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Sample records for central america modis

  1. Brucellosis in Central America.

    PubMed

    Moreno, Edgardo

    2002-12-20

    Brucellosis is a disease of domestic animals and humans in Central America (CA). Bovine and swine brucellosis caused by Brucella abortus and Brucella suis, respectively, have been identified in all CA countries, while ovine and caprine brucellosis caused by Brucella melitensis has been detected in Guatemala. The prevalence of bovine brucellosis is estimated between 4 and 8%, with higher prevalence in dairy herds, with losses calculated at 25 million US dollars per year. National Control Programs based in calf vaccination and removal of the reactors have had little impact in the control of brucellosis in CA. In a region where experimentation with new vaccines is not affordable, unrestricted adult vaccination by the conjunctival route with S19 is recommended. This strategy is expected to reduce the prevalence and density of the bacteria to numbers where "clean" vaccination would be possible. Thereafter, serological identification and elimination of the reactors could be initiated under more favorable conditions of herd infection. PMID:12414131

  2. Central America's shrinking forests.

    PubMed

    1992-01-01

    This news brief reports that 66% of deforestation in Central America has happened in the past 40 years, based on World Conservation Union (WCU) data. Deforestation is expected to continue. The population of Central America and Mexico grew by 28% between 1977 and 1987. Growth is decreasing but remains high at 2.5% in all countries of the region except Panama. 29 million was the regional population in 1990; the projection is for 63 million by 2025. Population is migrating to urban centers. Forests declined by 13% and croplands increased from 4% to 13% of total land area and pasture land from 2% to 37%. There was an increase in unproductive land from 145 to 24%, i.e., 50% of El Salvador's land had soil degradation as does 30% of Guatemala's. In addition to deforestation and soil degradation, there has been soil erosion leading to sedimentation buildup near dam sites and in rivers, which diminishes hydroelectric power capability. Silting also affects groundwater resources, which impact on a safe drinking water supply. Population growth results in increased demand for fuelwood, urban land, and agricultural land. New techniques practiced widely are needed in order to meet the region's needs or demands. Slowing population growth buys time for adjusting to the necessary changes needed for sustaining the region's population. WCU urges conservation organizations to raise awareness about the role population plays in environmental degradation, and to support efforts to reduce birth rates. Women's status needs to be improved through income-generating projects, for instance, and cooperation is needed between conservation groups and organizations involved with improving maternal and child health. PMID:12285833

  3. Rehabilitation innovations in Central America.

    PubMed

    Couch, R H

    1993-01-01

    In an extensive qualitative research project sponsored by the Partners of the Americas (32 professional and lay people from Panama, Costa Rica, Nicaragua, Honduras, El Salvador, Guatemala, Belize, the United States and the Dominican Republic) employment opportunities were examined for disabled youth in Central America. Despite economic and attitudinal barriers field researchers found innovations in financing, special education and rehabilitation programming, job development and job placement alternatives for those who live with disability in Central America. PMID:8486439

  4. Geothermal activities in Central America

    SciTech Connect

    Whetten, J.T.; Hanold, R.J.

    1985-09-11

    The Agency for International Development is funding a new program in energy and minerals for Central America. Geothermal energy is an important component. A country-wide geothermal assessment has started in Honduras, and other assessment activities are in progress or planned for Costa Rica, El Salvador, Guatemala, and Panama. Instrumentation for well logging has been provided to Costa Rica, and a self-contained logging truck will be made available for use throughout Central America. An important objective of this program is to involve the private sector in resource development. 4 refs., 3 figs.

  5. LEECHES OF NORTH AMERICA,CENTRAL AMERICA, AND CARIBBEAN SEA

    EPA Science Inventory

    Current(1999)alphabetical listing of the hierarchy, the taxonomy of freshwater leeches (Annelida: Hirudinea) of North America, Central America, islands in the Caribbean Sea, and selected references. The list contains 10 Families, 52 Genera, and 148 Species of leeches.

  6. Hazardous pesticides in Central America.

    PubMed

    Wesseling, C; Aragón, A; Castillo, L; Corriols, M; Chaverri, F; de la Cruz, E; Keifer, M; Monge, P; Partanen, T J; Ruepert, C; van Wendel de Joode, B

    2001-01-01

    Pesticides are an extensively documented occupational and environmental hazard in Central America. Yet, severe problems persist. Toxic pesticide use in the Region increased during 1985-1999. High exposure levels and ineffectiveness of personal protective equipment evidence the difficulties for risk reduction. Acute poisonings remain a severe problem. Delayed and/or long-lasting health effects include dermatoses, cancer, and genotoxic, neurotoxic, and respiratory effects. The use of hazardous pesticides persists through deficiencies in government-driven assessment and risk management; excessive focus on regional harmonization; short-term economic interests; strong links between industry and governments; aggressive marketing; weak trade unions; and failure of universities to reach decision makers. Regulation based on local data is lacking. An agreement of the Ministries of Health for restricting the most toxic pesticides in Central America has potential for progress. The most effective way to reduce risk is to greatly reduce pesticide use. Actions needed include development of multidisciplinary strategies for local studies on health and environmental impact of pesticides; development of sustainable nonchemical agricultural technologies; evaluation of interventions; extending and sharing of expertise within the Region; strengthening of unions and communities; and redefining the role of industry toward development of safer products, with responsible marketing and reliable information. PMID:11783858

  7. 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)

  8. 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

  9. 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)

  10. 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

  11. Comparison of Vegetation Phenology estimated from MODIS and AVHRR over North America

    NASA Astrophysics Data System (ADS)

    Tan, B.; Morisette, J. T.; Wolfe, R. E.; Gao, F.; Ederer, G. A.; Nightingale, J.; Pedelty, J. A.

    2008-12-01

    Vegetation indices (VIs) derived from satellite data are now commonly used for detecting vegetation phenology at continental to global scales. Vegetation phenology estimated from Moderate Resolution Imaging Spectroradiometer (MODIS) VIs over North America from 2001 to 2006 have been produced and freely available online from http://www.accweb.nascom.nasa.gov. The algorithm to produce this MODIS phenology metrics is based on revised TIMESAT software, which uses the 3rd derivation of a fitted Gauss curve to locate four key phenology dates - begin and end of the greenup and browndown. In order to achieve a long-term phenology record, the same phenology detection algorithm is applied to 1982-2002 GIMMS AVHRR NDVI data sets over North America. To make the phenology estimations from different sensors consistent and comparable, several different methods are utilized in this research. We first compare the phenology metrics estimated from MODIS NDVI and AVHRR NDVI in 2001 and 2002. We found no significant latitudinal gradients in the AVHRR phenology metrics. At the same time, the length of the growing season is artificially overestimated in Northern US and Southern Canada. Both phenomena indicates lower quality from the AVHRR phenology metrics, which is mainly due to the unreliable snow flag of AVHRR data and the absence of ancillary land surface temperature data. To improve the quality of the AVHRR phenology metrics, a more accurate definition of non-growing season is required. We first use the 21-year climatologic mean of minimum NDVI as a threshold to refine the non-growing season pixels. In addition, a sensitivity analysis is performed to address the impact of the threshold on derived phenology metrics. Overall, this research will provide a 25-year phenology product for North America using both MODIS and AVHRR NDVI, which can be applied in regional/continental climate variation analysis and vegetation monitoring. The method to calibrate MODIS and AVHRR phenology products

  12. Raising the Bar in Central America

    ERIC Educational Resources Information Center

    Campbell, Monica

    2007-01-01

    Several years ago, students in Central America rarely leave their countries to find work elsewhere. Such is the case of Sebastian Pinto who felt that his degree would not mean much beyond Guatemala, his country. But now, universities in Central American have started to offer regionally accredited degrees that would allow students' credentials to…

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Screwworm eradication program in Central America.

    PubMed

    Galvin, T J; Wyss, J H

    1996-07-23

    The Screwworm Eradication Program has been extremely successful in its efforts to achieve its goal of eradication of screwworms through Central America and establishment of a permanent biological barrier in the eastern half of Panama. Following eradication of screwworms from Mexico in 1991, eradication was achieved in Belize in 1992, in Guatemala in 1993, and in El Salvador in 1994. Honduras has been free of screwworms since January 1995, and the number of cases in Nicaragua has dropped, as of April 1995, to about 4% of the average number of cases found during the period June-August 1993. PMID:8784505

  19. Human Conservation in Central America, Summary of a Conference (Guatemala, Central America).

    ERIC Educational Resources Information Center

    Conservation Foundation, Washington, DC.

    This booklet is a resume consisting chiefly of extracts from papers that were presented at a conference on Human Conservation in Central America, held in Guatemala in 1965, as well as from discussions that took place during the conferences. With cooperation of numerous organizations and guidance from the Conservation Foundation, a discussion of…

  20. Protection of mammal diversity in Central America.

    PubMed

    Jenkins, Clinton N; Giri, Chandra

    2008-08-01

    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. PMID:18616739

  1. 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

  2. The Interannual Variability of Biomass Burning in North America using MODIS Data: Observations and Meteorological Influences

    NASA Astrophysics Data System (ADS)

    Peterson, D.; Wang, J.; Remer, L.; Ichoku, C.

    2008-12-01

    Meteorological impacts on the interannual variability of wildfires in North America including Alaska are investigated using six years of the MODIS fire and Aerosol Optical Depth (AOD) products, the meteorological data from North American Regional Reanalysis (NARR), and the lightning data collected by the National Lightning Detection Network (NLDN). The relationships of MODIS fire counts, fire radiative power, and AOD with over 13 meteorological variables were investigated in four sub-regions of the North American continent (Alaska, western U.S., Québec, and the rest of Canada). Atmospheric instability and anomalies in the 500 hPa geopotential height field explain more than 60% of the interannual variability in wildfires in Alaska and Quebec; while in the western Unites States, pre-season precipitation is a dominant factor. Lightning strike data show little correlation with fire counts in the western United States, suggesting the importance of anthropogenic cause of fires in this region. Relationships between fire occurrence, atmospheric instability, and smoke production were also investigated. It is revealed that although the Haines Index is widely used for fire forecasting, it is not sufficient to interpret the interannual variability of fires in Boreal North America, but its performance improves when used with 500mb geopotential height anomalies. Continuing work will focus on the meteorological impact and interannual variability of smoke production and subsequent transport between regions. In addition, analysis using lightning strike data may also be preformed for the Canada and Alaska regions via Environment Canada and the Bureau of Land Management (BLM) respectively.

  3. 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…

  4. 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.…

  5. High-Latitude Vegetation Trends in North America from Integration of MODIS, Landsat, and Dynamic Vegetation Models

    NASA Astrophysics Data System (ADS)

    Masek, J.; Morton, D. C.; Mcmanus, K. M.; Wang, D.; Nagol, J. R.; Poulter, B.; Boudreau, S.; Ropars, P.

    2011-12-01

    Dynamic Global Vegetation Models (DGVMs) generally predict poleward migration of temperate and boreal vegetation biomes in response to climate warming. Some models anticipate rapid migration of these biomes during the 21st century, suggesting that local vegetation shifts should already be observable in the satellite record. We have examined trends in high-latitude North American vegetation using long-term data records from Landsat and MODIS and model results from the Lund-Potsdam-Jena (LPJ) DGVM under a range of climate scenarios. Specifically, we have focused on NDVI trends observed from both Landsat and MODIS, as well as spectral changes in the Landsat record that could be related to compositional change. Unlike past studies that relied on integrated measures of growing season NDVI, we focused on "peak summer" trends, which are more closely related to the amount (e.g., leaf area index) and composition of vegetation, rather than variability in vegetation phenology. Analysis of a 25-year Landsat TM/ETM+ record for northern Quebec revealed widespread increases in mid-summer LAI in shrub tundra cover types since the 1980's. These increases are consistent with trends in Aqua MODIS NDVI for the most recent decade, field observations of increasing shrub cover in the region, and previous studies using AVHRR data (e.g. Pouliot et al., 2009, Int. J. Remote Sens). Continental analysis of MODIS data can place these trends in a wider context more suitable for comparisons with DGVM simulations. Across North America, we compared greening and browning trends in mid-summer Aqua MODIS NDVI to climate data records and LPJ model results. The satellite data record indicated a more complex vegetation response to climate warming across North America than model results, with both the magnitude and seasonal timing of warming playing a role. The remote sensing results will be discussed in the context of improving projections of future climate-driven biome shifts.

  6. 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

  7. 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

  8. 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.

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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…

  15. WILD POTATOES (SOLANUM SECTION PETOTA) OF NORTH AND CENTRAL AMERICA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solanum section Petota, the potato and its wild relatives, contains about 200 wild species distributed from the southwestern United States, to central Argentina and adjacent Chile. Although most species occur in South America, a secondary center of diversity peaks at 20 degrees north in the central ...

  16. Energy and development in Central America. Volume I: regional assessment

    SciTech Connect

    Park, W.; Neves, C.; Trehan, R.; Ackerman, E.; Gallagher, W.

    1980-02-01

    This report presents an energy assessment of six Central American countries - Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama - to assist these countries in defining, planning, and meeting energy requirements implicit in their economic and social development goals and also to assist the U.S. Agency for International Development and other development organizations in defining energy programs in Central America.

  17. Collaborative studies target volcanic hazards in Central America

    NASA Astrophysics Data System (ADS)

    Bluth, Gregg J. S.; Rose, William I.

    Central America is the second-most consistently active volcanic zone on Earth, after Indonesia. Centuries of volcanic activity have produced a spectacular landscape of collapsed calderas, debris flows, and thick blankets of pyroclastic materials. Volcanic activity dominates the history, culture, and daily life of Central American countries.January 2002 marked the third consecutive year in which a diverse group of volcanologists and geophysicists conducted focused field studies in Central America. This type of multi-institutional collaboration reflects the growing involvement of a number of U.S. and non-U.S. universities, and of other organizations, in Guatemala and El Salvador (Table 1).

  18. 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.

  19. Observations of TEC Depletions in South and Central America

    NASA Astrophysics Data System (ADS)

    Valladares, C. E.; Sheehan, R. E.; Pradipta, R.

    2014-12-01

    TEC values gathered with several networks of GPS receivers, which operated in South and Central America and the Caribbean region between 2010 and 2013, have been used to investigate the characteristics and morphology of TEC depletions that develop at these locations. In South America the TEC depletions are associated with low-latitude plasma bubbles. In Central America and the Caribbean region, we found that TEC depletions that occur during magnetically active conditions (Kp > 5o), persist for very long periods and sometimes remain even during afternoon hours. During quiet magnetic conditions, TEC depletions occur around the June solstice in Central America and during the December solstice in the Southern part of South America. We have also studied possible links between mid-latitude depletions and the formation of plasma bubbles at low latitudes. In addition, TEC measurements from North America have been utilized to determine the poleward extension of the mid-latitude depletions. These depletions do not appear to be related to auroral plasma processes or to storm enhanced densities (SED). We are studying the possibility that their initiation process is associated with the disturbance dynamo or the prompt penetrating electric field that develop during storm conditions.

  20. 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

  1. Is the Central America forearc sliver part of the North America plate?

    NASA Astrophysics Data System (ADS)

    Guzman-Speziale, M.

    2012-04-01

    The Central America Forearc sliver is located between the Central America volcanic arc and the Middle America trench. Several authors have suggested that the forearc is being displaced to the northwest with respect to the Caribbean plate; they point to right-lateral, normal-faulting earthquakes along the Central America volcanic arc as prime evidence of this displacement. Apparently, the forearc continues to the northwest into southeastern Mexico, although this portion of the forearc is not being displaced. I present evidence that suggests that the forearc indeed continues into southeastern Mexico and that it belongs to the North America plate. Physiographically, there is a continuity of the forearc into the Coastal plains of southeastern (Chiapas) Mexico, across the Motagua and Polochic faults. Offshore, cross-sections of the Middle America trench are similar along the mexican (Chiapas) segment, and the Central American segment. Furthermore, at the northwestern end of the coastal plain there are no compressive structures, which suggests that the coastal plain is not being displaced to the northwest. As a matter of fact, fault-plane solutions for shallow earthquakes show extension rather than compression. Shallow, interplate earthquakes along the trench show similar parameters along both segments. P-axes and earthquake slip vectors have consistent azimuths, which relate better with Cocos-North America convergence than with Cocos-Caribbean. Azimuth of T-axes for normal-faulting earthquakes also agree well with Cocos-North America convergence. Similarity in several parameters is thus found across both segments, the Chiapas coastal plain and the Central America forearc sliver proper. This suggests that both segments are continuous and probably one and the same, and belonging to the North America plate. Perhaps more properly, the forearc sliver extends into southeastern Mexico and is part of the zone of deformation associated to the Cocos-North America-Caribbean plates

  2. 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

  3. 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…

  4. 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.

  5. Women Farmers in Central America: Myths, Roles, Reality.

    ERIC Educational Resources Information Center

    Yudelman, Sally W.

    1994-01-01

    Improving economic opportunities for the increasing number of women farmers in rural Central America involves addressing low educational levels and challenging traditional social values. Government policies need to strengthen women's agricultural and natural-resource management skills by improving land access; encouraging membership in…

  6. Central Florida Community College, Exploring America's Communities. Progress Report.

    ERIC Educational Resources Information Center

    Central Florida Community Coll., Ocala.

    In 1996, Central Florida Community College (CFCC) participated in the American Association of Community Colleges' Exploring America's Communities project, which works to strengthen the teaching and learning of American history, literature, and culture at U.S. community colleges. CFCC's principal goals were to promote conversation among faculty…

  7. 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.

  8. 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

  9. Low-Temperature cooling history of a Modi Khola transect, central Nepalese Himalaya

    NASA Astrophysics Data System (ADS)

    Nadin, E. S.; Martin, A. J.

    2010-12-01

    While most of the convergence between the Indian and Eurasian plates is thought to be taken up on the Main Himalayan-Main Frontal thrust system in southern Nepal, it has been suggested that additional faults to the north are also active. Among these is the Main Central thrust (MCT), a major deformational feature that crosses the length of the Himalayan chain and whose surface trace overlies a seismically active region. Most researchers agree that motion on the MCT initiated in Early Miocene time, but debate continues regarding its post-Miocene history. In order to investigate the bedrock uplift histories in this part of the Nepalese Himalaya, we undertook fission-track and (U-Th)/He dating of apatites from Greater and Lesser Himalayan pelites and quartzites at nearly constant elevation. The transect across the Modi Khola, in the western Annapurna Range of central Nepal, also crossed slope breaks that have been attributed to recent fault motion. From the 15 samples analyzed, most fission track ages are ca. 0.8 Ma, and large uncertainties mean outliers cannot be distinguished with confidence to have a different age. Apatite He (AHe) ages are mainly ca. 0.5 Ma, also with large uncertainties. HeFTy inverse modeling of sample cooling paths, using fission-track lengths and both AHe and fission-track ages, likewise reveal no apparent differences in cooling histories between any of the samples, with the exception of the samples immediately below and above the MCT. The different cooling histories of these two samples might indicate different uplift histories for the footwall and hanging wall of the MCT within the past million years. However, other samples within 200 meters of the trace of the MCT do not show this pattern. Further, at the temporal resolution of the apatite fission-track and He data, there is little support for motion on other faults of the Modi Khola valley in the past ca. 1 Ma. Geologic map of part of the Modi Khola valley showing the study area.

  10. Metamorphism of Greater and Lesser Himalayan rocks exposed in the Modi Khola valley, central Nepal

    NASA Astrophysics Data System (ADS)

    Martin, Aaron J.; Ganguly, Jibamitra; Decelles, Peter G.

    2010-02-01

    Thermobarometric estimates for Lesser and Greater Himalayan rocks combined with detailed structural mapping in the Modi Khola valley of central Nepal reveal that large displacement thrust-sense and normal-sense faults and ductile shear zones mostly control the spatial pattern of exposed metamorphic rocks. Individual shear zone- or fault-bounded domains contain rocks that record approximately the same peak metamorphic conditions and structurally higher thrust sheets carry higher grade rocks. This spatial pattern results from the kinematics of thrust-sense faults and shear zones, which usually place deeper, higher grade rocks on shallower, lower grade rocks. Lesser Himalayan rocks in the hanging wall of the Ramgarh thrust equilibrated at about 9 kbar and 580°C. There is a large increase in recorded pressures and temperatures across the Main Central thrust. Data presented here suggest the presence of a previously unrecognized normal fault entirely within Greater Himalayan strata, juxtaposing hanging wall rocks that equilibrated at about 11 kbar and 720°C against footwall rocks that equilibrated at about 15 kbar and 720°C. Normal faults occur at the structural top and within the Greater Himalayan series, as well as in Lesser Himalayan strata 175 and 1,900 m structurally below the base of the Greater Himalayan series. The major mineral assemblages in the samples collected from the Modi Khola valley record only one episode of metamorphism to the garnet zone or higher grades, although previously reported ca. 500 Ma concordant monazite inclusions in some Greater Himalayan garnets indicate pre-Cenozoic metamorphism.

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Skylab photography applied to geologic mapping in northwestern Central America

    NASA Technical Reports Server (NTRS)

    Rose, W. I., Jr.; Johnson, D. J.; Hahn, G. A.; Johns, G. W.

    1975-01-01

    Two photolineation maps of southwestern Guatemala and Chiapas were made from S190 photographs along a ground track from Acajutla, El Salvador to San Cristobal de las Casas, Mexico. The maps document a structural complexity spanning the presumed triple junction of the Cocos, Americas, and Caribbean plates. The Polochic fault zone, supposedly the Americas-Caribbean plate boundary, is a sharply delineated feature across western Guatemala. Westward of the Mexican border it splays into a large number of faults with NW to SW trends. The structural pattern is quite different to the north (Americas plate) and to the south (Caribbean plate) of the Polochic fault, though both areas are dominated by NW-trending lineations. Within the Central American volcanic chain, the lineation patterns support the segmented model of the Benioff Zone, by showing a concentration of transverse lineations in the predicted locations, most notably NE-trending elements near Quezaltenango, Guatemala. The structural pattern obtained from the maps are compared to patterns described on recently published maps of more southerly parts of Central America, to begin a synthesis of the structure of the convergent plate boundary.

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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

  5. 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.

  6. 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. PMID:16153991

  7. 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.

  8. 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.

  9. 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.

  10. 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).

  11. 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.

  12. 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. PMID:21905395

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. The regime of aerosol optical depth over Central Asia based on MODIS Aqua Deep Blue data

    NASA Astrophysics Data System (ADS)

    Floutsi, Athina; KorrasCarraca, Marios; Matsoukas, Christos; Biskos, George

    2015-04-01

    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 therefore important to determine the aerosol load, and an effective way to do that is by measuring the aerosol optical depth (AOD). In this study we investigate the spatial and temporal variability of the AOD over the climatically sensitive region of Central Asia (36° N - 50° N, 46° E - 75° E), which has significant sources of both natural and anthropogenic particles. The primary source of anthropogenic particles is fossil fuel combustion occurring mainly at oil refineries in the Caspian Sea basin. Natural particles originate mostly from the two deserts in the region (namely Kara-Kum and Kyzyl-Kum), where persistent dust activity is observed. Another source is the Aral Sea region, which due to its phenomenal desertification also drives an intense salt and dust transport from the exposed sea-bed to the surrounding regions. This transport is of particular interest because of health-hazardous materials contained in the Aral Sea sea-bed. For our analysis we use Level-3 daily MODIS - Aqua Dark Target - Deep Blue combined product, from the latest MODIS collection (006), available in 1° x 1° resolution (about 100 km x 100 km) over the period 2002-2014.Our first results indicate a significant spatial variability of the aerosol load over the study region. The data also show a clear seasonal cycle, with large aerosol load being associated with strong dust activity during spring and summer (AOD up to 0.5), and low during autumn and winter (AOD up to 0.4). In spring and summer significant aerosol load is observed in the Garabogazköl basin, Northeast and South-southeast Caspian Sea (offshore North Iran and Azerbaijan), as well as southwest of the Aral Sea. In the later region, the high AOD values can be explained by export of

  19. Using MISR and MODIS Data For Detection and Analysis of Smoke Plume Injection Heights Over North America During Summer 2004

    NASA Astrophysics Data System (ADS)

    Mazzoni, D.; Tong, L.; Diner, D.; Li, Q.; Logan, J.

    2005-12-01

    We aim to investigate the relationship between climate, fires, and air quality in order to predict the effect of possible future climate changes on North American air quality. To initialize and calibrate chemistry transport models such as GEOS-Chem, we are using satellite imagery to gather statistics about smoke plumes from fires over North America for a five-year period. Statistics include the location, extent, and injection height of each plume, along with local weather, topography, and surface conditions from which correlative relationships can be derived. Stereoscopic height retrievals from NASA's Multi-angle Imaging SpectroRadiometer (MISR) are our primary data for establishing the plume injection heights. Oblique imagery from MISR also helps identify plumes that are more difficult to detect in nadir views. MODerate-resolution Imaging Spectroradiometer (MODIS) data help pinpoint fire locations. We use automated data mining techniques to identify smoke plumes and limit the amount of analysis that must be done by hand. We report here on analysis of data from June - September 2004, which we are using to refine our techniques. A Support Vector Machines (SVM) pixel classifier which uses spectral, angular, and textural features from MISR identifies pixels that contain smoke. Our results show that this classifier is 75% accurate at finding smoke at the 1.1-km pixel level, and catches some smoke pixels in any given plume with nearly 100% certainty. Next, we match areas containing smoke with fire locations identified by MODIS. For candidate scenes that appear to contain both smoke and fire, we apply machine vision techniques to look for evidence of plume-like shapes. When potential plumes are found, we automatically estimate source location, orientation, and injection height, using histograms of MISR stereo data for the latter. Lastly, a human expert examines all examples found and discards any false retrievals. Exhaustive analysis of our technique applied to data from

  20. 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.

  1. 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

  2. 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

  3. 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

  4. 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…

  5. 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

  6. Petroleum geology of Pacific margin of Central America and northern South America, from Guatemala to Ecuador

    SciTech Connect

    Scrutton, M.E.; Escalante, G.F.

    1986-07-01

    Exploration for hydrocarbons along the Pacific margin of Central America and northern South America has been limited and spasmodic. Less than 100 exploration wells have been drilled, with nearly 50 of these being in the Santa Elena, Progreso, and Guayas basins in Ecuador. Shows have been reported in some wells, and a few oil seeps are known. The only commercial production established to date has been from the Santa Elena Peninsula in Ecuador in the extreme south of the study area. Understanding of the geology in this part of the continental margin is incomplete at best. This paper reviews present-day knowledge in an attempt to define the sedimentary basins better, to characterize their structure and stratigraphy, and to assess their petroleum prospects. The area of continental margin reviewed is to the north, located northwest of the trench system where oceanic crust of the Cocos plate subducts under the Caribbean plate, and to the south, where the northern part of the Nazca plate collides with the South American plate. This plate tectonic setting forms the framework on which local structural and sedimentary events have created a series of relatively small trench-slope and forearc basins in what is now the coastal plain and adjacent offshore area of Central and South America, south or west of a line of mountain ranges with active volcanism. Sedimentary fill is generally of Tertiary age. The basins and subbasins recognized and described include: in Ecuador - Guayas, Santa Elena, Progreso, Valdivia, Bajo Grande, Manta, Muisne-Esmeraldas, and Borbon; in Colombia - Choco-Pacific; in Panama - Gulf of Panama basin complex (Santiago, Tonosi, Sambu), and Burica-Chiriqui; in Costa Rica - Terraba and Coronado/Tempisque; in Nicaragua - San Juan del Sur; and in the Honduras, El Salvador, and Guatemala - the Pacific coastal basin.

  7. 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.

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

    USGS Publications Warehouse

    Hearn,, Paul P., Jr.; 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.

  9. 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

  10. [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. PMID:15264547

  11. 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

  12. 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

  13. 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.

  14. 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 Section 319.56-25 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-25 Papayas from Central America...

  15. 77 FR 13618 - Agency Information Collection Activities: Dominican Republic-Central America-United States Free...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    ...-Central America-United States Free Trade Agreement (CAFTA-DR). This is a proposed extension of an... was approved by Congress in section 101(a) of the Dominican Republic- Central America-United States... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF...

  16. 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…

  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. Central America and Cuba in the new world order

    SciTech Connect

    Smith, W.; Gilbert, L.

    1994-03-01

    In Central America and the Caribbean, as in many other parts of the world, military institutions are being forced to define new roles for themselves in the post-Cold War era. In recent times, developments throughout the region, including the dismantling of Panama`s military, the downsizing of the armed forces in El Salvador and Nicaragua, a call by the new Honduran president for military reform and renewed peace talks in Guatemala, suggest that the time may be ripe to reinvigorate earlier regional political organizations and to press for a new round of talks to achieve regional arms control. During the 1980s, the ideological struggle between East and West, reignited by the Nicaraguan revolution in 1979, dragged the entire region into conflicts that devastated the isthmus in terms of human lives and economic infrastructure. Indigenous struggles that had developed during the 1970s were suddenly thrust upon the international stage, becoming part of a larger drama between the superpowers. Conflicts in El Salvador, Nicaragua and Guatemala provided impetus for larger armed forces throughout the region. This growth was justified as necessary to defend the state from external intervention and the established order from internal subversion, goals which were seen as complementary.

  20. 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.

  1. 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.

  2. 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.

  3. Trends in Land Surface Phenologies Across Central Asia and the Central Eurasian Grain Belt as Viewed From MODIS Collection 5 NBAR

    NASA Astrophysics Data System (ADS)

    Wright, C. R.; Henebry, G. M.; Kovalskyy, V.; de Beurs, K. M.

    2008-12-01

    The disintegration of the Soviet Union in 1991 precipitated a multitude of institutional changes, including the disestablishment of a centrally-planned agricultural sector. Our previous work with AVHRR data has shown that among the environmental consequences were significant shifts in land surface phenologies (LSPs) across Kazakhstan, Uzbekistan, and Turkmenistan. Here we explored trends in LSPs across Central Asia and the central Eurasian Grain Belt that stretches westward across northern Kazakhstan and southern Russia into eastern Ukraine. We used the recently released of MODIS Collection 5 Nadir BRDF Adjusted Reflectance (NBAR) product and the Global Precipitation Climatology Centre (GPCC) Full Data Reanalysis v4, a monthly 0.5 degree product. We characterized trends from 2000-2007 using the nonparametric seasonal Mann- Kendall trend test on a per-pixel basis, thereby generating surfaces of per-pixel trend estimates with corresponding estimates of model uncertainty at each pixel. In the Pontic Steppe ecoregion of northwestern Kazakhstan, a region characterized by temperate grasslands, savannas, and shrublands, we found spatially coherent, highly significant (p<0.01) negative trends in MODIS NDVI. This appears to be driven by regional drought, and visual inspection of Landsat TM imagery from the study area indicates drying of relatively abundant depressional wetlands accompanied by a number of large fires over the period of interest. In the neighboring Kazakh Steppe ecoregion, a landscape dominated by small-grain production, we find similar, but noisier negative trends (typically p<0.05), likely reflecting a combination of drought and highly heterogeneous land use practices. By contrast, in the Central Asian Southern Desert ecoregion of Uzbekistan, we find highly significant (p<0.01) positive trends in NDVI from 2000-2007. These xeric shrublands are nearly entirely dependent on winter and spring precipitation for water inputs. GPCC trends indicate in some regions

  4. Diabetes in South and Central America: an update.

    PubMed

    Aschner, Pablo; Aguilar-Salinas, Carlos; Aguirre, Loreto; Franco, Laercio; Gagliardino, Juan Jose; de Lapertosa, Sylvia Gorban; Seclen, Segundo; Vinocour, Mary

    2014-02-01

    The estimated population of the South and Central America (SACA) Region is 467.6 million and 64% is in the age range of 20-79 years but the population pyramid and age distribution are changing. The average prevalence of diabetes in the Region is 8.0% and is expected to reach 9.8% by the year 2035. Prevalence is much lower in rural settings than in urban and the differences attributed to lifestyle changes may be a target for intervention. The indigenous population is a particularly vulnerable group needing special attention. On average, 24% of the adult cases with diabetes are undiagnosed but in some countries this is still as high as 50%. Health expenditure due to diabetes in the Region is around 9% of the global total. Inadequate glycemic control, defined as HbA1c >7%, is a strong predictor of chronic complications which increase resource use in the Region and less than half of the patients enrolled in diabetes care programmes are at target. Fifty percent or more of the adult population is overweight/obese and around one third of the adult population has metabolic syndrome using regional cutoffs for waist circumference. The number of people with IGT is almost equal to those with diabetes presenting an additional challenge for prevention. Children with type 1 diabetes represent only 0.2% of the total population with diabetes but the incidence may be increasing. In many places they have limited access to insulin, and even when available, it is not used appropriately. The available epidemiological data provide the background to act in developing national diabetes programmes which integrate diabetes care with cardiovascular prevention and promote diabetes prevention as well. PMID:24439209

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. The Modi Taung-Nankwe gold district, Slate belt, central Myanmar: mesothermal veins in a Mesozoic orogen

    NASA Astrophysics Data System (ADS)

    Mitchell, A. H. G.; Ausa, C. A.; Deiparine, L.; Hlaing, T.; Htay, N.; Khine, A.

    2004-07-01

    The recently discovered quartz-gold veins comprising the Modi Taung-Nankwe gold district in central Myanmar are largely hosted by mudstones of the late Palaeozoic Slate belt. Mesozoic rocks of the Paunglaung-Mawchi zone separate the Slate belt from the Shan Scarp and Shan Plateau to the east. At Modi Taung 5 km of exploration adits indicate that the veins, within steeply dipping oblique reverse-slip shear zones, are displaced by movements along the shears, intruded by late Jurassic calc-alkaline dykes, and offset on conjugate cross-faults. Drill intercepts show that mineralization extends vertically for more than 500 m. Coarse visible gold, book-and-ribbon texture and stylolitic laminations, and trace metal values are consistent with mineralization at mesothermal depths of several kilometres in the brittle-ductile regime. Our field observations suggest that mineralization took place in the early Jurassic following collision of Myanmar on the passive western margin of a Greater Shan-Thai continental block with an oceanic arc on the overriding plate to the west. Collision generated intra-continental thrusting in and east of the Paunglaung-Mawchi zone, metamorphism of Plateau rocks thrust west beneath the Slate belt to form the Mogok Metamorphics, and ascent of mineralizing fluids expelled from dehydrating underthrust rocks. Reversal in orogenic polarity initiated late Jurassic eastward subduction of oceanic crust beneath Myanmar, and generation of a magmatic arc with dykes cutting the quartz-gold veins. Renewed east-directed thrusting translated the Slate belt over arc clastics, and probably resulted in exhumation of the Mogok Metamorphics and offsets of the veins on conjugate faults. Young K/Ar, Rb 87/Sr 86 and Ar 40/Ar 39 ages on the Mogok Metamorphic belt imply renewed Tertiary uplift and possibly intrusion of mid-Tertiary or Palaeogene granites.

  10. 78 FR 15349 - Trade Mission to Central America in Conjunction With the Trade Americas-Opportunities in Central...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-11

    ... region. Its deep-water port, Puerto Cort s, is the first port in Latin America to qualify under both the.../tradeamericas/tradeevents/trademissions/centralamericajuly2013/index.asp ), and other Internet Web sites,...

  11. 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…

  12. Energy and development in Central America. Volume I: Regional assessment. Final report October 1979-February 1980

    SciTech Connect

    Park, W.; Neves, C.; Trehan, R.; Ackerman, E.; Gallagher, W.

    1980-02-01

    This report presents an energy assessment of six Central American countries - Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama - to assist these countries in defining, planning, and meeting energy requirements implicit in their economic and social development goals and also to assist the U.S. Agency for International Development and other development organizations in defining energy programs in Central America.

  13. Energy and development in Central America. Volume II: Country assessments. Final report October 1979-February 1980

    SciTech Connect

    Park, W.; Neves, C.; Trehan, R.; Ackerman, E.; Gallagher, W.

    1980-03-01

    This report presents an energy assessment of six Central American countries - Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama - to assist these countries in defining, planning, and meeting energy requirements implicit in their economic and social development goals and also to assist the U.S. Agency for International Development and other development organizations in defining energy programs in Central America.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. On the classification and sub-classification of aerosol key types over south central peninsular India: MODIS-OMI algorithm.

    PubMed

    Sreekanth, V

    2014-01-15

    Long-term (8 years), simultaneous data on aerosol optical properties from MODIS and OMI satellite sensors are analyzed to study their temporal characteristics and to infer on the major aerosol types present over the study location, Bangalore situated in south central peninsular India. Investigations are carried out on Aerosol Optical Depths (AODs), Angstrom exponent (α) and Aerosol Index (AI) for the purpose. Aerosol parameters exhibited significant seasonal variations: AODs peaking during monsoon, α during post-monsoon and AI during summer. Seasonal air mass back trajectories are computed to infer on the transport component over the study region. By assigning proper thresholds (depending on the nature of the location and transport pathways) on AOD and α values, aerosols are discriminated into their major types viz., marine influenced, desert dust, urban/industrialized and mixed types. Further sub-categorization of the aerosols has been done on an annual scale taking into account of their absorptance information in terms of the OMI-AI values. Mixed type aerosols contributed the most during all the seasons. Next to mixed type aerosols, marine influenced aerosols dominated during winter, desert dust during monsoon and summer, urban/industrialized aerosols during post-monsoon. Considering the urban nature of the study location, urban/industrialized/carbonaceous type aerosols have been significantly underestimated in these methodologies. Finally, discussion has been made on the consistency of the results obtained from the methodologies (i) based on AODs and α; (ii) based on AODs, α and AI. PMID:24095970

  19. 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.

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

    PubMed

    Gutiérrez, José María

    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

  1. 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. PMID:21905396

  2. 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

  3. 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.

  4. 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.

  5. 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)

  6. 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. PMID:23878336

  7. 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

  8. 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.

  9. 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.

  10. 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,…

  11. Gulf of Fonseca, Pacifica coast of Central America as seen from Apollo 9

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Gulf of Fonseca, on the Pacific coast of Central America, as photographed from the Apollo 9 spacecraft during its earth-orbital mission. The Gulf is shared by the nations of El Salvador, Honduras, and Nicaragua. The prominent volcano on the peninsula in Nicaragua is Volcan Cosiguina.

  12. 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…

  13. 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);…

  14. Haplotyping studies of the potato psyllid, Bactericera cockerelli, in Mexico and Central America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a serious pest of potato and other solanaceous crops in North and Central America. This insect transmits “Candidatus Liberibacter solanacearum”, the putative causal agent of zebra chip disease of potato. Recent studies ha...

  15. 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…

  16. 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…

  17. Oil and gas developments in South America, Central America, Caribbean Area, and Mexico in 1984

    SciTech Connect

    Tappmeyer, D.M.

    1985-10-01

    For the 25 countries described in the region, exploration activity continued to be centered in proven petroleum provinces in 1984. Exploration activity increased in Brazil, Colombia, and Venezuela. Important, successful exploration efforts continued in areas around Cano Limon field in Colombia, and Guafita and La Victoria fields in Venezuela. Notable discoveries in South America included the 42-461X San Martin Cretaceous discovery by Shell in the Ucayali basin in Peru, the significant oil and gas discovery at Palmar Largo ES-1 by YPF in Argentina, and the first offshore gas discovery, the Pecten 1-SPS-20 wildcat in the Santo basin in Brazil. Oil production increased in Barbados, Brazil, Colombia, Ecuador, Mexico, Peru, Trinidad and Tobago, and Venezuela. A notable increase (40%) in oil production occurred in Brazil. Gas production increased in Argentina, Barbados, Colombia, Peru, and Trinidad and Tobago.

  18. [Experiences with early weaning of calves in Central America].

    PubMed

    Jarquín, R

    1989-09-01

    This study presents a review of traditional feed calves systems used in Central American specialized dairy farms. The systems discussed are considered costly, due to the high quantity of milk and concentrate required, besides causing shortage of milk for human consumption. The early weaning calf system developed by INCAP is also discussed, as well as its implementation with slight modifications oriented towards the application of research findings to achieve a reduction of the milk volume commonly used in the traditional rearing system. The development of appropriate concentrate formulations for animals of that age, using local feed ingredients, is also presented. PMID:2490888

  19. Energy and development in Central America. Volume II. country assesments

    SciTech Connect

    Park, W.; Neves, C.; Trehan, R.; Ackerman, E.; Gallagher, W.

    1980-03-01

    This volume presents a country-by-country energy assessment of six Central American countries: Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama. For each country it includes an assessment of geographic, social, and economic aspects of energy development, an assessment of energy resources, current and projected energy use, potential strategies for energy development, and finally recommendations to USAID for the orientation of its energy development programs. Each country assessment is supplemented with a summary of energy R and D activities and a description of each country's energy-related institutions.

  20. 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.

  1. 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.

  2. 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.

  3. A climatology of low level wind regimes over Central America using a weather type classification approach.

    NASA Astrophysics Data System (ADS)

    Sáenz, Fernán; Durán-Quesada, Ana María

    2015-04-01

    Based on the potential of the weather types classification method to study synoptic features, this study proposes the application of such methodology for the identification of the main large scale patterns related with weather in Central America. Using ERA Interim low-level winds in a domain that encompasses the intra-Americas sea, the eastern tropical Pacific, southern North America, Central America and northern South America; the K-means clustering algorithm was applied to find recurrent regimes of low-level winds. Eleven regimes were identified and good coherency between the results and known features of regional circulation was found. It was determined that the main large scale patterns can be either locally forced or a response to tropical-extratropical interactions. Moreover, the local forcing dominates the summer regimes whereas mid latitude interactions lead winter regimes. The study of the relationship between the large scale patterns and regional precipitation shows that winter regimes are related with the Caribbean-Pacific precipitation seesaw. Summer regimes, on the other hand, enhance the Caribbean-Pacific precipitation contrasting distribution as a function of the dominant regimes. A strong influence of ENSO on the frequency and duration of the regimes was found. It was determined that the specific effect of ENSO on the regimes depends on whether the circulation is locally forced or lead by the interaction between the tropics and the mid-latitudes. The study of the cold surges using the information of the identified regimes revealed that three regimes are linkable with the occurrence of cold surges that affect Central America and its precipitation. As the winter regimes are largely dependent of mid-latitude interaction with the tropics, the effect that ENSO has on the Jet Stream is reflected in the winter regimes. An automated analysis of large scale conditions based on reanalysis and/or model data seems useful for both dynamical studies and as a tool

  4. 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

  5. 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

  6. 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.

  7. The implications of trade liberalization for diet and health: a case study from Central America

    PubMed Central

    Thow, Anne Marie; Hawkes, Corinna

    2009-01-01

    Background Central America has undergone extensive trade liberalization over the past two decades, and has recently signed a Free Trade Agreement with the United States. The region is also experiencing a dual burden of malnutrition with the growth of dietary patterns associated with the global 'nutrition transition'. This study describes the relationship between trade liberalization policies and food imports and availability, and draws implications for diet and health, using Central America as a case study region. Methods Changes in tariff and non-tariff barriers for each country were documented, and compared with time-series graphs of import, production and availability data to show the outcome of changes in trade policy in relation to food imports and food availability. Results Changes in trade policy in Central America have directly affected food imports and availability via three avenues. First, the lowering of trade barriers has promoted availability by facilitating higher imports of a wide range of foods. Second, trade liberalization has affected food availability through promoting domestic meat production. Third, reductions in barriers to investment appear to be critical in expansion of processed food markets. This suggests that changes in trade policies have facilitated rising availability and consumption of meat, dairy products, processed foods and temperate (imported fruits) in Central America. Conclusion This study indicates that the policies of trade liberalization in Central American countries over the past two decades, particularly in relation to the United States, have implications for health in the region. Specifically, they have been a factor in facilitating the "nutrition transition", which is associated with rising rates of obesity and chronic diseases such as cardiovascular disease and cancer. Given the significant cost of chronic disease for the health care system, individuals and the wider community, it is critical that preventive health

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. The tobacco industry and secondhand smoke: lessons from Central and South America.

    PubMed

    Barnoya, Joaquin; Glantz, Stanton A

    2003-01-01

    For more than 20 years the tobacco industry has considered secondhand smoke to be a threat to its viability. In this article, we describe why secondhand smoke is important to tobacco control and how the tobacco industry's "Latin Project" sought to prevent the creation of smoke-free workplaces and public places in Central and South America. Eliminating secondhand smoke exposure not only reduces the risk of cardiovascular and other diseases, but also creates an environment that substantially reduces smoking and cigarette consumption among smokers. The "Latin Project" was initiated in 1991 by Philip Morris and British American Tobacco and managed by the law firm Covington & Burling. The project assembled a network of well-placed physicians and scientists to divert the attention away from secondhand smoke toward other indoor air pollutants. As proven in Central and South America, the tobacco industry has manipulated the secondhand smoke issue in order to avoid the development of smoke-free environments. Sub-Saharan Africa, facing an epidemiologic transition similar to the one experienced by Central and South America, should be aware of tobacco industry tactics. Further delay in implementing smoke-free environments will only increase the burden of cardiovascular disease in both areas of the world. PMID:13677420

  17. 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.

  18. 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

  19. Dissertations Concerning Social Change and Development in Central America and Panama (1960-1974): An Annotated Bibliography

    ERIC Educational Resources Information Center

    Brown, E. Leonard; Snarr, D. Neil

    1975-01-01

    Composed of Ph.D. dissertations accepted in U.S. universities since 1960, this annotated bibliography contains approximately 140 citations on social change and/or development in Central America and Panama. (JC)

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. [Lack of food and nutritional security in Central America: contributing factors and social exclusion].

    PubMed

    Delgado, H

    2001-12-01

    In August 2001, the XVII Meeting of the Health Sector in Central America and the Dominican Republic (RESSCAD) was held in Managua, Nicaragua. At the meeting, a resolution was adopted in support of strengthening and furthering the Central American initiative for the Promotion of Food and Nutritional Security. This paper examines the conceptual framework behind the initiative, which was approved by the XIV Central American Presidents Summit Meeting (Guatemala City, Guatemala) and launched in 1994 at the regional, national, and municipal levels (Guacimo, Costa Rica, 1994). It focuses on the accomplishments attributable to this initiative, the challenges it has faced over 2001 and those it will be facing over the next biennium, and the measures taken or recommended so far in order to ensure its long-term success. PMID:11820110

  5. A crustal section of northern Central America as inferred from wide angle reflections from shallow earthquakes

    NASA Astrophysics Data System (ADS)

    Kim, J. J.

    A three-layered crustal structure for a portion of northern Central America is derived using both travel time and amplitude data from seismograms recorded at Tegucigalpa, Honduras. The sources are shallow earthquakes that occurred along the Motagua fault in Guatemala 200 to 450 km (25-50 seconds in terms of S-P time) from the station. Since ray paths are almost parallel to the axis of the Middle America trench, approximately 250 km away, a homogeneous, horizontally layered crust may be reasonably assumed. At this distance range, which is far beyond critical distance for reflections from within the crust, shallow sources always generate a small first arrival followed by several large later arrivals. The first arrival is interpreted as Pn (the head wave from the Mohorovicic discontinuity) and the later arrivals are interpreted as wide angle (over-critical) reflections from layer boundaries. Three wide angle reflections (PmP, PiP, and PgP) are identified.

  6. 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

  7. Late Miocene to recent plate tectonic history of the southern Central America convergent margin

    NASA Astrophysics Data System (ADS)

    Morell, Kristin D.

    2015-10-01

    New plate reconstructions constrain the tectonic evolution of the subducting Cocos and Nazca plates across the southern Central American subduction zone from late Miocene to recent. Because of the strong relationships between lower and upper (Caribbean) plate dynamics along this margin, these constraints have wide-ranging implications for the timing and growth of upper plate deformation and volcanism in southern Central America. The reconstructions outline three important events in the Neogene history of this margin: (1) the coeval development of the Panama Triple Junction with the initiation of oblique subduction of the Nazca plate at ˜8.5 Ma; (2) the initiation of seamount and rough crust subduction beginning at ˜3-4 Ma; and (3) Cocos Ridge subduction from ˜2 to 3 Ma. A comparison of these events with independent geologic, geomorphic, volcanic, and stratigraphic data sets reveals that the timing, rates, and origin of subducting crust directly impacted the Neogene growth of upper plate deformation and volcanism in southern Central America. These analyses constrain the timing, geometry, and causes of a number of significant tectonic and volcanic processes, including rapid Plio-Quaternary arc-fore arc contraction due to Cocos Ridge subduction, the detachment of the Panama microplate at ˜1-3 Ma, and the late Miocene cessation of mantle-wedge-derived volcanism across ˜300 km of the subduction zone.

  8. 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

  9. 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

  10. 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

  11. 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.

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

    NASA Astrophysics Data System (ADS)

    Tanner, James G.; Shedlock, Kaye M.

    2004-10-01

    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.

  13. Diarrhea and respiratory symptoms among travelers to Asia, Africa, and South and Central America from Scotland.

    PubMed

    Redman, Christopher Allan; Maclennan, Alice; Wilson, Eleanor; Walker, Eric

    2006-01-01

    Surveillance using admissions to hospital, while being useful, is a poor indicator of the real incidence of disease encountered by travelers. An alternative is self-reported illness among those who attended at a pretravel clinic prior to their travels. Estimates of incidence and risk factors were determined for attendees at a travel clinic in Scotland using a questionnaire. Analysis for risk factors was carried out for those travelers visiting countries in Africa, Asia, or South and Central America, who had traveled for 1 week or more and had returned between 1997 and 2001 (N= 4,856). Multivariate logistic regression was used to test the hypotheses that time abroad and age-group would be significant for both respiratory and diarrheal symptoms regardless of which of the three geographical areas are visited. From 2006 returned questionnaires (response rate = 41.3%), diarrhea and respiratory symptoms were reported by 44.2 and 16.8% of respondents, respectively; the incidence was significantly greater among travelers to Asia for both diarrheal (55.5%) and respiratory (23.7%) symptoms than among travelers to Africa (36.6 and 12.2%, respectively) or South and Central America (39.5 and 16.2%, respectively). For diarrhea, age was a highly significant risk factor for travelers to Asia, South and Central America, and Africa. Being a self-organized tourist/backpacker, traveling to Asia was associated with increased risk, while for Africa and South and Central America visiting family or friends was associated with a lower risk. For travelers to Asia, traveling to the Indian subcontinent was significantly associated with increased risk. The majority of travelers had an adverse event while traveling abroad, with diarrhea and respiratory conditions being especially common despite attending a travel clinic for advice prior to departure. However, the limitations of this surveillance-based strategy have highlighted the requirement for more research to understand more fully the

  14. 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

  15. 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.

  16. 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

  17. Tectonics and sedimentary evolution of the Sandino forearc basin off Nicaragua, Central America

    NASA Astrophysics Data System (ADS)

    Costa Pisani, P.; Silver, E.; McIntosh, K.; Ahmed, I.; Ranero, C. R.; Taylor, B.

    2003-04-01

    The Sandino basin is the Nicaragua sector of the Central American forearc, where the Cocos plate subducts beneath the Middle America trench. Recently, Ranero et al. have interpreted a seismic section across the margin and proposed a history of formation of the forearc which is constrained by industry drilling in the basin. They suggested a late Cretaceous to Paleocene accretion event, followed by later subduction erosion processes. The margin wedge consists of the ophiolitic Nicoya complex. The seismic units, unconformities and tectonic features record a rich history of both local and regional vertical movements occurring since the Middle Eocene, which are linked to the evolution of the Pacific convergent margin. During June, 2000, 2800 kms of multichannel seismic reflection data were collected on the R/V Ewing off Nicaragua. Analysis of the 240 channels dataset indicates rapid changes along strike in the Sandino basin. The basin is relatively thin in the southern part, thinning quite rapidly southward against the Nicoya complex of the Santa Elena peninsula of Costa Rica. The forearc sediments thickness approaches and locally exceeds 10 kms in the central and northern parts of the Sandino basin. The oldest units (Upper Cretaceous-Middle Eocene) are very thick off northern Nicaragua, with relatively thin middle to late Cenozoic deposits. However, off central Nicaragua the latter units (Middle-Upper Miocene) attain great thicknesses and the older units appear to thin. This pattern suggests a history of successive deepening of the basin from north to south, after the convergent system evolved from accretion to subduction erosion processes. Present efforts are devoted to quantifying this change in development and using it to understand the dynamics of forearc basin evolution offshore of Central America.

  18. 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

  19. 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

  20. 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

  1. 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. PMID:21905390

  2. 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

  3. Neogene north American-Caribbean plate boundary across Northern Central America: Offset along the polochic fault

    NASA Astrophysics Data System (ADS)

    Burkart, Burke

    1983-12-01

    The Polochic fault was a segment of the North American-Caribbean plate boundary across Central America in the Neogene. Its 130 km of left slip was previously determined by matching structures and stratigraphie outcrop patterns of northwest and central Guatemala across the fault. Additional support for the model and the youthfulness of the recorded offset comes from an essentially perfect match of major geomorphic features across the fault. A reconstruction process which eliminates 123 km of left slip brings together rivers and drainage divides that existed before the Polochic became active. With the reconstruction carried across the isthmus on an east-west fault the regional structural geology assumes the coherent pattern of a continuous orogenic belt whose geometry is compatible with the model of collisional tectonics centered on the Motagua "suture zone". Confined within this belt, narrowed to some 60 km by the reconstruction, lie the major Laramide thrusts, folds and tectonically emplaced serpentinites of Guatemala. Crystalline rocks of Guatemala re-join the Chiapas Massif and Paleozoic sedimentary rocks, exposed in the core of an almost-continuous anticlinorium, extend from southern Chiapas to Lake Izabal. The Polochic does not bend in eastern Guatemala but continues eastward to the Motagua fault where it dies. Westward drift of the northern block resulted in rifting which extended from eastern Guatemala into the Caribbean along the Cayman trough. The Honduras depression may represent an element of a triple junction along with the Polochic and Izabal-Cayman rift. The Polochic continues westward into the Pacific Ocean and offsets the Middle America trench. The Polochic has offset the Miocene volcanic belt of northern Central America, confirming the previous estimate of a Neogene time of movement. About 300 km of relative east-west Neogene displacement has been recorded on the Mid-Cayman rise, only 130 km of which can be accounted for across the Polochic. It is

  4. Simulating Climate Change in Central America Using PRECIS Regional Modeling System

    NASA Astrophysics Data System (ADS)

    Karmalkar, A. V.; Bradley, R. S.; Diaz, H. F.

    2006-12-01

    Highland tropical forests are rich in endemic species and crucial in maintaining freshwater resources in many regions. Much of their remarkable biodiversity is due to the steep climate gradients found on tropical mountains. These gradients are significantly altered due to warming, affecting many species living on the mountain slopes. Costa Rica's Monteverde Cloud Forest shows biological changes associated with changes in climatic patterns. Our goal is to understand climate change at areas of high relief in the tropics and its potential impacts on ecosystem dynamics. We address this question by focusing on Central America, which is considered to be a biodiversity hotspot. The model used is the UK Hadley Center PRECIS(Providing REgional Climates for Impact Studies) model. The model is based on HadAM3H, an improved version of the atmospheric component of the latest Hadley Center coupled AOGCM, HadCM3 and is forced at the lateral boundaries by HadAM3P GCM. The surface boundary conditions include observed SSTs and sea-ice. We carried out a baseline run (1961-1990) and a doubled CO2 run (SRES A2 2071-2100) at a resolution of 25 km (0.22°) over the region of Central America that includes several biodiversity hotspots. Model verification is performed by comparing control run results with observations and reanalysis data. Preliminary analysis shows that PRECIS has successfully captured present-day spatial and temporal climate variability that has been observed in Central America. Elevation dependency of temperature is one of the important results of this study and will be investigated in great detail. The SRES A2 run shows average warming of about 3K, with more warming at higher altitudes in general. Precipitation and relative humidity analysis shows drier conditions in the region in 2 × CO2 world. Additional techniques are being developed to better quantify model performance in areas of high relief. We plan to expand this project to other models, and to additional

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

    PubMed Central

    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. PMID:19087253

  6. 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.

  7. 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.

  8. 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

  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). PMID:12787962

  10. 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

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

    PubMed

    Campbell, J M

    2014-01-01

    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

  12. 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.

  13. 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.

  14. 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

  15. [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

  16. 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. PMID:25654444

  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. 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. PMID:26194303

  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. 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…

  1. 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

  2. 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. PMID:22226702

  3. 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…

  4. Zebra Chip, a New Potato Disease in North and Central America, is Associated with the Potato Psyllid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zebra chip (ZC) is an important and emerging potato disease that is causing millions of dollars in losses to both potato producers and processors in the southwestern United States, Mexico, and Central America. This disease is characterized by symptoms that develop in fried chips from infected potato...

  5. 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…

  6. 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

    ...' commitments under the Labor Chapter. OTLA accepted the Submission for review on May 14, 2012 (77 FR 30329 (2012)), in accordance with its published Procedural Guidelines (71 FR 76694 (2006)). Acceptance... of the Secretary Dominican Republic--Central America--United States Free Trade Agreement; Notice...

  7. 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... changes that USTR should consider for modifying the CAFTA-DR's rules of origin under Article 4.14 of...

  8. 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.

  9. An improved age framework for late Quaternary silicic eruptions in northern Central America

    NASA Astrophysics Data System (ADS)

    Rose, William I.; Conway, F. Michael; Pullinger, Carlos R.; Deino, Alan; McIntosh, William C.

    Five new stepwise-heating 40Ar/39Ar ages and one new high-sensitivity 14C date of ash-fall and ash-flow deposits from late Quaternary silicic volcanoes in northern Central America document the eruption rates and frequencies of five major rhyodacite and rhyolite calderas (Atitlán, Amatitlán, Ayarza, Coatepeque, and Ilopango) located north of the basalt, andesite, and dacite stratovolcanoes of the Central American volcanic front. These deposits form extensive time-stratigraphic horizons that intercalate regionally, and knowledge of dates and stratigraphy provides a valuable framework for age determinations of more localized volcanic and nonvolcanic events. The new data, especially when integrated with previous stratigraphic and dating work, show that all five calderas erupted several times in the past 200ka and, despite a lack of historic activity, should be considered as active centers that could produce highly explosive eruptions again. Because of their locations near the highly vulnerable economic hearts of Guatemala and El Salvador, the risks of eruptions from these calderas should be carefully considered along with risks of major earthquakes and volcanic front volcanoes, which are much more frequent but inflict less severe and extensive damage. This investigation also includes some examples of dating efforts that failed to produce reasonable results.

  10. 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.

  11. 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

  12. 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

  13. [MODIS Investigation

    NASA Technical Reports Server (NTRS)

    Abbott, Mark R.

    1996-01-01

    The objectives of the last six months were: (1) Complete sensitivity analysis of fluorescence; line height algorithms (2) Deliver fluorescence algorithm code and test data to the University of Miami for integration; (3) Complete analysis of bio-optical data from Southern Ocean cruise; (4) Conduct laboratory experiments based on analyses of field data; (5) Analyze data from bio-optical mooring off Hawaii; (6) Develop calibration/validation plan for MODIS fluorescence data; (7) Respond to the Japanese Research Announcement for GLI; and (8) Continue to review plans for EOSDIS and assist ECS contractor.

  14. 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.

  15. Inner forearc response to subduction of the Panama Fracture Zone, southern Central America

    NASA Astrophysics Data System (ADS)

    Morell, Kristin D.; Fisher, Donald M.; Gardner, Thomas W.

    2008-01-01

    Subduction of the right-lateral Panama Fracture Zone, along the convergent margin of Central America creates abrupt lateral variations in convergence rate, obliquity, and subducting crustal thickness at its intersection with the Middle America Trench. This intersection, known as the Panama (CO-NZ-CA) Triple Junction, is migrating to the southeast at a rate of 55 mm/yr, and currently coincides with the lateral termination of the Fila Costeña Thrust Belt in the inner forearc of the overriding plate. Mapping in the inner forearc in the area that straddles the subducting Panama Fracture Zone reveals that Cocos-Caribbean convergence west of the triple junction leads to the development of an inner forearc thrust belt inboard of the colliding Cocos Ridge, while little deformation is evident inboard of Nazca-Caribbean convergence, east of the triple junction. This results in the lateral termination of the Fila Costeña Thrust Belt in the region of the forearc that projects over the Panama Fracture Zone, where four out of five mapped thrust faults tip out and are buried by lahars. Three new balanced cross-sections indicate a steep gradient in shortening from the center of the thrust belt to its southeastern termination. The short-term history of the inner forearc recorded in the landscape and topography of the Fila Costeña is consistent with the southeastward migration of the thrust belt and the Panama Triple Junction throughout the past ˜ 3 Ma, with evidence for the growth of a new topographic divide and reorganization of stream channel networks.

  16. [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.

  17. 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

  18. 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. PMID:22615408

  19. The origin of carbonate mud in isolated carbonate platforms of Belize, Central America

    NASA Astrophysics Data System (ADS)

    Gischler, Eberhard; Zingeler, Daniel

    2002-08-01

    Carbonate mud from three small isolated carbonate platforms of Belize (Central America) is largely a product of the breakdown of skeletal grains. The composition of the 63-20- and 20-4-µm fractions of 37 samples was determined by point counting under SEM; composition of the <4-µm fraction was assessed qualitatively under SEM. The 63-4-µm fractions are dominated by fragments of mollusks, the codiacean alga Halimeda, and other skeletal types. About one-third of the particles in the 63-4-µm fractions remained unidentified, probably due to obliteration of diagnostic features by early recrystallization processes such as micritization. Nanograins (<1 µm) and short (3-5 µm) aragonite needles are most common in the <4-µm fraction. These grains are interpreted to be largely fragments of codiacean algae (Halimeda, Penicillus). The 20-4- and <4-µm sediment fractions are composed of 80 and 75% aragonite on average, respectively. Trace element composition of strontium averages 7,900 ppm in the 20-4-µm fraction and in codiacean algae samples, and 5,600 ppm in the <4-µm fraction. Geochemical (trace element) data also argue against inorganic aragonite precipitation within the water column, and favor a skeletal origin. The lower strontium contents in the <4-µm fraction as compared with the 20-4-µm fraction may also be a consequence of early recrystallization processes.

  20. 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

  1. 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. PMID:15806545

  2. 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.

  3. Final report on SIM.M-S14: Mass comparison in Central America

    NASA Astrophysics Data System (ADS)

    Medina, Nieves; Edgardo Brito, Douglas; Lilieth Chinchilla, Wendy; Chow, Yanisareth; Ramos Alfaro, Olman Fernando; José Reyes Valverde, Renato; Salguero., Rómulo

    2014-01-01

    The scope of the comparison is the demonstration of the coherency of the calibration of 200 mg, 1 g, 50 g, 200 g, 1 kg and 2 kg stainless steel mass standard weights as realized by the participating institutes: CEM (pilot), CEHM, CENAME, CENAMEP, CIM, LACOMET and LANAMET. This comparison is based on a decision taken on 27 August 2013 as part of the program PRACAMS (Regional Program for Quality Support and Implementation of Sanitary and Phytosanitary Measures in Central America). Each participating NMI determined the true mass and conventional mass of 200 mg, 1 g, 50 g, 200 g, 1 kg and 2 kg stainless steel mass standard weights. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. A Single Early Introduction of HIV-1 Subtype B into Central America Accounts for Most Current Cases

    PubMed Central

    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

    2013-01-01

    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. PMID:23616665

  12. 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. PMID:23616665

  13. 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

  14. 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

  15. 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....

  16. 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.

  17. 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

  18. Slab Geometry Control on Mantle Flow Regime: A case study from Central South America Subduction Zone

    NASA Astrophysics Data System (ADS)

    Biryol, C. B.; Beck, S. L.; Zandt, G.; Wagner, L. S.

    2013-12-01

    The subduction of oceanic lithosphere along convergent plate margins plays an important role in the dynamics of the upper mantle beneath convergent margins and major orogenic belts. Many studies of mantle dynamics show that the flow pattern of the mantle varies greatly between different subduction zones as well as within the same subduction zone. The factors that control such variations are poorly understood and need to be investigated further in order to develop a better understanding of various subduction zone processes such as the deformation of mantle beneath convergent plate margins and transport of melts and volatiles in the mantle wedge above subducting slabs. Earlier studies of mantle flow inferred from seismic anisotropy via shear-wave splitting analysis indicated that the dynamics and deformation of subducting and overriding plates as well as the slab geometry have important roles on mantle flow regime. In an effort to test the significance of these factors in constraining the mantle dynamics along the central South America subduction zone, we carried out a shear-wave splitting analysis. Our study area covers southern Peru and northwestern Bolivia encompassing the northernmost Altiplano plateau where subduction of the Nazca plate begins to gradually flatten towards the north. The major part of the data for our analysis comes from the CAUGHT temporary seismic deployment (2010 - 2012) with 49 three-component broadband seismometers. In our study we used SKS, SKKS and PKS arrivals from over 80 teleseismic earthquakes, located between the distance-range of 60 to 140 degrees. We determined polarization direction and delay-time of shear-wave arrivals that are polarized into fast and slow components and split in time. The resultant fast polarization directions indicate the direction of mantle flow beneath the study area and the delay-times show the strength and depth extend of the associated seismic anisotropy. The results of our analysis revealed a

  19. 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.

  20. 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.

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

    PubMed

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

    1988-11-01

    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

  2. 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.

  3. 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.

  4. 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.

  5. A Geodynamical Perspective on the Subduction of Cocos and Rivera plates beneath Mexico and Central America

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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.

  6. A Geodynamical Perspective on the Subduction of Cocos and Rivera plates beneath Mexico and Central America

    NASA Astrophysics Data System (ADS)

    Constantin Manea, Vlad; Manea, Marina; Ferrari, Luca

    2013-04-01

    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.

  7. Comparison of atmospheric mercury speciation and deposition at nine sites across central and eastern North America

    NASA Astrophysics Data System (ADS)

    Engle, Mark A.; Tate, Michael T.; Krabbenhoft, David P.; Schauer, James J.; Kolker, Allan; Shanley, James B.; Bothner, Michael H.

    2010-09-01

    This study presents >5 cumulative years of tropospheric mercury (Hg) speciation measurements, over the period of 2003-2009, for eight sites in the central and eastern United States and one site in coastal Puerto Rico. The purpose of this research was to identify local and regional processes that impact Hg speciation and deposition (wet + dry) across a large swath of North America. Sites sampled were selected to represent both a wide range of mercury exposure and environmental conditions. Seasonal mean concentrations of elemental Hg (1.27 ± 0.31 to 2.94 ± 1.57 ng m-3; ? ± σ), reactive gaseous mercury (RGM; 1.5 ± 1.6 to 63.3 ± 529 pg m-3), and fine particulate Hg (1.2 ± 1.4 to 37.9 ± 492 pg m-3) were greatest at sites impacted by Hg point sources. Diel bin plots of Hgo and RGM suggest control by a variety of local/regional processes including impacts from Hg point sources and boundary layer/free tropospheric interactions as well as from larger-scale processes affecting Hg speciation (i.e., input of the global Hg pool, RGM formed from oxidation of Hgo by photochemical compounds at coastal sites, and elemental Hg depletion during periods of dew formation). Comparison of wet Hg deposition (measured), RGM and fine particulate Hg dry deposition (calculated using a multiple resistance model), and anthropogenic point source emissions varied significantly between sites. Significant correlation between emission sources and dry deposition was observed but was highly dependant upon inclusion of data from two sites with exceptionally high deposition. Findings from this study highlight the importance of environmental setting on atmospheric Hg cycling and deposition rates.

  8. Intellectual property and access to medicines: an analysis of legislation in Central America.

    PubMed

    Cerón, Alejandro; Godoy, Angelina Snodgrass

    2009-10-01

    Globalization of intellectual property (IP) protection for medicines has been advancing during the past decade. Countries are obliged to adapt their legislation as a requirement of their membership to the World Trade Organization or as a condition of being part of international trade agreements. There is a growing recognition that, in low-income countries, stronger IP protection is a barrier to access to medicines. At the same time, the number of low-income countries writing national legislation to protect IP for pharmaceutical products is growing worldwide, but little research has been done on the ways in which this process is happening at the national level. This paper aims to contribute to the understanding of the implementation of IP legislation at the national level by providing a comparative analysis of the countries that are part of the United States-Dominican Republic-Central America Free Trade Agreement (DR-CAFTA). The analysis shows three trends. First, countries have often implemented stronger IP protection than required by trade agreements. Second, some countries have adopted IP protection before signing the trade agreements. Third, the process of ratification of DR-CAFTA increased public debate around these issues, which in some cases led to IP legislation that considers public health needs. These trends suggest that industrialized countries and the pharmaceutical industry are using more tactics than just trade agreements to push for increased IP protection and that the process of national legislation is a valid arena for confronting public health needs to those of the industry. PMID:19876546

  9. 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

  10. [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