the opposite. The present work tries to show the process of meeting and intersection of the ancient ideas of Maya civilization and some of new ideas from the modern sciences.

  16. Cell scientist to watch--Maya Schuldiner.

    Science.gov (United States)

    Schuldiner, Maya; Bobrowska, Anna

    2015-11-15

    Maya Schuldiner pursued her PhD degree under the guidance of Prof. Nissim Benvenisty at the Hebrew University in Jerusalem. She carried out her postdoctoral training in the laboratory of Prof. Jonathan Weissman at the University of California, San Francisco, with support from the Human Frontiers Science Program and the Sandler Fellows Program. Since 2008, Maya has been running her own laboratory at the Weizmann Institute of Sciences in Rehovot, Israel. She received the Human Frontiers Science Program Career Development Award and the NIH Pathway to Independence Award, and she is a member of the EMBO Young Investigator programme and Faculty of 1000. Her current research interests are focused on unravelling novel functions of yeast proteins that are involved in organelle biology. © 2015. Published by The Company of Biologists Ltd.

  17. Ancient Maya astronomical tables from Xultun, Guatemala.

    Science.gov (United States)

    Saturno, William A; Stuart, David; Aveni, Anthony F; Rossi, Franco

    2012-05-11

    Maya astronomical tables are recognized in bark-paper books from the Late Postclassic period (1300 to 1521 C.E.), but Classic period (200 to 900 C.E.) precursors have not been found. In 2011, a small painted room was excavated at the extensive ancient Maya ruins of Xultun, Guatemala, dating to the early 9th century C.E. The walls and ceiling of the room are painted with several human figures. Two walls also display a large number of delicate black, red, and incised hieroglyphs. Many of these hieroglyphs are calendrical in nature and relate astronomical computations, including at least two tables concerning the movement of the Moon, and perhaps Mars and Venus. These apparently represent early astronomical tables and may shed light on the later books.

  18. Ancient Maya Astronomical Tables from Xultun, Guatemala

    Science.gov (United States)

    Saturno, William A.; Stuart, David; Aveni, Anthony F.; Rossi, Franco

    2012-05-01

    Maya astronomical tables are recognized in bark-paper books from the Late Postclassic period (1300 to 1521 C.E.), but Classic period (200 to 900 C.E.) precursors have not been found. In 2011, a small painted room was excavated at the extensive ancient Maya ruins of Xultun, Guatemala, dating to the early 9th century C.E. The walls and ceiling of the room are painted with several human figures. Two walls also display a large number of delicate black, red, and incised hieroglyphs. Many of these hieroglyphs are calendrical in nature and relate astronomical computations, including at least two tables concerning the movement of the Moon, and perhaps Mars and Venus. These apparently represent early astronomical tables and may shed light on the later books.

  19. Delineating genetic relationships among the Maya.

    Science.gov (United States)

    Ibarra-Rivera, Lisa; Mirabal, Sheyla; Regueiro, Manuela M; Herrera, Rene J

    2008-03-01

    By 250 AD, the Classic Maya had become the most advanced civilization within the New World, possessing the only well-developed hieroglyphic writing system of the time and an advanced knowledge of mathematics, astronomy and architecture. Though only ruins of the empire remain, 7.5 million Mayan descendants still occupy areas of Mexico, Guatemala, Belize, El Salvador, and Honduras. Although they inhabit distant and distinct territories, speak more than 28 languages, and have been historically divided by warfare and a city-state-like political system, and they share characteristics such as rituals, artistic, architectural motifs that distinguish them as unequivocally Maya. This study was undertaken to determine whether these similarities among Mayan communities mirror genetic affinities or are merely a reflection of their common culture. Four Mayan populations were investigated (i.e., the K'iche and Kakchikel from Guatemala and the Campeche and Yucatan from Mexico) and compared with previously published populations across 15 autosomal STR loci. As a whole, the Maya emerge as a distinct group within Mesoamerica, indicating that they are more similar to each other than to other Mesoamerican groups. The data suggest that although geographic and political boundaries existed among Mayan communities, genetic exchanges between the different Mayan groups have occurred, supporting theories of extensive trading throughout the empire.

  20. Mineralogy and Geochemistry of Upper Maastrichtian-Middle Eocene Clay - Rich Volcano - Sedimentary Units from South-Eastern of Elazıg Basin (Eastern Turkey)

    Science.gov (United States)

    Akkoca, Dicle Bal; Daş, Burhan

    2017-04-01

    Clay-rich Hazar-Maden volcano-sediments were deposited along the southern branch of the Neotethys Ocean margin during Upper Maastrichtian - Middle Eocene times. Mineralogy and geochemistry of Hatunkoy section from the south - easthern of Elazıg were studied by X-ray powder diffraction (XRD), ICP-AES, ICP-MS. The Upper Jurassic - Lower Cretaceous Guleman Ophiolites, Upper Maastrichtian - Middle Eocene Hazar Group, the Middle Eocene Maden Group, Pliocene-Quaternary alluvial deposits are situated in the study area. The Guleman Ophiolites are composed of dunite, harzburgite with podiform chromite, alternating dunite-wherlite, clinopyroxenite banded gabbro, quartz gabbro/diorite or plagiogranite and volcanites. The Hazar Group consists of limestone and interbedded shale and sandstone. The Maden Group has a complex lithology consisting of limestones, red-green clayey limestones, sandstone, agglomerate, tuffs, reddish mudstone and basaltic-andesitic pillow lavas. Mineralogy and geochemistry of Hazar and Maden Group samples are similar in Hatunkoy section. All samples consist of clay minerals (chlorite, illite), calcite, quartz, and feldspar. SiO2, Al2O3, Fe2O3, K2O contents show that samples are convenient with Fe shales and shales. The ratios of Zr/TiO2, Th/Sc, Zr/Sc, Y/Ni-Cr/V, Al/(Al+Fe+Mn) show dominance of neutral-basic volcanism in the area. Rare earth elements (REE) concentrations of samples are normalized to chondrite values and it is determined that low light rare earth elements (LREEs) are enriched in comparison to high rare earth elements (HREEs), and the absence of Eu anomalies shows that our samples are generally neutral-basic in composition. REE of samples were compared with North American shale composite (NASC), European shale (ES) and Post-Archean Australian shale (PAAS). Elements are not in concurrence with these compositions. Key Words:Mineralogy, Geochemistry, Volcano sedimentary Units, Eastern Turkey.

  1. Area group: an example of style and paste compositional covariation in Maya pottery

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, R.L.; Reents, D.J.; Harbottle, G.; Sayre, E.V.; van Zelst, L.

    1983-06-12

    This paper has addressed aspects of ceramic style and iconography as found in Late Classic Maya ceramic art, including the supplemental perspective afforded by the analysis of ceramic paste. The chemical data provide a means to assess the extent of stylistic-paste compositional covariation. Depending upon the strength of that covariation various inferences may be drawn about craft specialization, exchange and information flow within Maya society. At the least, it provides an empirical means of comparing stylistically similar vessels; and when they are members of a chemically homogeneous group, it permits style to be addressed in terms of its variation. Additionally, compositionally defined site or region specific reference units provide a chemical background against which the non-provenienced vessels may be compared, allowing the whole vessels to be related to the archaelogically recovered fragmentary material. Finally, this multidisciplinary approach has been illustrated by preliminary findings concerning a specific group of polychrome vessels, The Area Group.

  2. Handle with Care: A Conversation with Maya Angelou

    Science.gov (United States)

    Azzam, Amy M.

    2013-01-01

    The author opens this conversation with noted educator and authoress, Maya Angelou, by asking: "How does resilience develop, and how can we instill it in others?" Azzam notes that if there is anyone who knows something about "resilience" (the theme of this issue of "Educational Leadership") it is Maya Angelou. Dr.…

  3. The Construction of Orthography by Maya-Speaking Children.

    Science.gov (United States)

    Pellicer, Alejandra

    A discussion of the language skills of Maya-speaking children in Mexico describes the relationship of Maya and Spanish languages in this population's education and reports on a study of the construction of orthography by these children. The study first examines how language is used in literacy education and the difficulties of literacy in a…

  4. The Mayas of Yucatan, Mexico: Their Fight against School Dropout

    Science.gov (United States)

    Mijangos-Noh, Juan Carlos; Cardos-Dzul, Maria Paula

    2011-01-01

    This article analyzes the strategies that a sample of Maya men and women of Yucatan, Mexico used to avoid dropping out of school. Data from in-depth interviews, focus groups and life stories were analyzed using grounded theory techniques through a non-essentialist gender approach. Among the Maya, statistics show that women drop out of school…

  5. Deciphering Maya Hieroglyphic Writing: The State of the Art.

    Science.gov (United States)

    Fields, Virginia M.

    1990-01-01

    Describes the historical approaches to the decipherment of ancient Maya writing. Asserts that Mayan hieroglyphics are recognized as true writing because they represent the sounds and structure of spoken language. Discusses the history of Maya hieroglyphic writing and how it was used in that civilization. (PRA)

  6. Maya: A Simulation of Mayan Civilization during the Seventh Century.

    Science.gov (United States)

    Roth, Peter

    This simulation allows students to explore the lives of the great rulers of the Mayan culture. Students learn the mysterious history of the Maya by decoding glyphs, investigating the unusual religion of the Maya, unraveling the complex Mayan calendar, and discovering the Mayan number system's secret meanings. Specific cooperation skills are taught…

  7. Handle with Care: A Conversation with Maya Angelou

    Science.gov (United States)

    Azzam, Amy M.

    2013-01-01

    The author opens this conversation with noted educator and authoress, Maya Angelou, by asking: "How does resilience develop, and how can we instill it in others?" Azzam notes that if there is anyone who knows something about "resilience" (the theme of this issue of "Educational Leadership") it is Maya Angelou. Dr.…

  8. Deciphering Maya Hieroglyphic Writing: The State of the Art.

    Science.gov (United States)

    Fields, Virginia M.

    1990-01-01

    Describes the historical approaches to the decipherment of ancient Maya writing. Asserts that Mayan hieroglyphics are recognized as true writing because they represent the sounds and structure of spoken language. Discusses the history of Maya hieroglyphic writing and how it was used in that civilization. (PRA)

  9. The Mayas of Yucatan, Mexico: Their Fight against School Dropout

    Science.gov (United States)

    Mijangos-Noh, Juan Carlos; Cardos-Dzul, Maria Paula

    2011-01-01

    This article analyzes the strategies that a sample of Maya men and women of Yucatan, Mexico used to avoid dropping out of school. Data from in-depth interviews, focus groups and life stories were analyzed using grounded theory techniques through a non-essentialist gender approach. Among the Maya, statistics show that women drop out of school…

  10. A dearth of hurricanes cannot explain Maya collapse

    Science.gov (United States)

    Schultz, Colin

    2014-12-01

    A thousand years ago the great Maya culture of Central America collapsed. Climate change was one factor that stressed the civilization until it fractured: A prolonged period of intense and persistent drought left the Maya's descendants to carry on without a robust elite urban class.

  11. Stones of Light: The Use of Crystals in Maya Divination

    DEFF Research Database (Denmark)

    McGraw, John J.

    2016-01-01

    In this chapter, I aim to bridge the rewarding archaeological contributions from the earlier part of this volume to ethnographic work performed among contemporary Mayas, particularly as informed by ritual specialists. In considering the ritual use of quartz crystals by living Mayas we may gain...... of functional analysis that situate archaeological and ethnographic data without projecting a particularism onto Maya contexts that may be inappropriate given the local epistemologies. Finally, I draw from cognitive science and religious studies to present a theory regarding the popularity and importance...... of quartz crystals in ritual activity, not only among the Maya, but worldwide. It is hoped that the analyses presented not only clarify ideas regarding quartz crystals in divination, but more broadly address the nature and importance of scrying in Maya religion....

  12. Maternal maya ancestry and birth weight in Yucatan, Mexico.

    Science.gov (United States)

    Azcorra, Hugo; Vázquez-Vázquez, Adriana; Mendez, Nina; Carlos Salazar, Juan; Datta-Banik, Sudip

    2016-05-01

    The purpose of this study was to analyze the association between maternal Maya ancestry and the birth weight of infants born in Yucatan, Mexico, during 2013. A total of 30,435 singletons born at term (≥37 weeks) in Yucatan during 2013 were analyzed. Birth weights, gestational ages, and maternal socioeconomic data were provided by the Ministry of Health of Yucatan. Maternal Maya ancestry was defined by the presence of Maya surnames in: (1) non-Maya surnames (NM-NM), (2) one Maya surname (NM-M), and (3) two Maya surnames (M-M). Biological and socioeconomic parameters were compared between the categories of ancestry through one-way analysis of variance (ANOVA) and a multiple regression model was used to analyze the association between ancestry and infants' birth weight controlling for influence of covariates. Mean birth weight was 3,114 g (SD = 406) (NM-NM: 3,150 g [SD = 404], NM-M: 3,106 g [SD = 402], M-M: 3,088 g [SD = 408]). With the biological and socioeconomic variables statistically adjusted for, the presence of one and two maternal Maya surnames was associated with decreases in birth weight of 42 g and 63 g, respectively. None of the interactions between ancestry and other predictors was statistically significant. The lower mean birth weights of Maya infants are consistent with studies reporting poor growth and nutritional status of Maya children from Yucatan. Historically adverse socioeconomic conditions experienced by the Maya population are probably linked to the relatively lower birth weights of their infants. Am. J. Hum. Biol. 28:436-439, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  13. Prominence in Yucatec Maya: The Role of Stress in Yucatec Maya Words

    Science.gov (United States)

    Kidder, Emily

    2013-01-01

    Yucatec Maya (YM) is an indigenous language of Mexico that features both phonemic tonal distinctions and phonemic vowel length. These features are primarily associated with the phonetic cues of pitch and duration, which are also considered the primary correlates of stress in language. Though scholars have noted the existence of stress or accent…

  14. Prominence in Yucatec Maya: The Role of Stress in Yucatec Maya Words

    Science.gov (United States)

    Kidder, Emily

    2013-01-01

    Yucatec Maya (YM) is an indigenous language of Mexico that features both phonemic tonal distinctions and phonemic vowel length. These features are primarily associated with the phonetic cues of pitch and duration, which are also considered the primary correlates of stress in language. Though scholars have noted the existence of stress or accent…

  15. The ‘End’ of the Maya Long Count? 2012 and the Classic Maya

    Directory of Open Access Journals (Sweden)

    Erik Boot

    2013-06-01

    Full Text Available The second meeting of the AISI (Associazione Italiana Studi Iberoamericani was dedicated to “Apocalypse” in Latin American literature. In the year of 2012 this particular subject was chosen as various non- and pseudo-scientific and New Age publications hold that the Maya Long Count ends in 2012, more specifically on December 21. In this essay I present a short overview on how the idea of an ‘end’ of the Maya Long Count emerged, which ancient Maya hieroglyphic texts (from the Late Classic Maya period, ca. A.D. 550-900 refer to this particular date, and what the only text (from the site of Tortuguero, Tabasco, Mexico that may tell us something on 2012 reveals. I also present a short historic overview of the quality of the drawing of the Tortuguero text and how these influenced earlier decipherments, translations, and interpretations of this text. Ultimately, the hieroglyphic text itself is analyzed and one detail is discusses in more detail, the verb root tzutz- and which different, but not necessarily mutually exclusive, meanings it has in Mayan languages.

  16. Quantitative approach on SEM images of microstructure of clay soils

    Institute of Scientific and Technical Information of China (English)

    施斌; 李生林; M.Tolkachev

    1995-01-01

    The working principles of Videolab Image Processing System (VIPS), the examining methods of orientation of microstructural units of clay soils and analysing results on SEM images of some typical microstructures of clay soils using the VIPS are introduced.

  17. Synchrotron and simulations techniques applied to problems in materials science: catalysts and Azul Maya pigments.

    Science.gov (United States)

    Chianelli, Russell R; Perez De la Rosa, Myriam; Meitzner, George; Siadati, Mohammed; Berhault, Gilles; Mehta, Apurva; Pople, John; Fuentes, Sergio; Alonzo-Nuñez, Gabriel; Polette, Lori A

    2005-03-01

    Development of synchrotron techniques for the determination of the structure of disordered, amorphous and surface materials has exploded over the past 20 years owing to the increasing availability of high-flux synchrotron radiation and the continuing development of increasingly powerful synchrotron techniques. These techniques are available to materials scientists who are not necessarily synchrotron scientists through interaction with effective user communities that exist at synchrotrons such as the Stanford Synchrotron Radiation Laboratory. In this article the application of multiple synchrotron characterization techniques to two classes of materials defined as 'surface compounds' is reviewed. One class of surface compounds are materials like MoS(2-x)C(x) that are widely used petroleum catalysts, used to improve the environmental properties of transportation fuels. These compounds may be viewed as 'sulfide-supported carbides' in their catalytically active states. The second class of 'surface compounds' are the 'Maya blue' pigments that are based on technology created by the ancient Maya. These compounds are organic/inorganic 'surface complexes' consisting of the dye indigo and palygorskite, common clay. The identification of both surface compounds relies on the application of synchrotron techniques as described here.

  18. Synchroton and Simulations Techniques Applied to Problems in Materials Science: Catalysts and Azul Maya Pigments

    Energy Technology Data Exchange (ETDEWEB)

    Chianelli, R.

    2005-01-12

    Development of synchrotron techniques for the determination of the structure of disordered, amorphous and surface materials has exploded over the past twenty years due to the increasing availability of high flux synchrotron radiation and the continuing development of increasingly powerful synchrotron techniques. These techniques are available to materials scientists who are not necessarily synchrotron scientists through interaction with effective user communities that exist at synchrotrons such as the Stanford Synchrotron Radiation Laboratory (SSRL). In this article we review the application of multiple synchrotron characterization techniques to two classes of materials defined as ''surface compounds.'' One class of surface compounds are materials like MoS{sub 2-x}C{sub x} that are widely used petroleum catalysts used to improve the environmental properties of transportation fuels. These compounds may be viewed as ''sulfide supported carbides'' in their catalytically active states. The second class of ''surface compounds'' is the ''Maya Blue'' pigments that are based on technology created by the ancient Maya. These compounds are organic/inorganic ''surface complexes'' consisting of the dye indigo and palygorskite, a common clay. The identification of both surface compounds relies on the application of synchrotron techniques as described in this report.

  19. CLAY AND CLAY-SUPPORTED REAGENTS IN ORGANIC SYNTHESES

    Science.gov (United States)

    CLAY AND CLAY-SUPPORTED REAGENTS HAVE BEEN USED EXTENSIVELY FOR SYNTHETIC ORGANIC TRANSFORMATIONS. THIS OVERVIEW DESCRIBES THE SALIENT STRUCTURAL PROPERTIES OF VARIOUS CLAY MATERIALS AND EXTENDS THE DISCUSSION TO PILLARED CLAYS AND REAGENTS SUPPORTED ON CLAY MATERIALS. A VARIET...

  20. Kaqchikel Maya Language Analysis Project

    Science.gov (United States)

    Eddy de Pappa, Sarah

    2010-01-01

    The purpose of this analysis was to study the linguistic features of Kaqchikel, a Mayan language currently spoken in Guatemala and increasingly in the United States, in an effort to better prepare teachers of English as a second language (ESL) or English as a foreign language (EFL) to address the distinct needs of a frequently neglected and…

  1. [Cleft lip and palate in Campeche Mayas].

    Science.gov (United States)

    Weiss, K M; Georges, E; Levy, B; Aguirre, A; Portilla, R J; Gaitán, C L; Leyva, E; Rodríguez, T

    1988-07-01

    It has been suggested that among American Indians, as in some genetically-related Asiatic ethnic groups, incidence of cleft lip and/or cleft palate is higher than among people of Caucasian extraction. Such hypothesis, plus growing demand for services observed at a center for the surgery of cleft lip and cleft palate in Campeche state, led the authors to undertake research among the Maya residents of that region. However, neither careful review of case histories nor field research performed in several Indian communities could confirm the hypothesis of a higher incidence among this ethnic community.

  2. The University of Texas Maya Muon Project

    Energy Technology Data Exchange (ETDEWEB)

    Schwitters, Roy (University of Texas at Austin)

    2007-05-09

    Plans to explore the ruin of a Maya Pyramid in Belize using cosmic ray muon tomography will be described. Muon tomography was pioneered by Luis Alvarez in the 1960's to explore the Second Pyramid of Chephren in Egypt. Improvements in detector technology since the Alvarez experiment suggest that muon tomography may be a practical method for exploring and monitoring relatively large underground volumes when exposure times of order months are acceptable. A prototype detector based on Fermilab/MINOS scintillator strip/WLS fiber technology has been built and is being tested at UT Austin. Initial results using the detector will be discussed.

  3. Autodesk推出Maya 8

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    7月31日,Autodesk发布了Autodesk 3ds Maya 8软件,该软件实现了64位支持、多线程和算法最优化的组合,使用者可加载并以更高的效率处理大量数据集,软件在包括皮肤功能,铺嵌绘制和多边形代理图像功能(proxy)网络细分等关键领域都已经过多线程处理,

  4. A ÁFRICA DE MAYA ANGELOU

    OpenAIRE

    Maria Aparecida Andrade Salgueiro; Felipe Fanuel Xavier Rodrigues

    2016-01-01

    O presente artigo objetiva revisar a jornada de Maya Angelou em terras africanas, mediante a releitura crítica de sua narrativa autobiográfica relativa ao período em que viveu em Gana. Partindo de uma perspectiva ampla de análise cultural, o estudo se atenta para a busca identitária da autora afro-americana em sua relação com a África e seus significados. As características da escrita de Angelou são investigadas em paralelo com os temas que motivam sua obra, com o intuito de distinguir sua ap...

  5. Methods and future directions for paleoclimatology in the Maya Lowlands

    Science.gov (United States)

    Douglas, Peter M. J.; Brenner, Mark; Curtis, Jason H.

    2016-03-01

    A growing body of paleoclimate data indicates that periods of severe drought affected the Maya Lowlands of southeastern Mexico and northern Central America, especially during the Terminal Classic period (ca. 800-950 CE), raising the possibility that climate change contributed to the widespread collapse of many Maya polities at that time. A broad range of paleoclimate proxy methods have been applied in the Maya Lowlands and the data derived from these methods are sometimes challenging for archeologists and other non-specialists to interpret. This paper reviews the principal methods used for paleoclimate inference in the region and the rationale for climate proxy interpretation to help researchers working in the Maya Lowlands make sense of paleoclimate datasets. In particular, we focus on analyses of speleothems and lake sediment cores. These two paleoclimate archives have been most widely applied in the Maya Lowlands and have the greatest potential to provide insights into climate change impacts on the ancient Maya. We discuss the development of chronologies for these climate archives, the proxies for past climate change found within them, and how these proxy variables are interpreted. Finally, we present strategies for improving our understanding of proxy paleoclimate data from the Maya Lowlands, including multi-proxy analyses, assessment of spatial variability in past climate change, combined analysis of climate models and proxy data, and the integration of paleoclimatology and archeology.

  6. Common clay and shale

    Science.gov (United States)

    Virta, R.L.

    2011-01-01

    The article discusses the latest developments in the global common clay and shale industry, particularly in the U.S. It claims that common clay and shale is mainly used in the manufacture of heavy clay products like brick, flue tile and sewer pipe. The main producing states in the U.S. include North Carolina, New York and Oklahoma. Among the firms that manufacture clay and shale-based products are Mid America Brick & Structural Clay Products LLC and Boral USA.

  7. Petrographic report on clay-rich samples from Permian Unit 4 salt, G. Friemel No. 1 well, Palo Duro Basin, Deaf Smith County, Texas: unanalyzed data

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, L M

    1983-09-01

    This report presents the results of mineralogic and petrographic analyses performed on five samples of clay-rich rock from salt-bearing Permian strata sampled by drill core from G. Friemel No. 1 Well, Deaf Smith County, Texas. Five samples of clay-rich rock from depths of about 2457, 2458, 2521, 2548, and 2568 feet were analyzed to determine the amounts of soluble phase (halite) and the amounts and mineralogy of the insoluble phases. The amounts of halite found were 59, 79, 47, 40, and 4 weight percent, respectively, for the samples. The insoluble minerals are predominately clay (20 to 60 volume percent) and anhydrite (up to 17 volume percent), with minor (about 1.0%) and trace amounts of quartz, dolomite, muscovite, and gypsum. The clays include illite, chlorite, and interstratified chlorite-smectite. The results presented in this petrographic report are descriptive, uninterpreted data. 2 references, 7 tables.

  8. Clay at Nili Fossae

    Science.gov (United States)

    2006-01-01

    , the small mesa -- a flat-topped hill -- at the center of the image is a remnant of an overlying rock layer that was eroded away. The greenish clay areas at the base of the hill were exposed by erosion of the overlying rock. The images at the upper right and lower left both show that the reddish-toned olivine occurs as sand dunes on top of the greenish clay deposits. The image at the lower right shows details of the clay-rich rock, including that they are extensively fractured into small, polygonal blocks just a few meters in size. Taken together, the CRISM and HiRISE data show that the clay-rich rocks are the oldest at the site, that they are exposed where overlying rock has been eroded away, and that the olivine is not part of the clay-rich rock. Rather it occurs in sand dunes blowing across the clay. Many more images of Nili Fossae and other clay-rich areas will be taken over the next two years. They will be used to try to understand the earliest climate of Mars that is recorded in the planet's rocks. The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) is one of six science instruments on NASA's Mars Reconnaissance Orbiter. Led by The Johns Hopkins University Applied Physics Laboratory, the CRISM team includes expertise from universities, government agencies and small businesses in the United States and abroad. CRISM's mission: Find the spectral fingerprints of aqueous and hydrothermal deposits and map the geology, composition and stratigraphy of surface features. The instrument will also watch the seasonal variations in Martian dust and ice aerosols, and water content in surface materials o leading to new understanding of the climate. NASA's Jet Propulsion Laboratory, a division of the Califonia Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor and built the spacecraft.

  9. Ancient Maya Regional Settlement and Inter-Site Analysis: The 2013 West-Central Belize LiDAR Survey

    Directory of Open Access Journals (Sweden)

    Arlen F. Chase

    2014-09-01

    Full Text Available During April and May 2013, a total of 1057 km2 of LiDAR was flown by NCALM for a consortium of archaeologists working in West-central Belize, making this the largest surveyed area within the Mayan lowlands. Encompassing the Belize Valley and the Vaca Plateau, West-central Belize is one of the most actively researched parts of the Maya lowlands; however, until this effort, no comprehensive survey connecting all settlement had been conducted. Archaeological projects have investigated at least 18 different sites within this region. Thus, a large body of archaeological research provides both the temporal and spatial parameters for the varied ancient Maya centers that once occupied this area; importantly, these data can be used to help interpret the collected LiDAR data. The goal of the 2013 LiDAR campaign was to gain information on the distribution of ancient Maya settlement and sites on the landscape and, particularly, to determine how the landscape was used between known centers. The data that were acquired through the 2013 LiDAR campaign have significance for interpreting both the composition and limits of ancient Maya political units. This paper presents the initial results of these new data and suggests a developmental model for ancient Maya polities.

  10. Miniature sonar for obstacle detection on samll AUV Maya

    Digital Repository Service at National Institute of Oceanography (India)

    Afzulpurkar, S.; Desa, E.; Navelkar, G.; Mascarenhas, A.A.M.Q.; Maurya, P.K.; Martins, H.; Madhan, R.; Prabhudesai, S.; Pinto, R.; Marchon, N.

    that are communicated to the mission computer of Maya which uses a distributed CAN network architecture for internal subsystem communications. The mission computer can use this new heading data for navigation accordingly....

  11. Objetual Regime of the Maya during Classic period, a proposal

    Directory of Open Access Journals (Sweden)

    Antonio Jaramillo Arango

    2016-06-01

    Full Text Available Within the academic archaeology of the 20th Century, objects were only considered as sources for understanding human action. Based on recent theoretic anthropological proposals, this paper proposes a recursive archaeology, that is, to include the Classic Maya concepts as part of our analysis in order to understand things as truly protagonists of social relationships. In the Maya area, objects have different ways of being in the world which have been identified by the archeology of the Classic period: person-objects, parts of a dividual body and machines. These three ways are explored here through archaeologic contexts and epigraphic texts with the aim of approaching the construction of reality of the Classic Maya. With a multidisciplinary analysis that includes archaeology, epigraphy, history, linguistics and anthropology, a high number of examples coming from different regions in the Maya area is examined. Thus, an overall view of this phenomenon is presented.

  12. Autodesk Maya 8.5试用体验

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Maya8.5是alias被Autodesk收购不长的时间内出的第二个版本了。距Maya8.0发布仅半年后的Maya8.5版本又会有什么样的改进呢?会不会象前一个版本一样只是加强了Autodesk的风格呢?怀着这些疑问我打开了《Computer Arts数码艺术》杂志社送来的Maya8.5的媒体测试软件安装盘。

  13. Maya 6新功能全扫描

    Institute of Scientific and Technical Information of China (English)

    郑涛; 张嘉亮

    2004-01-01

    自从去年Maya 5.0获得奥斯卡科技奖之后.Alias可谓新闻多多,这次Maya 6的出台更是令人又惊又喜。下面就让我们直接进入正题。看看这次出人意料的升级到底带来了哪些新功能?

  14. Recent Advances in Maya Studies Using Remotely Sensed Data

    Science.gov (United States)

    Sever, Tom; Irwin, Daniel; Arnold, James E. (Technical Monitor)

    2001-01-01

    The Peten region of northern Guatemala is one of the last places on earth where major archeological sites remain to be discovered. It was in this region that the Maya civilization began, flourished, and abruptly disappeared. Remote sensing technology is helping to locate and map ancient Maya sites that are threatened today by accelerating deforestation and looting. Thematic Mapper and IKONOS satellite and airborne Star3i radar data, combined with Global Positioning System (GPS) technology, are successfully detecting ancient Maya features such as cities, roadways, canals, and water reservoirs. Satellite imagery is also being used to map the baJos, which are seasonally flooded swamps that cover over 40% of the land surface. The use of bajos for farming has been a source of debate within the professional community for many years. But the recent detection and verification of cultural features within the bajo system by our research team are providing conclusive evidence that the ancient Maya had adapted well to wetland environments from the earliest times and utilized them until the time of the Maya collapse. The combination of water management and bajo farming is an important resource for the future of the current inhabitants who are experiencing rapid population growth. Remote sensing imagery is also demonstrating that in the Preclassic period (600 BC- AD 250), the Maya had already achieved a high organizational level as evidenced by the construction of massive temples and an elaborate inter-connecting roadway system. Although they experienced several setbacks such as droughts and hurricanes, the Maya nevertheless managed the delicate forest ecosystem successfully for several centuries. However, around AD 800, something happened to the Maya to cause their rapid decline and eventual disappearance from the region. The evidence indicates that at this time there was increased climatic dryness, extensive deforestation, overpopulation, and widespread warfare. This raises a

  15. Leonora Carrington: El Mundo Magico de los Mayas

    OpenAIRE

    Giulia Ingarao

    2016-01-01

    El Mundo Magico de los Mayas is one of the most significant works of Leonora Carrington, who was the only foreign artist invited to decorate one of the rooms of Mexico City new National Museum of Anthropology in 1963. She was commissioned to decorate the room where artefacts coming from contemporary Maya civilization would have been displayed. The result was a multi-layered composition in which classical themes of surrealism coexisted with countless references to the Mayan culture.

  16. Leonora Carrington: El Mundo Magico de los Mayas

    Directory of Open Access Journals (Sweden)

    Giulia Ingarao

    2016-12-01

    Full Text Available El Mundo Magico de los Mayas is one of the most significant works of Leonora Carrington, who was the only foreign artist invited to decorate one of the rooms of Mexico City new National Museum of Anthropology in 1963. She was commissioned to decorate the room where artefacts coming from contemporary Maya civilization would have been displayed. The result was a multi-layered composition in which classical themes of surrealism coexisted with countless references to the Mayan culture.

  17. Modified clay sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Fogler, H.S.; Srinivasan, K.R.

    1990-04-10

    This patent describes a clay-based sorbent. It comprises a clay having an external surface and lamellar layers; and cationic surfactant ions having a hydrocarbon portion and a cationic head portion, the cationic surfactant ions being irreversibly bound to the external surface by the hydrocarbon portion. This patent also describes cetylpyridinium-aluminum hydroxy-montmorillonite; the clay-based sorbent wherein the clay is a non-expandable clay; and the clay-based sorbent wherein the cationic surfactant ions are selected from the group consisting of ionized cetylpyridinium chloride and cetylakonium chloride.

  18. No metaphorical timeline in gesture and cognition among yucatec mayas.

    Science.gov (United States)

    Le Guen, Olivier; Balam, Lorena Ildefonsa Pool

    2012-01-01

    In numerous languages, space provides a productive domain for the expression of time. This paper examines how time-to-space mapping is realized in Yucatec Maya. At the linguistic level, Yucatec Maya has numerous resources to express deictic time, whereas expression of sequential time is highly constrained. Specifically, in gesture, we do not find any metaphorical oriented timeline, but only an opposition between "current time" (mapped on the "here" space) and "remote time" (mapped on the "remote/distant space"). Additionally, past and future are not contrasted. Sequential or deictic time in language and gesture are not conceived as unfolding along a metaphorical oriented line (e.g., left-right or front-back) but as a succession of completed events not spatially organized. Interestingly, although Yucatec Maya speakers preferentially use a geocentric spatial frame of reference (FoR), especially visible in their use of gesture, time is not mapped onto a geocentric axis (e.g., east-west). We argue that, instead of providing a source for time mapping, the use of a spatial geocentric FoR in Yucatec Maya seems to inhibit it. The Yucatec Maya expression of time in language and gesture fits the more general cultural conception of time as cyclic. Experimental results confirmed, to some extent, this non-linear, non-directional conception of time in Yucatec Maya.

  19. No Metaphorical Timeline in Gesture and Cognition Among Yucatec Mayas

    Science.gov (United States)

    Le Guen, Olivier; Balam, Lorena Ildefonsa Pool

    2012-01-01

    In numerous languages, space provides a productive domain for the expression of time. This paper examines how time-to-space mapping is realized in Yucatec Maya. At the linguistic level, Yucatec Maya has numerous resources to express deictic time, whereas expression of sequential time is highly constrained. Specifically, in gesture, we do not find any metaphorical oriented timeline, but only an opposition between “current time” (mapped on the “here” space) and “remote time” (mapped on the “remote/distant space”). Additionally, past and future are not contrasted. Sequential or deictic time in language and gesture are not conceived as unfolding along a metaphorical oriented line (e.g., left-right or front-back) but as a succession of completed events not spatially organized. Interestingly, although Yucatec Maya speakers preferentially use a geocentric spatial frame of reference (FoR), especially visible in their use of gesture, time is not mapped onto a geocentric axis (e.g., east-west). We argue that, instead of providing a source for time mapping, the use of a spatial geocentric FoR in Yucatec Maya seems to inhibit it. The Yucatec Maya expression of time in language and gesture fits the more general cultural conception of time as cyclic. Experimental results confirmed, to some extent, this non-linear, non-directional conception of time in Yucatec Maya. PMID:22908000

  20. Wetland fields as mirrors of drought and the Maya abandonment.

    Science.gov (United States)

    Luzzadder-Beach, Sheryl; Beach, Timothy P; Dunning, Nicholas P

    2012-03-06

    Getting at the Maya Collapse has both temporal and geographic dimensions, because it occurred over centuries and great distances. This requires a wide range of research sites and proxy records, ranging from lake cores to geomorphic evidence, such as stratigraphy and speleothems. This article synthesizes these lines of evidence, together with previously undescribed findings on Maya wetland formation and use in a key region near the heart of the central Maya Lowlands. Growing lines of evidence point to dryer periods in Maya history, which correlate to major periods of transition. The main line of evidence in this paper comes from wetland use and formation studies, which show evidence for both large-scale environmental change and human adaptation or response. Based on multiproxy studies, Maya wetland fields had a long and varied history, but most evidence indicates the start of disuse during or shortly after the Maya Terminal Classic. Hence, the pervasiveness of collapse extended into a range of wetlands, including perennial wetlands, which should have been less responsive to drought as a driver of disuse. A synthesis of the lines of evidence for canal infilling shows no attempts to reclaim them after the Classic Period.

  1. Mayan Indigenous Society in Guatemala and Mexico: A Thematic Integrated Unit on the Contributions of the Maya Both Past and Present. Fulbright-Hays Summer Seminars Abroad Program, 2000 (Mexico and Guatemala).

    Science.gov (United States)

    Suchenski, Michelle

    This curriculum unit focuses on the contributions of the ancient Mayan people and how these contributions have been interwoven with contemporary society. The unit is divided into the following sections: (1) "Preface"; (2) "Mayan Civilization" (geography); (3) "Mayan Contributions" (written language); (4) "Mayan…

  2. Will America Fall Apart Like the Maya? Grade 7 Lesson. Schools of California Online Resources for Education (SCORE): Connecting California's Classrooms to the World.

    Science.gov (United States)

    McDonald, David

    If a civilization as powerful and technologically advanced during its time as the Maya could disappear, can the same tragic outcome befall the United States? In this lesson, students work in teams to research the ancient Mayan civilization, specifically the circumstances of its demise. Student teams prepare a report of their findings and recommend…

  3. Crafting connections: maya linkages between Guatemala’s Altiplano and El Norte

    Directory of Open Access Journals (Sweden)

    Michelle J. Moran-Taylor

    2004-07-01

    Full Text Available International migration constitutes one of the most significant phenomena impacting Guatemala today. About a million and a half Guatemalans live and work in rural and urban cities and towns across the United States and Canada. Like many other migrant groups, most Guatemalans sustain strong transnational linkages between their homeland and el norte (the United States. In the Guatemalan example highlighted in this article, such bonds owe much to the long-standing Guatemalan-U.S. historical connections, to the geographic proximity of the country to the United States. Drawing on ethnographic material, this article examines the divergent kinds of transnational connections that Maya indigenous (K´iche´ migrants craft and keep alive between their home community and their two primary destination localities in the United States—Houston, Texas and Los Angeles, California. The article shows the different means of communication and technology, as well as the varying types of transnational organizing —particularly grass-roots efforts— that help shape current linkages between those who go and those who stay. Keyword: Transnational migration, social ties, Guatemalan Maya migration, communications, grass-roots organizing.

  4. 78 FR 17744 - Culturally Significant Objects Imported for Exhibition Determinations: “Maya: Hidden Worlds...

    Science.gov (United States)

    2013-03-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Maya: Hidden Worlds Revealed... determine that the objects to be included in the exhibition ``Maya: Hidden Worlds Revealed,'' imported...

  5. An Iterative Approach to Ground Penetrating Radar at the Maya Site of Pacbitun, Belize

    Directory of Open Access Journals (Sweden)

    Sheldon Skaggs

    2016-09-01

    Full Text Available Ground penetrating radar (GPR surveys provide distinct advantages for archaeological prospection in ancient, complex, urban Maya sites, particularly where dense foliage or modern debris may preclude other remote sensing or geophysical techniques. Unidirectional GPR surveys using a 500 MHz shielded antenna were performed at the Middle Preclassic Maya site of Pacbitun, Belize. The survey in 2012 identified numerous linear and circular anomalies between 1 m and 2 m deep. Based on these anomalies, one 1 m × 4 m unit and three smaller units were excavated in 2013. These test units revealed a curved plaster surface not previously found at Pacbitun. Post-excavation, GPR data were reprocessed to best match the true nature of excavated features. Additional GPR surveys oriented perpendicular to the original survey confirmed previously detected anomalies and identified new anomalies. The excavations provided information on the sediment layers in the survey area, which allowed better identification of weak radar reflections of the surfaces of a burnt, Middle Preclassic temple in the northern end of the survey area. Additional excavations of the area in 2014 and 2015 revealed it to be a large square structure, which was named El Quemado.

  6. Diagonal Slices of 3D Young Diagrams in the Approach of Maya Diagrams

    Science.gov (United States)

    Cai, Li-Qiang; Wang, Li-Fang; Wu, Ke; Yang, Jie

    2014-09-01

    According to the correspondence between 2D Young diagrams and Maya diagrams and the relation between 2D and 3D Young diagrams, we construct 3D Young diagrams in the approach of Maya diagrams. Moreover, we formulate the generating function of 3D Young diagrams, which is the MacMahon function in terms of Maya diagrams.

  7. Meteor Showers in the Ancient Maya Hieroglyphic Codices

    Science.gov (United States)

    Kinsman, J. H.

    2014-07-01

    Researchers of the ancient Maya culture have long been fascinated with the Maya obsession concerning cyclical calendars and precise visual observations of astronomical bodies and phenomena, in particular the Sun, Moon, visible planets, and solar and lunar eclipses. Although considered possible, heretofore no record of specific sightings of comets or meteor showers in the Maya inscriptions has been firmly established by scholars. Besides difficulties with decipherment of the hieroglyphic script, investigators have had to grapple with an ancient Maya calendar that has not been accurately correlated to the European calendar. Recent examination by this researcher has found that it may be possible to recognize written accounts of meteor showers embedded in the hieroglyphic corpus, especially the codices, the screen-fold books that were the tools of the astronomer-priests of that day. By proposing an alternative decipherment of an astronomical sign and using the accompanying hieroglyphic texts and illustrations with appropriate dates, this researcher believes it is possible to demonstrate that the Maya may have recorded meteor showers occurring in the seventh through the tenth centuries AD.

  8. Drought, agricultural adaptation, and sociopolitical collapse in the Maya Lowlands

    Science.gov (United States)

    Douglas, Peter M. J.; Pagani, Mark; Canuto, Marcello A.; Brenner, Mark; Hodell, David A.; Eglinton, Timothy I.; Curtis, Jason H.

    2015-05-01

    Paleoclimate records indicate a series of severe droughts was associated with societal collapse of the Classic Maya during the Terminal Classic period (∼800-950 C.E.). Evidence for drought largely derives from the drier, less populated northern Maya Lowlands but does not explain more pronounced and earlier societal disruption in the relatively humid southern Maya Lowlands. Here we apply hydrogen and carbon isotope compositions of plant wax lipids in two lake sediment cores to assess changes in water availability and land use in both the northern and southern Maya lowlands. We show that relatively more intense drying occurred in the southern lowlands than in the northern lowlands during the Terminal Classic period, consistent with earlier and more persistent societal decline in the south. Our results also indicate a period of substantial drying in the southern Maya Lowlands from ∼200 C.E. to 500 C.E., during the Terminal Preclassic and Early Classic periods. Plant wax carbon isotope records indicate a decline in C4 plants in both lake catchments during the Early Classic period, interpreted to reflect a shift from extensive agriculture to intensive, water-conservative maize cultivation that was motivated by a drying climate. Our results imply that agricultural adaptations developed in response to earlier droughts were initially successful, but failed under the more severe droughts of the Terminal Classic period.

  9. Figurative Language on Maya Angelou selected Poetries

    Directory of Open Access Journals (Sweden)

    Risma Hayani

    2016-12-01

    Full Text Available This study aimed to find out the kinds of figurative language in the five selected poetries of Maya Angelou, the titles are: Alone, Caged Bird, Old Folks Laugh, Phenomenal Woman, Still I Rise. The focus of this study is figurative language which involves: Metaphor, Personification, Hyperbole, Simile, Metonymy, Synecdoche, Irony, Antithesis, Symbolism, and Paradox. Qualitative approach with design of content analysis was used in this study. The researcher acted as the main instrument since she was the one who analyzed the figurative language. Moreover checklist was also used to support her data collection. The data was analyzed through three stages; 1. Data reduction, 2. Data representation, 3. Conclusion. The result of her study showed there were 40 sentences that containing figurative language in five selected poetries of Maya Angelou. They were; Metaphor (13 sentences, Personification (9 sentences, Hyperbole (1 sentence, Simile (8 sentences, Synecdoche (1 sentence, Antithesis (1 sentence, Symbolism (5 sentences, and Paradox (2 sentences. The researcher conclude, if the figurative language used by Angelou to compare, or even symbolize the sentences to bring the meaning come up with beautiful language. Mostly of her poetries told about her experience in the past that rooted to history of the discrimination of American-African.

  10. Adaptations of a Yucatec Maya Multiple-Use Ecological Management Strategy to Ecotourism

    Directory of Open Access Journals (Sweden)

    Eduardo García-Frapolli

    2008-12-01

    Full Text Available Over the last 40 years, the Yucatan Peninsula has experienced the implementation and promotion of development programs that have economically and ecologically shaped this region of Mexico. Nowadays, tourist development has become the principal catalyst of social, economic, and ecological changes in the region. All these programs, which are based on a specialization rationale, have historically clashed with traditional Yucatec Maya management of natural resources. Using participant observation, informal and semi-structured interviews, and life-history interviews, we carried out an assessment of a Yucatec Maya natural resources management system implemented by three indigenous communities located within a natural protected area. The assessment, intended as an examination of the land-use practices and productive strategies currently implemented by households, was framed within an ecological-economic approach to ecosystems appropriation. To examine the influence of tourism on the multiple-use strategy, we contrasted productive activities among households engaged primarily in ecotourism with those more oriented toward traditional agriculture. Results show that households from these communities allocated an annual average of 586 work days to implement a total of 15 activities in five different land-use units, and that those figures vary significantly in accordance with households' productive strategy (agriculture oriented or service oriented. As the region is quickly becoming an important tourist destination and ecotourism is replacing many traditional activities, we discuss the need for a balance between traditional and alternative economic activities that will allow Yucatec Maya communities to diversify their economic options without compromising existing local management practices.

  11. Compositional attribution of non-provenienced Maya polychrome vessels

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, R.L.; Harbottle, G.; Reents, D.J.; Sayre, E.V.; van Zelst, L.

    1983-01-01

    Procedures and a few of the results of the Maya ceramic project are discussed from the perspective of non-provenienced vessel attribution ranging from site specific through a more inferential level to the rather hypothetical. The examples presented serve to illustrate the manner in which compositional and stylistic covariation are viewed in an investigation of Maya Ceramic art. The large data base from neutron activation analysis including archaeologically recovered pottery as well as the stylistically and iconographically elaborate vessels requires continued refinement in our methods of statistical analysis along with gaining a greater understanding of the sources of ceramic compositional variation in the Maya area. The mutually beneficial collaboration between science, art, and archaeology are emphasized.

  12. Diagnostic Emplotment in Q'eqchi' Maya Medicine.

    Science.gov (United States)

    Hatala, Andrew R; Waldram, James B

    2017-04-01

    Medical diagnosis is a process of illness discrimination, categorization, and identification on the basis of careful observation and is central in biomedicine and many traditional medical systems around the world. Through a detailed analysis of several illness episodes and healer interviews among Maya communities in southern Belize, we observe that the diagnostic processes of traditional Q'eqchi' healers reflect patterns of narrative 'emplotment' that engage not simply the individual patient but also significant spiritual and cosmological forces. Three diagnostic techniques of the Q'eqchi' Maya healers are described and their connections to Maya concepts of personhood and cosmovision are presented. This research fosters an appreciation of how Indigenous knowledge systems shape clinical encounters and healing dramas, widening the spheres of clinical narrative co-construction and dialogue beyond the material and physical contexts implicit within Western clinical encounters.

  13. Folkecology and commons management in the Maya Lowlands

    Science.gov (United States)

    Atran, Scott; Medin, Douglas; Ross, Norbert; Lynch, Elizabeth; Coley, John; Ek’, Edilberto Ucan; Vapnarsky, Valentina

    1999-01-01

    Three groups living off the same rainforest habitat manifest strikingly distinct behaviors, cognitions, and social relationships relative to the forest. Only the area’s last native Maya reveal systematic awareness of ecological complexity involving animals, plants, and people and practices clearly favoring forest regeneration. Spanish-speaking immigrants prove closer to native Maya in thought, action, and social networking than do immigrant Maya. There is no overriding “local,” “Indian,” or “immigrant” relationship to the environment. Results indicate that exclusive concern with rational self-interest and institutional constraints do not sufficiently account for commons behavior and that cultural patterning of cognition and access to relevant information are significant predictors. Unlike traditional accounts of relations between culture, cognition, and behavior, the models offered are not synthetic interpretations of people’s thoughts and behaviors but are emergent cultural patterns derived statistically from measurements of individual cognitions and behaviors. PMID:10377461

  14. Narrative Structures of Maya Mental Disorders.

    Science.gov (United States)

    Hatala, Andrew R; Waldram, James B; Caal, Tomas

    2015-09-01

    Several Indigenous communities around the globe maintain unique conceptions of mental illness and disorder. The Q'eqchi' Maya of southern Belize represent one Indigenous community that has maintained, due to highly "traditional" ways of life and the strong presence of many active localized healers or bush doctors, distinct conceptions of mental disorders as compared to Western psychiatric nosology. The purpose of this ethnographic study was to understand and interpret Q'eqchi' nosological systems of mental disorders involving the factors--spiritual, cultural, social, historical, cosmological, or otherwise--implicated in their articulation and construction. Over a period of 9 months, and with the help of cultural advisors from several Q'eqchi' communities, 94 interviews with five different traditional Q'eqchi' healers were conducted. This paper demonstrates that the mental illnesses recognized by the Q'eqchi' healers involved narrative structures with recognizable variations unfolding over time. What we present in this paper are 17 recognizable illnesses of the mind grouped within one of four broad "narrative genres." Each genre involves a discernible plot structure, casts of characters, themes, motifs, and a recognizable teleology or "directedness." In narrative terms, the healer's diagnostic and therapeutic work can be understood as an ability to discern plot, to understand and interpret a specific case within the board, empirically based structure of Q'eqchi' medical epistemology.

  15. A ÁFRICA DE MAYA ANGELOU

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Andrade Salgueiro

    2016-04-01

    Full Text Available O presente artigo objetiva revisar a jornada de Maya Angelou em terras africanas, mediante a releitura crítica de sua narrativa autobiográfica relativa ao período em que viveu em Gana. Partindo de uma perspectiva ampla de análise cultural, o estudo se atenta para a busca identitária da autora afro-americana em sua relação com a África e seus significados. As características da escrita de Angelou são investigadas em paralelo com os temas que motivam sua obra, com o intuito de distinguir sua apropriação do gênero autobiográfico. Sua identidade como sujeito negro diaspórico, que narra suas próprias experiências vividas para além dos históricos limites do colonialismo, revela uma herança africana única que encontra na imaginação criativa um meio de luta cultural.

  16. Thermostability of montmorillonitic clays

    OpenAIRE

    Petr Jelínek; Dobosz, Stanisław M.; Jaroslav Beňo

    2014-01-01

    Bentonite is one of the most widespread used clays connected with various applications. In the case of foundry technology, bentonite is primarily used as a binder for mold manufacture. Thermal stability of bentonites is a natural property of clay minerals and it depends on the genesis, source and chemical composition of the clay. This property is also closely connected to bentonite structure. According to DTA analysis if only one peak of dehydroxylation is observed (about 600 ºC), the cis- is...

  17. Autodesk降低Maya Unlimited价格并推出Maya2008扩展包2

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    近日,Autodesk宣布降低Autodesk Maya Unlimited3D建模、动画和渲染软件的价格。同时,Autodesk还推出了Maya2008扩展包2软件,该软件为多边形建模和UV纹理提供更强的创造性控制,也为MayaMuscle工具包带来了重大改进。Maya最近因其对游戏开发行业的杰出贡献而入选GameDeveloper FrontLine Award Hall of Fame奖项。

  18. Enchanted Clays: 44th Annual Meeting of the Clay Minerals Society (June 2007)

    Energy Technology Data Exchange (ETDEWEB)

    Randall T. Cygan

    2007-06-01

    “Enchanted Clays: 44th Annual Meeting of the Clay Minerals Society” was held in early June 2007 in beautiful and historic Santa Fe, New Mexico, USA. Santa Fe provided an idyllic location in the southwestern United States for the attendees to enjoy technical and social sessions while soaking up the diverse culture and wonderful climate of New Mexico—The Land of Enchantment. The meeting included a large and varied group of scientists, sharing knowledge and ideas, benefitting from technical interactions, and enjoying the wonderful historic and enchanted environs of Santa Fe. Including significant number of international scientists, the meeting was attended by approximately two hundred participants. The meeting included three days of technical sessions (oral and poster presentations), three days of field trips to clay and geological sites of northern New Mexico, and a full day workshop on the stabilization of carbon by clays. Details can be found at the meeting web site: www.sandia.gov/clay.

  19. Maya paleodemographics: what do we know?

    Science.gov (United States)

    Olga Hernández Espinoza, Patricia; Márquez Morfín, Lourdes

    2015-01-01

    We present a review of what is known about the population dynamics from Classic and Post-Classic Maya settlements in coastal areas of the Yucatan Peninsula such as Jaina, Chac Mool, El Meco and Xcambó and two other urban centers, Palenque and Copan. This contribution discusses the available data on mortality, survival, life expectancy, fertility and migration, obtained by paleodemographic methodology. Data for Xcambó and El Meco were obtained from Tiesler Bloss et al., (2005) and Ortega (2007); information from other sites was obtained from previous work conducted by the authors. This review proposes that the demographic dynamics of the Classical period are typical of densely populated and developing areas with overall average birth rates of six children per woman and a life expectancy at birth of between 20 and 42.2 years, which is equivalent to birth rates above 40 per thousand inhabitants. Post-Classic settlements show evidence of great population mobility with unfavorable changes in living conditions that lead us to think of fertility decrease and low life expectancies at birth. There are indications of a demographic change between the Late-Terminal Classic and Post-Classic periods. Life expectancies are lower than 30 years, a high infant mortality and low adult survival after 50 years is shown. The Post-Classic period is characterized by population rearrangements and mobility. Results obtained for both Chac Mool series showed deterioration in health and reduced life expectancy and fertility levels from one period to another. El Meco and Xcambó series showed differences with Chac Mool's due to higher growth rates. © 2015 Wiley Periodicals, Inc.

  20. Clay Portrait Boxes

    Science.gov (United States)

    Wilbert, Nancy Corrigan

    2009-01-01

    In an attempt to incorporate sculptural elements into her ceramics program, the author decided to try direct plaster casting of the face to make a plaster mold for clay. In this article, the author shares an innovative ceramics lesson that teaches students in making plaster casts and casting the face in clay. This project gives students the…

  1. Columns in Clay

    Science.gov (United States)

    Leenhouts, Robin

    2010-01-01

    This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

  2. Clay Mineral: Radiological Characterization

    Science.gov (United States)

    Cotomácio, J. G.; Silva, P. S. C.; Mazzilli, B. P.

    2008-08-01

    Since the early days, clays have been used for therapeutic purposes. Nowadays, most minerals applied as anti-inflammatory, pharmaceutics and cosmetic are the clay minerals that are used as the active ingredient or, as the excipient, in formulations. Although their large use, few information is available in literature on the content of the radionuclide concentrations of uranium and thorium natural series and 40K in these clay minerals. The objective of this work is to determine the concentrations of 238U, 232Th, 226Ra, 228Ra, 210Pb and 40K in commercial samples of clay minerals used for pharmaceutical or cosmetic purposes. Two kinds of clays samples were obtained in pharmacies, named green clay and white clay. Measurement for the determination of 238U and 232Th activity concentration was made by alpha spectrometry and gamma spectrometry was used for 226Ra, 228Ra, 210Pb and 40K determination. Some physical-chemical parameters were also determined as organic carbon and pH. The average activity concentration obtained was 906±340 Bq kg-1 for 40K, 40±9 Bq kg-1 for 226Ra, 75±9 Bq kg-1 for 228Ra, 197±38 Bq kg-1 for 210Pb, 51±26 Bq kg-1 for 238U and 55±24 Bq kg-1 for 232Th, considering both kinds of clay.

  3. Politics in the Western Maya Region (II: Emblem Glyphs

    Directory of Open Access Journals (Sweden)

    Péter Bíró

    2012-01-01

    Full Text Available In a series of articles I reflect on the use of various expressions which are connected to what we call the political in the inscriptions of the Classic Maya Western Region. These words express ideas and concepts which help to understand the intricate details of the interactions between the political entities and their internal organisations in the Classic Maya Lowlands. In this article I investigate the meaning of emblem glyphs. I suggest that originally they were toponyms but later on they became titles of origin which indicated descendance from a common origin place.En una serie de artículos investigo el uso de varias palabras en las inscripciones mayas de la época Clásica de la Región Occidental que se conectan con lo que nosotros llamamos "política". Estas palabras expresan ideas y conceptos que ayudan a entender los matices de las relaciones entre las entidades políticas de las Tierras Bajas Mayas y su organización interna. En este artículo investigo el significado de los glifos emblema. Propongo que originalmente fueron topónimos y después llegaron a ser títulos de origen que indicaron descendencia común de un lugar original.

  4. The Grammar of Ch'orti' Maya Folktales

    Science.gov (United States)

    Dugan, James Timothy

    2014-01-01

    This study describes the grammar of the Ch'orti' Maya language as it appears in a collection of oral literature. I collected the stories that form the basis of this study in and around Jocotan, Guatemala, during 2004 and 2005. I worked with bilingual story-tellers to make audio recordings of the original Ch'orti'-language tales, produce textual…

  5. The Grammar of Ch'orti' Maya Folktales

    Science.gov (United States)

    Dugan, James Timothy

    2014-01-01

    This study describes the grammar of the Ch'orti' Maya language as it appears in a collection of oral literature. I collected the stories that form the basis of this study in and around Jocotan, Guatemala, during 2004 and 2005. I worked with bilingual story-tellers to make audio recordings of the original Ch'orti'-language tales, produce textual…

  6. Deciding To Be Legal: A Maya Community in Houston.

    Science.gov (United States)

    Hagan, Jacqueline Maria

    This book examines the settlement process of undocumented migrant workers through an ethnographic study of a Houston (Texas) community of Mayas from a township in Totonicapan, Guatemala. The community is traced from its genesis in 1978, when a few men left the township in search of economic opportunity, to the complex effects of the 1986…

  7. Maya Angelou: More Than a Poet. African-American Biographies.

    Science.gov (United States)

    Lisandrelli, Elaine Silvinski

    This book explores the life of Maya Angelou, the author the autobiographical "I Know Why the Caged Bird Sings." The book details her life from the beginning in Stamps, Arkansas, and relates how she has overcome many obstacles throughout her life to become the successful, educated woman she is today--author, political activist, actress,…

  8. Core and Periphery Relations: A Case Study of the Maya

    Directory of Open Access Journals (Sweden)

    Stephanie M. Teixeira

    2015-08-01

    Full Text Available How do indigenous peoples relate to the core over the longue duree? In this paper, we explore the implications of colonialism from a world-systems perspective, examining interactions in the economic and political structures in addition to the effects of landlessness for indigenous peoples in one case: the Maya. After reviewing world-systems theory and applying it to indigenousness, we discuss Ragin’s (1992 conceptualization of cases and the comparative historical method. Then we introduce the relational concept, a tool that allows us to employ both the comparative historical method and world-systems theory in our analysis of the Maya and their relationship to the state of Mexico. We then present our data, which consist of the economic and political conditions, along with the cultural implications of landholding across time among the Maya and in Mexico. We analyze these data using the relational concept to understand the consequences of colonialism and globalization for the Maya people.

  9. Maya Angelou: More Than a Poet. African-American Biographies.

    Science.gov (United States)

    Lisandrelli, Elaine Silvinski

    This book explores the life of Maya Angelou, the author the autobiographical "I Know Why the Caged Bird Sings." The book details her life from the beginning in Stamps, Arkansas, and relates how she has overcome many obstacles throughout her life to become the successful, educated woman she is today--author, political activist, actress,…

  10. Maya Angelou. Humanitarian extraordinary + greatest living American poet.

    Science.gov (United States)

    2002-12-01

    Maya Angelou is testimony to the resilience of the human spirit. Rising above poverty and abuse to become one of the 100 best writers of the 20th century, she has used her extraordinary talents to crusade against injustice and prejudice. She measures her success by her ability to love and to care for others.

  11. Siderophore sorption to clays.

    Science.gov (United States)

    Maurice, Patricia A; Haack, Elizabeth A; Mishra, Bhoopesh

    2009-08-01

    Siderophores are low molecular weight organic ligands exuded by some aerobic organisms and plants to acquire Fe under Fe-limited conditions. The hydroxamate siderophores may sorb to aluminosilicate clays through a variety of mechanisms depending upon the nature of the clay and of the siderophore along with solution conditions such as pH, ionic strength, and presence of metal cations. They may also affect metal binding to clays. Here, we review previous studies of siderophore sorption to aluminosilicate clays; briefly discuss how the techniques of X-ray diffractometry, Fourier-transform infrared spectroscopy, and X-ray absorption spectroscopy may be applied to such studies; review effects of siderophores on metal sorption to clays; and highlight some areas for future research.

  12. Imaginando a los mayas de hoy: autorrepresentación y política

    Directory of Open Access Journals (Sweden)

    Ana Rosa Duarte Duarte

    2008-01-01

    Full Text Available En este artículo se analiza el proceso de representación y autorrepresentación de los mayas de Yucatán en Sáastal: Los hijos de la Santa Gracia, una video-ficción de cincuenta y cinco minutos. En Sáastal se pone en escena el drama de la vida cotidiana de una familia maya de acuerdo con la imaginación, tanto de los mayas que participamos en la producción como de los no mayas. Se analiza cómo la convivencia de la cultura maya con las diversas políticas civilizatorias, entre éstas, las de desarrollo, modernización y globalización, han influido en el imaginario de los mayas contemporáneos. Esta convivencia entre dos culturas ha llevado a los mayas a adoptar "identidades suaves", que les permiten actuar de acuerdo con las circunstancias. En Sáastal, los mayas "performamos", recreamos e instrumentalizamos la cultura y convertimos en ficticias nuestras propias identidades.In this article I analyze the processes of representation and self-representation of the Yucatec Maya in Sáastal: The Children of the Sacred Grace, a 55-minute video-fiction. Sáastal presents a dramatic account of the everyday life of a Yucatec Maya family as imagined both by the Maya and non-Maya participating in the production. I examine how this imaginary is influenced by the coexistence of the Mayan culture with the diverse civilizatory politics, such as the politics of development, modernization, and globalization. it is argued that this coexistence has led us, the Yucatec Maya, to adopt "soft identities" which allow us to act according to the circumstances. In Sáastal we therefore perform, recreate and instrumentalize our culture and, in this way, convert our own identities into fictions.

  13. New Concepts for a Unit on the Ancient Maya.

    Science.gov (United States)

    Lemmon, Sarah McCulloh

    1990-01-01

    Contends that social studies textbooks do not reflect recent archaeological research on pre-Columbian Americans. Summarizes recent research results and develops new concepts about Mayan civilization. Examines and rates 12 textbooks currently used in public schools regarding how well they incorporate the new research on Mayan civilization. (DB)

  14. Survey, Settlement, and Population History at the Ancient Maya Site of Pacbitun, Belize

    DEFF Research Database (Denmark)

    Healy, Paul F.; Helmke, Christophe G.B.; Awe, Jaime J.

    2007-01-01

    Survey and excavations of mounds on the outskirts of the site of Pacbitun in western Belize provide insights to the ancient Maya settlement pattern at this medium-sized regional center. This research employed two methods: analysis of structural remains from four separate 1000 m transect surveys...... to have been about 5000-6000 persons. This population estimate is compared with several coeval lowland Maya centers, and found to be reasonable for a medium-sized, Late Classic Maya center....

  15. Religión, fiestas y centros ceremoniales mayas de la Cruz Parlante

    Directory of Open Access Journals (Sweden)

    Manuel Buenrostro Alba

    2015-07-01

    Full Text Available En el trabajo se describe el principal santo de los mayas de Quintana Roo, la Cruz Parlante, así como los centros ceremoniales y las fiestas tradicionales relacionadas con esta advocación. Se incluyen datos etnográficos que describen el contexto en el que se centra el estudio. La Cruz Parlante permite a los mayas de Quintana Roo seguir existiendo y los protege, pero para ello debe estar custodiada por los propios mayas.

  16. An Analysis Of Feminism In Maya Angelou’s Selected Poems

    OpenAIRE

    Sembiring, Dian Bania Persada

    2011-01-01

    Judul skripsi ini adalah An Analysis of Feminism in Maya Angelou’s Selected Poems. Skripsi ini menganalisis tentang feminisme yang tergambar melalui tujuh puisi karya Maya Angelou, seorang penulis wanita kulit hitam pada abad ke-20. Feminisme merupakan paham yang memperjuangkan hak-hak kaum perempuan yang secara budaya, politik, maupun ekonomi berbeda dengan kaum laki-laki. Puisi Maya Angelou sendiri memiliki tema memperjuangkan hak-hak kaum perempuan melalui kepercayaan diri, kepribadian yan...

  17. Holocene Palaeosalinity in a Maya Wetland, Belize, Inferred from the Microfaunal Assemblage

    Science.gov (United States)

    Alcala-Herrera, Javier A.; Jacob, John S.; Castillo, Maria Luisa Machain; Neck, Raymond W.

    1994-01-01

    A 5.4-m sequence of peat and marl overlying a basal clay in a northern Belize wetland was studied to assess salinity changes over the past 7000 yr. The distribution of ostracods, gastropods, and foraminifers revealed initially freshwater conditions in a terrestrial wetland, changing to at least mesohaline conditions by about 5600 yr B.P. The mesohaline conditions corresponded to the formation of an open-water lagoon (and precipitation of a lacustrine marl) that was contemporaneous with rapidly rising sea level in the area. A mangrove peat filled the lagoon by 4800 yr B.P. probably as a result of increasingly shallow waters as sea level rise slowed and marl precipitation continued. A new lagoon began to form sometime after 3400 yr B.P. Freshwater ostracods and gastropods found in the marl of this lagoon suggest that it formed under near-limnetic conditions. Freshwater input likely resulted from massive deforestation by the Maya that began by 4400 yr B.P. Subsidence of the mangrove peat likely permitted the formation of a lagoon. A peat has filled the lagoon since at least 500 yr B.P.

  18. Clay and concrete brick

    CSIR Research Space (South Africa)

    Dlamini, MN

    2014-03-01

    Full Text Available are manufactured from raw clay as their primary ingredient. However concrete brick has also become a favoured material in recent times. This review will adumbrate the impact of these building materials on energy use and the environment....

  19. Clay goes patchy

    NARCIS (Netherlands)

    Kegel, W.K.; Lekkerkerker, H.N.W.

    2011-01-01

    Empty liquids and equilibrium gels have so far been only theoretical possibilities, predicted for colloids with patchy interactions. But evidence of both has now been found in Laponite, a widely studied clay.

  20. Preliminary study of pesticide drift into the Maya Mountain protected areas of Belize.

    Science.gov (United States)

    Kaiser, Kristine

    2011-01-01

    In Belize, Central America, many farms surrounding the Protected Areas of the Maya Mountains rely heavily on the application of agrochemicals. The purpose of this study was to test whether orographic drift of glyphosate and organophosphates into the nearby Maya Mountain Protected Areas occurred by collecting phytotelmic water from seven sites over 3 years. Regardless of location within the Maya Mountain Protected Areas, glyphosate was present; organophosphates were more common at ridge sites. Although glyphosate concentrations were low, due to the number of threatened species and the human use of stream water outside the Maya Mountain Protected Areas, better understanding of these effects is warranted.

  1. Human Migration and Agricultural Expansion: An Impending Threat to the Maya Biosphere Reserve

    Science.gov (United States)

    Sader, Steven; Reining, Conard; Sever, Thomas L.; Soza, Carlos

    1997-01-01

    Evidence is presented of the current threats to the Maya Biosphere Reserve in northern Guatemala as derived through time-series Landsat Thematic Mapper observations and analysis. Estimates of deforestation rates and trends are examined for different management units within the reserve and buffer zones. The satellite imagery was used to quantify and monitor rates, patterns, and trends of forest clearing during a time period corresponding to new road construction and significant human migration into the newly accessible forest region. Satellite imagery is appropriate technology in a vast and remote tropical region where aerial photography and extensive field-based methods are not cost-effective and current, timely data is essential for establishing conservation priorities.

  2. Kax and kol: Collapse and resilience in lowland Maya civilization

    Science.gov (United States)

    Dunning, Nicholas P.; Beach, Timothy P.; Luzzadder-Beach, Sheryl

    2012-01-01

    Episodes of population loss and cultural change, including the famous Classic Collapse, punctuated the long course of Maya civilization. In many cases, these downturns in the fortunes of individual sites and entire regions included significant environmental components such as droughts or anthropogenic environmental degradation. Some afflicted areas remained depopulated for long periods, whereas others recovered more quickly. We examine the dynamics of growth and decline in several areas in the Maya Lowlands in terms of both environmental and cultural resilience and with a focus on downturns that occurred in the Terminal Preclassic (second century Common Era) and Terminal Classic (9th and 10th centuries CE) periods. This examination of available data indicates that the elevated interior areas of the Yucatán Peninsula were more susceptible to system collapse and less suitable for resilient recovery than adjacent lower-lying areas. PMID:22371571

  3. Astronomical and Cosmological Aspects of Maya Architecture and Urbanism

    Science.gov (United States)

    Šprajc, I.

    2009-08-01

    Archaeoastronomical studies carried out so far have shown that the orientations in the ancient Maya architecture were, like elsewhere in Mesoamerica, largely astronomical, mostly referring to sunrises and sunsets on particular dates and allowing the use of observational calendars that facilitated a proper scheduling of agricultural activities. However, the astronomical alignments cannot be understood in purely utilitarian terms. Since the repeatedly occurring directions are most consistently incorporated in monumental architecture of civic and ceremonial urban cores, they must have had an important place in religion and worldview. The characteristics of urban layouts, as well as architectural and other elements associated with important buildings, reveal that the Maya architectural and urban planning was dictated by a complex set of rules, in which astronomical considerations related to practical needs were embedded in a broader framework of cosmological concepts substantiated by political ideology.

  4. EDGE REMOVAL OF 3D POLYGONAL MODEL USING MAYA API

    Directory of Open Access Journals (Sweden)

    SAMEER ARORA

    2010-09-01

    Full Text Available In various applications of computer graphics, 3D polygonal modeling is used, which consists millions of triangular polygon. In this polygon attributes – vertices, edges and faces’ details are to be stored. In order to control the processing time, storing space, and transfer speed, it is often required to reduce the information ofthese polygonal 3D models. In this paper an effort is made to reduce the number of edges. There are various methods to reduce faces and edges of these 3D models. A C++ dynamic link library as Maya Plugin has been created to remove number of edges of 3D triangular polygon model using the Quadric Error Metrics (QEM in MAYA v2010 x64 API. QEM allows fast and accurate geometric simplification of 3D models.

  5. Autodesk Maya 2009试用报告

    Institute of Scientific and Technical Information of China (English)

    孙浩

    2009-01-01

    Autodesk Maya一直是领先的3D建模、动画、效果和渲染解决方案.目标用户包括影视美术工程师、游戏开发人员、绘图设计师.数字出版专业人员、教师和学员等。Autodesk Maya 2009提供了众多旨在提升多边形和纹理处理效率的增强特性(包括真正的软选择.更新的对称建模、扭曲模式).以及使复杂的大型场景更易于管理的新工具(新的Maya Assets和Render Proxy特性)。

  6. Calm, Cool, and Comfortable in Clay

    Science.gov (United States)

    Stylianou, Xanthippi Cynthia

    2010-01-01

    The author's fourth-grade students had just finished a drawing unit that focused on the human figure. Projects included charcoal gesture drawings and chalk manikin drawings in chiaroscuro. She wanted to integrate a new medium for students to continue their study of the human figure. Since students are always excited to work with clay, making clay…

  7. geochemical and mineralogical characteristics of lithomargic clay ...

    African Journals Online (AJOL)

    Administrator

    GHANA: IMPLICATIONS FOR POSSIBLE INDUSTRIAL UTILIZATION. F.W.Y. Momade1 ... evaluative analyses, the lithomargic clay types could be exploited in the production of aluminium sulphate ... Two major processes have been reported to be ..... powder diffraction unit. .... for fats and oils used for soap, grease produc-.

  8. What We Think We Know About Maya Mathematics and Astronomy

    Science.gov (United States)

    Van Stone, M.

    2016-01-01

    In most cultures, mathematics and astronomy are obscure and arcane. Not so to the ancient Maya. Despite what we consider technological “deficiencies”—they lacked both metal tools and the wheel—their public inscriptions paid uniquely sophisticated attention to these sciences. At any given monument, fully half the text is devoted to situating events in time, particularly specifying the precise number of days between events, whether historical or mythological. Often these intervals have numerological significance, and many are precise multiples of the periodicities of heavenly bodies. The Maya apparently were fully aware of the exact length of the tropical year, the sidereal year, the cycles of Venus, and eclipses; and there is evidence that they even celebrated events reflecting the 26,000-year precession cycle. However, Maya illuminati had an agenda quite alien to our way of thinking. Clues to their knowledge are arcane, rare, and often difficult for us to recognize with eyes clouded by our modern worldview. The body of work left to us consists of just a few tantalizing sherds of a once-rich and diverse astromythological tradition. Moreover, there was no single pan-Mayan mythos. An astronomical alignment seen repeatedly in one city will be completely absent in others. Each city-state emphasized specific and often unique features, and they often contradict one another. But we soldier on. The diversity we find so frustrating is simply the fine structure of their worldview. Intellectual historians have for too long been, like Procrustes, trying to force all Maya science and religion into a single universal straitjacket.

  9. Evidencias de agroastronomía entre los antiguos mayas

    Directory of Open Access Journals (Sweden)

    Susan Milbrath

    2016-01-01

    Full Text Available This study focuses on an Postclassic Maya agricultural almanac in the Madrid Codex (12b-18b, which seems to show a registry of eclipses integraed with observations of Venus in the context of a 260-day calendar (Tzolkin. Using the dates of eclipses visibles in Yucatán, it is posible to date the events between 1452 and 1492, contemporary with the use of the codex.

  10. Agroforestry and ritual at the ancient Maya center of Lamanai

    OpenAIRE

    Lentz, D. L.; Graham, E; Vinaja, X.; Slotten, V.; Jain, R

    2016-01-01

    Paleoethnobotanical data retrieved from caches of Late Classic to Early Postclassic origin at the ancient Maya site of Lamanai, Belize, revealed carbonized maize kernels, cob fragments, common beans, coyol endocarps, and an abundance of wood charcoal, from both conifer and hardwood tree species. Pinus caribaea (Caribbean pine) was the most ubiquitous species in the Late and Terminal Classic sample set and the weight of Lamanai pine wood charcoal was more than the combined weight of all known ...

  11. El cemento y el concreto de los mayas

    Directory of Open Access Journals (Sweden)

    Horacio Ramírez de Alba

    1999-01-01

    Full Text Available Se realiza un estudio técnico sobre los materiales utilizados por los constructores mayas, quienes lograron obras cuyos vestigios maravillan hoy al mundo. Se presentan los resultados obtenidos al realizar pruebas físicas y químicas en muestras de estucos, morteros y concretos provenientes de zonas arqueológicas, principalmente Palenque y Yaxchilán, en el estado de Chiapas, México.

  12. Evidencias de agroastronomía entre los antiguos mayas

    OpenAIRE

    Susan Milbrath

    2016-01-01

    This study focuses on an Postclassic Maya agricultural almanac in the Madrid Codex (12b-18b), which seems to show a registry of eclipses integraed with observations of Venus in the context of a 260-day calendar (Tzolkin). Using the dates of eclipses visibles in Yucatán, it is posible to date the events between 1452 and 1492, contemporary with the use of the codex.

  13. Is the onset of the 6th century 'dark age' in Maya history related to explosive volcanism?

    NARCIS (Netherlands)

    Nooren, Kees; Hoek, Wim Z.; Van der Plicht, Hans; Sigl, Michael; Galop, Didier; Torrescano-Valle, Nuria; Islebe, Gerald; Huizinga, Annika; Winkels, Tim; Middelkoop, Hans; Van Bergen, Manfred

    2016-01-01

    Maya societies in Southern Mexico, Guatemala and Belize experienced a 'dark age' during the second half of the 6th century. This period, also known as the 'Maya Hiatus', is characterized by cultural downturn, political instability and abandonment of many sites in the Central Maya Lowlands. Many

  14. Is the onset of the 6th century 'dark age' in Maya history related to explosive volcanism?

    NARCIS (Netherlands)

    Nooren, Kees; Hoek, Wim Z.; Van der Plicht, Hans; Sigl, Michael; Galop, Didier; Torrescano-Valle, Nuria; Islebe, Gerald; Huizinga, Annika; Winkels, Tim; Middelkoop, Hans; Van Bergen, Manfred

    2016-01-01

    Maya societies in Southern Mexico, Guatemala and Belize experienced a 'dark age' during the second half of the 6th century. This period, also known as the 'Maya Hiatus', is characterized by cultural downturn, political instability and abandonment of many sites in the Central Maya Lowlands. Many theo

  15. Representing Mayas : Indigenous Authorities and the Local Politics of Identity in Guatemala

    NARCIS (Netherlands)

    Rasch, E.D.

    2008-01-01

    Against the backdrop of emerging indigenous movements in Latin America, the Maya Movement appeared as a political actor in the 1980s, bringing “the Indian Question” to the fore in Guatemalan politics. Rejecting racism and assimilationalist State policies, the Maya Movement seeks to recapture indigen

  16. Print Knowledge in Yucatec Maya-Spanish Bilingual Children: An Initial Inquiry

    Science.gov (United States)

    Bengochea, Alain; Justice, Laura M.; Hijlkema, Maria J.

    2015-01-01

    This study serves as an initial inquiry regarding the early print knowledge of emergent bilingual preschool-age children living in an Indigenous community in Mexico. In this research, we examine various dimensions of print knowledge with Yucatec Maya-Spanish bilingual children for whom one of their languages (Yucatec Maya) is seldom seen in print…

  17. Language Revitalisation from the Ground Up: Promoting Yucatec Maya on Facebook

    Science.gov (United States)

    Cru, Josep

    2015-01-01

    This paper looks at current grassroots efforts to revitalise Yucatec Maya, an indigenous language of Mexico, in social media and more specifically on Facebook. In contrast to the limitations of institutional language promotion, the inclusion of Maya on Facebook shows the possibilities that social networks offer not only for actual use of…

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  19. Language Revitalisation from the Ground Up: Promoting Yucatec Maya on Facebook

    Science.gov (United States)

    Cru, Josep

    2015-01-01

    This paper looks at current grassroots efforts to revitalise Yucatec Maya, an indigenous language of Mexico, in social media and more specifically on Facebook. In contrast to the limitations of institutional language promotion, the inclusion of Maya on Facebook shows the possibilities that social networks offer not only for actual use of…

  20. Print Knowledge in Yucatec Maya-Spanish Bilingual Children: An Initial Inquiry

    Science.gov (United States)

    Bengochea, Alain; Justice, Laura M.; Hijlkema, Maria J.

    2015-01-01

    This study serves as an initial inquiry regarding the early print knowledge of emergent bilingual preschool-age children living in an Indigenous community in Mexico. In this research, we examine various dimensions of print knowledge with Yucatec Maya-Spanish bilingual children for whom one of their languages (Yucatec Maya) is seldom seen in print…

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

    NARCIS (Netherlands)

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

    2012-01-01

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

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  3. Analysis of obsidian from moho cay, belize: new evidence on classic maya trade routes.

    Science.gov (United States)

    Healy, P F; McKillop, H I; Walsh, B

    1984-07-27

    Trace element analysis of obsidian artifacts from Moho Cay, Belize, reveals that the obsidian derives primarily from the El Chayal outcrop in highland Guatemala and not from the Ixtepeque source. This is contrary to the widely accepted obsidian trade route model for Classic Maya civilization and suggests that Classic Maya obsidian trade was a more complex economic phenomenon than has been recognized.

  4. Early ceremonial constructions at Ceibal, Guatemala, and the origins of lowland Maya civilization.

    Science.gov (United States)

    Inomata, Takeshi; Triadan, Daniela; Aoyama, Kazuo; Castillo, Victor; Yonenobu, Hitoshi

    2013-04-26

    The spread of plaza-pyramid complexes across southern Mesoamerica during the early Middle Preclassic period (1000 to 700 BCE) provides critical information regarding the origins of lowland Maya civilization and the role of the Gulf Coast Olmec. Recent excavations at the Maya site of Ceibal, Guatemala, documented the growth of a formal ceremonial space into a plaza-pyramid complex that predated comparable buildings at other lowland Maya sites and major occupations at the Olmec center of La Venta. The development of lowland Maya civilization did not result from one-directional influence from La Venta, but from interregional interactions, involving groups in the southwestern Maya lowlands, Chiapas, the Pacific Coast, and the southern Gulf Coast.

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

    Data.gov (United States)

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

  6. Discussion on the New Functions of the Cartoon Software Autodesk Maya2008%动画软件Autodesk Maya2008新增功能探索

    Institute of Scientific and Technical Information of China (English)

    王晔; 季勇; 高飞; 李小丹

    2008-01-01

    Maya是Alise/Wavefront公司在1998年推出的三维制作软件,是目前世界上最优秀的三维动画制作软件之一.短短的几年时间,Maya由最初的1.0版本发展到现在的Maya2008版.本文从Maya2008的突出特点入手,通过Maya的角色动画、粒子和动力学、高级模块、开创性制作工具以及Maya2008的工作流程和个性化操作等方面详细阐述了Maya2008的新增强大功能.

  7. Magnificent Clay Murals

    Science.gov (United States)

    Kirker, Sara Schmickle

    2007-01-01

    Each August, third grade artists at Apple Glen Elementary in Bentonville, Arkansas, start the school year planning, creating, and exhibiting a clay relief mural. These mural projects have helped students to acquire not only art knowledge and techniques, but an even more important kind of knowledge: what it means to plan and successfully complete a…

  8. Rattles of Clay.

    Science.gov (United States)

    Banning, Donna

    1983-01-01

    Using the rattles of Native American cultures as inspiration, students used pinching, coiling, and slab and molding techniques to form the bodies of rattles and clay pellets for sound. Surface decoration included glazed and unglazed areas as well as added handles, feathers, and leather. (IS)

  9. Los hacendados y rancheros mayas de Yucatán en el siglo XIX Maya hacendados and rancheros from Yucatán in the 19th Century

    Directory of Open Access Journals (Sweden)

    Laura Machuca Gallegos

    2010-01-01

    Full Text Available No sólo los grupos "blancos" y pudientes de la sociedad tuvieron haciendas, sino también los mayas. Al ser la hacienda una de las pocas actividades económicas productivas que se podían llevar a cabo en la península, algunos mayas (si bien son minoría se volvieron propietarios, incluso tuvieron trabajadores adeudados; por tanto, no permanecieron al margen del desarrollo económico y participaron activamente de éste. Así, en este trabajo nos ocupamos de los amos mayas, seguimos algunas de sus estrategias y reconstruimos sus lazos y sus relaciones. La principal fuente utilizada han sido documentos de carácter notarial, en particular los testamentos, de los cuales se han estudiado algunas variables como la de cónyuge, albacea testamentario y testigo.Haciendas were not exclusive for "white" powerful groups, since they were available for the Maya. Hacienda was one of the only productive economic activities in the peninsula, so the Maya (in spite of being a minority became the owners. They even had debtor workers. They were not marginalized from economic development but rather participated actively in it. This paper studies Maya masters by following some of their strategies and reconstructing both their binds and relations. Our main source are notarial documents, particularly testaments, where some variables like spouse, testamentary executor and witness are studied.

  10. Physical Properties of Latvian Clays

    OpenAIRE

    2012-01-01

    Physical and chemical properties of clays mostly depends on its mineral and chemical composition, particle size and pH value. The mutual influence of these parameters is complex. Illite is the most abundant clay mineral in Latvia and usually used in building materials and pottery. The viscosity and plasticity of Latvian clays from several deposits were investigated and correlated with mineral composition, particle size and pH value. Fractionated and crude clay samples were used. The p...

  11. Clay Animals and Their Habitats

    Science.gov (United States)

    Adamson, Kay

    2010-01-01

    Creating clay animals and their habitats with second-grade students has long been one of the author's favorite classroom activities. Students love working with clay and they also enjoy drawing animal homes. In this article, the author describes how the students created a diorama instead of drawing their clay animal's habitat. This gave students…

  12. Clay membrane made of natural high plasticity clay:

    DEFF Research Database (Denmark)

    Foged, Niels; Baumann, Jens

    1999-01-01

    Leachate containment in Denmark has throughout the years been regulated by the DIF Recommendation for Sanitary Landfill Liners (DS/R4669. It states that natural clay deposits may be used as membrane material provided the membrane and drainage system contains at least 95% of all leachate created...... into account advective ion transport as well as diffusion. Clay prospecting for clays rich in smectite has revealed large deposits of Tertiary clay of very high plasticity in the area around Rødbyhavn on the Danish island of Lolland. The natural clay contains 60-75% smectite, dominantly as a sodium......-type. The clay material has been evaluated using the standardized methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15-0.3 m thick clay membrane...

  13. A late Holocene tephrochronology for the Maya Lowlands, Central America

    Science.gov (United States)

    Nooren, K.; Huizinga, A.; Hoek, W.; Bergen, M. V.; Middelkoop, H.

    2012-12-01

    The Maya Lowlands in southern Mexico, Guatemala and Belize were densely populated for thousands of years, and have been the subject of intensive studies on the interaction between humans and their environment. Accurate radiocarbon dating of proxy records and disrupting events has proved to be difficult due to the lack of organic material in many deposits and the 'old carbon effect' related to the calcareous geology of the Yucatan Peninsula. So far, tephrostratigraphy has hardly been used to define time markers for palynological, limnological and archaeological studies in this region, despite the frequent occurrence of tephra fall. With the objective to fill this gap, we developed a tephrochronology for the Maya Lowlands using sediment cores from a flood basin of the Usumacinta-Grijalva delta in southern Mexico. Tephrostratigraphy and radiocarbon dating were used to estimate the timing of past volcanic eruptions, and chemical compositions of glass shards were used to identify potential sources. At least six tephralayers were deposited since 2000 BC, the most notable representing eruptions of El Chichón volcano in the 5th and 15th century AD. The high sulphur emissions accompanying El Chichón's eruptions allowed testing of our age-depth model through a correlation with volcanic sulphate peaks in ice cores from Greenland and Antarctica. We demonstrate the applicability of the established tephrochronological framework in a detailed chronological reconstruction of the formation of the world's largest late Holocene beach ridge plain in southern Mexico. This plain with over 500 beach ridges is a highly sensitive recorder of combined sea level rise, subsidence, storm activity and changes in climate and upstream land use since the dawn of Olmec and Maya cultures circa 5000 years ago.

  14. Evaluation of the importance of clay confining units on groundwaterflow in alluvial basins using solute and isotope tracers: the case of Middle San Pedro Basin in southeastern Arizona (USA)

    Science.gov (United States)

    Hopkins, Candice B.; McIntosh, Jennifer C.; Eastoe, Chris; Dickinson, Jesse E.; Meixner, Thomas

    2014-01-01

    As groundwater becomes an increasingly important water resource worldwide, it is essential to understand how local geology affects groundwater quality, flowpaths and residence times. This study utilized multiple tracers to improve conceptual and numerical models of groundwater flow in the Middle San Pedro Basin in southeastern Arizona (USA) by determining recharge areas, compartmentalization of water sources, flowpaths and residence times. Ninety-five groundwater and surface-water samples were analyzed for major ion chemistry (water type and Ca/Sr ratios) and stable (18O, 2H, 13C) and radiogenic (3H, 14C) isotopes, and resulting data were used in conjunction with hydrogeologic information (e.g. hydraulic head and hydrostratigraphy). Results show that recent recharge (recharged at high elevation in the fractured bedrock and has been extensively modified by water-rock reactions (increasing F and Sr, decreasing 14C) over long timescales (up to 35,000 years BP). Distinct solute and isotope geochemistries between the lower and upper basin fill aquifers show the importance of a clay confining unit on groundwater flow in the basin, which minimizes vertical groundwater movement.

  15. Variabilidad de un difrasismo maya : Emparejamientos con ch'ab

    OpenAIRE

    Hoppan, Jean-Michel; Jacquemot, Emilie

    2007-01-01

    International audience; Este artículo muestra varios casos de emparejamiento del lexema ch'ab ("(hacer) penitencia"), bajo la forma más frecuente de un difrasismo donde se asocia con el lexema que significa "(de) noche / oscuridad": ak'baal. Las numerosas ocurrencias de este difrasismo permiten reconstituir el recorrido histórico de sus empleos desde tiempos remotos, con ejemplos en las inscripciones mayas jeroglíficas del período Preclásico hasta el fin del Clásico para las inscripciones en ...

  16. Multi-indexed Jacobi polynomials and Maya diagrams

    Science.gov (United States)

    Takemura, Kouichi

    2014-11-01

    Multi-indexed Jacobi polynomials are defined by the Wronskian of four types of eigenfunctions of the Pöschl-Teller Hamiltonian. We give a correspondence between multi-indexed Jacobi polynomials and pairs of Maya diagrams, and we show that any multi-indexed Jacobi polynomial is essentially equal to some multi-indexed Jacobi polynomial of two types of eigenfunction. As an application, we show a Wronskian-type formula of some special eigenstates of the deformed Pöschl-Teller Hamiltonian.

  17. Paralelismo, ciclicidad y creatividad en el arte verbal maya yucateco

    OpenAIRE

    Valentina Vapnarsky

    2008-01-01

    Este artículo contribuye a demostrar que el recurso discursivo del paralelismo en la tradición maya juega un papel esencial en diferentes niveles de organización discursiva, y no sólo en cuanto al verso y unidades contiguas como se ha señalado generalmente. Analizamos la variedad de niveles en los cuales se pueden desarrollar los paralelismos, así como la relación con otras figuras retóricas, en especial la ciclicidad, que se destaca como un recurso importante para el despliegue de paralelism...

  18. Número embera-número maya, una experiencia de aula

    OpenAIRE

    Fernández, Oscar

    2012-01-01

    En este trabajo se muestra el desarrollo de una propuesta de enseñanza sobre pensamiento numérico con estudiantes indígenas Embera-Chamí de Risaralda, Colombia. Esta cultura es ancestralmente oral, por lo que se dificulta trabajar con la grafía del sistema decimal usado por la cultura de Occidente, que es una cultura con escritura. Se hizo un acercamiento a través de elementos del sistema numérico de la cultura Maya- K’iché de Guatemala, el cual tiene una base metafórica sobre su mitología sa...

  19. Condiciones alimentarias de los mayas macehuales de Quintana Roo

    Directory of Open Access Journals (Sweden)

    Virginia Ivonne Sánchez Vázquez

    2011-07-01

    Full Text Available Las políticas alimentarias ofrecen una visión oficial sobre las condiciones de la alimentación en México, y específicamente en el México rural indígena, pero a partir de un estudio de caso con los grupos mayas macehuales de Quintana Roo, se muestra el contexto de confrontación donde las comunidades despliegan sus pautas de reproducción social, ciertamente en desventaja estructural, pero no de manera pasiva, sino creando y recreando opciones bajo su marco cultural situado.

  20. Classic Period collapse of the Central Maya Lowlands: insights about human-environment relationships for sustainability.

    Science.gov (United States)

    Turner, B L; Sabloff, Jeremy A

    2012-08-28

    The ninth century collapse and abandonment of the Central Maya Lowlands in the Yucatán peninsular region were the result of complex human-environment interactions. Large-scale Maya landscape alterations and demands placed on resources and ecosystem services generated high-stress environmental conditions that were amplified by increasing climatic aridity. Coincident with this stress, the flow of commerce shifted from land transit across the peninsula to sea-borne transit around it. These changing socioeconomic and environmental conditions generated increasing societal conflicts, diminished control by the Maya elite, and led to decisions to move elsewhere in the peninsular region rather than incur the high costs of maintaining the human-environment systems in place. After abandonment, the environment of the Central Maya Lowlands largely recovered, although altered from its state before Maya occupation; the population never recovered. This history and the spatial and temporal variability in the pattern of collapse and abandonment throughout the Maya lowlands support the case for different conditions, opportunities, and constraints in the prevailing human-environment systems and the decisions to confront them. The Maya case lends insights for the use of paleo- and historical analogs to inform contemporary global environmental change and sustainability.

  1. Impacts of Climate Change on the Collapse of Lowland Maya Civilization

    Science.gov (United States)

    Douglas, Peter M. J.; Demarest, Arthur A.; Brenner, Mark; Canuto, Marcello A.

    2016-06-01

    Paleoclimatologists have discovered abundant evidence that droughts coincided with collapse of the Lowland Classic Maya civilization, and some argue that climate change contributed to societal disintegration. Many archaeologists, however, maintain that drought cannot explain the timing or complex nature of societal changes at the end of the Classic Period, between the eighth and eleventh centuries ce. This review presents a compilation of climate proxy data indicating that droughts in the ninth to eleventh century were the most severe and frequent in Maya prehistory. Comparison with recent archaeological evidence, however, indicates an earlier beginning for complex economic and political processes that led to the disintegration of states in the southern region of the Maya lowlands that precedes major droughts. Nonetheless, drought clearly contributed to the unusual severity of the Classic Maya collapse, and helped to inhibit the type of recovery seen in earlier periods of Maya prehistory. In the drier northern Maya Lowlands, a later political collapse at ca. 1000 ce appears to be related to ongoing extreme drought. Future interdisciplinary research should use more refined climatological and archaeological data to examine the relationship between climate and social processes throughout the entirety of Maya prehistory.

  2. Classic Period collapse of the Central Maya Lowlands: Insights about human–environment relationships for sustainability

    Science.gov (United States)

    Turner, B. L.; Sabloff, Jeremy A.

    2012-01-01

    The ninth century collapse and abandonment of the Central Maya Lowlands in the Yucatán peninsular region were the result of complex human–environment interactions. Large-scale Maya landscape alterations and demands placed on resources and ecosystem services generated high-stress environmental conditions that were amplified by increasing climatic aridity. Coincident with this stress, the flow of commerce shifted from land transit across the peninsula to sea-borne transit around it. These changing socioeconomic and environmental conditions generated increasing societal conflicts, diminished control by the Maya elite, and led to decisions to move elsewhere in the peninsular region rather than incur the high costs of maintaining the human–environment systems in place. After abandonment, the environment of the Central Maya Lowlands largely recovered, although altered from its state before Maya occupation; the population never recovered. This history and the spatial and temporal variability in the pattern of collapse and abandonment throughout the Maya lowlands support the case for different conditions, opportunities, and constraints in the prevailing human–environment systems and the decisions to confront them. The Maya case lends insights for the use of paleo- and historical analogs to inform contemporary global environmental change and sustainability. PMID:22912403

  3. The use of blunted Maya crude as alternating fuel to fuel oil; Uso de crudo Maya despuntado como combustiononble alterno al combustoleo

    Energy Technology Data Exchange (ETDEWEB)

    Salinas Bravo, Victor M.; Diego Marin, Antonio; Porcayo C; Jesus [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-07-01

    The Mexican fuel oil is characterized by its high viscosity and elevated contents of sulfur and vanadium. This particularity determines a problematic characteristic in the steam generators that use this fuel. Our country produces three types of crude petroleum: Olmeca, Istmo and Maya. The difference between these crudes remains in its density and the sulfur content. The Olmeca crude and the Istmo are classified as super-light and light, respectively; whereas the Maya crude is classified as a heavy crude, with a density of 1.0 to 0.92 g/cm and a minimum sulfur content of 3.3 %. For this reason the processing of the Maya crude is seen as an alternative. A table with the physicochemical analysis and properties of a fuel oil and the blunted Maya crude is given, and another one with the quantitative chemical analysis of some metals in fuel oil and in the blunted Maya crude. The stability tests of the fuel are studied giving a comparison of the effect of the aging time on the viscosity of a fuel oil and of the blunted Maya crude at 60 Celsius degrees. As well as a graph of thermograms obtained of a blunted Maya crude sample and of a typical fuel oil. Finally the corrosion tests are described that allow to know in real time the degradation process by corrosion of the materials. [Spanish] El combustoleo mexicano se caracteriza por su alta viscosidad y elevados contenidos de azufre y vanadio. Esta particularidad determina una problematica caracteristica en los generadores de vapor que utilizan este combustible. Nuestro pais produce tres tipos de petroleo crudo: Olmeca, Istmo y Maya. La diferencia entre estos crudos estriba en su densidad y el contenido de azufre. El crudo Olmeca y el Istmo estan clasificados como superligero y ligero, respectivamente; mientras que el crudo Maya esta clasificado como un crudo pesado, con una densidad de 1.0 a 0.92 g/cm y un contenido minimo de azufre de 3.3 %.Con el proposito se busca la alternativa de procesar el crudo Maya. Se da una tabla

  4. Thermostability of montmorillonitic clays

    Directory of Open Access Journals (Sweden)

    Petr Jelínek

    2014-05-01

    Full Text Available Bentonite is one of the most widespread used clays connected with various applications. In the case of foundry technology, bentonite is primarily used as a binder for mold manufacture. Thermal stability of bentonites is a natural property of clay minerals and it depends on the genesis, source and chemical composition of the clay. This property is also closely connected to bentonite structure. According to DTA analysis if only one peak of dehydroxylation is observed (about 600 ºC, the cis- isomerism of bentonite is expected, while two peaks of de-hydroxylation (about 550 and 850 ºC are expected in the trans- one. In this overview, the bentonite structure, the water – bentonite interaction and the swelling behavior of bentonite in connection with the general technological properties of bentonite molding mixture are summarized. Further, various types of methods for determination of bentonite thermostability are discussed, including instrumental analytical methods as well as methods that employ evaluation of various technological properties of bentonite binders and/or bentonite molding mixtures.

  5. Thermostability of montmorillonitic clays

    Institute of Scientific and Technical Information of China (English)

    Petr Jelnek; Stanisaw M.Dobosz; Jaroslav Beo; Katarzyna Major-Gabry

    2014-01-01

    Bentonite is one of the most widespread used clays connected with various applications. In the case of foundry technology, bentonite is primarily used as a binder for mold manufacture. Thermal stability of bentonites is a natural property of clay minerals and it depends on the genesis, source and chemical composition of the clay. This property is also closely connected to bentonite structure. According to DTA analysis if only one peak of dehydroxylation is observed (about 600 ºC), thecis- isomerism of bentonite is expected, while two peaks of de-hydroxylation (about 550 and 850 ºC) are expected in thetrans- one. In this overview, the bentonite structure, the water - bentonite interaction and the sweling behavior of bentonite in connection with the general technological properties of bentonite molding mixture are summarized. Further, various types of methods for determination of bentonite thermostability are discussed, including instrumental analytical methods as wel as methods that employ evaluation of various technological properties of bentonite binders and/or bentonite molding mixtures.

  6. RESEARCH OF SWELLING OF SUZAKH CLAYS

    Directory of Open Access Journals (Sweden)

    Kubetskiy Valeriy Leonidovich

    2012-07-01

    Full Text Available In the course of construction of Sangtudinsky hydropower plant-1 on the River Vakhsh, it was deemed necessary to identify clay swelling properties in the event of alterations of the humidity mode of fructured half-rock soils, or the Suzakh clay, that accommodated tunnel-shaped water outlets within a section that was 75 meters long. The depth of tunnels was about 100 m. Any interaction with swelling soils could lead to destruction of the tunnel lining. Suzakh clays demonstrated the following physical and mechanical properties: density of particles of soil ρ= 2,69 g/cm; soil density ρ = 2.40-2.47 g/cm; porosity of 8.2-10.8 %; ultimate resistance to uniaxial compression = 13.1-31.0 MPa. Water saturated clay samples disintegrated into cloddy fragments; the rate of a longitudinal ultrasonic wave in the area of unaltered soils was equal to = 2500 m/c; repulse coefficient k was equal to 15 MPa/m; solidity coefficient (according to Protodyakonov was equal to 1,5; modulus of deformation in the massif was equal to 0.23 х10 MPa. The author proposed a methodology and designed a pilot set of equipment units designated for the identification of the swelling properties of fractured half-rock soils. Results of the pilot unit operation are presented in the article. Swelling properties are based on the monolith testing results. The programme contemplated a set of experiments held in various limit states on the surface of monoliths. Dependence between the swelling pressure and the swelling deformation in the course of water saturation was identified. The experiment demonstrates that alterations of the humidity mode of free surface Suzakh clays cause the relative deformation of swelling up to 1.1 %, and if the lining is rigid, the swelling pressure can exceed 4 MPa.

  7. Les reconstructions de la vie de Jésus-Christ en aire maya

    Directory of Open Access Journals (Sweden)

    Stéphanie Geslin

    2007-06-01

    Full Text Available Les histoires mayas de Jésus-Christ Les recueils de tradition orale maya enregistrent au fil des terrains l’occurrence de l’histoire de Jésus-Christ dans plusieurs ethnies mayas, à différents moments du xxe siècle, et sous des formes stylistiques distinctes. L’aspect le plus frappant de ces versions est la pluralité des noms concurrents que porte Jésus-Christ selon le lieu de recueil : si Jesukristo est employé chez les Yucatèques, les Tzeltal, les Tzotzil, les K’iche’, les Mam ou encore les ...

  8. Finish your film! tips and tricks for making an animated short in Maya

    CERN Document Server

    Roy, Kenny

    2014-01-01

    Finish Your Film! Tips and Tricks for Making an Animated Short in Maya is a first-of-its-kind book that walks the reader step-by-step through the actual production processes of creating a 3D Short film with Maya. Other books focus solely on the creative decisions of 3D Animation and broadly cover the multiple phases of animation production with no real applicable methods for readers to employ. This book shows you how to successfully manage the entire Maya animation pipeline. This book blends together valuable technical tips on film production and real-world shortcuts in a step-by-step approach

  9. A Study of Clay-Epoxy Nanocomposites Consisting of Unmodified Clay and Organo Clay

    Directory of Open Access Journals (Sweden)

    Graham Edward

    2006-04-01

    Full Text Available Clay-epoxy nanocomposites were synthesized from DGEBA resin and montmorillonite clay with an in-situ polymerization. One type of untreated clay and two types of organo clay were used to produce the nanocompsoites. The aims of this study were to examine the nanocomposite structure using different tools and to compare the results between the unmodified clay and modified clays as nanofillers. Although diffractogram in reflection mode did not show any apparent peak of both types of materials, the transmitted XRD (X-Ray Difraction graphs, DSC (Differential Scanning Calorimeter analysis and TEM (Transmission Electron Microscope images revealed that the modified clay-epoxy and unmodified clay-epoxy provides different results. Interestingly, the micrographs showed that some of the modified clay layers possessed non-exfoliated layers in the modified clay-epoxy nanocomposites. Clay aggregates and a hackle pattern were found from E-SEM images for both types of nanocomposite materials. It is shown that different tools should be used to determine the nanocomposite structure.

  10. Sobre el ciclo maya de 819 días

    Directory of Open Access Journals (Sweden)

    Huberto Quiñones Garza

    2011-01-01

    Full Text Available Algunos autores consideran que los mayas manejaban un ciclo de 819 días, que habría tenido un carácter mágico o ritual, sin descartar alguna manifestación astrológica o astronómica. Un enfoque que no ha sido tomado en cuenta hasta hoy, es el puramente aritmético, el posible interés del sacerdocio maya en este número como tal. Se especula aquí que el número 819 está relacionado con el valor de TT, además de la probable vinculación que esta cifra podría guardar con sus sistemas numérico y calendárico. Dos situaciones se vislumbran como importantes contribuciones, el planteamiento epistemológico implícito y los resultados obtenidos como información básica para futuras investigaciones dentro de la etnomatemática y la antropología.

  11. Increasing temperature exacerbated Classic Maya conflict over the long term

    Science.gov (United States)

    Carleton, W. Christopher; Campbell, David; Collard, Mark

    2017-05-01

    The impact of climate change on conflict is an important but controversial topic. One issue that needs to be resolved is whether or not climate change exacerbates conflict over the long term. With this in mind, we investigated the relationship between climate change and conflict among Classic Maya polities over a period of several hundred years (363-888 CE). We compiled a list of conflicts recorded on dated monuments, and then located published temperature and rainfall records for the region. Subsequently, we used a recently developed time-series method to investigate the impact of the climatic variables on the frequency of conflict while controlling for trends in monument number. We found that there was a substantial increase in conflict in the approximately 500 years covered by the dataset. This increase could not be explained by change in the amount of rainfall. In contrast, the increase was strongly associated with an increase in summer temperature. These finding have implications not only for Classic Maya history but also for the debate about the likely effects of contemporary climate change.

  12. An Overview of Rha And Scba Clay Bricks

    Directory of Open Access Journals (Sweden)

    Er. Ravindra Kumar,

    2016-12-01

    Full Text Available Burnt clay brick is one of the major and widely used building units in construction around the world. The manufacturing of burnt clay bricks using waste materials can minimize the environmental overburden caused by waste deposition on open landfills and would also improve the brick performance at low production cost leading to more sustainable construction. These wastes utilization would not only be economical, but may also help to create a sustainable and pollution free environment. This study aims to evaluate the effect of the waste addition produced from two major crops: sugarcane and rice in clay bricks manufacturing.

  13. Utilization of crushed clay brick in cellular concrete production

    OpenAIRE

    Ali A. Aliabdo; Abd-Elmoaty M. Abd-Elmoaty; Hani H. Hassan

    2014-01-01

    The main objective of this research program is to study the effect of using crushed clay brick as an alternative aggregate in aerated concrete. Two series of mixtures were designed to investigate the physico-mechanical properties and micro-structural analysis of autoclave aerated concrete and foamed concrete, respectively. In each series, natural sand was replaced with crushed clay brick aggregate. In both series results showed a significant reduction in unit weight, thermal conductivity and ...

  14. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the thickness of the Bucatunna clay confining unit

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  15. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the thickness of the Bucatunna clay confining unit

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  16. Heteroaggregation of titanium dioxide nanoparticles with natural clay colloids.

    Science.gov (United States)

    Labille, Jérôme; Harns, Carrie; Bottero, Jean-Yves; Brant, Jonathan

    2015-06-02

    To better understand and predict the fate of engineered nanoparticles in the water column, we assessed the heteroaggregation of TiO2 nanoparticles with a smectite clay as analogues for natural colloids. Heteroaggregation was evaluated as a function of water salinity (10(-3) and 10(-1) M NaCl), pH (5 and 8), and selected nanoparticle concentration (0-4 mg/L). Time-resolved laser diffraction was used, coupled to an aggregation model, to identify the key mechanisms and variables that drive the heteroaggregation of the nanoparticles with colloids. Our data show that, at a relevant concentration, nanoparticle behavior is mainly driven by heteroaggregation with colloids, while homoaggregation remains negligible. The affinity of TiO2 nanoparticles for clay is driven by electrostatic interactions. Opposite surface charges and/or high ionic strength favored the formation of primary heteroaggregates via the attachment of nanoparticles to the clay. The initial shape and dispersion state of the clay as well as the nanoparticle/clay concentration ratio also affected the nature of the heteroaggregation mechanism. With dispersed clay platelets (10(-3) M NaCl), secondary heteroaggregation driven by bridging nanoparticles occurred at a nanoparticle/clay number ratio of greater than 0.5. In 10(-1) M NaCl, the clay was preaggregated into larger and more spherical units. This favored secondary heteroaggregation at lower nanoparticle concentration that correlated to the nanoparticle/clay surface area ratio. In this latter case, a nanoparticle to clay sticking efficiency could be determined.

  17. Genomic insights on the ethno-history of the Maya and the 'Ladinos' from Guatemala

    National Research Council Canada - National Science Library

    Söchtig, Jens; Álvarez-Iglesias, Vanesa; Mosquera-Miguel, Ana; Gelabert-Besada, Miguel; Gómez-Carballa, Alberto; Salas, Antonio

    2015-01-01

    ...' from Guatemala by means of uniparental and ancestry informative markers (AIMs). Analyses of uniparental genetic markers indicate that Maya have a dominant Native American ancestry (mitochondrial DNA [mtDNA]: 100%; Y-chromosome: 94...

  18. Las distancias biologicas entre los mexicas, mayas, toltecas, y totonacas de Mexico central y zona costera

    National Research Council Canada - National Science Library

    Willermet, Cathy; Edgar, Heather J.H; Ragsdale, Corey; Scott Aubry, B

    2013-01-01

    ..., los mexicas, los totonacas, y los mayas. Hemos calculado las seudodistancias de Mahalanobis D2 utilizando observaciones de 12 rasgos dentales para comparar los modelos basados en el grupo cultural, la geografia y el tiempo que puede haber...

  19. Lead (Pb) Isotope Baselines for Studies of Ancient Human Migration and Trade in the Maya Region

    National Research Council Canada - National Science Library

    Sharpe, Ashley E; Kamenov, George D; Gilli, Adrian; Hodell, David A; Emery, Kitty F; Brenner, Mark; Krigbaum, John

    2016-01-01

    .... We analyzed 60 rock samples for lead isotope ratios and a representative subset of samples for lead, uranium, and thorium concentrations across the Maya region, including the Northern Lowlands...

  20. Maya Angelou to speak during Virginia Tech's third annual Martin Luther King Jr. celebration

    OpenAIRE

    Williams, Meghan

    2008-01-01

    A remarkable woman who is hailed as one of the greatest voices of contemporary literature, Maya Angelou, will be a guest speaker during the third annual Dr. Martin Luther King Jr. celebration at Virginia Tech.

  1. Maya Angelou to visit Virginia Tech during third annual Martin Luther King, Jr. celebration

    OpenAIRE

    Williams, Meghan

    2007-01-01

    A remarkable woman who is hailed as one of the greatest voices of contemporary literature, Maya Angelou, will be a guest speaker during the third annual Dr. Martin Luther King Jr. celebration at Virginia Tech.

  2. Genetic Affiliation of Pre-Hispanic and Contemporary Mayas Through Maternal Linage.

    Science.gov (United States)

    Ochoa-Lugo, Mirna Isabel; Muñoz, María de Lourdes; Pérez-Ramírez, Gerardo; Beaty, Kristine G; López-Armenta, Mauro; Cervini-Silva, Javiera; Moreno-Galeana, Miguel; Meza, Adrián Martínez; Ramos, Eduardo; Crawford, Michael H; Romano-Pacheco, Arturo

    2016-04-01

    Maya civilization developed in Mesoamerica and encompassed the Yucatan Peninsula, Guatemala, Belize, part of the Mexican states of Tabasco and Chiapas, and the western parts of Honduras and El Salvador. This civilization persisted approximately 3,000 years and was one of the most advanced of its time, possessing the only known full writing system at the time, as well as art, sophisticated architecture, and mathematical and astronomical systems. This civilization reached the apex of its power and influence during the Preclassic period, from 2000 BCE to 250 CE. Genetic variation in the pre-Hispanic Mayas from archaeological sites in the Mexican states of Yucatan, Chiapas, Quintana Roo, and Tabasco and their relationship with the contemporary communities in these regions have not been previously studied. Consequently, the principal aim of this study was to determine mitochondrial DNA (mtDNA) variation in the pre-Hispanic Maya population and to assess the relationship of these individuals with contemporary Mesoamerican Maya and populations from Asia, Beringia, and North, Central, and South America. Our results revealed interactions and gene flow between populations in the different archaeological sites assessed in this study. The mtDNA haplogroup frequency in the pre-Hispanic Maya population (60.53%, 34.21%, and 5.26% for haplogroups A, C, and D, respectively) was similar to that of most Mexican and Guatemalan Maya populations, with haplogroup A exhibiting the highest frequency. Haplogroup B most likely arrived independently and mixed with populations carrying haplogroups A and C based on its absence in the pre-Hispanic Mexican Maya populations and low frequencies in most Mexican and Guatemalan Maya populations, although this also may be due to drift. Maya and Ciboneys sharing haplotype H10 belonged to haplogroup C1 and haplotype H4 of haplogroup D, suggesting shared regional haplotypes. This may indicate a shared genetic ancestry, suggesting more regional interaction

  3. Political and socioeconomic implications of Classic Maya lithic artifacts from the Main Plaza of Aguateca, Guatemala

    OpenAIRE

    AOYAMA, Kazuo

    2014-01-01

    Political and socioeconomic implications of Classic Maya lithic artifacts from the Main Plaza of Aguateca, Guatemala. This article discusses the results of an analysis of 4,076 lithic artifacts collected in and around the Main Plaza of Aguateca, Guatemala, by the Aguateca Restoration Project Second Phase with the objective of examining Classic Maya political and socioeconomic organization. First, combined with the results of analysis of 10,845 lithic artifacts collected in the Palace Group, t...

  4. Land, Water and Society in the Maya Lowlands

    Science.gov (United States)

    Murtha, T.; French, K.; Duffy, C.; Webster, D.

    2013-12-01

    This paper reports the results of our project investigating the long-term spatial and temporal dynamics of land use management, agricultural decision-making and patterns of resource availability in the tropical lowlands of Central America. Overall, our project combines diachronic environmental simulation with historic settlement pattern survey to address a series of long-standing questions about the coupled natural and human (CNH) landscape history in the Central Maya lowlands (at the UNESCO world heritage site of Tikal in the Maya Biosphere Reserve). The paper describes the preliminary results of our project, including changing patterns of land, water, settlement and political history using climate, soil and hydrologic modeling and time series spatial analysis of population and settlement patterns. The critical period of the study, 1000 BC until the present, begins with dispersed settlements accompanied by widespread deforestation and soil erosion. Population size and density grows rapidly for 800 years, while deforestation and erosion rates decline; however, there is striking evidence of political evolution during this period, including the construction of monumental architecture, hieroglyphic monuments detailing wars and alliances, and the construction of a defensive earthwork feature, signaling political territories and possibly delineating natural resource boundaries. Population decline and steady reforestation followed until more recent migration into the region, which has impacted the biosphere ecology. Building on our previous research regionally and comparative research completed in Belize and Mexico, we are modeling sample periods the 3,000-year landscape history of the region, comparing land and water availability to population distributions and what we know about political history. Simulations are generated using historic climate and land use data, primarily relying on the Erosion Productivity Impact Calculator (EPIC) and the Penn State Integrated

  5. Construction of an Yucatec Maya soil classification and comparison with the WRB framework

    Directory of Open Access Journals (Sweden)

    Zinck J Alfred

    2010-02-01

    Full Text Available Abstract Background Mayas living in southeast Mexico have used soils for millennia and provide thus a good example for understanding soil-culture relationships and for exploring the ways indigenous people name and classify the soils of their territory. This paper shows an attempt to organize the Maya soil knowledge into a soil classification scheme and compares the latter with the World Reference Base for Soil Resources (WRB. Methods Several participative soil surveys were carried out in the period 2000-2009 with the help of bilingual Maya-Spanish-speaking farmers. A multilingual soil database was built with 315 soil profile descriptions. Results On the basis of the diagnostic soil properties and the soil nomenclature used by Maya farmers, a soil classification scheme with a hierarchic, dichotomous and open structure was constructed, organized in groups and qualifiers in a fashion similar to that of the WRB system. Maya soil properties were used at the same categorical levels as similar diagnostic properties are used in the WRB system. Conclusions The Maya soil classification (MSC is a natural system based on key properties, such as relief position, rock types, size and quantity of stones, color of topsoil and subsoil, depth, water dynamics, and plant-supporting processes. The MSC addresses the soil properties of surficial and subsurficial horizons, and uses plant communities as qualifier in some cases. The MSC is more accurate than the WRB for classifying Leptosols.

  6. The first direct evidence of pre-columbian sources of palygorskite for Maya Blue

    Science.gov (United States)

    Arnold, Dean E.; Bohor, Bruce F.; Neff, Hector; Feinman, Gary M.; Williams, Patrick Ryan; Dussubieux, Laure; Bishop, Ronald

    2012-01-01

    Maya Blue, a nano-structured clay–organic complex of palygorskite and indigo, was used predominantly before the Spanish Conquest. It has fascinated chemists, material scientists, archaeologists and art historians for decades because it is resistant to the effect of acids, alkalis, and other reagents, and its rich color has persisted for centuries in the harsh tropical climate of southern Mesoamerica. One of its components, palygorskite, is part of modern Maya indigenous knowledge, and ethnohistoric and archaeological data suggest that its modern sources were probably utilized in Prehispanic times. Yet no direct evidence verifies that palygorskite was actually mined from these sources to make Maya Blue. Here we characterize these sources compositionally, and compare our analyses to those of Maya Blue from Chichén Itzá and Palenque. We demonstrate that the palygorskite in most of these samples came from modern mines, providing the first direct evidence for the use of these sources for making Maya Blue. These findings reveal that modern Maya indigenous knowledge about palygorskite, its mining, and its source locations, is at least seven centuries old.

  7. Classic Maya civilization collapse associated with reduction in tropical cyclone activity

    Science.gov (United States)

    Medina, M. A.; Polanco-Martinez, J. M.; Lases-Hernández, F.; Bradley, R. S.; Burns, S. J.

    2013-12-01

    In light of the increased destructiveness of tropical cyclones observed over recent decades one might assume that an increase and not a decrease in tropical cyclone activity would lead to societal stress and perhaps collapse of ancient cultures. In this study we present evidence that a reduction in the frequency and intensity of tropical Atlantic cyclones could have contributed to the collapse of the Maya civilization during the Terminal Classic Period (TCP, AD. 800-950). Statistical comparisons of a quantitative precipitation record from the Yucatan Peninsula (YP) Maya lowlands, based on the stalagmite known as Chaac (after the Mayan God of rain and agriculture), relative to environmental proxy records of El Niño/Southern Oscillation (ENSO), tropical Atlantic sea surface temperatures (SSTs), and tropical Atlantic cyclone counts, suggest that these records share significant coherent variability during the TCP and that summer rainfall reductions between 30 and 50% in the Maya lowlands occurred in association with decreased Atlantic tropical cyclones. Analysis of modern instrumental hydrological data suggests cyclone rainfall contributions to the YP equivalent to the range of rainfall deficits associated with decreased tropical cyclone activity during the collapse of the Maya civilization. Cyclone driven precipitation variability during the TCP, implies that climate change may have triggered Maya civilization collapse via freshwater scarcity for domestic use without significant detriment to agriculture. Pyramid in Tikal, the most prominent Maya Kingdom that collapsed during the Terminal Classic Period (circa C.E. 800-950) Rainfall feeding stalagmites inside Rio Secreto cave system, Yucatan, Mexico.

  8. Construction of an Yucatec Maya soil classification and comparison with the WRB framework.

    Science.gov (United States)

    Bautista, Francisco; Zinck, J Alfred

    2010-02-13

    Mayas living in southeast Mexico have used soils for millennia and provide thus a good example for understanding soil-culture relationships and for exploring the ways indigenous people name and classify the soils of their territory. This paper shows an attempt to organize the Maya soil knowledge into a soil classification scheme and compares the latter with the World Reference Base for Soil Resources (WRB). Several participative soil surveys were carried out in the period 2000-2009 with the help of bilingual Maya-Spanish-speaking farmers. A multilingual soil database was built with 315 soil profile descriptions. On the basis of the diagnostic soil properties and the soil nomenclature used by Maya farmers, a soil classification scheme with a hierarchic, dichotomous and open structure was constructed, organized in groups and qualifiers in a fashion similar to that of the WRB system. Maya soil properties were used at the same categorical levels as similar diagnostic properties are used in the WRB system. The Maya soil classification (MSC) is a natural system based on key properties, such as relief position, rock types, size and quantity of stones, color of topsoil and subsoil, depth, water dynamics, and plant-supporting processes. The MSC addresses the soil properties of surficial and subsurficial horizons, and uses plant communities as qualifier in some cases. The MSC is more accurate than the WRB for classifying Leptosols.

  9. Maya Healers' Conception of Cancer as Revealed by Comparison With Western Medicine.

    Science.gov (United States)

    Berger-González, Mónica; Gharzouzi, Eduardo; Renner, Christoph

    2016-04-01

    Cultural diversity in clinical encounters is common, yet mental constructions regarding cancer that influence expected treatment are poorly studied for indigenous people. We explored Maya healers' conceptions, diagnosis, and treatment of cancer to remedy this problem. In-depth structured interviews with 67 traditional Maya healers in Guatemala across Kaqchikel, Kiche', Mam, Mopan, and Q'eqchi' ethnolinguistic groups were conducted by using a transdisciplinary format. Analysis of qualitative data in categorized matrixes allowed for statistical examination of tendencies and the results were complemented by validation workshops with Maya representatives. Maya classification of diseases has broad categories of malignant diseases including cancer. Specific Maya terms might equate to particular cancer types, which would open new avenues for research. Notions of malignancy and metastasis were expressed by healers as core characteristics of cancer, a disease believed to be both material and spiritual. Resolution of and/or treatment for cancer is based on restoring physical, mental, emotional, and spiritual equilibrium of the patient and extending that equilibrium to his larger social circle. Maya conceptions of cancer determine how traditional diagnostic tools are used and dictate treatment options that include the patient's social-spiritual support system. Official health care providers' understanding of these principles can improve implementation of culturally appropriate protocols that increase indigenous patients' compliance and reduce rates of treatment abandonment.

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

    Science.gov (United States)

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

    2014-05-01

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

  11. Pore space analysis of NAPL distribution in sand-clay media

    Science.gov (United States)

    Matmon, D.; Hayden, N.J.

    2003-01-01

    This paper introduces a conceptual model of clays and non-aqueous phase liquids (NAPLs) at the pore scale that has been developed from a mathematical unit cell model, and direct micromodel observation and measurement of clay-containing porous media. The mathematical model uses a unit cell concept with uniform spherical grains for simulating the sand in the sand-clay matrix (???10% clay). Micromodels made with glass slides and including different clay-containing porous media were used to investigate the two clays (kaolinite and montmorillonite) and NAPL distribution within the pore space. The results were used to understand the distribution of NAPL advancing into initially saturated sand and sand-clay media, and provided a detailed analysis of the pore-scale geometry, pore size distribution, NAPL entry pressures, and the effect of clay on this geometry. Interesting NAPL saturation profiles were observed as a result of the complexity of the pore space geometry with the different packing angles and the presence of clays. The unit cell approach has applications for enhancing the mechanistic understanding and conceptualization, both visually and mathematically, of pore-scale processes such as NAPL and clay distribution. ?? 2003 Elsevier Science Ltd. All rights reserved.

  12. 80 FR 65469 - NESHAP for Brick and Structural Clay Products Manufacturing; and NESHAP for Clay Ceramics...

    Science.gov (United States)

    2015-10-26

    ... Clay Products Manufacturing; and NESHAP for Clay Ceramics Manufacturing; Final Rule #0;#0;Federal...; and NESHAP for Clay Ceramics Manufacturing AGENCY: Environmental Protection Agency (EPA). ACTION... NESHAP for Clay Ceramics Manufacturing. All major sources in these categories must meet...

  13. Río Bec (Basses Terres mayas) 2002-2008

    OpenAIRE

    Michelet, Dominique; Arnauld, Marie-Charlotte; Nondédéo, Philippe

    2014-01-01

    Bien plus qu’un site, Rio Bec est aussi une province culturelle maya au coeur de la péninsule du Yucatan (Mexique), définie a priori par un style architectural et iconographique. L’habitat y est dispersé, dénué de centre nucléé, mais le paysage apparaît nettement aménagé. Les travaux de terrain (2002-2008) ont d’abord eu pour objectif de mieux appréhender les fondements de l’originalité Río Bec (style et habitat, organisation sociale et politique), ainsi que de préciser les bases économiques ...

  14. Clay resources in the Netherlands

    NARCIS (Netherlands)

    Meulen, M.J. van der; Maljers, D.; Gessel, S.F. van; Gruijters, S.H.L.L.

    2007-01-01

    Clay is a common lithology in the Dutch shallow subsurface. It is used in earth constructions such as dikes, and as raw material for the fabricationof bricks, roof tiles etc. We present a new national assessment of Dutch clay resources, as part of a project that provides mineral-occurrenceinformatio

  15. Clay resources in the Netherlands

    NARCIS (Netherlands)

    Meulen, M.J. van der; Maljers, D.; Gessel, S.F. van; Gruijters, S.H.L.L.

    2007-01-01

    Clay is a common lithology in the Dutch shallow subsurface. It is used in earth constructions such as dikes, and as raw material for the fabrication of bricks, roof tiles etc. We present a new national assessment of Dutch clay resources, as part of a project that provides mineral-occurrence informat

  16. Fluoride retention by kaolin clay

    DEFF Research Database (Denmark)

    Kau, P. M. H.; Smith, D. W.; Binning, Philip John

    1997-01-01

    To evaluate the potential effectiveness of kaolin clay liners in storage of fluoride contaminated waste, an experimental study of the sorption and desorption behaviour of fluoride in kaolin clay was conducted. The degree of fluoride sorption by kaolin was found to depend on solution p...

  17. Viscous property of dried clay

    Institute of Scientific and Technical Information of China (English)

    XU Li-sheng; LI Jian-zhong

    2006-01-01

    One dimensional and triaxial compression tests of air-dried and oven-dried Fujinomori clay and Pisa clay were carried out. Water content is less than 4.5 % and 1.0% for air-dried and oven-dried clay specimens, respectively. In all tests, axial strain rate was changed stepwise many times and drained creep tests were performed several times during monotonic loading at a constant strain rate. Global unloading (and also reloading in some tests) was applied during which creep loading tests were performed several times. Cyclic loading with small stress amplitude and several cycles was also performed to calculate the modulus of elasticity of the clay in tests. Local displacement transducer was used in triaxial compression test to increase measuring accuracy of axial strain. The results show that air-dried and oven-dried clay have noticeable viscous properties; during global unloading, creep deformation changes from positive to negative, i.e. there exist neutral points (zero creep deformation or no creep deformation point) in global unloading part of strain-stress curve; viscous property of Fujinomori clay decreases when water content decreases, i.e. viscous property of air-dried Fujinomori clay is more significant than that of oven-dried Fujinomori clay.

  18. Utilization of crushed clay brick in cellular concrete production

    Directory of Open Access Journals (Sweden)

    Ali A. Aliabdo

    2014-03-01

    Full Text Available The main objective of this research program is to study the effect of using crushed clay brick as an alternative aggregate in aerated concrete. Two series of mixtures were designed to investigate the physico-mechanical properties and micro-structural analysis of autoclave aerated concrete and foamed concrete, respectively. In each series, natural sand was replaced with crushed clay brick aggregate. In both series results showed a significant reduction in unit weight, thermal conductivity and sound attenuation coefficient while porosity has increased. Improvement on compressive strength of autoclave aerated concrete was observed at a percentage of 25% and 50% replacement, while in foamed concrete compressive strength gradually decreased by increasing crushed clay brick aggregate content. A comparatively uniform distribution of pore in case of foamed concrete with natural sand was observed by scanning electron microscope, while the pores were connected mostly and irregularly for mixes containing a percentage higher than 25% clay brick aggregate.

  19. Clay minerals in pollution control

    Energy Technology Data Exchange (ETDEWEB)

    Tateo, F. [Consiglio Nazionale delle Ricerche, Istituto di Ricerca sulle Argille, Tito Scalo, PZ (Italy)

    2000-07-01

    Clay minerals are fundamental constituents of life, not only as possible actors in the development of life on the Earth (Cairns-Smith and Hartman, 1986), but mainly because they are essential constituents of soils, the interface between the solid planet and the continental biosphere. Many, many authors have devoted themselves to the study of clays and clay minerals since the publication of the early modern studies by Grim (1953, 1962) and Millot (1964). In those years two very important associations were established in Europe (Association Internationale pour l'Etude des Argiles, AIPEA) and in the USA (Clay Mineral Society, CMS). The importance of these societies is to put together people that work in very different fields (agronomy, geology, geochemistry, industry, etc.), but with a common language (clays), very useful in scientific work. Currently excellent texts are being published, but introductory notes are also available on the web (Schroeder, 1998).

  20. Mineral resource of the Month: Clay

    Science.gov (United States)

    Virta, Robert L.

    2010-01-01

    Clays were one of the first mineral commodities used by people. Clay pottery has been found in archeological sites that are 12,000 years old, and clay figurines have been found in sites that are even older.

  1. Maya Astronomy and the End of the World%玛雅天文学和2012世界末日

    Institute of Scientific and Technical Information of China (English)

    Michael H.SOFFEL

    2012-01-01

    With humanity coming up on 2012, should we worry about end of the world 2012 predictions? After a general introduction to Maya astronomy. Maya calendar is introduced in detail for the origin of the prediction that the world will end in 2012. In the author's eyes, nothing bad will happen to the Earth in 2012 and December 21, 2012 is the end of the Maya long-count period but then another long-count period begins for the Maya calendar.

  2. Viscosity and Plasticity of Latvian Illite Clays

    OpenAIRE

    2012-01-01

    Due to viscosity and plasticity, clays and clay minerals are used in civil engineering, pottery and also in cosmetics and medicine as thickening agents and emulsion and suspension stabilizers. The rheological properties of clay suspensions are complex. Mostly it is an interaction between mineral composition, clay particle size and pH value and also depends on clay minerals. Clay-water suspension is non-Newtonian fluid showing thixotropic and pseudoplastic properties. Results showed that plast...

  3. The New Emerging Adult in Chiapas, Mexico: Perceptions of Traditional Values and Value Change among First-Generation Maya University Students

    Science.gov (United States)

    Manago, Adriana M.

    2012-01-01

    Social changes in indigenous Maya communities in Chiapas, Mexico toward increasing levels of formal education, commercialization, and urbanization are transforming traditional Maya developmental pathways toward adulthood. This mixed-methods study is based on interviews with a sample of 14 first-generation Maya university students who have also…

  4. The New Emerging Adult in Chiapas, Mexico: Perceptions of Traditional Values and Value Change among First-Generation Maya University Students

    Science.gov (United States)

    Manago, Adriana M.

    2012-01-01

    Social changes in indigenous Maya communities in Chiapas, Mexico toward increasing levels of formal education, commercialization, and urbanization are transforming traditional Maya developmental pathways toward adulthood. This mixed-methods study is based on interviews with a sample of 14 first-generation Maya university students who have also…

  5. Clay membrane made of natural high plasticity clay:

    DEFF Research Database (Denmark)

    Foged, Niels; Baumann, Jens

    1999-01-01

    -type. The clay material has been evaluated using the standardized methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15-0.3 m thick clay membrane...... have been tested successfully. At a natural water content of w=40-45% it is possible to establish a homogeneous membrane with hydraulic conductivity k...

  6. Genomic insights on the ethno-history of the Maya and the 'Ladinos' from Guatemala.

    Science.gov (United States)

    Söchtig, Jens; Álvarez-Iglesias, Vanesa; Mosquera-Miguel, Ana; Gelabert-Besada, Miguel; Gómez-Carballa, Alberto; Salas, Antonio

    2015-02-25

    Guatemala is a multiethnic and multilingual country located in Central America. The main population groups separate 'Ladinos' (mixed Native American-African-Spanish), and Native indigenous people of Maya descent. Among the present-day Guatemalan Maya, there are more than 20 different ethnic groups separated by different languages and cultures. Genetic variation of these communities still remains largely unexplored. The principal aim of this study is to explore the genetic variability of the Maya and 'Ladinos' from Guatemala by means of uniparental and ancestry informative markers (AIMs). Analyses of uniparental genetic markers indicate that Maya have a dominant Native American ancestry (mitochondrial DNA [mtDNA]: 100%; Y-chromosome: 94%). 'Ladino', however, show a clear gender-bias as indicated by the large European ancestry observed in the Y-chromosome (75%) compared to the mtDNA (0%). Autosomal polymorphisms (AIMS) also mirror this marked gender-bias: (i) Native American ancestry: 92% for the Maya vs. 55% for the 'Ladino', and (ii) European ancestry: 8% for the Maya vs. 41% for the 'Ladino'. In addition, the impact of the Trans-Atlantic slave trade on the present-day Guatemalan population is very low (and only occurs in the 'Ladino'; mtDNA: 9%; 4%), in part mirroring the fact that Guatemala has a predominant orientation to the Pacific Ocean instead of a Caribbean one. Sequencing of entire Guatemalan mitogenomes has led to improved Native American phylogeny via the addition of new haplogroups that are mainly observed in Mesoamerica and/or the North of South America. The data reveal the existence of a fluid gene flow in the Mesoamerican area and a predominant unidirectional flow towards South America, most likely occurring during the Pre-Classic (1800 BC-200 AD) and the Classic (200-1000 AD) Eras of the Mesoamerican chronology, coinciding with development of the most distinctive and advanced Mesoamerican civilization, the Maya. Phylogenetic features of mtDNA data

  7. 75 FR 6249 - Culturally Significant Objects Imported for Exhibition Determinations: “Fiery Pool: The Maya and...

    Science.gov (United States)

    2010-02-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Fiery Pool: The Maya and the Mythic... hereby determine that the objects to be included in the exhibition ``Fiery Pool: The Maya and the...

  8. Maya phytomedicine in Guatemala - Can cooperative research change ethnopharmacological paradigms?

    Science.gov (United States)

    Hitziger, Martin; Heinrich, Michael; Edwards, Peter; Pöll, Elfriede; Lopez, Marissa; Krütli, Pius

    2016-06-20

    This paper presents one of the first large-scale collaborative research projects in ethnopharmacology, to bring together indigenous stakeholders and scientists both in project design and execution. This approach has often been recommended but rarely put into practice. The study was carried out in two key indigenous areas of Guatemala, for which very little ethnopharmacological fieldwork has been published. To document and characterize the ethno-pharmacopoeias of the Kaqchikel (highlands) and Q'eqchi' (lowlands) Maya in a transdisciplinary collaboration with the two groups Councils of Elders. The project is embedded in a larger collaboration with five Councils of Elders representing important indigenous groups in Guatemala, two of which participated in this study. These suggested healing experts reputed for their phytotherapeutic knowledge and skills. Ethnobotanical fieldwork was carried out over 20 months, accompanied by a joint steering process and validation workshops. The field data were complemented by literature research and were aggregated using a modified version of the International Classification of Diseases (ICD-10) and Trotter & Logan's consensus index. Similar numbers of species were collected in the two areas, with a combined total of 530 species. This total does not represent all of the species used for medicinal purposes. Remedies for the digestive system, the central nervous system & behavioral syndromes, and general tissue problems & infections were most frequent in both areas. Furthermore, remedies for the blood, immune & endocrine system are frequent in the Kaqchikel area, and remedies for the reproductive system are frequent in the Q'eqchi' area. Consensus factors are however low. The Kaqchikel, in contrast to the Q'eqchi', report more remedies for non-communicable illnesses. They also rely heavily on introduced species. The transdisciplinary research design facilitated scientifically rigorous and societally relevant large-scale fieldwork, which

  9. Economic and anthropological assessments of the health of children in Maya immigrant families in the US.

    Science.gov (United States)

    Smith, Patricia K; Bogin, Barry; Varela-Silva, Maria Inês; Loucky, James

    2003-06-01

    Immigration from developing countries to the US generally increases access to health care and clean water, but it also introduces some unhealthy lifestyle patterns, such as diets dense in energy and little regular physical activity. We present a transdisciplinary model of child health and examine the impact of immigration on the physical growth and health of Maya children in Guatemala and the US. Maya-American children are much taller and have longer legs, on average, than their counterparts in Guatemala. This suggests that immigration to the US improves their health. However, the Maya-American children also are much heavier than both Guatemalan Maya and White American children, and have high rates of overweight and obesity. Quantile regression analysis indicates that Maya are shorter except in the upper tail of the stature distribution, and have higher Body Mass Index (BMI) in the tails, but not in the middle of the BMI distribution. Leisure time spent in front of a television or computer monitor tends to raise BMI in the middle and lower tail of the distribution, but not in the upper tail.

  10. Los mayas del altiplano: supervivencia indígena en Chiapas y Guatemala

    Directory of Open Access Journals (Sweden)

    Lovell, W. George

    2002-06-01

    Full Text Available En el contexto americano, pocos grupos indígenas han demostrado la capacidad de sobrevivir a lo largo de la historia como los mayas del altiplano. Hoy día en Chiapas existen más de un millón de indígenas mayas, un número que asciende a cinco o seis millones en el caso de Guatemala. Los pueblos mayas han respondido a la invasión y a la dominación para conservar elementos importantes de su cultura. Este artículo discute las formas en que los mayas del altiplano se han adaptado para sobrevivir a casi cinco siglos de conquista, identificando tres fases claves en su trayectoria histórica: (1 la experiencia colonial, que abarca los años entre 1524 y 1821; (2 una época de reforma y revolución, que corre de 1821 a 1954; y (3 un período de marginalización y descuido desde 1954 en adelante. Pese al desfío, los mayas del altiplano están equipados culturalmente para perdurar.

  11. Evidence of Eta Aquariid outbursts recorded in the classic Maya hieroglyphic script using orbital integrations

    Science.gov (United States)

    Kinsman, J. H.; Asher, D. J.

    2017-09-01

    No firm evidence has existed that the ancient Maya civilization recorded specific occurrences of meteor showers or outbursts in the corpus of Maya hieroglyphic inscriptions. In fact, there has been no evidence of any pre-Hispanic civilization in the Western Hemisphere recording any observations of any meteor showers on any specific dates. The authors numerically integrated meteoroid-sized particles released by Comet Halley as early as 1404 BC to identify years within the Maya Classic Period, AD 250-909, when Eta Aquariid outbursts might have occurred. Outbursts determined by computer model were then compared to specific events in the Maya record to see if any correlation existed between the date of the event and the date of the outburst. The model was validated by successfully explaining several outbursts around the same epoch in the Chinese record. Some outbursts observed by the Maya were due to recent revolutions of Comet Halley, within a few centuries, and some to resonant behavior in older Halley trails, of the order of a thousand years. Examples were found of several different Jovian mean motion resonances as well as the 1:3 Saturnian resonance that have controlled the dynamical evolution of meteoroids in apparently observed outbursts.

  12. The collapse of the Maya: Effects of natural and human-induced drought

    Energy Technology Data Exchange (ETDEWEB)

    Oglesby, Robert J [ORNL; Erickson III, David J [ORNL

    2010-02-01

    The collapse of the Maya civilization during the ninth century A.D. is a major conundrum in the history of mankind. This civilization reached a spectacular peak but then almost completely collapsed in the space of a few decades. While numerous explanations have been put forth to explain this collapse, in recent years, drought has gained favor. This is because water resources were a key for the Maya, especially to ensure their survival during the lengthy dry season that occurs where they lived. Natural drought is a known, recurring feature of this region, as evidenced by observational data, reconstructions of past times, and global climate model output. Results from simulations with a regional climate model demonstrate that deforestation by the Maya also likely induced warmer, drier, drought-like conditions. It is therefore hypothesized that the drought conditions devastating the Maya resulted from a combination of natural variability and human activities. Neither the natural drought or the human-induced effects alone were sufficient to cause the collapse, but the combination created a situation the Maya could not recover from. These results may have sobering implications for the present and future state of climate and water resources in Mesoamerica as ongoing massive deforestation is again occurring.

  13. Constitutive model for overconsolidated clays

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Based on the relationships between the Hvorslev envelope,the current yield sur-face and the reference yield surface,a new constitutive model for overconsolidated clays is proposed. It adopts the unified hardening parameter,to which the potential failure stress ratio and the characteristic state stress ratio are introduced. The model can describe many characteristics of overconsolidated clays,including stress-strain relationships,strain hardening and softening,stress dilatancy,and stress path dependency. Compared with the Cam-clay model,the model only re-quires one additional soil parameter which is the slope of the Hvorslev envelope. Comparisons with data from triaxial drained compression tests for Fujinomori clay show that the proposed model can rationally describe overconsolidated properties. In addition,the model is also used to predict the stress-strain relationship in the isotropic consolidation condition and the stress paths in the undrained triaxial compression tests.

  14. Colloidal gels: Clay goes patchy

    Science.gov (United States)

    Kegel, Willem K.; Lekkerkerker, Henk N. W.

    2011-01-01

    Empty liquids and equilibrium gels have so far been only theoretical possibilities, predicted for colloids with patchy interactions. But evidence of both has now been found in Laponite, a widely studied clay.

  15. Porosity Investigation of Kosova's Clay

    OpenAIRE

    Makfire Sadiku; Naim Hasani; Altin Mele

    2011-01-01

    Problem statement: Acid activated clay minerals are used as catalysts in the desulphurization of crude oil or as catalyst carrier, as drilling mud, as bleaching earth. Approach: The efficiency of the acid activation can be described in two ways. As increase of the surface and as increase of the cumulative pore volume after the activation. Results: In different samples of the clay mineral the activation was done with different sulfuric acid concentrations for two and 3h. Afterwards the specifi...

  16. Clays in radioactive waste disposal

    OpenAIRE

    Delage, Pierre; Cui, Yu-Jun; Tang, Anh-Minh

    2010-01-01

    Clays and argillites are considered in some countries as possible host rocks for nuclear waste disposal at great depth. The use of compacted swelling clays as engineered barriers is also considered within the framework of the multi-barrier concept. In relation to these concepts, various research programs have been conducted to assess the thermo-hydro-mechanical properties of radioactive waste disposal at great depth. After introducing the concepts of waste isolation developed in Belgium, Fran...

  17. Using Clay as a Learning Resource for Teaching the History of Science.

    Science.gov (United States)

    De Angelis, Joseph M.

    Construction of laboratory equipment from earthenware clay uses art as a way to incorporate the element of science history into an Introductory Physical Science (IPS) unit on distillation. Classroom techniques for working with clay to construct distilling apparatus are outlined. Other supplementary material from the arts, including slide…

  18. Analysis of Causes Leading to High Bromine Number of C8+Aromatics and Short Clay Service Life and Countermeasures Proposed

    Institute of Scientific and Technical Information of China (English)

    Li Yousong; Ni Xiaoliang; Yan Jun

    2007-01-01

    After comparing the operating status of other catalytic reforming units and evaluation of the side-cut stream tests,the refinery investigated the influence of the feedstock property,clay types,and operating regime of the clay tower and catalytic reforming unit on the service life of the clay.Test results had revealed that the low potential aromatic content of the reformer feed and high operating severity were the critical causes leading to high bromine number of the C8+ aromatics feed for the PX unit and the shortened service life of clay.This article also puts forward the corresponding remedial measures.

  19. What makes a natural clay antibacterial?

    Science.gov (United States)

    Williams, Lynda B.; Metge, David W.; Eberl, Dennis D.; Harvey, Ronald W.; Turner, Amanda G.; Prapaipong, Panjai; Port-Peterson, Amisha T.

    2011-01-01

    Natural clays have been used in ancient and modern medicine, but the mechanism(s) that make certain clays lethal against bacterial pathogens has not been identified. We have compared the depositional environments, mineralogies, and chemistries of clays that exhibit antibacterial effects on a broad spectrum of human pathogens including antibiotic resistant strains. Natural antibacterial clays contain nanoscale (2+ solubility.

  20. Basic Deformation Parameters of Solid Clay Bricks and Small Masonry Walls

    Directory of Open Access Journals (Sweden)

    P. Bouška

    2000-01-01

    Full Text Available The basic mechanical properties of clay brick masonry and its components were experimentally investigated in the laboratories of the Klokner Institute. The test specimens of masonry materials and the relevant mechanical properties have been identified in solid clay bricks and cement-lime mortar. The aim of the research activity was to study both the deformability of the prevailing type of clay masonry in the existing buildings, i.e. the masonry made from the solid clay units and the lime-cement mortar, and the most important mechanical properties of masonry components.

  1. Wave liquefaction in soils with clay content

    DEFF Research Database (Denmark)

    Kirca, Özgür; Sumer, B. Mutlu; Fredsøe, Jørgen

    2012-01-01

    The paper presents the results of an experimental study of the influence of clay content (in silt-clay and sand-clay mixtures) on liquefaction beneath progressive waves. The experiments showed that the influence of clay content is very significant. Susceptibility of silt to liquefaction...... is increased with increasing clay content, up to 30%, beyond which the mixture of silt and clay is not liquefied. Sand may become prone to liquefaction with the introduction of clay, contrary to the general perception that this type of sediment is normally liquefaction resistant under waves....

  2. Geochemical of clay formations : study of Spanish clay REFERENCE; Geoquimica de formaciones arcillosas: estudio de la Arcilla Espanola de REFERENCE

    Energy Technology Data Exchange (ETDEWEB)

    Turrero, M. J.; Pena, J.

    2003-07-01

    Clay rocks are investigated in different international research programs in order to assess its feasibility for the disposal of high level radioactive wastes. This is because different sepcific aspects: they have low hydraulic conductivity (10''-11-10''-15 m/s), a high sorption capacity, self-sealing capacity of facults and discontinuities and mechanical resistance. Several research programs on clay formations are aimed to study the chemistry of the groundwater and the water-rock reactions that control it: e. g. Boom Clay (Mol, Belgium), Oxford Clay /Harwell, United Kingdom), Toarcian Clay (Tournemire, France), Palfris formation (Wellenberg, Switzerland), Opalinus Clay (Bure, France). Based on these studies, consdierable progress in the development of techniques for hydrologic, geochemical and hydrogeochemical characterization of mudstones has been accomplished (e. g. Beaufais et al. 1994, De Windt el al. 1998. Thury and Bossart 1999, Sacchi and Michelot 2000) with important advances in the knowledge of geochemical process in these materials (e. g. Reeder et al. 1993, Baeyens and Brandbury 1994, Beaucaire et al. 2000, Pearson et al., 2003).Furtermore, geochemical modeling is commonly used to simulate the evolution of water chemistry and to understand quantitatively the processescontrolling the groundwater chemistry (e. g. Pearson et al. 1998, Tempel and Harrison 2000, Arcos et al., 2001). The work presented here is part of a research program funded by Enresa in the context of its R&D program. It is focused on the characterization of a clay formation (reference Argillaceous Formation, RAF) located within the Duero Basin (north-centralSpain). The characterisation of th ephysical properties,, fluid composition, mineralogy, water-rock reaction processes, geochemical modelling and sorption properties of the clays from the mentioned wells is the main purpose of this work. (Author)

  3. Paleoenvironmental and Paleoecological Reconstruction of the Ancient Maya Port Site of Vista Alegre, Quintana Roo, Mexico

    Science.gov (United States)

    Rissolo, D.; Jaijel, R.; Glover, J. B.; Goodman, B.; Beddows, P. A.; Carter, A.; Smith, D.

    2013-12-01

    Ancient Maya ports along the largely unstudied northeast coast of the Yucatan Peninsula once supported a network of trade routes linking people, goods, and ideas from across Mesoamerica. The Costa Escondida Project has focused on the interrelationships between the ancient Maya and their dynamic coastal environment along the shores of the Laguna Holbox. Central to our interdisciplinary efforts is a paleoenvironmental and paleoecological reconstruction of the key port of Vista Alegre - a low-lying island surrounded by a complex mosaic of costal ecosystems, sedimentological facies, and hydrological conditions. Geoarchaeological field methods, such as sediment coring, have made possible multiproxy analyses that enable us to better understand sea level fluctuations and the morphology of the shoreline and harboring locations over time, as well as changes in ecosystem biodiversity, which would have presented the maritime Maya with unique challenges and opportunities.

  4. Redox tuning and species distribution in Maya Blue-type materials: a reassessment.

    Science.gov (United States)

    Doménech-Carbó, Antonio; Valle-Algarra, Francisco Manuel; Doménech-Carbó, María Teresa; Domine, Marcelo E; Osete-Cortina, Laura; Gimeno-Adelantado, José Vicente

    2013-08-28

    Maya Blue-type specimens prepared from indigo (1 wt %) plus kaolinite, montmorillonite, palygorskite, sepiolite, and silicalite are studied. Liquid chromatography with diode array detection, ultra-performance liquid chromatography coupled with mass spectrometry, and pyrolysis-silylation gas chromatography-mass spectrometry analyses of the extracts from these specimens combined with spectral and solid-state voltammetry, electrochemical impedance spectroscopy, and scanning electrochemical microscopy techniques provide evidence for the presence of a significant amount of dehydroindigo and isatin accompanying indigo and other minority organic compounds in all samples. Solid-state electrochemistry data permits the estimatation of indigo loading in archeological Maya Blue, which is in the range of 0.2 to 1.5 wt %. These results support a view of 'genuine' Maya Blue-type materials as complex polyfunctional organic-inorganic hybrids.

  5. Correlating the ancient Maya and modern European calendars with high-precision AMS 14C dating.

    Science.gov (United States)

    Kennett, Douglas J; Hajdas, Irka; Culleton, Brendan J; Belmecheri, Soumaya; Martin, Simon; Neff, Hector; Awe, Jaime; Graham, Heather V; Freeman, Katherine H; Newsom, Lee; Lentz, David L; Anselmetti, Flavio S; Robinson, Mark; Marwan, Norbert; Southon, John; Hodell, David A; Haug, Gerald H

    2013-01-01

    The reasons for the development and collapse of Maya civilization remain controversial and historical events carved on stone monuments throughout this region provide a remarkable source of data about the rise and fall of these complex polities. Use of these records depends on correlating the Maya and European calendars so that they can be compared with climate and environmental datasets. Correlation constants can vary up to 1000 years and remain controversial. We report a series of high-resolution AMS (14)C dates on a wooden lintel collected from the Classic Period city of Tikal bearing Maya calendar dates. The radiocarbon dates were calibrated using a Bayesian statistical model and indicate that the dates were carved on the lintel between AD 658-696. This strongly supports the Goodman-Martínez-Thompson (GMT) correlation and the hypothesis that climate change played an important role in the development and demise of this complex civilization.

  6. Cyanobacteria blooms: Maya peoples between the politics of risk and the threat of disaster.

    Science.gov (United States)

    Harvey, T S

    2012-01-01

    In October of 2009 an outbreak of cyanobacteria in Lake Atitlán, Guatemala gained international attention and global news coverage with interests coming from environmentalists, microbiologists, and local health agencies. A significantly less well-known aspect of the crisis was the perceptions and predicaments of Maya (indigenous) peoples for whom the lake is the primary source of life and livelihood. This research examines the communication of the public health risk of cyanobacteria to Maya peoples. Using an "ethnography of risk communication" approach, this work traces the circulation of the science of cyanobacteria and the construction of risk from government and public health translations through media transmissions to local Maya interpretations. The findings demonstrate how government and institutional translations (and media transmissions) of the science of cyanobacteria not only unwittingly produced misunderstandings about the health dangers but indirectly associated blame for the outbreak with indigenous peoples, calling into question their way of life.

  7. 81 FR 31234 - NESHAP for Brick and Structural Clay Products Manufacturing; and NESHAP for Clay Ceramics...

    Science.gov (United States)

    2016-05-18

    ... AGENCY NESHAP for Brick and Structural Clay Products Manufacturing; and NESHAP for Clay Ceramics... Brick and Structural Clay Products (BSCP) Manufacturing and the final NESHAP for Clay Ceramics... No. EPA-HQ-OAR-2013-0290 for Clay Ceramics Manufacturing. All documents in the dockets are listed...

  8. Maya Children. Helpers at the Farm (Karen L. Kramer

    Directory of Open Access Journals (Sweden)

    Gema Campos Hernando

    2007-01-01

    Full Text Available Los habitantes de Xculoc, una aldea maya en la península de Yucatán, viven de sus cultivos de maíz y mantienen una agricultura de subsistencia sin haber entrado a formar parte del mercado laboral ni de la economía regional. La aldea, en la que viven 316 habitantes distribuidos en 55 casas familiares, está a cinco horas de camino de cualquier vía asfaltada, sin electricidad ni agua corriente. Los habitantes de Xculoc tienen de particular una tasa de natalidad muy alta y una mortalidad infantil muy baja, en parte por la ausencia de aguas contaminadas en los alrededores del poblado, llegando a conformarse el núcleo familiar por la madre, el padre y hasta ocho hijos. Esta estructura familiar no se podría mantener con el exclusivo trabajo de los padres , las necesidades de consumo son cubiertas por todos los miembros de la familia, dependiendo sus aportaciones no sólo del tamaño de la familia sino también de la estructura de la misma según edades.

  9. An 8700 year paleoclimate reconstruction from the southern Maya lowlands

    Science.gov (United States)

    Wahl, David B.; Byrne, Roger; Anderson, Lysanna

    2014-01-01

    Analysis of a sediment core from Lago Puerto Arturo, a closed basin lake in northern Peten, Guatemala, has provided an ∼8700 cal year record of climate change and human activity in the southern Maya lowlands. Stable isotope, magnetic susceptibility, and pollen analyses were used to reconstruct environmental change in the region. Results indicate a relatively wet early to middle Holocene followed by a drier late Holocene, which we interpret as reflecting long-term changes in insolation (precession). Higher frequency variability is more likely attributable to changes in ocean/atmosphere circulation in both the North Atlantic and the Pacific Oceans. Pollen and isotope data show that most of the period of prehispanic agricultural settlement, i.e. ∼5000–1000 cal yr BP, was characterized by drier conditions than previous or subsequent periods. The presence ofZea (corn) pollen through peak aridity during the Terminal Classic period (∼1250–1130 cal yr BP) suggests that drought may not have had as negative an impact as previously proposed. A dramatic negative shift in isotope values indicates an increase in precipitation after ∼950 cal yr BP (hereafter BP).

  10. Materiales Maria Maya: community-based materials development.

    Science.gov (United States)

    Moran, B C

    1982-01-01

    Materials Maria Maya (MMM) is a Guatemalan organization which has dedicated itself to making health education more relevant to the rural Mayans who constitute the majority of Guatemala's population. The administration and direction of the project is in the hands of a team of qualified Mayan men and women. Funding is primarily through various charitable international organizations. The content of preexisting health education programs, strongly influenced by the dominant "ladino" Spanish speaking culture was found to be inappropriate to the goal of this program. MMM set about to formulate a new teaching format which would draw upon, rather than trample over, established cultural practices and life styles. By a process of trial and error, involving small scale field tests, a new program format was developed. By questioning local women about perceived priority areas, through the study of morbidity and mortality data, decisions were made as to topics to be covered. Investigators, authors, and artists worked together to form a "materials package" which was then subject to pretesting. Out of this effort, MMM has been able to come up with a method to encourage more effective participative teaching through the use of education materials.

  11. An 8700 year paleoclimate reconstruction from the southern Maya lowlands

    Science.gov (United States)

    Wahl, David; Byrne, Roger; Anderson, Lysanna

    2014-11-01

    Analysis of a sediment core from Lago Puerto Arturo, a closed basin lake in northern Peten, Guatemala, has provided an ˜8700 cal year record of climate change and human activity in the southern Maya lowlands. Stable isotope, magnetic susceptibility, and pollen analyses were used to reconstruct environmental change in the region. Results indicate a relatively wet early to middle Holocene followed by a drier late Holocene, which we interpret as reflecting long-term changes in insolation (precession). Higher frequency variability is more likely attributable to changes in ocean/atmosphere circulation in both the North Atlantic and the Pacific Oceans. Pollen and isotope data show that most of the period of prehispanic agricultural settlement, i.e. ˜5000-1000 cal yr BP, was characterized by drier conditions than previous or subsequent periods. The presence of Zea (corn) pollen through peak aridity during the Terminal Classic period (˜1250-1130 cal yr BP) suggests that drought may not have had as negative an impact as previously proposed. A dramatic negative shift in isotope values indicates an increase in precipitation after ˜950 cal yr BP (hereafter BP).

  12. Deforestation Along the Maya Mountain Massif Belize-Guatemala Border

    Science.gov (United States)

    Chicas, S. D.; Omine, K.; Arevalo, B.; Ford, J. B.; Sugimura, K.

    2016-06-01

    In recent years trans-boundary incursions from Petén, Guatemala into Belize's Maya Mountain Massif (MMM) have increased. The incursions are rapidly degrading cultural and natural resources in Belize's protected areas. Given the local, regional and global importance of the MMM and the scarcity of deforestation data, our research team conducted a time series analysis 81 km by 12 km along the Belize-Guatemalan border adjacent to the protected areas of the MMM. Analysis drew on Landsat imagery from 1991 to 2014 to determine historic deforestation rates. The results indicate that the highest deforestation rates in the study area were -1.04% and -6.78% loss of forested area per year in 2012-2014 and 1995-1999 respectively. From 1991 to 2014, forested area decreased from 96.9 % to 85.72 % in Belize and 83.15 % to 31.52 % in Guatemala. During the study period, it was clear that deforestation rates fluctuated in Belize's MMM from one time-period to the next. This seems linked to either a decline in deforestation rates in Guatemala, the vertical expansion of deforestation in Guatemalan forested areas and monitoring. The results of this study urge action to reduce incursions and secure protected areas and remaining forest along the Belize-Guatemalan border.

  13. TEATRO MAYA: RABINAL ACHÍ O DANZA DEL TUN

    Directory of Open Access Journals (Sweden)

    Patricia Henríquez Puentes

    2007-04-01

    Full Text Available El Rabinal Achí o Danza del Tun es teatro de origen maya puesto en escena desde el siglo XIII hasta nuestros días en la actual Guatemala. Es una composición inserta en el esquema religioso de las culturas mesoamericanas que, conservada a través de tradición oral hasta el siglo XIX, ha sido reescrita en este espacio escénico durante aproximadamente ochocientos años. El Rabinal Achí revela una forma de escribir con el cuerpo que articula danza, música y poesía, y representa ese momento en la historia del teatro en que el arte de la representación y rito compartían la misma escenaThe Rabinal Achí or Dance of the Tun is theatre of Mayan origen. The first performances date from the 13th century and continue into the present day in contemporary Guatemala. It is a composition that forms part of the religious scheme of the Indo-American cultures and, preserved through oral tradition up until the 19th century, has been rewritten in this scenic space for approximately eight hundred years. The Rabinal Achí reveals a way of writing with the body that articulates dance, music and poetry and represents a moment in the history of theatre in which the art of representation and the ritual share the same scene

  14. DEFORESTATION ALONG THE MAYA MOUNTAIN MASSIF BELIZE-GUATEMALA BORDER

    Directory of Open Access Journals (Sweden)

    S. D. Chicas

    2016-06-01

    Full Text Available In recent years trans-boundary incursions from Petén, Guatemala into Belize’s Maya Mountain Massif (MMM have increased. The incursions are rapidly degrading cultural and natural resources in Belize’s protected areas. Given the local, regional and global importance of the MMM and the scarcity of deforestation data, our research team conducted a time series analysis 81 km by 12 km along the Belize-Guatemalan border adjacent to the protected areas of the MMM. Analysis drew on Landsat imagery from 1991 to 2014 to determine historic deforestation rates. The results indicate that the highest deforestation rates in the study area were −1.04% and −6.78% loss of forested area per year in 2012-2014 and 1995-1999 respectively. From 1991 to 2014, forested area decreased from 96.9 % to 85.72 % in Belize and 83.15 % to 31.52 % in Guatemala. During the study period, it was clear that deforestation rates fluctuated in Belize's MMM from one time-period to the next. This seems linked to either a decline in deforestation rates in Guatemala, the vertical expansion of deforestation in Guatemalan forested areas and monitoring. The results of this study urge action to reduce incursions and secure protected areas and remaining forest along the Belize-Guatemalan border.

  15. Landscape Archeology: Remote Sensing Investigation of the Ancient Maya in the Peten Rainforest of Northern Guatemala

    Science.gov (United States)

    Sever, Thomas L.; Irwin, Daniel E.; Arnold, James E. (Technical Monitor)

    2002-01-01

    Through the use of airborne and satellite imagery we are improving our ability to investigate ancient Maya settlement, subsistence, and landscape modification in this dense forest region. Today the area is threatened by encroaching settlement and deforestation. However, it was in this region that the Maya civilization began, flourished, and abruptly disappeared for unknown reasons in the 9th century AD. At the time of their collapse they had attained one of the highest population densities in human history. How the Maya were able to successfully manage water and feed this dense population is not well understood at this time. A NASA-funded project used remote sensing technology to investigate large seasonal swamps (bajos) that make up 40 percent of the landscape. Through the use of remote sensing, ancient Maya features such as sites, roadways, canals and water reservoirs have been detected and verified through ground reconnaissance. The results of this preliminary research cast new light on the adaptation of the ancient Maya to their environment. Microenvironmental variation within the wetlands was elucidated and the different vegetation associations identified in the satellite imagery. More than 70 new archeological sites within and at the edges of the bajo were mapped and tested. Modification of the landscape by the Maya in the form of dams and reservoirs in the Holmul River and its tributaries and possible drainage canals in bajos was demonstrated. The use of Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM), one-meter IKONOS satellite imagery, as well as high resolution airborne STAR-3i radar imagery--2.5 meter backscatter/10 meter Digital Elevation Model (DEM)--are opening new possibilities for understanding how a civilization was able to survive for centuries upon a karat topographic landscape. This understanding is critical for the current population that is currently experiencing rapid population growth and destroying the landscape through

  16. Lead (Pb) Isotope Baselines for Studies of Ancient Human Migration and Trade in the Maya Region.

    Science.gov (United States)

    Sharpe, Ashley E; Kamenov, George D; Gilli, Adrian; Hodell, David A; Emery, Kitty F; Brenner, Mark; Krigbaum, John

    2016-01-01

    We examined the potential use of lead (Pb) isotopes to source archaeological materials from the Maya region of Mesoamerica. The main objectives were to determine if: 1) geologic terrains throughout the Maya area exhibit distinct lead isotope ratios (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb), and 2) a combination of lead and strontium ratios can enhance sourcing procedures in the Mesoamerica region. We analyzed 60 rock samples for lead isotope ratios and a representative subset of samples for lead, uranium, and thorium concentrations across the Maya region, including the Northern Lowlands of the Mexican Yucatan Peninsula, the Southern Lowlands of Guatemala and Belize, the Volcanic Highlands, the Belizean Maya Mountains, and the Metamorphic Province/Motagua Valley. Although there is some overlap within certain sub-regions, particularly the geologically diverse Metamorphic Province, lead isotopes can be used to distinguish between the Northern Lowlands, the Southern Lowlands, and the Volcanic Highlands. The distinct lead isotope ratios in the sub-regions are related to the geology of the Maya area, exhibiting a general trend in the lowlands of geologically younger rocks in the north to older rocks in the south, and Cenozoic volcanic rocks in the southern highlands. Combined with other sourcing techniques such as strontium (87Sr/86Sr) and oxygen (δ18O), a regional baseline for lead isotope ratios can contribute to the development of lead isoscapes in the Maya area, and may help to distinguish among geographic sub-regions at a finer scale than has been previously possible. These isotope baselines will provide archaeologists with an additional tool to track the origin and movement of ancient humans and artifacts across this important region.

  17. Modeling Coupled Processes in Clay Formations for Radioactive Waste Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hui-Hai; Rutqvist, Jonny; Zheng, Liange; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens

    2010-08-31

    As a result of the termination of the Yucca Mountain Project, the United States Department of Energy (DOE) has started to explore various alternative avenues for the disposition of used nuclear fuel and nuclear waste. The overall scope of the investigation includes temporary storage, transportation issues, permanent disposal, various nuclear fuel types, processing alternatives, and resulting waste streams. Although geologic disposal is not the only alternative, it is still the leading candidate for permanent disposal. The realm of geologic disposal also offers a range of geologic environments that may be considered, among those clay shale formations. Figure 1-1 presents the distribution of clay/shale formations within the USA. Clay rock/shale has been considered as potential host rock for geological disposal of high-level nuclear waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures induced by tunnel excavation. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at Mol site, Belgium (Barnichon et al., 2005) have all been under intensive scientific investigations (at both field and laboratory scales) for understanding a variety of rock properties and their relations with flow and transport processes associated with geological disposal of nuclear waste. Clay/shale formations may be generally classified as indurated and plastic clays (Tsang et al., 2005). The latter (including Boom clay) is a softer material without high cohesion; its deformation is dominantly plastic. For both clay rocks, coupled thermal, hydrological, mechanical and chemical (THMC) processes are expected to have a significant impact on the long-term safety of a clay repository. For

  18. How mobile are sorbed cations in clays and clay rocks?

    Science.gov (United States)

    Gimmi, T; Kosakowski, G

    2011-02-15

    Diffusion of cations and other contaminants through clays is of central interest, because clays and clay rocks are widely considered as barrier materials for waste disposal sites. An intriguing experimental observation has been made in this context: Often, the diffusive flux of cations at trace concentrations is much larger and the retardation smaller than expected based on their sorption coefficients. So-called surface diffusion of sorbed cations has been invoked to explain the observations but remains a controversial issue. Moreover, the corresponding surface diffusion coefficients are largely unknown. Here we show that, by an appropriate scaling, published diffusion data covering a broad range of cations, clays, and chemical conditions can all be modeled satisfactorily by a surface diffusion model. The average mobility of sorbed cations seems to be primarily an intrinsic property of each cation that follows inversely its sorption affinity. With these surface mobilities, cation diffusion coefficients can now be estimated from those of water tracers. In pure clays at low salinities, surface diffusion can reduce the cation retardation by a factor of more than 1000.

  19. Holocene Biomass Burning, Environmental Change, and Human Land Use in the Southern Maya Lowlands

    Science.gov (United States)

    Anderson, L.; Wahl, D.

    2013-12-01

    For several decades scholars have studied the dynamic relationship between the prehispanic Maya and their environment in order to test hypotheses that environmental change played a role in the abandonment of the Maya lowlands. Fire was inherent in Maya land use practices, arguably the primary tool used to alter the landscape and extract resources. Opening of forest for agriculture, building, and extraction/production of construction material necessitated burning. The extensive production of lime plaster for architectural and domestic use demanded harvesting and burning of vast quantities of green wood. While we understand the fundamental role of fire in Maya land use, there are very few records of prehispanic biomass burning from the Maya lowlands. Consequently, only a limited understanding exists of both natural fire regimes and patterns of anthropogenic burning in the tropical dry forests of Central America. Here we report two new well-dated, high-resolution records of biomass burning based on analysis of fossil charcoal recovered from lacustrine sediment cores, extending from the early Holocene to the present. The study sites, Lagos Paixban and Puerto Arturo are located in the southern Maya lowlands in modern northern Peten, Guatemala. Macroscopic charcoal data are presented along with previously published proxy data from the sites, and interpreted in the context of existing regional and local paleoenvironmental and archeological records. Results show that frequent fires occurred in the closed canopy forests of the region since at least the early mid-Holocene (~9000 BP), prior to occupation by sedentary agriculturalists. Following the arrival of sedentary agriculture at around 4600 BP, the system transitioned from climate controlled to anthropogenic control. During the Maya period, changes in fire regime are muted and do not appear to be driven by changes in climate conditions. Low charcoal influx and fire frequency in the Preclassic period suggest that land use

  20. Radar mapping, archaeology, and ancient land use in the Maya lowlands

    Science.gov (United States)

    Adams, R. E. W.; Brown, W. E., Jr.; Culbert, T. P.

    1981-01-01

    Data from the use of synthetic aperture radar in aerial survey of the southern Maya lowlands suggest the presence of very large areas drained by ancient canals for the purpose of intensive cultivation. Preliminary ground checks in several very limited areas confirm the existence of canals and raised fields. Excavations and ground surveys by several scholars provide valuable comparative information. Taken together, the new data suggest that Late Classic period Maya civilization was firmly grounded in large-scale and intensive cultivation of swampy zones.

  1. Uso múltiple y biodiversidad entre los Mayas Yucatecos (México)

    OpenAIRE

    2008-01-01

    Con base en una detallada revisión de literatura se hace un recuento del número de especies de la flora y fauna regionales utilizadas por los mayas yucatecos actuales, mediante su estrategia de uso múltiple de los recursos. La revisión ofrece datos sobre la biodiversidad útil en la milpa y otras prácticas agrícolas, los huertos familiares, la apicultura y meliponicultura, la extracción y recolección de recursos forestales, la caza y la pesca. Se estima que una comunidad maya de la Península d...

  2. Dominación y resistencia maya campesina en Dzidzantún, Yucatán

    OpenAIRE

    Mauricio Macossay Vallado

    2007-01-01

    Como resultado de una investigación directa y participativa realizada durante 2001 y 2002 en una comunidad maya, el autor presenta elementos y reflexiones que buscan aportar al conocimiento ycomprensión del poder, la dominación y la resistencia campesina en un área rural de Yucatán. Se muestra la manera en que los campesinos mayas se insertan en dichas estructuras y relaciones y cómo se organizan y llevan a cabo diversas estrategias de vida y resistencia frente a ellas

  3. Daily life of the ancient Maya recorded on murals at Calakmul, Mexico

    Science.gov (United States)

    Carrasco Vargas, Ramón; López, Verónica A. Vázquez; Martin, Simon

    2009-01-01

    Research into ancient societies frequently faces a major challenge in accessing the lives of those who made up the majority of their populations, since the available evidence so often concerns only the ruling elite. Our excavations at the ancient Maya site of Calakmul, Mexico, have uncovered a “painted pyramid:” a structure decorated with murals depicting scenes of its inhabitants giving, receiving, and consuming diverse foods, as well as displaying and transporting other goods. Many are accompanied by hieroglyphic captions that describe the participants, and include spellings of key subsistence items. Collectively, they offer insights into the social mechanisms by which goods were circulated within major Maya centers. PMID:19901331

  4. Ecos da solidão: uma autobiografia de Maya Angelou

    OpenAIRE

    Cláudia Maria Fernandes Corrêa

    2009-01-01

    Este trabalho centra sua atenção sobre a construção identitária por meio da palavra escrita, refletindo sobre o passado por meio da narrativa autobiográfica I Know Why the Caged Bird Sings (1970) da escritora afro-americana Maya Angelou. Utilizamos a obra de Maya Angelou devido ao seu esforço pioneiro em confrontar abertamente seu passado e fazer de suas mazelas pessoais um meio catártico: descer aos infernos, ou à morte para retornar transformada. This work focuses its attentio...

  5. The Costa Maya:  Evolution of a Touristic Landscape La Costa Maya : évolution d'un paysage touristique La Costa Maya : evolución de un paisaje turístico

    Directory of Open Access Journals (Sweden)

    Klaus J. Meyer-Arendt

    2010-06-01

    Full Text Available La Costa Maya est une région côtière du sud du Quintana Roo (Mexique, proche de l'îlet Ambergris au Bélize. Contrairement à la côte caribéenne du Mexique qui a souffert du développement du tourisme de masse à Cancun et le long de la Riviera Maya, la Costa Maya s'est orientée vers un développement durable avec notamment une faible densité de construction et le développement de l'écotourisme.Le développement s'est concentré autour de Puerto Costa Maya où un terminal de croisière a été construit en 2001. La station balnéaire (balneario de Majahual est devenue dépendante des 10-12 bateaux de touristes qui débarquaient chaque semaine. En dépit d'importants plans de développement, les plages reculées de la Costa Maya accueillaient tout au plus des écotouristes aisés et du tourisme lié à la plongée sous-marine.Le cyclone Dean, de catégorie 5, a dévasté le paysage en août 2007 et le rétablissement économique n'a pu être entamé que fin 2008, après la réouverture du terminal de croisière et la reconstruction de Majahual. Fin 2009, le trafic de croisière n'a pas retrouvé son niveau d'avant Dean et la récession mondiale couplée avec la grippe porcine et les violences liées à la drogue ont fait diminuer le tourisme en provenance des Etats-Unis. On ignore à quel niveau les nouvelles infrastructures tels l'aéroport international de Tulum qui propose un itinéraire de Chetumal à la plage et le nouveau complexe hôtelier à Xahuayxel, stimuleront la Costa Maya mexicaine créant peut-être une autoroute côtière reliée à San Pedro au Bélize.The Costa Maya is a vernacular coastal region of southeastern Quintana Roo (Mexico and adjacent Ambergris Cay, Belize.  As Mexico’s Caribbean coast suffered many growth pains associated with mass tourism development in Cancun and along the Riviera Maya, the Costa Maya by contrast was projected for more sustainable development including low-density housing and

  6. Charm of Purple Clay A private museum in Wuxi is devoted to purple-clay art

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Purple-clay art pieces will be on display in a museum opening soon in Wuxi, Jiangsu Province. The museum, named Shuaiyuan Purple Clay Museum, is part of the Shuaiyuan Purple Clay Art Exhibition Center

  7. Clay Bells: Edo Inspiration

    Science.gov (United States)

    Wagner, Tom

    2010-01-01

    The ceremonial copper and iron bells at the Smithsonian's National Museum of African Art were the author's inspiration for an interdisciplinary unit with a focus on the contributions various cultures make toward the richness of a community. The author of this article describes an Edo bell-inspired ceramic project incorporating slab-building…

  8. 80 FR 75817 - NESHAP for Brick and Structural Clay Products Manufacturing; and NESHAP for Clay Ceramics...

    Science.gov (United States)

    2015-12-04

    ... NESHAP for Clay Ceramics Manufacturing: Correction AGENCY: Environmental Protection Agency (EPA). ACTION...; and NESHAP for Clay Ceramics Manufacturing. These amendments make two technical corrections to...

  9. Intra-population dental morphological variability among the Prehispanic Maya.

    Science.gov (United States)

    Cucina, A

    2016-10-01

    The present paper proposes a new approach to the estimation of intra-site variability of dental morphological traits when they are dichotomized into presence vs absence. It rests on the assumption that (1) higher intra-site variability is the expression of intense population dynamics and gene flow; and (2) maximum variability is reached when each trait is expressed in the population with a frequency of 50%. The approach simulates the calculation of frequency of heterozygotes in Mendelian traits (2xiyi), where xi and yi are the frequency of presence and absence of the trait. For every population, the final value corresponds to the average of (2xiyi) calculated from all the scored traits. Two separate analyses were performed using 50 and 40 traits recorded in 11 Prehispanic Maya skeletal collections from the Yucatán Peninsula. Resulting average values were related to the sites' positions within the region's social, political and economic sphere of influence. Dental collections that were obtained from important city centers or by grouping many sites from a single region present the highest values of internal variability, followed by sites known to have played an important role in trade activities or in other socio-political contexts. At the other end, dental collections that represent smaller communities or more isolated, kin-related groups are set at the lower ranks of internal variability. One-way ANOVA tests for both 50 and 40 variables show that sample means present significant differences between the extreme ends of the ranked set of samples. Copyright © 2016 Elsevier GmbH. All rights reserved.

  10. Boron enrichment in martian clay.

    Directory of Open Access Journals (Sweden)

    James D Stephenson

    Full Text Available We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration.

  11. Boron Enrichment in Martian Clay

    Science.gov (United States)

    Nagashima, Kazuhide; Freeland, Stephen J.

    2013-01-01

    We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration. PMID:23762242

  12. Strength Properties of Aalborg Clay

    DEFF Research Database (Denmark)

    Iversen, Kirsten Malte; Nielsen, Benjaminn Nordahl; Augustesen, Anders Hust

    resulted in many damaged buildings in Aalborg. To provide sufficient bearing capacity it is therefore necessary either to remove the fill or to construct the building on piles. Both methods imply that the strength of Aalborg Clay is important for the construction. This paper evaluates the strength...... of Aalborg Clay by use of triaxial tests from four different locations. Both the drained strength (c and ϕ) and the undrained strength (cu) are assessed through two different methods: one where the strength is assumed to vary with the effective stress and another where the strength is found to be constant....

  13. Naturaleza, cultura e identidad. Reflexiones desde la tradición oral maya contemporánea Nature, culture, identity. Some thoughts from contemporary Maya oral tradition

    Directory of Open Access Journals (Sweden)

    Adriana C. Estrada Ochoa

    2009-01-01

    Full Text Available Este artículo presenta algunas reflexiones en torno a la problemática derivada de la construcción y el uso de los conceptos de naturaleza y cultura para el análisis antropológico, así como sus posibilidades de aplicación al estudio de las culturas mayas. Plantea que los pueblos mayas establecen distintas relaciones entre estos dominios, así como entre la humanidad y la animalidad. Frente a la perspectiva occidental, que establece rígidas fronteras y diferencias insalvables, la visión maya propone continuidades, reversibilidades e interconexiones, en un universo en el que la materialidad y el espacio ofrecen múltiples posibilidades de tránsito para la vida y el ser.This article presents some reflections about problems that may rise around the construction and use of nature and culture as concepts for anthropological analysis, and their possibilites for studying mayan cultures. It suggests that mayan communities establish different kind of relationships between this two domains, as well as between humanity and animality. In contrast with the western point of view, which establishes rigid borders and insoluble differences, the mayan vision presents continuities, reversibilities and interconnections, in a universe where materiality and space seem to offer multiple possiblities of passing through for life and being.

  14. Clay membrane made of natural high plasticity clay

    DEFF Research Database (Denmark)

    Foged, Niels; Baumann, Jens

    1998-01-01

    Leachate containment in Denmark has through years been regulated by the DIF Recommendation for Sanitary Landfill Liners (DS/R 466). It states natural clay deposits may be used for membrane material provided the membrane and drainage system may contain at least 95% of all leachate created throughout...

  15. Porosity anisotropy of Opalinus Clay: implications for the poroelastic behaviour

    Science.gov (United States)

    Keller, Lukas M.

    2017-03-01

    Regarding the storage of nuclear waste within clay rock formations, which are considered as natural seals, requires fundamental understanding of the poromechanical behaviour of this rock type with regard to the risk evaluation process. Here, the influence of pore fluid pressure on elastic properties of Opalinus Clay was studied on the basis of realistic pore microstructures, which were reconstructed from image data acquired by focused ion beam nanotomography. These microstructures were used as input pore geometries for linear elastic finite-element modeling in order to predict the anisotropic poroelastic properties of Opalinus Clay. The computational approach allowed determining complete sets of anisotropic poroelastic coefficients. It was found that the anisotropic pore structure of Opalinus Clay leads to a poroelastically anisotropic behaviour. In particular, the pore pressure affects vertical strain/stress differently when compared to the horizontal direction. Hence, long-term safety assessments related to a potential repository for nuclear waste within the Opalinus Clay unit should include anisotropic poroelasticity to predict the mechanical response of this geomaterial.

  16. Study of $^{13}$Be through isobaric analog resonances in the Maya active target

    CERN Multimedia

    Riisager, K; Orr, N A; Jonson, B N G; Raabe, R; Fynbo, H O U; Nilsson, T

    We propose to perform an experiment with a $^{12}$Be beam and the Maya active target. We intend to study the ground state of $^{13}$Be through the population of its isobaric analog resonance in $^{13}$B. The resonance will be identified detecting its proton- and neutron-decay channels.

  17. Issues of Language Use among the Guatemalan-Maya of Southeast Florida

    Science.gov (United States)

    Gladwin, R. F.

    2004-01-01

    Using oral survey methods, this study examined potential language maintenance or loss of Mayan languages among the Guatemalan-Maya communities of Southeast Florida. Among dislocated immigrants and their children, the language of the dominant socio-economic forces often displaces other languages (Fishman, 1967). A Guatemalan community in Los…

  18. Organización territorial de los antiguos mayas de Belice Central

    DEFF Research Database (Denmark)

    Helmke, Christophe; Awe, Jaime

    2008-01-01

    Los modelos propuestos para la organización territorial de los mayas del período clásico en Belice Central difieren significativamente de un investigador a otro. Debido a la escasez de datos jeroglíficos, la mayoría de los modelos se han formulado teniendo en cuenta tan solo datos arqueológicos y...

  19. Women's Schooling and Other Ecocultural Shifts: A Longitudinal Study of Historical Change among the Zinacantec Maya

    Science.gov (United States)

    Maynard, Ashley E.; Greenfield, Patricia M.

    2008-01-01

    Women's schooling has been lauded as having a large, important impact on child socialization. Although there may be positive effects of schooling, there may also be effects from concomitant cultural changes that come with modernization. In this article we examine the findings that changes in textile production among the Zinacantec Maya over the…

  20. Cultural Teaching: The Development of Teaching Skills in Maya Sibling Interactions.

    Science.gov (United States)

    Maynard, Ashley E.

    2002-01-01

    Examined the development of teaching skills in older siblings responsible for teaching their younger siblings to become competent members of their culture among children from a Zinacantec Maya village in Chiapas, Mexico. Found that by age 4, children took responsibility for initiating teaching situations with their younger siblings, and by 8,…

  1. 77 FR 53959 - Culturally Significant Object Imported for Exhibition Determinations: “Dancing Into Dreams, Maya...

    Science.gov (United States)

    2012-09-04

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Object Imported for Exhibition Determinations: ``Dancing Into Dreams, Maya Vases From..., 2003), I hereby determine that the object to be included in the exhibition ``Dancing Into Dreams,...

  2. Critical Pedagogy in HIV-AIDS Education for a Maya Immigrant Community

    Science.gov (United States)

    Schoorman, Dilys; Acosta, Maria Cristina; Sena, Rachel; Baxley, Traci

    2012-01-01

    In this article the authors discuss how the perspectives of Paulo Freire were instructive in addressing the challenges of HIV-AIDS education in Guatemalan Maya immigrant communities with minimal formal education and literacy. The forging of a community-based, collaborative, educational program offers several implications for effective teaching and…

  3. Principles of computer graphics theory and practice using OpenGL and Maya

    CERN Document Server

    Govil-Pai, Shalini

    2004-01-01

    Principles of Computer Graphics: Theory and Practice Using OpenGL and Maya' helps readers understand the principles of interactive computer graphics. Hands-on examples developed in OpenGL illustrate key concepts, and readers develop a professional animation, following traditional processes used in production houses.

  4. Chemical Tools of Octopus maya during Crab Predation Are Also Active on Conspecifics.

    Science.gov (United States)

    Pech-Puch, Dawrin; Cruz-López, Honorio; Canche-Ek, Cindy; Campos-Espinosa, Gabriela; García, Elpidio; Mascaro, Maite; Rosas, Carlos; Chávez-Velasco, Daniel; Rodríguez-Morales, Sergio

    2016-01-01

    Octopus maya is a major socio-economic resource from the Yucatán Peninsula in Mexico. In this study we report for the first time the chemical composition of the saliva of O. maya and its effect on natural prey, i.e. the blue crab (Callinectes sapidus), the crown conch snail (Melongena corona bispinosa), as well as conspecifics. Salivary posterior glands were collected from octopus caught by local fishers and extracted with water; this extract paralyzed and predigested crabs when it was injected into the third pereiopod. The water extract was fractionated by membrane ultrafiltration with a molecular weight cut-off of 3 kDa leading to a metabolic phase (>3 kDa) and a neurotoxic fraction (octopus saliva might be used among conspecifics for defense and for reduction of competition. Bioguided separation of the neurotoxic fraction by chromatography led to a paralysis fraction and a relaxing fraction. The paralyzing activity of the saliva was exerted by amino acids, while the relaxing activity was due to the presence of serotonin. Prey-handling studies revealed that O. maya punctures the eye or arthrodial membrane when predating blue crabs and uses the radula to bore through crown conch shells; these differing strategies may help O. maya to reduce the time needed to handle its prey.

  5. Women's Schooling and Other Ecocultural Shifts: A Longitudinal Study of Historical Change among the Zinacantec Maya

    Science.gov (United States)

    Maynard, Ashley E.; Greenfield, Patricia M.

    2008-01-01

    Women's schooling has been lauded as having a large, important impact on child socialization. Although there may be positive effects of schooling, there may also be effects from concomitant cultural changes that come with modernization. In this article we examine the findings that changes in textile production among the Zinacantec Maya over the…

  6. Critical Pedagogy in HIV-AIDS Education for a Maya Immigrant Community

    Science.gov (United States)

    Schoorman, Dilys; Acosta, Maria Cristina; Sena, Rachel; Baxley, Traci

    2012-01-01

    In this article the authors discuss how the perspectives of Paulo Freire were instructive in addressing the challenges of HIV-AIDS education in Guatemalan Maya immigrant communities with minimal formal education and literacy. The forging of a community-based, collaborative, educational program offers several implications for effective teaching and…

  7. Early Initiation of Breastfeeding Among Maya Mothers in the Western Highlands of Guatemala.

    Science.gov (United States)

    Atyeo, Natalie N; Frank, Tahvi D; Vail, Emma F; Sperduto, William A L; Boyd, David L

    2017-01-01

    Guatemala exhibits the sixth highest rate of child stunting worldwide, and stunting disproportionately affects Guatemala indigenous communities. In a country struggling to combat this result of malnutrition, early child nutrition is especially critical. Specifically, early initiation of breastfeeding is important for the development of newborn infants. Understanding beliefs and practices related to early initiation of breastfeeding in Maya Guatemala may provide an avenue to guide nutrition interventions in indigenous communities. Research aim: This study aimed to determine major beliefs and practices associated with early initiation of breastfeeding among Maya mothers in Lake Atitlán, Guatemala. As part of a larger study to assess child nutrition in the Lake Atitlán region, we created a series of semistructured interview questions to document breastfeeding practices and beliefs among mothers. We conducted and audio-recorded in-person interviews that were translated from Kaqchikel, the local language, to Spanish by a community assistant. We conducted 178 interviews with mothers; 76% practiced early initiation. Early initiation was associated with the village and complementary feeding practices. Mothers held a variety of beliefs about the value of colostrum, and these beliefs were associated with the village. Mothers who held negative beliefs toward colostrum were more likely to delay breastfeeding initiation. Although most Maya mothers practice early initiation, the intervillage disparity in breastfeeding practices demonstrates a need to geographically focus breastfeeding interventions. Our novel insights into the breastfeeding beliefs among Maya mothers will serve as a guide to structure culturally competent breastfeeding education interventions in indigenous communities.

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

    NARCIS (Netherlands)

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

    2016-01-01

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

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

    NARCIS (Netherlands)

    Osorio Vazqez, Maria Cristina; Bressers, Hans; Franco Garcia, Maria Laura; Boer, de Cheryl; Reyes Maya, Oscar Ivan

    2016-01-01

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

  10. Leveraging Social Networks to Support Reproductive Health and Economic Wellbeing among Guatemalan Maya Women

    Science.gov (United States)

    Prescott, Alexandra S.; Luippold-Roge, Genevieve P.; Gurman, Tilly A.

    2016-01-01

    Objective: Maya women in Guatemala are disproportionately affected by poverty and negative reproductive health outcomes. Although social networks are valued in many Indigenous cultures, few studies have explored whether health education programmes can leverage these networks to improve reproductive health and economic wellbeing. Design: This…

  11. Story Starters on the Aztecs, Incas, and Mayas. A Creative Writing Program.

    Science.gov (United States)

    Henrich, Steve; Henrich, Jean

    Designed to supplement an established language arts and social studies program, this books deals with the Aztecs, Incas, and Mayas of Latin America. All of the "Story Starter" books are intended to give a variety of vocabulary and story ideas to help with the writing process. Each of the books is divided into four main sections: (1) an…

  12. Story Starters on the Aztecs, Incas, and Mayas. A Creative Writing Program.

    Science.gov (United States)

    Henrich, Steve; Henrich, Jean

    Designed to supplement an established language arts and social studies program, this books deals with the Aztecs, Incas, and Mayas of Latin America. All of the "Story Starter" books are intended to give a variety of vocabulary and story ideas to help with the writing process. Each of the books is divided into four main sections: (1) an…

  13. Endothelial Nitric Oxide Synthase Haplotypes Are Associated with Preeclampsia in Maya Mestizo Women

    Directory of Open Access Journals (Sweden)

    Lizbeth Díaz-Olguín

    2011-01-01

    Full Text Available Preeclampsia is a specific disease of pregnancy and believed to have a genetic component. The aim of this study was to investigate if three polymorphisms in eNOS or their haplotypes are associated with preeclampsia in Maya mestizo women.

  14. Leveraging Social Networks to Support Reproductive Health and Economic Wellbeing among Guatemalan Maya Women

    Science.gov (United States)

    Prescott, Alexandra S.; Luippold-Roge, Genevieve P.; Gurman, Tilly A.

    2016-01-01

    Objective: Maya women in Guatemala are disproportionately affected by poverty and negative reproductive health outcomes. Although social networks are valued in many Indigenous cultures, few studies have explored whether health education programmes can leverage these networks to improve reproductive health and economic wellbeing. Design: This…

  15. An analysis of modern pollen rain from the Maya lowlands of northern Belize

    Science.gov (United States)

    Bhattacharya, T.; Beach, T.; Wahl, D.

    2011-01-01

    In the lowland Maya area, pollen records provide important insights into the impact of past human populations and climate change on tropical ecosystems. Despite a long history of regional paleoecological research, few studies have characterized the palynological signatures of lowland ecosystems, a fact which lowers confidence in ecological inferences made from palynological data. We sought to verify whether we could use pollen spectra to reliably distinguish modern ecosystem types in the Maya lowlands of Central America. We collected 23 soil and sediment samples from eight ecosystem types, including upland, riparian, secondary, and swamp (bajo) forests; pine savanna; and three distinct wetland communities. We analyzed pollen spectra with non-metric multidimensional scaling (NMDS), and found significant compositional differences in ecosystem types' pollen spectra. Forested sites had spectra dominated by Moraceae/Urticaceae pollen, while non-forested sites had significant portions of Poaceae, Asteraceae, and Amaranthaceae pollen. Upland, bajo, and riparian forest differed in representation of Cyperaceae, Bactris-type, and Combretaceae/Melastomataceae pollen. High percentages of pine (Pinus), oak (Quercus), and the presence of Byrsonima characterized pine savanna. Despite its limited sample size, this study provides one of the first statistical analyses of modern pollen rain in the Maya lowlands. Our results show that pollen assemblages can accurately reflect differences between ecosystem types, which may help refine interpretations of pollen records from the Maya area. ?? 2010 Elsevier B.V.

  16. From edible clay to a clay-containing formulation for optimization of oral delivery of some trace elements: a review.

    Science.gov (United States)

    Kikouama, Odilon Jean Richard; Balde, Lamine

    2010-12-01

    The present review describes the double beneficial effect of using clays for purposes of health and human nutrition: first, their chemical composition, which can enable the release of trace elements; and second, their mineralogical composition, which allows them to be used in the treatment of digestive diseases. The last part of the review is devoted to the release of trace elements contained in clay: clay-containing pellets designed for oral delivery of the trace elements iron and zinc. This multiple-unit pellet system is designed to be retained by flotation in the stomach cavity for a few hours (5 h), with simultaneous control of the release of the trace elements in order to optimize their gastrointestinal absorption. Finally, it is shown that the total amount of ions released from the clay was increased when the formulations were added, in comparison with raw clay, respectively as follows: Zn(2+) (60% versus 40%), Fe(3+) (70% versus 30%) and Fe(2+) (95% versus 40%).

  17. Using a Geographic Information System to Assess the Risk of Hurricane Hazards on the Maya Civilization

    Science.gov (United States)

    Weigel, A. M.; Griffin, R.; Sever, T.

    2014-12-01

    The extent of the Maya civilization spanned across portions of modern day Mexico, Belize, Guatemala, El Salvador and Honduras. Paleoclimatic studies suggest this region has been affected by strong hurricanes for the past six thousand years, reinforced by archeological evidence from Mayan records indicating they experienced strong storms. It is theorized hurricanes aided in the collapse of the Maya, damaging building structures, agriculture, and ceasing industry activities. Today, this region is known for its active tropical climatology, being hit by numerous strong storms including Hurricane Dean, Iris, Keith, and Mitch. This research uses a geographic information system (GIS) to model hurricane hazards, and assess the risk posed on the Maya civilization. GIS has the ability to handle various layer components making it optimal for combining parameters necessary for assessing the risk of experiencing hurricane related hazards. For this analysis, high winds, storm surge flooding, non-storm surge related flooding, and rainfall triggered landslides were selected as the primary hurricane hazards. Data sets used in this analysis include the National Climatic Data Center International Best Track Archive for Climate Stewardships (IBTrACS) hurricane tracks, Shuttle Radar Topography Mission Digital Elevation Model, WorldClim monthly accumulated precipitation, USGS HydroSHEDS river locations, Harmonized World Soil Database soil types, and known Maya site locations from the Electronic Atlas of Ancient Maya Sites. ArcGIS and ENVI software were utilized to process data and model hurricane hazards. To assess locations at risk of experiencing high winds, a model was created using ArcGIS Model Builder to map each storm's temporal wind profile, and adapted to simulate forward storm velocity, and storm frequency. Modeled results were then combined with physical land characteristics, meteorological, and hydrologic data to identify areas likely affected. Certain areas along the eastern

  18. Facile preparation of stable palygorskite/methyl violet@SiO2 "Maya Violet" pigment.

    Science.gov (United States)

    Zhang, Yujie; Zhang, Junping; Wang, Aiqin

    2015-11-01

    Maya Blue pigment has attracted considerable attention owing to their extraordinary stability. The growing interest in this field has largely expanded the study of Maya Blue-like pigments. Inspired by Maya Blue, a stable palygorskite/methyl violet@SiO2 (PAL/MV@SiO2) "Maya Violet" pigment was fabricated via adsorption of MV by PAL, and then deposition of a layer of SiO2 on the surface by polycondensation of tetraethoxysilane (TEOS) in the presence of cetyltrimethylammonium bromide (CTAB). The weight ratio of MV to PAL is as high as 10%. The pigments were characterized by scanning electron microscopy and a variety of analytical techniques, e.g., Fourier Transform infrared spectroscopy and zeta potential. The results indicate that MV molecules are fixed onto the exterior surface, the grooves and at the entrances of the channels of PAL. The PAL/MV@SiO2 pigment shows excellent stability against chemical attacks, e.g., 0.1 M HCl, 0.1 M NaOH and various organic solvents. Different from Maya Blue, grinding and heating treatment are virtually ineffective in improving stability of the PAL/MV pigment. CTAB and the SiO2 layer formed on the surface of PAL/MV contribute greatly to the improved stability of the pigment due to shielding effect. The optimal CTAB/TEOS/ammonia/H2O molar ratio for the surface modification of PAL/MV is 0.24/1/2.89/495. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Chemical Tools of Octopus maya during Crab Predation Are Also Active on Conspecifics.

    Directory of Open Access Journals (Sweden)

    Dawrin Pech-Puch

    Full Text Available Octopus maya is a major socio-economic resource from the Yucatán Peninsula in Mexico. In this study we report for the first time the chemical composition of the saliva of O. maya and its effect on natural prey, i.e. the blue crab (Callinectes sapidus, the crown conch snail (Melongena corona bispinosa, as well as conspecifics. Salivary posterior glands were collected from octopus caught by local fishers and extracted with water; this extract paralyzed and predigested crabs when it was injected into the third pereiopod. The water extract was fractionated by membrane ultrafiltration with a molecular weight cut-off of 3 kDa leading to a metabolic phase (>3 kDa and a neurotoxic fraction (<3 kDa. The neurotoxic fraction injected in the crabs caused paralysis and postural changes. Crabs recovered to their initial condition within two hours, which suggests that the effects of the neurotoxic fraction were reversible. The neurotoxic fraction was also active on O. maya conspecifics, partly paralyzing and sedating them; this suggests that octopus saliva might be used among conspecifics for defense and for reduction of competition. Bioguided separation of the neurotoxic fraction by chromatography led to a paralysis fraction and a relaxing fraction. The paralyzing activity of the saliva was exerted by amino acids, while the relaxing activity was due to the presence of serotonin. Prey-handling studies revealed that O. maya punctures the eye or arthrodial membrane when predating blue crabs and uses the radula to bore through crown conch shells; these differing strategies may help O. maya to reduce the time needed to handle its prey.

  20. Picasso Masks: Cubism in Clay

    Science.gov (United States)

    Daddino, Michelle

    2010-01-01

    This article describes an art project developed by the author which provides a way to further the children's understanding of Picasso's Cubism style in 3-D. Through this project, upper-elementary students learn a bit about the life and art of Picasso as they gain a firm understanding of the style of art known as Cubism, and apply clay techniques…

  1. ADSORPTION OF SURFACTANT ON CLAYS

    Science.gov (United States)

    Surfactants used to enhance remediation of soils by soil washing are often lost in the process. Neither the amount nor the cause of this loss is known. It is assumed that clays present in the soil are responsible for the loss of the surfactant. In this papere, adsorption prope...

  2. Biodegradable Pectin/clay Aerogels

    Science.gov (United States)

    Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. Addition of multivalent cations (Ca2+ and Al3+) resulted in apparent crosslinking of the polymer, and enhancement of aerogel p...

  3. Geotechnical properties of Karwar marine clay

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.T.; Nayak, B.U.; Naik, R.L.

    Karwar marine clay possesses high plasticity characteristics with natural water content higher than the liquid limit. Liquidity index was as high as 1.7. Predominant clay mineral was kaolinite. Undrained shear strength showed an increasing trend...

  4. 21 CFR 186.1256 - Clay (kaolin).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Clay (kaolin). 186.1256 Section 186.1256 Food and... Substances Affirmed as GRAS § 186.1256 Clay (kaolin). (a) Clay (kaolin) Al2O3.2SiO2.nH2O, Cas Reg. No. 1332-58-7) consists of hydrated aluminum silicate. The commercial products of clay (kaolin) contain...

  5. Plant Species and Their Uses In Homegardens of Migrant Maya and Mestizo Smallholder Farmers In Calakmul, Campeche, Mexico

    National Research Council Canada - National Science Library

    Korinna Neulinger; Christian R. Vogl; José A. Alayón-Gamboa

    2013-01-01

    ... and the high diversity of plant species found there. In 2008, an ethnobotanical research study was conducted in 20 Maya and Mestizo homegardens in Calakmul, Campeche, Mexico, a zone of outstanding biocultural diversity...

  6. Effects of Maya ancestry and environmental variables on knee height and body proportionality in growing individuals in Merida, Yucatan.

    Science.gov (United States)

    Vázquez-Vázquez, Adriana; Azcorra, Hugo; Falfán, Ina; Argáeź, Jorge; Kantun, Diódora; Dickinson, Federico

    2013-01-01

    Identify the biological, social, and economic conditions influencing the knee height/stature index (KHSI) in growing individuals of Maya ancestry in the city of Merida, Yucatan, Mexico. The hypothesis was that KHSI values would be lower in subjects with two Maya surnames. This was tested by analyzing the effect of a series of environmental, biological, and socioeconomic variables on stature and knee height (KH). Data were collected from 2008 to 2009 from 841 individuals (444 girls), 9 to 17 years of age, in Merida, Yucatan, Mexico. Ancestry was used as a proxy for genetics, and based on number of Maya surnames (2, 1, or none). The KHSI was calculated for all individuals. Multiple regression models were run to identify the variables that best explained variation in stature, KH, and KHSI. Ancestry negatively (P Mayas. Copyright © 2013 Wiley Periodicals, Inc.

  7. Mujeres mayas, abejas mayas

    OpenAIRE

    Negrín Muñoz, Eduardo

    2016-01-01

    El cultivo de las abejas sin aguijón (meliponas) se ha practicado en la península de Yucatán (México) desde tiempos remotos como lo indican diversas evidencias arqueológicas y documentales. Llama la atención que en la gran mayoría de la vasta literatura histórica que aborda el tema, no se haga mención de la mujer como participante de esa práctica; acaso debido a que, al igual que otros trabajos del campo y de muchos otros ámbitos, ha estado reservado exclusivamente para el hombre. Es hasta ti...

  8. Clay Cuffman: A Cool, Calm, Relaxed Guy

    Science.gov (United States)

    Booth, Gina

    2010-01-01

    This article describes Clay Cuffman, a simple clay-sculpture project that requires two or three sessions, and works for students from the upper-elementary level through high school. It takes about 1.5 pounds of clay per student--about the size of a small grapefruit. The Cuffman project is a great way for upper-elementary through high-school…

  9. Hydrodynamic erosion process of undisturbed clay

    NARCIS (Netherlands)

    Zhao, G.; Visser, P.J.; Vrijling, J.K.

    2011-01-01

    This paper describes the hydrodynamic erosion process of undisturbed clay due to the turbulent flow, based on theoretical analysis and experimental results. The undisturbed clay has the unique and complicated characteristics of cohesive force among clay particles, which are highly different from dis

  10. Clay & Children: More than Making Pots.

    Science.gov (United States)

    Kolbe, Ursula

    1997-01-01

    Working with clay enables young children to express, explore, and communicate their feelings and ideas. This resource booklet for early childhood practitioners and it promotes the clay table as a special place for shared discoveries, social interaction, and discussion. The booklet provides a glossary of terms used in clay work, as well as reasons…

  11. La legitimación de la realeza entre mayas del Preclásico Tardío. Los mascarones de El Tigre, Campeche Legitimizing royalty among Late Preclassic Maya. The masks from El Tigre-Campeche

    Directory of Open Access Journals (Sweden)

    Ernesto Vargas Pacheco

    2010-01-01

    Full Text Available En el arte monumental del periodo Clásico maya la imagen del señor ocupaba el sitio principal y todas las demás imágenes un lugar secundario. Con este trabajo se quiere demostrar que los soberanos mayas ya en el Preclásico Tardío, o desde antes, usaron la arquitectura para reproducir la topografía del universo y se sirvieron de los mascarones para transmitir la condición divina de sus antepasados, de sus dioses y la suya propia. En El Tigre, Campeche, se han explorado varios mascarones de estuco del Preclásico Tardío, que representan rostros humanos, los cuales bien podrían identificarse como ancestros: antepasados de gobernantes que pretenden divinizarlos para así legitimizar la realeza maya.The images of Maya dignitaries take the most important places in monumental art during Classic period, and all other representations occupy a secondary position in that context. This paper pretends to demonstrate that Maya kings tried to duplicate their conception of the Universe on civic architecture since Preclassic period, or even before; they used huge mask representations to transmit the sacred condition of their ancestors, their gods and their selves. At El Tigre site, in Campeche, have been explored several stucco masks of Late Preclassic date, showing human faces that may represent ancestors of the kings who tried to deify them in order to legitimate Maya royalty.

  12. ``Yo soy indígena'': identifying and using traditional ecological knowledge (TEK) to make the teaching of science culturally responsive for Maya girls

    Science.gov (United States)

    Hamlin, Maria L.

    2013-12-01

    This study examines how traditional ecological knowledge—TEK—can be identified and utilized to create culturally responsive science learning opportunities for Maya girls from a community in the Guatemalan highlands. Maya girls are situated in a complex socio-historical and political context rooted in racism and sexism. This study contextualizes the current situation of Maya women and girls in Guatemala and emphasizes the important need for educators to create science-learning opportunities that are culturally congruent. The author posits that when considering how to make the teaching and learning of science culturally responsive for Maya girls, educators must begin with the scientific knowledge inherent within Maya communities. Indigenous communities have a wealth of TEK that can be used to contextualize science curricula that can be purposely designed to meet the nuanced cultural needs of traditional Maya girls within and outside Guatemala.

  13. The systems containing clays and clay minerals from modified drug release: a review.

    Science.gov (United States)

    Rodrigues, Luís Alberto de Sousa; Figueiras, Ana; Veiga, Francisco; de Freitas, Rivelilson Mendes; Nunes, Lívio César Cunha; da Silva Filho, Edson Cavalcanti; da Silva Leite, Cleide Maria

    2013-03-01

    Clays are materials commonly used in the pharmaceutical industry, either as ingredients or as active ingredients. It was observed that when they are administered concurrently, they may interact with drugs reducing their absorption. Therefore, such interactions can be used to achieve technological and biopharmaceutical advantages, regarding the control of release. This review summarizes bibliographic (articles) and technological (patents) information on the use of systems containing clays and clay minerals in modified drug delivery. In this area, formulations such natural clay, commercial clay, synthetic clay, composites clay-polymers, nanocomposites clay-polymers, films and hidrogels composites clay-polymers are used to slow/extend or vectorize the release of drugs and consequently they increase their bioavailability. Finally, this review summarizes the fields of technology and biopharmaceutical applications, where clays are applied.

  14. A study on alluvial clays of Darrang and Kamrup district of Assam by x-ray and other physical methods

    Science.gov (United States)

    Saharia, Ganeswar

    The first Chapter gives a general introduction about the clays and alluvial clays. In this chapter a broad discussion on the general features of the clays and clay minerals have been explained. A short description on seven different types of clay, the areas of application in the past and present are incorporated. It gives an insight into the important industrial and commercial utility of the alluvial clays or clay. This chapter also deals with the review of previous and present work on clay minerals including home state. The objectives of the present study have been mentioned in the last part of this chapter. The Second chapter deals with the occurrence and formation of the clays. The structural features of the clays have been described with due emphasis on two layered Kaolinite group, three layered Illite and Montmorillonite group, Chlorite group and Vermiculite groups. Profiles of the clays have been described briefly in this chapter. Some causes are mentioned for which the plasticity of the clays developed. A general classification of the clays in relation to the clay mineral study and recommendations of AIPEA is shown in the Table No. 2.5(1) Here, the behaviour of clay minerals in relation to water and foreign Ions in acquons solution are briefly enumerated. A sketch diagram for behaviour of clays in relation to water is shown in Fig. 2.6(1). The third chapter deals with the experimental methodology and the areas of investigation or places from where the samples were collected are shown in Map (Fig. 3.1.) and in Chart 3.1.1. In this chapter the specimen collection process and procedures of preparatory washed and chemically treated samples are described elaborately. Here, the preparation of H+, K + and Mg++ clay, powder clay, pellet slide are mentioned. A general interpretation about the XRD, XRF and FTIR instrument and the procedure of treatments are synthesised. The different perimeters for this study are also mentioned here with their respective units and the

  15. Drought Impacts on Ancient Maya Maize Agriculture Inferred from Isotopic Analyses of Plant Biomarkers

    Science.gov (United States)

    Douglas, P. M.; Pagani, M.; Eglinton, T. I.; Brenner, M.; Hodell, D. A.; Curtis, J. H.

    2013-05-01

    There is increasing evidence suggesting that a series of droughts in the Maya lowlands of southeastern Mexico and northern Central America coincided with the Terminal Classic decline of the Classic Maya civilization (ca. 1250 to 1000 years BP). However, there is little evidence directly linking climatic change and changes in human activities in this region. In this study we combine plant-wax hydrogen and carbon analyses in two lake sediment cores from the Yucatan and northern Guatemala to develop coupled records of hydroclimate variability and human-driven vegetation change and assess drought impacts on maize agriculture In the Maya lowlands plant-wax hydrogen isotope ratios (δD) are controlled by the isotopic composition of precipitation and evapotranspiration, and are highly sensitive to changes in aridity. In this low-elevation tropical environment plant-wax carbon isotope ratios (δ13C) are largely controlled by the relative abundance of C3 and C4 plants. The ancient Maya practiced widespread maize (C4) agriculture and strongly influenced regional C3-C4 vegetation dynamics. Under natural conditions C4 plant coverage and plant-wax δD would tend to co-vary positively since C4 plants are well adapted for dry conditions. Under ancient Maya land-use, however, this relationship is likely to be decoupled, since drought would have disrupted C4 agriculture. Combined analyses of plant-wax δD and δ13C from two lake sediment cores in the Maya lowlands indicate co-evolving changes in hydroclimate and C4 plant coverage over the past 4000 years. Compound-specific radiocarbon analyses of plant-waxes provide independent chronologies for these plant-wax stable isotope records, and plant-wax δD records developed using these chronologies agree closely with other regional records of hydroclimate change. Trends in plant-wax δD and δ13C diverge following ca. 3500 years BP, around the onset of widespread ancient Maya agriculture. After this time high plant-wax δD values tend

  16. a Review of Late Holocene Fluvial Systems in the Karst Maya Lowlands with Focus on the Rio Bravo, Belize

    Science.gov (United States)

    Beach, T.; Luzzadder-Beach, S.; Krause, S.; Doyle, C.

    2015-12-01

    The Maya Lowlands is mostly an internally draining karst region with about 400 m of regional relief. Fluvial and fluviokarst systems drain the edges of this landscape either from low limestone uplands or igneous and metamorphic complexes. Thus far most fluvial research has focused around archaeology projects, and here we review the extant research conducted across the region and new research on the transboundary Rio Bravo watershed of Belize and Guatemala. The Rio Bravo drains a largely old growth tropical forest today, but was partly deforested around ancient Maya cities and farms from 3,000 to 1000 BP. Several studies estimate that 30 to 40 percent of forest survived through the Maya period. Work here has focused on soils and sediment movement along slope catenas, in floodplain sites, and on contributions from groundwater with high dissolved loads of sulfate and calcium. We review radiocarbon dates and present new dates and soil stratigraphy from these sequences to date slope and floodplain movement, and we estimate ancient land use from carbon isotopic and pollen evidence. Aggradation in this watershed occurred by flooding, gypsum precipitation, upland erosion, and ancient Maya canal building and filling for wetland farming. Soil erosion and aggradation started at least by 3,000 BP and continued through the ancient Maya period, though reduced locally by soil conservation, post urban construction, and source reduction, especially in Maya Classic period from 1700 to 1000 BP.

  17. Vital warmth and well-being: steambathing as household therapy among the Tzeltal and Tzotzil Maya of highland Chiapas, Mexico.

    Science.gov (United States)

    Groark, Kevin P

    2005-08-01

    Among the Maya, the cultural history of steambathing spans more than two millennia. Although it has largely disappeared from the lowlands, household-level steambathing persists in several highland Maya communities in Chiapas, Mexico. In this article, I present an overview of therapeutic steambathing among the Tzeltal and Tzotzil Maya. Through an extended discussion of the beliefs and practices surrounding steambathing, I develop several features of highland Maya thinking about physical health and "well-being". In particular, I examine a set of ethnophysiological representations relating to the "thermal" nature of functional bodies, and the relationship of these models to the maintenance and restoration of health. The highland Maya have articulated an elaborate understanding of physical health and well-being coded in an idiom of "vital warmth", and directed toward the preservation and augmentation of the endogenous heat necessary for vitality and vigor. These models simultaneously reflect empirical understandings of bodily states in health and illness, as well as metaphorical assumptions about the thermal nature of functional psychosocial identities. Steambathing draws on and reinforces these models, constituting a core cultural technology for radically altering the thermal state of the patient, an experience which the highland Maya regard as deeply beneficial. The paper closes with a discussion of recent biomedical research into the physiological effects of hyperthermal therapies.

  18. The influence of clay minerals on acoustic properties of sandstones

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Olav

    1997-12-31

    This thesis aims to provide better understanding of the relationship between the acoustic properties and the petrophysical/mineralogical properties in sand-prone rock. It emphasizes the influence of clay minerals. The author develops a method to deposit clay minerals/mineral aggregates in pore space of a rigid rock framework. Kaolinite aggregates were flushed into porous permeable Bentheimer sandstone to evaluate the effect of pore filling minerals on porosity, permeability and acoustic properties. The compressional velocity was hardly affected by the clay content and it was found that the effect of minor quantities of pore filling minerals may be acoustically modelled as an ideal suspension, where the pore fluid bulk modulus is modified by the bulk modulus of the clay minerals. The influence of clays on acoustic velocities in petroleum reservoir rocks was investigated through ultrasonic measurements of compressional- and shear-waves on core material from reservoir and non-reservoir units on the Norwegian Continental Shelf. The measured velocities decrease as the porosity increases, but are not strongly dependent on the clay content. The measured velocities are less dependent on the petrophysical and lithological properties than indicated by previous authors and published mathematical models, and stiffness reduction factors are introduced in two of the models to better match the data. Velocities are estimated along the wellbores based on non-sonic well logs and reflect well the actual sonic log well measurements. In some wells the compressional velocity cannot be modelled correctly by the models suggested. Very high compressional wave anisotropy was measured in the dry samples at atmospheric conditions. As the samples were saturated, the anisotropy was reduced to a maximum of about 30% and decreases further upon pressurization. Reservoir rocks retrieved from 2500 m are more stress dependent than those retrieved from less than 200 m depth. 168 refs., 117 figs., 24

  19. Mineral acquisition from clay by budongo forest chimpanzees

    NARCIS (Netherlands)

    Reynolds, Vernon; Lloyd, Andrew W.; English, Christopher J.; Lyons, Peter; Dodd, Howard; Hobaiter, Catherine; Newton-Fisher, Nicholas; Mullins, Caroline; Lamon, Noemie; Schel, Anne Marijke; Fallon, Brittany

    2015-01-01

    Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consum

  20. Magnetic properties of the Tertiary red clay from Gansu Province, China and its paleoclimatic significance

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The study on magnetic properties of the red clay indicates that the red clay and loess- paleosol sequence have a common magnetic mineralogy, with magnetite, maghemite, hematite (and possibly goethite) contributing to the magnetic behavior. The red clay magnetic susceptibility is also found to have a positive relation with extrafine superparamagnetic grains. This suggests that, like the Quaternary loess-paleosols, an ultrafine ferrimagnetic component produced during pe-dogenesis in the red clay under humid conditions also plays an important role in susceptibility enhancement in the soil units. This is supported by the correlation between Rb/Sr ratio and magnetic susceptibility. This signifies that, like the above loess-paleosol sequence, the magnetic susceptibility of the red clay can be used as a general proxy paleoclimatic indicator, although whether its susceptibility in the red clay is comparable to pedogenesis intensity and requires further investigation. Magnetic susceptibility variation in the red clay thus also provides an eo-lian/pedogenic record of paleoclimatic evolution. Study of the background susceptibility indicates that, on average, the absolute scale of the paleoclimatic shift from red clay development to Quaternary loess deposition is similar to the climatic shift from stage 5 (S1) to stage 2-4 (L1). This may suggest that during the Quaternary there is an evident strengthening of the absolute wind intensity to bring more (about double) coarser and less weathered (non-SP fraction) eolian magnetic input from the source regions to the Loess Plateau than during the Pliocene. The presence of eolian red clay since 7.5 Ma BP in central-northern China implies an important envi-ronmental change from the underlying Cretaceous red sandstone. The red clay development was closely related to global drying and climate cooling since the Cretaceous and closely associated with the abrupt uplift of the Qinghai-Xizang Plateau at about that time. This uplift of the

  1. Contact micromechanics in granular media with clay

    Energy Technology Data Exchange (ETDEWEB)

    Ita, Stacey Leigh [Univ. of California, Berkeley, CA (United States)

    1994-08-01

    Many granular materials, including sedimentary rocks and soils, contain clay particles in the pores, grain contacts, or matrix. The amount and location of the clays and fluids can influence the mechanical and hydraulic properties of the granular material. This research investigated the mechanical effects of clay at grain-to-grain contacts in the presence of different fluids. Laboratory seismic wave propagation tests were conducted at ultrasonic frequencies using spherical glass beads coated with Montmorillonite clay (SWy-1) onto which different fluids were adsorbed. For all bead samples, seismic velocity increased and attenuation decreased as the contact stiffnesses increased with increasing stress demonstrating that grain contacts control seismic transmission in poorly consolidated and unconsolidated granular material. Coating the beads with clay added stiffness and introduced viscosity to the mechanical contact properties that increased the velocity and attenuation of the propagating seismic wave. Clay-fluid interactions were studied by allowing the clay coating to absorb water, ethyl alcohol, and hexadecane. Increasing water amounts initially increased seismic attenuation due to clay swelling at the contacts. Attenuation decreased for higher water amounts where the clay exceeded the plastic limit and was forced from the contact areas into the surrounding open pore space during sample consolidation. This work investigates how clay located at grain contacts affects the micromechanical, particularly seismic, behavior of granular materials. The need for this work is shown by a review of the effects of clays on seismic wave propagation, laboratory measurements of attenuation in granular media, and proposed mechanisms for attenuation in granular media.

  2. Polyamide 66/Brazilian Clay Nanocomposites

    Directory of Open Access Journals (Sweden)

    E. M. Araújo

    2009-01-01

    Full Text Available Polyamide 66 (PA66/Brazilian clay nanocomposites were produced via direct melt intercalation. A montmorillonite sample from the Brazilian state of Paraíba was organically modified with esthearildimethylammonium chloride (Praepagen, quaternary ammonium salt and has been tested to be used in polymer nanocomposites. The dispersion analysis and the interlayer spacing of the clay particles in matrix were investigated by X-ray diffraction (XRD and transmission electron microscopy (TEM. Thermal behavior of the obtained systems was investigated by differential scanning calorimetry (DSC, thermogravimetry (TG, and heat deflection temperature (HDT was reported too. The nanocomposites exhibited a partially exfoliated structure, very interesting HDT values which are higher than those of pure PA66, and good thermal stability.

  3. Hands-on Virtual Clay

    OpenAIRE

    Pihuit, Adeline; Kry, Paul; Cani, Marie-Paule

    2008-01-01

    poster; International audience; This paper presents a new interaction system designed for hands-on 3D shape modeling and deformation through natural hand gestures. Our system is made of a Phantom haptic device coupled with a deformable foam ball that supports pressure sensors. These sensors detect forces exerted by the user's fingertips, and are used to control the configuration of a compliant virtual hand that is modeling soft virtual clay. During interaction, the user is provided both passi...

  4. Characterization of karak clay from pakistan for pharmaceutical and cosmetic applications

    Energy Technology Data Exchange (ETDEWEB)

    Shah, L.A. [University of Peshawar (Pakistan); Silva-Valenzuela, M.G.; Valenzuela-Diaz, F.R.; Sayeg, I.J.; Carvalho, F.M.S. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil)

    2012-07-01

    Full text: Clay, the most important, plentiful, and low cost naturally occurring mineral, is widely used in variety of industrial application including Pharmaceutical and cosmetic. Clay is the fine grained aluminosilicate mineral which shows the property of plasticity at appropriate water content, and becomes hard upon drying. In Pakistan there are different types of clay but till now neither of them properly identified nor characterize for specific industrial application. The objective of this work is to characterize Karak clay for pharmaceutical and cosmetic applications collected from deposit located at Shagai region, District Karak, Pakistan. The clay was characterized through Xray diffractometry (XRD), X-ray Fluorescence (XRF), trace elemental Analysis, Microbiological analysis, Cation exchange capacity (CEC), pH and swelling assays according to European, United States of America and Brazilian Pharmacopeias. Bulk Chemical analysis shows that the Aluminum oxide and silica oxide are present in large quantity which was confirmed by XRD that this sample has montmorillonite as a major while illite and kaolinite as minor clay minerals. Quartz of small quantity was also found as a non-clay mineral. After analyzing the results for sample it was concluded that the clay is a strong candidate for cosmetic purposes. (author)

  5. Porosity Investigation of Kosova's Clay

    Directory of Open Access Journals (Sweden)

    Makfire Sadiku

    2011-01-01

    Full Text Available Problem statement: Acid activated clay minerals are used as catalysts in the desulphurization of crude oil or as catalyst carrier, as drilling mud, as bleaching earth. Approach: The efficiency of the acid activation can be described in two ways. As increase of the surface and as increase of the cumulative pore volume after the activation. Results: In different samples of the clay mineral the activation was done with different sulfuric acid concentrations for two and 3h. Afterwards the specific surface was measured by means of nitrogen adsorption. All the measured isotherms belong to the pseudo-two kind. After the activation the surface enhanced from around 100-180 m2 g-1. The mesopore distribution is calculated out of the hysteresis between adsorption-desorption isotherms of the nitrogen. Conclusion: It is shown that the activation increases significantly the amount of mesopores which is reflected in the cumulative volume. The macrospore volume of the clay samples were measured by means of mercury intrusion porosimetry for pore sizes up to 320 nm. The volume of the macrospores results to an increase up to two times after the activation. The cumulative volume of all the pores is shown like a good parameter of the efficiency of the acid activation. The measurements were fulfilled in the newly equipped laboratory of the surface characterizations of the Tirana University. These analyses are of big interest for the industry in Albania and Kosove.

  6. Copper-ion-assisted self-assembly of silicate clays in rod- and disklike morphologies.

    Science.gov (United States)

    Tsai, Wei-Cheng; Lin, Jiang-Jen

    2010-06-15

    Self-assembled rodlike (0.3-2.5 microm in diameter and 5.3-31 microm in length) and disklike microstructures (1.8-10.6 microm in width and 0.1-1.0 microm in thickness) are uniquely present in amorphous clay aggregates. Clay units were prepared by intercalation of Na(+)-montmorillonite (Na(+)-MMT) with copper ions (Cu(2+)) and poly(oxypropylene)-amine salt (POP) in simultaneous or stepwise ionic exchange reactions. Differences in process control during incorporation of Cu(2+) and hydrophobic POP greatly affected the layer structure of the clay units (d spacing of 12-53 A) and consequently their amphiphilic dispersion properties. By controlling the dispersion in water and drying at 80 degrees C, highly ordered self-assembly structures were obtained, presumably as a result of self-piling of clay units in competing vertical and horizontal directions. In general, association with Cu(2+) yielded units with a disklike microstructure, in contrast to the rod-like structure obtained for POP-intercalated clay. The self-assembled structures were characterized using X-ray diffraction, UV adsorption, thermal gravimetric analysis, zeta potential, scanning electron microscopy, and energy-dispersive X-ray spectroscopy techniques. Control of the clay self-piling process provides a new synthetic route for the fabrication of bottom-up microstructures that are potentially useful for templates, sensors, and electronic devices.

  7. Modernity and putty-clay

    Science.gov (United States)

    Ganesh, Trichur Kailas

    This dissertation addresses issues arising out of the problems of capital accumulation, productivity growth and 'putty-clay' technology. The concept of economic modernity occupies a central place in the subject-matter studied here in that it expresses both the incessant drive for newness that characterizes economic reality and the persistence of dated techniques that successfully resist replacement. This study examines the way in which an expansive development-theoretic 'putty-clay' framework may be employed to explain the historical processes behind both the avalanche of newness (innovations) and the conservatism of technology in the U.S. economy. The guiding link is the fixity of investments in physical capital equipment over time and space. The dilemma of fixed capital is studied in the context of the constant entrepreneurial search for flexibility and liquidity. The thesis advanced is that a development (Entwicklung)-theoretic 'putty-clay' conceptualization of the economic system adequately addresses the recurring problems of fixity, flexibility, and liquidity, and thereby permits important insights into the enigma surrounding the persistent productivity growth slowdown and 'stagflation' of the late sixties and seventies and the related phenomena of physical 'capital obsolescence' and the financial or 'speculative explosions' of our times. The notion of 'putty-clay' used here is an innovative one in that it departs from the growth-theoretic literature to re-appear as a Schumpeterian theory of modernity modified by a Veblenite view of an economic system directed by the exigencies of the 'machine-process'. The empirical aptitude of a macroeconomic 'putty-clay' model to explain capital obsolescence mediated by the energy 'crises' (supply shocks) of the seventies and eighties is examined in a separate chapter with results that differ markedly from the standard (Berndt and Wood) conclusions for the U.S. economy. The final chapter in the dissertation reverts to the

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

    OpenAIRE

    2010-01-01

    En las comunidades mayas la apicultura continúa siendo una actividad relevante pero complementaria, cuya lógica y condiciones de producción se contraponen a las nuevas normas del mercado internacional. La integración de organizaciones apícolas se considera una estrategia para la "modernización" de la apicultura y la comercialización de la miel en mejores condiciones. Este trabajo se refiere al sentido que tanto la apicultura como estas organizaciones tienen para sus integrantes, a sus expecta...

  9. Maya 6.0发布会特别报道

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    每一个春季的到来都意味着一个Maya新版本的发布。本年度Maya 6.0发布会于2004年5月19日在北京好苑建国酒店如期举行。今年是Alias更名后Maya的第一次产品发布会,Alias公司的大中华地区销售总监马千里先生以及技术工程师Ken Taki先生参加了此次发布会,并在会上发言,Ken Taki先生对Maya 6.0的新功能做了详尽的介绍。

  10. Les Mayas, victimes de l’histoire dans la guerre civile du Guatemala, 1954-1996

    OpenAIRE

    2013-01-01

    Cet article vise à étudier les causes lointaines de la tension et de la haine qui ont mené à un génocide dirigé contre le peuple maya pendant la décennie des 1980. Il cherche à approfondir deux causes majeures de ces conflits entre l’élite du Guatemala et les peuples indigènes – la terre et le racisme. Chacun de ces thèmes a empoisonné les relations avec le peuple maya et ouvert la porte à la violence qui a marqué le pays de la période de la conquête jusqu’aux guerres du 20e siècle. Este a...

  11. Justicia indígena maya en el sureste de México

    Directory of Open Access Journals (Sweden)

    Juana Luisa Ríos Zamudio

    2011-01-01

    Full Text Available A más de diez años de haberse implementado en Quintana Roo, México, un sistema de justicia propio para las comunidades mayas de la entidad, y pese a lo acelerado de su crecimiento y arraigo, su estructura, funcionamiento y principios éticos que lo rigen han sido poco estudiados. Este trabajo tiene como objetivo analizar su funcionamiento desde la sociología jurídica, tomando como base las constancias de actuación de los jueces tradicionales. Se podrá ver que gracias a su polivalente actuación, los jueces tradicionales son hoy una figura socialmente legitimada al interior de las comunidades mayas, aun habiendo sido creada e implementada "desde fuera" por las autoridades estatales hace apenas poco más de una década.

  12. Collapse of Classic Maya civilization related to modest reduction in precipitation.

    Science.gov (United States)

    Medina-Elizalde, Martín; Rohling, Eelco J

    2012-02-24

    The disintegration of the Classic Maya civilization in the Yucatán Peninsula and Central America was a complex process that occurred over an approximately 200-year interval and involved a catastrophic depopulation of the region. Although it is well established that the civilization collapse coincided with widespread episodes of drought, their nature and severity remain enigmatic. We present a quantitative analysis that offers a coherent interpretation of four of the most detailed paleoclimate records of the event. We conclude that the droughts occurring during the disintegration of the Maya civilization represented up to a 40% reduction in annual precipitation, probably due to a reduction in summer season tropical storm frequency and intensity.

  13. Putting Us on the Map: Remote Sensing Investigation of the Ancient Maya Landscape

    Science.gov (United States)

    Sever, Thomas L.; Saturno, William

    2004-01-01

    A common problem for archaeologists studying ancient settlement in the Maya Lowlands is overcoming the dense vegetation in order to obtain an accurate regional perspective of the presence of archaeological sites, their exact locations and their overall extents. Most often this is done by extensive ground surveys in which many individuals chop parallel paths through the vegetation in search of sites. Once a site is found an effort is made to mark its location on a regional map and to explore its perimeter. Obtaining locational information has been made dramatically easier in recent years with the advent of improved Global Positioning Systems (GPS), however the process of initial identification of sites and the determination of their borders is exceedingly labor intensive and has remained relatively unchanged since the beginning of settlement surveys in the region in the 1950 s. Currently, we are revolutionizing settlement survey in the Maya Lowlands by using remotely sensed data from IKONOS, Quickbird, and Eo 1, satellites as well as airborne AIRSAR radar data. The Ancient Maya built their cities, towns and even their smallest hamlets using excavated limestone and lime plasters. We propose that the decay of these structures provides a unique microenvironment for the growth of vegetation as the levels of moisture and nutrition within the ruins vary substantially from those in the surrounding forest. These microenvironmental differences on the ground are likewise represented by compositional differences in the forest canopy both in the species present and in leaf color (representing moisture/nutritional stress) visible through the analysis of high-resolution satellite data. In this way the detailed analysis of forest composition can reveal a detailed picture of the ancient settlements that lie beneath it. Preliminary examinations using this technique have been very successful and we are refining these techniques in order to efficiently comprehend the details of

  14. Politics in the Western Maya Region (I: Ajawil/Ajawlel and Ch'e'n

    Directory of Open Access Journals (Sweden)

    Péter Bíró

    2011-01-01

    Full Text Available In a series of articles I reflect on the use of various expressions which are connected to what we call the political in the inscriptions of the Classic Maya Western Region. These words express concepts which help to understand the intricate details of the interactions between the political entities and their internal organisations in the Classic Maya Lowlands. Words such as 7ajawil, 7ajawlel, the kennings built on the base of ch'e7n (cave, pond, the emblem glyphs and titles will be examined in light of what they tell us about the functioning of the political organisation of the Classic Period in a constrained region.En una serie de artículos como éste investigo el uso de varias palabras en las inscripciones mayas de la época Clásica de la Región Occidental vinculadas con lo que nosotros llamamos "política". Estas palabras expresan conceptos que ayudan a entender los matices de las relaciones entre las entidades políticas de las Tierras Bajas Mayas y su organización interna. Términos como ajaw'ü I ajawlel, los difrasismos con base ch'e'n (cueva, pozo, los glifos emblemas y los títulos serán examinados tomando en cuenta la información que nos proporcionan sobre el funcionamiento de la organización política de la época Clásica en una región restringida.

  15. Perlindungan Merek Terdaftar Dari Kejahatan Dunia Maya Melalui Pembatasan Pendaftaran Nama Domain

    Directory of Open Access Journals (Sweden)

    Setia Dharma

    2015-05-01

    Full Text Available Abstract: The Protection of Registered Trademark of Cyber Crime Through The Restriction of The Domain Name Registration. The progress of science and technology has implications for the progress of the current trading method. It is not only done conventionally but also carried out through cyberspace. Trading in the virtual world requires the use of a domain name (cyber squatting as a differentiator between one company with other companies. Law No. 11 Year 2008 on Information and Electronic Transactions regulate the use of domain names and emphasize the element of good faith in the implementation. In practice, there is a breach of the domain name registration is a crime which is the trademark or name that has a commercial value. This paper is going to examine aspects of protection-registered trademark of cyber crime through the restriction of the domain name registration and implementation of good faith. Abstrak: Perlindungan Merek Terdaftar Dari Kejahatan Dunia Maya Melalui Pembatasan Pendaftaran Nama Domain. Kemajuan ilmu dan teknologi membawa implikasi pada kemajuan metode perdagangan yang saat ini bukan hanya dilakukan secara konvensional, namun juga dilakukan melalui dunia maya. Perdagangan dalam dunia maya mensyaratkan penggunaan nama domain (cyber squatting sebagai pembeda antara satu perusahaan dengan perusahaan yang lainnya. Undang-Undang No. 11 Tahun 2008 Tentang Informasi dan Transaksi elektronik mengatur penggunaan nama domain tersebut dan menekankan unsur iktikad baik dalam pelaksanaannya. Prakteknya, terdapat pelanggaran nama domain tersebut yang merupakan merupakan kejahatan pendaftaran merek dagang atau nama yang memiliki nilai komersial. Tulisan ini hendak mengkaji aspek perlindungan merek terdaftar dari kejahatan dunia maya melalui pembatasan pendaftaran nama domain dan pelaksanaan iktikad baik. DOI: 10.15408/jch.v1i2.1463

  16. A distribution analysis of the central Maya lowlands ecoinformation network: its rises, falls, and changes

    Directory of Open Access Journals (Sweden)

    Joel D. Gunn

    2017-03-01

    Full Text Available We report a study of central Maya lowland dynastic information networks, i.e., six cities' external elite ceramic influences, and how they reflect the decision-making practices of Maya elites over 3000 years. Forest cover, i.e., Moraceae family pollen, was added to the network analysis to provide ecological boundary conditions, thus ecologically moderated information networks. Principal components analysis revealed three dominant patterns. First, the networking of interior cities into powerful polities in the Late Preclassic and Classic periods (400 BCE-800 CE. In a second pattern, coastal cities emerged as key entrepôts based on marine navigation (Terminal and Postclassic periods, 800-1500 CE. Climate dynamics and sustainability considerations facilitated the transition. Forest cover, a measure of ecosystem health, shows interior forests diminished as interior cities networked but rebounded as their networks declined. By contrast, coastal forests flourished with networks implying that the marine-based economy was sustainable. Third, in the Classic, the network-dominant coast, west or east, changed with interior polities' political struggles, the critical transition occurring after 695 CE as Tikal gained dominance over the Calakmul-Caracol alliance. Beginning with the Late Preclassic about 2000 years ago, it is possible to assign names to the decision makers by referencing the growing literature on written Maya records. Although the detectable decision sequence evident in this analysis is very basic, we believe it does open possible avenues to much deeper understanding as the study proceeds into the future. The Integrated History and Future of People on Earth-Maya working group that sponsored the analysis anticipates that it will provide actionable social science intelligence for future decision making at the global scale.

  17. Genderinequalities in overweight and obesity Among indigenous Maya Chontales of Tabasco, Mexico

    OpenAIRE

    Cruz Sánchez, Marcelina; Tuñon Pablos, Esperanza; Villaseñor Farías, Martha; Álvarez Gordillo, Guadalupe del Carmen; Nigh Nielsen, Ronald

    2012-01-01

    Obesity has become a global epidemic with women registering higher rates than men. It is unknown why this phenonmenon occurs or whether it acquires specific characteristics among indigenous populations. Objective: To identifiy gender inequalities that underly excess body weight and obesity among the indigenous Maya Chontales of Tabasco. Materials and Methods: Qualitative study of 15 in-depth interviews of Chontal men and women. Interview themes included categories of lifestyle, ethnicity, cus...

  18. Putting Us on the Map: Remote Sensing Investigation of the Ancient Maya Landscape

    Science.gov (United States)

    Sever, Thomas L.; Saturno, William

    2004-01-01

    A common problem for archaeologists studying ancient settlement in the Maya Lowlands is overcoming the dense vegetation in order to obtain an accurate regional perspective of the presence of archaeological sites, their exact locations and their overall extents. Most often this is done by extensive ground surveys in which many individuals chop parallel paths through the vegetation in search of sites. Once a site is found an effort is made to mark its location on a regional map and to explore its perimeter. Obtaining locational information has been made dramatically easier in recent years with the advent of improved Global Positioning Systems (GPS), however the process of initial identification of sites and the determination of their borders is exceedingly labor intensive and has remained relatively unchanged since the beginning of settlement surveys in the region in the 1950 s. Currently, we are revolutionizing settlement survey in the Maya Lowlands by using remotely sensed data from IKONOS, Quickbird, and Eo 1, satellites as well as airborne AIRSAR radar data. The Ancient Maya built their cities, towns and even their smallest hamlets using excavated limestone and lime plasters. We propose that the decay of these structures provides a unique microenvironment for the growth of vegetation as the levels of moisture and nutrition within the ruins vary substantially from those in the surrounding forest. These microenvironmental differences on the ground are likewise represented by compositional differences in the forest canopy both in the species present and in leaf color (representing moisture/nutritional stress) visible through the analysis of high-resolution satellite data. In this way the detailed analysis of forest composition can reveal a detailed picture of the ancient settlements that lie beneath it. Preliminary examinations using this technique have been very successful and we are refining these techniques in order to efficiently comprehend the details of

  19. Use of marine robot`MAYA` for monitoring the Zuari and Mandovi esturine systems

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.A.M.Q.; Afzulpurkar, S.; Navelkar, G.S.; Maurya, P.K.; Fernandes, L.; Desa, E.S.; Madhan, R.; Shenoy, D.; Kurian, S.; Naik, H.; Nagvekar, S.; Vimalakumari, D.; Dalvi, H.S.; Manoharan, V.; deAraujo, B.A.; Lamani, V.; Naik, N.; Mohan, N.; Dias, Albertina; Dias, A.

    at the rear provides propulsion to the vehicle. Heading and diving manoeuvres are accomplished using four control surfaces. On surface MAYA communicates with the mother ship using a high speed radio link and uses GPS for navigation. During underwater... and velocity data, to perform control, guidance and navigation of the vehicle. Low level tasks like actuation and power monitoring are carried out using dedicated 8 bit microcontrollers. iX86 and the various microcontrollers are connected to each other using...

  20. Field Evaluation of the Sidestream Sensors for Filter/Separators and Clay Filters.

    Science.gov (United States)

    1987-02-01

    Report No. 552 OTC FILE COPY S ApOV FOR pffBU WAMES DISTRIBUTION UNUMITED FIELD EVALUATION OF THE SIDESTREAM SENSORS FOR FILTER/SEPARATORS AND CLAY FILTERS...SIDESTREA SENSORS FOR FILTER/SEPARATORS AND CLAY FILTERS (CRC PROJECT No. CA-47-70) IN FORMULATING AND APPROVING REPCRTS, THE APPROPRIATE COMMITTEE OF THE...noted that the filter/separator unit at Basle operated at an unusually high pressure drop. The deactivated coalescer was found to contain gummy

  1. From Maya Blue to 21st century materials -- a spectroscopic study

    Science.gov (United States)

    Manciu, Felicia; Reza, Layra; Torres, Brenda; Polette, Lori; Chianelli, Russell

    2006-10-01

    Maya Blue is a famous indigo-based pigment produced by the ancient Mayas. Samples for the present work are made by a synthetic route, and demonstrate similar chemical stability as the ancient Maya Blue samples. Since no direct proof exists that the indigo chemically binds to the inorganic palygorskite lattice, there is still controversy on the resting place of the indigo molecules; i.e. are they in the channels of palygorskite, on the surface, or both. Our analysis by FT-Raman and FT-IR spectroscopy proves the partial elimination of the selection rules for the centrosymmetric indigo, and shows the disappearance of the indigo N-H bonding, as the organic molecules incorporate into palygorskite material. Infrared data confirm the loss of zeolitic water and a partial removal of structural water after the heating process. Evidence of bonding between cationic aluminum and indigo through nitrogen is revealed by FT-Raman measurements. X-Ray photoemission spectroscopy and near-edge X-ray absorption fine structure studies performed at Stanford Synchrotron Radiation Laboratory support the aluminium bonding to the organic molecules. The oxygen carbonyl is also believed to interact with the metal.

  2. THE ASSISMENT OF MAYA VERNACULAR HERITAGE FROM UNIVERSE CONCEPT TO POVERTY CONCEPT

    Directory of Open Access Journals (Sweden)

    Aurelio Sánchez

    2014-08-01

    Full Text Available The traditional technique maya housing construction is the representation of the Mayan worldview, it is expressed through the name of each construction element meanings of the creation of the universe and man, is also referred to the body and the concept of a living. For many centuries it was the oral tradition and construction practices that kept this knowledge and knowing, until the process of deterioration with colonialism, the arrival of the Spanish was a watershed in its decline to the undervaluation and contempt. The international designations like vernacular architecture of little have served before the governmental programs that continue it cataloguing like noncompatible an inhabitable space with their criteria of “quality of life”, nor with the schemes of tie financing to industrialized materials. Recent proposals for housing support maya not provide its being as its spatial bioclimatic architecture and a way of life, encouraging new construction beyond its dynamic and undervalued the maya solar microhabitat. Urges a reassessment based on its original conception, in its sustainable architectural feature in your living space according to the social dynamics of its inhabitants and its recognition as a cultural heritage.

  3. Yellow fever: ecology, epidemiology, and role in the collapse of the Classic lowland Maya civilization.

    Science.gov (United States)

    Wilkinson, R L

    1995-07-01

    Mystery has long surrounded the collapse of the Classic lowland Mayan civilization of the Peten region in Guatemala. Recent population reconstructions derived from archaeological evidence from the central lowlands show population declines from urban levels of between 2.5 and 3.5 million to around 536,000 in the two hundred year interval between 800 A.D. and 1000 A.D., the period known as the Classic Maya Collapse. A steady, but lesser rate of population decline continued until the time of European contact. When knowledge of the ecology and epidemiology of yellow fever and its known mosquito vectors are compared with what is known of the ecological conditions of lowland Guatemala as modified by the Classic Maya, provocative similarities are observed. When infection and mortality patterns of more recent urban yellow fever epidemics are used as models for a possible series of Classic Maya epidemics, a correlation is noted between the modeled rate of population decline for a series of epidemics, and population decline figures reconstructed from archaeological evidence.

  4. Listening in the Pakal controversy: a matter of care in Ancient Maya studies.

    Science.gov (United States)

    Watson, Matthew C

    2014-12-01

    This article explores the fraught historical politics of a 20th-century controversy over a Classic Maya king. The controversy ostensibly concerned the age at death of a ruler discovered in 1952 in an elaborate sarcophagus at the Mexican site of Palenque. Combining osteological and epigraphic techniques, Mexican scholars estimated that the ruler died at about 40 or 50years of age. Two decades later, an emerging collective of US hieroglyph experts claimed to have determined the grammatical structure of Maya glyphs for the first time and reevaluated the sarcophagus inscriptions. They concluded that the king, given the name 'Pakal', lived a remarkably long life of 80years (603-683 CE). This reading sparked a controversy that would persist until 1999. At stake was not just how to tell the story of an ancient Maya lord, but who could tell it, with what evidence, and with what degree of certainty. The inclination of some Mexican archaeologists to adopt nationalist and Marxist orientations came into palpable tension with foreign scholars' liberal, universalist knowledge practices. To address this problem, I rethink Pakal's material mediation through bones and inscriptions as a 'matter of concern' (Bruno Latour) and 'matter of care' (Maria Puig de la Bellacasa). I show how these concepts facilitate the reconsideration of contradictory historical propositions as potential sites of coexistence among actors temporarily ill equipped to listen to each other's claims. Ultimately, I present 'listening' as a technique of cosmopolitical care that complements the extensive emphasis on speech and spokespersonship in Latourian cosmopolitics.

  5. Guatemala paleoseismicity: from Late Classic Maya collapse to recent fault creep

    Science.gov (United States)

    Brocard, Gilles; Anselmetti, Flavio S.; Teyssier, Christian

    2016-11-01

    We combine ‘on-fault’ trench observations of slip on the Polochic fault (North America-Caribbean plate boundary) with a 1200 years-long ‘near-fault’ record of seismo-turbidite generation in a lake located within 2 km of the fault. The lake record indicates that, over the past 12 centuries, 10 earthquakes reaching ground-shaking intensities ≥ VI generated seismo-turbidites in the lake. Seismic activity was highly unevenly distributed over time and noticeably includes a cluster of earthquakes spread over a century at the end of the Classic Maya period. This cluster may have contributed to the piecemeal collapse of the Classic Maya civilization in this wet, mountainous southern part of the Maya realm. On-fault observations within 7 km of the lake show that soils formed between 1665 and 1813 CE were displaced by the Polochic fault during a long period of seismic quiescence, from 1450 to 1976 CE. Displacement on the Polochic fault during at least the last 480 years included a component of slip that was aseismic, or associated with very light seismicity (magnitude 1 ky) punctuated by destructive earthquake clusters.

  6. Fat free mass explains the relationship between stunting and energy expenditure in urban Mexican Maya children.

    Science.gov (United States)

    Wilson, Hannah J; Dickinson, Federico; Hoffman, Daniel J; Griffiths, Paula L; Bogin, Barry; Varela-Silva, Maria Inês

    2012-09-01

    Childhood stunting has been associated with an increased risk of obesity in adulthood, but the causes are unclear. This study hypothesizes that stunting significantly reduces both resting and activity energy expenditure. To assess and describe energy expenditure of low socio-economic Maya children and to determine whether stunting is independently related to energy expenditure after controlling for lean mass. Thirty-three urban Maya children, 17 boys, aged 7-9 years, living in Merida, Mexico, were measured for height, weight and bioelectrical impedance analysis (BIA). Body composition was estimated from BIA. Energy expenditure was measured for one week using the Actiheart (combined heart rate and accelerometer). Stunting (height-for-age below the 5(th) percentile of NHANES III based references) affected 35% of these physically active children. Using multiple linear regression analysis, greater lean body mass predicted higher resting and activity energy expenditure. Stature was not a significant predictor of resting energy expenditure. A lower height-for-age z-score, but not stunting as a categorical variable, significantly predicted lower activity energy expenditure. The hypothesis that stunting reduces total energy expenditure (resting + active) in children is not supported. Rather, children with shorter stature and less lean body mass have lower total energy expenditure. Complex interactions between body size, body composition, and metabolic activity appear to elevate the risk for later life obesity in these Maya children.

  7. Mobility and Navigation among the Yucatec Maya: Sex Differences Reflect Parental Investment, Not Mating Competition.

    Science.gov (United States)

    Cashdan, Elizabeth; Kramer, Karen L; Davis, Helen E; Padilla, Lace; Greaves, Russell D

    2016-03-01

    Sex differences in range size and navigation are widely reported, with males traveling farther than females, being less spatially anxious, and in many studies navigating more effectively. One explanation holds that these differences are the result of sexual selection, with larger ranges conferring mating benefits on males, while another explanation focuses on greater parenting costs that large ranges impose on reproductive-aged females. We evaluated these arguments with data from a community of highly monogamous Maya farmers. Maya men and women do not differ in distance traveled over the region during the mate-seeking years, suggesting that mating competition does not affect range size in this monogamous population. However, men's regional and daily travel increases after marriage, apparently in pursuit of resources that benefit families, whereas women reduce their daily travel after marriage. This suggests that parental effort is more important than mating effort in this population. Despite the relatively modest overall sex difference in mobility, Maya men were less spatially anxious than women, thought themselves to be better navigators, and pointed more accurately to distant locations. A structural equation model showed that the sex by marital status interaction had a direct effect on mobility, with a weaker indirect effect of sex on mobility mediated by navigational ability.

  8. Forests, fields, and the edge of sustainability at the ancient Maya city of Tikal.

    Science.gov (United States)

    Lentz, David L; Dunning, Nicholas P; Scarborough, Vernon L; Magee, Kevin S; Thompson, Kim M; Weaver, Eric; Carr, Christopher; Terry, Richard E; Islebe, Gerald; Tankersley, Kenneth B; Grazioso Sierra, Liwy; Jones, John G; Buttles, Palma; Valdez, Fred; Ramos Hernandez, Carmen E

    2014-12-30

    Tikal has long been viewed as one of the leading polities of the ancient Maya realm, yet how the city was able to maintain its substantial population in the midst of a tropical forest environment has been a topic of unresolved debate among researchers for decades. We present ecological, paleoethnobotanical, hydraulic, remote sensing, edaphic, and isotopic evidence that reveals how the Late Classic Maya at Tikal practiced intensive forms of agriculture (including irrigation, terrace construction, arboriculture, household gardens, and short fallow swidden) coupled with carefully controlled agroforestry and a complex system of water retention and redistribution. Empirical evidence is presented to demonstrate that this assiduously managed anthropogenic ecosystem of the Classic period Maya was a landscape optimized in a way that provided sustenance to a relatively large population in a preindustrial, low-density urban community. This landscape productivity optimization, however, came with a heavy cost of reduced environmental resiliency and a complete reliance on consistent annual rainfall. Recent speleothem data collected from regional caves showed that persistent episodes of unusually low rainfall were prevalent in the mid-9th century A.D., a time period that coincides strikingly with the abandonment of Tikal and the erection of its last dated monument in A.D. 869. The intensified resource management strategy used at Tikal-already operating at the landscape's carrying capacity-ceased to provide adequate food, fuel, and drinking water for the Late Classic populace in the face of extended periods of drought. As a result, social disorder and abandonment ensued.

  9. Modern tree species composition reflects ancient Maya "forest gardens" in northwest Belize.

    Science.gov (United States)

    Ross, Nanci J

    2011-01-01

    Ecology and ethnobotany were integrated to assess the impact of ancient Maya tree-dominated home gardens (i.e., "forest gardens"), which contained a diversity of tree species used for daily household needs, on the modern tree species composition of a Mesoamerican forest. Researchers have argued that the ubiquity of these ancient gardens throughout Mesoamerica led to the dominance of species useful to Maya in the contemporary forest, but this pattern may be localized depending on ancient land use. The tested hypothesis was that species composition would be significantly different between areas of dense ancient residential structures (high density) and areas of little or no ancient settlement (low density). Sixty-three 400-m2 plots (31 high density and 32 low density) were censused around the El Pilar Archaeological Reserve in northwestern Belize. Species composition was significantly different, with higher abundances of commonly utilized "forest garden" species still persisting in high-density forest areas despite centuries of abandonment. Subsequent edaphic analyses only explained 5% of the species composition differences. This research provides data on the long-term impacts of Maya forests gardens for use in development of future conservation models. For Mesoamerican conservation programs to work, we must understand the complex ecological and social interactions within an ecosystem that developed in intimate association with humans.

  10. A review of WIPP (Waste Isolation Pilot Plant) repository clays and their relationship to clays of adjacent strata

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, J.L.; Kimball, K.M.; Stein, C.L.

    1990-12-01

    The Salado Formation is a thick evaporite sequence located in the Permian Delaware Basin of southeastern New Mexico. This study focuses on the intense diagenetic alteration that has affected the small amounts of clay, feldspar, and quartz washed into the basin during salt deposition. These changes are of more than academic interest since this formation also houses the WIPP (Waste Isolation Pilot Plant). Site characterization concerns warrant compiling a detailed data base describing the clays in and around the facility horizon. An extensive sampling effort was undertaken to address these programmatic issues as well as to provide additional insight regarding diagenetic mechanisms in the Salado. Seventy-five samples were collected from argillaceous partings in halite at the stratigraphic level of the Waste Isolation Pilot Plant (WIPP). These were compared with twenty-eight samples from cores of the Vaca Triste member of the Salado, a thin clastic unit at the top of the McNutt potash zone, and with a clay-rich sample from the lower contact of the Culebra Dolomite (in the overlying Rustler Formation). These settings were compared to assess the influence of differences in brine chemistry (i.e., halite and potash facies, normal to hypersaline marine conditions) and sediment composition (clays, sandy silt, dolomitized limestone) on diagenetic processes. 44 refs., 11 figs., 5 tabs.

  11. Thermal stability of PMMA–clay hybrids

    Indian Academy of Sciences (India)

    Tanushree Choudhury; Nirendra M Misra

    2010-04-01

    Materials with small particle size are being extensively used in composites and hybrid materials. Exfoliated clay–polymer hybrids show enhanced properties. Exfoliation of clay platelets can be affected by selecting dispersing agents. In the present work, clay dispersed by natural dispersant (soap stone powder), cetyl trimethyl ammonium bromide (CTAB) dispersed clay and acid clay (amorphous clay) are taken. They are then polymerized with poly methyl methacrylate (PMMA) by solution intercalation method. The thermal stability of these different clay–PMMA hybrids have been studied and compared with that of pure PMMA by differential scanning calorimeter (DSC). The bonding of clay with PMMA has been studied by IR. Morphology of clay–PMMA hybrids has been shown by SEM and XRD which indicate partially exfoliated structure in T606-4 and intercalated structures in T606-6 and T606-2.

  12. Mars, clays and the origins of life

    Science.gov (United States)

    Hartman, Hyman

    1989-01-01

    To detect life in the Martian soil, tests were designed to look for respiration and photosynthesis. Both tests (labeled release, LR, and pyrolytic release, PR) for life in the Martian soils were positive. However, when the measurement for organic molecules in the soil of Mars was made, none were found. The interpretation given is that the inorganic constituents of the soil of Mars were responsible for these observations. The inorganic analysis of the soil was best fitted by a mixture of minerals: 60 to 80 percent clay, iron oxide, quartz, and soluble salts such as halite (NaCl). The minerals most successful in simulating the PR and LR experiments are iron-rich clays. There is a theory that considers clays as the first organisms capable of replication, mutation, and catalysis, and hence of evolving. Clays are formed when liquid water causes the weathering of rocks. The distribution of ions such as aluminum, magnesium, and iron play the role of bases in the DNA. The information was stored in the distribution of ions in the octahedral and tetrahedral molecules, but that they could, like RNA and DNA, replicate. When the clays replicated, each sheet of clay would be a template for a new sheet. The ion substitutions in one clay sheet would give rise to a complementary or similar pattern on the clay synthesized on its surface. It was theorized that it was on the surface of replicating iron-rich clays that carbon dioxide would be fixed in the light into organic acids such as formic or oxalic acid. If Mars had liquid water during a warm period in its past, clay formation would have been abundant. These clays would have replicated and evolved until the liquid water was removed due to cooling of Mars. It is entirely possible that the Viking mission detected life on Mars, but it was clay life that awaits the return of water to continue its evolution into life based on organic molecules.

  13. Selective Clay Placement Within a Silicate-Clay Epoxy Blend Nanocomposite

    Science.gov (United States)

    Miller, Sandi G (Inventor)

    2013-01-01

    A clay-epoxy nanocomposite may be prepared by dispersing a layered clay in an alkoxy epoxy, such as a polypropylene oxide based epoxide before combining the mixture with an aromatic epoxy to improve the nanocomposite's thermal and mechanical properties.

  14. Ceramic clays from the western part of the Tamnava Tertiary Basin, Serbia: Deposits and clay types

    Directory of Open Access Journals (Sweden)

    Radosavljević Slobodan

    2014-01-01

    Full Text Available Based on geological, mineralogical, physical, chemical and technological investigations in the Tamnava Tertiary Basin near Šabac town (western Serbia, deposits of ceramic clays were studied. These ceramic clays are composed of kaolin-illite with a variable content of quartz, feldspars, mica, iron oxides and hydroxides, and organic matter. Four main types of commercial clays were identified: i red-yellow sandy-gravely (brick clays; ii grey-white poor sandy (ceramic clays; iii dark-carbonaceous (ceramic clays; and iv lamellar (“interspersed” fatty, poor sandy (highly aluminous and ferrous clays. Ceramic clays are defined as medium to high plastic with different ranges of sintering temperatures, which makes them suitable for the production of various kinds of materials in the ceramic industry. [Projekat Ministarstva nauke Republike Srbije, br. OI-176016

  15. El orientalismo como episteme: Frédéric de Waldeck y las ruinas mayas

    Directory of Open Access Journals (Sweden)

    Carolina Depetris

    2010-10-01

    Full Text Available Article in Spanish. Abtracts in English and Spanish.AbstractOne of the most persistent mysteries in America, has been the origin of vernacular peoples and their buildings. Elucidate such mysteries has been the aim of many voyageurs. Between 1832 and 1836, following the current of travellers such as Alexander von Humbold, Fréderic von Waldeck (supposedly an Czech Baron, found his way to sell an exploratory project regarding the Mayan ruins of Palenque and Uxmal, to the Mexican government. About this expedition, he leaves testimony in his numerous diaries which have remained inedited so far, and also in the book entitled Voyage pittoresque et archéologique dans la Province d’ Yucatan (1838. He essays in these writings to give some explanations about the origin of the Mayas. There, he continuously refers to Humboldt’s work. In a previous article, we saw how Weldeck assimilates the origin of the Mayas to one of the greatest biblical mysteries of historical root, as it is the one regarding the lost tribes of Israel. In this work, we present his second grand hypothesis: that one which links Yucatan to India, by means of interpreting and representing American reality having its definite “episteme” in European Orientalism.ResumenUno de los misterios más persistentes en América ha sido dilucidar el origen de los pueblos vernáculos y de sus edificios. Resolver ese misterio ha sido objetivo de numerosos viajeros. Entre 1832 y 1836, siguiendo la estela de viajeros como Alejandro de Humboldt, un supuesto barón checo, Frédéric de Waldeck, consigue vender al gobierno mexicano una empresa exploratoria por las ruinas mayas de Palenque y Uxmal. De esta expedición deja testimonio en numerosos diarios que permanecen inéditos hasta la fecha, y en el libro Voyage pittoresque et archéologique dans la Province d’ Yucatán (1838. En estos escritos ensaya algunas explicaciones sobre el origen de los mayas y, en sus disquisiciones y supuestos, hace

  16. The Maya Tropical Forest: Cascading Human impacts from Hillslopes to Floodplains

    Science.gov (United States)

    Beach, Timothy; Luzzadder-Beach, Sheryl; Doyle, Colin; Krause, Samantha; Brokaw, Nicholas; Yaeger, Jason

    2016-04-01

    We review the long-term human impact on fluvial systems in the Maya tropical forest region. Although most of this karstic region is drained by groundwater, the southern and coastal margins have several river systems that drain volcanic and metamorphic as well as sedimentary terrains. Some positive environmental impacts of Maya Civilization were the long-term impacts of both landesque capital, like wetland field systems, and other land uses that have enriched many soils. Some negative impacts included stripped soils and eutrophic rivers, both playing out again today with recent deforestation and intensive agriculture. We review trends in the region's fluvial systems, present new evidence on beneficial and detrimental impacts of Maya civilization, and present a new study using LiDAR mapping of fluvial geomorphology of the Belize River. Our new field research comes from the transboundary Rio Bravo watershed of Belize and Guatemala near the border with Mexico. This watershed today is mainly a well preserved tropical forest but from 3,000 to 1000 years ago was partly deforested by Maya cities, farms, roads, fires, and fields. We present studies of soils and sediment movement along slopes, floodplains, and water quality impacts of high dissolved loads of sulfate and calcium. We use AMS dates and soil stratigraphy to date slope and floodplain flux, and we use multiple proxies like pollen and carbon isotopes to reconstruct ancient land use. Aggradation in the floodplain and colluvial deposits began by at least 3,000 years ago and continued until 1100 years ago in several study sites. Some Classic period sites with peak human population and land use intensity experienced less soil erosion, perhaps due to soil conservation, post urban construction, and source reduction. Additional evidence suggests that ancient terraced sites and colluvial slopes that gained upslope sediment and soil nutrients from ancient Maya erosion had greater biodiversity. Lastly, we map fluvial

  17. Membrane behavior of clay liner materials

    Science.gov (United States)

    Kang, Jong Beom

    Membrane behavior represents the ability of porous media to restrict the migration of solutes, leading to the existence of chemico-osmosis, or the flow of liquid in response to a chemical concentration gradient. Membrane behavior is an important consideration with respect to clay soils with small pores and interactive electric diffuse double layers associated with individual particles, such as bentonite. The results of recent studies indicate the existence of membrane behavior in bentonite-based hydraulic barriers used in waste containment applications. Thus, measurement of the existence and magnitude of membrane behavior in such clay soils is becoming increasingly important. Accordingly, this research focused on evaluating the existence and magnitude of membrane behavior for three clay-based materials that typically are considered for use as liners for waste containment applications, such as landfills. The three clay-based liner materials included a commercially available geosynthetic clay liner (GCL) consisting of sodium bentonite sandwiched between two geotextiles, a compacted natural clay known locally as Nelson Farm Clay, and compacted NFC amended with 5% (dry wt.) of a sodium bentonite. The study also included the development and evaluation of a new flexible-wall cell for clay membrane testing that was used subsequently to measure the membrane behaviors of the three clay liner materials. The consolidation behavior of the GCL under isotropic states of stress also was evaluated as a preliminary step in the determination of the membrane behavior of the GCL under different effective consolidation stresses.

  18. The many ways of making anionic clays

    Indian Academy of Sciences (India)

    Michael Rajamathi; Grace S Thomas; P Vishnu Kamath

    2001-10-01

    Together with hydrotalcite-like layered double hydroxides, bivalent and trivalent metal hydroxides and their hydroxy salts are actually anionic clays consisting of positively charged hydroxide layers with anions intercalated in the interlayer region. The anionic clays exhibit anion sorption, anion diffusion and exchange properties together with surface basicity making them materials of importance for many modern applications. In this article, we discuss many different ways of making anionic clays and compare and contrast the rich diversity of this class of materials with the better-known cationic clays.

  19. Probing the water interactions in clay

    Energy Technology Data Exchange (ETDEWEB)

    Powell, D.H. [Lausanne Univ., Lausanne (Switzerland); Fischer, H.E. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Skipper, N.T. [Univ. College, London (United Kingdom)

    1999-11-01

    Clays, the microscopic mineral fraction of soils, are probably the most important substrate for interactions between water, the mineral world and the biosphere. A knowledge of the structuring of water and hydrated metal ions near clays surfaces is of importance in environmental science, including toxic and radioactive waste disposal, and in the industrial application of clays. The smectite clays, with their large hydrated internal surface areas represent excellent model systems for the interactions of aqueous phases with solid surface. We present the results of neutron diffraction experiments using isotopic substitutions to probe the structure in the aqueous interlayer region of Li-montmorillonite. (authors) 6 refs., 3 figs.

  20. "Yo Soy Indígena": Identifying and Using Traditional Ecological Knowledge (TEK) to Make the Teaching of Science Culturally Responsive for Maya Girls

    Science.gov (United States)

    Hamlin, Maria L.

    2013-01-01

    This study examines how traditional ecological knowledge--TEK--can be identified and utilized to create culturally responsive science learning opportunities for Maya girls from a community in the Guatemalan highlands. Maya girls are situated in a complex socio-historical and political context rooted in racism and sexism. This study contextualizes…

  1. "Yo Soy Indígena": Identifying and Using Traditional Ecological Knowledge (TEK) to Make the Teaching of Science Culturally Responsive for Maya Girls

    Science.gov (United States)

    Hamlin, Maria L.

    2013-01-01

    This study examines how traditional ecological knowledge--TEK--can be identified and utilized to create culturally responsive science learning opportunities for Maya girls from a community in the Guatemalan highlands. Maya girls are situated in a complex socio-historical and political context rooted in racism and sexism. This study contextualizes…

  2. Two Holocene paleofire records from Peten, Guatemala: Implications for natural fire regime and prehispanic Maya land use

    Science.gov (United States)

    Anderson, Lysanna; Wahl, David B.

    2016-01-01

    Although fire was arguably the primary tool used by the Maya to alter the landscape and extract resources, little attention has been paid to biomass burning in paleoenvironmental reconstructions from the Maya lowlands. Here we report two new well-dated, high-resolution records of biomass burning based on analysis of macroscopic fossil charcoal recovered from lacustrine sediment cores. The records extend from the early Holocene, through the full arc of Maya prehistory, the Colonial, and post-Colonial periods (~ 9000 cal yr BP to the present). (Hereafter BP) The study sites, Lago Paixban and Lago Puerto Arturo, are located in northern Peten, Guatemala. Results provide the first quantitative analysis from the region demonstrating that frequent fires have occurred in the closed canopy forests since at least the early Holocene (~ 9000 BP), prior to occupation by sedentary agriculturalists. Following the arrival of agriculture around 4600 BP, the system transitioned from climate controlled to anthropogenic control. During the Maya period, changes in fire regime are muted and do not appear to be driven by changes in climate conditions. Low charcoal influx and fire frequency in the Earliest Preclassic period suggest that land use strategies may have included intensive agriculture much earlier than previously thought. Preliminary results showing concentrations of soot/black-carbon during the middle and late Preclassic periods are lower than modern background values, providing intriguing implications regarding the efficiency of Maya fuel consumption.

  3. Is the onset of the 6th century 'dark age' in Maya history related to explosive volcanism?

    Science.gov (United States)

    Nooren, Kees; Hoek, Wim Z.; Van der Plicht, Hans; Sigl, Michael; Galop, Didier; Torrescano-Valle, Nuria; Islebe, Gerald; Huizinga, Annika; Winkels, Tim; Middelkoop, Hans; Van Bergen, Manfred

    2016-04-01

    Maya societies in Southern Mexico, Guatemala and Belize experienced a 'dark age' during the second half of the 6th century. This period, also known as the 'Maya Hiatus', is characterized by cultural downturn, political instability and abandonment of many sites in the Central Maya Lowlands. Many theories have been postulated to explain the occurrence of this 'dark age' in Maya history. A possible key role of a large volcanic eruption in the onset of this 'dark age' will be discussed. Volcanic deposits recovered from the sedimentary archive of lake Tuspán and the Usumacinta-Grijalva delta were studied in detail and the combination of multiple dating techniques allowed the reconstruction of the timing of a large 6th century eruption. Volcanic glass shards were fingerprinted to indicate the source volcano and high resolution pollen records were constructed to indicate the environmental impact of the eruption. Results are compared with available archaeological data and causality with the disruption of Maya civilization will be evaluated.

  4. Two Holocene paleofire records from Peten, Guatemala: Implications for natural fire regime and prehispanic Maya land use

    Science.gov (United States)

    Anderson, Lysanna; Wahl, David

    2016-03-01

    Although fire was arguably the primary tool used by the Maya to alter the landscape and extract resources, little attention has been paid to biomass burning in paleoenvironmental reconstructions from the Maya lowlands. Here we report two new well-dated, high-resolution records of biomass burning based on analysis of macroscopic fossil charcoal recovered from lacustrine sediment cores. The records extend from the early Holocene, through the full arc of Maya prehistory, the Colonial, and post-Colonial periods ( 9000 cal yr BP to the present). (Hereafter BP) The study sites, Lago Paixban and Lago Puerto Arturo, are located in northern Peten, Guatemala. Results provide the first quantitative analysis from the region demonstrating that frequent fires have occurred in the closed canopy forests since at least the early Holocene ( 9000 BP), prior to occupation by sedentary agriculturalists. Following the arrival of agriculture around 4600 BP, the system transitioned from climate controlled to anthropogenic control. During the Maya period, changes in fire regime are muted and do not appear to be driven by changes in climate conditions. Low charcoal influx and fire frequency in the Earliest Preclassic period suggest that land use strategies may have included intensive agriculture much earlier than previously thought. Preliminary results showing concentrations of soot/black-carbon during the middle and late Preclassic periods are lower than modern background values, providing intriguing implications regarding the efficiency of Maya fuel consumption.

  5. Chicanos: Mexicans in the United States. A Stepping-Stone Book.

    Science.gov (United States)

    Martin, Patricia Miles

    Written for second and third grade children, the book gives an account of Chicanos in the United States. Beginning with the Mayas, Toltecs, and Aztecs, it explains the history of Mexico, the Spanish conquest, and the northward movement of the "Mestizos". Subsequent chapters detail the immigration movement across the Rio Grande in search of work.…

  6. Consequences of preferential flow in cracking clay soils for contamination-risk of shallow aquifers

    NARCIS (Netherlands)

    Oostindie, K.; Bronswijk, J.J.B.

    1995-01-01

    A method is presented to asses the contamination risk of aquifers covered with cracking clay soils, with special emphasis on preferential flow through shrinkage cracks. A water extraction area was divided into units with homogeneous soil types and hydrological conditions. For each unit, a one-dimens

  7. Perceptions on Barriers to the Use of Burnt Clay Bricks for Housing Construction

    Directory of Open Access Journals (Sweden)

    Bernard K. Baiden

    2014-01-01

    Full Text Available Burnt clay bricks can be readily manufactured in Ghana as all ten regions have significant clay deposits with the Ashanti region having the highest estimated deposit of 37.1 million metric tonnes. In recent times, burnt clay bricks have been regarded as old fashioned and replaced by other perceived modern walling units within Kumasi, the metropolitan capital of Ashanti Region, despite its availability, unique advantages (aesthetics, low maintenance cost, etc., and structural and nonstructural properties. This study involved a questionnaire survey of 85 respondents made up of architects, brick manufacturing firms, and brick house owners or occupants in the Kumasi Metropolis of Ghana and sought to examine their perceptions on barriers to the use of burnt clay bricks for housing construction. The findings revealed that the key factors inhibiting the use of burnt clay bricks for housing construction are low material demand, excessive cost implications, inappropriate use in construction, noncompatibility of burnt clay bricks with other materials, unreliable production, and transportation problems. The findings however provide a platform for stakeholders to address the barriers to enable the extensive use of clay bricks in housing constructions.

  8. Clay membrane made of natural high plasticity clay

    DEFF Research Database (Denmark)

    Foged, Niels; Baumann, Jens

    1998-01-01

    has been evaluated using standardised methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15 to 0.3m thick clay membrane have been tested...... successfully. At natural watercontent w = 40 to 45% it is possible to establish a homogeneous membrane with hydraulic conductivity k tests used for establishing swell and deformation properties showed...... to be very dependent on the stress level. It varies from k = E-11 to 2 E-13 m/s at vertical stresses from 5 to 4800 kPa and is clearly related to a reduced effective porosity diminishing with stress. Preliminary diffusion tests indicate a similar influence on the effective diffusion coefficient being much...

  9. Painting with Clay Van Gogh Style.

    Science.gov (United States)

    Skophammer, Karen

    1999-01-01

    Discusses Vincent Van Gogh's painting "Starry Night" and describes a lesson where fifth- and sixth-grade students created their own version of the artwork. Explains that the students utilized four colors of Permoplast clay, using their hands and fingers as brushes and blending tools and the clay as paint. (CMK)

  10. Sectioning Clay Models Makes Anatomy & Development Tangible

    Science.gov (United States)

    Howell, Carina Endres; Howell, James Endres

    2010-01-01

    Clay models have proved to be useful teaching aids for many topics in biology that depend on three-dimensional reasoning. Students studying embryonic development struggle to mentally reconstruct the three-dimensional structure of embryos and larvae by observing prepared slides of cross-sectional slices. Students who build clay models of embryos…

  11. Quick clay and landslides of clayey soils

    NARCIS (Netherlands)

    Khaldoun, A.; Moller, P.; Fall, A.; Wegdam, G.; de Leeuw, B.; Méheust, Y.; Fossum, J.O.; Bonn, D.

    2009-01-01

    We study the rheology of quick clay, an unstable soil responsible for many landslides. We show that above a critical stress the material starts flowing abruptly with a very large viscosity decrease caused by the flow. This leads to avalanche behavior that accounts for the instability of quick clay s

  12. Moessbauer Spectra of Clays and Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, F. E.; Wagner, U. [Technische Universitaet Muenchen (Germany)

    2004-06-15

    The physical, chemical and mineralogical aspects of the use of Moessbauer spectroscopy in studies of clay-based ceramics are described. Moessbauer spectra of pottery clays fired under oxidising, reducing and changing conditions are explained, and the possibilities of using Moessbauer spectra to derive information on the firing temperatures and the kiln atmosphere during firing in antiquity are discussed and illustrated by examples.

  13. Dehydration-induced luminescence in clay minerals

    Science.gov (United States)

    Coyne, L. M.; Lahav, N.; Lawless, J. G.

    1981-01-01

    Reports of triboluminescent phenomena in organic crystalline materials prompted a search for related processes in clay minerals. The reported extensive mechanical distortion produced on freezing and drying of montmorillonite was particularly interesting because of studies of condensation reactions in a wet/dry cycled reaction sequence. The discovery of an unusual luminescent process in several clay minerals is reported and its characteristics are described.

  14. Análisis, estudio y conservación de los edificios astronómicos mayas. Arquitectura maya y urbanismo, una aproximación desde la astronomía y el paisaje.

    OpenAIRE

    MAY CASTILLO, MANUEL

    2016-01-01

    El presente trabajo representa el resultado final de seis años de investigación en la región maya y versa sobre las relaciones entre la arquitectura y el urbanismo con el paisaje y la astronomía. En una primera parte se presentan los fundamentos metódicos para el estudio de la arquitectura y el urbanismo maya, a partir de la lectura de los datos del paisaje circundante y las orientaciones arquitectónicas. A lo anterior se le suman los datos provistos por las fuentes pr...

  15. Las corridas de toros en los pueblos mayas orientales. Una aproximación etnográfica Bullfights at Eastern Maya Towns. An Etnographic Approach

    Directory of Open Access Journals (Sweden)

    Andrés Medina Hernández

    2010-01-01

    Full Text Available En este ensayo realizamos una descripción de las corridas de toros en los pueblos mayas del oriente de Yucatán; la intención principal es situar esta expresión festiva en el contexto de los rituales que configuran las fiestas patronales, de tal manera que se destaque un hecho central: la profunda transformación de una fiesta de claros orígenes ibéricos en una manifestación profundamente entramada con una visión del mundo de raíz mesoamericana. Un eje de análisis es el que corresponde a las nociones de sacrificio que articulan los acontecimientos en el coso taurino con los más discretos que suceden en el interior de las casas de los dirigentes de los gremios, donde el sacrificio de puercos y pavos constituye la base de una gastronomía ritual. Otro más es el reconocimiento de referentes simbólicos espaciales y temporales de raíz mesoamericana que subyacen en todo el conjunto ritual que compone estas celebraciones de los mayas peninsulares.In this essay we describe bullfighting among the Maya peoples in eastern Yucatan. The fundamental aim is to situate this festive expression in the context of the rituals that shape the patron feasts, so as to stress a central fact: the transformation of a feast of clear Iberian origin into a manifestation that is deeply intertwined with a world vision of Mesoamerican ancestry. An analytical axis corresponds to the notions of sacrifice that articulate the events inside the bullring with those more discrete, that take place within the homes of the leaders of the guilds. Here, sacrifice of turkeys and pigs constitute the basis of a ritual gastronomy. Another axis is the acknowledgement of symbolic space and time referents of Mesoamerican origin underlying, as a whole, the ritual compound in these peninsular Mayan celebrations.

  16. Active containment systems incorporating modified pillared clays

    Energy Technology Data Exchange (ETDEWEB)

    Lundie, P. [Envirotech (Scotland) Ltd., Aberdeen (United Kingdom)]|[Environmental Resource Industries Disposal Pty Ltd., Perth (Australia); McLeod, N. [Envirotreat Ltd., Kingswinford (United Kingdom)

    1997-12-31

    The application of treatment technologies in active containment systems provides a more advanced and effective method for the remediation of contaminated sites. These treatment technologies can be applied in permeable reactive walls and/or funnel and gate systems. The application of modified pillared clays in active containment systems provides a mechanism for producing permeable reactive walls with versatile properties. These pillared clays are suitably modified to incorporate reactive intercalatants capable of reacting with both a broad range of organic pollutants of varying molecular size, polarity and reactivity. Heavy metals can be removed from contaminated water by conventional ion-exchange and other reactive processes within the clay structure. Complex contamination problems can be addressed by the application of more than one modified clay on a site specific basis. This paper briefly describes the active containment system and the structure/chemistry of the modified pillared clay technology, illustrating potential applications of the in-situ treatment process for contaminated site remediation.

  17. Permeation properties of polymer/clay nanocomposites

    Science.gov (United States)

    Kalendova, A.; Merinska, D.; Gerard, J. F.

    2012-07-01

    The important characteristics of polymer/clay nanocomposites are stability, barrier properties and in the case of polyvinyl chloride also plasticizer migration into other materials. Therefore, the permeation properties of polymer/clay nanocomposites are discussed in this paper. The attention was focused to the polyethylene (PE) and polyvinyl chloride (PVC). Natural type of montmorillonite MMTNa+ and modified types of montmorillonite from Southern Clay Products were used as the inorganic phase. As the compounding machine, one screw Buss KO-kneader was employed. The principal aim is to fully exfoliate the clay into polymer matrix and enhanced the permeation properties. Prepared samples were tested for O2 and CO2 permeability. Polymer/clay nanocomposite structure was determined on the base of X-ray diffraction and electron microscopy (TEM).

  18. 1st International Conference on Calcined Clays for Sustainable Concrete

    CERN Document Server

    Favier, Aurélie

    2015-01-01

    This volume focuses on research and practical issues linked to Calcined Clays for Sustainable Concrete. The main subjects are geology of clays, hydration and performance of blended systems with calcined clays, alkali activated binders, economic and environmental impacts of the use of calcined clays in cement based materials. Topics addressed in this book include the influence of processing on reactivity of calcined clays, influence of clay mineralogy on reactivity, geology of clay deposits, Portland-calcined clay systems, hydration, durability, performance, Portland-calcined clay-limestone systems, hydration, durability, performance, calcined clay-alkali systems, life cycle analysis, economics and environmental impact of use of calcined clays in cement and concrete, and field applications. This book compiles the different contributions of the 1st International Conference on Calcined Clays for Sustainable Concrete, which took place in Lausanne, Switzerland, June, 23-25, 2015.The papers present the latest  res...

  19. Clay Dispersibility and Soil Friability-Testing the Soil Clay-to-Carbon Saturation Concept

    DEFF Research Database (Denmark)

    Schjønning, Per; de Jonge, Lis Wollesen; Munkholm, Lars Juhl;

    2012-01-01

    Soil organic carbon (OC) influences clay dispersibility, which affects soil tilth conditions and the risk of vertical migration of clay colloids. No universal lower threshold of OC has been identified for satisfactory stabilization of soil structure. We tested the concept of clay saturation with OC...... as a predictor of clay dispersibility and soil friability. Soil was sampled 3 yr in a field varying in clay content (∼100 to ∼220 g kg−1 soil) and grown with different crop rotations. Clay dispersibility was measured after end-over-end shaking of field-moist soil and 1- to 2-mm sized aggregates either air......-dried or rewetted to −100 hPa matric potential. Tensile strength of 1- to 2-, 2- to 4-, 4- to 8-, and 8- to 16-mm air-dried aggregates was calculated from their compressive strength, and soil friability estimated from the strength–volume relation. Crop rotation characteristics gave only minor effects on clay...

  20. Mineralogy and geotechnical characteristics of some pottery clay

    OpenAIRE

    Mujib Olamide ADEAGBO; Samuel Akinlabi OLA; Olumide Oluwapelumi OJURI

    2016-01-01

    The physical properties of soils, which are tremendously influenced by the active clay minerals in soil, are of great importance in geotechnical engineering. This paper investigates the clay-sized particles of the Igbara-Odo pottery clay, and compares results obtained with available data on the bulk sample, to determine their correlation and underline the dependence of the geotechnical properties of the bulk clay material on the clay-sized particles. The bulk clay sample consists of 52% sand-...

  1. Game Art Complete All-in-One; Learn Maya, 3ds Max, ZBrush, and Photoshop Winning Techniques

    CERN Document Server

    Gahan, Andrew

    2008-01-01

    A compilation of key chapters from the top Focal game art books available today - in the areas of Max, Maya, Photoshop, and ZBrush. The chapters provide the CG Artist with an excellent sampling of essential techniques that every 3D artist needs to create stunning game art. Game artists will be able to master the modeling, rendering, rigging, and texturing techniques they need - with advice from Focal's best and brightest authors. Artists can learn hundreds of tips, tricks and shortcuts in Max, Maya, Photoshop, ZBrush - all within the covers of one complete, inspiring reference

  2. Facial Expression Design Based on Maya%基于Maya的人物面部表情设计

    Institute of Scientific and Technical Information of China (English)

    赖传可

    2014-01-01

    Maya是现在最为流行的顶级3D动画软件。本文通过对卡通人物脸部模型的构建和面部表情的制作原理研究,然后运用Maya建立人物卡通模型,并制作出卡通的表情。%Maya is one of the most widely used 3D animation design software. With the help of Maya, this pa-per, by researching corresponding principles, establishes face models, as well as facial expressions of cartoon fig-ures.

  3. Quand les morts reviennent… Réflexion sur l’ancestralité chez les Mayas des Basses Terres

    OpenAIRE

    Le Guen, Olivier

    2014-01-01

    Quand les morts reviennent… Réflexion sur l’ancestralité chez les Mayas des Basses Terres. Le culte des ancêtres est souvent évoqué dans la littérature ethnologique amérindienne, sans que soit pourtant établie son existence. Cet article s’attache à montrer que certains groupes mayas des Basses Terres pratiquent un culte familial des ancêtres, dont le jour des morts, ou hanal pixan, apparaît comme la manifestation la plus prégnante. Nous fonderons notre raisonnement sur des critères précis emp...

  4. The Venus "Shell-over-Star" hieroglyph and Maya warfare: An examination of the interpretation of a Mayan symbol

    Science.gov (United States)

    Voit, Claudia Ann

    For decades, Maya scholars have associated the Mayan "Shell-Star" (also referred to as "Star-War") hieroglyph with Maya warfare. Put forward by scholars such as Floyd Lounsbury and David Kelley, and later advanced by Linda Schele, David Freidel, Ian Graham, Peter Matthews, Anthony Aveni and others, there are now dozens of published articles and chapters relating the hieroglyph to Venus and warfare. Venus is one of the most notable celestial objects outside of the Sun and Moon and was highly visible to the inhabitants of the Maya world. The Dresden Codex (an astronomical almanac) contains important information about the planet Venus, and the calendar section was deciphered by the librarian and mathematician, Ernst Förstemann in the late 1800s. In his decipherment, he deduced that the numbers contained in the tables must be connected to the orbital period of the planet. There is no other planet with the same orbital period 3 as Venus. Förstemann suggested that the decoded astronomy tables were used by the Maya to determine when to wage war. This interpretation, along with others, like Floyd Lounsbury`s study of Venus and the Long Count date at Bonampak were the seeds that have led to methodological errors that first began to take root in Maya research. The idea of the Venus association with warfare took hold and continues to propagate. Many scholars continue to assert that the "shell-star" glyph is related to warfare events. Others, like Gerardo Aldana, and Stanley Guenter, have recently come forward to reexamine and question the hieroglyph and its relationship, if any, to Maya warfare. I suggest, further, that methodological errors may have occurred along the way. I propose that these errors include data lost in translation, and inaccurate translations. In addition, the statistical analysis of Venus cycles has weak points. If this identification of the errors is correct, we need to re-evaluate the weakened foundation on which we are building our assertions about

  5. Las corridas de toros en los pueblos mayas orientales. Una aproximación etnográfica Bullfights at Eastern Maya Towns. An Etnographic Approach

    OpenAIRE

    Andrés Medina Hernández; Francisco Javier Rivas Cetina

    2010-01-01

    En este ensayo realizamos una descripción de las corridas de toros en los pueblos mayas del oriente de Yucatán; la intención principal es situar esta expresión festiva en el contexto de los rituales que configuran las fiestas patronales, de tal manera que se destaque un hecho central: la profunda transformación de una fiesta de claros orígenes ibéricos en una manifestación profundamente entramada con una visión del mundo de raíz mesoamericana. Un eje de análisis es el que corresponde a las no...

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

    Directory of Open Access Journals (Sweden)

    Margarita Rosales González

    2010-01-01

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

  7. SOBRE LA EDAD DE LOS HORNOS DE CAL EN EL ÁREA MAYA (About the age of the lime kilns in the Maya area

    Directory of Open Access Journals (Sweden)

    Soledad Ortiz Ruiz

    2015-12-01

    Full Text Available La investigación que presentamos es sobre el hallazgo y la datación arqueomagnética de hornos de cal en el área maya, México. La relevancia de la datación arqueomagnética consiste en localizar las construcciones arquitectónicas y dilucidar el periodo de utilización por las sociedades que habitaron la zona de ubicación de dichas construcciones. Asumimos que se trataba de hornos prehispánicos por su asociación con el contexto de la excavación. Sin embargo, los resultados de la combinación de dataciones y métodos arqueométricos permitieron ubicar estas estructuras en distintos periodos de utilización y, por tanto, asumir la continuidad de esta tecnología productiva más allá del periodo prehispánico. Asimismo los trabajos de datación nos permiten clarificar la utilización de esta tecnología y práctica productiva en dicha zona cultural. ENGLISH: The investigation presented here is related to the discovery and archaeomagnetic dating of lime kilns in the Maya area, Mexico. The relevance of such dating is to locate architectural constructions and elucidate the period of use by societies that are responsible for their construction. We assume a prehispanic period for the kilns because of their context within the excavation. The combination of dating methods and archaeometric experiments allowed the identification of different periods of use and, therefore, suggests the persistence of this production technology beyond the prehispanic period. Dating work also allows us to clarify the use of this technology and productive practices in this cultural area.

  8. Los dos cuerpos mayas: Esbozo de una antropología elemental indígena The two Maya bodies: An outline for an indigenous elemental Anthropology

    Directory of Open Access Journals (Sweden)

    Pedro Pitarch

    2011-01-01

    Full Text Available El propósito de este artículo es llamar la atención sobre la distinción indígena maya de dos clases de cuerpos humanos: uno carnal compartido con los animales y uno fenoménico específico de los seres humanos. Esta distinción resulta a su vez análoga a las dos clases de almas indígenas: una con la forma del cuerpo y otra con figura no humana, generalmente de algún animal. Semejante paralelismo entre cuerpos y almas me lleva a proponer una reorganización del concepto de persona en términos de un modelo cuaternario. Éste, sin dejar de ser fundamentalmente binario (cuerpo/alma, debe permitir integrar elementos que, como los dos cuerpos por una parte, y las dos almas por otra, se distinguen tanto como se requieren mutuamente para llegar a constituir la persona.The purpose of this paper is to draw attention to the indigenous Maya distinction between two types of human bodies: a carnal body, shared with animals, and a specifically human phenomenic body. This distinction, in turn, is equivalent to the indigenous distinction between two souls: a soul in a human shape and a soul in a non-human shape, generally of an animal species. The parallelism between bodies and souls leads me to propose a reorganization of the Mesoamerican concept of person in terms of a quaternary model which remains essentially binary (body/soul, yet permits the integration of elements which are different to each other, like the two bodies and the two souls, and yet mutually necessary to make up the person.

  9. El léxico cromático y la ideología maya Chromatic lexic and Maya ideology

    Directory of Open Access Journals (Sweden)

    Sanja Savkic

    2011-01-01

    Full Text Available Para acercarse al campo semántico de los colores, de primera importancia son diversos diccionarios de las lenguas mayances. El objetivo es hacer una descripción preliminar del vocabulario cromático, compuesto de cinco términos referidos a colores básicos que en el maya yucateco se llaman sak, ek', chak, k'an y ya'ax y significan "blanco", "negro", "rojo", "amarillo" y "verde-azul", respectivamente. El mismo vocabulario remite a determinadas categorías extralingüísticas que la lengua es capaz de acumular, reflejar y comunicar. Éstas dependen de una cultura particular, por lo que el estudio se amplía con las informaciones de diferentes fuentes escritas redactadas durante la época colonial. La intención es detectar los múltiples usos que se hacían en todos los ámbitos de la vida de los colores, lo cual a su vez permite considerar estos últimos como conceptualizaciones articuladas en pares de oposición o agrupamientos tripartitos.To gain greater insight into the color semantic field, it is important to consult various Mayance language dictionaries, in order to assemble a preliminary chromatic vocabulary, composed of five basic color terms which in Yucatec Maya are sak, ek', chak, k'an and ya'ax, or "white", "black", "red", "yellow" and "green-blue", respectively. The very vocabulary addresses certain extra-linguistic categories that language is capable of accumulating, reflecting, and communicating. These categories depend on a particular culture; consequently this study is amplified with greater information from different sources written during the colonial period in order to shed light on the many uses that the colors had in the aspects of human life which, at the same time, can be seen in conceptualizations articulated in pairs of opposition or tripartite groupings.

  10. Thermopreference, tolerance and metabolic rate of early stages juvenile Octopus maya acclimated to different temperatures.

    Science.gov (United States)

    Noyola, Javier; Caamal-Monsreal, Claudia; Díaz, Fernando; Re, Denisse; Sánchez, Adolfo; Rosas, Carlos

    2013-01-01

    Thermopreference, tolerance and oxygen consumption rates of early juveniles Octopus maya (O. maya; weight range 0.38-0.78g) were determined after acclimating the octopuses to temperatures (18, 22, 26, and 30°C) for 20 days. The results indicated a direct relationship between preferred temperature (PT) and acclimated temperature, the PT was 23.4°C. Critical Thermal Maxima, (CTMax; 31.8±1.2, 32.7±0.9, 34.8±1.4 and 36.5±1.0) and Critical Thermal Minima, (CTMin; 11.6±0.2, 12.8±0.6, 13.7±1.0, 19.00±0.9) increased significantly (P<0.05) with increasing acclimation temperatures. The endpoint for CTMax was ink release and for CTMin was tentacles curled, respectively. A thermal tolerance polygon over the range of 18-30°C resulted in a calculated area of 210.0°C(2). The oxygen consumption rate increased significantly α=0.05 with increasing acclimation temperatures between 18 and 30°C. Maximum and minimum temperature quotients (Q10) were observed between 26-30°C and 22-26°C as 3.03 and 1.71, respectively. These results suggest that O. maya has an increased capability for adapting to moderate temperatures, and suggest increased culture potential in subtropical regions southeast of México.

  11. Environmental and morphological changes around the Maritime Maya site Vista Alegre.

    Science.gov (United States)

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

    2016-04-01

    The untold story of the Maritime Maya from the ancient port site Vista Alegre, is being written for the first time using a multidisciplinary effort that aims to reconstruct the environmental and morphological history of the site. Vista Alegre is located on the north-eastern tip of the Yucatan peninsula, on the ancient Maritime Maya trade routes. This strategic point between the Caribbean Sea and the Gulf of Mexico, offers an ideal setting for this kind of research, which will add to the general Maritime Maya history. The multidisciplinary effort is part of a larger project called "Costa Escodida". The project's main goals are to learn how the ancient inhabitants adapted to the environment, and to understand how this coastal site was integrated into broader maritime trade routes. The portion of the research presented here concentrates on the sites geomorphology and climate during the past 2-3000 years through the multiproxy analysis of marine sediment core and surface samples combined with archaeological data. This study aids our understanding of the site's possible functions, the environmental challenges the local inhabits contended with, and the identification of ancient harboring locations. The site was inhabited from the 9th century B.C until the mid 16th century A.D., with an apparent two century abandonment phase from the mid 7th to 9th century A.D. According to the results, five depositional phases can be recognized, and the related shoreline reconstruction shows a general trend of a flooded terrestrial landscape. This 'flooding' relates well to relative sea-level curves published in the region. Continued analysis of results from the research, and future research activities, may make it possible to recognize hurricane proxies in the sediment, locate underwater manmade seafaring artifacts and facilities, determine the range of economic opportunities for past inhabitants and quantify the availability of potable water sources.

  12. A reassessment of the impact of drought cycles on the Classic Maya

    Science.gov (United States)

    Carleton, W. Christopher; Campbell, David; Collard, Mark

    2014-12-01

    The study reported here challenges the widely discussed hypothesis that cyclical droughts had a major impact on the Classic Maya. This hypothesis was developed by Hodell et al. (2001, 2005) on the basis of the results of time series analyses of cores from Lake Chichancanab in the Yucatán peninsula. Hodell et al.'s analyses indicated that the Maya region was affected by two drought cycles during the 1st millennium CE, one with a periodicity of 208 years and another with a periodicity of 50 years. The timing of the droughts was such, Hodell et al. argued, that they were likely responsible for several important sociopolitical events, including the collapse of Classic Maya society. In our study, we investigated two potentially important problems with Hodell et al.'s analyses: their use of interpolation to make their data regularly spaced, and their reliance on radiocarbon point estimates to generate age-depth models. We found that interpolation biased Hodell et al.'s results and that when it is avoided there is no evidence for a 208-year drought cycle in the Lake Chichancanab dataset. We also found that when the errors associated with the relevant radiocarbon dates are taken into account, there is no evidence for any drought cycles in the Lake Chichancanab dataset. Together, our analyses indicate that both the 208-year drought cycle and the 50-year drought cycle identified by Hodell et al. are methodological artifacts. The corollary of this is that the drought cycle hypothesis lacks an empirical basis and needs to be treated with skepticism.

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

    Science.gov (United States)

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

    2017-02-01

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

  14. Intergenerational changes in knee height among Maya mothers and their adult daughters from Merida, Mexico.

    Science.gov (United States)

    Azcorra, Hugo; RodrÍguez, Luis; Varela-Silva, Maria Inês; Datta Banik, Sudip; Dickinson, Federico

    2015-01-01

    To analyze differences in knee height (KH) between adult Maya mothers and daughters in Merida City, Mexico, and determine if these differences are associated with their childhood socioeconomic conditions. From September 2011 to January 2014, we measured KH and collected data on childhood conditions (place of birth, type of drinking water, family size, and fathers' occupation) from a sample of 180 Maya mother-daughter dyads. Mean KH intergenerational difference was calculated and compared for each category of socioeconomic variables and a multiple regression model was used to assess the association between childhood conditions and KH difference. A relative increase of 1.05 cm (SD = 2.3 cm) or 0.45 standard deviations (effect size of difference) was observed in KH between generations. Place of birth was significantly associated with KH. With three other variables statistically adjusted for, the intergenerational KH difference was 1.5 cm greater when mothers were born outside Merida but daughters were born in the city. Piped water consumption by mother-daughter dyads was associated with 1.5 cm of increase in KH difference compared with dyads who consumed well water (P = 0.058). The relative increase in KH between mothers and daughters represents a portion of the expected change in growth in a group that has experienced few substantial improvements in their living conditions. Some improvements in childhood living conditions resulting from the intergenerational transition from rural to urban environments seem to be linked to a modest, but statistically significant intergenerational increase in KH among Maya women in Merida. © 2015 Wiley Periodicals, Inc.

  15. Childhood body mass is positively associated with cesarean birth in Yucatec Maya subsistence farmers.

    Science.gov (United States)

    Veile, Amanda; Kramer, Karen L

    2017-03-01

    The epidemiologic link between cesarean birth and childhood obesity is unresolved, partly because most studies come from industrialized settings where many post-birth factors affect the risk for obesity. We take advantage of an unusual ethnographic situation where hospital and cesarean birth modes have recently been introduced among Yucatec Maya subsistence farmers, but young children have had minimal exposure to the nutritional transition. While we expect to find very low rates of childhood obesity, we predict that cesarean-born children will be larger and heavier than vaginally born children. Weight and height were collected monthly on 108 children aged 0-5 (3576 observations total). Birth mode and birthweight were collected by maternal interview. Data were analyzed using linear mixed models that compare child growth [Maya population-specific Z-scores for weight-for-age and body mass index-for-age (WAZ and BMIZ)] in cesarean and vaginally born children aged 0-5 years. The cesarean rate was 20%, no children were obese, and 5% were overweight. Cesarean birth was a significant predictor of child WAZ and BMIZ after accounting for maternal effects, child birthweight, and sex. Children who were born by cesarean to mothers with high BMI had the highest WAZ of all children by 5 years of age, and the highest BMIZ of all children at all ages. Cesarean-born Maya children had higher BMI than vaginally born children, even in the absence of many known confounding factors that contribute to childhood obesity. Child growth was most sensitive to birth mode when mothers had high BMI. © 2016 Wiley Periodicals, Inc.

  16. "Cuando alguien habla la Maya se nota que son pobres": Narrativas de identidad de los mayas yucatecos en torno a la radiodifusora indigenista La voz de los mayas, XEPET

    Directory of Open Access Journals (Sweden)

    Inés Cornejo Portugal

    2010-06-01

    Full Text Available En este trabajo se examinan las narrativas de identidad de los receptores culturales de la radiodifusora indigenista “La Voz de los Mayas, Xepet”, respecto de su relación con la oferta radiofónica de esta emisora ubicada en la cabecera municipal de Peto, al sur de Yucatán, México. El propósito es, por un lado, sistematizar, desde el análisis argumentativo, el uso, estructura y estrategias argumentativas de los maya hablantes radioescuchas de Xepet (bilingües o monolingües en torno a la oferta cultural de la misma, así como a la presencia cotidiana de esta emisora en su mundo de vida; y, por otro, reflexionar acerca de la radio indigenista en México como un recurso que podría contribuir a la “cultura de paz”.“U chíikul u t’aan maayao’ob” o “La voz de los mayas”, salió al aire el 29 de noviembre de 1982, en la frecuencia de los 740 khz de AM y fue reubicada al 730 en enero de 2001. Su área de cobertura abarca unos 100 km a la redonda, alcanzando cerca de mil comunidades de la península y parte de Quintana Roo, con una audiencia potencial de 500 mil personas. Su programación incluye géneros musicales y no musicales, compuestos estos últimos por programas informativos, de difusión cultural, servicio e infantiles. Xepet ha sido una de las radiodifusoras pioneras del sistema indigenista promovido por el Estado mexicano desde 1979, modelo que habría de extenderse en las más de veinte emisoras que aparecieron después. Hoy en día, la crítica respecto de la función, contenidos y operación de estas emisoras “oficiales” o “voceras del Gobierno” permanence, debido a que tanto la práctica indigenista como su experiencia radiofónica parecieran estar rebasadas por las demandas de los pueblos indios que reivindican su derecho a la libre determinación y a la autonomía, así como a la propiedad y gestión de sus propios medios de comunicación. Lo anterior reitera la necesidad de una propuesta radiof

  17. About the Glyph [T544.501] and the Classic Maya Geopolitical Communities

    Directory of Open Access Journals (Sweden)

    Rogelio Valencia Rivera

    2016-06-01

    Full Text Available This paper focuses on the Maya glyph [T544.501]. On one side the article offers a carefully review of the contexts where the hieroglyph appears for, from these, suggest that it may be a logogram with possible OCH ("entrance" reading. Moreover, considering the predominant appearance of this hieroglyph in contexts which relate to geopolitical groups, and beyond its phonetic value, the article also analyzes the historical dynamics that have experienced these Late Classic political groupings as narrate the texts where appears the glyph in question.

  18. Maya C++API开发自定义节点的简易方法

    Institute of Scientific and Technical Information of China (English)

    陈锋; 余颖; 张文俊; 张目

    2006-01-01

    Maya是目前最流行的三维设计软件之一,与其强大的三维制作功能一样,它的编程接口的性能也越来越完善。本文在深入剖析Maya C++API的基础上,结合实际应用,介绍一种简单而实用的Maya自定义节点的开发方法。

  19. La Blanca. La conservación y restauración de una ciudad Maya

    OpenAIRE

    Muñoz Cosme, Gaspar; Vidal Lorenzo, Cristina

    2006-01-01

    El proyecto La Blanca tiene como objetivo la excavación e investigación científica de una antigua ciudad maya situada en el Petén guatemalteco. Es un proyecto interdisciplinar en el que participan las Universidades de Valencia, San Carlos de Guatemala y Politécnica de Valencia a través de investigadores del Instituto de Restauración del Patrimonio. Desde el verano del año 2003, en que se realizaron las primeras prospecciones que dieron pie a la formulación del proyecto, se han realizado tres ...

  20. Dehydroindigo, the forgotten indigo and its contribution to the color of Maya Blue.

    Science.gov (United States)

    Rondão, Raquel; Seixas de Melo, J Sérgio; Bonifácio, Vasco D B; Melo, Maria J

    2010-02-04

    ), S(1), T(1). An additional study on the blue pigment Maya Blue was made, and the comparison between the solid-state spectra of indigo, DHI, and Maya Blue suggests that, in line with recent investigations, DHI is present together with indigo in Maya Blue. These results are relevant to the discussion of the involvement of dehydroindigo in the palette of colors of the ancient Maya Blue pigment.

  1. High-resolution speleothem record of precipitation from the Yucatan Peninsula spanning the Maya Preclassic Period

    Science.gov (United States)

    Medina-Elizalde, Martín; Burns, Stephen J.; Polanco-Martínez, Josué M.; Beach, Timothy; Lases-Hernández, Fernanda; Shen, Chuan-Chou; Wang, Hao-Cheng

    2016-03-01

    We produced a new high-resolution absolute U-Th dated stalagmite oxygen isotope record (δ18O) from Río Secreto, Playa del Carmen, Yucatan Peninsula (YP). This new 1434-year stalagmite record (named Itzamna after the Maya god of creation) spans the time interval between BCE 1037 and CE 397 with an average resolution of 8 ± 2 years. It provides a novel view of climate evolution over the Preclassic and early Classic periods in Maya history. To understand the controls of regional precipitation δ18O on seasonal time scales, we characterized the amount effect between precipitation amount (P) and precipitation δ18O (δP). We found that precipitation δ18O in the Yucatan Peninsula is controlled by the amount effect on seasonal scales (δP/ΔP = - 0.0137 ± 0.0031‰ per mm, r = 0.9), as suspected but never before demonstrated. Cave drip δ18O is consistent with the annual amount-weighted δ18O composition of precipitation. Multiple lines of evidence suggest that stalagmite δ18O reflects isotopic equilibrium conditions and thus stalagmite δ18O changes are interpreted to reflect precipitation amount. We determined quantitative precipitation changes from the stalagmite δ18O record following previous methods (Medina-Elizalde and Rohling, 2012). The stalagmite precipitation record suggests twelve periods of anomalous precipitation reductions ranging between about 30 and 70% below mean conditions at the time and with durations from 6 years to 31 years. Between BCE 520 and 166, the speleothem precipitation record suggests that the YP experienced an interval of high precipitation labeled the Late Preclassic Humid Period (LPHP) with precipitation maxima of up to + 86 ± 20%. Preclassic Maya cultural expansion in El Mirador Basin, located in northern Guatemala, took place while the peninsula transitioned from the LPHP to an interval with below average precipitation. We find that the Preclassic abandonment of major centers in the Mirador Basin and others around the Maya

  2. Los recursos marinos: una alternativa alimenticia para los mayas prehispánicos.

    OpenAIRE

    Quesada Domínguez, Ricardo Delfín

    2012-01-01

    Introducción Desde el punto de vista tradicional de que el maíz fue la piedra angular de la civilización prehispánica de los mayas de las tierras bajas puede ser erróneo. Investigaciones previas no tomaron en cuenta la posición geográfica peninsular de Yucatán y la riqueza de los recursos marinos disponibles. En este ensayo se examina la evidencia arqueológica, ecológica y documental para demostrar la utilización de subsistencia y religiosa de los recursos marinos, comparándolos con los datos...

  3. PIXE analysis on Maya blue in Prehispanic and colonial mural paintings

    Science.gov (United States)

    Sánchez del Río, M.; Martinetto, P.; Solís, C.; Reyes-Valerio, C.

    2006-08-01

    Particle induced X-ray emission (PIXE) experiments have been carried out at the AGLAE facility (Paris) on several mural samples containing Maya blue from different Prehispanic archaeological sites (Cacaxtla, El Tajín, Tamuin, Santa Cecilia Acatitlán) and from several colonial convents in the Mexican plateau (Jiutepec, Totimehuacán, Tezontepec and Cuauhtinchán). The analysis of the concentration of several elements permitted to extract some information on the technique used for painting the mural, usually fresco. Principal component analysis permitted to classify the samples into groups. This grouping is discussed in relation to geographic and historic data.

  4. Un estudio etnomatemático de las esteras (Pop) sagradas de los mayas

    OpenAIRE

    2006-01-01

    El contexto holístico de la etnomatemáticas busca estudiar, reflejar, y comprender las relaciones existentes entre los componentes del grupo cultural a través del análisis constante de cada individuo en el propio ambiente cultural. En este contexto, los mayas utilizaron padrones geométricos llamados de esteras o Pop que se tornaron sagrados. Esos padrones eran esculpidos en piedras, utilizados como joyas y dibujados en tejidos. Algunos objetos encontrados en México y en América Central muestr...

  5. Tratamiento del cuerpo y control social entre los mayas itzaes, siglos XVII-XVIII

    OpenAIRE

    Caso Barrera, Laura

    2015-01-01

    In many societies the human body is considered as a cosmological model and therefore of society. In the case of the Maya Itza we know that the human body is a reference to their territorial, social and religious organization. In this paper we analyze the importance of the human body as a symbolic model, focusing on aspects of Itza religion and rituals, related to the transformation and modification of the human body. We will analyze how Itza society controlled a population with the ability of...

  6. Mujeres mayas en Yucatán: experiencia participativa en una organización productiva

    OpenAIRE

    Amada Rubio-Herrera; María Teresa Castillo-Burguete

    2014-01-01

    Presentamos resultados de investigación sobre una experiencia participativa de un grupo de mujeres maya-yucatecas: Múuch’ Meyaj Ko’olelo’ob (mmk), dando cuenta del impacto que las intervenciones de un programa universitario tienen en la vida de ellas. Utilizamos un enfoque y técnicas cualitativas. La agrupación se integró como parte del fomento a empresas sociales de mujeres rurales, emprendido por el Sistema Nacional para el Desarrollo Integral de la Familia (dif) en 1997. Desde el inicio, s...

  7. Maya2012在教学中的几点思考

    Institute of Scientific and Technical Information of China (English)

    王美迎

    2012-01-01

    Maya是美国Autodesk公司出品的世界顶级的三维动画软件,应用对象是专业的影视广告,角色动画,电影特技等.Maya功能完善,工作灵活,易学易用,制作效率极高,渲染真实感极强,是电影级别的高端制作软件.本文就Maya2012学习过程中一些注意事项做了简单介绍.

  8. Las muchachas mayas de Yaxcabá, Yucatán

    Directory of Open Access Journals (Sweden)

    Maya Lorena Pérez Ruiz

    2017-01-01

    Full Text Available El tema de este artículo es el significado de ser mujer y ser joven en la cultura maya de Yucatán, México. Se presentan testimonios de muchachas de bachillerato del pueblo de Yaxcabá con el objetivo de conocer lo que para ellas significa ser mujer joven. Sus percepciones y sus proyectos de futuro se enmarcan en un campo de conflicto, en el que existe un enfrentamiento entre jóvenes y adultos para mantener o transformar los significados y las prácticas de ser joven.

  9. PIXE analysis on Maya blue in Prehispanic and colonial mural paintings

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez del Rio, M. [Departamento de Fisica, Universidad Autonoma Metropolitana, Iztapalapa, DF 09340 (Mexico); Martinetto, P. [Laboratoire de Cristallographie, CNRS, BP 166, F-30842 Grenoble (France); Solis, C. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Mexico, DF 04510 (Mexico)]. E-mail: corina@fisica.unam.mx; Reyes-Valerio, C. [Instituto Nacional de Antropologi' a e Historia, Mexico, DF (Mexico)

    2006-08-15

    Particle induced X-ray emission (PIXE) experiments have been carried out at the AGLAE facility (Paris) on several mural samples containing Maya blue from different Prehispanic archaeological sites (Cacaxtla, El Tajin, Tamuin, Santa Cecilia Acatitlan) and from several colonial convents in the Mexican plateau (Jiutepec, Totimehuacan, Tezontepec and Cuauhtinchan). The analysis of the concentration of several elements permitted to extract some information on the technique used for painting the mural, usually fresco. Principal component analysis permitted to classify the samples into groups. This grouping is discussed in relation to geographic and historic data.

  10. Civilización Maya (Uxmal-Chichén-Itzá)

    OpenAIRE

    2012-01-01

    Este artículo ofrece una caracterización general, en términos históricos, geográficos y culturales, de las ciudades mayas de Uxmal-Chichén-Itzá. Se adjuntan también dibujos que contienen la reproducción gráficas de templos, monumentos, pirámides, así como esquemas sobre la disposición y orientación espacial de varias construcciones.

  11. THE EFFECT OF CLAY DISPERSION ON THE CRYSTALLIZATION AND MORPHOLOGY OF POLYPROPYLENE/CLAY COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Qin Zhang; Xiao-lin Gao; Ke Wang; Qiang Fu

    2004-01-01

    PP/clay composites with different dispersions, namely, exfoliated dispersion, intercalated dispersion and agglomerates and panicle-like dispersion, were prepared by direct melt intercalation or compounding. The effect of clay dispersion on the crystallization and morphology of PP was investigated via PLM, SAXS and DSC. Experimental results show that exfoliated clay layers are much more efficient than intercalated clay and agglomerates of clay in serving as nucleation agent due to the nano-scale dispersion of clay, resulting in a dramatic decrease in crystal size (lamellar thickness and spherulites) and an increase of crystallization temperature and crystallization rate. On the other hand, a decrease of melting temperature and crystallinity was also observed in PP/clay composites with exfoliated dispersion, due to the strong interaction between PP and clay. Compared with exfoliated clay layers, the intercalated clay layers have a less important effect on the crystallization and crystal morphology. No effect is seen for samples with agglomerates and panicle-like dispersion, in regard to melting temperature, crystallization temperature, crystal thickness and crystallinity.

  12. Some Tests on Heather Field Moraine Clay

    DEFF Research Database (Denmark)

    Jørgensen, Mogens B.; Jacobsen, Moust

    This report deals with oedometer tests on three samples of moraine clay from the Heather Field in the English part of the North Sea. The tests have been carried out in the very unelastic apparatus used in Denmark and with special test procedures differing from the ones used elsewhere. In Denmark...... the English North Sea moraine clays with the corresponding Danish Moraine Clays. The Danish test procedures are explained in details and some comments are given in the hope that they may not be banalities all of them....

  13. Ni clay neoformation on montmorillonite surface.

    Science.gov (United States)

    Dähn, R; Scheidegger, A; Manceau, A; Schlegel, M; Baeyens, B; Bradbury, M H

    2001-03-01

    Polarized extended X-ray absorption fine structure spectroscopy (P-EXAFS) was used to study the sorption mechanism of Ni on the aluminous hydrous silicate montmorillonite at high ionic strength (0.3 M NaClO4), pH 8 and a Ni concentration of 0.66 mM. Highly textured self-supporting clay films were obtained by slowly filtrating a clay suspension after a reaction time of 14 days. P-EXAFS results indicate that sorbed Ni has a Ni clay-like structural environment with the same crystallographic orientation as montmorillonite layers.

  14. Sustaining Rainforest Plants, People and Global Health: A Model for Learning from Traditions in Holistic Health Promotion and Community Based Conservation as Implemented by Q’eqchi’ Maya Healers, Maya Mountains, Belize

    Directory of Open Access Journals (Sweden)

    Pablo Sanchez-Vindas

    2010-10-01

    Full Text Available The present work showcases a model for holistic, sustainable healthcare in indigenous communities worldwide through the implementation of traditional healing practices. The implementation of this model promotes public health and community wellness while addressing crucially important themes such as in situ and ex situ conservation of medicinal plant resources and associated biodiversity, generational transmission of knowledge, and the preservation of biological and cultural diversity for future generations. Being envisaged and implemented by Q’eqchi’ Maya traditional healers of the southern Maya Mountains, Belize, this model can be replicated in other communities worldwide. A ethnobotany study in collaboration with these healers led to collection of 102 medicinal species from Itzama, their traditional healing cultural center and medicinal garden. Of these 102 species, 40 of prior reported 106 consensus study plants were present in the garden. There were 62 plants not previously reported growing in the garden as well. A general comparison of these plants was also made in relation to species reported in TRAMIL network, Caribbean Herbal Pharmacopoeia (CHP, the largest regional medicinal pharmacopoeia. A relative few species reported here were found in the CHP. However, the majority of the CHP plants are common in Belize and many are used by the nearby Mopan and Yucatec Maya. Since these 102 species are relied upon heavily in local primary healthcare, this Q’eqchi’ Maya medicinal garden represents possibilities toward novel sustainable, culturally relative holistic health promotion and community based conservation practices.

  15. Clay Pots. Third World Science.

    Science.gov (United States)

    Jones, Natalie; Hughes, Wyn

    This unit, developed by the Third World Science Project, is designed to add a multicultural element to existing science syllabi (for students aged 11-16) in the United Kingdom. The project seeks to develop an appreciation of the: boundless fascination of the natural world; knowledge, skills, and expertise possessed by men/women everywhere;…

  16. High resolution stalagmite climate record from the Yucatán Peninsula spanning the Maya terminal classic period

    Science.gov (United States)

    Medina-Elizalde, Martín; Burns, Stephen J.; Lea, David W.; Asmerom, Yemane; von Gunten, Lucien; Polyak, Victor; Vuille, Mathias; Karmalkar, Ambarish

    2010-09-01

    The decline of the Classic Maya civilization was complex and geographically variable, and occurred over a ~ 150-year interval, known as the Terminal Classic Period (TCP, C.E. 800-950). Paleoclimate studies based on lake sediments from the Yucatán Peninsula lowlands suggested that drought prevailed during the TCP and was likely an important factor in the disintegration of the Classic Maya civilization. The lacustrine evidence for decades of severe drought in the Yucatán Peninsula, however, does not readily explain the long 150-year socio-political decline of the Classic Maya civilization. Here we present a new, absolute-dated, high-resolution stalagmite δ18O record from the northwest Yucatán Peninsula that provides a much more detailed picture of climate variability during the last 1500 years. Direct calibration between stalagmite δ18O and rainfall amount offers the first quantitative estimation of rainfall variability during the Terminal Classic Period. Our results show that eight severe droughts, lasting from 3 to 18 years, occurred during major depopulation events of Classic Maya city-states. During these droughts, rainfall was reduced by 52% to 36%. The number and short duration of the dry intervals help explain why the TCP collapse of the Mayan civilization occurred over 150 years.

  17. A comparative approach toward understanding the Mycenaean and Late Preclassic lowland Maya early civilisations through their art styles.

    NARCIS (Netherlands)

    Bajema, Marcus Jan

    2015-01-01

    My thesis provides a comparative analysis of early cilivilisations through archaeological sources. The two selected cases are Mycenaean Greece and the Late Preclassic lowland Maya. Specifically the study focuses on art and its role in social life of the two cases. Major methodological reflections

  18. Translating Maya Angelou's Theme, "We are more alike, my friends/Than we are unalike," into Effective Multicultural Study.

    Science.gov (United States)

    Neman, Beth S.

    Few would disagree that the essential purpose in multicultural studies is to promote compassionate understanding and to diminish hatred. The two basic approaches to this goal, celebrating differences and emphasizing unity, are suggested by Maya Angelou in her poem, "The Human Family." Most university courses do a good job of honoring…

  19. Mullins' effect in polymer/clay nanocomposites

    DEFF Research Database (Denmark)

    Drozdov, Aleksey; Christiansen, Jesper de Claville; Klitkou, Rasmus

    2012-01-01

    Abstract. Experimental data are reported on polypropylene/clay nanocomposites in uniaxial cyclic tensile tests at room temperature (oscillations between maximum strains and the zero minimum stress with maximum strains increasing monotonically with number of cycles). Observations reveal fading...

  20. Toward Accurate Adsorption Energetics on Clay Surfaces

    CERN Document Server

    Zen, Andrea; Cox, Stephen J; Hu, Xiao L; Sorella, Sandro; Alfè, Dario; Michaelides, Angelos

    2016-01-01

    Clay minerals are ubiquitous in nature, and the manner in which they interact with their surroundings has important industrial and environmental implications. Consequently, a molecular-level understanding of the adsorption of molecules on clay surfaces is crucial. In this regard computer simulations play an important role, yet the accuracy of widely used empirical force fields (FF) and density functional theory (DFT) exchange-correlation functionals is often unclear in adsorption systems dominated by weak interactions. Herein we present results from quantum Monte Carlo (QMC) for water and methanol adsorption on the prototypical clay kaolinite. To the best of our knowledge, this is the first time QMC has been used to investigate adsorption at a complex, natural surface such as a clay. As well as being valuable in their own right, the QMC benchmarks obtained provide reference data against which the performance of cheaper DFT methods can be tested. Indeed using various DFT exchange-correlation functionals yields...

  1. Mullins' effect in polymer/clay nanocomposites

    DEFF Research Database (Denmark)

    Drozdov, Aleksey; Christiansen, Jesper de Claville; Klitkou, Rasmus

    2012-01-01

    Abstract. Experimental data are reported on polypropylene/clay nanocomposites in uniaxial cyclic tensile tests at room temperature (oscillations between maximum strains and the zero minimum stress with maximum strains increasing monotonically with number of cycles). Observations reveal fading of ...

  2. The Basics in Pottery: Clay and Tools.

    Science.gov (United States)

    Larson, Joan

    1985-01-01

    Art teachers at the middle school or junior high school level usually find themselves in a program teaching ceramics. The most essential tools needed for a ceramics class are discussed. Different kinds of clay are also discussed. (RM)

  3. Speech and gesture in spatial language and cognition among the Yucatec Mayas.

    Science.gov (United States)

    Le Guen, Olivier

    2011-07-01

    In previous analyses of the influence of language on cognition, speech has been the main channel examined. In studies conducted among Yucatec Mayas, efforts to determine the preferred frame of reference in use in this community have failed to reach an agreement (Bohnemeyer & Stolz, 2006; Levinson, 2003 vs. Le Guen, 2006, 2009). This paper argues for a multimodal analysis of language that encompasses gesture as well as speech, and shows that the preferred frame of reference in Yucatec Maya is only detectable through the analysis of co-speech gesture and not through speech alone. A series of experiments compares knowledge of the semantics of spatial terms, performance on nonlinguistic tasks and gestures produced by men and women. The results show a striking gender difference in the knowledge of the semantics of spatial terms, but an equal preference for a geocentric frame of reference in nonverbal tasks. In a localization task, participants used a variety of strategies in their speech, but they all exhibited a systematic preference for a geocentric frame of reference in their gestures.

  4. Testing the ``tropical storm'' hypothesis of Yucatan Peninsula climate variability during the Maya Terminal Classic Period

    Science.gov (United States)

    Medina-Elizalde, Martín; Polanco-Martínez, Josué Moises; Lases-Hernández, Fernanda; Bradley, Raymond; Burns, Stephen

    2016-09-01

    We examine the "tropical storm" hypothesis that precipitation variability in the Yucatan Peninsula (YP) was linked to the frequency of tropical cyclones during the demise of the Classic Maya civilization, in the Terminal Classic Period (TCP, AD 750-950). Evidence that supports the hypothesis includes: (1) a positive relationship between tropical storm frequency and precipitation amount over the YP today (proof of feasibility), (2) a statistically significant correlation between a stalagmite (Chaac) quantitative precipitation record from the YP and the number of named tropical cyclones affecting this region today (1852-2004) (calibration sensu lato), and, (3) correlations between the stalagmite Chaac precipitation record and an Atlantic basin tropical cyclone count record and two proxy records of shifts in macro-scale climate and ocean states that influence Atlantic tropical cyclongenesis. At face value, regional paleotempestology proxy records suggest that tropical storm activity in the YP was either similar or significantly lower than today during the TCP. The "tropical storm" hypothesis has implications for our understanding of the role the hydrological cycle played in the collapse of Classic Maya polities and the role of tropical storms in possibly ameliorating future drought in the YP and other tropical regions.

  5. Conceptualizing socio-hydrological drought processes: the rise and fall of the Ancient Maya civilization

    Science.gov (United States)

    Kuil, Linda; Carr, Gemma; Viglione, Alberto; Prskawetz, Alexia; Bloeschl, Guenter

    2016-04-01

    Different communities have followed different paths to arrive at their present situation as a consequence of the continuous, specific interactions between the hydrological and social system. The need to understand the current and future pathways to water security becomes more and more pressing, considering the increasingly delicate balance between water demand and water supply. To contribute to addressing this challenge, we examine the link between water stress and society through socio-hydrological modeling. Within the spirit of the Easter Island model by Brander and Taylor and drawing from the vulnerability literature, we conceptualize the interactions of an agricultural society with its environment. We apply the model to the case of the ancient Maya, a civilization who occupied the Maya Lowlands (parts of present day Mexico, Guatemala, Belize) from around 2000 BC to after AD 830. The hypothesis that modest drought periods played a major role in the fall of the society is explored. We are able to simulate plausible feedbacks and find that a modest reduction in rainfall is a necessary, but not a sufficient condition in order to observe a collapse of 80 percent of the population. Equally important are actual population density and the impact of drought on crop growth. The model shows that reservoirs allow the society to grow larger, but also that the vulnerability to drought increases.

  6. Digestive Physiology of Octopus maya and O. mimus: Temporality of Digestion and Assimilation Processes.

    Science.gov (United States)

    Gallardo, Pedro; Olivares, Alberto; Martínez-Yáñez, Rosario; Caamal-Monsreal, Claudia; Domingues, Pedro M; Mascaró, Maite; Sánchez, Ariadna; Pascual, Cristina; Rosas, Carlos

    2017-01-01

    Digestive physiology is one of the bottlenecks of octopus aquaculture. Although, there are successful experimentally formulated feeds, knowledge of the digestive physiology of cephalopods is fragmented, and focused mainly on Octopus vulgaris. Considering that the digestive physiology could vary in tropical and sub-tropical species through temperature modulations of the digestive dynamics and nutritional requirements of different organisms, the present review was focused on the digestive physiology timing of Octopus maya and Octopus mimus, two promising aquaculture species living in tropical (22-30°C) and sub-tropical (15-24°C) ecosystems, respectively. We provide a detailed description of how soluble and complex nutrients are digested, absorbed, and assimilated in these species, describing the digestive process and providing insight into how the environment can modulate the digestion and final use of nutrients for these and presumably other octopus species. To date, research on these octopus species has demonstrated that soluble protein and other nutrients flow through the digestive tract to the digestive gland in a similar manner in both species. However, differences in the use of nutrients were noted: in O. mimus, lipids were mobilized faster than protein, while in O. maya, the inverse process was observed, suggesting that lipid mobilization in species that live in relatively colder environments occurs differently to those in tropical ecosystems. Those differences are related to the particular adaptations of animals to their habitat, and indicate that this knowledge is important when formulating feed for octopus species.

  7. Pathoecology and paleodiet in Postclassic: Historic Maya from northern coastal Belize

    Directory of Open Access Journals (Sweden)

    Christine White

    2006-12-01

    Full Text Available This paper examines the synergism among diet, disease, and ecology at two related coastal Maya sites in Belize (Marco Gonzalez and San Pedro for the Postclassic and Historic periods (1350-1650 AD, which immediately follow the Classic period collapse. Stable carbon- and nitrogen-isotope ratios in collagen and stable carbon-isotope ratios in structural carbonate were analysed for bones from 65 humans and a wide variety of faunal species. There are no apparent differences in whole diets or degree of carnivory between individuals with lesions indicative of anemia and those without, but those with lesions appear to have consumed significantly more C4 foods and protein from lower trophic levels. Non-specific infection (periostitis and vitamin C deficiency (scurvy are also present in high frequencies and appear to co-occur with lesions indicative of anemia, particularly in childhood. Individuals with scurvy also appear to have consumed significantly more C4 foods than normal individuals. Spondyloarthropathy is common in adults. These findings are discussed in light of: (1 the debate on how anemia versus scurvy are manifest and diagnosed, (2 Spanish ethnohistoric descriptions of the poor state of Maya health at the time of contact, and (3 the Osteological Paradox. We suggest that although this coastal environment exacerbated morbidity because of possible parasitic infection, the inhabitants were probably able to survive physiological stresses better than either their inland contemporaries or their modern counterparts.

  8. Endothelial Nitric Oxide Synthase Haplotypes Are Associated with Preeclampsia in Maya Mestizo Women

    Science.gov (United States)

    Díaz-Olguín, Lizbeth; Coral-Vázquez, Ramón Mauricio; Canto-Cetina, Thelma; Canizales-Quinteros, Samuel; Ramírez Regalado, Belem; Fernández, Genny; Canto, Patricia

    2011-01-01

    Preeclampsia is a specific disease of pregnancy and believed to have a genetic component. The aim of this study was to investigate if three polymorphisms in eNOS or their haplotypes are associated with preeclampsia in Maya mestizo women. A case-control study was performed where 127 preeclamptic patients and 263 controls were included. Genotyped and haplotypes for the -768T→C, intron 4 variants, Glu298Asp of eNOS were determined by PCR and real-time PCR allelic discrimination. Logistic regression analysis with adjustment for age and body mass index (BMI) was used to test for associations between genotype and preeclampsia under recessive, codominant and dominant models. Pairwise linkage disequilibrium between single nucleotide polymorphisms was calculated by direct correlation r2, and haplotype analysis was conducted. Women homozygous for the Asp298 allele showed an association of preeclampsia. In addition, analysis of the haplotype frequencies revealed that the -786C-4b-Asp298 haplotype was significantly more frequent in preeclamptic patients than in controls (0.143 vs. 0.041, respectively; OR = 3.01; 95% CI = 1.74–5.23; P = 2.9 × 10−4). Despite the Asp298 genotype in a recessive model associated with the presence of preeclampsia in Maya mestizo women, we believe that in this population the -786C-4b-Asp298 haplotype is a better genetic marker. PMID:21897002

  9. DIGITAL PRESERVATION OF ANCIENT MAYA CAVE ARCHITECTURE: RECENT FIELD EFFORTS IN QUINTANA ROO, MEXICO

    Directory of Open Access Journals (Sweden)

    D. Rissolo

    2017-08-01

    Full Text Available The presence of ancient Maya shrines in caves serves as unequivocal evidence for the ritual appropriation of these subterranean spaces and their significance with respect to Maya religious practice. Detailed study of the miniature masonry temples and altar features in the caves of Quintana Roo, Mexico reveals a strong stylistic and likely functional correspondence between these structures and their terrestrial counterparts at Postclassic sites. The Proyecto Arquitectura Subterranea de Quintana Roo (coordinated by the Center of Interdisciplinary Science for Art, Architecture, and Archaeology, or CISA3, at the University of California, San Diego and in collaboration with the Instituto Nacional de Antropologia e Historia in Mexico is conducting a survey and program of digital documentation of both the pristine and impacted cave shrines of the region. Once an area is developed and populated, and access is opened to caves containing ancient architectural features, they are soon vandalized – often resulting in the complete obliteration of these rare miniature buildings and their diagnostic architectural elements. This emergent situation necessitates the use of rapid reality-capture tools; however, the physical challenges of working in caves requires researchers of adapt increasingly common architectural documentation methodologies to more adverse field conditions.

  10. Digital Preservation of Ancient Maya Cave Architecture: Recent Field Efforts in Quintana Roo, Mexico

    Science.gov (United States)

    Rissolo, D.; Lo, E.; Hess, M. R.; Meyer, D. E.; Amador, F. E.

    2017-08-01

    The presence of ancient Maya shrines in caves serves as unequivocal evidence for the ritual appropriation of these subterranean spaces and their significance with respect to Maya religious practice. Detailed study of the miniature masonry temples and altar features in the caves of Quintana Roo, Mexico reveals a strong stylistic and likely functional correspondence between these structures and their terrestrial counterparts at Postclassic sites. The Proyecto Arquitectura Subterranea de Quintana Roo (coordinated by the Center of Interdisciplinary Science for Art, Architecture, and Archaeology, or CISA3, at the University of California, San Diego and in collaboration with the Instituto Nacional de Antropologia e Historia in Mexico) is conducting a survey and program of digital documentation of both the pristine and impacted cave shrines of the region. Once an area is developed and populated, and access is opened to caves containing ancient architectural features, they are soon vandalized - often resulting in the complete obliteration of these rare miniature buildings and their diagnostic architectural elements. This emergent situation necessitates the use of rapid reality-capture tools; however, the physical challenges of working in caves requires researchers of adapt increasingly common architectural documentation methodologies to more adverse field conditions.

  11. Jugadores de pelota maya en tiempos del oxlajuj b’ak’tún

    Directory of Open Access Journals (Sweden)

    Jairzinho Francisco Panqueba Cifuentes

    2012-12-01

    Full Text Available La presente reflexión hace parte de un proceso investigativo cuyo objeto ha sido la práctica contemporánea del juego de pelota maya en Guatemala. Es un acercamiento analítico a los testimonios de vida recabados a través de la metodología de investigación-aprehendizaje compartida con los actores del proceso. Sus trayectorias vitales nos permiten comprender en descripciones y acciones, los detalles contemporáneos de una manifestación cultural, lúdica y recreativa ancestral. Pero también de qué maneras el juego de pelota mesoamericano es fuente de conocimientos de los patrimonios corporales hasta ahora difusos entre discursos relacionados con el folclor, las etnicidades, las artes, el deporte, la cultura, las espiritualidades y en general con ciencias como la historia, la antropología y la arqueología. Las vidas cotidianas de los actuales jugadores de pelota ayudan a comprender una parte de las sabidurías ancestrales mayas. Se integran, por tanto, a los testimonios de las herencias inmateriales arqueológicas representadas en los campos de juego de pelota diseminados por Mesoamérica.

  12. Tratamiento del cuerpo y control social entre los mayas itzaes, siglos XVII-XVIII

    Directory of Open Access Journals (Sweden)

    Caso Barrera, Laura

    2015-12-01

    Full Text Available In many societies the human body is considered as a cosmological model and therefore of society. In the case of the Maya Itza we know that the human body is a reference to their territorial, social and religious organization. In this paper we analyze the importance of the human body as a symbolic model, focusing on aspects of Itza religion and rituals, related to the transformation and modification of the human body. We will analyze how Itza society controlled a population with the ability of transfiguration.En diversas sociedades el cuerpo humano se ha concebido como un modelo cosmológico y por lo tanto de la sociedad. En el caso de los mayas itzaes sabemos que el cuerpo humano es un referente para la organización territorial, social y religiosa. En este trabajo se analiza la importancia del cuerpo humano como modelo simbólico, centrándonos en aspectos de la religión y rituales itzaes relacionados con la transformación y modificación del cuerpo humano en el período colonial. Se examina el control que ejerció la sociedad itzá con respecto a una población con la capacidad de transfiguración.

  13. MAYA: An active target detector for the study of extremely exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Savajols, H. [GANIL - Bd Henri Becquerel, BP 55027, 14076 Caen Cedex 05 (France)], E-mail: savajols@ganil.fr; Demonchy, C.E. [CENBG Bordeaux, Chemin du Solarium, 33175 Gradignan Cedex (France); Mittig, W. [GANIL - Bd Henri Becquerel, BP 55027, 14076 Caen Cedex 05 (France); Caamano, M. [University of Santiago de Compostela, Dept. of Physics, E-15782, Santiago de Compostela Spain (Spain); Chartier, M. [University of Liverpool, Oliver Loge Laboratory, L69 7ZE (United Kingdom); Cortina-Gil, D. [University of Santiago de Compostela, Dept. of Physics, E-15782, Santiago de Compostela Spain (Spain); Gillibert, A. [SPhN Saclay, 91191 Gif sur Yvette Cedex (France); TRIUMF, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Roger, T.; Roussel-Chomaz, P. [GANIL - Bd Henri Becquerel, BP 55027, 14076 Caen Cedex 05 (France); Tanihata, I. [SPhN Saclay, 91191 Gif sur Yvette Cedex (France); TRIUMF, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada)

    2008-10-15

    With the recent improvements on production of radioactive beams at facilities such as SPIRAL at GANIL or ISAC at TRIUMF, a larger area of the nuclear chart is now accessible for experimentation. For these usually low-intensity and low-energy secondary beams, we have developed the new MAYA detector based on the active target concept. This device allows to use a relatively thick target without loss of resolution by using the detection gas as target material. A dedicated 3-D tracking, particle identification, energy loss and range measurements allow complete kinematics reconstruction of reactions taking place inside MAYA. Recent results from studies of {sup 7}H nuclear system performed at GANIL and of the outer skin structure of the exotic nucleus {sup 11}Li performed at TRIUMF will be reviewed. The capabilities of this new techniques in future experimental studies with secondary exotic beams near and beyond the drip lines, where large kinematics ranges are needed, including regions not accessible with the standard techniques, will be discussed.

  14. Interaction of Auramine O with montmorillonite clays

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Avelardo U.C.; Poli, Alessandra L.; Gessner, Fergus; Neumann, Miguel G. [Instituto de Química de São Carlos, Universidade de São Paulo, Caixa Postal 780, 13560-970 São Carlos SP (Brazil); Schmitt Cavalheiro, Carla C., E-mail: carla@iqsc.usp.br [Instituto de Química de São Carlos, Universidade de São Paulo, Caixa Postal 780, 13560-970 São Carlos SP (Brazil)

    2013-04-15

    The spectroscopic behaviour of Auramine O (AuO) in aqueous suspensions of montmorillonite clays was studied using absorption and static and dynamic fluorescence techniques. The fluorescence of Auramine O increases immediately after mixing the dye solution with the suspension of clay due to its adsorption on the external surface of the clays, which restricts the torsional molecular motion of Auramine. At longer times, the dye molecules migrate into the interlamellar region of the clay particles. Aggregation of the dye molecules can occur in the interlayer region, leading to the decrease of the fluorescence emission. The fluorescence quantum yields (Φ{sub F}) of AuO on the natural montmorillonites SAz-1, SWy-1, Syn-1 and Laponite clays were 0.015, 0.007, 0.016 and 0.017, respectively. These values are higher than the Φ{sub F} of AuO in aqueous solution and are of the same order of magnitude of the Φ{sub F} found for viscous solvents such as n-hexanol and n-heptanol (0.014 and 0.015). Time-resolved fluorescence spectroscopy studies of adsorbed Auramine on clays revealed multi-exponential decays with components in the 25–36, 219–362 and 1300–1858 ps ranges. The short-lived components can be attributed to species bound to external surface and the longer lifetime is assigned to dye molecules in interlayer spaces interacting strongly with the clay. It seems clear that the binding of Auramine to clays causes a significant reduction of the rate of internal conversion that does involve rotational diffusion, so that the clay will be locked in a conformational geometry unfavourable for internal conversion. -- Highlights: ► Auramine O was dissolved in dispersions of different clays. ► The fluorescence quantum yields were higher than in aqueous solution. ► Decrease of the emission and triexponential decays were observed on SAz-1, LapRDS and SYn-1. ► On Swy-1 the decrease was slower and the decay monoexponential. ► The dye produces aggregates on the internal

  15. 2 nd Mid-European Clay Conference

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The 2nd Mid-European Clay Conference (MECC'04) was held between 20-24th September 2004, in Miskolc, Hungary. The idea to hold common conferences was accepted by the national clay groups of four neighbouring countries, Poland, Slovakia, Hungary and Croatia, during the EUROCLAY Meeting in Cracow, Poland, in 1999. The first conference was held in 2001 at Stará Lesná, in the High Tatra Mts. in Slovakia.

  16. Cobalt sorption in silica-pillared clays.

    Science.gov (United States)

    Sampieri, A; Fetter, G; Bosch, P; Bulbulian, S

    2006-01-03

    Silicon pillared samples were prepared following conventional and microwave irradiation methods. The samples were characterized and tested in cobalt sorption. Ethylenediammine was added before cobalt addition to improve the amount of cobalt retained. The amount of cobalt introduced in the original clay in the presence of ethylenediammine was the highest. In calcined pillared clays the cobalt retention with ethylenediammine was lower (ca. 40%). In all cases the presence of ethylenediammine increased twice the amount of cobalt sorption measured for aqueous solutions.

  17. CLAY SOIL STABILISATION USING POWDERED GLASS

    OpenAIRE

    2014-01-01

    This paper assesses the stabilizing effect of powdered glass on clay soil. Broken waste glass was collected and ground into powder form suitable for addition to the clay soil in varying proportions namely 1%, 2%, 5%, 10% and 15% along with 15% cement (base) by weight of the soil sample throughout. Consequently, the moisture content, specific gravity, particle size distribution and Atterberg limits tests were carried out to classify the soil using the ASSHTO classification system. Based on the...

  18. Dynamic properties of composite cemented clay

    Institute of Scientific and Technical Information of China (English)

    蔡袁强; 梁旭

    2004-01-01

    In this work,the dynamic properties of composite cemented clay under a wide range of strains were studied considering the effect of different mixing ratio and the change of confining pressures through dynamic triaxial test. A simple and practical method to estimate the dynamic elastic modulus and damping ratio is proposed in this paper and a related empirical normalized formula is also presented. The results provide useful guidelines for preliminary estimation of cement requirements to improve the dynamic properties of clays.

  19. Quantifying the effect of squirt flow dispersion from compliant clay porosity in clay bearing sandstones

    DEFF Research Database (Denmark)

    Sørensen, Morten Kanne; Fabricius, Ida Lykke

    2013-01-01

    Compliant porosity in the form of cracks is known to cause significant attenuation and velocity dispersion through pore pressure gradients and consequent relaxation, dubbed squirt flow. Squirt flow from cracks vanish at high confining stress due to crack closing. Studies on clay bearing sandstones......-squirt flow on the bulk modulus of a clay bearing sandstone. The predicted magnitude of the clay-squirt effect on the bulk modulus is compared with experimental data. The clay-squirt effect is found to possibly account for a significant portion of the deviances from Gassmann fluid substitution in claybearing...

  20. On The Thermal Consolidation Of Boom Clay

    CERN Document Server

    Delage, Pierre; Cui, Yu-Jun

    2012-01-01

    When a mass of saturated clay is heated, as in the case of host soils surrounding nuclear waste disposals at great depth, the thermal expansion of the constituents generates excess pore pressures. The mass of clay is submitted to gradients of pore pressure and temperature, to hydraulic and thermal flows, and to changes in its mechanical properties. In this work, some of these aspects were experimentally studied in the case of Boom clay, so as to help predicting the response of the soil, in relation with investigations made in the Belgian underground laboratory at Mol. Results of slow heating tests with careful volume change measurements showed that a reasonable prediction of the thermal expansion of the clay-water system was obtained by using the thermal properties of free water. In spite of the density of Boom clay, no significant effect of water adsorption was observed. The thermal consolidation of Boom clay was studied through fast heating tests. A simple analysis shows that the hydraulic and thermal trans...

  1. Soil clay content underlies prion infection odds

    Science.gov (United States)

    David, Walter W.; Walsh, D.P.; Farnsworth, Matthew L.; Winkelman, D.L.; Miller, M.W.

    2011-01-01

    Environmental factors-especially soil properties-have been suggested as potentially important in the transmission of infectious prion diseases. Because binding to montmorillonite (an aluminosilicate clay mineral) or clay-enriched soils had been shown to enhance experimental prion transmissibility, we hypothesized that prion transmission among mule deer might also be enhanced in ranges with relatively high soil clay content. In this study, we report apparent influences of soil clay content on the odds of prion infection in free-ranging deer. Analysis of data from prion-infected deer herds in northern Colorado, USA, revealed that a 1% increase in the clay-sized particle content in soils within the approximate home range of an individual deer increased its odds of infection by up to 8.9%. Our findings suggest that soil clay content and related environmental properties deserve greater attention in assessing risks of prion disease outbreaks and prospects for their control in both natural and production settings. ?? 2011 Macmillan Publishers Limited. All rights reserved.

  2. Effects of Clay on Properties of Polycarboxylate Superplasticizer and Solutions

    Institute of Scientific and Technical Information of China (English)

    WANG Lin; WANG Dongmin

    2015-01-01

    The inlfuence law of clay on mortar lfuidity mixed with polycarboxylate superplasticizer was studied. Several methods of inhibiting clay adsorption of polycarboxylate superplasticizer were discussed. The experimental results show that clay has signiifcant effect on the dispersion of polycarboxylate superplasticizer and montmorillonite clay has more signiifcant impact on mortar lfuidity than other clays. The pH value and the salts of the solution can affect the adsorption of clay to polycarboxylate superplasticizer. The incorporation of a small amount of sodium hydroxide solution, sodium silicate or cationic surfactants can improve the effect of the clay on the dispersion of polycarboxylate superplasticizer.

  3. Feeling the pulse in Maya medicine: an endangered traditional tool for diagnosis, therapy, and tracking patients' progress.

    Science.gov (United States)

    Balick, Michael J; De Gezelle, Jillian M; Arvigo, Rosita

    2008-01-01

    Throughout history, diagnostic tools utilizing the human senses, such as pulse diagnosis, have developed all over the world. In many areas where medical technology is limited or absent, they persist, whereas in other areas these skills are in danger of extinction. The practice of pulse diagnosis by the accomplished Maya healer, Don Elijio Panti, who lived in Belize, Central America, was observed over the final decade of his life and work. Don Elijio used pulse palpation as a diagnostic tool, therapeutic tool, and as a means for tracking patients' progress. He could diagnose a wide array of both physical and spiritual afflictions and was observed diagnosing 42 different conditions or states throughout this period by feeling the pulse. He recognized at least 28 distinct pulse types. Herein, the authors report the detailed system of an endangered diagnostic tradition as practiced by the late, acclaimed Maya healer, including pulse-type descriptions and corresponding diagnoses. Pulse diagnosis is still practiced today among some of Belize's diminishing population of traditional healers, although no practice appears to be as developed as that of the previous generation of Maya healers. Furthermore, it is unlikely that there are new practitioners of pulse diagnosis in the Maya community to maintain and build on the disappearing tradition. Given the unfortunate paucity of data on Maya pulse diagnosis, the practice of pulse diagnosis in Traditional Chinese Medicine (TCM) is used as an illustrative framework for documenting Don Elijio's practice. Corresponding diagnoses from TCM and Don Elijio's system are compared, elucidating similarities between the two disparate medical systems.

  4. Sorption of organic cations to phyllosilicate clay minerals: CEC-normalization, salt dependency, and the role of electrostatic and hydrophobic effects.

    Science.gov (United States)

    Droge, Steven T J; Goss, Kai-Uwe

    2013-12-17

    Sorption to the phyllosilicate clay minerals Illite, kaolinite, and bentonite has been studied for a wide variety of organic cations using a flow-through method with fully aqueous medium as the eluent. Linear isotherms were observed at concentrations below 10% of the cation-exchange capacity (CEC) for Illite and kaolinite and below 1 mmol/kg (<1% CEC) for bentonite. Sorption to clays was strongly influenced by the electrolyte composition of the eluent but with a consistent trend for a diverse set of compounds on all clays, thus allowing for empirical correction factors. When sorption affinities for a given compound to a given clay are normalized to the CEC of the clay, the differences in sorption affinities between clays are reduced to less than 0.5 log units for most compounds. Although CEC-normalized sorption of quaternary ammonium compounds to clay was up to 10-fold higher than CEC-normalized sorption to soil organic matter, CEC-normalized sorption for most compounds was comparable between clays and soil organic matter. The clay fraction is thus a potentially relevant sorption phase for organic cations in many soils. The sorption data for organic cations to clay showed several regular trends with molecular structure but also showed quite a few systematic effects that we cannot explain. A model on the basis of the molecular size and charge density at the ionized nitrogen is used here as a tool to obtain benchmark values that elucidate the effect of specific polar moieties on the sorption affinity.

  5. Premiminary tests on modified clays for electrolyte contaminated drilling fluids

    OpenAIRE

    den Hamer, Davina; Di Emidio, Gemmina; Bezuijen, Adam; Verastegui Flores, Daniel

    2015-01-01

    The quality of a bentonite suspension declines in aggressive systems like brackish or saline pore water. An engineered clay (HYPER clay) was developed for sealing materials with enhanced resistance to aggressive conditions. The modified clay is produced by treating a sodium activated bentonite with a cellulose polymer following the HYPER clay process method. This study investigates the suitability of the modified clay for electrolyte contaminated drilling fluids. Drilling fluids become contam...

  6. NMR imaging and cryoporometry of swelling clays

    Science.gov (United States)

    Dvinskikh, Sergey V.; Szutkowski, Kosma; Petrov, Oleg V.; Furó, István.

    2010-05-01

    Compacted bentonite clay is currently attracting attention as a promising "self-sealing" buffer material to build in-ground barriers for the encapsulation of radioactive waste. It is expected to fill up the space between waste canister and surrounding ground by swelling and thus delay flow and migration from the host rock to the canister. In environmental sciences, evaluation and understanding of the swelling properties of pre-compacted clay are of uttermost importance for designing such buffers. Major goal of present study was to provide, in a non-invasive manner, a quantitative measure of bentonite distribution in extended samples during different physical processes in an aqueous environment such as swelling, dissolution, and sedimentation on the time scale from minutes to years. The propagation of the swelling front during clay expansion depending on the geometry of the confining space was also studied. Magnetic resonance imaging and nuclear magnetic resonance spectroscopy were adapted and used as main experimental techniques. With this approach, spatially resolved movement of the clay/water interface as well as clay particle distributions in gel phase can be monitored [1]. Bulk samples with swelling in a vertical tube and in a horizontal channel were investigated and clay content distribution profiles in the concentration range over five orders of magnitude and with sub-millimetre spatial resolution were obtained. Expansion rates for bulk swelling and swelling in narrow slits were compared. For sodium-exchanged montmorillonite in contact with de-ionised water, we observed a remarkable acceleration of expansion as compared to that obtained in the bulk. To characterize the porosity of the clay a cryoporometric study [2] has been performed. Our results have important implications to waste repository designs and for the assessment of its long-term performance. Further research exploring clay-water interaction over a wide variety of clay composition and water ionic

  7. Maya角色动画中IK-FK无缝切换的技术探讨%Discussion on IK-FK Seamless Switching Technology in Maya Character Animation

    Institute of Scientific and Technical Information of China (English)

    卢景峰

    2014-01-01

    This paper describes a theory of the transformation between Ik and FK in the Maya character animation, introducing seamless switching between IK and FK, which focuses on using the method of three sets of bones together with Maya Mel lan-guages to achieve seamless transition of skeletal between IK and FK. The author hopes to inspire and help those who like three di-mensional character animation of Maya design.%该文阐述maya角色动画中IK-FK相互转换的原理,介绍几种IK-FK无缝切换的几种思路,重点探讨利用三套骨骼配合Maya mel语言实现骨骼IK-FK之间无缝转换的实现方法,希望能给喜欢maya三维角色动画设计的朋友有所启发和帮助。

  8. La violencia sexual como genocidio. Memoria de las mujeres mayas sobrevivientes de violación sexual durante el conflicto armado en Guatemala

    National Research Council Canada - National Science Library

    Amandine Fulchiron

    2016-01-01

    ...). En l analizamos el uso sistem tico y masivo de la violaci n sexual contra las mujeres mayas dentro del marco de la pol tica contrainsurgente en Guatemala, nombr ndolo y denunci ndolo como feminicidio y genocidio...

  9. Utilization of crushed clay brick in concrete industry

    Directory of Open Access Journals (Sweden)

    Ali A. Aliabdo

    2014-03-01

    Full Text Available A comprehensive experimental program regarding the use of recycled aggregates produced from demolition of brick buildings is presented. The brick wastes were crushed, sorted and classified into coarse and fine aggregates as well as powder (CBP. The first phase of the research focuses on the effect of incorporating recycled aggregates on physico-mechanical properties of paste, mortar and concrete. Non-traditional tests including X-ray diffraction (XRD, thermo-gravimetric analysis (TGA and micro-structural analysis (MSA were performed. The second phase of the program explores the effect of using recycled aggregates on properties of concrete masonry units. A total of 44 mixtures were utilized throughout the program. Results show cement paste when modified with 25% CBP achieves smaller pore size and lower weight loss under high temperature than reference paste. Furthermore, the use of recycled aggregates reduces the overall unit weight of concrete masonry units. Actually, modified concrete masonry units incorporating recycled aggregates achieve lower unit weight, higher thermal resistance and absorption rate than reference units. Although considerable strength reduction is noticeable by substitution, compressive strength levels meet the Egyptian specifications limitations. Critical replacement ratios are suggested to produce load bearing-concrete masonry units. Based on experimental evidences, it can be stated that the use of recycled aggregate and dust made of clay bricks is promising in many applications where the thermal resistance, cost and environmental aspects are imperative.

  10. Fire performance of fiber board coated with nano kaolin-clay film

    Science.gov (United States)

    Zhijia Liu; John F. Hunt; Zhiyong Cai

    2013-01-01

    Fiberboard is a common interior material used both in China and the United States of America. The increase in demand for interior materials has raised concerns regarding combustibility of the materials. The pyrolysis characteristics of fiber, phenolic resin (PF), and nano kaolin-clay (NK) were investigated using thermogravimetry. The fire performances of samples coated...

  11. Relationship between heavy metal contents and clay mineral properties in surface sediments: Implications for metal pollution assessment

    Science.gov (United States)

    Chen, Yueh-Min; Gao, Jin-bo; Yuan, Yong-Qiang; Ma, Jun; Yu, Shen

    2016-08-01

    Clay minerals in surface sediments can affect the adsorption of heavy metals. However, few historical studies have focused on the influence of fine clay mineral characteristics on metal sorption. Since the reactions between heavy metals and fine clay minerals in sediments remain obscure, this study investigates the influence of fine clay mineral characteristics on metal sorption in a typical urbanizing small watershed. Clay minerals, including nanoparticles with various size fractions ranging from 1000 to 2000 (clay), 450-1000 (fine clay), and 220-450 (very fine clay) nm were used to demonstrate their transformation from well crystalline to poorly crystalline. The nanoparticles were collected and evaluated by determination of their surface area, X-ray diffraction, scanning electron microscopy (SEM) and chemical analyses. The relationship between metal content and properties of the surface sediments was also revealed by canonical correlation analysis. With smaller particle sizes, nanoparticles (very fine clay) were observed to be poorly crystalline, possibly indicating few repetitions of unit cells as a result of preferential structural disruption of other crystal planes caused by pressure-induced phase transition in the fine-size fractions. The first canonical matrix (M) variables of metal contents can be predicted by both surface area and pore volume, followed by kaolinite and illite contents. On the other hand, the category of metal, i.e., Cu, Cr, Zn, or Pb, was significantly correlated with the first 'M' canonical variables. The data obtained in the present study are of fundamental significance in advancing our understanding of the reactions between heavy metals and fine clay minerals in the terrestrial ecosystem.

  12. Ancient Maya Cultivation in a Dynamic Wetland Environment: Insights into the Functions of Anthropogenic Rock Alignments at El Edén Ecological Reserve, Quintana Roo, Mexico

    OpenAIRE

    Chmilar, Jennifer Andrea

    2013-01-01

    Cultivation has taken many forms throughout the Maya lowlands. In the Yalahau region of the northern Maya lowlands, a series of wetlands produce a dynamic environment of wet, dry, and intermediate areas depending on fluctuations of the annual hydrologic cycle. Within these wetlands, anthropogenic rock alignments suggest human use and manipulation of the environment dating to the late Preclassic period. The dissertation is based on research at a single wetland at El Edén Ecological Reserve, Q...

  13. Estudio arqueométrico de figurillas cerámicas mayas de Calakmul (Campeche, México

    Directory of Open Access Journals (Sweden)

    García-Heras, M.

    2006-08-01

    Full Text Available The results derived from an archaeometric characterization study undertaken on a representative ensemble of Late Classic ceramic figurines coming from the archaeological field work carried out in the Mayan town of Calakmul (Campeche, México are reported and discussed in this paper. The main goals of the research were to gather some information on the technology of manufacture of these ceramics and provide some insights into their probable provenance. The archaeometric characterization was accomplished through the following complementary techniques: conventional optical microscopy (OM, X-ray powder diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR and X-ray fluorescence (XRF. In order to isolate ceramic groups with a similar chemical profile, XRF data were also analyzed by exploratory multivariate statistical techniques. The resulting data indicate that most of the figurines were locally manufactured from a calcium carbonate (calcite-rich clay raw material. A small ceramic group containing mixed calcium and magnesium carbonates (dolomite, which could be foreign or from other area of the Calakmul region, was also identified. These data suggest that the production of ceramic figurines could be associated to workshops linked to the monopoly on ceramic production performed by the centralized power of the town of Calakmul during this period.

    En este trabajo se presentan y discuten los resultados de la caracterización arqueométrica realizada sobre un conjunto representativo de figurillas cerámicas del Clásico Tardío procedentes de las excavaciones arqueológicas efectuadas en la ciudad maya de Calakmul (Campeche, México. Los objetivos principales han sido recabar información sobre la tecnología de manufactura de estas cerámicas y evaluar su posible procedencia. La caracterización arqueométrica se ha llevado a cabo mediante las siguientes técnicas complementarias: microscopía óptica convencional (MO, difracción de

  14. Removal of boron from aqueous solution by clays and modified clays.

    Science.gov (United States)

    Karahan, Senem; Yurdakoç, Mürüvvet; Seki, Yoldaş; Yurdakoç, Kadir

    2006-01-01

    In order to increase the adsorption capacities of bentonite, sepiolite, and illite for the removal of boron form aqueous solution, the clay samples were modified by nonylammonium chloride. Specific surface areas of the samples were determined as a result of N2 adsorption-desorption at 77 K using the BET method. X-ray powder diffraction analysis of the clays and modified clays was used to determine the effects of modifying agents on the layer structure of the clays. The surface characterization of clays and modified clay samples was conducted using the FTIR technique before and after the boron adsorption. For the optimization of the adsorption of boron on clays and modified clays, the effect of pH and ionic strength was examined. The results indicate that adsorption of boron can be achieved by regulating pH values in the range of 8-10 and high ionic strength. In order to find the adsorption characteristics, Langmuir, Freundlich, and Dubinin-Radushkevich adsorption isotherms were applied to the adsorption data. The data were well described by Freundlich and Dubinin-Radushkevich adsorption isotherms while the fit of Langmuir equation to adsorption data was poor. It was reached that modification of bentonite and illite with nonylammonium chloride increased the adsorption capacity for boron sorption from aqueous solution.

  15. Determining Upper Bounds for the Clay-squirt Effect in Clay Bearing Sandstone

    DEFF Research Database (Denmark)

    Sørensen, Morten Kanne; Fabricius, Ida Lykke

    Sonic measurements of saturated bulk moduli of clay bearing sandstones show larger values than expected by Gassmann modelling from dry rock properties. This causes difficulties in extrapolation of laboratory data to different saturants or frequencies. Squirt flow from the clay phase of the rock...

  16. The Movement, the Mine and the Lake: New Forms of Maya Activism in Neoliberal Guatemala

    Directory of Open Access Journals (Sweden)

    J. T. Way

    2016-07-01

    Full Text Available This article explores the social, economic, cultural and political issues bound up in two matters relating to the environment in the Sololá and Lake Atitlán region of the Guatemalan Mayan highlands in 2004–2005: the violent breakup of an anti-mine protest and the various reactions to a tropical storm that threatened the lake ecosystem. It views these events as part of a historical conjuncture and centers them in a larger discussion of Maya political activism, environmentalism and neoliberal development in Guatemala from the 1990s–mid-2010s. It begins with the transition from war to peace in the 1990s, charting how Maya participation in municipal politics soared even as the official Mayan movement waned as the state turned to neoliberalism. Zooming in on municipal development and politics in Sololá in the early 2000s, it then traces at the ground level how a decentralizing, “multicultural” state promoted political participation while at the same time undermining the possibility for that participation to bring about substantive change. The center of the article delves deeper into the conjuncture of the first decade of the new millennium. By mapping events in Sololá against development, agrarian transformation and rural urbanization, it argues that resilient Maya community structures, although unable to stop the exploitative tide, continued to provide local cohesion and advocacy. Activists and everyday citizens became more globally attuned in the 2000s. The article’s final section analyzes municipal plans made between 2007 and 2012, arguing that creating and controlling community structures became increasingly important to the state in a time when Guatemala’s “outward” global turn was accompanied by an “inward” turn as people confronted spiraling violence in their communities. Critics called young people apolitical, but in 2015, massive demonstrations led to the imprisonment of the nation’s president and vice

  17. Identification of Postclassic Maya Constellations from the Venus Pages of the Dresden Codex

    Directory of Open Access Journals (Sweden)

    Changbom Park

    2010-01-01

    Full Text Available Ancient Mayan civilization, flourished from 1200 B.C. to 1500 A.D., has left numerous hieroglyphic texts on astronomical observations and calendar. In particular, the Dresden Codex contains the most details of such ancient Mayan heritage. Page 24 and those from 46 to 50 of the Dresden Codex describe the Mayan Venus calendar along with the augural descriptions. We note that the calendar in Dresden Codex is Venus-solar calendar. Our work focuses on the possibility that the calendar was made to work in conjunction with the periodic appearance of constellations on the sky. By analyzing the descriptions in the Venus pages, we propose that the columns in each page describe the motion of Venus with respect to major constellations at dates corresponding to special events while the calendar dates increase horizontally in the synodic period of Venus. We present twenty Mayan constellations identified from the Venus pages assuming that the first date of page 46 is February 6, 1228. We also report our understanding of verb expressions about the relative movement of constellations and Venus.La civilización maya, que floreció del 1200 a.C. a 1500 d.C., dejó numerosos textos jeroglíficos sobre el calendario y observaciones astronómicos. El Códice de Dresde, en particular, contiene el más detallado de dichos antiguos legados mayas. Las páginas 24 y 46 a 50 de dicho códice describen el calendario de Venus con los augurios correspondientes. Nosotros hemos notado que éste es un calendario Venus-Solar, y nuestro trabajo se enfoca sobre la posibilidad de que estuviera hecho para trabajar en conjunción con la aparición de determinadas constelaciones en el cielo. Es a través del análisis y descripción de las páginas de Venus que proponemos que las columnas en cada página describen el movimiento de Venus respecto de constelaciones mayores, en fechas que corresponden a eventos especiales, mientras que las fechas calendáricas se incrementan

  18. Gonad development during the early life of Octopus maya (Mollusca: Cephalopoda).

    Science.gov (United States)

    Avila-Poveda, Omar Hernando; Colin-Flores, Rafael Francisco; Rosas, Carlos

    2009-02-01

    Gonad development during the early life of Octopus maya is described in terms of histological, morphometric, oocytes growth, and somatic-oocyte relationship data obtained from octopus cultured at the UMDI-UNAM, in Sisal, Yucatan, Mexico. This study is the first publication on gonad development during the early life of Octopus maya. A total of 83 O. maya specimens were used; their sizes ranged from 6.5 to 76 mm of total length (TL), 4 to 28 mm of dorsal mantle length (DML), 2.5 to 20 mm of ventral mantle length (VML), and 0.0180 to 7.2940 g of fixed body weight (fBW). Animals were weighed and measured only after preservation. A loss of 10% of living weight was estimated for juvenile octopuses after formalin preservation. The relation of length to weight (VML, DML, TL/fBW) pooled for both sexes had a strong positive correlation (r), as shown by a potential power function that was quite close to 1. Compound images were produced from numerous microscopic fields. The histological examination revealed that, 4 months after hatching, male octopus (24.5 mm DML and 7.2940 g fBW) were in gonad stages 2 (maturing) to 3 (mature), with spermatogonia and spermatocytes in the tubule wall and abundant spermatids and spermatozoa in the central lumen of the seminiferous tubules, suggesting the occurrence of different phases of gonad development at different maturity stages. In contrast, females (22.5 mm DML and 4.8210 g fBW) at the same time since hatching were immature (stage 1), with many oogonia, few oocytes, and germinal epithelium. This suggests that males reach maturity earlier than females, indicating a probable onset of maturity for males at around 4 months of culture or 8 g of wet body weight. Our results indicate the possibility that the size-at-weight can be recognized early with a degree of certainty that allows the sexes to be separated for culture purposes; but more detailed studies on reproduction in relation to endocrinology and nutrition are needed.

  19. How useful is BMI in predicting adiposity indicators in a sample of Maya children and women with high levels of stunting?

    Science.gov (United States)

    Wilson, Hannah J; Dickinson, Federico; Griffiths, Paula L; Azcorra, Hugo; Bogin, Barry; Varela-Silva, Maria Inês

    2011-01-01

    Body mass index (BMI) is used frequently to estimate adiposity levels in children and adults. However, the applicability of BMI to populations with high levels of stunting has been questioned. Stunted people can have disproportionately short legs, which may increase BMI without increasing body fat because of the relatively larger trunk compared with the legs. A sample of 57 urban Maya schoolchildren, aged 7-9 years (31 boys), and 53 adult women underwent anthropometric assessments and bioelectrical impedance analysis. Multiple linear regression was performed to determine whether the ability of BMI to predict adiposity indicators is altered by stunting and sitting height ratio (SHR). The adiposity indicators were waist circumference, sum of skinfolds, upper arm muscle area, upper arm fat area, and arm fat index. BMI was the strongest predictor of all adiposity indicators and in most cases, explained more of the variance in adiposity of Maya children than Maya women. Abdominal adiposity was better predicted by BMI than peripheral adiposity in Maya women and Maya children. Stunting was significant in predicting adiposity in some models but never substantially changed the variance explained. SHR was never a significant predictor. The relationship between BMI and adiposity indicators is not changed by stunting status or body proportions in this short population of urban Maya children and women. BMI can be used as an indicator of adiposity for these children but not the women. It is recommended that BMI is used in conjunction with other estimates of body composition. Copyright © 2011 Wiley-Liss, Inc.

  20. Maya协同设计系统中的并发控制机制%Concurrency Control Mechanism in Maya Collaborative Design System

    Institute of Scientific and Technical Information of China (English)

    曹杰; 刘弘; 孙玉灵

    2011-01-01

    The design based on Maya is less studied. Owing to the particularity of Maya system, it modulates the concurrent control mechanism of Mel modeling instruction sequences through based on the characters and the priority of types of modeling instructions, overcome the disadvantages of traditional token ring mechanism and solve some conflict between multi-user coordination using Maya. It uses Maya WinSocket and C++ API technologies, and extends Maya collaboration design function through plug-ins, and demonstrate its validity through achieving a collaboration example based on LAN.%目前关于Maya系统的协同设计研究较少.为此,根据该系统的特殊性,采用基于角色及造型指令类型的优先级,调整Mel造型指令序列的并发控制机制,克服传统令牌环机制存在的缺点,解决Maya多用户协同的冲突问题.使用Maya C++ API以及WinSocket技术,通过插件扩展Maya协同设计功能.在局域网基础上的Maya协同实验验证了该机制的有效性.