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Sample records for central america modis

  1. Demographic tensions in Central America.

    PubMed

    1986-08-01

    This discussion of Central America focuses on the rapid growth of its population, its stagnating economy, and those countries that are socioeconomically advanced. Between 1950-85 the population of Central America tripled, from 9.1 million to 26. 4 million, due to marked mortality declines and the absence of off-setting fertility declines. The distribution of Central Americas's growing populations sets its population growth apart from that of other developing regions. Currently, almost half of all Central Americans live in cities. Although the average growth rate for Central American countries has fallen and is expected to drop further, the decline does not counterbalance the effect of the absolute rise in population numbers. The average annual growth rate of more than 3% annually in the 1960s fell to about 2.6% in recent years, but this decline is due primarily to socioeconomically advanced Costa Rica and Panama. Central America's age structure further complicates the population crisis. About 43% of Central Americans are under the age of 15. When the increasingly larger young population group enters it reproductive years, the potential for future growth (albeit the falling rate of population increase) is unparalleled. UN population projections show the region's population at 40 million by the year 2000. The 1973 oil crisis began a downward spiral for the buoyant post World War II Central American economy. Between 1950-79, real per capita income growth in Central America doubled, with Central American economies growing an average of 5.3% annually. By the early 1980s, overseas markets of the trade-dependent countries of Central America had dried up due to protectionism abroad and slumping basic commodity prices. These and other factors plunged Central America into its current economic malaise of falling real per capita income, rising unemployment, curtailed export led economic growth, and a rising cost of living. In general, economic growth in Central America

  2. Geothermal initiatives in Central America

    SciTech Connect

    Hanold, R.J.; Loose, V.W.; Laughlin, A.W.; Wade, P.E.

    1986-01-01

    The US Agency for International Development is supporting a new project in energy and resources exploitation for Central America. One of the largest components of the project involves exploration and reservoir development investigations directed at enhancing the production of electricity from the region's geothermal resources. An assessment of the geothermal resources of Honduras is in progress, and interesting geothermal regions in the Guanacaste Province of Costa Rica are being explored. Well-logging activities are in progress in the production wells at the Miravalles geothermal field in Costa Rica, and preparations are being made for logging critical wells at Ahuachapan in El Salvador. A self-contained logging truck, complete with high-temperature logging cable and logging tools designed for geothermal service, is being fabricated and will be made available for dedicated use throughout Central America. Geochemical and isotopic analyses of water samples collected in Panama are being evaluated to select a high-priority geothermal site in that country. Application of low- and medium-enthalpy geothermal fluids for industrial and agricultural processes is being investigated in Guatemala.

  3. Smoke from Fires in Central America Drifts over Texas

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Smoke from widespread fires in tropical Mexico and Central America appears to be drifting over the U.S. Gulf States. In 1998 similar circumstances resulted in air-quality warnings being issued in several U.S. states, including Texas and Louisiana. The top image shows smoke and fires (red pixels) observed by the Moderate-Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Terra satellite. Possibly hundreds of small fires are scattered across Guatemala, Belize, Honduras, and Mexico's Yucatan Peninsula. The lower image, acquired by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), shows smoke from these fires carried by the prevailing winds across the Gulf of Mexico and over the United States. Images courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA Goddard Space Flight Center and the SeaWiFS Project, NASA GSFC, and ORBIMAGE

  4. Children in Central America: Victims of War.

    ERIC Educational Resources Information Center

    Ronstrom, Anitha

    1989-01-01

    Discusses the armed conflicts in Central America and their influence on civilian populations. Discusses the psychosocial consequences and therapeutic considerations of warfare, displacement and refuge for children. (RJC)

  5. South America, Central America, the Caribbean, and Mexico

    SciTech Connect

    Deal, C.

    1981-10-01

    Summaries of oil and gas drillings, well completions, production, exploratory wells, exploration activity and wildcat drilling were given for South America, Central America, the Caribbean, and Mexico. The countries, islands, etc. included Argentina, Bahamas, Barbados, Belize, Bolivia, Brazil, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, French Guiana, Guatemala, Guyana, Haiti, Honduras, Jamaica, Leeward and Windward Islands, Mexico, Netherlands Antilles, Nicaragua, Panama, Paraguay, Peru, Puerto Rico, El Salvador, Surinam, Trinidad and Venezuela. 16 figures, 120 tables. (DP)

  6. Health and health services in Central America.

    PubMed

    Garfield, R M; Rodriguez, P F

    1985-08-16

    Despite rapid economic growth since World War II, health conditions improved only slowly in most of Central America. This is a result of poor medical, social, and economic infrastructure, income maldistribution, and the poor utilization of health investments. The economic crisis of the 1980s and civil strife have further endangered health in the region. Life expectancy has fallen among men in El Salvador and civil strife has become the most common cause of death in Guatemala, Nicaragua, and El Salvador. Large-scale US assistance has done little to improve conditions, and refugees continue to pour into North America. It is estimated that there are more than a million refugees within Central America, while a million have fled to the United States. Costa Rica and Nicaragua are partial exceptions to this dismal health picture. An effective approach to the many health problems in Central America will require joint planning and cooperation among all countries in the region.

  7. Health and health services in Central America.

    PubMed

    Garfield, R M; Rodriguez, P F

    1985-08-16

    Despite rapid economic growth since World War II, health conditions improved only slowly in most of Central America. This is a result of poor medical, social, and economic infrastructure, income maldistribution, and the poor utilization of health investments. The economic crisis of the 1980s and civil strife have further endangered health in the region. Life expectancy has fallen among men in El Salvador and civil strife has become the most common cause of death in Guatemala, Nicaragua, and El Salvador. Large-scale US assistance has done little to improve conditions, and refugees continue to pour into North America. It is estimated that there are more than a million refugees within Central America, while a million have fled to the United States. Costa Rica and Nicaragua are partial exceptions to this dismal health picture. An effective approach to the many health problems in Central America will require joint planning and cooperation among all countries in the region. PMID:4021026

  8. External Review Teams Training in Central America

    ERIC Educational Resources Information Center

    Silva-Trivino, Moises; Ramirez-Gatica, Soledad

    2004-01-01

    Many Latin American countries have started actions to promote a higher education quality assurance system. Central America appears as a regional effort that includes universities from all seven countries under the initiative of Central American University Higher Council (CSUCA). After focusing in quality management and self-study processes, CSUCA…

  9. Use of MODIS Snow-Cover Maps for Detecting Snowmelt Trends in North America

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Foster, James L.; Riggs, George A.; Robinson, David A.; Hoon-Starr, Jody A.

    2012-01-01

    Research has shown that the snow season in the Northern Hemisphere has been getting shorter in recent decades, consistent with documented global temperature increases. Specifically, the snow is melting earlier in the spring allowing for a longer growing season and associated land-cover changes. Here we focus on North America. Using the Moderate-Resolution Imaging Radiometer (MODIS) cloud-gap-filled standard snow-cover data product we can detect a trend toward earlier spring snowmelt in the approx 12 years since the MODIS launch. However, not all areas in North America show earlier spring snowmelt over the study period. We show examples of springtime snowmelt over North America, beginning in March 2000 and extending through the winter of 2012 for all of North America, and for various specific areas such as the Wind River Range in Wyoming and in the Catskill Mountains in New York. We also compare our approx 12-year trends with trends derived from the Rutgers Global Snow Lab snow cover climate-data record.

  10. Hydrological climate change projections for Central America

    NASA Astrophysics Data System (ADS)

    Hidalgo, Hugo G.; Amador, Jorge A.; Alfaro, Eric J.; Quesada, Beatriz

    2013-07-01

    Runoff climate change projections for the 21st century were calculated from a suite of 30 General Circulation Model (GCM) simulations for the A1B emission scenario in a 0.5° × 0.5° grid over Central America. The GCM data were downscaled using a version of the Bias Correction and Spatial Downscaling (BCSD) method and then used in the Variable Infiltration Capacity (VIC) macroscale hydrological model. The VIC model showed calibration skill in Honduras, Nicaragua, Costa Rica and Panama, but the results for some of the northern countries (Guatemala, El Salvador and Belize) and for the Caribbean coast of Central America was not satisfactory. Bias correction showed to remove effectively the biases in the GCMs. Results of the projected climate in the 2050-2099 period showed median significant reductions in precipitation (as much as 5-10%) and runoff (as much as 10-30%) in northern Central America. Therefore in this sub-region the prevalence of severe drought may increase significantly in the future under this emissions scenario. Northern Central America could warm as much as 3 °C during 2050-2099 and southern Central America could reach increases as much as 4 °C during the same period. The projected dry pattern over Central America is consistent with a southward displacement of the Intertropical Convergence Zone (ITCZ). In addition, downscaling of the NCEP/NCAR Reanalysis data from 1948 to 2012 and posterior run in VIC, for two locations in the northern and southern sub-regions of Central America, suggested that the annual runoff has been decreasing since ca. 1980, which is consistent with the sign of the runoff changes of the GCM projections. However, the Reanalysis 1980-2012 drying trends are generally much stronger than the corresponding GCM trends. Among the possible reasons for that discrepancy are model deficiencies, amplification of the trends due to constructive interference with natural modes of variability in the Reanalysis data, errors in the Reanalysis

  11. Snow-Cover Variability in North America in the 2000-2001 Winter as Determined from MODIS Snow Products

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Salomonson, Vincent V.; Riggs, George A.; Chien, Y. L.; Houser, Paul R. (Technical Monitor)

    2001-01-01

    Moderate Resolution Imaging Spectroradiometer (MODIS) snow-cover maps have been available since September 13, 2000. These products, at 500-m spatial resolution, are available through the National Snow and Ice Data Center Distributed Active Archive Center in Boulder, Colorado. By the 2001-02 winter, 5-km climate-modeling grid (CMG) products will be available for presentation of global views of snow cover and for use in climate models. All MODIS snow-cover products are produced from automated algorithms that map snow in an objective manner. In this paper, we describe the MODIS snow products, and show snow maps from the fall of 2000 in North America.

  12. Snow-Cover Variability in North America in the 2000-2001 Winter as Determined from MODIS Snow Products

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Salomonson, Vincent V.; Riggs, George A.; Chien, Janet Y. L.; Houser, Paul R. (Technical Monitor)

    2001-01-01

    Moderate Resolution Imaging Spectroradiometer (MODIS) snow-cover maps have been available since September 13, 2000. These products, at 500 m spatial resolution, are available through the National Snow and Ice Data Center Distributed Active Archive Center in Boulder, Colorado. By the 2001-02 winter, 5 km climate-modeling grid (CMG) products will be available for presentation of global views of snow cover and for use in climate models. All MODIS snow-cover products are produced from automated algorithms that map snow in an objective manner. In this paper, we describe the MODIS snow products, and show snow maps from the fall of 2000 in North America.

  13. Fragile isthmus under pressure. Central America.

    PubMed

    Ypsilantis, J

    1992-01-01

    In Costa Rica the 1300 hectares of rainforest that comprise La Selva Biological Station support more than 1.5 times the number of plant and animal species found in California. In Central America over 2/3 of all deforestation has occurred since 1950, and closed canopy forest has shrunk dramatically during the past 40 years. The population in Central America, plus Mexico, grew by around 28% during the period 1977-87. At the same time the surface of forests and woodlands decreased by 13%, to 26% of the total land area. Croplands grew by 4% during these 10 years, to 13% of the total land area, and pastures by 2% to 37%; and unproductive lands grew by 14% to 24% of total land area. 50% of land is seriously eroded or degraded in El Salvador and over 30% in Guatemala. Central America's population was 22 million in 1980, 29 million in 1990, and it is anticipated to reach 63 million by 2025. Central America's urban population reached 46% in the 1990s: over 13 million with continuing increases in the next few decades. The growing population's need for fuelwood and the demand for agricultural land pose the main threat to forests in the coming decades. Close to 90% of the energy used by households comes from fuelwood. In the Telire reserve in Costa Rica 366 Cabecars are not yet an environmental threat for the forest. The Peten area in Guatemala is inhabited by around 300,000 people whose destructive slash and burn practices pose a serious threat to the environment which is exacerbated by a high population growth rate of 5.5% a year. PMID:12317701

  14. Vietnam and Central America: Reflections on Power and Morality.

    ERIC Educational Resources Information Center

    Bresler, Robert J.

    1983-01-01

    Would the spread of Marxist revolution in Central America threaten America's vital interests? Would the people of that region be better off if we intervened? We cannot live forever under the shadow of Vietnam. It is not beyond our power to prevent a communist victory in Central America. (SR)

  15. Caribbean basin framework, 2: Northern Central America

    SciTech Connect

    Tyburski, S.A.; Gordon, M.B.; Mann, P. )

    1991-03-01

    There are four Jurassic to Recent basin-forming periods in northern Central America (honduras, Honduran Borderlands, Belize, Guatemala, northern Nicaragua): (1) Middle Jurassic-Early Cretaceous rifting and subsidence along normal faults in Honduras and Guatemala; rifts are suggested but are not well defined in Honduras by the distribution of clastic sediments and associated volcanic rocks. Rifting is attributed to the separation of Central America from the southern margin of the North American plate; (2) Cretaceous subsidence recorded by the development of a Cretaceous carbonate platform in Honduras, Guatemala, and Belize; subsidence is attributed to thermal subsidence of the rifted margins of the various blocks; (3) Late Cretaceous-Recent development of a volcanic arc along the western margin of Middle America and the northern margin of Honduras; (4) Late Cretaceous large-scale folding in Honduras, ophiolite obduction, and formation of a foredeep basin in Guatemala (Sepur trough); deformation is attributed to the collision between a north-facing arc in northern Honduras and the Nicaraguan Rise and the passive margin of Guatemala and Belize; and (5) Eocene to Recent strike-slip faulting along the present-day North American-Caribbean plate boundary in Guatemala, northern Honduras, and Belize. Strike-slip faults and basins form a California-type borderlands characterized by elongate basins that appear as half-grabens in profile. Counterclockwise rotation of the central honduras plateau, a thicker and topographically higher-than-average block within the plate boundary zone, is accommodated by rifting or strike-slip faults at its edges.

  16. Protection of mammal diversity in Central America

    USGS Publications Warehouse

    Jenkins, Clinton N.; Giri, Chandra

    2008-01-01

    Central America is exceptionally rich in biodiversity, but varies widely in the attention its countries devote to conservation. Protected areas, widely considered the cornerstone of conservation, were not always created with the intent of conserving that biodiversity. We assessed how well the protected-area system of Central America includes the region's mammal diversity. This first required a refinement of existing range maps to reduce their extensive errors of commission (i.e., predicted presences in places where species do not occur). For this refinement, we used the ecological limits of each species to identify and remove unsuitable areas from the range. We then compared these maps with the locations of protected areas to measure the habitat protected for each of the region's 250 endemic mammals. The species most vulnerable to extinction—those with small ranges—were largely outside protected areas. Nevertheless, the most strictly protected areas tended toward areas with many small-ranged species. To improve the protection coverage of mammal diversity in the region, we identified a set of priority sites that would best complement the existing protected areas. Protecting these new sites would require a relatively small increase in the total area protected, but could greatly enhance mammal conservation.

  17. Elimination of Rhodnius prolixus in Central America

    PubMed Central

    2012-01-01

    Rhodnius prolixus is one of the main vectors of Trypanosoma cruzi, causative agent of Chagas disease. In Central America, it was first discovered in 1915 in El Salvador, from where it spread northwest to Guatemala and Mexico, and southeast to Nicaragua and Costa Rica, arriving also in Honduras in the late 1950s. Indoor residual spraying (IRS) by the antimalaria services of Costa Rica prevented its spread southwards, and similar IRS programmes appear to have eliminated it from El Salvador by the late 1970s. In 1997, by resolution of the Ministers of Health of the seven Central American countries, a multinational initiative against Chagas disease (IPCA) was launched with one of the specific objectives being the elimination of R. prolixus from the region. As a result, more and more infested areas were encountered, and progressively sprayed using an IRS strategy already deployed against Triatoma infestans in the southern cone countries of South America. In 2008, Guatemala became the first of these countries to be formally certified as free of Chagas disease transmission due to R. prolixus. The other infested countries have since been similarly certified, and none of these has reported the presence of R. prolixus since June 2010. Further surveillance is required, but current evidence suggests that R. prolixus may now been eliminated from throughout the mesoamerican region, with a corresponding decline in the incidence of T. cruzi infections. PMID:22357219

  18. Art Bridging Boundaries: Central America and the United States.

    ERIC Educational Resources Information Center

    Goldman, Shifra M.

    This paper describes the organization, Artists Call, as well as several slides shown during the presentation to illustrate "visual solidarity" between artists of the United States and Central America. In 1983, artists in 27 U.S. cities as well as Paris and Mexico City organized Artists Call against U.S. Intervention in Central America. Numerous…

  19. Commercial Agriculture and Modern Transport in Central America.

    ERIC Educational Resources Information Center

    Horst, Oscar H.

    1981-01-01

    Describes an exercise for use in college-level geography courses dealing with the tandem development of transport networks and commercial agriculture in Central America. Using six maps, the author shows the parallels between highway and railroad construction and commercial crops, (coffee, bananas, and cotton) in Central America between 1855-1975.…

  20. Mantle Structure Beneath Central South America

    NASA Astrophysics Data System (ADS)

    Vandecar, J. C.; Silver, P. G.; James, D. E.; Assumpcao, M.; Schimmel, M.; Zandt, G.

    2003-12-01

    Making use of 60 digital broadband seismic stations that have operated across central South America in recent years, we have undertaken an inversion for the upper- and uppermost lower-mantle P- and S-wave velocity structures beneath the region. We have combined data from four portable PASSCAL-type experiments as well as the 3 GTSN permanent stations (LPAZ, BDFB and CPUP) and 1 Geoscope station (SPB) located in the region. The portable data were deployed at various times between 1992 and 1999 and include: 28 sites from the Brazilian Lithosphere Seismic Project (BLSP: Carnegie Institution of Washington and Universidade de Sao Paulo), 16 sites from the Broadband ANdean JOint experiment (BANJO: Carnegie Institution of Washington and University of Arizona), 8 sites from the Seismic Exploration of the Deep Altiplano project (SEDA: Lawrence Livermore National Laboratory) and 4 sites from the University of Brasilia. The P- and S-wave relative delay times are independently obtained via a multi-channel cross correlation of band-passed waveforms for each teleseismic event. These data are then inverted using an iterative, robust, non-linear scheme which parameterizes the 3-D velocity variations as splines under tension constrained at over 120,000 nodes across South America between latitudes of 15 and 30 degrees South. Amongst other features, we robustly image the high-velocity subducting Nazca plate penetrating into the lower mantle and the high-velocity root of the ~3.2 Gyr old Sao Francisco Craton extending to depths of 200-300 km. We will discuss the consistency between our tomographic models and predictions of dynamic mantle models based on plate tectonic reconstructions of subduction.

  1. A spatial downscaling procedure of MODIS derived actual evapotranspiration using Landsat images at central Greece

    NASA Astrophysics Data System (ADS)

    Spiliotopoulos, M.; Adaktylou, N.; Loukas, A.; Michalopoulou, H.; Mylopoulos, N.; Toulios, L.

    2013-08-01

    In this study, the Surface Energy Balance Algorithm for Land (SEBAL) was used to derive daily actual evapotranspiration (ETa) distributions from Landsat and MODIS images separately. The study area is the Lake Karla basin in Thessaly, Central Greece. Meteorological data from the archive of Center for Research and Technology, Thessaly (CERETETH) have also been used. The methodology was developed using satellite and ground data for the period of summer 2007. Landsat and MODIS imagery were combined in order to have data with high temporal and spatial resolution (downscaling). The downscaling technique applied is the output downscaling with regression between images. This technique disaggregates imagery by applying linear regression between two MODIS products to the previous or subsequent Landsat product. After the calculation of a first order linear regression between two MODIS-derived ETa maps the next step is the regression to the ETa map derived from the prior Landsat image to predict the disaggregated subsequent Landsat ETa map. The results are satisfactory, giving the general trend of ETa derived from the original SEBAL procedure.

  2. Development of Retinoblastoma Programs in Central America

    PubMed Central

    Wilimas, Judith A.; Wilson, Matthew W.; Haik, Barrett G.; Barnoya, Margarita; Fu, Ligia; Castellanos, Mauricio; Bonilla, Miguel; Phillips, Blanca; Helveston, Eugene M.; Luna-Fineman, Sandra; Ribeiro, Raul; Rodriguez-Galindo, Carlos

    2009-01-01

    Background Retinoblastoma, a curable eye tumor, is associated with poor survival in Central America (CA). To develop a retinoblastoma program in El Salvador, Guatemala, and Honduras, twinning initiatives were undertaken between local pediatric oncology centers, nonprofit foundations, St. Jude Children's Research Hospital, and the University of Tennessee Hamilton Eye Institute. Procedure The retinoblastoma program focused on developing early diagnosis programs in Honduras with national vaccination campaigns, developing treatment protocols suited to local conditions, building local networks of oncologists and ophthalmologists, training local healthcare providers, using modern donated equipment for diagnosis and treatment, and the ORBIS Cybersight consultation program and Internet meetings to further education and share expertise. Pediatric ophthalmologists and oncologists worked with foundations to treat patients locally with donated equipment and Internet consultations, or at the center in Guatemala. Results Number of patients successfully treated increased after the program was introduced. For 2000–2003 and 2004–2007, patients abandoning/refusing treatment decreased in Guatemala from 20 of 95 (21%) to 14 of 123 (11%) and in Honduras from 13 of 37 (35%) to 7 of 37 (19%). Survival in El Salvador was good and abandonment/refusal low for both periods. Of 18 patients receiving focal therapy for advanced disease, 14 have single remaining eyes. Conclusion Development of the program in CA has decreased abandonment/refusal and enabled ophthalmologists at local centers to use modern equipment to provide better treatment. This approach might serve as a guide for developing other multispecialty programs. PMID:19326423

  3. High resolution mapping of dust sources in Central Asia using MODIS imagery

    NASA Astrophysics Data System (ADS)

    Nobakht, Mohamad; Shahgedanova, Maria; White, Kevin

    2015-04-01

    Dust impacts the energy balance of the Earth via absorption and scattering of radiation in the atmosphere and through the mechanism by which aerosols modify the optical properties of clouds and land surfaces. It is now established that the deposition of mineral dust significantly affects high-altitude environments, including both snow pack and glacier ice. Central Asia is a region where large deserts are located in close proximity to the mountains whose extensive glaciers and snow pack provide runoff supporting agriculture in the densely populated foothills. More than 75% of the territory in Central Asia is desert lowland varying from sandy to stony, salt, and clay deserts. Significant amounts of wind-blown desert dust, originating from these deserts, are deposited on glaciers of Tian Shan Mountains in Central Asia. Satellite remote sensing using optical imagery has provided us with a powerful tool for identification and characterization of dust emission sources. In this study we investigated the spatial distribution and seasonal pattern of dust emissions in surrounding lowlands of the Tian Shan Mountains using Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. Seasonality of dust emission is studied by analyzing MODIS Deep Blue aerosol optical depth, acquired over a period of 12 years from January 2003 to December 2014. We analyzed the spatial distribution and frequency of occurrence of dust optical depth to identify the main dust sources in this region. In order to produce a detailed map of dust emission sources, we also employed a dust enhancement algorithm to obtain high resolution (1km) dust enhancement products from MODIS imageries. The high resolution of MODIS dust enhancement products enabled us to identify several small, eroding point sources within the dust source areas. Different seasonal patterns of dust emissions were observed in northern, western and southern deserts around the Tian Shan Mountains and their relation to climatological

  4. Modeling Gross Primary Production in North America with MODIS Images and Reanalysis Climate Data

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Xiao, X.; Jin, C.; Dong, J.; Zhou, S.; Wagle, P.; Joiner, J.; Guanter, L.; Zhang, Y.; Zhang, G.; Qin, Y.; Wang, J.; Moore, B., III

    2015-12-01

    Accurate estimation of gross primary production (GPP) of terrestrial ecosystems is vital for a better understanding of the spatial-temporal patterns of the global carbon cycle. In this study we estimated GPP in North America (NA), using the satellite-based Vegetation Photosynthesis Model (VPM), MODIS images at 8-day temporal and 500 m spatial resolution, and NCEP-NARR reanalysis climate data. The simulated GPP (GPPVPM) agreed well with the flux tower derived GPP (GPPEC) at 39 AmeriFlux sites (155 site-years). The GPPVPM in 2010 was spatially aggregated to 0.5 by 0.5 degree grid cell, and then evaluated with solar-induced chlorophyll fluorescence (SIF) data from GOME-2, which is often regarded as the proxy of direct measurement of vegetation photosynthesis. There were good agreements in spatial distribution and seasonal dynamics between GPPVPM and SIF. At biome scale, the relationship between GPPVPM and SIF showed strong linear correlations (R2 > 0.95) and small variations of slopes (4.60 - 5.55 g C m-2 year-1 / (mW m-2 nm-1 sr-1)). The total annual GPPVPM in NA in 2010 was approximately 13.53 Pg C year-1, which accounted for ~11.0% of the global terrestrial GPP and was within the range of annual GPP estimates from several other process-based and data-driven models (11.35 - 22.23 Pg C year-1). Forests contributed most (4.17 Pg C year-1) to the annual GPP in NA. Evergreen broadleaf forests were most productive with an average annual GPP exceeding 2000 g C m-2 year-1. The results from this study has demonstrated the reliable performance of VPM at the continental scale, and the resultant GPP product at 500-m spatial resolution provides more opportunities to improve the studies of carbon cycle, model inter-comparison, and benchmarking.

  5. Introduction: seismology and earthquake engineering in Central and South America.

    USGS Publications Warehouse

    Espinosa, A.F.

    1983-01-01

    Reports the state-of-the-art in seismology and earthquake engineering that is being advanced in Central and South America. Provides basic information on seismological station locations in Latin America and some of the programmes in strong-motion seismology, as well as some of the organizations involved in these activities.-from Author

  6. Private Higher Education in a Cold War World: Central America

    ERIC Educational Resources Information Center

    Harrington, James J.

    2009-01-01

    In Central America the Cold War support of the elites by the United States was designed to ward off the communist threat. At the same time social and economic demands by the working and middle classes created revolutionary movements in the face of rigid and violent responses by Central American governments. Issues of social justice pervaded the…

  7. 9 CFR 93.320 - Horses from Central America and the West Indies.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Horses from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Central America and the West Indies 17 § 93.320 Horses from Central America and the West Indies. Horses from Central America and...

  8. 9 CFR 93.320 - Horses from Central America and the West Indies.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Horses from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Central America and the West Indies 17 § 93.320 Horses from Central America and the West Indies. Horses from Central America and...

  9. 9 CFR 93.320 - Horses from Central America and the West Indies.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Horses from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Central America and the West Indies 17 § 93.320 Horses from Central America and the West Indies. Horses from Central America and...

  10. 9 CFR 93.320 - Horses from Central America and the West Indies.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Horses from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Central America and the West Indies 17 § 93.320 Horses from Central America and the West Indies. Horses from Central America and...

  11. 9 CFR 93.320 - Horses from Central America and the West Indies.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Horses from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Central America and the West Indies 17 § 93.320 Horses from Central America and the West Indies. Horses from Central America and...

  12. Historic America: The South Central States.

    ERIC Educational Resources Information Center

    Beardsley, Donna A.

    Many sites in the south central states recall the procession of people who came across the continent with the passing frontier. This paper elaborates on several historic sites in the south central United States. The purpose of the paper is to introduce a series of places to the students and teachers of U.S. history. The paper recommends that…

  13. Assessment of undiscovered petroleum resources in Central and South America

    USGS Publications Warehouse

    Schenk, C.J.

    2002-01-01

    The USGS has assessed undiscovered conventional oil and gas resources in 128 selected petroleum provinces of the world. Of these 128 provinces, 23 are in South America, Central America, and the Caribbean area. In the USGS 2000 Assessment, the provinces resulted in mean totals for undiscovered resource of 105 billion bbl of oil and 487 tcf of gas. The potential for giant oil and gas fields is greatest in the basins along the Atlantic margin of eastern South America, from the Santos Basin in the south to the Guyana-Suriname Basin in the north. The potential for giant fields is mainly offshore, in water depths up to 3600 m. The South and Central America region ranks third in the world for undiscovered conventional oil and gas behind the Middle East and the Former Soviet Union.

  14. The Relationship of Forest Fires Detected by MODIS and SRTM Derived Topographic Features in Central Siberia

    NASA Technical Reports Server (NTRS)

    Ranson, Jon K.; Kovacs, Katalin; Kharuk, Viatcheslav; Burke, Erin

    2006-01-01

    Fires are a common occurrence in the Siberian boreal forest. The MOD14 Thermal anomalies product of the Terra MODIS Moderate Resolution Spectroradiometer) product set is designed to detect thermal anomalies (i.e. hotspots or fires) on the Earth's surface. Recent field studies showed a dependence of fire occurrence on topography. In this study MODIS thermal anomaly data and SRTM topography data were merged and analyzed to evaluate if forest fires are more likely to occur at certain combinations of elevation, slope and aspect. Using the satellite data over a large area can lead to better understanding how topography and forest fires are related. The study area covers a 2.5 Million krn(exp 2) portion of the Central Siberian southern taiga from 72 deg to 110 deg East and from 50 deg to 60 deg North. About 57% of the study area is forested and 80% of the forest grows between 200 and 1000 m. Forests with pine (Pinus sylvestris), larch (Larix sibirica, L. gmelinii), Siberian pine (Pinus sibirica), spruce (Picea obovata.) and fir (Abies sibirica) cover most of the landscape. Deciduous stands with birch (Betula pendula, B. pubescens) and aspen (Populus tremula) cover the areas of lower elevation in this region. The climate of this area is distinctly continental with long, cold winters and short hot summers. The tree line in this part of the world is around 1500 m in elevation with alpine tundra, snow and ice fields and rock outcrops extending up to over 3800 m. A 500 m resolution landcover map was developed using 2001 MODIS MOD13 Normalized Vegetation Index (NDVI) and Middle Infrared (MIR) products for seven 16-day periods. The classification accuracy was over 87%. The SRTM version 2 data, which is distributed in 1 degree by 1 degree tiles were mosaiced using the ENVI software. In this study, only those MODIS pixels were used that were flagged as "nominal or high confidence fire" by the MODIS fire product team. Using MODIS data from the years 2000 to 2005 along with the

  15. Women farmers in Central America: myths, roles, reality.

    PubMed

    Yudelman, S W

    1994-01-01

    In Central America, women's productive roles are negated by the widely held belief that women do not work in agriculture or do so only temporarily for reasons of poverty. Working as unpaid laborers, working seasonally in cash crops, and engaging in informal sector activities off the farm, women are not seen as agricultural producers or full-time wage laborers. That notion is enhanced by rural women, who tend not to describe themselves as producers. Women farmers are therefore invisible and deprived of social and legal recognition and protection. Recent studies, however, have found that women throughout Central America have played a long-standing role in agriculture as permanent, not temporary, workers. Official statistics indicate that almost 20% of rural households are headed by women who are fully responsible for agricultural production. Indeed, there are villages in Central America inhabited solely or mainly by widows and single women and their children. Despite the growing body of evidence on women's true productive role in Central American societies, their agricultural roles still remain largely invisible in government census and labor statistics. The author discusses barriers to opportunity and supporting women farmers in Central America.

  16. Women farmers in Central America: myths, roles, reality.

    PubMed

    Yudelman, S W

    1994-01-01

    In Central America, women's productive roles are negated by the widely held belief that women do not work in agriculture or do so only temporarily for reasons of poverty. Working as unpaid laborers, working seasonally in cash crops, and engaging in informal sector activities off the farm, women are not seen as agricultural producers or full-time wage laborers. That notion is enhanced by rural women, who tend not to describe themselves as producers. Women farmers are therefore invisible and deprived of social and legal recognition and protection. Recent studies, however, have found that women throughout Central America have played a long-standing role in agriculture as permanent, not temporary, workers. Official statistics indicate that almost 20% of rural households are headed by women who are fully responsible for agricultural production. Indeed, there are villages in Central America inhabited solely or mainly by widows and single women and their children. Despite the growing body of evidence on women's true productive role in Central American societies, their agricultural roles still remain largely invisible in government census and labor statistics. The author discusses barriers to opportunity and supporting women farmers in Central America. PMID:12290750

  17. Comparison of Summer and Winter California Central Valley Aerosol Distributions from Lidar and MODIS Measurements

    NASA Technical Reports Server (NTRS)

    Lewis, Jasper R., Jr.; DeYoung, Russell J.; Chu, D. Allen

    2010-01-01

    Aerosol distributions from two aircraft lidar campaigns conducted in the California Central Valley are compared in order to identify seasonal variations. Aircraft lidar flights were conducted in June 2003 and February 2008. While the PM2.5 concentration is highest in the winter, the aerosol optical depth measured from MODIS is highest in the summer. A seasonal comparison shows that PM2.5 in the winter can exceed summer PM2.5 by 55%, while summer AOD exceeds winter AOD by 43%. Higher temperatures wildfires in the summer produce elevated aerosol layers that are detected by satellite measurements, but not surface particulate matter monitors. Measurements of the boundary layer height from lidar instruments are necessary to incorporate satellite measurements with air quality measurements.

  18. MODIS Snowcover in North America: A Comparison of Winter 2013/14 and 2014/15 to Median Condition

    NASA Astrophysics Data System (ADS)

    Trubilowicz, J. W.; Floyd, B. C.; D'Amore, D. V.; Bidlack, A.

    2015-12-01

    The winters from 2013-2015 had exceptionally low snow-packs in much of western North America. In particular, the winter of 2014/2015 had the lowest peak snow-water-equivalent (SWE) depths ever recorded in many areas of the Pacific Northwest. These low snow-packs have contributed to drought conditions from British Columbia to California. Along with the low SWE values, the snow covered area (SCA) of the previous two winters has been a significant departure from normal conditions. SCA is related to SWE, rain-on-snow events and the seasonal water supply, provides insulation for plant root systems from late season frost, and is an important factor in forest fire hazard, delaying the start of soil and fuel drying. Remote sensing can be a useful tool to monitor SCA over large regions, with the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments providing a suitable temporal (twice daily), and spatial resolution (500m) to create detailed maps, even with high frequencies of cloud covered days. While comparison of SWE at snow monitoring sites to historical values is a standard analysis, doing the same for SCA has been difficult due to the technical and logistical problems related to processing the large amounts of spatial data required to determine a 'normal' annual SCA cycle. Through the use of new cloud-based computation methods from Google Earth Engine, we have calculated the monthly median (from 2002-2015) MODIS SCA, at a 500 m resolution, for all of the major Pacific draining watersheds of North America. Determining the 'normal' SCA cycle of the past 13 years allowed us to compare the past two winters to the median SCA levels, showing which basins have seen the most significant departures from normal SCA levels. Results indicate more significant departures from normal in basins with significant maritime-influenced snow-packs.

  19. Combining MISR and MODIS data to automatically catalogue smoke plumes in North America

    NASA Technical Reports Server (NTRS)

    Mazzoni, Dominic; Tong, Lingling; Diner, David

    2005-01-01

    We are in the early stages of work on EPA task to investigate the effects of fires on air quality in North America, led by Jennifer Logan of Harvard University. JPL's contribution to this study is to find thousands of smoke plumes in satellite images of North America, and derive statistics about their geographic distribution, extent, orientation, and injection height.

  20. Visiting the Digital Divide: Women Entrepreneurs in Central America

    ERIC Educational Resources Information Center

    Tapper, Helena

    2006-01-01

    Micro and small enterprises comprise approximately 60-70% of enterprises in South and Central America. Most of these enterprises, particularly micro enterprises, are managed and owned by women. These women for the most part lack both skills and training in the use of computers and the Internet, and access to the use of information and…

  1. National Geothermal Association Trade Mission to Central America

    SciTech Connect

    Not Available

    1992-10-01

    The United States (US) geothermal industry, the world's most technically proficient, has been unable to achieve penetration into the markets of the developing nations. This report details the findings of an industry Trade Mission to Central America, tasked with determining the reasons for this shortfall and with developing a US industry geothermal export strategy designed to achieve immediate and long-term export benefits.

  2. Drought assessment for cropland of Central America using course-resolution remote sensing data

    NASA Astrophysics Data System (ADS)

    Chen, C. F.; Nguyen, S. T.; Chen, C. R.; Chiang, S. H.; Chang, L. Y.; Khin, L. V.

    2015-12-01

    Drought is one of the most frequent and costliest natural disasters, which imposes enormous effects to human societies and ecosystems. Agricultural drought is referred to an interval of time, such as weeks or months, when the soil moisture supply of a region consistently falls below the appropriate moisture supply leading to negative impacts on agricultural production. Millions of households in Central America were dependent upon major food crops, including maize, beans, and sorghum, for their daily subsistence. In recent years, impacts of climate change through global warming in forms of higher temperature and widespread rainfall deficits have however triggered severe drought during the primera cropping season (April-August) in the study region, causing profound impacts on agriculture, crop production losses, increased market food prices, as well as food security issues. This study focuses on investigating agricultural droughts for cropland of Central America using the Moderate Resolution Imaging Spectroradiometer (MODIS) data. We processed the data for a normal year 2013 and an abnormal year 2014 using a simple vegetation health index (VHI) that is developed based on the temperature condition index (TCI) and vegetation condition index (VCI). The VHI results were validated using the Advanced Microwave Scanning Radiometer 2 (AMSR2) precipitation data and temperature vegetation dryness index (TVDI) that is developed based on the empirical analysis of TCI and VCI data. The correlation coefficients (r) obtained by comparisons between the VHI data and the AMSR2 precipitation and TVDI data were higher than 0.62 and -0.61, respectively. The severe drought was intensive during the dry season (January-April) and likely backed to normal conditions in May with the onset of rainy season. The larger area of serve drought was observed for the 2014 primera season, especially during April-July. When investigating the cultivated areas affected by severe drought in the primera

  3. Social determinants of workers' health in Central America.

    PubMed

    Aragón, Aurora; Partanen, Timo; Felknor, Sarah; Corriols, Marianela

    2011-01-01

    This communication summarizes the available data on work-related determinants of health in Central America. The Central American working population is young and moving from agriculture toward industry and services. Ethnicity, gender, migration, subemployment and precarious work, informality, rural conditions, low-level educational, poverty, ubiquitous worksite health hazards, insufficient occupational health services, low labor inspection density, and weak unions define the constellation of social determinants of workers' health in Central America. Data are, however, scanty both for hazards and work-related illnesses and injuries. Governments and industries have the responsibility of opening decent work opportunities, especially for those facing multiple inequalities in social determinants of health. A first step would be the ratification and implementation of the ILO Convention (187) on occupational safety and health by the seven national governments of the region. PMID:21905391

  4. Contextualizing the Trauma Experience of Women Immigrants From Central America, South America, and Mexico

    PubMed Central

    Kaltman, Stacey; de Mendoza, Alejandra Hurtado; Gonzales, Felisa A.; Serrano, Adriana; Guarnaccia, Peter J.

    2012-01-01

    Trauma has been understudied among Latina immigrants from Central and South America. This study examined the types and context of trauma exposure experienced by immigrant women from Central America, South America, and Mexico living in the United States. Twenty-eight women seeking care in primary care or social service settings completed life history interviews. The majority of the women reported some type of trauma exposure in their countries of origin, during immigration, and/or in the United States. In the interviews, we identified types of trauma important to the experience of these immigrants that are not queried by trauma assessments typically used in the United States. We also identified factors that are likely to amplify the impact of trauma exposure. The study highlights the importance of utilizing a contextualized approach when assessing trauma exposure among immigrant women. PMID:22144133

  5. Contextualizing the trauma experience of women immigrants from Central America, South America, and Mexico.

    PubMed

    Kaltman, Stacey; Hurtado de Mendoza, Alejandra; Gonzales, Felisa A; Serrano, Adriana; Guarnaccia, Peter J

    2011-12-01

    Trauma has been understudied among Latina immigrants from Central and South America. This study examined the types and context of trauma exposure experienced by immigrant women from Central America, South America, and Mexico living in the United States. Twenty-eight women seeking care in primary care or social service settings completed life history interviews. The majority of the women reported some type of trauma exposure in their countries of origin, during immigration, and/or in the United States. In the interviews, we identified types of trauma important to the experience of these immigrants that are not queried by trauma assessments typically used in the United States. We also identified factors that are likely to amplify the impact of trauma exposure. The study highlights the importance of utilizing a contextualized approach when assessing trauma exposure among immigrant women.

  6. Earth and water resources and hazards in Central America

    USGS Publications Warehouse

    Cunningham, Charles G.; Fary, R.W.; Guffanti, Marianne; Laura, Della; Lee, M.P.; Masters, C.D.; Miller, R.L.; Quinones-Marques, Ferdinand; Peebles, R.W.; Reinemund, J.A.; Russ, D.P.

    1984-01-01

    Long-range economic development in Central America will depend in large part on production of indigenous mineral, energy, and water resources and on mitigation of the disastrous effects of geologic and hydrologic hazards such as landslides, earthquakes, volcanic eruptions, and floods. The region has six world-class metal mines at present as well as additional evidence of widespread mineralization. Systematic investigations using modern mineral exploration techniques should reveal more mineral deposits suitable for development. Widespread evidence of lignite and geothermal resources suggests that intensive studies could identify producible energy sources in most Central American countries. Water supply and water quality vary greatly from country to country. Local problems of ground- and surface-water availability and of contamination create a need for systematic programs to provide better hydrologic data, capital improvements, and management. Disastrous earthquakes have destroyed or severely damaged many cities in Central America. Volcanic eruptions, landslides, mudflows, and floods have devastated most of the Pacific side of Central America at one time or another. A regional approach to earthquake, volcano, and flood-risk analysis and monitoring, using modern technology and concepts, would provide the facilities and means for acquiring knowledge necessary to reduce future losses. All Central American countries need to strengthen institutions and programs dealing with earth and water resources and natural hazards. Some of these needs may be satisfied through existing or pending projects and technical and economic assistance from U.S. or other sources. The need for a comprehensive study of the natural resources of Central America and the requirements for their development is evident. The U.S. Caribbean Basin Initiative offers both an excellent opportunity for a regional approach to these pervasive problems and an opportunity for international cooperation.

  7. Surface energy flux consequences of bark beetle outbreaks in the south-central Rockies using MODIS data

    NASA Astrophysics Data System (ADS)

    Vanderhoof, M. K.; Williams, C. A.

    2012-12-01

    Changes in canopy cover due to disturbance-related mortality have been shown to profoundly impact parameters within the surface energy balance and water budget. A shift in such fluxes can have consequences for surface temperature, cloudiness, run-off and stream flow, forest regeneration and net primary productivity. Current outbreaks of native bark beetles in western North America are some of the largest and most severe in recorded history. In recent outbreaks, bark beetles have reduced the basal area of host-dominated forests by up to 70%; with over-story mortality often exceeding 90% in mature, even-aged stands. The magnitude, frequency and intensity of recent outbreaks have been attributed to warmer summer and winter temperatures and drought conditions as a result of climate change. However, despite the likelihood that canopy mortality from bark beetle attacks will have profound effects on forest albedo and evapotranspiration, consequences for this disturbance type remain largely un-documented. This study addressed the question: how does a bark beetle outbreak event influence surface albedo and evapotranspiration? Seasonal patterns of surface temperature, albedo, evapotranspiration, and radiative forcing were modeled for lodgepole and ponderosa pine stands by outbreak age using Moderate Resolution Imaging Spectroradiometer (MODIS) data within the south-central Rocky Mountains. Beetle damage data was derived from both field-based plots as well as aerial surveys. The prevalence of bark beetle outbreaks in high-elevation environments, which are exceedingly sensitive to climate change, necessitates the importance of understanding the energy and evapotranspiration consequences of such events.

  8. Neighbors' problems, our problems: population growth in Central America.

    PubMed

    Fox, R W

    1990-06-01

    A largely ignored issue, Central America faces its most pressing problem in its soaring population growth, one that is wreaking havoc on its economic and social infrastructures. Rising by a factor of 7, Central America's population -- presently 28.9 million -- is expected to reach 7.7 million by the year 2000, and 62.8 million by 2025. Typical of most of the Third World, Central America's population explosion stems from the fact that while the latter half of the 20th century has seen reductions of mortality rates, brought on by improvements of general health conditions, birth rates have remained excessively high. Despite moderate declines in the birth rate, Central American women still average 3-6 children. These demographic factors pose catastrophic consequences for Central America's natural resources, urban development and labor force. And they also threaten to increase migration to the US. Economic pressures have put great demands on the region's rain forests, exploited both for its resources and cleared away to create farmland. Today, only 40% of the original forest remains, and almost 3% more is destroyed annually. The area's capital cities have seen their populations increase 3-6 fold between 1950 and 1980. This explosion places further demands on already overburdened urban infrastructures, and has led to a mushrooming of squatter settlements. It has also led to a massive increase in the urban labor force which cannot be accommodated by the region's economies, which are in disarray due to falling export commodity earnings, limited natural resources, and scant investment capital. The economic woes could further increase the flow of workers to the US (15-20% of El Salvador's total population has already filed to the US). Historically, the region had attempted to offset population growth through economic development, but such expectations were not met, especially with the economic decline that wiped out gains made during the 1960s and 70s. Only recently have the

  9. Global burned-land estimation in Latin America using MODIS composite data.

    PubMed

    Chuvieco, Emilio; Opazo, Sergio; Sione, Walter; Del Valle, Hector; Anaya, Jesús; Di Bella, Carlos; Cruz, Isabel; Manzo, Lilia; López, Gerardo; Mari, Nicolas; González-Alonso, Federico; Morelli, Fabiano; Setzer, Alberto; Csiszar, Ivan; Kanpandegi, Jon Ander; Bastarrika, Aitor; Libonati, Renata

    2008-01-01

    This paper presents results of the AQL2004 project, which has been develope within the GOFC-GOLD Latin American network of remote sensing and forest fires (RedLatif). The project intended to obtain monthly burned-land maps of the entire region, from Mexico to Patagonia, using MODIS (moderate-resolution imaging spectroradiometer) reflectance data. The project has been organized in three different phases: acquisition and preprocessing of satellite data; discrimination of burned pixels; and validation of results. In the first phase, input data consisting of 32-day composites of MODIS 500-m reflectance data generated by the Global Land Cover Facility (GLCF) of the University of Maryland (College Park, Maryland, U.S.A.) were collected and processed. The discrimination of burned areas was addressed in two steps: searching for "burned core" pixels using postfire spectral indices and multitemporal change detection and mapping of burned scars using contextual techniques. The validation phase was based on visual analysis of Landsat and CBERS (China-Brazil Earth Resources Satellite) images. Validation of the burned-land category showed an agreement ranging from 30% to 60%, depending on the ecosystem and vegetation species present. The total burned area for the entire year was estimated to be 153 215 km2. The most affected countries in relation to their territory were Cuba, Colombia, Bolivia, and Venezuela. Burned areas were found in most land covers; herbaceous vegetation (savannas and grasslands) presented the highest proportions of burned area, while perennial forest had the lowest proportions. The importance of croplands in the total burned area should be taken with reserve, since this cover presented the highest commission errors. The importance of generating systematic products of burned land areas for different ecological processes is emphasized.

  10. Central America and the Caribbean: No place for the unwary

    SciTech Connect

    Goodwin, L.M.

    1994-11-15

    Central America and the Caribbean have not enjoyed the same high profile as more prominent independent power markets like India and China. Indeed, only one country in the region appeared in a recent survey of the 20 most promising markets: Panama, with a projected demand for 2,040 megawatts (MW) of new capacity, was ranked twentieth. Nevertheless, taken as a whole, Central America and the Caribbean offer significant opportunities for new development. Projected incremental capacity needs in some of the larger markets in the region include: Costa Rica (700-1,000 MW), Dominican Republic (1,100 MW), Guatemala (450 MW), Honduras (225 MW), Jamaica (729 MW), Panama (2,040 MW), and Trinidad & Tobago (200 MW). These markets represent an aggregate potential demand of 5,750 MW - more than the projected demand in Colombia, one of South America`s most active markets. Yet although its need for capacity is significant, the region presents developers with unique challenges because it comprises so many relatively small countries, each with its own special needs and characteristics.

  11. 9 CFR 93.423 - Ruminants from Central America and the West Indies.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Ruminants from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Ruminants Central America and West Indies 9 § 93.423 Ruminants from Central America and the West Indies. (a) Ruminants intended...

  12. 9 CFR 93.423 - Ruminants from Central America and the West Indies.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Ruminants from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Ruminants Central America and West Indies 9 § 93.423 Ruminants from Central America and the West Indies. (a) Ruminants intended...

  13. 9 CFR 93.423 - Ruminants from Central America and the West Indies.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Ruminants from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Ruminants Central America and West Indies 9 § 93.423 Ruminants from Central America and the West Indies. (a) Ruminants intended...

  14. 9 CFR 93.423 - Ruminants from Central America and the West Indies.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Ruminants from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Ruminants Central America and West Indies 9 § 93.423 Ruminants from Central America and the West Indies. (a) Ruminants intended...

  15. 9 CFR 93.423 - Ruminants from Central America and the West Indies.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Ruminants from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Ruminants Central America and West Indies 9 § 93.423 Ruminants from Central America and the West Indies. (a) Ruminants intended...

  16. National Geothermal Association Trade Mission to Central America

    SciTech Connect

    Not Available

    1992-10-01

    The United States (US) geothermal industry, the world`s most technically proficient, has been unable to achieve penetration into the markets of the developing nations. This report details the findings of an industry Trade Mission to Central America, tasked with determining the reasons for this shortfall and with developing a US industry geothermal export strategy designed to achieve immediate and long-term export benefits.

  17. Narco-scapes: Cocaine Trafficking and Deforestation in Central America

    NASA Astrophysics Data System (ADS)

    Wrathall, D.; McSweeney, K.; Nielsen, E.; Pearson, Z.

    2015-12-01

    Narcotics trafficking and drug interdiction efforts have resulted in a well-documented social crisis in Central America, but more recently, has been tightly linked to environmental catastrophe and accelerated deforestation in transit zones. This talk will outline synthesis findings from multi-country, interdisciplinary research on cocaine trafficking as an engine of forest loss in Central America. During the "narco-boom" of the mid-2000s, we observed a geographical evolution of cocaine flows into Central America, and the transit of cocaine through new spaces, accompanied by specific patterns of social and environmental change in new nodes of transit. We coarsely estimated that the total amount of cocaine flowing through Central America increased from 70 metric tons in 2000 to 350 mt in 2012, implying that total cocaine trafficking revenue in the region increased from roughly 600 million dollars to 3.5 billion in that time. We describe the mechanism by which these locally captured cocaine rents resulted in a rapid conversion of forest into cattle pasture. Narco-traffickers are drawn to invest in the cattle economy, as a direct means of laundering and formalizing proceeds. Ranching is a land intensive activity, and new narco-enriched cattle pastures can be isolated from other forms forest loss solely by their spatial and temporal change characteristics. A preliminary forest change study in Honduras, for example, indicated that areas of accelerated deforestation were in close proximity to known narcotics trafficking routes and were thirteen times more extensive on average than other forest clearings. Deforested areas commonly appeared in isolated and biodiverse lowland tropical rainforest regions that often intersected with protected areas and indigenous reserves. We find that narco-deforestation is a readily identifiable signal of the extent and health of the cocaine economy. This talk will feature summaries of both ethnographic and land cover change we have observed

  18. Comparison of Summer and Winter California Central Valley Aerosol Distributions from Lidar and MODIS Measurements

    NASA Technical Reports Server (NTRS)

    Lewis, Jasper; DeYoung, Russell; Ferrare, Richard; Chu, D. Allen

    2010-01-01

    Aerosol distributions from two aircraft lidar campaigns conducted in the California Central Valley are compared in order to identify seasonal variations. Aircraft lidar flights were conducted in June 2003 and February 2007. While the ground PM(sub 2.5) concentration is highest in the winter, the aerosol optical depth measured from MODIS is highest in the summer. A seasonal comparison shows that PM(sub 2.5) in the winter can exceed summer PM(sub 2.5) by 55%, while summer AOD exceeds winter AOD by 43%. Higher temperatures and wildfires in the summer produce elevated aerosol layers that are detected by satellite measurements, but not surface particulate matter monitors. Temperature inversions, especially during the winter, contribute to higher PM(sub 2.5) measurements at the surface. Measurements of the boundary layer height from lidar instruments provide valuable information need to understand the relationship between satellite measurements of optical depth and in-situ measurements of PM(sub 2.5).

  19. Acute pesticide poisoning and pesticide registration in Central America.

    PubMed

    Wesseling, Catharina; Corriols, Marianela; Bravo, Viria

    2005-09-01

    The International Code of Conduct on the Distribution and Use of Pesticides of the Food and Agriculture Organization (FAO) of the United Nations has been for 20 years the most acknowledged international initiative for reducing negative impact from pesticide use in developing countries. We analyzed pesticide use and poisoning in Central America, particularly in Costa Rica and Nicaragua, and evaluated whether registration decisions are based on such data, in accordance with the FAO Code. Extensive use of very hazardous pesticides continues in Central America and so do poisonings with organophosphates, carbamates, endosulfan and paraquat as the main causative agents. Central American governments do not carry out or commission scientific risk assessments. Instead, guidelines from international agencies are followed for risk management through the registration process. Documentation of pesticide poisonings during several decades never induced any decision to ban or restrict a pesticide. However, based on the official surveillance systems, in 2000, the ministers of health of the seven Central American countries agreed to ban or restrict twelve of these pesticides. Now, almost 4 years later, restrictions have been implemented in El Salvador and in Nicaragua public debate is ongoing. Chemical and agricultural industries do not withdraw problematic pesticides voluntarily. In conclusion, the registration processes in Central America do not comply satisfactorily with the FAO Code. However, international regulatory guidelines are important in developing countries, and international agencies should strongly extend its scope and influence, limiting industry involvement. Profound changes in international and national agricultural policies, steering towards sustainable agriculture based on non-chemical pest management, are the only way to reduce poisonings.

  20. Acute pesticide poisoning and pesticide registration in Central America

    SciTech Connect

    Wesseling, Catharina . E-mail: cwesseli@una.ac.cr; Corriols, Marianela; Bravo, Viria

    2005-09-01

    The International Code of Conduct on the Distribution and Use of Pesticides of the Food and Agriculture Organization (FAO) of the United Nations has been for 20 years the most acknowledged international initiative for reducing negative impact from pesticide use in developing countries. We analyzed pesticide use and poisoning in Central America, particularly in Costa Rica and Nicaragua, and evaluated whether registration decisions are based on such data, in accordance with the FAO Code. Extensive use of very hazardous pesticides continues in Central America and so do poisonings with organophosphates, carbamates, endosulfan and paraquat as the main causative agents. Central American governments do not carry out or commission scientific risk assessments. Instead, guidelines from international agencies are followed for risk management through the registration process. Documentation of pesticide poisonings during several decades never induced any decision to ban or restrict a pesticide. However, based on the official surveillance systems, in 2000, the ministers of health of the seven Central American countries agreed to ban or restrict twelve of these pesticides. Now, almost 4 years later, restrictions have been implemented in El Salvador and in Nicaragua public debate is ongoing. Chemical and agricultural industries do not withdraw problematic pesticides voluntarily. In conclusion, the registration processes in Central America do not comply satisfactorily with the FAO Code. However, international regulatory guidelines are important in developing countries, and international agencies should strongly extend its scope and influence, limiting industry involvement. Profound changes in international and national agricultural policies, steering towards sustainable agriculture based on non-chemical pest management, are the only way to reduce poisonings.

  1. Flying shells: historical dispersal of marine snails across Central America

    PubMed Central

    Miura, Osamu; Torchin, Mark E.; Bermingham, Eldredge; Jacobs, David K.; Hechinger, Ryan F.

    2012-01-01

    The geological rise of the Central American Isthmus separated the Pacific and the Atlantic oceans about 3 Ma, creating a formidable barrier to dispersal for marine species. However, similar to Simpson's proposal that terrestrial species can ‘win sweepstakes routes’—whereby highly improbable dispersal events result in colonization across geographical barriers—marine species may also breach land barriers given enough time. To test this hypothesis, we asked whether intertidal marine snails have crossed Central America to successfully establish in new ocean basins. We used a mitochondrial DNA genetic comparison of sister snails (Cerithideopsis spp.) separated by the rise of the Isthmus. Genetic variation in these snails revealed evidence of at least two successful dispersal events between the Pacific and the Atlantic after the final closure of the Isthmus. A combination of ancestral area analyses and molecular dating techniques indicated that dispersal from the Pacific to the Atlantic occurred about 750 000 years ago and that dispersal in the opposite direction occurred about 72 000 years ago. The geographical distribution of haplotypes and published field evidence further suggest that migratory shorebirds transported the snails across Central America at the Isthmus of Tehuantepec in southern Mexico. Migratory birds could disperse other intertidal invertebrates this way, suggesting the Central American Isthmus may not be as impassable for marine species as previously assumed. PMID:21920976

  2. Biennial relationship of rainfall variability between Central America and equatorial South America

    NASA Astrophysics Data System (ADS)

    Wu, Renguang; Zhang, Li

    2010-04-01

    Observations indicate that equatorial South American rainfall anomalies in boreal winter are preceded by the same sign Central American rainfall anomalies in boreal summer and tend to be succeeded by opposite sign Central American rainfall anomalies in the following summer. The in-phase relationship from summer to winter rainfall is attributed to direct effects of El Niño-Southern Oscillation (ENSO). Anomalous convection associated with warm ENSO events induces anomalous descent and suppresses precipitation along the convection region that migrates southeastward from Central America in boreal summer to tropical South America in boreal winter. The out-of-phase relationship from winter to summer rainfall is related to tropical North Atlantic sea surface temperature (SST) anomalies induced by wind-evaporation and cloud-radiation changes in response to ENSO-generated anomalous convection over tropical South America. In years when ENSO switches its phase from winter to summer, the direct effects of ENSO can also lead to the out-of-phase relationship.

  3. Seamount, ridge, and transform subduction in southern Central America

    NASA Astrophysics Data System (ADS)

    Morell, Kristin D.

    2016-02-01

    Understanding the factors that control subduction zone processes is a first-order goal in the study of convergent margins. In southern Central America, a growing body of research reveals strong links between the character of the subducting slab and the mechanics of important processes that include subduction erosion, fluid flow, deformation, and seismogenesis. In this paper, I evaluate the role that seamount, ridge, and transform subduction have in the development of upper plate deformation and volcanism by summarizing previous work across a >500 km long region of Central America where each of these three scenarios are present along strike. The data show that the subduction of short-wavelength bathymetry (e.g., seamounts and faults on the seafloor) produces short-wavelength deformation that persists for relatively short timescales (104-105 years), whereas the subduction of longer-wavelength bathymetry (e.g., the aseismic Cocos Ridge) results in longer-wavelength deformation that endures over a longer time scale (106 years). The timing and distribution of upper plate deformation are consistent with subhorizontal Cocos Ridge subduction driving upper plate deformation, and the increased crustal thickness (>20 km) of the subducting Cocos Ridge is likely one of the most important factors in the production of upper plate contraction and crustal thickening. The data illustrate a fundamental connection between lower plate properties and upper plate deformation and highlight the profound influence that bathymetry and crustal thickness have in the localization and kinematics of upper plate strain and volcanism in Middle America.

  4. Scene identification and clear-sky compositing algorithms for generating North America coverage at 250m spatial resolution from MODIS land channels

    NASA Astrophysics Data System (ADS)

    Luo, Yi; Trishchenko, Alexander P.; Khlopenkov, Konstantin V.; Park, William M.

    2007-09-01

    A new technology has been developed at the Canada Centre for Remote Sensing (CCRS) for generating North America continental scale clear-sky composites at 250 m spatial resolution of all seven MODIS land spectral bands (B1-B7). The MODIS Level 1B (MOD02) swath level data were used as input to circumvent the problems with image distortion in the mid-latitude and polar regions inherent to the sinusoidal (SIN) projection utilized for the standard MODIS data products. The new data products are stored in the Lambert Conformal Conical (LCC) projection for Canada and the Lambert Azimuthal Equal-Area (LAEA) projection for North America. The MODIS 500m data (B3-B7) were downscaled to 250m resolution using an adaptive regression algorithm. The clear-sky composites are generated using scene identification information produced at 250m resolution and multi-criteria selection which depends on pixel identification. Cloud shadows were also identified and removed from output product. It is demonstrated that new approach provides better results than any scheme based on a single compositing criterion, such as maximum NDVI, minimum visible reflectance, or combination of them. To account for surface bi-directional properties, two clear-sky composites for same time period are produced for the relative azimuth angles within 90°-270° and outside of this interval. Comparison with Landsat imagery and MODIS standard composite products demonstrated advantages of new technique for screening cloud and cloud shadow and providing the high spatial resolution. The final composites were produced for every 10-day intervals since March 2000. The composite products have been used for mapping albedo and vegetation properties as well as for land cover and change detections applications at 250m scale.

  5. Are there trends towards drier hydrological conditions in Central America?

    NASA Astrophysics Data System (ADS)

    Hidalgo, H. G.

    2013-12-01

    A summary of hydrological projections at the end of the century from 30 General Circulation Models (GCMs) is presented; and several hydrometeorological parameters are analyzed to validate if there are hydroclimatological trends during the observational period (1982-2005) consistent with the GCMs results. At the end of the century the median of 30 GCM simulations projects a drier future for Tegucigalpa and San Jose, with a marked increment in evapotranspiration in the first half of the rainy season along with reductions of soil moisture. With respect to the observations (1982-2005): 1) the Normalized Difference Vegetation Index showed negative trends in the North Pacific coast of Costa Rica, the border of Honduras and Nicaragua, and especially in southern Mexico (except the Yucatan Peninsula). Positive trends were found in the several parts of Central America, 2) the Palmer Drought Severity Index showed strong and consistent trends from Nicaragua to the North of Central America and southern Mexico (not including Yucatan), consistent with the direction of GCM projections; 3) negative precipitation trends in satellite data were found in Nicaragua, with strong trends in its Caribbean coast; 4) NCEP/NCAR Reanalysis precipitation showed strong negative trends in northern Central America, the Central Valley, the Dry Pacific of Costa Rica and the South-Pacific coast of Nicaragua, all consistent with the direction of GCM projections; and 5) station data showed no significant trends however, and 6) Reanalysis' temperature showed positive trends in southern Mexico (not including Yucatan) and negative trends in El Salvador. It can be concluded that several trends in drought indexes and precipitation are consistent with the future projected by the GCMs; that is, with some exceptions some of the trends were validated towards a drier future for the region, especially in the northern part.

  6. Central and South America GPS geodesy - CASA Uno

    NASA Technical Reports Server (NTRS)

    Kellogg, James N.; Dixon, Timothy H.

    1990-01-01

    In January 1988, scientists from over 25 organizations in 13 countries and territories cooperated in the largest GPS campaign in the world to date. A total of 43 GPS receivers collected approximately 590 station-days of data in American Samoa, Australia, Canada, Colombia, Costa Rica, Ecuador, New Zealand, Norway, Panama, Sweden, United States, West Germany, and Venezuela. The experiment was entitled CASA Uno. Scientific goals of the project include measurements of strain in the northern Andes, subduction rates for the Cocos and Nazca plates beneath Central and South America, and relative motion between the Caribbean plate and South America. A second set of measurements are planned in 1991 and should provide preliminary estimates of crustal deformation and plate motion rates in the region.

  7. Monitoring pesticide use and associated health hazards in Central America.

    PubMed

    Bravo, Viria; Rodríguez, Teresa; van Wendel de Joode, Berna; Canto, Nonato; Calderón, Gloria Ruth; Turcios, Miguel; Menéndez, Luis Armando; Mejía, Winston; Tatis, Anabel; Abrego, Federico Z; de la Cruz, Elba; Wesseling, Catharina

    2011-01-01

    We established methods for monitoring pesticide use and associated health hazards in Central America. With import data from Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama for 2000-2004, we constructed quantitative indicators (kg active ingredient) for general pesticide use, associated health hazards, and compliance with international regulations. Central America imported 33 million kg active ingredient per year. Imports increased 33% during 2000-2004. Of 403 pesticides, 13 comprised 77% of the total pesticides imported. High volumes of hazardous pesticides are used; 22% highly/extremely acutely toxic, 33% moderately/severely irritant or sensitizing, and 30% had multiple chronic toxicities. Of the 41 pesticides included in the Stockholm Convention on Persistent Organic Pollutants (POPs), the Rotterdam Convention on Prior Informed Consent (PIC), the Montreal Protocol on Substances that Deplete the Ozone Layer, the Pesticide Action Network (PAN) Dirty Dozen, and the Central American Dirty Dozen, 16 (17% total volume) were imported, four being among the 13 most imported pesticides. Costa Rica is by far the biggest consumer. Pesticide import data are good indicators of use trends and an informative source to monitor hazards and, potentially, the effectiveness of interventions.

  8. MODIS-Aqua detects Noctiluca scintillans and hotspots in the central Arabian Sea.

    PubMed

    Dwivedi, R; Priyaja, P; Rafeeq, M; Sudhakar, M

    2016-01-01

    Northern Arabian Sea is considered as an ecologically sensitive area as it experiences a massive upwelling and long-lasting algal bloom, Noctiluca scintillans (green tide) during summer and spring-winter, respectively. Diatom bloom is also found to be co-located with N. scintillans and both have an impact on ecology of the basin. In-house technique of detecting species of these blooms from Moderate Resolution Imaging Spectroradiometer (MODIS)-Aqua data was used to generate a time-series of images revealing their spatial distribution. A study of spatial-temporal variability of these blooms using satellite data expressed a cyclic pattern of their spread over a period of 13 years. An average distribution of the blooms for January-March period revealed a peak in 2015 and minimum in 2013. Subsequently, a time-series of phytoplankton species images were generated for these 2 years to study their inter-annual variability and the associated factors. Species images during active phase of the bloom (February) in 2015 indicated development of N. scintillans and diatom in the central Arabian Sea also, up to 12° N. This observation was substantiated with relevant oceanic parameters measured from the ship as well as satellite data and the same is highlight of the paper. While oxygen depletion and release of ammonia associated with N. scintillans are detrimental for waters on the western side; it is relatively less extreme and supports the entire food chain on the eastern side. In view of these contrasting eco-sensitive events, it is a matter of concern to identify biologically active persistent areas, hot spots, in order to study their ecology in detail. An ecological index, persistence of the bloom, was derived from the time-series of species images and it is another highlight of our study. PMID:26690080

  9. MODIS-Aqua detects Noctiluca scintillans and hotspots in the central Arabian Sea.

    PubMed

    Dwivedi, R; Priyaja, P; Rafeeq, M; Sudhakar, M

    2016-01-01

    Northern Arabian Sea is considered as an ecologically sensitive area as it experiences a massive upwelling and long-lasting algal bloom, Noctiluca scintillans (green tide) during summer and spring-winter, respectively. Diatom bloom is also found to be co-located with N. scintillans and both have an impact on ecology of the basin. In-house technique of detecting species of these blooms from Moderate Resolution Imaging Spectroradiometer (MODIS)-Aqua data was used to generate a time-series of images revealing their spatial distribution. A study of spatial-temporal variability of these blooms using satellite data expressed a cyclic pattern of their spread over a period of 13 years. An average distribution of the blooms for January-March period revealed a peak in 2015 and minimum in 2013. Subsequently, a time-series of phytoplankton species images were generated for these 2 years to study their inter-annual variability and the associated factors. Species images during active phase of the bloom (February) in 2015 indicated development of N. scintillans and diatom in the central Arabian Sea also, up to 12° N. This observation was substantiated with relevant oceanic parameters measured from the ship as well as satellite data and the same is highlight of the paper. While oxygen depletion and release of ammonia associated with N. scintillans are detrimental for waters on the western side; it is relatively less extreme and supports the entire food chain on the eastern side. In view of these contrasting eco-sensitive events, it is a matter of concern to identify biologically active persistent areas, hot spots, in order to study their ecology in detail. An ecological index, persistence of the bloom, was derived from the time-series of species images and it is another highlight of our study.

  10. Environmental impacts during geothermal development: Some examples from Central America

    SciTech Connect

    Goff, S.; Goff, F.

    1997-04-01

    The impacts of geothermal development projects are usually positive. However, without appropriate monitoring plans and mitigation actions firmly incorporated into the project planning process, there exists the potential for significant negative environmental impacts. The authors present five examples from Central America of environmental impacts associated with geothermal development activities. These brief case studies describe landslide hazards, waste brine disposal, hydrothermal explosions, and air quality issues. Improved Environmental Impact Assessments are needed to assist the developing nations of the region to judiciously address the environmental consequences associated with geothermal development.

  11. Geothermal corehole drilling and operations, Platanares, Honduras, Central America

    SciTech Connect

    Goff, S.; Rufenacht, H.D.; Laughlin, A.W.; Adams, A.; Planner, H.; Ramos, N.

    1987-01-01

    Two slim exploration coreholes to depths of 650 m and 428 m, respectively, have been completed at the Platanares geothermal site, Honduras, Central America. A third corehole is now being drilled. These boreholes have provided information on the stratigraphy, temperature variation with depth, nature and compositions of fluids, fracturing, permeability, and hydrothermal alterations associated with the geothermal reservoir. Eruptions of hot water occurred during the drilling of both the first and third boreholes. Recovery of >98% core has been obtained even under difficult superheated conditions.

  12. Forces of environmental flux in Central America during the holocene

    SciTech Connect

    Leyden, B. )

    1994-06-01

    A review of palynological and limnological data from Central America serves as a framework for evaluating environmental stability during the Holocene. The magnitude of climatic forcing after the early Holocene has not produced the dramatic changes that spanned the transition to post-glacial conditions. Nevertheless, climatic variability and human disturbance have had a significant impact on the vegetation of the region. This discussion has relevance for broader questions of species diversity and the long-term stability of vegetation associations in the tropics.

  13. Oil and gas developments in South America, Central America, Caribbean area, and Mexico in 1985

    SciTech Connect

    Wiman, W.D.

    1986-10-01

    Exploration activity in South America, Central America, the Caribbean area, and Mexico in 1985 was concentrated in proven petroleum provinces. Successful exploration and development efforts were most intense in Colombia and Venezuela, where activity centered around the Cano Limon field area. Initial production of 30,000 BOPD from Cano Limon started in December, raising Colombia again to the ranks of an exporting nation. Another significant discovery in Colombia was San Francisco field in the Upper Magdalena basin. Argentina reported significant discoveries by YPF in the Northwest Cretaceous and Neuquen basins and by Total offshore Tierra del Fuego. Brazil continued to discover major reserves in the offshore Campos basin in ever-increasing water depths. At year end, Venezuela was drilling Furrial-1 in eastern Venezuela. The well is reported to be the outstanding discovery of 1985, if not of the last 2 decades. 4 figures, 7 tables.

  14. Oil and gas developments in South America, Central America, Caribbean area, and Mexico in 1986

    SciTech Connect

    Wiman, W.D.

    1987-10-01

    Exploration activity in South America, Central America, the Caribbean area, and Mexico in 1986 was considerably reduced compared to 1985. Brazil, Colombia, Ecuador, Guatemala, and Venezuela had increased oil production, with Colombia showing a dramatic 71% increase attributed mainly to bringing on-stream the pipeline connecting Occidental-Shell-Ecopetrol's Cano Limon complex to the port of Covenas. Significant discoveries were reported from Argentina in the Olmedo, Oran, and San Jorge basins; Brazil in the offshore Campos and Amazon basins; Colombia in the Llanos basin; Ecuador in the Oriente basin; Mexico in the Bay of Campeche; Peru in the Ucayali basin; and Venezuela in the Eastern Venezuela basin. Eastern Venezuela's Furrial discovery is reported to have recoverable reserves of more than 1 million bbl of oil, and Shell's Ucayali basin discovery is reported to hold more than 7 tcf of gas. 7 figures, 10 tables.

  15. Exploration geothermal gradient drilling, Platanares, Honduras, Central America

    SciTech Connect

    Goff, S.J.; Laughlin, A.W.; Ruefenacht, H.D.; Goff, F.E.; Heiken, G.; Ramos, N.

    1988-01-01

    This paper is a review and summary of the core drilling operations component of the Honduras Geothermal Resource Development Project at the Platanares geothermal prospect in Honduras, Central America. Three intermediate depth (428 to 679 m) coreholes are the first continuously cored geothermal exploration boreholes in Honduras. These coring operations are part of the Central America Energy Resource Project (CAERP) effort funded by the Agency for International Development (AID) and implemented by the Los Alamos National Laboratory (Los Alamos) in cooperation with the Empresa Nacional de Energia Electrica (ENEE) and the United States Geological Survey (USGS). This report emphasizes coring operations with reference to the stratigraphy, thermal gradient, and flow test data of the boreholes. The primary objectives of this coring effort were (1) to obtain quantitative information on the temperature distribution as a function of depth, (2) to recover fluids associated with the geothermal reservoir, (3) to recover 75% or better core from the subsurface rock units, and (4) to drill into the subsurface rock as deeply as possible in order to get information on potential reservoir rocks, fracture density, permeabilities, and alteration histories of the rock units beneath the site. The three exploration coreholes drilled to depths of 650, 428 and 679 m, respectively, encountered several hot water entries. Coring operations and associated testing began in mid-October 1986 and were completed at the end of June 1987.

  16. Seismic array constraints on the D″ discontinuity beneath Central America

    NASA Astrophysics Data System (ADS)

    Whittaker, Stefanie; Thorne, Michael S.; Schmerr, Nicholas C.; Miyagi, Lowell

    2016-01-01

    We analyzed 16,150 transverse component seismic recordings from 54 deep-focus earthquakes in the South American and Caribbean regions recorded at broadband stations in North America between 2005 and 2012. We treated subgroups of seismic stations within 3° radius geographical bins as seismic arrays and performed vespagram analysis. We focused on the S, ScS, and Scd arrivals and collected data in the epicentral distance range from 55° to 90°. In particular, we searched for D″ discontinuity presence in the vespagrams in a 25° by 35° (or 1520 by 2130 km) area beneath Central America. Analysis of these data showed 125 clear Scd observations, 180 Scd observations of lesser quality, and 343 nonobservations. We produced a new map of the discontinuity height beneath Central America. Our map shows an average discontinuity height of 286 ± 6 km (σ = 76 km). The region is punctuated by a large topographic high centered at approximately 10°N and 90°W with a maximum height of 380 km. Two smaller topographic highs are located at approximately 4°N and 81°W (discontinuity height of 320 km) and at 4°N and 70°W (height of 315 km). The observation of multiple Scd arrivals collocated with the strongest gradients in inferred topography provides evidence for topographic variation on the discontinuity rather than multiple discontinuities. The regions where the discontinuity has the greatest height can be explained by localized enrichment of mid-ocean ridge basalt from the subducted Farallon slab impinging on the core-mantle boundary.

  17. Wind Energy Resource Assessment of the Caribbean and Central America

    SciTech Connect

    DL Elliott; CI Aspliden; GL Gower; CG Holladay, MN Schwartz

    1987-04-01

    A wind energy resource assessment of the Caribbean and Central America has identified many areas with good to outstanding wind resource potential for wind turbine applications. Annual average wind resource maps and summary tables have been developed for 35 island/country areas throughout the Caribbean and Central America region. The wind resource maps highlight the locations of major resource areas and provide estimates of the wind energy resource potential for typical well-exposed sites in these areas. The average energy in the wind flowing in the layer near the ground is expressed as a wind power class: the greater the average wind energy, the higher the wind power class. The summary tables that are included with each of the 35 island/country wind energy maps provide information on the frequency distribution of the wind speeds (expressed as estimates of the Weibull shape factor, k) and seasonal variations in the wind resource for the major wind resource areas identified on the maps. A new wind power class legend has been developed for relating the wind power classes to values of mean wind power density, mean wind speed, and Weibull k. Guidelines are presented on how to adjust these values to various heights above ground for different roughness and terrain characteristics. Information evaluated in preparing the assessment included existing meteorological data from airports and other weather stations, and from ships and buoys in offshore and coastal areas. In addition, new data from recent measurement sites established for wind energy siting studies were obtained for a few areas of the Caribbean. Other types of information evaluated in the assessment were climatological data and maps on winds aloft, surface pressure, air flow, and topography. The various data were screened and evaluated for their usefulness in preparing the wind resource assessment. Much of the surface data from airports and other land-based weather stations were determined to be from sheltered

  18. Performance of Early Warning Systems on Landslides in Central America

    NASA Astrophysics Data System (ADS)

    Strauch, W.; Devoli, G.

    2012-04-01

    We performed a reconnaissance about Early Warning Systems (EWS) on Landslides (EWSL) in the countries of Central America. The advance of the EWSL began in the 1990-ies and accelerated dramatically after the regional disaster provoked by Hurricane Mitch in 1998. In the last decade, Early Warning Systems were intensely promoted by national and international development programs aimed on disaster prevention. Early Warning on landslides is more complicated than for other geological phenomena. But, we found information on more than 30 EWSL in the region. In practice, for example in planning, implementation and evaluation of development projects, it is often not clearly defined what exactly is an Early Warning System. Only few of the systems can be classified as true EWSL that means 1) being directly and solely aimed at persons living in the well-defined areas of greatest risk and 2) focusing their work on saving lives before the phenomenon impacts. There is little written information about the work of the EWSL after the initial phase. Even, there are no statistics whether they issued warnings, if the warnings were successful, how many people were evacuated, if there were few false alerts, etc.. Actually, we did not find a single report on a successful landslide warning issued by an EWSL. The lack of information is often due to the fact that communitarian EWSL are considered local structures and do not have a clearly defined position in the governmental hierarchy; there is little oversight and no qualified support and long-term support. The EWSL suffer from severe problems as lack of funding on the long term, low technical level, and insufficient support from central institutions. Often the EWSL are implemented by NGÓs with funding from international agencies, but leave the project alone after the initial phase. In many cases, the hope of the local people to get some protection against the landslide hazard is not really fulfilled. There is one case, where an EWSL with a

  19. A Comparative Overview of the Education of Deaf Children in Central America, the Caribbean and Parts of South America.

    ERIC Educational Resources Information Center

    Delgado, Gilbert L.

    This paper describes the current state of education for deaf children in Central America and the Caribbean (with some mention of parts of South America), focusing on an historical description of events and forces impacting these regions; current educational philosophies; adult associations of deaf people; intra/intercountry networking; educational…

  20. Aerosol optical depth over central north Asia based on MODIS-Aqua data

    NASA Astrophysics Data System (ADS)

    Avgousta Foutsi, Athina; Korras Carraca, Marios Bruno; Matsoukas, Christos; Biskos, George

    2016-04-01

    Atmospheric aerosols, both natural and anthropogenic, can affect the regional and global climate through their direct, indirect, and semi-direct effects on the radiative energy budget of the Earth-atmosphere system. To quantify these effects it is important to determine the aerosol load, and an effective way to do that is by measuring the aerosol optical depth (AOD). The central Asia region (mainly the Caspian and Aral sea basins), the arid and semi-arid regions of Western China as well as Siberia are of great interest due to the significant natural sources of mineral aerosols originating from local deserts and biomass burning from wildfires in boreal forests. What is of particular interest in the region is the phenomenal shrinking and desertification of the Aral Sea that drives an intense salt and dust transport from the exposed sea-bed to the surrounding regions with important implications in regional air quality. Anthropogenic particles are also observed due to fossil-fuel combustion occurring mainly at oil refineries in the Caspian Sea basin. Here we investigate the spatial and temporal variability of the AOD at 550 nm over central Asia, Siberia and western China, in the region located between 35° N - 65° N and 45° E - 110° E. For our analysis we use Level-3 daily MODIS - Aqua Dark Target - Deep Blue combined product, from the latest collection (006), available in a 1°×1° resolution (ca. 100 km × 100 km) over the period 2002-2014. Our results indicate a significant spatial variability of the aerosol load over the study region. The highest AODs are observed over the Aral Sea year-round, with extreme values reaching 2.1 during July. In the rest of our study region a clear seasonal cycle with highest AOD values (up to 1.2 over the Taklamakan Desert) during spring and summer is observed. The arid parts of central north Asia are characterized by larger aerosol loads during spring, lower but still high AOD in summer and much lower values in autumn and spring

  1. Evolution of the Earthquake Catalog in Central America

    NASA Astrophysics Data System (ADS)

    Rojas, W.; Camacho, E. I.; Marroquín, G.; Molina, E.; Talavera, E.; Benito, M. B.; Lindholm, C.

    2013-05-01

    Central America (CA) is known as a seismically active region in which several historic destructive earthquakes have occurred. This fact has promoved the development of seismic hazard studies that provide necessary estimates for decision making and risk assessment efforts, requiring a complete and standardized seismic catalog. With this aim, several authors have contributed to the study of the historical seismicity of Central America (e.g. Grases, Feldaman; White y Harlow, 1993; White et al. 2004; Ambraseys y Adams, 2001; Peraldo y Montero, 1999), who complied historical data. A first catalogue was developed by Rojas (1993) that comprises the 1522 to 1993 period. This information was integrated in 2007, together with data from the International Seismological Centre (CASC) and the national catalogs of CA countries in a new regional catalogue. Since 2007 a continuous effort has been done in order to complete and update this CA earthquake catalog. In particular, two workshops were held in 2008 and 2011 in the Universidad Politécnica de Madrid (Spain), joining experts from the different CA countries who worked each one in its own catalogue covering the entire region and the border with northwestern Colombia and southern Mexico. These national catalogues were later integrated in a common regional catalogue in SEISAN format. At this aim it was necessary to solve some problems, like to avoid duplicity of events, specially close to the boundaries, to consider the different scales of magnitude adopted by different countries, to take into account the completeness by the different national networks, etc. Some solutions were adopted for obtaining a homogenized catalogue to Mw, containing historical and instrumental events with Mw > 3.5 from 1522 up to 2011. The catalogue updated to December 2007 was the basis for the first regional hazard study carried out by Benito et al., (2011) as part of the collaborative RESIS II project under coordination of NORSAR. The ones updated to

  2. Caribbean basin framework, 3: Southern Central America and Colombian basin

    SciTech Connect

    Kolarsky, R.A.; Mann, P. )

    1991-03-01

    The authors recognize three basin-forming periods in southern Central America (Panama, Costa Rica, southern Nicaragua) that they attempt to correlate with events in the Colombian basin (Bowland, 1984): (1) Early-Late Cretaceous island arc formation and growth of the Central American island arc and Late Cretaceous formation of the Colombian basin oceanic plateau. During latest Cretaceous time, pelagic carbonate sediments blanketed the Central American island arc in Panama and Costa Rica and elevated blocks on the Colombian basin oceanic plateau; (2) middle Eocene-middle Miocene island arc uplift and erosion. During this interval, influx of distal terrigenous turbidites in most areas of Panama, Costa Rica, and the Colombian basin marks the uplift and erosion of the Central American island arc. In the Colombian basin, turbidites fill in basement relief and accumulate to thicknesses up to 2 km in the deepest part of the basin. In Costa Rica, sedimentation was concentrated in fore-arc (Terraba) and back-arc (El Limon) basins; (3) late Miocene-Recent accelerated uplift and erosion of segments of the Central American arc. Influx of proximal terrigenous turbidites and alluvial fans in most areas of Panama, Costa Rica, and the Colombian basin marks collision of the Panama arc with the South American continent (late Miocene early Pliocene) and collision of the Cocos Ridge with the Costa Rican arc (late Pleistocene). The Cocos Ridge collision inverted the Terraba and El Limon basins. The Panama arc collision produced northeast-striking left-lateral strike-slip faults and fault-related basins throughout Panama as Panama moved northwest over the Colombian basin.

  3. Global GIS database; digital atlas of Central and South America

    USGS Publications Warehouse

    Hearn,, Paul P.; Hare, T.; Schruben, P.; Sherrill, D.; LaMar, C.; Tsushima, P.

    2000-01-01

    This CD-ROM contains a digital atlas of the countries of Central and South America. This atlas is part of a global database compiled from USGS and other data sources at the nominal scale of 1:1 million and is intended to be used as a regional-scale reference and analytical tool by government officials, researchers, the private sector, and the general public. The atlas includes free GIS software or may also be used with ESRI's ArcView software. Customized ArcView tools, specifically designed to make the atlas easier to use, are also included. The atlas contains the following datasets: country political boundaries, digital shaded relief map, elevation, slope, hydrology, locations of cities and towns, airfields, roads, railroads, utility lines, population density, geology, ecological regions, historical seismicity, volcanoes, ore deposits, oil and gas fields, climate data, landcover, vegetation index, and lights at night.

  4. First discovery of Quercus feeding Nepticulidae (Lepidoptera) in Central America.

    PubMed

    Stonis, Jonas R; Diškus, Arūnas; Remeikis, Andrius; Schuster, Jack

    2013-01-01

    Despite the high taxonomic diversity of oaks in Mexico and Central America, no Quercus feeding Nepticulidae have ever been recorded from the region. Here, we present seven species whose larvae are leaf-miners of Quercus (section Lobatae) in Guatemala. Except Stigmella nigriverticella (Chambers 1875), which was previously known from the United States, all other discovered species are new. We describe and name five new species (Stigmella jaguari Remeikis & Stonis, sp. nov., S. lauta Diškus & Stonis, sp. nov., S. sublauta Remeikis & Stonis, sp. nov., S. aurifasciata Diškus & Stonis, sp. nov. and S. guatemalensis Diškus & Stonis, sp. nov.); the remaining new species is described but left unnamed because of lack of adults (i. e. moths and genitalia are described from developed pupae). All seven treated species are illustrated with photographs of the leaf-mines, adults, and genitalia. PMID:25112733

  5. [Mangrove characterization of Central America with remote sensors].

    PubMed

    Lizano, O G; Amador, J; Soto, R

    2001-12-01

    Satellite images were used to study the mangrove distribution patterns in two different climatic regions of Central America: Gulf of Fonseca in Honduras-El Salvador and Sierpe-Térraba in Costa Rica. The Gulf of Fonseca has higher temperature and solar radiation, and lower precipitation, which can explain the higher structural development and species mixing of the Sierpe-Térraba mangrove. In the latter the transition between species or between heights in the same species is clear. The automatic classification made by the Geographic Information System (IDRISI) fits well the field mangrove distribution, but it was necessary to regroup some subdivisions that represent the same land use as identified by transects and an aerial video. Mixed species and clouds produced less satisfactory results in Sierpe-Térraba indicating a need for better satellite image resolution.

  6. The descriptive epidemiology of gastric cancer in Central America and comparison with United States Hispanic populations

    PubMed Central

    Corral, Juan E.; Delgado Hurtado, Juan J.; Domínguez, Ricardo L.; de Cuéllar, Marisabel Valdez; Cruz, Carlos Balmore; Morgan, Douglas R.

    2015-01-01

    Purpose Delineate the epidemiology of gastric adenocarcinoma in Central America and contrast it with Hispanic-Latino populations in the U.S. Methods Published literature and Central America Ministry of Health databases were used as primary data sources, including national, population-based and hospital-based registries. U.S. data was obtained from the NCI-SEER registry. Incident gastric adenocarcinoma cases were analyzed for available data between 1985–2011, including demographic variables and pathology information. Results In Central America, 19,741 incident gastric adenocarcinomas were identified. Two-thirds of cases were male, 20.5% were under age 55, and 58.5% were from rural areas. In the SEER database (n=7,871), 57.8% were male, and 28.9% were under age 55. Among the U.S. Hispanics born in Central America with gastric cancer (n=1,210), 50.3% of cases were male, and 38.1% were under age 55. Noncardia gastric cancer was more common in Central America (83.3%), among U.S. Hispanics (80.2%), and Hispanics born in Central America (86.3%). Cancers of the antrum were more common in Central America (73.6%), whereas cancers of the corpus were slightly more common among U.S. Hispanics (54.0%). Adenocarcinoma of the diffuse subtype was relatively common, both in Central America (35.7%), and U.S. Hispanics (69.5%), although Lauren classification was reported in only 50% of cases. Conclusions A significant burden of gastric adenocarcinoma is observed in Central America based upon limited available data. Differences are noted between Central America and U.S. Hispanics. Strengthening population-based registries is needed for improved cancer control in Central America, which may have implications for the growing U.S. Hispanic population. PMID:25412859

  7. Biogeography of cedrela (meliaceae, sapindales) in central and South america.

    PubMed

    Muellner, Alexandra N; Pennington, Terence D; Koecke, A Valerie; Renner, Susanne S

    2010-03-01

    Dated phylogenies have helped clarify the complex history of many plant families that today are restricted to the world's tropical forests, but that have Eocene, Oligocene, and Miocene fossils from the northern hemisphere. One such family is the Meliaceae. Here we infer the history of the neotropical Meliaceae genus Cedrela (17 species), the sister clade of which today is restricted to tropical Asia. Sequences from the nuclear ribosomal spacer region and five plastid loci obtained for all ingroup species and relevant outgroups were used to infer species relationships and for molecular-clock dating under two Bayesian relaxed clock models. The clock models differed in their handling of rate autocorrelation and sets of fossil constraints. Results suggest that (1) crown group diversification in Cedrela started in the Oligocene/Early Miocene and intensified in the Late Miocene and Early Pliocene, and (2) Central American Cedrela species do not form a clade, implying reentry into Central America after the closure of the Panamanian Isthmus. At present, Cedrela is distributed in both dry and humid habitats, but morphological features suggest an origin in dry forest under seasonal climates, fitting with Miocene and Pliocene Cedrela fossils from deciduous forests.

  8. Oil and gas developments in South America, Central America, Caribbean area, and Mexico in 1987

    SciTech Connect

    Wiman, W.D.

    1988-10-01

    Exploration activity in South America, Central America, the Caribbean area, and Mexico in 1987 showed significant increases in seismic acquisition in Belize, Bolivia, Brazil, Costa Rica, Guatemala, Mexico, Paraguay, and Peru, and a decrease in Chile and Venezuela. Exploratory drilling increased in most major producing countries but was accompanied by a decline in development drilling. Most of the increase could be attributed to private companies fulfilling obligations under risk contracts; however, state oil companies in Bolivia, Chile, and Colombia showed significant increased activity, with only Mexico showing a decrease. Colombia again had a dramatic increase in production (29% from 1986). Noteworthy discoveries were made in Bolivia (Villamontes-1); Brazil, in the Solimoes basin (1-RUC-1-AM); Chile (Rio Honda-1); Colombia, in the Llanos basin (Austral-1, La Reforma-1, Libertad Norte-1, Cravo Este-1, and Cano Yarumal-1), in the Upper Magdalena basin (Toldado-1 and Los Mangos-1); Ecuador (Frontera-1, a joint-exploration venture with Colombia); Mexico, in the Chiapas-Tabasco region (Guacho-1 and Iridi-1), in the Frontera Norte area (Huatempo-1); Peru, in the Madre de Dios basin (Armihuari-4X); Trinidad (West East Queen's Beach-1); and Venezuela (Musipan-1X). Brazil's upper Amazon (Solimoes basin) discovery, Colombia's Upper Magdalena basin discoveries Toldado-1 and Los Mangos-1, Mexico's Chiapas-Tabasco discoveries, Peru's confirmation of the giant Cashiriari discovery of 1986, and Venezuela's success in Monagas state were the highlights of 1987. 5 figs., 8 tabs.

  9. Universities in the Business of Repression: The Academic-Military-Industrial Complex and Central America.

    ERIC Educational Resources Information Center

    Feldman, Jonathan

    This book presents the thesis that U.S. universities have become part of an academic-military-industrial complex that support repression and murder in Central America. Part 1 explains how U.S. policies have been based on murder in Central America and examines the responsibility of transnational corporations and U.S. war planners in this…

  10. 7 CFR 319.56-25 - Papayas from Central America and Brazil.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Papayas from Central America and Brazil. 319.56-25... § 319.56-25 Papayas from Central America and Brazil. The Solo type of papaya may be imported into the... shipment to the United States in one of the following locations: (1) Brazil: State of Espirito Santo;...

  11. New Heat Flow Map of North and Central America

    NASA Astrophysics Data System (ADS)

    Blackwell, D.; Lewis, T. J.; Majorowicz, J.; Mareschal, J.

    2004-05-01

    A new heat flow map of North and Central America has been compiled. The map is based on all the available standard heat flow measurements on land and marine heat flow data, as well as on bottom hole temperature data, and constraints from geothermal springs. This new map confirms many established trends and improves the information on small scale heat flow variations. Both on the continent and in the oceans, there is a strong contrast between the eastern and the western parts of North America. For the oceanic part, the heat flow is high in the Pacific and heat flow contours closely follow the age of the sea floor. The heat flow is lower in the Atlantic than in the Pacific, but it also follows the age of the sea floor. There are small scale heat flow variations in the Labrador Sea and on the margin of Nova Scotia that do not fit a clear pattern. On the continent, heat flow variations occur at many different scales with a strong contrast between the low heat flow in the stable eastern provinces (30-60 {mW~m-2}) and high heat flow in the active western provinces (>60 {mW~m-2}) . The very low heat flow (<40 {mW~m-2}) on the east slopes of the Appalachians, Florida, and in the Gulf of Mexico are possibly due to the effect of groundwater flow and sediment deposition. There are small scale variations in heat flow within the Appalachians, the Canadian Shield, and the stable platform due to variations in crustal heat generation. In the dominantly high heat flow regions of Mexico, the western US and Canada, and Alaska, a striking contrast is formed by a low heat flow band (<45 {mW~m-2}) parallel to the present and past subduction zones. The map and CD Rom containing all the relevant information are available from the American Association of Petroleum Geologists.

  12. Toward a Comprehensive Model of Volcanism in Central America

    NASA Astrophysics Data System (ADS)

    Carr, M. J.

    2008-12-01

    In 1987, MJ Carr and WI Rose published CENTAM, a database primarily of major element analyses, but now much expanded and called CAGeochem. Our motivation included a desire to bypass editors who wanted to publish only representative analyses, and not the extensive data sets starting to be produced by semi- automated instruments. We felt a commitment to publish data that had been obtained with public funds (primarily NSF). We also provided the data in digital format, which is now trivial but was not at the time. We did not predict that the database itself would help produce the explosion of new research into the geochemistry, geophysics and tectonics of Central America. Because CENTAM provided a comprehensive geochemical outline of an entire convergent margin, Central America was recognized for several large regional variations in geochemistry that helped make it a choice of the NSF Margins Subduction Factory program. Margins and the cooperating German research programs centered at GEOMAR have revolutionized our understanding of Central America. Data and samples from CAGeochem have assisted research efforts at several universities including, Columbia, Washington Univ., Rice, New Mexico, Caltec, Boston College, GEOMAR. The primary result of the regional database was the discovery of large geographic variations in elemental and isotopic ratios (e.g. Ba/La, 10B/9Be, U/Th, 87Sr/86Sr) that trace the cycling of elements from the subducted plate. Tracers of subducted material reach maxima in Nicaragua in the center of the margin and decrease outward toward Costa Rica and Guatemala as well as decreasing across the margin. Estimates of the flux of elements, e.g. Ba and U, indicate a constant volcanic output along the margin. The regional variation occurs in La, Th etc, the denominators of the ratios, all of which change with degree of melting. There is a margin-wide correlation between element and isotope ratios that trace subduction and degree of melting. The tectonic factor

  13. Estimation of Surface Air Temperature Over Central and Eastern Eurasia from MODIS Land Surface Temperature

    NASA Technical Reports Server (NTRS)

    Shen, Suhung; Leptoukh, Gregory G.

    2011-01-01

    Surface air temperature (T(sub a)) is a critical variable in the energy and water cycle of the Earth.atmosphere system and is a key input element for hydrology and land surface models. This is a preliminary study to evaluate estimation of T(sub a) from satellite remotely sensed land surface temperature (T(sub s)) by using MODIS-Terra data over two Eurasia regions: northern China and fUSSR. High correlations are observed in both regions between station-measured T(sub a) and MODIS T(sub s). The relationships between the maximum T(sub a) and daytime T(sub s) depend significantly on land cover types, but the minimum T(sub a) and nighttime T(sub s) have little dependence on the land cover types. The largest difference between maximum T(sub a) and daytime T(sub s) appears over the barren and sparsely vegetated area during the summer time. Using a linear regression method, the daily maximum T(sub a) were estimated from 1 km resolution MODIS T(sub s) under clear-sky conditions with coefficients calculated based on land cover types, while the minimum T(sub a) were estimated without considering land cover types. The uncertainty, mean absolute error (MAE), of the estimated maximum T(sub a) varies from 2.4 C over closed shrublands to 3.2 C over grasslands, and the MAE of the estimated minimum Ta is about 3.0 C.

  14. Regional fire monitoring and characterization using global NASA MODIS fire products in dry lands of Central Asia

    NASA Astrophysics Data System (ADS)

    Loboda, Tatiana V.; Giglio, Louis; Boschetti, Luigi; Justice, Christopher O.

    2012-06-01

    Central Asian dry lands are grass- and desert shrub-dominated ecosystems stretching across Northern Eurasia. This region supports a population of more than 100 million which continues to grow at an average rate of 1.5% annually. Dry steppes are the primary grain and cattle growing zone within Central Asia. Degradation of this ecosystem through burning and overgrazing directly impacts economic growth and food supply in the region. Fire is a recurrent disturbance agent in dry lands contributing to soil erosion and air pollution. Here we provide an overview of inter-annual and seasonal fire dynamics in Central Asia obtained from remotely sensed data. We evaluate the accuracy of the Moderate Resolution Imaging Spectroradiometer (MODIS) global fire products within Central Asian dry lands and use these products to characterize fire occurrence between 2001 and 2009. The results show that on average ˜15 million ha of land burns annually across Central Asia with the majority of the area burned in August and September in grasslands. Fire is used as a common crop residue management practice across the region. Nearly 89% of all burning occurs in Kazakhstan, where 5% and 3% of croplands and grasslands, respectively, are burned annually.

  15. Federacion de Universidades Privadas de America Central y Panama: Boletin Estadistico (Federation of Private Universities of Central America and Panama: Statistical Bulletin).

    ERIC Educational Resources Information Center

    Serrano, Jorge A.

    This statistical bulletin provides details on the universities belonging to the Federation of Private Universities of Central America and Panama (FUPAC): Central American University, Rafael Landivar University, Saint John's College, University of Santa Maria La Antigua, Jose Simeon Canas University, Doctor Mariano Galvez University, and the…

  16. Recent crustal deformation in west-central South America

    NASA Astrophysics Data System (ADS)

    Pritchard, Matthew Earl

    I use interferometric synthetic aperture radar (InSAR) to create maps of crustal deformation along the coast and within the volcanic arc of central South America. I image deformation associated with six subduction zone earthquakes, four volcanic centers, at least one shallow crustal earthquake, and several salt flats. In addition, I constrain the magnitude and location of post-seismic deformation from the aforementioned subduction zone earthquakes. I combine InSAR observations with data from the Global Positioning System (GPS) and teleseismic data to explore each source of deformation. I use the observations to constrain earthquake and volcanic processes of this subduction zone, including the plumbing system of the volcanoes and the decadal along strike variations in the subduction zone earthquake cycle. I created interferograms of over 900 volcanoes in the central Andes spanning 1992--2002, and found four areas of deformation. I constrained the temporal variability of the deformation, the depth of the sources of deformation assuming a variety of source geometries and crustal structures, and the possible cause of the deformation. I do not observe deformation associated with eruptions at several volcanoes, and I discuss the possible explanations for this lack of deformation. In addition, I constrain the amount of co-seismic and post-seismic slip on the subduction zone fault interface from the following earthquakes: 1995 Mw 8.1 Antofagasta, Chile; 1996 Mw 7.7 Nazca, Peru; 1998 Mw 7.1 Antofagasta, Chile; and 2001 Mw 8.4 Arequipa, Peru. In northern Chile, I compare the location and magnitude of co-seismic slip from 5 Mw > 7 earthquakes during the past 15 years with the post-seismic slip distribution. There is little post-seismic slip from the 1995 and 1996 earthquakes relative to the 2001 event and other recent subduction zone earthquakes.

  17. 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

  18. Sustainability of water, sanitation and hygiene interventions in Central America

    PubMed Central

    Medlin, Elizabeth; Aquino, Gonzalo; Gelting, Richard J.

    2015-01-01

    The American Red Cross and U.S. Centers for Disease Control and Prevention collaborated on a sustainability evaluation of post-hurricane water, sanitation and hygiene (WASH) interventions in Central America. In 2006 and 2009, we revisited six study areas in rural El Salvador, Guatemala, Honduras and Nicaragua to assess sustainability of WASH interventions finalized in 2002, after 1998’s Hurricane Mitch. We used surveys to collect data, calculate indicators and identify factors that influence sustainability. Regional sustainability indicator results showed there was a statistically significant decline in access to water. The presence of sanitation facilities had not changed since the beginning of the project; however, maintenance and use of latrines declined but continued to meet the goal of 75% use after 7 years. The hygiene indicator, hand washing, initially declined and then increased. Declines in water access were due to operational problems related to storm events and population changes. Sanitation facilities were still present and sometimes used even though they reached or surpassed their original design life. Changes in hygiene practices appeared related to ongoing hygiene promotion from outside organizations. These results provide useful input for making WASH programs more sustainable and informing future, more in-depth research into factors influencing sustainability. PMID:26413262

  19. Proposal for a comprehensive vertical datum for North America, Central America and the Caribbean

    NASA Astrophysics Data System (ADS)

    Smith, D. A.; Roman, D. R.; Childers, V. A.; Eckl, M. C.; Youngman, M.

    2013-05-01

    As part of its Ten Year Strategic Plan (2013-2023), the National Geodetic Survey (NGS) of the USA is planning to replace the North American Vertical Datum of 1988 (NAVD 88) by the year 2022. The replacement vertical datum will be defined through a gravimetric geoid model and accessed via GNSS technology, in direct contrast to the definition and access of NAVD 88, which is through passive, generally unmonitored benchmarks connected through geodetic leveling. A USA-Canada-Mexico joint effort is underway to compute a single geoid model by 2022 for the entire region, which can be adopted as the vertical datum reference surface by all countries within the area. The proposed area ranges from the North Pole to the Equator and from the Aleutian Islands (in the west) to the islands of Newfoundland (in the east). As such, the entirety of the Caribbean Sea, all of Central America, all of Hawaii, plus parts of Greenland and South America will be covered. This will allow one singular, unified vertical datum to be accessible to every country in the region, alleviating the need for island-by-island vertical datums as is currently the case. A major component of the geoid modeling effort is NGS's GRAV-D project (Gravity for the Redefinition of the American Vertical Datum). That project has a two-fold approach: First, to collect a static, accurate "snapshot" of the entire gravity field. This is primarily being done through airborne gravity collection over the USA and its territories, as well as through improvements in and additions to terrestrial data holdings. A second, long-term effort of GRAV D is to monitor the geoid over time. This talk will discuss the prospects of improving the static gravity field holdings outside of the USA and its territories, including a discussion on existing holdings, data gaps and NGS's desire for potential collaborations with interested countries in the region both before and after the 2022 datum change.

  20. Geostrophic circulation between the Costa Rica Dome and Central America

    NASA Astrophysics Data System (ADS)

    Brenes, C. L.; Lavín, M. F.; Mascarenhas, Affonso S.

    2008-05-01

    The geostrophic circulation between the Costa Rica Dome and Central America is described from CTD observations collected in two surveys: (a) The Wet Cruise in September-October 1993, and the Jet Cruise in February-March 1994. Poleward coastal flow was present on both occasions, but the transition from flow around the dome to the poleward Costa Rica Coastal Current flow was quite tortuous because of the presence of mesoscale eddies. In particular, a warm anticyclonic eddy was found off the Gulf of Fonseca during both cruises, at an almost identical position and with similar dimensions (150 m deep, 250 km in diameter) and surface speed (0.5 m s -1). In the Gulf of Panama, poleward flow was also observed, weaker in February-March 1994 than in September-October 1993, when it penetrated to 600 m depth and transported 8.5 Sv. In September-October 1993, the current between the dome and the coast was mostly ˜100 m deep and weak (˜0.15 m s -1), although in its southern side it was deeper (˜450 m) and faster at 0.3 m s -1. The poleward transport between the dome and the coast was ˜7 Sv. In February-March 1994 the Costa Rica Dome was a closed ring adjacent to the continental shelf, ˜500 km in diameter, at least 400 m deep, had geostrophic surface speeds ˜0.25 m s -1, and subsurface maximum speed (0.15-0.20 m s -1) at ˜180 m depth; the associated uplift of the isotherms was ˜150 m. The flow in the south part of the dome splits into two branches, the weakest one going around the dome and the strongest one continuing east and turning south before reaching the Gulf of Panama.

  1. Some Recent USF Studies at Volcanoes in Central America

    NASA Astrophysics Data System (ADS)

    McNutt, S. R.

    2014-12-01

    Scientists at the University of South Florida (USF) have been working in Central America for several decades. Efforts have focused on Physical Volcanology in Nicaragua, GPS in Costa Rica, and assessment of Geothermal projects in El Salvador, amongst others. Two years ago a Seismology Lab was established at USF. Personnel now include three Professors, a Post-Doc, and 4 graduate students. Seismic and GPS networks were installed at Telica Volcano, Nicaragua, in 2010 by Roman, LaFemina and colleagues. Data are recorded on site and recovered several times per year at this persistently restless volcano, which has rates of 5 to 1400 low frequency seismic events per day (Rodgers et al., submitted). Proposals have been submitted to install instruments on other Nicaraguan volcanoes, including seismometers, GPS, infrasound, and lightning sensors. This suite of instruments has proven to be very effective to study a range of volcanic processes. The proposals have not been successful to date (some are pending), and alternative funding sources are being explored. One interesting scientific issue is the presence of strong seasonal effects, specifically a pronounced rainy season and dry season and possible interaction between shallow volcanic processes and surface waters. We are also pursuing a variety of studies that are complementary to the instrumental efforts. One such study is examining volcanic earthquake swarms, with the focus to date on identifying diagnostics. One clear pattern is that peak rates often occur early in swarms, whereas the largest M event occurs late. Additional evidence suggests that the seismic source size grows systematically, especially for events with similar waveforms (families). Recognition of such patterns, linked to processes, may help to improve monitoring and better take advantage of instrumental data to reduce vulnerability from eruptions.

  2. Seismic swarms and fluid flow offshore Central America

    NASA Astrophysics Data System (ADS)

    Dzierma, Yvonne; Thorwart, Martin; Hensen, Christian; Rabbel, Wolfgang; Wolf, Florian

    2010-05-01

    Offshore Nicaragua and Northern Costa Rica, the Cocos Plate subducts beneath the Caribbean Plate, carrying with it a large amount of fluids and volatiles. While some of these are set free at great depth beneath the volcanic arc, causing the extremely high water content observed in Nicaraguan mafic magmas (Carr et al., 2003; Kutterolf et al., 2007), some early dehydration reactions already release fluids from the subducting plate underneath the continental slope. Unlike in accretionary margins, where these fluids migrate up along the decollement towards the deformation front, fluid release at erosional margins seems to occur through fractures in the overriding plate (Ranero et al., 2008). Fluid seeps in this region have be observed at seafloor mounds, appearing as side-scan sonar backscatter anomalies or revealed by the presence of chemosynthetic communities (Sahling et al., 2008). In the framework of the General Research Area SFB 574 "Volatiles and Fluids in Subduction Zones", a network of 20 ocean-bottom-stations was deployed offshore Sta Elena Peninsula, Northern Costa Rica, from December 2005 to June 2006. Several distinct swarms of small earthquakes were observed at the seismic stations, which occurred clustered over a time period of several days and have very similar seismic waveforms. Since a correlation of fluid-release sites with the occurrence of sporadic seismic swarms would indicate that fluid migration and fracturing is the mechanism responsible for triggering the earthquake swarms, the events are re-analysed by double-difference localisation to enhance the resolution of the earthquake locations. The results are then considered to estimate the migration velocity and direction and compare the localisations with the known mound sites. Carr, M., Feigenson, M. D., Patino, L. C., and Walker, J. A., 2003: Volcanism and geochemistry in Central America: Progress and problems, in Eiler, J. (ed.), Inside the subduction factory, pp. 153-179, American Geophysical

  3. A Simple Statistical Model for Estimating Evapotranspiration of Tallgrass Prairies in the Central United States Using MODIS Data

    NASA Astrophysics Data System (ADS)

    Wagle, P.; Xiao, X.; Gowda, P. H.; Basara, J. B.

    2015-12-01

    Accurate estimation of evapotranspiration (ET) across space and time is of great significance for quantifying global water cycle and improving land and water resources management. The Moderate Resolution Imaging Spectroradiometer (MODIS)-derived enhanced vegetation index (EVI) and ground-based climatic variables were integrated with eddy covariance tower-based ET (ETEC) at six AmeriFlux tallgrass prairie sites in the Central United States to develop a simple and robust statistical model for predicting tallgrass prairie ET. The EVI tracked the seasonal variation of ETEC well at both individual (R2 > 0.70) and across six (R2 = 0.76) sites, suggesting that the EVI could be used to estimate ET. The inclusion of photosynthetically active radiation (PAR) measured at tower sites further improved the ET-EVI relationship (R2 = 0.86). Based on this result, we aggregated ETEC, EVI, and PAR (MJ m-2 d-1) data from four sites (15 site-years) to develop a statistical model (ET = 0.11 Rg + 5.49 EVI - 1.43, adj. R2 = 0.86, P < 0.0001) for predicting ET (mm d-1) at 8-day intervals. This predictive model was evaluated against additional two years of ETEC data from one of the four model development sites and two independent sites. The predicted ET (ETEVI+PAR) captured the seasonal patterns and magnitudes of ETEC, and correlated well with ETEC, with R2 of 0.87-0.96 and RMSE of 0.35-0.49 mm d-1, and it was significantly improved compared to the standard MODIS ET product and ET estimates from two remote sensing ET models (Coupling Photosynthesis and Transpiration Model and Vegetation Transpiration Model). Overall, the results from this study demonstrated that tallgrass prairie ET can be accurately predicted using a multiple regression model that uses EVI and PAR which can be readily derived from remote sensing data.

  4. 76 FR 75893 - Agency Information Collection Activities: Dominican Republic-Central America-United States Free...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-05

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Dominican Republic... information collection requirement concerning the Dominican Republic-Central America-United States Free Trade... soliciting comments concerning the following information collection: Title: Dominican...

  5. Rainfall Induced Natural Disaster in Central America, a challenge for Regional Risk Management

    NASA Astrophysics Data System (ADS)

    Estuardo Guinea Barrientos, Héctor; Swain, Ashok

    2013-04-01

    Rainfall induced natural disasters rank first among all natural disasters in Central America. According to the records of the EM-DAT international database, 248 out of 486 disasters registered in Central America were disasters triggered by rainfall invents, in countries like Belize and Honduras, rainfall-induced natural disasters, mainly floods and landslides, account for more than 90% of the total number of casualties as well as the economic damage of all the disasters. Due to the natural conditions of the Central American Isthmus, precipitation events often struck more than one country at the time, for example Hurricane Mitch in 1998 affected the entire Central American region causing more than 18,000 casualties. In this context, the Central America countries have been working on joint programs and policies aiming transboundary cooperation and management of natural disasters, a clear example of this effort is CEPREDENAC which is the intergovernmental body with the mandate of promoting activities, projects and programs towards reduction of the risks to disasters in order to avoid loss of life and economic assets in the Central America, however, transnational management face several challenges that fall mostly in the political, economical and technical areas. In this paper we described and analyzed the rainfall induced natural disasters, their impacts and the inherent management challenges in the Central American context. Key words: Central America, Natural Disasters, Risk Management, International Cooperation

  6. USAID Expands eMODIS Coverage for Famine Early Warning

    NASA Astrophysics Data System (ADS)

    Jenkerson, C.; Meyer, D. J.; Evenson, K.; Merritt, M.

    2011-12-01

    Food security in countries at risk is monitored by U.S. Agency for International Development (USAID) through its Famine Early Warning Systems Network (FEWS NET) using many methods including Moderate Resolution Imaging Spectroradiometer (MODIS) data processed by U.S. Geological Survey (USGS) into eMODIS Normalized Difference Vegetation Index (NDVI) products. Near-real time production is used comparatively with trends derived from the eMODIS archive to operationally monitor vegetation anomalies indicating threatened cropland and rangeland conditions. eMODIS production over Central America and the Caribbean (CAMCAR) began in 2009, and processes 10-day NDVI composites every 5 days from surface reflectance inputs produced using predicted spacecraft and climatology information at Land and Atmosphere Near real time Capability for Earth Observing Systems (EOS) (LANCE). These expedited eMODIS composites are backed by a parallel archive of precision-based NDVI calculated from surface reflectance data ordered through Level 1 and Atmosphere Archive and Distribution System (LAADS). Success in the CAMCAR region led to the recent expansion of eMODIS production to include Africa in 2010, and Central Asia in 2011. Near-real time 250-meter products are available for each region on the last day of an acquisition interval (generally before midnight) from an anonymous file transfer protocol (FTP) distribution site (ftp://emodisftp.cr.usgs.gov/eMODIS). The FTP site concurrently hosts the regional historical collections (2000 to present) which are also searchable using the USGS Earth Explorer (http://edcsns17.cr.usgs.gov/NewEarthExplorer). As eMODIS coverage continues to grow, these geographically gridded, georeferenced tagged image file format (GeoTIFF) NDVI composites increase their utility as effective tools for operational monitoring of near-real time vegetation data against historical trends.

  7. Developing a 30-m grassland productivity estimation map for central Nebraska using 250-m MODIS and 30-m Landsat-8 observations

    USGS Publications Warehouse

    Gu, Yingxin; Wylie, Bruce K.

    2015-01-01

    Accurately estimating aboveground vegetation biomass productivity is essential for local ecosystem assessment and best land management practice. Satellite-derived growing season time-integrated Normalized Difference Vegetation Index (GSN) has been used as a proxy for vegetation biomass productivity. A 250-m grassland biomass productivity map for the Greater Platte River Basin had been developed based on the relationship between Moderate Resolution Imaging Spectroradiometer (MODIS) GSN and Soil Survey Geographic (SSURGO) annual grassland productivity. However, the 250-m MODIS grassland biomass productivity map does not capture detailed ecological features (or patterns) and may result in only generalized estimation of the regional total productivity. Developing a high or moderate spatial resolution (e.g., 30-m) productivity map to better understand the regional detailed vegetation condition and ecosystem services is preferred. The 30-m Landsat data provide spatial detail for characterizing human-scale processes and have been successfully used for land cover and land change studies. The main goal of this study is to develop a 30-m grassland biomass productivity estimation map for central Nebraska, leveraging 250-m MODIS GSN and 30-m Landsat data. A rule-based piecewise regression GSN model based on MODIS and Landsat (r = 0.91) was developed, and a 30-m MODIS equivalent GSN map was generated. Finally, a 30-m grassland biomass productivity estimation map, which provides spatially detailed ecological features and conditions for central Nebraska, was produced. The resulting 30-m grassland productivity map was generally supported by the SSURGO biomass production map and will be useful for regional ecosystem study and local land management practices.

  8. The effect of precipitation and temperature anomalies for the Central-European forests based on Collection 6 MODIS data

    NASA Astrophysics Data System (ADS)

    Kern, Anikó; Marjanović, Hrvoje; Dobor, Laura; Barcza, Zoltán

    2016-04-01

    Forest phenology and productivity is intimately linked with the actual weather conditions, and in the long term with the local climate. Our current understanding on the environmental control on spring leaf-out and autumn senescence is incomplete. Causes of the interannual variability of tree growth and forest carbon balance are not well understood as well. Satellite remote sensing provides a feasible way to monitor and study the changes of forest functioning in general and to understand its relationship with the climate fluctuations. In the presented study the latest version (Collection 6) of the Enhanced Vegetation Index (EVI) and the Normalized Difference Vegetation Index (NDVI) products calculated from measurements of the MODIS sensor onboard the NASA Terra and Aqua satellites are used to characterize forest activity and its interannual variability in Central Europe (Hungary and Croatia). The applied EVI and NDVI dataset is part of the MOD13 product of NASA and covers the 2000-2015 time period. The newest, Collection 6 dataset is free from the sensor degradation effect (that was present in previous versions) which can contribute to the better characterization of the changes in forest phenology. Using the FORESEE climatological database the effects of drought is studied on the NDVI and EVI variations. Possible lagged effect of severe drought on NDVI variability during the consecutive years is studied at the selected sites. Drivers of forest phenology are studied in terms of linear relationships between temperature and onset/offset of the growing season.

  9. Mapping the extent of abandoned farmland in Central and Eastern Europe using MODIS time series satellite data

    NASA Astrophysics Data System (ADS)

    Alcantara, Camilo; Kuemmerle, Tobias; Baumann, Matthias; Bragina, Eugenia V.; Griffiths, Patrick; Hostert, Patrick; Knorn, Jan; Müller, Daniel; Prishchepov, Alexander V.; Schierhorn, Florian; Sieber, Anika; Radeloff, Volker C.

    2013-09-01

    The demand for agricultural products continues to grow rapidly, but further agricultural expansion entails substantial environmental costs, making recultivating currently unused farmland an interesting alternative. The collapse of the Soviet Union in 1991 led to widespread abandonment of agricultural lands, but the extent and spatial patterns of abandonment are unclear. We quantified the extent of abandoned farmland, both croplands and pastures, across the region using MODIS NDVI satellite image time series from 2004 to 2006 and support vector machine classifications. Abandoned farmland was widespread, totaling 52.5 Mha, particularly in temperate European Russia (32 Mha), northern and western Ukraine, and Belarus. Differences in abandonment rates among countries were striking, suggesting that institutional and socio-economic factors were more important in determining the amount of abandonment than biophysical conditions. Indeed, much abandoned farmland occurred in areas without major constraints for agriculture. Our map provides a basis for assessing the potential of Central and Eastern Europe’s abandoned agricultural lands to contribute to food or bioenergy production, or carbon storage, as well as the environmental trade-offs and social constraints of recultivation.

  10. Central America: Theme IV. Social Studies Grade 5: The Western Hemisphere. Teacher Strategies and Student Worksheets.

    ERIC Educational Resources Information Center

    Neeson, Eileen; And Others

    This curriculum guide presents materials for teaching about Central America and emphasizes the concepts of environment, culture, interdependence, and citizenship. The guide is designed to integrate the study of geographic, economic, historic, political, and social features of Central American nations. The major theme of the document deals with how…

  11. eMODIS Expedited: Overview of a Near Real Time MODIS Production System for Operational Vegetation Monitoring

    NASA Astrophysics Data System (ADS)

    Jenkerson, C.; Meyer, D. J.; Werpy, J.; Evenson, K.; Merritt, M.

    2010-12-01

    The expedited MODIS, or eMODIS production system derives near-real time Normalized Difference Vegetation Index (NDVI) from Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance provided by the Land and Atmosphere Near-real time Capability for EOS (LANCE). There are currently three regions covered by this U.S. Geological Survey (USGS) capability, including the continental U.S., Africa, and the Central America/Caribbean regions. Each of the eMODIS production streams is configured to output its data in map projections, compositing intervals, spatial resolutions, and file formats specific to its region and user community. The challenges of processing 1,000-meter, 500-m, and especially 250-m products by midnight on the last day of a product interval have been met with increasingly effective software and system architecture. An anonymous file transfer protocol (FTP) distribution site (ftp://emodisftp.cr.usgs.gov/eMODIS) allows users direct access to eMODIS NDVI products for operational (near-real time) monitoring of vegetation conditions like drought, crop failure, insect infestation, and other threats, thus supporting subsequent early warning of famine and the targeting of vulnerable populations for insecure food situations.

  12. Central Wind Forecasting Programs in North America by Regional Transmission Organizations and Electric Utilities: Revised Edition

    SciTech Connect

    Rogers, J.; Porter, K.

    2011-03-01

    The report and accompanying table addresses the implementation of central wind power forecasting by electric utilities and regional transmission organizations in North America. The first part of the table focuses on electric utilities and regional transmission organizations that have central wind power forecasting in place; the second part focuses on electric utilities and regional transmission organizations that plan to adopt central wind power forecasting in 2010. This is an update of the December 2009 report, NREL/SR-550-46763.

  13. Climate change, workplace heat exposure, and occupational health and productivity in Central America.

    PubMed

    Kjellstrom, Tord; Crowe, Jennifer

    2011-01-01

    Climate change is increasing heat exposure in places such as Central America, a tropical region with generally hot/humid conditions. Working people are at particular risk of heat stress because of the intrabody heat production caused by physical labor. This article aims to describe the risks of occupational heat exposure on health and productivity in Central America, and to make tentative estimates of the impact of ongoing climate change on these risks. A review of relevant literature and estimation of the heat exposure variable wet bulb globe temperature (WBGT) in different locations within the region were used to estimate the effects. We found that heat stress at work is a real threat. Literature from Central America and heat exposure estimates show that some workers are already at risk under current conditions. These conditions will likely worsen with climate change, demonstrating the need to create solutions that will protect worker health and productivity.

  14. Current challenges for confronting the public health problem of snakebite envenoming in Central America.

    PubMed

    Gutiérrez, José María

    2014-03-06

    Snakebite envenoming is a serious public health problem in Central America, where approximately 5,500 cases occur every year. Panama has the highest incidence and El Salvador the lowest. The majority, and most severe, cases are inflicted by the pit viper Bothrops asper (family Viperidae), locally known as 'terciopelo', 'barba amarilla' or 'equis'. About 1% of the bites are caused by coral snakes of the genus Micrurus (family Elapidae). Despite significant and successful efforts in Central America regarding snakebite envenomings in the areas of research, antivenom manufacture and quality control, training of health professionals in the diagnosis and clinical management of bites, and prevention of snakebites, much remains to be done in order to further reduce the impact of this medical condition. This essay presents seven challenges for improving the confrontation of snakebite envenoming in Central America. Overcoming these challenges demands a coordinated partnership of highly diverse stakeholders though inter-sectorial and inter-programmatic interventions.

  15. Health outcomes among HIV-positive Latinos initiating antiretroviral therapy in North America versus Central and South America

    PubMed Central

    Cesar, Carina; Koethe, John R; Giganti, Mark J; Rebeiro, Peter; Althoff, Keri N; Napravnik, Sonia; Mayor, Angel; Grinsztejn, Beatriz; Wolff, Marcelo; Padgett, Denis; Sierra-Madero, Juan; Gotuzzo, Eduardo; Sterling, Timothy R; Willig, James; Levison, Julie; Kitahata, Mari; Rodriguez-Barradas, Maria C; Moore, Richard D; McGowan, Catherine; Shepherd, Bryan E; Cahn, Pedro

    2016-01-01

    Introduction Latinos living with HIV in the Americas share a common ethnic and cultural heritage. In North America, Latinos have a relatively high rate of new HIV infections but lower rates of engagement at all stages of the care continuum, whereas in Latin America antiretroviral therapy (ART) services continue to expand to meet treatment needs. In this analysis, we compare HIV treatment outcomes between Latinos receiving ART in North America versus Latin America. Methods HIV-positive adults initiating ART at Caribbean, Central and South America Network for HIV (CCASAnet) sites were compared to Latino patients (based on country of origin or ethnic identity) starting treatment at North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) sites in the United States and Canada between 2000 and 2011. Cox proportional hazards models compared mortality, treatment interruption, antiretroviral regimen change, virologic failure and loss to follow-up between cohorts. Results The study included 8400 CCASAnet and 2786 NA-ACCORD patients initiating ART. CCASAnet patients were younger (median 35 vs. 37 years), more likely to be female (27% vs. 20%) and had lower nadir CD4 count (median 148 vs. 195 cells/µL, p<0.001 for all). In multivariable analyses, CCASAnet patients had a higher risk of mortality after ART initiation (adjusted hazard ratio (AHR) 1.61; 95% confidence interval (CI): 1.32 to 1.96), particularly during the first year, but a lower hazard of treatment interruption (AHR: 0.46; 95% CI: 0.42 to 0.50), change to second-line ART (AHR: 0.56; 95% CI: 0.51 to 0.62) and virologic failure (AHR: 0.52; 95% CI: 0.48 to 0.57). Conclusions HIV-positive Latinos initiating ART in Latin America have greater continuity of treatment but are at higher risk of death than Latinos in North America. Factors underlying these differences, such as HIV testing, linkage and access to care, warrant further investigation. PMID:26996992

  16. Vegetation structure and greenness in Central Africa from Modis multi-temporal data.

    PubMed

    Gond, Valéry; Fayolle, Adeline; Pennec, Alexandre; Cornu, Guillaume; Mayaux, Philippe; Camberlin, Pierre; Doumenge, Charles; Fauvet, Nicolas; Gourlet-Fleury, Sylvie

    2013-01-01

    African forests within the Congo Basin are generally mapped at a regional scale as broad-leaved evergreen forests, with the main distinction being between terra-firme and swamp forest types. At the same time, commercial forest inventories, as well as national maps, have highlighted a strong spatial heterogeneity of forest types. A detailed vegetation map generated using consistent methods is needed to inform decision makers about spatial forest organization and their relationships with environmental drivers in the context of global change. We propose a multi-temporal remotely sensed data approach to characterize vegetation types using vegetation index annual profiles. The classifications identified 22 vegetation types (six savannas, two swamp forests, 14 forest types) improving existing vegetation maps. Among forest types, we showed strong variations in stand structure and deciduousness, identifying (i) two blocks of dense evergreen forests located in the western part of the study area and in the central part on sandy soils; (ii) semi-deciduous forests are located in the Sangha River interval which has experienced past fragmentation and human activities. For all vegetation types enhanced vegetation index profiles were highly seasonal and strongly correlated to rainfall and to a lesser extent, to light regimes. These results are of importance to predict spatial variations of carbon stocks and fluxes, because evergreen/deciduous forests (i) have contrasted annual dynamics of photosynthetic activity and foliar water content and (ii) differ in community dynamics and ecosystem processes.

  17. Vegetation structure and greenness in Central Africa from Modis multi-temporal data

    PubMed Central

    Gond, Valéry; Fayolle, Adeline; Pennec, Alexandre; Cornu, Guillaume; Mayaux, Philippe; Camberlin, Pierre; Doumenge, Charles; Fauvet, Nicolas; Gourlet-Fleury, Sylvie

    2013-01-01

    African forests within the Congo Basin are generally mapped at a regional scale as broad-leaved evergreen forests, with the main distinction being between terra-firme and swamp forest types. At the same time, commercial forest inventories, as well as national maps, have highlighted a strong spatial heterogeneity of forest types. A detailed vegetation map generated using consistent methods is needed to inform decision makers about spatial forest organization and their relationships with environmental drivers in the context of global change. We propose a multi-temporal remotely sensed data approach to characterize vegetation types using vegetation index annual profiles. The classifications identified 22 vegetation types (six savannas, two swamp forests, 14 forest types) improving existing vegetation maps. Among forest types, we showed strong variations in stand structure and deciduousness, identifying (i) two blocks of dense evergreen forests located in the western part of the study area and in the central part on sandy soils; (ii) semi-deciduous forests are located in the Sangha River interval which has experienced past fragmentation and human activities. For all vegetation types enhanced vegetation index profiles were highly seasonal and strongly correlated to rainfall and to a lesser extent, to light regimes. These results are of importance to predict spatial variations of carbon stocks and fluxes, because evergreen/deciduous forests (i) have contrasted annual dynamics of photosynthetic activity and foliar water content and (ii) differ in community dynamics and ecosystem processes. PMID:23878336

  18. Improving Timeliness of Winter Wheat Production Forecast in United States of America, Ukraine and China Using MODIS Data and NCAR Growing Degree Day

    NASA Astrophysics Data System (ADS)

    Vermote, E.; Franch, B.; Becker-Reshef, I.; Claverie, M.; Huang, J.; Zhang, J.; Sobrino, J. A.

    2014-12-01

    Wheat is the most important cereal crop traded on international markets and winter wheat constitutes approximately 80% of global wheat production. Thus, accurate and timely forecasts of its production are critical for informing agricultural policies and investments, as well as increasing market efficiency and stability. Becker-Reshef et al. (2010) used an empirical generalized model for forecasting winter wheat production. Their approach combined BRDF-corrected daily surface reflectance from Moderate resolution Imaging Spectroradiometer (MODIS) Climate Modeling Grid (CMG) with detailed official crop statistics and crop type masks. It is based on the relationship between the Normalized Difference Vegetation Index (NDVI) at the peak of the growing season, percent wheat within the CMG pixel, and the final yields. This method predicts the yield approximately one month to six weeks prior to harvest. In this study, we include the Growing Degree Day (GDD) information extracted from NCEP/NCAR reanalysis data in order to improve the winter wheat production forecast by increasing the timeliness of the forecasts while conserving the accuracy of the original model. We apply this modified model to three major wheat-producing countries: United States of America, Ukraine and China from 2001 to 2012. We show that a reliable forecast can be made between one month to a month and a half prior to the peak NDVI (meaning two months to two and a half months prior to harvest) while conserving an accuracy of 10% in the production forecast.

  19. Very-to-barely remote sensing of prehistoric features under tephra in Central America

    NASA Technical Reports Server (NTRS)

    Sheets, Payson D.

    1991-01-01

    A wide variety of remote sensing instruments have been utilized to attempt to detect archaeological features under volcanic ash in Central America. Some techniques have not been successful, such as seismic refraction, for reasons that are not difficult to understand. Others have been very successful and provide optimism for archaeologists witnessing the destruction of unburied sites throughout Central America. The sudden burial of buildings, gardens, and footpaths by volcanic ash can preserve them extremely well providing a rich data base for understanding human life and culture at certain points in time.

  20. Scholastic Achievement of Adolescent Refugees from Cambodia and Central America.

    ERIC Educational Resources Information Center

    Rousseau, Cecile; Drapeau, Aline

    2000-01-01

    Central American and Cambodian students in six Canadian high schools and their parents were interviewed to assess the students' emotional problems and pre- and postmigration family environment. Findings indicate that the relationship between the emotional problems and scholastic achievement of teenaged refugees was tenuous. (Author/MKA)

  1. Educating the Special Child in the Caribbean and Central America.

    ERIC Educational Resources Information Center

    Harris-Stowe State Coll., St. Louis, MO. Teacher Education Dept.

    This paper represents the perspectives of 25 special education teacher scholarship students from 13 Caribbean and Central American countries (Barbados, Belize, Costa Rica, Guatemala, Honduras, Nevis, Nicaragua, El Salvador, Dominica, St. Vincent and the Grenadines, Jamaica, Grenada, and Antigua) on the status of special education in their…

  2. A New Weave: Popular Education in Canada and Central America.

    ERIC Educational Resources Information Center

    Arnold, Rick; And Others

    Written from the perspective of the Central American experience of education for fundamental social change, this booklet provides ideas and guidelines for developing popular education, a learning process based on the concept that education can serve the interests of the poor and that the people themselves can define the content and context of…

  3. A new seismically constrained subduction interface model for Central America

    NASA Astrophysics Data System (ADS)

    Kyriakopoulos, C.; Newman, A. V.; Thomas, A. M.; Moore-Driskell, M.; Farmer, G. T.

    2015-08-01

    We provide a detailed, seismically defined three-dimensional model for the subducting plate interface along the Middle America Trench between northern Nicaragua and southern Costa Rica. The model uses data from a weighted catalog of about 30,000 earthquake hypocenters compiled from nine catalogs to constrain the interface through a process we term the "maximum seismicity method." The method determines the average position of the largest cluster of microseismicity beneath an a priori functional surface above the interface. This technique is applied to all seismicity above 40 km depth, the approximate intersection of the hanging wall Mohorovičić discontinuity, where seismicity likely lies along the plate interface. Below this depth, an envelope above 90% of seismicity approximates the slab surface. Because of station proximity to the interface, this model provides highest precision along the interface beneath the Nicoya Peninsula of Costa Rica, an area where marked geometric changes coincide with crustal transitions and topography observed seaward of the trench. The new interface is useful for a number of geophysical studies that aim to understand subduction zone earthquake behavior and geodynamic and tectonic development of convergent plate boundaries.

  4. Central America: Current Crisis and Future Prospects. Foreign Policy Association Headline Series, No. 271.

    ERIC Educational Resources Information Center

    Dominguez, Jorge I.; Lindenberg, Marc

    One of a series of booklets on world issues, this document summarizes some of the salient aspects of Central America with special attention given to Nicaragua and El Salvador. The booklet identifies the interests, policies, and choices of the major actors in the drama that engulfs the region and, increasingly, much of the world. Chapter one…

  5. U.S. Blacks' Perceptions, Experiences, and Scholarship regarding Central and South America--1822 to 1959

    ERIC Educational Resources Information Center

    Fikes, Robert, Jr.

    2006-01-01

    Instances of U.S. Black Americans having direct contact with the inhabitants of Central and South America, whose majority populations are not Black, can be traced back to the early nineteenth century. Slaves and freemen were aware of the possibility of a better life in these regions and a few found their way there to experience trials,…

  6. Development in Mexico and Central America. Fulbright-Hays Summer Seminars Abroad Program. Summer 1991.

    ERIC Educational Resources Information Center

    Institute of International Education, New York, NY.

    This document features writings and curriculum projects by teachers who traveled to Mexico and Central America in the summer of 1991 as members of a Fulbright-Hays Summer Seminar. The following items are among the 20 included: Curriculum Project: "'Escritoras Mexicanas Contemporaneas': A Survey of Mexican Women Fiction Writers" (Laura J. Beard);…

  7. Annotated zoogeography of non-marine Tardigrada. Part I: Central America.

    PubMed

    Kaczmarek, Łukasz; Michalczyk, Łukasz; McInnes, Sandra J

    2014-02-05

    Dividing the world into nine regions, this first paper describes literature records of the limno-terrestrial tardigrades (Tardigrada) reported from Central America. Updating previously published species lists we have revised the taxonomy and provided additional habitat, geographic co-ordinates, and biogeographic comments. It is hoped this work will serve as a reference point and background for further zoogeographic studies.

  8. Annotated zoogeography of non-marine Tardigrada. Part I: Central America.

    PubMed

    Kaczmarek, Łukasz; Michalczyk, Łukasz; McInnes, Sandra J

    2014-01-01

    Dividing the world into nine regions, this first paper describes literature records of the limno-terrestrial tardigrades (Tardigrada) reported from Central America. Updating previously published species lists we have revised the taxonomy and provided additional habitat, geographic co-ordinates, and biogeographic comments. It is hoped this work will serve as a reference point and background for further zoogeographic studies. PMID:24870276

  9. Planting the Seeds of a New Agriculture: Living with the Land in Central America.

    ERIC Educational Resources Information Center

    Adriance, Jim

    1995-01-01

    Central America's macroeconomics, land tenure patterns, and population growth are forcing small-scale farmers to alternatives based on farmer-to-farmer teaching and farming in concert with the environment. Discusses major schools of thought that have fueled this phenomenon, and how extension services and isolated groups are joining to form a…

  10. In the Shadow of the Cold War: The Caribbean and Central America in U.S. Foreign Policy. Revised Edition.

    ERIC Educational Resources Information Center

    Malkasian, Mark; Davidson, Louise K.

    In this document, students examine the economic and military concerns that linked the history of the Caribbean and Central America to the United States. Organized into four chapters, the first chapter examines the history of U.S. relations with the Caribbean and Central America from the early 19th century to 1961. The second chapter focuses on the…

  11. 77 FR 66870 - Dominican Republic-Central America-United States Free Trade Agreement; Notice of Extension of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... of the Secretary Dominican Republic--Central America--United States Free Trade Agreement; Notice of... Dominican Republic--Central America--United States Free Trade Agreement (CAFTA-DR). On March 26, 2012, OTLA...' commitments under the Labor Chapter. OTLA accepted the Submission for review on May 14, 2012 (77 FR...

  12. Large-volume volcanic edifi ce failures in Central America and associated hazards

    USGS Publications Warehouse

    Siebert, L.; Alvarado, Guillermo E.; Vallance, J.W.; Van Wyk de Vries, B.

    2006-01-01

    Edifi ce-collapse phenomena have, to date, received relatively little attention in Central America, although ??40 major collapse events (??0.1 km3) from about two dozen volcanoes are known or inferred in this volcanic arc. Volcanoes subjected to gravitational failure are concentrated at the arc's western and eastern ends. Failures correlate positively with volcano elevation, substrate elevation, edifi ce height, volcano volume, and crustal thickness and inversely with slab descent angle. Collapse orientations are strongly infl uenced by the direction of slope of the underlying basement, and hence are predominately perpendicular to the arc (preferentially to the south) at its extremities and display more variable failure directions in the center of the arc. The frequency of collapse events in Central America is poorly constrained because of the lack of precise dating of deposits, but a collapse interval of ??1000-2000 yr has been estimated during the Holocene. These high-impact events fortunately occur at low frequency, but the proximity of many Central American volcanoes to highly populated regions, including some of the region's largest cities, requires evaluation of their hazards. The primary risks are from extremely mobile debris avalanches and associated lahars, which in Central America have impacted now-populated areas up to ??50 km from a source volcano. Lower probability risks associated with volcanic edifi ce collapse derive from laterally directed explosions and tsunamis. The principal hazards of the latter here result from potential impact of debris avalanches into natural or man-made lakes. Much work remains on identifying and describing debris-avalanche deposits in Central America. The identifi cation of potential collapse sites and assessing and monitoring the stability of intact volcanoes is a major challenge for the next decade. ?? 2006 Geological Society of America.

  13. Markets for renewable energy in Central America and the Caribbean

    SciTech Connect

    Patil, P.G.; Sloop, J.L.

    1982-01-01

    For market studies of renewable energy and conservation equipment, Costa Rica was selected as the most favorable Central American country and representative of the rest. The Dominican Republic, Jamaica, Barbados, and Antigua were selected as representative of the Caribbean islands, from the largest to one of the smallest. Best markets in Costa Rica are judged to be micro and mini hydroelectric systems, heat pumps for large hot water users, photovoltaic systems for low-power remote devices, small distilleries for producing alcohol from sugar cane, solar dryers for bagasse, and energy conservation equipment. Market prospects for the Caribbean islands are very good, including micro and mini hydroelectric systems for those countries with water resources, solar drying of bagasse, solar water heaters, solar ponds/solar thermal systems for electric power or heat processes, wind-electric systems for utility grids and farms, photovoltaics for small power uses, and energy conservation equipment.

  14. Central America Regional Climate Change Program: Tools for Your Use

    NASA Technical Reports Server (NTRS)

    Irwin, Dan; Irving, Bill; Yeager, Carey

    2006-01-01

    USAID/E-CAM and EGAT's Global Climate Change Team, in partnership with EPA, NASA, Oak Ridge National Lab, and the Central American Commission for Environment and Development (CCAD), have had a significant impact on the region's ability to monitor, mitigate, and adapt to environmental threats. Environmental decision-making tools and data are posted on a website (SERVIR: http://servir.nsstc.nasa.pov/home.html)that provides satellite and geographic data and maps to anybody with an Internet connection. The SERVIR program has been identified as the model for the Global Earth Observation System of Systems (GEOSS) - a major international effort to develop a 21st century system for environmental management and disaster response. In coordination with the USAID/EPA program, NASA has developed a GIs tool that enables countries to examine their forest cover and document changes on an annual basis. This information is used in calculating carbon emissions as part of greenhouse gas inventories, but also serves a valuable monitoring function. In addition, USAID/E-CAM and EGAT's Global Climate Change Team in collaboration with EPA are helping countries meet their obligations as signatories to the United Nations Framework Convention on Climate Change (UNFCCC). EPA is assisting Central American governments to improve the quality of their greenhouse gas emission inventories reported to the UNFCCC through the development of tools and improvements in data quality. New EPA tools developed include software to automatically calculate greenhouse gas emissions for the agricultural and forestry sector inventories, determine key sources of greenhouse gas emissions, and document institutional arrangements. Several of these tools are state of the art and are comparable to tools currently used in the U.S.

  15. Effectiveness of statistical method for estimation of water use efficiency in temperate and boreal forests of North America exclusively using MODIS data

    NASA Astrophysics Data System (ADS)

    Wang, Mengjie; Chen, Yunhao; Quan, Jinling

    2015-04-01

    Water use efficiency (WUE) is an important biophysical variable reflecting the couple of water and carbon cycle in the ecosystem. The canopy level WUE including ecosystem WUE (eWUE) and inherent WUE (iWUE) can be estimated at flux towers, where eWUE is derived from the ratio of gross primary product (GPP) to evapotranspiration (ET) and iWUE is the product of eWUE and vapor pressure deficit (VPD). Upscaling methods are necessary to obtain spatially continuous WUE. Previous methods require field measurement which cannot be easily acquired by remote sensing. Moreover, the effectiveness of statistical method for estimation WUE across different forest types and climates, exclusively using remote sensing, remains unknown. In this study, we calculate 16-day forest WUE at temperate and boreal forests (including deciduous and evergreen forests) of North America using flux tower data and conduct a linear regression between WUE and related variables derived from Moderate Resolution Imaging Spectroradiometer (MODIS), including enhanced vegetation index (EVI), daytime land surface temperature (dLST), leaf area index (LAI), fraction of absorbed photosynthetically active radiation (fPAR) and normalized difference water index (NDWI). Results show that the correlation varies among different sites and variables. EVI, LAI and fPAR result in higher correlation coefficients (R2) of 0.34-0.75, 0.39-0.68, and 0.35-0.76, respectively, at five deciduous forest sites without much disturbance (e.g. drought). For all of the deciduous forest sites, EVI has the closest relation with eWUE (R2=0.35, p

  16. Neurocysticercosos in South-Central America and the Indian subcontinent. A comparative evaluation.

    PubMed

    Singh, G

    1997-09-01

    Neurocysticercosis is an important public health problem in South-Central American and South Asia. A review of the differences in epidemiological and clinical attributes of cysticercosis and taeniasis in South Central America and India, respectively, is undertaken in the present communication. Intestinal taeniasis is hyperendemic in several American countries. In comparison, the prevalence of Taenia solium infestation is lower in India. The clinical manifestations in several American neurocysticercosis series comprise epilepsy, intracranial hypertension and meningeal-racemose cysticercosis, in roughly equal proportions. An overwhelming majority of the Indian subjects present with seizures. The commonest pathological substrate of the disorder in Indian patients is the solitary parenchymal degenerating cyst. The reasons for the predominance of solitary forms in India, and of multilesional forms in South Central America are discussed. The magnitude of Taenia solium infestation and the frequency of pork consumption in a given population appear to influence the quantum of cyst load in affected individuals.

  17. Molecular characterization of adenovirus circulating in Central and South America during the 2006–2008 period

    PubMed Central

    García, Josefina; Sovero, Merly; Laguna‐Torres, Victor Alberto; Gomez, Jorge; Chicaiza, Wilson; Barrantes, Melvin; Sanchez, Felix; Jimenez, Mirna; Comach, Guillermo; De Rivera, Ivette L.; Agudo, Roberto; Arango, Ana E.; Barboza, Alma; Aguayo, Nicolas; Kochel, Tadeusz J.

    2009-01-01

    Background  Human Adenoviruses are recognized pathogens, causing a broad spectrum of diseases. Serotype identification is critical for epidemiological surveillance, detection of new strains and understanding of HAdvs pathogenesis. Little data is available about HAdvs subtypes in Latin America. Methods  In this study, we have molecularly characterized 213 adenoviruses collected from ILI presenting patients, during 2006‐08, in Central and South America. Results  Our results indicate that 161(76%) adenoviruses belong to subgroup C, 45 (21%) to subgroup B and 7 (3%) to subtype E4. PMID:19903214

  18. High level of molecular and phenotypic biodiversity in Jatropha curcas from Central America compared to Africa, Asia and South America

    PubMed Central

    2014-01-01

    Background The main bottleneck to elevate jatropha (Jatropha curcas L.) from a wild species to a profitable biodiesel crop is the low genetic and phenotypic variation found in different regions of the world, hampering efficient plant breeding for productivity traits. In this study, 182 accessions from Asia (91), Africa (35), South America (9) and Central America (47) were evaluated at genetic and phenotypic level to find genetic variation and important traits for oilseed production. Results Genetic variation was assessed with SSR (Simple Sequence Repeat), TRAP (Target Region Amplification Polymorphism) and AFLP (Amplified fragment length polymorphism) techniques. Phenotypic variation included seed morphological characteristics, seed oil content and fatty acid composition and early growth traits. Jaccard’s similarity and cluster analysis by UPGM (Unweighted Paired Group Method) with arithmetic mean and PCA (Principle Component Analysis) indicated higher variability in Central American accessions compared to Asian, African and South American accessions. Polymorphism Information Content (PIC) values ranged from 0 to 0.65. In the set of Central American accessions. PIC values were higher than in other regions. Accessions from the Central American population contain alleles that were not found in the accessions from other populations. Analysis of Molecular Variance (AMOVA; P < 0.0001) indicated high genetic variation within regions (81.7%) and low variation across regions (18.3%). A high level of genetic variation was found on early growth traits and on components of the relative growth rate (specific leaf area, leaf weight, leaf weight ratio and net assimilation rate) as indicated by significant differences between accessions and by the high heritability values (50–88%). The fatty acid composition of jatropha oil significantly differed (P < 0.05) between regions. Conclusions The pool of Central American accessions showed very large genetic variation as

  19. Hydrogeochemical investigation of six geothermal sites in Honduras, Central America

    SciTech Connect

    Goff, F.E.; Truesdell, A.H.; Grigsby, C.O.; Janik, C.J.; Shevenell, L.A.; Paredes, J.R.; Gutierrez, J.W.; Trujillo, Jr.; Counce, D.A.

    1987-06-01

    We conducted detailed hydrogeochemical investigations at six geothermal sites in western Honduras: Azacualpa, El Olivar, Pavana, Platanares, Sambo Creek, and San Ignacio. None of the sites is associated with Quaternary silicic volcanism, although El Olivar lies adjacent to a small Quaternary basalt field and Pavana is part of a belt of hot spring activity parallel to and 35 km east of the Central American volcanic arc. None of the sites contains acid-sulfate waters indicative of vapor-dominated conditions. Thermal fluids are characterized by pH between 7 and 10, Cl<125 mg/l, HCO/sub 3/>Cl, SO/sub 4/greater than or equal toCl, Bless than or equal to17 mg/l, Liless than or equal to4 mg/l, and Asless than or equal to1.25 mg/l. Stable isotope analyses of the water show that recharge to the geothermal systems generally occurs from areas of higher elevation adjacent to the sites. Tritium contents of apparently undiluted thermal fluids range from 0 to 0.4 T.U., indicating residence times of fluids in the systems of more than 500 y. Various geochemical indicators show that mixing of hot and cold end-member fluids occurs in the system at Platanares and, to a lesser degree, in the systems at San Ignacio and Azacualpa. No mixing is apparent in the fluids discharging at Pavana, Sambo Creek, or El Olivar. Boiling is the dominant process responsible for subtle geochemical variations at Azacualpa and, possibly, San Ignacio. Our best estimates of subsurface reservoir temperatures are 225/sup 0/C at Platanares, 190/sup 0/C at San Ignacio, 185/sup 0/C at Azacualpa, 155/sup 0/C at Sambo Creek, 150/sup 0/C at Pavana, and 120/sup 0/C at El Olivar. The estimated power output of the three hottest sites is 45 thermal megawatts at Platanares, 14 thermal megawatts at San Ignacio, and 13 thermal megawatts at Azacualpa.

  20. Mapping agricultural landscapes and characterizing adaptive capacity in Central America

    NASA Astrophysics Data System (ADS)

    Holland, M. B.; Imbach, P. A.; Bouroncle, C.; Donatti, C.; Leguia, E.; Martinez, M.; Medellin, C.; Saborio-Rodriguez, M.; Shamer, S.; Zamora, J.

    2013-12-01

    One of the key challenges in developing adaptation strategies for smallholder farmers in developing countries is that of a data-poor environment, where spatially-explicit information about where the most vulnerable smallholder communities are located is lacking. Developing countries tend to lack consistent and reliable maps on agricultural land use, and have limited information available on smallholder adaptive capacity. We developed a novel participatory and expert mapping process to overcome these barriers and develop detailed national-scale maps that allow for a characterization of unique agricultural landscapes based on profiles of adaptive capacity for smallholder agriculture in each area. This research focuses specifically on the Central American nations of Costa Rica, Guatemala, and Honduras, where our focus is on coffee and basic grains as the two main cropping systems. Here we present the methodology and results of a series of in-depth interviews and participatory mapping sessions with experts working within the broader agricultural sector in each country. We held individual interviews and mapping sessions with approximately thirty experts from each country, and used a detailed survey instrument for each mapping session to both spatially identify distinct agricultural landscapes, and to further characterize each area based on specific farm practices and social context. The survey also included a series of questions to help us assess the relative adaptive capacity of smallholder agriculture within each landscape. After all expert mapping sessions were completed in each country we convened an expert group to assist in both validating and refining the set of landscapes already defined. We developed a characterization of adaptive capacity by aggregating indicators into main assets-based criteria (e.g. land tenure, access to credit, access to technical assistance, sustainable farm practices) derived from further expert weighting of indicators through an online

  1. Large-volume volcanic edifice failures in Central America and associated hazards

    USGS Publications Warehouse

    Siebert, Lee; Alvarado, Guillermo E.; Vallance, James W.; van Wyk de Vries, Benjamin

    2006-01-01

    Edifice-collapse phenomena have, to date, received relatively little attention in Central America, although ∼40 major collapse events (≥0.1 km3) from about two dozen volcanoes are known or inferred in this volcanic arc. Volcanoes subjected to gravitational failure are concentrated at the arc's western and eastern ends. Failures correlate positively with volcano elevation, substrate elevation, edifice height, volcano volume, and crustal thickness and inversely with slab descent angle. Collapse orientations are strongly influenced by the direction of slope of the underlying basement, and hence are predominately perpendicular to the arc (preferentially to the south) at its extremities and display more variable failure directions in the center of the arc.The frequency of collapse events in Central America is poorly constrained because of the lack of precise dating of deposits, but a collapse interval of ∼1000–2000 yr has been estimated during the Holocene. These high-impact events fortunately occur at low frequency, but the proximity of many Central American volcanoes to highly populated regions, including some of the region's largest cities, requires evaluation of their hazards. The primary risks are from extremely mobile debris avalanches and associated lahars, which in Central America have impacted now-populated areas up to ∼50 km from a source volcano. Lower probability risks associated with volcanic edifice collapse derive from laterally directed explosions and tsunamis. The principal hazards of the latter here result from potential impact of debris avalanches into natural or man-made lakes. Much work remains on identifying and describing debris-avalanche deposits in Central America. The identification of potential collapse sites and assessing and monitoring the stability of intact volcanoes is a major challenge for the next decade.

  2. Constraints from finite element modeling on the active tectonics of northern Central America and the Middle America Trench

    NASA Astrophysics Data System (ADS)

    ÁLvarez-Gómez, José A.; Meijer, Paul T.; MartíNez-DíAz, José J.; Capote, Ramón

    2008-02-01

    We have developed an elastic finite element model in order to study the role of the different forces acting on the northwestern part of the Central American Volcanic Arc and the Chortis Block. We present synthetic focal mechanisms, maps of tectonic regime, and strain crosses to analyze the results. The models show that to achieve the observed state of stress on the volcanic arc, the arc must be modeled as a lithospheric weak zone. Also, the forces related to the eastward drift of the Caribbean plate must be higher than those related to the subduction of the Cocos plate. The coupling on the subduction interface must be low, with or without slip-partitioning due to the obliquity of the subduction at the trench. At Guatemala the western edge of the Chortis block is pinned against North America, even with low trench-normal forces, making the triple junction between the Cocos, North American, and Caribbean plates a zone of diffuse deformation. The extension in the western part of the Chortis block, from Guatemala to the Honduras depression, is explained by the geometry of the North American-Caribbean plate boundary and the direction of motion of the Caribbean plate with respect to North America. The direction of extension in the Chortis block is always E-W regardless of the magnitude of the applied forces, and the main part of the deformation is absorbed between the Ipala graben and the Honduras depression, both features being consistent with our models.

  3. A rapid diversification of rainforest trees (Guatteria; Annonaceae) following dispersal from Central into South America.

    PubMed

    Erkens, Roy H J; Chatrou, Lars W; Maas, Jan W; van der Niet, Timotheüs; Savolainen, Vincent

    2007-07-01

    Several recent studies have suggested that a substantial portion of today's plant diversity in the Neotropics has resulted from the dispersal of taxa into that region rather than vicariance, but more data are needed to substantiate this claim. Guatteria (Annonaceae) is, with 265 species, the third largest genus of Neotropical trees after Inga (Fabaceae) and Ocotea (Lauraceae), and its widespread distribution and frequent occurrence makes the genus an excellent model taxon to study diversification patterns. This study reconstructed the phylogeny of Guatteria and inferred three major biogeographical events in the history of the genus: (1) a trans-oceanic Miocene migration from Central into South America before the closing of the Isthmus of Panama; (2) a major diversification of the lineage within South America; and (3) several migrations of South American lineages back into Central America via the closed Panamanian land bridge. Therefore, Guatteria is not an Amazonian centred-genus sensu Gentry but a major Miocene diversification that followed its dispersal into South America. This study provides further evidence that migration into the Neotropics was an important factor in the historical assembly of its biodiversity. Furthermore, it is shown that phylogenetic patterns are comparable to those found in Ocotea and Inga and that a closer comparison of these genera is desirable.

  4. Mineral deposits of Central America, with a section on manganese deposits of Panama

    USGS Publications Warehouse

    Roberts, Ralph Jackson; Irving, Earl Montgomery; Simons, F.S.

    1957-01-01

    The mineral deposits of Central America were studied between 1942 and 1945, in cooperation with the United States Department of State and the Foreign Economic Administration. Emphasis was originally placed on the study of strategic-mineral deposits, especially of antimony, chromite, manganese, quartz, and mica, but deposits of other minerals that offered promise of significant future production were also studied. A brief appraisal of the base-metal deposits was made, and deposits of iron ore in Honduras and of lead and zinc ores in Guatemala were mapped. In addition, studies were made of the regional geology of some areas, data were collected from many sources, and a new map of the geology of Central America was compiled.

  5. Towards a redefinition of security in Central America: the case of natural disasters.

    PubMed

    Pettiford, L

    1995-06-01

    Over the past 25 years Central America has suffered a number of major disasters: the Managua Earthquake (1972), Hurricane Fifi (1974), the Guatemalan Earthquake (1976), the San Salvador Earthquake (1986) and Hurricane Joan (1988). These events are briefly described, with special reference to their political aspects and implications. Recognition of the political importance of disasters in Central America leads to a questioning of the traditional notion that security is essentially a matter of defending the state from outside aggression. It is suggested that the analysis of disasters should be part of the debate that is currently underway in international relations about redefining the concept of security in the post-Cold War world. PMID:7600057

  6. Deformation Survey of Volcanoes in Central America Using Japanese L-Band SAR Satellite ALOS-1

    NASA Astrophysics Data System (ADS)

    Amelug, F.; Lebowitz, J.

    2015-12-01

    The Japanese L-Band SAR satellite ALOS-1 has proven intself to be a useful tool for deformation monitoring of active volcanoes. Here we present a systematic deformation survey of volcanoes in Central America for the 2007-2011 time frame using the Small Baseline InSAR time-series approach. We present results for deforming volcanoes and non-deforming volcanoes, including simple elastic source models for the volcanoes that show surface deformation.

  7. A key to the Mexican and Central America Genera of Anthonomini (Curculionidae, Curculioninae)

    PubMed Central

    Hernández, Macotulio Soto; Jones, Robert W.; Castillo, Pedro Reyes

    2013-01-01

    Abstract Presently the only keys available for identification of genera of Anthonomini are limited to those of the United States of America and Canada. A dichotomous key is presented to identify all genera of Mexican and Central American Anthonomini. Previous keys do not include the genera Achia, Botanebius, Loncophorus, Loncophorellus and Melexerus. A brief synopsis is given for each genus and photographs of representative species are included. PMID:23717181

  8. A dynamic landslide hazard assessment system for Central America and Hispaniola

    NASA Astrophysics Data System (ADS)

    Kirschbaum, D. B.; Stanley, T.; Simmons, J.

    2015-10-01

    Landslides pose a serious threat to life and property in Central America and the Caribbean Islands. In order to allow regionally coordinated situational awareness and disaster response, an online decision support system was created. At its core is a new flexible framework for evaluating potential landslide activity in near real time: Landslide Hazard Assessment for Situational Awareness. This framework was implemented in Central America and the Caribbean by integrating a regional susceptibility map and satellite-based rainfall estimates into a binary decision tree, considering both daily and antecedent rainfall. Using a regionally distributed, percentile-based threshold approach, the model outputs a pixel-by-pixel nowcast in near real time at a resolution of 30 arcsec to identify areas of moderate and high landslide hazard. The daily and antecedent rainfall thresholds in the model are calibrated using a subset of the Global Landslide Catalog in Central America available for 2007-2013. The model was then evaluated with data for 2014. Results suggest reasonable model skill over Central America and poorer performance over Hispaniola due primarily to the limited availability of calibration and validation data. The landslide model framework presented here demonstrates the capability to utilize globally available satellite products for regional landslide hazard assessment. It also provides a flexible framework to interchange the individual model components and adjust or calibrate thresholds based on access to new data and calibration sources. The availability of free satellite-based near real-time rainfall data allows the creation of similar models for any study area with a spatiotemporal record of landslide events. This method may also incorporate other hydrological or atmospheric variables such as numerical weather forecasts or satellite-based soil moisture estimates within this decision tree approach for improved hazard analysis.

  9. A dynamic landslide hazard assessment system for Central America and Hispaniola

    NASA Astrophysics Data System (ADS)

    Kirschbaum, D. B.; Stanley, T.; Simmons, J.

    2015-04-01

    Landslides pose a serious threat to life and property in Central America and the Caribbean Islands. In order to allow regionally coordinated situational awareness and disaster response, an online decision support system was created. At its core is a new flexible framework for evaluating potential landslide activity in near real-time: Landslide Hazard Assessment for Situational Awareness. This framework was implemented in Central America and the Caribbean by integrating a regional susceptibility map and satellite-based rainfall estimates into a binary decision tree, considering both daily and antecedent rainfall. Using a regionally distributed, percentile-based threshold approach, the model outputs a pixel-by-pixel nowcast in near real-time at a resolution of 30 arcsec to identify areas of moderate and high landslide hazard. The daily and antecedent rainfall thresholds in the model are calibrated using a subset of the Global Landslide Catalog in Central America available for 2007-2013. The model was then evaluated with data for 2014. Results suggest reasonable model skill over Central America and poorer performance over Hispaniola, due primarily to the limited availability of calibration and validation data. The landslide model framework presented here demonstrates the capability to utilize globally available satellite products for regional landslide hazard assessment. It also provides a flexible framework to interchange the indiviual model components and adjust or calibrate thresholds based on access to new data and calibration sources. The availability of free, satellite-based near real-time rainfall data allows the creation of similar models for any study area with a spatiotemporal record of landslide events. This method may also incorporate other hydrological or atmospheric variables such as numerical weather forecasts or satellite-based soil moisture estimates within this decision tree approach for improved hazard analysis.

  10. Modeling the Agroecological Land Suitability for Coffea arabica L. in Central America

    NASA Astrophysics Data System (ADS)

    Lara, Leonel; Rasche, Livia; Schneider, Uwe

    2016-04-01

    Coffee production is an important income source for small farms in Central America, but climate change threatens the production. In order to develop efficient adaptation strategies, an assessment of local conditions and opportunities is essential. Lack or uncertainty of information are common challenges for such assessments. A tool to resolve these challenges is Bayesian network analysis. In this study, we developed ALECA, the first Bayesian network model to evaluate the agroecological land suitability for Coffea arabica L. A new set of suitability functions was created and subsequently used to populate the conditional probability tables of the variables. The variables include temperature, precipitation and dry season length for the climate, slope and aspect for the landform, and soil pH, cation exchange capacity and texture for the soil component. We validated ALECA by comparing a map of current coffee areas, and specific coffee areas with known suitability for coffee production in Central America to the suitability evaluations of the model; and proceeded to explore 1) the capabilities of the model to manage data uncertainty, and 2) the changes to suitability scores under climate change. The results showed that the area suitable for coffee production will decline in Central America under climate change, underlining the need for models like ALECA, which can be used to produce reliable land evaluations at local, national and regional scales under uncertainty.

  11. Active mountain building and the distribution of core Maxillariinae species in tropical Mexico and Central America

    USGS Publications Warehouse

    Kirby, Stephen H.

    2011-01-01

    The observation that southeastern Central America is a hotspot for orchid diversity has long been known and confirmed by recent systematic studies and checklists. An analysis of the geographic and elevation distribution demonstrates that the most widespread species of “core” Maxillariinae are all adapted to life near sea level, whereas the most narrowly endemic species are largely distributed in wet highland environments. Drier, hotter lowland gaps exist between these cordilleras and evidently restrict the dispersal of the species adapted to wetter, cooler conditions. Among the recent generic realignments of “core” Maxillariinae based on molecular phylogenetics, the Camaridium clade is easily the most prominent genus in Central America and is largely restricted to the highlands of Costa Rica and Panama, indicating that this region is the ancestral home of this genus and that its dispersal limits are drier, lowland cordilleran gaps. The mountains of Costa Rica and Panama are among the geologically youngest topographic features in the Neotropics, reflecting the complex and dynamic interactions of numerous tectonic plates. From consideration of the available geological evidence, I conclude that the rapid growth of the mountain ranges in Costa Rica and Panama during the late Cenozoic times created, in turn, very rapid ranges in ecological life zones and geographic isolation in that part of the isthmus. Thus, I suggest that these recent geologic events were the primary drivers for accelerated orchid evolution in southeastern Central America.

  12. Current challenges for confronting the public health problem of snakebite envenoming in Central America

    PubMed Central

    2014-01-01

    Snakebite envenoming is a serious public health problem in Central America, where approximately 5,500 cases occur every year. Panama has the highest incidence and El Salvador the lowest. The majority, and most severe, cases are inflicted by the pit viper Bothrops asper (family Viperidae), locally known as ‘terciopelo’, ‘barba amarilla’ or ‘equis’. About 1% of the bites are caused by coral snakes of the genus Micrurus (family Elapidae). Despite significant and successful efforts in Central America regarding snakebite envenomings in the areas of research, antivenom manufacture and quality control, training of health professionals in the diagnosis and clinical management of bites, and prevention of snakebites, much remains to be done in order to further reduce the impact of this medical condition. This essay presents seven challenges for improving the confrontation of snakebite envenoming in Central America. Overcoming these challenges demands a coordinated partnership of highly diverse stakeholders though inter-sectorial and inter-programmatic interventions. PMID:24602234

  13. Parvitermes (Isoptera, Termitidae, Nasutitermitinae) in Central America: Two new termite species and reassignment of Nasutitermes mexicanus

    PubMed Central

    Scheffrahn, Rudolf H.

    2016-01-01

    Abstract The termite genus Parvitermes is now recognized on the Central American mainland to include Parvitermes mexicanus, new combination (previously in Nasutitermes) and two new species, Parvitermes mesoamericanus sp. n. and Parvitermes yucatanus sp. n., herein described from soldiers and workers. These three species, nine West Indian Parvitermes, and Antillitermes subtilis all share characteristic enteric valve spines that orientate against intestinal flow. All species are subterranean nesters and cellulose feeders. Evidence is mounting that generic-level endemicity may be completely absent among the West Indian nasutitermitine fauna and that its origins stem from Central America. PMID:27667954

  14. Parvitermes (Isoptera, Termitidae, Nasutitermitinae) in Central America: Two new termite species and reassignment of Nasutitermes mexicanus.

    PubMed

    Scheffrahn, Rudolf H

    2016-01-01

    The termite genus Parvitermes is now recognized on the Central American mainland to include Parvitermes mexicanus, new combination (previously in Nasutitermes) and two new species, Parvitermes mesoamericanus sp. n. and Parvitermes yucatanus sp. n., herein described from soldiers and workers. These three species, nine West Indian Parvitermes, and Antillitermes subtilis all share characteristic enteric valve spines that orientate against intestinal flow. All species are subterranean nesters and cellulose feeders. Evidence is mounting that generic-level endemicity may be completely absent among the West Indian nasutitermitine fauna and that its origins stem from Central America. PMID:27667954

  15. Parvitermes (Isoptera, Termitidae, Nasutitermitinae) in Central America: Two new termite species and reassignment of Nasutitermes mexicanus

    PubMed Central

    Scheffrahn, Rudolf H.

    2016-01-01

    Abstract The termite genus Parvitermes is now recognized on the Central American mainland to include Parvitermes mexicanus, new combination (previously in Nasutitermes) and two new species, Parvitermes mesoamericanus sp. n. and Parvitermes yucatanus sp. n., herein described from soldiers and workers. These three species, nine West Indian Parvitermes, and Antillitermes subtilis all share characteristic enteric valve spines that orientate against intestinal flow. All species are subterranean nesters and cellulose feeders. Evidence is mounting that generic-level endemicity may be completely absent among the West Indian nasutitermitine fauna and that its origins stem from Central America.

  16. Quantitative estimates of tropical temperature change in lowland Central America during the last 42 ka

    NASA Astrophysics Data System (ADS)

    Grauel, Anna-Lena; Hodell, David A.; Bernasconi, Stefano M.

    2016-03-01

    Determining the magnitude of tropical temperature change during the last glacial period is a fundamental problem in paleoclimate research. Large discrepancies exist in estimates of tropical cooling inferred from marine and terrestrial archives. Here we present a reconstruction of temperature for the last 42 ka from a lake sediment core from Lake Petén Itzá, Guatemala, located at 17°N in lowland Central America. We compared three independent methods of glacial temperature reconstruction: pollen-based temperature estimates, tandem measurements of δ18O in biogenic carbonate and gypsum hydration water, and clumped isotope thermometry. Pollen provides a near-continuous record of temperature change for most of the glacial period but the occurrence of a no-analog pollen assemblage during cold, dry stadials renders temperature estimates unreliable for these intervals. In contrast, the gypsum hydration and clumped isotope methods are limited mainly to the stadial periods when gypsum and biogenic carbonate co-occur. The combination of palynological and geochemical methods leads to a continuous record of tropical temperature change in lowland Central America over the last 42 ka. Furthermore, the gypsum hydration water method and clumped isotope thermometry provide independent estimates of not only temperature, but also the δ18O of lake water that is dependent on the hydrologic balance between evaporation and precipitation over the lake surface and its catchment. The results show that average glacial temperature was cooler in lowland Central America by 5-10 °C relative to the Holocene. The coldest and driest times occurred during North Atlantic stadial events, particularly Heinrich stadials (HSs), when temperature decreased by up to 6 to 10 °C relative to today. This magnitude of cooling is much greater than estimates derived from Caribbean marine records and model simulations. The extreme dry and cold conditions during HSs in the lowland Central America were associated

  17. Prevalence, Distributions and Determinants of Obesity and Central Obesity in the Southern Cone of America

    PubMed Central

    Bazzano, Lydia; Rubinstein, Adolfo; Calandrelli, Matias; Chen, Chung-Shiuan; Elorriaga, Natalia; Gutierrez, Laura; Manfredi, Jose A.; Seron, Pamela; Mores, Nora; Poggio, Rosana; Ponzo, Jacqueline; Olivera, Hector; He, Jiang; Irazola, Vilma E.

    2016-01-01

    Background Obesity is a major determinant of cardiovascular disease in South America. However, population-based data are limited. Methods A total of 7,524 women and men, aged 35 to 74 years old, were randomly selected from 4 cities in the Southern Cone of Latin America between February 2010 and December 2011. Obesity clinical measurements and cardiovascular risk factors were measured using standard methodology. Results The prevalence of obesity and central obesity were 35.7% and 52.9%, respectively. The prevalence of obesity and central obesity were higher in women, and even higher in women with lower education compared with women with higher education. In men and women obesity was associated with a higher prevalence of diabetes, odds ratio (OR) 2.38 (95% Confidence Interval [CI]: 1.86 to 3.05) and 3.01 (95%CI 2.42 to 3.74) respectively, hypertension (OR 2.79 (95%CI 2.32 to 3.36) and 2.40 (95%CI 2.05 to 2.80) respectively, dyslipidemia (OR 1.83 (95%CI 1.50 to 2.24) and 1.69 (95%CI 1.45 to 1.98), respectively, low physical activity (OR 1.38(95%CI 1.14 to 1.68) and 1.38 (95%CI 1.18 to 1.62) respectively and a lower prevalence of smoking (OR, 0.65 (95%CI 0.53 to 0.80) and 0.58(95%CI 0.48 to 0.70) respectively. Conclusions Obesity and central obesity are highly prevalent in the general population in the Southern Cone of Latin America and are strongly associated with cardiovascular risk factor prevalence. These data suggest that efforts toward prevention, treatment, and control of obesity should be a public health priority in the Southern Cone of Latin America. PMID:27741247

  18. Diurnal and Seasonal Trends in Canopy Transpiration and Conductance of Pristine Forest Types in Belize, Central America

    NASA Technical Reports Server (NTRS)

    Zimmermann, R.; Oren, R.; Billings, S.; Muller-Ezards, C.; Schaaff, C.; Strohmeier, P.; Obermaier, E.

    1994-01-01

    Five semi-deciduous broadleaf forest types growing over tropical karst in Belize, Central America, were monitored for three years to study diurnal and seasonal changes of transpiration and micro-meteorologic conditions.

  19. Pre-Hispanic agricultural decline prior to the Spanish Conquest in southern Central America

    NASA Astrophysics Data System (ADS)

    Taylor, Zachary P.; Horn, Sally P.; Finkelstein, David B.

    2013-08-01

    Archeological and paleoenvironmental records from southern Central America attribute population collapse to the Spanish Conquest about 500 years ago. Paleoclimate records from the circum-Caribbean have shown evidence of severe, regional droughts that contributed to the collapse of the Mayan Civilization, but there are few records of these droughts in southern Central America and no records of their effects on prehistoric populations in the region. Here we present a high-resolution lake sediment record of prehistoric agricultural activities using bulk sediment stable carbon isotopes from Laguna Zoncho, Costa Rica. We find isotopic evidence that agriculture was nearly absent from the watershed approximately 220 years prior to the Spanish arrival in Costa Rica and identify two distinct periods of agricultural decline, 1150-970 and 860-640 cal yr BP, which correspond to severe droughts in central Mexico. We attribute decreases in agriculture to a weakened Central American monsoon, which would have shortened the growing season at Laguna Zoncho, reduced crop yields, and negatively affected prehistoric populations.

  20. Landscape evolution within a retreating volcanic arc, Costa Rica, Central America

    NASA Astrophysics Data System (ADS)

    Marshall, Jeffrey S.; Idleman, Bruce D.; Gardner, Thomas W.; Fisher, Donald M.

    2003-05-01

    Subduction of hotspot-thickened seafloor profoundly affects convergent margin tectonics, strongly affecting upper plate structure, volcanism, and landscape evolution. In southern Central America, low-angle subduction of the Cocos Ridge and seamount domain largely controls landscape evolution in the volcanic arc. Field mapping, stratigraphic correlation, and 40Ar/39Ar geochronology for late Cenozoic volcanic rocks of central Costa Rica provide new insights into the geomorphic response of volcanic arc landscapes to changes in subduction parameters (slab thickness, roughness, dip). Late Neogene volcanism was focused primarily along the now-extinct Cordillera de Aguacate. Quaternary migration of the magmatic front shifted volcanism northeastward to the Caribbean slope, creating a new topographic divide and forming the Valle Central basin. Stream capture across the paleo Aguacate divide led to drainage reversal toward the Pacific slope and deep incision of reorganized fluvial networks. Pleistocene caldera activity generated silicic ash flows that buried the Valle Central and descended the Tárcoles gorge to the Orotina debris fan at the coast. Growth of the modern Cordillera Central accentuated relief along the new divide, establishing the Valle Central as a Pacific slope drainage basin. Arc migration, relocation of the Pacific-Caribbean drainage divide, and formation of the Valle Central basin resulted from slab shallowing as irregular, hotspot-thickened crust entered the subduction zone. The geomorphic evolution of volcanic arc landscapes is thus highly sensitive to changes in subducting plate character.

  1. Development and Analysis of a Hurricane Hazard Model for Disaster Risk Assessment in Central America

    NASA Astrophysics Data System (ADS)

    Pita, G. L.; Gunasekera, R.; Ishizawa, O. A.

    2014-12-01

    Hurricane and tropical storm activity in Central America has consistently caused over the past decades thousands of casualties, significant population displacement, and substantial property and infrastructure losses. As a component to estimate future potential losses, we present a new regional probabilistic hurricane hazard model for Central America. Currently, there are very few openly available hurricane hazard models for Central America. This resultant hazard model would be used in conjunction with exposure and vulnerability components as part of a World Bank project to create country disaster risk profiles that will assist to improve risk estimation and provide decision makers with better tools to quantify disaster risk. This paper describes the hazard model methodology which involves the development of a wind field model that simulates the gust speeds at terrain height at a fine resolution. The HURDAT dataset has been used in this study to create synthetic events that assess average hurricane landfall angles and their variability at each location. The hazard model also then estimates the average track angle at multiple geographical locations in order to provide a realistic range of possible hurricane paths that will be used for risk analyses in all the Central-American countries. This probabilistic hurricane hazard model is then also useful for relating synthetic wind estimates to loss and damage data to develop and calibrate existing empirical building vulnerability curves. To assess the accuracy and applicability, modeled results are evaluated against historical events, their tracks and wind fields. Deeper analyses of results are also presented with a special reference to Guatemala. The findings, interpretations, and conclusions expressed in this paper are entirely those of the authors. They do not necessarily represent the views of the International Bank for Reconstruction and Development/World Bank and its affiliated organizations, or those of the

  2. A five-year analysis of MODIS NDVI and NDWI for grassland drought assessment over the central Great Plains of the United States

    USGS Publications Warehouse

    Gu, Y.; Brown, J.F.; Verdin, J.P.; Wardlow, B.

    2007-01-01

    A five-year (2001-2005) history of moderate resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) data was analyzed for grassland drought assessment within the central United States, specifically for the Flint Hills of Kansas and Oklahoma. Initial results show strong relationships among NDVI, NDWI, and drought conditions. During the summer over the Tallgrass Prairie National Preserve, the average NDVI and NDWI were consistently lower (NDVI 0.6 and NDWI>0.4). NDWI values exhibited a quicker response to drought conditions than NDVI. Analysis revealed that combining information from visible, near infrared, and short wave infrared channels improved sensitivity to drought severity. The proposed normalized difference drought index (NDDI) had a stronger response to summer drought conditions than a simple difference between NDVI and NDWI, and is therefore a more sensitive indicator of drought in grasslands than NDVI alone. Copyright 2007 by the American Geophysical Union.

  3. MODIS Global Sea Surface Temperature

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Every day the Moderate-resolution Imaging Spectroradiometer (MODIS) measures sea surface temperature over the entire globe with high accuracy. This false-color image shows a one-month composite for May 2001. Red and yellow indicates warmer temperatures, green is an intermediate value, while blues and then purples are progressively colder values. The new MODIS sea surface temperature product will be particularly useful in studies of temperature anomalies, such as El Nino, as well as research into how air-sea interactions drive changes in weather and climate patterns. In the high resolution image, notice the amazing detail in some of the regional current patterns. For instance, notice the cold water currents that move from Antarctica northward along South America's west coast. These cold, deep waters upwell along an equatorial swath around and to the west of the Galapagos Islands. Note the warm, wide currents of the Gulf Stream moving up the United States' east coast, carrying Caribbean warmth toward Newfoundland and across the Atlantic toward Western Europe. Note the warm tongue of water extending from Africa's east coast to well south of the Cape of Good Hope. MODIS was launched in December 1999 aboard NASA's Terra satellite. For more details on this and other MODIS data products, please see NASA Unveils Spectacular Suite of New Global Data Products from MODIS. Image courtesy MODIS Ocean Group, NASA GSFC, and the University of Miami

  4. The view from the shore: Central America's Indians encounter the quincentenary.

    PubMed

    Chapin, M

    1992-01-01

    Indigenous peoples of the Caribbean, except in small areas of the Dominican Republic and Cuba, have vanished through the years since Columbus landed. In the South, indigenous populations were "largely broken and demoralized, and political institutions shattered." In the 500-year celebration of Christopher Columbus's voyage to the Americas, many materials have been produced. In this article, the focus is on the unknown Indian of Latin America, who is invisible and usually isolated. The 40 million surviving Indians make up various percentages of a country's population, from among 50% in Peru to as little as under 1% in Brazil. The political upheavals of the 1980s have propelled Central America into the public eye. Central America's indigenous population is 4-5.5 million people in 43 different ethnic/linguistic groups (16-22% of Central America's total population of 25 million). Population growth of indigenous people has increased in the last 20 years. Most live in the difficult to reach regions of the jagged volcanic highlands of Guatemala and the densely forested Caribbean coastal plains from Belize to the Colombian border. These isolated locations were selected as protection from the colonists; these regions now are threatened by loggers, cattle ranchers, and landless peasants. In Guatemala, the 4.5 million Indians belong to 22 different Mayan language groups, who have been studied extensively by scientists. In Costa Rica, Indians receive limited protection in 21 reservations, and in El Salvador there is a denial of the "naturales" existence and what was owned before the Conquest is long gone. Most of the Indians are poverty stricken and lack basic social services. Indian organizations have appeared; their involvement in Indian welfare is recounted, e.g., the Kuna of Panama organized the first Indigenous Congress on Natural Resources and the Environment in 1989. An obstacle to the Indians survival is the legacy of Conquest: subjugation, humiliation, and

  5. Central America in Transition: From Maize to Wheat. Challenges and Opportunities

    PubMed Central

    Peña, Amado Salvador; Crusius, Jakob Bart Arie

    2015-01-01

    The Central American countries: Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama are in transition from a dietary culture based mainly on maize to a wheat-containing diet. Several other changes are occurring, such as a decrease of parasitic and infectious diseases. The environmental changes permit a prediction of an increase of celiac disease and other autoimmune diseases such as type I diabetes and thyroid disease in these genetically heterogeneous countries. At present, celiac disease and gluten-related disorders are considered to be of no relevance at the level of public health in these nations. This review documents the presence of celiac disease in Central America. It draws attention to some of the challenges in planning systematic studies in the region since up until recently celiac disease was unknown. The aim of this review is to disseminate knowledge obtained with preliminary data, to stimulate clinical and basic scientists to study these diseases in Central America and to alert authorities responsible for the planning of education and health, to find possibilities to avoid a rise in these disorders before the epidemics start, as has occurred in the Mediterranean countries. PMID:26343711

  6. Central America in Transition: From Maize to Wheat Challenges and Opportunities.

    PubMed

    Peña, Amado Salvador; Crusius, Jakob Bart Arie

    2015-09-01

    The Central American countries: Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama are in transition from a dietary culture based mainly on maize to a wheat-containing diet. Several other changes are occurring, such as a decrease of parasitic and infectious diseases. The environmental changes permit a prediction of an increase of celiac disease and other autoimmune diseases such as type I diabetes and thyroid disease in these genetically heterogeneous countries. At present, celiac disease and gluten-related disorders are considered to be of no relevance at the level of public health in these nations. This review documents the presence of celiac disease in Central America. It draws attention to some of the challenges in planning systematic studies in the region since up until recently celiac disease was unknown. The aim of this review is to disseminate knowledge obtained with preliminary data, to stimulate clinical and basic scientists to study these diseases in Central America and to alert authorities responsible for the planning of education and health, to find possibilities to avoid a rise in these disorders before the epidemics start, as has occurred in the Mediterranean countries. PMID:26343711

  7. LISN: Measurement of TEC values, and TID characteristics over South and Central America (Invited)

    NASA Astrophysics Data System (ADS)

    Valladares, C. E.

    2013-12-01

    The Low-latitude Ionospheric Sensor Network (LISN) is a distributed observatory designed to provide the climatology and weather of the low latitude ionosphere over the South American continent. Presently, the LISN observatory consists of 47 GPS receivers able to transmit TEC and scintillation values to a central server in a real-time basis. Historical TEC values from these receivers and from about 300 other GPSs that operated in South and Central America between 2008 and 2012 were used to derive regional maps of TEC and TIDs. A prominent feature of the TEC maps is the intense day-to-day variability that is observed during all seasons and under quiet and active magnetic conditions. To assess the TEC dependencies a non-linear least-square fit was conducted to simultaneously extract the solar flux, magnetic and seasonal variability for each square cell of the TEC maps and for each 30-min local time sector. It was found that TEC values and the anomaly intensity increase as a function of the solar flux. The latitudinal separation increases with magnetic activity, and TEC values in Central America become the largest when Kp is equal to 5o or more. TIDs are seen quite frequently over the Caribbean region and in the northern part of South America. To calculate the TIDs travel velocities, their propagation direction, and the scale-size of the disturbances a multi-site multi-dimension cross-correlation method was applied to the TEC database. Phase velocities of order 150 m/s and scale sizes between 100 and 400 km were typically observed. This paper will present the morphology and statistics of TIDs as a function of latitude, longitude, local time and season. It is also introduced the results of an investigation to correlate the appearance, phase velocity and angle of propagation of TIDs and tropospheric phenomena observed with the TRMM satellite.

  8. Climate change in Central America and Mexico: regional climate model validation and climate change projections

    NASA Astrophysics Data System (ADS)

    Karmalkar, Ambarish V.; Bradley, Raymond S.; Diaz, Henry F.

    2011-08-01

    Central America has high biodiversity, it harbors high-value ecosystems and it's important to provide regional climate change information to assist in adaptation and mitigation work in the region. Here we study climate change projections for Central America and Mexico using a regional climate model. The model evaluation shows its success in simulating spatial and temporal variability of temperature and precipitation and also in capturing regional climate features such as the bimodal annual cycle of precipitation and the Caribbean low-level jet. A variety of climate regimes within the model domain are also better identified in the regional model simulation due to improved resolution of topographic features. Although, the model suffers from large precipitation biases, it shows improvements over the coarse-resolution driving model in simulating precipitation amounts. The model shows a dry bias in the wet season and a wet bias in the dry season suggesting that it's unable to capture the full range of precipitation variability. Projected warming under the A2 scenario is higher in the wet season than that in the dry season with the Yucatan Peninsula experiencing highest warming. A large reduction in precipitation in the wet season is projected for the region, whereas parts of Central America that receive a considerable amount of moisture in the form of orographic precipitation show significant decreases in precipitation in the dry season. Projected climatic changes can have detrimental impacts on biodiversity as they are spatially similar, but far greater in magnitude, than those observed during the El Niño events in recent decades that adversely affected species in the region.

  9. Seismic hazard maps of Mexico, the Caribbean, and Central and South America

    USGS Publications Warehouse

    Tanner, J.G.; Shedlock, K.M.

    2004-01-01

    The growth of megacities in seismically active regions around the world often includes the construction of seismically unsafe buildings and infrastructures due to an insufficient knowledge of existing seismic hazard and/or economic constraints. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. We have produced a suite of seismic hazard estimates for Mexico, the Caribbean, and Central and South America. One of the preliminary maps in this suite served as the basis for the Caribbean and Central and South America portion of the Global Seismic Hazard Map (GSHM) published in 1999, which depicted peak ground acceleration (pga) with a 10% chance of exceedance in 50 years for rock sites. Herein we present maps depicting pga and 0.2 and 1.0 s spectral accelerations (SA) with 50%, 10%, and 2% chances of exceedance in 50 years for rock sites. The seismicity catalog used in the generation of these maps adds 3 more years of data to those used to calculate the GSH Map. Different attenuation functions (consistent with those used to calculate the U.S. and Canadian maps) were used as well. These nine maps are designed to assist in global risk mitigation by providing a general seismic hazard framework and serving as a resource for any national or regional agency to help focus further detailed studies required for regional/local needs. The largest seismic hazard values in Mexico, the Caribbean, and Central and South America generally occur in areas that have been, or are likely to be, the sites of the largest plate boundary earthquakes. High hazard values occur in areas where shallow-to-intermediate seismicity occurs frequently. ?? 2004 Elsevier B.V. All rights reserved.

  10. Characterising droughts in Central America with uncertain hydro-meteorological data

    NASA Astrophysics Data System (ADS)

    Quesada Montano, B.; Westerberg, I.; Wetterhall, F.; Hidalgo, H. G.; Halldin, S.

    2015-12-01

    Droughts studies are scarce in Central America, a region frequently affected by droughts that cause significant socio-economic and environmental problems. Drought characterisation is important for water management and planning and can be done with the help of drought indices. Many indices have been developed in the last decades but their ability to suitably characterise droughts depends on the region of application. In Central America, comprehensive and high-quality observational networks of meteorological and hydrological data are not available. This limits the choice of drought indices and denotes the need to evaluate the quality of the data used in their calculation. This paper aimed to find which combination(s) of drought index and meteorological database are most suitable for characterising droughts in Central America. The drought indices evaluated were the standardised precipitation index (SPI), deciles (DI), the standardised precipitation evapotranspiration index (SPEI) and the effective drought index (EDI). These were calculated using precipitation data from the Climate Hazards Group Infra-Red Precipitation with station (CHIRPS), CRN073, the Climate Research Unit (CRU), ERA-Interim and station databases, and temperature data from the CRU database. All the indices were calculated at 1-, 3-, 6-, 9- and 12-month accumulation times. As a first step, the large-scale meteorological precipitation datasets were compared to have an overview of the level of agreement between them and find possible quality problems. Then, the performance of all the combinations of drought indices and meteorological datasets were evaluated against independent river discharge data, in form of the standardised streamflow index (SSI). Results revealed the large disagreement between the precipitation datasets; we found the selection of database to be more important than the selection of drought index. We found that the best combinations of meteorological drought index and database were

  11. Evaluating regional differences in macroinvertebrate communities from forested depressional wetlands across eastern and central North America.

    SciTech Connect

    Batzer, Darold, P.; Dietz-Brantley, Susan E.; Taylor, Barbera E.; DeBiase, Adrienne E.

    2005-02-12

    Batzer, Darold, P., Susan E. Dietz-Brantley, Barbera E. Taylor, and Adrienne E. DeBiase. 2005. Evaluating regional differences in macroinvertebrate communities from forested depressional wetlands across eastern and central North America. J. N. Am. Benthol. Soc. 24(2):403-414. Abstract. Forested depressional wetlands are an important seasonal wetland type across eastern and central North America. Macroinvertebrates are crucial ecosystem components of most forested depressional wetlands, but community compositions can vary widely across the region. We evaluated variation in macroinvertebrate faunas across eastern and central North America using 5 published taxa lists from forested depressional wetlands in Michigan, Ontario, Wisconsin, Florida, and Georgia. We supplemented those data with quantitative community descriptions generated from 17 forested depressional wetlands in South Carolina and 74 of these wetlands in Minnesota. Cluster analysis of presence/absence data from these 7 locations indicated that distinct macroinvertebrate communities existed in northern and southern areas. Taxa characteristic of northern forested depressionalwetlands included Sphaeriidae, Lumbriculidae, Lymnaeidae, Physidae, Limnephilidae, Chirocephalidae, and Hirudinea (Glossophoniidae and/or Erpodbellidae) and taxa characteristic of southern sites included Asellidae, Crangonyctidae, Noteridae, and Cambaridae. Quantitative sampling in South Carolina and Minnesota indicated that regionally characteristic taxa included some of the most abundant organisms, with Sphaeriidae being the 2nd most abundant macroinvertebrate in Minnesota wetlands and Asellidae being the 2nd most abundant macroinvertebrate in South Carolina wetlands. Mollusks, in general, were restricted to forested depressional wetlands of northern latitudes, a pattern that may reflect a lack of Ca needed for shell formation in acidic southern sites. Differences in community composition probably translate into region

  12. Interannual variability of the midsummer drought in Central America and the connection with sea surface temperatures

    NASA Astrophysics Data System (ADS)

    Maldonado, Tito; Rutgersson, Anna; Alfaro, Eric; Amador, Jorge; Claremar, Björn

    2016-04-01

    The midsummer drought (MSD) in Central America is characterised in order to create annual indexes representing the timing of its phases (start, minimum and end), and other features relevant for MSD forecasting such as the intensity and the magnitude. The MSD intensity is defined as the minimum rainfall detected during the MSD, meanwhile the magnitude is the total precipitation divided by the total days between the start and end of the MSD. It is shown that the MSD extends along the Pacific coast, however, a similar MSD structure was detected also in two stations in the Caribbean side of Central America, located in Nicaragua. The MSD intensity and magnitude show a negative relationship with Niño 3.4 and a positive relationship with the Caribbean low-level jet (CLLJ) index, however for the Caribbean stations the results were not statistically significant, which is indicating that other processes might be modulating the precipitation during the MSD over the Caribbean coast. On the other hand, the temporal variables (start, minimum and end) show low and no significant correlations with the same indexes.The results from canonical correlation analysis (CCA) show good performance to study the MSD intensity and magnitude, however, for the temporal indexes the performance is not satisfactory due to the low skill to predict the MSD phases. Moreover, we find that CCA shows potential predictability of the MSD intensity and magnitude using sea surface temperatures (SST) with leading times of up to 3 months. Using CCA as diagnostic tool it is found that during June, an SST dipole pattern upon the neighbouring waters to Central America is the main variability mode controlling the inter-annual variability of the MSD features. However, there is also evidence that the regional waters are playing an important role in the annual modulation of the MSD features. The waters in the PDO vicinity might be also controlling the rainfall during the MSD, however, exerting an opposite effect at

  13. A revision of the spider genus Selenops Latreille, 1819 (Arachnida, Araneae, Selenopidae) in North America, Central America and the Caribbean

    PubMed Central

    Crews, Sarah C.

    2011-01-01

    Abstract The spider genus Selenops Latreille, 1819 occurs in both the Old World and New World tropics and subtropics and contains nearly half of the species in the family Selenopidae Simon, 1897. In this paper the members of the genus Selenops found in North America, Central America, and on islands of the Caribbean are revised, excluding Cuban endemics. No taxonomic changes are currently made to the species from the southwestern United States. In total, 21 new species are described, including Selenops arikok sp. n., Selenops chamela sp. n., Selenops amona sp. n., Selenops baweka sp. n., Selenops bocacanadensis sp. n., Selenops enriquillo sp. n, Selenops ixchel sp. n., Selenops huetocatl sp. n., Selenops kalinago sp. n., Selenops oviedo sp. n., Selenops morro sp. n., Selenops denia sp. n., Selenops duan sp. n., Selenops malinalxochitl sp. n., Selenops oricuajo sp. n., Selenops petenajtoy sp. n., Selenops guerrero sp. n., Selenops makimaki sp. n., Selenops souliga sp. n., Selenops wilmotorum sp. n., and Selenops wilsoni sp. n. Six species names were synonymized: Selenops lunatus Muma, 1953 syn. n. = Selenops candidus Muma, 1953; Selenops tehuacanus Muma 1953 syn. n., Selenops galapagoensis Banks, 1902 syn. n. and Selenops vagabundus Kraus, 1955 syn. n. = Selenops mexicanus Keyserling, 1880; Selenops santibanezi Valdez-Mondragón, 2010 syn. n. = Selenops nigromaculatus Keyserling, 1880; and Selenops salvadoranus Chamberlin, 1925 syn. n. = Selenops bifurcatus Banks, 1909. Lectotypes are designated for the following three species: Selenops marginalis F. O. Pickard-Cambridge, 1900 (♂), Selenops morosus Banks, 1898 (♂), and Selenops mexicanus Keyserling, 1880 (♀). The female neotype is designated for Selenops aissus Walckenaer, 1837. The males of Selenops bani Alayón-García, 1992 and Selenops marcanoi Alayón-García, 1992 are described for the first time, and the females of Selenops phaselus Muma, 1953 and Selenops geraldinae Corronca, 1996 are described for the

  14. The 10 April 2014 Earthquake in Central Nicaragua: Evidence of Complex Crustal Deformation in Central America

    NASA Astrophysics Data System (ADS)

    Suarez, G.; Muñoz, A.; Talavera, E.; Tenorio, V.; Farraz, I.; Novelo-Casanova, D. A.; Sánchez, A.

    2014-12-01

    On 10 April 2014 a magnitude Mw 6.1 struck central Nicaragua. The main event and the aftershocks were clearly recorded by the Nicaraguan seismic network. These crustal earthquakes were strongly felt but caused relatively little damage to the city of Managua and to the surrounding cities and towns. This is in sharp contrast to the destructive effects of the 1972 earthquake in the capital city of Managua. The differences in damage stem from the fact that in 1972, the earthquake occurred on a fault beneath the city; in contrast, the 2014 event lies offshore, under Lake Managua. The distribution of aftershocks shows two clusters of seismic activity. In the northwestern part of Lake Managua, an alignment of aftershocks suggests a southeast trending fault. The reported source mechanism suggests right-lateral strike slip motion on a plane with the same azimuth as the aftershock sequence. A second cluster of seismic activity occurred simultaneously, but spatially separated, beneath Apoyeque volcano. There is no clear alignment of the epicenters in this cluster. Seismic scaling relations between magnitude and the fault length predict a length of approximately 10 km for an earthquake of this magnitude. This is in agreement with the extent of the fault defined by the aftershock sequence. The northeast - southwest trending Tiscapa and Ciudad Jardín faults that broke during the 1972 and 1931 Managua earthquakes are orthogonal to the fault where the 10 April earthquake occurred. This set of conjugate faults confirms that Central Nicaragua is being deformed in a complex tectonic style of deformation. The forearc sliver between the trench and the volcanic arc moves to the northwest relative to the Caribbean plate. This deformation, however, does not take place on a single set of faults. The motion is apparently accommodated by a system of conjugate faults: right lateral, strike-slip faults oriented parallel to the volcanic arc and another set of faults trending northeast

  15. SALTRA: a regional program for workers' health and sustainable development in Central America.

    PubMed

    Wesseling, Catharina; Aragón, Aurora; Elgstrand, Kaj; Flores, Reinaldo; Hogstedt, Christer; Partanen, Timo

    2011-01-01

    In 2003, the university-based Program on Work and Health in Central America, SALTRA, was launched to build national and regional capacities in occupational safety and health with the goal of preventing and reducing poverty in Central America. SALTRA has implemented 20 projects including action projects in priority sectors (e.g., construction, sugarcane, hospitals, migrant coffee workers); strengthening of surveillance (occupational health profiles, carcinogenic exposures, fatal injuries and pesticides); a participatory model for training and risk monitoring by workers; building occupational health capacity for professionals, employers, and workers, with collaborating networks between the countries; strengthening of universities in work, environment, and health; studies of serious occupational and environmental situations; communication channels; and continued efforts to raise political awareness. SALTRA has placed issues of workers' health on political, business, and academic agendas throughout the region and has laid the foundations for achieving substantial future improvements in health conditions of all workers in the region. External evaluators envisioned SALTRA as an innovative development model.

  16. Do pathogens become more virulent as they spread? Evidence from the amphibian declines in Central America.

    PubMed

    Phillips, Ben L; Puschendorf, Robert

    2013-09-01

    The virulence of a pathogen can vary strongly through time. While cyclical variation in virulence is regularly observed, directional shifts in virulence are less commonly observed and are typically associated with decreasing virulence of biological control agents through coevolution. It is increasingly appreciated, however, that spatial effects can lead to evolutionary trajectories that differ from standard expectations. One such possibility is that, as a pathogen spreads through a naive host population, its virulence increases on the invasion front. In Central America, there is compelling evidence for the recent spread of pathogenic Batrachochytrium dendrobatidis (Bd) and for its strong impact on amphibian populations. Here, we re-examine data on Bd prevalence and amphibian population decline across 13 sites from southern Mexico through Central America, and show that, in the initial phases of the Bd invasion, amphibian population decline lagged approximately 9 years behind the arrival of the pathogen, but that this lag diminished markedly over time. In total, our analysis suggests an increase in Bd virulence as it spread southwards, a pattern consistent with rapid evolution of increased virulence on Bd's invading front. The impact of Bd on amphibians might therefore be driven by rapid evolution in addition to more proximate environmental drivers.

  17. Do pathogens become more virulent as they spread? Evidence from the amphibian declines in Central America

    PubMed Central

    Phillips, Ben L.; Puschendorf, Robert

    2013-01-01

    The virulence of a pathogen can vary strongly through time. While cyclical variation in virulence is regularly observed, directional shifts in virulence are less commonly observed and are typically associated with decreasing virulence of biological control agents through coevolution. It is increasingly appreciated, however, that spatial effects can lead to evolutionary trajectories that differ from standard expectations. One such possibility is that, as a pathogen spreads through a naive host population, its virulence increases on the invasion front. In Central America, there is compelling evidence for the recent spread of pathogenic Batrachochytrium dendrobatidis (Bd) and for its strong impact on amphibian populations. Here, we re-examine data on Bd prevalence and amphibian population decline across 13 sites from southern Mexico through Central America, and show that, in the initial phases of the Bd invasion, amphibian population decline lagged approximately 9 years behind the arrival of the pathogen, but that this lag diminished markedly over time. In total, our analysis suggests an increase in Bd virulence as it spread southwards, a pattern consistent with rapid evolution of increased virulence on Bd's invading front. The impact of Bd on amphibians might therefore be driven by rapid evolution in addition to more proximate environmental drivers. PMID:23843393

  18. Phylogeny and biogeography of the Poecilia sphenops species complex (Actinopterygii, Poeciliidae) in Central America.

    PubMed

    Alda, Fernando; Reina, Ruth G; Doadrio, Ignacio; Bermingham, Eldredge

    2013-03-01

    We inferred the phylogenetic relationships among members of the Poecilia sphenops species complex to resolve the colonization process and radiation of this group in Central America. We analyzed 2550 base pairs (bp) of mitochondrial DNA (mtDNA), including ATP synthase 6 and 8, cytochrome oxidase subunit I and NADH dehydrogenase subunit 2 genes, and 906bp of the nuclear S7 ribosomal protein of 86 ingroup individuals from 61 localities spanning most of its distribution from Mexico to Panama. Our mitochondrial data rendered a well-supported phylogeny for the P. sphenops complex that differed with the nuclear data set topology, which did not recover the monophyly of the P. mexicana mitochondrial lineage. Coalescent-based simulations tests indicated that, although hybridization cannot be completely ruled out, this incongruence is most likely due to incomplete lineage sorting in this group, which also showed the widest geographic distribution. A single colonization event of Central America from South America was estimated to have occurred between the early Paleocene and Oligocene (53-22millionyears ago). Subsequently, two largely differentiated evolutionary lineages diverged around the Early Oligocene-Miocene (38-13million years ago), which are considered two separate species complexes: P. sphenops and P. mexicana, which can also be distinguished by their tricuspid and unicuspid inner jaw teeth, respectively. Ultimately, within lineage diversification occurred mainly during the Miocene (22-5million years ago). All major cladogenetic events predated the final closure of the Isthmus of Panama. The allopatric distribution of lineages together with the long basal internodes suggest that vicariance and long term isolations could be the main evolutionary forces promoting radiation in this group, although dispersal through water barriers might also have occurred. Lastly, our results suggest the need to review the current species distribution and taxonomy of the P. sphenops

  19. Phylogeny and biogeography of the Poecilia sphenops species complex (Actinopterygii, Poeciliidae) in Central America.

    PubMed

    Alda, Fernando; Reina, Ruth G; Doadrio, Ignacio; Bermingham, Eldredge

    2013-03-01

    We inferred the phylogenetic relationships among members of the Poecilia sphenops species complex to resolve the colonization process and radiation of this group in Central America. We analyzed 2550 base pairs (bp) of mitochondrial DNA (mtDNA), including ATP synthase 6 and 8, cytochrome oxidase subunit I and NADH dehydrogenase subunit 2 genes, and 906bp of the nuclear S7 ribosomal protein of 86 ingroup individuals from 61 localities spanning most of its distribution from Mexico to Panama. Our mitochondrial data rendered a well-supported phylogeny for the P. sphenops complex that differed with the nuclear data set topology, which did not recover the monophyly of the P. mexicana mitochondrial lineage. Coalescent-based simulations tests indicated that, although hybridization cannot be completely ruled out, this incongruence is most likely due to incomplete lineage sorting in this group, which also showed the widest geographic distribution. A single colonization event of Central America from South America was estimated to have occurred between the early Paleocene and Oligocene (53-22millionyears ago). Subsequently, two largely differentiated evolutionary lineages diverged around the Early Oligocene-Miocene (38-13million years ago), which are considered two separate species complexes: P. sphenops and P. mexicana, which can also be distinguished by their tricuspid and unicuspid inner jaw teeth, respectively. Ultimately, within lineage diversification occurred mainly during the Miocene (22-5million years ago). All major cladogenetic events predated the final closure of the Isthmus of Panama. The allopatric distribution of lineages together with the long basal internodes suggest that vicariance and long term isolations could be the main evolutionary forces promoting radiation in this group, although dispersal through water barriers might also have occurred. Lastly, our results suggest the need to review the current species distribution and taxonomy of the P. sphenops

  20. A review of bioinformatics training applied to research in molecular medicine, agriculture and biodiversity in Costa Rica and Central America.

    PubMed

    Orozco, Allan; Morera, Jessica; Jiménez, Sergio; Boza, Ricardo

    2013-09-01

    Today, Bioinformatics has become a scientific discipline with great relevance for the Molecular Biosciences and for the Omics sciences in general. Although developed countries have progressed with large strides in Bioinformatics education and research, in other regions, such as Central America, the advances have occurred in a gradual way and with little support from the Academia, either at the undergraduate or graduate level. To address this problem, the University of Costa Rica's Medical School, a regional leader in Bioinformatics in Central America, has been conducting a series of Bioinformatics workshops, seminars and courses, leading to the creation of the region's first Bioinformatics Master's Degree. The recent creation of the Central American Bioinformatics Network (BioCANET), associated to the deployment of a supporting computational infrastructure (HPC Cluster) devoted to provide computing support for Molecular Biology in the region, is providing a foundational stone for the development of Bioinformatics in the area. Central American bioinformaticians have participated in the creation of as well as co-founded the Iberoamerican Bioinformatics Society (SOIBIO). In this article, we review the most recent activities in education and research in Bioinformatics from several regional institutions. These activities have resulted in further advances for Molecular Medicine, Agriculture and Biodiversity research in Costa Rica and the rest of the Central American countries. Finally, we provide summary information on the first Central America Bioinformatics International Congress, as well as the creation of the first Bioinformatics company (Indromics Bioinformatics), spin-off the Academy in Central America and the Caribbean.

  1. Similarity and difference among rainforest fruit-feeding butterfly communities in Central and South America.

    PubMed

    Devries, Philip J; Alexander, Laura G; Chacon, Isidro A; Fordyce, James A

    2012-03-01

    1. Documenting species abundance distributions in natural environments is critical to ecology and conservation biology. Tropical forest insect faunas vary in space and time, and these partitions can differ in their contribution to overall species diversity. 2. In the Neotropics, the Central American butterfly fauna is best known in terms of general natural history, but butterfly community diversity is best documented by studies on South American fruit-feeding butterflies. Here, we present the first long-term study of fruit-feeding nymphalid species diversity from Central America and provide a unique comparison between Central and South American butterfly communities. 3. This study used 60 months of sampling among multiple spatial and temporal partitions to assess species diversity in a Costa Rican rainforest butterfly community. Abundance distributions varied significantly at the species and higher taxonomic group levels, and canopy and understorey samples were found to be composed of distinct species assemblages. 4. Strong similarities in patterns of species diversity were found between this study and one from Ecuador; yet, there was an important difference in how species richness was distributed in vertical space. In contrast to the Ecuadorian site, Costa Rica had significantly higher canopy richness and lower understorey richness. 5. This study affirms that long-term sampling is vital to understanding tropical insect species abundance distributions and points to potential differences in vertical structure among Central and South American forest insect communities that need to be explored.

  2. Using Seismic Observations and Modeling to Place Constraint on the Structure Beneath Japan and Central America

    NASA Astrophysics Data System (ADS)

    Long, Hui

    Understanding Earth's internal structure by seismic observations, both temporally and spatially, is key in seismology. In this thesis, I constrained structural changes beneath the Japan subduction zone based on a newly developed theory, and detailed mid to lower mantle structure beneath Central America by waveform and travel time observations and modeling. A newly developed theory states that the differential wave field of two repeated sources in a temporally changed medium can be equivalently treated as wave fields propagating from virtual point sources or volumetric sources. The virtual point sources or volumetric sources are located at the place of temporal changes, and their strengths are equal to the product of magnitude of medium property change and magnitude of the initial wave fields from the repeated sources. Applying the theory to the Japan subduction zone, we then locate the temporal change of seismic properties beneath this area between 2011 and 2013 to be at (37.2°N,142°E), and estimate the magnitude of the conceptual body force associated with the temporal change to be 1.15x10. 10N, or as a reference, a 0.87% density change for an assumed volume of temporal change of 10. 3 km3. Seismic waveform and travel time observations sampling the mid to lower mantle beneath Central America are analyzed and modeled. Waveform observations show complex reflection phases and exhibit significant variations with azimuth and distance, and travel time analyses show increasing S residuals of up to 9 seconds as distance increases from 45° to 80°. Forward waveform and travel time modeling reveals that several sub-horizontal 10-20 km thick segments with -10% shear wave velocity perturbation are buried inside a "trapezoid-like" low velocity region with -2% shear wave velocity perturbation extending between 1000 and 2750 km depth. In addition, analyses of the ScSH-SH and PcP-P differential travel time residuals suggest a structural transition in the lowermost mantle

  3. Central America Field Epidemiology Training Program (CA FETP): a pathway to sustainable public health capacity development.

    PubMed

    López, Augusto; Cáceres, Victor M

    2008-01-01

    The Central America Field Epidemiology Training Program (CA FETP) is a public health capacity-building training programme aimed at developing high-caliber field epidemiologists at various levels of the public health system. It began in 2000 as part of the effort to rebuild public health infrastructure in six Central American and Caribbean countries following the devastation of Hurricanes Mitch and Georges in late 1998. Since then, the CA FETP has evolved from one regional training programme managed by CDC to several national FETPs with each country assuming ownership of its domestic programme. The curriculum is competency-based, and is divided into a three-tiered training pyramid that corresponds to the needs at the local, district and central levels of the health system. Trainees at each tier spend about 20% of their time in the classroom and 80% in the field implementing what they have learned while being mentored by graduates of the programme. FETP trainees have responded to multiple natural disasters and conducted hundreds of investigations including surveillance evaluations, outbreak responses and planned studies. Also graduates of the CA FETP are assuming influential positions in their respective ministries. As countries meet the challenge of institutionalizing their programmes, the CA FETP concept will increasingly be recognized as a model for sustainable public health capacity development.

  4. Multi-year GNSS monitoring of atmospheric IWV over Central and South America for climate studies

    NASA Astrophysics Data System (ADS)

    Bianchi, Clara Eugenia; Mendoza, Luciano Pedro Oscar; Fernández, Laura Isabel; Natali, María Paula; Meza, Amalia Margarita; Francisco Moirano, Juan

    2016-07-01

    Atmospheric water vapour has been acknowledged as an essential climate variable. Weather prediction and hazard assessment systems benefit from real-time observations, whereas long-term records contribute to climate studies. Nowadays, ground-based global navigation satellite system (GNSS) products have become widely employed, complementing satellite observations over the oceans. Although the past decade has seen a significant development of the GNSS infrastructure in Central and South America, its potential for atmospheric water vapour monitoring has not been fully exploited. With this in mind, we have performed a regional, 7-year-long and homogeneous analysis, comprising 136 GNSS tracking stations, obtaining high-rate and continuous observations of column-integrated water vapour and troposphere zenith total delay. As a preliminary application for this data set, we have estimated local water vapour trends, their significance, and their relation with specific climate regimes. We have found evidence of drying at temperate regions in South America, at a rate of about 2 % per decade, while a slow moistening of the troposphere over tropical regions is also weakly suggested by our results. Furthermore, we have assessed the regional performance of the empirical model GPT2w to blindly estimate troposphere delays. The model reproduces the observed mean delays fairly well, including their annual and semi-annual variations. Nevertheless, a long-term evaluation has shown systematical biases, up to 20 mm, probably inherited from the underlying atmospheric reanalysis. Additionally, the complete data set has been made openly available as supplementary material.

  5. Consensus between genes and stones in the biogeographic and evolutionary history of Central America

    NASA Astrophysics Data System (ADS)

    Gutiérrez-García, Tania Anaid; Vázquez-Domínguez, Ella

    2013-05-01

    Results from genetic and geologic studies can be combined to elucidate some general patterns of the biogeographic and evolutionary history of Central America (CA) and of its biota. Based on an ample review of geologic, biogeographic and genetic studies, our aim was to examine how common genetic patterns can be linked with geologic processes. Considering information about geologic and tectonic evolution of CA, we subdivided the region into four tectonic blocks: Maya, Chortis, Chorotega and Chocó. Species exchange between North/South America and CA encompasses three events: a first migration during the Late Cretaceous-Early Paleocene, a second through a terrestrial corridor preceding the formation of the Isthmus of Panama (IP), and the third involving a major dispersion through the IP. Such events caused similar genetic differentiation patterns and left a signature on the diversification of extant taxa, which we propose as three evolutionary groups: 1) Mayan, characterized by marked genetic structure and divergence, multiple refugia and formation of cryptic species; 2) Mid-CA, defined by high differentiation at the population level and between highland and lowlands, associated with intense volcanic activity; 3) Panamian, distinguished by migration from north to south and vice versa via de IP, with markedly high species divergence and speciation.

  6. Suitability of soil bioengineering techniques in Central America: a case study in Nicaragua

    NASA Astrophysics Data System (ADS)

    Petrone, A.; Preti, F.

    2008-02-01

    In the last few years "D. I. A. F." (Department of Agriculture and Forestry Engineering of Florence University), has been testing the effectiveness of Soil Bio-Engineering techniques in Central America. The focus of the present study was to find out which native plants were most suited for soil bio-engineering purposes, particularly in the realization of riverbank protection. Furthermore, we have also been aiming at economic efficiency. In the context of sustainable watershed management, these techniques seem to be appropriate, especially in underdeveloped countries. Concerning the plants to be used, we considered three native species, Gliricidia Sepium, Cordia dentata and Jatropha curcas, to be appropriate for this type of work. Economically speaking, the low cost of such interventions in underdeveloped countries, has been shown by the construction of riverbank protection using vegetated crib-walls in Nicaragua.

  7. Suitability of soil bioengineering techniques in Central America: a case study in Nicaragua

    NASA Astrophysics Data System (ADS)

    Petrone, A.; Preti, F.

    2008-10-01

    In the last few years "D. I. A. F." (Department of Agriculture and Forestry Engineering of Florence University), has been testing the effectiveness of soil bioengineering techniques in Central America. The focus of the present study was to find out which native plants were most suited for soil bioengineering purposes, particularly in the realization of riverbank protection in Nicaragua. Furthermore, we have also been aiming at economic efficiency. These techniques are appropriate for sustainable watershed management especially in underdeveloped countries. Concerning the plants to be used we experimented four native species. Gliricidia Sepium, Cordia dentata and Jatropha curcas are suitable for soil bioengineering more than Bursera Simaruba. Economically speaking, the sustainability of such interventions in underdeveloped countries, has been shown by the evaluation of the cost of riverbank protection using vegetated crib-walls in Nicaragua compared to the cost in different contexts.

  8. First record of the invasive Asian fish tapeworm Bothriocephalus acheilognathi in Honduras, Central America

    PubMed Central

    Salgado-Maldonado, Guillermo; Matamoros, Wilfredo A.; Kreiser, Brian R.; Caspeta-Mandujano, Juan Manuel; Mendoza-Franco, Edgar F.

    2015-01-01

    This paper provides the first report of the invasive Asian fish tapeworm, Bothriocephalus acheilognathi Yamaguti, 1934, in Honduras. The cestode was found in Profundulus portillorum (Cyprinodontiformes: Profundulidae), which represents a new host record, and which is a member of a genus faced with a variety of conservation challenges, now potentially complicated by the presence of this pathogenic cestode. Nearly complete sequence data from the ITS-1 5.8S and ITS-2 regions corroborate the determination based on morphological characteristics. Several species of carp were introduced to Honduras for aquaculture purposes in the early 1980s and the presence of the Asian fish tapeworm in Honduras may be related to these introductions. In addition, this report documents the currently known geographical distribution of this parasite in Central America, first recorded from Panamá and now from Honduras. PMID:25654444

  9. Screening of anti-bacterial activity of medicinal plants from Belize (Central America).

    PubMed

    Camporese, A; Balick, M J; Arvigo, R; Esposito, R G; Morsellino, N; De Simone, F; Tubaro, A

    2003-07-01

    Twenty-one extracts from seven herbal drugs, Aristolochia trilobata (Aristolochiaceae) leaves and bark, Bursera simaruba (Burseraceae) bark, Guazuma ulmifolia (Sterculiaceae) bark, Hamelia patens (Rubiaceae) leaves and Syngonium podophyllum (Araceae) leaves and bark, used in traditional medicine of Belize (Central America) as deep and superficial wound healers, were evaluated for their anti-bacterial properties. Activity was tested against standard strains of Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212. Almost all the extracts were able to inhibit the growth of one or more of the bacterial strains, except that of Enterococcus faecalis. For the first time an anti-microbial activity is reported for Aristolochia trilobata as well as for Syngonium podophyllum. The hexane extracts of Aristolochia trilobata leaves and bark were the most active extracts against Staphylococcus aureus (MIC=0.31 and 0.625mg/ml, respectively).

  10. The genus Cephaloleia (Coleoptera:Chrysomelidae) in Central America and the West Indies.

    PubMed

    Staines, C L

    1996-01-01

    The species of Cephaloleia Chevrolat known to occur in Central America and the West Indies are revised and a key to the 88 species is presented. Most species are illustrated. Twenty new species of Cephaloleia are described: amblys, cylindrica, eumorpha, erugatus, facetus, formosus, lepida, scitulus, and weisei from Panamá; delectabilis and presignis from México; brunnea and rubra from Trinidad; immaculata, triangularis, and viltata from Costa Rica; splendida and uhmanni from Costa Rica and Panamá; cyanea from Costa Rica, Colombia, and Venezuela; and varabilis from Panamá and Colombia. Three new synonyms are given: abscissa Uhmann (= dilaticollis Baly), beckeri Weise (= gratiosa Baly), and quadrimaculata Uhmann (= fenestrata Weise). Lectotypes are designated for eleven species: belti Baly, consanguinea Baly, elegantula Baly, fulvicollis Weise, instabilis Baly, nigropicta Baly, postuma Weise, quadrilineata Baly, separata Baly, stenosoma Baly, and vicina Baly. Two species are transferred from Demotispa to Cephaloleia: coeruleata Sanderson and costaricensis Uhmann. Cephaloleia coeruleata (Sanderson) is renamed C. sandersoni.

  11. [Thysanopterans of the generic group Anaphothrips (Thripidae: Thripinae) with emphasis in Central America].

    PubMed

    Retana-Salazar, Axel P

    2007-03-01

    A taxonomic revision and phylogenetic analysis of the generic group Anaphothrips are presented. Several genera in Central America are closely related to this generic group. Based on the analysis of characters and its possible evolution, the new genus Nakaharathrips has been segregated from Anaphothrips, and the taxonomic status of the subspecies of Aurantothrips has been changed to the species level. The phylogenetic analysis shows a close relationship between the genera Anaphothrips, Ranjana, Nakaharathrips n.gen., Aurantothrips, Nicolemma n.gen., Ameranathrips, Baileyothrips and Gonzalezya n.gen., where the first lineage is formed by the genera (Ranjana (Aurantothrips+Nicolemma)) and the second lineage contains the genera [(Anaphothrips+Nakaharathrips)(Baileyothrips (Ameranathrips+Gonzalezya)]. PMID:18457141

  12. New species and records of Charisius Champion from Mexico and Central America (Coleoptera, Tenebrionidae, Alleculinae)

    PubMed Central

    Campbell, J. M.

    2014-01-01

    Abstract The species of the genus Charisius Champion, from Mexico and Central America are reviewed. The flightless genus Narses Champion, with one included species, N. subalatus Champion, is placed in synonymy with the genus Charisius. Four new species are described and illustrated, C. granulatus and C. punctatus (from Guatemala) and C. apterus and C. howdenorum (from Mexico). Charisius subalatus (Champion) is redescribed and illustrated. The species C. interstitialis Champion is placed in synonymy with C. zunilensis Champion. The genus is redescribed to include the four new species and N. subalatus. New distributional records are presented for all other species of the genus and a revised key is presented for identification of all the species of the genus. PMID:25009430

  13. First record of the invasive Asian fish tapeworm Bothriocephalus acheilognathi in Honduras, Central America.

    PubMed

    Salgado-Maldonado, Guillermo; Matamoros, Wilfredo A; Kreiser, Brian R; Caspeta-Mandujano, Juan Manuel; Mendoza-Franco, Edgar F

    2015-01-01

    This paper provides the first report of the invasive Asian fish tapeworm, Bothriocephalus acheilognathi Yamaguti, 1934, in Honduras. The cestode was found in Profundulus portillorum (Cyprinodontiformes: Profundulidae), which represents a new host record, and which is a member of a genus faced with a variety of conservation challenges, now potentially complicated by the presence of this pathogenic cestode. Nearly complete sequence data from the ITS-1 5.8S and ITS-2 regions corroborate the determination based on morphological characteristics. Several species of carp were introduced to Honduras for aquaculture purposes in the early 1980s and the presence of the Asian fish tapeworm in Honduras may be related to these introductions. In addition, this report documents the currently known geographical distribution of this parasite in Central America, first recorded from Panamá and now from Honduras.

  14. Open Skies aerial photography of selected areas in Central America affected by Hurricane Mitch

    USGS Publications Warehouse

    Molnia, Bruce; Hallam, Cheryl A.

    1999-01-01

    Between October 27 and November 1, 1998, Central America was devastated by Hurricane Mitch. Following a humanitarian relief effort, one of the first informational needs was complete aerial photographic coverage of the storm ravaged areas so that the governments of the affected countries, the U.S. agencies planning to provide assistance, and the international relief community could come to the aid of the residents of the devastated area. Between December 4 and 19, 1998 an Open Skies aircraft conducted five successful missions and obtained more than 5,000 high-resolution aerial photographs and more than 15,000 video images. The aerial data are being used by the Reconstruction Task Force and many others who are working to begin rebuilding and to help reduce the risk of future destruction.

  15. A new species of arboreal pitviper from the Atlantic versant of northern Central America.

    PubMed

    Campbell, J A; Smith, E N

    2000-12-01

    A new species of green, prehensile-tailed pitviper of the genus Bothriechis is described from the Atlantic slopes of eastern Guatemala and western Honduras. This species appears to be most closely related to B. bicolor of the Pacific versant of Chiapas (Mexico) and Guatemala. Several other species of Bothriechis occur on the Atlantic versant of northern Central America, including two montane species, B. aurifer and B. marchi but, with one possible exception, these are not known to be sympatric with the new species and occur in different mountain ranges. The widespread B. schlegelii occurs up to at least 900 m on the Sierra de Caral, where the lowest elevation recorded for the new species is 885 m. PMID:11487920

  16. A new species of Leptoderma Vaillant, 1886 (Osmeriformes: Alepocephalidae) from the Pacific coast of Central America.

    PubMed

    Angulo, Arturo; Baldwin, Carole C; Robertson, D Ross

    2016-01-01

    A new species of Leptoderma Vaillant, 1886 is described from a single specimen trawled at 1368-1406 m depth off El Salvador, Central America, tropical eastern Pacific. Leptoderma ospesca n. sp. can be readily distinguished from its congeners by the following combination of characters: dermal papillae absent along the lateral line, pectoral-fin rays 6, pelvic-fin rays 5, pre-dorsal length 54.9% of SL, both dorsal and anal fins separated from the caudal fin, dorsal- and anal-fin rays long, procurrent caudal-fin rays numerous and extending far forward on caudal peduncle, caudal-fin rays 16, and total pre-ural vertebrae 60. A key to the species of the genus is presented. PMID:27395850

  17. Seismicity at Fuego, Pacaya, Izalco, and San Cristobal Volcanoes, Central America, 1973-1974

    USGS Publications Warehouse

    McNutt, S.R.; Harlow, D.H.

    1983-01-01

    Seismic data collected at four volcanoes in Central America during 1973 and 1974 indicate three sources of seismicity: regional earthquakes with hypocentral distances greater than 80 km, earthquakes within 40 km of each volcano, and seismic activity originating at the volcanoes due to eruptive processes. Regional earthquakes generated by the underthrusting and subduction of the Cocos Plate beneath the Caribbean Plate are the most prominent seismic feature in Central America. Earthquakes in the vicinity of the volcanoes occur on faults that appear to be related to volcano formation. Faulting near Fuego and Pacaya volcanoes in Guatemala is more complex due to motion on a major E-W striking transform plate boundary 40 km north of the volcanoes. Volcanic activity produces different kinds of seismic signatures. Shallow tectonic or A-type events originate on nearby faults and occur both singly and in swarms. There are typically from 0 to 6 A-type events per day with b value of about 1.3. At very shallow depths beneath Pacaya, Izalco, and San Cristobal large numbers of low-frequency or B-type events are recorded with predominant frequencies between 2.5 and 4.5 Hz and with b values of 1.7 to 2.9. The relative number of B-type events appears to be related to the eruptive states of the volcanoes; the more active volcanoes have higher levels of seismicity. At Fuego Volcano, however, low-frequency events have unusually long codas and appear to be similar to tremor. High-amplitude volcanic tremor is recorded at Fuego, Pacaya, and San Cristobal during eruptive periods. Large explosion earthquakes at Fuego are well recorded at five stations and yield information on near-surface seismic wave velocities (??=3.0??0.2 km/sec.). ?? 1983 Intern. Association of Volcanology and Chemistry of the Earth's Interior.

  18. A Dynamic Model for Rainfall-Triggered Landslides in Central America

    NASA Astrophysics Data System (ADS)

    Simmons, J. M. D.

    2014-12-01

    Rainfall-triggered landslides are a consistent threat to life and property around the world and are extremely challenging to physically model over large areas. The Dynamic Landslide Assessment model combines a static landslide susceptibility map with a decision tree approach that considers satellite-derived rainfall and soil moisture thresholds to designate landslide "warning" or null value for the evaluated pixel. This model is used in order to facilitate the development and implementation of an online landslide 'nowcast' system for the region of Central America. For initial diagnostics, receiver operating characteristic (ROC) curves were generated from a 3-year model run of 125 landslide points in Central America. To optimize the threshold necessary to trigger a landslide, normalized rainfall was evaluated against landslide occurrence in each model run and the True Positive Rates (TPR) and False Positive Rates (FPR) recorded. Each curve is evaluated against other instances by locating the minimum distance from a perfect fit (TPR = 1and FPR = 0) on a calculated ROC curve. The preliminary runs of the model are promising; the smallest R value is associated with a TPR of 0.79 and a FPR of 0.21. In addition, the inclusion of soil moisture data improves the skill of the model when rainfall is considered within a temporal window of a single day. However, consideration of larger precipitation windows (e.g. 3-day) somewhat diminishes the effectiveness of the inclusion of soil moisture data. Nevertheless, the simplicity of the model will continue to facilitate evaluation and inclusion of new data sources and metrics, as well as rapid integration of the model components within the developing online system.

  19. GIS Representation of Coal-Bearing Areas in North, Central, and South America

    USGS Publications Warehouse

    Tewalt, Susan J.; Kinney, Scott A.; Merrill, Matthew D.

    2008-01-01

    Worldwide coal consumption and international coal trade are projected to increase in the next several decades (Energy Information Administration, 2007). A search of existing literature indicates that in the Western Hemisphere, coal resources are known to occur in about 30 countries. The need exists to be able to depict these areas in a digital format for use in Geographic Information System (GIS) applications at small scales (large areas) and in visual presentations. Existing surficial geology GIS layers of the appropriate geologic age have been used as an approximation to depict the extent of coal-bearing areas in North, Central, and South America, as well as Greenland (fig. 1). Global surficial geology GIS data were created by the U.S. Geological Survey (USGS) for use in world petroleum assessments (Hearn and others, 2003). These USGS publications served as the major sources for the selection and creation of polygons to represent coal-bearing areas. Additional publications and maps by various countries and agencies were also used as sources of coal locations. GIS geologic polygons were truncated where literature or hardcopy maps did not indicate the presence of coal. The depicted areas are not adequate for use in coal resource calculations, as they were not adjusted for geologic structure and do not include coal at depth. Additionally, some coal areas in Central America could not be represented by the mapped surficial geology and are shown only as points based on descriptions or depictions from scientific publications or available maps. The provided GIS files are intended to serve as a backdrop for display of coal information. Three attributes of the coal that are represented by the polygons or points include geologic age (or range of ages), published rank (or range of ranks), and information source (published sources for age, rank, or physical location, or GIS geology base).

  20. Seismic hazard map of North and Central America and the Caribbean

    USGS Publications Warehouse

    Shedlock, K.M.

    1999-01-01

    Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. National, state, and local government, decision makers, engineers, planners, emergency response organizations, builders, universities, and the general public require seismic hazard estimates for land use planning, improved building design and construction (including adoption of building construction codes), emergency response preparedness plans, economic forecasts, housing and employment decisions, and many more types of risk mitigation. The seismic hazard map of North and Central America and the Caribbean is the concatenation of various national and regional maps, involving a suite of approaches. The combined maps and documentation provide a useful regional seismic hazard framework and serve as a resource for any national or regional agency for further detailed studies applicable to their needs. This seismic hazard map depicts Peak Ground Acceleration (PGA) with a 10% chance of exceedance in 50 years. PGA, a short-period ground motion parameter that is proportional to force, is the most commonly mapped ground motion parameter because current building codes that include seismic provisions specify the horizontal force a building should be able to withstand during an earthquake. This seismic hazard map of North and Central America and the Caribbean depicts the likely level of short-period ground motion from earthquakes in a fifty-year window. Short-period ground motions effect short-period structures (e.g., one-to-two story buildings). The highest seismic hazard values in the region generally occur in areas that have been, or are likely to be, the sites of the largest plate boundary earthquakes.

  1. Mercury in Forage Fish from Mexico and Central America: Implications for Fish-Eating Birds.

    PubMed

    Elliott, John E; Kirk, David A; Elliott, Kyle H; Dorzinsky, Jessica; Lee, Sandi; Inzunza, Ernesto Ruelas; Cheng, Kimberly M T; Scheuhammer, Tony; Shaw, Patrick

    2015-11-01

    Mercury (Hg) is a global contaminant of aquatic food chains. Aquatic birds, such as the osprey (Pandion haliaetus), with migratory populations breeding in Canada and the northern United States and wintering in the Central and South America, can be exposed to mercury on both the breeding and wintering ranges. We examined Hg levels in 14 fish taxa from 24 osprey wintering sites identified from satellite telemetry. Our main goal was to determine whether fish species that feature in the diet of overwintering and resident fish-eating birds reached toxicity thresholds for Hg. Mean Hg levels in fish whole carcasses ranged from a high of 0.18 µg g(-1) (wet weight) in Scomberomorus sierra to a low of 0.009 µg g(-1) in Catostomidae. Average Hg levels were within published toxicity threshold values in forage fish for only two sites in Mexico (Puerto Vallarta and San Blas Estuary), and all were marine species, such as mackerel (Scomberomorus sierra), sea catfish (Ariopus spp.), and sardinas species (Centropomus spp.). Except for one sample from Nicaragua, sea catfish from Puerto Morazan, none of the fish from sites in Central America had Hg levels which exceeded the thresholds. Nonmetric multidimensional scaling revealed geographical differences in Hg levels with significant pairwise differences between sites along the Pacific Ocean (Mexico) versus the Bay of Campeche, partly due to differences in species composition of sampled fish (and species distributions). Hg increased with trophic level, as assessed by nitrogen stable isotope ratios (δ(15)N but not δ(13)C), in freshwater and marine, but not estuarine, environments. Hg concentrations in forage fish do not account for the elevated Hg reported for many osprey populations on the breeding grounds, thus primary sources of contamination appear to be in the north.

  2. A five-year analysis of MODIS NDVI and NDWI for grassland drought assessment over the central Great Plains of the United States

    NASA Astrophysics Data System (ADS)

    Gu, Yingxin; Brown, Jesslyn F.; Verdin, James P.; Wardlow, Brian

    2007-03-01

    A five-year (2001-2005) history of moderate resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) data was analyzed for grassland drought assessment within the central United States, specifically for the Flint Hills of Kansas and Oklahoma. Initial results show strong relationships among NDVI, NDWI, and drought conditions. During the summer over the Tallgrass Prairie National Preserve, the average NDVI and NDWI were consistently lower (NDVI < 0.5 and NDWI < 0.3) under drought conditions than under non-drought conditions (NDVI>0.6 and NDWI>0.4). NDWI values exhibited a quicker response to drought conditions than NDVI. Analysis revealed that combining information from visible, near infrared, and short wave infrared channels improved sensitivity to drought severity. The proposed normalized difference drought index (NDDI) had a stronger response to summer drought conditions than a simple difference between NDVI and NDWI, and is therefore a more sensitive indicator of drought in grasslands than NDVI alone.

  3. Catalogo General de Universidades, 1970-1971: Federacion de Universidades Privadas de America Central y Panama (General Catalog of Universities, 1970-1971: Federation of Private Universities of Central America and Panama).

    ERIC Educational Resources Information Center

    Federacion de Universidades Privadas de America Central y Panama, Guatemala City (Guatemala).

    This document contains the 1970-1971 catalogues of five universities belonging to the Federation of Private Universities of Central America and Panama (FUPAC). The catalogues provide information on university administrators and staff, historical background, admission requirements, degree programs, scholarships, and courses. The catalogues included…

  4. [MODIS Investigation

    NASA Technical Reports Server (NTRS)

    Abbott, Mark R.

    1996-01-01

    Our first activity is based on delivery of code to Bob Evans (University of Miami) for integration and eventual delivery to the MODIS Science Data Support Team. As we noted in our previous semi-annual report, coding required the development and analysis of an end-to-end model of fluorescence line height (FLH) errors and sensitivity. This model is described in a paper in press in Remote Sensing of the Environment. Once the code was delivered to Miami, we continue to use this error analysis to evaluate proposed changes in MODIS sensor specifications and performance. Simply evaluating such changes on a band by band basis may obscure the true impacts of changes in sensor performance that are manifested in the complete algorithm. This is especially true with FLH that is sensitive to band placement and width. The error model will be used by Howard Gordon (Miami) to evaluate the effects of absorbing aerosols on the FLH algorithm performance. Presently, FLH relies only on simple corrections for atmospheric effects (viewing geometry, Rayleigh scattering) without correcting for aerosols. Our analysis suggests that aerosols should have a small impact relative to changes in the quantum yield of fluorescence in phytoplankton. However, the effect of absorbing aerosol is a new process and will be evaluated by Gordon.

  5. Phylogeny and biogeography of Poecilia (Cyprinodontiformes: Poeciliinae) across Central and South America based on mitochondrial and nuclear DNA markers.

    PubMed

    Ho, Adeljean L F C; Pruett, Christin L; Lin, Junda

    2016-08-01

    Poeciliids are a diverse group of small Neotropical fishes, and despite considerable research attention as models in ecology and evolutionary biology, our understanding of their biogeographic and phylogenetic relationships is still limited. We investigated the phylogenetic relationships of South and Central American Poecilia, by examining 2395 base pairs of mitochondrial DNA (ATPase 8/6, COI) and nuclear DNA (S7) for 18 species across six subgenera. Fifty-eight novel sequences were acquired from newly collected specimens and 20 sequences were obtained from previously published material. Analyses of concatenated and partitioned mitochondrial DNA and nuclear DNA sets resulted in a well-supported phylogeny that resolved several monophyletic groups corresponding to previously hypothesized subgenera and species complexes. A divergence-dating analysis supported the hypothesis of the genus Poecilia dispersing into Central America in the early Pliocene (ancestors of Psychropoecilia+Allopoecilia+Mollienesia: 7.3-2.0Mya) from predominantly South America. Subsequently, one lineage (subgenus Allopoecilia: 5.1-1.3Mya) expanded deeper into South America from Lower-Central America, and one lineage expanded from Nuclear-Central America into South America (subgenus Mollienesia: 0.71-0.14Mya). The subgenus Mollienesia diverged into three monophyletic groups that can be identified by nuptial male dorsal fin morphology and inner jaw dentition. A subclade of the unicuspid short-fins (subgenus Mollienesia) was the lineage that expanded into South America during the middle Pleistocene. Species in this subclade are now distributed across northern South America, where they are partially sympatric with Allopoecilia. However the P. (A.) caucana complex was not monophyletic, with P. (A.) wandae clustering in the Mollienesia subclade that expanded into South America. It is apparent that characters (body size, scale count, pigmentation, and gonopodium morphology) used to define the P. (A

  6. Molecular genotyping of Toxoplasma gondii from Central and South America revealed high diversity within and between populations.

    PubMed

    Rajendran, C; Su, C; Dubey, J P

    2012-03-01

    Recent population studies revealed that a few major clonal lineages of Toxoplasma gondii dominate in different geographical regions. The Type II and III lineages are widespread in all continents and dominate in Europe, Africa and North America. In addition, the type 12 lineage is the most common type in wildlife in North America, the Africa 1 and 3 are among the major types in Africa, and ToxoDB PCR-RFLP #9 is the major type in China. Overall the T. gondii strains are more diverse in South America than any other regions. Here, we analyzed 164 T. gondii isolates from three countries in Central America (Guatemala, Nicaragua, Costa Rica), from one country in Caribbean (Grenada) and five countries from South America (Venezuela, Colombia, Peru, Chile, and Argentina). The multilocous polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) based genotyping of 11 polymorphic markers (SAG1, SAG2, alt.SAG2, SAG3, BTUB, GRA6, L358, PK1, C22-8, C29-2 and Apico) were applied to 148 free-range chicken (Gallus domesticus) isolates and 16 isolates from domestic cats (Felis catus) in Colombia; 42 genotypes were identified. Linkage disequilibrium analysis indicated more frequent genetic recombination in populations of Nicaragua and Colombia, and to a lesser degree in populations of Costa Rica and Argentina. Bayesian structural analysis identified at least three genetic clusters, and phylogenetic network analysis identified four major groups. The ToxoDB PCR-RFLP #7, Type III and II were major lineages identified from Central and South America, with high frequencies of the closely related ToxoDB PCR-RFLP #7 and Type III lineages. Taken together, this study revealed high diversity within and between T. gondii populations in Central and South America, and the dominance of Type III and its closely related ToxoDB PCR-RFLP #7 lineages.

  7. Characterization of Anopheles darlingi (Diptera: Culicidae) larval habitats in Belize, Central America

    NASA Technical Reports Server (NTRS)

    Manguin, S.; Roberts, D. R.; Andre, R. G.; Rejmankova, E.; Hakre, S.

    1996-01-01

    Surveys for larvae of Anopheles darlingi Root were conducted in April, May, and August 1994 in riverine habitats of central Belize (Cayo and Belize districts). An. darlingi was present during both the dry and wet seasons. Larvae were encountered most frequently in patches of floating debris along river margins. The floating mats were often formed by bamboo hanging over the banks and dense submersed bamboo roots. Larvae were found less frequently in lake margins, small lagoons, and ground pools with submersed roots and patches of floating leaves or vegetation. In addition to their association with floating debris, larvae of An. darlingi were associated positively with shade and submersed plants in riverine environments. Samples from river habitats showed the larvae of Anopheles albimanus Wiedemann to be strongly associated with sun-exposed sites containing green or blue-green algae. Unlike An. darlingi, An. albimanus was an ubiquitous mosquito, the immatures of which occurred in a wide variety of riverine and nonriverine aquatic habitats. Based on published reports and our experience, the association of An. darlingi with river systems was verified, and its distribution in Central America and Mexico was mapped.

  8. Geoid modeling in Mexico and the collaboration with Central America and the Caribbean.

    NASA Astrophysics Data System (ADS)

    Avalos, D.; Gomez, R.

    2012-12-01

    The model of geoidal heights for Mexico, named GGM10, is presented as a geodetic tool to support vertical positioning in the context of regional height system unification. It is a purely gravimetric solution computed by the Stokes-Helmert technique in resolution of 2.5 arc minutes. This product from the Instituto Nacional de Estadistica y Geografia (INEGI) is released together with a series of 10 gravimetric models which add to the improvements in description of the gravity field. In the recent years, the INEGI joined the initiative of the U.S. National Geodetic Survey and the Canada's Geodetic Survey Division to promote the regional height system unification. In an effort to further improve the compatibility among national geoid models in the region, the INEGI has begun to champion a network of specialists that includes national representatives from Central America and the Caribbean. Through the opening of opportunities for training and more direct access to international agreements and discussions, the tropical region is gaining participation. Now a significantly increased number of countries is pushing for a future North and Central American geoid-based vertical datum as support of height system unification.eoidal height in Mexico, mapped from the model GGM10.

  9. Controls on the fore-arc CO2 flux along the Central America margin

    NASA Astrophysics Data System (ADS)

    Hilton, D. R.; Barry, P. H.; Ramirez, C. J.; Kulongoski, J. T.; Patel, B. S.; Virrueta, C.; Blackmon, K.

    2015-12-01

    The subduction of carbon to the deep mantle via subduction zones is interrupted by outputs via the fore-arc, volcanic front, and back-arc regions. Whereas output fluxes for arc and back-arc locales are well constrained for the Central America Volcanic Arc (CAVA) [1-2], the fore-arc flux via cold seeps and ground waters is poorly known. We present new He and CO2 data (isotopes and relative abundances) for the volcanic front and inner fore-arc of western Panama to complement on-going studies of fore-arc C-fluxes in Costa Rica [3-4] and to determine tectonic controls on the fore-arc C-outgassing fluxes. Helium isotope (3He/4He) values at Baru, La Yeguada, and El Valle volcanoes are high (5-8RA), consistent with results for other Central America volcanoes. However, CO2/3He values are variable (from > 1012 to < 108). Baru has an arc-like δ13C of - 4‰, whereas the other volcanoes have δ13C < -10 ‰. Cold seeps collected in the coastal fore-arc of Panama show a trend of decreasing He-isotopes from west (~6RA) to east (~1RA). This trend is mirrored by δ13C (-5‰ to <-20‰) values. CO2/3He values of the seeps are also variable and fall between 106 and 1012. Using CO2/3He-δ13C mixing plots with conventional endmember values for Limestone, Organic Sediment and Mantle CO2, we show that several Panama samples have been extensively modified by crustal processes. Nevertheless, there are clear west-to east trends (both volcanoes and coastal seeps), whereby L dominates the CO2 inventory in the west, similar to Costa Rica, and S-derived CO2 increases eastward towards central Panama. Previously [4], we limited the Costa Rica subaerial fore-arc flux to ~ 6 × 107 gCkm-1yr-1, or ~ 4% of the total incoming sedimentary C-load. This flux diminishes to zero within ~400 km to the east of Baru volcano. The transition from orthogonal subduction of the Cocos Plate to oblique subduction of the Nazca Plate, relative to the common over-riding Caribbean Plate, is the major impediment to

  10. 77 FR 9724 - Request for Petitions To Modify the Rules of Origin Under the Dominican Republic-Central America...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-17

    ... TRADE REPRESENTATIVE Request for Petitions To Modify the Rules of Origin Under the Dominican Republic...-apparel products rules of origin under the Dominican Republic--Central America--United States Free Trade... Agreement's origin rules. In the United States, those rules are implemented through the Dominican...

  11. 77 FR 51828 - Dominican Republic-Central America-United States Free Trade Agreement; Notice of Extension of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-27

    ... of the Secretary Dominican Republic--Central America--United States Free Trade Agreement; Notice of Extension of the Period of Review for Submission 2011-03 (Dominican Republic) AGENCY: Bureau of... Dominican Republic (the Submission) filed under Chapter Sixteen (the Labor Chapter) of the...

  12. In the Shadow of the Cold War: The Caribbean and Central America in U.S. Foreign Policy.

    ERIC Educational Resources Information Center

    Malkasian, Mark; Davidson, Louise K.

    With the improvement of U.S.-Soviet relations in recent years, there is much reason to take a fresh look at U.S. foreign policy. This unit provides secondary students with an opportunity to examine U.S. policy toward the Caribbean and Central America. Composed of four chapters, the first chapter examines the economic and military concerns that…

  13. A Popular Education Handbook. An Educational Experience Taken from Central America and Adapted to the Canadian Context.

    ERIC Educational Resources Information Center

    Arnold, Rick; Burke, Bev

    In this booklet two members of a Canadian educational development organization share their experiences during 1983 in trying to adapt the popular education they had experienced in Central America to the Canadian context. The guide is organized in five chapters. Chapter 1 defines popular education and describes its characteristics and the role of…

  14. Languages of North, Central, and South America. A Survey of Materials for the Study of the Uncommonly Taught Languages.

    ERIC Educational Resources Information Center

    Johnson, Dora E.; And Others

    This is an annotated bibliography of basic tools of access for the study of the uncommonly taught languages of North, Central, and South America. It is one of eight fascicles which constitute a revision of "A Provisional Survey of Materials for the Study of the Neglected Languages" (CAL 1969). The emphasis is on materials for the adult learner…

  15. Mantle Response to a Slab Gap and Three-dimensional Slab Interaction in Central America

    NASA Astrophysics Data System (ADS)

    Jadamec, M. A.; Fischer, K. M.

    2013-12-01

    Seismically constrained global slab geometries suggest the Middle America-South American subduction system contains a gap on the order of 500 km separating the east-dipping Cocos and Nazca slabs at depth (Gudmundsson and Sambridge, 1998; Syracuse and Abers, 2006; Hayes et al., 2012). The location of the gap correlates with tectonic features impinging on the Pacific side of the Middle America trench, in particular the incoming young buoyant oceanic lithosphere and oceanic ridges associated with the Galapagos hotspot and Cocos-Nazca spreading center (Protti et al., 1994; Mann et al., 2007; Muller et al., 2008). Moreover, geochemical studies focusing on the arc chemistry in the Central American volcanic front argue for a slab window of some kind in this region (Johnston and Thorkelson, 1997; Abratis and Worner, 2001; Hoernle et al., 2008). We use high-resolution, three-dimensional (3D) geodynamic modeling of the Middle America-South American subduction system to investigate the role of the incoming young oceanic lithosphere and a gap between the Cocos and Nazca slabs in controlling mantle flow velocity and geochemical signatures beneath Central America. The geodynamic models are geographically referenced with the geometry and thermal structure for the overriding and subducting plates based on geological and geophysical observables and constructed with the multi-plate subduction generator code, SlabGenerator (Jadamec and Billen, 2010; Jadamec et al., 2012; Jadamec and Billen, 2012). The viscous flow simulations are solved using the mantle convection finite-element code, CitcomCU (Zhong, 2006), modified by Jadamec and Billen (2010) to take into account the experimentally derived flow law for olivine and allow for variable 3D plate interface geometries and magnitudes of inter-plate coupling. The 3D numerical models indicate the gap between the Cocos and Nazca slabs serves as a conduit for Pacific-Cocos mantle to pass into the Caribbean, with toroidal flow around the

  16. Risk for transfusion-transmitted infectious diseases in Central and South America.

    PubMed Central

    Schmunis, G. A.; Zicker, F.; Pinheiro, F.; Brandling-Bennett, D.

    1998-01-01

    We report the potential risk for an infectious disease through tainted transfusion in 10 countries of South and Central America in 1993 and in two countries of South America in 1994, as well as the cost of reagents as partial estimation of screening costs. Of the 12 countries included in the study, nine screened all donors for HIV; three screened all donors for hepatitis B virus (HBV); two screened all donors for Trypanosoma cruzi; none screened all donors for hepatitis C virus (HCV); and six screened some donors for syphilis. Estimates of the risk of acquiring HIV through blood transfusion were much lower than for acquiring HBV, HCV, or T. cruzi because of significantly higher screening and lower prevalence.rates for HIV. An index of infectious disease spread through blood transfusion was calculated for each country. The highest value was obtained for Bolivia (233 infections per 10,000 transfusions); in five other countries, it was 68 to 103 infections per 10,000. The risks were lower in Honduras (nine per 10,000), Ecuador (16 per 10,000), and Paraguay (19 per 10,000). While the real number of potentially infected units or infected persons is probably lower than our estimates because of false positives and already infected recipients, the data reinforce the need for an information system to assess the level of screening for infectious diseases in the blood supply. Since this information was collected, Chile, Colombia, Costa Rica, and Venezuela have made HCV screening mandatory; serologic testing for HCV has increased in those countries, as well as in El Salvador and Honduras. T. cruzi screening is now mandatory in Colombia, and the percentage of screened donors increased not only in Colombia, but also in Ecuador, El Salvador, and Paraguay. Laws to regulate blood transfusion practices have been enacted in Bolivia, Guatemala, and Peru. However, donor screening still needs to improve for one or more diseases in most countries. PMID:9452393

  17. Projected impact of twenty-first century ENSO changes on rainfall over Central America and northwest South America from CMIP5 AOGCMs

    NASA Astrophysics Data System (ADS)

    Steinhoff, Daniel F.; Monaghan, Andrew J.; Clark, Martyn P.

    2015-03-01

    Due to the importance that the El Niño-Southern Oscillation (ENSO) has on rainfall over the tropical Americas, future changes in ENSO characteristics and teleconnections are important for regional hydroclimate. Projected changes to the ENSO mean state and characteristics, and the resulting impacts on rainfall anomalies over Central America, Colombia, and Ecuador during the twenty-first century are explored for several forcing scenarios using a suite of coupled atmosphere-ocean global climate models (AOGCMs) from the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Mean-state warming of eastern tropical Pacific sea surface temperatures, drying of Central America and northern Colombia, and wetting of southwest Colombia and Ecuador are consistent with previous studies that used earlier versions of the AOGCMs. Current and projected future characteristics of ENSO (frequency, duration, amplitude) show a wide range of values across the various AOGCMs. The magnitude of ENSO-related rainfall anomalies are currently underestimated by most of the models, but the model ensembles generally simulate the correct sign of the anomalies across the seasons around the peak ENSO effects. While the models capture the broad present-day ENSO-related rainfall anomalies, there is not a clear sense of projected future changes in the precipitation anomalies.

  18. A comparative study of Taiwan's short-term medical missions to the South Pacific and Central America

    PubMed Central

    2012-01-01

    Background Taiwan has been dispatching an increasing number of short-term medical missions (STMMs) to its allied nations to provide humanitarian health care; however, overall evaluations to help policy makers strengthen the impact of such missions are lacking. Our primary objective is to identify useful strategies by comparing STMMs to the South Pacific and Central America. Methods The data for the evaluation come from two main sources: the official reports of 46 missions to 11 countries in Central America and 25 missions to 8 countries in the South Pacific, and questionnaires completed by health professionals who had participated in the above missions. In Central America, STMMs were staffed by volunteer health professionals from multiple institutions. In the South Pacific, STMMs were staffed by volunteer health professionals from single institutions. Results In comparison to STMMs to Central America, STMMs to the South Pacific accomplished more educational training for local health providers, including providing heath-care knowledge and skills (p<0.05), and training in equipment administration (p<0.001) and drug administration (p<0.005). In addition, language constraints were more common among missions to Central America (p<0.001). There was no significant difference in the performance of clinical service between the two regions. Conclusions Health-care services provided by personnel from multiple institutions are as efficient as those from single institutions. Proficiency in the native language and provision of education for local health-care workers are essential for conducting a successful STMM. Our data provide implications for integrating evidence into the deployment of STMMs. PMID:23270459

  19. Naturalization of central European plants in North America: species traits, habitats, propagule pressure, residence time.

    PubMed

    Pyšek, Petr; Manceur, Ameur M; Alba, Christina; McGregor, Kirsty F; Pergl, Jan; Stajerová, Katerina; Chytrý, Milan; Danihelka, Jiří; Kartesz, John; Klimesova, Jitka; Lucanova, Magdalena; Moravcová, Lenka; Nishino, Misako; Sadlo, Jiri; Suda, Jan; Tichy, Lubomir; Kühn, Ingolf

    2015-03-01

    The factors that promote invasive behavior in introduced plant species occur across many scales of biological and ecological organization. Factors that act at relatively small scales, for example, the evolution of biological traits associated with invasiveness, scale up to shape species distributions among different climates and habitats, as well as other characteristics linked to invasion, such as attractiveness for cultivation (and by extension propagule pressure). To identify drivers of invasion it is therefore necessary to disentangle the contribution of multiple factors that are interdependent. To this end, we formulated a conceptual model describing the process of invasion of central European species into North America based on a sequence of "drivers." We then used confirmatory path analysis to test whether the conceptual model is supported by a statistical model inferred from a comprehensive database containing 466 species. The path analysis revealed that naturalization of central European plants in North America, in terms of the number of North American regions invaded, most strongly depends on residence time in the invaded range and the number of habitats occupied by species in their native range. In addition to the confirmatory path analysis, we identified the effects of various biological traits on several important drivers of the conceptualized invasion process. The data supported a model that included indirect effects of biological traits on invasion via their effect on the number of native range habitats occupied and cultivation in the native range. For example, persistent seed banks and longer flowering periods are positively correlated with number of native habitats, while a stress-tolerant life strategy is negatively correlated with native range cultivation. However, the importance of the biological traits is nearly an order of magnitude less than that of the larger scale drivers and highly dependent on the invasion stage (traits were associated

  20. First Complete Day from MODIS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This spectacular, full-color image of the Earth is a composite of the first full day of data gathered by the Moderate-resolution Imaging Spectroradiometer (MODIS) aboard NASA's Terra spacecraft. MODIS collected the data for each wavelength of red, green, and blue light as Terra passed over the daylit side of the Earth on April 19, 2000. Terra is orbiting close enough to the Earth so that it cannot quite see the entire surface in a day, resulting in the narrow gaps around the equator. Although the sensor's visible channels were combined to form this true-color picture, MODIS collects data in a total of 36 wavelengths, ranging from visible to thermal infrared energy. Scientists use these data to measure regional and global-scale changes in marine and land-based plant life, sea and land surface temperatures, cloud properties, aerosols, fires, and land surface properties. Notice how cloudy the Earth is, and the large differences in brightness between clouds, deserts, oceans, and forests. The Antarctic, surrounded by clockwise swirls of cloud, is shrouded in darkness because the sun is north of the equator at this time of year. The tropical forests of Africa, Southeast Asia, and South America are shrouded by clouds. The bright Sahara and Arabian deserts stand out clearly. Green vegetation is apparent in the southeast United States, the Yucatan Peninsula, and Madagascar. Image by Mark Gray, MODIS Atmosphere Team, NASA GSFC

  1. Application of Spectral Analysis Techniques in the Intercomparison of Aerosol Data: Part III. Using Combined PCA to Compare Spatiotemporal Variability of MODIS, MISR and OMI Aerosol Optical Depth

    NASA Technical Reports Server (NTRS)

    Li, Jing; Carlson, Barbara E.; Lacis, Andrew A.

    2014-01-01

    Satellite measurements of global aerosol properties are very useful in constraining aerosol parameterization in climate models. The reliability of different data sets in representing global and regional aerosol variability becomes an essential question. In this study, we present the results of a comparison using combined principal component analysis (CPCA), applied to monthly mean, mapped (Level 3) aerosol optical depth (AOD) product from Moderate Resolution Imaging Spectroradiometer (MODIS), Multiangle Imaging Spectroradiometer (MISR), and Ozone Monitoring Instrument (OMI). This technique effectively finds the common space-time variability in the multiple data sets by decomposing the combined AOD field. The results suggest that all of the sensors capture the globally important aerosol regimes, including dust, biomass burning, pollution, and mixed aerosol types. Nonetheless, differences are also noted. Specifically, compared with MISR and OMI, MODIS variability is significantly higher over South America, India, and the Sahel. MODIS deep blue AOD has a lower seasonal variability in North Africa, accompanied by a decreasing trend that is not found in either MISR or OMI AOD data. The narrow swath of MISR results in an underestimation of dust variability over the Taklamakan Desert. The MISR AOD data also exhibit overall lower variability in South America and the Sahel. OMI does not capture the Russian wild fire in 2010 nor the phase shift in biomass burning over East South America compared to Central South America, likely due to cloud contamination and the OMI row anomaly. OMI also indicates a much stronger (boreal) winter peak in South Africa compared with MODIS and MISR.

  2. Application of spectral analysis techniques in the intercomparison of aerosol data: Part III. Using combined PCA to compare spatiotemporal variability of MODIS, MISR, and OMI aerosol optical depth

    NASA Astrophysics Data System (ADS)

    Li, Jing; Carlson, Barbara E.; Lacis, Andrew A.

    2014-04-01

    Satellite measurements of global aerosol properties are very useful in constraining aerosol parameterization in climate models. The reliability of different data sets in representing global and regional aerosol variability becomes an essential question. In this study, we present the results of a comparison using combined principal component analysis (CPCA), applied to monthly mean, mapped (Level 3) aerosol optical depth (AOD) product from Moderate Resolution Imaging Spectroradiometer (MODIS), Multiangle Imaging Spectroradiometer (MISR), and Ozone Monitoring Instrument (OMI). This technique effectively finds the common space-time variability in the multiple data sets by decomposing the combined AOD field. The results suggest that all of the sensors capture the globally important aerosol regimes, including dust, biomass burning, pollution, and mixed aerosol types. Nonetheless, differences are also noted. Specifically, compared with MISR and OMI, MODIS variability is significantly higher over South America, India, and the Sahel. MODIS deep blue AOD has a lower seasonal variability in North Africa, accompanied by a decreasing trend that is not found in either MISR or OMI AOD data. The narrow swath of MISR results in an underestimation of dust variability over the Taklamakan Desert. The MISR AOD data also exhibit overall lower variability in South America and the Sahel. OMI does not capture the Russian wild fire in 2010 nor the phase shift in biomass burning over East South America compared to Central South America, likely due to cloud contamination and the OMI row anomaly. OMI also indicates a much stronger (boreal) winter peak in South Africa compared with MODIS and MISR.

  3. Medicinal Plants from Mexico, Central America, and the Caribbean Used as Immunostimulants.

    PubMed

    Alonso-Castro, Angel Josabad; Juárez-Vázquez, María Del Carmen; Campos-Xolalpa, Nimsi

    2016-01-01

    A literature review was undertaken by analyzing distinguished books, undergraduate and postgraduate theses, and peer-reviewed scientific articles and by consulting worldwide accepted scientific databases, such as SCOPUS, Web of Science, SCIELO, Medline, and Google Scholar. Medicinal plants used as immunostimulants were classified into two categories: (1) plants with pharmacological studies and (2) plants without pharmacological research. Medicinal plants with pharmacological studies of their immunostimulatory properties were subclassified into four groups as follows: (a) plant extracts evaluated for in vitro effects, (b) plant extracts with documented in vivo effects, (c) active compounds tested on in vitro studies, and (d) active compounds assayed in animal models. Pharmacological studies have been conducted on 29 of the plants, including extracts and compounds, whereas 75 plants lack pharmacological studies regarding their immunostimulatory activity. Medicinal plants were experimentally studied in vitro (19 plants) and in vivo (8 plants). A total of 12 compounds isolated from medicinal plants used as immunostimulants have been tested using in vitro (11 compounds) and in vivo (2 compounds) assays. This review clearly indicates the need to perform scientific studies with medicinal flora from Mexico, Central America, and the Caribbean, to obtain new immunostimulatory agents. PMID:27042188

  4. Application of scientific core drilling to geothermal exploration: Platanares, Honduras and Tecuamburro Volcano, Guatemala, Central America

    SciTech Connect

    Goff, S.J.; Goff, F.E.; Heiken, G.H.; Duffield, W.A.; Janik, C.J.

    1994-04-01

    Our efforts in Honduras and Guatemala were part of the Central America Energy Resource Project (CAERP) funded by the United States Agency for International Development (AID). Exploration core drilling operations at the Platanares, Honduras and Tecuamburro Volcano, Guatemala sites were part of a geothermal assessment for the national utility companies of these countries to locate and evaluate their geothermal resources for electrical power generation. In Honduras, country-wide assessment of all thermal areas determined that Platanares was the site with the greatest geothermal potential. In late 1986 to middle 1987, three slim core holes were drilled at Platanares to a maximum depth of 680 m and a maximum temperature of 165{degree}C. The objectives were to obtain information on the geothermal gradient, hydrothermal alterations, fracturing, and possible inflows of hydrothermal fluids. Two holes produced copious amounts of water under artesian conditions and a total of 8 MW(t) of energy. Geothermal investigations in Guatemala focused on the Tecuamburro Volcano geothermal site. The results of surface geological, volcanological, hydrogeochemical, and geophysical studies at Tecuamburro Volcano indicated a substantial shallow heat source. In early 1990 we drilled one core hole, TCB-1, to 808 m depth. The measured bottom hole temperature was 238{degree}C. Although the borehole did not flow, in-situ samples indicate the hole is completed in a vapor-zone above a probable 300{degree}C geothermal reservoir.

  5. Phenology and recruitment of Caryocar costaricense (Caryocaceae), an endemic tree species of Southern Central America.

    PubMed

    Solís, Silvia; Lobo, Jorge; Grimaldo, Mayori

    2009-09-01

    Basic aspects of the reproductive biology are largely unknown for most tropical tree species, although they are important elements to understand the impacts of anthropogenic activities as logging and forest fragmentation on these populations. In this study, data are presented on leaf and reproductive phenology, fruit production and seedling demography of a population of an endemic tree species of Southern Central America, Caryocar costaricense. This species has been affected by selective logging and forest fragmentation of its habitat. Phenology was studied by observation of 15-22 tree crowns during two reproductive periods (2003 and 2005). Circular plots were established around 11 adult trees to count the number of fallen fruits and seedlings during three years (2003, 2004, 2005). Although reproductive phenology is restricted to the short dry season in this species, seed germination occurred year-round. Fruit and seedling production shows a strong inter-individual variation within the study populations, with two large trees producing nearly 50%-70% of the fruits and seedlings during two years. Most of the seeds that fall beneath the tree crown are covered by litterfall or removed by fauna. We found evidence that many of these seeds become part of a seed bank in the forest floor. Because of the observed reproductive dominance of few large trees in these populations, we propose that selective logging on reproductive trees can severely impact the recruitment of this species. PMID:19928470

  6. Medicinal Plants from Mexico, Central America, and the Caribbean Used as Immunostimulants

    PubMed Central

    Juárez-Vázquez, María del Carmen; Campos-Xolalpa, Nimsi

    2016-01-01

    A literature review was undertaken by analyzing distinguished books, undergraduate and postgraduate theses, and peer-reviewed scientific articles and by consulting worldwide accepted scientific databases, such as SCOPUS, Web of Science, SCIELO, Medline, and Google Scholar. Medicinal plants used as immunostimulants were classified into two categories: (1) plants with pharmacological studies and (2) plants without pharmacological research. Medicinal plants with pharmacological studies of their immunostimulatory properties were subclassified into four groups as follows: (a) plant extracts evaluated for in vitro effects, (b) plant extracts with documented in vivo effects, (c) active compounds tested on in vitro studies, and (d) active compounds assayed in animal models. Pharmacological studies have been conducted on 29 of the plants, including extracts and compounds, whereas 75 plants lack pharmacological studies regarding their immunostimulatory activity. Medicinal plants were experimentally studied in vitro (19 plants) and in vivo (8 plants). A total of 12 compounds isolated from medicinal plants used as immunostimulants have been tested using in vitro (11 compounds) and in vivo (2 compounds) assays. This review clearly indicates the need to perform scientific studies with medicinal flora from Mexico, Central America, and the Caribbean, to obtain new immunostimulatory agents. PMID:27042188

  7. Comparison of GNSS integrated water vapor and NWM reanalysis data over Central and South America

    NASA Astrophysics Data System (ADS)

    Fernández, Laura Isabel; Natali, Maria Paula; Meza, Amalia; Mendoza, Luciano; Bianchi, Clara

    2016-07-01

    Integrated water vapor (IWV) derived from Global Navigation Satellite Systems (GNSS) and Numerical Weather Models (NWM) reanalysis data were compared in order to assess the consistency between the different datasets over the extended geographical region of Central and South America. The analysis was performed for the seven years period between 2007 and 2013. We analyzed two different NWM: the European Centre for Medium-Range Weather Forecast (ECMWF) reanalysis data (ERA Interim) and the Modern-Era Retrospective analysis for Research and Applications (MERRA) from the National Aeronautics and Space Administration (NASA). The statistical analysis of the differences was performed in 110 GNSS sites (GPS + GLONASS), although the most interesting results came from the 73 sites which have more than 5 years of data. The selected area involves different climate types, from polar to tropical, and it is characterized by large temporal variability of the integrated total humidity content. Moreover, the scarce coverage of operational radio sounding stations is noticeable in large areas of the selected region; hence the contribution of IWV-GNSS is essential to improve the weather understanding. Considering that the atmospheric water vapor has a highly variable and complex distribution which knowledge is essential for weather prediction and local meteorological studies. This study aims to provide IWV-GNSS observations able to be assimilated by operational weather centers, for both prediction and simulation, as well for improving regional modeling.

  8. Evidence of avian pneumovirus spread beyond Minnesota among wild and domestic birds in central North America.

    PubMed

    Bennett, R S; Nezworski, J; Velayudhan, B T; Nagaraja, K V; Zeman, D H; Dyer, N; Graham, T; Lauer, D C; Njenga, M K; Halvorson, D A

    2004-12-01

    To detect avian pneumovirus (APV) in central North America, nasal turbinates or choanal deft tissues from domestic turkeys and wild birds were examined for the presence of APV RNA by reverse transcriptase-polymerase chain reaction (RT-PCR), whereas serum samples from domestic turkeys were analyzed for APV antibodies by enzyme-linked immunosorbent assay (ELISA). In 2002, the seroprevalence of disease in domestic turkeys in Minnesota remained high (42.3% of the flocks). In addition, there is evidence the disease has spread to turkey flocks in North Dakota (8.2%), South Dakota (7%), Iowa (10%), and Wisconsin (8.6%) as detected by RT-PCR and/or ELISA. House sparrows and ring-billed gulls sampled in Minnesota and snow geese from Saskatchewan, Canada, were found to harbor APV RNA. Sequence analysis of wild bird APV strains showed high amino acid sequence identity among wild bird isolates (<97%) and between wild bird and turkey viral isolates (93.2%-99.3%). This study demonstrated that APV infections were present in domestic turkey flocks and wild birds outside the state of Minnesota; however, the role of wild birds in spreading APV to domestic turkeys remains unclear. PMID:15666873

  9. AMOR: a proposed cooperative effort to improve outcomes of childhood cancer in Central America.

    PubMed

    Antillon, Federico; Baez, Fulgencio L; Barr, Ronald; Barrantes Zamorra, Jose C; Carrasco, Ligia Fu; Moreno, Belgica; Bonilla, Miguel M; Tognoni, Gianni; Valsecch, Maria G; Howard, Scott; Ribeiro, Raul C; Masera, Giuseppe

    2005-08-01

    The dramatic reduction of pediatric cancer mortality rates has been one of the greatest accomplishments of contemporary medicine. About 80% of children with cancer are now expected to be cured by current therapies. However, most of the world's children have no access to cancer treatment. The translation of effective pediatric cancer therapies to impoverished regions of the world presents an enormous challenge to the health care profession. Over the past 20 years, efforts have been under way to extend adequate cancer treatment to an increasing number of children in developing countries. These initiatives, collectively designated "twinning programs," consist essentially of a partnership between a pediatric cancer unit in a developing country and a group of health care providers in the developed world. Here we review the twinning programs that have been implemented in Central America, discuss their impact on the development of local resources and the outcome of childhood cancer, and propose a collaborative research initiative aimed at improving the international dissemination of progress in pediatric hematology-oncology.

  10. Asymmetric forest transition driven by the interaction of socioeconomic development and environmental heterogeneity in Central America

    PubMed Central

    Redo, Daniel J.; Grau, H. Ricardo; Aide, T. Mitchell; Clark, Matthew L.

    2012-01-01

    Forest transitions (FT) have been observed in many developed countries and more recently in the developing world. However, our knowledge of FT from tropical regions is mostly derived from case studies from within a particular country, making it difficult to generalize findings across larger regions. Here we overcome these difficulties by conducting a recent (2001–2010) satellite-based analysis of trends in forest cover across Central America, stratified by biomes, which we related to socioeconomic variables associated with human development. Results show a net decrease of woody vegetation resulting from 12,201 km2 of deforestation of moist forests and 6,825 km2 of regrowth of conifer and dry forests. The Human Development Index was the socioeconomic variable best associated with forest cover change. The least-developed countries, Nicaragua and Guatemala, experienced both rapid deforestation of moist forests and significant recovery of conifer and dry forests. In contrast, the most developed countries, Panama and Costa Rica, had net woody vegetation gain and a more stable forest cover configuration. These results imply a good agreement with FT predictions of forest change in relation to socioeconomic development, but strong asymmetry in rates and directions of change largely dependent upon the biome where change is occurring. The FT model should be refined by incorporating ecological and socioeconomic heterogeneity, particularly in multicountry and regional studies. These asymmetric patterns of forest change should be evaluated when developing strategies for conserving biodiversity and environmental services. PMID:22615408

  11. Asymmetric forest transition driven by the interaction of socioeconomic development and environmental heterogeneity in Central America.

    PubMed

    Redo, Daniel J; Grau, H Ricardo; Aide, T Mitchell; Clark, Matthew L

    2012-06-01

    Forest transitions (FT) have been observed in many developed countries and more recently in the developing world. However, our knowledge of FT from tropical regions is mostly derived from case studies from within a particular country, making it difficult to generalize findings across larger regions. Here we overcome these difficulties by conducting a recent (2001-2010) satellite-based analysis of trends in forest cover across Central America, stratified by biomes, which we related to socioeconomic variables associated with human development. Results show a net decrease of woody vegetation resulting from 12,201 km(2) of deforestation of moist forests and 6,825 km(2) of regrowth of conifer and dry forests. The Human Development Index was the socioeconomic variable best associated with forest cover change. The least-developed countries, Nicaragua and Guatemala, experienced both rapid deforestation of moist forests and significant recovery of conifer and dry forests. In contrast, the most developed countries, Panama and Costa Rica, had net woody vegetation gain and a more stable forest cover configuration. These results imply a good agreement with FT predictions of forest change in relation to socioeconomic development, but strong asymmetry in rates and directions of change largely dependent upon the biome where change is occurring. The FT model should be refined by incorporating ecological and socioeconomic heterogeneity, particularly in multicountry and regional studies. These asymmetric patterns of forest change should be evaluated when developing strategies for conserving biodiversity and environmental services.

  12. Microsatellite data suggest significant population structure and differentiation within the malaria vector Anopheles darlingi in Central and South America

    PubMed Central

    Mirabello, Lisa; Vineis, Joseph H; Yanoviak, Stephen P; Scarpassa, Vera M; Póvoa, Marinete M; Padilla, Norma; Achee, Nicole L; Conn, Jan E

    2008-01-01

    Background Anopheles darlingi is the most important malaria vector in the Neotropics. An understanding of A. darlingi's population structure and contemporary gene flow patterns is necessary if vector populations are to be successfully controlled. We assessed population genetic structure and levels of differentiation based on 1,376 samples from 31 localities throughout the Peruvian and Brazilian Amazon and Central America using 5–8 microsatellite loci. Results We found high levels of polymorphism for all of the Amazonian populations (mean RS = 7.62, mean HO = 0.742), and low levels for the Belize and Guatemalan populations (mean RS = 4.3, mean HO = 0.457). The Bayesian clustering analysis revealed five population clusters: northeastern Amazonian Brazil, southeastern and central Amazonian Brazil, western and central Amazonian Brazil, Peruvian Amazon, and the Central American populations. Within Central America there was low non-significant differentiation, except for between the populations separated by the Maya Mountains. Within Amazonia there was a moderate level of significant differentiation attributed to isolation by distance. Within Peru there was no significant population structure and low differentiation, and some evidence of a population expansion. The pairwise estimates of genetic differentiation between Central America and Amazonian populations were all very high and highly significant (FST = 0.1859 – 0.3901, P < 0.05). Both the DA and FST distance-based trees illustrated the main division to be between Central America and Amazonia. Conclusion We detected a large amount of population structure in Amazonia, with three population clusters within Brazil and one including the Peru populations. The considerable differences in Ne among the populations may have contributed to the observed genetic differentiation. All of the data suggest that the primary division within A. darlingi corresponds to two white gene genotypes between Amazonia (genotype 1) and

  13. [MODIS Investigation

    NASA Technical Reports Server (NTRS)

    Abbott, Mark R.

    1998-01-01

    The objectives of the last six months were: (1) Revise the algorithms for the Fluorescence Line Height (FLH) and Chlorophyll Fluorescence Efficiency (CFE) products, especially the data quality flags; (2) Revise the MOCEAN validation plan; (3) Deploy and recover bio-optical instrumentation at the Hawaii Ocean Time-series (HOT) site as part of the Joint Global Ocean Flux Study (JGOFS); (4) Prepare for field work in the Antarctic Polar Frontal Zone as part of JGOFS; (5) Submit manuscript on bio-optical time scales as estimated from Lagrangian drifters; (6) Conduct chemostat experiments on fluorescence; (7) Interface with the Global Imager (GLI) science team; and (8) Continue development of advanced data system browser. We are responsible for the delivery of two at-launch products for AM-1: Fluorescence line height (FLH) and chlorophyll fluorescence efficiency (CFE). We also considered revising the input chlorophyll, which is used to determine the degree of binning. We have refined the quality flags for the Version 2 algorithms. We have acquired and installed a Silicon Graphics Origin 200. We are working with the University of Miami team to develop documentation that will describe how the MODIS ocean components are linked together.

  14. An investigation of thermal anomalies in the Central American volcanic chain and evaluation of the utility of thermal anomaly monitoring in the prediction of volcanic eruptions. [Central America

    NASA Technical Reports Server (NTRS)

    Stoiber, R. E. (Principal Investigator); Rose, W. I., Jr.

    1975-01-01

    The author has identified the following significant results. Ground truth data collection proves that significant anomalies exist at 13 volcanoes within the test site of Central America. The dimensions and temperature contrast of these ten anomalies are large enough to be detected by the Skylab 192 instrument. The dimensions and intensity of thermal anomalies have changed at most of these volcanoes during the Skylab mission.

  15. Geomorphological impact on agroforestry systems in the interior highlands of Nicaragua, Central America

    NASA Astrophysics Data System (ADS)

    Mentler, Axel; Wriessnig, Karin; Ottner, Franz; Schomakers, Jasmin; Benavides González, Álvaro; Cisne Contreras, José Dolores; Querol Lipcovich, Daniel

    2013-04-01

    Cerro el Castillo is located in the NW of Nicaragua, Central America, close to the border of Honduras (Provincia Central de las Cordilleras) at 1000-1200m above sea level. In this region, small and medium-sized farms are agroforestry systems with mangos, avocados, coffee, papayas, bananas, strawberries, maize, pumpkins, beans and other vegetables. The production systems are strongly linked to facilities for raising small domestic animals and cows. Main regional agricultural production problems are steep slopes, soil erosion, varying precipitation and distribution, water management and the unstable family income. An investigation of topsoil properties with comparable management systems showed on small scales significant differences in key values of soil chemistry and mineralogy. The outline of the analytical parameters included determination of pH, electrical conductivity (EC), cation exchange capacity (CEC), organic carbon (TOC), dissolved organic carbon (DOC), total nitrogen (TN) and dissolved nitrogen (DN) in soil solution, and plant available nutrients (P and K). The soil's mineralogical composition was determined by X-ray diffraction analysis. The area is a highly weathered karst landscape within a tropical limestone region displaying different amounts of volcanic pyroclastic parent material. The dominant Nitisoils and Andosols show degraded argic and andic horizons along the upper half of the mountainside. The pH values in the topsoil are moderate from pH 5.0 to 5.6. The upland topsoil is decalcified and the amount of plant available phosphorous is very low with significant low Ca concentration at the sorption complex. The mineralogical composition points to the high weathering intensity of this area (high content of kaolinite and a lower concentration of potassium and plagioclase feldspars and andesite). Along the upper half of the mountain, the soil profiles show wider C:N ratios and lower amounts of organic matter. Topsoil at lower altitude and with a lower

  16. Merging IceSAT GLAS and Terra MODIS Data in Order to Derive Forest Type Specific Tree Heights in the Central Siberian Boreal Forest

    NASA Technical Reports Server (NTRS)

    Ranson, K. Jon; Sun, Guoqing; Kimes, Daniel; Kovacs, Katalin; Kharuk, Viatscheslav

    2006-01-01

    Mapping of boreal forest's type, biomass, and other structural parameters are critical for understanding of the boreal forest's significance in the carbon cycle, its response to and impact on global climate change. We believe the nature of the forest structure information available from MISR and GLAS can be used to help identify forest type, age class, and estimate above ground biomass levels beyond that now possible with MODIS alone. The ground measurements will be used to develop relationships between remote sensing observables and forest characteristics and provide new information for understanding forest changes with respect to environmental change. Lidar is a laser altimeter that determines the distance from the instrument to the physical surface by measuring the time elapsed between the pulse emission and the reflected return. Other studies have shown that the returned signal may identify multiple returns originating from trees, building and other objects and permits the calculation of their height. Studies using field data have shown that lidar data can provide estimates of structural parameters such as biomass, stand volume and leaf area index and allows remarkable differentiation between primary and secondary forest. NASA's IceSAT Geoscience Laser Altimeter System (GLAS) was launched in January 2003 and collected data during February and September of that year. This study used data acquired over our study sites in central Siberia to examine the GLAS signal as a source of forest height and other structural characteristics. The purpose of our Siberia project is to improve forest cover maps and produce above-ground biomass maps of the boreal forest in Northern Eurasia from MODIS by incorporating structural information inherent in the Terra MISR and ICESAT Geoscience Laser Altimeter System (GLAS) instruments. A number of forest cover classifications exist for the boreal forest. We believe the limiting factor in these products is the lack of structural

  17. Tsunami hazard assessment in El Salvador, Central America, from seismic sources through flooding numerical models.

    NASA Astrophysics Data System (ADS)

    Álvarez-Gómez, J. A.; Aniel-Quiroga, Í.; Gutiérrez-Gutiérrez, O. Q.; Larreynaga, J.; González, M.; Castro, M.; Gavidia, F.; Aguirre-Ayerbe, I.; González-Riancho, P.; Carreño, E.

    2013-11-01

    El Salvador is the smallest and most densely populated country in Central America; its coast has an approximate length of 320 km, 29 municipalities and more than 700 000 inhabitants. In El Salvador there were 15 recorded tsunamis between 1859 and 2012, 3 of them causing damages and resulting in hundreds of victims. Hazard assessment is commonly based on propagation numerical models for earthquake-generated tsunamis and can be approached through both probabilistic and deterministic methods. A deterministic approximation has been applied in this study as it provides essential information for coastal planning and management. The objective of the research was twofold: on the one hand the characterization of the threat over the entire coast of El Salvador, and on the other the computation of flooding maps for the three main localities of the Salvadorian coast. For the latter we developed high-resolution flooding models. For the former, due to the extension of the coastal area, we computed maximum elevation maps, and from the elevation in the near shore we computed an estimation of the run-up and the flooded area using empirical relations. We have considered local sources located in the Middle America Trench, characterized seismotectonically, and distant sources in the rest of Pacific Basin, using historical and recent earthquakes and tsunamis. We used a hybrid finite differences-finite volumes numerical model in this work, based on the linear and non-linear shallow water equations, to simulate a total of 24 earthquake-generated tsunami scenarios. Our results show that at the western Salvadorian coast, run-up values higher than 5 m are common, while in the eastern area, approximately from La Libertad to the Gulf of Fonseca, the run-up values are lower. The more exposed areas to flooding are the lowlands in the Lempa River delta and the Barra de Santiago Western Plains. The results of the empirical approximation used for the whole country are similar to the results

  18. Tsunami hazard assessment in El Salvador, Central America, from seismic sources through flooding numerical models

    NASA Astrophysics Data System (ADS)

    Álvarez-Gómez, J. A.; Aniel-Quiroga, Í.; Gutiérrez-Gutiérrez, O. Q.; Larreynaga, J.; González, M.; Castro, M.; Gavidia, F.; Aguirre-Ayerbe, I.; González-Riancho, P.; Carreño, E.

    2013-05-01

    El Salvador is the smallest and most densely populated country in Central America; its coast has approximately a length of 320 km, 29 municipalities and more than 700 000 inhabitants. In El Salvador there have been 15 recorded tsunamis between 1859 and 2012, 3 of them causing damages and hundreds of victims. The hazard assessment is commonly based on propagation numerical models for earthquake-generated tsunamis and can be approached from both Probabilistic and Deterministic Methods. A deterministic approximation has been applied in this study as it provides essential information for coastal planning and management. The objective of the research was twofold, on the one hand the characterization of the threat over the entire coast of El Salvador, and on the other the computation of flooding maps for the three main localities of the Salvadorian coast. For the latter we developed high resolution flooding models. For the former, due to the extension of the coastal area, we computed maximum elevation maps and from the elevation in the near-shore we computed an estimation of the run-up and the flooded area using empirical relations. We have considered local sources located in the Middle America Trench, characterized seismotectonically, and distant sources in the rest of Pacific basin, using historical and recent earthquakes and tsunamis. We used a hybrid finite differences - finite volumes numerical model in this work, based on the Linear and Non-linear Shallow Water Equations, to simulate a total of 24 earthquake generated tsunami scenarios. In the western Salvadorian coast, run-up values higher than 5 m are common, while in the eastern area, approximately from La Libertad to the Gulf of Fonseca, the run-up values are lower. The more exposed areas to flooding are the lowlands in the Lempa River delta and the Barra de Santiago Western Plains. The results of the empirical approximation used for the whole country are similar to the results obtained with the high resolution

  19. A single early introduction of HIV-1 subtype B into Central America accounts for most current cases.

    PubMed

    Murillo, Wendy; Veras, Nazle; Prosperi, Mattia; de Rivera, Ivette Lorenzana; Paz-Bailey, Gabriela; Morales-Miranda, Sonia; Juarez, Sandra I; Yang, Chunfu; DeVos, Joshua; Marín, José Pablo; Mild, Mattias; Albert, Jan; Salemi, Marco

    2013-07-01

    Human immunodeficiency virus type 1 (HIV-1) variants show considerable geographical separation across the world, but there is limited information from Central America. We provide the first detailed investigation of the genetic diversity and molecular epidemiology of HIV-1 in six Central American countries. Phylogenetic analysis was performed on 625 HIV-1 pol gene sequences collected between 2002 and 2010 in Honduras, El Salvador, Nicaragua, Costa Rica, Panama, and Belize. Published sequences from neighboring countries (n = 57) and the rest of the world (n = 740) were included as controls. Maximum likelihood methods were used to explore phylogenetic relationships. Bayesian coalescence-based methods were used to time HIV-1 introductions. Nearly all (98.9%) Central American sequences were of subtype B. Phylogenetic analysis revealed that 437 (70%) sequences clustered within five significantly supported monophyletic clades formed essentially by Central American sequences. One clade contained 386 (62%) sequences from all six countries; the other four clades were smaller and more country specific, suggesting discrete subepidemics. The existence of one large well-supported Central American clade provides evidence that a single introduction of HIV-1 subtype B in Central America accounts for most current cases. An introduction during the early phase of the HIV-1 pandemic may explain its epidemiological success. Moreover, the smaller clades suggest a subsequent regional spread related to specific transmission networks within each country.

  20. Brief communication: the Uto-Aztecan premolar in early hunter-gatherers from South-Central North America.

    PubMed

    Taylor, Matthew S

    2012-10-01

    The Uto-Aztecan premolar is a discrete dental trait found in low frequency (<2%) among world populations. The highest frequencies of the trait have been found among the indigenous populations of North America and, to a lesser extent, South America. Because of the trait's relatively higher frequency in the Western Hemisphere, the antiquity and distribution of the feather is important for reconstructing the biocultural interactions of prehistoric populations. While early research concluded that the Uto-Aztecan premolar originated in the American Southwest around 4,000 years Before Present (BP), more recent studies have discovered the trait across the Americas and in parts of Europe and Asia. For this study, over 300 dentitions representing foragers and farmers in south-central North America were examined. The trait was found in relatively high frequency (over 11%) in Archaic hunter-gatherer populations from Central Texas, with high frequencies also found in the adjacent western Gulf Coastal Plain. The presence of this trait in Early Archaic populations suggests that the trait was present by 8,000 BP and persisted at a high frequency into the Late Archaic period.

  1. 75 FR 34311 - To Implement Certain Provisions of the Dominican Republic-Central America-United States Free...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-16

    ... ] TD16JN10.011 ] TD16JN10.012 [FR Doc. 2010-14728 Filed 6-15-10; 11:15 am] Billing code 7020-02-P #0; #0; ... Republic-Central America-United States Free Trade Agreement With Respect to Costa Rica, and for Other... ``Agreement'') with Costa Rica, the Dominican Republic, El Salvador, Guatemala, Honduras, and Nicaragua....

  2. Preface to the special issue on "Regional moment tensors and stress field in South and Central America"

    NASA Astrophysics Data System (ADS)

    Audemard, Franck; Zahradnik, Jiri; Assumpção, Marcelo

    2016-11-01

    This special issue follows from the Symposium "Regional Moment Tensor Solutions: advances and new applications" held in Bogotá, Colombia, at the I Regional Assembly of the IASPEI's Latin American and Caribbean Seismological Commission (LACSC) in 2014. Seven papers are presented dealing with determination of moment tensors, focal mechanisms and the stress field in Central and South America. The study areas of each paper are indicated in the index Map of Fig. 1.

  3. Calibration of strong motion models for Central America region and its use in seismic hazard assessment

    NASA Astrophysics Data System (ADS)

    Climent, A.; Benito, M. B.; Piedra, R.; Lindholm, C.; Gaspar-Escribano, J.

    2013-05-01

    We present the results of a study aimed at choosing the more suitable strong-motion models for seismic hazard analysis in the Central America (CA) Region. After a careful revision of the state of the art, different models developed for subduction and volcanic crustal zones, in tectonic environment similar to those of CA, were selected. These models were calibrated with accelerograms recorded in Costa Rica, Nicaragua and El Salvador. The peak ground acceleration PGA and Spectral Acceleration SA (T) derived from the records were compared with the ones predicted by the models in similar conditions of magnitude, distance and soil. The type of magnitude (Ms, Mb, MW), distance (Rhyp, Rrup, etc) and ground motion parameter (maximum horizontal component, geometrical mean, etc ) was taken into account in the comparison with the real data. As results of the analysis, the models which present a best fit with the local data were identified. These models have been applied for carrying out seismic hazard analysis in the region, in the frame of the RESIS II project financed by the Norwegian Foreign Department and also by the Spanish project SISMOCAES. The methodology followed is based on the direct comparison between PGA and SA 5 % damped response values extracted from actual records with the corresponding acceleration values predicted by the selected ground-motion models for similar magnitude, distance and soil conditions. Residuals between observed and predicted values for PGA, and SA (1sec) are calculated and plotted as a function of distance and magnitude, analyzing their deviation from the mean value. Besides and most important, a statistical analysis of the normalized residuals was carry out using the criteria proposed by Scherbaum et al. (2004), which consists in categorizing ground motion models based in a likelihood parameter that reflects the goodness-of-fit of the median values as well as the shape of the underlying distribution of ground motion residuals. Considering

  4. Active mountain building and the distribution of “core” Maxillariinae species in tropical Mexico and Central America

    USGS Publications Warehouse

    Kirby, Stephen H.

    2011-01-01

    The observation that southeastern Central America is a hotspot for orchid diversity has long been known and confirmed by recent systematic studies and checklists. An analysis of the geographic and elevation distribution demonstrates that the most widespread species of “core” Maxillariinae are all adapted to life near sea level, whereas the most narrowly endemic species are largely distributed in wet highland environments. Drier, hotter lowland gaps exist between these cordilleras and evidently restrict the dispersal of the species adapted to wetter, cooler conditions. Among the recent generic realignments of “core” Maxillariinae based on molecular phylogenetics, the Camaridium clade is easily the most prominent genus in Central America and is largely restricted to the highlands of Costa Rica and Panama, indicating that this region is the ancestral home of this genus and that its dispersal limits are drier, lowland cordilleran gaps. The mountains of Costa Rica and Panama are among the geologically youngest topographic features in the Neotropics, reflecting the complex and dynamic interactions of numerous tectonic plates. From consideration of the available geological evidence, I conclude that the rapid growth of the mountain ranges in Costa Rica and Panama during the late Cenozoic times created, in turn, very rapid ranges in ecological life zones and geographic isolation in that part of the isthmus. Thus, I suggest that these recent geologic events were the primary drivers for accelerated orchid evolution in southeastern Central America.

  5. Analysis of VLF signals associated to AGILE Terrestrial Gamma-ray Flashes detected over Central America

    NASA Astrophysics Data System (ADS)

    Marisaldi, Martino; Lyu, Fanchao; Cummer, Steven; Ursi, Alessandro

    2016-04-01

    Analysis of radio signals detected on ground and associated to Terrestrial Gamma-ray Flashes (TGFs) have proven to be a successful tool to extract information on the TGF itself and the possible associated lightning process. Triangulation of Very Low Frequency (VLF) signals by means of the Time Of Arrival technique provides TGF location with few km accuracy. The AGILE satellite is routinely observing TGFs on a narrow band across the Equator, limited by the small satellite orbital inclination (2.5°). However, until recently it was not possible to provide firm associations between AGILE TGFs and radio signals, because of two main limiting factors. First, dead-time effects led to a bias towards long duration events in AGILE TGF sample, which are less likely associated to strong radio pulses. In addition, most VLF detection networks are less sensitive along the equatorial region. Since the end of March 2015 a major change in the AGILE MiniCalorimeter instrument configuration resulted in a ten fold increase in TGF detection rate, and in the detection of events as short as 20 microseconds. 14% of the events in the new sample resulted simultaneous (within 200 microseconds) to sferics detected by the World Wide Lightning Location Network (WWLLN), therefore a source localisation is available for these events. We present here the first analysis of VLF waveforms associated to AGILE TGFs observed above Central America, detected by magnetic field sensors deployed in Puerto Rico. Among the seven TGFs with a WWLLN location at a distance lower than 10000 km from the sensors, four of them have detectable signals. These events are the closest to the sensors, with distance less than 7500 km. We present here the properties of these TGFs and the characteristics of the associated radio waveforms.

  6. Applications of a GIS on Georisks for Nicaragua and Central America

    NASA Astrophysics Data System (ADS)

    Strauch, W.; Chavez, G.; Gutierrez, V.; Feldhaus, L.; Schillinger, S.; Schmidt, R.

    2007-05-01

    A GIS on Georisks in Nicaragua was developed in the last years at the Instituto Nicaraguense de Estudios Territoriales (INETER) in cooperation with Federal Institute for Geosciences and Natural Resources (BGR, Germany). This GIS includes extensive topographical coverage and a large part of the data obtained in Nicaragua in many recent projects on natural hazard, vulnerability and risk. It contains numerous data on elements under risk, for instance cadastre data of Nicaraguan cities. Activities include the integration of the GIS with the monitoring and early warning systems of INETER to update certain parts of the data base continuously and in real time. The GIS is used on a routine basis at INETER and the GIS data base provides an efficient starting point for multiple new projects on georisks in Nicaragua which after their termination deliver their products to the GIS to assure the continuous growth of the system. Local universities, governmental institutions, local administrations, NGO´s make use of the GIS data base. Examples of important datasets are the seismicity data of Nicaragua with around 30,000 events, landslide coverage with 17,000 events, seismic vulnerability of 212,000 buildings in Managua city, seismic microzonation data of several towns, and multidisciplinary hazard and vulnerability data for 30 municipalities in Western Nicaragua. An interdisciplinary group of Nicaraguan geoscientists, informatics engineers and GIS specialists at INETER was trained to develop and use the GIS in their daily work. Web mapping services were put onto INETER´s website to provide the general public in Nicaragua with direct access to the data. Based on the experience in Nicaragua a regional GIS on Georisks for Central America is under development in cooperation with other institutions in El Salvador, Guatemala and Honduras.

  7. A geodynamical perspective on the subduction of Cocos and Rivera plates beneath Mexico and Central America

    NASA Astrophysics Data System (ADS)

    Manea, V. C.; Manea, M.; Ferrari, L.

    2013-12-01

    The Middle America subduction zone (MASZ) is one of the world’ most complex convergent margins as it involves the subduction of the Rivera and Cocos young oceanic plates beneath the North American and Caribbean plates and is bounded by the Gulf of California rift and the Panama slab window. Characterized by contorted and unusual slab geometry, irregularly distributed seismicity and volcanism, exceptionally large slow slip events (SSE) and non-volcanic tremors (NVT), this subduction system represents a great natural laboratory for better understanding geodynamic processes at a fundamental level. Based on a solid observational foundation, and incorporating the latest experimental results into a coherent geodynamical framework, we shed light on the main processes controlling the subduction system evolution in this region. The tectonics, volcanism, slab geometry and segmentation along the margin are reviewed from a geodynamical perspective. We proposed and discussed a series of evolutionary scenarios for the Mexican and Central American subduction zones, providing a coherent starting base for future geodynamical modeling studies tailored to this active margin. We discuss comparatively the recently discovered SSEs and NVTs along the MASZ, and try to differentiate among the proposed mechanisms responsible for these observations. Finally we discuss the recent seismic anisotropy observations in a geodynamic context, offering an integrated view of mantle flow pattern along the entire active margin. Although the MASZ as a whole may be considered a fairly complicated region with many unusual features and sometimes controversial interpretations, its complexity and unusual characteristics can improve our knowledge about the linkage between deep and surface processes associated with subduction zone dynamics.

  8. Micro and Macroscale Drivers of Nutrient Concentrations in Urban Streams in South, Central and North America

    PubMed Central

    Loiselle, Steven A.; Gasparini Fernandes Cunha, Davi; Shupe, Scott; Valiente, Elsa; Rocha, Luciana; Heasley, Eleanore; Belmont, Patricia Pérez; Baruch, Avinoam

    2016-01-01

    Global metrics of land cover and land use provide a fundamental basis to examine the spatial variability of human-induced impacts on freshwater ecosystems. However, microscale processes and site specific conditions related to bank vegetation, pollution sources, adjacent land use and water uses can have important influences on ecosystem conditions, in particular in smaller tributary rivers. Compared to larger order rivers, these low-order streams and rivers are more numerous, yet often under-monitored. The present study explored the relationship of nutrient concentrations in 150 streams in 57 hydrological basins in South, Central and North America (Buenos Aires, Curitiba, São Paulo, Rio de Janeiro, Mexico City and Vancouver) with macroscale information available from global datasets and microscale data acquired by trained citizen scientists. Average sub-basin phosphate (P-PO4) concentrations were found to be well correlated with sub-basin attributes on both macro and microscales, while the relationships between sub-basin attributes and nitrate (N-NO3) concentrations were limited. A phosphate threshold for eutrophic conditions (>0.1 mg L-1 P-PO4) was exceeded in basins where microscale point source discharge points (eg. residential, industrial, urban/road) were identified in more than 86% of stream reaches monitored by citizen scientists. The presence of bankside vegetation covaried (rho = –0.53) with lower phosphate concentrations in the ecosystems studied. Macroscale information on nutrient loading allowed for a strong separation between basins with and without eutrophic conditions. Most importantly, the combination of macroscale and microscale information acquired increased our ability to explain sub-basin variability of P-PO4 concentrations. The identification of microscale point sources and bank vegetation conditions by citizen scientists provided important information that local authorities could use to improve their management of lower order river

  9. Population amalgamation and genetic variation: observations on artificially agglomerated tribal populations of Central and South America.

    PubMed Central

    Chakraborty, R; Smouse, P E; Neel, J V

    1988-01-01

    The interpretation of data on genetic variation with regard to the relative roles of different evolutionary factors that produce and maintain genetic variation depends critically on our assumptions concerning effective population size and the level of migration between neighboring populations. In humans, recent population growth and movements of specific ethnic groups across wide geographic areas mean that any theory based on assumptions of constant population size and absence of substructure is generally untenable. We examine the effects of population subdivision on the pattern of protein genetic variation in a total sample drawn from an artificial agglomerate of 12 tribal populations of Central and South America, analyzing the pooled sample as though it were a single population. Several striking findings emerge. (1) Mean heterozygosity is not sensitive to agglomeration, but the number of different alleles (allele count) is inflated, relative to neutral mutation/drift/equilibrium expectation. (2) The inflation is most serious for rare alleles, especially those which originally occurred as tribally restricted "private" polymorphisms. (3) The degree of inflation is an increasing function of both the number of populations encompassed by the sample and of the genetic divergence among them. (4) Treating an agglomerated population as though it were a panmictic unit of long standing can lead to serious biases in estimates of mutation rates, selection pressures, and effective population sizes. Current DNA studies indicate the presence of numerous genetic variants in human populations. The findings and conclusions of this paper are all fully applicable to the study of genetic variation at the DNA level as well. PMID:3189334

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  11. Central America arc volcanic geochemistry: What do we know and what more do we need?

    NASA Astrophysics Data System (ADS)

    Jordan, E. K.; Stern, R. J.

    2013-12-01

    This study uses geochemical data for the Central America volcanic arc (CAVA) from the most comprehensive online data portal, Earthchem.org, to assess the quality of data available to the scientific community, geographic sampling bias versus volcano volume, and statistical analyses of CAVA geochemistry. These statistical studies use new or underutilized visualization techniques to present and interpret volcanic heterogeneities and trends associated with tectonic features along the arc. CAVA volcanoes range widely in type, volume, and composition within individual volcanoes and between volcanic complexes. Mean volcanic complex SiO2 concentrations range from 50-70% wt% and Mg# from 44-66. El Salvadoran and Nicaraguan samples, some of which erupted through continental crust of the Chortis terrane, are dominated by high- to medium-Fe tholeiitic to calcalkalic lavas. These lavas have lower incompatible trace element concentrations than do Guatemalan and Costa Rican lavas, erupted through accreted oceanic island arc and Chorotega oceanic plateau crust, which define medium- to low-Fe calcalkalic suites. In addition to providing a valuable representation of CAVA geochemistry, this comprehensive study is useful in identifying where data is lacking. Comprehensive volcanic arc studies are difficult to implement due to the complexity of the tectonic system. Sampling sites are limited due to rugged terrain, limited road access, extreme foliage, or political boundaries. For example, the data obtained for this study show that nearly 21% of samples are from Arenal volcano, which represents less than 0.5% of the volume of the volcanic arc complexes in the data set. Meanwhile, Irazú-Turrialba makes up 11% of the arc volume and less than 4% of the sample set. Since most of the volcano volume is buried by younger lavas, only the outer volcanic layers are typically sampled.

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

    NASA Astrophysics Data System (ADS)

    Perez-Rodriguez, I. M.; Sievert, S. M.; Fogel, M. L.; Foustoukos, D.

    2014-12-01

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

  13. Fires and Smoke Observed from the Earth Observing System MODIS Instrument: Products, Validation, and Operational Use

    NASA Technical Reports Server (NTRS)

    Kaufman, Y. J.; Ichoku, C.; Giglio, L.; Korontzi, S.; Chu, D. A.; Hao, W. M.; Justice, C. O.; Lau, William K. M. (Technical Monitor)

    2001-01-01

    The MODIS sensor, launched on NASA's Terra satellite at the end of 1999, was designed with 36 spectral channels for a wide array of land, ocean, and atmospheric investigations. MODIS has a unique ability to observe fires, smoke, and burn scars globally. Its main fire detection channels saturate at high brightness temperatures: 500 K at 4 microns and 400 K at 11 microns, which can only be attained in rare circumstances at the I kin fire detection spatial resolution. Thus, unlike other polar orbiting satellite sensors with similar thermal and spatial resolutions, but much lower saturation temperatures (e.g. AVHRR and ATSR), MODIS can distinguish between low intensity ground surface fires and high intensity crown forest fires. Smoke column concentration over land is for the first time being derived from the MOMS solar channels, extending from 0.41 microns to 2.1 microns. The smoke product has been provisionally validated both globally and regionally over southern Africa and central and south America. Burn scars are observed from MODIS even in the presence of smoke, using the 1.2 to 2.1 micron channels. MODIS burned area information is used to estimate pyrogenic emissions. A wide range of these fire and related products and validation are demonstrated for the wild fires that occurred in northwestern United States in the summer of 2000. The MODIS rapid response system and direct broadcast capability is being developed to enable users to obtain and generate data in near real time. It is expected that health and land management organizations will use these systems for monitoring the occurrence of fires and the dispersion of smoke within two to six hours after data acquisition.

  14. [Agrarian movements, development alternatives and food security in Central America: scenarios of transition].

    PubMed

    Rodriguez Rojas, R

    1991-01-01

    This article, based on personal experiences with a network of organizations of small and medium agricultural producers in Central America, aims to present the views of peasant organizations concerning agrarian problems in the region. The 3 major sections of work define the place of peasant agriculture in the traditional agrarian structure and the new problems resulting from the structural adjustment programs of the 1980s; separately describe the new peasant movements emerging in Honduras, El Salvador, Nicaragua, Costa Rica, and Panama, identifying common themes an efforts at international collaboration; and explore the positions of the peasant organizations on the optimal strategies for agricultural development and agrarian change. Agriculture remains the backbone of the Central American economies. But because the economic model in the region is 1 of accumulation characterized by dependency, concentration of capital, and social marginalization, the agrarian structure is at the basis of social tensions. Efforts to develop peasant agriculture and to give small producers access to marketing and credit services have been weak and sporadic. The new peasant movements are less inclined than those of the past to employ tactics of confrontation in their efforts to secure access to land and better working conditions. The new movement is the expression of small market producers sometimes grouped into associations who are oriented to production of basic foodstuffs for the internal market. A new concern with adaptation and negotiation is evident. The new organizations have in common a belief in their ability to propose new solutions to regional problems. Their views are founded on a positive assessment of the ability of peasant agriculture to produce food and add dynamism to the regional economy after barriers to credit, technological progress, and modernization in general are removed. Signs of increased cooperation are evident between peasant organizations and other groups

  15. Along and across arc geochemical variations in NW Central America: Evidence for involvement of lithospheric pyroxenite

    NASA Astrophysics Data System (ADS)

    Heydolph, Ken; Hoernle, Kaj; Hauff, Folkmar; Bogaard, Paul van den; Portnyagin, Maxim; Bindeman, Ilya; Garbe-Schönberg, Dieter

    2012-05-01

    The Central American Volcanic Arc (CAVA) has been the subject of intensive research over the past few years, leading to a variety of distinct models for the origin of CAVA lavas with various source components. We present a new model for the NW Central American Volcanic Arc based on a comprehensive new geochemical data set (major and trace element and Sr-Nd-Pb-Hf-O isotope ratios) of mafic volcanic front (VF), behind the volcanic front (BVF) and back-arc (BA) lava and tephra samples from NW Nicaragua, Honduras, El Salvador and Guatemala. Additionally we present data on subducting Cocos Plate sediments (from DSDP Leg 67 Sites 495 and 499) and igneous oceanic crust (from DSDP Leg 67 Site 495), and Guatemalan (Chortis Block) granitic and metamorphic continental basement. We observe systematic variations in trace element and isotopic compositions both along and across the arc. The data require at least three different endmembers for the volcanism in NW Central America. (1) The NW Nicaragua VF lavas require an endmember with very high Ba/(La, Th) and U/Th, relatively radiogenic Sr, Nd and Hf but unradiogenic Pb and low δ18O, reflecting a largely serpentinite-derived fluid/hydrous melt flux from the subducting slab into a depleted N-MORB type of mantle wedge. (2) The Guatemala VF and BVF mafic lavas require an enriched endmember with low Ba/(La, Th), U/Th, high δ18O and radiogenic Sr and Pb but unradiogenic Nd and Hf isotope ratios. Correlations of Hf with both Nd and Pb isotopic compositions are not consistent with this endmember being subducted sediments. Granitic samples from the Chiquimula Plutonic Complex in Guatemala have the appropriate isotopic composition to serve as this endmember, but the large amounts of assimilation required to explain the isotope data are not consistent with the basaltic compositions of the volcanic rocks. In addition, mixing regressions on Nd vs. Hf and the Sr and O isotope plots do not go through the data. Therefore, we propose that this

  16. Seasonal changes of extreme climate indices in Mexico and Central America during the 21st century using CMIP5

    NASA Astrophysics Data System (ADS)

    Cavazos, T.; de Grau, P.; Salinas, J. A.; Colorado, G.

    2013-05-01

    We evaluated historical (1961-2000) and climate change projections of temperature and precipitation from 15 general circulation models (GCMs) of the Climate Model Intercomparison Project phase 5 (CMIP5) for Mexico and Central America. Annual cycles, interannual variations and seasonal extreme percentiles (P10 and P90) of temperature and precipitation were validated with observed data from the Climatic Research Unit (CRU). Climate change scenarios for the mean GCM ensemble (ens_GCM) were obtained for the 2075-2099 period, relative to 1961-2000, for low (RCP4.5) and high (RCP8.5) radiating forcings. The ens_GCM was obtained by the Reliability Ensemble Averaging (REA) technique (Giorgi and Mearns 2001). Maximum temperature (Tmax) is underestimated (~2oC) by the ens_GCM in almost all Mexico, while minimum temperature (Tmin) is overestimated. Part of the underestimation may be related to the excess of rainfall that many models produce, especially in autumn and winter. For example, in the monsoon region, the models fail to produce the retreat of the summer rains in autumn, a feature also observed in the CMIP3 models. The ens_GCM overestimates rainfall in the semiarid regions of Northern Mexico and the Southwestern United States, but underestimates rainfall in southern Mexico and Central America, where extreme rainfall (P90 in JJA) can be larger than 8 mm d-1. Seasonal thresholds for extreme climatic indices (P90 and P10) were produced for Mexico and Central America. The largest observed P90 threshold for Tmax from the CRU dataset occurs in JJA along the US-Mexico border (~35-40oC), where the ens_GCM underestimates it by ~5oC; in some coastal regions of Central America the largest thresholds are between 30-35oC. The results for the RCP8.5 scenario show that the P90 threshold for Tmax in JJA may increase (>3oC) in almost all the study region, and >5oC along the Sierra Madre Occidental in the monsoon region. This may have important implications for the monsoon dynamics. The

  17. [MODIS Investigation

    NASA Technical Reports Server (NTRS)

    Abbott, Mark R.

    1998-01-01

    The objective of the last six months were: (1) Continue analysis of Hawaii Ocean Time-series (HOT) bio-optical mooring data, and Southern Ocean bio-optical drifter data; (2) Complete development of documentation of MOCEAN algorithms and software for use by MOCEAN team and GLI team; (3) Deploy instrumentation during JGOFS cruises in the Southern Ocean; (4) Participate in test cruise for Fast Repetition Rate (FRR) fluorometer; (5) Continue chemostat experiments on the relationship of fluorescence quantum yield to environmental factors; and (6) Continue to develop and expand browser-based information system for in situ bio-optical data. We are continuing to analyze bio-optical data collected at the Hawaii Ocean Time Series mooring as well as data from bio-optical drifters that were deployed in the Southern Ocean. A draft manuscript has now been prepared and is being revised. A second manuscript is also in preparation that explores the vector wind fields derived from NSCAT measurements. The HOT bio-optical mooring was recovered in December 1997. After retrieving the data, the sensor package was serviced and redeployed. We have begun preliminary analysis of these data, but we have only had the data for 3 weeks. However, all of the data were recovered, and there were no obvious anomalies. We will add second sensor package to the mooring when it is serviced next spring. In addition, Ricardo Letelier is funded as part of the SeaWiFS calibration/validation effort (through a subcontract from the University of Hawaii, Dr. John Porter), and he will be collecting bio-optical and fluorescence data as part of the HOT activity. This will provide additional in situ measurements for MODIS validation. As noted in the previous quarterly report, we have been analyzing data from three bio-optical drifters that were deployed in the Southern Ocean in September 1996. We presented results on chlorophyll and drifter speed. For the 1998 Ocean Sciences meeting, a paper will be presented on

  18. Neglected tropical diseases in Central America and Panama: review of their prevalence, populations at risk and impact on regional development.

    PubMed

    Hotez, Peter J; Woc-Colburn, Laila; Bottazzi, Maria Elena

    2014-08-01

    A review of the literature since 2009 reveals a staggering health and economic burden resulting from neglected tropical diseases in Panama and the six countries of Central America (referred to collectively here as 'Central America'). Particularly at risk are the 10.2million people in the region who live on less than $2 per day, mostly in Guatemala, Honduras, Nicaragua and El Salvador. Indigenous populations are especially vulnerable to neglected tropical diseases. Currently, more than 8million Central American children require mass drug treatments annually (or more frequently) for their intestinal helminth infections, while vector-borne diseases are widespread. Among the vector-borne parasitic infections, almost 40% of the population is at risk for malaria (mostly Plasmodium vivax infection), more than 800,000 people live with Chagas disease, and up to 39,000 people have cutaneous leishmaniasis. In contrast, an important recent success story is the elimination of onchocerciasis from Central America. Dengue is the leading arbovirus infection with 4-5million people affected annually and hantavirus is an important rodent-borne viral neglected tropical disease. The leading bacterial neglected tropical diseases include leptospirosis and trachoma, for which there are no disease burden estimates. Overall there is an extreme dearth of epidemiological data on neglected tropical diseases based on active surveillance as well as estimates of their economic impact. Limited information to date, however, suggests that neglected tropical diseases are a major hindrance to the region's economic development, in both the most impoverished Central American countries listed above, as well as for Panama and Costa Rica where a substantial (but largely hidden) minority of people live in extreme poverty.

  19. Molecular genotyping of Toxoplasma gondii from Central and South America revealed highly diverse populations and suggested possible different origins of the three archetypal lineages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most T. gondii strains in North America and Europe belong to three archetypal clonal lineages including the Type I, II and III but, isolates from Brazil are highly diverse. Here, we analyzed 164 T. gondii isolates from three countries in Central America (Guatemala, Nicaragua, Costa Rica), from one c...

  20. Water Balance of the San Simon Groundwater Basin, El Salvador, Central America

    NASA Astrophysics Data System (ADS)

    Sullivan, M.; Lopez, D. L.; Matus, A.

    2008-05-01

    The Berlin hydrothermal field in El Salvador, Central America is located in the San Simon River Basin on the northwest slope of the Berlin-Tecapa volcanic complex, in the eastern portion of the country. This hydrothermal field, which has been exploited since 1992, is a liquid-dominated system governed by faults and caldera structures allowing infiltration and transport of meteoric fluids. San Simon River is a tributary of the Lempa River, the largest river in the country. Geophysical studies have found that the Berlin field is composed of three aquifers (Shallow, Intermediate, Deep). Exploitation involves the removal of hot fluids from the geothermal reservoir (deep aquifer) and re-injection of lower temperature fluids. This study analyzes the surficial hydrology and groundwater storage change (since exploitation) in the hydrothermal reservoir to produce a water budget. Field monitoring of springs, fumarolic activity, domestic wells, tributaries to the San Simon River, and meteorological data provide constraints on the hydrology. Springs occur in the system close to fault zones or at contacts between different lithologies. The water balance for the San Simon groundwater basin (July 2004 - June 2005) indicates that 2.51 - 3.46 E7 m3/yr of water are infiltrated to the ground, 1.30 - 1.45E7 m3/yr comprises the overland flow, 5.74 E6 m3/yr form the base flow of the San Simon River, and 1.54 E5 m3/yr is released thru the evaporation of Alegria Lake. The shallow aquifer is affected by pumping of 4.78 E6 m3/yr by the national water company. To complete the water balance of the San Simon Basin, a correlation between the composition of the fumarolic gases and the diffuse flux of soil CO2 was performed. The flux of water released from fumarolic areas was estimated at 1.48 E5 m3/yr. An analysis of the increase in chloride concentration with time in the deep aquifer and the net mass withdrawn from this aquifer allow an estimation of the decrease in storage in the hydrothermal

  1. Constraining the Fore-Arc Flux Along the Central America Margin

    NASA Astrophysics Data System (ADS)

    Hilton, D. R.; Barry, P. H.; Ramirez, C. J.; Kulongoski, J. T.; Patel, B. S.; Blackmon, K.

    2014-12-01

    The transport of carbon to the deep mantle via subduction zones is interrupted by outputs via the fore-arc, volcanic front, and back-arc regions. Whereas output fluxes for the front and back-arc locales are well constrained for Central America (CA) [1], the fore-arc flux via cold seeps and groundwaters is virtually unknown. We present new He and CO2 data for the inner fore-arc of Costa Rica and western Panama to complement our study [2] of offshore CO2fluxes on the outer-forearc. On the Nicoya Peninsula, the Costa Rica Pacific coastline (including the Oso Peninsula) and the Talamanca Mountain Range, as well as coastal seeps in Panama, coupled CO2-He studies allow recognition of mantle (3He/4He up to 6RA) and crustal inputs to the volatile inventory. We associate the crustal component with CO2 derived from limestone (L) and organic sediments (S) on the subducting slab, and see a decrease in the L/S ratio trench-ward with the lowest values akin to those of diatomaceous ooze in the uppermost sequence of the subducting sediment package. This observation is consistent with the removal of the uppermost organic-rich sediment from deep subduction by under-plating. As the input carbon fluxes of the individual sedimentary layers are well constrained [3], we can limit the potential steady-state flux of carbon loss at the subaerial fore-arc to ~ 6 × 107 gCkm-1yr-1, equivalent to ~88% of the input flux of C associated with the ooze, or <4% of the total incoming sedimentary C. This study confirms that the greatest loss of slab-derived carbon at the CA margin occurs at the volcanic front with recycling efficiencies between 12% (Costa Rica) and 29% (El Salvador) of the sedimentary input [1]. It also demonstrates the utility of the coupled He-CO2approach for mass balance studies at subduction zones. [1] De Leeuw et al., EPSL, 2007; [2] Furi et al., G-cubed, 2010; [3] Li and Bebout, JGR, 2005.

  2. Chronological refinement of an ice core record at Upper Fremont Glacier in south central North America

    SciTech Connect

    Schuster, Paul F.; White, David E.; Naftz, David L.; Cecil, L. DeWayne

    2000-02-27

    alpine regions of central North America may have occurred on a relatively short (decadal) timescale. (c) 2000 American Geophysical Union.

  3. Chronological refinement of an ice core record at Upper Fremont Glacier in south central North America

    USGS Publications Warehouse

    Schuster, P.F.; White, D.E.; Naftz, D.L.; Cecil, L.D.

    2000-01-01

    The potential to use ice cores from alpine glaciers in the midlatitudes to reconstruct paleoclimatic records has not been widely recognized. Although excellent paleoclimatic records exist for the polar regions, paleoclimatic ice core records are not common from midlatitude locations. An ice core removed from the Upper Fremont Glacier in Wyoming provides evidence for abrupt climate change during the mid-1800s. Volcanic events (Krakatau and Tambora) identified from electrical conductivity measurements (ECM) and isotopic and chemical data from the Upper Fremont Glacier were reexamined to confirm and refine previous chronological estimates of the ice core. At a depth of 152 m the refined age-depth profile shows good agreement (1736 ?? 10 A.D.) with the 14C age date (1729 ?? 95 A.D.). The ??18O profile of the Upper Fremont Glacier (UFG) ice core indicates a change in climate known as the Little Ice Age (LIA). However, the sampling interval for ??18O is sufficiently large (20 cm) such that it is difficult to pinpoint the LIA termination on the basis of ??18O data alone. Other research has shown that changes in the ??18O variance are generally coincident with changes in ECM variance. The ECM data set contains over 125,000 data points at a resolution of 1 data point per millimeter of ice core. A 999-point running average of the ECM data set and results from f tests indicates that the variance of the ECM data decreases significantly at about 108 m. At this depth, the age-depth profile predicts an age of 1845 A.D. Results indicate the termination of the LIA was abrupt with a major climatic shift to warmer temperatures around 1845 A.D. and continuing to present day. Prediction limits (error bars) calculated for the profile ages are ??10 years (90% confidence level). Thus a conservative estimate for the time taken to complete the LIA climatic shift to present-day climate is about 10 years, suggesting the LIA termination in alpine regions of central North America may have

  4. Late Cretaceous Arc Initiation on the Edge of an Oceanic Plateau (Southern Central America)

    NASA Astrophysics Data System (ADS)

    Buchs, D. M.; Baumgartner, P. O.; Arculus, R.

    2007-12-01

    The Caribbean Plate comprises one or several late Cretaceous oceanic plateaus imbricated between the Northern and Southern Americas. Uplifted portions of plateau(s) along plate boundaries have been recognized in many sites, including that underlying the south Central American Volcanic Arc. We provide new constraints for the role of the plateau in the evolution of this arc obtained by mapping of the uplifted forearc area between southern Costa Rica and western Panama. An oceanic plateau, accreted seamounts and arc rocks were identified, and a new tectono-stratigraphy defined. The arc basement is composed of a Coniacian oceanic plateau. In the outer margin, late Cretaceous-Eocene accreted seamounts are in contact with the plateau along tectonic mélanges and active faults. Campanian-Maastrichtian primitive arc rocks are found 40-110 km to the trench on the top of -or as dykes within- the plateau. The location of these rocks correlates to previous observations and indicates that the arc front migrated away from the trench during the late Cretaceous, potentially in response to subduction erosion or slab flattening [Lissinna et al., EGU 2006]. The first island arc lavas were deposited under sea level, over a broad area. They were quickly followed by more evolved intrusives and lavas, which were emplaced along a volcanic front during the late Cretaceous-Paleocene. Detrital and volcanic records along the Central American isthmus indicate that a continuous volcanic arc extended between eastern Panama and northern Costa Rica in this time. In southern Costa Rica (Golfito complex) and western Panama (Sona-Azuero-Coiba complex), the oceanic plateau consists mainly of pillowed and massive low Fe (tholeiitic) basalts. These rocks have a highly consistent geochemistry characterized by flat, primitive upper mantle-normalized incompatible element patterns with low Pb and high Nb-Ti contents. Primitive arc igneous samples are low-medium Fe basalts to trachyandesites found as pillow

  5. Genetic divergence disclosing a rapid prehistorical dispersion of Native Americans in Central and South America.

    PubMed

    He, Yungang; Wang, Wei R; Li, Ran; Wang, Sijia; Jin, Li

    2012-01-01

    An accurate estimate of the divergence time between Native Americans is important for understanding the initial entry and early dispersion of human beings in the New World. Current methods for estimating the genetic divergence time of populations could seriously depart from a linear relationship with the true divergence for multiple populations of a different population size and significant population expansion. Here, to address this problem, we propose a novel measure to estimate the genetic divergence time of populations. Computer simulation revealed that the new measure maintained an excellent linear correlation with the population divergence time in complicated multi-population scenarios with population expansion. Utilizing the new measure and microsatellite data of 21 Native American populations, we investigated the genetic divergences of the Native American populations. The results indicated that genetic divergences between North American populations are greater than that between Central and South American populations. None of the divergences, however, were large enough to constitute convincing evidence supporting the two-wave or multi-wave migration model for the initial entry of human beings into America. The genetic affinity of the Native American populations was further explored using Neighbor-Net and the genetic divergences suggested that these populations could be categorized into four genetic groups living in four different ecologic zones. The divergence of the population groups suggests that the early dispersion of human beings in America was a multi-step procedure. Further, the divergences suggest the rapid dispersion of Native Americans in Central and South Americas after a long standstill period in North America. PMID:22970308

  6. Genetic Divergence Disclosing a Rapid Prehistorical Dispersion of Native Americans in Central and South America

    PubMed Central

    He, Yungang; Wang, Wei R.; Li, Ran; Wang, Sijia; Jin, Li

    2012-01-01

    An accurate estimate of the divergence time between Native Americans is important for understanding the initial entry and early dispersion of human beings in the New World. Current methods for estimating the genetic divergence time of populations could seriously depart from a linear relationship with the true divergence for multiple populations of a different population size and significant population expansion. Here, to address this problem, we propose a novel measure to estimate the genetic divergence time of populations. Computer simulation revealed that the new measure maintained an excellent linear correlation with the population divergence time in complicated multi-population scenarios with population expansion. Utilizing the new measure and microsatellite data of 21 Native American populations, we investigated the genetic divergences of the Native American populations. The results indicated that genetic divergences between North American populations are greater than that between Central and South American populations. None of the divergences, however, were large enough to constitute convincing evidence supporting the two-wave or multi-wave migration model for the initial entry of human beings into America. The genetic affinity of the Native American populations was further explored using Neighbor-Net and the genetic divergences suggested that these populations could be categorized into four genetic groups living in four different ecologic zones. The divergence of the population groups suggests that the early dispersion of human beings in America was a multi-step procedure. Further, the divergences suggest the rapid dispersion of Native Americans in Central and South Americas after a long standstill period in North America. PMID:22970308

  7. Mid-term evaluation of the NRECA (National Rural Electric Cooperative Association) Central America Rural Electrification Support Program (CARES)

    SciTech Connect

    Perlack, R.D. ); Jones, H.G. ); Garcia, A. III . Dept. of Agricultural Engineering); Flores, E. , Guatemala City )

    1990-09-01

    Oak Ridge National Laboratory was requested by the Regional Office for Central America and Panama to conduct a mid-term evaluation of the Cares Project, which is being implemented by the National Rural Electric Cooperative Association. This evaluation was conducted over a three week period by a four person team. Overall, the project has had numerous successes and is highly valued by local counterpart utilities and USAID Missions. Notwithstanding the significant results of the project, changes can be made in certain operating procedures and in the direction of some programmatic activities that can lead to an even more effective project.

  8. Revision of the genus Lepidoblepharis (Reptilia: Squamata: Sphaerodactylidae) in Central America, with the description of three new species.

    PubMed

    Batista, Abel; Ponce, Marcos; Vesely, Milan; Mebert, Konrad; Hertz, Andreas; Köhler, Gunther; Carrizo, Arcadio; Lotzkat, Sebastian

    2015-01-01

    Based on morphological and molecular data, we describe three new species of the genus Lepidoblepharis with granular dorsals from Panama (Lepidoblepharis emberawoundule sp. nov., Lepidoblepharis rufigularis sp. nov., and Lepidoblepharis victormartinezi sp. nov.). The results of our molecular analyses confirm the existence of five deeply differentiated genealogical lineages among Panamanian Lepidoblepharis. We present detailed descriptions of their morphology, including some new valuable scalation characters (ventral and subfemoral escutcheon) and hemipenes, as well as comparisons with the other two species of the genus known to occur in Panama (L. sanctaemartae and L. xanthostigma) and their South American congeners. Last, we provide an updated identification key for the genus Lepidoblepharis in Central America. PMID:26250268

  9. Revision of the genus Lepidoblepharis (Reptilia: Squamata: Sphaerodactylidae) in Central America, with the description of three new species.

    PubMed

    Batista, Abel; Ponce, Marcos; Vesely, Milan; Mebert, Konrad; Hertz, Andreas; Köhler, Gunther; Carrizo, Arcadio; Lotzkat, Sebastian

    2015-01-01

    Based on morphological and molecular data, we describe three new species of the genus Lepidoblepharis with granular dorsals from Panama (Lepidoblepharis emberawoundule sp. nov., Lepidoblepharis rufigularis sp. nov., and Lepidoblepharis victormartinezi sp. nov.). The results of our molecular analyses confirm the existence of five deeply differentiated genealogical lineages among Panamanian Lepidoblepharis. We present detailed descriptions of their morphology, including some new valuable scalation characters (ventral and subfemoral escutcheon) and hemipenes, as well as comparisons with the other two species of the genus known to occur in Panama (L. sanctaemartae and L. xanthostigma) and their South American congeners. Last, we provide an updated identification key for the genus Lepidoblepharis in Central America.

  10. Development and Validation of a Nutritional Education Pamphlet for Low-Literacy Pediatric Oncology Caregivers in Central America

    PubMed Central

    Garcia, Melissa; Chismark, Elisabeth A.; Mosby, Terezie; Day, Sara

    2013-01-01

    Background A culturally appropriate nutrition education pamphlet was developed and validated for low-literacy caregivers in Honduras, El Salvador, and Guatemala. Methods The pamphlet was developed after a preliminary survey of pediatric oncology nurses in the 3 countries to assess the need for education materials, caregiver literacy levels, and local eating habits. Experts in nutrition and low-literacy patient education and nurses validated the pamphlet’s content and design. Results and Conclusions Nurses expressed the need for nutrition-related pamphlets in developing countries. The pamphlet was validated positively by experts and nurses and has been circulated to pediatric oncology caregivers in Central America. PMID:20300913

  11. Tree-ring records of near-Younger Dryas time in central North America - Preliminary results from the Lincoln quarry site, central Illinois, USA

    USGS Publications Warehouse

    Panyushkina, Irina P.; Leavitt, Steven W.; Wiedenhoeft, A.; Noggle, S.; Curry, B.; Grimm, E.

    2004-01-01

    The abrupt millennial-scale changes associated with the Younger Dryas (YD) event ("chronozone") near the dawn of the Holocene are at least hemispheric, if not global, in extent. Evidence for the YD cold excursion is abundant in Europe but fairly meager in central North America. We are engaged in an investigation of high-resolution environmental changes in mid-North America over several millennia (about 10,000 to 14,000 BP) during the Late Glacial-Early Holocene transition, including the YD interval. Several sites containing logs or stumps have been identified and we are in the process of initial sampling or re-sampling them for this project. Here, we report on a site in central Illinois containing a deposit of logs initially thought to be of YD age preserved in alluvial sands. The assemblage of wood represents hardwood (angiosperm) trees, and the ring-width characteristics are favorable to developing formal tree-ring chronologies. However, 4 new radiocarbon dates indicate deposition of wood may have taken place over at least 8000 14C yr (6000-14,000 BP). This complicates the effort to develop a single floating chronology of several hundred years at this site, but it may provide wood from a restricted region over a long period of time from which to develop a sequence of floating chronologies, the timing of deposition and preservation of which could be related to paleoclimatic events and conditions.

  12. Evaluating Ultraviolet Radiation Exposures Determined from TOMS Satellite Data at Sites of Amphibian Declines in Central and South America

    NASA Technical Reports Server (NTRS)

    Middleton, Elizabeth M.; Smith, David E. (Technical Monitor)

    2000-01-01

    Many amphibian species have experienced substantial population declines, or have disappeared altogether, during the last several decades at a number of amphibian census sites in Central and South America. This study addresses the use of satellite-derived trends in solar ultraviolet-B (UV-B; 280-320 nm) radiation exposures at these sites over the last two decades, and is intended to demonstrate a role for satellite observations in determining whether UV-B radiation is a contributing factor in amphibian declines. UV-B radiation levels at the Earth's surface were derived from the Total Ozone Mapping Spectrometer (TOMS) satellite data, typically acquired daily since 1979. These data were used to calculate the daily erythemal (sunburning) UV-B, or UV-B(sub ery), exposures at the latitude, longitude, and elevation of each of 20 census sites. The annually averaged UV-B(sub ery) dose, as well as the maximum values, have been increasing in both Central and South America, with higher levels received at the Central American sites. The annually averaged UV-B(sub ery) exposures increased significantly from 1979-1998 at all 11 Central American sites examined (r(exp 2) = 0.60 - 0.79; P<=0.015), with smaller but significant increases at five of the nine South American sites (r(exp 2) = 0.24-0.42; P<=0.05). The contribution of the highest UV-B(sub ery) exposure levels (>= 6750 J/sq m*d) to the annual UV-B(sub ery) total has increased from approx. 5% to approx. 15% in Central America over the 19 year period, but actual daily exposures for each species are unknown. Synergy among UV-B radiation and other factors, especially those associated with alterations of water chemistry (e.g., acidification) in aqueous habitats is discussed. These findings justify further research concerning whether UV-B(sub ery) radiation plays a role in amphibian population declines and extinctions.

  13. Sea Surface Temperature and Vegetation Index from MODIS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is a composite MODIS image showing the 'green wave' of spring in North America and sea surface temperature in the ocean, collected over an 8-day period during the first week in April 2000. On land, the darker green pixels show where the most green foliage is being produced due to photosynthetic activity. Yellows on land show where there is little or no productivity and red is a boundary zone. In the ocean, orange and yellows show warmer waters and blues show colder values. (MODIS Data Type: MODIS-PFM)

  14. Information to act: household characteristics are predictors of domestic infestation with the Chagas vector Triatoma dimidiata in Central America.

    PubMed

    Bustamante Zamora, Dulce María; Hernández, Marianela Menes; Torres, Nuria; Zúniga, Concepción; Sosa, Wilfredo; de Abrego, Vianney; Monroy Escobar, María Carlota

    2015-07-01

    The interruption of vectorial transmission of Chagas disease by Triatoma dimidiata in central America is a public health challenge that cannot be resolved by insecticide application alone. In this study, we collected information on previously known household risk factors for infestation in 11 villages and more than 2,000 houses in Guatemala, Honduras, and El Salvador, and we constructed multivariate models and used multimodel inference to evaluate their importance as predictors of infestation in the region. The models had moderate ability to predict infested houses (sensitivity, 0.32-0.54) and excellent ability to predict noninfested houses (specificity higher than 0.90). Predictive ability was improved by including random village effects and presence of signs of infestation (insect feces, eggs, and exuviae) as fixed effects. Multimodel inference results varied depending on factors included, but house wall materials (adobe, bajareque, and palopique) and signs of infestation were among the most important predictive factors. Reduced models were not supported suggesting that all factors contributed to predictions. Previous knowledge and information from this study show that we have evidence to prioritize rural households for improvement to prevent house infestation with Triatoma dimidiata in Central America. House improvement will most likely have other health co-benefits. PMID:25870430

  15. The complex biogeography of the plant pathogen Xylella fastidiosa: genetic evidence of introductions and Subspecific introgression in Central America.

    PubMed

    Nunney, Leonard; Ortiz, Beatriz; Russell, Stephanie A; Ruiz Sánchez, Rebeca; Stouthamer, Richard

    2014-01-01

    The bacterium Xylella fastidiosa is a plant pathogen with a history of economically damaging introductions of subspecies to regions where its other subspecies are native. Genetic evidence is presented demonstrating the introduction of two new taxa into Central America and their introgression into the native subspecies, X. fastidiosa subsp. fastidiosa. The data are from 10 genetic outliers detected by multilocus sequence typing (MLST) of isolates from Costa Rica. Six (five from oleander, one from coffee) defined a new sequence type (ST53) that carried alleles at six of the eight loci sequenced (five of the seven MLST loci) diagnostic of the South American subspecies Xylella fastidiosa subsp. pauca which causes two economically damaging plant diseases, citrus variegated chlorosis and coffee leaf scorch. The two remaining loci of ST53 carried alleles from what appears to be a new South American form of X. fastidiosa. Four isolates, classified as X. fastidiosa subsp. fastidiosa, showed a low level of introgression of non-native DNA. One grapevine isolate showed introgression of an allele from X. fastidiosa subsp. pauca while the other three (from citrus and coffee) showed introgression of an allele with similar ancestry to the alleles of unknown origin in ST53. The presence of X. fastidiosa subsp. pauca in Central America is troubling given its disease potential, and establishes another route for the introduction of this economically damaging subspecies into the US or elsewhere, a threat potentially compounded by the presence of a previously unknown form of X. fastidiosa. PMID:25379725

  16. First report of Babesia gibsoni in Central America and survey for vector-borne infections in dogs from Nicaragua

    PubMed Central

    2014-01-01

    Background Although many vector-borne diseases are important causes of morbidity and mortality in dogs in tropical areas and potential zoonoses, there is little information on these conditions in Central America. Methods Seven qPCRs for vector-borne pathogens were performed on a Roche LightCycler PCR Instrument to investigate their prevalence in a convenience sample of whole blood samples from apparently healthy dogs in Nicaragua. Also, a qPCR targeting the canine hydroxymethylbilane synthase (HMBS) gene was used as an endogenous internal control and verified the quality and quantity of DNA in the samples was appropriate for the study. Results We found DNA of Rickettsia felis (5%), Babesia spp. (26%), Hepatozoon canis (51%), Anaplasma platys (13%) and Ehrlichia canis (56%) in the 39 dogs studied. The qPCRs for Coxiella burnetii and Dirofilaria immitis were negative. Of the 30 (80%) dogs that were positive by qPCR, 12 (31%) were positive for one agent, 11 (28%) for two, 3 (8%) for three, and 4 (10%) for four agents. Conclusions This is the first report of B. gibsoni in dogs from Central America and the first recording of vector-borne agents in dogs from Nicaragua. Dogs in Nicaragua are commonly infected with a variety of vector-borne pathogens, some of which may also infect people. PMID:24667065

  17. Simulated influences of Lake Agassiz on the climate of central North America 11,000 years ago

    USGS Publications Warehouse

    Hostetler, S.W.; Bartlein, P.J.; Clark, P.U.; Small, E.E.; Solomon, A.M.

    2000-01-01

    Eleven thousand years ago, large lakes existed in central and eastern North America along the margin of the Laurentide Ice Sheet. The large-scale North American climate at this time has been simulated with atmospheric general circulation models, but these relatively coarse global models do not resolve potentially important features of the mesoscale circulation that arise from interactions among the atmosphere, ice sheet, and proglacial lakes. Here we present simulations of the climate of central and eastern North America 11,000 years ago with a high-resolution, regional climate model nested within a general circulation model. The simulated climate is in general agreement with that inferred from palaeoecological evidence. Our experiments indicate that through mesoscale atmospheric feedbacks, the annual delivery of moisture to the Laurentide Ice Sheet was diminished at times of a large, cold Lake Agassiz relative to periods of lower lake stands. The resulting changes in the mass balance of the ice sheet may have contributed to fluctuations of the ice margin, thus affecting the routing of fresh water to the North Atlantic Ocean. A retreating ice margin during periods of high lake level may have opened an outlet for discharge of Lake Agassiz into the North Atlantic. A subsequent advance of the ice margin due to greater moisture delivery associated with a low lake level could have dammed the outlet, thereby reducing discharge to the North Atlantic. These variations may have been decisive in causing the Younger Dryas cold even.

  18. Information to Act: Household Characteristics are Predictors of Domestic Infestation with the Chagas Vector Triatoma dimidiata in Central America

    PubMed Central

    Zamora, Dulce María Bustamante; Hernández, Marianela Menes; Torres, Nuria; Zúniga, Concepción; Sosa, Wilfredo; de Abrego, Vianney; Escobar, María Carlota Monroy

    2015-01-01

    The interruption of vectorial transmission of Chagas disease by Triatoma dimidiata in central America is a public health challenge that cannot be resolved by insecticide application alone. In this study, we collected information on previously known household risk factors for infestation in 11 villages and more than 2,000 houses in Guatemala, Honduras, and El Salvador, and we constructed multivariate models and used multimodel inference to evaluate their importance as predictors of infestation in the region. The models had moderate ability to predict infested houses (sensitivity, 0.32–0.54) and excellent ability to predict noninfested houses (specificity higher than 0.90). Predictive ability was improved by including random village effects and presence of signs of infestation (insect feces, eggs, and exuviae) as fixed effects. Multimodel inference results varied depending on factors included, but house wall materials (adobe, bajareque, and palopique) and signs of infestation were among the most important predictive factors. Reduced models were not supported suggesting that all factors contributed to predictions. Previous knowledge and information from this study show that we have evidence to prioritize rural households for improvement to prevent house infestation with Triatoma dimidiata in Central America. House improvement will most likely have other health co-benefits. PMID:25870430

  19. Age and geochemistry of basaltic complexes in western Costa Rica: Contributions to the geotectonic evolution of Central America

    NASA Astrophysics Data System (ADS)

    Hauff, Folkmar; Hoernle, Kaj; van den Bogaard, Paul; Alvarado, Guillermo; Garbe-Schönberg, Dieter

    2000-05-01

    The age and origin of magmatic complexes along the Pacific Coast of Central America have important implications for the origin and tectonic evolution of this convergent plate margin. Here we present new 40Ar/39Ar laser age dates, major and trace element data, and initial Sr-Nd-Pb isotope ratios. The 124-109 Ma tholeiitic portions of the Santa Elena complex formed in a primitive island arc setting, believed to be part of the Chortis subduction zone. The geochemical similarities between the Santa Elena and Tortugal alkaline volcanic rocks suggest that Chortis block may extend south of the Hess Escarpment. The Nicoya, Herradura, Golfito, and Burica complexes and the tholeiitic Tortugal unit formed between 95 and 75 Ma and appear to be part of the Caribbean Large Igneous Province, thought to mark the initiation of the Galápagos hotspot. The Quepos and Osa complexes (65-59 Ma) represent accreted sections of an ocean island and an aseismic ridge, respectively, interpreted to reflect part of the Galápagos paleo-hotspot track. An Oligocene unconformity throughout Central America may be related to the mid-Eocene accretion of the Quepos and Osa complexes.

  20. Estimation of speciated and total mercury dry deposition at monitoring locations in eastern and central North America

    USGS Publications Warehouse

    Zhang, L.; Blanchard, P.; Gay, D.A.; Prestbo, E.M.; Risch, M.R.; Johnson, D.; Narayan, J.; Zsolway, R.; Holsen, T.M.; Miller, E.K.; Castro, M.S.; Graydon, J.A.; St. Louis, V.L.; Dalziel, J.

    2012-01-01

    Dry deposition of speciated mercury, i.e., gaseous oxidized mercury (GOM), particulate-bound mercury (PBM), and gaseous elemental mercury (GEM), was estimated for the year 2008–2009 at 19 monitoring locations in eastern and central North America. Dry deposition estimates were obtained by combining monitored two- to four-hourly speciated ambient concentrations with modeled hourly dry deposition velocities (Vd) calculated using forecasted meteorology. Annual dry deposition of GOM+PBM was estimated to be in the range of 0.4 to 8.1 μg m−2 at these locations with GOM deposition being mostly five to ten times higher than PBM deposition, due to their different modeled Vd values. Net annual GEM dry deposition was estimated to be in the range of 5 to 26 μg m−2 at 18 sites and 33 μg m−2 at one site. The estimated dry deposition agrees very well with limited surrogate-surface dry deposition measurements of GOM and PBM, and also agrees with litterfall mercury measurements conducted at multiple locations in eastern and central North America. This study suggests that GEM contributes much more than GOM+PBM to the total dry deposition at the majority of the sites considered here; the only exception is at locations close to significant point sources where GEM and GOM+PBM contribute equally to the total dry deposition. The relative magnitude of the speciated dry deposition and their good comparisons with litterfall deposition suggest that mercury in litterfall originates primarily from GEM, which is consistent with the limited number of previous field studies. The study also supports previous analyses suggesting that total dry deposition of mercury is equal to, if not more important than, wet deposition of mercury on a regional scale in eastern North America.

  1. Methodological and Practical Considerations for DevelopingMultiproject Baselines for Electric Power and Cement Industry Projects inCentral America

    SciTech Connect

    Murtishaw, Scott; Sathaye, Jayant; Galitsky, Christina; Dorion,Kristel

    2004-09-02

    The Lawrence Berkeley National Laboratory (Berkeley Lab) andthe Center for Sustainable Development in the Americas (CSDA) conductedtechnical studies and organized two training workshops to developcapacity in Central America for the evaluation of climate changeprojects. This paper describes the results of two baseline case studiesconducted for these workshops, one for the power sector and one for thecement industry, that were devised to illustrate certain approaches tobaseline setting. Multiproject baseline emission rates (BERs) for themain Guatemalan electricity grid were calculated from 2001 data. Inrecent years, the Guatemalan power sector has experienced rapid growth;thus, a sufficient number of new plants have been built to estimateviable BERs. We found that BERs for baseload plants offsetting additionalbaseload capacity ranged from 0.702 kgCO2/kWh (using a weighted averagestringency) to 0.507 kgCO2/kWh (using a 10th percentile stringency),while the baseline for plants offsetting load-followingcapacity is lowerat 0.567 kgCO2/kWh. For power displaced from existing load-followingplants, the rate is higher, 0.735 kgCO2/kWh, as a result of the age ofsome plants used for meeting peak loads and the infrequency of their use.The approved consolidated methodology for the Clean Development Mechanismyields a single rate of 0.753 kgCO2/kWh. Due to the relatively smallnumber of cement plants in the region and the regional nature of thecement market, all of Central America was chosen as the geographicboundary for setting cement industry BERs. Unfortunately, actualoperations and output data were unobtainable for most of the plants inthe region, and many data were estimated. Cement industry BERs rangedfrom 205 kgCO2 to 225 kgCO2 per metric ton of cement.

  2. Introduction: seismology and earthquake engineering in Mexico and Central and South America.

    USGS Publications Warehouse

    Espinosa, A.F.

    1982-01-01

    The results from seismological studies that are used by the engineering community are just one of the benefits obtained from research aimed at mitigating the earthquake hazard. In this issue of Earthquake Information Bulletin current programs in seismology and earthquake engineering, seismic networks, future plans and some of the cooperative programs with different internation organizations are described by Latin-American seismologists. The article describes the development of seismology in Latin America and the seismological interest of the OAS. -P.N.Chroston

  3. Remote Sensing of Radiative and Microphysical Properties of Clouds During TC (sup 4): Results from MAS, MASTER, MODIS, and MISR

    NASA Technical Reports Server (NTRS)

    King, Michael D.; Platnick, Steven; Wind, Galina; Arnold, G. Thomas; Dominguez, Roseanne T.

    2010-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) Airborne Simulator (MAS) and MODIS/Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Airborne Simulator (MASTER) were used to obtain measurements of the bidirectional reflectance and brightness temperature of clouds at 50 discrete wavelengths between 0.47 and 14.2 microns (12.9 microns for MASTER). These observations were obtained from the NASA ER-2 aircraft as part of the Tropical Composition, Cloud and Climate Coupling (TC4) experiment conducted over Central America and surrounding Pacific and Atlantic Oceans between 17 July and 8 August 2007. Multispectral images in eleven distinct bands were used to derive a confidence in clear sky (or alternatively the probability Of cloud) over land and ocean ecosystems. Based on the results of individual tests run as part of the cloud mask, an algorithm was developed to estimate the phase of the clouds (liquid water, ice, or undetermined phase). The cloud optical thickness and effective radius were derived for both liquid water and ice clouds that were detected during each flight, using a nearly identical algorithm to that implemented operationally to process MODIS Cloud data from the Aqua and Terra satellites (Collection 5). This analysis shows that the cloud mask developed for operational use on MODIS, and tested using MAS and MASTER data in TC(sup 4), is quite capable of distinguishing both liquid water and ice clouds during daytime conditions over both land and ocean. The cloud optical thickness and effective radius retrievals use five distinct bands of the MAS (or MASTER), and these results were compared with nearly simultaneous retrievals of marine liquid water clouds from MODIS on the Terra spacecraft. Finally, this MODIS-based algorithm was adapted to Multiangle Imaging SpectroRadiometer (MISR) data to infer the cloud optical thickness Of liquid water clouds from MISR. Results of this analysis are compared and contrasted.

  4. Assessing the suitability of Holocene environments along the central Belize coast, Central America, for the reconstruction of hurricane records

    NASA Astrophysics Data System (ADS)

    Adomat, Friederike; Gischler, Eberhard

    2016-03-01

    Since the Belize coast was repeatedly affected by hurricanes and the paleohurricane record for this region is poor, sediment cores from coastal lagoon environments along the central Belize coast have been examined in order to identify storm deposits. The paleohurricane record presented in this study spans the past 8000 years and exhibits three periods with increased evidences of hurricane strikes occurring at 6000-4900, 4200-3600 and 2200-1500 cal yr BP. Two earlier events around 7100 and 7900 cal yr BP and more recent events around 180 cal yr BP and during modern times have been detected. Sand layers, redeposited corals and lagoon shell concentrations have been used as proxies for storm deposition. Additionally, hiatuses and reversed ages may indicate storm influence. While sand layers and corals represent overwash deposits, the lagoon shell concentrations, which mainly comprise the bivalve Anomalocardia cuneimeris and cerithid gastropods, have been deposited due to changes in lagoon salinity during and after storm landfalls. Comparison with other studies reveals similarities with one record from Belize, but hardly any matches with other published records. The potential for paleotempestology reconstructions of the barrier-lagoon complexes along the central Belize coast differs depending on geomorphology, and deposition of washovers in the lagoon basins is limited, probably due to the interplay of biological, geological and geomorphological processes.

  5. Jahnula species from North and Central America, including three new species.

    PubMed

    Raja, H A; Shearer, C A

    2006-01-01

    Three new species of loculoascomycetes collected from freshwater habitats in North America are described as new species of Jahnula (Jahnulales, Dothideomycetes). All three share these morphological features: hyaline to blackish translucent, membranous ascomata with subtending, wide, septate brown, spreading hyphae; peridia composed of large angular cells; hamathecium of septate pseudoparaphyses; 8-spored, clavate to cylindrical asci; and 1-septate, broadly fusiform, brown, multiguttulate ascospores. Four additional species, J. aquatica, J. bipolaris, J. potamophila, and J. seychellensis, are reported for the first time from the western hemisphere. PMID:16894977

  6. Paleocene Paleomagnetic Pole for north America from alkalic intrusions, central Montana

    SciTech Connect

    Jacobson, D.; Beck, M.E. Jr.; Diehl, J.F.; Hearn, B.C. Jr.

    1980-07-01

    The apparent polar wandering path from Late Cretaceous through early Tertiary time is not well defined. We have collected 33 paleomagnetic sites from the Paleocena Moccasin, Judith, and Little Rocky Mountains and from these a North American Paleocene paleomagnetic pole position has been determined at 174.9 /sup 0/W long., 80.5 /sup 0/N lat., with a circle of 95% confidence of 3.6 /sup 0/. This pole location serves as a Paleocene reference pole and enhances the North America apparent polar wandering path for a critical period of its history.

  7. Mapping Crop Patterns in Central US Agricultural Systems from 2000 to 2014 Based on Landsat Data: To What Degree Does Fusing MODIS Data Improve Classification Accuracies?

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Radeloff, V.; Ives, A. R.; Barton, B.

    2015-12-01

    Deriving crop pattern with high accuracy is of great importance for characterizing landscape diversity, which affects the resilience of food webs in agricultural systems in the face of climatic and land cover changes. Landsat sensors were originally designed to monitor agricultural areas, and both radiometric and spatial resolution are optimized for monitoring large agricultural fields. Unfortunately, few clear Landsat images per year are available, which has limited the use of Landsat for making crop classification, and this situation is worse in cloudy areas of the Earth. Meanwhile, the MODerate Resolution Imaging Spectroradiometer (MODIS) data has better temporal resolution but cannot capture fine spatial heterogeneity of agricultural systems. Our question was to what extent fusing imagery from both sensors could improve crop classifications. We utilized the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) algorithm to simulate Landsat-like images at MODIS temporal resolution. Based on Random Forests (RF) classifier, we tested whether and by what degree crop maps from 2000 to 2014 of the Arlington Agricultural Research Station (Wisconsin, USA) were improved by integrating available clear Landsat images each year with synthetic images. We predicted that the degree to which classification accuracy can be improved by incorporating synthetic imagery depends on the number and acquisition time of clear Landsat images. Moreover, multi-season data are essential for mapping crop types by capturing their phenological dynamics, and STARFM-simulated images can be used to compensate for missing Landsat observations. Our study is helpful for eliminating the limits of the use of Landsat data in mapping crop patterns, and can provide a benchmark of accuracy when choosing STARFM-simulated images to make crop classification at broader scales.

  8. Phylogenetic analysis of classical swine fever virus (CSFV) field isolates from outbreaks in South and Central America.

    PubMed

    Pereda, A J; Greiser-Wilke, I; Schmitt, B; Rincon, M A; Mogollon, J D; Sabogal, Z Y; Lora, A M; Sanguinetti, H; Piccone, M E

    2005-06-01

    To date, there is little information concerning the epidemiological situation of classical swine fever (CSF) in the Americas. Besides summarizing the available data, genotyping of isolates from outbreaks in domestic pigs in several countries of South and Central America was performed. For this, a 190 base fragment of the E2 envelope glycoprotein gene was used. European strains and isolates, and historical isolates from the United States (US) were included for comparison. In contrast to the situation in most parts of Europe, where group 2 isolates predominate, it was found that all the isolates from the American continent analyzed belonged to group 1 and were further resolved into three subgroups. The Cuban isolates clustered in subgroup 1.2, whereas the isolates from Honduras and Guatemala clustered in subgroup 1.3. The remaining isolates from Argentina, Brazil, Colombia and Mexico generated four poorly resolved clusters in subgroup 1.1, together with the vaccine strains, with historical European and US isolates, and with a recent Russian isolate. While the vaccine strains and the historical European isolates formed a relatively distinct cluster, one of the US isolates clustered together with the Mexican, and another one with Colombian isolates. Historically, CSF (hog cholera) was observed almost simultaneously in the US and in Europe in the first half of the 19th century, and its origin remains a matter of discussion. Our results showed that the US isolates are closely related to isolates from South America, while appearance of isolates in Cuba on one hand and in Honduras and Guatemala on the other hand, seems to have been due to unrelated events. This allows to speculate that at least in the American continent, CSF virus may have appeared independently in several regions, and spreading may have been a secondary effect.

  9. Delineating Surface Water Features In The Prairie Pothole Wetlands With MODIS Data

    NASA Astrophysics Data System (ADS)

    Ji, L.; Wylie, B. K.; Zhang, L.; Rover, J.; Tieszen, L. L.

    2007-12-01

    The Prairie Pothole Region (PPR), covered with thousands of shallow ponds known as potholes, is a large wetland area in central North America. The PPR wetlands are valuable because of the ecosystem services they provide, including water balance and flood mediation, habitat for migratory birds and waterfowl production, and carbon sequestration. During the last century, impacts of intense land use (agricultural and commercial development) and climate change have caused drastic reductions of surface water area and wetland habitat in the PPR. Spatial and temporal characterizations of the surface water dynamics are important for understanding the hydrological and ecological characteristics in the PPR wetlands. In this study, we use the Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance data processed as 8-day composites at 500-meter resolution from 2000 to 2006. The modified normalized difference water index [MNDWI = (band 4 ¡§C band 6)/(band 4 + band 6)] was computed to delineate water features. By adjusting the MNDWI threshold, we generated three land-cover classes: water, land, and water/land mixture. Additionally, we acquired 26 Landsat TM/ETM+ scenes, 14 to calibrate the MODIS MDNWI threshold and 12 to independently validate the MODIS water feature products. For the validation, the maps of percent water area derived from MODIS were compared with the maps generated from the Landsat images at a 5-kilometer grid level. The comparison illustrates a low root mean square error (0.0034 percent) and a high correlation coefficient (0.95), suggesting satisfactory accuracy of the MODIS water products. We have produced and illustrated the MODIS water feature maps for the U.S. portion of the PPR at 32-day intervals for the growing seasons from 2000 to 2006. The time series of MODIS-derived water feature maps are useful for delineating water features and monitoring water area dynamics in this area, and these products provide coarse resolution information

  10. MODIS Land Data Products: Generation, Quality Assurance and Validation

    NASA Technical Reports Server (NTRS)

    Masuoka, Edward; Wolfe, Robert; Morisette, Jeffery; Sinno, Scott; Teague, Michael; Saleous, Nazmi; Devadiga, Sadashiva; Justice, Christopher; Nickeson, Jaime

    2008-01-01

    The Moderate Resolution Imaging Spectrometer (MODIS) on-board NASA's Earth Observing System (EOS) Terra and Aqua Satellites are key instruments for providing data on global land, atmosphere, and ocean dynamics. Derived MODIS land, atmosphere and ocean products are central to NASA's mission to monitor and understand the Earth system. NASA has developed and generated on a systematic basis a suite of MODIS products starting with the first Terra MODIS data sensed February 22, 2000 and continuing with the first MODIS-Aqua data sensed July 2, 2002. The MODIS Land products are divided into three product suites: radiation budget products, ecosystem products, and land cover characterization products. The production and distribution of the MODIS Land products are described, from initial software delivery by the MODIS Land Science Team, to operational product generation and quality assurance, delivery to EOS archival and distribution centers, and product accuracy assessment and validation. Progress and lessons learned since the first MODIS data were in early 2000 are described.

  11. A Critical Examination of Spatial Biases Between MODIS and MISR Aerosol Products - Application for Potential AERONET Deployment

    NASA Technical Reports Server (NTRS)

    Shi, Y.; Zhang, J.; Reid, J. S.; Hyer, E. J.; Eck, T. F.; Holben, B. N.; Kahn, R. A.

    2011-01-01

    AErosol RObotic NETwork (AERONET) data are the primary benchmark for evaluating satellite-retrieved aerosol properties. However, despite its extensive coverage, the representativeness of the AERONET data is rarely discussed. Indeed, many studies have shown that satellite retrieval biases have a significant degree of spatial correlation that may be problematic for higher-level processes or inverse-emissions-modeling studies. To consider these issues and evaluate relative performance in regions of few surface observations, cross-comparisons between the Aerosol Optical Depth (AOD) products of operational MODIS Collection 5.1 Dark Target (DT) and operational MODIS Collection 5.1 Deep Blue (DB) with MISR version 22 were conducted. Through such comparisons, we can observe coherent spatial features of the AOD bias while side-stepping the full analysis required for determining when or where either retrieval is more correct. We identify regions where MODIS to MISR AOD ratios were found to be above 1.4 and below 0.7. Regions where lower boundary condition uncertainty is likely to be a dominant factor include portions of Western North America, the Andes mountains, Saharan Africa, the Arabian Peninsula, and Central Asia. Similarly, microphysical biases may be an issue in South America, and specific parts of Southern Africa, India Asia, East Asia, and Indonesia. These results help identify high-priority locations for possible future deployments of both in situ and ground based remote sensing measurements. The Supplement includes a km1 file.

  12. Temporal Trends in Age at HIV Diagnosis in Cohorts in the United States, the Caribbean, and Central and South America

    PubMed Central

    Crabtree-Ramírez, Brenda; Vega, Yanink Neried Caro; Shepherd, Bryan E.; Turner, Megan; Carriquiry, Gabriela; Fink, Valeria; Luz, Paula M.; Cortes, Claudia P.; Rouzier, Vanessa; Padgett, Denis; Jayathilake, Karu; McGowan, Catherine C.; Person, Anna K.

    2015-01-01

    In the United States (USA), the age of those newly diagnosed with HIV is changing, particularly among men who have sex with men (MSM). A retrospective analysis included HIV-infected adults from 7 sites in the Caribbean, Central and South America network (CCASAnet) and the Vanderbilt Comprehensive Care Clinic (VCCC-Nashville, Tennessee, USA). We estimate the proportion of patients <25 years at HIV diagnosis by calendar year among the general population and MSM. 19,466 (CCASAnet) and 3,746 (VCCC) patients were included. The proportion <25 years at diagnosis in VCCC increased over time for both the general population and MSM (p<0.001). Only in the Chilean site for the general population and the Brazilian site for MSM were similar trends seen. Subjects <25 years of age at diagnosis were less likely to be immunocompromised at enrollment at both the VCCC and CCASAnet. Recent trends in the USA of greater numbers of newly diagnosed young patients are not consistently observed in Latin America and the Caribbean. Prevention efforts tailored to young adults should be increased. PMID:25613592

  13. Porphyry copper assessment of Central America and the Caribbean Basin: Chapter I in Global mineral resource assessment

    USGS Publications Warehouse

    Gray, Floyd; Hammarstrom, Jane M.; Ludington, Stephen; Zürcher, Lukas; Nelson, Carl E.; Robinson,, Gilpin R.; Miller, Robert J.; Moring, Barry C.

    2014-01-01

    This assessment estimated a total mean of 37 undiscovered porphyry copper deposits within the assessed permissive tracts in Central America and the Caribbean Basin. This represents more than five times the seven known deposits. Predicted mean (arithmetic) resources that could be associated with these undiscovered deposits are about 130 million metric tons of copper and about 5,200 metric tons of gold, as well as byproduct molybdenum and silver. The reported identified resources for the seven known deposits total about 39 million metric tons of copper and about 930 metric tons of gold. The assessment area is estimated to contain nearly four times as much copper and six times as much gold in undiscovered porphyry copper deposits as has been identified to date.

  14. Population biology of the portunid crab Callinectes arcuatus Ordway in the Gulf of Nicoya, Costa Rica, Central America

    NASA Astrophysics Data System (ADS)

    Dittel, Ana I.; Epifanio, C. E.; Chavarria, Juan Bautista

    1985-05-01

    Tropical blue crabs Callinectes arcuatus were collected by trawling in the Gulf of Nicoya on the Pacific coast of Costa Rica, Central America. The gulf population was generally dominated by females. Adult females were common in the upper, more estuarine regions of the gulf during rainy season, but appeared to migrate to the lower gulf during dry season for spawning. Biomass varied with seasonal changes in abundance, but was generally similar to biomass of C. sapidus in Chesapeake Bay. Analysis of size frequency indicated that the population is numerically dominated by adults during January and February and that juveniles are common during the remainder of the year. Extrapolation of available data suggests that female crabs reach maturity in approximately one year after hatching.

  15. Microevolution of the Chibcha-speaking peoples of lower Central America: rare genes in an Amerindian complex.

    PubMed Central

    Thompson, E A; Neel, J V; Smouse, P E; Barrantes, R

    1992-01-01

    Models are developed for the survival, history, and spread of variant alleles, in order to consider what can, and what cannot, be inferred from this type of data. The high variances of the processes involved, and questions of sampling, place severe limitations on inferences. Nonetheless, by combining information on a number of rare variants observed in a group of interrelated populations, reliable qualitative inferences are possible. These ideas and models are developed in the context of data on five rare variants and six private polymorphisms observed in eight Chibcha-speaking tribes of Costa Rica and Panama. The decline and fragmentation of the Amerindian populations of Central America over the last 300 years create considerable difficulties in attempting inference of past genetic events. However, these tribes have been well studied genetically, anthropologically, and linguistically and thus provide an excellent framework for the study of rare-variant spread. PMID:1496991

  16. Structural Vulnerability Among Migrating Women and Children Fleeing Central America and Mexico: The Public Health Impact of "Humanitarian Parole".

    PubMed

    Valdez, Elizabeth Salerno; Valdez, Luis A; Sabo, Samantha

    2015-01-01

    Since October 2013, US Customs and Border Patrol has apprehended 15,979 families on the Southwest Border of the US. Daily, migrating women and children from Mexico and Central America that qualify for humanitarian parole are released from immigration detention to a humanitarian aid organization in Southern Arizona. After several days in detention facilities, these families arrive tired, hungry, dehydrated, and with minimal direction regarding their final destination, and adherence to the parameters of their parole. Project helping hands (PHHs) utilizes a network of volunteers to provide the women and children with food, water, clothing, hygiene products, hospitality, and legal orientation. The aim of this assessment was to document the experiences of families granted humanitarian parole through the lens of structural vulnerability. Here, we apply qualitative methods to elicit PHH lead volunteer perspectives regarding the migration experience of migrating families. Using inductive analysis, we found six major themes emerged from the qualitative data: reasons for leaving, experience on the journey, dehumanization in detention, family separation, vulnerability, and resiliency. These findings elucidate the different physical and psychological distresses that migrating families from Mexico and Central America experience before, during and after their arrival at the US-Mexico border. We posit that these distresses are a result of, or exacerbated by, structural vulnerability. Structural vulnerability has life-long health implications for a sub-population of young mothers and their children. The number of migrating families who have experienced traumatic events before and during their migration experience continues to expand and thus warrants consideration of mental health surveillance and intervention efforts for these families. More public health research is needed to better understand and combat the health challenges of this growing population.

  17. Genetic composition of contemporary swine influenza viruses in the West Central region of the United States of America

    PubMed Central

    Evseenko, Vasiliy A.; Boon, Adrianus C. M.; Brockwell‐Staats, Christy; Franks, John; Rubrum, Adam; Daniels, Curt S.; Gramer, Marie R.; Webby, Richard J.

    2011-01-01

    Please cite this paper as: Evseenko et al. (2011) Genetic composition of contemporary swine influenza viruses in the West Central region of the United States of America. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2010.00189.x. Background  Because of continuous circulation in different animal species and humans, influenza viruses have host‐specific phenotypic and genetic features. Reassortment of the genome segments can significantly change virus phenotype, potentially generating virus with pandemic potential. In 2009, a new pandemic influenza virus emerged. Objectives  In this study, we attempted to find precursor viruses or genes of pandemic H1N1 influenza 2009 among 25 swine influenza viruses, isolated in the West Central region of the United States of America (USA), between 2007 and 2009. The Phylogenetically Similar Triple‐Reassortant Internal Genes (PSTRIG) cassette of all the viruses studied here as well as the PSTRIG cassette of pandemic H1N1 viruses have close but equidistant phylogenetic relationships to the early triple‐reassortant swine H3N2 influenza A isolated in the USA in 1998. Methods  Samples (nasal swabs and lung tissue lavage) were taken from swine with or without clinical signs of respiratory disease via farmer‐funded syndromic surveillance. All studied viruses were isolated in Madin–Darby Canine Kidney cell cultures from the above‐mentioned samples according to standard protocols recommended for influenza virus isolation. Sequences were obtained using BigDye Terminator v3.1 Cycle Sequencing kit. Phylogenetic trees were built with MEGA 4.0 software using maximum composite likelihood algorithm and neighbor‐joining method for tree topology reconstruction. Results  Among the 25 viruses studied, we have not found any gene segments of Eurasian origin. Our results suggest that pandemic H1N1 viruses diverged and are not directly descended from swine viruses that have been circulating in USA since 1998

  18. Structural Vulnerability Among Migrating Women and Children Fleeing Central America and Mexico: The Public Health Impact of "Humanitarian Parole".

    PubMed

    Valdez, Elizabeth Salerno; Valdez, Luis A; Sabo, Samantha

    2015-01-01

    Since October 2013, US Customs and Border Patrol has apprehended 15,979 families on the Southwest Border of the US. Daily, migrating women and children from Mexico and Central America that qualify for humanitarian parole are released from immigration detention to a humanitarian aid organization in Southern Arizona. After several days in detention facilities, these families arrive tired, hungry, dehydrated, and with minimal direction regarding their final destination, and adherence to the parameters of their parole. Project helping hands (PHHs) utilizes a network of volunteers to provide the women and children with food, water, clothing, hygiene products, hospitality, and legal orientation. The aim of this assessment was to document the experiences of families granted humanitarian parole through the lens of structural vulnerability. Here, we apply qualitative methods to elicit PHH lead volunteer perspectives regarding the migration experience of migrating families. Using inductive analysis, we found six major themes emerged from the qualitative data: reasons for leaving, experience on the journey, dehumanization in detention, family separation, vulnerability, and resiliency. These findings elucidate the different physical and psychological distresses that migrating families from Mexico and Central America experience before, during and after their arrival at the US-Mexico border. We posit that these distresses are a result of, or exacerbated by, structural vulnerability. Structural vulnerability has life-long health implications for a sub-population of young mothers and their children. The number of migrating families who have experienced traumatic events before and during their migration experience continues to expand and thus warrants consideration of mental health surveillance and intervention efforts for these families. More public health research is needed to better understand and combat the health challenges of this growing population. PMID:26157791

  19. Holocene Evolution of Precipitation Patterns in the Southwestern US, Mexico, Central America, and Caribbean: Comparison with Tropical SST Records

    NASA Astrophysics Data System (ADS)

    Barron, J. A.; Metcalfe, S. E.; Davies, S. J.

    2014-12-01

    We evaluate proxy reconstructions of Holocene records precipitation in the North American Monsoon region (SW US and northern Mexico) and regions to the south (southern Mexico, Central America, and the Caribbean). Seventy-seven precipitation records are tabulated at 2-3 kyr increments for the past 12 kyr, with results displayed mainly on maps. Sites currently dominated by summer precipitation, coupled with proxy records that distinguish summer vs. winter vegetation are used to estimate summer precipitation. Resulting patterns of precipitation variability are evaluated against SST reconstructions from surrounding tropical seas -eastern tropical Pacific, Gulf of California (GoC), Caribbean, and Gulf of Mexico (GoM), which are source areas for summer precipitation. During the Younger Dryas, ca. 12 ka, widespread drying in southern regions contrasted with evidence for wetter conditions in multiple records from the SW US. By 9 ka wetter conditions had spread to the southern regions, likely reflecting an increased Caribbean low-level jet associated with an enhanced Bermuda High. Pacific westerlies contributed significant winter precipitation to the southwestern US and northernmost Mexico at 9 ka. The modern geographical pattern of summer precipitation was established by 6 ka, as the Bermuda High moved northward following the demise of the Laurentide Ice Sheet. SSTs in the GoC and GoM increased, and the NAM strengthened. Increased regional precipitation differences are apparent by 4 ka, likely reflecting enhanced ENSO variability. Most of the southern region experienced increased precipitation during the Medieval Climate Anomaly (MCA), whereas winter drought dominated in the north. In contrast, much of the Little Ice Age (LIA) was characterized by generally drier conditions in Central America and Mexico, with wetter conditions in the SW US. Results are broadly supportive of enhanced La Niña-like conditions during the MCA vs. increased ENSO variability during the LIA.

  20. Migration patterns in Central America seen in the context of economic integration and the need for sustainable development.

    PubMed

    Stein, E

    1993-08-01

    This exploratory discussion of migration policy in Central America focuses on actual procedures in a multisectoral framework that assumes economic integration and sustainable development. The article follows the following format: the author's perspective and general approach to the problems of migration policy and integrated development, an analysis and review of the inadequacies of concepts and methodologies and the need for strengthening Central America's policies, arguments for changing present development strategies, and suggestions for regional economic integration. New policies must be equitable, sustainable, and suitable for agricultural frontier areas at the present level of economic integration. The further development of practical and concrete solutions in the region is based on the current groundwork. New policies should emphasize community participation, a grassroots approach rather than a top-down one, and an alternative model. An alternative system which promotes and facilitates the vertical development of small and medium farmers needs both a Rural Communal Financing System and a System for Communal Marketing to eliminate all speculative economic practices which impede small farmers from making a profit. Buffer zones in the frontier agricultural areas are required. Small farms need to gradually improve farming practices rather than to transfer miraculous technologies. A number of forest products could be collected and commercialized for various purposes, if the knowledgeable indigenous population is informed and involved in participatory research on the technical and ethnological culture and action programs. Many sectors are involved, problems are complex, and the speed of change is very rapid in the region. An approach that seeks to relate sustainable development, economic integration, and migration policy must incorporate the perspective of integrated development and a structural analysis of poverty. The approach suggested in this article would

  1. Higher Education in Central America: Historical Foundations for Its Future Projection.

    ERIC Educational Resources Information Center

    Arriaza, Ricardo Sol

    1996-01-01

    Three trends in Central American higher education are examined in historical context: (1) inertia from lack of mobility, bureaucracy, and corporate influence; (2) elitism as a response to budgetary constraints; and (3) attempts to increase responsiveness to educational needs and demands. Issues examined include earlier attempts at change, slow…

  2. Programmes, resources, and needs of HIV-prevention nongovernmental organizations (NGOs) in Africa, Central/Eastern Europe and Central Asia, Latin America and the Caribbean

    PubMed Central

    KELLY, J. A.; SOMLAI, A. M.; BENOTSCH, E. G.; AMIRKHANIAN, Y. A.; FERNANDEZ, M. I.; STEVENSON, L. Y.; SITZLER, C. A.; MCAULIFFE, T. L.; BROWN, K. D.; OPGENORTH, K. M.

    2008-01-01

    This study assessed the programmes, resources, and needs of HIV-prevention nongovernmental organizations (NGOs) in 75 countries in Africa, Central/Eastern Europe and Central Asia, Latin America and the Caribbean. Multiple databases and expert recommendations were used to identify one major HIV-prevention NGO in the capital or a large city in each country, and in-depth interviews were conducted with each NGO Director. Most NGOs are carrying out their programmes with minimal funding and few regularly employed personnel. Most are highly dependent on international donors, but reliance on small grants with short funding periods limits programme development capacity. HIV-prevention activities varied by region, with African NGOs most likely to use peer education and community awareness events; Eastern European NGOs most likely to offer needle exchange; Latin American NGOs to have resource centres and offer risk reduction programmes; and Caribbean organizations to use mass education approaches. Across regions, NGOs most often targeted the general public and youth, although specialized at-risk groups were the additional focus of attention in some regions. Limited funding, governmental indifference or opposition, AIDS stigma, and social discomfort discussing sex were often cited as barriers to new HIV-prevention programmes. NGOs are critical service providers. However, their funding, programmes, and resource capacities must be strengthened if NGOs are to realize their full potential in HIV prevention. PMID:16282071

  3. Rainforest understory beetles of the Neotropics, Mizotrechus Bates 1872, a generic synopsis with descriptions of new species from Central America and northern South America (Coleoptera, Carabidae, Perigonini)

    PubMed Central

    Erwin, Terry L.

    2011-01-01

    Abstract Information on the single previously described species, Mizotrechus novemstriatus Bates 1872 (type locality: Brazil – Amazonas, Tefé), is updated and 17 new species for the genus from Nicaragua, Costa Rica, Panamá, Colombia, Venezuela, and Guyane are described. The species records in the literature and on determined specimens in some collections of Mizotrechus novemstriatus Bates from Central America are not that species; currently, Mizotrechus novemstriatus is known only from its type locality in Amazonian Brazil. For the new species described, their known general distributions are as follows: Mizotrechus batesi sp. n. (Guyane), Mizotrechus bellorum sp. n. (Guyane), Mizotrechus brulei sp. n. (Guyane), Mizotrechus belevedere sp. n. (Guyane), Mizotrechus costaricensis sp. n. (Costa Rica), Mizotrechus dalensi sp. n. (Guyane), Mizotrechus edithpiafae sp. n. (provenance unknown), Mizotrechus fortunensis sp. n. (Panamá), Mizotrechus gorgona. sp. n. (Colombia), Mizotrechus grossus sp. n. (Guyane), Mizotrechus jefe sp. n. (Panamá), Mizotrechus marielaforetae sp. n. (Guyane), Mizotrechus minutus sp. n. (Guyane), Mizotrechus neblinensis sp. n. (Guyane, Venezuela), Mizotrechus poirieri sp. n. (Guyane), and Mizotrechus woldai sp. n. (Panamá). Long-term use of flight intercept traps in Guyane provided so many new species that apparently the use of FITs is the way to collect adults of this taxon, previously known from very few specimens. Many more species of this genus can be expected to be discovered throughout the Neotropics; the present contribution is a preliminary synopsis with identification key and adult images of all known species. Likely numerous species are yet to be discovered throughout tropical climes. PMID:22287885

  4. Active tectonics and Quaternary landscape evolution across the western Panama block, Costa Rica, Central America

    NASA Astrophysics Data System (ADS)

    Marshall, Jeffrey Scott

    Three aspects of active tectonism are examined across central Costa Rica: (1) fault kinematics; (2) volcanic arc retreat; and (3) spatially variable coastal uplift. Diffuse faulting along the Central Costa Rica Deformed Belt (CCRDB) defines the western margin of the Panama block and aligns with the rough-smooth boundary (RSB) on the subducting Cocos plate. Sub-horizontal subduction of rough, hotspot thickened crust (Cocos Ridge and seamounts) shifts active shortening into the volcanic arc along the CCRDB. Mesoscale faults express variable kinematics across three domains: transtension in the forearc, transcurrent motion across the volcanic arc, and transpression in the back arc. Fault kinematics agree with seismicity and GPS data, and isotopic ages confirm that faulting postdates the late Neogene onset of shallow subduction. Stratigraphic correlation augmented by 40Ar/39Ar dating constrain the timing of Quaternary arc migration from the Neogene Aguacate range to the modern Cordillera Central. The Valle Central basin, between the cordilleras, filled with thick sequences of lavas, pyroclastic flows, and lahars. Middle Pleistocene drainage capture across the Aguacate arc linked the Valle Central with the Pacific slope and ash flows descended onto the coastal Orotina debris fan. Arc retreat reflects slab shallowing and enhanced tectonic erosion as rough crust entered the subduction zone. Differing subduction parameters across the RSB (crustal age, slab dip, roughness) produce marked contrasts in coastal tectonism. Varying uplift rates across coastal faults reflect sub-horizontal subduction of seamount roughness. Three groups (I--III) of fluvial terraces are correlated along the coast by isotopic ages and geomorphic characteristics. Base level fluctuations and terrace genesis reflect interaction between eustatic sea level and spatially variable rock uplift. Low uplift rates (north of RSB), yield one surface per terrace group, whereas moderate rates (south of RSB

  5. The interdependence of lake ice and climate in central North America

    NASA Technical Reports Server (NTRS)

    Jelacic, A. J. (Principal Investigator)

    1972-01-01

    There are no author-identified significant results in this report. This investigation is to identify any correlations between the freeze/ thaw cycles of lakes and regional weather variations. ERTS-1 imagery of central Canada and north central United States is examined on a seasonal basis. The ice conditions of certain major study lakes are noted and recorded on magnetic tape, from which the movement of a freeze/thaw transition zone may be deduced. Weather maps and tables are used to establish any obvious correlations. The process of selecting major study lakes is discussed, and a complete lake directory is presented. Various routines of the software support library are described, accompanied by output samples. Procedures used for ERTS imagery processing are presented along with the data analysis plan. Application of these procedures to selected ERTS imagery has demonstrated their utility. Preliminary results show that the freeze/thaw transition zone can be monitored from ERTS.

  6. Changing Drug Markets Under New Intellectual Property Regimes: The View From Central America

    PubMed Central

    Cerón, Alejandro

    2011-01-01

    The intellectual property rules inscribed in the Central American Free Trade Agreement have generated concern about access to medicines. We examined the implementation of the new intellectual property regime by tracking the policies and practices in place across 4 Central American countries. Although all 4 were responding to the same requirements under the agreement, their implementation of intellectual property rules differed. Not only were institutional practices different, but the lists of drugs to which intellectual property protection was applied varied in both volume and content. We also found that even without the influence of intellectual property, drug pricing in the region was often unpredictable and that lower cost was not the only motivation driving governments' purchasing decisions. PMID:21566033

  7. Validation of attenuation models for ground motion applications in central and eastern North America

    SciTech Connect

    Pasyanos, Michael E.

    2015-11-01

    Recently developed attenuation models are incorporated into standard one-dimensional (1-D) ground motion prediction equations (GMPEs), effectively making them two-dimensional (2-D) and eliminating the need to create different GMPEs for an increasing number of sub-regions. The model is tested against a data set of over 10,000 recordings from 81 earthquakes in North America. The use of attenuation models in GMPEs improves our ability to fit observed ground motions and should be incorporated into future national hazard maps. The improvement is most significant at higher frequencies and longer distances which have a greater number of wave cycles. This has implications for the rare high-magnitude earthquakes, which produce potentially damaging ground motions over wide areas, and drive the seismic hazards. Furthermore, the attenuation models can be created using weak ground motions, they could be developed for regions of low seismicity where empirical recordings of ground motions are uncommon and do not span the full range of magnitudes and distances.

  8. Solar activity and human health at middle and low geomagnetic latitudes in Central America

    NASA Astrophysics Data System (ADS)

    Mendoza, Blanca; Sánchez de La Peña, Salvador

    2010-08-01

    The study of the possible effect of solar variability on living organisms is one of the most controversial issues of present day science. It has been firstly and mainly carried on high latitudes, while at middle and low latitudes this study is rare. In the present review we focused on the work developed at middle and low geomagnetic latitudes of America. At these geomagnetic latitudes the groups consistently dedicated to this issue are mainly two, one in Cuba and the other in Mexico. The Cuban and Mexican studies show that at such latitudes there are biological consequences to the solar/geomagnetic activity, coinciding in four points: (1) the male population behave differently from the female population, (2) the most vulnerable age group to geomagnetic perturbations is that of ⩾65 years old, (3) there is a tendency for myocardial infarctions (death or occurrence) to increase one day after a geomagnetic Ap index large value or during the day of the associated Forbush decrease, and (4) the myocardial infarctions (death or occurrence) increase as the geomagnetic perturbation increases. Additionally, the Cuban group found seasonal periodicities from their data, and also that increases of female myocardial infarctions occurred before and after the day of the geomagnetic disturbance. The Mexican group found that the male sex is more vulnerable to geomagnetic perturbations and that the myocardial infarction deaths present the conspicuous cycle of ˜7 days.

  9. Validation of attenuation models for ground motion applications in central and eastern North America

    DOE PAGES

    Pasyanos, Michael E.

    2015-11-01

    Recently developed attenuation models are incorporated into standard one-dimensional (1-D) ground motion prediction equations (GMPEs), effectively making them two-dimensional (2-D) and eliminating the need to create different GMPEs for an increasing number of sub-regions. The model is tested against a data set of over 10,000 recordings from 81 earthquakes in North America. The use of attenuation models in GMPEs improves our ability to fit observed ground motions and should be incorporated into future national hazard maps. The improvement is most significant at higher frequencies and longer distances which have a greater number of wave cycles. This has implications for themore » rare high-magnitude earthquakes, which produce potentially damaging ground motions over wide areas, and drive the seismic hazards. Furthermore, the attenuation models can be created using weak ground motions, they could be developed for regions of low seismicity where empirical recordings of ground motions are uncommon and do not span the full range of magnitudes and distances.« less

  10. Recent warming by latitude associated with increased length of ragweed pollen season in central North America.

    PubMed

    Ziska, Lewis; Knowlton, Kim; Rogers, Christine; Dalan, Dan; Tierney, Nicole; Elder, Mary Ann; Filley, Warren; Shropshire, Jeanne; Ford, Linda B; Hedberg, Curtis; Fleetwood, Pamela; Hovanky, Kim T; Kavanaugh, Tony; Fulford, George; Vrtis, Rose F; Patz, Jonathan A; Portnoy, Jay; Coates, Frances; Bielory, Leonard; Frenz, David

    2011-03-01

    A fundamental aspect of climate change is the potential shifts in flowering phenology and pollen initiation associated with milder winters and warmer seasonal air temperature. Earlier floral anthesis has been suggested, in turn, to have a role in human disease by increasing time of exposure to pollen that causes allergic rhinitis and related asthma. However, earlier floral initiation does not necessarily alter the temporal duration of the pollen season, and, to date, no consistent continental trend in pollen season length has been demonstrated. Here we report that duration of the ragweed (Ambrosia spp.) pollen season has been increasing in recent decades as a function of latitude in North America. Latitudinal effects on increasing season length were associated primarily with a delay in first frost of the fall season and lengthening of the frost free period. Overall, these data indicate a significant increase in the length of the ragweed pollen season by as much as 13-27 d at latitudes above ~44°N since 1995. This is consistent with recent Intergovernmental Panel on Climate Change projections regarding enhanced warming as a function of latitude. If similar warming trends accompany long-term climate change, greater exposure times to seasonal allergens may occur with subsequent effects on public health.

  11. One Rural Hospital's Experience Implementing the Society for Healthcare Epidemiology of America Guidelines to Decrease Central Line Infections.

    PubMed

    Curlej, Maria H; Katrancha, Elizabeth

    2016-01-01

    In an effort to take advantage of the Highmark Quality Blue Initiative () requiring information from hospitals detailing their central line-associated blood stream infections (CLABSIs) surveillance system, quality improvement program, and statistics regarding the CLABSI events, this institution investigated the latest evidence-based recommendations to reduce CLABSIs. Recognizing the baseline rate of 2.4 CLABSIs per 1,000 central line days and its effect on patient outcomes and medical costs, this hospital made a commitment to improve their CLABSI outcomes. As a result, the facility adopted the Society for Healthcare Epidemiology of America (SHEA) guidelines. The purpose of this article is to review the CLABSI rates and examine the prevention strategies following implementation of the SHEA guidelines. A quantitative, descriptive retrospective program evaluation examined the hospital's pre- and post-SHEA implementation methods of decreasing CLABSIs and the subsequent CLABSI rates over 3 time periods. Any patient with a CLABSI infection admitted to this hospital July 2007 to June 2010 (N = 78). CLABSI rates decreased from 1.9 to 1.3 over the study period. Compliance with specific SHEA guidelines was evaluated and measures were put into place to increase compliance where necessary. CLABSI rates at this facility remain below the baseline of 2.4 for calendar year 2013 (0.79), 2014 (0.07), and 2015 (0.33). PMID:27618377

  12. Differential effects of landscape-level environmental features on genetic structure in three codistributed tree species in Central America.

    PubMed

    Poelchau, Monica F; Hamrick, J L

    2012-10-01

    Landscape genetic studies use spatially explicit population genetic information to determine the physical and environmental causes of population genetic structure on regional scales. Comparative studies that identify common barriers to gene flow across multiple species within a community are important to both understand the evolutionary trajectories of populations and prioritize habitat conservation. Here, we use a comparative landscape genetic approach to ask whether gradients in temperature or precipitation seasonality structure genetic variation across three codistributed tree species in Central America, or whether a simpler (geographic distance) or more complex, species-specific environmental niche model is necessary to individually explain population genetic structure. Using descriptive statistics and causal modelling, we find that different factors best explain genetic distance in each of the three species: environmental niche distance in Bursera simaruba, geographic distance in Ficus insipida and historical barriers to gene flow or cryptic reproductive barriers for Brosimum alicastrum. This study confirms suggestions from previous studies of Central American tree species that imply that population genetic structure of trees in this region is determined by complex interactions of both historical and current barriers to gene flow.

  13. Trichospermum lessertianum comb. n., the correct name for the Cuban species of Trichospermum (Malvaceae, Grewioideae) also found in Mexico and Central America

    PubMed Central

    Dorr, Laurence J.

    2011-01-01

    Abstract The correct name for the Cuban species of Trichospermum Bl. (Malvaceae: Grewioideae) also found in Mexico and Central America is Trichospermum lessertianum (Hochr.) Dorr, comb. n. The name Trichospermum mexicanum (DC.) Baill., incorrectly applied to this Cuban species, should be restricted to a species endemic to western and southern Mexico. PMID:22171172

  14. In the Shadow of the Cold War: The Caribbean and Central America in U.S. Foreign Policy. Teacher's Resource Book.

    ERIC Educational Resources Information Center

    Malkasian, Mark; Davidson, Louise K.

    With the improvement of U.S.-Soviet relations in recent years, there is much reason to take a fresh look at U.S. foreign policy. This teacher's resource book is designed to accompany a unit that provides high school students with an opportunity to examine U.S. policy toward the Caribbean and Central America. Composed of four chapters, the first…

  15. In the Shadow of the Cold War: The Caribbean and Central America in U.S. Foreign Policy. Teacher's Resource Book. Revised Edition.

    ERIC Educational Resources Information Center

    Malkasian, Mark; Davidson, Louise K.

    This teacher's resource book is designed to be used with "In the Shadow of the Cold War: The Caribbean and Central America in U.S. Foreign Policy," which was written to help high school students to weigh important U.S. foreign policy issues. The resource book includes eight lessons. Lessons 3-6 focus specifically on the dimension of the triangular…

  16. Discovery of new Ohbayashinema spp. (nematoda: heligomosomoidea) in Ochotona princeps and O. cansus (lagomorpha: ochotonidae) from western North America and central Asia, with considerations of historical biogeography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three new species of Ohbayashinema (Nematoda, Heligmosomoidea) are described from localities in western North America and central Asia. Two of these species, Ohbayashinema nearctica n. sp and O. aspeira n. sp. are parasitic in American pika, Ochotona princeps. Ohbayashinema nearctica is differentiat...

  17. Genetic Analysis of Influenza A/H1N1 of Swine Origin Virus (SOIV) Circulating in Central and South America

    PubMed Central

    Sovero, Merly; Garcia, Josefina; Laguna-Torres, V. Alberto; Gomez, Jorge; Aleman, Washington; Chicaiza, Wilson; Barrantes, Melvin; Sanchez, Felix; Jimenez, Mirna; Comach, Guillermo; de Rivera, Ivette Lorenzana; Barboza, Alma; Aguayo, Nicolas; Kochel, Tadeusz

    2010-01-01

    Since the first detection of swine origin virus (SOIV) on March 28, 2009, the virus has spread worldwide and oseltamivir-resistant strains have already been identified in the past months. Here, we show the phylogenetic analysis of 63 SOIV isolates from eight countries in Central and South America, and their sensitivity to oseltamivir. PMID:20810843

  18. Understanding key drivers controlling daily stable isotope variations in precipitation of Costa Rica, Central America

    NASA Astrophysics Data System (ADS)

    Sanchez-Murillo, Ricardo; Welsh, Kristin; Birkel, Christian; Esquivel-Hernández, Germain; Corrales-Salazar, Jose; Boll, Jan; Brooks, Erin; Roupsard, Olivier; Katchan, Irina; Arce-Mesén, Rafael; Soulsby, Chris; Araguás-Araguás, Luis

    2015-04-01

    Costa Rica is located on the Central American Isthmus, which receives direct moisture inputs from the Caribbean Sea and the Pacific Ocean. The relatively narrow, but high relief Central American land bridge is characterized by unique mountainous and lowland microclimates. However, only limited knowledge exists about the impact of relief and regional atmospheric circulation patterns on precipitation origin, transport, and isotopic composition in this tropical region. Therefore, the main scope of this study is to identify the key drivers controlling variations in meteoric waters of Costa Rica using stable isotopes based on daily sample collection for the year 2013. The monitoring sites comprise three strategic locations across Costa Rica: Heredia (Central Valley), Turrialba (Caribbean slope), and Caño Seco (South Pacific slope). Sporadic dry season rain is mostly related to isolated enriched events ranging from -5.8‰ d18O up to -0.9‰ d18O. By mid-May, the Intertropical Convergence Zone reaches Costa Rica resulting in a notable depletion in isotope ratios (up to -18.5‰ d18O). HYSPLIT back air mass trajectories indicate the strong influence on the origin and transport of precipitation of two main moisture transport mechanisms, the Caribbean Low Level Jet and the Colombian Low Level Jet as well as localized convection events. Multiple linear regression models constructed based on Random Forests of surface meteorological information and atmospheric sounding profiles suggest that Lifted Condensation Level and surface relative humidity are the main factors controlling isotopic variations. These findings diverge from the recognized 'amount effect' in monthly composite samples across the tropics. Understanding of stable isotope dynamics in tropical precipitation can be used to enhance catchment and groundwater modeling efforts in ungauged basins where scarcity of long-term monitoring data drastically limit current and future water resources management.

  19. Reconstructing the Timing and Dispersion Routes of HIV-1 Subtype B Epidemics in The Caribbean and Central America: A Phylogenetic Story

    PubMed Central

    Pagán, Israel; Holguín, África

    2013-01-01

    The Caribbean and Central America are among the regions with highest HIV-1B prevalence worldwide. Despite of this high virus burden, little is known about the timing and the migration patterns of HIV-1B in these regions. Migration is one of the major processes shaping the genetic structure of virus populations. Thus, reconstruction of epidemiological network may contribute to understand HIV-1B evolution and reduce virus prevalence. We have investigated the spatio-temporal dynamics of the HIV-1B epidemic in The Caribbean and Central America using 1,610 HIV-1B partial pol sequences from 13 Caribbean and 5 Central American countries. Timing of HIV-1B introduction and virus evolutionary rates, as well as the spatial genetic structure of the HIV-1B populations and the virus migration patterns were inferred. Results revealed that in The Caribbean and Central America most of the HIV-1B variability was generated since the 80 s. At odds with previous data suggesting that Haiti was the origin of the epidemic in The Caribbean, our reconstruction indicated that the virus could have been disseminated from Puerto Rico and Antigua. These two countries connected two distinguishable migration areas corresponding to the (mainly Spanish-colonized) Easter and (mainly British-colonized) Western islands, which indicates that virus migration patterns are determined by geographical barriers and by the movement of human populations among culturally related countries. Similar factors shaped the migration of HIV-1B in Central America. The HIV-1B population was significantly structured according to the country of origin, and the genetic diversity in each country was associated with the virus prevalence in both regions, which suggests that virus populations evolve mainly through genetic drift. Thus, our work contributes to the understanding of HIV-1B evolution and dispersion pattern in the Americas, and its relationship with the geography of the area and the movements of human populations

  20. Reconstructing the timing and dispersion routes of HIV-1 subtype B epidemics in the Caribbean and Central America: a phylogenetic story.

    PubMed

    Pagán, Israel; Holguín, Africa

    2013-01-01

    The Caribbean and Central America are among the regions with highest HIV-1B prevalence worldwide. Despite of this high virus burden, little is known about the timing and the migration patterns of HIV-1B in these regions. Migration is one of the major processes shaping the genetic structure of virus populations. Thus, reconstruction of epidemiological network may contribute to understand HIV-1B evolution and reduce virus prevalence. We have investigated the spatio-temporal dynamics of the HIV-1B epidemic in The Caribbean and Central America using 1,610 HIV-1B partial pol sequences from 13 Caribbean and 5 Central American countries. Timing of HIV-1B introduction and virus evolutionary rates, as well as the spatial genetic structure of the HIV-1B populations and the virus migration patterns were inferred. Results revealed that in The Caribbean and Central America most of the HIV-1B variability was generated since the 80 s. At odds with previous data suggesting that Haiti was the origin of the epidemic in The Caribbean, our reconstruction indicated that the virus could have been disseminated from Puerto Rico and Antigua. These two countries connected two distinguishable migration areas corresponding to the (mainly Spanish-colonized) Easter and (mainly British-colonized) Western islands, which indicates that virus migration patterns are determined by geographical barriers and by the movement of human populations among culturally related countries. Similar factors shaped the migration of HIV-1B in Central America. The HIV-1B population was significantly structured according to the country of origin, and the genetic diversity in each country was associated with the virus prevalence in both regions, which suggests that virus populations evolve mainly through genetic drift. Thus, our work contributes to the understanding of HIV-1B evolution and dispersion pattern in the Americas, and its relationship with the geography of the area and the movements of human populations.

  1. Intercontinental transport of pollution from North America to Europe: Airborne trace gas measurements over Central and Northern Europe during CONTRACE

    NASA Astrophysics Data System (ADS)

    Huntrieser, H.; Schlager, H.; Heland, J.; Forster, C.; Stohl, A.; Lawrence, M.; Arnold, F.; Aufmhoff, H.; Cooper, O.

    2003-04-01

    The CONTRACE project investigates the uplift of pollution in frontal systems (warm conveyor belts) over North America and the transport of these air masses to Europe. The first airborne field experiment was carried out from Southern Germany in fall 2001. The DLR research aircraft Falcon was equipped with a complex instrumentation to measure NO, NOy, CO, CO2, O3, J(NO2), acetone, SO2, ions, H2O2, formaldehyde, NMHC, J(O1D) and particles. An extensive set of chemical and meteorological forecast products, including trajectory calculations, was developed and used in combination with satellite images to plan the flights. A passive tracer for surface emissions (CO) was included in the forecast models to separate the regional and intercontinental transport of polluted air masses. For the first time it succeeded to guide the Falcon aircraft into pollution plumes transported all the way from North America (NA). On 22nd November a complex chemical weather situation was predicted for Central Europe with lifting of European emissions into the lower troposphere ahead of an approaching cold front and simultaneously, the advection of a pollution plume from Eastern NA in mid tropospheric layers. Similar CO mixing ratios were observed in both plumes making it difficult to distinguish the two plumes without additional trace gas information. The European pollution plume was characterized by large enhancements in the CO (150 ppbv) and NOy (6 ppbv) mixing ratios. The NOy/CO ratio was 0.135 (typical value for fresh emissions). In comparison the estimated NOy/CO ratio for the NA pollution plume was 0.010 which indicate a tracer age of 4 days. The observed CO and NOy mixing ratios in this plume were 160 ppbv and 1 ppbv. The two plumes were also characterized by very different O3/CO relationships. In the plume from NA a positive O3/CO slope was observed indicating photochemical ozone production (O3 mixing ratios up to 50 ppbv were observed). Most likely O3 was produced photochemically in

  2. A GPS and modelling study of deformation in northern Central America

    NASA Astrophysics Data System (ADS)

    Rodriguez, M.; DeMets, C.; Rogers, R.; Tenorio, C.; Hernandez, D.

    2009-09-01

    We use GPS measurements at 37 stations in Honduras and El Salvador to describe active deformation of the western end of the Caribbean Plate between the Motagua fault and Central American volcanic arc. All GPS sites located in eastern Honduras move with the Caribbean Plate, in accord with geologic evidence for an absence of neotectonic deformation in this region. Relative to the Caribbean Plate, the other stations in the study area move west to west-northwest at rates that increase gradually from 3.3 +/- 0.6 mm yr-1 in central Honduras to 4.1 +/- 0.6 mm yr-1 in western Honduras to as high as 11-12 mm yr-1 in southern Guatemala. The site motions are consistent with slow westward extension that has been inferred by previous authors from the north-striking grabens and earthquake focal mechanisms in this region. We examine the factors that influence the regional deformation by comparing the new GPS velocity field to velocity fields predicted by finite element models (FEMs) that incorporate the regional plate boundary faults and known plate motions. Our modelling suggests that the obliquely convergent (~20°) direction of Caribbean-North American Plate motion relative to the Motagua fault west of 90°W impedes the ENE-directed motion of the Caribbean Plate in southern Guatemala, giving rise to extension in southern Guatemala and western Honduras. The FEM predictions agree even better with the measured velocities if the plate motion west of the Central American volcanic arc is forced to occur over a broad zone rather than along a single throughgoing plate boundary fault. Our analysis confirms key predictions of a previous numerical model for deformation in this region, and also indicates that the curvature of the Motagua fault causes significant along-strike changes in the orientations of the principal strain-rate axes in the fault borderlands, in accord with earthquake focal mechanisms and conclusions reached in a recent synthesis of the structural and morphologic data

  3. Lithospheric expression of geological units in central and eastern North America from full waveform tomography

    NASA Astrophysics Data System (ADS)

    Yuan, Huaiyu; French, Scott; Cupillard, Paul; Romanowicz, Barbara

    2014-09-01

    The EarthScope TA deployment has provided dense array coverage throughout the continental US and with it, the opportunity for high resolution 3D seismic velocity imaging of both lithosphere and asthenosphere in the continent. Building upon our previous long-period waveform tomographic modeling in North America, we present a higher resolution 3D isotropic and radially anisotropic shear wave velocity model of the North American lithospheric mantle, constructed tomographically using the spectral element method for wavefield computations and waveform data down to 40 s period. The new model exhibits pronounced spatial correlation between lateral variations in seismic velocity and anisotropy and major tectonic units as defined from surface geology. In the center of the continent, the North American craton exhibits uniformly thick lithosphere down to 200-250 km, while major tectonic sutures of Proterozoic age visible in the surface geology extend down to 100-150 km as relatively narrow zones of distinct radial anisotropy, with Vsv>Vsh. Notably, the upper mantle low velocity zone is present everywhere under the craton between 200 and 300 km depth. East of the continental rift margin, the lithosphere is broken up into a series of large, somewhat thinner (150 km) high velocity blocks, which extend laterally 200-300 km offshore into the Atlantic Ocean. Between the craton and these deep-rooted blocks, we find a prominent narrow band of low velocities that roughly follows the southern and eastern Laurentia rift margin and extends into New England. We suggest that the lithosphere along this band of low velocities may be thinned due to the combined effects of repeated rifting processes and northward extension of the hotspot related Bermuda low-velocity channel across the New England region. We propose that the deep rooted high velocity blocks east of the Laurentia margin represent the Proterozoic Gondwanian terranes of pan-African affinity, which were captured during the Rodinia

  4. Psaironeura angeloi, a new species of damselfly (Zygoptera: Coenagrionidae) from Central and South America.

    PubMed

    Tennessen, Kenneth J

    2016-01-01

    Psaironeura angeloi sp. nov. (Holotype male deposited in FSCA: ECUADOR, Esmeraldas Province, small stream 5.6 km NW of Lita, 00.893°N 78.510°W, 4.II.1997, KJT leg.) is described and illustrated based on specimens from Ecuador, Panama, Costa Rica, and Nicaragua, bringing the total number of species in the genus to five. The new species is closely related to P. remissa (Calvert), a Mexican/northern Central American species with broad, foliate male cerci, but is distinct in that the long flagella of the genital ligula lack a small sharp spine unique to P. remissa, labrum and clypeus are orange-red, and the back of the head is mostly pale in both males and females. In life, the eyes of the new species are bright red in males versus green and black in P. remissa. PMID:27395961

  5. Coral zonation and diagenesis of an emergent Pleistocene patch reef, Belize, Central America

    SciTech Connect

    Lighty, R.G.; Russell, K.L.

    1985-01-01

    Transect mapping and petrologic studies reveal a new depositional model and limited diagenesis of a well-exposed Pleistocene reef outcrop at Ambergris Cay, northern Belize. This emergent shelf-edge reef forms a rocky wave-washed headland at the northern terminus of the present-day 250 km long flourishing Belize Barrier Reef. Previously, the Belize reef outcrop was thought to extend southward in the subsurface beneath the modern barrier reef as a Pleistocene equivalent. The authors study indicate that this outcrop is a large, coral patch reef and not part of a barrier reef trend. Sixteen transects 12.5 m apart described in continuous cm increments from fore reef to back reef identified: extensive deposits of broken Acropora cervicornis; small thickets of A. palmata with small, oriented branches; and muddy skeletal sediments with few corals or reef rubble. Thin section and SEM studies show three phases of early submarine cementation: syntaxial and rosette aragonite; Mg-calcite rim cement and peloids; and colloidal Mg-calcite geopetal fill. Subaerial exposure in semi-arid northern Belize caused only minor skeletal dissolution, some precipitation of vadose whisker calcite, and no meteoric phreatic diagenesis. Facies geometry, coral assemblages, lack of rubble deposits, coralline algal encrustations and Millepora framework, and recognition of common but discrete submarine cements, all indicate that this Pleistocene reef was an isolated, coral-fringed sediment buildup similar to may large patch reefs existing today in moderate-energy shelf environments behind the modern barrier reef in central and southern Belize.

  6. Volcanoes in the pre-Columbian life, legend, and archaeology of Costa Rica (Central America)

    NASA Astrophysics Data System (ADS)

    Alvarado, Guillermo E.; Soto, Gerardo J.

    2008-10-01

    Costa Rica is located geographically in the southern part of the Central American Volcanic Front, a zone where interaction between the Mesoamerican and South American cultures occurred in pre-Columbian times. Several volcanoes violently erupted during the Holocene, when the first nomadic human hunters and later settlers were present. Volcanic rocks were the most important geo-resource in making artifacts and as construction materials for pre-Columbian inhabitants. Some pottery products are believed to resemble smoking volcanoes, and the settlements around volcanoes would seem to indicate their influence on daily life. Undoubtedly, volcanic eruptions disrupted the life of early settlers, particularly in the vicinity of Arenal and Irazú volcanoes, where archaeological remains show transient effects and displacement caused by periodical eruptions, but later resilient occupations around the volcanoes. Most native languages are extinct, with the exception of those presently spoken in areas far away from active volcanoes, where no words are related to volcanic phenomena or structures. The preserved legends are ambiguous, suggesting that they were either produced during the early Spanish conquest or were altered following the pre-Columbian period.

  7. Geology of the Pavana geothermal area, Departamento de Choluteca, Honduras, Central America: Field report

    SciTech Connect

    Eppler, D.B.; Heiken, G.; Wohletz, K.; Flores, W.; Paredes, J.R.; Duffield, W.A.

    1987-09-01

    The Pavana geothermal area is located in southern Honduras near the Gulf of Fonseca. This region is underlain by late Tertiary volcanic rocks. Within ranges near the geothermal manifestations, the rock sequences is characterized by intermediate to mafic laharic breccias and lavas overlain by silicic tuffs and lavas, which are in turn overlain by intermediate to mafic breccias, lavas, and tuffs. The nearest Quaternary volcanoes are about 40 km to the southwest, where the chain of active Central American volcanoes crosses the mouth of the Gulf of Fonseca. Structure of the Pavana area is dominated by generally northwest-trending, southwest-dipping normal faults. This structure is topographically expressed as northwest-trending escarpments that bound blocks of bedrock separated by asymmetric valleys that contain thin alluvial deposits. Thermal waters apparently issue from normal faults and are interpreted as having been heated during deep circulation along fault zones within a regional environment of elevated heat flow. Natural outflow from the main thermal area is about 3000 l/min of 60/sup 0/C water. Geothermometry of the thermal waters suggests a reservoir base temperature of about 150/sup 0/C.

  8. Spatio-temporal variations of optical properties of aerosols in East Asia measured by MODIS and relation to the ground-based mass concentrations observed in central Korea during 2001˜2010

    NASA Astrophysics Data System (ADS)

    Kim, Hak-Sung; Chung, Yong-Seung; Kim, Joon-Tae

    2014-02-01

    Long-term variations and trends of atmospheric aerosols in the East Asian region were analyzed by using aerosol optical depth (AOD or τ), and ångström exponent (AE or α) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) from 2001 to 2010. The increased emission of anthropogenic fine aerosols in east China resulted in the high AOD in this region during summer. The steady increasing emission of anthropogenic fine aerosols caused an increasing trend of AOD in east China, and the large-scale transport of sandstorms and smoke plume caused by forest fires affected intense inter-annual variations of AOD in the East Asian region. While in the central part of South Korea, located in the lee side of the East Asian continent, AE tended to rise to a level higher than in east China, the ground-based mass concentrations continued to decline. A noticeable decrease of PM10 mass concentration in spring and winter in central Korea is most likely attributable to decreases in sandstorms in the source region of East Asia. However, the ratio of PM2.5 mass concentration to PM10 increases overall with a high level in summer. Aerosol types were classified into dust, smoke plume, and sulphate by using satellite data over Cheongwon in central Korea. The columnar AOD, with different aerosol types, was compared with the ground-based mass concentrations at Cheongwon, and the relatively high level of the correlations presented between PM2.5 and AOD produced in sulphate. Growth and increases of fine hygroscopic aerosols generated as gas-to-particle conversion particularly in summer contribute to increases of columnar AOD in the East Asian region.

  9. 21st century projections of snowfall and winter severity across central-eastern North America

    NASA Astrophysics Data System (ADS)

    Notaro, M.; Lorenz, D. J.; Hoving, C.; Schummer, M.

    2014-12-01

    Statistically downscaled climate projections from nine global climate models (GCMs) are used to force a snow accumulation and ablation model (SNOW-17) across the central-eastern North American Landscape Conservation Cooperatives (LCCs) to develop high-resolution projections of snowfall, snow depth, and winter severity index (WSI) by the mid- and late 21st century. Here, we use projections of a cumulative WSI (CWSI) known to influence autumn-winter waterfowl migration to demonstrate the utility of SNOW-17 results. The application of statistically downscaled climate data and a snow model leads to a better representation of lake processes in the Great Lakes Basin, topographic effects in the Appalachian Mountains, and spatial patterns of climatological snowfall, compared to the original GCMs. Annual mean snowfall is simulated to decline across the region, particularly in early winter (December-January), leading to a delay in the mean onset of the snow season. Due to a warming-induced acceleration of snowmelt, the percentage loss in snow depth exceeds that of snowfall. Across the Plains and Prairie Potholes LCC and Upper Midwest and Great Lakes LCC, daily snowfall events are projected to become less common, but more intense. The greatest reductions in the number of days per year with a present snowpack are expected close to the historical position of the -5°C isotherm in DJFM, around 44°N. The CWSI is projected to decline substantially during December-January, leading to increased likelihood of delays in timing and intensity of autumn-winter waterfowl migrations.

  10. Cancer in HIV-infected Persons from the Caribbean, Central and South America

    PubMed Central

    Fink, Valeria I.; Shepherd, Bryan E.; Cesar, Carina; Krolewiecki, Alejandro; Wehbe, Firas; Cortés, Claudia P.; Crabtree-Ramírez, Brenda; Padgett, Denis; Shafaee, Maryam; Schechter, Mauro; Gotuzzo, Eduardo; Bacon, Melanie; McGowan, Catherine; Cahn, Pedro; Masys, Daniel

    2011-01-01

    Background HIV infected individuals have heightened cancer risk. With the advent of HAART, the frequency of some AIDS defining cancers (ADC) has decreased while certain non-AIDS defining cancers (NADC) are becoming more frequent. Cancers among HIV-infected individuals in Latin American and the Caribbean have not yet been carefully studied. Methods Cancer cases among the Caribbean, Central and South American network for HIV Research (CCASAnet) cohort were identified reviewing clinical records and preexisting databases. Results There were 406 cancers reported: 331 ADC (224 Kaposi´s sarcomas and 98 non Hodgkin lymphomas). Most frequent NADC (n=75) were Hodgkin lymphoma and skin cancers. Seventy-three percent of NADC and 45% of ADC were diagnosed >1 year after HIV diagnosis. 56% of ADC occurred before HAART start. Median time from HAART start until cancer diagnosis was 2.5 years for NADC and 0.5 years for ADC (p=<0.001). Within 3372 HAART starters, 158 were diagnosed with 165 cancers (82.4% ADC); 85 cases were previous to or concomitant with HAART initiation. Incidence of cancer after HAART initiation in 8080 person-years of follow-up was 7.2 per 1000 person-years (95%CI= 5.5–9.3) for ADC and 2.7 (95%CI= 1.8–4.1) for NADC; incidence was higher in the first two months, particularly for ADC (47.6). A pre-HAART ADC was a predictor of mortality after adjusting for age, sex, and CD4 at HAART initiation. Conclusions ADC were the most frequent cancers in this region and were often diagnosed close to HIV diagnosis and HAART start. Incidence of cancer was highest around HAART initiation. PMID:21239992

  11. Ecological consequences of hydropower development in Central America: Impacts of small dams and water diversion on neotropical stream fish assemblages

    USGS Publications Warehouse

    Anderson, Elizabeth P.; Freeman, Mary C.; Pringle, C.M.

    2006-01-01

    Small dams for hydropower have caused widespread alteration of Central American rivers, yet much of recent development has gone undocumented by scientists and conservationists. We examined the ecological effects of a small hydropower plant (Dona Julia Hydroelectric Center) on two low-order streams (the Puerto Viejo River and Quebradon stream) draining a mountainous area of Costa Rica. Operation of the Dona Julia plant has dewatered these streams, reducing discharge to ~ 10% of average annual flow. This study compared fish assemblage composition and aquatic habitat upstream and downstream of diversion dams on two streams and along a ~ 4 km dewatered reach of the Puerto Viejo River in an attempt to evaluate current instream flow recommendations for regulated Costa Rican streams. Our results indicated that fish assemblages directly upstream and downstream of the dam on the third order Puerto Viejo River were dissimilar, suggesting that the small dam (< 15 in high) hindered movement of fishes. Along the ~ 4 km dewatered reach of the Puerto Viejo River, species count increased with downstream distance from the dam. However, estimated species richness and overall fish abundance were not significantly correlated with downstream distance from the dam. Our results suggested that effects of stream dewatering may be most pronounced for a subset of species with more complex reproductive requirements, classified as equilibrium-type species based on their life-history. In the absence of changes to current operations, we expect that fish assemblages in the Puerto Viejo River will be increasingly dominated by opportunistic-type, colonizing fish species. Operations of many other small hydropower plants in Costa Rica and other parts of Central America mirror those of Doha Julia; the methods and results of this study may be applicable to some of those projects.

  12. Herbarium specimens reveal the footprint of climate change on flowering trends across north-central North America.

    PubMed

    Calinger, Kellen M; Queenborough, Simon; Curtis, Peter S

    2013-08-01

    Shifting flowering phenology with rising temperatures is occurring worldwide, but the rarity of co-occurring long-term observational and temperature records has hindered the evaluation of phenological responsiveness in many species and across large spatial scales. We used herbarium specimens combined with historic temperature data to examine the impact of climate change on flowering trends in 141 species collected across 116,000 km(2) in north-central North America. On average, date of maximum flowering advanced 2.4 days °C(-1), although species-specific responses varied from - 13.5 to + 7.3 days °C(-1). Plant functional types exhibited distinct patterns of phenological responsiveness with significant differences between native and introduced species, among flowering seasons, and between wind- and biotically pollinated species. This study is the first to assess large-scale patterns of phenological responsiveness with broad species representation and is an important step towards understanding current and future impacts of climate change on species performance and biodiversity. PMID:23786499

  13. Impact of population expansion on genetic diversity and structure of river otters (Lontra canadensis) in Central North America.

    PubMed

    Brandt, Jessica R; Brandt, Adam L; Ammer, Frank K; Roca, Alfred L; Serfass, Thomas L

    2014-01-01

    Populations of North American river otters (Lontra canadensis) declined throughout large portions of the continent during the early 1900s due to habitat degradation and unregulated trapping. River otters had been extirpated in North Dakota (ND), but the Red River Valley has since been recolonized, with potential source populations including the neighboring states of Minnesota or South Dakota, or the Canadian province of Manitoba (MB). We genotyped 9 microsatellite loci in 121 samples to determine the source population of river otters in the Red River Valley of ND, as well as to assess population structure and diversity of river otters in central North America. Overall, genetic diversity was high, with an average observed heterozygosity of 0.58. Genetic differentiation was low (F ST < 0.05) between river otters in ND and those of Minnesota, suggesting that eastern ND was recolonized by river otters from Minnesota. River otters from MB were genetically distinct from all other sampled populations. Low genetic differentiation (F ST = 0.044) between South Dakota and Louisiana (LA) suggested that reintroductions using LA stock were successful. The genetic distinctiveness of river otters from different geographic regions should be considered when deciding on source populations for future translocations.

  14. Effectiveness of Behavior Change Communications for Reducing Transmission Risks Among People Living with HIV in 6 Countries in Central America.

    PubMed

    Vu, Lung; Nieto-Andrade, Benjamin; DiVincenzo, Allison; Rivas, Jorge; Firestone, Rebecca; Wheeler, Jennifer; Lungo, Sussy

    2015-07-01

    This first region-wide study (N = 2,818) aims to estimate prevalence of HIV-related risks (sexual behavior, HIV disclosure, number of sex partners, violence) and factors associated with these risks as well as evaluate a behavior change communications program targeted to PLHIV in 6 countries in Central America. After 2 years, the program achieved moderate coverage, with 21 % of the sample reporting exposure to interpersonal communications (IPC) and 52 % to mass media program components. The odds of condom use, HIV disclosure, and participation in a self-help group increased by 1.4-1.8 times with exposure to mass media. Exposure to IPC increased odds of condom use by 2.7 and participation in self-help groups by 4.4 times. In addition, being in HIV care or taking ART was associated with condom use and HIV-status disclosure. About 30 % experienced physical or sexual violence, and those who did were 4 times less likely to use condoms. Findings suggest that behavioral interventions for PLHIV can reduce HIV-transmission risks and increase access to care.

  15. [Spatial-temporal dynamics of red tide precursor organisms at the Pacific coast of North and Central America].

    PubMed

    Sierra-Beltrán, A P; Lluch-Cota, D B; Lluch-Cota, S E; Cortés-Altamirano, R; Cortés-Lara, M C; Castillo-Chávez, M; Carrillo, L; Pacas, L; Víquez, R; García-Hansen, I

    2004-09-01

    The Pacific coast of Central and North America has long been and still is impacted by the flourishing of microalgal populations known as Harmful Algal Blooms (HABs). The organisms that have caused recent HABs episodes in the region are among others, Gymnodinium catenatum, Pyrodinium bahamense var. compressum, and recently Cochlodinium cf. catenatum. In spite of the accumulated effects on the human health, the economic activities and the environment, scarce information is available on the subject. The augmented use of coastal zones for human activities is also paralleled by increased awareness of global climate changes. Thus, it is not an easy task to discriminate anthropogenic or natural phenomena, or both, as the major driving forces. The long-term data sets available for limited regions, as well as some sporadic observations during notorious blooms, allowed us to discriminate major changes in the biodiversity and biogeography of HAB organisms. Main changes refer to number of events, covered area, duration and frequency, number of blooming species and appearance of not previously reported harmful taxa. The variables more clearly related to these dynamic phenomena, seems to be sea surface temperature and wind force, but it is not yet possible to weight their contributions. The participation of rain is not fully evaluated to date. The collaborative communication among small-budget monitoring operations in the region allowed to "pass the voice" about peaking concentrations of HAB organisms, diminishing the risk of poisoning. PMID:17465122

  16. Zonda downslope winds in the central Andes of South America in a 20-year climate simulation with the Eta model

    NASA Astrophysics Data System (ADS)

    Antico, Pablo L.; Chou, Sin Chan; Mourão, Caroline

    2015-12-01

    The Zonda wind is a local version of the alpine foehn in the central Andes Mountains in South America. It blows on the eastern slopes and produces an extremely warm and dry condition in Argentina. In this study, the occurrence of Zonda wind events during a 20-year simulation from the regional Eta model is analyzed and results are compared to previous studies of Zonda wind events based on weather observations. We define a set of parameters to account for the zonal pressure gradient across the mountain, vertical movement, and air humidity typical of Zonda wind events. These parameters are applied to characterize Zonda wind events in model run and to classify them as surface-level or high-level episodes. The resulting annual distribution of Zonda occurrences based on composite analyses shows a preference for winter and spring with rare occurrences during summer. For the surface-level Zonda wind events, the highest frequency occurs during spring. Whereas surface-level Zonda wind episodes more commonly initiate in the afternoon, high-level Zonda wind events show no preference for a given initiation time. Our results are mostly in agreement with previous observational results.

  17. Herbarium specimens reveal the footprint of climate change on flowering trends across north-central North America

    PubMed Central

    Calinger, Kellen M; Queenborough, Simon; Curtis, Peter S

    2013-01-01

    Shifting flowering phenology with rising temperatures is occurring worldwide, but the rarity of co-occurring long-term observational and temperature records has hindered the evaluation of phenological responsiveness in many species and across large spatial scales. We used herbarium specimens combined with historic temperature data to examine the impact of climate change on flowering trends in 141 species collected across 116,000 km2 in north-central North America. On average, date of maximum flowering advanced 2.4 days °C−1, although species-specific responses varied from − 13.5 to + 7.3 days °C−1. Plant functional types exhibited distinct patterns of phenological responsiveness with significant differences between native and introduced species, among flowering seasons, and between wind- and biotically pollinated species. This study is the first to assess large-scale patterns of phenological responsiveness with broad species representation and is an important step towards understanding current and future impacts of climate change on species performance and biodiversity. PMID:23786499

  18. Subsurface flow reedbeds using alternative media for the treatment of domestic greywater in Monteverde, Costa Rica, Central America.

    PubMed

    Dallas, S; Ho, G

    2005-01-01

    This paper describes the performance of reedbeds using plastic (PET) bottle segments as an alternative low-cost media for the treatment of domestic greywater in Monteverde, Costa Rica, Central America. Twelve reedbeds consisting of four sets of triplicates were monitored through wet and dry seasons in order to determine the effect of media type (PET versus crushed rock) and the effect of plants. In both seasons, performance of the planted reedbeds with PET media, for BOD and fecal coliform removal, was either comparable to, or better than, that of the crushed rock systems. The planted PET reedbeds achieved fecal coliform removal rates > 99.9% in all cases equating to reductions of between 3 and nearly 5 log, with an average BOD outflow of 12.9 mg/L over both seasons. The hydraulic loading rate varied between 1.33 and 2.67 cm/day and hydraulic retention times (HRT) ranged from 3.5 to 7.5 days. The six reedbeds planted with Coix lacryma-jobi proved to be significantly more effective in pathogen removal and BOD reduction than the unplanted reedbeds. The planted PET reedbeds also increased their biomass by twice that of the planted crushed rock reedbeds during the study period. The majority of this increase was shown to be due to root growth. This paper discusses the implications of the above results for developing countries and identifies potential areas for further research.

  19. Three-dimensional Effects and Shortwave Cloud Radiative Forcing Associated with Shallow Cumuli Over Central North America

    SciTech Connect

    Berg, Larry K.; Kassianov, Evgueni I.; Long, Charles N.; Mills, Jr., David

    2009-09-30

    Shallow cumuli are ubiquitous over large areas of the globe, including both the interior of continents and the trade wind regions over the oceans. Measurements made at the Atmospheric Radiation Measurement (ARM) Climate Research Facility, located in central North America, provide a unique long-term data set that can be used to investigate the influence that these clouds have on the shortwave surface energy budget at a continental location. Using data collected for the summers of 2000 through 2007, inclusive, over 900 hours with fair-weather cumuli were identified using data from a Total Sky Imager, cloud-radar and lidar. Data from a suite of surface radiometers was used to determine the shortwave forcing. This analysis estimates the three-dimensional effects of shallow cumuli by examining the occurrences of both positive and negative shortwave forcing. We show that the average surface shortwave forcing is approximately -45.5 W m-2. When the data are adjusted to account for periods without shallow clouds, the shortwave forcing over the entire summer (defined as May through August) are reduced in magnitude, with forcings of -2.1 W m-2.

  20. Phenotypic and genotypic heterogeneity among Streptococcus iniae isolates recovered from cultured and wild fish in North America, Central America and the Caribbean Islands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae, the etiological agent of streptococcosis in fish, is an important pathogen of cultured and wild fish worldwide. During the last decade outbreaks of streptococcosis have occurred in a wide range of cultured and wild fish in the Americas and Caribbean islands. To gain a better und...

  1. Towards understanding carbon recycling at subduction zones - lessons from Central America

    NASA Astrophysics Data System (ADS)

    Hilton, D. R.; Barry, P. H.; Fischer, T. P.

    2010-12-01

    Subduction zones provide the essential pathways for input of carbon from Earth’s external reservoirs (crust, sediments, oceans) to the mantle. However, carbon input to the deep interior is interrupted by outputs via the fore-arc, volcanic front, and back-arc regions. Coupled CO2 and He isotope data for geothermal fluids from throughout Central American (CA) are used to derive estimates of the output carbon flux for comparison with inputs estimated for the subducting Cocos Plate. The carbon flux carried by the incoming sediments is ~1.6 × 109 gCkm-1yr-1[1], as is the ratio of input carbon derived from pelagic limestone (L) and organic sediment (S), i.e., L/S ~10.7. Additionally, the upper 7 km of oceanic (crustal) basement supplies ~9.1 × 108 gCkm-1yr-1[2]: this flux is dominated by L-derived CO2. In terms of output, measured carbon concentrations coupled with flow rates for submarine cold seeps sites at the Costa Rica outer forearc yield CO2 and CH4 fluxes of ~ 6.1 × 103 and 8.0 × 105 (gCkm-1yr-1), respectively [3]. On the Nicoya Peninsula, the Costa Rica Pacific coastline (including the Oso Peninsula) and the Talamanca Mountain Range, coupled CO2-He studies allow recognition of a deep input (3He/4He up to 4RA) and resolution of CO2 into L- and S-components. There is an increase in the L/S ratio arc-ward with the lowest values lying close to diatomaceous ooze in the uppermost sequence of subducting sediment package. This observation is consistent with under-plating and removal of the uppermost organic-rich sediment from deeper subduction. As the input carbon fluxes of the individual sedimentary layers are well constrained [1], we can limit the potential steady-state flux of carbon loss at the subaerial fore-arc to ~ 6 × 107 gCkm-1yr-1, equivalent to ~88% of the input flux of the diatomaceous ooze, or < 4% of the total incoming sedimentary carbon. The greatest loss of slab-derived carbon occurs at the volcanic front. Estimates of the output CO2 flux along the

  2. Analysis of the weekly cycle of aerosol optical depth using AERONET and MODIS data

    NASA Astrophysics Data System (ADS)

    Xia, Xiangao; Eck, Tom F.; Holben, Brent N.; Phillippe, Goloub; Chen, Hongbin

    2008-07-01

    Multi-year Aerosol Robotic Network (AERONET) and Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) data are used to study AOD weekly variations at the global scale. A clear weekly cycle of AOD is observed in the United States (U.S.) and Central Europe. AOD during the weekday is larger than that during the weekend in 36 out of 43 AERONET sites in the U.S. The average U.S. weekend effect (the percent difference in AOD during the weekday and the weekend) is 3.8%. A weekly periodicity with lower AODs on Sunday and Monday and higher AODs from Wednesday until Saturday is revealed over Central Europe and the average weekend effect there is 4.0%. The weekly cycle in urban sites is greater than that in rural sites. AOD during the weekday is also significantly larger than that during the weekend in urban AERONET sites in South America and South Korea. However, a reversed AOD weekly cycle is observed in the Middle East and India. AODs on Thursday and Friday, the "weekend" for Middle East cultures, are relatively lower than AODs on other days. There is no clear weekly variation of AOD over eastern China. The striking feature in this region is the occurrence of much higher AOD on Sunday and this phenomenon is independent of season. The analysis of MODIS aerosol data is in good agreement with that of AERONET data.

  3. Cold episodes in the Peruvian Central Andes: Composites, Types, and their Impacts over South America (1958-2014)

    NASA Astrophysics Data System (ADS)

    Sulca, J. C.; Vuille, M. F.; Roundy, P. E.; Trasmonte, G.; Silva, Y.; Takahashi, K.

    2015-12-01

    The Mantaro basin (MB) is located in the central Peruvian Andes. Occasionally, cold episodes are observed during austral summer (January-March), that strongly damage crops. However, little is known about the causes and impacts of such cold episodes. The main goal of this study is thus to characterize cold episodes in the MB and assess their large-scale circulation and teleconnections over South America (SA) during austral summer. To identify cold events in the MB daily minimum temperature (Tmin) for the period 1958-2014 from Huayao station, located within the MB was used. A cold episode is defined when daily minimum temperature drops below its 10-percentile for at least one day. Additionally, to study the sensitivity between physical mechanisms associated with cold episodes and temperature, cold episodes are classified in three groups: Weak cold episodes (7.5 ≤ Tmin ≤ 10 percentile), strong cold episodes (Tmin ≤ 2.5 percentile), but excluding the 9 coldest events (Tmin ≤ 0 ͦ C), henceforth referred to as extraordinary cold episodes. Several gridded reanalysis were used to characterize the large-scale circulation, cloud cover and rainfall over SA associated with these events. Weak and strong cold episodes in the MB are mainly associated with a weakening of the Bolivian High-Nordeste Low system by tropical-extratropical interactions. Both types of cold episodes are associated with westerly wind anomalies at mid- and upper-tropospheric levels aloft the Peruvian Central Andes, which inhibit the influx of humid air masses from the lowlands to the east and hence limit the development of cloud cover (e.g., positive OLR anomalies over MB). The resulting clear sky conditions cause nighttime temperatures to drop, leading to cold extremes below 10-percentile. Simultaneously, northeastern Brazil (NEB) registers negative OLR anomalies, strong convection and enhanced cloud cover because displacement of the South Atlantic Convergence Zone (SACZ) toward the northeast of

  4. MODIS Atmospheric Data Handler

    NASA Technical Reports Server (NTRS)

    Anantharaj, Valentine; Fitzpatrick, Patrick

    2008-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) Atmosphere Data Handler software converts the HDF data to ASCII format, and outputs: (1) atmospheric profiles of temperature and dew point and (2) total precipitable water. Quality-control data are also considered in the export procedure.

  5. The use of MODIS data and aerosol products for air quality prediction

    NASA Astrophysics Data System (ADS)

    Hutchison, Keith D.; Smith, Solar; Faruqui, Shazia

    2004-09-01

    The Center for Space Research (CSR) is exploring new approaches to integrate data collected by the MODerate resolution Imaging Spectroradiometer (MODIS) sensor, flown on NASA's Earth Observing System (EOS) satellites, into a real-time prediction methodology to support operational air quality forecasts issued by the Monitoring Operations Division (MOD) of the Texas Commission on Environmental Quality (TCEQ). Air pollution is a widespread problem in the United States, with over 130 million individuals exposed to levels of air pollution that exceed one or more health-based standards. Texas air quality is under assault by a variety of anthropogenic sources associated with a rapidly growing population along with increases in emissions from the diesel engines that drive international trade between the US and Central America. The challenges of meeting air quality standards established by the Environmental Protection Agency are further impacted by the transport of pollution into Texas that originates from outside its borders and are cumulative with those generated by local sources. In an earlier study, CSR demonstrated the value of MODIS imagery and aerosol products for monitoring ozone-laden pollution that originated in the central US before migrating into Texas and causing TCEQ to issue a health alert for 150 counties. Now, data from this same event are re-analyzed in an attempt to predict air quality from MODIS aerosol optical thickness (AOT) observations. The results demonstrate a method to forecast air quality from remotely sensed satellite observations when the transient pollution can be isolated from local sources. These pollution sources can be separated using TCEQ's network of ground-based Continuous Air quality Monitoring (CAM) stations.

  6. A new species of Charinus Simon, 1892 from northeastern Brazil with comments on the potential distribution of the genus in Central and South Americas (Arachnida: Amblypygi: Charinidae).

    PubMed

    Vasconcelos, Ana Caroline Oliveira; Giupponi, Alessandro Ponce De Leão; Ferreira, Rodrigo Lopes

    2013-01-01

    A new species of the genus Charinus Simon, 1892 is described from caves in the Rio Grande do Norte, Brazil. This is the first record of the genus for the state. This paper presents a map of the Charinus species distribution in Brazil with new records and a map of potential distribution of the genus in South and Central Americas. An updated key for Charinus species from Brazil is also presented.

  7. First imported Plasmodium ovale malaria in Central America: case report of a Guatemalan soldier and a call to improve its accurate diagnosis.

    PubMed

    Castellanos, María Eugenia; Díaz, Sheilee; Parsons, Emily; Peruski, Leonard F; Enríquez, Fabiola; Ramírez, Juan Luis; Padilla, Norma

    2015-01-01

    The Mesoamerican Ministers of Health have set 2020 as the target for malaria elimination to be achieved in the region. Imported malaria cases are a potential threat to countries attempting elimination or working to prevent resurgence. We report the first imported Plasmodium ovale infection with molecular confirmation in Central America, which occurred in a Guatemalan soldier that had been deployed in Africa. The obstacles for its diagnosis using the standard microscopy technique and the need to improve its detection are discussed.

  8. Application-ready expedited MODIS data for operational land surface monitoring of vegetation condition

    USGS Publications Warehouse

    Brown, Jesslyn; Howard, Daniel M.; Wylie, Bruce K.; Frieze, Aaron; Ji, Lei; Gacke, Carolyn

    2015-01-01

    Monitoring systems benefit from high temporal frequency image data collected from the Moderate Resolution Imaging Spectroradiometer (MODIS) system. Because of near-daily global coverage, MODIS data are beneficial to applications that require timely information about vegetation condition related to drought, flooding, or fire danger. Rapid satellite data streams in operational applications have clear benefits for monitoring vegetation, especially when information can be delivered as fast as changing surface conditions. An “expedited” processing system called “eMODIS” operated by the U.S. Geological Survey provides rapid MODIS surface reflectance data to operational applications in less than 24 h offering tailored, consistently-processed information products that complement standard MODIS products. We assessed eMODIS quality and consistency by comparing to standard MODIS data. Only land data with known high quality were analyzed in a central U.S. study area. When compared to standard MODIS (MOD/MYD09Q1), the eMODIS Normalized Difference Vegetation Index (NDVI) maintained a strong, significant relationship to standard MODIS NDVI, whether from morning (Terra) or afternoon (Aqua) orbits. The Aqua eMODIS data were more prone to noise than the Terra data, likely due to differences in the internal cloud mask used in MOD/MYD09Q1 or compositing rules. Post-processing temporal smoothing decreased noise in eMODIS data.

  9. Spatio-temporal variations in the estimation of PM10 from MODIS-derived aerosol optical depth for the urban areas in the Central Indo-Gangetic Plain

    NASA Astrophysics Data System (ADS)

    Chitranshi, Shikha; Sharma, Satya Prakash; Dey, Sagnik

    2015-02-01

    Particulate air pollution poses a serious health problem to the urban centers in the central Indo-Gangetic plain (IGP) in northern India. Health management planning is constrained by the lack of availability of continuous dataset of particulate matter (PM) at a regional scale. Recently, researchers have established the strength of regression models for estimating PM from satellite-derived aerosol optical depth (AOD) and meteorological factors. The present study is focused on three cities, namely, Agra, Kanpur and Varanasi located in the central IGP. The study envisages four approaches of multi-linear regression modeling to estimate PM10 (particulates smaller than 10 µm) from AOD and the meteorological parameters. The first approach consists of four regional models, three of which estimate regional mean PM10 and the fourth one estimates the distributed PM10. These models have a weak-to-moderate coefficient of determination ( R 2 = 0.37-0.63). Spatial and temporal variations in the estimators are separately addressed by the second modeling approach, i.e., city models (CMs) and the third modeling approach, i.e., seasonal models (SMs), respectively. R 2 of these models varies from 0.40 to 0.68. Finally, the spatio-temporal variability of the estimators are addressed by the fourth modeling approach, i.e., city-wise seasonal models (CSMs) which exhibited better results ( R 2 = 0.49-0.88). Remarkable variations in the regression estimators of the CSMs are observed both spatially and temporally. The model adequacy checks and the validation studies also support CSMs for more reliable estimation of PM10 in the central IGP. The proposed methodology can, therefore, be reliably used in generating the regional PM10 concentration maps for health impact studies.

  10. Mechanisms that triggered hydrological changes in the tropical lowlands of northern Central America during the past 85 ka

    NASA Astrophysics Data System (ADS)

    Sylvestre, Florence; Perez, Liseth; Paillès, Christine; Schwalb, Antje; Kutterolf, Steffen; Brenner, Mark; Curtis, Jason; Ariztegui, Daniel; Anselmetti, Flavio; Hodell, David

    2016-04-01

    ). Moreover, between 80 and 61 ka, fresher sea surface waters are inferred from the adjacent oceans, associated with globally warmer temperatures, implying moister conditions for the Yucatán Peninsula (Leduc et al., 2007). Our results highlight shifts through time in the major forcing mechanisms that triggered water-level changes in Lake Petén Itzá. These new paleoenvironmental proxy data will be useful for selecting parameters to be included in future modelling experiments that test forcing of tropical climatic changes during the late Quaternary. Hodell, D.A., Anselmetti, F.S., Ariztegui, D., Brenner, M., Curtis, J.H., Gilli, A., Grzesik, D.A., Guilderson, T.J., Muller, A.D., Bush, M.B., Correa-Metrio, Y.A., Escobar, J., and Kutterolf, S., 2008. An 85-ka Record of Climate Change in Lowland Central America, Quaternary Science Reviews, 27, 1152- 1165. Leduc, G., Vidal, L., Tachikawa, K., Rostek, F., Sonzogni, C., Beaufort, L., Bard, E., 2007. Moisture transport across Central America as a positive feedback on abrupt climatic changes. Nature, 445, 908-911.

  11. Assessing and mapping drought hazard in Africa and South-Central America with a Meteorological Drought Severity Index

    NASA Astrophysics Data System (ADS)

    Carrao, Hugo; Barbosa, Paulo; Vogt, Jürgen

    2015-04-01

    the intra-annual variability of precipitation in estimating the severity of events that can impact on seasonal activities. The MDSI is standardized in space and time, and considers the relative monthly precipitation deficits and the seasonal influence of precipitation regimes in the meteorological drought severity computation. In this study, the calculation of the MDSI is performed with monthly precipitation totals from the Full Data Reanalysis Monthly Product Version 6.0 of the Global Precipitation Climatology Centre (GPCC). This dataset provides a global analysis at 0.5 dd latitude/longitude grid spacing of monthly precipitation over land from operational in situ rain gauges collected between January 1901 and December 2010. Using the MDSI, we estimated the severity of drought events that occurred in the past 100 years in Africa and South-Central America, and produced drought hazard maps based on the probability of exceedance the median historical severity. Overall, results indicate that drought hazard is high for semiarid areas, such as Northeastern and Southern South America, as well as Eastern and Southwestern Africa. Since available water resources in semiarid areas are already insufficient to permanently meet the demands of human activities, the outcomes highlight the aggravated risk for food security and confirm the need for the implementation of disaster mitigation measures in those regions.

  12. Biologic and genetic characteristics of Toxoplasma gondii isolates in free-range chickens from Costa Rica, Central America.

    PubMed

    Dubey, J P; Su, C; Oliveira, J; Morales, J A; Bolaños, R V; Sundar, N; Kwok, O C H; Shen, S K

    2006-06-30

    The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 144 free-range chickens (Gallus domesticus) from Costa Rica was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT), and found in 60 (40.1%) of 144 chickens with titers of 1:5 in 16, 1:10 in 5, 1:20 in 2, 1:40 in 3, 1:80 in 5, and 1:160 or higher in 29. Tissues of all chickens were bioassayed for T. gondii in mice or cats. Hearts and brains of 52 chickens with titers of 1:5 or higher and 16 chickens with doubtful titers were pooled and bioassayed in mice. Tissues from 76 chickens with MAT titers of 1:10 or less were pooled and fed to three T. gondii-free cats. Fecal floats of cats were bioassayed orally in mice but were negative for T. gondii oocysts. T. gondii was isolated by bioassay in mice from 32 chickens with MAT titers of 1:10 or higher. All infected mice from 4 of the 32 isolates died of toxoplasmosis. Genotyping of these 32 isolates using polymorphisms at the loci SAG1, SAG2, SAG3, BTUB and GRA6 revealed five genotypes. Five isolates had type I alleles and one isolate had type III alleles at all loci. The rest 26 isolates contained the combination of type I and II or I and III alleles and were divided into three genotypes. None was found to have genotype II alleles at all five loci. This is the first report of genetic characterization of T. gondii isolates from Costa Rica, Central America.

  13. A comparison of two commercial mosquito traps for the capture of malaria vectors in northern belize, central america.

    PubMed

    Wagman, Joseph; Grieco, John P; Bautista, Kim; Polanco, Jorge; Briceño, Ireneo; King, Russell; Achee, Nicole L

    2014-09-01

    To achieve maximum success from any vector control intervention, it is critical to identify the most efficacious tools available. The principal aim of this study was to evaluate the efficacy of 2 commercially available adult mosquito traps for capturing Anopheles albimanus and An. vestitipennis, 2 important malaria vectors in northern Belize, Central America. Additionally, the impact of outdoor baited traps on mosquito entry into experimental huts was assessed. When operated outside of human-occupied experimental huts, the Centers for Disease Control and Prevention (CDC) miniature light trap, baited with human foot odors, captured significantly greater numbers of female An. albimanus per night (5.1 ± 1.9) than the Biogents Sentinel™ trap baited with BG-Lure™ (1.0 ± 0.2). The 2 trap types captured equivalent numbers of female An. vestitipennis per night, 134.3 ± 45.6 in the CDC trap and 129.6 ± 25.4 in the Sentinel trap. When compared to a matched control hut using no intervention, the use of baited CDC light traps outside an experimental hut did not impact the entry of An. vestitipennis into window interception traps, 17.1 ± 1.3 females per hour in experimental huts vs. 17.2 ± 1.4 females per hour in control huts. However, the use of outdoor baited CDC traps did significantly decrease the entry of An. albimanus into window interception traps from 3.5 ± 0.5 females per hour to 1.9 ± 0.2 females per hour. These results support existing knowledge that the underlying ecological and behavioral tendencies of different Anopheles species can influence trap efficacy. Furthermore, these findings will be used to guide trap selection for future push-pull experiments to be conducted at the study site.

  14. Earthquake cycle deformation in Mexico and Central America constrained by GPS: Implications for coseismic, postseismic, and slow slip

    NASA Astrophysics Data System (ADS)

    Graham, Shannon E.

    Using surface deformation measured by GPS stations within Mexico and Central America, I model coseismic slip, Coulomb stress changes, postseismic afterslip, and slow slip events in order to increase our knowledge of the earthquake deformation cycle in seismically hazardous regions. In Chapter 1, I use GPS data to estimate coseismic slip due to the May 28, 2009 Swan Islands fault earthquake off the coast of Honduras and then use the slip distribution to calculate Coulomb stress changes for the earthquake. Coulomb stress change calculations resolve stress transfer to the seismically hazardous Motagua fault and further show an unclamping of normal faults in northern Honduras. In Chapter 2, the focus shifts to southern Mexico, where continuous GPS measurements since the mid-1990s are revolutionizing our understanding of the flatly subducting Cocos plate. I perform a time-dependent inversion of continuous GPS observations of the 2011-2012 slow slip event (SSE) to estimate the location and magnitude of slow slip preceding the March 20, 2012 Ometepec earthquake. Coulomb stress changes as a result of slip during the SSE are consistent with the hypothesis that the SSE triggered the Ometepec earthquake. Chapter 3 describes inversions for slip both during and after the Ometepec earthquake. Time-dependent modeling of the first six months of postseismic deformation reveals that fault afterslip extended ˜250 km inland to depths of ˜50 km along the Cocos plate subduction. The postseismic afterslip and previous SSEs in southern Mexico occur at similar depths down-dip from the seismogenic zone, indicating that transitional areas of the subduction interface underlie much of southern Mexico. Finally, I perform the first time-dependent modeling of SSEs below Mexico and the first to exploit all available continuous GPS stations in southern and central Mexico. The results provide a more complete and consistent catalog of modeled SSE for the Mexico subduction zone (MSZ) than is

  15. Profiles of Central America.

    ERIC Educational Resources Information Center

    Interracial Books for Children Bulletin, 1982

    1982-01-01

    In order to provide information missing from elementary and secondary educational materials, briefly reviews the history, geography, and current political, economic, demographic, and social characteristics of El Salvador, Guatemala, Honduras, and Nicaragua. Some information is also given about Costa Rica, Panama, and Belize.

  16. Association of winter weather variability in Central and Eastern North America with tropical Pacific sea surface temperature

    NASA Astrophysics Data System (ADS)

    Montroy, David L.

    exhibited strong similarities to the features common to the 1950-92 events. The analysis of North American daily precipitation and temperature distributions during warm and cold TP SSTA events identified unique changes. In the southeastern U.S., increased precipitation during January-March warm TP SSTA events was generally linked to more frequent daily precipitation totals above 10 mm, while the increased November precipitation in similar regions resulted from increased daily precipitation totals of all amounts. Further, below average January precipitation in the southwestern Appalachian Mountain region during warm TP SSTA events was associated with the lack of occurrence of very large (>25 mm) daily precipitation totals. During cold TP SSTA events, below average November precipitation principally was associated with reduced frequency of larger (>10 mm) precipitation events. Similarly unique relationships were identified in monthly average daily temperature extremes. Cooler than average February daily minimum temperatures in the central U.S. Great Plains mainly arose from the lack of occurrence of observations well below the monthly mean. Also, cooler than average daily maximum temperatures in the southern U.S. were associated principally with relatively few observations well above the monthly mean. For many other locations, the shifts in the daily maximum and minimum temperature distributions were quantified. The surface climate anomalies with the longest duration are the temperature anomalies in the northern U.S. Great Plains and south-central Canada during warm TP SSTA events. During warm TP SSTA events, these regions observed noticeably warmer than average temperatures that last for as many as 14 consecutive days during December-March. Other regions exhibited anomalies with shorter durations. For all regions, the key feature was the location of positive geopotential height anomalies located over North America and the placement of negative geopotential height anomalies

  17. Mapping Africa Biomass with MODIS Imagery

    NASA Astrophysics Data System (ADS)

    Laporte, N.; Baccini, A.; Houghton, R.

    2006-12-01

    Central Africa contains the second largest block of tropical forest remaining in the world, and is one of the largest carbon reservoirs on Earth. The carbon dynamics of the region differ substantially from other tropical forests because most deforestation and land use is associated with selective logging and small-scale landholders practicing traditional "slash-and-burn" agriculture. Despite estimates of 1-2 PgC/yr released to the atmosphere from tropical deforestation, the amount released from Central Africa is highly uncertain relative to the amounts released from other tropical forest areas. The uncertainty in carbon fluxes results from inadequate estimates of both rates of deforestation and standing stocks of carbon (forest biomass). Here we present new results mapping above-ground forest biomass for tropical Africa using machine learning techniques to integrate MODIS 1km spectral reflectance with forest inventory measurements to calibrate an empirical relationship. The derived forest biomass at each MODIS pixel shows the spatial distribution of forest biomass over the entire tropical forest region. The model has been tested in Uganda, Mali and part of Republic of Congo where field data were available. The regression tree model based on MODIS NBAR surface reflectance for Uganda, Mali and Republic of Congo explains 94 percent of the variance in above-ground biomass with a root mean square error (RMSE) of 27 Tons/ha. The approach shows promise for use of optical remote sensing data in mapping the spatial distribution of forest biomass across the region.

  18. Biologic and genetic characteristics of Toxoplasma gondii isolates in free-range chickens from Nicaragua, Central America.

    PubMed

    Dubey, J P; Sundar, N; Pineda, N; Kyvsgaard, N C; Luna, L A; Rimbaud, E; Oliveira, J B; Kwok, O C H; Qi, Y; Su, C

    2006-11-30

    infection in intermediate hosts such as chickens may facilitate genetic exchange between different parasite lineages in definitive feline hosts. This is the first report of genetic characterization of T. gondii isolates from Nicragua, Central America.

  19. The Relation between Sea Surface Temperature at the Subtropical South-Central Pacific and Precipitation in Southeastern South America.

    NASA Astrophysics Data System (ADS)

    Barros, Vicente R.; Silvestri, Gabriel E.

    2002-02-01

    This paper deals with the relationship between the interannual variability of sea surface temperature (SST) and its associated atmospheric circulation and rainfall variability over southeastern South America (SSA), namely the subtropical region east of the Andes between 20° and 40°S, during the austral spring. Rainfall in SSA and SST interannual variability is studied using canonical correlation analysis. The first two modes show the well-known warm-wet and cold-dry pattern between the equatorial SST and rainfall over most of this part of the world. However, SST in the equatorial regions does not modulate rainfall variability among El Niño (EN) years or among La Niña (LN) years. On the other hand, it does modulate this variability between EN and LN cases as a whole and among neutral cases indicating that the SSA rainfall response to equatorial Pacific SST is not linear over the observed SST range, having no dependence on the extremes of this range. In contrast, among EN events, SST in the subtropical south-central Pacific (SSCP) modulates the seasonal rainfall over most of SSA. Also, when all the years are considered, this SST has a correlation with precipitation of magnitude similar to those corresponding to the SST in EN regions. Consistent with this, the circulation field has enhanced cyclonic (anticyclonic) advection over subtropical SSA when SST in the SSCP is cold (warm).SSTs in EN-3 or EN-3.4 regions and in the SSCP are negatively correlated, but their correlation is practically zero when only EN cases or only neutral cases are considered, and very small in LN cases. This allows a stratification analysis composing cases according to different SSTs in EN-3 and EN-3.4 regions with almost constant SST in the SSCP and similarly according to different SST in the SSCP with approximately constant SST in EN regions. The composite difference fields with constant equatorial SST and with constant SST in the SSCP have a wave train in the Pacific similar to the ENSO

  20. Regional modeling of lateral heterogeneity near the CMB from central America to the eastern part of the Pacific LLSVP

    NASA Astrophysics Data System (ADS)

    Ventosa, Sergi; Romanowicz, Barbara

    2014-05-01

    Lateral structure variations at the base of the mantle are not precisely known. There is currently an active debate on the wavelengths of the core-mantle boundary (CMB) topography, the lateral variations on Vp and Vs, anisotropy and the trade-offs between them. Most seismological studies compare 1D or 3D global models to local observations of relatively-weak seismic phases but with strong CMB interaction, such as PcP, ScS, PcS and Sdiff. To reduce upper Mantle contamination these observations are conventionally measured relative to much strong reference phases, such as P and S. The two major observations are travel-times differences and amplitude ratios. Current major challenges in extracting clean observations are low signal-to-noise ratios (SNR) of CMB phases, and interference with a plethora of mantle phases. Low SNR hinders the extraction of accurate observations in low-magnitude events. While, PcP and ScS is frequently hidden in the coda of P and S, respectively, especially at large distance. Additional, s and p depth phases from P and S overlap precious portions of PcP and ScS phases for intermediate depth events. We face these problems using high-density seismic networks. We introduce seismic data-processing techniques that use dense arrays to create filters that separate locally signals in slowness, without compromising resolution. We specifically use the local slant-stack transform in the time-scale domain (Ventosa et al., EUSIPCO, 2011) to decompose each seismogram in slowness in a scale-smart way, merging the wavelet and local slant-stack transforms. In the particular case of PcP-P, we are able to extract accurate observations for events with magnitude of mW>5.4 and maximum distances up to 80 degrees. We conduct a regional study of the CMB structure from central America to the edge of the Pacific large-low shear-velocity provinces (LLSVP). Our approach allows us to sample regions of the eastern Pacific LLSVP boundary with unprecedented resolution, and

  1. On the Development of Multi-Hazard Early Warning Networks: Practical experiences from North and Central America.

    NASA Astrophysics Data System (ADS)

    Mencin, David; Hodgkinson, Kathleen; Braun, John; Meertens, Charles; Mattioli, Glen; Phillips, David; Blume, Fredrick; Berglund, Henry; Fox, Otina; Feaux, Karl

    2015-04-01

    The GAGE facility, managed by UNAVCO, maintains and operates about 1300 GNSS stations distributed across North and Central America as part of the EarthScope Plate Boundary Observatory (PBO) and the Continuously Operating Caribbean GPS Observational Network (COCONet). UNAVCO has upgraded about 450 stations in these networks to real-time and high-rate (RT-GNSS) and included surface meteorological instruments. The majority of these streaming stations are part of the PBO but also include approximately 50 RT-GNSS stations in the Caribbean and Central American region as part of the COCONet and TLALOCNet projects. Based on community input UNAVCO has been exploring ways to increase the capability and utility of these resources to improve our understanding in diverse areas of geophysics including seismic, volcanic, magmatic and tsunami deformation sources, extreme weather events such as hurricanes and storms, and space weather. The RT-GNSS networks also have the potential to profoundly transform our ability to rapidly characterize geophysical events, provide early warning, as well as improve hazard mitigation and response. Specific applications currently under development with university, commercial, non-profit and government collaboration on national and international scales include earthquake and tsunami early warning systems and near real-time tropospheric modeling of hurricanes and precipitable water vapor estimate assimilation. Using tsunami early warning as an example, an RT-GNSS network can provide multiple inputs in an operational system starting with rapid assessment of earthquake sources and associated deformation which informs the initial modeled tsunami. The networks can then can also provide direct measurements of the tsunami wave heights and propagation by tracking the associated ionospheric disturbance from several 100's of km away as the waves approaches the shoreline. These GNSS based constraints can refine the tsunami and inundation models and potentially

  2. Slab roll-back and trench retreat as controlling factor for basin subsidence in southern Central America

    NASA Astrophysics Data System (ADS)

    Brandes, Christian; Winsemann, Jutta

    2015-04-01

    Slab roll-back and trench retreat are important factors for basin subsidence, magma generation and volcanism in arc-trench systems. Based on the sedimentary and tectonic record of the southern Central American island-arc we conclude that repeated phases of slab roll-back and trench retreats occurred the arc-trench system since the Late Cretaceous. These trench retreats were most probably related to the subduction of oceanic plateaus and seamounts and effected both the fore-arc and back-arc evolution. We used numerical basin modelling techniques to analyse the burial history of fore-arc and back-arc basins in Central America and combined the results with field data of the sedimentological evolution of the basin-fills. From the basin models, geohistory curves were extracted for the fore-arc and back-arc basins to derive the subsidence evolution. The Sandino Fore-arc Basin is characterized by low subsidence during the first 40 Myr. Since the Late Cretaceous the basin has a linear moderate subsidence with a phase of accelerated subsidence in the Oligocene. In the North and South Limón Back-arc Basin, subsidence started at approximately the same time as in the Sandino Fore-arc Basin. The North and South Limón Basins show a linear subsidence trend in the Paleocene and Eocene. Evidence for trench retreats is given by pulses of uplift in the outer-arc area, followed by subsidence in both the fore-arc and back-arc basins. The first slab roll-back probably occurred during the Early Paleocene. This is indicated by the collapse of carbonate platforms, and the re-deposition of large carbonate blocks into deep-water turbidites. A new pulse of uplift or decreased subsidence, respectively during the Late Eocene is attributed to subduction of rough crust. A subsequent slab detachment and the establishment of a new subduction zone further westward was described by Walther et al. (2000). Strong uplift affected the entire fore-arc area, which led to the deposition of very coarse

  3. Impact of Sensor Degradation on the MODIS NDVI Time Series

    NASA Technical Reports Server (NTRS)

    Wang, Dongdong; Morton, Douglas; Masek, Jeffrey; Wu, Aisheng; Nagol, Jyoteshwar; Xiong, Xiaoxiong; Levy, Robert; Vermote, Eric; Wolfe, Robert

    2011-01-01

    Time series of satellite data provide unparalleled information on the response of vegetation to climate variability. Detecting subtle changes in vegetation over time requires consistent satellite-based measurements. Here, we evaluated the impact of sensor degradation on trend detection using Collection 5 data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on the Terra and Aqua platforms. For Terra MODIS, the impact of blue band (Band 3, 470nm) degradation on simulated surface reflectance was most pronounced at near-nadir view angles, leading to a 0.001-0.004/yr decline in Normalized Difference Vegetation Index (NDVI) under a range of simulated aerosol conditions and surface types. Observed trends MODIS NDVI over North America were consistent with simulated results, with nearly a threefold difference in negative NDVI trends derived from Terra (17.4%) and Aqua (6.7%) MODIS sensors during 2002-2010. Planned adjustments to Terra MODIS calibration for Collection 6 data reprocessing will largely eliminate this negative bias in NDVI trends over vegetation.

  4. Impact of Sensor Degradation on the MODIS NDVI Time Series

    NASA Technical Reports Server (NTRS)

    Wang, Dongdong; Morton, Douglas Christopher; Masek, Jeffrey; Wu, Aisheng; Nagol, Jyoteshwar; Xiong, Xiaoxiong; Levy, Robert; Vermote, Eric; Wolfe, Robert

    2012-01-01

    Time series of satellite data provide unparalleled information on the response of vegetation to climate variability. Detecting subtle changes in vegetation over time requires consistent satellite-based measurements. Here, the impact of sensor degradation on trend detection was evaluated using Collection 5 data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on the Terra and Aqua platforms. For Terra MODIS, the impact of blue band (Band 3, 470 nm) degradation on simulated surface reflectance was most pronounced at near-nadir view angles, leading to a 0.001-0.004 yr-1 decline in Normalized Difference Vegetation Index (NDVI) under a range of simulated aerosol conditions and surface types. Observed trends in MODIS NDVI over North America were consistentwith simulated results,with nearly a threefold difference in negative NDVI trends derived from Terra (17.4%) and Aqua (6.7%) MODIS sensors during 2002-2010. Planned adjustments to Terra MODIS calibration for Collection 6 data reprocessing will largely eliminate this negative bias in detection of NDVI trends.

  5. Greening Trends in North American Boreal Forest and Tundra during 2000-2009 from MODIS and in situ Measurements

    NASA Astrophysics Data System (ADS)

    Wang, D.; Morton, D. C.; Masek, J. G.; McManus, K. M.; Sexton, J. O.

    2010-12-01

    High northern latitudes have experienced the strongest warming trends during the satellite era (1970-present). The response of boreal forest and tundra vegetation to recent and projected warming plays a pivotal role for carbon cycling in these ecosystems and related feedbacks within the Earth system. Long time series of normalized differenced vegetation index (NDVI), calculated from historical Advanced Very High Resolution Radiometer (AVHRR) data, provided the first opportunity to evaluate vegetation dynamics over decadal temporal scales and continental to global spatial scales. However, due to coarse spatial resolution (1-8 km), previous studies of greening in North America with aggregated AVHRR NDVI data were unable to separate the contributions from changes in growing season length and vegetation cover to the greening signal in forest and tundra ecosystems. In this study, we isolated trends in peak growing season vegetation cover using NDVI data from the MODerate resolution Imaging Spectroradiometer (MODIS) during 2000-2009. Our time series analysis compared 500 m NDVI data from the same 16-day composite period during peak growing season months to characterize changes in vegetation abundance during 2000-2009. This approach minimized impacts of phenology, changes in growing season length, and clouds or other data artifacts. For comparison with satellite-based observations, we used measurements of upwelling and downwelling spectral radiances over FLUXNET tower sites to derive broadband NDVI values. Trends in vegetation cover from MODIS NDVI during 2000-2009 differ from previous studies with AVHRR data. Approximately 26% of all vegetated area exhibited significant linear trends in NDVI during 2000-2009 (ptrend<0.05). However, only one third of all trends were positive (greening), corresponding to 8.6% of the boreal forest and tundra biomes in North America. Tundra in Quebec, Newfoundland and west Alaska exhibited the strongest greening trends during 2000

  6. 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.

  7. A review of the genus Agapetus Curtis (Trichoptera: Glossosomatidae) in eastern and central North America, with description of 12 new species

    USGS Publications Warehouse

    Etnier, David A.; Parker, Charles R.; Baxter, John T.; Long, Todd M.

    2010-01-01

    Twenty-nine species of caddisflies in the genus Agapetus Curtis in eastern and central North America are reviewed. Twelve are described as new species: Agapetus aphallus (known only from females); Agapetus baueri, Agapetus flinti, Agapetus harrisi, Agapetus hesperus, Agapetus ibis, Agapetus kirchneri, Agapetus meridionalis, Agapetus pegram, Agapetus ruiteri, Agapetus stylifer, and Agapetus tricornutus. Agapetus rossi Denning 1941 is recognized as a junior subjective synonym of Agapetus walkeri (Betten and Mosely 1940), new synonym. A key to males is provided, and species’ distributions are mapped.

  8. Airborne LIDAR Measurements of Water Vapor, Ozone, Clouds, and Aerosols in the Tropics Near Central America During the TC4 Experiment

    NASA Technical Reports Server (NTRS)

    Kooi, Susan; Fenn, Marta; Ismail, Syed; Ferrare, Richard; Hair, John; Browell, Edward; Notari, Anthony; Butler, Carolyn; Burton, Sharon; Simpson, Steven

    2008-01-01

    Large scale distributions of ozone, water vapor, aerosols, and clouds were measured throughout the troposphere by two NASA Langley lidar systems on board the NASA DC-8 aircraft as part of the Tropical Composition, Cloud, and Climate Coupling Experiment (TC4) over Central and South America and adjacent oceans in the summer of 2007. Special emphasis was placed on the sampling of convective outflow and transport, sub-visible cirrus clouds, boundary layer aerosols, Saharan dust, volcanic emissions, and urban and biomass burning plumes. This paper presents preliminary results from this campaign, and demonstrates the value of coordinated measurements by the two lidar systems.

  9. Microevolution in lower Central America: genetic characterization of the Chibcha-speaking groups of Costa Rica and Panama, and a consensus taxonomy based on genetic and linguistic affinity.

    PubMed Central

    Barrantes, R; Smouse, P E; Mohrenweiser, H W; Gershowitz, H; Azofeifa, J; Arias, T D; Neel, J V

    1990-01-01

    There is evidence that Amerindians have continuously occupied the lower Central American Isthmus for as long as 10,000 years. There remains some doubt about the relationships of these original colonizers to the resident peoples of this zone at the time of European contact (approximately A.D. 1500). We present new genetic data for up to 48 genetic loci for 570 members of six Chibcha-speaking tribes of lower Central America--the Boruca, Bribri, Cabecar, and Guatuso of Costa Rica and the Kuna and Teribe of Panama--and delineate the genetic affinities among the various groups (these six tribes and the Guaymi and Bokota) of lower Central America. We convert standard genetic distance metrics into a form that is linear with the effective time since divergence, and we compare the genetic distances with linguistic distances for the same groups (r = .74, P less than .001). Geographic affinity accounts for some of the genetic divergence among groups (r = .49, P less than .084) and for some of the linguistic divergence (r = .53, P less than .037), but the correspondence between geographic position and taxonomic affinity is not high. We combine all of the genetic and linguistic data to construct a synthetic overview taxonomy of the lower Central American Chibcha. Both the genetic and linguistic data exhibit hierarchical organization of tribal groups, showing a general east-to-west pattern of grouping, with greater affinities between close neighbors. The presence of private genetic variants of some antiquity within the region and their absence outside the zone, coupled with the essential absence of the DI*A polymorphism of mongoloid origin that is widespread outside the zone, argue for a relatively isolated development of the Central American Chibcha. Our results do not support the old view of lower Central America as a frontier between more advanced cultures to the north and south. Any such explanation would require recent waves of migration from outside the region, migration

  10. Educacion y Pueblos Indigenas en Centroamerica: Un Balance Critico (Education and Indigenous People in Central America: A Critical Balance).

    ERIC Educational Resources Information Center

    Amadio, Massimo, Comp.; And Others

    Global society is polarized between the modern capitalist sector and the marginal sector, which is composed of indigenous, poor, and ethnic, tribal people. The problems of education for groups in Latin America, key issues in planning to meet their needs, and strategies to resolve them, are the focus of this publication. Nine papers provide a…

  11. Carbon cycle dynamics and solar activity embedded in a high-resolution 14C speleothem record from Belize, Central America

    NASA Astrophysics Data System (ADS)

    Lechleitner, Franziska A.; Breitenbach, Sebastian F. M.; McIntyre, Cameron; Asmerom, Yemane; Prufer, Keith M.; Polyak, Victor; Culleton, Brendan J.; Kennett, Douglas J.; Eglinton, Timothy I.; Baldini, James U. L.

    2015-04-01

    Speleothem 14C has recently emerged as a potentially powerful proxy for climate reconstruction. Several studies have highlighted the link between karst hydrology and speleothem 14C content, and a number of possible causes for this relationship have been proposed, such as dripwater flow dynamics in the karst and changes in soil organic matter (SOM) turnover time (e.g. Griffiths et al., 2012). Here we present a high resolution 14C record for a stalagmite (YOK-I) from Yok Balum cave in southern Belize, Central America. YOK-I grew continuously over the last 2000 years, and has been dated very precisely with the U-Th method (40 dates, mean uncertainty < 10 years). The excellent chronological control for this stalagmite allows us to calculate 14C activity (a14C) at the time of speleothem deposition (a14Cinit), as well as the dead carbon fraction (DCF), predominantly a measure of the reservoir effect introduced by limestone dissolution in the karst (Genty et al., 2001). Both records show striking similarities to atmospheric a14C (IntCal13) and reconstructions of solar activity and 14C production rate. We infer close coupling between cave environment and atmosphere, with minimal signal dampening, an observation supported by monitoring data (Ridley et al., in press). DCF fluctuates between approximately 10% and 16% over the entire record, with distinctly lower DCF values and higher a14Cinit during a period of reduced rainfall between ca. 700-1100 AD (linked to the Classic Maya Collapse). This behavior is consistent with observations made elsewhere, and suggests that DCF responds to karst hydrological variability, specifically open-closed system transitions. YOK-I a14Cinit typically lags atmospheric values by 10-100 cal years. A shorter lag appears to be linked to periods of drought, suggesting a response of SOM dynamics above the cave to rainfall reduction. Specifically, drought is inferred to lead to reduced bioproductivity and soil carbon turnover, lowering contributions

  12. The 1.1-Ga Midcontinent Rift System, central North America: sedimentology of two deep boreholes, Lake Superior region

    NASA Astrophysics Data System (ADS)

    Ojakangas, Richard W.; Dickas, Albert B.

    2002-03-01

    The Midcontinent Rift System (MRS) of central North America is a 1.1-Ga, 2500-km long structural feature that has been interpreted as a triple-junction rift developed over a mantle plume. As much as 20 km of subaerial lava flows, mainly flood basalts, are overlain by as much as 10 km of sedimentary rocks that are mostly continental fluvial red beds. This rock sequence, known as the Keweenawan Supergroup, has been penetrated by a few deep boreholes in the search for petroleum. In this paper, two deep boreholes in the Upper Peninsula of Michigan are described in detail for the first time. Both the Amoco Production #1-29R test, herein referred to as the St. Amour well, and the nearby Hickey Creek well drilled by Cleveland Cliffs Mining Services, were 100% cored. The former is 7238 ft (2410 m) deep and the latter is 5345 ft (1780 m) deep. The entirety of the stratigraphic succession of the Hickey Creek core correlates very well with the upper portion of the St. Amour core, as determined by core description and point-counting of 43 thin sections selected out of 100 studied thin sections. Two Lower Paleozoic units and two Keweenawan red bed units—the Jacobsville Sandstone and the underlying Freda Sandstone—are described. The Jacobsville is largely a feldspatholithic sandstone and the Freda is largely a lithofeldspathic sandstone. Below the Freda, the remaining footage of the St. Amour core consists of a thick quartzose sandstone unit that overlies a heterogenous unit of intercalated red bed units of conglomerate, sandstone, siltstone, and shale; black shale; individual basalt flows; and a basal ignimbritic rhyolite. This lower portion of the St. Amour core presents an enigma, as it correlates very poorly with other key boreholes located to the west and southwest. While a black shale sequence is similar to the petroleum-bearing Nonesuch Formation farther west, there is no conglomerate unit to correlate with the Copper Harbor Conglomerate. Other key boreholes are

  13. Argentina from MODIS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Moderate-resolution Imaging Spectroradiometer (MODIS) image over Argentina was acquired on April 24, 2000, and was produced using a combination of the sensor's 250-m and 500-m resolution 'true color' bands. This image was presented on June 13, 2000 as a GIFt to Argentinian President Fernando de la Rua by NASA Administrator Dan Goldin. Note the Parana River which runs due south from the top of the image before turning east to empty into the Atlantic Ocean. Note the yellowish sediment from the Parana River mixing with the redish sediment from the Uruguay River as it empties into the Rio de la Plata. The water level of the Parana seems high, which could explain the high sediment discharge. A variety of land surface features are visible in this image. To the north, the greenish pixels show forest regions, as well as characteristic clusters of rectangular patterns of agricultural fields. In the lower left of the image, the lighter green pixels show arable regions where there is grazing and farming. (Image courtesy Jacques Descloitres, MODIS Land Group, NASA GSFC)

  14. U-Pb zircon geochronology of Paleozoic units in Western and Central Guatemala: insights into the tectonic evolution of Middle America

    NASA Astrophysics Data System (ADS)

    Solari, L. A.; Ortega-Gutierrez, F.; Elias-Herrera, M.; Schaaf, P.; Norman, M.; Torres de Leon, R.; Ortega-Obregon, C.; Moran Ical, S.; Chiquin, M.

    2007-05-01

    Precambrian and Paleozoic basements are present in southern Mexico and Central America, where several crustal blocks are recognized by their different geologic record, and juxtaposed along lateral faults. Some of those crustal blocks are currently located between southernmost north America (the Maya block) and Central America (Chortis block).To better understand the geology of these crustal blocks, and to establish comparisons between their geologic history, U-Pb ages of both igneous and metasedimentary key units cropping out in central and western Guatemala are presented here. In the Altos Cuchumatanes (Maya block) granites yield both Permian (269 +/- 29 Ma) and Early Devonian (391 +/- 7.4 Ma) U-Pb ages. LA-ICPMS detrital zircon ages from rocks of the San Gabriel sequence, interpreted as the oldest metasedimentary unit of the Maya block, and overlain by the Late Paleozoic Upper Santa Rosa Group, yield Precambrian detrital zircons bracketed between 920 Ma and 1,000 Ma. The presence of these metasedimentary units, as well as Early Devonian to Silurian granites in the Mayan continental margin, from west (Altos Cuchumatanes), to east (Maya Mountains of Belize) indicate a more or less continuous belt of Lower Paleozoic igneous activity, also suggesting that the continental margin of the Maya block can be extended south of the Polochic fault, up to the Baja Verapaz shear zone. A metasedimentary sample belonging to the Chuacus Complex yielded detrital zircons with ages between 440 Ma and 1,325 Ma. The younger ages are similar to the igneous ages reported from the entire southern Maya continental margin, and show proximity of the Complex in the Middle-Late Palaeozoic. The S. Diego Phyllite, which overlies high-grade basement units of the Chortis block, contains zircons that are Lower Cambrian (538 Ma), Mesoproterozoic (980 to 1,150 Ma) and even Paleoproterozoic (1,820 Ma). Absence of younger igneous zircons in the San Diego Phyllite indicates that either its sedimentation

  15. 21st century projections of summer precipitation over Mexico and Central America from the Phase I CORDEX RegCM hyper-Matrix simulations

    NASA Astrophysics Data System (ADS)

    Fuentes-Franco, R.; Giorgi, F.; Coppola, E.; Pavia, E. G.; Diro, G. T.; Graef, F.

    2013-05-01

    Changes in inter-annual variability of summer precipitation over Mexico and Central America are assessed from an ensemble of future climate projections performed with the regional climate model RegCM4. The RCP8.5 greenhouse gas emission scenario of two different Global Climate Models (GCMs) from the Coupled Model Intercomparison Project phase 5 (CMIP5) are used to provide boundary conditions for two different RegCM4 configurations. An intensification and extension of the mid-summer drought is found over Southern Mexico and Central America. Also a delayed onset of the rainy season is found over Northwestern Mexico. An increase in the inter-annual variability of precipitation and temperature is simulated, together with a warming greater than 4 degrees C in the mean seasonal temperature and a drying of more than 20%. A greater warming of the Eastern Pacific Ocean compared to the Tropical North Atlantic Ocean generates a strengthened North Atlantic Subtropical High Pressure and a stronger Caribbean Low Level Jet. This future ENSO-like state appears to be the mechanism driving the changes on the precipitation over the region.

  16. Migration and wintering areas of American Bitterns (Botaurus lentiginosus) that summer in central North America as determined by satellite and radio telemetry, 1998-2003

    USGS Publications Warehouse

    Huschle, Guy; Toepfer, John E.; Douglas, David C.

    2013-01-01

    Twenty adult male American Bitterns (Botaurus lentiginosus) were marked on summer range in central North America with satellite tracking Platform Transmitter Terminals (PTTs) to document migration routes and wintering range. Nineteen complete fall migration routes were documented for 17 individuals. Of the successful migrations, 63% (n = 12) went to southern Florida, 32% (n = 6) to southern Louisiana, and 5% (n = 1) to the Gulf coast of Texas. Spring migrations for nine birds were documented, and 78% (n = 7) showed fidelity to breeding range. Two complete migrations for two individuals were documented, and they demonstrated fidelity to winter range. The longest, fastest movement documented was 2,300 km in less than 74 hr. Extensive, post-breeding dispersal was not observed in the adult male American Bitterns in this study. Six male American Bitterns were marked with PTTs on winter range in Florida and Texas. Spring migration for these birds was documented to Nebraska, North Dakota, Saskatchewan, Manitoba and Ontario. Sixty-seven American Bitterns were marked with Very High Frequency radio transmitters on summer ranges, and 16% (n = 11) were located on wintering grounds used by the satellite-tracked birds, further documenting the importance of the Everglades and the Louisiana coast as winter habitat for American Bitterns that breed in Central North America.

  17. MODIS and AERONET characterization of the global aerosol

    NASA Astrophysics Data System (ADS)

    Kaufman, Y. J.; Remer, L. A.; Tanre, D.

    2002-05-01

    Recently produced daily MODIS aerosol data for the whole year of 2001 are used to show the concentration and dynamics of aerosol over ocean and large parts of the continents. The data were validated against the Aerosol Robotic Network (AERONET) measurements over land and ocean. Monthly averages and a movie based on the daily data are produced and used to demonstrate the spatial and temporal evolution of aerosol. The MODIS wide spectral range is used to distinguish fine smoke and pollution aerosol from coarse dust and salt. The movie produced from the MODIS data provides a new dimension to aerosol observations by showing the dynamics of the system. For example in February smoke and dust emitted from the Sahel and West Africa is shown to travel to the North-East Atlantic. In April heavy dust and pollution from East Asia is shown to travel to North America. In May-June pollution and dust play a dynamical dance in the Arabian Sea and Bay of Bengal. In Aug-September smoke from South Africa and South America is shown to pulsate in tandem and to periodically to be transported to the otherwise pristine Southern part of the Southern Hemisphere. To use the MODIS data for global assessment of aerosol forcing AERONET data are used to answer some key critical questions: - Are MODIS data collected at 10:30 am representative of the daily forcing? - What is the concentration and properties of background aerosol and that of anthropogenic aerosol These questions and more will be answered in the talk

  18. Fiesta! Mexico and Central America: A Global Awareness Program for Children in Grades 2-5. Bridges between Nations Series.

    ERIC Educational Resources Information Center

    Linse, Barbara; Judd, Dick

    Mexican and Central American cultures are a blend of Native American influences and Spanish traditions and religions. These are seen in aspects of Mexican and Central American celebrations. This book explores those celebrations through activities in art, folk and classical music, dances and fiestas. The book is organized into two sections to…

  19. Cloud Inhomogeneity from MODIS

    NASA Technical Reports Server (NTRS)

    Oreopoulos, Lazaros; Cahalan, Robert F.

    2004-01-01

    Two full months (July 2003 and January 2004) of MODIS Atmosphere Level-3 data from the Terra and Aqua satellites are analyzed in order to characterize the horizontal variability of cloud optical thickness and water path at global scales. Various options to derive cloud variability parameters are discussed. The climatology of cloud inhomogeneity is built by first calculating daily parameter values at spatial scales of l degree x 1 degree, and then at zonal and global scales, followed by averaging over monthly time scales. Geographical, diurnal, and seasonal changes of inhomogeneity parameters are examined separately for the two cloud phases, and separately over land and ocean. We find that cloud inhomogeneity is weaker in summer than in winter, weaker over land than ocean for liquid clouds, weaker for local morning than local afternoon, about the same for liquid and ice clouds on a global scale, but with wider probability distribution functions (PDFs) and larger latitudinal variations for ice, and relatively insensitive to whether water path or optical thickness products are used. Typical mean values at hemispheric and global scales of the inhomogeneity parameter nu (roughly the mean over the standard deviation of water path or optical thickness), range from approximately 2.5 to 3, while for the inhomogeneity parameter chi (the ratio of the logarithmic to linear mean) from approximately 0.7 to 0.8. Values of chi for zonal averages can occasionally fall below 0.6 and for individual gridpoints below 0.5. Our results demonstrate that MODIS is capable of revealing significant fluctuations in cloud horizontal inhomogenity and stress the need to model their global radiative effect in future studies.

  20. 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.

  1. The geometry of the Wadati-Benioff zone under southern Central America and its tectonic significance: results from a high-resolution local seismographic network

    NASA Astrophysics Data System (ADS)

    Protti, Marino; Gu¨ndel, Federico; McNally, Karen

    1994-07-01

    We present here a detailed geometry of the Wadati-Benioff zone under Costa Rica, obtained from seismicity recorded by a dense local seismographic network jointly operated by the Costa Rica Volcanological and Seismological Observatory, National University, and the Charles F. Richter Seismological Laboratory, University of California, Santa Cruz. Underneath the Nicaragua-Costa Rica border the Wadati-Benioff zone smoothly contorts (from steep to shallow dip angles, NW to SE), but does not show evidence of a brittle tear, as postulated by others. However, further to the SE, NE of Puerto Caldera, Costa Rica, the Wadati-Benioff zone does show a segmentation (the Quesada Sharp Contortion) at intermediate depths ( h > 70km). NW of this sharp contortion the deepest portion of the seismically active slab dips at about 80° and reaches maximum depths ranging from 200 km, near the Nicaragua-Costa Rica border, to 135 km under Ciudad Quesada. To the SE the deeper portion of the Wadati-Benioff zone dips at about 60° and the seismicity does not extend below depths ranging from 125 km, behind the volcanic arc, to 50 km, east of Quepos. In southern Costa Rica, east of 83°55'W, we find no evidence of the Wadati-Benioff zone deeper than 50 km. The obtained geometry and other known tectonic features related to the subduction of the Cocos plate under the Caribbean plate along the southern terminus of the Middle America Trench (Nicaragua and Costa Rica) correlate well with along-trench variations in age of the subducted Cocos plate. Some of these tectonic features are: (1) the shallowing of Middle America Trench bathymetry from NW to SE; (2) variations in the energy release within the subducted slab; (3) differences in coupling between Cocos and Caribbean plates; (4) the termination of the Central America Volcanic Chain in central Costa Rica; (5) distinct stress field variations on the overriding Caribbean plate. The subduction of the Cocos Ridge under southern Costa Rica is partially

  2. An enhanced TIMESAT algorithm for estimating vegetation phenology metrics from MODIS data

    USGS Publications Warehouse

    Tan, B.; Morisette, J.T.; Wolfe, R.E.; Gao, F.; Ederer, G.A.; Nightingale, J.; Pedelty, J.A.

    2011-01-01

    An enhanced TIMESAT algorithm was developed for retrieving vegetation phenology metrics from 250 m and 500 m spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indexes (VI) over North America. MODIS VI data were pre-processed using snow-cover and land surface temperature data, and temporally smoothed with the enhanced TIMESAT algorithm. An objective third derivative test was applied to define key phenology dates and retrieve a set of phenology metrics. This algorithm has been applied to two MODIS VIs: Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). In this paper, we describe the algorithm and use EVI as an example to compare three sets of TIMESAT algorithm/MODIS VI combinations: a) original TIMESAT algorithm with original MODIS VI, b) original TIMESAT algorithm with pre-processed MODIS VI, and c) enhanced TIMESAT and pre-processed MODIS VI. All retrievals were compared with ground phenology observations, some made available through the National Phenology Network. Our results show that for MODIS data in middle to high latitude regions, snow and land surface temperature information is critical in retrieving phenology metrics from satellite observations. The results also show that the enhanced TIMESAT algorithm can better accommodate growing season start and end dates that vary significantly from year to year. The TIMESAT algorithm improvements contribute to more spatial coverage and more accurate retrievals of the phenology metrics. Among three sets of TIMESAT/MODIS VI combinations, the start of the growing season metric predicted by the enhanced TIMESAT algorithm using pre-processed MODIS VIs has the best associations with ground observed vegetation greenup dates. ?? 2010 IEEE.

  3. An Enhanced TIMESAT Algorithm for Estimating Vegetation Phenology Metrics from MODIS Data

    NASA Technical Reports Server (NTRS)

    Tan, Bin; Morisette, Jeffrey T.; Wolfe, Robert E.; Gao, Feng; Ederer, Gregory A.; Nightingale, Joanne; Pedelty, Jeffrey A.

    2012-01-01

    An enhanced TIMESAT algorithm was developed for retrieving vegetation phenology metrics from 250 m and 500 m spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indexes (VI) over North America. MODIS VI data were pre-processed using snow-cover and land surface temperature data, and temporally smoothed with the enhanced TIMESAT algorithm. An objective third derivative test was applied to define key phenology dates and retrieve a set of phenology metrics. This algorithm has been applied to two MODIS VIs: Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). In this paper, we describe the algorithm and use EVI as an example to compare three sets of TIMESAT algorithm/MODIS VI combinations: a) original TIMESAT algorithm with original MODIS VI, b) original TIMESAT algorithm with pre-processed MODIS VI, and c) enhanced TIMESAT and pre-processed MODIS VI. All retrievals were compared with ground phenology observations, some made available through the National Phenology Network. Our results show that for MODIS data in middle to high latitude regions, snow and land surface temperature information is critical in retrieving phenology metrics from satellite observations. The results also show that the enhanced TIMESAT algorithm can better accommodate growing season start and end dates that vary significantly from year to year. The TIMESAT algorithm improvements contribute to more spatial coverage and more accurate retrievals of the phenology metrics. Among three sets of TIMESAT/MODIS VI combinations, the start of the growing season metric predicted by the enhanced TIMESAT algorithm using pre-processed MODIS VIs has the best associations with ground observed vegetation greenup dates.

  4. First recognition of the genus Verneuilia Hall and Clarke (Brachiopoda, Spiriferida) from North America (west-central Alaska)

    USGS Publications Warehouse

    Blodgett, R.B.; Johnson, J.G.

    1994-01-01

    The brachiopod genus Verneuilia Hall and Clarke, 1893, is recognized for the first time in North America, where it is represented by a new species described here. V. langenstrasseni. This occurrence extends not only the geographic range of the genus, but also the lower age and stratigraphic limit into the Eifelian (early Middle Devonian). Previously, the oldest known species was the type, V. cheiropteryx d'Archiac and de Verneuil, 1842, from the Givetian (late Middle Devonian) of Germany. Internal structures of V. langenstrasseni n.sp. are similar to those of genera in the ambocoeliid subfamily Rhynchospiriferinae, providing the first good evidence of a systematic relationship. -Authors

  5. Travelers With Chikungunya Virus Infection Returning to Northwest Italy From the Caribbean and Central America During June-November 2014.

    PubMed

    Burdino, Elisa; Ruggiero, Tina; Milia, Maria Grazia; Proietti, Alex; Sergi, Giuseppina; Torta, Ilaria; Calleri, Guido; Caramello, Pietro; Tiberti, Donatella; Ghisetti, Valeria

    2015-01-01

    Chikungunya virus (CHIKV) has recently emerged in the Caribbean. In Italy, CHIKV vector is documented in the Po river valley; therefore, a risk for autochthonous outbreaks is present. We report a case series of seven imported CHIKV infections in travelers returning from the Caribbean and Latin America occurring between June and November 2014, in the area of Turin, Northwest Italy, 3 years after the last imported cases were reported. These cases are a reminder of the need to always consider CHIKV infection in travelers from these epidemic areas as well as the importance of a prompt diagnosis. PMID:26080943

  6. Human parainfluenza virus in patients with influenza-like illness from Central and South America during 2006–2010

    PubMed Central

    Villaran, Manuel V; García, Josefina; Gomez, Jorge; Arango, Ana E; Gonzales, Marina; Chicaiza, Wilson; Alemán, Washington; Lorenzana de Rivera, Ivette; Sanchez, Felix; Aguayo, Nicolas; Kochel, Tadeusz J; Halsey, Eric S

    2014-01-01

    Background Human parainfluenza viruses (HPIVs) are common viral causes of community-acquired pneumonia, particularly in children. The four types of HPIV have world-wide distribution; however, limited information exists about the epidemiological profile of HPIV in Latin-America. Objective Provide epidemiologic and phylogenetic information about HPIVs that circulated in Latin America between 2006 and 2010 to better characterize the extent and variability of this respiratory virus in the region. Methods Oropharyngeal swabs, demographic data and clinical characteristics were obtained from individuals with influenza-like illness in 10 Latin-American countries between 2006–2010. Specimens were analyzed with culture and molecular methods. Results A total of 30 561 individuals were enrolled; 991 (3·2%) were HPIV positive. Most infected participants were male (53·7%) and under 5 years of age (68·7%). The HPIV type most frequently isolated was HPIV-3 (403, 40·7%). In 66/2007 (3·3%) hospitalized individuals, HPIV was identified. The most frequent symptoms at enrollment were cough and rhinorrhea. We identified certain patterns for HPIV-1, -2 and -3 in specific cities. Phylogenetic analysis revealed a homogeneous distribution in the region. Conclusions In the current scenario, no vaccine or treatment is available for this pathogen. Our results contribute to the scarce epidemiologic and phylogenetic information of HPIV in the region that could support the development of specific management. PMID:24286248

  7. Intraplate mountain building in response to continent continent collision—the Ancestral Rocky Mountains (North America) and inferences drawn from the Tien Shan (Central Asia)

    NASA Astrophysics Data System (ADS)

    Dickerson, Patricia Wood

    2003-04-01

    The intraplate Ancestral Rocky Mountains of western North America extend from British Columbia, Canada, to Chihuahua, Mexico, and formed during Early Carboniferous through Early Permian time in response to continent-continent collision of Laurentia with Gondwana—the conjoined masses of Africa and South America, including Yucatán and Florida. Uplifts and flanking basins also formed within the Laurentian Midcontinent. On the Gondwanan continent, well inboard from the marginal fold belts, a counterpart structural array developed during the same period. Intraplate deformation began when full collisional plate coupling had been achieved along the continental margin; the intervening ocean had been closed and subduction had ceased—that is, the distinction between upper versus lower plates became moot. Ancestral Rockies deformation was not accompanied by volcanism. Basement shear zones that formed during Mesoproterozoic rifting of Laurentia were reactivated and exerted significant control on the locations, orientations, and modes of displacement on late Paleozoic faults. Ancestral Rocky Mountain uplifts extend as far south as Chihuahua and west Texas (28° to 33°N, 102° to 109°W) and include the Florida-Moyotes, Placer de Guadalupe-Carrizalillo, Ojinaga-Tascotal and Hueco Mountain blocks, as well as the Diablo and Central Basin Platforms. All are cored with Laurentian Proterozoic crystalline basement rocks and host correlative Paleozoic stratigraphic successions. Pre-late Paleozoic deformational, thermal, and metamorphic histories are similar as well. Southern Ancestral Rocky Mountain structures terminate along a line that trends approximately N 40°E (present coordinates), a common orientation for Mesoproterozoic extensional structures throughout southern to central North America. Continuing Tien Shan intraplate deformation (Central Asia) has created an analogous array of uplifts and basins in response to the collision of India with Eurasia, beginning in late

  8. Comparison of bean biochemical composition and beverage quality of Arabica hybrids involving Sudanese-Ethiopian origins with traditional varieties at various elevations in Central America.

    PubMed

    Bertrand, Benoit; Vaast, Philippe; Alpizar, Edgardo; Etienne, Hervé; Davrieux, Fabrice; Charmetant, Pierre

    2006-09-01

    For buyers of Arabica coffee (Coffea arabica L.) in Central America, elevation and variety are important indicators of quality. We compared coffee produced by three types of varieties established in various trials at elevations ranging from 700-1600 m in three countries (El Salvador, Costa Rica and Honduras). Arabica hybrids resulting from crosses of Sudanese-Ethiopian origins with either traditional varieties or with introgressed lines derived from the hybrid of Timor (C. arabica x Coffea canephora Pierre ex Froehn) were compared with traditional cultivars (TC). Effects of elevation and variety on bean biochemical composition (caffeine, chlorogenic acid, trigonelline, fat and sucrose) were evaluated by predictive models based on calibration of near-infrared (NIR) spectra and by chemometric analysis of the global NIR spectrum. Beverage quality tests were performed by a panel of ten professional cup-tasters. Experiment 1 was carried out on the slopes of the Poas volcano (Costa Rica) with the traditional cultivar 'Caturra'. Experiment 2 compared the three varieties in a network of trials established in three countries of Central America. Significant linear regressions with elevation were observed in Experiment 1 with Caturra and in Experiment 2 for the traditional cultivars, and trends were established relating variation in biochemical compounds and cup quality to elevation. Convergence or divergence of the new hybrids in relation to these trends was observed. For the traditional cultivars, elevation had a significant effect on bean biochemical composition, with chlorogenic acid and fat concentrations increasing with increasing elevation. For the Arabica hybrids, elevation explained little of the variation in chlorogenic acid concentration and none of the variation in fat concentration. Nevertheless, Arabica hybrids had 10-20% higher fat concentrations than the traditional varieties at low elevations and similar fat concentrations at high elevations. The samples

  9. Undiagnosed MODY: Time for Action.

    PubMed

    Kleinberger, Jeffrey W; Pollin, Toni I

    2015-12-01

    Maturity-onset diabetes of the young (MODY) is a monogenic form of diabetes that accounts for at least 1 % of all cases of diabetes mellitus. MODY classically presents as non-insulin-requiring diabetes in lean individuals typically younger than 25 with evidence of autosomal dominant inheritance, but these criteria do not capture all cases and can also overlap with other diabetes types. Genetic diagnosis of MODY is important for selecting the right treatment, yet ~95 % of MODY cases in the USA are misdiagnosed. MODY prevalence and characteristics have been well-studied in some populations, such as the UK and Norway, while other ethnicities, like African and Latino, need much more study. Emerging next-generation sequencing methods are making more widespread study and clinical diagnosis increasingly feasible; at the same time, they are detecting other mutations in the same genes of unknown clinical significance. This review will cover the current epidemiological studies of MODY and barriers and opportunities for moving toward a goal of access to an appropriate diagnosis for all affected individuals. PMID:26458381

  10. MODIS and AERONET Characterization of the Global Aerosol

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram; Reme, Lorraine; Tanre, Didier; Lau, William K. M. (Technical Monitor)

    2002-01-01

    Recently produced daily MODIS aerosol data for the whole year of 2001 are used to show the concentration and dynamics of aerosol over ocean and large parts of the continents. The data were validated against the Aerosol Robotic Network (AERONET) measurements over land and ocean. Monthly averages and a movie based on the daily data are produced and used to demonstrate the spatial and temporal evolution of aerosol. The MODIS wide spectral range is used to distinguish fine smoke and pollution aerosol from coarse dust and salt. The movie produced from the MODIS data provides a new dimension to aerosol observations by showing the dynamics of the system. For example in February smoke and dust emitted from the Sahel and West Africa is shown to travel to the North-East Atlantic. In April heavy dust and pollution from East Asia is shown to travel to North America. In May-June pollution and dust play a dynamical dance in the Arabian Sea and Bay of Bengal. In Aug-September smoke from South Africa and South America is shown to pulsate in tandem and to periodically to be transported to the otherwise pristine Southern part of the Southern Hemisphere.

  11. The moderate resolution imaging spectrometer (MODIS) science and data system requirements

    NASA Technical Reports Server (NTRS)

    Ardanuy, Philip E.; Han, Daesoo; Salomonson, Vincent V.

    1991-01-01

    The Moderate Resolution Imaging Spectrometer (MODIS) has been designated as a facility instrument on the first NASA polar orbiting platform as part of the Earth Observing System (EOS) and is scheduled for launch in the late 1990s. The near-global daily coverage of MODIS, combined with its continuous operation, broad spectral coverage, and relatively high spatial resolution, makes it central to the objectives of EOS. The development, implementation, production, and validation of the core MODIS data products define a set of functional, performance, and operational requirements on the data system that operate between the sensor measurements and the data products supplied to the user community. The science requirements guiding the processing of MODIS data are reviewed, and the aspects of an operations concept for the production of data products from MODIS for use by the scientific community are discussed.

  12. Genetic characterization and phylogenetic analysis of skunk-associated rabies viruses in North America with special emphasis on the central plains.

    PubMed

    Davis, Rolan; Nadin-Davis, Susan A; Moore, Michael; Hanlon, Cathleen

    2013-06-01

    Across North America the skunk acts as a reservoir for several rabies virus variants. Some of these variants are geographically restricted in range as is the case for the California skunk variant and two distinct variants present in Mexico. In contrast the North Central and South Central skunk rabies viruses are dispersed in overlapping ranges over large areas of the Midwestern region of the United States with the former extending into southern parts of the Canadian prairies. Despite this extensive range, there has been only very limited molecular characterization of these two viral variants. This study has examined the genetic diversity of the rabies viruses associated with North American skunks, with particular emphasis on the South Central skunk variant which was found to comprise three distinct geographically restricted groups of viruses that could in some cases be further sub-divided. The phylogenetic relationships of these groups and sub-groups allowed us to infer the likely direction of spread of these variants in some instances. Patterns of amino acid replacement of North American skunk-associated rabies viruses for both the nucleoprotein and glycoprotein products are also examined. These patterns reflect the virus phylogeny but no amino acid residues associated specifically with the skunk host were identified. PMID:23524137

  13. Genetic characterization and phylogenetic analysis of skunk-associated rabies viruses in North America with special emphasis on the central plains.

    PubMed

    Davis, Rolan; Nadin-Davis, Susan A; Moore, Michael; Hanlon, Cathleen

    2013-06-01

    Across North America the skunk acts as a reservoir for several rabies virus variants. Some of these variants are geographically restricted in range as is the case for the California skunk variant and two distinct variants present in Mexico. In contrast the North Central and South Central skunk rabies viruses are dispersed in overlapping ranges over large areas of the Midwestern region of the United States with the former extending into southern parts of the Canadian prairies. Despite this extensive range, there has been only very limited molecular characterization of these two viral variants. This study has examined the genetic diversity of the rabies viruses associated with North American skunks, with particular emphasis on the South Central skunk variant which was found to comprise three distinct geographically restricted groups of viruses that could in some cases be further sub-divided. The phylogenetic relationships of these groups and sub-groups allowed us to infer the likely direction of spread of these variants in some instances. Patterns of amino acid replacement of North American skunk-associated rabies viruses for both the nucleoprotein and glycoprotein products are also examined. These patterns reflect the virus phylogeny but no amino acid residues associated specifically with the skunk host were identified.

  14. Structural geology and kinematics associated with the collision of the Wrangellia composite terrane and North America, south-central Alaska

    NASA Astrophysics Data System (ADS)

    Bier, Sara Elizabeth

    The collision of the Insular superterrane, and thus, the Wrangellia composite terrane (WCT), with the Mesozoic margin of North America is one of the most important, yet enigmatic events in the tectonic history of North American cordillera. The location and therefore the nature of the collision of the Insular superterrane with North America remains controversial. In southern Alaska, the suture zone between the WCT and North America consists of the Kahiltna assemblage, Jurassic-Cretaceous submarine fan deposits. Structural investigation of the Kahiltna assemblage provides additional data on the kinematics of the collision and suggests an oblique collision with a significant component of right-lateral shearing. The first study of the dissertation presents the results across a transect at the northern end of Broad Pass where the depositional and deformational history of three tectonostratigraphic units enables determination of the tectonic evolution of the suture zone. The Reindeer Hills exposes melange units that include oceanic lithologies and represent a remnant of an accretionary complex that formed during subduction prior to the collision of the WCT. Structures within the Kahiltna assemblage in the Talkeetna Mountains indicate oblique northwest-directed thrusting and right-lateral shear during the collision of the WCT. The Jack River conglomerate, a fluvial clast-supported conglomerate unconformably overlies the Reindeers Hills melange and represents uplift, erosion, and deposition late in the collision. The second study is on the other side of Broad Pass, in the southern Alaska Range, and consists of a composite transect across the Peters and Dutch Hills and Chelatna Lake. Horizontal stretching lineations and steeply-dipping foliation indicate that deformation occurred during transpression as a result of an oblique collision. Strain analysis of pressure shadows indicate a counterclockwise rotation of the extension direction and thus, right-lateral shearing during

  15. A 14-year-long Measurement of the Convergence Rate of the Juan de Fuca and North America Plates Offshore Central Oregon using GPS-Acoustics

    NASA Astrophysics Data System (ADS)

    Chadwell, C. D.; Webb, S. C.; Nooner, S. L.

    2015-12-01

    The motion of the sea floor was measured at a 3000-m-deep site approximately 120 km offshore Central Oregon using the GPS-Acoustic technique in 2000, 2001, 2002, 2003 and 2014. The GPS-Acoustic derived motion relative to the interior of North America agrees with the geomagnetically-derived value within their measurement uncertainties. The time series from the early 2000's was resurrected using two new innovations. The first innovation, a permanent benchmark that has locating channels and mating pins, allows reoccupation of an established benchmark at any later date using an ROV to replace the transponder on the benchmark. The second innovation: an autonomous platform based on a Waveglider that carries a GPS navigated acoustic transponder interrogation system that is wave and solar powered. This enables measurements to be obtained over a GPSA site without requiring a large ship, greatly reducing the cost of a GPSA measurement. Combining data at this site with data from two other GPS-Acoustic seafloor sites on the Juan de Fuca plate, makes it possible to determine a present-day Euler Pole for the Juan de Fuca - North America plates using GPS-Acoustics seafloor geodesy.

  16. At the foot of the shrew: manus morphology distinguishes closely-related Cryptotis goodwini and Cryptotis griseoventris (Mammalia: Soricidae) in Central America

    USGS Publications Warehouse

    Woodman, Neal; Stephens, Ryan B.

    2010-01-01

    Small-eared shrews (Mammalia, Soricidae) of the New World genus Cryptotis are distributed from eastern North America to the northern Andes of South America. One well-defined clade in this genus is the Central American Cryptotis mexicana group, whose members are set off from other species in the genus by their variably broader fore feet and more elongate and broadened fore claws. Two species in the C. mexicana group, Cryptotis goodwini Jackson and Cryptotis griseoventris Jackson, inhabit highlands in Guatemala and southern Mexico and are presumed to be sister species whose primary distinguishing feature is the larger body size of C. goodwini. To better characterize these species and confirm the identification of recently-collected specimens, we obtained digital X-ray images of the manus from large series of dried skins of both species. Measurements of the metacarpals and phalanges successfully separated most specimens of C. goodwini and C. griseoventris. These measurements also show that the fore feet of C. griseoventris from Chiapas, Mexico, are morphologically distinct from those of members of the species inhabiting Guatemala. Univariate, bivariate, and multivariate analyses indicate that fore foot characters are more conservative within species of the C. mexicana group than are cranio-mandibular characters. Patterns of evolution of fore foot characters that superficially appear to be linear gradations are actually more complex, illustrating individual evolutionary trajectories.

  17. Interannual Variability of the Bimodal Distribution of Summertime Rainfall Over Central America and Tropical Storm Activity in the Far-Eastern Pacific

    NASA Technical Reports Server (NTRS)

    Curtis, Scott; Starr, David OC. (Technical Monitor)

    2002-01-01

    The summer climate of southern Mexico and Central America is characterized by a mid summer drought (MSD), where rainfall is reduced by 40% in July as compared to June and September. A mid-summer reduction in the climatological number of eastern Pacific tropical cyclones has also been noted. Little is understood about the climatology and interannual variability of these minima. The present study uses a novel approach to quantify the bimodal distribution of summertime rainfall for the globe and finds that this feature of the annual cycle is most extreme over Pan America and adjacent oceans. One dominant interannual signal in this region occurs the summer before a strong winter El Nino/Southern Oscillation ENSO. Before El Nino events the region is dry, the MSD is strong and centered over the ocean, and the mid-summer minimum in tropical cyclone frequency is most pronounced. This is significantly different from Neutral cases (non-El Nino and non-La Nina) when the MSD is weak and positioned over the land bridge. The MSD is highly variable for La Nina years, and there is not an obvious mid-summer minimum in the number of tropical cyclones.

  18. Hantaviruses in Central South America: phylogenetic analysis of the S segment from HPS cases in Paraná, Brazil.

    PubMed

    Raboni, Sonia M; Probst, Christian M; Bordignon, Juliano; Zeferino, Aurélio; dos Santos, Claudia N Duarte

    2005-08-01

    We sequenced the complete S segments of hantaviruses detected from 12 HPS patients living in southern of Brazil. Samples were obtained from patients diagnosed in different years, in distinct areas, and with a broad spectrum of clinical signs. Despite these differences, all the S proteins of hantavirus from Paraná were identical, except for one amino acid substitution. Phylogenetic analyses of the complete S segment nucleotide and amino acid sequences indicated that hantaviruses from Paraná form a distinct clade from those circulating in South and North America. Other hantaviruses from Brazil were not placed in the same clade. The Oligoryzomys nigripes-associated strains ITA37 and ITA38 from Paraguay were found to belong to the same clade as the hantaviruses from Paraná. Paraguay and Paraná state are located at the same latitude and some ecosystems are similar in both places. The geographic position and common rodent hosts could explain this phylogenetic relationship.

  19. Is violence associated with increased risk behavior among MSM? Evidence from a population-based survey conducted across nine cities in Central America

    PubMed Central

    Wheeler, Jennifer; Anfinson, Katherine; Valvert, Dennis; Lungo, Susana

    2014-01-01

    Background/Objective There is a dearth of research examining the linkages between violence and HIV risk behavior among men who have sex with men (MSM), including those who identify as transgender women (TW), particularly in Central America where violence is widespread. In this paper, we use population-based survey results to independently examine the correlations between physical, emotional and sexual violence and HIV risk behavior among MSM populations in five countries in Central America. Design As part of USAID's Combination Prevention for HIV program in Central America, PASMO conducted population based surveys using respondent-driven sampling (RDS) in nine cities in Guatemala, El Salvador, Nicaragua, Costa Rica, and Panama. Initial seeds were recruited using the following criteria: individuals who represented subgroups of MSM by self-identification (homosexual vs. heterosexual or bisexual vs. transgender), social economic strata, and by sex work practices. This study examines the association between violence and 1) HIV risk behaviors relevant to the study populations; 2) protective behaviors; and 3) reported STIs. Individualized RDS estimator weights for each outcome variable were calculated using RDSAT software, and logistic regression analysis was used to determine associations between different forms of violence and the outcome variables. Results MSM who experienced physical violence were more likely to be engaged in transactional sex (OR: 1.76 [1.42–2.18]), have multiple partners in the past 30 days (OR: 1.37 [1.09–1.71]), and have engaged in sex under the influence of alcohol or drugs (OR: 1.51 [1.24–1.83]). Both physical violence and psychological/verbal violence were also associated with reporting STI symptoms or diagnosis within the past 12 months (OR: 1.72 [1.34–2.21] and 1.80 [1.45–2.23]). The effects of violence on the outcomes were observed after controlling for other risk factors. Transgender women were 3.9 times more likely to report

  20. Rapid assessment of soil erosion in the Rio Lempa Basin, Central America, using the universal soil loss equation and geographic information systems.

    PubMed

    Kim, John B; Saunders, Peter; Finn, John T

    2005-12-01

    Soil erosion is a severe problem for many developing regions that lack adequate infrastructure to combat the problem. The authors established a first-order method for prioritizing areas to be examined and remediated using preexisting data and expert knowledge where data are lacking. The Universal Soil Loss Equation was applied to the Rio Lempa Basin in Central America using geographic information systems and remote sensing technologies, and the estimated erosion rates were compared with sediment delivery ratios. Spatial analysis indicates that agriculture on very steep slopes contributes only a small fraction to the total estimated soil erosion, whereas agriculture on gentle and moderately steep slopes contributes a large fraction of the erosion. Although much of the basin is in El Salvador, the greatest estimated amount of erosion is from Honduras. Data quality and availability were impaired by a lack of coordination among agencies and across countries. Several avenues for improving the authors' methods are described.

  1. Geologic observations of the northern boundary of the Caribbean plate across central America as seen by Seasat and SIR-A

    NASA Technical Reports Server (NTRS)

    Rebillard, P.; Dixon, T.; Farr, T.

    1982-01-01

    The radar data analyzed here extend from the Amatique Bay (Golfo de Honduras) in the northeast to the Pacific Ocean (Puenta Remedios) in the southwest. Space Shuttle Imaging Radar (SIR-A) data-take 18 overlaps the principal part of the Seasat mosaic. SIR-A data make possible more observations over the Central American Cordillera, where strong layover limited the amount of information obtained by Seasat. The radar coverage delineates the principal strike-slip faults of the region (Cuilco-Chixoy-Polochic, Motagua and Jocotan), which have acted as the Caribbean-Americas plate boundary. It also demarcates volcanic terranes related to subduction of the Cocos Plate under the Caribbean Plate. Within pumice fields of the Tertiary volcanic belt, the use of two Seasat look directions (rev 759 and rev 1211), in conjunction with SIR-A data, makes possible some rock discrimination.

  2. Hypericum species in the Páramos of Central and South America: a special focus upon H. irazuense Kuntze ex N. Robson

    PubMed Central

    Crockett, Sara; Eberhardt, Marianne; Kunert, Olaf; Schühly, Wolfgang

    2010-01-01

    Knowledge about members of the flowering plant family Clusiaceae occurring in the tropical mountain regions of the world is limited, in part due to endemism and restricted distributions. High altitude vegetation habitats (Páramos) in Central and South America are home to numerous native Hypericum species. Information related to the phytochemistry of páramo Hypericum, as well as ecological factors with the potential to influence chemical defenses in these plants, is briefly reviewed. Results of the phytochemical analysis of Hypericum irazuense, a species collected in the páramo of the Cordillera de Talamanca in Costa Rica, are presented. Lastly, guidelines for the viable and sustainable collections of plant material, to facilitate future investigations of these interesting plants, are given. PMID:21151765

  3. Structural Vulnerability Among Migrating Women and Children Fleeing Central America and Mexico: The Public Health Impact of “Humanitarian Parole”

    PubMed Central

    Valdez, Elizabeth Salerno; Valdez, Luis A.; Sabo, Samantha

    2015-01-01

    Since October 2013, US Customs and Border Patrol has apprehended 15,979 families on the Southwest Border of the US. Daily, migrating women and children from Mexico and Central America that qualify for humanitarian parole are released from immigration detention to a humanitarian aid organization in Southern Arizona. After several days in detention facilities, these families arrive tired, hungry, dehydrated, and with minimal direction regarding their final destination, and adherence to the parameters of their parole. Project helping hands (PHHs) utilizes a network of volunteers to provide the women and children with food, water, clothing, hygiene products, hospitality, and legal orientation. The aim of this assessment was to document the experiences of families granted humanitarian parole through the lens of structural vulnerability. Here, we apply qualitative methods to elicit PHH lead volunteer perspectives regarding the migration experience of migrating families. Using inductive analysis, we found six major themes emerged from the qualitative data: reasons for leaving, experience on the journey, dehumanization in detention, family separation, vulnerability, and resiliency. These findings elucidate the different physical and psychological distresses that migrating families from Mexico and Central America experience before, during and after their arrival at the US–Mexico border. We posit that these distresses are a result of, or exacerbated by, structural vulnerability. Structural vulnerability has life-long health implications for a sub-population of young mothers and their children. The number of migrating families who have experienced traumatic events before and during their migration experience continues to expand and thus warrants consideration of mental health surveillance and intervention efforts for these families. More public health research is needed to better understand and combat the health challenges of this growing population. PMID:26157791

  4. Education for Management in Central America. The Role of the Library of the Instituto Centroamericano de Administracion de Empresas

    ERIC Educational Resources Information Center

    Bloch, Thomas

    1973-01-01

    The institute, established in 1968, is a multinational organization for education in management at the post-graduate level. Its library, with five staff members, now has 4,000 volumes and receives 300 periodical publications: it should eventually become a Central American business and economic management information and research center. (Author/SJ)

  5. Working Together to Make a Difference in Rural America: North Central Regional Center for Rural Development, 2010 Annual Report

    ERIC Educational Resources Information Center

    North Central Regional Center for Rural Development, 2011

    2011-01-01

    The North Central Regional Center for Rural Development (NCRCRD) is one of four regional centers in the United States that have worked to improve the quality of life in rural communities for nearly 40 years. With funding from the USDA National Institute of Food and Agriculture and the land-grant universities in our 12-state region, the NCRCRD…

  6. The University as Agent of Social Transformation: The Case of the University of Central America in El Salvador

    ERIC Educational Resources Information Center

    Valiente, Orfilio Ernesto

    2015-01-01

    In 1965, the Jesuit-run Central American University (UCA) was launched in El Salvador as the wealthy family's educational alternative to the increasingly leftist National University. But within a decade, the UCA would shift its focus to the inequalities and injustice experienced by the country's popular majorities and to its own role as society's…

  7. Flooding in Central Siberia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A mixture of snowmelt and ice jams in late May and June of this year caused the Taz River (left) and the Yenisey River (right) in central Siberia to overflow their banks. The flooding can be seen in this image taken on June 11, 2002, by the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra satellite. Normally, the rivers would resemble thin black lines in MODIS imagery. In the false-color images sage green and rusty orange is land, and water is black. Clouds are white and pink. Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  8. MODIS Snow-Cover Products

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Riggs, George A.; Salomonson, Vincent V.; DiGirolamo, Nicole E.; Bayr, Klaus J.; Houser, Paul R. (Technical Monitor)

    2002-01-01

    On December 18, 1999, the Terra satellite was launched with a complement of five instruments including the Moderate Resolution Imaging Spectroradiometer (MODIS). Many geophysical products are derived from MODIS data including global snow-cover products. MODIS snow and ice products have been available through the National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC) since September 13, 2000. MODIS snow-cover products represent potential improvement to or enhancement of the currently-available operational products mainly because the MODIS products are global and 500-m resolution, and have the capability to separate most snow and clouds. Also the snow-mapping algorithms are automated which means that a consistent data set may be generated for long-term climate studies that require snow-cover information. Extensive quality assurance (QA) information is stored with the products. The MODIS snow product suite begins with a 500-m resolution, 2330-km swath snow-cover map which is then gridded to an integerized sinusoidal grid to produce daily and 8-day composite tile products. The sequence proceeds to a climate-modeling grid (CMG) product at about 5.6-km spatial resolution, with both daily and 8-day composite products. Each pixel of the CMG contains fraction of snow cover from 40 - 100%. Measured errors of commission in the CMG are low, for example, on the continent of Australia in the spring, they vary from 0.02 - 0.10%. Near-term enhancements include daily snow albedo and fractional snow cover. A case study from March 6, 2000, involving MODIS data and field and aircraft measurements, is presented to show some early validation work.

  9. MODIS Snow-Cover Products

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Riggs, George A.; Salomonson, Vinvent V.; DiGirolamo, Nicolo; Bayr, Klaus J.; Houser, Paul (Technical Monitor)

    2001-01-01

    On December 18, 1999, the Terra satellite was launched with a complement of five instruments including the Moderate Resolution Imaging Spectroradiometer (MODIS). Many geophysical products are derived from MODIS data including global snow-cover products. These products have been available through the National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC) since September 13, 2000. MODIS snow-cover products represent potential improvement to the currently available operation products mainly because the MODIS products are global and 500-m resolution, and have the capability to separate most snow and clouds. Also the snow-mapping algorithms are automated which means that a consistent data set is generated for long-term climates studies that require snow-cover information. Extensive quality assurance (QA) information is stored with the product. The snow product suite starts with a 500-m resolution swath snow-cover map which is gridded to the Integerized Sinusoidal Grid to produce daily and eight-day composite tile products. The sequence then proceeds to a climate-modeling grid product at 5-km spatial resolution, with both daily and eight-day composite products. A case study from March 6, 2000, involving MODIS data and field and aircraft measurements, is presented. Near-term enhancements include daily snow albedo and fractional snow cover.

  10. Accessing and Understanding MODIS Data

    NASA Technical Reports Server (NTRS)

    Leptoukh, Gregory; Jenkerson, Calli B.; Jodha, Siri

    2003-01-01

    The National Aeronautics and Space Administration (NASA) launched the Terra satellite in December 1999, as part of the Earth Science Enterprise promotion of interdisciplinary studies of the integrated Earth system. Aqua, the second satellite from the series of EOS constellation, was launched in May 2002. Both satellites carry the MODerate resolution Imaging Spectroradiometer (MODIS) instrument. MODIS data are processed at the Goddard Space Flight Center, Greenbelt, MD, and then archived and distributed by the Distributed Active Archive Centers (DAACs). Data products from the MODIS sensors present new challenges to remote sensing scientists due to specialized production level, data format, and map projection. MODIS data are distributed as calibrated radiances and as higher level products such as: surface reflectance, water-leaving radiances, ocean color and sea surface temperature, land surface kinetic temperature, vegetation indices, leaf area index, land cover, snow cover, sea ice extent, cloud mask, atmospheric profiles, aerosol properties, and many other geophysical parameters. MODIS data are stored in HDF- EOS format in both swath format and in several different map projections. This tutorial guides users through data set characteristics as well as search and order interfaces, data unpacking, data subsetting, and potential applications of the data. A CD-ROM with sample data sets, and software tools for working with the data will be provided to the course participants.

  11. MODIS. Volume 1: MODIS level 1A software baseline requirements

    NASA Technical Reports Server (NTRS)

    Masuoka, Edward; Fleig, Albert; Ardanuy, Philip; Goff, Thomas; Carpenter, Lloyd; Solomon, Carl; Storey, James

    1994-01-01

    This document describes the level 1A software requirements for the moderate resolution imaging spectroradiometer (MODIS) instrument. This includes internal and external requirements. Internal requirements include functional, operational, and data processing as well as performance, quality, safety, and security engineering requirements. External requirements include those imposed by data archive and distribution systems (DADS); scheduling, control, monitoring, and accounting (SCMA); product management (PM) system; MODIS log; and product generation system (PGS). Implementation constraints and requirements for adapting the software to the physical environment are also included.

  12. Estimating the Effect of Gypsy Moth Defloiation Using MODIS

    NASA Technical Reports Server (NTRS)

    deBeurs, K. M.; Townsend, P. A.

    2008-01-01

    The area of North American forests affected by gypsy moth defoliation continues to expand despite efforts to slow the spread. With the increased area of infestation, ecological, environmental and economic concerns about gypsy moth disturbance remain significant, necessitating coordinated, repeatable and comprehensive monitoring of the areas affected. In this study, our primary objective was to estimate the magnitude of defoliation using Moderate Resolution Imaging Spectroradiometer (MODIS) imagery for a gypsy moth outbreak that occurred in the US central Appalachian Mountains in 2000 and 2001. We focused on determining the appropriate spectral MODIS indices and temporal compositing method to best monitor the effects of gypsy moth defoliation. We tested MODIS-based Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Normalized Difference Water Index (NDWI), and two versions of the Normalized Difference Infrared index (NDIIb6 and NDIIb7, using the channels centered on 1640 nm and 2130 nm respectively) for their capacity to map defoliation as estimated by ground observations. In addition, we evaluated three temporal resolutions: daily, 8-day and 16-day data. We validated the results through quantitative comparison to Landsat based defoliation estimates and traditional sketch maps. Our MODIS based defoliation estimates based on NDIIb6 and NDIIb7 closely matched Landsat defoliation estimates derived from field data as well as sketch maps. We conclude that daily MODIS data can be used with confidence to monitor insect defoliation on an annual time scale, at least for larger patches (greater than 0.63 km2). Eight-day and 16-day MODIS composites may be of lesser use due to the ephemeral character of disturbance by the gypsy moth.

  13. Inorganic particles in the skin of inhabitants of volcanic areas of Central America: their possible immunomodulatory influence in leishmaniasis and leprosy.

    PubMed

    Convit, J; Ulrich, M; Castillo, J; De Lima, H; Pérez, M; Caballero, N; Hung, J; Arana, B; Pérez, P

    2006-08-01

    We have evaluated biopsies from patients with atypical nodular and typical ulcerated lesions of cutaneous leishmaniasis, from leishmanin reactions and skin from normal individuals from Nicaragua, Honduras and Guatemala for the presence of inorganic particles using confocal microscopy with a polarised light source and conventional histopathological techniques. Analysis by semiquantitative confocal microscopy permitted the demonstration of significantly larger numbers of particles in atypical lesions. Silica and aluminium, important components of these particles, were less abundant in particles from normal skin. The histology of these atypical lesions, characterised by 'naked' sarcoidal granulomas with epithelioid differentiation but very few lymphocytes, was very similar to the histological reaction observed after 14 days in persisting inflammation at leishmanin skin test sites. The presence of these unusual lesions in areas of Central American countries characterised by the presence of large amounts of volcanic ash, as well the unexpectedly low prevalence of leprosy in Central America, suggest that environmental factors may contribute significantly to the frequency and clinical manifestations of these infections. Among possible environmental features, the presence of inorganic particles with immunomodulatory properties in the skin may be a significant factor.

  14. The Moderate Resolution Imaging Spectrometer (MODIS)

    NASA Technical Reports Server (NTRS)

    Salomonson, Vincent V.

    1990-01-01

    The Moderate Resolution Imaging Spectrometer (MODIS) observing facility on the Earth Observing System (EOS) is composed of two instruments, MODIS-Nadir (N) and MODIS-Tilt (T). MODIS-N has 36 spectral bands between 0.4 and 14.2 micrometers with spatial resolution between 214 and 856 meters. MODIS-T has 32 bands with 10-15 nanometer bandwidths between 0.4 and 0.9 micrometers. MODIS-T scans fore and aft + or - 50 degrees. Both instruments scan cross-track so as to provide daily (MODIS-N) or once every 2 days (MODIS-T) coverage at 705 kilometers altitude. Both instruments are entering into the execution phases of their development in 1990.

  15. Tomographic images of subducted oceans matched to the accretionary records of orogens - Case study of North America and relevance to Central Asia

    NASA Astrophysics Data System (ADS)

    Sigloch, Karin; Mihalynuk, Mitchell G.; Hosseini, Kasra

    2016-04-01

    Accretionary orogens are the surface record of subduction on the 100-million-year timescale; they aggregate buoyant crustal welts that resisted subduction. The other record of subduction is found in the deep subsurface: oceanic lithosphere preserved in the mantle that records ocean basin closure between successive generations of arcs. Seismic tomography maps out these crumpled paleo-oceans down to the core-mantle boundary, where slab accumulates. One such accumulation of enormous scale is under Eastern Asia, recording the assembly of the Central Asian Orogenic Belt (CAOB). Deep CAOB slab has hardly been explored because tomographic image resolution in the lowermost mantle is limited, but this is rapidly improving. We present new images of the CAOB slabs from our P-wave tomography that includes core-diffracted waves as a technical novelty. The previous slab blur sharpens into the type of elongated geometries expected to trace paleo-trench lines. Since the North American Cordillera is younger than the CAOB (mostly <200 m.y. versus ~650-250 m.y.), its slabs have descended only to mid-mantle depths (<2000 km), where tomographic resolution is much better. Hence we can make a detailed, spatiotemporal match between 3-D slab geometries and the accretion history of the Cordillera - a blueprint for continental-scale investigations in other accretionary orogens, including what may become possible for the CAOB. Lower-mantle slabs beneath North America reveal evolving configurations of arc-trench positions back to the breakup of Pangea. These can be combined with quantitative plate reconstructions to show where and when the westward-drifting continent overrode pre-existing, intra-oceanic subduction zones, and accreted their associated arcs and basement terranes in Jurassic and Cretaceous times. Tectonic predictions from this "tomographic time machine" can be checked against the geological record. To demonstrate, we propose a resolution to the longstanding debate of how and when

  16. GPS-derived coupling estimates for the Central America subduction zone and volcanic arc faults: El Salvador, Honduras and Nicaragua

    NASA Astrophysics Data System (ADS)

    Correa-Mora, F.; DeMets, C.; Alvarado, D.; Turner, H. L.; Mattioli, G.; Hernandez, D.; Pullinger, C.; Rodriguez, M.; Tenorio, C.

    2009-12-01

    We invert GPS velocities from 32 sites in El Salvador, Honduras and Nicaragua to estimate the rate of long-term forearc motion and distributions of interseismic coupling across the Middle America subduction zone offshore from these countries and faults in the Salvadoran and Nicaraguan volcanic arcs. A 3-D finite element model is used to approximate the geometries of the subduction interface and strike-slip faults in the volcanic arc and determine the elastic response to coupling across these faults. The GPS velocities are best fit by a model in which the forearc moves 14-16 mmyr-1 and has coupling of 85-100 per cent across faults in the volcanic arc, in agreement with the high level of historic and recent earthquake activity in the volcanic arc. Our velocity inversion indicates that coupling across the potentially seismogenic areas of the subduction interface is remarkably weak, averaging no more than 3 per cent of the plate convergence rate and with only two poorly resolved patches where coupling might be higher along the 550-km-long segment we modelled. Our geodetic evidence for weak subduction coupling disagrees with a seismically derived coupling estimate of 60 +/- 10 per cent from a published analysis of earthquake damage back to 1690, but agrees with three other seismologic studies that infer weak subduction coupling from 20th century earthquakes. Most large historical earthquakes offshore from El Salvador and western Nicaragua may therefore have been intraslab normal faulting events similar to the Mw 7.3 1982 and Mw 7.7 2001 earthquakes offshore from El Salvador. Alternatively, the degree of coupling might vary with time. The evidence for weak coupling indirectly supports a recently published hypothesis that much of the Middle American forearc is escaping to the west or northwest away from the Cocos Ridge collision zone in Costa Rica. Such a hypothesis is particularly attractive for El Salvador, where there is little or no convergence obliquity to drive the

  17. Changes in maximum and minimal temperatures at high elevation stations in the central Andes of South America

    SciTech Connect

    Quintana-Gomez, R.A.

    1997-11-01

    Temperature trends and deviations were evaluated for the central Andes portion of Bolivia. Data were collected primarily from stations located at very high altitude (3,000 m above sea level and higher) for a 73-year period from 1918 to 1990. The analysis determined maximum and minimum temperature trends and the daily temperature range (DTR) at each station. The minimum temperature series showed a rather sustained increase starting in the 1960s and continuing to the present, and a reduction of the differential rate of warming for the same interval. The high elevation, rural area data appears to reinforce evidence of a global and generalized rise of minimum temperature and decrease of the DTR. 3 refs., 2 figs., 1 tab.

  18. Transmitted drug-resistance in human immunodeficiency virus-infected adult population in El Salvador, Central America.

    PubMed

    Holguín, Á; Yebra, G; Martín, L; de Pineda, A T; Ruiz, L E; Quezada, A Y; Nieto, A I; Escobar, G

    2013-12-01

    El Salvador harbours one of the largest Central American human immunodeficiency virus (HIV) epidemics, but few studies have analysed it in depth. Here, we describe the presence of transmitted drug resistance (TDR) and HIV variants in the HIV-infected adult population in El Salvador. Dried blood spots from 119 HIV-infected antiretroviral-naive adults attended in El Salvador were collected in 2011. The TDR was assessed according to the list recommended by the WHO. HIV-1 variants were described using phylogeny. Pol sequences could be amplified in 88 patients (50.6% men), with a mean age of 35 years. Almost all (96.7%) were infected with HIV through sexual practice and 58.7% were recently diagnosed. The mean CD4(+) count was 474 cells/mm(3) and 43.1% and 15.5% of patients showed moderate (<500 CD4 cells) or severe (<200) immune suppression, respectively. HIV-1 viral load was >100 000 copies/mL in 24.7% of patients and <2000 copies/mL in 9.1%. Five samples (5.7%) harboured any TDR mutation: 2.3% for nucleoside reverse transcriptase inhibitor (NRTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI), and 1.4% for protease inhibitor (PI). All showed only one TDR single-class resistance mutation: M184I (two cases) for NRTI, K101E and K103N for NNRTI and L23I for PI. All viruses excepting one (URF_BG) belonged to subtype B. No phylogenetic TDR networks were found. In conclusion, we report a TDR prevalence of 5.7% in El Salvador, lower than in other Central American studies. Periodical studies are essential to monitor and prevent TDR emergence in low-income and middle-income regions. Also, more efforts are needed to promote early diagnosis and prevention of infection in El Salvador.

  19. Geology, K-Ar geochronology and paleomagnetism of parts of the coastal cordillera of central Chile, South America

    SciTech Connect

    Irwin, J.J.

    1986-01-01

    A complex composed of ultrabasic and basaltic lavas, chert-argillite, arkose and conglomerate was assembled in the coast of north central Chile prior to 220 Ma ago. Three major episodes of deformation and metamorphism have been observed in this area. The first episode of deformation and metamorphism (F/sub 1/) produced a compositional layering (S/sub 1/) and amphibolite facies metamorphism within the formations listed above. This episode of deformation and metamorphism occurred coevally with intrusion of a regionally extensive 220-200 Ma fine grained gabbro and granitic complex. The second episode of deformation and metamorphism locally formed tight, recumbent folds in S/sub 1/ and at least one low angle reverse fault. K-Ar and Rb-Sr ages on units in which F/sub 2/ folds are well developed range between 163 and 140 Ma. A third episode of deformation and low grade metamorphism (F/sub 3/) locally formed upright, open to tight folds with sharp hinges and axial planes that strike north and dip steeply east. Igneous intrusions that were affected by F/sub 3/ yield K-Ar ages between 140 Ma and 126 Ma. Undeformed cross cutting mafic dykes have been dated by K-Ar at 121 Ma. Paleomagnetic samples collected from 19 sites in radioisotopically dated (using the K-Ar and /sup 40/Ar-/sup 39/Ar techniques) Jurassic mafic dykes and plutons in the coastal cordillera of Chile yield mean paleomagnetic poles that are consistent with the average pole from coeval sequences within the South American craton. The paleomagnetic directions are consistent over the latitudinal range and variety of lithologies encompassed by this study. Paleomagnetic results presented here indicate that no major rotation or translation of crustal blocks has been taken place in this part of central Chile since middle Jurassic time.

  20. Magmas with slab fluid and decompression melting signatures coexisting in the Gulf of Fonseca: Evidence from Isla El Tigre volcano (Honduras, Central America)

    NASA Astrophysics Data System (ADS)

    Mattioli, Michele; Renzulli, Alberto; Agostini, Samuele; Lucidi, Roberto

    2016-01-01

    Isla El Tigre volcano is located in the Gulf of Fonseca (Honduras) along the Central America volcanic front, where a significant change in the strike of the volcanic chain is observed. The studied samples of this poorly investigated volcano are mainly subalkaline basic to intermediate lavas (basalts and basaltic andesites) and subordinate subalkaline/alkaline transitional basalts, both having the typical mineralogical and geochemical characteristics of arc volcanic rocks. On the basis of petrographic and geochemical features, two groups of rocks have been distinguished. Lavas from the main volcanic edifice are highly porphyritic and hy-qz normative, and have lower MgO contents (< 5 wt.%). They show significant LILE and LREE enrichments and Nb-Ta depletions, and have a strong slab signature as well as incompatible element contents similar to those of the main front of the adjacent volcanoes in El Salvador and Nicaragua (e.g., Ba/La up to 80). In contrast, lavas from the parasitic cones have higher MgO contents (> 5 wt.%), are ol-hy normative and show lower HFSE depletions relative to LILE and LREE, with lower Ba/La, Ba/Nb and Zr/Nb ratios. This suggests that mantle-derived magmas were not produced by the same process throughout the activity of the volcano. The bulk rock geochemistry and 87Sr/86Sr (0.70373-0.70382), 143Nd/144Nd (0.51298-0.51301), 206Pb/204Pb (18.55-18.58), 207Pb/204Pb (15.54-15.56) and 208Pb/204Pb (38.23-38.26) isotopic data of Isla El Tigre compared with the other volcanoes of the Gulf of Fonseca and all available literature data for Central America suggests that this stratovolcano was mainly built by mantle-derived melts driven by slab-derived fluid-flux melting, while magmas erupted through its parasitic cones have a clear signature of decompression melting with minor slab contribution. The coexistence of these two different mantle melting generation processes is likely related to the complex geodynamic setting of the Gulf of Fonseca, where the

  1. Major subsidence of the south-central United States of America and future inundation of coastal areas

    NASA Astrophysics Data System (ADS)

    Dokka, R. K.

    2004-12-01

    The northern shore of the Gulf of Mexico is the site of America's greatest wetland, the gateway to vast energy resources, and home to over 10 million people. This critical area is being increasingly threatened by progressive inundation by the relative rise of the Gulf of Mexico. This slow inundation was detected several decades ago and has been generally attributed to eustatic sea level rise, sediment starvation of the delta due to construction of flood control levees along the Mississippi River, and subsidence of the land relative to sea level. Although the former two effects are reasonably well understood, the lack of precise quantitative spatial data on the later related to a well defined, common datum has prevented the development of a satisfactory theory to explain modern surface motions. Analysis of National Geodetic Survey (NGS) 1st order leveling data produced vertical velocities for over 2700 benchmarks in Louisiana, Mississippi, Alabama, Texas, Arkansas, Florida, and Tennessee. All motions were related to NAVD88 and show that subsidence is not limited to coastal wetland areas, but rather includes the entire coastal zone as well as inland areas several hundred km from the shore. Subsidence can also be tracked to the north and follows the trend of the alluvial valley of the Mississippi River. Regionally, vertical velocities range from less than -30 mm/yr along the coast to over +5 mm/yr in peripheral areas of eastern Mississippi-Alabama. The mean rate is ~11 mm/yr in most coastal parishes of Louisiana. In the Mississippi River deltaic plain, subsidence was significantly higher than previous estimates based on long-term geologic measurements. The data also indicate that adjacent alluvial ridges where the population is concentrated have been similarly affected. In the Chenier plain of southwest Louisiana, a region previously thought to be subsiding at slowly, rates of sinking are similar to those of the deltaic plain. Demonstration that all areas of the

  2. A 400-ka tephrochronological framework for Central America from Lake Petén Itzá (Guatemala) sediments

    NASA Astrophysics Data System (ADS)

    Kutterolf, S.; Schindlbeck, J. C.; Anselmetti, F. S.; Ariztegui, D.; Brenner, M.; Curtis, J.; Schmid, D.; Hodell, D. A.; Mueller, A.; Pérez, L.; Pérez, W.; Schwalb, A.; Frische, M.; Wang, K.-L.

    2016-10-01

    Lake Petén Itzá, northern Guatemala, lies within a hydrologically closed basin in the south-central area of the Yucatán Peninsula, and was drilled under the auspices of the International Continental Scientific Drilling Program (ICDP) in 2006. At 16°55‧N latitude, the lake is ideally located for study of past climate and environmental conditions in the Neotropical lowlands. Because of its great depth (>160 m), Lake Petén Itzá has a record of continuous sediment accumulation that extends well into the late Pleistocene. A key obstacle to obtaining long climate records from the region is the difficulty of establishing a robust chronology beyond ∼40 ka, the limit of 14C dating. Tephra layers within the Lake Petén Itzá sediments, however, enable development of age/depth relations beyond 40 ka. Ash beds from large-magnitude, Pleistocene-to-Holocene silicic eruptions of caldera volcanoes along the Central American Volcanic Arc (CAVA) were found throughout drill cores collected from Lake Petén Itzá. These ash beds were used to establish a robust chronology extending back 400 ka. We used major- and trace-element glass composition to establish 12 well-constrained correlations between the lacustrine tephra layers in Lake Petén Itzá sediments and dated deposits at the CAVA source volcanoes, and with their marine equivalents in eastern Pacific Ocean sediments. The data also enabled revision of eight previous determinations of erupted volumes and masses, and initial estimates for another four eruptions, as well as the designation of source areas for 14 previously unknown eruptions. The new and revised sedimentation rates for the older sediment successions identify the interglacial of MIS5a between 84 and 72 ka, followed by a stadial between 72 and 59 ka that corresponds to MIS4. We modified the age models for the Lake Petén Itzá sediment sequences, extended the paleoclimate and paleoecological record for this Neotropical region to ∼400 ka, and determined the

  3. Controls on reef development and the terrigenous-carbonate interface on a shallow shelf, Nicaragua (Central America)

    NASA Astrophysics Data System (ADS)

    Roberts, H. H.; Murray, S. P.

    1983-06-01

    Marine geology and physical oceanographic data collected during two field projects (˜4 months) on the Caribbean shelf of Nicaragua indicate a surprising dominance of carbonate deposition and reef growth on a shelf that is receiving an abnormally large volume of terrigenous sediments. High rainfall rates (˜400 500 cm/year), coupled with a warm tropical climate, encourage rapid denudation of the country's central volcanic highland and transport of large volumes of terrigenous sediment and fresh water to the coast. Estimates suggest that three times more fresh water and fifteen times more sediment are introduced per unit length of coastline than on the east coast of the United States. Distribution of the terrigenous facies, development of carbonate sediment suites, and the location and quality of viable reefs are strongly controlled by the dynamic interaction near the coasts of highly turbid fresh to brackish water effluents from thirteen rivers with clear marine waters of the shelf. Oceanic water from the central Caribbean drift current intersects the shelf and moves slowely in a dominant northwest direction toward the Yucatan Channel. A sluggish secondary gyre moves to the south toward Costa Rica. In contrast, the turbid coastal water is deflected to the south in response to density gradients, surface water slopes, and momentum supplied by the steady northeast trade winds. A distinct two-layered flow is commonly present in the sediment-rich coastal boundary zone, which is typically 10 20 km wide. The low-salinity upper layer is frictionally uncoupled from the ambient shelf water and therefore can expand out of the normally coherent coastal boundary zone during periods of abnormal flooding or times when instability is introduced into the northeast trades. Reef distribution, abruptness of the terrigenous-carbonate interface, and general shelf morphology reflect the long-term dynamic structure of the shelf waters. A smooth-bottomed ramp of siliciclastic sands to

  4. Notes from the field: hospitalizations for respiratory disease among unaccompanied children from Central America - multiple States, June-July 2014.

    PubMed

    Nyangoma, Edith N; Arriola, Carmen Sofia; Hagan, Jose; Socias, Christina; Tomczyk, Sara; Watkins, Louise Francois; Westercamp, Matthew; Kim, Curi

    2014-08-15

    During October 2013-June 2014, approximately 54,000 unaccompanied children, mostly from the Central American countries of El Salvador, Guatemala, and Honduras, were identified attempting entry into the United States from Mexico, exceeding numbers reported in previous years. Once identified in the United States, U.S. Customs and Border Protection, an agency of the U.S. Department of Homeland Security, processes the unaccompanied children and transfers them to the Office of Refugee Resettlement (ORR), an office of the Administration for Children and Families, U.S. Department of Health and Human Services. ORR cares for the children in shelters until they can be released to a sponsor, typically a parent or relative, who can care for the child while their immigration case is processed. In June 2014, in response to the increased number of unaccompanied children, U.S. Customs and Border Protection expanded operations to accommodate children at a processing center in Nogales, Arizona. ORR, together with the U.S. Department of Defense, opened additional large temporary shelters for the children at Lackland Air Force Base, Texas; U.S. Army Garrison Ft. Sill, Oklahoma; and Naval Base Ventura County, California.

  5. 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.

  6. Replacing America's Job Bank

    ERIC Educational Resources Information Center

    Vollman, Jim

    2009-01-01

    The Job Central National Labor Exchange (www.jobcentral.com) has become the effective replacement for America's Job Bank with state workforce agencies and, increasingly, with community colleges throughout the country. The American Association of Community Colleges (AACC) has formed a partnership with Job Central to promote its use throughout the…

  7. Short-term risk of anaemia following initiation of combination antiretroviral treatment in HIV-infected patients in countries in sub-Saharan Africa, Asia-Pacific, and central and South America

    PubMed Central

    2012-01-01

    Background The objective was to examine the short-term risk and predictors of anaemia following initiation of combination antiretroviral therapy (cART) in HIV-infected patients from the Western Africa, Eastern Africa, Southern Africa, Central Africa, Asian-Pacific, and Caribbean and Central and South America regions of the International Epidemiologic Databases to Evaluate AIDS (IeDEA) collaboration. Methods Anaemia was defined as haemoglobin of < 10 g/dL. Patients were included if they started cART with three or more drugs, had prior haemoglobin of > = 10 g/dL, and had one or more follow-up haemoglobin tests. Factors associated with anaemia up to 12 months were examined using Cox proportional hazards models and stratified by IeDEA region. Results Between 1998 and 2008, 19,947 patients initiated cART with baseline and follow-up haemoglobin tests (7358, 7289, 2853, 471, 1550 and 426 in the Western Africa, Eastern Africa, Southern Africa, Central Africa, Asian-Pacific, and Caribbean and Central and South America regions, respectively). At initiation, anaemia was found in 45% of Western Africa patients, 29% of Eastern Africa patients, 21% of Southern Africa patients, 36% of Central Africa patients, 15% of patients in Asian-Pacific and 14% of patients in Caribbean and Central and South America. Among patients with haemoglobin of > = 10 g/dL at baseline (13,445), the risks of anaemia were 18.2, 6.6, 9.7, 22.9, 11.8 and 19.5 per 100 person-years in the Western Africa, Eastern Africa, Southern Africa, Central Africa, Asian, and Caribbean and Central and South America regions, respectively. Factors associated with anaemia were female sex, low baseline haemoglobin level, low baseline CD4 count, more advanced disease stage, and initial cART containing zidovudine. Conclusions In data from 34 cohorts of HIV-infected patients from sub-Saharan Africa, Central and South America, and Asia, the risk of anaemia within 12 months of initiating cART was moderate. Routine haemoglobin

  8. Evaluation of VIIRS and MODIS thermal emissive band calibration consistency using Dome C

    NASA Astrophysics Data System (ADS)

    Madhavan, Sriharsha; Wu, Aisheng; Brinkmann, Jake; Wenny, Brian; Xiong, Xiaoxiong

    2015-10-01

    The S-NPP Visible Infrared Imaging Radiometer Suite (VIIRS) instrument is designed based on MODIS heritage and uses a similar on-board calibrating source - a V-grooved blackbody for the Thermal Emissive Bands (TEBs). Except for the 10.7 μm band, the central wavelengths of the rest of the VIIRS TEBs match well with MODIS. To ensure the continuity and consistency of data records between VIIRS and MODIS TEBs, it is important to assess any systematic differences between the two instruments for scenes with temperatures significantly lower than blackbody operating temperatures at ~290 K. In previous studies, the MODIS Calibration and Characterization Support Team (MCST) at NASA/GSFC uses recurrent observations of Dome C, Antarctica by both Terra and Aqua MODIS over the mission lifetime to track their calibration stability and consistency. Near-surface temperature measurements from an Automatic Weather Station (AWS) provide a proxy reference useful for tracking the stability and determining the relative bias between the two MODIS instruments. In this study, the same approach is applied to VIIRS TEBs and the results are compared with those from the matched MODIS TEBs. The results of this study provide a quantitative assessment for VIIRS TEBs performance over the first three years of the mission.

  9. Genetic and morphological divergence among Cooper's Hawk (Accipiter cooperii) populations breeding in north-central and western North America

    USGS Publications Warehouse

    Sonsthagen, Sarah A.; Rosenfield, Robert N.; Bielefeldt, John; Murphy, Robert K.; Stewart, Andrew C.; Stout, William C.; Driscoll, Timothy G.; Bozek, Michael A.; Sloss, Brian L.; Talbot, Sandra L.

    2012-01-01

    Cooper's Hawk (Accipiter cooperii) populations breeding in the northern portion of the species' range exhibit variation in morphological traits that conforms to predictions based on differences in prey size, tree stand density, and migratory behavior. We examined genetic structure and gene flow and compared divergence at morphological traits (PST) and genetic markers (FST) to elucidate mechanisms (selection or genetic drift) that promote morphological diversification among Cooper's Hawk populations. Cooper's Hawks appear to conform to the genetic pattern of an east-west divide. Populations in British Columbia are genetically differentiated from north-central populations (Wisconsin, Minnesota, and North Dakota; pairwise microsatellite FST= 0.031-0.050; mitochondrial DNA ΦST = 0.177-0.204), which suggests that Cooper's Hawks were restricted to at least two Pleistocene glacial refugia. The strength of the Rocky Mountains—Great Plains area as a barrier to dispersal is further supported by restricted gene-flow rates between British Columbia and other sampled breeding populations. Divergence in morphological traits (PST) was also observed across study areas, but with British Columbia and North Dakota differentiated from Wisconsin and Minnesota, a pattern not predicted on the basis of FST and ΦST interpopulation estimates. Comparison of PSTand FSTestimates suggests that heterogeneous selection may be acting on Cooper's Hawks in the northern portion of their distribution, which is consistent with hypotheses that variation in prey mass and migratory behavior among populations may be influencing overall body size and wing chord. We were unable to distinguish between the effects of genetic drift and selection on tail length in the study populations.

  10. Evidence and future scenarios of a low-carbon energy transition in Central America: a case study in Nicaragua

    NASA Astrophysics Data System (ADS)

    Barido, Diego Ponce de Leon; Johnston, Josiah; Moncada, Maria V.; Callaway, Duncan; Kammen, Daniel M.

    2015-10-01

    The global carbon emissions budget over the next decades depends critically on the choices made by fast-growing emerging economies. Few studies exist, however, that develop country-specific energy system integration insights that can inform emerging economies in this decision-making process. High spatial- and temporal-resolution power system planning is central to evaluating decarbonization scenarios, but obtaining the required data and models can be cost prohibitive, especially for researchers in low, lower-middle income economies. Here, we use Nicaragua as a case study to highlight the importance of high-resolution open access data and modeling platforms to evaluate fuel-switching strategies and their resulting cost of power under realistic technology, policy, and cost scenarios (2014-2030). Our results suggest that Nicaragua could cost-effectively achieve a low-carbon grid (≥80%, based on non-large hydro renewable energy generation) by 2030 while also pursuing multiple development objectives. Regional cooperation (balancing) enables the highest wind and solar generation (18% and 3% by 2030, respectively), at the least cost (US127 MWh-1). Potentially risky resources (geothermal and hydropower) raise system costs but do not significantly hinder decarbonization. Oil price sensitivity scenarios suggest renewable energy to be a more cost-effective long-term investment than fuel oil, even under the assumption of prevailing cheap oil prices. Nicaragua’s options illustrate the opportunities and challenges of power system decarbonization for emerging economies, and the key role that open access data and modeling platforms can play in helping develop low-carbon transition pathways.

  11. Volcanic Threat in Central America: Assessment and Comparison of Volcanic Hazards and Associated Vulnerability in Guatemala, El Salvador, Nicaragua and Costa Rica.

    NASA Astrophysics Data System (ADS)

    Palma, J. L.; Rose, W. I.; Escobar, R.

    2008-12-01

    Within the Central American volcanic arc, that runs through Guatemala, El Salvador, Nicaragua and Costa Rica, there are 72 volcanoes that have exhibited historical (>26) or Holocene (>37) activity. Some of these volcanoes are immediately adjacent to large cities with several thousand inhabitants. A striking example is San Salvador volcano, in El Salvador, with more than 500,000 people living within 10 km from its summit. Other presently active volcanoes, such as Fuego and Santiaguito in Guatemala, continually threaten local communities established nearby, where appropriate monitoring strategies and mitigation plans have only recently started to develop. This contribution presents an assessment of volcanic threat in Central America based on the historic volcanic activity registered at each volcano, recognition of the hazards most likely to occur, and exposure of inhabitants and infrastructure near volcanic vents, next to potential lahar paths and downwind. Parameters used to quantify the compound hazard and vulnerability, include those presented by Ewert et al. (2005) as part of the Framework for a National Volcano Early Warning System in the US, NVEWS (USGS open-file report 2005-1164). New parameters are devised to improve threat assessment by including evaluation of the enormous variability in depth and extent of information, the differing social factors that influence vulnerability (Wisner et al, 2003, At Risk) and the sophistication of monitoring efforts. The volcano dataset used was compiled from the Smithsonian's Global Volcanism Program's website, as well as other relevant publications. Information about population and infrastructure was obtained from the LandScan population database and census data compiled by local governments.

  12. Phylogeography and Genetic Variation of Triatoma dimidiata, the Main Chagas Disease Vector in Central America, and Its Position within the Genus Triatoma

    PubMed Central

    Bargues, María Dolores; Klisiowicz, Debora R.; Gonzalez-Candelas, Fernando; Ramsey, Janine M.; Monroy, Carlota; Ponce, Carlos; Salazar-Schettino, Paz María; Panzera, Francisco; Abad-Franch, Fernando; Sousa, Octavio E.; Schofield, Christopher J.; Dujardin, Jean Pierre; Guhl, Felipe; Mas-Coma, Santiago

    2008-01-01

    Background Among Chagas disease triatomine vectors, the largest genus, Triatoma, includes species of high public health interest. Triatoma dimidiata, the main vector throughout Central America and up to Ecuador, presents extensive phenotypic, genotypic, and behavioral diversity in sylvatic, peridomestic and domestic habitats, and non-domiciliated populations acting as reinfestation sources. DNA sequence analyses, phylogenetic reconstruction methods, and genetic variation approaches are combined to investigate the haplotype profiling, genetic polymorphism, phylogeography, and evolutionary trends of T. dimidiata and its closest relatives within Triatoma. This is the largest interpopulational analysis performed on a triatomine species so far. Methodology and Findings Triatomines from Mexico, Guatemala, Honduras, Nicaragua, Panama, Cuba, Colombia, Ecuador, and Brazil were used. Triatoma dimidiata populations follow different evolutionary divergences in which geographical isolation appears to have had an important influence. A southern Mexican–northern Guatemalan ancestral form gave rise to two main clades. One clade remained confined to the Yucatan peninsula and northern parts of Chiapas State, Guatemala, and Honduras, with extant descendants deserving specific status. Within the second clade, extant subspecies diversity was shaped by adaptive radiation derived from Guatemalan ancestral populations. Central American populations correspond to subspecies T. d. dimidiata. A southern spread into Panama and Colombia gave the T. d. capitata forms, and a northwestern spread rising from Guatemala into Mexico gave the T. d. maculipennis forms. Triatoma hegneri appears as a subspecific insular form. Conclusions The comparison with very numerous Triatoma species allows us to reach highly supported conclusions not only about T. dimidiata, but also on different, important Triatoma species groupings and their evolution. The very large intraspecific genetic variability found in T

  13. Noninvasive individual and species identification of jaguars (Panthera onca), pumas (Puma concolor) and ocelots (Leopardus pardalis) in Belize, Central America using cross-species microsatellites and faecal DNA.

    PubMed

    Wultsch, Claudia; Waits, Lisette P; Kelly, Marcella J

    2014-11-01

    There is a great need to develop efficient, noninvasive genetic sampling methods to study wild populations of multiple, co-occurring, threatened felids. This is especially important for molecular scatology studies occurring in challenging tropical environments where DNA degrades quickly and the quality of faecal samples varies greatly. We optimized 14 polymorphic microsatellite loci for jaguars (Panthera onca), pumas (Puma concolor) and ocelots (Leopardus pardalis) and assessed their utility for cross-species amplification. Additionally, we tested their reliability for species and individual identification using DNA from faeces of wild felids detected by a scat detector dog across Belize in Central America. All microsatellite loci were successfully amplified in the three target species, were polymorphic with average expected heterozygosities of HE = 0.60 ± 0.18 (SD) for jaguars, HE = 0.65 ± 0.21 (SD) for pumas and HE = 0.70 ± 0.13 (SD) for ocelots and had an overall PCR amplification success of 61%. We used this nuclear DNA primer set to successfully identify species and individuals from 49% of 1053 field-collected scat samples. This set of optimized microsatellite multiplexes represents a powerful tool for future efforts to conduct noninvasive studies on multiple, wild Neotropical felids.

  14. How does land use link terrestrial and aquatic carbon in western North America?: Implications from an agricultural case study in central Montana

    NASA Astrophysics Data System (ADS)

    Ewing, S. A.; Sigler, W. A.

    2014-12-01

    The fate of soil organic matter with expanding human land use is of increasing concern for planetary health and ecological sustainability. In North American grasslands, cultivation has commonly resulted in loss of stored soil organic carbon to dissolved phases in groundwater and surface water, as well as to atmospheric CO2 via decomposition. In addition, cultivation has released nutrients stored in organic matter and facilitated water movement through soils to benefit crops, increasing groundwater recharge rates. This has altered groundwater chemistry both by changing biogeochemistry of the terrestrial-aquatic interface and by increasing addition of nutrients, herbicides, and pesticides to these systems. In this presentation, we consider the effects of food production practices on terrestrial-aquatic carbon linkages in former grassland ecosystems of western North America. Our data from an agricultural area in central Montana begin to reveal how elevated nitrate and pesticide levels in groundwater on an isolated landform reflect transformation over the last century of a temperate grassland ecosystem for wheat and cattle production. Rates and pathways of carbon and nitrogen loss are inferred from the concentration and isotopic character of both water and carbon and nitrogen over three years in soils, shallow groundwater, emergent springs and surface waters. In this semi-arid, non-irrigated context, the fate of soil organic matter is linked with redistribution of pedogenic carbonate as well as other soil and rock derived solutes. We consider implications for future trends in dissolved carbon and nitrogen in surface waters in the region.

  15. Noninvasive individual and species identification of jaguars (Panthera onca), pumas (Puma concolor) and ocelots (Leopardus pardalis) in Belize, Central America using cross-species microsatellites and faecal DNA.

    PubMed

    Wultsch, Claudia; Waits, Lisette P; Kelly, Marcella J

    2014-11-01

    There is a great need to develop efficient, noninvasive genetic sampling methods to study wild populations of multiple, co-occurring, threatened felids. This is especially important for molecular scatology studies occurring in challenging tropical environments where DNA degrades quickly and the quality of faecal samples varies greatly. We optimized 14 polymorphic microsatellite loci for jaguars (Panthera onca), pumas (Puma concolor) and ocelots (Leopardus pardalis) and assessed their utility for cross-species amplification. Additionally, we tested their reliability for species and individual identification using DNA from faeces of wild felids detected by a scat detector dog across Belize in Central America. All microsatellite loci were successfully amplified in the three target species, were polymorphic with average expected heterozygosities of HE = 0.60 ± 0.18 (SD) for jaguars, HE = 0.65 ± 0.21 (SD) for pumas and HE = 0.70 ± 0.13 (SD) for ocelots and had an overall PCR amplification success of 61%. We used this nuclear DNA primer set to successfully identify species and individuals from 49% of 1053 field-collected scat samples. This set of optimized microsatellite multiplexes represents a powerful tool for future efforts to conduct noninvasive studies on multiple, wild Neotropical felids. PMID:24751217

  16. Two new species of Urocleidoides Mizelle et Price, 1964 (Monogenoidea) from the gill lamellae of profundulids and poeciliids from Central America and southern Mexico.

    PubMed

    Mendoza-Franco, Edgar F; Caspeta-Mandujano, Juan Manuel; Salgado-Maldonado, Guillermo; Matamoros, Wilfredo Antonio

    2015-01-01

    During investigations of gill ectoparasites (Platyhelminthes) parasitising freshwater fish from Central America (Guatemala, Honduras, El Salvador and Panama) and southeastern Mexico (Guerrero, Oaxaca and Chiapas), the following dactylogyrid monogenoidean were found: Urocleidoides simonae sp. n. from Profundulus punctatus (Günther) (type host), Profundulus balsanus Ahl, Profundulus guatemalensis (Günther), Profundulus kreiseri Matamoros, Shaefer, Hernández et Chakrabarty, Profundulus labialis (Günther), Profundulus oaxacae (Meek), Profundulus sp. 1 and Profundulus sp. 2 (all Profundulidae); Urocleidoides vaginoclaustroides sp. n. from Pseudoxiphophorus bimaculata (Heckel) (type host) and Poeciliopsis retropinna (Regan) (both Poeciliidae); and Urocleidoides vaginoclaustrum Jogunoori, Kritsky et Venkatanarasaiah, 2004 from P. labialis, Profundulus portillorum Matamoros et Shaefer and Xiphophorus hellerii Heckel (Poeciliidae). Urocleidoides simonae sp. n. differs from all other congeneric species in having anchors with well-differentiated roots, curved elongate shaft and short point. Urocleidoides vaginoclaustroides sp. n. most closely resembles U. vaginoclaustrum, but differs from this species mainly in the shape of its anchors (i.e. evenly curved shaft and short point vs curved shaft and elongate point extending just past the tip of the superficial anchor root). The complexity of potential hosts for species of Urocleidoides and their effect on its distribution on profundulid and poeciliid fishes are briefly discussed. PMID:26580223

  17. Public purchasers contracting external primary care providers in Central America for better responsiveness, efficiency of health care and public governance: issues and challenges.

    PubMed

    Macq, Jean; Martiny, Patrick; Villalobos, Luis Bernardo; Solis, Alejandro; Miranda, Jose; Mendez, Hilda Cecilia; Collins, Charles

    2008-09-01

    Several national health systems in Latin America initiated health reforms to counter widespread criticisms of low equity and efficiency. For public purchasing agencies, these reforms often consisted in contracting external providers for primary care provision. This paper intends to clarify both the complex and intertwined issues characterizing such contracting as well as health system performances within the context of four Central American countries. It results from a European Commission financed project lead between 2002 and 2005, involving participants from Costa Rica, Guatemala, Nicaragua, Salvador, United Kingdom, Netherlands and Belgium, whose aim was to promote exchanges between these participants. The findings presented in this paper are the results of a two stage process: (a) the design of an initial analytical framework, built upon findings from the literature, interlinking characteristics of contractual relation with health systems performances criteria and (b) the use of that framework in four case studies to identify cross-cutting issues. This paper reinforces two pivotal findings: (a) contracting requires not only technical, but also political choices and (b) it cannot be considered as a mechanical process. The unpredictability of its evolution requires a flexible and reactive approach. This should be better assimilated by national and international organizations involved in health services provision, so as to progressively come out of dogmatic approaches in deciding to initiate contractual relation with external providers for primary care provision. PMID:18342980

  18. Soil bioengineering measures for disaster mitigation and environmental restoration in Central America: authochtonal cuttings suitability and economic efficiency

    NASA Astrophysics Data System (ADS)

    Petrone, A.; Preti, F.

    2009-04-01

    The use of Soil Bio-Engineering techniques in Developing countries is a relevant issue for Disaster mitigation, environmental restoration and poverty reduction. Research on authochtonal plants suitable for this kind of works and on economic efficiency is essential for the divulgation of this Discipline. The present paper is focused on this two issues related to the realization of various typologies of Soil Bio-engineering works in the Humid tropic of Nicaragua. In the area of Río Blanco, located in the Department of Matagalpa, Soil bio-engineering installations were built in several sites. The particular structures built were: drainages with live fascine mattress, a live palisade, a vegetated live crib wall for riverbank protection, a vegetative covering made of a metallic net and biotextile coupled with a live palisade made of bamboo. In order to evaluate the suitability of the various plants used in the works, monitorings were performed, one in the live palisade alongside an unpaved road and the other on the live crib wall along a riverbank, collecting survival rate and morphological parameters data. Concerning the economic efficiency we proceed to a financial analysis of the works and once the unit price was obtained, we converted the amount in EPP Dollars (Equal Purchasing Power) in order to compare the Nicaraguan context with the Italian one. Among the used species we found that Madero negro (Gliricidia sepium) and Roble macuelizo (Tabebuia rosea) are adequate for Soil-bioengineering measure on slopes while Helequeme (Erythrina fusca) reported a successful behaviour only in the crib wall for riverbank protection. In the comparison of the costs in Nicaragua and in Italy, the unit price reduction for the central American country ranges between 1.5 times (for the vegetative covering) and almost 4 times (for the fascine mattress) if it's used the EPP dollar exchange rate. Thus, a conclusion can be reached with regard to hydrological-risk mitigating actions

  19. A New Endemic Focus of Chagas Disease in the Northern Region of Veraguas Province, Western Half Panama, Central America

    PubMed Central

    Saldaña, Azael; Pineda, Vanessa; Martinez, Inri; Santamaria, Giovanna; Santamaria, Ana Maria; Miranda, Aracelis; Calzada, Jose E.

    2012-01-01

    Background Chagas disease was originally reported in Panama in 1931. Currently, the best knowledge of this zoonosis is restricted to studies done in historically endemic regions. However, little is known about the distribution and epidemiology of Chagas disease in other rural areas of the country. Methods and Findings A cross-sectional descriptive study was carried out between May 2005 – July 2008 in four rural communities of the Santa Fe District, Veraguas Province. The study included an entomologic search to collect triatomines, bloodmeal type identification and infection rate with trypanosomes in collected vectors using a dot- blot and PCR analysis, genotyping of circulating Trypanosoma cruzi (mini-exon gene PCR analysis) and the detection of chagasic antibodies among inhabitants. The vector Rhodnius pallescens was more frequently found in La Culaca and El Pantano communities (788 specimens), where it was a sporadic household visitor. These triatomines presented darker coloration and larger sizescompared with typical specimens collected in Central Panama. Triatoma dimidiata was more common in Sabaneta de El Macho (162 specimens). In one small sub-region (El Macho), 60% of the houses were colonized by this vector. Of the examined R. pallescens, 54.7.0% (88/161) had fed on Didelphis marsupialis, and 24.6% (34/138) of T. dimidiata specimens collected inside houses were positive for human blood. R. pallescens presented an infection index with T. cruzi of 17.7% (24/136), with T. rangeli of 12.5% (17/136) and 50.7% (69/136) were mixed infections. In 117 T. dimidiata domestic specimens the infection index with T. cruzi was 21.4%. Lineage I of T. cruzi was confirmed circulating in these vectors. A T. cruzi infection seroprevalence of 2.3% (24/1,056) was found in this population. Conclusions This is the first report of Chagas disease endemicity in Santa Fe District, and it should be considered a neglected public health problem in this area of Panama. PMID:22558095

  20. Historical Glacier Variations in Southern South America since the Little Ice Age: Examples from Lago Viedma (Southern Patagonia) and Mendoza (Central Andes), Argentina

    NASA Astrophysics Data System (ADS)

    Nussbaumer, S. U.; Masiokas, M.; Pitte, P.; Berthier, E.; Guerrido, C.; Luckman, B. H.; Villalba, R.

    2013-12-01

    The evaluation of historical information can give valuable insight into past glacier dynamics, especially before the onset of modern measurements. Early photographs and maps depict changes for selected glaciers in southern South America. Within this study, written documents and pictorial historical records (drawings, sketches, engravings, photographs, chronicles, topographic maps) are analysed critically, with a particular focus on two regions: Lago Viedma (El Chaltén, southern Patagonia, 49.5°S, 73.0°W) and the Río Mendoza basin (Mendoza, central Andes, 33.1°S, 69.9°W). For the Lago Viedma area, early historical data for the end of the 19th century stem from the expedition of the Chilean-Argentinean border commission. In addition, the expedition by the German Scientific Society, conducted between 1910 and 1916, and the later photographs by Alberto M. de Agostini give an excellent depiction of the glaciers. Glaciar Viedma is a calving glacier which shows distinct retreat from 1896 until the present (though with a stationary or possibly advancing glacier front between 1930/31 and 1951/52), similar to the neighbouring glaciers. On the contrary, nearby Glaciar Perito Moreno shows an exceptional behaviour: the glacier front has been advancing during the first half of the 20th century, staying in an advanced position until the present. At the beginning of the 20th century, Robert Helbling explored the Argentinean-Chilean Andes together with his friend Friedrich Reichert. In the summer of 1909/10, they started a detailed survey of the highly glacierized Juncal-Tupungato mountains (Río Mendoza basin), leading to the first accurate topographic map of the area published in 1914. Its outstanding quality allows a comparison with contemporary satellite imagery. The area received attention in 1934, when the sudden drainage of a glacier-dammed lake in the upper Río del Plomo valley caused fatalities and considerable damage to constructions and the Transandine Railway. A

  1. Aerosol Lidar and MODIS Satellite Comparisons for Future Aerosol Loading Forecast

    NASA Technical Reports Server (NTRS)

    DeYoung, Russell; Szykman, James; Severance, Kurt; Chu, D. Allen; Rosen, Rebecca; Al-Saadi, Jassim

    2006-01-01

    Knowledge of the concentration and distribution of atmospheric aerosols using both airborne lidar and satellite instruments is a field of active research. An aircraft based aerosol lidar has been used to study the distribution of atmospheric aerosols in the California Central Valley and eastern US coast. Concurrently, satellite aerosol retrievals, from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra and Aqua satellites, were take over the Central Valley. The MODIS Level 2 aerosol data product provides retrieved ambient aerosol optical properties (e.g., optical depth (AOD) and size distribution) globally over ocean and land at a spatial resolution of 10 km. The Central Valley topography was overlaid with MODIS AOD (5x5 sq km resolution) and the aerosol scattering vertical profiles from a lidar flight. Backward air parcel trajectories for the lidar data show that air from the Pacific and northern part of the Central Valley converge confining the aerosols to the lower valley region and below the mixed layer. Below an altitude of 1 km, the lidar aerosol and MODIS AOD exhibit good agreement. Both data sets indicate a high presence of aerosols near Bakersfield and the Tehachapi Mountains. These and other results to be presented indicate that the majority of the aerosols are below the mixed layer such that the MODIS AOD should correspond well with surface measurements. Lidar measurements will help interpret satellite AOD retrievals so that one day they can be used on a routine basis for prediction of boundary layer aerosol pollution events.

  2. Sensitivity of the Weather Research and Forecast/Community Multiscale Air Quality modeling system to MODIS LAI, FPAR, and albedo

    NASA Astrophysics Data System (ADS)

    Ran, Limei; Gilliam, Robert; Binkowski, Francis S.; Xiu, Aijun; Pleim, Jonathan; Band, Larry

    2015-08-01

    This study aims to improve land surface processes in a retrospective meteorology and air quality modeling system through the use of Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation and albedo products for more realistic vegetation and surface representation. MODIS leaf area index (LAI), fraction of absorbed photosynthetically active radiation (FPAR), and albedo are incorporated into the Pleim-Xiu land surface model (PX LSM) used in a combined meteorology and air quality modeling system. The current PX LSM intentionally exaggerates vegetation coverage and LAI in western dry lands so that its soil moisture nudging scheme is more effective in simulating surface temperature and mixing ratio. Reduced vegetation coverage from the PX LSM with MODIS input results in hotter and dryer daytime conditions with reduced ozone dry deposition velocities in much of western North America. Evaluations of the new system indicate greater error and bias in temperature, but reduced error and bias in moisture with the MODIS vegetation input. Hotter daytime temperatures and reduced dry deposition result in greater ozone concentrations in the western arid regions even with deeper boundary layer depths. MODIS albedo has much less impact on the meteorology simulations than MODIS LAI and FPAR. The MODIS vegetation and albedo input does not have much influence in the east where differences in vegetation and albedo parameters are less extreme. Evaluation results showing increased temperature errors with more accurate representation of vegetation suggests that improvements are needed in the model surface physics, particularly the soil processes in the PX LSM.

  3. MODIS Solar Reflective Calibration Traceability

    NASA Technical Reports Server (NTRS)

    Xiong, Xiaoxiong; Butler, Jim

    2009-01-01

    Long-term climate data records often consist of observations made by multiple sensors. It is, therefore, extremely important to have instrument overlap, to be able to track instrument stability, to quantify, measurement uncertainties, and to establish absolute scale traceable to the International System of Units (SI). The Moderate Resolution Imaging Spectroradiometer (MODIS) is a key instrument for both the Terra and Aqua missions, which were launched in December 1999 and May 2002, respectively. It has 20 reflective solar bands (RSB) with wavelengths from 0.41 to 2.2 micrometers and observes the Earth at three nadir spatial resolutions: 0.25km, 0.5km, and 1km. MODIS RSB on-orbit calibration is reflectance based with reference to the bidirectional reflectance factor (BRF) of its on-board solar diffuser (SD). The SD BRF characterization was made pre-launch by the instrument vendor using reference samples traceable directly to the National Institute of Standards and Technology (NIST). On-orbit SD reflectance degradation is tracked by an on-board solar diffuser monitor (SDSM). This paper provides details of this calibration chain, from prelaunch to on-orbit operation, and associated uncertainty assessments. Using MODIS as an example, this paper also discusses challenges and key design requirements for future missions developed for accurate climate studies.

  4. Validation of MODIS Aerosol Retrieval Over Ocean

    NASA Technical Reports Server (NTRS)

    Remer, Lorraine A.; Tanre, Didier; Kaufman, Yoram J.; Ichoku, Charles; Mattoo, Shana; Levy, Robert; Chu, D. Allen; Holben, Brent N.; Dubovik, Oleg; Ahmad, Ziauddin; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The MODerate resolution Imaging Spectroradiometer (MODIS) algorithm for determining aerosol characteristics over ocean is performing with remarkable accuracy. A two-month data set of MODIS retrievals co-located with observations from the AErosol RObotic NETwork (AERONET) ground-based sunphotometer network provides the necessary validation. Spectral radiation measured by MODIS (in the range 550 - 2100 nm) is used to retrieve the aerosol optical thickness, effective particle radius and ratio between the submicron and micron size particles. MODIS-retrieved aerosol optical thickness at 660 nm and 870 nm fall within the expected uncertainty, with the ensemble average at 660 nm differing by only 2% from the AERONET observations and having virtually no offset. MODIS retrievals of aerosol effective radius agree with AERONET retrievals to within +/- 0.10 micrometers, while MODIS-derived ratios between large and small mode aerosol show definite correlation with ratios derived from AERONET data.

  5. In the Shadow of the Cold War: The Caribbean and Central America in U.S. Foreign Policy. [and] Teacher's Resource Book. Revised. Choices for the 21st Century.

    ERIC Educational Resources Information Center

    Brown Univ., Providence, RI. Thomas J. Watson, Jr. Inst. for International Studies.

    This unit examines the economic and military concerns that have linked the Caribbean and Central America to the United States. The first section of the first booklet reviews the history of U.S. involvement in the region from the mid-1800s to the early 1960s. Part 2 focuses on the Cuban missile crisis of 1962 and presents a day-by-day account of…

  6. MODIS Science Algorithms and Data Systems Lessons Learned

    NASA Technical Reports Server (NTRS)

    Wolfe, Robert E.; Ridgway, Bill L.; Patt, Fred S.; Masuoka, Edward J.

    2009-01-01

    For almost 10 years, standard global products from NASA's Earth Observing System s (EOS) two Moderate Resolution Imaging Spectroradiometer (MODIS) sensors are being used world-wide for earth science research and applications. This paper discusses the lessons learned in developing the science algorithms and the data systems needed to produce these high quality data products for the earth sciences community. Strong science team leadership and communication, an evolvable and scalable data system, and central coordination of QA and validation activities enabled the data system to grow by two orders of magnitude from the initial at-launch system to the current system able to reprocess data from both the Terra and Aqua missions in less than a year. Many of the lessons learned from MODIS are already being applied to follow-on missions.

  7. Fault kinematics in northern Central America and coupling along the subduction interface of the Cocos Plate, from GPS data in Chiapas (Mexico), Guatemala and El Salvador

    NASA Astrophysics Data System (ADS)

    Franco, A.; Lasserre, C.; Lyon-Caen, H.; Kostoglodov, V.; Molina, E.; Guzman-Speziale, M.; Monterosso, D.; Robles, V.; Figueroa, C.; Amaya, W.; Barrier, E.; Chiquin, L.; Moran, S.; Flores, O.; Romero, J.; Santiago, J. A.; Manea, M.; Manea, V. C.

    2012-06-01

    New GPS measurements in Chiapas (Mexico), Guatemala and El Salvador are used to constrain the fault kinematics in the North America (NA), Caribbean (CA) and Cocos (CO) plates triple junction area. The regional GPS velocity field is first analysed in terms of strain partitioning across the major volcano-tectonic structures, using elastic half-space modelling, then inverted through a block model. We show the dominant role of the Motagua Fault with respect to the Polochic Fault in the accommodation of the present-day deformation associated with the NA and CA relative motion. The NA/CA motion decreases from 18-22 mm yr-1 in eastern Guatemala to 14-20 mm yr-1 in central Guatemala (assuming a uniform locking depth of 14-28 km), down to a few millimetres per year in western Guatemala. As a consequence, the western tip of the CA Plate deforms internally, with ≃9 mm yr-1 of east-west extension (≃5 mm yr-1 across the Guatemala city graben alone). Up to 15 mm yr-1 of dextral motion can be accommodated across the volcanic arc in El Salvador and southeastern Guatemala. The arc seems to mark the northern boundary of an independent forearc sliver (AR), pinned to the NA plate. The inversion of the velocity field shows that a four-block (NA, CA, CO and AR) model, that combines relative block rotations with elastic deformation at the block boundaries, can account for most of the GPS observations and constrain the overall kinematics of the active structures. This regional modelling also evidences lateral variations of coupling at the CO subduction interface, with a fairly high-coupling (≃0.6) offshore Chiapas and low-coupling (≃0.25) offshore Guatemala and El Salvador.

  8. Organophosphate pesticide method development and presence of chlorpyrifos in the feet of nearctic-neotropical migratory songbirds from Canada that over-winter in Central America agricultural areas.

    PubMed

    Alharbi, Hattan A; Letcher, Robert J; Mineau, Pierre; Chen, Da; Chu, Shaogang

    2016-02-01

    Recent modeling analysis suggests that numerous birds may be at risk of acute poisoning in insecticide-treated fields. Although the majority of avian field studies on pesticides have focused on treated seed, granule, insect or vegetation (oral exposure) ingestion, dermal exposure is an important exposure route when birds come into contact with deposited pesticides on foliage and other surfaces. Some nearctic-neotropical migratory songbirds are likely exposed to pesticides on their non-breeding habitats and include treated crops, plantations or farmlands. In the present study, we developed a method for four environmentally-relevant organophosphate (OP) pesticides (fenthion, fenamiphos, chlorpyrifos and diazinon) in the feet of migratory songbirds (i.e. Common yellowthroat, Gray catbird, Indigo bunting, America redstart, Northern waterthrush, Northern parula, and an additional 12 species of warblers). A total of 190 specimens of the 18 species of songbirds were sampled from available window-killed birds (spring of 2007 and 2011) in downtown Toronto, Canada. The species that were available most likely over-wintered in Mexican/Central American crops such as citrus, coffee and cacao. The feet of the dead birds were sampled and where OP foot exposure likely occurred during over-wintering foraging on pesticide-treated crops. Chlorpyrifos was the only measurable OP (pg mg feet weight(-1)) and in the 2011-collected feet of Black throated blue warbler (0.5), Tennessee warbler (1.0), Northern parula (1.2), Northern waterthrush (0.6), Common yellowthroat (1.0) and the Blue winged warbler (0.9). Dermal contact with OP pesticides during over-wintering in agricultural areas resulted in low levels of chlorpyrifos and long time retention on the feet of a subset of songbirds. PMID:26421621

  9. Health Care Providers and Human Trafficking: What do They Know, What do They Need to Know? Findings from the Middle East, the Caribbean, and Central America

    PubMed Central

    Viergever, Roderik F.; West, Haley; Borland, Rosilyne; Zimmerman, Cathy

    2015-01-01

    Background: Human trafficking is a crime that commonly results in acute and chronic physical and psychological harm. To foster more informed health sector responses to human trafficking, training sessions for health care providers were developed and pilot-tested in the Middle East, Central America, and the Caribbean. This study presents the results of an investigation into what health care providers knew and needed to know about human trafficking as part of that training program. Methods: Participants attended one of seven two-day training courses in Antigua and Barbuda, Belize, Costa Rica, Egypt, El Salvador, Guyana, and Jordan. We assessed participants’ knowledge about human trafficking and opinions about appropriate responses in trafficking cases via questionnaires pre-training, and considered participant feedback about the training post-training. Results: 178 participants attended the trainings. Pre-training questionnaires were completed by 165 participants (93%) and post-training questionnaires by 156 participants (88%). Pre-training knowledge about health and human trafficking appeared generally high for topics such as the international nature of trafficking and the likelihood of poor mental health outcomes among survivors. However, many participants had misconceptions about the characteristics of trafficked persons and a provider’s role in responding to cases of trafficking. The most valued training components included the “Role of the Health Provider,” “Basic Definitions and Concepts,” and “Health Consequences of Trafficking.” Discussion: Training health care providers on caring for trafficked persons has the potential to improve practitioners’ knowledge about human trafficking and its health consequences, and to increase safe practices when responding in cases of trafficking. This study provides lessons for the design of training programs on human trafficking that aim to help health care providers identify and refer victims, and provide

  10. Early childhood diarrhea and cardiometabolic risk factors in adulthood: The Institute of Nutrition of Central America and Panama (INCAP) Nutritional Supplementation Longitudinal Study

    PubMed Central

    DeBoer, Mark D.; Chen, David; Burt, David R.; Ramirez-Zea, Manuel; Guerrant, Richard L.; Stein, Aryeh D.; Martorell, Reynaldo; Luna, Max A.

    2015-01-01

    Background Nutritional deficits in early life have been associated with a higher prevalence of metabolic syndrome (MetS) in adulthood. Early childhood diarrhea contributes to under-nutrition and may potentially increase the risk for adult non-communicable diseases. Our objective was to examine associations between early childhood diarrhea burden and later development of MetS. Methods We studied individuals who participated in the Institute of Nutrition of Central America and Panama Nutritional Supplementation Longitudinal Study (1969–1977) and were followed up in 2002–04. We used logistic regression to determine associations of diarrhea burden at ages 0–6 mo, 6–12 mo, and 12–24 mo with odds of MetS and elevations in its components as adults. Results Among 389 adults age 25–42 years at follow-up the prevalence of MetS was 29%. Adjusting for several confounders including adult BMI, each absolute 1% increase in diarrhea burden at age 0–6 mo (but not at other time periods) was associated with increased odds of MetS (odds ratio 1.03; 95% CI 1.01–1.06). This was attributable primarily to associations with elevated BP (OR 1.03, 1.00–1.06) and waist circumference (OR 1.03, 1.00–1.06). Conclusions Childhood diarrhea burden 0–6 months is associated with MetS in adulthood after controlling for childhood growth parameters and adult BMI. PMID:23608305

  11. Organophosphate pesticide method development and presence of chlorpyrifos in the feet of nearctic-neotropical migratory songbirds from Canada that over-winter in Central America agricultural areas.

    PubMed

    Alharbi, Hattan A; Letcher, Robert J; Mineau, Pierre; Chen, Da; Chu, Shaogang

    2016-02-01

    Recent modeling analysis suggests that numerous birds may be at risk of acute poisoning in insecticide-treated fields. Although the majority of avian field studies on pesticides have focused on treated seed, granule, insect or vegetation (oral exposure) ingestion, dermal exposure is an important exposure route when birds come into contact with deposited pesticides on foliage and other surfaces. Some nearctic-neotropical migratory songbirds are likely exposed to pesticides on their non-breeding habitats and include treated crops, plantations or farmlands. In the present study, we developed a method for four environmentally-relevant organophosphate (OP) pesticides (fenthion, fenamiphos, chlorpyrifos and diazinon) in the feet of migratory songbirds (i.e. Common yellowthroat, Gray catbird, Indigo bunting, America redstart, Northern waterthrush, Northern parula, and an additional 12 species of warblers). A total of 190 specimens of the 18 species of songbirds were sampled from available window-killed birds (spring of 2007 and 2011) in downtown Toronto, Canada. The species that were available most likely over-wintered in Mexican/Central American crops such as citrus, coffee and cacao. The feet of the dead birds were sampled and where OP foot exposure likely occurred during over-wintering foraging on pesticide-treated crops. Chlorpyrifos was the only measurable OP (pg mg feet weight(-1)) and in the 2011-collected feet of Black throated blue warbler (0.5), Tennessee warbler (1.0), Northern parula (1.2), Northern waterthrush (0.6), Common yellowthroat (1.0) and the Blue winged warbler (0.9). Dermal contact with OP pesticides during over-wintering in agricultural areas resulted in low levels of chlorpyrifos and long time retention on the feet of a subset of songbirds.

  12. Comparasion of Cloud Cover restituted by POLDER and MODIS

    NASA Astrophysics Data System (ADS)

    Zeng, S.; Parol, F.; Riedi, J.; Cornet, C.; Thieuxleux, F.

    2009-04-01

    PARASOL and AQUA are two sun-synchronous orbit satellites in the queue of A-Train satellites that observe our earth within a few minutes apart from each other. Aboard these two platforms, POLDER and MODIS provide coincident observations of the cloud cover with very different characteristics. These give us a good opportunity to study the clouds system and evaluate strengths and weaknesses of each dataset in order to provide an accurate representation of global cloud cover properties. This description is indeed of outermost importance to quantify and understand the effect of clouds on global radiation budget of the earth-atmosphere system and their influence on the climate changes. We have developed a joint dataset containing both POLDER and MODIS level 2 cloud products collocated and reprojected on a common sinusoidal grid in order to make the data comparison feasible and veracious. Our foremost work focuses on the comparison of both spatial distribution and temporal variation of the global cloud cover. This simple yet critical cloud parameter need to be clearly understood to allow further comparison of the other cloud parameters. From our study, we demonstrate that on average these two sensors both detect the clouds fairly well. They provide similar spatial distributions and temporal variations:both sensors see high values of cloud amount associated with deep convection in ITCZ, over Indonesia, and in west-central Pacific Ocean warm pool region; they also provide similar high cloud cover associated to mid-latitude storm tracks, to Indian monsoon or to the stratocumulus along the west coast of continents; on the other hand small cloud amounts that typically present over subtropical oceans and deserts in subsidence aeras are well identified by both POLDER and MODIS. Each sensor has its advantages and inconveniences for the detection of a particular cloud types. With higher spatial resolution, MODIS can better detect the fractional clouds thus explaining as one part

  13. MODIS Satellite Data and GOCART Model Characterization of the Global Aerosol

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram; Chin, Mian; Remer, Lorraine; Tanre, Didier; Lau, William K.-M. (Technical Monitor)

    2003-01-01

    Recently produced daily MODIS aerosol data for the whole year of 2001 are used to show the concentration and dynamics of aerosol over ocean and large parts of the continents. The data were validated against the Aerosol Robotic Network (AERONET) measurements over land and ocean. Monthly averages and a movie based on the daily data are produced and used to demonstrate the spatial and temporal evolution of aerosol. The MODIS wide spectral range is used to distinguish fine smoke and pollution aerosol from coarse dust and salt. The aerosol is observed above ocean and land. The movie produced from the MODIS data provides a new dimension to aerosol observations by showing the dynamics of the system. For example in February smoke and dust emitted from the Sahel and West Africa is shown to travel to the North-East Atlantic. In April heavy dust and pollution from East Asia is shown to travel to North America. In May-June pollution and dust play a dynamical dance in the Arabian Sea and Bay of Bengal. In Aug-September smoke from South Africa and South America is shown to pulsate in tandem and to periodically to be transported to the otherwise pristine Southern part of the Southern Hemisphere. The MODIS data are compared with the GOCART model and used to estimate the first observation based direct anthropogenic radiative forcing of climate by aerosol.

  14. Biomass Burning Aerosol Absorption Measurements with MODIS Using the Critical Reflectance Method

    NASA Technical Reports Server (NTRS)

    Zhu, Li; Martins, Vanderlei J.; Remer, Lorraine A.

    2010-01-01

    This research uses the critical reflectance technique, a space-based remote sensing method, to measure the spatial distribution of aerosol absorption properties over land. Choosing two regions dominated by biomass burning aerosols, a series of sensitivity studies were undertaken to analyze the potential limitations of this method for the type of aerosol to be encountered in the selected study areas, and to show that the retrieved results are relatively insensitive to uncertainties in the assumptions used in the retrieval of smoke aerosol. The critical reflectance technique is then applied to Moderate Resolution Imaging Spectrometer (MODIS) data to retrieve the spectral aerosol single scattering albedo (SSA) in South African and South American 35 biomass burning events. The retrieved results were validated with collocated Aerosol Robotic Network (AERONET) retrievals. One standard deviation of mean MODIS retrievals match AERONET products to within 0.03, the magnitude of the AERONET uncertainty. The overlap of the two retrievals increases to 88%, allowing for measurement variance in the MODIS retrievals as well. The ensemble average of MODIS-derived SSA for the Amazon forest station is 0.92 at 670 nm, and 0.84-0.89 for the southern African savanna stations. The critical reflectance technique allows evaluation of the spatial variability of SSA, and shows that SSA in South America exhibits higher spatial variation than in South Africa. The accuracy of the retrieved aerosol SSA from MODIS data indicates that this product can help to better understand 44 how aerosols affect the regional and global climate.

  15. Object-based Mapping of the Circumpolar Taiga-Tundra Ecotone with MODIS Tree Cover

    NASA Technical Reports Server (NTRS)

    Ransom, Kenneth J.; Montesano, Paul M.; Nelson, Ross F.

    2011-01-01

    The circumpolar taiga-tundra ecotone was delineated using an image segmentation based mapping approach with multi-annual MODIS Vegetation Continuous Fields (VCF) tree cover data. Circumpolar tree canopy cover (TCC) throughout the ecotone was derived by averaging MODIS VCF data from 2000 - 2005 and adjusting the averaged values using linear equations relating MODIS TCC to Quickbird-derived tree cover estimates. The adjustment helped mitigate VCF's overestimation of tree cover in lightly forested regions. An image segmentation grouped pixels representing similar tree cover into polygonal features (objects) that form the map of the transition zone. Eachfeature represents an area much larger than the 500m MODIS pixel to characterize thepatterns of sparse forest patches on a regional scale. Comparisons of the adjusted average tree cover data were made with (1) two existing tree line definitions aggregated for each 1deg longitudinal interval in North America and Eurasia and (2) Landsat-derived Canadianproportion of forest cover for Canada. The adjusted TCC from MODIS VCF shows, on average, greater than 12% TCC for all but one regional zone at the intersection with independently delineated tree lines. Adjusted values track closely with Canadian proportion of forest cover data in areas of low tree cover. Those polygons near the boreal/tundra interface with either (1) mean adjusted TCC values between 5-20% , or (2) mean adjusted TCC values <5% but with a standard deviation > 5% were used to identify the ecotone.

  16. The Fate of Saharan Dust Across the Atlantic and Implications for a Central American Dust Barrier

    NASA Technical Reports Server (NTRS)

    Nowottnick, E.; Colarco, P.; da Silva, A.; Hlavka, D.; McGill, M.

    2011-01-01

    Saharan dust was observed over the Caribbean basin during the summer 2007 NASA Tropical Composition, Cloud, and Climate Coupling (TC4) field experiment. Airborne Cloud Physics Lidar (CPL) and satellite observations from MODIS suggest a barrier to dust transport across Central America into the eastern Pacific. We use the NASA GEOS-5 atmospheric transport model with online aerosol tracers to perform simulations of the TC4 time period in order to understand the nature of this barrier. Our simulations are driven by the Modem Era Retrospective-Analysis for Research and Applications (MERRA) meteorological analyses. We evaluate our baseline simulated dust distributions using MODIS and CALIOP satellite and ground-based AERONET sun photometer observations. GEOS-5 reproduces the observed location, magnitude, and timing of major dust events, but our baseline simulation does not develop as strong a barrier to dust transport across Central America as observations suggest. Analysis of the dust transport dynamics and lost processes suggest that while both mechanisms play a role in defining the dust transport barrier, loss processes by wet removal of dust are about twice as important as transport. Sensitivity analyses with our model showed that the dust barrier would not exist without convective scavenging over the Caribbean. The best agreement between our model and the observations was obtained when dust wet removal was parameterized to be more aggressive, treating the dust as we do hydrophilic aerosols.

  17. MODIS Radiometric Calibration and Uncertainty Assessment

    NASA Technical Reports Server (NTRS)

    Xiong, Xiaoxiong; Chiang, Vincent; Sun, Junqiang; Wu, Aisheng

    2011-01-01

    Since launch, Terra and Aqua MODIS have collected more than II and 9 years of datasets for comprehensive studies of the Earth's land, ocean, and atmospheric properties. MODIS observations are made in 36 spectral bands: 20 reflective solar bands (RSB) and 16 thermal emissive bands (TEB). Compared to its heritage sensors, MODIS was developed with very stringent calibration and uncertainty requirements. As a result, MODIS was designed and built with a set of state of the art on-board calibrators (OBC), which allow key sensor performance parameters and on-orbit calibration coefficients to be monitored and updated if necessary. In terms of its calibration traceability, MODIS RSB calibration is reflectance based using an on-board solar diffuser (SD) and the TEB calibration is radiance based using an on-board blackbody (BB). In addition to on-orbit calibration coefficients derived from its OBC, calibration parameters determined from sensor pre-launch calibration and characterization are used in both the RSB and TEB calibration and retrieval algorithms. This paper provides a brief description of MODIS calibration methodologies and discusses details of its on-orbit calibration uncertainties. It assesses uncertainty contributions from individual components and differences between Terra and Aqua MODIS due to their design characteristics and on-orbit periormance. Also discussed in this paper is the use of MODIS LIB uncertainty index CUI) product.

  18. Discovery of new Ohbayashinema spp. (Nematoda: Heligmosomoidea) in Ochotona princeps and Ochotona cansus (Lagomorpha: Ochotonidae) from western North America and Central Asia, with considerations of historical biogeography.

    PubMed

    Durette-Desset, M-C; Galbreath, K E; Hoberg, E P

    2010-06-01

    Three new species of Ohbayashinema (Nematoda, Heligmosomoidea) are described from localities in western North America and central Asia. Two of these species, Ohbayashinema nearctica n. sp. and Ohbayashinema aspeira n. sp., are parasitic in American pika, Ochotona princeps. Ohbayashinema nearctica is differentiated from the 5 known species of the genus parasitic in Ochotonidae from the Old World by very long spicules and an oblique axis of orientation for the ridges composing the synlophe. Ohbayashinema aspeira, described only from females, is similar to Oh. nearctica based on the number of cuticular ridges at the mid-body. It is mainly differentiated by an uncoiled anterior extremity and by near equal dimensions of the vestibule and the uterus. The third species, Ohbayashinema patriciae n. sp., is parasitic in Gansu pika, Ochotona cansus , from China. It is similar to Ohbayashinema erbaevae parasitic in Ochotona dauurica from Buriatia and Ohbayashinema ochotoni in Ochotona macrotis from Nepal, based on the length of the spicules and the ratio of spicule length to body length. It differs from the former species by possessing a smaller number of cuticular ridges and in the comparative length of the vestibule and infundibulum. Related to Oh. ochotoni by an identical number of cuticular ridges at the mid-body, it differs from this species in having smaller ridges in the dorsal rather than ventral field and in the dimensions of the dorsal ray where rays 9 are less than rays 10. Species of Ohbayashinema appear to be host-specific among the Ochotonidae but had not been previously reported in pikas from the Nearctic. Although much remains to be demonstrated about the diversity for helminths in pikas, it is apparent that factors associated with the assembly and structure of parasite faunas have been complex, involving episodic processes for geographic and host colonization along with coevolutionary mechanisms. Understanding the historical factors, particularly climate

  19. A Novel Educational Strategy Targeting Health Care Workers in Underserved Communities in Central America to Integrate HIV into Primary Medical Care

    PubMed Central

    Flys, Tamara; González, Rosalba; Sued, Omar; Suarez Conejero, Juana; Kestler, Edgar; Sosa, Nestor; McKenzie-White, Jane; Monzón, Irma Irene; Torres, Carmen-Rosa; Page, Kathleen

    2012-01-01

    Background Current educational strategies to integrate HIV care into primary medical care in Central America have traditionally targeted managers or higher-level officials, rather than local health care workers (HCWs). We developed a complementary online and on-site interactive training program to reach local HCWs at the primary care level in underserved communities. Methods The training program targeted physicians, nurses, and community HCWs with limited access to traditional onsite training in Panama, Nicaragua, Dominican Republic, and Guatemala. The curriculum focused on principles of HIV care and health systems using a tutor-supported blended educational approach of an 8-week online component, a weeklong on-site problem-solving workshop, and individualized project-based interventions. Results Of 258 initially active participants, 225 (225/258 = 87.2%) successfully completed the online component and the top 200 were invited to the on-site workshop. Of those, 170 (170/200 = 85%) attended the on-site workshop. In total, 142 completed all three components, including the project phase. Quantitative and qualitative evaluation instruments included knowledge assessments, reflexive essays, and acceptability surveys. The mean pre and post-essay scores demonstrating understanding of social determinants, health system organization, and integration of HIV services were 70% and 87.5%, respectively, with an increase in knowledge of 17.2% (p<0.001). The mean pre- and post-test scores evaluating clinical knowledge were 70.9% and 90.3%, respectively, with an increase in knowledge of 19.4% (p<0.001). A survey of Likert scale and open-ended questions demonstrated overwhelming participant satisfaction with course content, structure, and effectiveness in improving their HIV-related knowledge and skills. Conclusion This innovative curriculum utilized technology to target HCWs with limited access to educational resources. Participants benefited from technical skills acquired

  20. The integripennis species group of Geocharidius Jeannel, 1963 (Carabidae, Bembidiini, Anillina) from Nuclear Central America: a taxonomic review with notes about biogeography and speciation

    PubMed Central

    Sokolov, Igor M.; Kavanaugh, David H.

    2014-01-01

    Abstract Our review recognizes 15 species of the integripennis species group of Geocharidius from Nuclear Central America, include three species previously described (Geocharidius gimlii Erwin, Geocharidius integripennis (Bates) and Geocharidius zullinii Vigna Taglianti) and 12 described here as new. They are: Geocharidius andersoni sp. n. (type locality: Chiapas, Chiapas Highlands, Cerro Huitepec) and Geocharidius vignatagliantii sp. n. (type locality: Chiapas, Motozintla, Sierra Madre de Chiapas, Benito Juárez) from Mexico; Geocharidius antigua sp. n. (type locality: Sacatepéquez, 5 km SE of Antigua), Geocharidius balini sp. n. (type locality: Suchitepéquez, 4 km S of Volcan Atitlán), Geocharidius erwini sp. n. (type locality: Quiché Department, 7 km NE of Los Encuentros), Geocharidius jalapensis sp. n. (type locality: Jalapa Department, 4 km E of Mataquescuintla), Geocharidius longinoi, sp. n. (type locality: El Progreso Department, Cerro Pinalón), and Geocharidius minimus sp. n. (type locality: Sacatepéquez Department, 5 km SE of Antigua) from Guatemala; and Geocharidius celaquensis sp. n. (type locality: Lempira Department, Celaque National Park), Geocharidius comayaguanus sp. n. (type locality: Comayagua Department, 18 km ENE of Comayagua), Geocharidius disjunctus sp. n. (type locality: Francisco Morazán, La Tigra National Park), and Geocharidius lencanus sp. n. (type locality: Lempira Department, Celaque National Park) from Honduras. For all members of the group, adult structural characters, including male and female genitalia, are described, and a taxonomic key for all members of the integripennis species group is presented based on these characters. Behavioral and biogeographical aspects of speciation in the group are discussed, based on the morphological analysis. In all cases of sympatry, pairs of closely related species show greater differences in sizes than pairs of more remotely related species. Integripennis group species occupy six different

  1. Trends in MODIS Geolocation Error Analysis

    NASA Technical Reports Server (NTRS)

    Wolfe, R. E.; Nishihama, Masahiro

    2009-01-01

    Data from the two MODIS instruments have been accurately geolocated (Earth located) to enable retrieval of global geophysical parameters. The authors describe the approach used to geolocate with sub-pixel accuracy over nine years of data from M0DIS on NASA's E0S Terra spacecraft and seven years of data from MODIS on the Aqua spacecraft. The approach uses a geometric model of the MODIS instruments, accurate navigation (orbit and attitude) data and an accurate Earth terrain model to compute the location of each MODIS pixel. The error analysis approach automatically matches MODIS imagery with a global set of over 1,000 ground control points from the finer-resolution Landsat satellite to measure static biases and trends in the MO0lS geometric model parameters. Both within orbit and yearly thermally induced cyclic variations in the pointing have been found as well as a general long-term trend.

  2. MODIS Instrument Operation and Calibration Improvements

    NASA Technical Reports Server (NTRS)

    Xiong, X.; Angal, A.; Madhavan, S.; Link, D.; Geng, X.; Wenny, B.; Wu, A.; Chen, H.; Salomonson, V.

    2014-01-01

    Terra and Aqua MODIS have successfully operated for over 14 and 12 years since their respective launches in 1999 and 2002. The MODIS on-orbit calibration is performed using a set of on-board calibrators, which include a solar diffuser for calibrating the reflective solar bands (RSB) and a blackbody for the thermal emissive bands (TEB). On-orbit changes in the sensor responses as well as key performance parameters are monitored using the measurements of these on-board calibrators. This paper provides an overview of MODIS on-orbit operation and calibration activities, and instrument long-term performance. It presents a brief summary of the calibration enhancements made in the latest MODIS data collection 6 (C6). Future improvements in the MODIS calibration and their potential applications to the S-NPP VIIRS are also discussed.

  3. Floods in Central China

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This pair of true- and false-color images from the Moderate resolution Imaging Spectroradiometer (MODIS) shows flooding in central China on July 4, 2002. In the false-color image vegetation appears orange and water appears dark blue to black. Because of the cloud cover and the fact that some of the water is filled with sediment, the false-color image provides a clearer picture of where rivers have exceeded their banks and lakes have risen. The river in this image is the Yangtze River, and the large lake is the Poyang Hu. Credits: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  4. Space environment's effect on MODIS calibration

    NASA Astrophysics Data System (ADS)

    Dodd, J. L.; Wenny, B. N.; Chiang, K.; Xiong, X.

    2010-09-01

    The MODerate resolution Imaging Spectroradiometer flies on board the Earth Observing System (EOS) satellites Terra and Aqua in a sun-synchronous orbit that crosses the equator at 10:30 AM and 2:30 PM, respectively, at a low earth orbit (LEO) altitude of 705 km. Terra was launched on December 18,1999 and Aqua was launched on May 4, 2002. As the MODIS instruments on board these satellites continue to operate beyond the design lifetime of six years, the cumulative effect of the space environment on MODIS and its calibration is of increasing importance. There are several aspects of the space environment that impact both the top of atmosphere (TOA) calibration and, therefore, the final science products of MODIS. The south Atlantic anomaly (SAA), spacecraft drag, extreme radiative and thermal environment, and the presence of orbital debris have the potential to significantly impact both MODIS and the spacecraft, either directly or indirectly, possibly resulting in data loss. Efforts from the Terra and Aqua Flight Operations Teams (FOT), the MODIS Instrument Operations Team (IOT), and the MODIS Characterization Support Team (MCST) prevent or minimize external impact on the TOA calibrated data. This paper discusses specific effects of the space environment on MODIS and how they are minimized.

  5. Flooding in Central China

    NASA Technical Reports Server (NTRS)

    2002-01-01

    During the summer of 2002, frequent, heavy rains gave rise to floods and landslides throughout China that have killed over 1,000 people and affected millions. This false-color image of the western Yangtze River and Dongting Lake in central China was acquired on August 21, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. (right) The latest flooding crisis in China centers on Dingtong Lake in the center of the image. Heavy rains have caused it to swell over its banks and swamp lakefront towns in the province of Hunan. As of August 23, 2002, more than 250,000 people have been evacuated, and over one million people have been brought in to fortify the dikes around the lake. Normally the lake would appear much smaller and more defined in the MODIS image. Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC.

  6. Polarization Modeling of the MODIS Instrument

    NASA Technical Reports Server (NTRS)

    Waluschka, Eugene; Xiong, Xiao-Xiong; Esaias, Wayne E.; Voss, Kenneth; Souaidia, Nordine; Pellicori, Samuel; Moyer, David; Guenther, Bruce; Barnes, William

    2004-01-01

    Sunlight reflected from the earth is, to a certain extent, polarized. Radiometers, such as the MODIS instrument on board the TERRA and AQUA spacecraft, are to a certain extent polarizers. Accurate radiometric measurements must take into account both the polarization state of the scene and the polarization sensitivity of the measuring instrument. The measured polarization characteristics of the MODIS instruments are contained in various radiometric models. Continued use of these radiometric math models, over a number of years, have shown where these models can be improved. The current MODIS polarization modeling effort is discussed in the context and limitations of past modeling efforts.

  7. Modis-N airborne simulator

    NASA Technical Reports Server (NTRS)

    Cech, Steven D.

    1992-01-01

    All required work associated with the above referenced contract has been successfully completed at this time. The Modis-N Airborne Simulator has been developed from existing AB184 Wildfire spectrometer parts as well as new detector arrays, optical components, and associated mechanical and electrical hardware. The various instrument components have been integrated into an operational system which has undergone extensive laboratory calibration and testing. The instrument has been delivered to NASA Ames where it will be installed on the NASA ER-2. The following paragraphs detail the specific tasks performed during the contract effort, the results obtained during the integration and testing of the instrument, and the conclusions which can be drawn from this effort.

  8. Oceanic terranes of S-Central America - 200 Million years of accretion history recorded on the W-edge of the Caribbean Plate.

    NASA Astrophysics Data System (ADS)

    Baumgartner, P. O.; Flores, K.; Bandini, A.; Buchs, D.; Andjic, G.; Baumgartner-Mora, C.

    2012-04-01

    The W-edge of the Caribbean Plate is characterized by two major basement domains, separated today by a SW-NE trending diffuse fault zone located SE of the Nicoya Peninsula (Costa Rica) and possibly connecting with the Hess Escarpment. To the NW, in the area originally called "Chortis Block", oceanic island/arc basements range in age from Late Triassic to Early Cretaceous and form a complicated puzzle of geodynamic units. To the SE of this fault line, no age older than Turonian-Santonian (90-85 Ma) is known. This area only represents the trailing edge of the Caribbean Large Igensous Procince (CLIP). The Mesquito Composite Oceanic Terrane (MCOT) comprises the southern half of the "Chortis Block", classically considered as a continental fragment of N-America. The MCOT is defined by isolated outcrops of ultramafic, mafic oceanic/arc rocks, and radiolarites of Late Triassic, Jurassic and Early Cretaceous age: Rhaetian (latest Triassic) radiolarites found in the El Castillo Mélange (S-MCOT: S-Nicaragua/N- Costa Rica). They are associated with blocks of OIB-metabasalts. These rocks document the presence of a Late Triassic oceanic basement that must have been the substrate of the 174 -177 Ma old (Early/Middle Jurassic) Petit-Spot-like alkaline volcanics that intruded Early Jurassic radiolarites. These rocks form tectonic slivers in the middle Cretaceous Santa Rosa Accretionary Complex (relative autochthonous of the Santa Elena ultramafic unit, N-Costa Rica). The oldest rocks of the Nicoya Complex s. str. (NW-Nicoya Peninsula, Costa Rica) are Bajocian (Middle Jurassic) radiolarites, that occur as blocks magmatically engulfed in plateau-type basalts and intrusives that range in age thoughout the pre-Campanian Cretaceous (130-83 Ma). Middle and Late Jurassic metaradiolarites occur as blocks in the Siuna Serpentinite Médange (NE-Nicaragua), along with High-p, arc-related mafics. We envision an oceanic arc that collided in the latest Jurassic with the Agua Fria arc system

  9. Late Cretaceous-recent tectonic assembly of diverse crustal blocks in Central America, the Nicaraguan Rise, the Colombian Basin and northern South America as seen on a 1600-km-long, geologic and structural transect

    NASA Astrophysics Data System (ADS)

    Sanchez, J.; Mann, P.

    2015-12-01

    We have constructed a 1600-km-long transect from northern Honduras to northern Colombia that crosses northeastward-striking crustal blocks using a combination of offshore seismic data, gravity and magnetic data, well subsidence information, nearby outcrop information, and results from previous thermochronological, geochronological, geochemical and paleostress studies. The transect defines three major crustal and structural provinces: 1) Precambrian-Paleozoic, Chortis continental block whose northern edge is defined by the North America-Caribbean plate boundary. Events in this ~20-25-km-thick province include two major unconformities at the top of the Cretaceous and Eocene, associated southeast-dipping thrust faults related to collision of the Great Arc of the Caribbean (GAC) and Caribbean Large Igneous Province (CLIP) with the Chortis continental block. A third event is Eocene to recent subsidence and transtensional basins formed during the opening of the Cayman trough; 2) Late Cretaceous GAC and CLIP of oceanic arc and plateau origin, whose northern, deformed edge corresponds to the mapped Siuna belt of northern Nicaragua. This crustal province has a ~15-20-km-thick crust and is largely undeformed and extends across the Lower Nicaraguan Rise, Hess fault, to the southern limit of the Colombian basin where about 300 km of this province has been subducted beneath the accretionary wedge of the South Caribbean deformed belt of northwestern South America; and 3) Eocene to recent accretionary prism and intramontane basins on continental crust of northern South America, where Miocene accelerated exhumation and erosion of Paleogene and Cretaceous rocks reflect either shallow subduction of the CLIP or the Panama collisional event to the southwest.

  10. Moderate Resolution Imaging Spectroradiometer (MODIS) Overview

    USGS Publications Warehouse

    ,

    2008-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) is an instrument that collects remotely sensed data used by scientists for monitoring, modeling, and assessing the effects of natural processes and human actions on the Earth's surface. The continual calibration of the MODIS instruments, the refinement of algorithms used to create higher-level products, and the ongoing product validation make MODIS images a valuable time series (2000-present) of geophysical and biophysical land-surface measurements. Carried on two National Aeronautics and Space Administration (NASA) Earth Observing System (EOS) satellites, MODIS acquires morning (EOS-Terra) and afternoon (EOS-Aqua) views almost daily. Terra data acquisitions began in February 2000 and Aqua data acquisitions began in July 2002. Land data are generated only as higher-level products, removing the burden of common types of data processing from the user community. MODIS-based products describing ecological dynamics, radiation budget, and land cover are projected onto a sinusoidal mapping grid and distributed as 10- by 10-degree tiles at 250-, 500-, or 1,000-meter spatial resolution. Some products are also created on a 0.05-degree geographic grid to support climate modeling studies. All MODIS products are distributed in the Hierarchical Data Format-Earth Observing System (HDF-EOS) file format and are available through file transfer protocol (FTP) or on digital video disc (DVD) media. Versions 4 and 5 of MODIS land data products are currently available and represent 'validated' collections defined in stages of accuracy that are based on the number of field sites and time periods for which the products have been validated. Version 5 collections incorporate the longest time series of both Terra and Aqua MODIS data products.

  11. MODIS On-orbit Calibration Uncertainty Assessment

    NASA Technical Reports Server (NTRS)

    Chiang, Vincent; Sun, Junqiang; Wu, Aisheng

    2011-01-01

    MODIS has 20 reflective solar bands (RSB) and 16 thermal emissive bands (TEB). Compared to its heritage sensors, MODIS was developed with very stringent calibration uncertainty requirements. As a result, MODIS was designed and built with a set of on-board calibrators (OBC), which allow key sensor performance parameters and on-orbit calibration coefficients to be monitored and updated. In terms of its calibration traceability, MODIS RSB calibration is reflectance based using an on-board solar diffuser (SD) and the TEB calibration is radiance based using an on-board blackbody (BB). In addition to on-orbit calibration coefficients derived from its OBC, calibration parameters determined from sensor pre-launch calibration and characterization are used in both the RSB and TEB calibration and retrieval algorithms. This paper provides a brief description of MODIS calibration methodologies and an in-depth analysis of its on-orbit calibration uncertainties. Also discussed in this paper are uncertainty contributions from individual components and differences due to Terra and Aqua MODIS instrument characteristics and on-orbit performance.

  12. Distance metric-based forest cover change detection using MODIS time series

    NASA Astrophysics Data System (ADS)

    Huang, Xiaoman; Friedl, Mark A.

    2014-06-01

    More than 12 years of global observations are now available from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS). As this time series grows, the MODIS archive provides new opportunities for identification and characterization of land cover at regional to global spatial scales and interannual to decadal temporal scales. In particular, the high temporal frequency of MODIS provides a rich basis for monitoring land cover dynamics. At the same time, the relatively coarse spatial resolution of MODIS (250-500 m) presents significant challenges for land cover change studies. In this paper, we present a distance metric-based change detection method for identifying changed pixels at annual time steps using 500 m MODIS time series data. The approach we describe uses distance metrics to measure (1) the similarity between a pixel's annual time series to annual time series for pixels of the same land cover class and (2) the similarity between annual time series from different years at the same pixel. Pre-processing, including gap-filling, smoothing and temporal subsetting of MODIS 500 m Nadir BRDF-adjusted Reflectance (NBAR) time series is essential to the success of our method. We evaluated our approach using three case studies. We first explored the ability of our method to detect change in temperate and boreal forest training sites in North America and Eurasia. We applied our method to map regional forest change in the Pacific Northwest region of the United States, and in tropical forests of the Xingu River Basin in Mato Grosso, Brazil. Results from these case studies show that the method successfully identified pixels affected by logging and fire disturbance in temperate and boreal forest sites. Change detection results in the Pacific Northwest compared well with a Landsat-based disturbance map, yielding a producer's accuracy of 85%. Assessment of change detection results for the Xingu River Basin demonstrated that detection accuracy improves as the fraction of

  13. Monitoring vegetation phenology using MODIS

    USGS Publications Warehouse

    Zhang, Xiayong; Friedl, Mark A.; Schaaf, Crystal B.; Strahler, Alan H.; Hodges, John C.F.; Gao, Feng; Reed, Bradley C.; Huete, Alfredo

    2003-01-01

    Accurate measurements of regional to global scale vegetation dynamics (phenology) are required to improve models and understanding of inter-annual variability in terrestrial ecosystem carbon exchange and climate–biosphere interactions. Since the mid-1980s, satellite data have been used to study these processes. In this paper, a new methodology to monitor global vegetation phenology from time series of satellite data is presented. The method uses series of piecewise logistic functions, which are fit to remotely sensed vegetation index (VI) data, to represent intra-annual vegetation dynamics. Using this approach, transition dates for vegetation activity within annual time series of VI data can be determined from satellite data. The method allows vegetation dynamics to be monitored at large scales in a fashion that it is ecologically meaningful and does not require pre-smoothing of data or the use of user-defined thresholds. Preliminary results based on an annual time series of Moderate Resolution Imaging Spectroradiometer (MODIS) data for the northeastern United States demonstrate that the method is able to monitor vegetation phenology with good success.

  14. Retrieval of Aerosol Properties from MODIS Terra, MODIS Aqua, and VIIRS SNPP: Calibration Focus

    NASA Technical Reports Server (NTRS)

    Levy, Robert C.; Mattoo, Shana; Sawyer, Virginia; Kleidman, Richard; Patadia, Falguni; Zhou, Yaping; Gupta, Pawan; Shi, Yingxi; Remer, Lorraine; Holz, Robert

    2016-01-01

    MODIS-DT Collection 6 - Aqua/Terra level 2, 3; entire record processed - "Trending" issues reduced - Still a 15% or 0.02 Terra vs Aqua offset. - Terra/Aqua convergence improved with C6+, but bias remains. - Other calibration efforts yield mixed results. VIIRS-­-DT in development - VIIRS is similar, yet different then MODIS - With 50% wider swath, VIIRS has daily coverage - Ensures algorithm consistency with MODIS. - Currently: 20% NPP vs Aqua offset over ocean. - Only small bias (%) over land (2012-­-2016) - Can VIIRS/MODIS create aerosol CDR? Calibration for MODIS - VIIRS continues to fundamentally important. It's not just Terra, or just Aqua, or just NPP-­-VIIRS, I really want to push synergistic calibration.

  15. Building America

    SciTech Connect

    Brad Oberg

    2010-12-31

    IBACOS researched the constructability and viability issues of using high performance windows as one component of a larger approach to building houses that achieve the Building America 70% energy savings target.

  16. The Latin-American region and the challenges to develop one homogeneous and harmonized hazard model: preliminary results for the Caribbean and Central America regions in the GEM context

    NASA Astrophysics Data System (ADS)

    Garcia, J.; Arcila, M.; Benito, B.; Eraso, J.; García, R.; Gomez Capera, A.; Pagani, M.; Pinho, R.; Rendon, H.; Torres, Y.

    2013-05-01

    Latin America is a seismically active region with complex tectonic settings that make the creation of hazard models challenging. Over the past two decades PSHA studies have been completed for this region in the context of global (Shedlock, 1999), regional (Dimaté et al., 1999) and national initiatives. Currently different research groups are developing new models for various nations. The Global Earthquake Model (GEM), an initiative aiming at the creation of a large global community working collaboratively on building hazard and risk models using open standards and tools, is promoting the collaboration between different national projects and groups so as to facilitate the creation of harmonized regional models. The creation of a harmonized hazard model can follow different approaches, varying from a simple patching of available models to a complete homogenisation of basic information and the subsequent creation of a completely new PSHA model. In this contribution we describe the process and results of a first attempt aiming at the creation of a community based model covering the Caribbean and Central America regions. It consists of five main steps: 1- Identification and collection of available PSHA input models; 2- Analysis of the consistency, transparency and reproducibility of each model; 3- Selection (if more then a model exists for the same region); 4- Representation of the models in a standardized format and incorporation of new knowledge from recent studies; 5- Proposal(s) of harmonization We consider some PHSA studies completed over the latest twenty years in the region comprising the Caribbean (CAR), Central America (CAM) and northern South America (SA), we illustrate a tentative harmonization of the seismic source geometries models and we discuss the steps needed toward a complete harmonisation of the models. Our will is to have a model based on best practices and high standards created though a combination of knowledge and competences coming from the

  17. Use of linkage mapping and centrality analysis across habitat gradients to conserve connectivity of gray wolf populations in western North America.

    PubMed

    Carroll, Carlos; McRae, Brad H; Brookes, Allen

    2012-02-01

    Centrality metrics evaluate paths between all possible pairwise combinations of sites on a landscape to rank the contribution of each site to facilitating ecological flows across the network of sites. Computational advances now allow application of centrality metrics to landscapes represented as continuous gradients of habitat quality. This avoids the binary classification of landscapes into patch and matrix required by patch-based graph analyses of connectivity. It also avoids the focus on delineating paths between individual pairs of core areas characteristic of most corridor- or linkage-mapping methods of connectivity analysis. Conservation of regional habitat connectivity has the potential to facilitate recovery of the gray wolf (Canis lupus), a species currently recolonizing portions of its historic range in the western United States. We applied 3 contrasting linkage-mapping methods (shortest path, current flow, and minimum-cost-maximum-flow) to spatial data representing wolf habitat to analyze connectivity between wolf populations in central Idaho and Yellowstone National Park (Wyoming). We then applied 3 analogous betweenness centrality metrics to analyze connectivity of wolf habitat throughout the northwestern United States and southwestern Canada to determine where it might be possible to facilitate range expansion and interpopulation dispersal. We developed software to facilitate application of centrality metrics. Shortest-path betweenness centrality identified a minimal network of linkages analogous to those identified by least-cost-path corridor mapping. Current flow and minimum-cost-maximum-flow betweenness centrality identified diffuse networks that included alternative linkages, which will allow greater flexibility in planning. Minimum-cost-maximum-flow betweenness centrality, by integrating both land cost and habitat capacity, allows connectivity to be considered within planning processes that seek to maximize species protection at minimum cost

  18. Application of MODIS GPP to Forecast Risk of Hantavirus Pulmonary Syndrome Based on Fluctuations in Reservoir Population Density

    NASA Astrophysics Data System (ADS)

    Loehman, R.; Heinsch, F. A.; Mills, J. N.; Wagoner, K.; Running, S.

    2003-12-01

    Recent predictive models for hantavirus pulmonary syndrome (HPS) have used remotely sensed spectral reflectance data to characterize risk areas with limited success. We present an alternative method using gross primary production (GPP) from the MODIS sensor to estimate the effects of biomass accumulation on population density of Peromyscus maniculatus (deer mouse), the principal reservoir species for Sin Nombre virus (SNV). The majority of diagnosed HPS cases in North America are attributed to SNV, which is transmitted to humans through inhalation of excretions and secretions from infected rodents. A logistic model framework is used to evaluate MODIS GPP, temperature, and precipitation as predictors of P. maniculatus density at established trapping sites across the western United States. Rodent populations are estimated using monthly minimum number alive (MNA) data for 2000 through 2002. Both local meteorological data from nearby weather stations and 1.25 degree x 1 degree gridded data from the NASA DAO were used in the regression model to determine the spatial sensitivity of the response. MODIS eight-day GPP data (1-km resolution) were acquired and binned to monthly average and monthly sum GPP for 3km x 3km grids surrounding each rodent trapping site. The use of MODIS GPP to forecast HPS risk may result in a marked improvement over past reflectance-based risk area characterizations. The MODIS GPP product provides a vegetation dynamics estimate that is unique to disease models, and targets the fundamental ecological processes responsible for increased rodent density and amplified disease risk.

  19. Enhanced snow cover products from MODIS for the hydrologic sciences

    NASA Astrophysics Data System (ADS)

    Painter, T. H.; Bales, R.

    2004-12-01

    Near mountain ranges of the globe, over a billion people use melt of the seasonal snow cover as the dominant source of their water resources. These regions are increasingly experiencing the pressing, coupled implications of climate change, drought, and population/demand increase. Enhanced snow cover products have been developed using a multiple endmember spectral mixture analysis model that inverts MODIS surface reflectance products (MOD09) for fractional snow cover, plus the grain size and albedo of the fractional snow cover. Referred to as the MODIS Snow Covered Area and Grain Size/Albedo (MODSCAG) model, this tool is specifically aimed at providing an accurate estimate of snowcover for regional studies in mountainous areas across the globe. The model uses spectral libraries generated with a radiative transfer model for varying grain size snow, adapting the spectral library according to the specific scene solar geometry. Both the albedo and snow-covered area products stimulate advances in hydrologic forecasting by providing more accurate, spatially distributed data than are currently available for assimilation and model evaluation. Data are being developed and provided through an end-to-end NASA REASoN project that includes: (i) standard and custom product development, (ii) distribution through multiple user interfaces and (iii) user support for product evaluation and applications. Currently, MODSCAG is producing snow cover products for hydrologic research clients working in the Colorado River Basin, the Sierra Nevada of California, the Columbia River Basin, and central Tibet. Within the framework of the REASoN project, MODSCAG is designed to address `client' research needs in snow-covered basins around the globe. In this work, we present the introduction of the MODSCAG fractional snow cover products into a model of basin hydrology in the Sierra Nevada. We analyze the differences between the MODSCAG fractional product and the standard MODIS binary snowcover

  20. Dynamics and Properties of Global Aerosol using MODIS, AERONET and GOCART Model

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram; Chin, Mian; Reme, Lorraine; Tanre, Didier; Mattoo, Shana

    2002-01-01

    Recently produced daily Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol data for the whole year of 2001 are used to show the concentration and dynamics of aerosol over ocean and large parts of the continents. The data were validated against the Aerosol Robotic Network (AERONET) measurements over land and ocean in a special issue in GRL now in press. Monthly averages and a movie based on the daily data are produced and used to demonstrate the spatial and temporal evolution of aerosol. The MODIS wide spectral range is used to distinguish fine smoke and pollution aerosol from coarse dust and salt. The aerosol is observed above ocean and land. The movie produced from the MODIS data provides a new dimension to aerosol observations by showing the dynamics of the system. For example in February smoke and dust emitted from the Sahel and West Africa is shown to travel to the North-East Atlantic. In April heavy dust and pollution from East Asia is shown to travel to North America. In May-June pollution and dust play a dynamical dance in the Arabian Sea and Bay of Bengal. In Aug-September smoke from South Africa and South America is shown to pulsate in tandem and to periodically to be transported to the otherwise pristine Southern part of the Southern Hemisphere. The MODIS data are compared with the Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation Transport (GOCART) model to test and adjust source and sink strengths in the model and to study the effect of clouds on the representation of the satellite data.