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Sample records for crudo maya despuntado

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

    ERIC Educational Resources Information Center

    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…

  2. Maya Calendars in the Classroom

    ERIC Educational Resources Information Center

    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…

  3. Maya-American Children: A Biocultural View.

    ERIC Educational Resources Information Center

    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.…

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

    ERIC Educational Resources Information Center

    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…

  5. Mapping the Ancient Maya Landscape from Space

    NASA Technical Reports Server (NTRS)

    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

  6. Ownership of Language in Yucatec Maya Revitalization Pedagogy

    ERIC Educational Resources Information Center

    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…

  7. Soil and Human Interactions in Maya Wetlands

    NASA Astrophysics Data System (ADS)

    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

  8. Zodiacal references in the Maya codices.

    NASA Astrophysics Data System (ADS)

    Bricker, H. M.; Bricker, V. R.

    The authors examine the evidence for the proposition that the pre-Columbian Maya were concerned also with recording the stations of the sidereal year and commensurating these stations with their calendrical cycles. The stations of the sidereal year must be defined with reference to the fixed stars, and there is every reason to expect that for the Maya, as for other prescientific peoples in both hemispheres, what was most salient was the patterning of bright stars within a few degrees of the ecliptic. In other words, what this chapter is concerned with is evidence that the pre-Columbian Maya recognized zodiacal constellations and related the cyclical pattern of their appearance and disappearance to other astronomical or calendrical cycles of interest.

  9. The Ancient Maya Landscape from Space

    NASA Technical Reports Server (NTRS)

    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.

  10. Mapping The Ancient Maya Landscape From Space

    NASA Technical Reports Server (NTRS)

    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

  11. Discovering the Ancient Maya From Space

    NASA Technical Reports Server (NTRS)

    Sever, T. L.

    2007-01-01

    The Peten 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 o f 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.

  12. Discovering the Ancient Maya from Space

    NASA Technical Reports Server (NTRS)

    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.

  13. Man and climate in the Maya lowlands

    NASA Astrophysics Data System (ADS)

    Leyden, Barbara W.

    1987-11-01

    A 15-m sedimentary core from Lake Salpeten provides the first complete Holocene sequence for the lowlying Peten District, Guatemala. Today, Lake Salpeten is a brackish, calcium sulfate lake near saturation surrounded by tropical semievergreen forest. The basal pollen record depicts sparse juniper scrub surrounding a lake basin that held ephermal pools and halophytic marshes. The lake rapidly deepened to > 27 m in the early Holocene and may have been meromictic, because nearly 2 m of gypsum "mush" was deposited. Mesic forests were quickly established and persisted until the Maya entered the district 3000 yr ago and caused extensive deforestation. Any climatic information contained in the pollen record of the Maya period is thus masked, but a regional pollen sequence linked to the archaeological record is substantiated because environmental disturbance was pervasive. Local intensification of occupation and population growth are seen as an increased deposition of pollen of agricultural weeds and colluviation into the lake, while the Classic Maya collapse is marked by a temporary decline in Compositae pollen. Effects of perturbations induced by the Maya persist in the pollen and limnetic record 400 yr after the Spanish conquest.

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

    ERIC Educational Resources Information Center

    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…

  15. Maya Art: Classroom and Museum Activity Book.

    ERIC Educational Resources Information Center

    Fuerst, Ann H.

    Illustrated with reproductions of Mayan art and architecture, this activity book contains readings and activities about the Maya, including bilingual lesson sheets. The materials link middle school classroom studies of Mayan culture with history, social studies, and community resources. Eight lesson units explore the central aspects of Mayan art.…

  16. Cell scientist to watch--Maya Schuldiner.

    PubMed

    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. PMID:26574503

  17. Maya blue: a clay-organic pigment?

    PubMed

    Van Olphen, H

    1966-11-01

    Maya Blue, a pigment used by the Mayas in Yucatan, is remarkably stable: the color is not destroyed by hot concentrated mineral acids or by heating to about 250 degrees C. The principal constituent is the colorless mineral attapulgite. It is proposed that the pigment is an adsorption complex of attapulgite and natural indigo; a synthetic equivalent may be prepared from attapulgite and either indoxylester or indigo, or by applying the vat-dyeing technique, with reduced indigo.The low dye content of the pigment (less than 0.5 percent) indicates that the dye is absorbed only on the external surfaces of the attapulgite particles and not throughout the channels in their structures. The complex as such is not stable to acids, but the stability displayed by Maya Blue is achieved simply by heating the complex to from 75 degrees to 150 degrees C for several days. An analogous stable pigment can be prepared from sepiolite and indigo. No stable pigments could be prepared from clays with platelike structures or from zeolites. PMID:17778806

  18. Territorial organization of the lowland classic maya.

    PubMed

    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. The Construction of Orthography by Maya-Speaking Children.

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

    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)

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

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

    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…

  3. Maya Blue Paint: An Ancient Nanostructured Material

    PubMed

    Jose-Yacaman; Rendon; Arenas; Serra Puche MC

    1996-07-12

    Maya blue paint was often used in Mesoamerica. The origin of its color and its resistance to acids and biocorrosion have not been fully understood. High-resolution transmission electron microscopy, electron energy loss spectroscopy, and x-ray microanalysis studies of authentic samples show that palygorskite crystals in the paint form a superlattice that probably occurs as a result of mixing with indigo molecules. An amorphous silicate substrate contains inclusions of metal nanoparticles encapsulated in the substrate and oxide nanoparticles on the surface. The beautiful tone of the color is obtained only when both the particles and the superlattice are present. PMID:8662502

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Recent Advances in Maya Studies Using Remotely Sensed Data

    NASA Technical Reports Server (NTRS)

    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

  6. Peopling the past: New perspectives on the ancient Maya

    PubMed Central

    Robin, Cynthia

    2001-01-01

    The new direction in Maya archaeology is toward achieving a greater understanding of people and their roles and their relations in the past. To answer emerging humanistic questions about ancient people's lives Mayanists are increasingly making use of new and existing scientific methods from archaeology and other disciplines. Maya archaeology is bridging the divide between the humanities and sciences to answer questions about ancient people previously considered beyond the realm of archaeological knowledge. PMID:11136245

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

    PubMed Central

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

    2012-01-01

    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. PMID:22371605

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

    PubMed Central

    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

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

    PubMed

    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

  10. 78 FR 17744 - Culturally Significant Objects Imported for Exhibition Determinations: “Maya: Hidden Worlds...

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...

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

    PubMed Central

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

    2015-01-01

    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. PMID:25902508

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

    PubMed

    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. PMID:25902508

  13. Meteor Showers in the Ancient Maya Hieroglyphic Codices

    NASA Astrophysics Data System (ADS)

    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.

  14. Narrative Structures of Maya Mental Disorders.

    PubMed

    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. PMID:25676172

  15. Folkecology and commons management in the Maya Lowlands

    PubMed Central

    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

  16. Compositional attribution of non-provenienced Maya polychrome vessels

    SciTech Connect

    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.

  17. Recent Advances in Maya Studies Using Remotely Sensed Data

    NASA Technical Reports Server (NTRS)

    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

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

    ERIC Educational Resources Information Center

    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, and singer.…

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

    SciTech Connect

    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.

  20. U/Pb Geochronology of the Maya Block, Guatemala

    NASA Astrophysics Data System (ADS)

    Martens, U.; Ratschbacher, L.; McWilliams, M.

    2005-12-01

    The Maya Block can be defined as Guatemala north of the Motagua transform fault, Belize, and part of southern Mexico. The absence of radiometric ages has hindered an understanding of the geologic evolution of the Maya Block and its connections with adjacent blocks in North America, South America and the Caribbean. We present an exploratory study of SHRIMP U/Pb ages from zircons collected in central and western Guatemala that shows ubiquitous Grenvillian inheritance, magmatism at ~ 1020 Ma, ~ 975 Ma and ~ 175 Ma, Devonian-Silurian and Triassic tectonomagmatic events, and Cretaceous metamorphism. Grenvillian orthogneisses were identified in the northern flank of the Sierra de Chuac'{u}s whose magmatic ages are 1020 ± 35 Ma and 975 ± 15 Ma with possible Pb-loss at ~ 420 Ma. Zircons of the Rabinal Granite show an important ~ 975 Ma inheritance and concordant ages in the 400-500 Ma range. We interpret the Devonian-Silurian ages as magmatic and correlate the peraluminous Rabinal Granite with similar intrusions in the Maya Mountains of Belize. Coeval events recorded in Chuac'{u}s orthogneisses and the Rabinal Granite suggest connections since Early Paleozoic time between the Chuac'{u}s complex and the Maya Block north of the Baja Verapaz shear zone that separates rocks of contrasting metamorphic grade. The magmatic age for deformed granites south of Sacapulas in central-western Guatemala is 174 ± 3 Ma. Migmatitic paragneisses collected south of Huehuetenango yield Triassic metamorphic ages at 223 ± 4 Ma, coeval with anatexis in the basement of Chiapas, Mexico. Medium to high-grade metasedimentary rocks on the southern flank of the Sierra de Chuac'{u}s do not record a Silurian-Devonian provenance. Instead, they yield clear Grenvillian and Triassic (240-210 Ma) components. Dating of zircon rims at 74 ± 1 Ma yields a precise age for the peak Cretaceous epidote-amphibolite metamorphic event in the Chuac'{u}s complex. Ductile structures exhibiting at least 4 tectonic

  1. Solar Forcing of Drought Frequency in the Maya Lowlands

    NASA Astrophysics Data System (ADS)

    Hodell, David A.; Brenner, Mark; Curtis, Jason H.; Guilderson, Thomas

    2001-05-01

    We analyzed lake-sediment cores from the Yucatan Peninsula, Mexico, to reconstruct the climate history of the region over the past 2600 years. Time series analysis of sediment proxies, which are sensitive to the changing ratio of evaporation to precipitation (oxygen isotopes and gypsum precipitation), reveal a recurrent pattern of drought with a dominant periodicity of 208 years. This cycle is similar to the documented 206-year period in records of cosmogenic nuclide production (carbon-14 and beryllium-10) that is thought to reflect variations in solar activity. We conclude that a significant component of century-scale variability in Yucatan droughts is explained by solar forcing. Furthermore, some of the maxima in the 208-year drought cycle correspond with discontinuities in Maya cultural evolution, suggesting that the Maya were affected by these bicentennial oscillations in precipitation.

  2. Solar forcing of drought frequency in the Maya lowlands.

    PubMed

    Hodell, D A; Brenner, M; Curtis, J H; Guilderson, T

    2001-05-18

    We analyzed lake-sediment cores from the Yucatan Peninsula, Mexico, to reconstruct the climate history of the region over the past 2600 years. Time series analysis of sediment proxies, which are sensitive to the changing ratio of evaporation to precipitation (oxygen isotopes and gypsum precipitation), reveal a recurrent pattern of drought with a dominant periodicity of 208 years. This cycle is similar to the documented 206-year period in records of cosmogenic nuclide production (carbon-14 and beryllium-10) that is thought to reflect variations in solar activity. We conclude that a significant component of century-scale variability in Yucatan droughts is explained by solar forcing. Furthermore, some of the maxima in the 208-year drought cycle correspond with discontinuities in Maya cultural evolution, suggesting that the Maya were affected by these bicentennial oscillations in precipitation. PMID:11359010

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

    PubMed Central

    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

  4. The Maya Project: Numerical Simulations of Black Hole Collisions

    NASA Astrophysics Data System (ADS)

    Smith, Kenneth; Calabrese, Gioel; Garrison, David; Kelly, Bernard; Laguna, Pablo; Lockitch, Keith; Pullin, Jorge; Shoemaker, Deirdre; Tiglio, Manuel

    2001-04-01

    The main objective of the MAYA project is the development of a numerical code to solve the vacuum Einstein's field equations for spacetimes containing multiple black hole singularities. Incorporating knowledge gained from previous similar efforts (Binary Black Holes Alliance and the AGAVE project) as well as one-dimensional numerical studies, MAYA has been built from the ground up within the architecture of Cactus 4.0, with particular attention paid to the software engineering aspects of code development. The goal of this new effort is to ultimately have a robust, efficient, readable, and stable numerical code for black hole evolution. This poster presents an overview of the project, focusing on the innovative aspects of the project as well as its current development status.

  5. Astronomical and Cosmological Aspects of Maya Architecture and Urbanism

    NASA Astrophysics Data System (ADS)

    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.

  6. Raman and infrared studies of synthetic Maya Blue pigment

    NASA Astrophysics Data System (ADS)

    Reza, Layra; Manciu, Felicia; Ramirez, Alejandra; Chianelli, Russell

    2008-10-01

    A fascinating aspect of Maya pigments is that despite the environmentally harsh humidity and high temperatures they resist fading and they have unprecedented stability. In this investigation, we address the question of how organic dye binds to inorganic palygorskite to form a pigment similar to Maya Blue. We also address how such binding might be affected by varying the proportion of dye relative to that of the mineral, and by varying the length of heating time used in preparation of the pigment. Our analysis by Raman and infrared absorption spectroscopies 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 palygorskite and indigo through oxygen is revealed by both spectroscopic measurements.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Ancient Maya documents concerning the movements of Mars.

    PubMed

    Bricker, H M; Aveni, A F; Bricker, V R

    2001-02-13

    A large part of the pre-Columbian Maya book known as the Dresden Codex is concerned with an exploration of commensurate relationships among celestial cycles and their relationship to other, nonastronomical cycles of cultural interest. As has long been known, pages 43b--45b of the Codex are concerned with the synodic cycle of Mars. New work reported here with another part of the Codex, a complex table on pages 69--74, reveals a concern on the part of the ancient Maya astronomers with the sidereal motion of Mars as well as with its synodic cycle. Two kinds of empiric sidereal intervals of Mars were used, a long one (702 days) that included a retrograde loop and a short one that did not. The use of these intervals, which is indicated by the documents in the Dresden Codex, permitted the tracking of Mars across the zodiac and the relating of its movements to the terrestrial seasons and to the 260-day sacred calendar. While Kepler solved the sidereal problem of Mars by proposing an elliptical heliocentric orbit, anonymous but equally ingenious Maya astronomers discovered a pair of time cycles that not only accurately described the planet's motion, but also related it to other cosmic and terrestrial concerns. PMID:11172084

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

    PubMed

    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. PMID:17813262

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

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

    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…

  12. Maya medicine in the biological gaze: bioprospecting research as herbal fetishism.

    PubMed

    Nigh, Ronald

    2002-06-01

    The relationship of human societies to territory and natural resources is being drastically altered by a series of global agreements concerning trade, intellectual property, and the conservation and use of genetic resources. Through a characteristic style of collective appropriation of their tropical ecosystems, Maya societies have created local institutions for governing access to their common resources. However, new mechanisms of global governance require access to Maya biodiversity for world commercial interests. The Chiapas Highland Maya already face this prospect in the International Cooperative Biodiversity Group drug discovery project, which proposes to use Maya medical knowledge to screen plants for potential pharmaceuticals. The ethnobiological focus of the project emphasizes the naturalistic aspects of Maya medicine, primarily the use of herbal remedies. This biological gaze decontextualizes the situated knowledge of Maya healers, ignoring the cultural context in which they create and apply that knowledge. The search for raw materials for the production of universal medical technology results in symbolic violence to the cultural logic of Maya peoples. Only the full recognition of Maya peoples' collective rights to territory and respect for their local common-resource institutions will provide ultimate protection for their cultural and natural patrimony. PMID:12152634

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    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

  15. Spectroscopic Studies of Azul Maya: Novel Organic/Inorganic Complexes

    NASA Astrophysics Data System (ADS)

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

    2006-10-01

    Maya pigments are novel organic/inorganic hybrid materials with multiple technological applications. The materials are surface compounds formed by heating an organic molecule such as indigo with an inorganic compound such as palygorskite, which is a common clay. The organic molecule upon heating forms a strong interaction with the clay surface stabilizing both entities. This strong interaction is exhibited through a color change from deep blue to the well-known Maya Blue indicating an exchange of electron density at the surface. Analysis by infrared absorption and Raman spectroscopy demonstrate the disappearance of nitrogen-hydrogen (N-H) bonding, as the indigo molecule incorporates into the inorganic palygorskite material. Infrared data confirm the loss of zeolitic water and a partial removal of structural water after the heating process. Carbon and oxygen studies at Stanford Synchrotron Radiation Laboratory by X-Ray photoemission spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS), respectively, suggest possible cationic (Al^+3) bonding of the organic molecule to palygorskite compound.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27094624

  17. On the fringes of conquest: maya-spanish contact in colonial belize.

    PubMed

    Graham, E; Pendergast, D M; Jones, G D

    1989-12-01

    The defeat of the Aztecs of Mexico by Hernán Cortés in 1521 was but the beginning of a long and torturous conquest of Central America that did not always result in the mastery of people and production for which the Spanish had hoped. The Maya of the resource-poor Yucatán peninsula were spared the heavy colonial hand that held fast to central Mexico and its riches. In addition, the dense forests of the peninsula served as a haven for refugees fleeing oppressive conditions in colonial towns. Despite the paucity of documentary information on Maya communities of the frontier, knowledge of Maya-Spanish relations in the 16th and 17th centuries has advanced in recent years through archeological and ethnohistorical research. Work in one region of the Maya lowlands has brought us closer to an understanding of the early interaction of the rulers and the ruled. PMID:17832220

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

    PubMed

    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. PMID:27094624

  19. Land, Water and Society in the Maya Lowlands

    NASA Astrophysics Data System (ADS)

    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

  20. [Anita: a Maya peasant woman on the rise].

    PubMed

    Elmendorf, M

    1980-01-01

    Chan Kom, a village of 623 inhabitants in the Yucatan peninsula whose population lives primarily by slash-and-burn maize agriculture, has been well studied by social scientists for over 50 years. The roles of women during that time have been interpreted by men, and it is the object of this article to examine the needs and desires of women and the ways in which they seek to improve life for themselves and their families. Anita at 38 has 7 living children from 10 pregnancies. Her husband is a subsistence farmer who works part time at a variety of jobs. The oldest daughter married at 17. A 16-year-old son Emiliano attended an agricultural vocational school to which his family sent him after great sacrifice. After completing school Emiliano became a promoter for the National Indigenist Institute. A daughter finishiing primary school wished to continue studying but her father objected that she would probably get married and her mother worried about her safety if she left home to study. She and a sister were sent to live with the daughter of her mother's comadre in a nearby city in the hope that she would learn office work. A 12-year-old son at home, who is not such a good student, helps the father in farming. 2 little girls are the only other children still at home. Anita's last 2 deliveries were difficult and dangerous, and for 3 years she and her husband have been attempting to avoid another pregnancy, using a combination of withdrawal and rhythm. She and her husband discussed vasectomy with a Maya-speaking North American doctor, but came to no decision. Anita states that many Maya women do not menstruate between pregnancies, or do so only once or twice. Anita has had 2 miscarriages and 2 daughters since deciding that she wanted no more children. She accepted a prescription for pills but was afraid to take them. Fear of disturbing the "tipte," a regulating organ believed by Maya women to lie behind the navel, prevented her from choosing sterilization. PMID:12264283

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

    NASA Astrophysics Data System (ADS)

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    2010-01-01

    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. PMID:20152047

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

    PubMed

    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. PMID:24519220

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

    USGS Publications Warehouse

    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.

  6. A review of human and natural changes in Maya Lowland wetlands over the Holocene

    NASA Astrophysics Data System (ADS)

    Beach, Tim; Luzzadder-Beach, Sheryl; Dunning, Nicholas; Jones, John; Lohse, Jon; Guderjan, Tom; Bozarth, Steve; Millspaugh, Sarah; Bhattacharya, Tripti

    2009-08-01

    In the Maya Lowlands of Mexico, Belize, and Guatemala two main types of wetlands have played important roles in human history: bajos or intermittently wet environments of the upland, interior Yucatán and perennial wetlands of the coastal plains. Many of the most important Maya sites encircle the bajos, though our growing evidence for human-wetland interactions is still sparse. The deposits of these wetlands record two main eras of slope instability and wetland aggradation: the Pleistocene-Holocene transition as rainfall increased and forests eclipsed savannas and the Maya Preclassic to Classic as deforestation, land-use intensity, and drying increased. The ancient Maya adapted with terraces around these bajo margins but retracted in the Late Preclassic in some areas. The perennial wetlands of the coastal plains have different histories, and the first conceptual model of human-wetland interaction described intensive wetland agriculture in the Preclassic through Classic based on raised fields and canals. But a second model arose that interpreted the wetland stratigraphy and canals as more indicative of natural aggradation by accelerated erosion and gypsum precipitation that buried Archaic and Preclassic fields and there was little Classic era use. We present new data on a third and fourth model in this study. The third is a hybrid of the models one and two, including the Archaic to Preclassic aggradation of the second model, and the first model's Classic period fields and canals as piecemeal attempts by the Maya to adapt to these and other environmental changes. The fourth conceptual model describes a very Late/Terminal Classic, preplanned project on a floodplain. These wetland fields were short-lived, aggraded rapidly but with some reoccupation in the Postclassic. All of these new models display the burgeoning evidence for intricate Maya interactions with wetlands, and the diversity of evidence from the relatively few studies underscores the infancy of our

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

    ERIC Educational Resources Information Center

    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…

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

    PubMed

    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. PMID:26196708

  9. Finds in Belize document Late Classic Maya salt making and canoe transport

    PubMed Central

    McKillop, Heather

    2005-01-01

    How did people in preIndustrial ancient civilizations produce and distribute bulk items, such as salt, needed for everyday use by their large urban populations? This report focuses on the ancient Maya who obtained quantities of salt at cities in the interior of the Yucatan peninsula of Mexico, Belize, and Guatemala in an area where salt is scarce. I report the discovery of 41 Late Classic Maya saltworks (anno Domini 600–900) in Punta Ycacos Lagoon on the south coast of Belize, including one with the first-known ancient Maya canoe paddle. The discoveries add important empirical information for evaluating the extent of surplus salt production and river transport during the height of Late Classic civilization in the southern Maya lowlands. The discovery of the saltworks indicates that there was extensive production and distribution of goods and resources outside the cities in the interior of the Yucatan. The discovery of a wooden canoe paddle from one of the Punta Ycacos saltworks, Ka'k' Naab', ties the production of salt to its inland transport by rivers and documents the importance of canoe trade between the coast and the interior during the Late Classic. Archaeological discovery of multiple saltworks on the Belizean coast represents surplus production of salt destined largely for the inland Peten Maya during their Late Classic peak, underscoring the importance of non-state-controlled workshop production in preIndustrial societies. PMID:15809426

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

    SciTech Connect

    Oglesby, Robert J; Erickson III, David J

    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.

  11. Migration to the Maya Biosphere Reserve, Guatemala: Why place matters

    PubMed Central

    Carr, David L.

    2009-01-01

    Virtually all migration research examines international migration or urbanization. Yet understudied rural migrants are of critical concern for environmental conservation and rural sustainable development. Despite the fact that a relatively small number of all migrants settle remote rural frontiers, these are the agents responsible for perhaps most of the tropical deforestation on the planet. Further, rural migrants are among the most destitute people worldwide in terms of economic and human development. While a host of research has investigated deforestation resulting from frontier migration, and a modest literature has emerged on frontier development, this article explores the necessary antecedent to tropical deforestation and poverty along agricultural frontiers: out-migration from origin areas. The data come from a 2000 survey with community leaders and key informants in 16 municipios of migrant origin to the Maya Biosphere Reserve (MBR), Petén, Guatemala. A common denominator among communities of migration origin to the Petén frontier was unequal resource access, usually land. Nevertheless, the factors driving resource scarcity were widely variable. Land degradation, land consolidation, and population growth prevailed in some communities but not in others. Despite similar exposure to community and regional level push factors, most people in the sampled communities did not out-migrate, suggesting that any one or combination of factors is not necessarily sufficient for out-migration. PMID:19657470

  12. The Maya calendar: why 13, 20 and 260?

    NASA Astrophysics Data System (ADS)

    Polyakova, O.

    Starting from August 13, 3114 BCE, a sort of a mathematical and astronomical measure of time for the Maya was the head of Draco, a constellation in the northern circumpolar sky, which (the head) passed the sky line in 13 days. The other part of the constellation, Draco's neck, passed with respect to the sky line 4 more times of 13 days each. Thus, in one ascension/descension, Draco's head and neck passed the sky line in 5×13 = 65 days. A descension was followed by an ascension, then a descension again and an ascension again -- to take on the whole 4×5×13 days until 30 April, i.e., 20×13 = 260 days. After that, in summer time, due to short nights, Draco was high above the sky line and was not considered relative to it, but the started count continued, to be repeated in another 260 days. Owing to the fact that the constellation is the closest to the Pole of the Ecliptic, its head and neck were always, in the same time of the year, observable for 4×5×13 = 260 days.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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).

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

    USGS Publications Warehouse

    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).

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

    PubMed

    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. PMID:22985108

  17. Correlating the Ancient Maya and Modern European Calendars with High-Precision AMS 14C Dating

    PubMed Central

    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 14C 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. PMID:23579869

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

    NASA Technical Reports Server (NTRS)

    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

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

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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

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

    ERIC Educational Resources Information Center

    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.

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

    ERIC Educational Resources Information Center

    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,…

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

    ERIC Educational Resources Information Center

    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…

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

    USGS Publications Warehouse

    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.

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

    ERIC Educational Resources Information Center

    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…

  6. 77 FR 53959 - Culturally Significant Object Imported for Exhibition Determinations: “Dancing Into Dreams, Maya...

    Federal Register 2010, 2011, 2012, 2013, 2014

    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,...

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

    ERIC Educational Resources Information Center

    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…

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

    PubMed Central

    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 3kDa leading to a metabolic phase (>3kDa) and a neurotoxic fraction (<3kDa). 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. PMID:26895025

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

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed

    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 (<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. PMID:26895025

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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. PMID:15950091

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

    PubMed

    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. PMID:22363005

  16. Secular trend for stature in adult male Yucatec Maya to 1968.

    PubMed

    McCullough, J M

    1982-06-01

    Statures for 64 adult male Yucatec Maya (18 + years old, sons of campesinos) were measured in 1968 and compared with mean statures presented in results for previous studies. There were no significant changes in mean stature since 1895. If the sample is divided into 5-year age groups, no secular trend is evident. Using osteological information from as early as the Late Preclassic, stature of adult Maya males has decreased 119 mm in a little more than 20 centuries (-0.06 cm/decade). Comparing the results with measurements from other Mesoamerican groups, only one--the Otomí--show evidence of significant secular change. It is possible that modern economic development schemes in Mesoamerica are too recent or ineffective to have had an effect on stature. PMID:7114203

  17. Epilithic and endolithic bacterial communities in limestone from a Maya archaeological site.

    PubMed

    McNamara, Christopher J; Perry, Thomas D; Bearce, Kristen A; Hernandez-Duque, Guillermo; Mitchell, Ralph

    2006-01-01

    Biodeterioration of archaeological sites and historic buildings is a major concern for conservators, archaeologists, and scientists involved in preservation of the world's cultural heritage. The Maya archaeological sites in southern Mexico, some of the most important cultural artifacts in the Western Hemisphere, are constructed of limestone. High temperature and humidity have resulted in substantial microbial growth on stone surfaces at many of the sites. Despite the porous nature of limestone and the common occurrence of endolithic microorganisms in many habitats, little is known about the microbial flora living inside the stone. We found a large endolithic bacterial community in limestone from the interior of the Maya archaeological site Ek' Balam. Analysis of 16S rDNA clones demonstrated disparate communities (endolithic: >80% Actinobacteria, Acidobacteria, and Low GC Firmicutes; epilithic: >50% Proteobacteria). The presence of differing epilithic and endolithic bacterial communities may be a significant factor for conservation of stone cultural heritage materials and quantitative prediction of carbonate weathering. PMID:16391878

  18. Experimental and theoretical spectroscopic studies of dye modification in synthetic Maya Blue pigment

    NASA Astrophysics Data System (ADS)

    Reza, Layra; Manciu, Felicia; Ramirez, Alejandra; Chianelli, Russell

    2009-03-01

    Maya pigments are hybrid organic/inorganic materials with multiple technology applications that possess unprecedented stability with respect to harsh environment conditions. In this investigation, we address the question of how the organic indigo dye modifies as it binds to the inorganic palygorskite clay to form a pigment similar to Maya Blue after a heating treatment is applied. Both infrared and Raman spectroscopic data demonstrate the disappearance of nitrogen-hydrogen (N-H) bonding, as the indigo molecule incorporates into the inorganic palygorskite material. This effect suggests a transformation of the dye from indigo to dehydroindigo. Furthermore, the Raman and infrared absorption results demonstrate partial elimination of the selection rules for the centrosymmetric indigo, which provides further evidence for this conversion. Theoretical spectroscopic studies are also addressed in this investigation to confirm the transformation of the dye into dehydroindigo.

  19. Paleomagnetic evidence for Post-Jurassic stability of southeastern Mexico: Maya Terrane

    NASA Astrophysics Data System (ADS)

    Guerrero, Jose C.; Herrero-Bervera, Emilio; Helsley, Charles E.

    1990-05-01

    The tectonic evolution of southeastern Mexico has been a subject of major controversy, not only in regard to past geometry but also in the timing of proposed geological events as well. For the past 10 years, most, if not all, investigators agree that the Gulf of Mexico Basin was formed by Late Jurassic time and that the Maya Terrane was in its current location prior to the Cretaceous. In order to gain further insight into the drift history of the Maya Terrane we have undertaken a paleomagnetic study of the uppermost Jurassic-Lower Cretaceous (Tithonian-lower Neocomian?) San Ricardo Formation in southeastern Mexico, at 93.7°W, 16.8°N. The sampling site is located east of the Isthmus of Tehuantepec, on the southwest side of the Maya block, at the base of the Yucatan Peninsula. A suite of 133 samples was collected in stratigraphic succession from a 114-m-thick sequence of red shales and sandstones near Cintalapa, Chiapas, Mexico. After progressive thermal demagnetization of all samples at six steps from 350°C to 630°C, 89 samples were selected for final paleopole analysis on the basis of their magnetic stability. Four different polarity intervals were observed, the sequence being from bottom to top: N, R, N, R which assists in the assessment of the reliability of the observations. The mean pole position obtained, 160.0°E, 69.8°N, agrees with the mean pole position of the upper part of the Morrison Formation of Colorado, a unit of virtually identical age. These results indicate that no discernible rotation or displacement of the Maya block has occurred since at least early Neocomian times.

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

    NASA Technical Reports Server (NTRS)

    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

  1. Putting us on the Map: Remote Sensing Investigation of the Ancient Maya Landscape

    NASA Technical Reports Server (NTRS)

    Sever, Thomas L.; Saturno, William; Irwin, Daniel E.

    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 Eol, satellites. 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 Ancient Maya settlement in the Lowlands.

  2. Patterned Ground in Wetlands of the Maya Lowlands: Anthropogenic and Natural Causes

    NASA Astrophysics Data System (ADS)

    Beach, T.; Beach, S. L.

    2004-12-01

    We use geological and archaeological evidence to understand the formation of patterned ground in perennial and seasonal wetlands in the karst depressions of Belize and Guatemala. Some scholars have argued that these features are the remnants of ancient Maya wetland fields, chinampas, on which intensive cultivation produced food that could begin to nourish the extremely high population of the Late Classic (A.D. 550-850). Others have argued that these were natural features or that they represent landscape manipulation for rising sea level in the Preclassic (1000 B.C. -A.D. 250). We present the evidence for ancient intensive agriculture and natural landscape formation with multiple proxies: excavated field and canal features, artifacts, pollen, soil stratigraphy, and water chemistry. Evidence thus far suggests that many regional depressions have Preclassic (1200 BC to AD 200) or earlier paleosols, buried from 1-2 m by eroded soils induced by Maya land use practices. These paleosols were buried by eroded sediments from uplands and by precipitation of gypsum from rising groundwater. The sedimentation occurred largely between the Preclassic and Late Classic, when ancient Maya farmers built canals in pre-existing low spots to reclaim these wetlands. Thus, stable natural processes, environmental change, and human manipulation have acted together to form patterned wetland ground over the later Holocene.

  3. Electron-microscopic observations of the gravity receptor epithelia of normal and spinner juvenile Octopus maya.

    PubMed

    Fermin, C D; Colmers, W F; Igarashi, M

    1985-01-01

    Light and electron microscopy of the gravity receptor epithelia (maculae) of statocysts of normal and "spinner" juvenile Octopus maya showed differences between the structures of the hair cells, supporting cells, and afferent neurons of these cephalopods. The maculae of spinner animals were approximately 30% smaller in their surface area and had 40% fewer hair cells. Moreover, the average distance between randomly-chosen hair bundles in scanning electron micrographs of maculae of normal animals was significantly greater (4.33 +/- 6.47 microns) than those of maculae of spinner animals (3.38 +/- 4.90 microns; P less than 0.0001). The sectional area of the supporting cell's microvilli in spinner maculae was larger (0.16 +/- 0.18 microns) than those of normal (0.10 +/- 0.10 micron; P less than 0.0001) O. maya. The morphological differences observed between certain structural components of the maculae of normal and spinner O. maya may be related to the absence and/or malformation of the neuroepithelial suprastructures in spinners. This may have direct or indirect effects to their inability to orient to gravity with these organs. PMID:2861903

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

    PubMed

    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. PMID:26650606

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Cultural and Climatic History of Cobá, a Lowland Maya City in Quintana Roo, Mexico

    NASA Astrophysics Data System (ADS)

    Leyden, Barbara W.; Brenner, Mark; Dahlin, Bruce H.

    1998-01-01

    Lake Cobá, within the archaeological site of Cobá, provides evidence bearing on lowland Maya development. Palynological and geochemical data record multidecadal precipitation cycles from a 8.80-m, >8370-yr lake-sediment sequence terminating on bedrock. Late Classic sedimentation rates are rapid, but an anthropogenically derived colluvium layer is lacking. Initial vegetation was medium semi-deciduous and swamp forest. Forest clearance began 1650 B.C. (Early Preclassic) and maize first occurred at 850 B.C. (Middle Preclassic). Lakeside milpas existed until A.D. 720 (Late Classic) and then were moved from the city center as urbanization intensified and Lake Cobá was diked as a reservoir. Cobá was at most briefly vacated during the Classic Collapse and was abandoned after A.D. 1240, although some habitation persisted. The paleoecological record matches the archaeological history for Cobá, but pervasive disturbance muted the climatic signal, as the Late Classic drought is barely evident. The question whether economic trees were maintained within the city is unresolved. Maize cultivation allowed the Maya to develop a complex society and support a large population, but dependence on maize was ultimately doomed by variable rainfall. Precipitation in extreme years was insufficient to support crops, while native vegetation was not directly affected by drought that devastated Maya agriculture.

  7. Relative Changes in C3 and C4 Biomass Recorded by Carbon Isotopes of Lipid Biomarkers in the Maya Lowlands of Petén, Guatemala

    NASA Astrophysics Data System (ADS)

    Newell, S. D.; Hodell, D. A.; Curtis, J. H.; Brenner, M.; Rosenmeier, M. F.

    2003-12-01

    Forest disturbance in the Petén region of northern Guatemala, beginning approximately 3000 cal yrs BP, was associated with the agricultural practices of the Maya. Expansion of the Maya civilization during the Preclassic and Classic periods was accompanied by widespread deforestation of Petén watersheds and accelerated rates of soil erosion. Palynological data from the Petén region suggest the near elimination of high forest taxa during the period of Classic Maya occupation. The validity of pollen records has been questioned, however, because they represent only a small percentage of tropical vegetation that is pollinated by wind. To estimate changes in the proportion of C3 to C4 vegetation in the Maya forest, we measured the δ 13C of long chain n-alkanes (C29 and C31) produced by higher terrestrial plants in a 4.1-m sediment core from Lake Sacnab, Guatemala. Deforestation during the period of Maya occupation is reflected in sediments cores by a distinct, clay-rich interval (termed the "Maya clay") that is characterized by low magnetic susceptibility and low organic carbon content. The δ 13C of long chain n-alkanes average -28‰ within the Maya clay, and decreases by 10‰ above the clay unit following the demise of the Classic Maya civilization in the 9th century A.D. Our results suggest that vegetation was dominated by C4 biomass during the Classic Maya period and is consistent with previous palynological interpretations. Reforestation following the demise of the Classic Maya is apparent in the pollen and compound-specific δ 13C records and indicates a switch back to a C3 dominated ecosystem once human pressures were curtailed. Compound-specific δ 13C analyses of biomarkers in Lake Sacnab sediment provide further evidence that the Maya had a profound impact on their lowland neotropical environment.

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    ERIC Educational Resources Information Center

    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…

  12. Latent and manifest empiricism in Q'eqchi' Maya healing: a case study of HIV/AIDS.

    PubMed

    Waldram, James B; Hatala, Andrew R

    2015-02-01

    This paper presents a case study of the traditional treatment of a Q'eqchi' Maya man in southern Belize in 2011 who is suffering from AIDS-related sickness. The purpose is to detail the empirical nature of Q'eqchi' Maya medicine, distinguishing between manifest and latent empiricism, as evidenced in the healers evolving attempts to treat the patient in the absence of knowledge of his biomedical diagnosis. The paper argues for a more complete understanding of the empirical nature of much Indigenous healing, which parallels aspects of scientific medicine, and for better collaboration among traditional healers and biomedical practitioners in strongly Indigenous areas. PMID:25497726

  13. The Venus "Shell-over-Star" hieroglyph and Maya warfare: An examination of the interpretation of a Mayan symbol

    NASA Astrophysics Data System (ADS)

    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

  14. Thermopreference, tolerance and metabolic rate of early stages juvenile Octopus maya acclimated to different temperatures.

    PubMed

    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. PMID:24229799

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

    PubMed Central

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

    2014-01-01

    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. PMID:25512500

  16. Environmental and morphological changes around the Maritime Maya site Vista Alegre.

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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. PMID:25512500

  18. A reassessment of the impact of drought cycles on the Classic Maya

    NASA Astrophysics Data System (ADS)

    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.

  19. Devonian-Ordovician Magmatism in Chiapas Massif, Southern Maya Block, Mexico

    NASA Astrophysics Data System (ADS)

    Pompa-Mera, V.; Schaaf, P.; Weber, B.; Solis-Pichardo, G.; Hernandez-Trevino, T.; Ortega-Gutierrez, F.

    2008-12-01

    The Chiapas Massif (CM) is located in SE Mexico and extends over an area of more than 20,000 Km2 parallel to the Pacific coast between the Isthmus of Tehuantepec and the Guatemalan border. It constitutes the largest batholitic complex in Mexico and belongs to the Maya Block. The CM is predominantly formed by igneous, metaigneous and metasedimentary rocks. In the central CM several magmatic and metamorphic events have been identified in igneous rocks between Late Permian and Triassic times (220-240 Ma), together with a Jurassic tectonothermal event. Recent geochronological studies have been focused on granitic rocks from the central-southeastern CM and from this area, single grain zircon ages were also obtained from metasedimentary rocks. The results suggest that the basement rocks of the eastern CM and the Maya Block underwent several tectonothermal events since Ordovician and Devonian times. In this work, we present new data of magmatic and metamorphic rocks from the easternmost part of CM which confirms this hypothesis. Additionally, we present a semi-detailed geological map of this area showing some field relationship between the different units. We identified a new basal sequence significantly older than the Santa Rosa Formation, which has been considered up to now as forming the major underlying sequence of the CM, as well as the occurrence of several magmatic events in the Maya Block and in rocks from surrounding areas. The petrological, geochemical and geochronological features of these rocks show continuous crust recycling, the occurrence of within-plate magmatism in some parts with inherited Greenvillian and Archaean zircon grains as well as the occurrence of arc magmatism previous to accretion, deformation and terrane separation of the crustal blocks. Our new geochronological results obtained from the south easternmost part of the CM include a Rb-Sr biotite-muscovite age of 392+/-9 Ma and an Ar-Ar muscovite age of 406+/- 4 Ma from a tectonized granitic

  20. High-resolution speleothem record of precipitation from the Yucatan Peninsula spanning the Maya Preclassic Period

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    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.

  3. Laboratory maintenance, breeding, rearing, and biomedical research potential of the Yucatan octopus (Octopus maya).

    PubMed

    Van Heukelem, W F

    1977-10-01

    Eggs of the Yucatan octopus, Octopus maya, were collected at Campeche, Mexico, transported to Hawaii, and incubated in glass funnels. Benthic juveniles hatched from the large (17-mm) eggs and were reared on a variety of live and frozen foods. As many as 200 animals were reared for the first month in a 20-liter aquarium. No disease or parasite problems were encountered and nearly all well-fed juveniles survived to sexual maturity. The species was reared through four generations in the laboratory. Animals weighed 0.1 g at hatching and within 8.5 months attained an average weight of 3231 g. Mating was promiscuous and sperm were stored in the oviducts until spawning. Spawning occurred at 8-9 months of age. Up to 5,000 eggs were laid by large females and nearly 100% of fertilized eggs developed to hatching. Females brooded eggs during the 45-day period of development but artificial was as successful as natural incubation by the mother. Pos-reproductive senescent decline of both males and females was rapid and average life span was 300 days from hatching. Areas of biomedical research in which O maya could be a useful model were suggested and included neurobiology, comparative psychology, ontogeny of behavior, immunology, endocrinology, and studies of aging. PMID:592733

  4. [Growth of Octopus maya (Mollusca: Cephalopoda) of the Yucatan coast, Mexico: a long-term analysis].

    PubMed

    Nepita Villanueva, M R; Defeo, O

    2001-03-01

    Growth of the octopus (Octopus maya) off Yucatan (Mexico) was estimated from a long-term study (seven years) by the length-based methods ELEFAN, PROJMAT and SLCA. Some 19,251 octopuses with a range of mantle length between 50 and 240 mm were sampled from commercial landings in 1983-1987, 1989 and 1992. The jackknife technique was applied to deal with uncertainty in growth estimates resulting from chance variations in sampling design. The growth index phi' was used for comparative purposes. Results differed markedly among methods: ELEFAN produced parameter estimates within the range reported in the literature, whereas PROJMAT and SLCA showed problems to converge in an optimum combination of parameters, and tended to underestimate them. Jackknife analysis revealed very low intraannual variability in phi' but high variability among years, especially when applying PROJMAT. No significant differences were found in precision parameters--percent error and coefficient of variation--among methods. Estimates of phi' derived by ELEFAN varied between 4.19 and 5.23 and agreed with those reported in the literature (between 4.25 and 4.91), whereas PROJMAT and SLCA estimates were significantly lower. We suggest the use of ELEFAN, together with jackknife, to estimate growth parameters of Octopus maya. PMID:11795175

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

    PubMed Central

    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

  6. Conceptualizing socio-hydrological drought processes: the rise and fall of the Ancient Maya civilization

    NASA Astrophysics Data System (ADS)

    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.

  7. Speech and gesture in spatial language and cognition among the Yucatec Mayas.

    PubMed

    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. PMID:21668826

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

    ERIC Educational Resources Information Center

    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…

  9. Translating Maya Angelou's Theme, "We are more alike, my friends/Than we are unalike," into Effective Multicultural Study.

    ERIC Educational Resources Information Center

    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 differences,…

  10. Feeling the pulse in Maya medicine: an endangered traditional tool for diagnosis, therapy, and tracking patients' progress.

    PubMed

    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. PMID:18316054

  11. Gonad development during the early life of Octopus maya (Mollusca: Cephalopoda).

    PubMed

    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. PMID:19218496

  12. The African-American grandmother in autobiographical works by Frederick Douglass, Langston Hughes, and Maya Angelou.

    PubMed

    Hill-Lubin, M A

    1991-01-01

    Using the autobiographies of Frederick Douglass, Langston Hughes, and Maya Angelou, this article demonstrates that the portrait of the African-American grandmother is one of action, involvement, hope, and dignity. In examining the works, we observe her functioning in three areas: as the preserver and most tenacious survivor of the African extended family; second, as repository and distributor of the family history, wisdom, and black lore; this role places her at the foundation of the Black, oral and written, literary and creative traditions; and third, as the retainer and transmitter of values and ideals that support and enhance her humanity, her family, and her community. This function emphasizes her spirituality. It is suggested that the grandmother, having played an important role in the growth, development, and artistic flowering of the autobiographer, can become a model and source of empowerment for future generations. PMID:1955211

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

    NASA Technical Reports Server (NTRS)

    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.

  14. A mask for high-intensity heavy-ion beams in the MAYA active target

    NASA Astrophysics Data System (ADS)

    Rodríguez-Tajes, C.; Pancin, J.; Damoy, S.; Roger, T.; Babo, M.; Caamaño, M.; Farget, F.; Grinyer, G. F.; Jacquot, B.; Pérez-Loureiro, D.; Ramos, D.; Suzuki, D.

    2014-12-01

    The use of high-intensity and/or heavy-ion beams in active targets and time-projection chambers is often limited by the strong ionization produced by the beam. Besides the difficulties associated with the saturation of the detector and electronics, beam-related signals may hide the physical events of interest or reduce the detector performance. In addition, space-charge effects may deteriorate the homogeneity of the electric drift field and distort the subsequent reconstruction of particle trajectories. In anticipation of future projects involving such conditions, a dedicated beam mask has been developed and tested in the MAYA active target. Experimental results with a 136Xe beam are presented.

  15. 12C+p resonant elastic scattering in the Maya active target

    NASA Astrophysics Data System (ADS)

    Sambi, S.; Raabe, R.; Borge, M. J. G.; Caamano, M.; Damoy, S.; Fernández-Domínguez, B.; Flavigny, F.; Fynbo, H.; Gibelin, J.; Grinyer, G. F.; Heinz, A.; Jonson, B.; Khodery, M.; Nilsson, T.; Orlandi, R.; Pancin, J.; Perez-Loureiro, D.; Randisi, G.; Ribeiro, G.; Roger, T.; Suzuki, D.; Tengblad, O.; Thies, R.; Datta, U.

    2015-03-01

    In a proof-of-principle measurement, the Maya active target detector was employed for a 12C( p, p) resonant elastic scattering experiment in inverse kinematics. The excitation energy region from 0 to 3MeV above the proton breakup threshold in 13N was investigated in a single measurement. By using the capability of the detector to localize the reaction vertex and record the tracks of the recoiling protons, data covering a large solid angle could be utilized, at the same time keeping an energy resolution comparable with that of direct-kinematics measurements. The excitation spectrum in 13N was fitted using the R-matrix formalism. The level parameters extracted are in good agreement with previous studies. The active target proved its potential for the study of resonant elastic scattering in inverse kinematics with radioactive beams, when detection efficiency is of primary importance.

  16. Coca-colonization and hybridization of diets among the Tz'utujil Maya.

    PubMed

    Nagata, Jason M; Barg, Frances K; Valeggia, Claudia R; Bream, Kent D W

    2011-01-01

    Biomedical health professionals express increasing concern that rising consumption of soft drinks and processed foods in Mayan and Latin American eating patterns may lead to detrimental nutritional and health consequences. Scholars debate whether the pervading presence of Coca-Cola and Pepsi in developing countries represents "Coca-Colonization," synonymous with cultural imperialism, or cultural hybridization. Using mixed qualitative and quantitative research methods, including participant observation and semi-structured interviews, this study explores the development of Coca-Colonization and cultural hybridization among the Tz'utujil Maya of Santiago Atitlán, Guatemala. By specifically examining biomedical perspectives, cycles of conquest, the political economy, religion, celebrations, and the physical environment through the lens of soft drinks, this study finds that Coca-Colonization and cultural hybridization are complementary rather than mutually exclusive processes that contribute to dietary transitions, economic development, and differential health beliefs related to soft drink consumption. PMID:21888598

  17. Paleomagnetism of the Todos Santos Formation in the Maya Block, Chiapas, Mexico: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Godinez-Urban, A.; Molina-Garza, R. S.; Iriondo, A.; Geissman, J. W.

    2008-12-01

    Preliminary results of a paleomagnetic study on jurassic volcanic rocks (U-Pb 188.8 +/- 3.2Ma) locally interbedded with red beds assigned to the Todos Santos Formation, sampled in the Homoclinal Tectonic Province of the Neogene Fold Belt, Chiapas-Mexico, reveal multi component magnetizations acquired during pre- and post- folding of these rocks. The samples responded well to thermal demagnetization, but not so to AF demagnetization, suggesting that a high coercivity mineral phase like hematite is the main remanence carrier. The post-folding B-component direction of Dec=174.3 Inc=-30.6 (k=46; alpha95=13.6; N=4) represents a recent Tertiary? overprint; while the pre-folding C-component direction of Dec=329.9 Inc=7.8 (k=12.5; alpha95=16.3; N=8) is in agreement with a previously reported small data set for the Todos Santos Formation. When compared to the North American reference direction (Jurassic Kayenta Formation) the observed direction indicates a counterclockwise rotation of 35.9 +/- 16.6 degrees, and moderate north to south latitudinal displacement. If a reference pole from NE North America is used, the amount of counterclockwise rotation and latitudinal displacement are both slightly reduced. If the assumption that Jurassic strata in Chiapas reflect displacement of the Maya Block, then these data are consistent with reconstructions of the Maya Block in the Gulf of Mexico region. Other sites sampled in Jurassic strata suggest that in addition to the interpreted regional rotation, local (vertical-axis) rotations may have affected the region in more recent times.

  18. Analysis of 16 autosomal STRs and 17 Y-STRs in an indigenous Maya population from Guatemala.

    PubMed

    Cardoso, Sergio; Sevillano, Rubén; Illescas, María J; de Pancorbo, Marian Martínez

    2016-03-01

    The aim of this study was to contribute new data on autosomal STR and Y-STR markers of the Mayas from Guatemala in order to improve available databases of forensic interest. We analyzed 16 autosomal STR markers in a population sample of 155 indigenous Maya and 17 Y-chromosomal STR markers in the 100 males of the sample. Deviations from Hardy-Weinberg equilibrium and linkage disequilibrium between autosomal STR markers were not observed at any loci. The combined power of exclusion was estimated as 99.9991% and the combined power of discrimination was >99.999999999999%. Haplotype diversity of Y-STRs was calculated as 0.9984 ± 0.0018 and analysis of pairwise genetic distances (Rst) supported the Native American background of the population. PMID:25935237

  19. Inferring Ancient Technology and Practices of the Elite Maya Kingship Through the Application of Materials Engineering Characterization Modalities

    NASA Astrophysics Data System (ADS)

    Cheung, Kristina Alyssa

    This project focuses on the characterization of materials from burial offerings and painted decoration in a royal Maya tomb at El Zotz, Guatemala, and their association with mortuary rituals. Archaeological findings included vessels, jade masks, organic materials (wood, cord, and textiles), specular hematite cubes, shells with powdered cinnabar, green (malachite) painted stucco assumed to have decorated the wooden bier where the king was resting, and caches of lip-to-lip Aguila Orange bowls containing human phalanges. This paper describes findings from non-invasive and non-destructive analytical techniques including XRF, VPSEM-EDS, and XRD, emphasizing the potential of these combined technologies in the identification of organic and inorganic markers to infer burial customs. The nature and location of the findings, the evidence of pigment coloration on the bones employing hematite and cinnabar, and the indication of exposure of the bones to high temperatures suggest highly complex, even protracted mortuary practices of Maya elite.

  20. High Resolution, Multi-Proxy Records of Holocene Biomass Burning, Environmental Change, and Human Occupation in the Southern Maya Lowlands

    NASA Astrophysics Data System (ADS)

    Anderson, L.; Wahl, D.

    2011-12-01

    Understanding the relationship between the prehistoric Maya and their environment continues to be a primary research focus, particularly with respect to discerning the role of humans versus climate in driving environmental change. Fire was fundamental to prehistoric Maya architectural and agricultural land use practices. Burning was used to open forest for cultivation as well as for the construction of site centers and settlements. The production of lime plaster, and important building material, was dependent on significant amounts of green wood for kiln fuel. Large populations employing land use strategies dependent on burning would have put tremendous demands on forest resources. Despite the significance of fire in Maya pre-history, there has been no focused effort to produce records of biomass burning and its impacts. Here we present preliminary high-resolution fossil charcoal data that span the Holocene from a network of lacustrine and paludal sites across Peten, Guatemala. Charcoal influx data from the early to mid Holocene, prior to the arrival of sedentary agriculturalists, provides a baseline to infer natural fire regimes under specific climatic conditions, increasing our understanding of tropical fire ecology. Charcoal deposition that co-varies with evidence of agriculture and human activity can be attributed to anthropogenic burning. Results are synthesized with existing data (pollen, δ18O and δ13C, magnetic susceptibility, and physical properties) in an effort to understand the processes driving the location, timing, and extent of fires across the region. Placed in the context of changes in vegetation, sedimentation regime, and hydrology, these data provide new insight into topical fire ecology before the period of human occupation, as well as the dynamic relationship between the prehistoric Maya and their environment.

  1. Population dynamics and stock assessment for Octopus maya (Cephalopoda: Octopodidae) fishery in the Campeche Bank, Gulf of Mexico.

    PubMed

    Arreguín-Sánchez, F; Solís-Ramírez, M J; González de la Rosa, M E

    2000-01-01

    The octopus (Octopus maya) is one of the most important fish resources in the Mexican Gulf of Mexico with a mean annual yield of 9000 ton, and a reasonable number of jobs created; O. maya represents 80% of the total octopus catch, followed by Octopus vulgaris. There are two artisanal fleets based on Octopus maya and a middle-size fleet that covers both species. Catch-at-length structured data from the artisanal fleets, for the 1994 season (August 1st to December 15th) were used to analyze the O. maya population dynamics and stock and to estimate the current level of exploitation. Von Bertalanffy growth parameters were: L infinity = 252 mm, mantle length; K = 1.4 year-1; oscillation parameters C = 1.0, WP = 0.6; and tz = 0.842 years. A rough estimate of natural mortality was M = 2.2, total mortality from catch curve Z = 8.77, and exploitation rate F/Z = 0.75. This last value suggests an intensive exploitation, even when yield per recruit analysis indicates both fleets may increase the minimum legal size on about 10% to increase yields. The length-based VPA also shows that the stock is being exploited under its maximum acceptable biological limit. These apparently contradictory results are explained by biological and behavioral characteristics of this species. Because most females die after reproduction, a new gross estimation of natural mortality was computed as M = 3.3. The new estimate of exploitation rate was F/Z = 0.57. This new value coincides with results from the length-VPA and the Thompson and Bell methods, the former suggesting that a reduction of 20% in fishing mortality may provide larger yields. This fishery resource is fully exploited and current management measures must be revised to sustain and probably optimize yields. PMID:11354940

  2. “Symptoms, Attitudes and Treatment Choices Surrounding Menopause among the Q’eqchi Maya of Livingston, Guatemala”

    PubMed Central

    Michel, Joanna L.; Veliz, Mario; Soejarto, Doel D.; Caceres, Armando; Mahady, Gail B

    2006-01-01

    The present study explored symptoms, attitudes and treatments surrounding women’s health and menopause among the Q’eqchi Maya of the eastern tropical lowlands of Guatemala. Data were obtained through participant observation, semi-structured interviews, focus groups and plant walks with 50 Q’eqchi community members from the state of Izabal, Municipality of Livingston, including 5 midwives, 5 traditional male healers and 8 postmenopausal women. Results indicate that the Q’eqchi Maya of Livingston possess their own cultural perceptions of women’s health which affect attitudes, symptoms and treatment choices during the menopausal transition. Since discussions of menstruation and menopause are considered cultural taboos among the Q’eqchi, many women mentioned experiencing excessive preoccupation when unanticipated and unfamiliar symptoms occurred. Furthermore, many women suffered from additional hardship when their spouse misinterpreted menopausal symptoms (vaginal dryness, sexual disinterest) as infidelity. Seven of the eight postmenopausal women interviewed indicated experiencing one or more symptoms during the menopausal transition, including headaches, anxiety, muscular pain, depression, and hot flashes. These results differ from the lack of symptomatology reported in previous studies in Mexico, but are in line with the result of menopausal research conducted among other Maya groups from the highlands of Guatemala. Although the Q’eqchi did not use a specific term for “hot flash”, three Q’eqchi women used the expression “baja presion” or a “lowering of blood pressure” to explain symptoms of profuse sweating followed by chills, heart palpitations, and emotional instability. The Q’eqchi Maya mentioned a number of herbal remedies to treat menopausal symptoms. Further research on these botanical treatments is needed in order to ascertain their safety and efficacy for continued use. PMID:16580764

  3. Classic Maya Bloodletting and the Cultural Evolution of Religious Rituals: Quantifying Patterns of Variation in Hieroglyphic Texts

    PubMed Central

    Munson, Jessica; Amati, Viviana; Collard, Mark; Macri, Martha J.

    2014-01-01

    Religious rituals that are painful or highly stressful are hypothesized to be costly signs of commitment essential for the evolution of complex society. Yet few studies have investigated how such extreme ritual practices were culturally transmitted in past societies. Here, we report the first study to analyze temporal and spatial variation in bloodletting rituals recorded in Classic Maya (ca. 250–900 CE) hieroglyphic texts. We also identify the sociopolitical contexts most closely associated with these ancient recorded rituals. Sampling an extensive record of 2,480 hieroglyphic texts, this study identifies every recorded instance of the logographic sign for the word ch’ahb’ that is associated with ritual bloodletting. We show that documented rituals exhibit low frequency whose occurrence cannot be predicted by spatial location. Conversely, network ties better capture the distribution of bloodletting rituals across the southern Maya region. Our results indicate that bloodletting rituals by Maya nobles were not uniformly recorded, but were typically documented in association with antagonistic statements and may have signaled royal commitments among connected polities. PMID:25254359

  4. A likely case of scurvy in a rural Early Classic Maya burial from Actun Uayazba Kab, Belize.

    PubMed

    Wrobel, Gabriel

    2014-11-01

    A Maya burial of a late adolescent (Burial 98-3) found in the rockshelter entrance of Actun Uayazba Kab (AUK), Belize, displays a combination of lesions that is consistent with scurvy. Signs include large, active lesions on the posterior surfaces of maxilla; relatively mild porotic hyperostosis along the midline of the skull on the parietals and occipital; cribra orbitalia; potential pinprick lesions on the greater wings of sphenoid and temporal; reactive lesions on the palate, temporal lines of frontal and parietals, and external and internal surfaces of zygomatics; small lesions on the popliteal surfaces of both femora; and periodontal disease. Identification of scurvy at AUK potentially informs the analysis of other primary burials and scattered bone found there and at other nearby sites, which often reveal evidence of nonspecific lesions that are usually attributed to anemia and infection, but that are also consistent with scurvy. The social and ecological context of this Protoclassic (0-AD 300) individual, who lived in a rural agricultural community with no evidence of complex social hierarchy, contrasts with typical discussions of disease among the Maya, which tend to focus on the degrading effects of overcrowding and resource deficiencies. While scurvy has been largely overlooked in the Maya area, this study supports earlier arguments for its presence that were based largely on clinical and ethnographic analogies and suggests the need to incorporate scurvy into broader synergistic models of ancient health. PMID:25105478

  5. Three-dimensional visualization of nanostructured surfaces and bacterial attachment using Autodesk® Maya®

    PubMed Central

    Boshkovikj, Veselin; Fluke, Christopher J.; Crawford, Russell J.; Ivanova, Elena P.

    2014-01-01

    There has been a growing interest in understanding the ways in which bacteria interact with nano-structured surfaces. As a result, there is a need for innovative approaches to enable researchers to visualize the biological processes taking place, despite the fact that it is not possible to directly observe these processes. We present a novel approach for the three-dimensional visualization of bacterial interactions with nano-structured surfaces using the software package Autodesk Maya. Our approach comprises a semi-automated stage, where actual surface topographic parameters, obtained using an atomic force microscope, are imported into Maya via a custom Python script, followed by a ‘creative stage', where the bacterial cells and their interactions with the surfaces are visualized using available experimental data. The ‘Dynamics' and ‘nDynamics' capabilities of the Maya software allowed the construction and visualization of plausible interaction scenarios. This capability provides a practical aid to knowledge discovery, assists in the dissemination of research results, and provides an opportunity for an improved public understanding. We validated our approach by graphically depicting the interactions between the two bacteria being used for modeling purposes, Staphylococcus aureus and Pseudomonas aeruginosa, with different titanium substrate surfaces that are routinely used in the production of biomedical devices. PMID:24577105

  6. Development of sedentary communities in the Maya lowlands: Coexisting mobile groups and public ceremonies at Ceibal, Guatemala

    PubMed Central

    Inomata, Takeshi; MacLellan, Jessica; Triadan, Daniela; Munson, Jessica; Burham, Melissa; Aoyama, Kazuo; Nasu, Hiroo; Pinzón, Flory; Yonenobu, Hitoshi

    2015-01-01

    Our archaeological investigations at Ceibal, a lowland Maya site located in the Pasión region, documented that a formal ceremonial complex was built around 950 B.C. at the onset of the Middle Preclassic period, when ceramics began to be used in the Maya lowlands. Our refined chronology allowed us to trace the subsequent social changes in a resolution that had not been possible before. Many residents of Ceibal appear to have remained relatively mobile during the following centuries, living in ephemeral post-in-ground structures and frequently changing their residential localities. In other parts of the Pasión region, there may have existed more mobile populations who maintained the traditional lifestyle of the preceramic period. Although the emerging elite of Ceibal began to live in a substantial residential complex by 700 B.C., advanced sedentism with durable residences rebuilt in the same locations and burials placed under house floors was not adopted in most residential areas until 500 B.C., and did not become common until 300 B.C. or the Late Preclassic period. During the Middle Preclassic period, substantial formal ceremonial complexes appear to have been built only at a small number of important communities in the Maya lowlands, and groups with different levels of sedentism probably gathered for their constructions and for public rituals held in them. These collaborative activities likely played a central role in socially integrating diverse groups with different lifestyles and, eventually, in developing fully established sedentary communities. PMID:25831523

  7. Three-dimensional visualization of nanostructured surfaces and bacterial attachment using Autodesk® Maya®.

    PubMed

    Boshkovikj, Veselin; Fluke, Christopher J; Crawford, Russell J; Ivanova, Elena P

    2014-01-01

    There has been a growing interest in understanding the ways in which bacteria interact with nano-structured surfaces. As a result, there is a need for innovative approaches to enable researchers to visualize the biological processes taking place, despite the fact that it is not possible to directly observe these processes. We present a novel approach for the three-dimensional visualization of bacterial interactions with nano-structured surfaces using the software package Autodesk Maya. Our approach comprises a semi-automated stage, where actual surface topographic parameters, obtained using an atomic force microscope, are imported into Maya via a custom Python script, followed by a 'creative stage', where the bacterial cells and their interactions with the surfaces are visualized using available experimental data. The 'Dynamics' and 'nDynamics' capabilities of the Maya software allowed the construction and visualization of plausible interaction scenarios. This capability provides a practical aid to knowledge discovery, assists in the dissemination of research results, and provides an opportunity for an improved public understanding. We validated our approach by graphically depicting the interactions between the two bacteria being used for modeling purposes, Staphylococcus aureus and Pseudomonas aeruginosa, with different titanium substrate surfaces that are routinely used in the production of biomedical devices. PMID:24577105

  8. Classic Maya bloodletting and the cultural evolution of religious rituals: quantifying patterns of variation in hieroglyphic texts.

    PubMed

    Munson, Jessica; Amati, Viviana; Collard, Mark; Macri, Martha J

    2014-01-01

    Religious rituals that are painful or highly stressful are hypothesized to be costly signs of commitment essential for the evolution of complex society. Yet few studies have investigated how such extreme ritual practices were culturally transmitted in past societies. Here, we report the first study to analyze temporal and spatial variation in bloodletting rituals recorded in Classic Maya (ca. 250-900 CE) hieroglyphic texts. We also identify the sociopolitical contexts most closely associated with these ancient recorded rituals. Sampling an extensive record of 2,480 hieroglyphic texts, this study identifies every recorded instance of the logographic sign for the word ch'ahb' that is associated with ritual bloodletting. We show that documented rituals exhibit low frequency whose occurrence cannot be predicted by spatial location. Conversely, network ties better capture the distribution of bloodletting rituals across the southern Maya region. Our results indicate that bloodletting rituals by Maya nobles were not uniformly recorded, but were typically documented in association with antagonistic statements and may have signaled royal commitments among connected polities. PMID:25254359

  9. Raman and infrared study of synthetic Maya pigments as a function of heating time and dye concentration

    NASA Astrophysics Data System (ADS)

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

    2007-03-01

    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. The oxygen carbonyl is also believed to interact with the metal.

  10. Purification and partial characterization of an agglutinin from Octopus maya serum.

    PubMed

    Alpuche, Juan; Pereyra, Ali; Mendoza-Hernández, Guillermo; Agundis, Concepción; Rosas, Carlos; Zenteno, Edgar

    2010-05-01

    A 66-kDa lectin (OmA) was purified from the serum of the Yucatan peninsula endemic octopus (Octopus maya) by a single step affinity chromatography on glutaraldehyde-fixed stroma from rat erythrocytes. OmA corresponds to 0.8% of the total circulating protein in the hemolymph; it is composed of three equal subunits of 22kDa each, and 7.4% of linked carbohydrates. The amino acids' composition indicated that agglutinin contained mainly aspartic and glutamic acids, and cysteine and methionine were identified in minor proportion. OmA agglutinates mainly rat, guinea pig, and rabbit erythrocytes, and this activity is partially inhibited by galactosamine, melobiose, galacturonic acid, mannose, and methyl alpha and beta galactosides. Hemagglutinating activity is not dependent on divalent cations, such as Ca(2+), Mg(2+), or Mn(2+). The OmA subunits showed no identity for any lectin in databases but partial identity with the type A hemocyanin from Octopus dolfleini hemolymph; the main similarities are related to tyrosinase domains and copper A and B sites that conform to the oxygen-binding site of hemocyanin. PMID:20105460

  11. Holocene vegetation change in the northern Peten and its implications for Maya prehistory

    NASA Astrophysics Data System (ADS)

    Wahl, David; Byrne, Roger; Schreiner, Thomas; Hansen, Richard

    2006-05-01

    An ˜8400 cal yr record of vegetation change from the northern Peten, Guatemala, provides new insights into the environmental history of the archaeological area known as the Mirador Basin. Pollen, loss on ignition, and magnetic susceptibility analyses indicate warm and humid conditions in the early to mid-Holocene. Evidence for a decrease in forest cover around 4600 cal yr B.P. coincides with the first appearance of Zea mays pollen, suggesting that human activity was responsible. The period between 3450 cal yr B.P. and 1000 cal yr B.P. is characterized by a further decline in forest pollen types, includes an abrupt increase in weedy taxa, and exhibits the highest magnetic susceptibility values since the early Holocene, all of which suggest further agricultural disturbance in the watershed. A brief drop in disturbance indicators around 1800 cal yr B.P. may represent the Preclassic abandonment of the area. Changing pollen frequencies around 1000 cal yr B.P. indicate a cessation of human disturbance, which represents the Late Classic collapse of the southern Maya lowlands.

  12. Cultural teaching: the development of teaching skills in Maya sibling interactions.

    PubMed

    Maynard, Ashley E

    2002-01-01

    Psychology has considered the development of learning, but the development of teaching in childhood has not been considered. The data presented in this article demonstrate that children develop teaching skills over the course of middle childhood. Seventy-two Maya children (25 boys, 47 girls) ranging in age from 3 to 11 years (M = 6.8 years) were videotaped in sibling caretaking interactions with their 2-year-old brothers and sisters (18 boys, 18 girls). In the context of play, older siblings taught their younger siblings how to do everyday tasks such as washing and cooking. Ethnographic observations, discourse analyses, and quantification of discourse findings showed that children's teaching skills increased over the course of middle childhood. By the age of 4 years, children took responsibility for initiating teaching situations with their toddler siblings. By the age of 8 years, children were highly skilled in using talk combined with manual demonstrations, verbal feedback, explanations, and guiding the body of younger learners. Children's developing competence in teaching helped their younger siblings increase their participation in culturally important tasks. PMID:12038563

  13. Architecture as animate landscape: circular shrines in the ancient Maya lowlands.

    PubMed

    Harrison-Buck, Eleanor

    2012-01-01

    In this study, I develop a theory of landscape archaeology that incorporates the concept of “animism” as a cognitive approach. Current trends in anthropology are placing greater emphasis on indigenous perspectives, and in recent decades animism has seen a resurgence in anthropological theory. As a means of relating in (not to) one's world, animism is a mode of thought that has direct bearing on landscape archaeology. Yet, Americanist archaeologists have been slow to incorporate this concept as a component of landscape theory. I consider animism and Nurit Bird-David's (1999) theory of “relatedness” and how such perspectives might be expressed archaeologically in Mesoamerica. I examine the distribution of marine shells and cave formations that appear incorporated as architectural elements on ancient Maya circular shrine architecture. More than just “symbols” of sacred geography, I suggest these materials represent living entities that animate shrines through their ongoing relationships with human and other-than-human agents in the world. PMID:22662354

  14. Antifungal Saponins from the Maya Medicinal Plant Cestrum schlechtendahlii G. Don (Solanaceae).

    PubMed

    Ta, Chieu Anh Kim; Guerrero-Analco, J Antonio; Roberts, Elizabeth; Liu, Rui; Mogg, Christopher D; Saleem, Ammar; Otárola-Rojas, Marco; Poveda, Luis; Sanchez-Vindas, Pablo; Cal, Victor; Caal, Federico; Subramaniam, Rajagopal; Smith, Myron L; Arnason, John T

    2016-03-01

    Bioassay-guided fractionation of the crude extract (80% EtOH) of the leaves of Cestrum schlechtendahlii, a plant used by Q'eqchi' Maya healers for treatment of athlete's foot, resulted in the isolation and identification of two spirostanol saponins (1 and 2). Structure elucidation by MS, 1D-NMR, and 2D-NMR spectroscopic methods identified them to be the known saponin (25R)-1β,2α-dihydroxy-5α-spirostan-3-β-yl-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-galactopyranoside (1) and new saponin (25R)-1β,2α-dihydroxy-5α-spirostan-3-β-yl-O-β-D-galactopyranoside (2). While 2 showed little or no antifungal activity at the highest concentration tested, 1 inhibited growth of Saccharomyces cerevisiae (minimum inhibitory concentration (MIC) of 15-25 μM), Candida albicans, Cryptococcus neoformans, and Fusarium graminearum (MIC of 132-198 μM). PMID:26666462

  15. Cacao domestication I: the origin of the cacao cultivated by the Mayas.

    PubMed

    Motamayor, J C; Risterucci, A M; Lopez, P A; Ortiz, C F; Moreno, A; Lanaud, C

    2002-11-01

    Criollo cacao (Theobroma cacao ssp. cacao) was cultivated by the Mayas over 1500 years ago. It has been suggested that Criollo cacao originated in Central America and that it evolved independently from the cacao populations in the Amazon basin. Cacao populations from the Amazon basin are included in the second morphogeographic group: Forastero, and assigned to T. cacao ssp. sphaerocarpum. To gain further insight into the origin and genetic basis of Criollo cacao from Central America, RFLP and microsatellite analyses were performed on a sample that avoided mixing pure Criollo individuals with individuals classified as Criollo but which might have been introgressed with Forastero genes. We distinguished these two types of individuals as Ancient and Modern Criollo. In contrast to previous studies, Ancient Criollo individuals formerly classified as 'wild', were found to form a closely related group together with Ancient Criollo individuals from South America. The Ancient Criollo trees were also closer to Colombian-Ecuadorian Forastero individuals than these Colombian-Ecuadorian trees were to other South American Forastero individuals. RFLP and microsatellite analyses revealed a high level of homozygosity and significantly low genetic diversity within the Ancient Criollo group. The results suggest that the Ancient Criollo individuals represent the original Criollo group. The results also implies that this group does not represent a separate subspecies and that it probably originated from a few individuals in South America that may have been spread by man within Central America. PMID:12399997

  16. Women's labor, fertility, and the introduction of modern technology in a rural Maya village.

    PubMed

    Kramer, K L; Mcmillan, G P

    1999-01-01

    The introduction of mechanized technology into a rural Maya agricultural community in the mid 1970s markedly increased the technology with which maize could be ground and water collected, which in turn introduced a possible savings in the time spent working. This study investigated the response of female fertility to the introduction of this labor-saving technology. Using two proximate determinants of female fertility, the association between the advent of modern technology and changes in the age at which women give birth to their first child and the length of mothers' birth intervals was examined. Analyses showed that women begin their reproductive careers at a younger age after the laborsaving technology was introduced. Estimate of the median age at first birth from the distribution function dropped from 21.2 years before the introduction to 19.5 years after the introduction of the technology. In addition, modeling results show that the probability of a woman giving birth to her first child doubles for any age after the introduction of laborsaving technology. However, changes in birth intervals are less conclusive since the differences of smoothed probability distributions are not significant. Moreover, findings indicate that women who initiate reproduction at a younger age can potentially have longer reproductive careers and larger families. PMID:12295624

  17. The Maya ball game. Comparison of the physical load with modern ball games.

    PubMed

    Blümchen, Gerhard

    2009-01-01

    The Maya ball game (MBG) originated more than 3,000 years ago. As best as is now known from archaeological and iconographical sources as well as the structure of the sport courts, this was a very physically taxing and important part of Mayan culture. The objective of this paper was to determine the physical load on those who participated in MBG as best as could be done from present perspectives. The load appears to be similar to that observed in soccer-tennis, in which heart rate rises to 140-160 beats/min and systolic blood pressure to 150-170 mm Hg. This is considered a light-to-moderate workload (4.5-5.5 metabolic equivalents) comparable to intensities reached in baseball, cycling (10 km/h), cross-country skiing (7 km/h), tournament dancing, swimming (2 km/h), doubles tennis and hiking (7 km/h). Thus, the cardiovascular demands of popular sports seem to have remained relatively similar through several millennia. PMID:19246899

  18. Combined hydrogen and carbon isotopes of plant waxes as an indicator of drought impacts on ancient Maya agriculture

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    There is increasing evidence suggesting that a series of droughts in the Yucatan Peninsula 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 δD, δ13C, and Δ14C analyses in two lake sediment cores from southeastern Mexico and northern Guatemala to develop coupled records of hydroclimate variability and human-driven vegetation change. Plant-wax specific Δ14C ages indicate a large input of pre-aged plant waxes into lake sediment. Comparison of plant-wax δD records with other regional hydroclimate proxy records suggest that plant-wax ages are evenly distributed around plant-wax radiocarbon ages, and that applying an age model based on plant-wax radiocarbon ages is appropriate for these lake sediments. We evaluate how differences in plant-wax age distributions influence stable isotope records to assess the age uncertainty associated with records of climate and vegetation change derived from plant-wax stable isotopes. In this low-elevation tropical environment plant-wax δ13C is 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 δ13C 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 analysis of plant-wax δD and δ13C from both lakes indicates increasingly divergent trends following ca. 3500 years BP, around the onset of widespread ancient Maya agriculture. After this time high plant-wax δD values tend to correspond with low plant-wax δ13C values and vice versa. This pattern is consistent with

  19. Evidence disputing deforestation as the cause for the collapse of the ancient Maya polity of Copan, Honduras

    PubMed Central

    McNeil, Cameron L.; Burney, David A.; Burney, Lida Pigott

    2009-01-01

    Archaeologists have proposed diverse hypotheses to explain the collapse of the southern Maya lowland cities between the 8th and 10th centuries A.D. Although it generally is believed that no single factor was responsible, a commonly accepted cause is environmental degradation as a product of large-scale deforestation. To date, the most compelling scientific evidence used to support this hypothesis comes from the archaeological site of Copan, Honduras, where the analysis of a sediment core suggested a dramatic increase in forest clearance in the Late Classic period (A.D. 600–900). By contrast, in the work presented here, the authors’ analysis of a longer sediment core demonstrates that forest cover increased from A.D. 400 to A.D. 900, with arboreal pollen accounting for 59.8–71.0% of the pollen assemblage by approximately A.D. 780–980. The highest levels of deforestation are found about 900 B.C. when, at its peak, herb pollen made up 89.8% of the assemblage. A second, although less pronounced, period of elevated deforestation peaked at approximately A.D. 400 when herb pollen reached 65.3% of the assemblage. The first deforestation event likely coincided with the widespread adoption of agriculture, a pattern found elsewhere in Mesoamerica. The second period of forest clearance probably was associated with the incursion of Maya speakers into the Copan Valley and their subsequent construction of the earliest levels of the Copan Acropolis. These results refute the former hypothesis that the ancient Maya responded to their increasingly large urban population by exhausting, rather than conserving, natural resources. PMID:20018691

  20. The Linguistic Interdependence Hypothesis and the language development of Yucatec Maya-Spanish bilingual children

    NASA Astrophysics Data System (ADS)

    Vrooman, Michael D.

    2000-11-01

    The Linguistic Interdependence Hypothesis as developed by Cummins (1978) argues that certain first language (L1) knowledge can be positively transferred during the process of second language (L2) acquisition. The L1 linguistic knowledge and skills that a child possesses can be extremely instrumental to the development of corresponding abilities in the L2. An integral component of these facilitative aspects of language influence is that the L1 be sufficiently developed prior to the extensive exposure to the L2 as would be found, for example, in an educational environment. An additional theoretical framework that has motivated this study incorporates principles of Universal Grammar, namely, that there are innate properties of language shared by the human species, and that language acquisition is the result of the interaction between these biologically determined aspects of language with the learner's linguistic environment. The principal goal of this dissertation is to examine children's knowledge of one area of Yucatec Maya L1 syntax, specifically, the word order of simple transitive sentences. By means of an experiment conducted with 28 Mayan children of 4 and 5 years of age, data were gathered and analyzed. Overall, the findings suggest that the subjects of the study are still in the process of acquiring the syntactic structure under investigation, that their L1 is still developing. Very few of the subjects demonstrated mastery of the structure under investigation. With regards to pedagogical concerns within the context of minority language education, the potentiality for these findings to enhance or inhibit the subsequent acquisition of Spanish as an L2 is examined.

  1. Lacandon Maya ecosystem management: sustainable design for subsistence and environmental restoration.

    PubMed

    Diemont, Stewart A W; Martin, Jay F

    2009-01-01

    Indigenous groups have designed and managed their ecosystems for generations, resulting in biodiversity protection while producing for their family's needs. Here we describe the agroecosystem of the Lacandon Maya, an indigenous group who live in Chiapas, Mexico. The Lacandon practice a form of swidden agriculture that conserves the surrounding rain forest ecosystem while cycling the majority of their land through five successional stages. These stages include an herbaceous stage, two shrub stages, and two forest stages. A portion of their land is kept in primary forest. This study presents the Lacandon traditional ecological knowledge (TEK) for agroforestry and quantitatively describes the plant community and the associated soil ecology of each successional stage. Also documented is the knowledge of the Lacandon regarding the immediate use of plant species and plant species useful for soil fertility enhancement. Woody plant diversity increases during the successional stages of the Lacandon system, and by the beginning of the first forest stage, the diversity is similar to that of the primary forest. In all stages, Lacandon use 60% of the available plant species for food, medicine, and raw materials. Approximately 45% of the woody plant species present in each fallow stage were thought by the Lacandon to enhance soil fertility. Total soil nitrogen and soil organic matter increased with successional stage and with time from intentional burn. Nutrient and soil nematode dynamics in shrub stages related to the presence of introduced and managed plants, indicating engineered soil enhancement by the Lacandon. The effects on biodiversity and soil ecology coupled with productivity for agricultural subsistence indicate that Lacandon TEK may offer tools for environmental conservation that would provide for a family's basic needs while maintaining a biodiverse rain forest ecosystem. Tools such as these may offer options for regional restoration and conservation efforts such as

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

    PubMed

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

    2016-07-01

    Two new dicyemid species are described from the endemic cephalopod Octopus maya Voss & Solis-Ramirez collected off Yucatan, Mexico. The renal sacs of 40 juvenile and adult octopuses from four localities were examined. Dicyema hochbergi n. sp. is a medium-sized species that reaches 2,245 µm in length. The vermiform stages consist of 18-24 peripheral cells, a conical calotte and the extension of the axial cell between the base and middle of the metapolar cells. Infusoriform embryos consist of 39 cells with urn cell containing one germinal cell, two nuclei and solid refringent bodies. Dicyema mexcayae n. sp. is a relatively small species that reaches 1,114 µm in length. The vermiform stages are constituted by 14-16 peripheral cells, an elongate calotte and the axial cell extending forward to the middle of the metapolar cells. The infusoriform embryos consist of 37 cells, two solid refringent bodies and urn cells with two nuclei each. The present study represents the first description of a dicyemid species from O. maya and increases the number of described species from Mexican waters to 11. PMID:27307168

  3. Earliest Mexican Turkeys (Meleagris gallopavo) in the Maya Region: Implications for Pre-Hispanic Animal Trade and the Timing of Turkey Domestication

    PubMed Central

    Thornton, Erin Kennedy; Emery, Kitty F.; Steadman, David W.; Speller, Camilla; Matheny, Ray; Yang, Dongya

    2012-01-01

    Late Preclassic (300 BC–AD 100) turkey remains identified at the archaeological site of El Mirador (Petén, Guatemala) represent the earliest evidence of the Mexican turkey (Meleagris gallopavo) in the ancient Maya world. Archaeological, zooarchaeological, and ancient DNA evidence combine to confirm the identification and context. The natural pre-Hispanic range of the Mexican turkey does not extend south of central Mexico, making the species non-local to the Maya area where another species, the ocellated turkey (Meleagris ocellata), is indigenous. Prior to this discovery, the earliest evidence of M. gallopavo in the Maya area dated to approximately one thousand years later. The El Mirador specimens therefore represent previously unrecorded Preclassic exchange of animals from northern Mesoamerica to the Maya cultural region. As the earliest evidence of M. gallopavo found outside its natural geographic range, the El Mirador turkeys also represent the earliest indirect evidence for Mesoamerican turkey rearing or domestication. The presence of male, female and sub-adult turkeys, and reduced flight morphology further suggests that the El Mirador turkeys were raised in captivity. This supports an argument for the origins of turkey husbandry or at least captive rearing in the Preclassic. PMID:22905156

  4. The Role of Deforestation in the Collapse of Classic Maya Civilization: Lessons for the Current Land Use Management in Northern Mesoamerica

    NASA Astrophysics Data System (ADS)

    Ray, D. K.; Nair, U. S.; Welch, R. M.; Lawton, R. O.; Oglesby, R. J.; Pielke, R. A.; Sever, T. A.; Irwin, D.

    2005-12-01

    The classic Maya civilization produced thriving cities that attained population densities comparable to modern day cities during the zenith of its growth approximately around 750 A.D. The Mayan civilization then experienced a catastrophic collapse between 750-950 A.D. Among the various hypothesis forwarded to explain the sudden collapse, one that has recently attracted attention, is the role of deforestation and decreases of regional rainfall that could have affected the day-to-day lives of the ancient Mayas. Deep-rooted rainforest vegetation has access to water stored in deep soil layers, and this deep water is made available to the hydrological cycle through transpiration. Removal of rainforests for agricultural purposes, which is accompanied by soil compaction and reduction in the organic material at the surface, leads to increased runoff and decreased soil water storage. Shallow-rooted vegetation that replaces the deep-rooted rainforests cannot efficiently access the moisture in the deep soil layers, reducing flux of water vapor to the atmosphere. In this study the Colorado State University Regional Atmospheric Modeling System (CSU RAMS) is utilized to examine differences in precipitation between current and forested conditions and between current and deforested conditions similar to those that archaeologists believe were prevalent prior to the collapse. Moreover, current deforestation rates in this region is converting the landscape into one that is similar to those prior to the Maya collapse. The simulated rainfall is compared against climatological rain gauge rainfall values. The statistical scores such as probability of detection, false alarm ratio, and the threat scores all compare favorably with those reported in the literature. Our results suggest that with the removal of forests the rainfall can be expected to decrease by 10 to 100mm in the Maya lowlands. Averaged over the entire Maya lowlands region, dry season rainfall for the forested conditions is

  5. Terror, silencing and children: international, multidisciplinary collaboration with Guatemalan Maya communities.

    PubMed

    Lykes, M B

    1994-02-01

    In recent years psychologists and other mental health workers have begun to document the effects of state-sponsored violence and civil war on civilians and to develop specific clinical and community interventions to address these issues. During the past decade between 50,000 to 100,000 Guatemalans have been murdered and at least 38,000 people disappeared. Over 400 rural villages were destroyed and the Guatemalan army's scorched earth policy forced hundreds of thousands who survived to flee, either to another part of the country or to leave Guatemala altogether. State-sponsored terror and silencing persists in Guatemala despite a return to civilian government. This article describes some of the problems encountered by Maya children in situations of ongoing war and state-sponsored terror and the development of one specific response, Creative Workshops for Children, an international, interdisciplinary program organized by mental health workers from Argentina, Guatemala and United States. The inadequacies of psychological theory based on a medical model that sees trauma as an intrapsychic phenomenon and conceptualizes its effects in situations of war as post-traumatic stress are described and a reconceptualization of trauma as psychosocial is proposed. The accompanying need to address the "normal abnormality" of war and state-sponsored terror through a community-based group process is presented. The model incorporates drawing, story telling, collage and dramatization in a group process that seeks to create a space and time in which the child can express him or herself, communicate experiences to others, and discharge energy and emotion connected to previous traumatic experiences. The work draws on existing cultural traditions (e.g. oral story telling and dramatization) and resources (e.g. nature, plants) of indigenous communities, offering additional resources to those seeking to collaborate in the development of mental health in their communities and suggesting

  6. Proyecto Costa Escondida: Interdisciplinary Research at the Ancient Maya Port Site of Vista Alegre, Quintana Roo, Mexico

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    At the northeast tip of the Yucatan Peninsula - where the Caribbean meets the Gulf - lies the ancient Maya port site of Vista Alegre. The inhabitants of this site, much like the people living nearby today, were forced to contend with the challenging coastal environment of Laguna Holbox. The sediment-rich, low gradient of the north coast presents a contrasting landscape compared to the Caribbean coast, where water resources are of much larger magnitude and evident in the extensive systems of cenotes (sinkholes) and underground rivers that supported pre-Columbian sites along this eastern rocky sediment-poor coastline. For past inhabitants the north coast was a mosaic of low-lying, non-arable zones where access to potable water was a challenge for inhabitants well into the 20th century. By bringing together scholars from the fields of archaeology, coastal ecology, geoarchaeology, and hydrogeology, the Proyecto Costa Escondida is focusing on the dynamic relationship between the Maya and their coastal landscape over the past 3000 years. To date we have collected 12 manual push-cores from the shallow waters surrounding Vista Alegre, which have been analyzed at 1 cm resolution using standard methods for Loss on Ignition (LOI), δ18Ocarb and δ13Ccarb of bulk carbonate, granulometry, micropalentology, and AMS radiocarbon dating. In addition to have baseline comparative data, we have conducted near-shore and terrestrial coastal ecological surveys along with the mapping of coastal water salinity and temperatures in the dry and wet seasons. Overall, the chemical proxies, lithology, and paleosalinity model reconstructed to date reveal four onlapping parasequences representing an overall transgression of the coastline with strong seasonality of water chemistry that has been changing under the control of rising sea levels over the past 3000 years. The sedimentation rate and timing of the transition to marine is in reasonable agreement with local sea level curves meaning that the

  7. Measurement of the Isoscalar Monopole Response in the Neutron-Rich Nucleus 68Ni using the Active Target MAYA

    NASA Astrophysics Data System (ADS)

    Vandebrouck, M.; Gibelin, J.; Khan, E.; Achouri, N. L.; Baba, H.; Beaumel, D.; Blumenfeld, Y.; Caamaño, M.; Càceres, L.; Colò, G.; Delaunay, F.; Fernandez-Dominguez, B.; Garg, U.; Grinyer, G. F.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Keeley, N.; Mittig, W.; Pancin, J.; Raabe, R.; Roger, T.; Roussel-Chomaz, P.; Savajols, H.; Sorlin, O.; Stodel, C.; Suzuki, D.; Thomas, J. C.

    We report the measurement of the isoscalar monopole strength in the unstable nucleus 68Ni using inelastic alpha scattering at 50A MeV in inverse kinematics. This experiment has been performed at GANIL with LISE spectrometer using a dedicated detector: the active target MAYA. A part of the isoscalar giant monopole resonance (ISGMR) has been measured at 21.1 ± 1.9 MeV and indications for a soft monopole mode are provided for the first time at 12.9 ± 1.0 MeV. Distorted-wave born approximation (DWBA) with random-phase approximation (RPA) transition densities have been used to study angular distribution and indicate that the L = 0 multipolarity dominates the cross-section for the ISGMR, and significantly contributes to the soft mode.

  8. A 3400 year paleolimnological record of prehispanic human–environment interactions in the Holmul region of the southern Maya lowlands

    USGS Publications Warehouse

    Wahl, David B.; Estrada-Belli, Francisco; Anderson, Lysanna

    2015-01-01

    The timing, magnitude and drivers of late Holocene environmental change in the Holmul region of the southern Maya lowlands are examined by combining paleoenvironmental and archeological data. Environmental proxy analyses on a ~ 3350 cal yr lacustrine sediment record include pollen, charcoal, loss on ignition, magnetic suscep- tibility, and elemental geochemistry. Archeological evidence is derived from extensive settlement surveys conducted near the study site. Results indicate nearby settlement and agricultural activity taking place in an environment characterized by open forest from around 3350 to 950 cal yr BP. The fire history shows a dramatic increase in burning during the Classic period, possibly reflecting changing agricultural strategies. A distinct band of carbonate deposited from 1270 to 1040 cal yr BP suggests decreased hydrologic input associated with drier conditions. Abrupt changes in proxy data around 940 cal yr BP indicate a cessation of human disturbance and local abandonment of the area.

  9. A tale of two analogues: learning at a distance from the ancient greeks and maya and the problem of deciphering extraterrestrial radio transmissions

    NASA Astrophysics Data System (ADS)

    Finney, Ben; Bentley, Jerry

    The transmission of ancient Greek learning and science to medieval western Europe via the translation of Greek and Arab texts is often cited as a terrestrial example of "learning at a distance" that could occur by means of the decipherment of radio messages from advanced extraterrestrial civilizations. However, the translation between such closely related languages as Greek, Latin and Arabic and the decipherment of radio messages from an extraterrestrial civilization to the point where humans could understand them are only nominally analogous tasks. A terrestrial example of such "learning at a distance" from an ancient civilization that perhaps better prepares us for thinking about the immense task inherent in any interstellar knowledge transmission is provided by the lengthy and troubled efforts of western scholars to decipher the inscriptions left by the ancient Maya and to learn from them about this ancient civilization. Only recently, with the rejection of the ideographic fallacy that Maya glyphs symbolized ideas directly without the mediation of language and with the application of linguistic knowledge of Maya languages has it been possible to decipher the Maya inscriptions and learn from them about their science and culture. This experience suggests that without any knowledge of languages in which extraterrestrial messages might be composed, their decipherment could be most problematic. The Maya case is also relevant to the common suggestion that advanced extraterrestrials would deliberately compose messages not in their own natural languages but in artificial ones using logic, numbers, and scientific constants presumably shared among all intelligent civilizations, or at least those in their radio-communicative phases. Numbers and calendrical dating system were the first parts of the Mayan inscriptions to be translated, albeit with the aid of partial "Rosetta stones" left by the Spanish conquerors. This success served, however, to reinforce the ideographic

  10. Effects of harvest on the sustainability and leaf productivity of populations of two palm species in Maya homegardens.

    PubMed

    Martínez-Ballesté, Andrea; Martorell, Carlos

    2015-01-01

    Traditional management practices are usually thought to be sustainable. The Maya manage Sabal (Arecaceae) palms in homegardens, using their leaves for thatching. The sustainability of such production systems depends on the long-term persistence of palm populations, whereas resource availability also depends on the number of leaves on individual palms. We examined how leaf harvest affects Sabal yapa and S. mexicana population growth rates (λ) and leaf production, comparing traditional and alternative harvest regimes in terms of sustainability and productivity. Demographic, harvest and leaf production data were recorded for three years in two homegardens. We used general integral projection models linked to leaf-production models to describe population dynamics and productivity. Harvest had no effect on S. yapa's vital rates or on λ, but it changed the growth rate of individuals of S. mexicana, with a negligible impact on λ. Homegardens affected λ values, reflecting the species' ecological affinities. S. mexicana, introduced from mesic forests, required watering and shade; therefore, its population declined rapidly in the homegarden that lacked both water and shade. The λ of the xerophilic S. yapa was slightly larger without watering than with watering. Palms usually compensated for leaf extraction, causing the number of leaves harvested per individual to increase with harvest intensity. Nevertheless, traditional management is relatively mild, allowing standing leaves to accumulate but reducing the homegarden's yield. Apparently, the Maya do not seek to maximize annual production but to ensure the availability of large numbers of leaves in homegardens. These leaves may then be used when the entire roof of a hut needs to be replaced every few years. PMID:25803029

  11. Effects of Harvest on the Sustainability and Leaf Productivity of Populations of Two Palm Species in Maya Homegardens

    PubMed Central

    Martínez-Ballesté, Andrea; Martorell, Carlos

    2015-01-01

    Traditional management practices are usually thought to be sustainable. The Maya manage Sabal (Arecaceae) palms in homegardens, using their leaves for thatching. The sustainability of such production systems depends on the long-term persistence of palm populations, whereas resource availability also depends on the number of leaves on individual palms. We examined how leaf harvest affects Sabal yapa and S. mexicana population growth rates (λ) and leaf production, comparing traditional and alternative harvest regimes in terms of sustainability and productivity. Demographic, harvest and leaf production data were recorded for three years in two homegardens. We used general integral projection models linked to leaf-production models to describe population dynamics and productivity. Harvest had no effect on S. yapa’s vital rates or on λ, but it changed the growth rate of individuals of S. mexicana, with a negligible impact on λ. Homegardens affected λ values, reflecting the species’ ecological affinities. S. mexicana, introduced from mesic forests, required watering and shade; therefore, its population declined rapidly in the homegarden that lacked both water and shade. The λ of the xerophilic S. yapa was slightly larger without watering than with watering. Palms usually compensated for leaf extraction, causing the number of leaves harvested per individual to increase with harvest intensity. Nevertheless, traditional management is relatively mild, allowing standing leaves to accumulate but reducing the homegarden’s yield. Apparently, the Maya do not seek to maximize annual production but to ensure the availability of large numbers of leaves in homegardens. These leaves may then be used when the entire roof of a hut needs to be replaced every few years. PMID:25803029

  12. Well-being changes in response to 30 years of regional integration in Maya populations from Yucatan, Mexico.

    PubMed

    Gurri, F D; Pereira, G B; Moran, E F

    2001-01-01

    Infant mortality rate (IMR), overall frequency of linear enamel hypoplasia (LEH), sexual dimorphism in LEH, age of onset of LEH, and age at menarche were used as indicators to test the hypothesis that the origin and development of the tourist industry and increased state participation on Maya subsistence agriculturists in the early 1970s had improved the well-being of the Maya. Two historical moments where inferred from the data. The first was derived from cheap and effective immunization and sanitation campaigns that reduced IMR from 143.4/1,000 live births in the early 1960s to 97.4 in the early 1970s. State participation broke the undernutrition-disease cycle enough to reduce LEH frequencies significantly (from 71.9% in individuals born before 1971 to 51.5% in those born in 1971 or after, chi(2) = 55.72; 1 df; alpha = 0.00001) and to eliminate the sex difference in LEH expression (from a 14.8% LEH difference between men and women before 1971 [Male/Female Odds Radio = 0.45, alpha significant at 0.05] to a nonsignificant 2% difference). Improvement in overall living conditions reflected in a "modern stage" infant mortality regime and an almost disappearance of LEHs, resulted from gradual improvements in living conditions that did not become apparent until the 1980s. Trends in the age at menarche are not statistically significant, probably due to methodological limitations. However, if overall living conditions continue to improve or stay as they are today, accelerations in maturation should become noticeable. PMID:11505467

  13. Two millennia of tropical cyclone-induced mud layers in a northern Yucatán stalagmite: Multiple overlapping climatic hazards during the Maya Terminal Classic "megadroughts"

    NASA Astrophysics Data System (ADS)

    Frappier, Amy Benoit; Pyburn, James; Pinkey-Drobnis, Aurora D.; Wang, Xianfeng; Corbett, D. Reide; Dahlin, Bruce H.

    2014-07-01

    An annually laminated stalagmite from the northern Yucatán Peninsula contains mud layers from 256 cave flooding events over 2240 years. This new conservative proxy for paleotempestology recorded cave flooding events with a recurrence interval of 8.3 years during the twentieth century, with the greatest frequency during the twentieth century and the least frequent during the seventeenth century. Tropical cyclone (TC) events are unlikely to flood the cave during drought when the water table is depressed. Applying TC masking to the Chaac paleorainfall reconstruction suggests that the severity of the Maya "megadroughts" was underestimated. Without a high-resolution radiometric geochronology of individual local TC events, speleothem isotope records cannot resolve whether the Terminal Classic Period in the northern Maya Lowlands was punctuated by several brief drought breaks with normal TCs, or whether the region was very dry and peppered by unusually severe and frequent hurricane seasons.

  14. A late Holocene paleoenvironmental reconstruction from Agua Caliente, southern Belize, linked to regional climate variability and cultural change at the Maya polity of Uxbenká

    NASA Astrophysics Data System (ADS)

    Walsh, Megan K.; Prufer, Keith M.; Culleton, Brendan J.; Kennett, Douglas J.

    2014-07-01

    We report high-resolution macroscopic charcoal, pollen and sedimentological data for Agua Caliente, a freshwater lagoon located in southern Belize, and infer a late Holocene record of human land-use/climate interactions for the nearby prehistoric Maya center of Uxbenká. Land-use activities spanning the initial clearance of forests for agriculture through the drought-linked Maya collapse and continuing into the historic recolonization of the region are all reflected in the record. Human land alteration in association with swidden agriculture is evident early in the record during the Middle Preclassic starting ca. 2600 cal yr BP. Fire slowly tapered off during the Late and Terminal Classic, consistent with the gradual political demise and depopulation of the Uxbenká polity sometime between ca. 1150 and 950 cal yr BP, during a period of multiple droughts evident in a nearby speleothem record. Fire activity was at its lowest during the Maya Postclassic ca. 950-430 cal yr BP, but rose consistent with increasing recolonization of the region between ca. 430 cal yr BP and present. These data suggest that this environmental record provides both a proxy for 2800 years of cultural change, including colonization, growth, decline, and reorganization of regional populations, and an independent confirmation of recent paleoclimate reconstructions from the same region.

  15. Comparison of Vegetation Change Inferred From Palynology and Compound-Specific Carbon Isotopes of Lipid Biomarkers in the Maya Lowlands of Peten, Guatemala

    NASA Astrophysics Data System (ADS)

    Newell, S. D.; Hodell, D. A.; Curtis, J. H.; Brenner, M.; Venz-Curtis, K.

    2005-12-01

    The Petén region of northern Guatemala has been occupied by humans for more than 3000 years. Expansion of the Maya civilization during the Preclassic (~1000 BC to AD 250) and Classic (AD 250 to AD 900) Periods was accompanied by increasing deforestation of Petén watersheds and accelerated rates of soil erosion. Palynological data from Petén lake cores illustrate the near elimination of high forest taxa and prevalence of disturbance taxa (grasses, weeds) during the height of Classic Maya occupation (~AD 500 to AD 800). After flourishing during the Classic Period between AD 250 and 800, Maya population densities declined significantly in the Petén, thereby curtailing human pressures on the landscape. This cycle of population expansion and decline in the Petén provides a natural historical experiment that has been used to study the response of tropical vegetation to long-term changes in land-use by humans. We measured the carbon isotopic composition of long-chain n-alkanes of leaf waxes in two cores from Lakes Sacnab and Salpetén in the Petén Lake District of the southern Maya Lowlands. The carbon isotopic composition of leaf waxes has been shown to be a reliable indicator of the relative proportion of C3 to C4 biomass in a watershed. Biomarker results were compared directly to a pollen profile from Lake Salpetén. Although the general pattern of increased C4 abundance inferred from δ13C of long-chain n-alkanes and increased disturbance taxa from pollen studies agree during the period of Maya occupation, the two proxies differ in detail suggesting they are recording different characteristics of watershed vegetation. For example, the highest long-chain δ13C values (representing greatest C4 biomass) occurred during early settlement of the basins in the early to middle Preclassic Period (1300 to 500 BC) when Maya population densities were relatively low. This period also corresponded to the time of greatest erosion rates in the Salpetén basin (Anselmetti et al

  16. The role of sensorial processes in Q'eqchi' Maya healing: A case study of depression and bereavement.

    PubMed

    Hatala, Andrew R; Waldram, James B

    2016-02-01

    Theory and research on the healing practices of Indigenous communities around the globe have often been influenced by models of "symbolic healing" that privilege the way patients consciously interpret or derive meaning from a healing encounter. In our work with a group of Q'eqchi' Maya healers in southern Belize, these aspects of "symbolic healing" are not always present. Such empirical observations force us to reach beyond models of symbolic healing to understand how healing might prove effective. Through the extended analysis of a single case study of rahil ch'ool or "depression," we propose to advance understanding of forms of healing which are not dependent on a shared "mythic" or "assumptive world" between patient and healer or where therapeutic efficacy does not rely on the patient's ability to "believe" in or consciously "know" what is occurring during treatment. In this we demonstrate how the body, as a site of experience, transformation, and communication, becomes the therapeutic locus in healing encounters of this kind and argue that embodied mediums of sensorial experience be considered central in attempts to understand healing efficacy. PMID:26337478

  17. Mother and Youth Access (MAYA) Maternal Chlorhexidine, Counseling and Pediatric Fluoride Varnish Randomized Clinical Trial to Prevent Early Childhood Caries

    PubMed Central

    Ramos-Gomez, Francisco J.; Gansky, Stuart A.; Featherstone, John D.B.; Jue, Bonnie; Gonzalez-Beristain, Rocio; Santo, William; Martinez, Ed; Weintraub, Jane A.

    2011-01-01

    Background Mexican-American children have a higher caries prevalence than the US average. The Mothers and Youth Access (MAYA) study was a randomized clinical trial initiated to address this problem. Aim Comparison of the efficacy of two prevention interventions in reducing early childhood caries (ECC). Design All 361 randomized mother-child dyads received oral health counseling. Beginning at 4 months postpartum, intervention mothers received chlorhexidine (CHX) mouthrinse for 3 months beginning 4 months postpartum and children received fluoride varnish (FV) every 6 months from age 12–36 months. Control group children received FV if precavitated lesions developed. Salivary mutans streptococci (MS) and lactobacilli were assessed. Results No significant difference in children’s 36-month caries incidence between groups; 34% in each group developed caries ((d2+fs) > 0). About half of control group developed precavitated lesions and received therapeutic FV. Maternal MS levels declined during CHX use, but increased when discontinued. Conclusions Maternal postpartum CHX regimen, oral health counseling, and preventive child FV applications were not more efficacious than maternal counseling with child therapeutic FV for precavitated lesions for ECC prevention. FV for young children with brief maternal CHX use and oral health counseling may need to be combined with additional or longer-term therapies to significantly reduce ECC in high-risk populations. PMID:21999806

  18. Geomorphic analysis of transient landscapes in the Sierra Madre de Chiapas and Maya Mountains (northern Central America): implications for the North American-Caribbean-Cocos plate boundary

    NASA Astrophysics Data System (ADS)

    Andreani, L.; Gloaguen, R.

    2016-01-01

    We use a geomorphic approach in order to unravel the recent evolution of the diffuse triple junction between the North American, Caribbean, and Cocos plates in northern Central America. We intend to characterize and understand the complex tectonic setting that produced an intricate pattern of landscapes using tectonic geomorphology, as well as available geological and geophysical data. We classify regions with specific relief characteristics and highlight uplifted relict landscapes in northern Central America. We also analyze the drainage network from the Sierra Madre de Chiapas and Maya Mountains in order to extract information about potential vertical displacements. Our results suggest that most of the landscapes of the Sierra Madre de Chiapas and Maya Mountains are in a transient stage. Topographic profiles and morphometric maps highlight elevated relict surfaces that are characterized by a low-amplitude relief. The river longitudinal profiles display upper reaches witnessing these relict landscapes. Lower reaches adjust to new base-level conditions and are characterized by multiple knickpoints. These results backed by published GPS and seismotectonic data allow us to refine and extend existing geodynamic models of the triple junction. Relict landscapes are delimited by faults and thus result from a tectonic control. The topography of the Sierra Madre de Chiapas evolved as the result of (1) the inland migration of deformation related to the coupling between the Chiapas Massif and the Cocos forearc sliver and (2) the compression along the northern tip of the Central American volcanic arc. Although most of the shortening between the Cocos forearc sliver and the North American Plate is accommodated within the Sierra de Chiapas and Sierra de los Cuchumatanes, a small part may be still transmitted to the Maya Mountains and the Belize margin through a "rigid" Petén Basin.

  19. Geomorphic analysis of transient landscapes from the Sierra Madre de Chiapas and Maya Mountains (northern Central America): implications for the North American-Caribbean-Cocos plate boundary

    NASA Astrophysics Data System (ADS)

    Andreani, L.; Gloaguen, R.

    2015-09-01

    We use a geomorphic approach in order to unravel the recent evolution of the diffuse triple junction between the North American, Caribbean, and Cocos plates in northern Central America. The complex tectonic setting produced an intricate pattern of landscapes that we try to systemize using remote sensing tectonic geomorphology and available geological and geophysical data. We classify regions with specific relief characteristics and highlight uplifted relict landscapes in northern Central America. We also analyze the drainage network from the Sierra Madre de Chiapas and Maya Mountains in order to extract information about potential vertical displacements. Our results suggest that most of the landscapes of the Sierra Madre de Chiapas and Maya Mountains are in transient stage. Topographic profiles and morphometric maps highlight elevated relict surfaces that are characterized by a low amplitude relief. The river longitudinal profiles display upper reaches witnessing these relict landscapes while lower segments characterized by multiple knickpoints, that adjust to new base-level conditions. These results backed by published GPS and seismotectonic data allow us to refine and extend existing geodynamic models of the triple junction. Relict landscapes are delimited by faults and thus result from a tectonic control. The topography of the Sierra Madre de Chiapas evolved as the result of (1) the inland migration of deformation related to the coupling between the Chiapas Massif and the Cocos fore-arc sliver, and (2) the compression along the northern tip of the Central America Volcanic Arc. Although most of the shortening between the Cocos fore-arc sliver and the North American plate is accommodated within the Sierra de Chiapas and Sierra de los Cuchumatanes, a small part may be still transmitted to the Maya Mountains and the Belize margin through a "rigid" Petén basin.

  20. Sustaining plants and people: traditional Q'eqchi' Maya botanical knowledge and interactive spatial modeling in prioritizing conservation of medicinal plants for culturally relative holistic health promotion.

    PubMed

    Pesek, Todd; Abramiuk, Marc; Garagic, Denis; Fini, Nick; Meerman, Jan; Cal, Victor

    2009-03-01

    Ethnobotanical surveys were conducted to locate culturally important, regionally scarce, and disappearing medicinal plants via a novel participatory methodology which involves healer-expert knowledge in interactive spatial modeling to prioritize conservation efforts and thus facilitate health promotion via medicinal plant resource sustained availability. These surveys, conducted in the Maya Mountains, Belize, generate ethnobotanical, ecological, and geospatial data on species which are used by Q'eqchi' Maya healers in practice. Several of these mountainous species are regionally scarce and the healers are expressing difficulties in finding them for use in promotion of community health and wellness. Based on healers' input, zones of highest probability for locating regionally scarce, disappearing, and culturally important plants in their ecosystem niches can be facilitated by interactive modeling. In the present study, this is begun by choosing three representative species to train an interactive predictive model. Model accuracy was then assessed statistically by testing for independence between predicted occurrence and actual occurrence of medicinal plants. A high level of accuracy was achieved using a small set of exemplar data. This work demonstrates the potential of combining ethnobotany and botanical spatial information with indigenous ecosystems concepts and Q'eqchi' Maya healing knowledge via predictive modeling. Through this approach, we may identify regions where species are located and accordingly promote for prioritization and application of in situ and ex situ conservation strategies to protect them. This represents a significant step toward facilitating sustained culturally relative health promotion as well as overall enhanced ecological integrity to the region and the earth. PMID:19455273

  1. Round and large: morphological and genetic consequences of artificial selection on the gourd tree Crescentia cujete by the Maya of the Yucatan Peninsula, Mexico

    PubMed Central

    Aguirre-Dugua, Xitlali; Eguiarte, Luis E.; González-Rodríguez, Antonio; Casas, Alejandro

    2012-01-01

    Background and Aims Artificial selection, the main driving force of domestication, depends on human perception of intraspecific variation and operates through management practices that drive morphological and genetic divergences with respect to wild populations. This study analysed the recognition of varieties of Crescentia cujete by Maya people in relation to preferred plant characters and documents ongoing processes of artificial selection influencing differential chloroplast DNA haplotype distribution in sympatric wild and home-garden populations. Methods Fifty-three home gardens in seven villages (93 trees) and two putative wild populations (43 trees) were sampled. Through semi-structured interviews we documented the nomenclature of varieties, their distinctive characters, provenance, frequency and management. Phenotypic divergence of fruits was assessed with morphometric analyses. Genetic analyses were performed through five cpDNA microsatellites. Key Results The Maya recognize two generic (wild/domesticated) and two specific domesticated (white/green) varieties of Crescentia cujete. In home gardens, most trees (68 %) were from domesticated varieties while some wild individuals (32 %) were tolerated. Cultivation involves mainly vegetative propagation (76 %). Domesticated fruits were significantly rounder, larger and with thicker pericarp than wild fruits. Haplotype A was dominant in home gardens (76 %) but absent in wild populations. Haplotypes B–F were found common in the wild but at low frequency (24 %) in home gardens. Conclusions The gourd tree is managed through clonal and sexual propagules, fruit form and size being the main targets of artificial selection. Domesticated varieties belong to a lineage preserved by vegetative propagation but propagation by seeds and tolerance of spontaneous trees favour gene flow from wild populations. Five mutational steps between haplotypes A and D suggest that domesticated germplasm has been introduced to the region

  2. Provenance Ages of Protoliths From the Chiapas Massif Complex and Adjacent Strata of the Southern Maya Block - Implications on the Paleozoic Reconstruction of Middle America.

    NASA Astrophysics Data System (ADS)

    Weber, B.; Schaaf, P.; Valencia, V. A.; Lopez-Martinez, M.; Ortega-Gutierrez, F.

    2007-05-01

    The basement of the Maya block is exposed in the Maya Mountains of Belize, the Chuacús Complex of Guatemala, and in the Chiapas Massif Complex (CMC) of SE Mexico. In the CMC medium- to high-grade metasedimentary rocks occur as isolated domains in mostly metaigneous crystalline rocks. The most important tectonothermal event in the entire CMC is of late Permian age, culminating in partial anatexis and the intrusion of the Chiapas batholith. In this work we present U-Pb data obtained by LA-MC-ICPMS from detrital zircon cores of metasediments from the CMC and from detrital zircons of Paleozoic strata exposed in SE Chiapas. The Pennsylvanian-Permian Santa Rosa Formation (SRF) contains mostly Pan-African (500-650 Ma) zircons, minor populations of Silurian-Early Devonian (400-420 Ma) and Grenville (1.0-1.25 Ga) zircons, and few Paleoproterozoic and Archean grains. The maximum sedimentation age is documented by ~320 Ma old zircons. Metagreywacke and metasandstones of the central CMC have inherited detrital zircon cores with age distributions indistinguishable from those of the SRF. High-grade metapelites and para-amphibolites from the CMC, instead, have inherited zircon cores with one single population of 1.0 Ga or with populations at 1.0, 1.2, and 1.5 Ga. In the southern part of the CMC leucocratic granites intrude sedimentary rocks whose detrital zircons yielded mostly 1.53 Ga ages with some grains in the range of 1.6-1.7 Ga, but no younger zircons. White mica grown in contact with the leucogranite has a 40Ar- 39Ar age of 406 ± 4 Ma, defining a minimum age for both deposition of the sediments and intrusion of the leucogranite. Our data indicate that the CMC has a composite pre-metamorphic basement, containing sedimentary protoliths from the Pennsylvanian-Permian SRF and from early Paleozoic strata intruded by Silurian-Early Devonian granites. This favors a similar pre-Permian geologic history for the CMC as for the Maya Mountains of Belize. The early Paleozoic

  3. Reconstructing the role of landuse change on water yield at the Maya urban center Tikal, Guatemala [700-800 AD

    NASA Astrophysics Data System (ADS)

    Shu, L.; Duffy, C.; French, K. D.; Murtha, T., Jr.; Garcia-Gonzalez, S. E.

    2014-12-01

    In recent years scientists have been debating the role of climate on the trajectory of Maya culture in the Late Classic period, 600-900 AD. Paleo-climatologists have reconstructed realizations of climate [Haug 2003; Medina-Elizalde 2012; Hodell 1995] that offer evidence for reduced precipitation in the Late Classic period. Recently French et al [2014] proposed that landuse change may also play an important role in the available water supply at Tikal, with the removal of tropical forest and conversion to maize-agriculture and urban landuse leading to extensive development of sophisticated water storage systems and rainfall harvesting for water supply and irrigation. Rapid population growth is a concurrent and compounding factor [Scarborough 2012; Shaw 2003] where landuse impacts the distribution and availability of water storage in the surrounding watershed. Although proposed climate scenarios for the Late Classic offer a quantitative scenario for possible atmospheric conditions at Tikal, the impact of land use change on the distribution and availability of water supply has not been evaluated. In this research we reconstruct the plausible vulnerability of the water supply at Tikal under the combined forces of climatic and land use change. The Penn State Integrated Hydrologic Model (PIHM) [Qu and Duffy 2007] is used to simulate the daily-to-seasonal space and time distribution of soil moisture, groundwater and surface water storage for the period 700-800 AD, the peak of Tikal's population history. The analysis includes a quantitative assessment of the likely changes in available water storage as tropical forest is converted to maize agriculture and urban land. In particular we examine the important control that reduced canopy interception plays in the seasonal availability of water. Preliminary simulations suggest that removing tropical forest increases runoff and available water storage, which may serve to moderate seasonal and long-term drought conditions.

  4. Differential usage of storage carbohydrates in the CAM bromeliad Aechmea 'Maya' during acclimation to drought and recovery from dehydration.

    PubMed

    Ceusters, Johan; Borland, Anne M; Londers, Elsje; Verdoodt, Veerle; Godts, Christof; De Proft, Maurice P

    2009-02-01

    CAM requires a substantial investment of resources into storage carbohydrates to account for nocturnal CO(2) uptake, thereby restricting carbohydrate partitioning to other metabolic activities, including dark respiration, growth and acclimation to abiotic stress. Flexible modulation of carbon flow to the different competing sinks under changing environmental conditions is considered a key determinant for the growth, productivity and ecological success of the CAM pathway. The aim of the present study was to examine how shifts in carbohydrate partitioning could assure maintenance of photosynthetic integrity and a positive carbon balance under conditions of increasing water deprivation in CAM species. Measurements of gas exchange, leaf water relations, malate, starch and soluble sugar (glucose, fructose and sucrose) contents were made in leaves of the CAM bromeliad Aechmea 'Maya' over a 6-month period of drought and subsequently over a 2-month period of recovery from drought. Results indicated that short-term influences of water stress were minimized by elevating the level of respiratory recycling, and carbohydrate pools were maintained at the expense of export for growth while providing a comparable nocturnal carbon gain to that in well-watered control plants. Longer term drought resulted in a disproportionate depletion of key carbohydrate reserves. Sucrose, which was of minor importance for providing substrate for the dark reactions under well-watered conditions, became the major source of carbohydrate for nocturnal carboxylation as drought progressed. Flexibility in terms of the major carbohydrate source used to sustain dark CO(2) uptake is therefore considered a crucial factor in meeting the carbon and energy demands under limiting environmental conditions. Recovery from CAM-idling was found to be dependent on the restoration of the starch pool, which was used predominantly for provision of substrate for nocturnal carboxylation, while net carbon export was limited

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

    PubMed

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

    2011-08-01

    Patterns of carious lesions were analyzed in the Classic period coastal Maya population of Xcambó, a salt production and administration center in northern Yucatan. To this end, the study investigated caries in the permanent dentitions of 163 adult skeletons, 23 from the Early Classic (AD 250-550) and 140 from the Late Classic period (AD 550-750), equally distributed between sexes. The archaeological and bioarchaeological evidence indicates a wealthy and socially homogeneous population dedicated to salt production and administration in the Early Classic that switched to pure administrative functions in the Late Classic. The results indicate an increase in caries from 7.4% and 21.2% (males and females respectively) from the Early Classic to 14.0% in males and 27.4% in females from the Late Classic period. The rate of caries in the Early and in the Late Classic phases of continuous occupation is not consistent with a simple interpretation of a heavier reliance on maize during the latter phase, characterized by a sedentary lifestyle, particularly for the male segment of the society now dedicated completely to the administration of the salt mines. Rather, the increase in caries rates in both sexes is best explained within a broader context of overall food habits, new cariogenic foods for both sexes, and the changes in lifestyle imposed by the increased socioeconomic role of the site. Our conclusions stress the limitations imposed by interpreting carious lesions solely in terms of single dietary components, such as maize consumption, without taking into account broader aspects of cultural and socioeconomic relevance. PMID:21590750

  6. a Web-Based Interactive Tool for Multi-Resolution 3d Models of a Maya Archaeological Site

    NASA Astrophysics Data System (ADS)

    Agugiaro, G.; Remondino, F.; Girardi, G.; von Schwerin, J.; Richards-Rissetto, H.; De Amicis, R.

    2011-09-01

    Continuous technological advances in surveying, computing and digital-content delivery are strongly contributing to a change in the way Cultural Heritage is "perceived": new tools and methodologies for documentation, reconstruction and research are being created to assist not only scholars, but also to reach more potential users (e.g. students and tourists) willing to access more detailed information about art history and archaeology. 3D computer-simulated models, sometimes set in virtual landscapes, offer for example the chance to explore possible hypothetical reconstructions, while on-line GIS resources can help interactive analyses of relationships and change over space and time. While for some research purposes a traditional 2D approach may suffice, this is not the case for more complex analyses concerning spatial and temporal features of architecture, like for example the relationship of architecture and landscape, visibility studies etc. The project aims therefore at creating a tool, called "QueryArch3D" tool, which enables the web-based visualisation and queries of an interactive, multi-resolution 3D model in the framework of Cultural Heritage. More specifically, a complete Maya archaeological site, located in Copan (Honduras), has been chosen as case study to test and demonstrate the platform's capabilities. Much of the site has been surveyed and modelled at different levels of detail (LoD) and the geometric model has been semantically segmented and integrated with attribute data gathered from several external data sources. The paper describes the characteristics of the research work, along with its implementation issues and the initial results of the developed prototype.

  7. Potent anti-inflammatory activity of sesquiterpene lactones from Neurolaena lobata (L.) R. Br. ex Cass., a Q'eqchi' Maya traditional medicine.

    PubMed

    Walshe-Roussel, Brendan; Choueiri, Christine; Saleem, Ammar; Asim, Muhammd; Caal, Federico; Cal, Victor; Rojas, Marco Otarola; Pesek, Todd; Durst, Tony; Arnason, John Thor

    2013-08-01

    The widespread use of Neurolaena lobata (L.) R. Br. ex Cass. by Q'eqchi' Maya and indigenous healers throughout the Caribbean for inflammatory conditions prompted the study of the anti-inflammatory activity of this traditional medicine. The objectives of this study were to conduct a detailed ethnobotanical investigation of the uses of N. lobata by the Q'eqchi' Maya of Belize for a variety of inflammatory symptoms and to evaluate the in vitro anti-inflammatory activity of leaf extract and isolated sesquiterpene lactones. The crude 80% EtOH extract of N. lobata leaves administered at 100 μg/mL reduced LPS-stimulated TNF-α production in THP-1 monocytes by 72% relative to the stimulated vehicle control. Isolated sesquiterpene lactones, neurolenins B, C+D, lobatin B and 9α-hydroxy-8β-isovalerianyloxy-calyculatolide were more active (IC50=0.17-2.32 μM) than the positive control parthenolide (IC50=4.79 μM). The results provide a pharmacological and phytochemical basis for the traditional use of this leaf for inflammatory conditions. PMID:23747054

  8. Medical potential of plants used by the Q’eqchi Maya of Livingston, Guatemala for the treatment of women’s health complaints

    PubMed Central

    Michel, Joanna; Duarte, Reinel Eduardo; Yao, Ping; Bolton, Judy L.; Huang, Yue; Cáceres, Armando; Veliz, Mario; Soejarto, Djaja Doel; Mahady, Gail B.

    2007-01-01

    Investigation on the medical ethnobotany of the Q’eqchi Maya of Livingston, Izabal, Guatemala, was undertaken in order to explore Q’eqchi perceptions, attitudes, and treatment choices related to women’s health. Through participant observation and interviews a total of 48 medicinal plants used to treat conditions related to pregnancy, childbirth, menstruation, and menopause were collected and identified followed by the evaluation of 20 species in bioassays relevant to women’s health. Results of field interviews indicate that Q’eqchi cultural perceptions affect women’s health experiences while laboratory results (estrogen receptor and serotonin receptor binding assays) provide a scientific correlation between empirical medicinal plant use among the Q’eqchi and the pharmacological basis for their administration. These data can contribute to Guatemala’s national effort to promote a complementary relationship between traditional Maya medicine and public health services and can serve as a basis for further pharmacology and phytochemistry on Q’eqchi medicinal plants for the treatment of women’s health conditions. PMID:17826926

  9. Assessing sedimentation rates at Usumacinta and Grijalva river basin (Southern Mexico) using OSL and suspended sediment load analysis: A study from the Maya Classic Period

    NASA Astrophysics Data System (ADS)

    Munoz-Salinas, E.; Castillo, M.; Sanderson, D.; Kinnaird, T.; Cruz-Zaragoza, E.

    2013-12-01

    Studying sedimentation rates on floodplains is key to understanding environmental changes occurred through time in river basins. The Usumacinta and Grijalva rivers flow most of their travel through the southern part of Mexico, forming a large river basin, crossing the states of Chiapas and Tabasco. The Usumacinta-Grijalva River Basin is within the 10 major rivers of North America, having a basin area of ~112 550 km2. We use the OSL technique for dating two sediment profiles and for obtaining luminescence signals in several sediment profiles located in the streambanks of the main trunk of the Usumacinta and Grijalva rivers. We also use mean annual values of suspended sediment load spanning ~50 years to calculate the sedimentation rates. Our OSL dating results start from the 4th Century, when the Maya Civilization was at its peak during the Classic Period. Sedimentation rates show a notable increase at the end of the 19th Century. The increase of the sedimentation rates seems to be related to changes in land uses in the Sierra Madre de Chiapas and Altos de Chiapas, based on deforestation and land clearing for developing new agrarian and pastoral activities. We conclude that the major environmental change in the basin of the Usumacinta and Grijalva Rivers since the Maya Classic Period was generated since the last Century as a result of an intense anthropogenic disturbance of mountain rain forest in Chiapas.

  10. First archeointensity determinations on Maya incense burners from Palenque temples, Mexico: New data to constrain the Mesoamerica secular variation curve

    NASA Astrophysics Data System (ADS)

    Fanjat, G.; Camps, P.; Alva Valdivia, L. M.; Sougrati, M. T.; Cuevas-Garcia, M.; Perrin, M.

    2013-02-01

    We present archeointensity data carried out on pieces of incense burners from the ancient Maya city of Palenque, Chiapas, Mexico, covering much of the Mesoamerican Classic period, from A.D. 400 to A.D. 850. We worked on pieces from 24 incense burners encompassing the five Classic ceramic phases of Palenque: Motiepa (A.D. 400-500), Cascadas (A.D. 500-600), Otulum (A.D. 600-700), Murcielagos (A.D. 700-770), and Balunté (A.D. 770-850). All the samples come from highly elaborate, flanged pedestal of incense burners that are undoubtedly assigned to a ceramic phase by means of their iconographic, morphological and stylistic analyses. Archeointensity measurements were performed with the Thellier-Thellier's method on pre-selected samples by means of their magnetic properties. We obtained archeointensities of very good technical quality from 19 of 24 pieces, allowing the determination of a precise mean value for each ceramic phase, between 29.1±0.9 μT and 32.5±1.2 μT. The firing temperatures of ceramics were estimated with Mössbauer spectroscopy between 700 °C and 1000 °C. These values ensure that a full thermo-remanent magnetization was acquired during the original heating. Our results suggest a relative stability of the field intensity during more than 400 years in this area. The abundance of archeological material in Mesoamerica contrasts with the small amount of archeomagnetic data available that are, in addition, of uneven quality. Thus, it is not possible to establish a trend of intensity variations in Mesoamerica, even using the global databases and secular variation predictions from global models. In this context, our high technical quality data represent a strong constraint for the Mesoamerican secular variation curve during the first millennium AD. The corresponding Virtual Axial Dipole Moments (VADM) are substantially smaller than the ones predicted by the last global geomagnetic models CALS3k.4, suggesting the need for additional data to develop a

  11. Exploring the nexus between climate change, food security, and deforestation in Q'eqchi' Maya communities, Guatemala

    NASA Astrophysics Data System (ADS)

    Pope, I.; Harbor, J.

    2013-12-01

    The challenges of food security in the central Highlands of Guatemala are linked to deforestation, land degradation, and climate change. The Q'eqchi' Maya people that inhabit this region are smallholder farmers who rely on subsistence agriculture for survival. The Q'eqchi' support themselves with timber products and ecosystem services provided by the cloud forest, a unique ecosystem where a substantial portion of water is obtained through the condensation of water droplets onto vegetation via cloud filtration. Over the past 30 years, small-scale deforestation of the cloud forest in the Sierra Yalijux and Sacranix has increased as demand for agricultural land has risen. A link between the decline of cloud forest cover and an increase in severe precipitation events that drive soil erosion has been observed in the study area. As a result, land degradation poses a serious threat to the long-term food security of Q'eqchi' communities. We have examined the social, cultural, and land tenure dynamics that impact the ability of the Q'eqchi' to adapt to the rapidly changing climate, as well as to implement recommendations for grassroots initiatives to enhance these adaptations. Using remote-sensing we constructed three land use change maps that show that deforestation rates have increased by over 200% between 1986-2006 in the Sierra Yaljux and Sacranix mountain ranges, largely due to slash and burn agriculture. Using these land use change maps as an input into the Revised Universal Soil Loss Equation we show that implementation of agroecological techniques to counter the impacts of land use change drastically reduces soil erosion and is the best management practice. Surveys and focus groups in several Q'eqchi' villages revealed that precipitation events have become less frequent and more intense over the past 30 years, and temperatures have generally been increasing as well. Q'eqchi' people have observed that increasing severe precipitation events have accelerated soil

  12. Combining charcoal sediment and molecular markers to infer a Holocene fire history in the Maya lowlands of Petén, Guatemala

    NASA Astrophysics Data System (ADS)

    Kirchgeorg, Torben; Schüpbach, Simon; Colombaroli, Daniele; Beffa, Giorgia; Radaelli, Marta; Kehrwald, Natalie; Barbante, Carlo

    2015-04-01

    Holocene vegetation changes in the Maya Lowlands during the Holocene are a result of changing climate conditions, solely anthropogenic activities, or interactions of both factors. As a consequence, it is difficult to assess how tropical ecosystems will cope with projected changes in precipitation and land-use intensification over the next decades. We investigated the role of fire during the Holocene by combining different proxies. We distinguished between three different morphotypes (grass, wood and leaves) in macroscopic charcoal. We also determined the molecular fire proxies levoglucosan, mannosan and galactosan. Combining these different fire proxies allows a more robust understanding of the complex history of fire regimes at different spatial scales during the Holocene. Comparing the two biomass burning proxies may help increase our understanding about advantages and limitations of molecular markers as proxies for past fire reconstruction in lake sediments. In order to infer changes in past biomass burning, we analysed a lake sediment core from Lake Petén Itzá, Guatemala (17°00'N, 89°50'W, 110 m above sea level), and compared our results with millennial-scale vegetation and climate change data available in this area. Some differences were observed between the two records and we assumed that while macroscopic charcoal represents a local fire signal, the molecular fire proxies records seem to be influenced by regional to supra-regional fire or low temperature fires. During the Holocene we detected three periods of high fire activity: 9500-6000 cal yr BP, 3800 cal yr BP and 2700 cal yr BP. We attributed the first maximum (9500-6000 cal yr BP) to only climate conditions, which corresponds with observations from previous studies in this region. The fast decrease in the relative abundance of woody charcoal to grass charcoal at the 3800 cal yr BP fire maximum may result from human activity, but we cannot exclude that this shift was related to climate conditions

  13. New insights into the history and origin of the southern Maya block, SE Mexico: U-Pb-SHRIMP zircon geochronology from metamorphic rocks of the Chiapas massif

    USGS Publications Warehouse

    Weber, Bodo; Iriondo, Alexander; Premo, Wayne R.; Hecht, Lutz; Schaaf, Peter

    2007-01-01

    The histories of the pre-Mesozoic landmasses in southern México and their connections with Laurentia, Gondwana, and among themselves are crucial for the understanding of the Late Paleozoic assembly of Pangea. The Permian igneous and metamorphic rocks from the Chiapas massif as part of the southern Maya block, México, were dated by U–Pb zircon geochronology employing the SHRIMP (sensitive high resolution ion microprobe) facility at Stanford University. The Chiapas massif is composed of deformed granitoids and orthogneisses with inliers of metasedimentary rocks. SHRIMP data from an anatectic orthogneiss demonstrate that the Chiapas massif was part of a Permian (∼ 272 Ma) active continental margin established on the Pacific margin of Gondwana after the Ouachita orogeny. Latest Permian (252–254 Ma) medium- to high-grade metamorphism and deformation affected the entire Chiapas massif, resulting in anatexis and intrusion of syntectonic granitoids. This unique orogenic event is interpreted as the result of compression due to flat subduction and accretionary tectonics. SHRIMP data of zircon cores from a metapelite from the NE Chiapas massif yielded a single Grenvillian source for sediments. The majority of the zircon cores from a para-amphibolite from the SE part of the massif yielded either 1.0–1.2 or 1.4–1.5 Ga sources, indicating provenance from South American Sunsás and Rondonian-San Ignacio provinces.

  14. Combining charcoal sediment and molecular markers to infer a Holocene fire history in the Maya Lowlands of Petén, Guatemala

    NASA Astrophysics Data System (ADS)

    Schüpbach, Simon; Kirchgeorg, Torben; Colombaroli, Daniele; Beffa, Giorgia; Radaelli, Marta; Kehrwald, Natalie M.; Barbante, Carlo

    2015-05-01

    Vegetation changes in the Maya Lowlands during the Holocene are a result of changing climate conditions, solely anthropogenic activities, or interactions of both factors. As a consequence, it is difficult to assess how tropical ecosystems will cope with projected changes in precipitation and land-use intensification over the next decades. We investigated the role of fire during the Holocene by combining macroscopic charcoal and the molecular fire proxies levoglucosan, mannosan and galactosan. Combining these two different fire proxies allows a more robust understanding of the complex history of fire regimes at different spatial scales during the Holocene. In order to infer changes in past biomass burning, we analysed a lake sediment core from Lake Petén Itzá, Guatemala, and compared our results with millennial-scale vegetation and climate change available in the area. We detected three periods of high fire activity during the Holocene: 9500-6000 cal yr BP, 3700 cal yr BP and 2700 cal yr BP. We attribute the first maximum mostly to climate conditions and the last maximum to human activities. The rapid change between burned vegetation types at the 3700 cal yr BP fire maximum may result from human activity.

  15. Values for gender roles and relations among high school and non-high school adolescents in a Maya community in Chiapas, Mexico.

    PubMed

    Manago, Adriana M

    2015-02-01

    In the current study, I describe values for gender roles and cross-sex relations among adolescents growing up in a southern Mexican Maya community in which high school was introduced in 1999. A total of 80 adolescent girls and boys, half of whom were attending the new high school, provided their opinions on two ethnographically derived vignettes that depicted changes in gender roles and relations occurring in their community. Systematic coding revealed that adolescents not enrolled in high school tended to prioritise ascribed and complementary gender roles and emphasise the importance of family mediation in cross-sex relations. Adolescents who were enrolled in high school tended to prioritise equivalent and chosen gender roles, and emphasised personal responsibility and personal fulfillment in cross-sex relations. Perceptions of risks and opportunities differed by gender: girls favourably evaluated the expansion of adult female role options, but saw risks in personal negotiations of cross-sex relations; boys emphasised the loss of the female homemaker role, but favourably evaluated new opportunities for intimacy in cross-sex relations. PMID:25501543

  16. ANATOMICAL MNEMONICS OF THE GENETIC CODE: A FUNCTIONAL ICOSAHEDRON AND THE VIGESIMAL SYSTEM OF THE MAYA TO REPRESENT THE TWENTY PROTEINOGENIC AMINO ACIDS

    PubMed Central

    CASTRO-CHAVEZ, FERNANDO

    2016-01-01

    In programming and bioinformatics, the graphical interface is vital to describe and to abbreviate aspects and concepts of the physical world. The Mayan Culture developed the vigesimal system, a numerical system based on their count of fingers and toes. My objective is to equate the Mayan system and their numerical representation to the twenty amino acids according to size, except for the number one, represented by a dot, that here is given to cysteine, which acts as glue among peptides as one of its properties; in such a way, two vertical dots will be easily used to represent its related selenocysteine. The Mayan numerical system included the zero, represented by the Maya with an empty shell that here is used to represent the stop codons. On the other hand, the Chinese had a binary numerical system, similar to the binary comparisons of the three properties of Nucleotides within the double helix: H-Bonds, C-Rings and Tautomerism, called the I Ching which here is applied to the natural groups of amino acids that result of the 64-codons compared in binary in their H-Bonds versus their C-Rings, used here to successfully represent the mature sequence of the glucagon amino acids. Additional anatomical tools for the mnemonics of the genetic code and of its amino acid groups are also presented, as well as a functional icosahedron to represent them. Concluding, tools are presented for the visual analysis of proteins and peptide sequencing in bioinformatics and education to teach the genetic code and its resulting amino acids, plus their numerical systems. PMID:27081676

  17. Prevalence and factors associated with musculoskeletal disorders and rheumatic diseases in indigenous Maya-Yucateco people: a cross-sectional community-based study.

    PubMed

    Peláez-Ballestas, I; Alvarez-Nemegyei, J; Loyola-Sánchez, A; Escudero, M L

    2016-07-01

    This study aimed to estimate the prevalence of musculoskeletal disorders and rheumatic diseases in indigenous Maya-Yucateco communities using Community-Oriented Program for Control of Rheumatic Diseases (COPCORD) methodology. The study population comprised subjects aged ≥18 years from 11 communities in the municipality of Chankom, Yucatan. An analytical cross-sectional study was performed, and a census was used. Subjects positive for musculoskeletal (MSK) pain were examined by trained physicians. A total of 1523 community members were interviewed. The mean age was 45.2 years (standard deviation (SD) 17.9), and 917 (60.2 %) were women. Overall, 592 individuals (38.8 %; 95 % CI 36.3-41.3 %) had experienced MSK pain in the last 7 days. The pain intensity was reported as "strong" to "severe" in 43.4 %. The diagnoses were rheumatic regional pain syndromes in 165 (10.8 %; 95 % CI 9.4-12.5), low back pain in 153 (10.0 %; 95 % CI 8.5-11.6), osteoarthritis in 144 (9.4 %; 95 % CI 8.0-11.0), fibromyalgia in 35 (2.2 %; 95 % CI 1.6-3.1), rheumatoid arthritis in 17 (1.1 %; 95 % CI 0.6-1.7), undifferentiated arthritis in 8 (0.5 %; 95 % CI 0.2-0.8), and gout in 1 (0.06 %; 95 % CI 0.001-0.3). Older age, being female, disability, and physically demanding work were associated with a greater likelihood of having a rheumatic disease. In conclusion, MSK pain and rheumatic diseases were highly prevalent. The high impact of rheumatic diseases on daily activities in this indigenous population suggests the need to organize culturally-sensitive community interventions for the prevention of disabilities caused by MSK disorders and diseases. PMID:26438109

  18. The impact of arthritis on the physical function of a rural Maya-Yucateco community and factors associated with its prevalence: a cross sectional, community-based study.

    PubMed

    Loyola-Sanchez, Adalberto; Richardson, Julie; Pelaez-Ballestas, Ingris; Alvarez-Nemegyei, José; Lavis, John N; Wilson, Michael G; Wilkins, Seanne

    2016-07-01

    This study aims to evaluate the impact of arthritis on the physical function of people living in a Maya-Yucateco rural community and to assess the association of known modifiable risk factors with the prevalence of overall arthritis and its main types (osteoarthritis and rheumatoid arthritis). Using a cross-sectional, community-based census design, data collected from the adult population (≥18 years) of the Municipality of Chankom, Yucatán, México, were analyzed (n = 1523). Participants' physical function was assessed using a culturized version of the health assessment questionnaire disability index. Social, physical, and behavioral factors linked to overall arthritis, osteoarthritis, and rheumatoid arthritis, were assessed through the "Community-Oriented-Program-for-the-Control-of-Rheumatic-Diseases [COPCORD]" questionnaire. A physiatrist and a rheumatologist confirmed all osteoarthritis and rheumatoid arthritis cases using the American College of Rheumatology criteria. Arthritis was confirmed in 169 cases (22 %, 95 % confidence interval (CI) 19-25) of those assessed for musculoskeletal symptoms (n = 779): osteoarthritis = 144, rheumatoid arthritis = 17, and non-specific arthritis = 8. Arthritis was associated with a higher prevalence of disability after controlling for age, gender, and number of comorbidities (odds ratio = 4.0, 95 % CI 3.0-6.0). Higher level of wealth was associated with lower arthritis prevalence (odds ratio = 0.9, 95% CI 0.8-0.9). Higher body mass index was associated with higher hip and/or knee osteoarthritis prevalence (odds ratio = 1.1, 95 % CI 1.03-1.1). Arthritis is highly associated with disability in the Mayan people living in Chankom. The prevalence of arthritis in Chankom is associated with social factors, such as people's level of wealth, while the prevalence of low-extremity osteoarthritis is associated with people's body mass index. PMID:26445940

  19. Thermal biology of prey (Melongena corona bispinosa, Strombus pugilis, Callinectes similis, Libinia dubia) and predators (Ocyurus chrysurus, Centropomus undecimalis) of Octopus maya from the Yucatan Peninsula.

    PubMed

    Noyola Regil, Javier; Mascaro, Maite; Díaz, Fernando; Denisse Re, Ana; Sánchez-Zamora, Adolfo; Caamal-Monsreal, Claudia; Rosas, Carlos

    2015-10-01

    On the Yucatan Peninsula there is an upwelling which allows access to a body of cold water that controls temperature in this area. This modulates the ecology and distribution of organisms that inhabit the continental shelf. The objective of this study was to determine the effect of different acclimation temperatures on the thermal biology of prey as mollusc, crustacean (Melongena corona bispinosa, Strombus pugilis, Callinectes similis, Libinia dubia) and predators as fish (Ocyurus chrysurus, Centropomus undecimalis) of Octopus maya. Octopus prey preferred temperatures between 23.5°C and 26.0°C, while predators preferred temperatures 26.4-28.5°C. The species with largest thermal windows were M. corona bispinosa (328.8°C(2)), C. similis (322.8°C(2)), L. dubia (319.2°C(2)), C. undecimalis (288.6°C(2)), O. chrysurus (237.5°C(2)), while the smallest thermal window was for S. pugilis (202.0°C(2)). The acclimation response ratios (ARR) estimated for prey ranged from 0.24-0.55 in animals exposed to CTMax and 0.21-0.65 in those exposed to CTMin. Amongst predators, ARR ranged from 0.30 to 0.60 and 0.41 to 0.53 for animals exposed to CTMax and CTMin, respectively. Correlating the optimal temperature limits of prey and predators with surface temperatures on the continental shelf and those 4m deep showed that the main prey, Callinectes similis and L. dubia, shared a thermal niche and that an increase in temperature could force these species to migrate to other sites to find optimal temperatures for their physiological functions. As a consequence the continental shelf community would undergo a structural change. Predators were found to be near their optimal temperatures in surface temperatures on the continental shelf. We conclude that they would remain in the area in a warming scenario. The size of the thermal window was related to the type of ecosystem inhabited by these species. These ARR intervals allowed us to categorize the species as temperate or tropical

  20. Sub-seasonally resolved coral records of Caribbean sea surface conditions during the demise of the Maya civilization (~AD 800-1050)

    NASA Astrophysics Data System (ADS)

    Wu, H.; Felis, T.; Kölling, M.; Giry, C.; Scholz, D.; Scheffers, S.

    2012-04-01

    We present a unique collection of annually banded fossil Montastraea coral colonies from Bonaire (Netherlands Antilles) in the southern Caribbean Sea that reveals growth between ~AD 800-1050. Coincidentally, this time interval was known for the demise of the classic Maya civilization in the lowlands of the Yucatán Peninsula termed the Terminal Classic Period (roughly AD 750-1050). Explanations for the downfall ranged from foreign invasion to social turmoil, but paleoclimatic evidence suggests severe climate change such as prolonged dry cycles as the primary influence. The Bonaire corals provide the first sub-seasonally resolved proxy records of surface ocean conditions in the Caribbean region during the Terminal Classic Period, and are completely different than the terrestrial-driven and summer-influenced precipitation proxy records from locations in the Yucatán and the Cariaco Basin. The corals display uninterrupted growth patterns ranging ~30-60 years and overlap each other at various time periods during the Terminal Classic Period. Our preliminary coral radiocarbon ages will be refined by precise U-series dating. The aragonitic skeletons of modern and fossil Montastraea colonies have been analyzed for Sr/Ca and δ18O at sub-seasonal resolution as proxies of sea surface temperature (SST), sea surface salinity (SSS), and hydrological changes. Evaluation of the modern coral record provides a modern baseline condition as basis of comparison to track the changing SST and SSS in the southern Caribbean during the Terminal Classic Period. The modern record indicates that seasonal to interannual variability in southern Caribbean Sea coral δ18O is predominantly driven by SST where Sr/Ca and δ18O records are tightly coupled and in-phase reflecting a similar source of influence. However, the fossil coral records display distinct interannual variability and longer-term decadal variability (8-15 years) in both Sr/Ca and δ18O that are decoupled from each other indicating

  1. Sub-seasonally resolved coral records of Caribbean sea surface conditions during the demise of the Maya civilization (~AD 800-1000)

    NASA Astrophysics Data System (ADS)

    Wu, H. C.; Felis, T.; Scholz, D.; Kölling, M.; Giry, C.; Scheffers, S.

    2012-12-01

    We present a unique collection of annually banded fossil Montastraea coral colonies from Bonaire (Netherlands Antilles) in the southern Caribbean Sea that reveals growth between ~AD 800-1000. Coincidentally, this time interval was known for the demise of the classic Maya civilization in the lowlands of the Yucatán Peninsula termed the Terminal Classic Period (TCP; ~AD 750-1050). Explanations for the downfall ranged from foreign invasion to social turmoil, but recent paleoclimatic evidence suggests climate change such as prolonged dry cycles and decrease in precipitation as the primary influence. The Bonaire corals provide the first sub-seasonally resolved proxy records of surface ocean conditions in the Caribbean region during the TCP, and are completely different than the terrestrial-driven and summer-influenced precipitation proxy records from locations in the Yucatán and the Cariaco Basin. One modern and six fossil Montastraea colonies were analyzed for Sr/Ca and δ18O at sub-seasonal resolution as proxies of sea surface temperature (SST), sea surface salinity (SSS), and hydrological changes. The corals display uninterrupted growth patterns ranging ~30-70 years and overlap each other at various time periods during the TCP with age verification by precision 230Th/U dating. Evaluation of the modern coral record provides a modern baseline condition as basis of comparison to track the changing SST and SSS in the southern Caribbean during the TCP. The modern colony recorded in-phase and tightly coupled variability between the two proxies indicating a similar source of influence that is predominantly driven by SST over seasonal to interannual timescales. However, the fossil coral records display distinct interannual variability and longer-term decadal variability (~11-14 years) in both Sr/Ca and δ18O that are decoupled from each other indicating deviations in SSS and differences in primary drivers of proxy variability between past and modern conditions. In addition

  2. Spoken (Yucatec) Maya. [Preliminary Edition].

    ERIC Educational Resources Information Center

    Blair, Robert W.; Vermont-Salas, Refugio

    This two-volume set of 18 tape-recorded lesson units represents a first attempt at preparing a course in the modern spoken language of some 300,000 inhabitants of the peninsula of Yucatan, the Guatemalan department of the Peten, and certain border areas of Belize. (A short account of the research and background of this material is given in the…

  3. Theatre of the Ancient Maya

    ERIC Educational Resources Information Center

    Klein, Maxine

    1971-01-01

    There is at least one Western theatre that the historians consistently overlook. This is the theatre of the Mayan Civilization, one that antedates any other in the Western world by hundreds of years. (Author)

  4. Kaqchikel Maya Language Analysis Project

    ERIC Educational Resources Information Center

    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…

  5. First report of the presence of Acartia bispinosa Carl, 1907 (Copepoda, Calanoida) in a semi-enclosed Bay (Sharm El-Maya), northern Red Sea with some notes on its seasonal variation in abundance and body size

    PubMed Central

    El-Sherbiny, Mohsen M.; Al-Aidaroos, Ali M.

    2014-01-01

    Abstract The calanoid copepod, Acartia bispinosa Carl, 1907, is reported for the first time in the Red Sea, where it is found to be an important copepod in the mesozooplankton community structure of the Sharm El-Maya Bay. Female and male are fully redescribed and illustrated of as the mouthparts of this species have never previously been described and figured. Acartia bispinosa was collected in the plankton samples throughout the year and showed two peaks of abundance, a pronounced one in April (4234 individuals m-3), and second smaller peak during November (1784 individuals m-3). The average total length of females varied between 1.32 and 1.53 mm at the end of June and January respectively. For males, the average total length fluctuated between 1.07 and 1.16 mm at end of June and March respectively. Temperature showed an inverse relationship with the body length (P > 0.001) and seemed to be one of the prime factors affecting the body length of both sexes. PMID:25349502

  6. Preliminary results of the correlation between ion concentrations in rainwater samples and atmospheric back trajectories as a part of the study {open_quotes}impact to acid rain in the deterioration of Mexican Maya monuments{close_quotes} (project Conacyt-UNAM: 0128T9106)

    SciTech Connect

    Bravo, A.H.; Saavedra, M.I.; Snchez, P.; Camacho, R.

    1996-12-31

    The environmental Pollution Section at the Center of Atmospheric Sciences, National Autonomus University of Mexico (UNAM), has been conducting a research project on their potential of impact of acid rain on the Mexican Maya monuments since 1993. As a part of such study, 49 rainwater samples were collected during the years 1994 through 1995 at the Puerto Morelos Oceanographic Station Located close to the Tulum Maya ruins in the State of Qintana Roo. The rain water samples were collected using an automatic rain collector. After the rain event, the water samples were transferred to clean Nalgene bottles. The bottles were stored under refrigeration prior to their shipment to the UNAM laboratory in Mexico City. Concentrations of anions Cl{sup -}, NO{sup -}{sub 3}, and SO{sup 2-}{sub 4} and cations Na{sup +}, NH{sup +}{sub 4}, K{sup +}, Mg{sup 2+} an Ca{sup 2+} were determined by the High Pressure Ion Chromatographic Procedure. The pH of samples was measured in the laboratory. Also, wind back upper trajectories which arrived to the Puerto Morelos are at the same date of each rain event, were calculated using the GMCC atmospheric trajectory program at NOAA. A thorough analysis on the relations between anions and cations is made and preliminary correlations of these results with the calculated long range trajectories are explored in order to find the possible origin of the event.

  7. Chemical composition of precipitation in a Mexican Maya region

    NASA Astrophysics Data System (ADS)

    Bravo, H. A.; Saavedra, M. I. R.; Sánchez, P. A.; Torres, R. J.; Granada, L. M. M.

    The chemical characteristics of wet precipitation in Puerto Morelos, Quintana Roo State, Mexico, were measured from April 1994 to December 1995. Puerto Morelos is located in the Caribbean Mayan coastal region of the Peninsula of Yucatan, and is normally exposed to winds from the Caribbean region. Wetfall was analyzed for pH, conductivity and Cl -, NO 3-, SO 42-, Na +, NH 4+, K +, Mg 2+ and Ca 2+ ion concentrations. Volume-weighted mean pH for the whole sampling period was 5.35, although values as low as 4.6 were measured in several rain samples. Concentrations of all species correlated negatively with rain volume. Sea-salt aerosols contributed with most of the Na +, Cl -, Mg 2+, K + and SO 42- found in wet precipitation. The mean [SO 42-excess] was 9.7 μEq l -1, which agrees with the background hemispheric values of ≈10 μEq l -1 reported elsewhere. The mean [NO 3-] was 11.4 μEq l -1, almost four times higher than the background hemispheric value of ≈2.5 μEq l -1 reported elsewhere. However, a major component causing the slight acidity character of rain in Puerto Morelos seems to be H 2SO 4.

  8. Comets and meteors in the beliefs of ancient mayas

    NASA Astrophysics Data System (ADS)

    Yershova, G. G.

    2001-12-01

    Data concerning the Mayan approach to comets and meteors have till now been available mostly from ethnographical and folklore sources which dealt, as a rule, with various beliefs and tokens. The studies of hieroglyphic texts of the Classic Period (AD 600-900) have proved that comets and meteors were undoubtedly known in this culture through astronomical observations and their periodicity.

  9. An Environmental Expedition Course in Search of the Maya.

    ERIC Educational Resources Information Center

    Loret, John

    1978-01-01

    Sponsoring an interdisciplinary program (over 30 lecture hours of geology, ecology, anthropology, ethnology, and agriculture of the Yucatan and Meso-America), Queens College and the University of Connecticut provide expeditions to Mexico and study of local geomorphology, stratigraphy, climate, topography, soils, archeological sites, flora, and…

  10. Las bases y fundamentos del derecho indigena del pueblo maya de Guatemala (The Foundations and Principles of Indigenous Rights of the Maya People of Guatemala).

    ERIC Educational Resources Information Center

    Tovar, Marcela; Chavajay, Miriam

    2000-01-01

    The Guatemalan peace accord recognizes the institutions and local authorities of indigenous peoples, as well as their customs, common lands, and the "customary right" (common law) that structures intracommunity relations. However, it is difficult to define "customary right" and its applications and limits. A systematic study of traditional…

  11. Considering the Art History of El Mundo Maya: Some Issues Regarding the Inquiry Process.

    ERIC Educational Resources Information Center

    Labadie, John Antoine

    The project sees study of art culture through primary source inquiry as a valuable experience for the art educator. Regardless of the culture, artist, or time period studied, the work of art makes itself known through both intellectual and emotive responses to it. Through description of Mayan culture, society, and artifacts, art as an extension…

  12. Pride of the Maya -- basic education project for Mayan girls in bilingual and bicultural manners.

    PubMed

    1996-11-01

    Girls Education Project, a two-year program sponsored by the Japan International Cooperation Agency (JICA), seeks to address the educational needs of Mayan girls in rural Guatemala. The program is being implemented under the framework of the Japan-US Common Agenda for Cooperation in Global Perspectives. Preliminary fieldwork revealed the importance of ensuring that entire communities, including teachers and parents, appreciate the human right of rural girls to a basic education. The project team will conduct three-day workshops in each of the four pilot states in 1997 to discuss teaching methods, materials, and curricula to promote girls' participation and improve their achievement levels. Also planned is a three-day national seminar involving governmental officials and representatives from the public and private sectors, nongovernmental organizations, professional groups, universities, and ethnic and cultural groups. The bilingual/bicultural method selected for the intervention seeks to implement basic education for Mayan girls in both Spanish and the four main Mayan languages. Another focus is to encourage the students to maintain pride in their cultural heritage. PMID:12292096

  13. AGRO-ECOLOGICAL DRIVERS OF RURAL OUT-MIGRATION TO THE MAYA BIOSPHERE RESERVE, GUATEMALA.

    PubMed

    López-Carr, David

    2012-01-01

    Migration necessarily precedes environmental change in the form of deforestation and soil degradation in tropical agricultural frontiers. But what environmental factors may contribute to these migration streams in the first place? Identifying environmental characteristics related to this process is crucial for understanding how environmental change and migration may form recurrent feedback loops. Further understanding this process could be useful for developing policies to reduce both environmentally induced migration from origin areas and also to palliate significant environmental change unleashed by settler deforestation in destination areas. Evidently, apprehending this holistic process cannot be approached only from the destination since this ignores environmental and other antecedents to rural out-migration. This paper presents data from surveys conducted in areas of high out-migration to the agricultural frontier in northern Guatemala. Results suggest that land scarcity and degradation in origin communities are linked to out-migration in general and to the forest frontier of northern Guatemala in particular. PMID:24069068

  14. Agro-ecological drivers of rural out-migration to the Maya Biosphere Reserve, Guatemala

    NASA Astrophysics Data System (ADS)

    López-Carr, David

    2012-12-01

    Migration necessarily precedes environmental change in the form of deforestation and soil degradation in tropical settlement frontiers. But what environmental factors may contribute to these migration streams in the first place? Identification of the environmental characteristics related to this process is crucial for understanding how environmental change and migration may form recurrent feedback loops. Further understanding of this process could be useful for developing policies to both reduce environmentally induced migration from origin areas and also palliate significant environmental change unleashed by settler deforestation in destination areas. Evidently, apprehension of this holistic process cannot be approached only from the destination since this ignores environmental and other antecedents to rural out-migration. This letter presents data from surveys conducted in areas of high out-migration to the agricultural frontier in northern Guatemala. The results suggest that land scarcity and degradation in origin communities are linked to out-migration in general and to the forest frontier of northern Guatemala in particular.

  15. Trace element analysis of obsidian artifacts from a classic Maya residential group at Nohmul, Belize

    SciTech Connect

    Hammond, N.; Neivens, M.D.; Harbottle, G.

    1984-01-01

    Forty-nine obsidian artifacts from a classic period residential group at Nohmul, northern Belize, have been analyzed by neutron activation analysis. The majority of the samples originated from Ixtepeque, and the remainder from El Chayal. Increasing prominence of the Ixtepeque source from the late Classic into the Terminal Classic (i.e., before and after ca. A.D. 800) suggests greater use of a coastal distribution route known to have originated in the formative and to have remained in use through the colonial period.

  16. Peasant agriculture and global change: A maya response to energy development in southeastern Mexico

    SciTech Connect

    Collier, G.A. ); Mountjoy, D.C. ); Nigh, R.B. )

    1994-06-01

    This article combines data and perspectives from anthropology, agricultural economics, and landscape ecology to study how peasant activity mediates the influence of global economic driving forces on land-use patterns. Southeastern Mexico underwent rapid energy development during the 1960's and 1970's. The state used oil revenues to complete projects such as two major new hydroelectric power projects. As energy development went into high gear, the southeastern region, which had been primarily agrarian, began to supply Mexico with 50% of its energy and much of its export oil and the agricultural base declined. Discussed in this article are the following related areas: sectoral changes under the energy development boom; landscape dynamics; off-farm activities of peasants during the energy boom; Ainacanteco agriculture transformed after 1982; off-farm peasant production and agrarian transformation; peasant versatility and environmental policy. 28 refs., 7 figs.

  17. Cultures of Teaching in Childhood: Formal Schooling and Maya Sibling Teaching at Home

    ERIC Educational Resources Information Center

    Maynard, Ashley E.

    2004-01-01

    Culture can be thought of a set of shared practices, beliefs, and values that are transmitted across generations through language [Bruner, J. (1990). "Acts of meaning". Cambridge, MA: Harvard University Press]. Teaching is one way that culture is transmitted, but forms of teaching vary across cultures and across activity settings within cultures.…

  18. Indigenous Languages: Nahuatl, Quechua, & Maya--A Study of Multilingual Immigrant Students & Their Families

    ERIC Educational Resources Information Center

    Perez, Carlos

    2009-01-01

    This study investigated how immigrants from Latin America who speak indigenous languages perceive and respond to social, racial, linguistic, and cultural factors in the United States. It examined the multicultural and multilingual experiences of six participants, five of whom speak an indigenous language. There were three interviews conducted with…

  19. Telling Stories--Rethreading Lives: Community Education, Women's Development and Social Change among the Maya Ixil.

    ERIC Educational Resources Information Center

    Lykes, M. Brinton

    1999-01-01

    Describes development of a rural Guatemalan women's organization created to respond to the psychological, economic, and educational consequences of long-term war, massacre, military occupation, poverty, and exile. The association's genesis and current work reflect collaborative processes of interethnic and transnational nonformal education,…

  20. Menominee and Maya: Indigenous Cultures and their Forests Inspire and Support Each Other

    ERIC Educational Resources Information Center

    Benton, Sherrole

    2005-01-01

    Historically, indigenous people lived in a sustainable economy, making a living from the land in a way that did not destroy the ecosystem. Today, the market economy is driven by the demands of consumers, and supplying their demands is taking a toll on the environment. This article discusses the Menominee tribe in northeastern Wisconsin, and the…

  1. Sign Language, Culture and Community in a Traditional Yucatec Maya Village.

    ERIC Educational Resources Information Center

    Johnson, Robert E.

    1991-01-01

    Examines a traditional Mayan village in the Yucatan where deaf inhabitants use a sign language that is distinct from that used in other Mexican communities. Because the hearing villagers are able to communicate in this sign language, the deaf inhabitants are almost fully integrated into the social and economic life of the village. (22 references)…

  2. Teaching as a Sensory Activity: Making the Maya Come to Life.

    ERIC Educational Resources Information Center

    Banks, Dennis; Gallagher, Deborah

    1993-01-01

    Presents an interdisciplinary instructional unit focusing on the Mayan Civilization. Describes the use of interactive story telling and guided imagery to heighten student interest and involvement. Provides suggestions for using these methods to teach about other countries or civilizations. (CFR)

  3. Systems Thinking : Ancient Maya's Evolution of Consciousness and Contemporary Systems Thinking

    NASA Astrophysics Data System (ADS)

    Jere Lazanski, Tadeja

    2010-11-01

    Systems thinking as a modern approach for problem solving was revived after WWII even though it had been an ancient philosophy. We can track systems thinking back to antiquity. Making a distinction from Western rationalist traditions of philosophy, C. West Churchman often identified with the I Ching as a systems approach sharing a frame of reference similar to pre-Socratic philosophy and Heraclitus. In this paper, we will compare the evolutionary system of consciousness, which was presented in the Tun calendar of Mayan Indians and contemporary systems theory and systems thinking, which is nothing else but highly evolved human consciousness in society. We will present Mayan calendar systems to contemporary systems thinking principles and explain the answer to the Ackoff's judgment on four hundred years of analytical thinking as the dominant mode of society. We will use the methods of historical comparison and a method of a systems approach. We will point out the big picture and Mayan divine plan as main systems principles. The Mayan numerical system and long count units has been proven as one of the most accurate systems for describing the present and future of the civilization in which we have all evolved. We will also explain the Mayan nine-level pyramids system that represents the evolutionary system, i.e. the consciousness, which in our time shows the actual level of human consciousness. Deriving from all described, we will show the main systems principles, discussed by contemporary systems authors and Mayan systems principles, which differ only in one expression—they named "the big picture" as "the divine plan". The final results can be perfectly applied to the society we live in. Seeing the world from the big picture point of view is reaching a level of awareness, in which linear thinking is replaced by systems thinking. The Mayans explained that the civilization would achieve the system of conscious co-creation. We can claim that linear thinking guides us to a limited consciousness, whereas systems thinking opens the possibilities of conscious co-creation for the benefits of sustainable society and future of the planet.

  4. From Vatican II to Speaking in Tongues: Theology and Language Policy in a Q'eqchi'-Maya Catholic Parish

    ERIC Educational Resources Information Center

    Hoenes del Pinal, Eric

    2016-01-01

    One of the most far-reaching reforms undertaken by the Catholic Church as part of the Second Vatican Council was the adoption of vernacular languages in the liturgy. The transition from Latin to vernaculars was not unproblematic, however, as it raised several practical and theoretical questions regarding the relationship between local churches and…

  5. Search for Tikal: Lost City of the Maya. Fulbright-Hays Summer Seminars Abroad Program, 2000 (Mexico and Guatemala).

    ERIC Educational Resources Information Center

    Karem, Kenny

    This curriculum unit takes the form of historical fiction, an original story for middle school students which revolves around the 16th-century Spanish conquest of Guatemala and the Mayan people. Incorporated into the story are many of the Mayan sites, ruins, geography, culture, legends, historical characters, and cities. The climax is set at the…

  6. History through Art and Architecture: The Art and Architecture of the Maya. Teacher's Manual [and] Creative Workbook.

    ERIC Educational Resources Information Center

    Campbell, Ann; Hoag, John, Ed.

    This packet--a teacher's manual, student workbook, and color poster--was designed to accompany a 2-part videotape program. The teacher's manual provides a script of the videotape, and is organized in 2 sections. Part 1, "Kings, Glyphs, Temples and Ball Courts", looks at the written glyph language and the Solar and Ritual calendars of the early…

  7. Emic-Etic Conflicts as Explanation of Nonparticipation in Adult Education among the Maya of Western Guatemala.

    ERIC Educational Resources Information Center

    Cutz, German; Chandler, Paul

    2000-01-01

    Causes for lack of participation of Mayan adults in literacy programs were investigated in ethnographic interviews. Emic deterrents at the individual, family, community, and national levels included personal needs, self-perception, rigid moral values, machismo, ethnic and cultural identity, community loyalty, and teaching formats. Successful…

  8. A Community Health Worker Intervention for Diabetes Self-Management Among the Tz'utujil Maya of Guatemala.

    PubMed

    Micikas, Mary; Foster, Jennifer; Weis, Allison; Lopez-Salm, Alyse; Lungelow, Danielle; Mendez, Pedro; Micikas, Ashley

    2015-07-01

    Despite the high prevalence of diabetes in rural Guatemala, there is little education in diabetes self-management, particularly among the indigenous population. To address this need, a culturally relevant education intervention for diabetic patients was developed and implemented in two rural communities in Guatemala. An evaluative research project was designed to investigate if the structured, community-led diabetes self-management intervention improved selected health outcomes for participants. A one-group, pretest-posttest design was used to evaluate the effectiveness of the educational intervention by comparing measures of health, knowledge, and behavior in patients pre- and postintervention. A survey instrument assessed health beliefs and practices and hemoglobin A1c (HgA1c) measured blood glucose levels at baseline and 4 months post initiation of intervention (n = 52). There was a significant decrease (1.2%) in the main outcome measure, mean HgA1c from baseline (10.1%) and follow-up (8.9%; p = .001). Other survey findings were not statistically significant. This study illustrates that a culturally specific, diabetes self-management program led by community health workers may reduce HgA1c levels in rural populations of Guatemala. However, as a random sample was not feasible for this study, this finding should be interpreted with caution. Limitations unique to the setting and patient population are discussed in this article. PMID:26113496

  9. "From la Malinche and Menchu to Modern-Day "Mayas": Women Forging Paths through the Maze of Higher Education"

    ERIC Educational Resources Information Center

    Hall, Vickie A.

    2010-01-01

    "Beneath the rule of men entirely great, the pen is mightier than the sword." Bulwer-Lytton recognized this strength years ago, and its truth continues to ring true in the works of authors: Tzvetan Todorov, Octavio Paz, Carlos Fuentes, Rigoberta Menchu, and Deborah Tannen. Language is a centuries-old weapon wielded in the struggle against…

  10. How Working Poor Maya Migrant Families Acculturate to an Urban Setting--Daily Routines and Adaptation Strategies

    ERIC Educational Resources Information Center

    Tovote, Katrin Erika

    2012-01-01

    Globally, an increasing number of people migrate from their rural communities to large cities. Despite the pervasive thinking that indigenous communities are solidified in space and strictly conserve cultural traditions, indigenous individuals and families increasingly leave their homelands to set up a new life in an urban environment mostly…

  11. Conservation, Community, and Culture? New Organizational Challenges of Community Forest Concessions in the Maya Biosphere Reserve of Guatemala

    ERIC Educational Resources Information Center

    Taylor, Peter Leigh

    2010-01-01

    Community-based forestry has received much recent attention as an effort to protect threatened Southern forests by linking conservation with sustainable livelihoods. Many researchers have emphasized the importance of effective organization for successful community-based forestry. While significant attention has been paid to community-level…

  12. Maya the Bee, Scooby Doo and Other Stories: How the Public and Private Distinction Is Depicted in Children's Bidialectal Interactions in Kindergarten

    ERIC Educational Resources Information Center

    Sophocleous, Andry

    2013-01-01

    The complex notion of the public/private distinction of social spheres has not been systematically investigated in sociolinguistics; particularly in the case of bidialectal kindergarten age children and how they construct their social lives around this distinction in a public environment such as that of school. No simple continuum can clearly…

  13. Microevolution of Anthrax from a Young Ancestor (M.A.Y.A.) Suggests a Soil-Borne Life Cycle of Bacillus anthracis

    PubMed Central

    Braun, Peter; Grass, Gregor; Aceti, Angela; Serrecchia, Luigina; Affuso, Alessia; Marino, Leonardo; Grimaldi, Stefania; Pagano, Stefania; Hanczaruk, Matthias; Georgi, Enrico; Northoff, Bernd; Schöler, Anne; Schloter, Michael; Antwerpen, Markus; Fasanella, Antonio

    2015-01-01

    During an anthrax outbreak at the Pollino National Park (Basilicata, Italy) in 2004, diseased cattle were buried and from these anthrax-foci Bacillus anthracis endospores still diffuse to the surface resulting in local accumulations. Recent data suggest that B. anthracis multiplies in soil outside the animal-host body. This notion is supported by the frequent isolation of B. anthracis from soil lacking one or both virulence plasmids. Such strains represent an evolutionary dead end, as they are likely no longer able to successfully infect new hosts. This loss of virulence plasmids is explained most simply by postulating a soil-borne life cycle of the pathogen. To test this hypothesis we investigated possible microevolution at two natural anthrax foci from the 2004 outbreak. If valid, then genotypes of strains isolated from near the surface at these foci should be on a different evolutionary trajectory from those below residing in deeper-laying horizons close to the carcass. Thus, the genetic diversity of B. anthracis isolates was compared conducting Progressive Hierarchical Resolving Assays using Nucleic Acids (PHRANA) and next generation Whole Genome Sequencing (WGS). PHRANA was not discriminatory enough to resolve the fine genetic relationships between the isolates. Conversely, WGS of nine isolates from near-surface and nine from near-carcass revealed five isolate specific SNPs, four of which were found only in different near-surface isolates. In support of our hypothesis, one surface-isolate lacked plasmid pXO1 and also harbored one of the unique SNPs. Taken together, our results suggest a limited soil-borne life cycle of B. anthracis. PMID:26266934

  14. A Curriculum Unit on Human Rights of the Mayas of Guatemala. Fulbright-Hays Summer Seminars Abroad Program, 2000 (Mexico and Guatemala).

    ERIC Educational Resources Information Center

    Shilha, Marianne M.

    This curriculum unit is intended for upper-level high school students. The unit aims for students to gain a basic understanding of the history of Mayan human rights in Guatemala and of the present situation in Guatemala. The unit uses a variety of media and teaching techniques. It lists 30 questions which are to be completed after reading the…

  15. QND &NDASH; DESIGNING A PARTICIPATORY SCENARIO MODELING TOOL TO INTEGRATE TECHNOLOGY, ECOLOGY, AND SOCIOLOGY IN GUATEMALA&RSQUO;S MAYA BIOSPHERE RESERVE AND BEYOND

    EPA Science Inventory

    Participatory scenario modeling – an interactive method for visualizing the future – is one of the most promising tools for achieving sustainable land use agreements amongst diverse stakeholder groups. The method has the potential to bridge the gap between the high...

  16. A theoretical study of special acoustic effects caused by the staircase of the El Castillo pyramid at the Maya ruins of Chichen-Itza in Mexico

    NASA Astrophysics Data System (ADS)

    Declercq, Nico F.; Degrieck, Joris; Briers, Rudy; Leroy, Oswald

    2004-12-01

    It is known that a handclap in front of the stairs of the great pyramid of Chichen Itza produces a chirp echo which sounds more or less like the sound of a Quetzal bird. The present work describes precise diffraction simulations and attempts to answer the critical question what physical effects cause the formation of the chirp echo. Comparison is made with experimental results obtained from David Lubman. Numerical simulations show that the echo shows a strong dependence on the kind of incident sound. Simulations are performed for a (delta function like) pulse and also for a real handclap. The effect of reflections on the ground in front of the pyramid is also discussed. The present work also explains why an observer seated on the lowest step of the pyramid hears the sound of raindrops falling in a water filled bucket instead of footstep sounds when people, situated higher up the pyramid, climb the stairs. .

  17. Transdisciplinary Research on Cancer-Healing Systems Between Biomedicine and the Maya of Guatemala: A Tool for Reciprocal Reflexivity in a Multi-Epistemological Setting.

    PubMed

    Berger-González, Mónica; Stauffacher, Michael; Zinsstag, Jakob; Edwards, Peter; Krütli, Pius

    2016-01-01

    Transdisciplinarity (TD) is a participatory research approach in which actors from science and society work closely together. It offers means for promoting knowledge integration and finding solutions to complex societal problems, and can be applied within a multiplicity of epistemic systems. We conducted a TD process from 2011 to 2014 between indigenous Mayan medical specialists from Guatemala and Western biomedical physicians and scientists to study cancer. Given the immense cultural gap between the partners, it was necessary to develop new methods to overcome biases induced by ethnocentric behaviors and power differentials. This article describes this intercultural cooperation and presents a method of reciprocal reflexivity (Bidirectional Emic-Etic tool) developed to overcome them. As a result of application, researchers observed successful knowledge integration at the epistemic level, the social-organizational level, and the communicative level throughout the study. This approach may prove beneficial to others engaged in facilitating participatory health research in complex intercultural settings. PMID:26679941

  18. Use of Network Centrality Measures to Explain Individual Levels of Herbal Remedy Cultural Competence among the Yucatec Maya in Tabi, Mexico

    PubMed Central

    Hopkins, Allison

    2011-01-01

    Common herbal remedy knowledge varies and is transmitted among individuals who are connected through a social network. Thus, social relationships have the potential to account for some of the variation in knowledge. Cultural consensus analysis (CCA) and social network analysis (SNA) were used together to study the association between intracultural variation in botanical remedy knowledge and social relationships in Tabi, Yucatan, Mexico. CCA, a theory of culture as agreement, was used to assess the competence of individuals in a domain of herbal remedies by measuring individual competence scores within that domain. There was a weak but positive association between these competence scores and network centrality scores. This association disappeared when age was included in the model. People in Tabi, who have higher competence in herbal remedies tend to be older and more centrally located in the herbal remedy inquiry network. The larger implication of the application of CCA and SNA for understanding the acquisition and transmission of cultural knowledge is also explored. PMID:21909235

  19. The Sound of Silence in Nohya: A Preliminary Account of Sign Language Use by the Deaf in a Maya Community in Yucatan, Mexico.

    ERIC Educational Resources Information Center

    Shuman, Malcom L.

    1980-01-01

    A description of the sign language used in a Mexican village shows its parallels with other sign languages, its similarity to the folk gestural system of Mexico and its distinguishing aspects. Examples illustrate its syntax, grammar and lexicon. (PMJ)

  20. Adults' Orientation of Children--And Children's Initiative to Pitch In--To Everyday Adult Activities in a Tsotsil Maya Community.

    PubMed

    Martínez-Pérez, Margarita

    2015-01-01

    This chapter examines how 2-year-old children attempt to actively participate in adult work in a Mayan community in Chiapas, Mexico, and how adults contribute and accommodate to the contributions. As children enter into activities and adults orient and reorient the activity to direct the children, teaching from expert to novice is generated by children's agency in co-participatory interactions. The chapter enriches the LOPI model by focusing on the structure of participation and communication, social and community organization, and the evaluation that occurs in the activity itself. PMID:26955925

  1. On the Paleotectonic Evolution of the Pacific Margin of Southern Mexico, the Maya and Juchatengo Terranes and Chochal Formation Guatemala:Insights from Paleomagnetic and Isotopic Studies

    NASA Astrophysics Data System (ADS)

    Guerrero Garcia, J. C.; Herrero-Bervera, E.

    2009-05-01

    In the paleogeographic reconstruction of Mexico and northern Central America, evidence shows that the entire region is a collage of suspect terranes transported from abroad, whose timing and sense of motion are now beginning to be understood. Among these, the Chortis block and the Baja California Peninsula have been proposed as pieces of continent separated from the Pacific coast of southwestern Mexico, that have moved either southeastward by the Farallon plate or northwestward by the Kula plate. Isotopic mineral ages from coastal granites along the coast from Puerto Vallarta, Jalisco (80 Ma) to Puerto Angel, Oaxaca (11 Ma) record systematic decrease of cooling ages from NW to SE. These results also constrain the position of the Kula- Farallon spreading axis north of Puerto Vallarta. Previous studies mainly confined to the northern margin of the Chortis block, confirmed a left-lateral displacement of 130 km in Neogene time. Further studies suggested times of detachment increased to 30 Ma, 40 Ma, and 66 Ma. We conclude that several indicators, namely: (a) the truncated nature of the Pacific coast of SW Mexico; (b) the genesis of the Kula-Farallon ridge at 85 Ma; (c) the 2,600 km of northward transport of Baja British Columbia from the present-day latitude of the Baja California Peninsula, beginning at 85 Ma; (d) the paleomagnetic counterclockwise rotations of areas both in the Chortis block and along the Mexican coast, during Late Cretaceous-Paleogene time, and (e) the systematic NW-SE decrease of radiometric dates beginning at 85 Ma in Puerto Vallarta and ending at approximately 11 Ma in Puerto Angel, Oaxaca , point to this time and region for the onset of strike-slip drifting of the Chortis block toward its current position. On the other hand, in the reconstruction of past movements of tectonic plates, the determination of reliable paleomagnetic poles is of utmost importance. To achieve accurate results, a full knowledge of the rock magnetic properties of the samples is required particularly for Curie points and for grain-size analyses in addition to thermal and af demagnetization experiments. We present the comparative results of 20 sites drilled at 3 different Paleozoic areas: The Permian rocks of the Juchatengo area in Oaxaca, Mexico; the Late Silurian (~418 Ma) Mountain Pine Ridge Granite, the Hummingbird Granite in Belize, and the Early Leonardian Chochal Limestone in Guatemala. The samples of all 20 sites were subjected to AF demagnetization in 16 steps from NRM to 100 mT and the thermally demagnetized cleaned in 15 increasing temperature steps from NRM up to 675 C. Principal component analysis was applied to the samples in order to obtain their respective mean directions. SIRM, hysteresis loops, and coercivity experiments performed indicate that about 90 percent of the samples were characterized by Multi-Domain (MD) grain sizes and the rest were PSD. Curie point determinations results ranged from 190 to 660 C, indicating the presence of titanomagnetites as well as hematite. In the Juchatengo area reliable poles were obtained from 3 sites, in Belize 3 sites and only 2 sites in Guatemala in the Permian Chochal Formation yielded useful results

  2. Use of Network Centrality Measures to Explain Individual Levels of Herbal Remedy Cultural Competence among the Yucatec Maya in Tabi, Mexico.

    PubMed

    Hopkins, Allison

    2011-08-01

    Common herbal remedy knowledge varies and is transmitted among individuals who are connected through a social network. Thus, social relationships have the potential to account for some of the variation in knowledge. Cultural consensus analysis (CCA) and social network analysis (SNA) were used together to study the association between intracultural variation in botanical remedy knowledge and social relationships in Tabi, Yucatan, Mexico. CCA, a theory of culture as agreement, was used to assess the competence of individuals in a domain of herbal remedies by measuring individual competence scores within that domain. There was a weak but positive association between these competence scores and network centrality scores. This association disappeared when age was included in the model. People in Tabi, who have higher competence in herbal remedies tend to be older and more centrally located in the herbal remedy inquiry network. The larger implication of the application of CCA and SNA for understanding the acquisition and transmission of cultural knowledge is also explored. PMID:21909235

  3. Microevolution of Anthrax from a Young Ancestor (M.A.Y.A.) Suggests a Soil-Borne Life Cycle of Bacillus anthracis.

    PubMed

    Braun, Peter; Grass, Gregor; Aceti, Angela; Serrecchia, Luigina; Affuso, Alessia; Marino, Leonardo; Grimaldi, Stefania; Pagano, Stefania; Hanczaruk, Matthias; Georgi, Enrico; Northoff, Bernd; Schöler, Anne; Schloter, Michael; Antwerpen, Markus; Fasanella, Antonio

    2015-01-01

    During an anthrax outbreak at the Pollino National Park (Basilicata, Italy) in 2004, diseased cattle were buried and from these anthrax-foci Bacillus anthracis endospores still diffuse to the surface resulting in local accumulations. Recent data suggest that B. anthracis multiplies in soil outside the animal-host body. This notion is supported by the frequent isolation of B. anthracis from soil lacking one or both virulence plasmids. Such strains represent an evolutionary dead end, as they are likely no longer able to successfully infect new hosts. This loss of virulence plasmids is explained most simply by postulating a soil-borne life cycle of the pathogen. To test this hypothesis we investigated possible microevolution at two natural anthrax foci from the 2004 outbreak. If valid, then genotypes of strains isolated from near the surface at these foci should be on a different evolutionary trajectory from those below residing in deeper-laying horizons close to the carcass. Thus, the genetic diversity of B. anthracis isolates was compared conducting Progressive Hierarchical Resolving Assays using Nucleic Acids (PHRANA) and next generation Whole Genome Sequencing (WGS). PHRANA was not discriminatory enough to resolve the fine genetic relationships between the isolates. Conversely, WGS of nine isolates from near-surface and nine from near-carcass revealed five isolate specific SNPs, four of which were found only in different near-surface isolates. In support of our hypothesis, one surface-isolate lacked plasmid pXO1 and also harbored one of the unique SNPs. Taken together, our results suggest a limited soil-borne life cycle of B. anthracis. PMID:26266934

  4. Textiles as a Reflection of Ancient and Contemporary Maya Cultures: An Interdisciplinary Unit for 6th and 7th Grade Students at John F. Kennedy Middle School, Northampton, MA. Fulbright-Hays Summer Seminars Abroad Program, 2000 (Mexico and Guatemala).

    ERIC Educational Resources Information Center

    Schlichting, Kimberly

    This curriculum unit on textiles is intended for middle school students who have previously studied the cultures of modern and ancient Latin America. The unit does not employ Spanish language skills. Its lessons apply to individual, small group, and whole group work, and may take from 30 minutes to three class periods. The guide lists necessary…

  5. Clinical Commentary by Barbara Segal, a Consultant Child and Adolescent Psychotherapist Working in University College London Hospitals

    ERIC Educational Resources Information Center

    Segal, Barbara

    2010-01-01

    This moving clinical account describes the psychotherapeutic work of a child psychotherapist undertaken in a hospital room with 13-year-old Maya, after the sudden onset of a terrifying and serious illness, Guillain-Barre syndrome, leaving her with paralysis and extreme weakness. The first session takes place almost three weeks after Maya's…

  6. Increasing Student Engagement by Using Morrowind to Analyze Choices and Consequences

    ERIC Educational Resources Information Center

    Kadakia, Maya

    2005-01-01

    During the 2004-2005 school year, Maya Kadakia conducted a pilot study of her master's project which focuses on how student engagement is affected by a curriculum that incorporates popular culture. She created a Language Arts unit which incorporates the video game Morrowhid. Maya teaches seventh grade Language Arts and Social Studies at a diverse…

  7. Meemul Tziij: An Indigenous Sign Language Complex of Mesoamerica

    ERIC Educational Resources Information Center

    Tree, Erich Fox

    2009-01-01

    This article examines sign languages that belong to a complex of indigenous sign languages in Mesoamerica that K'iche'an Maya people of Guatemala refer to collectively as Meemul Tziij. It explains the relationship between the Meemul Tziij variety of the Yukatek Maya village of Chican (state of Yucatan, Mexico) and the hitherto undescribed Meemul…

  8. Sister R. Leadership: Doing the Seemingly Impossible

    ERIC Educational Resources Information Center

    Sena, Rachel; Schoorman, Dilys; Bogotch, Ira

    2013-01-01

    Sister R., the first author, is a Dominican Sister of Peace. Until recently, Sister R. had been the director of the Maya Ministry Family Literacy Program, working with the Maya Community in Lake Worth, Palm Beach County, Florida. She described her work with these indigenous, preliterate, hardworking peoples as "a university of the poor" in which…

  9. Alternative Approaches to Contemporary Mayan Cultures. An Annotated Bibliography. Revised.

    ERIC Educational Resources Information Center

    Pardue, David

    This document presents a bibliography of works dealing with the modern Maya. The titles listed are intended to complement the many academic studies devoted to the present day Maya. The document is divided into four sections: (1) personal histories, (2) dream analyses, (3) folktales, and (4) pictorial works. Each section is further divided between…

  10. Assays for important Mexican crudes updated

    SciTech Connect

    Manriguez, L.; Moreno, A.; Anaya, C.G. )

    1991-03-04

    Compared to Isthmus and Maya, Olmeca crude is the lightest of the Mexican export. It has fewer contaminants, and its 540{degrees} C. TBP distillation produces the largest quantity of distillate. The Olmeca fractions also have the lowest total sulfur content. The Maya crude is heavy, with an API gravity of 22.2{sup {degrees}}. It has a high contaminant content that induces corrosion in process equipment and causes low running times in thermal cracking units, such as visbreakers and cokers. A proposed refining scheme for the bottom of the Maya barrel consists of atmospheric distillation, vacuum distillation, the Impex process, and visbreaking.

  11. 76 FR 17419 - Agency Information Collection Activities; Proposed Collection; Comment Request; Extension of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-29

    ... Title VII Grantees. DATES: Submit written or electronic comments on the collection of information by May...A). This information will be used for Federal oversight of Title III Programs and Title...

  12. La Ciencia de los Antiguos Mexicanos: Una Bibliografia Selecta

    ERIC Educational Resources Information Center

    Ortiz-Franco, Luis; Magana, Maria

    1973-01-01

    Fifty-five citations pertaining to the scientific and mathematic development of ancient Mexicans, particularly the Mayas, are given in this select bibliography. The introduction and descriptions of resource libraries in 8 States are in Spanish. (NQ)

  13. 78 FR 73819 - Forest Resource Coordinating Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ... Forest Service Forest Resource Coordinating Committee AGENCY: Forest Service, USDA. ACTION: Notice of...-18, 2013 meeting of the Forest Resource Coordinating Committee due to the Government partial shutdown... INFORMATION CONTACT: Maya Solomon, Forest Resource Coordinating Committee Program Coordinator; by phone...

  14. The Books of Chilam Balam: astronomical content and the Paris Codex.

    NASA Astrophysics Data System (ADS)

    Paxton, M.

    Written predominantly in the Maya language but almost entirely in European script, the Books of Chilam Balam are post-Conquest counterparts of pre-Columbian hieroglyphic codices. Not all of the texts have been fully analyzed. The Books of Chilam Balam is historical celendrical, astrological, prophetic, medical, and religious, these works offer promise of broad information on pre-Hispanic Maya practices. In reviewing the astronomical content of the sections of the Books of Chilam Balam identified in the Miram study as generally pre-Columbian in origin, it is evident that some passages contain complex metaphors. Thus it is possible to gain some understanding of the celestial concepts of the ancient Maya from the poetic and esoteric accounts. However, as much of this information may pass unnoticed by non-Mayans, the clearest insights concerning pre-Columbian Maya astronomy come from the sections of the Books of Chilam Balam that are more computational in nature.

  15. Ancient Mayan Glyphs

    ERIC Educational Resources Information Center

    McNally, Ellen

    2009-01-01

    The Maya civilization developed from about 300 B.C., predating the Aztecs who flourished in the 14th, 15th and 16th centuries. One of the challenges of this lesson is to present a cohesive history of the Maya to fourth- and fifth-graders within the context of an art lesson. A glyph is a symbol. A symbol is something that represents something else,…

  16. Environmental and Archaeological Research in the Peten, Guatemala

    NASA Technical Reports Server (NTRS)

    Sever, Thomas L.

    1999-01-01

    The Peten, Northern Guatemala, was once inhabited by a population of several million Maya before their collapse in the 9th century A.D.. The seventh and eight centuries were a time of crowning glory four millions of Maya; by 930 A.D. only a few scattered houses remained, testifying to the greatest disaster in human history. What is known is that at the time of their collapse the Maya had cut down most of their trees. After centuries of regeneration the Peten now represent the largest remaining tropical forest in Central America but is experiencing rapid deforestation in the wake of an invasion of settlers. The successful adaptive techniques of the indigenous population are being abandoned in favor of the destructive techniques of monoculture and cattle raising. Remote sensing and Geographic Information System (GIS) analysis are being used to address issues in Maya archeology as well as monitor the effects of increasing deforestation in the area today. One thousand years ago the forests of the Peten were nearly destroyed by the ancient Maya who after centuries of successful adaptation finally overused their resources. Current inhabitants are threatening to do the same thing today in a shorter time period with a lesser population. Through the use of remote sensing/GIS analysis we are attempting to answer questions about the past in order to protect the resources of the future.

  17. Archaeological and Environmental Research of the Peten, Guatemala, Using Remote Sensing/GIS Research

    NASA Technical Reports Server (NTRS)

    Sever, Thomas L.

    2000-01-01

    The Peten, northern Guatemala, was once inhabited by a population of several million Maya before their collapse in the 9th century AD. Although the seventh and eight centuries were a time of crowning glory for millions of Maya; by 930 A.D. only a few scattered houses remained. What is known, is that at the time of their collapse, the Maya had cut down most of their trees. After centuries of regeneration the Peten now represent the largest remaining tropical forest in Central America but is experiencing rapid deforestation in the wake of an invasion of settlers. The successful adaptive techniques of the indigenous population are being abandoned in favor of the destructive techniques of monoculture and cattle raising. These techniques also contribute to the destruction and looting of unrecorded archeological sites. Remote sensing and GIS analysis are being used to address issues in Maya archeology as well as monitor the effects of increasing deforestation in the area today. One thousand years ago the forests of the Peten were nearly destroyed by the ancient Maya, who, after centuries of successful adaptation, finally overused their resources. Current inhabitants are threatening to do the same thing today in a shorter time period with a lesser population. Through the use of remote sensing/GIS analysis we are attempting to answer questions about the past in order to protect the resources of the future.

  18. Acoustical features of two Mayan monuments at Chichen Itza: Accident or design?

    NASA Astrophysics Data System (ADS)

    Lubman, David

    2002-11-01

    Chichen Itza dominated the early postclassic Maya world, ca. 900-1200 C.E. Two of its colossal monuments, the Great Ball Court and the temple of Kukulkan, reflect the sophisticated, hybrid culture of a Mexicanized Maya civilization. The architecture seems intended for ceremony and ritual drama. Deducing ritual practices will advance the understanding of a lost civilization, but what took place there is largely unknown. Perhaps acoustical science can add value. Unexpected and unusual acoustical features can be interpreted as intriguing clues or irrelevant accidents. Acoustical advocates believe that, when combined with an understanding of the Maya worldview, acoustical features can provide unique insights into how the Maya designed and used theater spaces. At Chichen Itza's monuments, sound reinforcement features improve rulers and priests ability to address large crowds, and Ball Court whispering galleries permit speech communication over unexpectedly large distances. Handclaps at Kukulkan stimulate chirps that mimic a revered bird (''Kukul''), thus reinforcing cultic beliefs. A ball striking playing field wall stimulates flutter echoes at the Great Ball Court; their strength and duration arguably had dramatic, mythic, and practical significance. Interpretations of the possible mythic, magic, and political significance of sound phenomena at these Maya monuments strongly suggests intentional design.

  19. The Living Astronomy and People of the Mayan World Today: Engaging Hispanic Populations in Science

    NASA Astrophysics Data System (ADS)

    Hawkins, I.; Tapia, F.

    2008-06-01

    From long ago, the Maya civilizations of Mesoamerica have been keenly attuned to the cycles of nature. The Maya have always been careful observers, and more than a thousand years ago, they recorded the motion of the planets, the Sun, and the Moon, and predicted eclipses. These observations were used to create a complex calendar to organize the events of their world. The Maya built great cities containing buildings aligned with the Sun, Moon, and the stars to mark important times of the year. Many astronomical traditions are still practiced today by the Maya of the Yucatán peninsula, Southern states in México, and other areas in Mesoamerica. Traditional farming communities time the cultivation of corn by observing the sky. The living culture of the Mayan people in the Yucatan integrates science and astronomy with every other aspect of their culture. Yucatec Maya, the language spoken by more than 1 million people in the Yucatán today, still carries through oral histories the ancient knowledge of nature. Our hope is that you'll increase your interest and knowledge of the Mayan people and of the enduring wisdom reflected in the daily lives of Mayan families. We present the results of education and public outreach efforts that position astronomy within its cultural context as an effective means of capturing the interest and enabling authentic participation of under-represented populations in science.

  20. Production of duck-chicken chimeras by transferring early blastodermal cells.

    PubMed

    Li, Z D; Deng, H; Liu, C H; Song, Y H; Sha, J; Wang, N; Wei, H

    2002-09-01

    Duck blastodermal cells isolated from Stage X embryos of Maya ducks were injected into subgerminal cavity of recipient Stage X chicken embryos treated with gamma-irradiation or untreated. Eleven somatic chimeras were obtained based on plumage color and were raised to sexual maturity. To test for germline chimerism, progeny tests were performed by mating the chimeras with Maya ducks. A total of 622 eggs was collected and incubated. Fertility rate and hatchability were 2.9% (18/622) and 1.0% (6/622), respectively. The six duck hatchlings were from Chimera 9801 and were considered to be derived from the germ cells developed from the donor Maya blastodermal cells, indicating that Chimera 9801 is a germline chimera. PMID:12269617

  1. Validating Prehistoric and Current Social Phenomena Upon the Landscape of the Peten, Guatemala

    NASA Technical Reports Server (NTRS)

    Sever, Thomas L.

    1997-01-01

    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 on a scale that can only result in soil loss and regional degradation. In view of the current deforestation trends, the question emerges as to how millions of ancient Maya lived successfully in the area for centuries when relatively fewer occupants today threaten the sustainability of the landscape with current agricultural practices. The use of remote sensing 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.

  2. Water and sustainable land use at the ancient tropical city of Tikal, Guatemala.

    PubMed

    Scarborough, Vernon L; Dunning, Nicholas P; Tankersley, Kenneth B; Carr, Christopher; Weaver, Eric; Grazioso, Liwy; Lane, Brian; Jones, John G; Buttles, Palma; Valdez, Fred; Lentz, David L

    2012-07-31

    The access to water and the engineered landscapes accommodating its collection and allocation are pivotal issues for assessing sustainability. Recent mapping, sediment coring, and formal excavation at Tikal, Guatemala, have markedly expanded our understanding of ancient Maya water and land use. Among the landscape and engineering feats identified are the largest ancient dam identified in the Maya area of Central America; the posited manner by which reservoir waters were released; construction of a cofferdam for dredging the largest reservoir at Tikal; the presence of ancient springs linked to the initial colonization of Tikal; the use of sand filtration to cleanse water entering reservoirs; a switching station that facilitated seasonal filling and release; and the deepest rock-cut canal segment in the Maya Lowlands. These engineering achievements were integrated into a system that sustained the urban complex through deep time, and they have implications for sustainable construction and use of water management systems in tropical forest settings worldwide. PMID:22802627

  3. Water and sustainable land use at the ancient tropical city of Tikal, Guatemala

    PubMed Central

    Scarborough, Vernon L.; Dunning, Nicholas P.; Tankersley, Kenneth B.; Carr, Christopher; Weaver, Eric; Grazioso, Liwy; Lane, Brian; Jones, John G.; Buttles, Palma; Valdez, Fred; Lentz, David L.

    2012-01-01

    The access to water and the engineered landscapes accommodating its collection and allocation are pivotal issues for assessing sustainability. Recent mapping, sediment coring, and formal excavation at Tikal, Guatemala, have markedly expanded our understanding of ancient Maya water and land use. Among the landscape and engineering feats identified are the largest ancient dam identified in the Maya area of Central America; the posited manner by which reservoir waters were released; construction of a cofferdam for dredging the largest reservoir at Tikal; the presence of ancient springs linked to the initial colonization of Tikal; the use of sand filtration to cleanse water entering reservoirs; a switching station that facilitated seasonal filling and release; and the deepest rock-cut canal segment in the Maya Lowlands. These engineering achievements were integrated into a system that sustained the urban complex through deep time, and they have implications for sustainable construction and use of water management systems in tropical forest settings worldwide. PMID:22802627

  4. Academy Engages Incarcerated Youths

    ERIC Educational Resources Information Center

    Zehr, Mary Ann

    2010-01-01

    It's not easy to keep young people on task for learning in a youth prison, but David Domenici, the principal of the Maya Angelou Academy, a charter-like school serving incarcerated juveniles, is trying to do it while at the same time creating a model program for improving educational services for young offenders. Located at the New Beginnings…

  5. Women's Voices in Experiential Education.

    ERIC Educational Resources Information Center

    Warren, Karen, Ed.

    This book is a collection of feminist analyses of various topics in experiential education, particularly as it applies to outdoors and adventure education, as well as practical examples of how women's experiences can contribute to the field as a whole. Following an introduction, "The Quilt of Women's Voices" (Maya Angelou), the 25 chapters are:…

  6. The Mexican American Heritage: With Writing Exercises.

    ERIC Educational Resources Information Center

    Jimenez, Carlos M.

    Written by a Los Angeles history teacher frustrated by the lack of culturally relevant materials, this book covers some of the most interesting events in the history of Mexico and the heritage of Mexican Americans. Chapters are: (1) Indian Mexico (Teotihuacan, the Maya, the Toltecs, and the Aztecs); (2) La Conquista (Cortes and Moctezuma, conquest…

  7. "Greco-Roman Knowledge Only" in Arizona Schools: Indigenous Wisdom Outlawed Once Again

    ERIC Educational Resources Information Center

    Rodriguez, Roberto Cintli

    2010-01-01

    Students at Tucson High School in Arizona, part of Tucson Unified School District's highly successful Mexican American Studies (MAS) K-12 program, the largest in the nation, are taught Indigenous concepts, including Panche Be (seek the root of the truth), and the Aztec and Maya calendars. The author speaks to the students about the relationship…

  8. Community-Based Education in San Juan La Laguna, Solola, Guatemala

    ERIC Educational Resources Information Center

    Abreo, Christina

    2010-01-01

    Indigenous education in Guatemala is currently undergoing a massive overhaul in the depth and breadth of its reach in Maya areas. Although much can be said about the re-evaluation and incorporation of indigenous culture, language and worldview into the schools' curricula, it is still failing to reach the country's adult population. As a result of…

  9. Images of Commitment: 20th Century Women Artists. A Fine Art Print Program: Junior/Senior High.

    ERIC Educational Resources Information Center

    Kordich, Diane D.

    This teacher's resource guide is designed to accompany resource packets that include fine art reproductions. The resource introduces students to the accomplishments and contributions of eight 20th century women artists: Isabel Bishop; Jenny Holzer; Kathe Kollwitz; Maya Ying Lin; Mary Ellen Mark; Maria Martinez; Alice Neel; and Faith Ringgold. This…

  10. Mayan Astronomy

    NASA Astrophysics Data System (ADS)

    Kelley, D.; Murdin, P.

    2000-11-01

    The Mayas of Mexico, Belize, Guatemala and Honduras developed an urban civilization in the tropical rain forests. In their cities are many monuments, mainly stone, which contain accounts of their rulers' families, conquests, sacrifices, rituals and building programs. These are integrated into an elaborate calendrical system, which gives dates to the day. We also have pottery, painted with elabora...

  11. Boletin del Consejo Hispano de Alfabetizacion (Bulletin of the Hispanic Literacy Council).

    ERIC Educational Resources Information Center

    Boletin del Consejo Hispano de Alfabetizacion, 1990

    1990-01-01

    The three issues of this newsletter published during 1990 contain the following articles: "You Can't Run before You Learn To Walk" (Jose Manuel Ventura); "The Truth about Police Torture" (J. Maya R.); "A Student's Testimony"; "Voices from the Community" (Gabriel Ramirez and Others); "Books and Authors" (Jose Hunter); "You and Your Health" (Arnaldo…

  12. International Reports on Literacy Research: Malaysia

    ERIC Educational Resources Information Center

    David, Maya K.; Amer, Aly Anwar

    2004-01-01

    Maya K. David reports an interesting view of reading in Malaysia through the eyes of graduate student Mohd Nazri bin Hamid (2003), who conducted an exploratory study about the culture of reading in an academy of Islamic studies. The purposes of Nazri's investigation were (a) to examine undergraduate students' reading habits, (b) to offer a…

  13. Female Role Models: Implications for Leadership.

    ERIC Educational Resources Information Center

    Daniels, Roberta R.

    1995-01-01

    The lives of six prominent female leaders (Sandra Day O'Connor, Maya Angelou, Wilma Mankiller, Hillary Rodham Clinton, Elizabeth Dole, and Mary Kay Ash) are summarized. Similarities are noted and questions and activities provided to encourage discussion by teachers and students. (DB)

  14. Expanding Horizons and Encouraging New Perspectives through Myths: Experiments in Interactive Storytelling in an Elementary School Library

    ERIC Educational Resources Information Center

    Giffard, Sue

    2016-01-01

    The scenario that the author encountered when she began working in her present position was not unusual for an elementary school library: the students study a culture, and the librarian reads the stories of that culture to them to enrich the study and to make the culture come alive. The fourth-graders studied the Maya in the fall and the ancient…

  15. Dia de Dar Gracias. Modulo Nivel Primario. (Day to Give Thanks. Module Primary Level.)

    ERIC Educational Resources Information Center

    Espinoza, Delia; Lopez, Santiago, III

    Dia de Dar Gracias (Thanksgiving) is the subject of this primary level unit. The unit objectives are to: (1) know about El Dia de Dar Gracias as it is celebrated in the United States; (2) know how the Mayas celebrated it; (3) understand the context of the stories in the unit; (4) know about the main food used, the turkey; (5) distinguish other…

  16. The Power of Maps.

    ERIC Educational Resources Information Center

    Walsh, Patricia

    1998-01-01

    American Indians and other Native peoples are using maps to chart their resources, fight for their land, and remember their history. Describes the efforts of the Zuni Pueblo in the Southwest; the Gitxsan Nation (Canada); the Kuna, Embera, and Wounaan tribes (Panama); and the Mayas (Belize). A sidebar lists Geographic Information Systems (GIS)…

  17. The Courage of Their Convictions: Empowering Voices of Girls.

    ERIC Educational Resources Information Center

    Will, Katherine

    1994-01-01

    Reviews childhood trauma/abuse experienced by Maya Angelou and discusses how Angelou survived and triumphed over these experiences. Relates Angelou's story to moral developmental theory for women proposed by Carol Gilligan, focusing on Gilligan's metaphor of having a "voice." (NB)

  18. Ethnic Succession in a Highland Chiapas Community.

    ERIC Educational Resources Information Center

    Whitmeyer, Joseph M.

    1997-01-01

    Since the 1950s, ethnic relations in Tenejapa (Chiapas, Mexico) have shifted toward greater equality and less antagonism between formerly dominant mestizos and formerly dominated "indigenas" (Maya Indians). An important cause is the long-term promotion of indigenous education by a national agency, Instituto Nacional Indigenista, imparting to…

  19. Political Ideology: A Comparative Study of Three Chicano Youth Organizations.

    ERIC Educational Resources Information Center

    Garcia, Richard A.

    The study investigated the political ideology of three Chicano youth groups in El Paso, Texas: Mexican American Youth Association (MAYA), Mexican American Political Association (MAPA), and the Alianza. Purpose of the study was to identify and compare the political ideas and attitudes of the three organizations. Questionnaires were administered to…

  20. Learning Achievement Packages. Mexican American Studies, English-Spanish.

    ERIC Educational Resources Information Center

    Astacio, Ramon; Iruegas, Efrain

    Developed originally for grades 7-12, the three bilingual Mexican American studies curriculum units on the pre-Hispanic cultures of the Olmecs, Mayas, and Aztecs present information for the teacher and for the student, a glossary, worksheets, an answer key, a test, and a bibliography in Spanish and English. The cross section of materials are…

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

    ERIC Educational Resources Information Center

    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.…

  2. Mexico's Oxbridge.

    ERIC Educational Resources Information Center

    Haussman, Fay

    1979-01-01

    For 400 years the National Autonomous University of Mexico has remained at the hub of the country's intellectual and political life. The history of the University from the Mayas and the Aztecs, University expansion, upward mobility of students, and student pressure groups and politics are described. (MLW)

  3. "Mayan Eyes Have Seen the Glory..." or "Please Don't Squeeze the Shaman!" An Interdisciplinary, Integrated, Thematic Study "Chaac" Full of Culture and "Jaded" History of the Mayan Civilization. Fulbright-Hays Summer Seminars Abroad Program, 2000 (Mexico/Guatemala).

    ERIC Educational Resources Information Center

    Radkey, Tom

    This curriculum unit, intended for students in grade 6, covers the Mayas, Mayan history, and ancient civilizations. The unit was developed using Roger Taylor's collaborative team model "Connecting the Curriculum: Using an Integrated, Interdisciplinary, Thematic Approach." The unit addresses multiple intelligences, brain research, constructivist…

  4. To Create the American Film Institute as an Independent Agency; Hearings before the Select Subcommittee on Education of the Committee on Education and Labor, House of Representatives, 93rd Congress, Second Session, on H.R. 17021, A Bill to Amend the National Foundation on the Arts and Humanities Act of 1965 to Create the American Film Institute as an Independent Agency, Held in Washington, D.C. Oct. 7 and 8, 1974.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Education and Labor.

    This report is on the hearings before the House Select Subcommittee on Education, conducted on October 7 and 8, 1974, to consider the creation of the American Film Institute as an independent agency. Witnesses testifying before the subcommittee included: Maya Angelou, Ellen Burstyn, John Culkin, Ed Emshwiller, John Hancock, Nancy Hanks, Charlton…

  5. Virtual Quests As Learning Environments for K-12 Students.

    ERIC Educational Resources Information Center

    Spudic, Linda

    Perhaps some of the most engaging, unique, Web-based activities are virtual quests that take student participants along on real expeditions, following a team in the field as they explore new territory or do research on authentic scientific problems. Virtual quests, such as the MayaQuest expedition produced by Classroom Connect, are excellent…

  6. Racism against the Mayan Population in Yucatan, Mexico: How Current Education Contradicts the Law

    ERIC Educational Resources Information Center

    Mijangos-Noh, Juan Carlos

    2009-01-01

    The discriminatory situation suffered by the Maya population in the Mexican state of Yucatan is discussed using the concept of neo-racism. Statistical evidence about the school system is presented, along with testimonies of Mayan speakers which uncover a phenomena frequently denied or obliterated by politically correct speeches that actually serve…

  7. Using Ethnography to Link School and Community in Rural Yucatan.

    ERIC Educational Resources Information Center

    Stearns, Robert David

    1986-01-01

    Examines the use of "directed ethnography," a collaborative ethnographic approach, found to improve the work of Ladino teachers in rural Yucatan community schools. The participating teachers analyze the collected community data and modify their teaching style/curriculum materials to reflect the experience of their Maya Grade 3 students. (KH)

  8. Muscodor yucatenensis, a new endophytic ascomycete from Mexican chakah, Bursera simaruba

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During a study on the fungal endophytic associations with some trees of the dry tropical forest of El Eden Ecological Reserve located in the northeast of the Yucatan Peninsula of Mexico, a new fungal species was isolated as an endophyte of a tree named chakah, chachah or huk´up by indigenous mayas. ...

  9. Learning in Order To Teach in Chicxulub Puerto, Yucatan, Mexico.

    ERIC Educational Resources Information Center

    Wilber, Cynthia J.

    2000-01-01

    Describes a community-based computer education program for the young people (and adults) of Chicxulub Puerto, a small fishing village in Yucatan, Mexico. Notes the children learn Maya, Spanish, and English in the context of learning computer and telecommunication skills. Concludes that access to the Internet has made a profound difference in a…

  10. John Lloyd Stephens and Frederick Catherwood: Mayan Explorers.

    ERIC Educational Resources Information Center

    McDermott, Michael

    This mini-unit focuses on the lives and accomplishments of John Lloyd Stephens and Frederick Catherwood and their contacts with the Maya. This project deals specifically with how Stephens' published accounts and Catherwood's drawings became the basis from which all further Mayan research developed. These two explorers were the first to describe…

  11. Columbus's Legacy, Conquest or Invasion? A Guatemalan Example of Counterhegemonic Teacher Practice and Curriculum.

    ERIC Educational Resources Information Center

    Wilhelm, Ronald W.

    Evidence is presented that demonstrates the projection in some school settings of nuanced interpretations of the historical events and meanings related to 1492 and to the subsequent Spanish settlement of the Americas. In particular, the Maya language-Spanish language bilingual curriculum (Programa Nacional de Educacion Bilingue, PRONEBI) and Maya…

  12. The Risks We Are Willing to Take: Youth Civic Development in "Postwar" Guatemala

    ERIC Educational Resources Information Center

    Bellino, Michelle J.

    2015-01-01

    In this article, Michelle J. Bellino explores contrasting approaches to civic education in two rural schools serving indigenous Maya youth in post-civil war Guatemala. Through comparative ethnography, she examines how youth civic pathways intersect with legacies of authoritarianism while young people shape their identity as members of historically…

  13. Guatemala, the Peace Accords and Education: A Post-Conflict Struggle for Equal Opportunities, Cultural Recognition and Participation in Education

    ERIC Educational Resources Information Center

    Poppema, Margriet

    2009-01-01

    The Guatemalan educational system has been the most unequal system in the Latin American region ever since the 1950s. The indigenous Maya people, who constitute around half of the population, experienced the state mainly through repression, exploitative labour relationships and exclusion from education. The return to democracy and the peace…

  14. A Rainbow of Threads

    ERIC Educational Resources Information Center

    Mack, Stevie

    2011-01-01

    In the highlands of Guatemala, the Maya Indians weave colorful, vibrant textiles. Many of these beautiful fabrics are used to make traditional clothing for the men, women, and children who live in the rural villages. In Mayan culture, dress is important for more than just keeping warm and covered. It serves as a sort of uniform that immediately…

  15. On Being a Good Neighbor, or Things I Learned in the Field

    ERIC Educational Resources Information Center

    Stephens, William C.

    2014-01-01

    This article explores the possibility of anthropology as Bildung, or self-cultivation. As an educational mode, Bildung is focused on the moral education of students, encouraging them to broaden themselves in their encounters with others. I will discuss this process in terms of a lesson I learned from the highland Maya about being a good neighbor…

  16. Linguistic Relativity in Japanese and English: Is Language the Primary Determinant in Object Classification?

    ERIC Educational Resources Information Center

    Mazuka, Reiko; Friedman, Ronald S.

    2000-01-01

    Tested claims by Lucy (1992a, 1992b) that differences between the number marking systems used by Yucatec Maya and English lead speakers of these languages to differentially attend to either the material composition or the shape of objects. Replicated Lucy's critical objects' classification experiments using speakers of English and Japanese.…

  17. A Theory of the Origin of the State

    ERIC Educational Resources Information Center

    Carneiro, Robert L.

    1970-01-01

    Suggests that states evolve in response to ecological or social circumscription, or resource concentration. When dense populations develop, fighting over land forces loser into political subordination or incorporation. This modification of coercive theories explain lack of state in Amazon basin and origin of Inca, Maya, Hwang Valley states.…

  18. A Response to Louise Pascale, "Dispelling the Myth of the Non-Singer: Embracing Two Aesthetics for Singing"

    ERIC Educational Resources Information Center

    Hoover, Maya

    2005-01-01

    In her paper, Louise Pascale encouraged a redefinition of the word "singer" and suggested ways to make it apply to a broader spectrum of people. The problem with the current definition, she believes, is that it is outdated and needs to be changed in order to better embrace the ideals of current society. Maya Hoover, responds by saying that in…

  19. Best Audiobooks of 2008

    ERIC Educational Resources Information Center

    Kuzyk, Raya

    2009-01-01

    This article presents a list of the best audiobooks of 2008, selected by intrepid band of audio reviewers, range from tales of Bengali and Haitian immigrants to political autobiographies. There's "cake" from Sloane Crosley and emotional pyromania from David Sedaris; a biographical tribute to Maya Angelou and debut novels laced with the…

  20. Protein stability: a single recorded mutation aids in predicting the effects of other mutations in the same amino acid site

    PubMed Central

    Wainreb, Gilad; Wolf, Lior; Ashkenazy, Haim; Dehouck, Yves; Ben-Tal, Nir

    2011-01-01

    Motivation: Accurate prediction of protein stability is important for understanding the molecular underpinnings of diseases and for the design of new proteins. We introduce a novel approach for the prediction of changes in protein stability that arise from a single-site amino acid substitution; the approach uses available data on mutations occurring in the same position and in other positions. Our algorithm, named Pro-Maya (Protein Mutant stAbilitY Analyzer), combines a collaborative filtering baseline model, Random Forests regression and a diverse set of features. Pro-Maya predicts the stability free energy difference of mutant versus wild type, denoted as ΔΔG. Results: We evaluated our algorithm extensively using cross-validation on two previously utilized datasets of single amino acid mutations and a (third) validation set. The results indicate that using known ΔΔG values of mutations at the query position improves the accuracy of ΔΔG predictions for other mutations in that position. The accuracy of our predictions in such cases significantly surpasses that of similar methods, achieving, e.g. a Pearson's correlation coefficient of 0.79 and a root mean square error of 0.96 on the validation set. Because Pro-Maya uses a diverse set of features, including predictions using two other methods, it also performs slightly better than other methods in the absence of additional experimental data on the query positions. Availability: Pro-Maya is freely available via web server at http://bental.tau.ac.il/ProMaya. Contact: nirb@tauex.tau.ac.il; wolf@cs.tau.ac.il Supplementary Information: Supplementary data are available at Bioinformatics online. PMID:21998155

  1. Late Silurian plutons in Yucatan

    NASA Astrophysics Data System (ADS)

    Steiner, M. B.; Walker, J. Douglas

    1996-08-01

    U-Pb measurements of zircons from two composite plutons in the Maya Mountains of the Yucatan Block (Belize) give Late Silurian ages. Zircons from one of the five compositional phases of the Mountain Pine Ridge pluton yield an age of 418±3.6 Ma. A second compositional phase gives a minimum age of 404 Ma, and zircons from a third phase, although plagued with high common Pb, yield ages consistent with the other two. Zircons from one compositional phase of the Hummingbird-Mullins River pluton indicate an age of about 410-420 Ma. These data demonstrate that two of the three Maya Mountains plutons residing among the strata of the Late Pennsylvanian through Permian Santa Rosa Group are older than that sedimentation. Although the third pluton was not dated, both the similarity of sedimentary facies patterns adjacent to it to those adjacent to one of the plutons dated as Late Silurian and a published single Rb-Sr age of 428 ± 41 Ma suggest this third pluton also was emergent during Santa Rosa deposition. Thus the new U/Pb dates and other data suggest that all three Maya Mountains plutons pre-date Late Carboniferous sedimentation and that none intrude the Santa Rosa Group. Although very uniform ages of about 230 Ma amongst all plutons, derived from abundant earlier dating by the K-Ar system, led to the conclusion that intrusion mostly had occurred in the Late Triassic, the U-Pb ages (obtained from the same sites as the K-Ar dates) demonstrate that the K-Ar ages do not derive from a Late Triassic intrusive episode. The K-Ar dates probably are a signature of the rifting associated with Pangean breakup and formation of the Gulf of Mexico. In a reconstructed Pangea, the position of the Maya Mountains Late Silurian plutons suggests that the Late Silurian Acadian-Caledonian orogen of eastern North America extended through the region of the future Gulf of Mexico. Finally, the U-Pb ages of the Maya Mountains plutons are the same as those of a group of shocked zircons found in the

  2. Climate regime shifts in paleoclimate time series from the Yucatán Peninsula: from the Preclassic to Classic period

    NASA Astrophysics Data System (ADS)

    Polanco Martínez, Josue M.; Medina-Elizalde, Martin; Burns, Stephen J.; Jiang, Xiuyang; Shen, Chuan-Chou

    2015-04-01

    It has been widely accepted by the paleoclimate and archaeology communities that extreme climate events (especially droughts) and past climate change played an important role in the cultural changes that occurred in at least some parts of the Maya Lowlands, from the Pre-Classic (2000 BC to 250 AD) to Post-Classic periods (1000 to 1521 AD) [1, 2]. In particular, a large number of studies suggest that the decline of the Maya civilization in the Terminal Classic Period was greatly influenced by prolonged severe drought events that probably triggered significant societal disruptions [1, 3, 4, 5]. Going further on these issues, the aim of this work is to detect climate regime shifts in several paleoclimate time series from the Yucatán Peninsula (México) that have been used as rainfall proxies [3, 5, 6, 7]. In order to extract information from the paleoclimate data studied, we have used a change point method [8] as implemented in the R package strucchange, as well as the RAMFIT method [9]. The preliminary results show for all the records analysed a prominent regime shift between 400 to 200 BCE (from a noticeable increase to a remarkable fall in precipitation), which is strongest in the recently obtained stalagmite (Itzamna) delta18-O precipitation record [7]. References [1] Gunn, J. D., Matheny, R. T., Folan, W. J., 2002. Climate-change studies in the Maya area. Ancient Mesoamerica, 13(01), 79-84. [2] Yaeger, J., Hodell, D. A., 2008. The collapse of Maya civilization: assessing the interaction of culture, climate, and environment. El Niño, Catastrophism, and Culture Change in Ancient America, 197-251. [3] Hodell, D. A., Curtis, J. H., Brenner, M., 1995. Possible role of climate in the collapse of Classic Maya civilization. Nature, 375(6530), 391-394. [4] Aimers, J., Hodell, D., 2011. Societal collapse: Drought and the Maya. Nature 479(7371), 44-45 (2011). [5] Medina-Elizalde, M., Rohling, E. J., 2012. Collapse of Classic Maya civilization related to modest reduction

  3. Relationships that Heal: Beyond the Patient-Healer Dyad in Mayan Therapy.

    PubMed

    Berger-González, Mónica; Vides-Porras, Ana; Strauss, Sarah; Heinrich, Michael; Taquirá, Simeón; Krütli, Pius

    2016-01-01

    Biomedicine fosters particular styles of interaction and behaviors, with the therapeutic relationship seen as occurring between a doctor and patient. In contrast, where alternative modalities of healing are practiced, relationships go beyond a dyadic interaction and include wider social networks. In this article, we propose the existence of a 'therapeutic unit' in Maya healing practices in Guatemala that binds healer, wellness seeker, family, and community members, along with the spiritual and natural realms, into a coherent system requiring all of these elements to achieve success. Drawing on interviews with 67 Maya healers, we describe healers' understanding of raxnaq'il nuk'aslemal (well-being), and show how these interactions activate wider networks that play crucial roles during treatments. We highlight how holism is expressed in relationships typical of indigenous healing systems, and how an appreciation of this is important for developing culturally appropriate health care provision systems. PMID:26794851

  4. Amerindian mitochondrial DNAs have rare Asian mutations at high frequencies, suggesting they derived from four primary maternal lineages.

    PubMed Central

    Schurr, T G; Ballinger, S W; Gan, Y Y; Hodge, J A; Merriwether, D A; Lawrence, D N; Knowler, W C; Weiss, K M; Wallace, D C

    1990-01-01

    The mitochondrial DNA (mtDNA) sequence variation of the South American Ticuna, the Central American Maya, and the North American Pima was analyzed by restriction-endonuclease digestion and oligonucleotide hybridization. The analysis revealed that Amerindian populations have high frequencies of mtDNAs containing the rare Asian RFLP HincII morph 6, a rare HaeIII site gain, and a unique AluI site gain. In addition, the Asian-specific deletion between the cytochrome c oxidase subunit II (COII) and tRNA(Lys) genes was also prevalent in both the Pima and the Maya. These data suggest that Amerindian mtDNAs derived from at least four primary maternal lineages, that new tribal-specific variants accumulated as these mtDNAs became distributed throughout the Americas, and that some genetic variation may have been lost when the progenitors of the Ticuna separated from the North and Central American populations. Images Figure 1 PMID:1968708

  5. Aggregates structure analysis of petroleum asphaltenes with small-angle neutron scattering.

    SciTech Connect

    Tanaka, R.; Hunt, J. E.; Winans, R. E.; Thiyagarajan, P.; Sato, S.; Takanohashi, T.; Idemitsu Kosan Co.; National Institute of Advanced Industrial Science and Technology

    2003-01-01

    The objective of this study is to examine changes in the structures of petroleum asphaltene aggregates in situ with small-angle neutron scattering (SANS). Asphaltenes were isolated from three different crude oils: Maya, Khafji, and Iranian Light. An aliquot of the 5 wt % asphaltene solution in deuterated Decalin, 1-methylnaphthalene, or quinoline was loaded in a special stainless steel cell for SANS measurements. SANS data measured at various temperatures from 25 to 350 {sup o}C showed various topological features different with asphaltene or solvent species. A fractal network was formed only with asphaltene of Maya in Decalin, and it remained even at 350 {sup o}C. In all of the solvents, asphaltenes aggregate in the form of a prolate ellipsoid with a high aspect ratio at 25 {sup o}C and got smaller with increasing temperature. That became a compact sphere with the size of around 25 {angstrom} in radius at 350 {sup o}C.

  6. Meta!Blast computer game: a pipeline from science to 3D art to education

    NASA Astrophysics Data System (ADS)

    Schneller, William; Campbell, P. J.; Bassham, Diane; Wurtele, Eve Syrkin

    2012-03-01

    Meta!Blast (http://www.metablast.org) is designed to address the challenges students often encounter in understanding cell and metabolic biology. Developed by faculty and students in biology, biochemistry, computer science, game design, pedagogy, art and story, Meta!Blast is being created using Maya (http://usa.autodesk.com/maya/) and the Unity 3D (http://unity3d.com/) game engine, for Macs and PCs in classrooms; it has also been exhibited in an immersive environment. Here, we describe the pipeline from protein structural data and holographic information to art to the threedimensional (3D) environment to the game engine, by which we provide a publicly-available interactive 3D cellular world that mimics a photosynthetic plant cell.

  7. Role of the resid solvent in catalytic coprocessing with finely divided catalysts. Quarterly report, January--March 1995

    SciTech Connect

    Curtis, C.W.

    1995-07-01

    The research reported in this progress report describes the continuation of coal-resid coprocessing reactions that were discussed in the July to September 1994 Quarterly Report. During previous quarters, Maya and FHC-623 resids were evaluated in noncatalytic and catalytic reactions at 400{degrees}C with Pittsburgh No. 8 and DECS-17 Blind Canyon coals. From the complete reaction matrix containing the two coals and two resids, it was found that the influence of resids on coprocessing depended on the type of coal used; for example, under catalytic reaction conditions, the hexane solubles of Maya resid increased coal conversion of Pittsburgh No. 8 coal but decreased that of DECS-17. In order to observe the intrinsic behavior of resids during coprocessing, another resid, Manji, and another coal, Illinois No. 6, are being tested. These reactions were begun this quarter. The results obtained are reported in this report.

  8. Distribution of Herbal Remedy Knowledge in Tabi, Yucatan, Mexico

    PubMed Central

    Hopkins, Allison; Stepp, John Richard

    2013-01-01

    The distribution of herbal remedy knowledge among a group of people is studied for two main reasons: (1) to identify plants that are promising for pharmacological analysis, and (2) to examine the factors that lead to herbal remedy knowledge erosion as opposed to dynamism in the acquisition of knowledge. The goal of this particular study, which is aligned with the second reason, is to establish the variation in herbal remedy knowledge among the Yucatec Maya in Tabi, Yucatan, Mexico. Free listing and cultural consensus analysis revealed that knowledge about a few medicinal plants and herbal remedies was distributed widely among the Yucatec Maya in Tabi, whereas the majority of knowledge was idiosyncratic. This finding was consistent with other studies of herbal remedy knowledge distribution among indigenous groups in Latin America and Africa. Assessing patterns in the distribution of herbal remedy knowledge is an important next step in determining the degree of dynamism or erosion in knowledge acquisition and transmission in Tabi. PMID:23539665

  9. Monoalkoxy BODIPYs—A Fluorophore Class for Bioimaging

    PubMed Central

    2015-01-01

    Small molecule fluorophores are indispensable tools for modern biomedical imaging techniques. In this report, we present the development of a new class of BODIPY dyes based on an alkoxy-fluoro-boron-dipyrromethene core. These novel fluorescent dyes, which we term MayaFluors, are characterized by good aqueous solubility and favorable in vitro physicochemical properties. MayaFluors are readily accessible in good yields in a one-pot, two-step approach starting from well-established BODIPY dyes, and allow for facile modification with functional groups of relevance to bioconjugate chemistry and bioorthogonal labeling. Biological profiling in living cells demonstrates excellent membrane permeability, low nonspecific binding, and lack of cytotoxicity. PMID:24797834

  10. Early Earthquakes of the Americas

    NASA Astrophysics Data System (ADS)

    Ni, James

    2004-11-01

    Robert Kovach's second book looks at the interplay of earthquake and volcanic events, archeology, and history in the Americas. Throughout history, major earthquakes have caused the deaths of millions of people and have damaged countless cities. Earthquakes undoubtedly damaged prehistoric cities in the Americas, and evidence of these events could be preserved in archeological records. Kovach asks, Did indigenous native cultures-Indians of the Pacific Northwest, Aztecs, Mayas, and Incas-document their natural history? Some events have been explicitly documented, for example, in Mayan codices, but many may have been recorded as myth and legend. Kovach's discussions of how early cultures dealt with fearful events such as earthquakes and volcanic eruptions are colorful, informative, and entertaining, and include, for example, a depiction of how the Maya would talk to maize plants in their fields during earthquakes to reassure them.

  11. Surface and optical analyses of a dye-mineral composite -- an XPS, FTIR and Raman study

    NASA Astrophysics Data System (ADS)

    Durrer, William; Manciu, Felicia; Ramirez, Alejandra; Chianelli, Russell

    2007-10-01

    Maya Purple is a pigment produced by mixing the dye thioindigo with the clay mineral palygorskite. In this investigation, we address the questions of how the dye binds to the clay and how such binding might be affected by the organic-inorganic material ratio and of the heating time used in the preparation of the pigment. Synthetically prepared Maya Purple samples were examined using XPS, FTIR, and Raman spectroscopy. XPS measurements show that pigment preparation results in interactions between the dye and the mineral that give rise to several different binding states of the key elemental components oxygen, sulfur, and aluminum. These results are in good agreement with the Raman analysis, where the appearance and disappearance of bands in the 600 cm-1, 1100 cm-1, and 1600 cm-1 regions demonstrate interaction affecting oxygen and sulfur. The data are further corroborated by vibrational line shifting in the FTIR data.

  12. Guatemala's green revolution: synthetic fertilizer, public health, and economic autonomy in the Mayan highland.

    PubMed

    Carey, David

    2009-01-01

    Despite extensive literature both supporting and critiquing the Green Revolution, surprisingly little attention has been paid to synthetic fertilizers' health and environmental effects or indigenous farmers' perspectives. The introduction of agrochemicals in the mid-twentieth century was a watershed event for many Mayan farmers in Guatemala. While some Maya hailed synthetic fertilizers' immediate effectiveness as a relief from famines and migrant labor, other lamented the long-term deterioration of their public health, soil quality, and economic autonomy. Since the rising cost of agrochemicals compelled Maya to return to plantation labor in the 1970s, synthetic fertilizers simply shifted, rather than alleviated, Mayan dependency on the cash economy. By highlighting Mayan farmers' historical narratives and delineating the relationship between agricultural science and postwar geopolitics, the constraints on agriculturists' agency become clear. In the end, politics, more than technology or agricultural performance, influenced guatemala's shift toward the Green Revolution. PMID:19824230

  13. Platinum potential of mafic-ultramafic massifs in the western part of the Dambuka ore district (Upper Amur Region, Russia)

    NASA Astrophysics Data System (ADS)

    Melnikov, A. V.; Stepanov, V. A.; Moiseenko, V. G.

    2016-02-01

    New data on the Pt potential of mafic-ultramafic massifs of the Khani-Maya, Uldegit, and Dzhalta complexes in the western part of the Dambuka ore district are discussed. The Khani-Maya Complex is represented by metamorphosed gabbro, gabbronorites, gabbro anorthosites, subordinate pyroxenites, hornblendites, and peridotites. The Uldegit Complex is composed of pyroxenites, hornblendites, gabbro, gabbronorites, norites, troctolites, peridotites, dunites, actinolite-tremolites, serpentinites, anthophyllites, and tremolite-plagioclase rocks. The Dzhalta Complex is formed of peridotites, gabbro, eclogitized gabbro, hornblendites, cortlandites, and pyroxenites. All these complexes differ from each other by the concentrations of Ni, Cu, Co, Au, and platinoids depending on the composition of the constituting rocks and the presence of sulfide minerals.

  14. Distribution of Herbal Remedy Knowledge in Tabi, Yucatan, Mexico.

    PubMed

    Hopkins, Allison; Stepp, John Richard

    2012-09-01

    The distribution of herbal remedy knowledge among a group of people is studied for two main reasons: (1) to identify plants that are promising for pharmacological analysis, and (2) to examine the factors that lead to herbal remedy knowledge erosion as opposed to dynamism in the acquisition of knowledge. The goal of this particular study, which is aligned with the second reason, is to establish the variation in herbal remedy knowledge among the Yucatec Maya in Tabi, Yucatan, Mexico. Free listing and cultural consensus analysis revealed that knowledge about a few medicinal plants and herbal remedies was distributed widely among the Yucatec Maya in Tabi, whereas the majority of knowledge was idiosyncratic. This finding was consistent with other studies of herbal remedy knowledge distribution among indigenous groups in Latin America and Africa. Assessing patterns in the distribution of herbal remedy knowledge is an important next step in determining the degree of dynamism or erosion in knowledge acquisition and transmission in Tabi. PMID:23539665

  15. A deoxyribozyme-based molecular automaton.

    PubMed

    Stojanovic, Milan N; Stefanovic, Darko

    2003-09-01

    We describe a molecular automaton, called MAYA, which encodes a version of the game of tic-tac-toe and interactively competes against a human opponent. The automaton is a Boolean network of deoxyribozymes that incorporates 23 molecular-scale logic gates and one constitutively active deoxyribozyme arrayed in nine wells (3x3) corresponding to the game board. To make a move, MAYA carries out an analysis of the input oligonucleotide keyed to a particular move by the human opponent and indicates a move by fluorescence signaling in a response well. The cycle of human player input and automaton response continues until there is a draw or a victory for the automaton. The automaton cannot be defeated because it implements a perfect strategy. PMID:12923549

  16. Development of trainable deoxyribozyme-based game playing automaton.

    PubMed

    Pei, Renjun; Macdonald, Joanne; Stojanovic, Milan N

    2012-01-01

    Molecular automata are self-operating machines serially exchanging information with their environment while changing their configurations. Molecular protoautomata are devices trained in a series of sessions with an operator to become molecular automata. Reconfigurable deoxyribozyme-based logic gates can be used to build multipurpose protoautomata, reprogrammable devices that go beyond single-purpose "hard-wired" molecular automata. Molecular array of YES and AND gates (MAYA)-III is such a protoautomaton that can be taught by example to play a game. Training of MAYA-III is a process that does not require the operator to be familiar with the underlying molecular programming. Herein we provide the instructions to construct this protoautomaton, with particular focus on the optimization of computing components. PMID:22315084

  17. Development of Archaeoastronomy in the English-Speaking World

    NASA Astrophysics Data System (ADS)

    Salt, Alun

    While there are early examples of work that are now recognized as archaeoastronomy, the development of archaeoastronomy as a discipline has nearly all happened in the past 50 years. Development accelerated with the foundation of regular conference series. This in turn widened interest in astronomy from Megalithic Europe and the Maya to encompass wider geographical and historical range. This is turn has required archaeoastronomers to embrace a variety of methodological approaches.

  18. Review of the Ambrysus stali La Rivers species complex (Heteroptera: Nepomorpha: Naucoridae) with the description of a new species from Mesoamerica.

    PubMed

    Sites, Robert W; Reynoso-Velasco, Daniel

    2015-01-01

    The Neotropical Ambrysus stali La Rivers species complex is reviewed and includes A. bifidus La Rivers & Nieser, A. scolius La Rivers, A. stali La Rivers, and A. tricuspis La Rivers. Ambrysus oblongulus Montandon is removed as a member of this complex. Features uniting these species are related to male genitalia and associated structures. Ambrysus maya n. sp. is the fifth species in the complex and is described from Belize, Guatemala, and Mexico based on specimens from recent collecting and museum collections. PMID:26624041

  19. Hydroarchaeology: Measuring the Ancient Human Impact on the Palenque Watershed

    NASA Astrophysics Data System (ADS)

    French, K. D.; Duffy, C. J.

    2010-03-01

    Palenque, one of the best known Classic Maya centers, has what is arguably the most unique and intricate system of water management known anywhere in the Maya Lowlands. Years of archaeological research, including intensive mapping between 1997 and 2000, reveal that this major center, situated on a narrow escarpment at the base of a high mountain range in northern Chiapas, Mexico, began as a modest settlement about AD 100. Then, during the seventh and eighth centuries, Palenque experienced explosive growth, mushrooming into a dense community with an estimated population of 6000 and approximately 1500 structures — residences, palaces, and temples¬ - under a series of powerful rulers. This process of "urban" growth led to obvious changes in landcover. In order to better understand the effects that landcover and climate change have on the availability of water for an ancient city a new approach is required. In this paper we explore a hydroarchaeological approach that utilizes simulated daily paleoclimate data, watershed modeling, and traditional archaeology to view the response of ancient human impact within the watershed surrounding Palenque. There is great potential for watershed-climate modeling in developing plausible scenarios of water use and supply, and the effect of extreme conditions (flood and drought), all of which cannot be fully represented by atmosphere-based climate and weather projections. The first objective of the paper is to test the hypothesis that drought was a major cause for Palenque’s collapse. Did the Maya abandon Palenque in search of water? Secondly, we evaluate the hydraulic design of the water management features at Palenque against extreme meteorological events. How successful was the hydraulic engineering of the Maya in coping with droughts and floods? The archaeological implications for this non-invasive "virtual" method are many, including detecting periods of stress within a community, estimating population by developing caps

  20. Applications of ecological concepts and remote sensing technologies in archaeological site reconnaissance

    NASA Technical Reports Server (NTRS)

    Miller, W. Frank; Sever, Thomas L.; Lee, C. Daniel

    1991-01-01

    The concept of integrating ecological perspectives on early man's settlement patterns with advanced remote sensing technologies shows promise for predictive site modeling. Early work with aerial imagery and ecosystem analysis is discussed with respect to the development of a major project in Maya archaeology supported by NASA and the National Geographic Society with technical support from the Mississippi State Remote Sensing Center. A preliminary site reconnaissance model will be developed for testing during the 1991 field season.

  1. Classroom Simulations: Proceed with Caution

    ERIC Educational Resources Information Center

    Drake, Ingrid

    2008-01-01

    When Maya Saakvitne's parents sent her for a three-day school field trip two years ago at Nature's Classroom, a camp in western Massachusetts, they did not expect her to come home with a tale of her feet falling asleep after counselors asked her to kneel in the hold of a make-believe slave ship and keep her head down even though some of the other…

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

    NASA Technical Reports Server (NTRS)

    Duller, Charles E.

    1990-01-01

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

  3. Rainbows in the clouds.

    PubMed

    Disch, Joanne; Steffen, Lori

    2008-01-01

    On October 14, 2007 master storyteller, scholar, and poet Maya Angelou launched the second Summit of Sages, hosted by the University of Minnesota School of Nursing. This event was a forum for people with a common interest in examining social justice--to become informed, engaged, and committed to action. Presented below are our separate, yet complementary, thoughts about the impact of her words. PMID:18655512

  4. Physicochemical properties and biodegradability of crude oil

    SciTech Connect

    Sugiura, Keiji; Ishihara, Masami; Shimauchi, Toshitsugu; Harayama, Shigeaki

    1997-01-01

    The biodegradation of four different crude oil samples, namely, Arabian light, Dubai, Maya, and Shengli, by acinetobacter sp. T4 and by a microbial consortium called SM8 was examined. SM8 exhibited higher activity than Acinetobacter for the biodegradation of all four crude oil samples. The degree of biodegradation of crude oil components differed according to the crude oil, the saturated fraction being more susceptible to biodegradation than the aromatic fraction in all the crude oil samples. The extent of biodegradation by acinetobacter and SM8 was found to be in the order of Arabian light > Dubai > Maya = Shengli; the crude oil samples with higher APl gravity being more susceptible to biodegradation. Saturated compounds of smaller molecular weight were preferentially degraded by both cultures. Acinetobacter could not degrade polycyclic aromatic compounds in the crude oil samples such as (alkyl)naphthalenes, (alky)phenanthrenes, (alkyl)fluorenes, and (alkyl)dibenzothiophenes. However, this strain was capable of degrading more than 10% of the molecules in the aromatic fraction of Arabian light crude oil. An NMR analysis demonstrated that the alkyl side chain of some aromatic molecules was degraded by this organism. In contrast, SM8 degraded the polycyclic aromatic compounds in the crude oil samples, the extent of degradation being in the order of Maya > Shengli > Arabian light > Dubai. 17 refs., 4 figs., 4 tabs.

  5. Development of analytical procedures for coprocessing

    SciTech Connect

    Vogh, J.W.; Anderson, R.P.

    1990-05-01

    Maya crude residue and Illinois No. 6 coal have been processed together over a range of reactant ratios to produce material for study of the product composition and of the coprocessing chemistry. The reaction conditions have been described in previous reports. Acid fractions have been derivatized to produce {sup 13}C tagged products suitable for NMR analysis. The acids have been identified as phenols and other oxygen acids, nitrogen acids including carbazoles, and benzylic and sulfur acids. All of the acid fractions appear to be essentially monofunctional. Base fractions were analyzed by nonaqueous titration and were shown to consist of azaarenes and arylamines. Two of the distillates boiling below 175{degrees}C were analyzed by PIANO capillary gas chromatography. Maya crude petroleum fractions similar to those obtained from coprocessing products have been analyzed for carbon isotope ratios. These fractions were prepared directly from the Maya crude without application of hydrogenation or other processing chemistry. Trends indicating isotopic fractionation coprocessing to that reported earlier for coprocessing products were observed. 14 figs., 13 tabs.

  6. Characterization of multiple lineages of Tc1-like elements within the genome of the amphibian Xenopus tropicalis.

    PubMed

    Sinzelle, Ludivine; Pollet, Nicolas; Bigot, Yves; Mazabraud, André

    2005-04-11

    We have used genomic sequencing data extracted from the first assembly of the Xenopus tropicalis genome combined with a degenerated PCR approach to identify multiple lineages of Tc1 related transposable elements. Full-length elements were isolated in each lineage and were characterized. Most of them exhibit the typical characteristics of Tc1-like elements (TLEs). An open reading frame (ORF) encoding a 340-350 aa transposase containing a [D, D(34)E] signature was found as well as conserved inverted terminal repeats (ITRs) at each extremities. These ITRs could vary in length, depending on the TLE lineage. These new TLEs were named Eagle, Froggy, Jumpy, Maya, Xeminos, XtTXr and XtTXz. Phylogenetic analyses indicate that their closest relatives are present in the genomes of actinopterygian and amphibian. Interestingly, Maya and Xeminos share remarkable characteristics. Maya contains a [D,D(36)E] motif but is not related to any described TLE so far. Xeminos is the first vertebrate TLE strongly related to an invertebrate lineage. Finally, we have identified for most of these TLEs, copies containing an intact transposase ORF suggesting that these elements may still be active. PMID:15777729

  7. Alternative diets for maintaining and rearing cephalopods in captivity.

    PubMed

    DeRusha, R H; Forsythe, J W; DiMarco, F P; Hanlon, R T

    1989-07-01

    The requirement of live marine prey for cephalopod mariculture has restricted its practicality for inland research laboratories, commercial enterprises and home aquarists. We evaluated acceptability and resultant growth on: (a) frozen marine shrimps, (b) live and frozen marine polychaete worms, (c) live and frozen marine crabs, (d) frozen marine fishes, (e) live adult brine shrimp, (f) live freshwater fish and (g) live freshwater crayfish. The diets were presented for periods of 2 to 11 weeks to octopuses, cuttlefishes or squids and in most trials the results were compared to animals fed control diets of live marine shrimps, crabs or fish. Overall, frozen marine shrimp proved to be the best alternative diet tested. Adult Octopus maya on frozen marine shrimp diets grew as well as those on control diets at 2.8% body weight per day (%/d) compared to 2.0%/d on live freshwater crayfish, 1.4%/d on live marine polychaete worms and 0.8%/d on live freshwater fish (Tilapia sp.). Juvenile Octopus maya and Octopus bimaculoides also grew comparably to controls when fed frozen marine shrimps; growth rates ranged from near 3.0%/d at 3 months of age to nearly 2.5%/d at 6 months of age. Thus, these alternatives are acceptable as the octopuses end their exponential growth phase at an age of 3 - 5 months. Attempts to rear O. maya hatchlings and juveniles (up to 1 month of age) on dead foods resulted in high mortality and slow or negative growth. No live or dead alternative diet has been found yet that will promote good growth and survival in hatchling octopuses. Hatchling F3 generation Sepia officinalis (the European cuttlefish) were reared for 6 weeks exclusively on adult brine shrimp (Artemia salina).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2761235

  8. Impact of the 3-D model strategy on science learning of the solar system

    NASA Astrophysics Data System (ADS)

    Alharbi, Mohammed

    The purpose of this mixed method study, quantitative and descriptive, was to determine whether the first-middle grade (seventh grade) students at Saudi schools are able to learn and use the Autodesk Maya software to interact and create their own 3-D models and animations and whether their use of the software influences their study habits and their understanding of the school subject matter. The study revealed that there is value to the science students regarding the use of 3-D software to create 3-D models to complete science assignments. Also, this study aimed to address the middle-school students' ability to learn 3-D software in art class, and then ultimately use it in their science class. The success of this study may open the way to consider the impact of 3-D modeling on other school subjects, such as mathematics, art, and geography. When the students start using graphic design, including 3-D software, at a young age, they tend to develop personal creativity and skills. The success of this study, if applied in schools, will provide the community with skillful young designers and increase awareness of graphic design and the new 3-D technology. Experimental method was used to answer the quantitative research question, are there significant differences applying the learning method using 3-D models (no 3-D, premade 3-D, and create 3-D) in a science class being taught about the solar system and its impact on the students' science achievement scores? Descriptive method was used to answer the qualitative research questions that are about the difficulty of learning and using Autodesk Maya software, time that students take to use the basic levels of Polygon and Animation parts of the Autodesk Maya software, and level of students' work quality.

  9. Correlation between the Mayan calendar and ours: Astronomy helps to answer why the most popular correlation (GMT) is wrong

    NASA Astrophysics Data System (ADS)

    Klokočník, J.; Kostelecký, J.; Böhm, V.; Böhm, B.; Vondrák, J.; Vítek, F.

    2008-05-01

    The Maya used their own very precise calendar. When transforming data from the Mayan calendar to ours, or vice versa, a surprisingly large uncertainty is found. The relationship between the two calendars has been investigated by many researchers during the last century and about 50 different values of the transformation coefficient, known as the correlation, have been deduced. They can differ by centuries, potentially yielding an incredibly large error in the relation of Mayan history to the history of other civilizations. The most frequently used correlation is the GMT one (of Goodman-Martínez-Thompson), based largely on historical evidence from colonial times. Astronomy (celestial mechanics) may resolve the problem of the correlation, provided that historians have correctly decoded the records of various astronomical phenomena discovered, namely, in one extremely important and rare Mayan book, the Dresden Codex (DC). This describes (among other matters) observations of various astronomical phenomena (eclipses, conjunctions, maximum elongations, heliacal aspects, etc), made by the Maya. Modern celestial mechanics enables us to compute exactly when the phenomena occurred in the sky for the given place on the Earth, even though far back in time. Here we check (by a completely independent method), confirming the value of the correlation obtained by Böhm & Böhm (1996, 1999). In view of these tests, we advocate rejecting the GMT correlation and replacing it by the Böhm's correlation. We also comment on the criticism of GMT by some investigators. The replacement of GMT by another correlation seems, however, unacceptable to many Mayanists, as they would need to rewrite the whole history of Mesoamerica. The history of the Maya would be - for example with Böhm's correlation - closer to our time by 104 years.

  10. Analysis of Polymorphisms in Interleukin-10, Interleukin-6, and Interleukin-1 Receptor Antagonist in Mexican-Mestizo Women with Pre-eclampsia

    PubMed Central

    Valencia Villalvazo, Elith Yazmin; Canto-Cetina, Thelma; Romero Arauz, Juan Fernando; Coral-Vázquez, Ramón Mauricio; Canizales-Quinteros, Samuel; Coronel, Agustín; Carlos Falcón, Juan; Hernández Rivera, Jaime; Ibarra, Roberto; Polanco Reyes, Lucila

    2012-01-01

    Due to the fact that studies seeking associations of polymorphisms in regulatory regions of cytokine genes with pre-eclampsia (PE) have not always been consistent in different population analyses, the aim of this study was to investigate the possible association between rs1800896 of interleukin-10 (IL-10), rs1800795 of interleukin-6 (IL-6), and the variable number of tandem repeats (VNTR) in intron 2 of interleukin-1 receptor antagonist (IL-1Ra), as well as gene–gene interactions between these three polymorphisms with the presence of PE in Mexican-Mestizo women and one Amerindian population from México (Maya). A case–control study was performed where 411 pre-eclamptic cases and 613 controls were genotyped. For the rs1800896 of IL-10 and rs1800795 of IL-6, we used real-time polymerase chain reaction (PCR) allelic discrimination and for the VNTR of IL-1Ra, PCR. Allele frequency differences were assessed by Chi-squared test; logistic regression was used to test for associations; a gene–gene interaction was conducted. Genotypic and allelic distribution of the polymorphisms was similar in our population. The estimated of the gene–gene interaction between the polymorphisms did not differ significantly. However, we observed important differences in the distribution of the alleles and genotypes of the three polymorphisms analyzed between Mestiza-Mexicanas and Maya-Mestizo women. In conclusion, we did not find an association between polymorphisms in IL-10, IL-6, and IL-1Ra and PE in Mexican-Mestizo and Maya-Mestizo women. To our knowledge, this is the first time that these three polymorphisms were analyzed together with gene–gene interaction in women with PE. PMID:23013217

  11. Measurement of the Two-Halo Neutron Transfer Reaction {sup 1}H({sup 11}Li,{sup 9}Li){sup 3}H at 3A MeV

    SciTech Connect

    Tanihata, I.; Alcorta, M.; Bandyopadhyay, D.; Bieri, R.; Buchmann, L.; Davids, B.; Galinski, N.; Howell, D.; Mills, W.; Mythili, S.; Openshaw, R.; Padilla-Rodal, E.; Ruprecht, G.; Sheffer, G.; Shotter, A. C.; Trinczek, M.; Walden, P.; Savajols, H.; Roger, T.; Caamano, M.

    2008-05-16

    The p({sup 11}Li,{sup 9}Li)t reaction has been studied for the first time at an incident energy of 3A MeV at the new ISAC-2 facility at TRIUMF. An active target detector MAYA, built at GANIL, was used for the measurement. The differential cross sections have been determined for transitions to the {sup 9}Li ground and first excited states in a wide range of scattering angles. Multistep transfer calculations using different {sup 11}Li model wave functions show that wave functions with strong correlations between the halo neutrons are the most successful in reproducing the observation.

  12. The importance of weeds in ethnopharmacology.

    PubMed

    Stepp, J R; Moerman, D E

    2001-04-01

    Tropical primary forest is often considered to be the most important habitat for traditional peoples to gather medicinal plants. However, the role of weeds, commonly found in disturbed areas, in traditional medicinal floras has been overlooked. Data are presented showing the significant representation of weeds in the medicinal floras of the Highland Maya in Chiapas, Mexico and in the medicinal flora of Native North Americans as a whole. The frequency with which weeds appear in these pharmacopoeias is significantly larger (P<0.0001) than what would be predicted by the frequency of weed species in general. Explanations based on human ecology and biochemical ecology are presented. PMID:11282438

  13. Octopus automutilation syndrome.

    PubMed

    Reimschuessel, R; Stoskopf, M K

    1990-05-01

    This paper describes an automutilation syndrome (OAS) in three species of captive octopuses, Octopus dolfleini, O. bimaculoides, and O. maya, characterized by external arm and mantle lesions. Three clinical patterns in nine animals had similar and characteristic gross and histopathologic features. Axial nerve or brachial artery lesions were observed in six of the nine cases and vascular lesions were seen in two of eight cases with mantle ulcerations. A relationship between automutilation in the octopus and dysesthesias due to neural or vascular pathology is proposed. PMID:2351844

  14. Review of the Mexican species of Erythmelus (Hymenoptera: Mymaridae),
    with description of two new species.

    PubMed

    Guzmán-Larralde, Adriana J; Triapitsyn, Serguei V; Huber, John T; González-Hernández, Alejandro

    2015-01-01

    The Mexican species of Erythmelus Enock (Hymenoptera: Mymaridae) are revised. A key to females of 13 species is provided in both English and Spanish. Two new taxa are described-E. maya Guzmán-Larralde & Triapitsyn, sp. n. and E. tigres Guzmán-Larralde & Triapitsyn, sp. n. Six species are newly recorded from Mexico-E. angustatus Ogloblin, E. cingulatus Ogloblin, E. clavatus Ogloblin, E. gracilis (Howard), E. nanus Dozier, and E. noeli (Dozier), besides new geographic records for E. miridiphagus Dozier, E. picinus (Girault), E. psallidis Gahan, and E. rex (Girault) which were previously known from the country. PMID:26248908

  15. Astronomy at Teotihuacan

    NASA Astrophysics Data System (ADS)

    Iwaniszewski, Stanisław

    Located 37 km from Mexico City, during the first part of the first millennium AD, Teotihuacan was one of the world's largest and most populated cities. The city controlled the obsidian mines and developed far-reaching economic and political interactions, especially with the Classic Maya dynasties, Monte Albán in the Valley of Oaxaca and the Mexican Gulf Coast. Teotihuacan-made pottery and jewelry along with talud-tablero architectural style and the cult of the Feathered Serpent and Rain gods was spread throughout Mesoamerica.

  16. Black Hole - Neutron Star Binary Simulations at Georgia Tech

    NASA Astrophysics Data System (ADS)

    Haas, Roland

    2009-05-01

    Mixed compact object binaries consisting of a black hole and a neutron star are expected to be not only one of the primary sources of gravitational radiation to be observed by interferometric detectors but also the central engine of short gamma-ray bursts. We report on the status of our effort at Georgia Tech to model these mixed binary systems using the moving puncture method. The results are obtained with an enhanced version our vacuum MayaKranc code coupled to the hydrodynamics Whisky code. We present preliminary results of gravitational waveforms and the disruption of the neutron star for simple polytropic equations of state.

  17. Aztec arithmetic: positional notation and area calculation.

    PubMed

    Harvey, H R; Williams, B J

    1980-10-31

    Texcocan-Aztec peoples in the Valley of Mexico used both picture symbols and lines and dots for numerical notation. Decipherment and analysis of mid-16th-century native pictorial land documents from the Texcocan region indicate that the line-and-dot system incorporated a symbol for zero and used position to ascribe values. Positional line-and-dot notation was used to record areas of agricultural fields, and analysis of the documentary data suggests that areas were calculated arithmetically. These findings demonstrate that neither positional notation nor the zero were unique to the Maya area, and they imply an equally sophisticated mathematical development among the Aztecs. PMID:17841389

  18. Archeological/Environmental Research

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Landsat/Seasat remote sensing was used by Ames Research Center to evaluate environmental influence on ancient Mayan civilization. Over 35 archeological sites were imaged and valuable information concerning Maya settlement patterns, environment, and resource usage resulted. The imagery was also used by Mexican authorities to develop coastal management plans, establish Biosphere Reserves and assess damage from the 1988 Hurricane Gilbert. Imagery showed evidence of ancient coastlines, changes in sea level, an ancient river plain and Mayan canal systems. Previously unknown Mayan reservoirs were discovered. The project is considered a pioneering effort combining remote sensing, environmental studies and archeology.

  19. Miocene mollusks from the Simojovel area in Chiapas, southwestern Mexico

    NASA Astrophysics Data System (ADS)

    del Carmen Perrilliat, María; Vega, Francisco J.; Coutiño, Marco A.

    2010-11-01

    The fauna of gastropods and bivalves from the amber-bearing lithostratigraphic units of the Simojovel area, Chiapas is reported, including the description of two new species and one subspecies: Turbinella maya new species, Melongena corona tzeltal new subspecies and Agladrillia ( Eumetadrillia) vermeiji new species. Stratigraphic affinities of the previously described species suggest an Early Miocene age for the Mazantic Shale, and a Middle Miocene age for the overlying Balumtum Sandstone. One specimen of gastropod, with a relatively large piece of amber attached to the adapertural part of the shell is representative for an Early Miocene age and estuarine paleoenvironmental interpretation for the Mazantic Shale. Mollusca, Miocene, Chiapas, Amber, Mexico.

  20. Mineral resource of the month: mica

    USGS Publications Warehouse

    Hedrick, J.B.

    2008-01-01

    Humans have been using mica for millennia. Mica was first mined in India about 4,000 years ago, where it was used primarily in medicines, and some Hindu physicians still incorporate biotite mica into medicines today. Early civilizations also used mica for decorations, as windows and as surfaces on which to draw or paint. Maya temples were decorated with mica pigments, which were incorporated into the stucco to make it sparkle in the sun. In North America, ancient inhabitants adorned gravesites and burial mounds with animal figures made of mica.

  1. 3DRT-MPASS

    NASA Technical Reports Server (NTRS)

    Lickly, Ben

    2005-01-01

    Data from all current JPL missions are stored in files called SPICE kernels. At present, animators who want to use data from these kernels have to either read through the kernels looking for the desired data, or write programs themselves to retrieve information about all the needed objects for their animations. In this project, methods of automating the process of importing the data from the SPICE kernels were researched. In particular, tools were developed for creating basic scenes in Maya, a 3D computer graphics software package, from SPICE kernels.

  2. The political collapse of Chichén Itzá in climatic and cultural context

    NASA Astrophysics Data System (ADS)

    Hoggarth, Julie A.; Breitenbach, Sebastian F. M.; Culleton, Brendan J.; Ebert, Claire E.; Masson, Marilyn A.; Kennett, Douglas J.

    2016-03-01

    Chichén Itzá dominated the political landscape of the northern Yucatán during the Terminal Classic Period (AD 800-1000). Chronological details of the rise and fall of this important polity are obscure because of the limited corpus of dated hieroglyphic records and by a restricted set of radiocarbon dates for the site. Here we compile and review these data and evaluate them within the context of political and climatic change in northern Yucatán at the end of the Classic period. The available data point to the end of elite activity at Chichén Itzá around AD 1000, a century after the collapse of Puuc Maya cities and other interior centers. Evidence supports a population shift in the eleventh century towards some coastal locations during a time associated with the end of monumental construction and art at Chichén Itzá. Our results suggest that regional political disintegration came in two waves. The first was the asynchronous collapse of multiple polities between AD 850 and 925 associated with a regional drying trend and punctuated by a series of multi-decadal droughts in the ninth and tenth centuries. The second wave was the political collapse at Chichén Itzá that coincides with the longest and most severe drought recorded in regional climate records between AD 1000 and 1100. This is a time that some scholars have characterized as a "dark age" across the northern Maya lowlands. Political developments during the Postclassic period (AD 1000-1517) correspond with a return to higher rainfall. These patterns support a strong relationship between political disintegration and climatic stress in the Maya lowlands. This research employs Bayesian radiocarbon models in conjunction with calendar dates on carved monuments and climate proxies to evaluate the rise and fall of Maya political centers and serves as an example of the impact of climate change on rainfall-dependent societies in Mesoamerica.

  3. Antiprotozoal activity of the constituents of Rubus coriifolius.

    PubMed

    Alanís, Alma Delia; Calzada, Fernando; Cedillo-Rivera, Roberto; Meckes, Mariana

    2003-06-01

    Extraction of the aerial parts of Rubus coriifolius, a medicinal plant used by the Maya communities in Southern Mexico to treat bloody diarrhoea, resulted in the isolation of seven known compounds (-)-epicatechin, (+)-catechin, hyperin, nigaichigoside F1, beta-sitosterol 3-O-beta-d-glucopyranoside, gallic acid and ellagic acid. All compounds were tested for their antiprotozoal activity against Entamoeba histolytica and Giardia lambia. Epicatechin was the main responsible for the antiprotozoal activity of the extract against both protozoa, its activity was comparable to emetine, but no exceeded that of metronidazole. PMID:12820241

  4. A phase-transition model for the rise and collapse of ancient civilizations: A pre-ceramic Andean case study

    NASA Astrophysics Data System (ADS)

    Flores, J. C.

    2015-12-01

    For ancient civilizations, the shift from disorder to organized urban settlements is viewed as a phase-transition simile. The number of monumental constructions, assumed to be a signature of civilization processes, corresponds to the order parameter, and effective connectivity becomes related to the control parameter. Based on parameter estimations from archaeological and paleo-climatological data, this study analyzes the rise and fall of the ancient Caral civilization on the South Pacific coast during a period of small ENSO fluctuations (approximately 4500 BP). Other examples considered include civilizations on Easter Island and the Maya Lowlands. This work considers a typical nonlinear third order evolution equation and numerical simulations.

  5. Archaeoastronomy in the New World

    NASA Astrophysics Data System (ADS)

    Aveni, Anthony F.

    2010-01-01

    List of contributors; 1. Introduction A. F. Aveni; 2. Archaeoastronomy in the Maya region A. F. Aveni; 3. Historical archaeoastronomy: the Hopi example S. C. McCluskey; 4. The Sidereal Lunar Calendar of the Incas R. T. Zuidema; 5. Astronomical norms in Mesoamerican rituals and time-reckoning G. Brotherston; 6. Astronomical knowledge and its uses at Bonampak, Mexico F. G. Lounsbury; 7. Lunar markings of Fajada Butte, Chaco Canyon A. Sofaer, R. M. Sinclair and L. E. Doggett; 8. The Skidi Pawnee earth lodge as an observatory V. D. Chamberlain; 9. Caldendrical petroglyphs of Northern Mexico W. B. Murray; 10. Casa Rinconada, twelfth-century Anasazi Kiva R. A. Williamson.

  6. Octopus lipid and vitamin E composition: interspecies, interorigin, and nutritional variability.

    PubMed

    Torrinha, Alvaro; Cruz, Rebeca; Gomes, Filipa; Mendes, Eulália; Casal, Susana; Morais, Simone

    2014-08-20

    Octopus vulgaris, Octopus maya, and Eledone cirrhosa from distinct marine environments [Northeast Atlantic (NEA), Northwest Atlantic (NWA), Eastern Central Atlantic, Western Central Atlantic (WCA), Pacific Ocean, and Mediterranean Sea] were characterized regarding their lipid and vitamin E composition. These species are those commercially more relevant worldwide. Significant interspecies and interorigin differences were observed. Unsaturated fatty acids account for more than 65% of total fatty acids, mostly ω-3 PUFA due to docosahexaenoic (18.4-29.3%) and eicosapentanoic acid (11.4-23.9%) contributions. The highest ω-3 PUFA amounts and ω-3/ω-6 ratios were quantified in the heaviest specimens, O. vulgaris from NWA, with high market price, and simultaneously in the lowest graded samples, E. cirrhosa from NEA, of reduced dimensions. Although having the highest cholesterol contents, E. cirrhosa from NEA and O. maya from WCA have also higher protective fatty acid indexes. Chemometric discrimination allowed clustering the selected species and several origins based on lipid and vitamin E profiles. PMID:25087929

  7. High resolution renderings and interactive visualization of the 2006 Huntington Beach experiment

    NASA Astrophysics Data System (ADS)

    Im, T.; Nayak, A.; Keen, C.; Samilo, D.; Matthews, J.

    2006-12-01

    The Visualization Center at the Scripps Institution of Oceanography investigates innovative ways to represent graphically interactive 3D virtual landscapes and to produce high resolution, high quality renderings of Earth sciences data and the sensors and instruments used to collect the data . Among the Visualization Center's most recent work is the visualization of the Huntington Beach experiment, a study launched in July 2006 by the Southern California Ocean Observing System (http://www.sccoos.org/) to record and synthesize data of the Huntington Beach coastal region. Researchers and students at the Visualization Center created visual presentations that combine bathymetric data provided by SCCOOS with USGS aerial photography and with 3D polygonal models of sensors created in Maya into an interactive 3D scene using the Fledermaus suite of visualization tools (http://www.ivs3d.com). In addition, the Visualization Center has produced high definition (HD) animations of SCCOOS sensor instruments (e.g. REMUS, drifters, spray glider, nearshore mooring, OCSD/USGS mooring and CDIP mooring) using the Maya modeling and animation software and rendered over multiple nodes of the OptIPuter Visualization Cluster at Scripps. These visualizations are aimed at providing researchers with a broader context of sensor locations relative to geologic characteristics, to promote their use as an educational resource for informal education settings and increasing public awareness, and also as an aid for researchers' proposals and presentations. These visualizations are available for download on the Visualization Center website at http://siovizcenter.ucsd.edu/sccoos/hb2006.php.

  8. Technical report on the surface reconstruction of stacked contours by using the commercial software

    NASA Astrophysics Data System (ADS)

    Shin, Dong Sun; Chung, Min Suk; Hwang, Sung Bae; Park, Jin Seo

    2007-03-01

    After drawing and stacking contours of a structure, which is identified in the serially sectioned images, three-dimensional (3D) image can be made by surface reconstruction. Usually, software is composed for the surface reconstruction. In order to compose the software, medical doctors have to acquire the help of computer engineers. So in this research, surface reconstruction of stacked contours was tried by using commercial software. The purpose of this research is to enable medical doctors to perform surface reconstruction to make 3D images by themselves. The materials of this research were 996 anatomic images (1 mm intervals) of left lower limb, which were made by serial sectioning of a cadaver. On the Adobe Photoshop, contours of 114 anatomic structures were drawn, which were exported to Adobe Illustrator files. On the Maya, contours of each anatomic structure were stacked. On the Rhino, superoinferior lines were drawn along all stacked contours to fill quadrangular surfaces between contours. On the Maya, the contours were deleted. 3D images of 114 anatomic structures were assembled with their original locations preserved. With the surface reconstruction technique, developed in this research, medical doctors themselves could make 3D images of the serially sectioned images such as CTs and MRIs.

  9. Role of the resid solvent in catalytic coprocessing with finely divided catalysts. Quarterly report, April 1995--June 1995

    SciTech Connect

    1996-01-01

    The research reported in this progress report describes the continuation of coal-resid coprocessing reactions that were discussed in the January to March 1995 Quarterly Report. During previous quarters, Maya and FHC-623 resids were evaluated in non-catalytic and catalytic reactions at 400{degrees}C with Pittsburgh No. 8 and DECS-17 Blind Canyon coals. From the complete reaction matrix containing the two coals and two resids, it was found that the influence of resids on coprocessing depended on the type of coal used; for example, under catalytic reaction conditions, the hexane solubles of Maya resid increased coal conversion of Pittsburgh No. 8 coal but decreased that of DECS-17. In order to observe the intrinsic behavior of resids during coprocessing, another resid, Manjii, and another coal, Illinois No. 6, are being tested. These reactions were begun this quarter. The results are reported herein. In order to evaluate the role of the different components in resids, the resids were separated into hexane soluble materials and hexane insoluble materials. The hexane solubles, which should contain the naphthenes present in the resid, and the untreated whole resids were reacted with coal at equivalent liquefaction conditions and at the same conditions as when the resids were reacted individually.

  10. Guatemalan women's paper making co-op.

    PubMed

    Stewart, B M

    1999-01-01

    Founded in 1992, is an independent grassroots organization whose goal is to assist community development, health, education, clean water and income generation. The Q'eqchi' Maya Indians constitute the fourth largest indigenous group located on the banks of Rio Dulce, in the eastern rainforest of Guatemala. Project Ak'Tenamit helped the Q'eqchi' people revive their ancient art of paper making as a viable and self-sustainable source of income. As the material used by the ancient Maya--cork husk and banana stalks--are still abundant, it was decided that this art could be successfully re-introduced. With papermaking, the Q'eqchi women were able to earn money from their own production without even compromising their respective households. Ak'Tenamit was responsible for the distribution of paper making products in stores throughout Guatemala. Although there are still many obstacles confronting these women, the paper making cooperative provides employment opportunities and is indeed a great help to them. They produce a total of 15 different products including bowls, cards, and bookmarks. PMID:12295253

  11. Surface Reconstruction and Optimization of Cerebral Cortex for Application Use.

    PubMed

    Shin, Dong Sun; Park, Sang Kyu

    2016-03-01

    For the purposes of virtual surgery, medical education, medical communication, and realistic surface models of anatomic structures are required. In the most involved method, surface models can be made using segmentation and three-dimensional reconstruction procedures. Such models, however, are computationally expensive, and can be difficult to use. Therefore, optimization is often performed manually, but this is a time-consuming job that requires considerable artistic talent. In this article, the authors describe a method that uses Maya and ZBrush to construct optimized surface models of anatomic structures. The authors take 235 anatomic images generated from a cadaver, and perform segmentation and surface reconstruction using Photoshop and Mimics. Reconstructed surface models of the cerebral cortex are then optimized and divided by a morphing technique in Maya and ZBrush for use in medical applications. The optimized surface models do not require significant storage space, and are easily manufactured and modified. The resulting surface models can be displayed off-line and on-line in real time, as well as on smart phones. Using commercial software with the specialized functions described in this study, it is expected that the efficiencies produced by the proposed method will enable researchers to conveniently create surface models from serially sectioned images such as computed tomographs and magnetic resonance images. The surface models created in this research will also have widespread applications in both medical education and communication. PMID:26854785

  12. Climate change and archaeology in Mesoamerica

    NASA Astrophysics Data System (ADS)

    Beach, Timothy

    2016-03-01

    I first encountered Mesoamerican paleoclimate in a graduate seminar taught by Herb Wright, Jr. in Geology at the University of Minnesota in 1984. Herb passed away in 2015 at 98 after decades of studying paleoclimate and many other aspects of Quaternary studies. In 1984 there were few Maya paleoclimate studies, and a Science article on Mayan Urbanism by Deevey et al. (1979) was still current. Mark Brenner was one of the authors of that piece and he has been constant over these decades, appearing again as a coauthor of two articles in this issue. Several recent articles have noted the expansion in Maya climate studies from the perspectives of Climate Science, to Paleotempestology, and to Archeology (Douglas et al., in this issue;Beach et al., 2015; Luzzadder-Beach et al., in press). This special issue grew out of the recognition of that explosion of studies and the need to bring some important current findings together in one issue. This special issue does that by incorporating new reviews and specific studies that help us refine the trends of climate change and the drivers of climate and their connections to what we know of human history and archeology in the region.

  13. Reconstructed summer Palmer Drought Severity Index since 1850 AD based on δ13C of larch tree rings in eastern Siberia

    NASA Astrophysics Data System (ADS)

    Tei, Shunsuke; Yonenobu, Hitoshi; Sugimoto, Atsuko; Ohta, Takeshi; Maximov, Trofim C.

    2015-10-01

    We present a tree-ring reconstruction of Palmer Drought Severity Index (PDSI) in Ust-Maya region (60°00‧N, 133°49‧E), central part of eastern Siberia using total ring (TR) widths and latewood (LW) δ13C chronologies from larch trees (1850-2008 AD). Summer (JJA) PDSI was correlated positively and negatively with the TR widths and LW δ13C, respectively. Using a multiple liner regression approach, we reconstructed summer PDSI using the time series of TR widths and LW δ13C. The reconstruction showed an interannual to decadal wet/dry fluctuation with several moist periods before 1950s and a severe drought event from 1991 to 1993. Comparison of the reconstruction with reconstructed July PDSI for the Yakutsk region, 300 km northwest of Ust-Maya, showed heterogeneous changes in the mean states of soil moisture, but synchronous year-to-year changes. These results indicate that regional studies are quite important to precisely depict the spatio-temporal variability of hydrological changes in the central part of eastern Siberia.

  14. The role of the resid solvent in coprocessing with finely divided catalysts. Quarterly report, January--March 1994

    SciTech Connect

    Curtis, C.W.

    1994-07-01

    The research reported in this progress report describes the continuation of coal-resid coprocessing reactions which were begun last quarter (October to December 1993). During, last quarter, Maya and FHC-623 resid were evaluated as whole resids and as the hexane soluble fraction in noncatalytic and catalytic reactions at 400{degree}C. During this current quarter, reactions were performed using Pittsburgh No. 8 bituminous coal and several different solvents including Maya and FHC-623 resids. In order to evaluate the role of the different components in resids, the resids were separated into hexane soluble materials and hexane insoluble materials. The hexane solubles, which should contain the naphthene present in the resid, and the untreated whole resids were reacted with coal at the same liquefaction conditions as when the resids were reacted individually. In the catalytic reactions, a Mo naphthenate precursor was used in the presence of sulfur. The catalyst generated in situ was MoS{sub 2} . The effect of different reaction conditions on the resid was monitored by gas chromatography in which the retention times of the eluting peaks were determined. The amount of eluent present at different retention times was determined and compared. The effect of the reaction system on coal behavior during liquefaction was determined by coal conversion to THF solubles and solvent fractionation of the reaction products.

  15. Delta-sarcoglycan gene polymorphism frequency in Amerindian and Mestizo populations of Mexico.

    PubMed

    Ordoñez-Razo, Rosa María; Canizales-Quinteros, Samuel; Rodríguez-Cruz, Maricela; Peñaloza, Rosenda; Minauro-Sanmiguel, Fernando; Canto-Cetina, Thelma; Canto, Patricia; Coral-Vázquez, Ramón; Salamanca-Gómez, Fabio

    2010-04-01

    Mutations on the delta-sarcoglycan gene have been associated with the development of both hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy. Recently, the polymorphism c.-94C>G was associated with HCM in Japanese patients. The aim of our study was to evaluate the frequency of c.-94C>G polymorphism in Mexican-Amerindian and Mexican-Mestizo populations. We analyzed the frequency of this polymorphism in 165 Mexican-Amerindian individuals (23 Triquis, 25 Zapotecos, 24 Mayas, 41 Nahuas, and 52 Mixtecos) and 100 unrelated Mexican-Mestizos. Allele frequencies were similar in all Amerindian groups (0.33 Triquis, 0.54 Zapotecos, 0.54 Mayas, 0.46 Nahuas, and 0.49 Mixtecos). When compared with Mexican-Mestizos, only Triquis were different (p = 0.00742). However, when comparing the total sample of the Amerindian population with the Mestizos, the difference was not significant (p = 0.12225). Allele frequencies of Mexican populations were higher than in Asians and less than African and European populations (p < 0.05). These data show that the distribution of the C allele is higher in Mexican populations studied and consequently it is necessary to define if this may be associated with genetic susceptibility for HCM in the Mexican patients. PMID:20384457

  16. The determination of residence times in a pilot plant

    NASA Astrophysics Data System (ADS)

    Ramírez, F. Pablo; Cortés, M. Eugenia

    2004-01-01

    It is well known that residence time distributions (RTD) are very important in many chemical processes such as separation, reforming, hydrocracking, fluid catalytic cracking, hydrodesulfuration, hydrogenation among others [3 Procédés de transformation, Editions Technip, Institute Francais du Petrole, Paris, France, 1998]. In addition, tracers can be used to measure the velocity, distribution and residence time of any stream through any part of an industrial [Guidebook on Radioisotope Tracers in Industry, IAEA, Vienna, 1990] or experimental system. Perhaps the best quality of radiotracers is that they do not interfere with normal unit operations or production scheduling. In this paper are presented the RTDs obtained in a pilot plant for a hydrogenation process [IMP, Technical Report, Determinación del tiempo de residencia promedio en el reactor de la planta piloto de hidroagotamiento de crudo, 2002]. The RTDs show a random phenomenon, which is not typical of this type of chemical processes. Several RTDs were determined in order to confirm this random behavior. The data were obtained using as a tracer a radioactive form of sodium iodide containing iodine-131 [The Condensed Chemical Dictionary, 10th Ed., Van Nostrand Reinhold, USA, 1981]. The process works with two phases in a countercurrent flow, inside a packed column. The liquid phase goes down by gravity. The gas phase goes up due to pressure difference [3 Procédés de transformation, Editions Technip, Institute Francais du Petrole, Paris, France, 1998]. The tracer was selected such that it would follow the liquid phase.

  17. Volcanic history of El Chichon Volcano (Chiapas, Mexico) during the Holocene, and its impact on human activity

    USGS Publications Warehouse

    Espindola, J.M.; Macias, J.L.; Tilling, R.I.; Sheridan, M.F.

    2000-01-01

    Before its devastating eruption in 1982, El Chichon Volcano was little known and did not appear on any listings of hazardous volcanoes. Subsequent geologic studies, based on stratigraphic and radiocarbon investigations, showed that at least three explosive eruptions had occurred previously at this volcano. In this paper, we present the result of recent studies on the stratigraphy of the volcano and new radiocarbon ages which show that at least 11 eruptions have taken place at El Chichon in the past 8000 years. Explosive events, most of them producing block-and-ash flow and surge deposits, occurred around 550, 900, 1250, 1500, 1600, 1900, 2000, 2500, 3100, 3700 and 7700 years BP. The juvenile products of these eruptions have a trachyandesitic composition with similar degree of evolution, as evidenced from their SiO2 abundance and depletion in MgO, CaO, TiO2, as well as trace and rare earth elements. This suggests segregation of olivine and orthopyroxene from the melt. Since human settlements in southeast Mexico and Central America can be traced as far back as approximately 2500 years BP, most of these events probably affected human activity. In fact, there are reports of pottery shards and other artifacts in deposits from the eruption of 1250 BP. Pottery fragments in deposits of an eruption that took place 2500 BP are also reported in this paper. Thus, the impact of the volcano on human activities has been frequent, with most of the repose intervals lasting between 100 to 600 years. The impact of the eruptions was probably of greater than local extent, because airfall tephra could reach distant sites and possibly even affect weather. The eruptive history of El Chichon also offers clues in the investigation of the Maya civilization. Several researchers have considered the volcano as an important factor in the answer to some intriguing questions such as the extensive use of volcanic ash in Late Classic Maya ceramics or, of greater importance, the causes of the

  18. El Niño, Climate and Societies

    NASA Astrophysics Data System (ADS)

    Haug, G. H.; Peterson, L. C.; Yancheva, G.

    2010-03-01

    One tropical climate archive with an appropriate memory for the societal most relevant sub-centennial to sub-decadal scale climate swings is the anoxic Cariaco Basin off northern Venezuela. Millimeter to micrometer-scale geochemical data in the laminated sediments of the Cariaco Basin have been interpreted to reflect variations in the hydrological cycle and the mean annual position of the Intertropical Convergence Zone (ITCZ) over tropical South America during the past millennia. These data with decadal to (sub)annual resolution show that the Terminal Collapse of the Classic Maya civilization occurred during an extended dry period. In detail, the Cariaco record reveals evidence for three separate droughts during the period of Maya downfall, each lasting a decade or less. These data suggest that climate change was potentially one immediate cause of the demise of Mayan civilization, with a century-scale decline in rainfall putting a general strain on resources and several multi-year events of more intense drought pushing Mayan society over the edge. An archive of comparable quality and resolution are sediments of lake Huguang Maar in coastal southeast China. The titanium content and redox-sensitive magnetic properties record the strength of winter monsoon winds at subdecadal resolution over the last 16 thousand years. The record indicates a stronger winter monsoon prior to the Bølling Allerød warming, during the Younger Dryas, and during the middle and late Holocene, when cave stalagmite oxygen isotope data indicate a weaker summer monsoon. The anti-correlation between winter and summer monsoon strength is best explained by migrations in the ITCZ that occurred simultaneously in central America and Africa. Drought associated with southward ITCZ migration may have played a role in the termination of several Chinese dynasties. A remarkable similarity of ITCZ migration in east Asia and the Americas from 700 to 900 AD raises the possibility that the coincident declines

  19. Volcanic history of El Chichón Volcano (Chiapas, Mexico) during the Holocene, and its impact on human activity

    NASA Astrophysics Data System (ADS)

    Espíndola, J. M.; Macías, J. L.; Tilling, R. I.; Sheridan, M. F.

    Before its devastating eruption in 1982, El Chichón Volcano was little known and did not appear on any listings of hazardous volcanoes. Subsequent geologic studies, based on stratigraphic and radiocarbon investigations, showed that at least three explosive eruptions had occurred previously at this volcano. In this paper, we present the result of recent studies on the stratigraphy of the volcano and new radiocarbon ages which show that at least 11 eruptions have taken place at El Chichón in the past 8000years. Explosive events, most of them producing block-and-ash flow and surge deposits, occurred around 550, 900, 1250, 1500, 1600, 1900, 2000, 2500, 3100, 3700 and 7700years BP. The juvenile products of these eruptions have a trachyandesitic composition with similar degree of evolution, as evidenced from their SiO2 abundance and depletion in MgO, CaO, TiO2, as well as trace and rare earth elements. This suggests segregation of olivine and orthopyroxene from the melt. Since human settlements in southeast Mexico and Central America can be traced as far back as approximately 2500years BP, most of these events probably affected human activity. In fact, there are reports of pottery shards and other artifacts in deposits from the eruption of 1250 BP. Pottery fragments in deposits of an eruption that took place 2500 BP are also reported in this paper. Thus, the impact of the volcano on human activities has been frequent, with most of the repose intervals lasting between 100 to 600years. The impact of the eruptions was probably of greater than local extent, because airfall tephra could reach distant sites and possibly even affect weather. The eruptive history of El Chichón also offers clues in the investigation of the Maya civilization. Several researchers have considered the volcano as an important factor in the answer to some intriguing questions such as the extensive use of volcanic ash in Late Classic Maya ceramics or, of greater importance, the causes of the collapse

  20. Pangean Reconstruction of the Yucatan Block and its Permian, Triassic, and Jurassic Geologic and Tectonic History

    NASA Astrophysics Data System (ADS)

    Steiner, M.

    2004-12-01

    Paleomagnetic studies of Paleozoic sedimentary and plutonic rocks demonstrate that the Yucatan Block lay inverted off the NW coast of South America (SA) in Pangea, and rotated in a series of clockwise motions as SA and NA separated. Mid-Permian Yucatan was a fragment of the western margin of Pangea, just south of the equator. By 230 Ma, Yucatan rotated ˜20° clockwise and moved to the equator. Clockwise rotation continued through the Jurassic: ˜54° between 230 Ma and about Oxfordian, and another ˜32° between ˜Oxfordian and Tithonian, when the approximate present orientation was achieved. Passage of the Yucatan Block into the gap created by the separation of North and South America requires left-lateral motion relative to North America, perhaps by translation along the Mojave Sonora megashear. One remanence, carried by magnetite in red bed strata from the margins of the marine Santa Rosa basin (Maya Mtns), decays exceedingly linearly to the origin of orthogonal-axes plots. Biostratigraphy indicates a Late Pennsylvanian to Middle Permian age, and the presence of dual polarities in a 110 m, four polarity, magnetostratigraphic sequence demonstrates a post-Late Paleozoic Reversed Superchron (i.e., Middle Permian) age. Plutonic rocks exhibit a second, also dual-polarity, remanence, which corresponds to a paleopole 60° clockwise of the mid-Permian pole. The spatial relationship between the Permian and pluton paleopoles is very similar to that of the North American Permian and Late Triassic poles. Moreover, exceedingly uniform K/Ar ages of 231±7 Ma characterize all Maya Mtns plutons and the southern volcanic complex, indicating a 230 Ma resetting of the K/Ar radiometric systems of plutons dated by U/Pb as Late Silurian (Steiner and Walker, 1996). Metamorphic aureoles developed in the Pennsylvanian-Permian Santa Rosa strata bordering the Silurian plutonic complexes suggest the occurrence of a post-intrusion hydrothermal event. The 230 Ma reset K/Ar systems

  1. Tropical Climate Dynamics and Civilizations

    NASA Astrophysics Data System (ADS)

    Haug, G. H.; Yancheva, G.; Peterson, L. C.

    2005-12-01

    Dr. James P. Kennett has been a leader in the area of rapid climate change. Jim and his son Douglas J. Kennett, a scientific archeologist, were among the first to make a serious effort to combine high-quality climate data with archeological information to study the impact of climate on societies. They argued about the 'strong relationship between climatically induced changes in environmental conditions and social, political, and economic responses' in coastal California during the past 2 millennia. One tropical climate archive with an appropriate memory for the most relevant sub-centennial to sub-decadal scale climate swings is the anoxic Cariaco Basin off northern Venezuela. Millimeter to micrometer-scale geochemical data in the laminated sediments of the Cariaco Basin have been interpreted to reflect variations in the hydrological cycle and the mean annual position of the Intertropical Convergence Zone (ITCZ) over tropical South America during the past millennia. These data with decadal to (sub)annual resolution show that the Terminal Collapse of the Classic Maya civilization occurred during an extended dry period. In detail, the Cariaco record reveals evidence for three separate droughts during the period of Maya downfall, each lasting a decade or less. These data suggest that climate change was potentially one immediate cause of the demise of Mayan civilization, with a century-scale decline in rainfall putting a general strain on resources and several multi-year events of more intense drought pushing Mayan society over the edge. Here, we present a new data set of comparable quality and resolution from Southern China. In the sediments of lake Huguang Maar in coastal southeast China, the titanium content and redox-sensitive magnetic properties record the strength of winter monsoon winds at subdecadal resolution over the last 16 thousand years. The record indicates a stronger winter monsoon prior to the Boelling-Alleroed warming, during the Younger Dryas, and

  2. Advances in heavy oil hydroprocessing

    SciTech Connect

    Mendizabal, O.B. )

    1988-06-01

    The world increase in heavy crudes has forced refiners to develop different processes that upgrade the yields and product properties recovered from these crudes. However, some of the optimized and new processes are not able to handle whole heavy crude oils, due to the high viscosity and corrosion of their long and short residues. The different processes for heavy crudes can be classified in two areas: physical (vg. Liquid Extraction) and chemical processes. The catalytic hydrotreating process, which belongs to this last classification, has demonstrated to be an economical upgrading process for heavy crude oil. This paper describes the development by the Mexican Petroleum Institute of the process to hydrotreat maya heavy crude. The effect of the operating conditions, the catalyst ---- development and the technical - economical analysis are presented. The product properties and yields are compared with the results obtained with light crude oil like isthmus.

  3. Hallucinations in the classical Indian system of Ayurveda: A brief overview.

    PubMed

    Balsavar, Anuradha; Deshpande, Smita N

    2014-10-01

    The ancient Indian system of medicine "Ayurveda" is a compendium of various health related theories and practices and explained the abnormal state of mind, i.e., psychopathology in various contexts. Hallucinations were deemed abnormal. In Ayurvedic classics, hallucinations were called false perceptions (mithyajnana), illusions (maya), infatuations (moha), or confusion (bhrama). Hallucinations were not independent but a symptom of mental disorder (manasa roga). Hallucinations of different sensory organs were observed and explained. These symptoms could be observed in patients suffering from any illness of tridosha origin, organic disease or psychiatric disorder. False perceptions observed in patients were used as tools to understand the prognosis of the condition. This article may help provide preliminary insight and encourage interdisciplinary study toward understanding one of the main symptoms of schizophrenia. PMID:25568471

  4. Improving general relativistic astrophysics workflows with ADIOS

    NASA Astrophysics Data System (ADS)

    Bode, Tanja; Slawinska, Magdalena; Logan, Jeremy; Clark, Michael; Kinsey, Matthew; Wolf, Matthew; Klasky, Scott; Laguna, Pablo

    2013-04-01

    There are many challenges in analyzing and visualizing data from current cutting-edge general relativistic astrophysics simulations. Many of the associated tasks are time-consuming, with large performance degradation due to the magnitude and complexity of the data. The Adaptable IO System (ADIOS) is a componentization of the IO layer that has demonstrated remarkable IO performance improvements on applications running on leadership class machines while also offering new in-memory ``staging'' operations for transforming data in situ. We have incorporated ADIOS staging technologies into our Maya numerical relativity code based on Cactus infrastructure and Carpet mesh refinement. We present results that demonstrate how ADIOS yields significant gains on IO performance while utilizing leveraged investments in ADIOS plugins for visualization tools such as VisIt.

  5. Toxic exposure to ethylene dibromide and mercuric chloride: effects on laboratory-reared octopuses.

    PubMed

    Adams, P M; Hanlon, R T; Forsythe, J W

    1988-01-01

    The effects of acute and chronic exposure to either ethylene dibromide (EDB) or mercuric chloride (MC) were studied in laboratory-reared Octopus joubini, O. maya and O. bimaculoides. The advantages of using octopuses were that the responses were immediate, highly visible and sensitive. All species demonstrated signs of toxicity to acute and chronic exposure to EDB and to MC. A dosage-sensitive relationship for the loss and subsequent recovery of locomotor response and of chromatophore expansion was found for each species after acute exposure. For each species the LC50 for chronic exposure occurred within 12 hr at 100 mg/l for EDB and within 3 hr at 1,000 mg/l for MC. This study demonstrated the potential usefulness of laboratory-reared octopuses in evaluating the toxicity of marine environmental pollutants. PMID:3072470

  6. Indigo adsorption on a silicate surface: a theoretical density functional study.

    PubMed

    Iuga, Cristina; Sainz-Díaz, C Ignacio; Ortíz, Elba; Vivier-Bunge, Annik

    2014-07-01

    The applicability of naturally available low-cost and eco-friendly adsorbent materials for the removal of hazardous dyes from aqueous waste is of increasing environmental interest. Among the adsorption treatments available, clays seem to be economically attractive due to their abundance and adsorption capabilities. Indeed, many ancient coloring materials utilized clays mixed with natural dyes (e.g., indigo in Maya Blue). In this work, we performed a quantum-mechanical theoretical study of the adsorption of the indigo molecule onto the (001) surface of a phyllosilicate. Different methods and approaches were applied and compared. We found that the presence of a tetrahedral charge and a sodium counterion significantly increased the adsorption energy of the indigo molecule. The vibrational spectrum of the dye-surface system was also studied, and some interesting shifts in the frequencies of the main vibrational modes of indigo due to its interaction with the surface of the clay mineral were identified. PMID:24958302

  7. Autonomous molecular cascades for evaluation of cell surfaces.

    PubMed

    Rudchenko, Maria; Taylor, Steven; Pallavi, Payal; Dechkovskaia, Alesia; Khan, Safana; Butler, Vincent P; Rudchenko, Sergei; Stojanovic, Milan N

    2013-08-01

    Molecular automata are mixtures of molecules that undergo precisely defined structural changes in response to sequential interactions with inputs. Previously studied nucleic acid-based automata include game-playing molecular devices (MAYA automata) and finite-state automata for the analysis of nucleic acids, with the latter inspiring circuits for the analysis of RNA species inside cells. Here, we describe automata based on strand-displacement cascades directed by antibodies that can analyse cells by using their surface markers as inputs. The final output of a molecular automaton that successfully completes its analysis is the presence of a unique molecular tag on the cell surface of a specific subpopulation of lymphocytes within human blood cells. PMID:23892986

  8. Prehispanic agriculture and climate on the Pacific slope of Guatemala

    NASA Astrophysics Data System (ADS)

    Connolly, Elizabeth Wilcut

    The relationship between agriculture and social complexity is a complicated one through both time and space; this is no less true in prehispanic Mesoamerica. Human occupation of the Pacific Coast of Gualtemala prior to Spanish contact was affected by humans' relationship with their physical environment, including the vegetation and climate. I examined multiple lines of evidence, including phytolith, pollen, and settlement data, seeking to detect changes within the paleoenviromental, paleoclimatic, and socio-cultural records from the Middle and Late Formative (1000 BC to AD 150) through the Classic (AD 150 to 600) and Post-Classic (ca. AD 1000) periods. This work reveals that social complexity on the Pacific Slope of Gualtemala developed alongside agricultural intensification. More significantly, however, it also reveals that while there was a population "collapse" on the Pacific Slope at the end of the Late Formative period, there was not the correlating drought or decline in agriculture seen in other areas of the Maya homeland.

  9. The Interface of Art and Science in the Museum: Disclosing a 4th Dimension of Art Preservation and Connoisseurship

    ScienceCinema

    Casadio, Franceska [Art Institute of Chicago, Chicago, Illinois, United States

    2010-01-08

    Drawing from her most recent experience at the Art Institute and past experiences in Italy, Dr. Casadio will discuss examples of applications of scientific analysis to the field of Cultural Heritage, including: 1) The use of instrumental analysis to address fundamental questions regarding artists' techniques, and as an aid to unraveling paint technology, as with the fascinating pre-Columbia pigment Maya Blue; 2) The investigation into deterioration of artifacts, the design of innovative conservation materials and the testing of their durability, expemplified with the case study of the conservation of the facade of the gothic Cathedral of Milan; 3) Development of fine-tuned conservation strategies for the cleaning of Michelangelo's David; 4) The study of the effect of environmental parameters on objects in exhibitions and storage to help design compatible display cases; 5) The role of scientific analysis in matters of authentication and dating. Future trends that increasingly see science as a tool for virtual restoration will be discussed.

  10. The mushroom and the water lily: literary and pictorial evidence for Nymphaea as a ritual psychotogen in Mesoamerica.

    PubMed

    Emboden, W A

    1982-03-01

    In reconstructing early uses of psychotogens in Mesoamerica, mushrooms have occupied the attention of botanists and anthropologists almost the exclusion of other plant motifs. Not all the images and literary fragments extant lend themselves to mycological interpretation. Some authors have interpreted the peltate leaves and flower buds of the psychotogen Nymphaea ampla as being green mushrooms and/or stalked sea shells. The context of presentation, information on the water lily in Maya antiquity, and recent information on the chemistry of this white water lily suggest that we must reassess the role of Nymphaea ampla. In a reevaluation of these ancient literary and iconographic sources, it would seem that both mushrooms and water lilies emerge as important ritual psychotogens. While the contextual use of mushrooms is well known, the water lily has been largely ignored. This presentation provides some perspective on both of these important New World narcotics. PMID:7035751

  11. Is a `Brane' Electron Modeled by a Closed-loop String of Neutrinos, is time formally a periodic function, and can tornadoes be ``turned off''?

    NASA Astrophysics Data System (ADS)

    McLeod, Roger; McLeod, David

    2006-03-01

    Model a `planar' electron by a closed string of vibrating neutrinos; displacement values are proportional to the speed of light times the square root of the mass. `Spin' supplies required inward spherical fields in three spatial dimensions. Interlocked quark loops model protons or neutrons; ideas like strong and weak forces, or an uncertainty principle, arise. Subtle, longer string-like `vibrating,' quasi-periodic, lighted phenomena we detect are at locations used by some of our Native American forebears, or by the Hopi or Maya -locations indicated by problematic constructions, by `sacred' place-names, or by individuals with `titles' identified as names. Lighted `tubes,' associated with EMF, required by our model for tornado generation, imply breaking the EMF lines will `kill' any tornado. `Kokopelli's hair,' is the place to construct a designated current loop.

  12. uPy: a ubiquitous computer graphics Python API with Biological Modeling Applications

    PubMed Central

    Autin, L.; Johnson, G.; Hake, J.; Olson, A.; Sanner, M.

    2015-01-01

    In this paper we describe uPy, an extension module for the Python programming language that provides a uniform abstraction of the APIs of several 3D computer graphics programs called hosts, including: Blender, Maya, Cinema4D, and DejaVu. A plugin written with uPy is a unique piece of code that will run in all uPy-supported hosts. We demonstrate the creation of complex plug-ins for molecular/cellular modeling and visualization and discuss how uPy can more generally simplify programming for many types of projects (not solely science applications) intended for multi-host distribution. uPy is available at http://upy.scripps.edu PMID:24806987

  13. uPy: a ubiquitous CG Python API with biological-modeling applications.

    PubMed

    Autin, Ludovic; Johnson, Graham; Hake, Johan; Olson, Arthur; Sanner, Michel

    2012-01-01

    The uPy Python extension module provides a uniform abstraction of the APIs of several 3D computer graphics programs (called hosts), including Blender, Maya, Cinema 4D, and DejaVu. A plug-in written with uPy can run in all uPy-supported hosts. Using uPy, researchers have created complex plug-ins for molecular and cellular modeling and visualization. uPy can simplify programming for many types of projects (not solely science applications) intended for multihost distribution. It's available at http://upy.scripps.edu. The first featured Web extra is a video that shows interactive analysis of a calcium dynamics simulation. YouTube URL: http://youtu.be/wvs-nWE6ypo. The second featured Web extra is a video that shows rotation of the HIV virus. YouTube URL: http://youtu.be/vEOybMaRoKc. PMID:24806987

  14. Unraveling the geodynamic evolution and tectonic history of the Guatemala Suture Zone: a world-class natural laboratory

    NASA Astrophysics Data System (ADS)

    Flores, K. E.; Brocard, G. Y.; Harlow, G. E.

    2013-12-01

    The Guatemala Suture Zone (GSZ) is the fault-bound region in central Guatemala that contains the present North American-Caribbean plate boundary. It is bounded by the Maya Block to the north and by the Chortís Block to the south. This major composite geotectonic unit contains a variety of ophiolites, serpentinite mélanges, and metavolcano-sedimentary sequences along with high-grade schist, gneisses, low-grade metasediments and metagranites thrusted north and south of the active Motagua fault system (MFS). This modern plate boundary has accommodated at least ~1100 km of left-lateral strike-slip motion over the Cenozoic and brings into contact the geological provinces described above. Classically, the GSZ has been interpreted as the result of a single progressive collision of a Chortís Block-related island arc with the passive margin of the Maya Block. This model was based on geochemical signatures of basaltic rocks in oceanic crust sequences both north and south of the MFS. However, results from our research challenge this single collision hypothesis. Oceanic and continental high-pressure-low-temperature (HP-LT) rocks astride the MFS have recorded multiple tectonic events revealed by their multiple metamorphic ages (Sm-Nd, U-Pb and Ar-Ar) and distinct PT paths. These tectonic events differ in age north and south of the MFS. Moreover, the continental and oceanic sequences across the MFS are geochemically and stratigraphically distinct, suggesting different tectonic origins. The southern margin of the Maya Block and the northern section of the GSZ can be clearly interpreted as a Cretaceous-Paleocene flexural passive margin tectonically overridden by ultramafic rocks and a Cretaceous island arc sequence. In contrast, the southern section of the GSZ is composed of a Carboniferous-Jurassic active margin tectonically imbricated with ultramafic rocks and a circum-Pacific Jurassic MORB and IAT metavolcano-sedimentary sequence. Thus, based on these results, we identify at

  15. The use of diagnostic ratios, biomarkers and 3-way Kohonen neural networks to monitor the temporal evolution of oil spills.

    PubMed

    Fernández-Varela, R; Gómez-Carracedo, M P; Ballabio, D; Andrade, J M

    2015-07-15

    Oil spill identification relies usually on a wealth of chromatographic data which requires advanced data treatment (chemometrics). A simple approach based on Kohonen neural networks to handle three-dimensional arrays is presented. A suite of 28 diagnostic ratios was considered to monitor six oils along four months. It was found that some traditional diagnostic ratios were not stable enough. In particular, alkylated PAHs (e.g. 1-methyldibenzothiophene, 4-methylpyrene, 27bbSTER and the TA21 and TA26 triaromatic steroids) seemed less resistant to medium-weathering than biomarkers. One (or two) ratios were found to differentiate each product: 30O, 28ab (and 25nor30ab), C3-dbt/C3-phe, 27Ts, TA26 and 29Ts characterized Ashtart, Brent, Maya, Sahara, IFO and Prestige oils, respectively. PMID:25935805

  16. Meeting Review: Bioinformatics and Medicine – From Molecules to Humans, Virtual and Real

    PubMed Central

    2002-01-01

    The Industrialization Workshop Series aims to promote and discuss integration, automation, simulation, quality, availability and standards in the high-throughput life sciences. The main issues addressed being the transformation of bioinformatics and bioinformaticsbased drug design into a robust discipline in industry, the government, research institutes and academia. The latest workshop emphasized the influence of the post-genomic era on medicine and healthcare with reference to advanced biological systems modeling and simulation, protein structure research, protein-protein interactions, metabolism and physiology. Speakers included Michael Ashburner, Kenneth Buetow, Francois Cambien, Cyrus Chothia, Jean Garnier, Francois Iris, Matthias Mann, Maya Natarajan, Peter Murray-Rust, Richard Mushlin, Barry Robson, David Rubin, Kosta Steliou, John Todd, Janet Thornton, Pim van der Eijk, Michael Vieth and Richard Ward. PMID:18628854

  17. The Interface of Art and Science in the Museum: Disclosing a 4th Dimension of Art Preservation and Connoisseurship

    SciTech Connect

    Casadio, Franceska

    2004-11-03

    Drawing from her most recent experience at the Art Institute and past experiences in Italy, Dr. Casadio will discuss examples of applications of scientific analysis to the field of Cultural Heritage, including: 1) The use of instrumental analysis to address fundamental questions regarding artists' techniques, and as an aid to unraveling paint technology, as with the fascinating pre-Columbia pigment Maya Blue; 2) The investigation into deterioration of artifacts, the design of innovative conservation materials and the testing of their durability, expemplified with the case study of the conservation of the facade of the gothic Cathedral of Milan; 3) Development of fine-tuned conservation strategies for the cleaning of Michelangelo's David; 4) The study of the effect of environmental parameters on objects in exhibitions and storage to help design compatible display cases; 5) The role of scientific analysis in matters of authentication and dating. Future trends that increasingly see science as a tool for virtual restoration will be discussed.

  18. Early Astronomy

    NASA Astrophysics Data System (ADS)

    Thurston, Hugh

    The earliest investigations that can be called scientific are concerned with the sky: they are the beginnings of astronomy. Many early civilizations produced astronomical texts, and several cultures that left no written records left monuments and artifacts-ranging from rock paintings to Stonehenge-that show a clear interest in astronomy. Civilizations in China, Mesopotamia, India and Greece had highly developed astronomies, and the astronomy of the Mayas was by no means negligible. Greek astronomy, as developed by the medieval Arab philosophers, evolved into the astronomy of Copernicus. This displaced the earth from the central stationary position that almost all earlier astronomies had assumed. Soon thereafter, in the first decades of the seventeenth century, Kepler found the true shape of the planetary orbits and Galileo introduced the telescope for astronomical observations.

  19. Observation of isoscalar multipole strengths in exotic doubly-magic 56Ni in inelastic α scattering in inverse kinematics

    NASA Astrophysics Data System (ADS)

    Bagchi, S.; Gibelin, J.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Achouri, N. L.; Akimune, H.; Bastin, B.; Boretzky, K.; Bouzomita, H.; Caamaño, M.; Càceres, L.; Damoy, S.; Delaunay, F.; Fernández-Domínguez, B.; Fujiwara, M.; Garg, U.; Grinyer, G. F.; Kamalou, O.; Khan, E.; Krasznahorkay, A.; Lhoutellier, G.; Libin, J. F.; Lukyanov, S.; Mazurek, K.; Najafi, M. A.; Pancin, J.; Penionzhkevich, Y.; Perrot, L.; Raabe, R.; Rigollet, C.; Roger, T.; Sambi, S.; Savajols, H.; Senoville, M.; Stodel, C.; Suen, L.; Thomas, J. C.; Vandebrouck, M.; Van de Walle, J.

    2015-12-01

    The Isoscalar Giant Monopole Resonance (ISGMR) and the Isoscalar Giant Dipole Resonance (ISGDR) compression modes have been studied in the doubly-magic unstable nucleus 56Ni. They were measured by inelastic α-particle scattering in inverse kinematics at 50 MeV/u with the MAYA active target at the GANIL facility. The centroid of the ISGMR has been obtained at Ex = 19.1 ± 0.5 MeV. Evidence for the low-lying part of the ISGDR has been found at Ex = 17.4 ± 0.7 MeV. The strength distribution for the dipole mode shows similarity with the prediction from the Hartree-Fock (HF) based random-phase approximation (RPA) [1]. These measurements confirm inelastic α-particle scattering as a suitable probe for exciting the ISGMR and the ISGDR modes in radioactive isotopes in inverse kinematics.

  20. Isoscalar response of 68Ni to α -particle and deuteron probes

    NASA Astrophysics Data System (ADS)

    Vandebrouck, M.; Gibelin, J.; Khan, E.; Achouri, N. L.; Baba, H.; Beaumel, D.; Blumenfeld, Y.; Caamaño, M.; Càceres, L.; Colò, G.; Delaunay, F.; Fernandez-Dominguez, B.; Garg, U.; Grinyer, G. F.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Keeley, N.; Mittig, W.; Pancin, J.; Raabe, R.; Roger, T.; Roussel-Chomaz, P.; Savajols, H.; Sorlin, O.; Stodel, C.; Suzuki, D.; Thomas, J. C.

    2015-08-01

    Isoscalar giant resonances have been measured in the unstable 68Ni nucleus using inelastic alpha and deuteron scattering at 50 A MeV in inverse kinematics with the active target MAYA at GANIL. Using alpha scattering, the extracted isoscalar giant monopole resonance (ISGMR) centroid was determined to be 21.1 ±1.9 MeV and the isoscalar giant quadrupole resonance (ISGQR) to be 15.9 ±1.3 MeV. Indications for soft isoscalar monopole and dipole modes are provided. Results obtained with both (α ,α' ) and (d ,d' ) probes are compatible. The evolution of isoscalar giant resonances along the Ni isotopic chain from 56Ni to 68Ni is discussed.

  1. Collaboration on Scene Graph Based 3D Data

    NASA Astrophysics Data System (ADS)

    Ammon, Lorenz; Bieri, Hanspeter

    Professional 3D digital content creation tools, like Alias Maya or discreet 3ds max, offer only limited support for a team of artists to work on a 3D model collaboratively. We present a scene graph repository system that enables fine-grained collaboration on scenes built using standard 3D DCC tools by applying the concept of collaborative versions to a general attributed scene graph. Artists can work on the same scene in parallel without locking out each other. The artists' changes to a scene are regularly merged to ensure that all artists can see each others progress and collaborate on current data. We introduce the concept of indirect changes and indirect conflicts to systematically inspect the effects that collaborative changes have on a scene. Inspecting indirect conflicts helps maintaining scene consistency by systematically looking for inconsistencies at the right places.

  2. NASA Astrophysics Data System (ADS)

    Morisset, C.; Delgado-Inglada, G.; Torres-Peimbert, S.

    2014-04-01

    Most - if not all - planetary nebulae exhibit a complex structure, far from the spherical shape. The reasons for this dramatic change in symmetry, that occurs in early stage of the development of the nebula, remain controversial. The same physics operates in a variety of stars, from young (winds from young stars and/or high mass stars) to old (novae, symbiotic stars). The aim of the APN series of conferences has been to offer the opportunity to anyone involved in the study of asymmetric planetary nebulae (and related objects) to discuss the latest results obtained in this field. The APN VI conference was organized by the Instituto de Astronomia (UNAM) and took place on Riviera Maya, Quintana Roo, México, 4-8 Nov. 2013

  3. Raman and Infrared Absorption Study of Indigoid-based Pigments

    NASA Astrophysics Data System (ADS)

    Manciu, Felicia; Durrer, William; Reza, Layra; Ramirez, Alejandra; Chianelli, Russell

    2009-04-01

    A fascinating aspect of Maya pigments is that despite the environmentally harsh humidity and high temperatures they resist fading and they have unprecedented stability. In this investigation, we address the question of how organic dye binds to inorganic palygorskite to form pigments. Our analysis by Raman and infrared absorption spectroscopies proves that different processes are taking place for the indigo-palygorskite system as compared with the thioindigo-palygorskite complex. While partial elimination of the selection rules for the centrosymmetric indigo and disappearance of the indigo N-H bonding, with conversion to dehydroindigo, is observed for the first compound, the latter shows no evident structure modification. The interaction between indigo and palygorskite is likely through oxygen and nitrogen. Only oxygen plays this role for the thioindigo-palygorskite complex.

  4. Blood pressure, ethnic group, and salt intake in Belize.

    PubMed Central

    Simmons, D

    1983-01-01

    A total of 1316 individuals were studied in seven villages in Belize, Central America. This represented 92% of the area population aged over 18. Generally, they were members of three ethnic groups--Maya, Spanish, and Creole. The systolic and diastolic IV and V blood pressures were recorded using standardised procedure. Significant differences in blood pressure, weight, and obesity were found between ethnic groups in both sexes, Creoles having higher means than the other groups. Significant relationships with blood pressure were found with obesity, age, and number of children. An early morning urine specimen was obtained from a random 50% of the men, and only in Creoles was there an association between raised blood pressure and sodium/potassium urinary excretion ratio. PMID:6875443

  5. Independent focuses Philippines exploration on Visayan basin

    SciTech Connect

    Rillera, F.G.

    1995-08-21

    Cophil Exploration Corp., a Filipino public company, spearheaded 1995 Philippine oil and gas exploration activity with the start of its gas delineation drilling operations in Libertad, northern Cebu. Cophil and its Australian partners, Coplex Resources NL and PacRim Energy NL, have set out to complete a seven well onshore drilling program within this block this year. The companies are testing two modest shallow gas plays, Libertad and Dalingding, and a small oil play, Maya, all in northern Cebu about 500 km southeast of Manila. Following a short discussion on the geology and exploration history of the Visayan basin, this article briefly summarizes Cophil`s ongoing Cebu onshore drilling program. Afterwards, discussion focuses on identified exploration opportunities in the basin`s offshore sector.

  6. [Teeth decoration back after a long and forgotten history].

    PubMed

    Dijs, F

    2004-09-01

    After the last ice-age modern man started to remove, file, dye and inlay teeth. The teeth had such a central role in the imagination that the habit of more or less ritual decoration by incurable manipulation of the teeth spread all over the world. The most skillful and artistic work was done by craftsmen of the Maya. Between 1500 and 1900 modern researchers classified the habits as primitive and barbarian but during the twentieth century some of them took the question seriously. In the last decennium tooth jewelery is sold more and more often. In two articles the history of teeth decoration is outlined. In this article the significance of the manipulations is emphasized. The second will focus on the changing appreciation of the phenomenon. PMID:15495505

  7. [Tooth decoration back after a long and forgotten history 2].

    PubMed

    Dijs, F

    2004-11-01

    After the last ice-age modern man started to remove, file, dye and inlay teeth. The teeth had such a central role in the imagination that the habit of more or less ritual decoration by incurable manipulation of the teeth spread all over the world. The most skillful and artistic work was done by craftsmen of the Maya. Between 1500 and 1900 CE modern researchers classified the habits as primitive and barbarian but during the twentieth century some of them took the question serious. In the last decennium tooth jewellery is sold more and more often. In two articles the history of teeth decoration is outlined. In the first article the significance of the manipulations was emphasized. This second article will focus on the changing appreciation of the phenomenon. PMID:15626135

  8. Divergent evolution of feeding substrate preferences in a phylogenetically young species flock of pupfish ( Cyprinodon spp.)

    NASA Astrophysics Data System (ADS)

    Horstkotte, Joachim; Plath, Martin

    2008-12-01

    A fundamental question in sympatric speciation is how trophic divergence is achieved. We used an extremely young (<8,000 years) species flock of pupfish ( Cyprinodon spp.) from Laguna Chichancanab in south-eastern Mexico to examine divergent evolution of preferences for different feeding substrates. In a test aquarium, we presented four feeding substrates (sand, gravel, a plastic plant, and blank bottom), but no actual food was offered. The four feeding substrates were chosen to mirror the most common substrate types in Laguna Chichancanab. Previous studies demonstrated that benthic food items prevail in the diet of most Cyprinodon species. C. beltrani preferred sand, whereas C. labiosus preferred gravel. F1 hybrids of both species showed intermediate preferences. C. maya searched for food equally at all substrates. As the test fish were reared under identical laboratory conditions (i.e., in the absence of feeding substrates), the species-specific preferences appear to be genetically fixed, suggesting rapid divergent evolution of feeding behaviors.

  9. The Interface of Art and Science in the Museum: Disclosing a 4th Dimension of Art Preservation and Connoisseurship

    SciTech Connect

    Casadio, Franceska

    2009-11-03

    Drawing from her most recent experience at the Art Institute and past experiences in Italy, Dr. Casadio will discuss examples of applications of scientific analysis to the field of Cultural Heritage, including: 1) The use of instrumental analysis to address fundamental questions regarding artists' techniques, and as an aid to unraveling paint technology, as with the fascinating pre-Columbia pigment Maya Blue; 2) The investigation into deterioration of artifacts, the design of innovative conservation materials and the testing of their durability, expemplified with the case study of the conservation of the facade of the gothic Cathedral of Milan; 3) Development of fine-tuned conservation strategies for the cleaning of Michelangelo's David; 4) The study of the effect of environmental parameters on objects in exhibitions and storage to help design compatible display cases; 5) The role of scientific analysis in matters of authentication and dating. Future trends that increasingly see science as a tool for virtual restoration will be discussed.

  10. Hallucinations in the classical Indian system of Ayurveda: A brief overview

    PubMed Central

    Balsavar, Anuradha; Deshpande, Smita N.

    2014-01-01

    The ancient Indian system of medicine “Ayurveda” is a compendium of various health related theories and practices and explained the abnormal state of mind, i.e., psychopathology in various contexts. Hallucinations were deemed abnormal. In Ayurvedic classics, hallucinations were called false perceptions (mithyajnana), illusions (maya), infatuations (moha), or confusion (bhrama). Hallucinations were not independent but a symptom of mental disorder (manasa roga). Hallucinations of different sensory organs were observed and explained. These symptoms could be observed in patients suffering from any illness of tridosha origin, organic disease or psychiatric disorder. False perceptions observed in patients were used as tools to understand the prognosis of the condition. This article may help provide preliminary insight and encourage interdisciplinary study toward understanding one of the main symptoms of schizophrenia. PMID:25568471

  11. Recruiting and retaining pregnant women from a community health center at the US–Mexico border for the Mothers and Youth Access clinical trial

    PubMed Central

    Ramos-Gomez, Francisco; Chung, Lisa H; Gonzalez Beristain, Rocio; Santo, William; Jue, Bonnie; Weintraub, Jane; Gansky, Stuart

    2014-01-01

    Background Recruitment and retention in clinical trials of minorities is low, particularly in rural underserved populations. This has slowed progress in addressing racial/ethnic disparities in oral health. Purpose To describe factors associated with successful recruitment, and identify predictors of continued retention of pregnant women attending a community health center into a randomized controlled clinical trial to prevent early childhood caries. Methods The Mothers and Youth Access (MAYA) Trial recruited women in the second trimester of pregnancy. At baseline, consenting women completed an oral health questionnaire and received a dental exam and oral health counseling. Four months postpartum, women returned with their babies for randomization with follow up at 9-, 12-, 18-, 24-, 30-, and 36-month postpartum visits. To assess predictors of retention, data about respondents’ demographics, and oral health-related knowledge, attitudes, and behaviors were obtained by questionnaire and analyzed by logistic and discrete time-to-event regression analyses. Results Of 556 predominantly Mexican-American women recruited at baseline, 195 (35%) were excluded after baseline for not meeting inclusion criteria; 361 (65%) continued to randomization. Factors such as race/ethnicity, annual household income, household composition, oral health-related knowledge and behaviors significantly related to retention until randomization. In multivariable models, women reporting a higher annual household income were less likely to be lost to attrition before randomization (odds ratio = 0.73, 95% confidence interval (CI) 0.60–0.89); while Mexican/Mexican-American women were less likely to be lost beyond randomization (hazard ratio = 0.53, 95% CI 0.26–1.08). Limitations Factors not measured at baseline may have been important in predicting attrition. The MAYA Trial is expected to finish by November 2008; therefore, complete results for total retention may differ from those reported here

  12. Influence of maternal stature, pregnancy age, and infant birth weight on growth during childhood in Yucatan, Mexico: a test of the intergenerational effects hypothesis.

    PubMed

    Varela-Silva, Maria Inês; Azcorra, Hugo; Dickinson, Federico; Bogin, Barry; Frisancho, A R

    2009-01-01

    In developing nations, obesity has increased dramatically in the last decade, but a high prevalence of stunting still coexists. The intergenerational influences hypothesis (IIH) is one explanation for this. We test the IIH regarding variation in maternal stature, mother's age at pregnancy, and infant birth weight in relation to risk for overweight and stunting in 206 Maya children (4-6 years old) from Mérida, Yucatan, Mexico. The Maya children are compared with growth references (Frisancho 2008: Anthropometric Standards: An Interactive Nutritional Reference of Body Size and Body Composition for Children and Adults. Ann Arbor, MI: The University of Michigan Press. 335 pp) for height, weight, and body mass index (BMI). Almost 70% of the mothers are shorter than 150 cm. Mothers' height and child's birth weight predict overweight. Children with a mother shorter than 150 cm are less than half as likely (OR = 0.44) to be overweight compared to children whose mothers are equal to or taller than 150 cm. Children with birth weights below 3,000 g are only a third as likely to be overweight (OR = 0.28) than their peers within the range of normal birth weight (3,000-3,500 g). Sex of the child, mother's height, and birth weight predict stunting. Girls are only 40% as likely as boys to be stunted. Children with a mother below 150 cm are 3.6 times more likely of being stunted. Children with birth weights below 3000 g are over 3 times more likely to be stunted relative to children with birth weights within the normal range. Mother's age at pregnancy is not a predictor of overweight or stunting. Our findings conform the IIH and with similar studies of populations undergoing nutritional/epidemiological transitions from traditional to globalized lifestyles. PMID:19214997

  13. Crassulacean acid metabolism under severe light limitation: a matter of plasticity in the shadows?

    PubMed

    Ceusters, Johan; Borland, Anne M; Godts, Christof; Londers, Elsje; Croonenborghs, Sarah; Van Goethem, Davina; De Proft, Maurice P

    2011-01-01

    Despite the increased energetic costs of CAM compared with C(3) photosynthesis, it is hypothesized that the inherent photosynthetic plasticity of CAM allows successful acclimation to light-limiting conditions. The present work sought to determine if CAM presented any constraints to short and longer term acclimation to light limitation and to establish if and how metabolic and photosynthetic plasticity in the deployment of the four phases of CAM might facilitate acclimation to conditions of deep shade. Measurements of leaf gas exchange, organic acids, starch and soluble sugar (glucose, fructose, and sucrose) contents were made in the leaves of the constitutive CAM bromeliad Aechmea 'Maya' over a three month period under severe light limitation. A. 'Maya' was not particularly tolerant of severe light limitation in the short term. A complete absence of net CO(2) uptake and fluctuations in key metabolites (i.e. malate, starch or soluble sugars) indicated a dampened metabolism whilst cell death in the most photosynthetically active leaves was attributed to an over-acidification of the cytoplasm. However, in the longer term, plasticity in the use of the different phases of gas exchange and different storage carbohydrate pools, i.e. a switch from starch to sucrose as the major carbohydrate source, ensured a positive carbon balance for this CAM species under extremely low levels of irradiance. As such, co-ordinated plasticity in the use of C(3) and C(4) carboxylases and different carbohydrate pools together with an increase in the abundance of light-harvesting complexes, appear to underpin the adaptive radiation of the energetically costly CAM pathway within light-limiting environments such as wet cloud forests and shaded understoreys of tropical forests. PMID:20861137

  14. The Yucatan, a Laurentian or Gondwanan fragment? Geophysical and palinspastic constraints

    NASA Astrophysics Data System (ADS)

    Keppie, D. Fraser; Keppie, J. Duncan

    2014-07-01

    Current reconstructions suggest that the Yucatan block has Gondwanan provenance and orient the Yucatan E-W in the Ouachita embayment where it overlaps southern Laurentia and Florida. Alternatively, if the Yucatan is oriented NE-SW, it fits neatly into the Ouachita embayment with minimal overlap. Furthermore, many of the V-shaped, magnetic anomalies in the Yucatan that are discordant in the E-W reconstruction can be traced across the Yucatan-Laurentian boundary in the NE-SW reconstruction: (a) NW-trending anomalies continue into southern Laurentia where they are associated with Cambrian mafic rocks in the southern Oklahoma and Reelfoot rifts and (b) NE-trending anomalies in the eastern Yucatan are parallel to those over Grenvillian rocks in the western Appalachians. Furthermore, Silurian plutons in the Maya Mountains of Belize that have no counterpart in Texas may be correlated with the Concord-Salisbury plutons in Carolinia, a terrane of Gondwanan provenance in the southern Appalachians. Nd isotopic data from the Chicxulub ejecta in the northern Yucatan block are similar to those in the Llano Grenvillian rocks and differ from those in Oaxaquia. These correlations suggest that much of the Yucatan is of Laurentian provenance and implies that the Laurentia-Gondwana suture crosses the Yucatan west of the Maya Mountains. In this scenario, the Ouachita embayment results from the formation of the Gulf of Mexico during the breakup of Pangea, rather than the Cambrian removal of the Argentine Cuyania terrane. Cambrian (515 Ma) paleomagnetic and faunal data are consistent with Cuyania forming either east of the Yucatan or off eastern Laurentia.

  15. The Great Warming Brian Fagan

    NASA Astrophysics Data System (ADS)

    Fagan, B. M.

    2010-12-01

    The Great Warming is a journey back to the world of a thousand years ago, to the Medieval Warm Period. Five centuries of irregular warming from 800 to 1250 had beneficial effects in Europe and the North Atlantic, but brought prolonged droughts to much of the Americas and lands affected by the South Asian monsoon. The book describes these impacts of warming on medieval European societies, as well as the Norse and the Inuit of the far north, then analyzes the impact of harsh, lengthy droughts on hunting societies in western North America and the Ancestral Pueblo farmers of Chaco Canyon, New Mexico. These peoples reacted to drought by relocating entire communities. The Maya civilization was much more vulnerable that small-scale hunter-gatherer societies and subsistence farmers in North America. Maya rulers created huge water storage facilities, but their civilization partially collapsed under the stress of repeated multiyear droughts, while the Chimu lords of coastal Peru adapted with sophisticated irrigation works. The climatic villain was prolonged, cool La Niñalike conditions in the Pacific, which caused droughts from Venezuela to East Asia, and as far west as East Africa. The Great Warming argues that the warm centuries brought savage drought to much of humanity, from China to Peru. It also argues that drought is one of the most dangerous elements in today’s humanly created global warming, often ignored by preoccupied commentators, but with the potential to cause over a billion people to starve. Finally, I use the book to discuss the issues and problems of communicating multidisciplinary science to the general public.

  16. Contribution of Grenvillian events to the formation of most complete Riphean sedimentary successions in Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Maslov, A. V.; Podkovyrov, V. N.; Gareev, E. Z.; Ronkin, Yu. L.

    2014-03-01

    The Grenvillian orogeny (˜1250 to 980 Ma) was one of the most significant Riphean events. It determined the formation of many structures observable now in North and South America, northwestern Europe, South Africa, Western Australia, Antarctica, and other regions. Nevertheless, its reflections in the most complete and relatively well investigated Upper Precambrian sedimentary sections of northern Eurasia such as the Riphean stratotype (Bashkir meganticlinorium) and hypostratotype (Uchur-Maya region) still remain unknown. This is primarily true of the petrographic and chemical compositions of terrigenous rocks. This work is dedicated to the analysis of peculiar features in variations of the whole-rock chemical composition of sandstones and fine-grained clastic rocks (shales, mudstones, fine-grained clayey siltstones) that constitute Middle-Upper Riphean boundary layers of the Bashkir meganticlinorium, Kama-Belaya aulacogen, and Uchur-Maya region. The analysis reveals no tendency for the decrease in the degree of the chemical and, consequently, mineralogical maturity in the upward direction through the Middle-Upper Riphean sections in the above-mentioned regions. The whole-rock compositions of fine-grained clastic rocks associated with sandstones correspond mostly to that of "common" Upper Precambrian clayey rocks. The formation of practically the entire Yurmatinian-Karatavian succession in the Bashkir meganticlinorium proceeded under relatively stable TDM and ɛNd(T) values. The period of 1250 to 980 Ma in the central and eastern parts of the Siberian Platform was marked by repeated rifting episodes alternating with accumulation of mature platformal sediments, although repercussions of Grenvillian collisional processes are missing from this region as well. The performed analysis provides grounds for the conclusion that contribution of the Grenvillian events to the formation of most complete Riphean successions in northern Eurasia was insignificant.

  17. Dating of Mayan Calendar using Long-periodic Astronomical Phenomena in Dresden Codex

    NASA Astrophysics Data System (ADS)

    Bohm, V.; Bohm, B.; Klokocnik, J.; Vondrak, J.; Kostelecky, J.

    2013-06-01

    The relationship between Mayan and our calendar is expressed by a coefficient known as `correlation' which is a number of days that we have to add to the Mayan Long Count date to get Julian Date used in astronomy. There is a surprisingly large uncertainty in the value of the correlation, yielding a shift between both calendars (and thus between the history of Maya and of our world) of typically several hundred years. There are more than 50 diverse values of the correlation, some of them derived from historical, other by astronomical data. We test here (among others) the well established Goodman-Martínez-Thompson correlation (GMT) based on historical data, and the Böhms' one (B&B) based on astronomical data decoded from the Dresden Codex (DC); this correlation differs by about +104 years from the GMT. In our previous works we used several astronomical phenomena as recorded in the DC for a check. We clearly demonstrated that (i) the GMT was not capable to predict these phenomena that really happened in nature and (ii) that the GMT predicts them on the days when they did not occur. The phenomena used till now in the test are, however, short-periodic and the test then may suffer from ambiguity. Therefore, we add long-periodic astronomical phenomena, decoded successfully from the DC, to the testing. These are (i) a synchrony of Venusian heliacal risings with the solar eclipses, (ii) a synchrony of Venus and Mars conjunctions with eclipses, (iii) conjunctions of Jupiter and Saturn repeated in a rare way, and (iv) a synchrony of synodic and sideric periods of Mercury with the tropical year. Based on our analysis, we find that the B&B correlation yields the best agreement with the astronomical phenomena observed by the Maya. Therefore, we recommend to reject the GMT and support the B&B correlation.

  18. Prevalence of rheumatic regional pain syndromes in Latin-American indigenous groups: a census study based on COPCORD methodology and syndrome-specific diagnostic criteria.

    PubMed

    Alvarez-Nemegyei, José; Peláez-Ballestas, Ingris; Goñi, Mario; Julián-Santiago, Flor; García-García, Conrado; Quintana, Rosana; Silvestre, Adriana M R; García-Olivera, Imelda; Mathern, Nora A; Loyola-Sanchez, Adalberto; Conti, Silvana; Sanabria, Alvaro J; Pons-Estel, Bernardo A

    2016-07-01

    This study assessed the overall and specific prevalence of the main rheumatic regional pain syndromes (RRPS) in four Latin-American indigenous groups. A Community Oriented Program for Control of Rheumatic Diseases (COPCORD) methodology-based census study was performed in 4240 adults (participation rate: 78.88 %) in four indigenous groups: Chontal (Oaxaca, Mexico, n = 124), Mixteco (Oaxaca, Mexico; n = 937), Maya-Yucateco (Yucatán, Mexico; n = 1523), and Qom (Rosario, Argentina; n = 1656). Subjects with musculoskeletal pain were identified using a cross-cultural, validated COPCORD questionnaire administered by bilingual personnel, and reviewed by general practitioners or rheumatologists using standardized case definitions for the 12 most frequent RRPS. The overall prevalence of RRPS was confirmed in 239 cases (5.64 %, 95 % CI: 4.98-6.37). The prevalence in each group was Chontal n = 19 (15.32 %, 95 % CI: 10.03-22.69); Maya-Yucateco n = 165 (10.83 %, 95 % CI: 9.37-12.49); Qom n = 48 (2.90 %, 95 % CI: 2.19-3.82); and Mixteco n = 7 (0.75 %, 95 % CI: 0.36-1.53). In the whole sample, the syndrome-specific prevalence was rotator cuff tendinopathy: 1.98 % (95 % CI: 1.60-2.45); lateral epicondylalgia: 0.83 % (95 % CI: 0.59-1.15); medial epicondylalgia: 0.73 % (95 % CI: 0.52-1.04); biceps tendinopathy: 0.71 % (95 % CI: 0.50-1.01); anserine syndrome: 0.64 % (95 % CI: 0.44-0.92); inferior heel pain: 0.61 % (95 % CI: 0.42-0.90); trochanteric syndrome: 0.49 % (95 % CI: 0.25-0.64); de Quervain's tendinopathy: 0.45 % (95 % CI: 0.29-0.70); trigger finger: 0.42 % (95 % CI: 0.27-0.67); carpal tunnel syndrome: 0.28 % (95 % CI: 0.16-0.49); Achilles tendinopathy (insertional): 0.12 % (95 % CI: 0.05-0.28); and Achilles tendinopathy (non-insertional): 0.07 % (95 % CI: 0.02-0.21). Leaving aside the comparison between Maya-Yucateco and Chontal groups (p = 0.18), we found significant differences (p < 0.001) in

  19. Middle America - Regional Geological Integrity, Hydrocarbon Implications.

    NASA Astrophysics Data System (ADS)

    James, K. H.

    2008-05-01

    Dogma holds that the Caribbean Plate and its islands formed in the Pacific and comprise oceanic crust and intra- oceanic arc rocks. Middle America, between N and S America, manifests a regional, N35°E and N60°W tectonic fabric. The NE trend results from Triassic-Jurassic reactivation of Palaeozoic convergent structures as extensional faults during Pangean rifting and commencement of N America drift. The NW trend parallels major inter-continental faults and oceanic fractures along which extension and drift occurred. Triassic-Jurassic red beds accumulated in the NE trending, intra-continental rifts of N, S and Central America. Proximal extended continental margins subsided to accommodate thick Cretaceous carbonate sections (Florida - Bahamas, Campeche, Nicaragua Rise). Distal margins formed continental blocks flanked by seaward-dipping wedges. Seismic and drilling in basins along the eastern seaboard of N America (Baltimore Canyon to Blake Plateau) document Triassic-Jurassic red beds overlain by salt and carbonates. Hydrocarbons are present. In Middle America the Gulf of Mexico remained "intra-continental", surrounded by continental blocks (N America, Maya, Florida). The area further south experienced greater extension, manifest by diverging oceanic fracture patterns to the east and west. Seismic data over the Caribbean Plateau reveal deep architecture of NE trending highs flanked by dipping wedges of reflections, similar to eastern N America distal basins. DSDP drilling calibrated the overlying smooth seismic Horizon B" as recording Cenomanian basalts. Smoothness, great lateral extent and coeval exposed sections with palaeosols followed by shallow marine carbonates suggest they were sub-aerial. Adjacent, rough seismic Horizon B" probably records top of submarine, serpentinized mantle. Seismic over the plateau also reveals features identical to drilled Sigsbee salt diapirs of the Gulf of Mexico. The regional tectonic fabric demonstrates a shared geological history

  20. A High-Resolution Reconstruction of Late Holocene Environmental Change from Laguna Ek'Naab, Northern Holmul Region, Peten, Guatemala

    NASA Astrophysics Data System (ADS)

    Anderson, L.; Wahl, D.; Estrada-Belli, F.

    2015-12-01

    Widespread demographic shifts in the southern Maya lowlands at the end of the Classic period have been attributed to environmental change caused by human activity and/or climate variability. Fire was essential to landscape modification and was a primary agent of environmental change associated with prehispanic land use. While several studies have provided insight into the dynamic relationship between natural and anthropogenic drivers of change, defining the specific interplay between natural environmental change, human modification of the environment, and cultural response to changes remains a persistent challenge. Here we present the results of a multi-proxy study that reconstructs fire history, agricultural land use, and environmental change during and after Pre-Columbian Maya settlement. Results are interpreted in the context of settlement history as inferred from archaeological mapping around the study site. Our findings suggest landscape disturbance, as indicated by erosion, local burning, and nearby maize agriculture, was at its peak during the Early Classic period. This disturbance was likely due to large-scale settlement at the nearby site of Witzna'. All proxies indicate a slow decline in disturbance into the Late Classic period, beginning around 1300 cal yr BP. Cival and Chanchich, two proximal site centers to the south of Laguna Ek'Naab, supported their largest populations during the Late Preclassic and Late Classic, with little or no settlement during the Early Classic. The data from Laguna Ek'Naab suggests that Witzna' may have been an important center during the Early Classic. Whether the decreasing environmental degradation after 1240 cal yr BP is do to a decline in local population or changing land use strategies is not discernable based on the data thus far. However, the near complete absence of burning and continued decrease in erosion from 1240-1090 cal yr BP suggests little anthropogenic activity in the area. Burning resumes in the watershed

  1. Effects of Holocene Climate Variability on Lago Paixban, a Perennial Wetland in Peten, Guatemala

    NASA Astrophysics Data System (ADS)

    Wahl, D.

    2007-12-01

    This paper presents the results of analyses carried out on a 6-m long sediment core from Lago Paixban, a perennial wetland in northern Peten, Guatemala. Pollen, δ13Corg, magnetic susceptibility, and LOI have been used to track the vegetation and hydrology of this karstic basin from 10,000 cal yr B.P. to present. Lack of fossil preservation in the basal sediments indicates relatively dry conditions leading into the early Holocene, followed by increased humidity and the presence of a shallow marsh by ~9,000 cal yr B.P. An approximately 3-cm thick band of calcite was deposited around 8,200 cal yr B.P., representing a distinct hydrological shift likely associated with the North Atlantic 8.2 ka event. Increased humidity in the early Holocene led to the formation of an open-water lake in the basin by 7,500 cal yr B.P., which persisted for around 2,000 years. At 5,500 cal yr B.P. lake levels dropped dramatically, marked by an abrupt transition to a 1-m thick peat horizon dominated by wetland taxa. This shift from lake to marsh reflects the onset of regionally drier conditions in the latter part of the Holocene. Ecological changes during this late Holocene dry period suggest lowest recorded water levels from ~5,500-4,500 cal yr B.P., followed by increased water levels and the establishment of an extensive sawgrass marsh. Anthropogenic impacts are recorded as a dramatic increase of disturbance and agricultural taxa during the period of prehistoric Maya settlement in the late Holocene. This interval, from ~3,500-1,100 cal yr B.P., is marked by a 1-m thick horizon of calcareous clay marl, indicating a change in local hydrological conditions. It is difficult to determine whether hydrological changes during this `Maya Period` were primarily driven by climate or human activity. Shortly after the area was abandoned, a perennial wetland dominated by sawgrass ( Cladium jamaicense) developed and has persisted to the present.

  2. ETHNICITY AND INCOME IMPACT ON BMI AND STATURE OF SCHOOL CHILDREN LIVING IN URBAN SOUTHERN MEXICO.

    PubMed

    Mendez, Nina; Barrera-Pérez, The Late Mario; Palma-Solis, Marco; Zavala-Castro, Jorge; Dickinson, Federico; Azcorra, Hugo; Prelip, Michael

    2016-03-01

    Obesity affects quality of life and increases the risk of morbidity and mortality. Mexico, a middle-income country, has a high prevalence of overweight and obesity among urban children. Merida is the most populated and growing city in southern Mexico with a mixed Mayan and non-Maya population. Local urbanization and access to industrialized foods have impacted the eating habits and physical activity of children, increasing the risk of overweight and obesity. This study aimed to contribute to the existing literature on the global prevalence of overweight and obesity and examined the association of parental income, ethnicity and nutritional status with body mass index (BMI) and height in primary school children in Merida. The heights and weights of 3243 children aged 6-12 from sixteen randomly selected schools in the city were collected between April and December 2012. Multinomial logistic regression models were used to examine differences in the prevalence of BMI and height categories (based on WHO reference values) by ethnicity and income levels. Of the total students, 1648 (50.9%) were overweight or obese. Stunting was found in 227 children (7%), while 755 (23.3%) were defined as having short stature. Combined stunting and overweight/obesity was found in 301 students (9.3%) and twelve (0.4%) were classified as stunted and of low weight. Having two Mayan surnames was inversely associated with having adequate height (OR=0.69, p<0.05) and the presence of two Maya surnames in children increased the odds of short stature and stunting. Children from lower income families had twice the odds of being stunted and obese. Overweight, obesity and short stature were frequent among the studied children. A significant proportion of Meridan children could face an increased risk of developing cardiovascular disease and its associated negative economic and social outcomes unless healthier habits are adopted. Action is needed to reduce the prevalence of obesity among southern

  3. Geochemical Constraints on the pre-Cenozoic Subduction History of two Margins of the Chortis Block (Northern Central America)

    NASA Astrophysics Data System (ADS)

    Geldmacher, J.; Martens, U.; Hoernle, K.; Hauff, F.; Bogaard, P.; Kluegel, A.

    2007-12-01

    The igneous forearc basement along the Pacific coast of northern Central America (between southern Mexico and Costa Rica) comprises a highly tectonized accretionary assemblage of igneous and ultramafic rocks. Volcanic and gabbroic rocks with primitive arc geochemical signatures formed between ~100 and ~180 Ma and are interpreted to have originated by arc magmatism resulting from subduction of the Pacific/Farallon plate. Additionally, the forearc contains geochemically enriched ocean island basalt (OIB)-like units that are interpreted as accreted seamounts and islands of a 100 to ~220 Ma old hotspot track, which most likely originated from a long-extinct hotspot located in the Pacific. Based on their combined Pb, Nd, Hf isotopic compositions an affiliation of these isotopically strongly enriched rocks with the Caribbean Large Igneous Province or the Galápagos hotspot appears unlikely. Rocks of similar age and geochemistry are exposed in the Santa Elena Peninsula of Costa Rica, suggesting that the same type of forearc basement is accreted to the continental Chortis block all the way from southern Mexico to Costa Rica. In contrast, gabbroic rocks of the Motagua suture zone in central Guatemala (El Tambor accretionary complex) show depleted MORB signatures and have igneous ages of ~130Ma. These MOR Gabbros were accreted on the current northern margin of the Chortis block during subduction of proto-Caribbean crust. In contrast, geochemistry of gabbros and diorites of the Sierra de Santa Cruz (SSC) indicate medium to high K-series arc affinity and their Ar/Ar ages range from ~75 to 130 Ma. The SSC is interpreted as the western extension of the early Cuban arc that collided with the Maya block in the latest Cretaceous. Arc-derived volcanic clasts were subsequently shed into the Paleocene Sepur Formation of the Maya block. No evidence of accretion of OIB-like material was found in the Motagua suture or the SSC so far. These new data suggest that proto-Caribbean crust

  4. Phenotypic differentiation between wild and domesticated varieties of Crescentia cujete L. and culturally relevant uses of their fruits as bowls in the Yucatan Peninsula, Mexico

    PubMed Central

    2013-01-01

    Background Selection criteria are important for analyzing domestication of perennial plant species, which experience a selection pressure throughout several human generations. We analyze the preferred morphological characteristics of Crescentia cujete fruits, which are used as bowls by the Maya of Yucatan, according to the uses they are given and the phenotypic consequences of artificial selection between one wild and three domesticated varieties. Methods We performed 40 semi-structured interviews in seven communities. We calculated Sutrop’s salience index (S) of five classes of ceremonial and daily life uses, and of each item from the two most salient classes. We sampled 238 bowls at homes of people interviewed and compared their shape, volume and thickness with 139 fruits collected in homegardens and 179 from the wild. Morphology of varieties was assessed in fruit (n = 114 trees) and vegetative characters (n = 136 trees). Differences between varieties were evaluated through linear discriminant analysis (LDA). Results Use of bowls as containers for the Day of the Dead offerings was the most salient class (S = 0.489) with chocolate as its most salient beverage (S = 0.491), followed by consumption of daily beverages (S = 0.423), especially maize-based pozol (S = 0.412). The sacred saka’ and balche' are offered in different sized bowls during agricultural and domestic rituals. Roundness was the most relevant character for these uses, as bowls from households showed a strong selection towards round shapes compared with wild and homegarden fruits. Larger fruits from domesticated varieties were also preferred over small wild fruits, although in the household different sizes of the domesticated varieties are useful. LDA separated wild from domesticated trees (p < 0.001) according to both fruit and vegetative variables, but domesticated varieties were not different among themselves. Conclusions The association between C. cujete bowls and

  5. Generating useful images for medical applications from the Visible Korean Human.

    PubMed

    Park, Jin Seo; Jung, Yong-Wook; Lee, Jun Won; Shin, Dong Sun; Chung, Min Suk; Riemer, Martin; Handels, Heinz

    2008-12-01

    For the Visible Korean Human (VKH), a male cadaver was serially ground off to acquire the serially sectioned images (SSIs) of a whole human body. Thereafter, more than 700 structures in the SSIs were outlined to produce detailed segmented images; the SSIs and segmented images were volume- and surface-reconstructed to create three-dimensional models. For outlining and reconstruction, popular software (Photoshop, MRIcro, Maya, AutoCAD, 3ds max, and Rhino) was mainly used; the technique can be reproduced by other investigators for creating their own images. For refining the segmentation and volume reconstruction, the VOXEL-MAN system was used. The continuously upgraded technique was applied to a female cadaver's pelvis to produce the SSIs with 0.1mm sized intervals and 0.1mm x 0.1mm sized pixels. The VKH data, distributed worldwide, encouraged researchers to develop virtual dissection, virtual endoscopy, and virtual lumbar puncture contributing to medical education and clinical practice. In the future, a virtual image library including all the Visible Human Project data, Chinese Visible Human data, and VKH data will hopefully be established where users will be able to download one of the data sets for medical applications. PMID:18782644

  6. Influences of organically and conventionally grown strawberry cultivars on anthocyanins content and color in purees and low-sugar jams.

    PubMed

    Bursać Kovačević, Danijela; Putnik, Predrag; Dragović-Uzelac, Verica; Vahčić, Nada; Babojelić, Martina Skendrović; Levaj, Branka

    2015-08-15

    The objective of this study was to detect influences of cultivar, cultivation and processing on anthocyanin content and color in purees and low-sugar jams produced from strawberry cultivars (Elsanta, Maya, Marmolada, Queen Elisa), grown under conventional and organic cultivation. Color was determined by CIELab values while anthocyanins were quantified by HPLC-UV/VIS-PDA. Queen Elisa was the best cultivar for processing as it had highest total anthocyanin content (TAC) that was well preserved in processing. On average, processing purees to jams decreased TAC for 28% where pelargonidin-3-glucoside revealed most noticeable loss (53%) and cyanidin-3-rutinoside was best preserved in processing. Obtained results indicated that measurement of colorimetric parameters are strongly correlated with content of anthocyanins. In other words, loss of anthocyanins during processing was accompanied by noticeable decrease in lightness, red/yellow color and total color change. Results showed that change of color is useful predictor for estimating anthocyanins in strawberry purees and jams. PMID:25794726

  7. Belize model, a carbonate-clastic shelf buildup

    SciTech Connect

    Shepard, W.

    1987-05-01

    Belize, a small Central American country located on the Caribbean Sea south of the Yucatan Peninsula, offers an excellent modern analog of a mixed carbonate/clastic shelf buildup. Its 175-mi long reef tract, second longest in the world, restricts a shallow shelf depobasin into which terrigenous clastics source from the Maya Mountains to the west and carbonates dominate from the east. Mixed lithologies occur along strandlines, in submarine channels, and in lagoons and river-delta fronts, which are scattered throughout the depobasin. Energy sources from both land and sea influence sedimentation. Heavy summer rains flood the basin with arkosic and quartzose clastics, and periodic sea storms and hurricanes drive carbonate particles from the reef tract landward into the basin. Modern environments include the reef tract, carbonate tidal flats, shallow shelf patch reefs, lagoons, cayes, mainland coast deltas, estuaries, lagoons, and beach/bar barriers. Modern sediments include reef metazoans, algae, coralline algae, lime mud, quartz, and feldspathic sand and clay. The setting for the model has been influenced by Tertiary tectonics and Pleistocene sea level changes. Karstification occurred during the past 10,000 years, partly controlling topography and resulting Holocene sediment patterns. Facies patterns of the Belize Holocene are compared to the Jurassic of Montana. The Middle Jurassic Piper Formation exhibits a nearly 100-mi long carbonate barrier/buildup restricting a clastic-dominated shelf. Other ancient mixed carbonate/clastic terranes may fit this model as well.

  8. Exploring the use of numerical relativity waveforms in burst analysis of precessing black hole mergers

    SciTech Connect

    Fischetti, Sebastian; Cadonati, Laura; Mohapatra, Satyanarayan R. P.; Healy, James; London, Lionel; Shoemaker, Deirdre

    2011-02-15

    Recent years have witnessed tremendous progress in numerical relativity and an ever improving performance of ground-based interferometric gravitational wave detectors. In preparation for the Advanced Laser Interferometer Gravitational Wave Observatory (Advanced LIGO) and a new era in gravitational wave astronomy, the numerical relativity and gravitational wave data analysis communities are collaborating to ascertain the most useful role for numerical relativity waveforms in the detection and characterization of binary black hole coalescences. In this paper, we explore the detectability of equal mass, merging black hole binaries with precessing spins and total mass M{sub T}(set-membership sign)[80,350]M{sub {center_dot}}, using numerical relativity waveforms and templateless search algorithms designed for gravitational wave bursts. In particular, we present a systematic study using waveforms produced by the MayaKranc code that are added to colored, Gaussian noise and analyzed with the Omega burst search algorithm. Detection efficiency is weighed against the orientation of one of the black-hole's spin axes. We find a strong correlation between the detection efficiency and the radiated energy and angular momentum, and that the inclusion of the l=2, m={+-}1, 0 modes, at a minimum, is necessary to account for the full dynamics of precessing systems.

  9. Maize diversity and ethnolinguistic diversity in Chiapas, Mexico.

    PubMed

    Perales, Hugo R; Benz, Bruce F; Brush, Stephen B

    2005-01-18

    The objective of this study is to investigate whether ethnolinguistic diversity influences crop diversity. Factors suggest a correlation between biological diversity of crops and cultural diversity. Although this correlation has been noted, little systematic research has focused on the role of culture in shaping crop diversity. This paper reports on research in the Maya highlands (altitude >1,800 m) of central Chiapas in southern Mexico that examined the distribution of maize (Zea mays) types among communities of two groups, the Tzeltal and Tzotzil. The findings suggest that maize populations are distinct according to ethnolinguistic group. However, a study of isozymes indicates no clear separation of the region's maize into two distinct populations based on ethnolinguistic origin. A reciprocal garden experiment shows that there is adaptation of maize to its environment but that Tzeltal maize sometimes out-yields Tzotzil maize in Tzotzil environments. Because of the proximity of the two groups and selection for yield, we would expect that the superior maize would dominate both groups' maize populations, but we find that such domination is not the case. The role of ethnolinguistic identity in shaping social networks and information exchange is discussed in relation to landrace differentiation. PMID:15640353

  10. Maize diversity and ethnolinguistic diversity in Chiapas, Mexico

    PubMed Central

    Perales, Hugo R.; Benz, Bruce F.; Brush, Stephen B.

    2005-01-01

    The objective of this study is to investigate whether ethnolinguistic diversity influences crop diversity. Factors suggest a correlation between biological diversity of crops and cultural diversity. Although this correlation has been noted, little systematic research has focused on the role of culture in shaping crop diversity. This paper reports on research in the Maya highlands (altitude > 1,800 m) of central Chiapas in southern Mexico that examined the distribution of maize (Zea mays) types among communities of two groups, the Tzeltal and Tzotzil. The findings suggest that maize populations are distinct according to ethnolinguistic group. However, a study of isozymes indicates no clear separation of the region's maize into two distinct populations based on ethnolin-guistic origin. A reciprocal garden experiment shows that there is adaptation of maize to its environment but that Tzeltal maize sometimes out-yields Tzotzil maize in Tzotzil environments. Because of the proximity of the two groups and selection for yield, we would expect that the superior maize would dominate both groups' maize populations, but we find that such domination is not the case. The role of ethnolinguistic identity in shaping social networks and information exchange is discussed in relation to landrace differentiation. PMID:15640353

  11. Association of Indigo with Zeolites for Improved Color Stabilization

    NASA Astrophysics Data System (ADS)

    Dejoie, Catherine; Martinetto, Pauline; Dooryhée, Eric; van Elslande, Elsa; Blanc, Sylvie; Bordat, Patrice; Brown, Ross; Porcher, Florence; Anne, Michel

    2010-10-01

    The durability of an organic colour and its resistance against external chemical agents and exposure to light can be significantly enhanced by hybridizing the natural dye with a mineral. In search for stable natural pigments, the present work focuses on the association of indigo blue with several zeolitic matrices (LTA zeolite, mordenite, MFI zeolite). The manufacturing of the hybrid pigment is tested under varying oxidising conditions, using Raman and UV-visible spectrometric techniques. Blending indigo with MFI is shown to yield the most stable composite in all of our artificial indigo pigments. In absence of defects and substituted cations such as aluminum in the framework of the MFI zeolite matrix, we show that matching the pore size with the dimensions of the guest indigo molecule is the key factor. The evidence for the high colour stability of indigo@MFI opens a new path for modeling the stability of indigo in various alumino-silicate substrates such as in the historical Maya Blue pigment.

  12. Sarcodon in the Neotropics I: new species from Guyana, Puerto Rico and Belize.

    PubMed

    Grupe, Arthur C; Baker, Anthony D; Uehling, Jessie K; Smith, Matthew E; Baroni, Timothy J; Lodge, D Jean; Henkel, Terry W

    2015-01-01

    Four species of the ectomycorrhizal (ECM) genus Sarcodon (Bankeraceae, Thelephorales, Basidiomycota) are described as new to science. Sarcodon pakaraimensis sp. nov. is described from forests dominated by the ECM trees Pakaraimaea dipterocarpacea (Dipterocarpaceae) and Dicymbe jenmanii (Fabaceae subfam. Caesalpinioideae) in the Pakaraima Mountains of Guyana. Sarcodon portoricensis sp. nov. is described from lower montane wet forest within the El Yunque National Forest of Puerto Rico. Sarcodon quercophilus sp. nov. and Sarcodon umbilicatus sp. nov. are described from Quercus (Fagaceae) cloud forests within the Maya Mountains of Belize. The discovery of these species is significant given that the majority of the approximately 87 described Sarcodon species are north temperate or boreal in distribution and frequently associate with coniferous host plants; these constitute the most recent records for Sarcodon from the greater Neotropics. Each of the new species is morphologically consistent with accepted diagnostic characters for Sarcodon: pileate-stipitate stature, a dentate hymenophore, determinate basidiomatal development, fleshy, non-zonate context and brown, tuberculate basidiospores. DNA (ITS) sequence analysis corroborated the generic placement of S. pakaraimensis, S. portoricensis, S. quercophilus and S. umbilicatus and, along with morphological differences, supported their recognition as distinct species. Macromorphological, micromorphological, habitat and DNA sequence data from the nuc rDNA internal transcribed spacer region (ITS) are provided for each of the new species. A key to Neotropical Sarcodon species and similar extralimital taxa is provided. PMID:25661714

  13. IRBP-like proteins in the eyes of six cephalopod species--immunochemical relationship to vertebrate interstitial retinol-binding protein (IRBP) and cephalopod retinal-binding protein.

    PubMed

    Fong, S L; Lee, P G; Ozaki, K; Hara, R; Hara, T; Bridges, C D

    1988-01-01

    SDS polyacrylamide gel electrophoresis and immunoblotting were used to examine soluble proteins from the eyes of six species of cephalopods i.e. Lolliguncula brevis, Sepia officinalis, Octopus maya, Octopus bimaculoides, Rossia pacifica and Loligo opalescens. All species had a protein ("IRBP") with molecular weight virtually identical with vertebrate interstitial retinol-binding protein (IRBP) averaging 132,400 +/- 700 (n = 6). "IRBP" reacted on nitrocellulose blot transfers with rabbit antibovine IRBP and rabbit antifrog IRBP antibodies. Unlike vertebrate IRBP, cephalopod "IRBP" (from L. brevis) did not bind exogenous retinol or concanavalin A. The N-terminal amino acid appeared to be blocked in samples electroeluted from SDS gels. The antifrog IRBP antibodies also reacted with a series of proteins with molecular weights between 46,000 and 47,000, identified as retinal-binding protein (RALBP) with anti-RALBP antibodies. Anti-IRBP also reacted with pure RALBP prepared from Todarodes pacificus. Occasionally, anti-RALBP antibodies were seen to react weakly with "IRBP" in some cephalopods. We conclude that RALBP, cephalopod "IRBP" and vertebrate IRBP share a common but distant ancestry, and that a protein resembling IRBP appeared before the vertebrates diverged from the invertebrates. Both RALBP and IRBP appear to have analogous functions in shuttling retinoids between rhodopsin and the corresponding isomerizing system, retinochrome in the cephalopods and retinol isomerase in the vertebrates. The function of cephalopod "IRBP" is unknown. PMID:3195063

  14. Determination of the depth profile distribution of guest species in microporous materials using the voltammetry of immobilized particles methodology: application to lapachol attachment to palygorskite and kaolinite.

    PubMed

    Doménech-Carbó, Antonio; Martini, Mariele; Valle-Algarra, Francisco Manuel

    2014-09-21

    A model for determining the in-depth profile distribution of electroactive species hosted in inorganic microporous matrixes using the voltammetry of immobilized particles methodology is described. The method, based on the analysis of cyclic voltammetric data at different potential scan rates, allows us to determine the in-depth profile variation of the concentration of electroactive guest species as well as the evaluation of the (oxidized form)/(reduced form) concentration ratio in cases where two oxidation states of the electroactive species coexist. The application to Maya blue-type materials prepared from lapachol, a naphtoquinonic dye, and palygorskite and kaolinite clays is reported. The determination of the in-depth distribution of guest molecules is not easy due to the heterogeneity of the clay particle size distribution and the appearance of cyclization and redox tuning reactions. Electrochemical data revealed differences in the in-depth distribution of the dye molecules in the grains of the channelled (palygorskite) and the laminar (kaolinite) clays that suggest that lapachol compounds can ingress into the channels of the palygorskite framework whereas remain externally adsorbed onto the kaolinite crystals. PMID:25093430

  15. Development of analytical procedures for coprocessing. Final technical report

    SciTech Connect

    Anderson, R.P.; Green, J.B.; Vogh, J.W.

    1991-07-01

    One phase of improving understanding of the fundamental chemistry of coprocessing involves development of the ability to distinguish between products originating from coal versus those originating from petroleum resid. A primary objective of this project was to develop analytical techniques to determine the source (coal versus resid) of the various compound types found in coprocessing products. A corollary objective was to develop an expanded knowledge of the detailed composition of coprocessing products. Two approaches were evaluated for distinguishing between products originating from coal and those originating from petroleum resid. One was based on the use of carbon isotope ratios and the other was based on variations in compound classes in response to changes in the ratio of coal to resid in the coprocessing feed. Other researchers using carbon isotope ratios to determine the origin of products have typically examined distillation fractions. This project involved determination of the origin of chemical classes (e.g., saturates, neutral aromatics, phenols, indoles, etc.) rather than distillate classes. Maya resid and Illinois No. 6 coal (with coal feed varying from 2 to 40 percent) were coprocessed in a batch autoclave to obtain products for detailed analysis.

  16. Automatic Texture Mapping of Architectural and Archaeological 3d Models

    NASA Astrophysics Data System (ADS)

    Kersten, T. P.; Stallmann, D.

    2012-07-01

    Today, detailed, complete and exact 3D models with photo-realistic textures are increasingly demanded for numerous applications in architecture and archaeology. Manual texture mapping of 3D models by digital photographs with software packages, such as Maxon Cinema 4D, Autodesk 3Ds Max or Maya, still requires a complex and time-consuming workflow. So, procedures for automatic texture mapping of 3D models are in demand. In this paper two automatic procedures are presented. The first procedure generates 3D surface models with textures by web services, while the second procedure textures already existing 3D models with the software tmapper. The program tmapper is based on the Multi Layer 3D image (ML3DImage) algorithm and developed in the programming language C++. The studies showing that the visibility analysis using the ML3DImage algorithm is not sufficient to obtain acceptable results of automatic texture mapping. To overcome the visibility problem the Point Cloud Painter algorithm in combination with the Z-buffer-procedure will be applied in the future.

  17. Provenance analysis of obsidian artifacts from the northern ridge of Lake Atitlan in the Guatemalan southern highlands

    SciTech Connect

    James, W.D.; Woodward, M.R.; Bruchez, M.S.

    1996-12-31

    The use of chemical composition of archaeological obsidian artifacts to study ancient cultures has become widespread over the last two decades. The focus of this paper is the correlation of artifacts collected from surface surveys of a region just to the north of Lake Atitlan in the southern Guatemalan highlands to known source outcroppings. The obsidian experiments are one facet of a larger project that seeks to develop evidence of ritual behavior among the inhabitants of the original Cakchiquel kingdom on the lake shores. These rituals are said to have provided the order of their social organization. Specific goals of the study include the development of a chronological sequence from Preclassic Maya (2000 B.C. to A.D. 200) to the Spanish colonial period. Supporting goals involve developing a preliminary view of site organization based on the distribution of features and cultural items, definition of particular activities from functional assessment of the site organization, and determination of occupational information. The results of these studies are expected to be a starting point for understanding the process of sociocultural evolution in the area.

  18. Chinese tombs oriented by a compass: evidence from paleomagnetic declination changes versus tombs age

    NASA Astrophysics Data System (ADS)

    Charvatova, Ivanka; Klokocnik, Jaroslav; Kolmas, Josef; Kostelecky, Jan

    2010-05-01

    The use of the magnetic compass in China is documented at least since the Han dynasty (206 BC-220 AD), but may be older. Geomancy (fengshui) practicised for a long time had a profound influence on the face of China's landscape and city plans. The tombs (pyramids) near Xian (together with suburban fields and roads) have strange space orientations, sometimes in the basic south-north direction (with respect to the geographic pole), but ussually with deviations of several degrees to east or west. The use of the compass means that the needle is directed to the actual magnetic pole at the time of construction or last reconstruction of the given tomb. The magnetic pole however, relative to the 'fixed' geographic pole, wanders significantly in time. We successfully correlated (found a close trends), by using paleomagnetic data (for the central China and the time interval of interest), the starting date of pyramids building with respect to the magnetic pole position at that time. As in Mesoamerica, where according to Fuson hypothesis, the Olmecs and Maya oriented their ceremonial buildings and pyramids by compass even before the Chinese, here in central China the same technique may have been used. The agreeement of building alignments with likely magnetic pole positions at the time is fairly good. There are several written records that the knowledge of the various ancient types of compass in China is older than from the Han period but paleomagnetic declinations for China are generally so far not too precise.

  19. Coca-colonization of diets in the Yucatan.

    PubMed

    Leatherman, Thomas L; Goodman, Alan

    2005-08-01

    Over the past three decades, tourism-based economic development has transformed social and economic conditions in the Yucatan Peninsula, Mexico. Mayan communities have become directly involved in the changing economy as the main source of inexpensive labor for construction and service jobs at tourism centers, and as sites of ecotourism and archeotourism. In this paper, we address how these macro-processes of change intersect locally with the commoditization of food systems, diets and nutrition in four Yucatec Mayan communities with differing relationships to the tourist economy. Yucatec Mayan diets have become increasingly dependent on purchased foods, and reflect a greater consumption of commercialized processed foods. Coca-Cola, an international icon of US culture, along with other local and internationally owned calorie-dense but nutrient-poor snack foods, is now a common element of Mayan diets, leading to what we call "coca-colonization." The consequences of this diet, likely exacerbated by the increased consumption of snack foods, include an apparent increase in overweight and obese adults as well as signs of growth stunting in children. The Maya we talked with recognize both the potential disruption that tourism brings to all aspects of their lives and the necessity of jobs that tourism creates to meet their families' basic needs. PMID:15950095

  20. Sikhism, spirituality and psychiatry.

    PubMed

    Kalra, Gurvinder; Bhui, Kamaldeep S; Bhugra, Dinesh

    2012-12-01

    Sikhism has millions of followers in India and among the Indian diaspora. As a religion it is relatively young but carries with it unique perspectives which are often not well known. The holy book of Sikhism, Guru Granth Sahib, is not only the last Guru, but also remained a key text for this religion. Using descriptions of the religion and its followers we attempt to understand the context of spirituality within this religion and attempt to apply it to clinical settings. We explored various texts to understand the notions of spirituality and ethics and directions for living one's life. We studied both the Gurumukhi version as well as the English translation of the Sikh holy text. In the context of history of the Sikhs, various descriptions related to mental well being were identified. In this paper we describe the history, development and the core values of the religion and we also review their role on psychiatric and mental health settings for managing Sikh patients. Guru Granth Sahib offers a very useful insight into what is understood by the term equivalent to depression and its phenomenology. The notions of dukh (loosely translated as pain, but can also mean sadness or suffering) and maya (illusion) and their role in daily living are also discussed. In this paper these descriptions are explored further and their importance explained. PMID:23174442

  1. Alcohol Use Behaviors Among Indigenous Migrants: A Transnational Study on Communities of Origin and Destination

    PubMed Central

    Pinedo, Miguel; Campos, Yasmin; Leal, Daniela; Fregoso, Julio; Goldenberg, Shira M.

    2014-01-01

    The association between international and domestic migration and alcohol use among indigenous communities is poorly understood. We explored migration-related factors associated with alcohol use behaviors among an indigenous Mayan, binational population. From January to March 2012, 650 indigenous participants from the high-emigration town of Tunkás in the Mexican state of Yucatán (n = 650) residing in Mexico and California completed surveys. Multivariate logistic regression identified migration-related factors associated with alcohol use behaviors. US migration of shorter duration (<5 years) was independently associated with at-risk drinking (adjusted odds ratio (AOR) 2.34; 95 % confidence interval (CI) 1.09–5.03), as was longer-duration domestic migration (≥5 years) (AOR 2.34; 95 % CI 1.12–4.87). Ability to speak Maya (AOR 0.26; 95 % CI 0.13–0.48) was protective against at-risk drinking. Culturally appropriate alcohol use prevention interventions are needed for domestic and international indigenous Mexican migrants to address alcohol use behavior in the context of migration. PMID:24366542

  2. 2200-years of hydrological flickering and megadroughts in Yucatán using variographic analysis of stalagmite annual layers

    NASA Astrophysics Data System (ADS)

    Frappier, A. E.; Brill, M. E.

    2013-05-01

    Variograph analysis is a useful new tool for assessing annually layered speleothem data for paleoclimate information content and the temporal scales of climate variation which are represented in the proxy archive. We present a variograph analysis of annual layer thickness data from stalagmite CH-1, which grew in Cenote Chaltun Ha, Huhí, Yucatán, Mexico for about two millennia until it was collected in 2007. Our previous analyses of CH-1 showed that growth rates were very consistent throughout the entire growth period, with a sudden shift from a rapid growth regime to a slow growth regime at about 419+/-2 C.E. We also documented changes in cave flood frequencies due to tropical cyclone activity and high water tables on interannual to multicentennial timescales, with tropical cyclone activity generally tracking regional paleotempestology results showing very low cave flooding frequencies from the 13th to 18th centuries, high cave flooding frequencies prior to the early 5th century, and evidence for intense tropical cyclone activity during the Maya Terminal Classic so-called 'Megadroughts'. Results from the CH-1 variograph analysis, including flickering intensity, information content, and range, will be presented in comparison with other hydroclimatic proxy indicators in CH-1, including stable oxygen and carbon isotope ratios, fluorescence intensity, and cave flooding events, and discussed in terms of the implications of these findings for the understanding of past hydroclimatic variability in the northern Yucatán peninsula during the last 2200 years.

  3. The Utility of Inquiry-Based Exercises in Mexican Science Classrooms: Reports from a Professional Development Workshop for Science Teachers in Quintana Roo, Mexico

    NASA Astrophysics Data System (ADS)

    Racelis, A. E.; Brovold, A. A.

    2010-12-01

    The quality of science teaching is of growing importance in Mexico. Mexican students score well below the world mean in math and science. Although the government has recognized these deficiencies and has implemented new policies aimed to improve student achievement in the sciences, teachers are still encountering in-class barriers to effective teaching, especially in public colleges. This paper reports on the utility of inquiry based exercises in Mexican classrooms. In particular, it describes a two-day professional development workshop with science teachers at the Instituto Tecnologico Superior in Felipe Carrillo Puerto in the Mexican state of Quintana Roo. Felipe Carrillo Puerto is an indigenous municipality where a significant majority of the population speak Maya as their first language. This alone presents a unique barrier to teaching science in the municipality, but accompanied with other factors such as student apathy, insufficient prior training of both students and teachers, and pressure to deliver specific science curriculum, science teachers have formidable challenges for effective science teaching. The goals of the workshop were to (1) have a directed discussion regarding science as both content and process, (2) introduce inquiry based learning as one tool of teaching science, and (3) get teachers to think about how they can apply these techniques in their classes.

  4. Sr isotopic characteristic of neoproterozoic carbonate sediments from the southern Yenisei Ridge

    NASA Astrophysics Data System (ADS)

    Vishnevskaya, I. A.; Kochnev, B. B.; Letnikova, E. F.; Kuznetsov, A. B.; Proshenkin, A. I.

    2012-04-01

    This paper presents the first Sr isotopic data for the Late Precambrian carbonate rocks of the southern Yenisei Ridge. Their geochemical study allowed estimation of the degree of secondary alterations and gave the possibility to reveal rocks with a less disturbed Rb-Sr isotopic system. The Sr isotopic data indicated Neoproterozoic sedimentation of the rocks about 1070-750 Ma ago. Sr and C isotopic data showed that carbonate rocks of the Sukhoi Pit, Tungusik, and Shirokino groups are Late Riphean and could be comparable with sedimentary sequences of three Precambrian key sections of the Northern Eurasia: the subsequent Derevnino, Burovaya, and Shorikha formations from the Turukhansk Uplift, the Lakhanda Group from the Uchur-Maya region, and the Karatav Group from the South Urals. All studied carbonate rocks are older than 750 Ma and, according to the International Stratigraphic Chart, accumulated prior to global glaciations in the Cryogenian. This is evident from sedimentological study indicating the absence of tillite horizons in the studied sections. δ13C values in the sections vary from +0.4 up to +5.3‰, which testifies to the absence of periods of great cold.

  5. Female social response to male sexual harassment in poeciliid fish: a comparison of six species

    PubMed Central

    Dadda, Marco

    2015-01-01

    Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki), when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of six poeciliid species (Girardinus metallicus, Girardinus falcatus, G. holbrooki, Poecilia reticulata, Xiphophorus hellerii, and Xiphophorus mayae) that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females' social distance when a male is present may indeed serve to reduce the costs of male sexual harassment. PMID:26483719

  6. [Dental care, dental diseases and dentistry in antiquity].

    PubMed

    Józsa, László

    2009-01-01

    Numerous written relicts, belletristic works (poems of Martial, Juvenal, Ovid etc.) indicate that oral hygiene and its tools (toothbrush, toothpick, use of tooth pastes and tooth-powder) were used long before our times. Already ancient people started to remove, file, dye and inlay teeth. The teeth were dyed red, green or black in Egypt, red or brown (with henna or betel) in India, white by Romans. The teeth decoration has a long but forgotten history. The most skillful and artistic work was done by the Maya's between 900 BC and 1500 AD. The modification of contours (more than fifty forms) of the incisors were practiced also in Mesoamerica. Dentistry was surely practiced in ancient Egypt, India, China, Greece and Rome, while odontology and especially suitable dental appliances arose only by Etruscan. Dental prosthesis, including bridges and simple retention bands were invented by the Etruscans 2500 years ago. These Etruscan bridges were worn mostly by females, suggesting that cosmetics was the principal dental concern. Some,--if not all--of the Roman and other prostheses have been purely ornamental. Orthodontic appliances are also Etruscan invention. The holes caused by caries were filled with garlic, incense, caraway seed in Egypt, with wood or lead in Rome, and with "silver-paste" (amalgam) in ancient China. The toothache was cured with poppy-tee, or hashish and nightshade plants (Solanaceae) in Egypt, Greece, Roman Empire while with coca (Erythroxylon coca) in South-America. PMID:20481107

  7. Astronomical Knowledge in Holy Books

    NASA Astrophysics Data System (ADS)

    Farmanyan, Sona V.; Mickaelian, Areg M.

    2015-08-01

    We investigate religious myths related to astronomy from different cultures in an attempt to identify common subjects and characteristics. The paper focuses on astronomy in religion. The initial review covers records from Holy books about sky related superstitious beliefs and cosmological understanding. The purpose of this study is to introduce sky related religious and national traditions (particularly based on different calendars; Solar or Lunar). We carried out a comparative study of astronomical issues contained in a number of Holy books: Ancient Egyptian Religion (Pyramid Texts), Zoroastrianism (Avesta), Hinduism (Vedas), Buddhism (Tipitaka), Confucianism (Five Classics), Sikhism (Guru Granth Sahib), Christianity (Bible), Islam (Quran), Druidism (Mabinogion) and Maya Religion (Popol Vuh). These books include various information on the creation of the Universe, Sun and Moon, the age of the Universe, Cosmic sizes, understanding about the planets, stars, Milky Way and description of the Heavens in different religions. We come to the conclusion that the perception of celestial objects varies from culture to culture, and from religion to religion and preastronomical views had a significant impact on humankind, particularly on religious diversities. We prove that Astronomy is the basis of cultures, and that national identity and mythology and religion were formed due to the special understanding of celestial objects.

  8. The history and science of chocolate.

    PubMed

    Verna, R

    2013-12-01

    This article gives an account of the origins, evolution and properties of chocolate. Chocolate is processed from the pod or cabosside of the cacao plant, grown in the tropical belt. The origins of chocolate are traced back to the Maya people who were probably the first to cultivate the cacao plant. The early chocolate drink, considered a "drink of the Gods" was mixed with cinnamon and pepper, tasting bitter and strong, and was most appreciated for its invigorating and stimulating effects than for its taste. Imported from the Americas, the softened version soon spread in Europe. From the 1800s to the 20th Century, it evolved from a drink to its current pleasurable varieties (such as fondant, Gianduja, milky and white chocolate), gaining much momentum in industry and also made great impact as a romantic item and art form. Important components in chocolate are flavonoids (antioxidants), cocoa butter, caffeine, theobromine and phenylethylamine, whereas the presence of psychoactive substances account for its pleasurable effects. Caffeine, theophylline and theobromine constitutes the methylxanthines, known to enhance the action of cAMP, which plays an important role in the transmission of intracellular signals. Chocolate is noted to have anti-inflammatory, neuroprotective and cardioprotective effects, and improves the bioavailability of nitric oxide, which action improves the pressure, platelet function and fluidity of blood. PMID:24362474

  9. Surface models of the male urogenital organs built from the Visible Korean using popular software

    PubMed Central

    Shin, Dong Sun; Park, Jin Seo; Shin, Byeong-Seok

    2011-01-01

    Unlike volume models, surface models, which are empty three-dimensional images, have a small file size, so they can be displayed, rotated, and modified in real time. Thus, surface models of male urogenital organs can be effectively applied to an interactive computer simulation and contribute to the clinical practice of urologists. To create high-quality surface models, the urogenital organs and other neighboring structures were outlined in 464 sectioned images of the Visible Korean male using Adobe Photoshop; the outlines were interpolated on Discreet Combustion; then an almost automatic volume reconstruction followed by surface reconstruction was performed on 3D-DOCTOR. The surface models were refined and assembled in their proper positions on Maya, and a surface model was coated with actual surface texture acquired from the volume model of the structure on specially programmed software. In total, 95 surface models were prepared, particularly complete models of the urinary and genital tracts. These surface models will be distributed to encourage other investigators to develop various kinds of medical training simulations. Increasingly automated surface reconstruction technology using commercial software will enable other researchers to produce their own surface models more effectively. PMID:21829759

  10. Resource use in the tropical karstlands of central Belize

    SciTech Connect

    Day, M.

    1993-06-01

    Rural tropical ecosystems are subject to many traditional land uses that employ the indigenous karst resources: rock, water, soil, vegetation, and wildlife. Individual resource pressures often are subtle, but their combined impact can precipitate stability in the tropical karst environment, potentially resulting in disruption of food, water, and fuel supplies. The karst of central Belize was used intensively for some six centuries by Maya farmers, but between the 10th and 19th centuries AD most of it reverted to secondary forest. Commercial logging dominated the 19th and early 20th centuries, followed by the expansion of subsistence and commercial agriculture after 1945. In the 1980s resource use has accelerated as population and other pressures increase. Much karst remains forested, but there is increasing clearance for agricultural uses, particularly for citrus cultivation and small-scale mixed agriculture. Soil depletion has begun to occur, water resources are increasingly taxed, and some wildlife is threatened by habitat destruction and increased hunting. Lime production for the citrus industry has promoted quarrying, water extraction, and fuelwood use. Environmental stresses currently do not exceed the threshold of instability, but the rapidly developing rural economy warrants careful monitoring of resource pressures. 33 refs., 3 figs.

  11. Change in the Pathologic Supraspinatus: A Three-Dimensional Model of Fiber Bundle Architecture within Anterior and Posterior Regions.

    PubMed

    Kim, Soo Y; Sachdeva, Rohit; Li, Zi; Lee, Dongwoon; Rosser, Benjamin W C

    2015-01-01

    Supraspinatus tendon tears are common and lead to changes in the muscle architecture. To date, these changes have not been investigated for the distinct regions and parts of the pathologic supraspinatus. The purpose of this study was to create a novel three-dimensional (3D) model of the muscle architecture throughout the supraspinatus and to compare the architecture between muscle regions and parts in relation to tear severity. Twelve cadaveric specimens with varying degrees of tendon tears were used. Three-dimensional coordinates of fiber bundles were collected in situ using serial dissection and digitization. Data were reconstructed and modeled in 3D using Maya. Fiber bundle length (FBL) and pennation angle (PA) were computed and analyzed. FBL was significantly shorter in specimens with large retracted tears compared to smaller tears, with the deeper fibers being significantly shorter than other parts in the anterior region. PA was significantly greater in specimens with large retracted tears, with the superficial fibers often demonstrating the largest PA. The posterior region was absent in two specimens with extensive tears. Architectural changes associated with tendon tears affect the regions and varying depths of supraspinatus differently. The results provide important insights on residual function of the pathologic muscle, and the 3D model includes detailed data that can be used in future modeling studies. PMID:26413533

  12. Inter-cohort growth for three tropical resources: tilapia, octopus and lobster.

    PubMed

    Velázquez-Abunader, Iván; Gómez-Muñoz, Victor Manuel; Salas, Silvia; Ruiz-Velazco, Javier M J

    2015-09-01

    Growth parameters are an important component for the stock assessment of exploited aquatic species. However, it is often difficult to apply direct methods to estimate growth and to analyse the differences between males and females, particularly in tropical areas. The objective of this study was to analyse the inter-cohort growth of three tropical resources and discuss the possible fisheries management implications. A simple method was used to compare individual growth curves obtained from length frequency distribution analysis, illustrated by case studies of three tropical species from different aquatic environments: tilapia (Oreochromis aureus), red octopus (Octopus maya) and the Caribbean spiny lobster (Panulirus argus). The analysis undertaken compared the size distribution of males and females of a given cohort through modal progression analysis. The technique used proved to be useful for highlighting the differences in growth between females and males of a specific cohort. The potential effect of extrinsic and intrinsic factors on the organism's development as reflected in the size distribution of the cohorts is discussed. PMID:26666119

  13. The dichloromethane extract of the ethnomedicinal plant Neurolaena lobata inhibits NPM/ALK expression which is causal for anaplastic large cell lymphomagenesis.

    PubMed

    Unger, Christine; Popescu, Ruxandra; Giessrigl, Benedikt; Laimer, Daniela; Heider, Susanne; Seelinger, Mareike; Diaz, Rene; Wallnöfer, Bruno; Egger, Gerda; Hassler, Melanie; Knöfler, Martin; Saleh, Leila; Sahin, Emine; Grusch, Michael; Fritzer-Szekeres, Monika; Dolznig, Helmut; Frisch, Richard; Kenner, Lukas; Kopp, Brigitte; Krupitza, Georg

    2013-01-01

    The present study investigates extracts of Neuolaena lobata, an anti-protozoan ethnomedicinal plant of the Maya, regarding its anti-neoplastic properties. Firstly, extracts of increasing polarity were tested in HL-60 cells analyzing inhibition of cell proliferation and apoptosis induction. Secondly, the most active extract was further tested in anaplastic large cell lymphoma (ALCL) cell lines of human and mouse origin. The dichloromethane extract inhibited proliferation of HL-60, human and mouse ALCL cells with an IC50 of ~2.5, 3.7 and 2.4 µg/ml, respectively and arrested cells in the G2/M phase. The extract induced the checkpoint kinases Chk1 and Chk2 and perturbed the orchestrated expression of the Cdc25 family of cell cycle phosphatases which was paralleled by the activation of p53, p21 and downregulation of c-Myc. Importantly, the expression of NPM/ALK and its effector JunB were drastically decreased, which correlated with the activation of caspase 3. Subsequently also platelet derived growth factor receptor β was downregulated, which was recently shown to be transcriptionally controlled by JunB synergizing with ALK in ALCL development. We show that a traditional healing plant extract downregulates various oncogenes, induces tumor suppressors, inhibits cell proliferation and triggers apoptosis of malignant cells. The discovery of the 'Active Principle(s)' is warranted. PMID:23135783

  14. Climate change on the Yucatan Peninsula during the Little Ice Age

    NASA Astrophysics Data System (ADS)

    Hodell, David A.; Brenner, Mark; Curtis, Jason H.; Medina-González, Roger; Ildefonso-Chan Can, Enrique; Albornaz-Pat, Alma; Guilderson, Thomas P.

    2005-03-01

    We studied a 5.1-m sediment core from Aguada X'caamal (20° 36.6'N, 89° 42.9'W), a small sinkhole lake in northwest Yucatan, Mexico. Between 1400 and 1500 A.D., oxygen isotope ratios of ostracod and gastropod carbonate increased by an average of 2.2‰ and the benthic foraminifer Ammonia beccarii parkinsoniana appeared in the sediment profile, indicating a hydrologic change that included increased lake water salinity. Pollen from a core in nearby Cenote San José Chulchacá showed a decrease in mesic forest taxa during the same period. Oxygen isotopes of shell carbonate in sediment cores from Lakes Chichancanab (19° 53.0'N, 88° 46.0'W) and Salpeten (16° 58.6'N, 89° 40.5'W) to the south also increased in the mid-15th century, but less so than in Aguada X'caamal. Climate change in the 15th century is also supported by historical accounts of cold and famine described in Maya and Aztec chronicles. We conclude that climate became drier on the Yucatan Peninsula in the 15th century A.D. near the onset of the Little Ice Age (LIA). Comparison of results from the Yucatan Peninsula with other circum-Caribbean paleoclimate records indicates a coherent climate response for this region at the beginning of the LIA. At that time, sea surface temperatures cooled and aridity in the circum-Caribbean region increased.

  15. Analytical design of conformally invisible cloaks for arbitrarily shaped objects.

    PubMed

    Jiang, Wei Xiang; Chin, Jessie Yao; Li, Zhuo; Cheng, Qiang; Liu, Ruopeng; Cui, Tie Jun

    2008-06-01

    To design conformally invisible cloaks for arbitrarily shaped objects, we use the nonuniform rational B -spline (NURBS) to represent the geometrical modeling of the arbitrary object. Based on the method of optical transformation, analytical formulas of the permittivity and permeability tensors are proposed for arbitrarily shaped invisible cloaks. Such formulas can be easily implemented in the design of arbitrary cloaks. Full-wave simulations are given for heart-shaped invisible cloaks and perfectly electrical conducting (PEC) objects, in which we observe that the power-flow lines of incoming electromagnetic waves will be bent smoothly in the cloaks and will return to their original propagation directions after propagating around the object. We also show that the scattered field from the PEC object coated with the invisible cloak is much smaller than that from the PEC core. The application of NURBS in the design of arbitrary cloaks shows transformation optics to be a very general tool to interface with commercial softwares like 3D STUDIOMAX and MAYA. PMID:18643390

  16. Promoting emotional health through haiku, a form of Japanese poetry.

    PubMed

    Massey, M S

    1998-02-01

    This teaching technique can be adapted to use with young children. The use of rhymes may be easier and more fun for younger students. Also, this teaching technique can be used to address numerous health issues, which makes it appropriate for all health content areas. In addition to using student selections that illustrate various emotions, other resources are available for this activity. Libraries and bookstores offer wide selections of books containing poetry and quotations. In addition to books about haiku, consider general poetry selections by Maya Angelou, e.e. cummings, Ogden Nash, and Shel Silverstein. Musical selections can represent different styles, such as the Beatles' "Yesterday"; Blind Melon's "Change"; Garth Brooks' "The Dance"; Eric Clapton's "Tears from Heaven"; Gloria Estefan's "Coming Out of the Dark"; Whitney Houston's "Emotional" and "I Will Always Love You"; and Elton John's "Circle of Life." Internet sites also can be accessed for poetry samples (see Internet Resources). An Internet resource for ordering discounted books, including selections about haiku and poetry, is Amazon.com--Earth's Largest Book store, at http:www.amazon.com/exec/obidos/ subst/home/home.html/0184-8423170-571096. PMID:9571577

  17. Tectonics and sedimentology along the Monkey River and Big Creek, southern Belize, Central America: Modern analog of select Morrow sands

    SciTech Connect

    Gries, J.C.; Full, W.E. )

    1991-08-01

    Big Creek is presently a relatively short river draining the flat coastal plain at the southern edge of the North American plate, south-central Belize. The recent sediments in this river consists of very fine-grained silts and clays derived from the local coastal plain. Offshore from the mouth of the Big Creek are shallow sand bars, channels, and eroding islands consisting of well-sorted, coarse sand comprised dominantly of feldspathic minerals. The location and geometry of these sands suggest that Big Creek was the fluvial source for this material. The sedimentology implication is that the nearshore and offshore parts of Big Creek represent a relatively large drowned deltaic complex, a modern analog of some lower Morrow depositional systems. Coarse feldspathic material found in the Cockscomb basin in the Maya Mountains is transported by the Swasey branch of the Monkey River toward the Big Creek drainage to the coast. However, the Swasey branch is abruptly diverted southward to intersect the present-day Monkey River. Drainage analysis suggests that structural features subsidiary to the Chixoy-Polochic fault zone bounding the North American plate may have diverted flow southward, beheading Big Creek. Field observations have not found any major relief changes which would have drainage analysis support tectonic diversion of the head waters of Big Creek into present-day Monkey River. Similar processes are hypothesized to have occurred during Morrow deposition.

  18. Pre-Columbian medicine and the kidney.

    PubMed

    Peña, J C

    1999-01-01

    Medicine in Mesoamerican cultures began in the year 1500 BC and ended with the conquest and destruction of Mexico-Tenochtitlan in 1521 by Spain. Mesoamerica started with the Olmec civilization followed by the Teoitihuacanes, Toltecs, and Mayas and perished with the Nahoa Empire. The medicine used by the Aztecs (ticiotl) is undoubtedly the sum of all Mesoamerican medicine. The medical history of the ticiotl was recovered in the years that followed the conquest from the works of Bernardino de Sahagún and Francisco Hernández and the Cruz-Badiano codex. All these works describe the use of plants and herbs in the treatment of diseases, including, edema, urinary retention, kidney stones, and podagra. The Aztec doctors (titicih) were also well acquainted with innumerable diseases and were excellent healers of wounds and fractures. The works of modern historians confirm the theory of the ticiotl medicine and its application by the titicih and define the differences between the hippocratic-galenic medicine and the ticiotl medicine. The latter used a complex and philosophically elaborated medical theory based on the polarity cold/warm, different from the four-humor theory. They demonstrate that every culture is capable to understand and 'invent' the meaning of disease and its cure, even when it is different from our modern medical views. PMID:10213809

  19. Astronomy and its role in ancient Mesoamerica

    NASA Astrophysics Data System (ADS)

    Šprajc, Ivan

    2011-06-01

    The observation of the sky had an important rôle among the Maya, Aztecs and other prehispanic peoples of Mesoamerica. Their familiarity with the regularities of the apparent motion of the Sun, the Moon and bright planets is attested in a large amount of astronomical data contained in codices and monumental hieroglyphic inscriptions, as well as in their sophisticated calendrical system. On the other hand, the study of architectural alignments has disclosed that civic and ceremonial buildings were largely oriented on astronomical grounds, mostly to sunrises and sunsets on certain dates, allowing the use of observational calendars that facilitated a proper scheduling of agricultural and the associated ritual activities in the yearly cycle. Both accurate knowledge and other astronomically-derived concepts reveal that the significance attributed to certain celestial events by the ancient Mesoamericans can be explained in terms of the relationship of these phenomena with specific environmental and cultural facts, such as seasonal climatic changes and subsistence strategies. It was particularly due to its practical utility that astronomy, intertwined with religious ideas and practices, had such an important place in the worldview and, consequently, in the cosmologically substantiated political ideology of Mesoamerican societies

  20. The History of Soil Science in Mexico

    NASA Astrophysics Data System (ADS)

    Gonzalez, J. M.; Ventura, E., Jr.; Castellanos, J. Z.; Brevik, E. C.

    2012-04-01

    There is a lack of information concerning the history of soil science in developing countries such as Mexico. Soil knowledge in the pre-Colombian era was a notable attribute of indigenous people in Mexico. Mayas and Aztecs classified soils based on properties and land use and developed a terminology still used by locals. International organizations and institutions advocating modern agricultural practices have played an important role in the development of soil science in Mexico, in conjunction with the Green Revolution in which the use of fertilizers for crop production was implemented. Soil fertility, as an area of study, has developed significantly in the country. One of the most significant impacts of the Green Revolution on the development of soil science in Mexico was through academic exchange, in which Mexican soil scientists obtained graduate-level degrees in the United States and later returned to Mexico to conduct research programs. Although Mexico has a long history of soil knowledge, soil scientists are facing several challenges today, including a lack of communication between farmers and scientists, soil erosion, soil contamination, and water usage. Some researchers have suggested that ethnopedological knowledge should be incorporated into modern Mexican soil science.

  1. Semantic processing of English sentences using statistical computation based on neurophysiological models

    PubMed Central

    Mitchell, Marcia T.

    2015-01-01

    Computer programs that can accurately interpret natural human language and carry out instructions would improve the lives of people with language processing deficits and greatly benefit society in general. von Neumann in theorized that the human brain utilizes its own unique statistical neuronal computation to decode language and that this produces specific patterns of neuronal activity. This paper extends von Neumann's theory to the processing of partial semantics of declarative sentences. I developed semantic neuronal network models that emulate key features of cortical language processing and accurately compute partial semantics of English sentences. The method of computation implements the MAYA Semantic Technique, a mathematical technique I previously developed to determine partial semantics of sentences within a natural language processing program. Here I further simplified the technique by grouping repeating patterns into fewer categories. Unlike other natural language programs, my approach computes three partial semantics. The results of this research show that the computation of partial semantics of a sentence uses both feedforward and feedback projection which suggest that the partial semantic presented in this research might be a conscious activity within the human brain. PMID:26106331

  2. Measurement of the isoscalar monopole response in the neutron-rich nucleus 68Ni.

    PubMed

    Vandebrouck, M; Gibelin, J; Khan, E; Achouri, N L; Baba, H; Beaumel, D; Blumenfeld, Y; Caamaño, M; Càceres, L; Colò, G; Delaunay, F; Fernandez-Dominguez, B; Garg, U; Grinyer, G F; Harakeh, M N; Kalantar-Nayestanaki, N; Keeley, N; Mittig, W; Pancin, J; Raabe, R; Roger, T; Roussel-Chomaz, P; Savajols, H; Sorlin, O; Stodel, C; Suzuki, D; Thomas, J C

    2014-07-18

    The isoscalar monopole response has been measured in the unstable nucleus (68)Ni using inelastic alpha scattering at 50A  MeV in inverse kinematics with the active target MAYA at GANIL. The isoscalar giant monopole resonance (ISGMR) centroid was determined to be 21.1 ± 1.9 MeV and indications for a soft monopole mode are provided for the first time at 12.9 ± 1.0 MeV. Analysis of the corresponding angular distributions using distorted-wave-born approximation with random-phase approximation transition densities indicates that the L = 0 multipolarity dominates the cross section for the ISGMR and significantly contributes to the low-energy mode. The L=0 part of this low-energy mode, the soft monopole mode, is dominated by neutron excitations. This demonstrates the relevance of inelastic alpha scattering in inverse kinematics in order to probe both the ISGMR and isoscalar soft modes in neutron-rich nuclei. PMID:25083638

  3. Why Go There? Evolution of Mobility and Spatial Cognition in Women and Men : An Introduction to the Special Issue.

    PubMed

    Cashdan, Elizabeth; Gaulin, Steven J C

    2016-03-01

    Males in many non-monogamous species have larger ranges than females do, a sex difference that has been well documented for decades and seems to be an aspect of male mating competition. Until recently, parallel data for humans have been mostly anecdotal and qualitative, but this is now changing as human behavioral ecologists turn their attention to matters of individual mobility. Sex differences in spatial cognition were among the first accepted psychological sex differences and, like differences in ranging behavior, are documented for a growing set of species. This special issue is dedicated to exploring the possible adaptive links between these cognitive and ranging traits. Multiple hypotheses, at various levels of analysis, are considered. At the functional (ultimate) level, a mating-competition hypothesis suggests that range expansion may augment mating opportunities, and a fertility-and-parental-care hypothesis suggests that range contraction may facilitate offspring provisioning. At a more mechanistic (proximate) level, differences in cue availability may support or inhibit particular sex-specific navigation strategies, and spatial anxiety may usefully inhibit travel that would not justify its costs. Studies in four different cultures-Twe, Tsimane, Yucatec Maya, and Faroese-as well as an experimental study using virtual reality tools are the venue for testing these hypotheses. Our hope is to stimulate more research on the evolutionary and developmental processes responsible for this suite of linked behavioral and cognitive traits. PMID:26768735

  4. Change in the Pathologic Supraspinatus: A Three-Dimensional Model of Fiber Bundle Architecture within Anterior and Posterior Regions

    PubMed Central

    Kim, Soo Y.; Sachdeva, Rohit; Li, Zi; Lee, Dongwoon; Rosser, Benjamin W. C.

    2015-01-01

    Supraspinatus tendon tears are common and lead to changes in the muscle architecture. To date, these changes have not been investigated for the distinct regions and parts of the pathologic supraspinatus. The purpose of this study was to create a novel three-dimensional (3D) model of the muscle architecture throughout the supraspinatus and to compare the architecture between muscle regions and parts in relation to tear severity. Twelve cadaveric specimens with varying degrees of tendon tears were used. Three-dimensional coordinates of fiber bundles were collected in situ using serial dissection and digitization. Data were reconstructed and modeled in 3D using Maya. Fiber bundle length (FBL) and pennation angle (PA) were computed and analyzed. FBL was significantly shorter in specimens with large retracted tears compared to smaller tears, with the deeper fibers being significantly shorter than other parts in the anterior region. PA was significantly greater in specimens with large retracted tears, with the superficial fibers often demonstrating the largest PA. The posterior region was absent in two specimens with extensive tears. Architectural changes associated with tendon tears affect the regions and varying depths of supraspinatus differently. The results provide important insights on residual function of the pathologic muscle, and the 3D model includes detailed data that can be used in future modeling studies. PMID:26413533

  5. Literacy shapes thought: the case of event representation in different cultures

    PubMed Central

    Dobel, Christian; Enriquez-Geppert, Stefanie; Zwitserlood, Pienie; Bölte, Jens

    2013-01-01

    There has been a lively debate whether conceptual representations of actions or scenes follow a left-to-right spatial transient when participants depict such events or scenes. It was even suggested that conceptualizing the agent on the left side represents a universal. We review the current literature with an emphasis on event representation and on cross-cultural studies. While there is quite some evidence for spatial bias for representations of events and scenes in diverse cultures, their extent and direction depend on task demands, one‘s native language, and importantly, on reading and writing direction. Whether transients arise only in subject-verb-object languages, due to their linear sentential position of event participants, is still an open issue. We investigated a group of illiterate speakers of Yucatec Maya, a language with a predominant verb-object-subject structure. They were compared to illiterate native speakers of Spanish. Neither group displayed a spatial transient. Given the current literature, we argue that learning to read and write has a strong impact on representations of actions and scenes. Thus, while it is still under debate whether language shapes thought, there is firm evidence that literacy does. PMID:24795665

  6. Carbonate facies and Landsat imagery of shelf off Belize, central America

    SciTech Connect

    Jordan, C.F. Jr.; Pusey, W.C. III; Belcher, R.C.; Borger, R.L.

    1985-02-01

    A reevaluation of Holocene sediments on the Belize shelf is based on (1) a newly constructed composite of 7 Landsat images, enhanced and registered to form a regional base map, and (2) a Holocene facies map based on a rigorous treatment of compositional and textural parameters for approximately 600 bottom samples. The sediments are mapped in terms usually applied to lithified carbonate rocks, allowing direct comparisons with carbonate facies in the subsurface. By combining Landsat imagery with this facies map, it is possible to point out the following geologic features: (1) major tectonic elements, such as the Maya Mountains, the Yucatan Plateau, several offshore bridges, and 3 large atolls, (2) major physiographic features such as the Belize barrier reef with its reef platform and crest, middle-shelf shoal deposits, middle-shelf patch reefs (including lagoon reefs or rhomboid reefs), (3) Holocene facies patterns with potential reservoir facies of foraminifera-grainstone bars, Halimeda grainstones, and branching-coral, encrusting red-algae boundstones, and (4) nearshore clastics and a sharp transition eastward to carbonate sediments. An understanding of Holocene facies patterns on the Belize shelf is important to the explorationist, because these facies patterns are living examples of exploration fairways and invite comparisons with several petroleum provinces: (1) Cretaceous reefs of Texas, (2) upper Paleozoic skeletal-grainstone bars in west Texas, and (3) Devonian reefs of the Alberta basin.

  7. A model of the 4000-year paleohydrology (δ18O) record from Lake Salpetén, Guatemala

    NASA Astrophysics Data System (ADS)

    Rosenmeier, Michael F.; Brenner, Mark; Hodell, David A.; Martin, Jonathan B.; Curtis, Jason H.; Binford, Michael W.

    2016-03-01

    A simple mass-balance model provides insights into the influence of catchment vegetation changes and climate variability on the hydrologic and stable oxygen isotope (δ18O) evolution of Lake Salpetén, in the Maya Lowlands of northern Guatemala. Model simulations for the last 4000 years incorporate pollen-inferred changes in vegetation cover and account for 75% of the variance observed in the biogenic carbonate δ18O record from a long lake sediment core. Vegetation-driven hydrologic changes, however, failed to capture the full range of late Holocene sediment core δ18O variability. The model requires incorporation of additional shifts in catchment vegetation cover, inclusion of regional precipitation changes, or likely both, to explain the fluctuations observed in the lake core oxygen isotope record. Climatic interpretation of the model results suggests that there was relatively greater moisture availability between about 2400 and 1800 years ago, but increased δ18O values centered at ~ 3300, 2900, 500, and 200 calendar years before present (cal yr BP) indicate abrupt precipitation decreases. There is evidence for protracted aridity between 1500 and 800 cal yr BP.

  8. Mesoamerican cosmovision: an hypothesis.

    NASA Astrophysics Data System (ADS)

    Franch, J. A.

    In the present conference the author explains a new hypothesis to interpret the cosmogonic vision of the people and the cultures from the Mesoamerican area during the precolumbian period. The hypothesis at issue consists in irregular octahedrical form, or as two pyramids jointed by the base in such a manner that the celestial pyramid has thirteen heavens in the form of platforms in such a way that the zenith is the seventh platform; on the contrary, the infraworld pyramid has nine platforms. The sequence of the heavens comes to an end in the number 13 heaven, or the West side of the world, that is to say the Omeyocan or the Tamoanchan, whereas the ninth infraworld is the Apochcalocan. This is the point of the intercommunication between the celestial world and the infraworld, the place of Death and Birth. In order to develop that hypothesis the author has a great number of ethnographic testimonies taken from Totonacs, Tzotziles, Mayas and, along with this, from Southamerican areas, as it is the case of the Kogi, of Colombia. The author has also considered the evidence that proceeds from the ancient codices as well as numerous samples of sculptures and reliefs, especially from the Aztec culture.

  9. Role of the resid solvent in catalytic coprocessing with finely divided catalysts. Final report

    SciTech Connect

    Curtis, C.W.

    1996-01-01

    The role of the resid in coprocessing coal with petroleum resid has been investigated using model systems. The primary question being investigated is whether resid is participating in reactions with coal or if the resid is acting simply as a diluent. Since hydrogen transfer is an important mechanism by which solvent interacts with coal, hydrogen transfer between naphthenes, saturated alicyclic molecules, that represent resid and aromatic molecules that represent coal were examined in reactions with a high pressure H{sub 2} atmosphere that is typical of actual coprocessing. The model naphthene, perhydropyrene, was chosen as the donor species and the models, anthracene, phenanthrene, and benzophenone, were chosen as the acceptor species. Coprocessing reactions of coal with petroleum resid were performed to evaluate the effect of the chemistry of both constituents on coal conversion and the upgrading of the heavy resid. Three heavy resids, Maya, FHC-623 and Manji were used as the whole resid and as fractions that has been separates into hexane solubles and saturate fractions.

  10. Conference Committees: Conference Committees

    NASA Astrophysics Data System (ADS)

    2009-09-01

    International Programm Committee (IPC) Harald Ade NCSU Sadao Aoki University Tsukuba David Attwood Lawrence Berkeley National Laboratory/CXRO Christian David Paul Scherrer Institut Peter Fischer Lawrence Berkeley National Laboratory Adam Hitchcock McMaster University Chris Jacobsen SUNY, Stony Brook Denis Joyeux Lab Charles Fabry de l'Institut d'Optique Yasushi Kagoshima University of Hyogo Hiroshi Kihara Kansai Medical University Janos Kirz SUNY Stony Brook Maya Kiskinova ELETTRA Ian McNulty Argonne National Lab/APS Alan Michette Kings College London Graeme Morrison Kings College London Keith Nugent University of Melbourne Zhu Peiping BSRF Institute of High Energy Physics Francois Polack Soleil Christoph Quitmann Paul Scherrer Institut Günther Schmahl University Göttingen Gerd Schneider Bessy Hyun-Joon Shin Pohang Accelerator Lab Jean Susini ESRF Mau-Tsu Tang NSRRC Tony Warwick Lawrence Berkeley Lab/ALS Local Organizing Committee Christoph Quitmann Chair, Scientific Program Charlotte Heer Secretary Christian David Scientific Program Frithjof Nolting Scientific Program Franz Pfeiffer Scientific Program Marco Stampanoni Scientific Program Robert Rudolph Sponsoring, Financials Alfred Waser Industry Exhibition Robert Keller Public Relation Markus Knecht Computing and WWW Annick Cavedon Proceedings and Excursions and Accompanying Persons Program Margrit Eichler Excursions and Accompanying Persons Program Kathy Eikenberry Excursions and Accompanying Persons Program Marlies Locher Excursions and Accompanying Persons Program

  11. An ˜1500 year history of El Niño Southern Oscillation rainfall anomalies and land use for the Isthmus of Panama from speleothem calcite

    NASA Astrophysics Data System (ADS)

    Lachniet, M. S.; Burns, S. J.; Piperno, D. R.; Asmerom, Y.; Polyak, V. P.

    2003-12-01

    The history of the El Niño Southern Oscillation (ENSO) over the past two millennia remains poorly constrained. To document further the tropical paleoclimatic response to ENSO, we present a precisely-dated (180 B.C. to 1310 A.D.), high-resolution ( ˜3 yr / sample), cave calcite isotopic time series from the Isthmus of Panama, a region that experiences ENSO-forced rainfall anomalies. We show evidence for rapid and dramatic rainfall variation in southern Central America, as inferred from stalagmite δ 18O isotope stratigraphy. Isthmian convective rainfall from 550 A.D. to 1300 A.D. was both less intense and more variable than the period 180 B.C. to 550 A.D. Speleothem growth spanned the interval of the Classic Maya Collapse (750 - 950 A.D.), and provides additional evidence for dry anomalies at this time. Carbon isotopes document changing vegetation from native rainforest to grasslands and/or maize, a period of soil erosion associated with pre-Colombian agriculture, and final forest recovery. We suggest that ENSO-forced sea surface temperature anomalies in the eastern equatorial Pacific Ocean resulted in isthmian rainfall anomalies over much of the past two millennia. Our data suggest that El Niño events are associated with decreased isthmian rainfall, and that increased ENSO activity results in generally drier and more variable conditions.

  12. Female social response to male sexual harassment in poeciliid fish: a comparison of six species.

    PubMed

    Dadda, Marco

    2015-01-01

    Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki), when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of six poeciliid species (Girardinus metallicus, Girardinus falcatus, G. holbrooki, Poecilia reticulata, Xiphophorus hellerii, and Xiphophorus mayae) that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females' social distance when a male is present may indeed serve to reduce the costs of male sexual harassment. PMID:26483719

  13. Reconstruction and 3D visualisation based on objective real 3D based documentation.

    PubMed

    Bolliger, Michael J; Buck, Ursula; Thali, Michael J; Bolliger, Stephan A

    2012-09-01

    Reconstructions based directly upon forensic evidence alone are called primary information. Historically this consists of documentation of findings by verbal protocols, photographs and other visual means. Currently modern imaging techniques such as 3D surface scanning and radiological methods (computer tomography, magnetic resonance imaging) are also applied. Secondary interpretation is based on facts and the examiner's experience. Usually such reconstructive expertises are given in written form, and are often enhanced by sketches. However, narrative interpretations can, especially in complex courses of action, be difficult to present and can be misunderstood. In this report we demonstrate the use of graphic reconstruction of secondary interpretation with supporting pictorial evidence, applying digital visualisation (using 'Poser') or scientific animation (using '3D Studio Max', 'Maya') and present methods of clearly distinguishing between factual documentation and examiners' interpretation based on three cases. The first case involved a pedestrian who was initially struck by a car on a motorway and was then run over by a second car. The second case involved a suicidal gunshot to the head with a rifle, in which the trigger was pushed with a rod. The third case dealt with a collision between two motorcycles. Pictorial reconstruction of the secondary interpretation of these cases has several advantages. The images enable an immediate overview, give rise to enhanced clarity, and compel the examiner to look at all details if he or she is to create a complete image. PMID:21979427

  14. Mechanisms Underlying Early Medieval Droughts in Mesoamerica

    NASA Astrophysics Data System (ADS)

    Bhattacharya, T.; Chiang, J. C. H.

    2015-12-01

    Multidecadal drought during the early Medieval Climate Anomaly (MCA, 800-1200 CE) in Mesoamerica has been implicated in the demise of many pre-Columbian societies, including the Maya. The mechanisms behind these droughts, however, are poorly understood. Researchers most often interpret these records as tracking the mean position of the ITCZ, with a southward shifted ITCZ resulting in Mesoamerican drought. This is puzzling, however, because our dynamical understanding of the ITCZ and its role in interhemispheric heat transport would suggest a more northward shifted ITCZ during the MCA. Here, we evaluate two hypotheses to reconcile existing proxies and dynamics. First, we assess whether evidence for dry conditions during the MCA is robust across multiple Mesoamerican proxy records, focusing on the influence of radiometric dating uncertainty on estimates of drought timing. Second, we use control simulations of CCSM4 and HadCM3, as well as a broader synthesis of oceanic and terrestrial proxies, to explore the mechanisms responsible for long-term drought in Mesoamerica. Ultimately, we suggest that a temporary slowdown of the AMOC, either internally or externally forced, combined with local and regional land surface feedbacks can explain these droughts in Mesoamerica.

  15. Hydroconversion reactions catalyzed by highly stable pillared clays

    SciTech Connect

    Gomez, S.A.; Mosqueira, L.; Espinosa, J.; Fuentes, G.A.

    1993-12-31

    Al-pillared clays (Al-PILC) and Al-X-PILC (X = Ga, Ni), structurally stable at high temperature - in the case of Ga above 800{degrees}C-have been synthesized by controlling intercalation steps and stabilization procedures. New bidimensional materials with an interlaminar distance about 10-12{angstrom} and with different chemical reactivities in the pillars have thus been produced. The analytical techniques employed to characterize the materials and the processes involved during stabilization include N{sub 2} adsorption, AA, XRD, NH{sub 3}-TPD, TGA-DTA, HR- and MAS-NMR (Al, Si, and Ga) and in-situ IR and DRIFTS. Chemical characterization using high pressure reactions with probe molecules such as diphenylmethane and tert-butylbenzene shows selectivity patterns than can be clearly associated with the microstructure of the PILC used, as well as an effect due to the composition of the pillars. Similar studies with zeolites give patterns that differ from those of PILC, probably because of the change in dimensionality of the internal structure. Poisoning studies with metal porphyrins prove that PLIC have improved resistance compared to standard catalysts. Hydrotreatment of Maya crude results a significant reduction in total sulfur under conditions suitable for commercial operation.

  16. Calcium Transport by Corn Mitochondria 1

    PubMed Central

    Silva, Marco Aurelio P.; Carnieri, Eva G. S.; Vercesi, Anibal E.

    1992-01-01

    Mitochondria from some plant tissues possess the ability to take up Ca2+ by a phosphate-dependent mechanism associated with a decrease in membrane potential, H+ extrusion, and increase in the rate of respiration (AE Vercesi, L Pereira da Silva, IS Martins, CF Bernardes, EGS Carnieri, MM Fagian [1989] In G Fiskum, ed, Cell Calcium Metabolism. Plenum Press, New York, pp 103-111). The present study reexamined the nature of the phosphate requirement in this process. The main observations are: (a) Respiration-coupled Ca2+ uptake by isolated corn (Zea mays var Maya Normal) mitochondria or carbonyl cyanide p-trifluoromethoxyphenylhydrazone-induced efflux of the cation from such mitochondria are sensitive to mersalyl and cannot be dissociated from the silmultaneous movement of phosphate in the same direction. (b) Ruthenium red-induced efflux is not affected by mersalyl and can occur in the absence of phosphate movement. (c) In Ca2+-loaded corn mitochondria, mersalyl causes net Ca2+ release unrelated to a decrease in membrane potential, probably due to an inhibition of Ca2+ cycling at the level of the influx pathway. It is concluded that corn mitochondria (and probably other plant mitochondria) do possess an electrophoretic influx pathway that appears to be a mersalyl-sensitive Ca2+/inorganic phosphate-symporter and a phosphate-independent efflux pathway possibly similar to the Na2+-independent Ca2+ efflux mechanism of vertebrate mitochondria, because it is not stimulated by Na+. PMID:16668661

  17. Toxicity of binary mixtures of oil fractions to sea urchin embryos.

    PubMed

    Rial, Diego; Vázquez, José A; Menduiña, Araceli; García, Ana M; González, M Pilar; Mirón, Jesús; Murado, Miguel A

    2013-12-15

    The assumption of additive toxicity for oil compounds is related to a narcotic mode of action. However, the joint toxicity of oil fractions has not been fully investigated. A fractionation of Maya crude oil into aliphatics, aromatics and polars was performed, fractions were dissolved in dimethyl sulfoxide (DMSO) and subsequently toxicity of single fractions and binary mixtures was assessed using the sea urchin embryo test. The descriptive ability of Concentration Addition (CA), Independent Action (IA) and modifications of both models for describing the joint toxicity of mixtures has also been evaluated. The hydrocarbon content extractable with dichloromethane of the fractions dissolved in DMSO was: 12.0 ± 1.8 mg mL(-1), 39.0 ± 0.5 mg mL(-1) and 20.5 ± 2.5 mg mL(-1) for aliphatics, aromatics and polars, respectively. The toxicity of the extracts in DMSO of the fractions as EC50 (μLL(-1)) was: aliphatics (165.8-242.3)

  18. GET_HOMOLOGUES, a versatile software package for scalable and robust microbial pangenome analysis.

    PubMed

    Contreras-Moreira, Bruno; Vinuesa, Pablo

    2013-12-01

    GET_HOMOLOGUES is an open-source software package that builds on popular orthology-calling approaches making highly customizable and detailed pangenome analyses of microorganisms accessible to nonbioinformaticians. It can cluster homologous gene families using the bidirectional best-hit, COGtriangles, or OrthoMCL clustering algorithms. Clustering stringency can be adjusted by scanning the domain composition of proteins using the HMMER3 package, by imposing desired pairwise alignment coverage cutoffs, or by selecting only syntenic genes. The resulting homologous gene families can be made even more robust by computing consensus clusters from those generated by any combination of the clustering algorithms and filtering criteria. Auxiliary scripts make the construction, interrogation, and graphical display of core genome and pangenome sets easy to perform. Exponential and binomial mixture models can be fitted to the data to estimate theoretical core genome and pangenome sizes, and high-quality graphics can be generated. Furthermore, pangenome trees can be easily computed and basic comparative genomics performed to identify lineage-specific genes or gene family expansions. The software is designed to take advantage of modern multiprocessor personal computers as well as computer clusters to parallelize time-consuming tasks. To demonstrate some of these capabilities, we survey a set of 50 Streptococcus genomes annotated in the Orthologous Matrix (OMA) browser as a benchmark case. The package can be downloaded at http://www.eead.csic.es/compbio/soft/gethoms.php and http://maya.ccg.unam.mx/soft/gethoms.php. PMID:24096415

  19. Soil conservation in Central America and Panama: current problems.

    PubMed

    Popenoe, H

    1976-06-01

    Soil conservation measures in Central America go back to the Maya civilization, in which terracing was employed. After the Spanish conquest, plowing, livestock raising, and the succession of social and political changes all contributed to accelerate erosion. Through the past few decades, awareness of the need for soil conservation has again increased; El Salvador and Costa Rica began efforts in that direction in 1943. For sometime, the use of machinery and chemical fertilizers has masked the loss of topsoil, but under recent increases in population pressures, soil conservation measures are gaining in importance. Important agents of erosion in the tropics are heavy seasonal rains at high elevations, alternating with long dry seasons; wind erosion; and landslides after saturation of the soil during prolonged rains. Modern machinery often hastens soil removal, as do also overgrazing, deforestation and vertical crop rows. Under the present energy crisis, human labor is becoming again a significant element in crop production, and soil conservation becomes thereby more feasible and more important. PMID:948649

  20. Measurement of the Isoscalar Monopole Response in the Neutron-Rich Nucleus Ni68

    NASA Astrophysics Data System (ADS)

    Vandebrouck, M.; Gibelin, J.; Khan, E.; Achouri, N. L.; Baba, H.; Beaumel, D.; Blumenfeld, Y.; Caamaño, M.; Càceres, L.; Colò, G.; Delaunay, F.; Fernandez-Dominguez, B.; Garg, U.; Grinyer, G. F.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Keeley, N.; Mittig, W.; Pancin, J.; Raabe, R.; Roger, T.; Roussel-Chomaz, P.; Savajols, H.; Sorlin, O.; Stodel, C.; Suzuki, D.; Thomas, J. C.

    2014-07-01

    The isoscalar monopole response has been measured in the unstable nucleus Ni68 using inelastic alpha scattering at 50A MeV in inverse kinematics with the active target MAYA at GANIL. The isoscalar giant monopole resonance (ISGMR) centroid was determined to be 21.1±1.9 MeV and indications for a soft monopole mode are provided for the first time at 12.9±1.0 MeV. Analysis of the corresponding angular distributions using distorted-wave-born approximation with random-phase approximation transition densities indicates that the L =0 multipolarity dominates the cross section for the ISGMR and significantly contributes to the low-energy mode. The L=0 part of this low-energy mode, the soft monopole mode, is dominated by neutron excitations. This demonstrates the relevance of inelastic alpha scattering in inverse kinematics in order to probe both the ISGMR and isoscalar soft modes in neutron-rich nuclei.

  1. Heavy resid asphaltene characterization using high resolution and laser desorption mass spectrometry

    SciTech Connect

    Hunt, J.E.; Kim, Y.; Winans, R.E.

    1995-12-31

    Resid is the nondistillable portion of crude oil, generally thought to consist largely of unsaturated molecules of considerable size and ring number. Such molecules must be upgraded to more saturated compounds if they are to be used as fuel sources. Current processing of resid is performed though coking, thermal and catalytic cracking, deasphalting and hydroprocessing. Thermal treatments, however, produce large quantities of low-value coke and hydroprocessing is expensive. Asphaltenes comprise the most process resistant portion of the resid. They contain high concentrations of heteroatoms and a high degree of unsaturation. Because these undesirable characteristics are concentrated in asphaltenes, finding an improved method of upgrading asphaltenes is a prerequisite to improving the upgrading of whole resid to viable fuel. Asphaltenes have, at present, only an operational definition. They are insoluble in straight chain saturated hydrocarbons. Very little is known about the structure of compounds in asphaltenes. They are a highly diverse group of compounds that are resistant to analysis by conventional methods. Conclusions about the structures of asphaltenes tends to be speculative. In this study desorption electron impact (HREIMS), chemical ionization high resolution mass spectrometry (HRCIMS), and laser desorption mass spectrometry (LD) have been applied to deasphalted oils (DAO) and asphaltenes derived from heavy Maya resid. LD data should yield information on the high molecular weight aromatic compounds, while HRMS can provide molecular characterization.

  2. Environmental predictors of pre-European deforestation on Pacific islands.

    PubMed

    Rolett, Barry; Diamond, Jared

    2004-09-23

    Some Pacific island societies, such as those of Easter Island and Mangareva, inadvertently contributed to their own collapse by causing massive deforestation. Others retained forest cover and survived. How can those fateful differences be explained? Although the answers undoubtedly involve both different cultural responses of peoples and different susceptibilities of environments, how can one determine which environmental factors predispose towards deforestation and which towards replacement of native trees with useful introduced tree species? Here we code European-contact conditions and nine environmental variables for 81 sites on 69 Pacific islands from Yap in the west to Easter in the east, and from Hawaii in the north to New Zealand in the south. We thereby detect statistical decreases in deforestation and/or forest replacement with island rainfall, elevation, area, volcanic ash fallout, Asian dust transport and makatea terrain (uplifted reef), and increases with latitude, age and isolation. Comparative analyses of deforestation therefore lend themselves to much more detailed interpretations than previously possible. These results might be relevant to similar deforestation-associated collapses (for example, Fertile Crescent, Maya and Anasazi) or the lack thereof (Japan and highland New Guinea) elsewhere in the world. PMID:15386010

  3. Mineral content as a basis for food selection by western lowland gorillas in a forest clearing.

    PubMed

    Magliocca, Florence; Gautier-Hion, Annie

    2002-06-01

    The forests in northwest Republic of Congo contain a number of herbaceous swamp clearings that provide foraging sites for lowland gorillas (G.g. gorilla). A 10-month study at the Maya Nord clearing (Parc National d'Odzala) showed that feeding activities occupied 72% of the time visiting gorillas spent on the clearing. They fed on four plant species: Enydra fluctuans (Asteraceae), Cyperus sp., Pycreus mundtii, and Rhynchospora corymbosa (Cyperaceae) among the 45 species recorded on the clearing. These clearing food species have higher mineral contents (especially Na and Ca) than the dominant Marantaceae species (Haumania liebrechtsiana) that constituted a staple food plant for gorillas in this forest. They also have higher potassium contents and contain less lignin than non-eaten clearing items/species. Finally, the most actively searched for clearing food (Enydra fluctuans) was characterized by the highest amount of Na and Ca. These results suggest that the mineral content (especially in Na, Ca, and/or K) could determine the feeding selectivity of gorillas at the clearing. They also tend to confirm that the amount of fiber plays a deterrent role in food selectivity, as has been found by many authors. The high density of gorillas in that region could result from the combination of the large areas of Marantaceae forests that provide abundant though monotonous food, and the number of clearings that provide sufficient mineral supplies. Clearings should thus be considered as key habitats for the conservation of gorillas. PMID:12111682

  4. Presentation of Anatomical Variations Using the Aurasma Mobile App

    PubMed Central

    Bézard, Georg; Lozanoff, Beth K; Labrash, Steven; Lozanoff, Scott

    2015-01-01

    Knowledge of anatomical variations is critical to avoid clinical complications and it enables an understanding of morphogenetic mechanisms. Depictions are comprised of photographs or illustrations often limiting appreciation of three-dimensional (3D) spatial relationships. The purpose of this study is to describe an approach for presenting anatomical variations utilizing video clips emphasizing 3D anatomical relationships delivered on personal electronic devices. An aberrant right subclavian artery (ARSA) was an incidental finding in a routine dissection of an 89-year-old man cadaver during a medical student instructional laboratory. The specimen was photographed and physical measurements were recorded. Three-dimensional models were lofted and rendered with Maya software and converted as Quicktime animations. Photographs of the first frame of the animations were recorded and registered with Aurasma Mobile App software (www.aurasma.com). Resulting animations were viewed on mobile devices. The ARSA model can be manipulated on the mobile device enabling the student to view and appreciate spatial relationships. Model elements can be de-constructed to provide even greater spatial resolution of anatomical relationships. Animations provide a useful approach for visualizing anatomical variations. Future work will be directed at creating a library of variants and underlying mechanism of formation for presentation through the Aurasma application. PMID:26793410

  5. Resource use in the tropical karstlands of central Belize

    NASA Astrophysics Data System (ADS)

    Day, M.

    1993-06-01

    Rural tropical ecosystems are subject to many traditional land uses that employ the indigenous karst resources: rock, water, soil, vegetation, and wildlife. Individual resource pressures often are subtle, but their combined impact can precipitate instability in the tropical karst environment, potentially resulting in disruption of food, water, and fuel supplies. The karst of central Belize was used intensively for some six centuries by Maya farmers, but between the 10th and 19th centuries AD most of it reverted to secondary forest. Commercial logging dominated the 19th and early 20th centuries, followed by the expansion of subsistence and commercial agriculture after 1945. In the 1980s resource use has accelerated as population and other pressures increase. Much karst remains forested, but there is increasing clearance for agricultural uses, particularly for citrus cultivation and small-scale mixed agriculture. Soil depletion has begun to occur, water resources are increasingly taxed, and some wildlife is threatened by habitat destruction and increased hunting. Lime production for the citrus industry has promoted quarrying, water extraction, and fuelwood use. Environmental stresses currently do not exceed the threshold of instability, but the rapidly developing rural economy warrants careful monitoring of resource pressures.

  6. The interaction of disturbances and small mammal community dynamics in a lowland forest in Belize.

    PubMed

    Klinger, R

    2006-11-01

    1. Three floods (July 2000, August 2002, September 2003) and a hurricane (October 2001) that occurred in a lowland forest in the southern Maya Mountains of Belize presented an opportunity to evaluate the influence of these disturbances on the structure of a small mammal assemblage. 2. Four terrestrial and four primarily scansorial/arboreal species were trapped July 2000-March 2005 in six grids over 14 irregularly spaced trapping periods. 3. Community dynamics were characterized more by changes in species composition than changes in diversity. The dynamics were driven by species-specific variation in abundance, with changes in composition generally, but not exclusively, due to the occurrence or disappearance of species at low abundance. Despite the disturbances, species richness remained relatively constant. Evenness within the assemblage was consistently low, primarily as a result of dominance by one species, Heteromys desmarestianus. 4. Effects of flooding on community structure were direct but relatively brief (< 1 year), and varied with the duration and intensity of flooding. Effects from the hurricane were indirect but long-lasting and strongly related to severely reduced food resources. 5. This study suggests that long-term dynamics in the structure of many animal communities in the tropics often results from interactions between direct and indirect effects of disturbance. It also suggests that community resistance will depend on variation in disturbance type and regime, but resilience will be determined by the life-history characteristics of each species. PMID:17032355

  7. Climate drying and associated forest decline in the lowlands of northern Guatemala during the late Holocene

    NASA Astrophysics Data System (ADS)

    Mueller, Andreas D.; Islebe, Gerald A.; Hillesheim, Michael B.; Grzesik, Dustin A.; Anselmetti, Flavio S.; Ariztegui, Daniel; Brenner, Mark; Curtis, Jason H.; Hodell, David A.; Venz, Kathryn A.

    2009-03-01

    Palynological studies document forest disappearance during the late Holocene in the tropical Maya lowlands of northern Guatemala. The question remains as to whether this vegetation change was driven exclusively by anthropogenic deforestation, as previously suggested, or whether it was partly attributable to climate changes. We report multiple palaeoclimate and palaeoenvironment proxies (pollen, geochemical, sedimentological) from sediment cores collected in Lake Petén Itzá, northern Guatemala. Our data indicate that the earliest phase of late Holocene tropical forest reduction in this area started at ˜ 4500 cal yr BP, simultaneous with the onset of a circum-Caribbean drying trend that lasted for ˜ 1500 yr. This forest decline preceded the appearance of anthropogenically associated Zea mays pollen. We conclude that vegetation changes in Petén during the period from ˜ 4500 to ˜ 3000 cal yr BP were largely a consequence of dry climate conditions. Furthermore, palaeoclimate data from low latitudes in North Africa point to teleconnective linkages of this drying trend on both sides of the Atlantic Ocean.

  8. Recruitment to a ritual role.

    PubMed

    Paul, L

    1975-01-01

    In the Zutuhil-Maya community of San Pedro la Laguna, a Guatemalan highland settlement with a population of 5000 Indians, midwives are recruited from the pool of married women in the 35-40 year age range who have heavy responsibilities as wives and mothers. They are relatively few in number and carry heavier patient loads than midwives in other communities. Their office is owed to divine mandate, and their work is guided by supernatural tutelaries. Duties of the midwives in this community include ritual performances. As sacred professionals, Pedrano midwives enjoy high status. The biography of Juana, a prototypical midwife, is recounted to illustrate how some Pedrano women do manage to become midwives. In San Pedro, midwives are born and not made, yet this is only the 1st step in the selection process. The common elements of the pattern of selection and recruitment include birth signs, enigmatic dreams in preadolescent years, the onset during married life of misforture and persisting illness accompanied by dream revelation, confirmation by a shaman of the woman's true destiny, discovery of strange objects mysteriously placed in her path, and disappearance of ill health and ill fortune upon beginning practice. The women who go this entire route and become successful midwives tend to share certain characteristics related to family background, parental expectation, and economic situation. PMID:12336264

  9. Production of two novel laccase isoforms by a thermotolerant strain of Pycnoporus sanguineus isolated from an oil-polluted tropical habitat.

    PubMed

    Dantán-González, Edgar; Vite-Vallejo, Odón; Martínez-Anaya, Claudia; Méndez-Sánchez, Mónica; González, María C; Palomares, Laura A; Folch-Mallol, Jorge

    2008-09-01

    A thermotolerant and halotolerant strain of Pycnoporus sanguineus was isolated from an oil-polluted site in a tropical area located in Veracruz, Mexico. This strain was able to grow at 47 degrees C and in culture medium containing 500 mM NaCl. The strain was also tolerant to the presence of 30,000 ppm of crude Maya oil. A 68-kDa protein purified from submerged cultures exhibited laccase activity towards 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), guaiacol, syringaldazine, and o-dianisidine, for which it presented the highest affinity (Km = 43 microM). Two-dimensional gel electrophoresis analysis showed that, unusual for laccases, the enzyme has two active isoforms, with isoelectric points of 7.00 and 7.08. The purified enzyme showed high thermostability, retaining 40% of its original activity after 3 h at 60 degrees C. This property seems to correlate with a long "shelf-life," given that at 40 degrees C enzyme activity was only gradually lost over a 5-day period incubation. Both the fungus and its laccase are likely to have high potential for biotechnological applications. PMID:18843594

  10. Impact-generated Hydrothermal Activity at the Chicxulub Crater

    NASA Astrophysics Data System (ADS)

    Kring, D. A.; Zurcher, L.; Abramov, O.

    2007-05-01

    Borehole samples recovered from PEMEX exploration boreholes and an ICDP scientific borehole indicate the Chicxulub impact event generated hydrothermal alteration throughout a large volume of the Maya Block beneath the crater floor and extending across the bulk of the ~180 km diameter crater. The first indications of hydrothermal alteration were observed in the crater discovery samples from the Yucatan-6 borehole and manifest itself in the form of anhydrite and quartz veins. Continuous core from the Yaxcopoil-1 borehole reveal a more complex and temporally extensive alteration sequence: following a brief period at high temperatures, impact- melt-bearing polymict breccias and a thin, underlying unit of impact melt were subjected to metasomatism, producing alkali feldspar, sphene, apatite, and magnetite. As the system continued to cool, smectite-series phyllosilicates appeared. A saline solution was involved. Stable isotopes suggest the fluid was dominated by a basinal brine created mostly from existing groundwater of the Yucatan Peninsula, although contributions from down-welling water also occurred in some parts of the system. Numerical modeling of the hydrothermal system suggests circulation occurred for 1.5 to 2.3 Myr, depending on the permeability of the system. Our understanding of the hydrothermal system, however, is still crude. Additional core recovery projects, particularly into the central melt sheet, are needed to better evaluate the extent and duration of hydrothermal alteration.

  11. Detection of ground deformation over Sharm El-Sheikh-Ras Nasrani coastal zone, South Sinai (Egypt), by using time series SAR interferometry

    NASA Astrophysics Data System (ADS)

    Seleem, Tarek A.; Parcharidis, Issaak; Foumelis, Michael; Kourkouli, Penelope

    2011-03-01

    The investigation area is located in the most southern part of Sinai Peninsula boarded from the west by the Gulf of Suez and from the east by the Gulf of Aqaba. The present study concerns the application of stacking and persistent scattering of SAR interferometry in order to monitor ground deformation in the southern part of Sharm El-Shiekh area. The specific techniques were applied in order to reduce the influence of atmospheric effects on the ground deformation estimates. For this purpose a total number of 26 ENVISAT ASAR scenes covering the period between 2003 and 2009 were processed and analyzed. Interferometric processing results show both patterns of uplift and downlift in the study area. Specifically an area along the coastline with a N-S direction, corresponding to the build up zone of Sharm El-Sheikh, shows annual average subsidence rates between 5 and 7 mm/yr along the line of sight (LOS). On the contrary, Sharm El-Maya, an inner zone, parallel to the above subsided area; shows maximum slant range uplift of 5 mm/yr. The obtained results of both stacking and persistent scattering indicate that the ground deformation in Sharm El-Sheikh-Ras Nasrani coastal zone is attributed to several effecting factors compromising water pumping, lithology, seismicity, and possible active fracture. The contribution of all these factors is discussed in the context.

  12. Semantic processing of English sentences using statistical computation based on neurophysiological models.

    PubMed

    Mitchell, Marcia T

    2015-01-01

    Computer programs that can accurately interpret natural human language and carry out instructions would improve the lives of people with language processing deficits and greatly benefit society in general. von Neumann in theorized that the human brain utilizes its own unique statistical neuronal computation to decode language and that this produces specific patterns of neuronal activity. This paper extends von Neumann's theory to the processing of partial semantics of declarative sentences. I developed semantic neuronal network models that emulate key features of cortical language processing and accurately compute partial semantics of English sentences. The method of computation implements the MAYA Semantic Technique, a mathematical technique I previously developed to determine partial semantics of sentences within a natural language processing program. Here I further simplified the technique by grouping repeating patterns into fewer categories. Unlike other natural language programs, my approach computes three partial semantics. The results of this research show that the computation of partial semantics of a sentence uses both feedforward and feedback projection which suggest that the partial semantic presented in this research might be a conscious activity within the human brain. PMID:26106331

  13. The Sun in Time

    NASA Technical Reports Server (NTRS)

    Adams, Mitzi L.; Sever, Thomas L.; Bero, Elizabeth

    1998-01-01

    Using a grant from NASA's Initiative to Develop Education through Astronomy and Space Science (IDEAS) program, we have developed an inter-disciplinary curriculum for middle-school students which targets both history and astronomy. Our curriculum explores the attitudes and techniques of ancient spiritual leaders, specifically those of the Maya and Inca cultures, who observed and tried to control the Sun. We wish students to understand the probable importance of astronomical observations to these ancient peoples. In addition, using the experience of an archaeologist, we show how modern techniques of viewing the Earth through satellite imagery, has allowed the re-discovery of ancient sites where solar observations and attempted manipulation of the universe took place. To contrast ancient observations of the Sun with modern ones, we use the experience of a solar astronomer and bring to the classroom up-to-date information about solar astronomy and the impact of solar activity on the Earth's environment. In this presentation, we will present fragments of our curriculum as well as results from pre- and post-tests given to participating groups of students. Finally, we will discuss comments from local middle-school teachers who were asked to evaluate our curriculum.

  14. The Sun in Time

    NASA Technical Reports Server (NTRS)

    Adams, Mitzi L.; Bero, Elizabeth; Sever, Thomas L.

    1999-01-01

    Leveraging funds from NASA's Initiative to Develop Education through Astronomy and Space Science (IDEAS) program, we combined the expertise of an archaeoastronomer, a solar scientist, and a teacher to trace humankind's view of the Sun and how that has changed, from the time of Stonehenge in about 1800 B.C.E., to the time of the Maya in 700 C.E., up to the modem era. Our program was aimed at middle-school students in an attempt to explain not only how science is done today, but how science has evolved from the observations of ancient societies. From these varied cultures, we touched on methods of observing the Sun, ideas of the composition of the Sun, and the relationship of the Sun to everyday life. Further, using the von Braun Astronomical Society's Planetarium in Huntsville, Alabama as a test-bed for the program, we illustrated concepts such as solstices, equinoxes, and local noon with approximately 800 eighth grade students from the local area. Our presentation to SEPA will include a description of NASA's IDEAS program and how to go about partnering with a NASA astronomer, some slides from our planetarium program and web-site, and some hands-on activities.

  15. Population genetics of 14 ethnic groups using phenotypic data from VNTR loci.

    PubMed

    Balazs, I

    1993-01-01

    Population genetic studies were performed using five VNTR loci (D2S44, D4S163, D14S13, D17S79, D18S27). The populations examined were Caucasian (Australia, Brazil and U.S.A.), Australian aborigine, Chinese, Amerindian (Cheyenne, Maya, Navajo, Pima, Tobas/Wicnis), North American Black, North American Hispanic (California, Miami, New York, Texas). The overall size range of the alleles for these loci, in PstI-digested DNA, was the same in all populations. The major difference among populations was the relative frequency of particular groups of alleles. These differences were small among similar ethnic groups, while sometimes varying several fold among some of the more distinct populations. However, groups of alleles that were rare in the major ethnic groups (Caucasian, Black, Chinese) were also rare in the other populations. The frequency databases generated by typing individuals for 4 loci were used to compare the random DNA profile frequencies among populations. The results show that the estimated frequency of any 4 locus profile is very low in all populations examined (e.g., median value < 10(-8)). Analysis of relative genetic similarity among populations was used to create the most likely clustering of these ethnic groups. Results show an uncanny similarity between the clusters generated and genetic distance measurements obtained with traditional calculations of conventional genetic markers. PMID:8104559

  16. Secrets of long life: cross-cultural explorations in sustainably enhancing vitality and promoting longevity via elders' practice wisdom.

    PubMed

    Pesek, Todd; Reminick, Ronald; Nair, Murali

    2010-01-01

    In searching for different patterns of practice, lifestyle, and environment supportive of optimal health, we look to our elders around the world, who in the wisdom that has sustained them, we learn from with careful attention. Thirty-seven elders who live by their traditions participated in the present study. They assisted in the refinement of the methodology and collections and preparation of these data. These participants are well-respected, representative elders and traditional healers of their regions. These data, from study sites of the Eastern Afromontane and Albertine Rift region of Ethiopia, Africa; the Maya Mountains region of Belize, Central America; the Western Ghats region of India; and the Appalachian Mountains region of the United States, were grouped into three major categories: (1) philosophy, attitudes, and outlook, (2) lifestyle practices, and (3) dietary and nutritional practices. These elders demonstrate a relatively comprehensive but simple set of practices that can enhance our vitality and promote longevity sustainably. In essence, these practices, or practice wisdom, of our longest living elders, promote propagation of healthful lifestyles by following traditional ways and taking care of body, mind, spirit and our environment. Further field research among a larger cohort is required to fully generalize the findings of this study, but much of it is consistent with what we already know should be done. These data begin illustration of practice wisdom for implementation and serve to engage our universities, our hospitals, our industries, and our students, who we must position toward social change. PMID:21040883

  17. [Social diseases, civilization diseases or lifestyle diseases?].

    PubMed

    Betlejewski, Stansław

    2007-01-01

    In general, the development of civilization is viewed as a positive step for the well-being of the human species, leading to an increased duration and quality of life. The accelerated progress of civilization (mainly industrialization, urbanization and nutrition) has lead to new possibilities for adverse effects on human health. In former high civilization--like old Egypt, Greece, Roman, Chinese, Indian, Maya civilizations--the "modem civilization diseases" were unknown. Modem science through improved sanitation, vaccination and antibiotics as well as improved social and economical conditions, has eliminated the threat of death from most infectious diseases. In the years after World War II the social, economic and health conditions changed. Most deaths have resulted from heart disease, stroke, cancer and other diseases as a result of an inappropriate relationship of people with their environment and changed lifestyle. Lifestyle diseases are different from other diseases because they are potentially preventable and can be lowered with changes in diet, lifestyle and environment. PMID:18350729

  18. Exploratory coprocessing research

    SciTech Connect

    Hirschon, A.S.; Tse, D.S.; Malhorta, R.; McMillen, D.F.; Ross, D.S.

    1990-04-01

    The objectives of this quarter's work were to conduct coprocessing experiments in our new microreactor system, where the reactors are agitated by an electric reciprocating saw. Since Wyodak coal was shown to be more susceptible to pretreatment in the larger, 300-mL autoclaves, we decided to begin with this coal. Coprocessing experiments were conducted using pretreatments at 250{degrees}C and at 350{degrees}C, where a ratio of 1 part coal and 2 parts Maya ATB and 1200 psig of hydrogen was heated at 425{degrees}C. In each case the pretreatment increased the conversions, in agreement with the experiments in the larger autoclave. Based on hexane insoluble material, coal conversions ranged from 40% for conversions with no pretreatment, to 60% conversion with pretreatment at 350{degrees}C. The 350{degrees}C pretreatment gave the greatest degree of conversion which is consistent with FIMS pyrolysis data described in the previous quarter. In future work, pretreatment by other methods will also be conducted, as well as a more thorough evaluation of the aqueous pretreatment. 4 refs., 1 fig., 1 tab.

  19. Fun and Games: using Games and Immersive Exploration to Teach Earth and Space Science

    NASA Astrophysics Data System (ADS)

    Reiff, P. H.; Sumners, C.

    2011-12-01

    We have been using games to teach Earth and Space Science for over 15 years. Our software "TicTacToe" has been used continuously at the Houston Museum of Natural Science since 2002. It is the single piece of educational software in the "Earth Forum" suite that holds the attention of visitors the longest - averaging over 10 minutes compared to 1-2 minutes for the other software kiosks. We now have question sets covering solar system, space weather, and Earth science. In 2010 we introduced a new game technology - that of immersive interactive explorations. In our "Tikal Explorer", visitors use a game pad to navigate a three-dimensional environment of the Classic Maya city of Tikal. Teams of students climb pyramids, look for artifacts, identify plants and animals, and site astronomical alignments that predict the annual return of the rains. We also have a new 3D exploration of the International Space Station, where students can fly around and inside the ISS. These interactive explorations are very natural to the video-game generation, and promise to bring educational objectives to experiences that had previously been used strictly for gaming. If space permits, we will set up our portable Discovery Dome in the poster session for a full immersive demonstration of these game environments.

  20. A new reference collection of documented human skeletons from Mérida, Yucatan, Mexico.

    PubMed

    Chi-Keb, J R; Albertos-González, V M; Ortega-Muñoz, A; Tiesler, V G

    2013-10-01

    This report documents the history and composition of a new reference collection currently composed of 84 identified human skeletons from the modern cemetery of Xoclán in Mérida, Yucatan, Mexico. The skeletal sample is the first of its kind in the Yucatan peninsula, a region with a population short of two million mostly local and non-local Mexican residents and descendants of the ancient Maya. The growing collection is curated at the Facultad de Ciencias Antropológicas (School of Anthropological Sciences) of the Autonomous University of Yucatan. Here we describe recovery procedures, preservation, background information and validation measures of the individuals who make up the collection. Detailed information on the generational pattern, sex, and age distribution, along with socioeconomic context and provenance of the skeletons are provided. The majority of the skeletal series is represented by males and by older individuals of both sexes. Almost all of these individuals come from Mérida's middle and lower socioeconomic sectors and died within the urban city boundaries. Biographic information was collected on each individual at the municipal civil registry and confronted with information of national and municipal censuses (2000 and 2005), to be validated and to be discussed here in terms of the representativeness of the reference series and its potential uses in forensic, anthropological and medical research. PMID:23830157

  1. Previous Violent Events and Mental Health Outcomes in Guatemala

    PubMed Central

    Puac-Polanco, Victor D.; Lopez-Soto, Victor A.; Kohn, Robert; Xie, Dawei; Richmond, Therese S.

    2015-01-01

    Objectives. We analyzed a probability sample of Guatemalans to determine if a relationship exists between previous violent events and development of mental health outcomes in various sociodemographic groups, as well as during and after the Guatemalan Civil War. Methods. We used regression modeling, an interaction test, and complex survey design adjustments to estimate prevalences and test potential relationships between previous violent events and mental health. Results. Many (20.6%) participants experienced at least 1 previous serious violent event. Witnessing someone severely injured or killed was the most common event. Depression was experienced by 4.2% of participants, with 6.5% experiencing anxiety, 6.4% an alcohol-related disorder, and 1.9% posttraumatic stress disorder (PTSD). Persons who experienced violence during the war had 4.3 times the adjusted odds of alcohol-related disorders (P < .05) and 4.0 times the adjusted odds of PTSD (P < .05) compared with the postwar period. Women, indigenous Maya, and urban dwellers had greater odds of experiencing postviolence mental health outcomes. Conclusions. Violence that began during the civil war and continues today has had a significant effect on the mental health of Guatemalans. However, mental health outcomes resulting from violent events decreased in the postwar period, suggesting a nation in recovery. PMID:25713973

  2. Raman, SEM-EDS and XRPD investigations on pre-Columbian Central America "estucado" pottery.

    PubMed

    Casanova Municchia, Annalaura; Micheli, Mario; Ricci, Maria Antonietta; Toledo, Michelle; Bellatreccia, Fabio; Lo Mastro, Sergio; Sodo, Armida

    2016-03-01

    Seventeen different colored fragments from six selected pre-Columbian estucado ceramics from El Salvador have been investigated by Raman spectroscopy, scanning electron microscope coupled to an energy dispersive spectrometer (SEM/EDS) and X-ray powder diffraction (XRPD). The peculiarity of this kind of ceramics consist of the unusual presence of a white engobe, traditionally termed stucco, between the ceramic body and the decoration elements, hence the name estucado ceramics. The aim of this work was to study the unusual manufacturing technique and to identify the chemical composition of the engobe and of the pigment palette. The results showed that the stucco layer is made of clay (kaolinite) with traces of titanium oxide (anatase). Remarkably, this is the same composition of the white pigments used for the decoration layer, thus excluding an early use of natural titanium oxide as a white pigment in the estucado productions as suggested in previous investigations. Moreover, the presence of kaolinite and anatase both in the stucco and in the decoration layer suggests a cold-working or low temperature technique. The red, yellow and green decorations were realized by the use of natural ochre, while in all the blue and gray decorations Maya blue pigment was identified. Finally, an amorphous carbon pigment of vegetal origin and manganese oxide were used to obtain black pigments. PMID:26641285

  3. Raman, SEM-EDS and XRPD investigations on pre-Columbian Central America "estucado" pottery

    NASA Astrophysics Data System (ADS)

    Casanova Municchia, Annalaura; Micheli, Mario; Ricci, Maria Antonietta; Toledo, Michelle; Bellatreccia, Fabio; Lo Mastro, Sergio; Sodo, Armida

    2016-03-01

    Seventeen different colored fragments from six selected pre-Columbian estucado ceramics from El Salvador have been investigated by Raman spectroscopy, scanning electron microscope coupled to an energy dispersive spectrometer (SEM/EDS) and X-ray powder diffraction (XRPD). The peculiarity of this kind of ceramics consist of the unusual presence of a white engobe, traditionally termed stucco, between the ceramic body and the decoration elements, hence the name estucado ceramics. The aim of this work was to study the unusual manufacturing technique and to identify the chemical composition of the engobe and of the pigment palette. The results showed that the stucco layer is made of clay (kaolinite) with traces of titanium oxide (anatase). Remarkably, this is the same composition of the white pigments used for the decoration layer, thus excluding an early use of natural titanium oxide as a white pigment in the estucado productions as suggested in previous investigations. Moreover, the presence of kaolinite and anatase both in the stucco and in the decoration layer suggests a cold-working or low temperature technique. The red, yellow and green decorations were realized by the use of natural ochre, while in all the blue and gray decorations Maya blue pigment was identified. Finally, an amorphous carbon pigment of vegetal origin and manganese oxide were used to obtain black pigments.

  4. New neotropical species of Opiinae (Hymenoptera, Braconidae) reared from fruit-infesting and leaf-mining Tephritidae (Diptera) with comments on the  Diachasmimorpha mexicana species group and the genera Lorenzopius and Tubiformopius

    PubMed Central

    Wharton, Robert; Ward, Lauren; Miko, Istvan

    2012-01-01

    Abstract Four new species of opiine Braconidae are described from Mexico. These are Diachasmimorpha martinalujai Wharton reared from Rhagoletis infesting fruits of Crataegus spp., Diachasmimorpha norrbomi Wharton reared from Euphranta mexicana infesting fruits of Ribes pringlei, Eurytenes (Stigmatopoea) norrbomi Wharton reared from Trypeta concolor mining leaves of Barkleyanthus salicifolia and Eurytenes (Stigmatopoea) maya Wharton reared from Rhagoletis pomonella infesting apples and fruits of Crataegus spp. Morphological features of the first metasomal segment and occipital carina, useful for placement of these species, are discussed relative to the genera Diachasmimorpha, Eurytenes, Lorenzopius, Tubiformopius, and Opius s.l. Descriptions and diagnoses are referenced to the Hymenoptera Anatomy Ontology. The following represent new combinations: Diachasmimorpha hildagensis, Lorenzopius euryteniformis, and Tubiformopius tubibasis. Revised diagnoses are provided for Diachasmimorpha hildagensis, Diachasmimorpha mexicana, Diachasmimorpha sanguinea, Eurytenes (Stigmatopoea), Lorenzopius, Lorenzopius euryteniformis, Tubiformopius, Tubiformopius tubigaster, Tubiformopius tubibasis, Opius incoligma, and Opius rugicoxis. Two species groups are delineated within Lorenzopius and a key to species of Diachasmimorpha occurring in the New World is provided. PMID:23818811

  5. Applying x-ray tomography in the field of vertebrate biology: form, function, and evolution of the skull of caecilians (Lissamphibia: Gymnophiona)

    NASA Astrophysics Data System (ADS)

    Kleinteich, Thomas; Beckmann, Felix; Herzen, Julia; Summers, Adam P.; Haas, Alexander

    2008-08-01

    Evolutionary research in biology relies on the comparison of different individuals of different species in order to explore the history of today's biodiversity. Synchrotron radiation based high resolution X-ray tomography (SRμCT) rapidly generates detailed three dimensional datasets. At the beamlines W2 and BW2 of the storage ring DORIS at DESY, Hamburg, Germany, we used SRμCT to study the cranial anatomy of different species and different developmental stages of caecilians (Lissamphibia: Gymnophiona). Here we describe a work-flow for analysis of the SRμCT data that covers segmentation of tissues in Amira® (Mercury Computer Systems), photorealistic rendering and animation in MayaTM, rapid prototyping, and morphometrics. The integration of different analyses of SRμCT data in our study resulted in a comprehensive understanding of form, function, and evolution of caecilian skulls. SRμCT imaging has the potential to become a standard technique for life sciences applications in the near future.

  6. Genetic Variations in the TP53 Pathway in Native Americans Strongly Suggest Adaptation to the High Altitudes of the Andes.

    PubMed

    Jacovas, Vanessa Cristina; Rovaris, Diego Luiz; Peréz, Orlando; de Azevedo, Soledad; Macedo, Gabriel Souza; Sandoval, José Raul; Salazar-Granara, Alberto; Villena, Mercedes; Dugoujon, Jean-Michel; Bisso-Machado, Rafael; Petzl-Erler, Maria Luiza; Salzano, Francisco Mauro; Ashton-Prolla, Patricia; Ramallo, Virginia; Bortolini, Maria Cátira

    2015-01-01

    The diversity of the five single nucleotide polymorphisms located in genes of the TP53 pathway (TP53, rs1042522; MDM2, rs2279744; MDM4, rs1563828; USP7, rs1529916; and LIF, rs929271) were studied in a total of 282 individuals belonging to Quechua, Aymara, Chivay, Cabanaconde, Yanke, Taquile, Amantani, Anapia, Uros, Guarani Ñandeva, and Guarani Kaiowá populations, characterized as Native American or as having a high level (> 90%) of Native American ancestry. In addition, published data pertaining to 100 persons from five other Native American populations (Surui, Karitiana, Maya, Pima, and Piapoco) were analyzed. The populations were classified as living in high altitude (≥ 2,500 m) or in lowlands (< 2,500 m). Our analyses revealed that alleles USP7-G, LIF-T, and MDM2-T showed significant evidence that they were selected for in relation to harsh environmental variables related to high altitudes. Our results show for the first time that alleles of classical TP53 network genes have been evolutionary co-opted for the successful human colonization of the Andes. PMID:26382048

  7. Genetic Variations in the TP53 Pathway in Native Americans Strongly Suggest Adaptation to the High Altitudes of the Andes

    PubMed Central

    Peréz, Orlando; de Azevedo, Soledad; Macedo, Gabriel Souza; Sandoval, José Raul; Salazar-Granara, Alberto; Villena, Mercedes; Dugoujon, Jean-Michel; Bisso-Machado, Rafael; Petzl-Erler, Maria Luiza; Salzano, Francisco Mauro; Ashton-Prolla, Patricia; Ramallo, Virginia; Bortolini, Maria Cátira

    2015-01-01

    The diversity of the five single nucleotide polymorphisms located in genes of the TP53 pathway (TP53, rs1042522; MDM2, rs2279744; MDM4, rs1563828; USP7, rs1529916; and LIF, rs929271) were studied in a total of 282 individuals belonging to Quechua, Aymara, Chivay, Cabanaconde, Yanke, Taquile, Amantani, Anapia, Uros, Guarani Ñandeva, and Guarani Kaiowá populations, characterized as Native American or as having a high level (> 90%) of Native American ancestry. In addition, published data pertaining to 100 persons from five other Native American populations (Surui, Karitiana, Maya, Pima, and Piapoco) were analyzed. The populations were classified as living in high altitude (≥ 2,500 m) or in lowlands (< 2,500 m). Our analyses revealed that alleles USP7-G, LIF-T, and MDM2-T showed significant evidence that they were selected for in relation to harsh environmental variables related to high altitudes. Our results show for the first time that alleles of classical TP53 network genes have been evolutionary co-opted for the successful human colonization of the Andes. PMID:26382048

  8. Transnational opposition and negotiation: Challenges to an oil pipeline in Ecuador

    NASA Astrophysics Data System (ADS)

    Widener, Patricia

    The literature on transnational networks portrays transnational collaborations as advantageous to domestic stakeholders. Yet, the gains of transnational engagement may be accompanied by hardship for domestic groups. This dissertation examines how domestic stakeholders experienced the benefits and burdens of transnational collaboration in challenging the construction of the oil pipeline, the Oleoducto de Crudos Pesados, in Ecuador. Four community cases along the pipeline's route were selected for analysis. Each case varied by the experienced externalities of the oil industry and distributive struggle with the industry and the state. Lago Agrio, an oil town on the edge of the Amazon, represented a community with 30 years of oil saturation that engaged the state to determine just compensation. The capital Quito represented the nation's environmental organizations that sought a role in directing oil-funded conservation efforts. The third site, the eco-tourism community of Mindo, mobilized to reject the pipeline's route near their private reserves and to promote eco-tourism as an economic alternative to oil extraction. The final site was Esmeraldas, a coastal community experienced in tanker loading and oil refining that achieved a collective dignity in pressing for community-determined compensation. To better understand the impacts of transnational activities, this dissertation synthesizes theories of social movements, environmental justice and development. In its longitudinal and case study design, the examination of one project at four sites of contention offers insight into how transnational mobilization drives or hinders environmental justice and how grassroots groups gain or lose a forum for participation. My findings indicate that transnational campaigns benefited locals by providing expert assessments, facilitating international access and influencing international financing policies. However, the unintended consequences included a focus on international concerns

  9. Apoyo a Estudios Geodinamicos con GPS en Guatemala

    NASA Astrophysics Data System (ADS)

    Robles, V. R.

    2013-05-01

    El Instituto Geografico Nacional de Guatemala implemento 17 estaciones GNSS en el año 2009, como un proyecto de credito mixto de donacion de equipamiento del Gobierno de Suiza, el cual, este equipamiento de estaciones CORS GNSS es un sistema de recepción y transmisión de datos crudos GPS RInex que utiliza la tecnologia Spider Web de Leica, asi mismo este sistema esta sirviendo para el espablecimiento de un marco geodesico nacional de coordenadas geodesicas oficiales, el cual se calculan u obtienen las velocidades en tiempos temporales programados de las 17 Estaciones CORS. La infraestructura del marco geodesico de Guatemala esta sirviendo de base para las aplicaciones de estudios geodinamicos como el monitoreo de del desplazamiento de las placas tectonicas por medio de un estudio que se inicio en el año de 1999, llamado medicion con GPS el sistema de Fallas de los rios Polochic Motagua de Guatemala, tambien para un estudio que se implemento para deformación de corteza terrestre local en un Volcan Activo de Guatemala llamado Pacaya. Para el estudio de medicion con GPS en el sistema de falla de los Rios del polochic Motagua se implementaron 16 puntos para medir con GPS de dos frecuencias en el año de 1999, el cual, tres puntos son estaciones geodesicas CORS IGS llamados GUAT, ELEN y HUEH, despues en el año de 2003 se hizo otra medicion en un total de 20 puntos, que permitió calcular las velocidades de desplazamieinto de los puntos en mención, usando como referencia el modelo NUVEL 1A de DeMets de la placa de Norteamerica. Este estudio fue en cooperación internacional por la universidad de Nice de Francia y el IGNde Francia. Para el estudio del monitoreo con GPS del volcan activo de Guatemala, se implementaron cuatro puntos al rededor del volcan, el cual, se realizan cuatro mediciones al año, que permiten determinar axialmente la distancias entre los puntos, y rebisar estadisticamente cual es el comportamiento de las distancias en funcion del tiempo, si

  10. Revision of the Neotropical bark mantis genus Liturgusa Saussure, 1869 (Insecta, Mantodea, Liturgusini)

    PubMed Central

    Svenson, Gavin J.

    2014-01-01

    Abstract The praying mantis genus Liturgusa Saussure, 1869 occurs only in Central and South America and represents the most diverse genus of Neotropical Liturgusini (Ehrmann 2002). The genus includes bark dwelling species, which live entirely on the trunks and branches of trees and run extremely fast. All species included within the genus Liturgusa are comprehensively revised with a distribution stretching from central Mexico, the island of Dominica to the southeastern regions of Brazil and southern Bolivia. All known species are redescribed to meet the standards of the new treatment of the genus (11 species). Three new genera are described including Fuga gen. n., Velox gen. n., and Corticomantis gen. n. for species previously included in Liturgusa as well as Hagiomantis. Liturgusa mesopoda Westwood, 1889 is moved to within the previously described genus Hagiomantis Audinet Serville, 1838. A total of 19 species are newly described within Liturgusa, Fuga, and Velox including L. algorei sp. n., L. bororum sp. n., L. cameroni sp. n., L. cura sp. n., L. dominica sp. n., L. fossetti sp. n., L. kirtlandi sp. n., L. krattorum sp. n., L. manausensis sp. n., L. maroni sp. n., L. milleri sp. n., L. neblina sp. n., L. purus sp. n., L. stiewei sp. n., L. tessae sp. n., L. trinidadensis sp. n., L. zoae sp. n., F. grimaldii sp. n., and V. wielandi sp. n. Four species names are synonymized: Liturgusa peruviana Giglio-Tos, 1914, syn. n. = Liturgusa nubeculosa Gerstaecker, 1889 and Hagiomantis parva Piza, 1966, syn. n., Liturgusa sinvalnetoi Piza, 1982, syn. n., and Liturgusa parva Giglio-Tos, 1914, syn. n. = Mantis annulipes Audinet Serville, 1838. Lectotypes are designated for the following two species: Liturgusa maya Saussure & Zehntner, 1894 and Fuga annulipes (Audinet Serville, 1838). A male neotype is designated for Liturgusa guyanensis La Greca, 1939. Males for eight species are described for the first time including Liturgusa cayennensis Saussure, 1869, Liturgusa lichenalis

  11. Chicxulub's Cretaceous-Tertiary Boundary Twin Crater. Was There a Double Impact in the Yucatan Peninsula?

    NASA Astrophysics Data System (ADS)

    Camargo, A. Z.; Juarez, J. S.

    2004-05-01

    Crater would fit the karstic depressions E-SE of the Chicxulub crater. We found that an 82 km diameter circle fits well the semi circle of dark spots, and interpret it as a portion of the rim of the IZAMAL impact crater. The interpreted relationships and origin of the Chicxulub and Izamal craters are: The Chicxulub crater was created after Izamal. They were created by two different impact bodies. The craters are of the same age. They were formed by two parts of the same celestial body, the MAYA BOLIDE. The diameter of the fragment impacted in Izamal is estimated to be about 4 km. This finding has implications on studies related to the K/T extinction event. Some scientists argue that the Chicxulub crater is somewhat small to account for the global K/T extinction all by itself. The double impact may account for the observed effects. Also, multiple impacts at sea may have put into the atmosphere much more sea water salts capable of dissociating into damaging chlorine compounds. Furthermore, the impact sequence may help explain the origin of the K/T boundary glasses from Haiti and better define the ballistic trajectories of the impacts ejecta and its effects on the extinctions. And the Maya Bolide orbit can be investigated to define its origin and characteristics as a comet or asteroid.

  12. Revision of the Neotropical bark mantis genus Liturgusa Saussure, 1869 (Insecta, Mantodea, Liturgusini).

    PubMed

    Svenson, Gavin J

    2014-01-01

    The praying mantis genus Liturgusa Saussure, 1869 occurs only in Central and South America and represents the most diverse genus of Neotropical Liturgusini (Ehrmann 2002). The genus includes bark dwelling species, which live entirely on the trunks and branches of trees and run extremely fast. All species included within the genus Liturgusa are comprehensively revised with a distribution stretching from central Mexico, the island of Dominica to the southeastern regions of Brazil and southern Bolivia. All known species are redescribed to meet the standards of the new treatment of the genus (11 species). Three new genera are described including Fuga gen. n., Velox gen. n., and Corticomantis gen. n. for species previously included in Liturgusa as well as Hagiomantis. Liturgusa mesopoda Westwood, 1889 is moved to within the previously described genus Hagiomantis Audinet Serville, 1838. A total of 19 species are newly described within Liturgusa, Fuga, and Velox including L. algorei sp. n., L. bororum sp. n., L. cameroni sp. n., L. cura sp. n., L. dominica sp. n., L. fossetti sp. n., L. kirtlandi sp. n., L. krattorum sp. n., L. manausensis sp. n., L. maroni sp. n., L. milleri sp. n., L. neblina sp. n., L. purus sp. n., L. stiewei sp. n., L. tessae sp. n., L. trinidadensis sp. n., L. zoae sp. n., F. grimaldii sp. n., and V. wielandi sp. n. Four species names are synonymized: Liturgusa peruviana Giglio-Tos, 1914, syn. n. = Liturgusa nubeculosa Gerstaecker, 1889 and Hagiomantis parva Piza, 1966, syn. n., Liturgusa sinvalnetoi Piza, 1982, syn. n., and Liturgusa parva Giglio-Tos, 1914, syn. n. = Mantis annulipes Audinet Serville, 1838. Lectotypes are designated for the following two species: Liturgusa maya Saussure & Zehntner, 1894 and Fuga annulipes (Audinet Serville, 1838). A male neotype is designated for Liturgusa guyanensis La Greca, 1939. Males for eight species are described for the first time including Liturgusa cayennensis Saussure, 1869, Liturgusa lichenalis

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  14. Observing Exercises in Astronomy: An Opportunity to Incorporate a Multicultural Approach to Astronomy Education

    NASA Astrophysics Data System (ADS)

    Phelps, R. L.

    2001-05-01

    As part of an Introductory Astronomy course (AS 4), a set of "Night Observing Exercises" have been developed to help students learn about astronomical events and motions, and to help them better understand their place in the Universe. These exercises are specifically intended to help California State University, Sacramento (CSUS) students, who often have evening jobs and family obligations, fit the exercises in around their schedules. This differs from a traditional astronomy lab that requires a student to be on campus during evening hours. The observations (e.g., location of sunset on the horizon, motions of stars throughout the semester) are made at home or at work, and use crude measurement techniques (e.g., angles are measured using the student's outstretched hand), but they nonetheless give the precision needed to demonstrate astronomical concepts. Additionally, the measurements are used, at the end of the semester, to answer specific astronomical questions while incorporating the uncertainties associated with the student's measurements. In this way, therefore, students gain an appreciation of the beauty of the astronomical sky, understand the motions that occur, and get a sense of the importance of uncertainties in scientific measurements. The CSUS student body is also among the most diverse in the Western U.S. A unique aspect of these Night Observing Exercises is the ability to enhance the multicultural component of astronomical teaching. The Inca and the Maya, for example, were maticulous observers of the Sun and Venus, respectively. This paper presents presents a report on techniques that can be used to show students, from cultures typically underrepresented in science, how astronomy is part of their own heritage. This work was supported, in part, by a Pedagogy Enhancement grant from the California State University, Sacramento

  15. Morphological variation of henequen (Agave fourcroydes, Agavaceae) germplasm and its wild ancestor (A. angustifolia) under uniform growth conditions: diversity and domestication.

    PubMed

    Colunga-Garciamarin, P; May-Pat, F

    1997-11-01

    selection and cultivation of populations such as those from Tropical deciduous forest may well have been the path taken by the ancient Maya during henequen domestication. PMID:21708552

  16. Forest Cover Change and Soil Erosion in Toledo's Rio Grande Watershed

    NASA Astrophysics Data System (ADS)

    Chicas, S.; Omine, K.

    2015-04-01

    Toledo, the southernmost district, is the hub of Belize's Mayan population, descendants of the ancient Mayan civilization. The Toledo District is primarily inhibited by Kekchi and Mopan Mayans whose subsistence needs are met by the Milpa slash-and-burn agricultural system and the extraction of forest resources. The poverty assessment in the country indicates that Toledo is the district with the highest percentage of household an individual indigence of 37.5 % and 49.7 % respectively. Forest cover change in the area can be attributed to rapid population growth among the Maya, together with increase in immigration from neighboring countries, logging, oil exploration and improvement and construction of roads. The forest cover change analysis show that from 2001 to 2011 there was a decrease of Lowland broad-leaved wet forest of 7.53 km sq, Shrubland of 4.66 km sq, and Wetland of 0.08 km sq. Forest cover change has resulted in soil erosion which is causing the deterioration of soils. The land cover types that are contributing the most to total erosion in the Rio Grande watershed are no-forest, lowland broad-leaved wet forest and submontane broad-leaved wet forest. In this study the Revised Universal Soil Loss Equation (RUSLE) was employed in a GIS platform to quantify and assess forest cover change and soil erosion. Soil erosion vulnerability maps in Toledo's Rio Grande watershed were also created. This study provides scientifically sound information in order to understand and respond effectively to the impacts of soil erosion in the study site.

  17. Sibling Competition & Growth Tradeoffs. Biological vs. Statistical Significance

    PubMed Central

    Kramer, Karen L.; Veile, Amanda; Otárola-Castillo, Erik

    2016-01-01

    Early childhood growth has many downstream effects on future health and reproduction and is an important measure of offspring quality. While a tradeoff between family size and child growth outcomes is theoretically predicted in high-fertility societies, empirical evidence is mixed. This is often attributed to phenotypic variation in parental condition. However, inconsistent study results may also arise because family size confounds the potentially differential effects that older and younger siblings can have on young children’s growth. Additionally, inconsistent results might reflect that the biological significance associated with different growth trajectories is poorly understood. This paper addresses these concerns by tracking children’s monthly gains in height and weight from weaning to age five in a high fertility Maya community. We predict that: 1) as an aggregate measure family size will not have a major impact on child growth during the post weaning period; 2) competition from young siblings will negatively impact child growth during the post weaning period; 3) however because of their economic value, older siblings will have a negligible effect on young children’s growth. Accounting for parental condition, we use linear mixed models to evaluate the effects that family size, younger and older siblings have on children’s growth. Congruent with our expectations, it is younger siblings who have the most detrimental effect on children’s growth. While we find statistical evidence of a quantity/quality tradeoff effect, the biological significance of these results is negligible in early childhood. Our findings help to resolve why quantity/quality studies have had inconsistent results by showing that sibling competition varies with sibling age composition, not just family size, and that biological significance is distinct from statistical significance. PMID:26938742

  18. The Morphology and Adhesion Mechanism of Octopus vulgaris Suckers

    PubMed Central

    Tramacere, Francesca; Beccai, Lucia; Kuba, Michael; Gozzi, Alessandro; Bifone, Angelo; Mazzolai, Barbara

    2013-01-01

    The octopus sucker represents a fascinating natural system performing adhesion on different terrains and substrates. Octopuses use suckers to anchor the body to the substrate or to grasp, investigate and manipulate objects, just to mention a few of their functions. Our study focuses on the morphology and adhesion mechanism of suckers in Octopus vulgaris. We use three different techniques (MRI, ultrasonography, and histology) and a 3D reconstruction approach to contribute knowledge on both morphology and functionality of the sucker structure in O. vulgaris. The results of our investigation are two-fold. First, we observe some morphological differences with respect to the octopus species previously studied (i.e., Octopus joubini, Octopus maya, Octopus bimaculoides/bimaculatus and Eledone cirrosa). In particular, in O. vulgaris the acetabular chamber, that is a hollow spherical cavity in other octopuses, shows an ellipsoidal cavity which roof has an important protuberance with surface roughness. Second, based on our findings, we propose a hypothesis on the sucker adhesion mechanism in O. vulgaris. We hypothesize that the process of continuous adhesion is achieved by sealing the orifice between acetabulum and infundibulum portions via the acetabular protuberance. We suggest this to take place while the infundibular part achieves a completely flat shape; and, by sustaining adhesion through preservation of sucker configuration. In vivo ultrasonographic recordings support our proposed adhesion model by showing the sucker in action. Such an underlying physical mechanism offers innovative potential cues for developing bioinspired artificial adhesion systems. Furthermore, we think that it could possibly represent a useful approach in order to investigate any potential difference in the ecology and in the performance of adhesion by different species. PMID:23750233

  19. Cephalopod culture: current status of main biological models and research priorities.

    PubMed

    Vidal, Erica A G; Villanueva, Roger; Andrade, José P; Gleadall, Ian G; Iglesias, José; Koueta, Noussithé; Rosas, Carlos; Segawa, Susumu; Grasse, Bret; Franco-Santos, Rita M; Albertin, Caroline B; Caamal-Monsreal, Claudia; Chimal, Maria E; Edsinger-Gonzales, Eric; Gallardo, Pedro; Le Pabic, Charles; Pascual, Cristina; Roumbedakis, Katina; Wood, James

    2014-01-01

    A recent revival in using cephalopods as experimental animals has rekindled interest in their biology and life cycles, information with direct applications also in the rapidly growing ornamental aquarium species trade and in commercial aquaculture production for human consumption. Cephalopods have high rates of growth and food conversion, which for aquaculture translates into short culture cycles, high ratios of production to biomass and high cost-effectiveness. However, at present, only small-scale culture is possible and only for a few species: the cuttlefish Sepia officinalis, the loliginid squid Sepioteuthis lessoniana and the octopuses Octopus maya and O. vulgaris. These four species are the focus of this chapter, the aims of which are as follows: (1) to provide an overview of the culture requirements of cephalopods, (2) to highlight the physical and nutritional requirements at each phase of the life cycle regarded as essential for successful full-scale culture and (3) to identify current limitations and the topics on which further research is required. Knowledge of cephalopod culture methods is advanced, but commercialization is still constrained by the highly selective feeding habits of cephalopods and their requirement for large quantities of high-quality (preferably live) feed, particularly in the early stages of development. Future research should focus on problems related to the consistent production of viable numbers of juveniles, the resolution of which requires a better understanding of nutrition at all phases of the life cycle and better broodstock management, particularly regarding developments in genetic selection, control of reproduction and quality of eggs and offspring. PMID:24880794

  20. The morphology and adhesion mechanism of Octopus vulgaris suckers.

    PubMed

    Tramacere, Francesca; Beccai, Lucia; Kuba, Michael; Gozzi, Alessandro; Bifone, Angelo; Mazzolai, Barbara

    2013-01-01

    The octopus sucker represents a fascinating natural system performing adhesion on different terrains and substrates. Octopuses use suckers to anchor the body to the substrate or to grasp, investigate and manipulate objects, just to mention a few of their functions. Our study focuses on the morphology and adhesion mechanism of suckers in Octopus vulgaris. We use three different techniques (MRI, ultrasonography, and histology) and a 3D reconstruction approach to contribute knowledge on both morphology and functionality of the sucker structure in O. vulgaris. The results of our investigation are two-fold. First, we observe some morphological differences with respect to the octopus species previously studied (i.e., Octopus joubini, Octopus maya, Octopus bimaculoides/bimaculatus and Eledone cirrosa). In particular, in O. vulgaris the acetabular chamber, that is a hollow spherical cavity in other octopuses, shows an ellipsoidal cavity which roof has an important protuberance with surface roughness. Second, based on our findings, we propose a hypothesis on the sucker adhesion mechanism in O. vulgaris. We hypothesize that the process of continuous adhesion is achieved by sealing the orifice between acetabulum and infundibulum portions via the acetabular protuberance. We suggest this to take place while the infundibular part achieves a completely flat shape; and, by sustaining adhesion through preservation of sucker configuration. In vivo ultrasonographic recordings support our proposed adhesion model by showing the sucker in action. Such an underlying physical mechanism offers innovative potential cues for developing bioinspired artificial adhesion systems. Furthermore, we think that it could possibly represent a useful approach in order to investigate any potential difference in the ecology and in the performance of adhesion by different species. PMID:23750233