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Sample records for africa central america

  1. 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

  2. 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

  3. Cancer survival in Africa, Asia, the Caribbean and Central America: database and attributes.

    PubMed

    Swaminathan, R; Lucas, E; Sankaranarayanan, R

    2011-01-01

    Thirty-one registries in 17 countries submitted data for systematic and centralized scrutiny. Data on 564 606 cases of different cancers ranging 1-56 sites/types from 27 registries in 14 low-/medium-resource countries in Eastern and Western Africa, the Caribbean, Central America and four regions of Asia, registered during 1990-2001 (period varying for individual registries) were reported. The database for this survival study comprised data that were classified as mandatory and optional. Mandatory variables provided by all registries included case-ID, age at diagnosis, sex, incidence date, most valid basis of diagnosis, cancer site/type (ICD-10 codes C00-96), vital status at follow-up and corresponding date. Clinical extent of disease was prominent among the optional variables provided by 17 registries and analysed. The grouping of cancer sites for analysis was based on standard norms, and only categories with at least 25 cases were reported. Cases registered based on a death certificate only, cases lacking any follow-up after initial registration, or cases rejected based on validation checks were excluded from the survival analysis. An easy guide to contents in subsequent chapters, especially tables and graphs describing data quality indices, survival statistics and online dynamic functions, is provided.

  4. Cancer survival in Africa, Asia, the Caribbean and Central America. Introduction.

    PubMed

    Sankaranarayanan, R

    2011-01-01

    The dearth of reliable survival statistics from developing countries was very evident until the mid-1990s. This prompted the International Agency for Research on Cancer (IARC) to undertake a project that facilitated hands-on-training and thereby transfer of knowledge and technology on cancer survival analysis to a majority of researchers from the participating population-based cancer registries, which culminated in the publication of the first volume of the IARC scientific publication on Cancer Survival in Developing Countries in 1998. The present study is the second in the series with wider geographical coverage and is based on data from 27 registries in 14 countries in Africa, Asia, the Caribbean and Central America. The calendar period of registration of incident cases for the present study ranges between 1990 and 2001. Data on 564 606 cases of 1-56 cancer sites from different registries are reported. Data from eleven registries were utilized for eliciting survival trend and seventeen registries for reporting survival by clinical extent of disease. Besides chapters on every registry and general chapters on methodology, database and overview, the availability of online comparative statistics on cancer survival data by participating registries or cancer site in the form of tables or graphs is an added feature (available online at http://survcan.iarc.fr).

  5. Assessing and mapping drought hazard in Africa and South-Central America with a Meteorological Drought Severity Index

    NASA Astrophysics Data System (ADS)

    Carrao, Hugo; Barbosa, Paulo; Vogt, Jürgen

    2015-04-01

    the intra-annual variability of precipitation in estimating the severity of events that can impact on seasonal activities. The MDSI is standardized in space and time, and considers the relative monthly precipitation deficits and the seasonal influence of precipitation regimes in the meteorological drought severity computation. In this study, the calculation of the MDSI is performed with monthly precipitation totals from the Full Data Reanalysis Monthly Product Version 6.0 of the Global Precipitation Climatology Centre (GPCC). This dataset provides a global analysis at 0.5 dd latitude/longitude grid spacing of monthly precipitation over land from operational in situ rain gauges collected between January 1901 and December 2010. Using the MDSI, we estimated the severity of drought events that occurred in the past 100 years in Africa and South-Central America, and produced drought hazard maps based on the probability of exceedance the median historical severity. Overall, results indicate that drought hazard is high for semiarid areas, such as Northeastern and Southern South America, as well as Eastern and Southwestern Africa. Since available water resources in semiarid areas are already insufficient to permanently meet the demands of human activities, the outcomes highlight the aggravated risk for food security and confirm the need for the implementation of disaster mitigation measures in those regions.

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

    PubMed Central

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

    2008-01-01

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

  7. Short-term risk of anaemia following initiation of combination antiretroviral treatment in HIV-infected patients in countries in sub-Saharan Africa, Asia-Pacific, and central and South America

    PubMed Central

    2012-01-01

    Background The objective was to examine the short-term risk and predictors of anaemia following initiation of combination antiretroviral therapy (cART) in HIV-infected patients from the Western Africa, Eastern Africa, Southern Africa, Central Africa, Asian-Pacific, and Caribbean and Central and South America regions of the International Epidemiologic Databases to Evaluate AIDS (IeDEA) collaboration. Methods Anaemia was defined as haemoglobin of < 10 g/dL. Patients were included if they started cART with three or more drugs, had prior haemoglobin of > = 10 g/dL, and had one or more follow-up haemoglobin tests. Factors associated with anaemia up to 12 months were examined using Cox proportional hazards models and stratified by IeDEA region. Results Between 1998 and 2008, 19,947 patients initiated cART with baseline and follow-up haemoglobin tests (7358, 7289, 2853, 471, 1550 and 426 in the Western Africa, Eastern Africa, Southern Africa, Central Africa, Asian-Pacific, and Caribbean and Central and South America regions, respectively). At initiation, anaemia was found in 45% of Western Africa patients, 29% of Eastern Africa patients, 21% of Southern Africa patients, 36% of Central Africa patients, 15% of patients in Asian-Pacific and 14% of patients in Caribbean and Central and South America. Among patients with haemoglobin of > = 10 g/dL at baseline (13,445), the risks of anaemia were 18.2, 6.6, 9.7, 22.9, 11.8 and 19.5 per 100 person-years in the Western Africa, Eastern Africa, Southern Africa, Central Africa, Asian, and Caribbean and Central and South America regions, respectively. Factors associated with anaemia were female sex, low baseline haemoglobin level, low baseline CD4 count, more advanced disease stage, and initial cART containing zidovudine. Conclusions In data from 34 cohorts of HIV-infected patients from sub-Saharan Africa, Central and South America, and Asia, the risk of anaemia within 12 months of initiating cART was moderate. Routine haemoglobin

  8. Gangs in Central America

    DTIC Science & Technology

    2007-08-02

    introduced – H.R. 1645 ( Gutierrez ), S. 330 (Isakson), and S. 1348 (Reid) – that includes provisions to increase cooperation among U.S., Mexican, and...America, Colombia, and Mexico, U.S. Attorney General Alberto Gonzales stated that “the United States stands with all of our neighbors in our joint fight...deportations on Central America. Legislation in the 110th Congress The 110th Congress has considered immigration legislation – H.R. 1645 ( Gutierrez ), S

  9. Education in Central America.

    ERIC Educational Resources Information Center

    Waggoner, George R.; Waggoner, Barbara Ashton

    The first chapter of this book describes the physical and cultural environment of Central America and includes analytical comments showing the complexity of the problems confronting the region. Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama are then treated in separate chapters including: 1) political, economic, social and…

  10. West and Central Africa.

    PubMed

    Lydie, N; Robinson, N J

    1998-01-01

    This article reviews scientific and other literature during the 1990s that links migration and mobility with the spread of sexually transmitted diseases (STDs), including HIV/AIDS. The focus is on key population groups linked to the spread of HIV and STDs in West and Central Africa: migrant laborers, truck drivers, itinerant traders, commercial sex workers (CSWs), and refugees. Countries with high emigration and immigration tend to have high levels of HIV infection, with the exception of Senegal. The main destination of immigrants are Senegal, Nigeria, and Cote d'Ivoire in West Africa and Cameroon, Congo, Gabon, and Congo in Central Africa. The risk of infection and the spread of HIV is variable among migrants. There is little in the literature that substantiates hypotheses about the strong association between migration and HIV-positive status. Information is needed on the duration, frequency of return visits, living conditions, sexual activities with multiple partners, and information before departure, along the routes, at final destination, and at the time of returns. Action-based research in five West African countries (Burkina Faso, Cote d'Ivoire, Mali, Niger, and Senegal) should produce results in late 1998. Comparable studies in Central Africa are unknown. Regional studies should be complemented by local studies. Prevention would benefit from studies on the relative size of these five population groups by geographic location.

  11. Fires in Central Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Hundreds of fires are set every year during the dry season in Central Africa. This true color image from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) shows dozens of smoke plumes in the Democratic Republic of the Congo on June 29, 2000. Residents burn away scrub and brush annually in the woody savanna to clear land for farming and grazing. For more information, visit the SeaWiFS Home Page, Global Fire Monitoring Fact Sheet, and 4km2 Fire Data Image Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  12. 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.

  13. Mexico and Central America.

    PubMed

    Bronfman, M

    1998-01-01

    This article reviews the literature on migration and HIV/AIDS in Mexico and Central America, including Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and Panama. Most migrants travel to the US through Mexico. US-Mexico trade agreements created opportunities for increased risk of HIV transmission. The research literature focuses on Mexico. Most countries, with the exception of Belize and Costa Rica, are sending countries. Human rights of migrants are violated in transit and at destination. Migration policies determine migration processes. The Mexican-born population in the US is about 3% of US population and 8% of Mexico's population. About 22% arrived during 1992-97, and about 500,000 are naturalized US citizens. An additional 11 million have a Mexican ethnic background. Mexican migrants are usually economically active men who had jobs before leaving and were urban people who settled in California, Texas, Illinois, and Arizona. Most Mexican migrants enter illegally. Many return to Mexico. The main paths of HIV transmission are homosexual, heterosexual, and IV-drug-injecting persons. Latino migrants frequently use prostitutes, adopt new sexual practices including anal penetration among men, greater diversity of sexual partners, and use of injectable drugs.

  14. An overview of cancer survival in Africa, Asia, the Caribbean and Central America: the case for investment in cancer health services.

    PubMed

    Sankaranarayanan, R; Swaminathan, R; Jayant, K; Brenner, H

    2011-01-01

    Population-based cancer survival data, a key indicator for monitoring progress against cancer, are reported from 27 population-based cancer registries in 14 countries in Africa, Asia, the Caribbean and Central America. In China, Singapore, the Republic of Korea, and Turkey, the 5-year age-standardized relative survival ranged from 76-82% for breast, 63-79% for cervical, 71-78% for bladder, and 44-60% for large-bowel cancer. Survival did not exceed 22% for any cancer site in The Gambia, or 13% for any cancer site except breast (46%) in Uganda. For localized cancers of the breast, large bowel, larynx, ovary, urinary bladder and for regional diseases at all sites, higher survival rates were observed in countries with more rather than less developed health services. Inter- and intra-country variations in survival imply that the levels of development of health services and their efficiency to provide early diagnosis, treatment and clinical follow-up care have a profound impact on survival from cancer. These are reliable baseline summary estimates to evaluate improvements in cancer control and emphasise the need for urgent investment to improve awareness, population-based cancer registration, early detection programmes, health-services infrastructure, and human resources in these countries in the future.

  15. Diversity analyses of Aeschynomene symbionts in Tropical Africa and Central America reveal that nod-independent stem nodulation is not restricted to photosynthetic bradyrhizobia.

    PubMed

    Miché, Lucie; Moulin, Lionel; Chaintreuil, Clémence; Contreras-Jimenez, José Luis; Munive-Hernández, José-Antonio; Del Carmen Villegas-Hernandez, María; Crozier, Françoise; Béna, Gilles

    2010-08-01

    Tropical aquatic legumes of the genus Aeschynomene are unique in that they can be stem-nodulated by photosynthetic bradyrhizobia. Moreover, a recent study demonstrated that two Aeschynomene indica symbionts lack canonical nod genes, thereby raising questions about the distribution of such atypical symbioses among rhizobial-legume interactions. Population structure and genomic diversity were compared among stem-nodulating bradyrhizobia isolated from various Aeschynomene species of Central America and Tropical Africa. Phylogenetic analyses based on the recA gene and whole-genome amplified fragment length polymorphism (AFLP) fingerprints on 110 bacterial strains highlighted that all the photosynthetic strains form a separate cluster among bradyrhizobia, with no obvious structuring according to their geographical or plant origins. Nod-independent symbiosis was present in all sampling areas and seemed to be linked to Aeschynomene host species. However, it was not strictly dependent on photosynthetic ability, as exemplified by a newly identified cluster of strains that lacked canonical nod genes and efficiently stem-nodulated A. indica, but were not photosynthetic. Interestingly, the phenotypic properties of this new cluster of bacteria were reflected by their phylogenetical position, as being intermediate in distance between classical root-nodulatingBradyrhizobium spp. and photosynthetic ones. This result opens new prospects about stem-nodulating bradyrhizobial evolution.

  16. Central and southern Africa

    SciTech Connect

    McGrew, H.J.

    1981-10-01

    Exploration in central and southern Africa continued to expand during 1980. The greatest concentration of activity was in Nigeria. However, there was considerable increase in the level of exploratory work in Cameroon and Congo. Significant new finds have been made in Ivory Coast. Geological and geophysical activity was carried out in 18 of the countries, with those in the western part having the largest share. Seismic work involved 225 party months of operation. Most of this time was spent on land, but marine operations accounted for 73,389 km of new control. Gravity and magnetic data were recorded during the marine surveys, and several large aeromagnetic projects were undertaken to obtain a total of 164,498 line km of data. Exploratory and development drilling accounted for a total of 304 wells and 2,605,044 ft (794,212 m) of hole. The 92 exploratory wells that were drilled resulted in 47 oil and gas discoveries. In development drilling 89% of the 212 wells were successful. At the end of the year, 27 exploratory wells were underway, and 34 development wells were being drilled for a total of 61. Oil production from the countries that this review covers was 918,747,009 bbl in 1980, a drop of about 9% from the previous year. Countries showing a decline in production were Nigeria, Gabon, Cabinda, and Zaire. Increases were recorded in Cameroon, Congo, and Ghana. A new country was added to the list of producers when production from the Belier field in Ivory Coast came on stream. 33 figures, 15 tables.

  17. Demographic tensions in Central America.

    PubMed

    1986-08-01

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

  18. Volcanic hazards in Central America

    USGS Publications Warehouse

    Rose, William I.; Bluth, Gregg J.S.; Carr, Michael J.; Ewert, John W.; Patino, Lina C.; Vallance, James W.

    2006-01-01

    This volume is a sampling of current scientific work about volcanoes in Central America with specific application to hazards. The papers reflect a variety of international and interdisciplinary collaborations and employ new methods. The book will be of interest to a broad cross section of scientists, especially volcanologists. The volume also will interest students who aspire to work in the field of volcano hazards mitigation or who may want to work in one of Earth’s most volcanically active areas.

  19. Subseasonal teleconnections South America - South Africa

    NASA Astrophysics Data System (ADS)

    Grimm, Alice; Reason, Chris

    2016-04-01

    There is marked subseasonal variability over South America and southern Africa. Based on previous work showing that a teleconnection exists between the South American monsoon system and interannual summer rainfall variability over southern Africa, this study shows teleconnections between subseasonal variability over these landmasses. Observed daily gauge precipitation data for 1970-1999 are gridded to 1° resolution for South America and 2.5° for South Africa. At each grid point, anomalies of daily precipitation are calculated and submitted to a bandpass Lanczos filter to isolate subseasonal oscillations in the 20-90 day band. For each season, the filtered precipitation anomalies for the South African grid boxes are correlated with filtered precipitation anomalies in the grid boxes over South America. Lags from 0 up to 12 days are applied to the South African data, in order to investigate convection anomalies over South America that could produce atmospheric perturbations associated with South African precipitation anomalies. The significance of correlation between the filtered data takes autocorrelation into account and uses effective sample sizes. The results shown represent the best correlations for different climatic regimes such as the winter-rainfall dominated southwestern Cape, the all season rainfall South Coast and the summer-rainfall dominated Limpopo region. NCEP re-analyses are used to composite subseasonal anomalies in OLR, 200 hPa streamfunction, and vertically integrated moisture flux associated with precipitation anomaly above one standard deviation in the filtered series (positive phases) of the South African selected regions. The possible origin of the atmospheric circulation anomalies associated with those positive phases is determined using influence functions (IFs) of a vorticity equation model with a divergence source. The model is linearized about a realistic basic state and includes the divergence of the basic state and the advection of

  20. Mineralogical maturity in dunefields of North America, Africa and Australia

    USGS Publications Warehouse

    Muhs, D.R.

    2004-01-01

    Studies of dunefields in central and western North America show that mineralogical maturity can provide new insights into the origin and evolution of aeolian sand bodies. Many of the world's great sand seas in Africa, Asia and Australia are quartz-dominated and thus can be considered to be mineralogically mature. The Algodones (California) and Parker (Arizona) dunes in the southwestern United States are also mature, but have inherited a high degree of mineralogical maturity from quartz-rich sedimentary rocks drained by the Colorado River. In Libya, sediments of the Zallaf sand sea, which are almost pure quartz, may have originated in a similar fashion. The Fort Morgan (Colorado) and Casper (Wyoming) dunefields in the central Great Plains of North America, and the Namib sand sea of southern Africa have an intermediate degree of mineralogical maturity because their sources are large rivers that drained both unweathered plutonic and metamorphic rocks and mature sedimentary rocks. Mojave Desert dunefields in the southwestern United States are quite immature because they are in basins adjacent to plutonic rocks that were their sources. Other dunefields in the Great Plains of North America (those in Nebraska and Texas) are more mature than any possible source sediments and therefore reflect mineralogical evolution over time. Such changes in composition can occur because of either of two opposing long-term states of the dunefield. In one state, dunes are stable for long periods of time and chemical weathering depletes feldspars and other weatherable minerals in the sediment body. In the other state, which is most likely for the Great Plains, abrasion and ballistic impacts deplete the carbonate minerals and feldspars because the dunes are active for longer periods than they are stable. ?? 2003 Elsevier B.V. All rights reserved.

  1. 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)

  2. 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…

  3. External Review Teams Training in Central America

    ERIC Educational Resources Information Center

    Silva-Trivino; Moises; Ramirez-Gatica, Soledad

    2004-01-01

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

  4. Characteristics of Extreme Summer Convection over equatorial America and Africa

    NASA Astrophysics Data System (ADS)

    Zuluaga, M. D.; Houze, R.

    2013-12-01

    Fourteen years of Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) version 7 data for June-August show the temporal and spatial characteristics of extreme convection over equatorial regions of the American and African continents. We identify three types of extreme systems: storms with deep convective cores (contiguous convective 40 dBZ echoes extending ≥10 km in height), storms with wide convective cores (contiguous convective 40 dBZ echoes with areas >1,000 km2) and storms with broad stratiform regions (stratiform echo >50,000 km2). European Centre for Medium-Range Weather Forecast (ECMWF) reanalysis is used to describe the environmental conditions around these forms of extreme convection. Storms with deep convective cores occur mainly over land: in the equatorial Americas, maximum occurrence is in western Mexico, Northern Colombia and Venezuela; in Africa, the region of maximum occurrence is a broad zone enclosing the central and west Sudanian Savanna, south of the Sahel region. Storms with wide convective radar echoes occur in these same general locations. In the American sector, storms with broad stratiform precipitation regions (typifying robust mesoscale convective systems) occur mainly over the eastern tropical Pacific Ocean and the Colombia-Panama bight. In the African sector, storms with broad stratiform precipitation areas occur primarily over the eastern tropical Atlantic Ocean near the coast of West Africa. ECMWF reanalyses show how the regions of extreme deep convection associated with both continents are located mainly in regions affected by diurnal heating and influenced by atmospheric jets in regions with strong humidity gradients. Composite analysis of the synoptic conditions leading to the three forms of extreme convection provides insights into the forcing mechanisms in which these systems occur. These analyses show how the monsoonal flow directed towards the Andes slopes is mainly what concentrates the occurrence of extreme

  5. Hydrological climate change projections for Central America

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

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

  6. Central America: A Regional Study.

    ERIC Educational Resources Information Center

    Mowry, George; Lacy, Ann

    This lesson is a series of activities and multi-media presentations designed to enable students to understand the historic and geographic roots of some of the problems that Central American nations have faced. Geography, history, writing, and storytelling are used as ways of understanding a multicultural world. Creative thinking and participation…

  7. Writing the Pentecostal History of Africa, Asia and Latin America

    ERIC Educational Resources Information Center

    Anderson, Allan

    2004-01-01

    This article examines the writing of Pentecostal history and in particular, the biases and presuppositions associated with it. The problem of sources and the neglect of the important role of indigenous ("native") workers in the historiography of Pentecostalism in Africa, Asia and Latin America is the main focus. It refutes the idea of an…

  8. Family Planning in Five Continents: Africa, America, Asia, Europe, Oceania.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    Population growth trends and family planning activities in Africa, America, Asia, Europe, and Oceania are summarized in this booklet developed by the International Planned Parenthood Federation. Narrative information for each continent gives a resume of population growth trends, reasons for the trends, population problems, policy formation, family…

  9. English Language Assessment in Central America.

    ERIC Educational Resources Information Center

    Crandall, JoAnn; And Others

    This document, the final report of a project assessing the general status of English language training (ELT) in Central America, includes an overview of the process, general recommendations, and country-specific information and recommendations for training and policy development. The purpose was to assess the potential effects of the ELT situation…

  10. Regional Strategic Appraisal of Central America

    DTIC Science & Technology

    2007-11-02

    person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control ...since the early 1960’s. During the last ten years Central America has experimented significant economic, social and political progress. These advances...3 ECONOMIC TRENDS/CHALLENGES/RISKS ................................................................ 6 SOCIAL

  11. Africa, Asia, Europe, and Latin America.

    ERIC Educational Resources Information Center

    Loh, Eudora I.

    1994-01-01

    Annotates 25 publications from 19 countries: Bolivia, Brazil, Cape Verde, Chile, Dominican Republic, Hungary, India, Ireland, Jamaica, Malaysia, Mexico, Morocco, Mozambique, Netherlands, Niger, Nigeria, Peru, South Africa, and Venezuela. Topics include the environment, women's role, and household consumption and expenditures. The publication of an…

  12. Africa, Asia, Europe, and Latin America.

    ERIC Educational Resources Information Center

    Loh, Eudora I.

    1992-01-01

    This annotated bibliography lists 30 government documents published between 1988 and 1991 by Argentina, Bolivia, Brazil, Burundi, Chile, China, Columbia, Denmark, France, Gambia, Guinea Bissau, Hong Kong, India, Italy, Luxembourg, Mexico, Nepal, Nigeria, Portugal, Rwanda, South Africa, and Thailand. Topics addressed include the environment,…

  13. 7 CFR 319.56-25 - Papayas from Central America and South America.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Papayas from Central America and South America. 319.56... Vegetables § 319.56-25 Papayas from Central America and South America. Commercial consignments of the Solo type of papaya may be imported into the United States only in accordance with this section and...

  14. 7 CFR 319.56-25 - Papayas from Central America and South America.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Papayas from Central America and South America. 319.56... Vegetables § 319.56-25 Papayas from Central America and South America. Commercial consignments of the Solo type of papaya may be imported into the United States only in accordance with this section and...

  15. 7 CFR 319.56-25 - Papayas from Central America and South America.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Papayas from Central America and South America. 319.56... Vegetables § 319.56-25 Papayas from Central America and South America. Commercial consignments of the Solo type of papaya may be imported into the United States only in accordance with this section and...

  16. 7 CFR 319.56-25 - Papayas from Central America and South America.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Papayas from Central America and South America. 319.56... Vegetables § 319.56-25 Papayas from Central America and South America. Commercial consignments of the Solo type of papaya may be imported into the United States only in accordance with this section and...

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

    ERIC Educational Resources Information Center

    Bresler, Robert J.

    1983-01-01

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

  18. 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.

  19. An investigation of MAGSAT and complementary data emphasizing precambrian shields and adjacent areas of West Africa and South America

    NASA Technical Reports Server (NTRS)

    Hastings, D. A. (Principal Investigator)

    1981-01-01

    Accomplishments with regard to the mapping and analysis of MAGSAT data for the investigation of correlations between the magnetic field characteristics of South American and African shields are reported. Significant results in the interpretation of the global total-field anomalies and the anomaly patterns of Africa and South America are discussed. The central position of the Brazilian shield tends to form a negative total-field anomaly, consistent with findings for shields in equatorial Africa. Sedimentary sequences in the Amazon basin and in the Rio de Janeiro-Sao Paolo areas exhibit positive anomalies, also consistent with equatorial Africa. Results for the Caribbean Sea and Guyana regions are also described.

  20. 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

  1. Trypanosomiasis vector control in Africa and Latin America

    PubMed Central

    Schofield, Chris J; Kabayo, John P

    2008-01-01

    Vectors of trypanosomiasis – tsetse (Glossinidae) in Africa, kissing-bugs (Triatominae) in Latin America – are very different insects but share demographic characteristics that render them highly vulnerable to available control methods. For both, the main operational problems relate to re-invasion of treated areas, and the solution seems to be in very large-scale interventions covering biologically-relevant areas rather than adhering to administrative boundaries. In this review we present the underlying rationale, operational background and progress of the various trypanosomiasis vector control initiatives active in both continents. PMID:18673535

  2. Hydrological trends in Congo basin (Central Africa)

    NASA Astrophysics Data System (ADS)

    Laraque, A.

    2015-12-01

    The last studies concerning some main Congo basin rivers allowed to subdivide their multi-annual flows into several homogeneous phases. As in West Africa, 1970 was the year of the major hydroclimatic event announcing a weaker flowing period. In the absence of long, reliable and available flow series in the whole Congo basin of 3,8 106km2 area, the present study concerns only the Congo River at Brazzaville/Kinshasa and two of the main tributaries of its right bank, Ubangui at Bangui and Sangha at Ouesso, with hydrologic data available from the first half of the 20th century. For Congo River, in comparison with its secular average, after an excess flow noted during the sixties, a significant drop of 10% occurs in the eighties. However, a return to normal conditions is recorded from 1995. For Ubangui and Sangha, the flows remain weaker since 1970. Within the bi-modal hydrological regimes of Sangha and Congo river, because they are equatorial, we also observe since many years a small decline of the secondary flood of april-june. This phenomenon was emphasized especially these last years and is founded in others rivers of Central Africa, where it reflects the variations of de rainfall patterns and the surfaces features. For the Congo basin, the situation is worrying because that affects the inland waterway transport. Moreover that wakes also the project of junction by a canal of the Congo and Chari basins for fighting against the hydrological decline of Lake Chad.

  3. Expansion of industrial logging in Central Africa.

    PubMed

    Laporte, Nadine T; Stabach, Jared A; Grosch, Robert; Lin, Tiffany S; Goetz, Scott J

    2007-06-08

    Industrial logging has become the most extensive land use in Central Africa, with more than 600,000 square kilometers (30%) of forest currently under concession. With use of a time series of satellite imagery for the period from 1976 to 2003, we measured 51,916 kilometers of new logging roads. The density of roads across the forested region was 0.03 kilometer per square kilometer, but areas of Gabon and Equatorial Guinea had values over 0.09 kilometer per square kilometer. A new frontier of logging expansion was identified within the Democratic Republic of Congo, which contains 63% of the remaining forest of the region. Tree felling and skid trails increased disturbance in selectively logged areas.

  4. Drug Trafficking as a Lethal Regional Threat in Central America

    DTIC Science & Technology

    2011-12-16

    and Central America are only found in some magazines like TIME, and “Nueva Sociedad ” [New Society]. Another good source for analysis of current...relacion compleja” [Drugs and Insecurity in Latin America: a complex relation] published by the Colombian magazine Nueva Sociedad in July-August 2000...Organization of American States. 65 Table 1. Police Ratios in Central America Source: Author Interviews; Observatoriapara la violencia , Honduras; CIA

  5. 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.…

  6. Mantle Structure Beneath Central South America

    NASA Astrophysics Data System (ADS)

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

    2003-12-01

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

  7. Cocaine and Instability in Africa: Lessons from Latin America and the Caribbean (Africa Security Brief, Number 5, July 2010)

    DTIC Science & Technology

    2010-07-01

    originated from South Amer- ica . Its cargo added to the mounting cocaine traffic from Latin America that transships West Africa on AFRICA SECURITY...security. Cocaine traffic has provided a vital financial re- source to insurgency groups as well. Recent reports from Peru indicate that the military

  8. Development of Retinoblastoma Programs in Central America

    PubMed Central

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

    2009-01-01

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

  9. 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

  10. Central America: Region in Conflict; A Selective Bibliography.

    DTIC Science & Technology

    1983-09-01

    bibliography lists books, general and legal periodical articles,0and congilessional materials on the topic of Central America, including the countries of...Wilson International Center for Scholars Latin American Program, 1983. 63 p. P1408 .A65 1983 Anderson, Thomas P. POLITICS IN CENTRAL AMERICA: GUATEMALA...IN EL SALVADOR: ORIGINS AND EVOLUTION. Boulder, CO: Westview, 1982. 252 p. F1488.3 .M66 1982 Morris, James A. HONDURAN ELECTORAL POLITICS AND MILITARY

  11. Evaluation of United States Strategy In Central America

    DTIC Science & Technology

    1989-03-03

    General Treaty for Central American Integration, signed by the five coun- tries in 1960, led to the establishment of a Central American Common Market ...The Bipartisan Commission on Central America de- scribed this period as follows: The common market inspired a surge of energy and optimism throughout...regional tensions and unrest collapsing the Central American Common Market and causing capital flight; bad government policies resulting in dis- incentives

  12. Central Africa: Global climate change and development. Overview. Technical report

    SciTech Connect

    Not Available

    1993-01-01

    The preliminary study focuses on the six countries of central Africa which contain the largest remaining contiguous block of closed forests in sub-Saharan Africa: Cameroon, Central African Republic, the Congo, Equatorial Guinea, Gabon, and Zaire. The carbon in the vegetation and soils in these moist tropical forests and surrounding seasonal woodlands constitute the greatest potential source of future carbon dioxide (CO2) emissions from sub-Saharan Africa. This study also considers the importance of savanna burning, although in less depth since the small savanna area in central Africa precludes this activity from being a large regional source of emissions. Analysis of biogeophysical and socioeconomic issues relevant to global climate change, and research containing both space-based and ground-based components, were undertaken.

  13. 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…

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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).

  20. 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.

  1. Coast Guard Support of USSOUTHCOM Missions in Central America

    DTIC Science & Technology

    1994-02-08

    Central America armies have traditionally been a source for poor youths to find meaningful employment and education, neither of which they would...fears of U.S. domination, in order to achieve a meaningful , productive and secure relationship, and a basis for stability in the Americas. 10 CHAPTER... meaningful opposition to the U.S. intervention in Panama in 1989 or the U.S.-dominated coalition in Kuwait in 1990.Y Since then, with the rapid U.S

  2. 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

  3. 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.

  4. Energy and development in Central America. Volume 2: Country assessments

    NASA Astrophysics Data System (ADS)

    Park, W.; Neves, C.; Trehan, R.; Gallagher, W.; Palmedo, P.; Doenberg, A.; Oberg, K.; Kyle, S.

    1980-03-01

    An energy assessment for each of six Central American countries - Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama is presented. The program assists the U.S. Agency for International Development and other development organizations in defining energy programs in Central America. The following issues are treated separately for each individual country; geographic, social and economic aspects; energy resources; current and future energy use; energy strategies.

  5. 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…

  6. 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…

  7. 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.

  8. CASA Central and South America GPS geodesy

    NASA Astrophysics Data System (ADS)

    Kellogg, James; Dixon, Timothy; Neilan, Ruth

    In January 1988, scientists from over 25 organizations in 13 countries and territories cooperated in the largest Global Positioning System (GPS) campaign in the world to date (Table 1) [Neilan et al., 1988]. From January 18 to February 5, 1988, 43 GPS receivers collected about 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, an acronym for Central and South America—and “uno” is Spanish for “one,” designating first-epoch measurements. The CASA UNO experiment was the first civilian effort at implementing an extended GPS satellite-tracking network and established the first major GPS network in the northern Andean margin and the western Caribbean.

  9. 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

  10. 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.

  11. A dated phylogeny of the palm tribe Chamaedoreeae supports Eocene dispersal between Africa, North and South America.

    PubMed

    Cuenca, Argelia; Asmussen-Lange, Conny B; Borchsenius, Finn

    2008-02-01

    The palm tribe Chamaedoreeae reaches its higher diversity in Central America, however, its distribution ranges from the north eastern part of Mexico to Bolivia with a disjunction to the Mascarene Islands in the Indian Ocean. The disjunct distribution of Chamaedoreeae is generally considered a result of Gondwana vicariance and extinction from Africa and/or Madagascar. However, latitudinal migrations and their role in shaping the distribution of this tribe in the Americas have been largely overlooked. In this study we used seven plastid and two nuclear DNA regions to investigate the phylogenetic relationships and biogeography of the Chamaedoreeae. The resulting phylogeny fully resolved the generic relationships within the tribe. The exact area of origin of the tribe remains uncertain, but dating analyses indicated an initial diversification of the Chamaedoreeae during the Early Eocene, followed by long distance dispersion to the Mascarene Islands in the late Miocene. The radiation of Hyophorbe could have taking place on islands in the Indian Ocean now submerged, but its former presence in Africa or Madagascar cannot be ruled out. At least two independent migrations between North and South America predating the rise of the Panama isthmus need to be postulated to explain the distribution of Chamaedoreeae, one during the Middle Eocene and a second during the Miocene. Whereas the traditional interpretation of distribution of Chamaedoreeae species assumes a west Gondwana origin of the group, the findings presented in this paper make it equally possible to interpret the group as a primarily boreotropical element.

  12. Family Planning in Five Continents: Africa, America, Asia, Europe, Oceania. October 1973 Update.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    Population growth trends and family planning activities in Africa, America, Asia, Europe, and Oceania are summarized in this booklet developed by the International Planned Parenthood Federation. Narrative information for each continent gives a resume of population growth trends, reasons for the trends, population problems, policy formation, family…

  13. 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.

  14. An investigation of MAGSAT and complementary data emphasizing precambrian shields and adjacent areas of West Africa and South America

    NASA Technical Reports Server (NTRS)

    Hastings, D. A. (Principal Investigator)

    1982-01-01

    Both MAGSAT data and preliminary results emphasizing Africa, Latin America, and the Caribbean were presented to geologists in Jamaica, Guyana, Brazil, and Argentina. Preliminary interpretations were discussed. A synopsis tectonic map of South America was completed. Semi-final modeling of northern South America was initiated.

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. Out of Africa: a molecular perspective on the introduction of yellow fever virus into the Americas.

    PubMed

    Bryant, Juliet E; Holmes, Edward C; Barrett, Alan D T

    2007-05-18

    Yellow fever virus (YFV) remains the cause of severe morbidity and mortality in South America and Africa. To determine the evolutionary history of this important reemerging pathogen, we performed a phylogenetic analysis of the largest YFV data set compiled to date, representing the prM/E gene region from 133 viral isolates sampled from 22 countries over a period of 76 years. We estimate that the currently circulating strains of YFV arose in Africa within the last 1,500 years and emerged in the Americas following the slave trade approximately 300-400 years ago. These viruses then spread westwards across the continent and persist there to this day in the jungles of South America. We therefore illustrate how gene sequence data can be used to test hypotheses of viral dispersal and demographics, and document the role of human migration in the spread of infectious disease.

  20. Distribution and ecology of Haemagogus aeritinctus in Belize, Central America.

    PubMed

    Taylor, D S

    1993-03-01

    Immatures of Haemagogus aeritinctus are reported from a black mangrove (Avicennia germinans) tree hole on an offshore key in the Belize barrier reef. This is the first report of this species from other than coastal mainland sites in Central America. The high salinity (10,000 ppm) recorded in the tree hole water suggests that this species has a tolerance, or possibly a requirement, for soluble salts that may explain its affiliation solely with mangrove habitats.

  1. 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

  2. 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.

  3. Central Africa: Global climate change and development. Synopsis

    SciTech Connect

    Not Available

    1992-01-01

    Central Africa contains the largest remaining contiguous expanse of moist tropical forest on the African continent and the second largest in the world. However, deforestation rates are rising as the result of rapid population growth, inappropriate economic policies, economic downturns, and weak management capacities. If clearing rates continue to rise, a substantial amount of carbon dioxide will be released into the atmosphere, thus contributing to global climate change. The report summarizes a study designed as a first step in understanding the complex dynamics of the causes and effects of global climate change in Central Africa. The current state of the region's forests, greenhouse gas emissions from deforestation and biomass burning, and the potential impacts of global climate change are discussed.

  4. 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.

  5. Monitoring the quality of medicines: results from Africa, Asia, and South America.

    PubMed

    Hajjou, Mustapha; Krech, Laura; Lane-Barlow, Christi; Roth, Lukas; Pribluda, Victor S; Phanouvong, Souly; El-Hadri, Latifa; Evans, Lawrence; Raymond, Christopher; Yuan, Elaine; Siv, Lang; Vuong, Tuan-Anh; Boateng, Kwasi Poku; Okafor, Regina; Chibwe, Kennedy M; Lukulay, Patrick H

    2015-06-01

    Monitoring the quality of medicines plays a crucial role in an integrated medicines quality assurance system. In a publicly available medicines quality database (MQDB), the U.S. Pharmacopeial Convention (USP) reports results of data collected from medicines quality monitoring (MQM) activities spanning the period of 2003-2013 in 17 countries of Africa, Asia, and South America. The MQDB contains information on 15,063 samples collected and tested using Minilab® screening methods and/or pharmacopeial methods. Approximately 71% of the samples reported came from Asia, 23% from Africa, and 6% from South America. The samples collected and tested include mainly antibiotic, antimalarial, and antituberculosis medicines. A total of 848 samples, representing 5.6% of total samples, failed the quality test. The failure proportion per region was 11.5%, 10.4%, and 2.9% for South America, Africa, and Asia, respectively. Eighty-one counterfeit medicines were reported, 86.4% of which were found in Asia and 13.6% in Africa. Additional analysis of the data shows the distribution of poor-quality medicines per region and by therapeutic indication as well as possible trends of counterfeit medicines.

  6. Monitoring the Quality of Medicines: Results from Africa, Asia, and South America

    PubMed Central

    Hajjou, Mustapha; Krech, Laura; Lane-Barlow, Christi; Roth, Lukas; Pribluda, Victor S.; Phanouvong, Souly; El-Hadri, Latifa; Evans, Lawrence; Raymond, Christopher; Yuan, Elaine; Siv, Lang; Vuong, Tuan-Anh; Boateng, Kwasi Poku; Okafor, Regina; Chibwe, Kennedy M.; Lukulay, Patrick H.

    2015-01-01

    Monitoring the quality of medicines plays a crucial role in an integrated medicines quality assurance system. In a publicly available medicines quality database (MQDB), the U.S. Pharmacopeial Convention (USP) reports results of data collected from medicines quality monitoring (MQM) activities spanning the period of 2003–2013 in 17 countries of Africa, Asia, and South America. The MQDB contains information on 15,063 samples collected and tested using Minilab® screening methods and/or pharmacopeial methods. Approximately 71% of the samples reported came from Asia, 23% from Africa, and 6% from South America. The samples collected and tested include mainly antibiotic, antimalarial, and antituberculosis medicines. A total of 848 samples, representing 5.6% of total samples, failed the quality test. The failure proportion per region was 11.5%, 10.4%, and 2.9% for South America, Africa, and Asia, respectively. Eighty-one counterfeit medicines were reported, 86.4% of which were found in Asia and 13.6% in Africa. Additional analysis of the data shows the distribution of poor-quality medicines per region and by therapeutic indication as well as possible trends of counterfeit medicines. PMID:25897073

  7. Institutional Research in Emerging Countries of Southern Africa, Latin America, and the Middle East and North Africa: Global Frameworks and Local Practices

    ERIC Educational Resources Information Center

    Lange, Lis; Saavedra, F. Mauricio; Romano, Jeanine

    2013-01-01

    This chapter presents a synthesis of the conceptualization and practice of institutional research (IR) in higher education (HE) in emerging countries across Southern Africa, Latin America and the Middle East and North Africa (MENA) regions. The chapter contextualizes the growing need for IR in these regions, identifies problems and challenges…

  8. An investigation of MAGSAT and complementary data emphasizing precambrian shields and adjacent areas of West Africa and South America

    NASA Technical Reports Server (NTRS)

    Hastings, D. A. (Principal Investigator)

    1982-01-01

    Some MAGSAT data and preliminary results emphasizing Africa, Latin America, and the Caribbean were presented to geologists in Jamaica, Guyana, Brazil, and Argentina who then expressed interest in collaborating on linking computer modeling of MAGSAT data to tectionic and metallogenic interpretation for South America and in making the final interpretation. Modeling continues with the preparation of a synopsis tectonic map of South America and the initiation of semi-final modeling of northern South America.

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

    PubMed Central

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

    2012-01-01

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

  10. How do Biomass Burning Carbon Monixide Emissions from South America influence Satellite Observed Columns over Africa?

    NASA Astrophysics Data System (ADS)

    Krol, M. C.; van Leeuwen, T. T.; Aouizerats, B.; van der Werf, G.

    2015-12-01

    Large amounts of Carbon Monoxide (CO) are emitted during biomass burning events. These emissions severely perturb the atmospheric composition. For this reason, satellite observations of CO can help to constrain emissions from biomass burning. Other sources of CO, such as the production of CO from naturally emitted non-methane hydrocarbons, may interfere with CO from biomass burning and inverse modeling efforts to estimate biomass burning emissions have to account for these CO sources. The atmospheric lifetime of CO varies from weeks to months, depending on the availability of atmospheric OH for atmospheric oxidation of CO to carbon dioxide. This means that CO can be transported over relatively long distances. It also implies that satellite-observed CO does not necessarily originate from the underlying continent, but may be caused by distant emissions transported to the observation location. In this presentation we focus on biomass burning emissions from South America and Southern Africa during 2010. This year was particularly dry over South America with a large positive anomaly in biomass burning in the 2010 burning season (July-October). We will adress the question how CO plumes from South America biomass burning influence satellite observations from the Infrared Atmospheric Sounding Interferometer (IASI) instrument over Southern Africa. For this we employ the TM5 atmospheric chemistry model, with 1x1 degree zoom resolutions over Africa and South America. Also, we use the TM5-4DVAR code to estimate CO biomass burning emissions using IASI CO observations. The accompanying image shows IASI CO oberservations over Africa on August 27, 2010, compared to the columns simulated with TM5. Clear signs of intercontinental transport from South America are visible over the Southermost region.

  11. 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.

  12. Posttraumatic stress in immigrants from Central America and Mexico.

    PubMed

    Cervantes, R C; Salgado de Snyder, V N; Padilla, A M

    1989-06-01

    International migration has been associated with increased levels of psychological disturbance, particularly among refugees who have fled from war or political unrest. This study examined self-reported symptoms of depression, anxiety, somatization, generalized distress, and posttraumatic stress disorder (PTSD) in a community sample of 258 immigrants from Central America and Mexico and 329 native-born Mexican Americans and Anglo Americans. Immigrants were found to have higher levels of generalized distress than native-born Americans. Fifty-two percent of Central American immigrants who migrated as a result of war or political unrest reported symptoms consistent with a diagnosis of PTSD, compared with 49 percent of Central Americans who migrated for other reasons and 25 percent of Mexican immigrants. The authors call for more research to document the psychosocial aspects of migration.

  13. 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.

  14. 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.

  15. Cocos-Nazca slab window beneath Central America

    NASA Astrophysics Data System (ADS)

    Johnston, Stephen T.; Thorkelson, Derek J.

    1997-02-01

    Integration of petrologic and tectonic data favours a model of slab window formation beneath Central America in the Pliocene-Pleistocene. Central America has been the site of voluminous Cenozoic arc volcanism. The Cocos and Nazca plates, which are subducting beneath Central America, are diverging along the east-trending Cocos-Nazca spreading ridge. Since 25 Ma the Americas have advanced about 1800 km west over the ridge-transform system. Since at least 8 Ma, plate integrity and the ridge-transform configuration have been preserved during convergence, resulting in subduction of the spreading ridge and development of a slab window. The Panama fracture zone, an active transform fault, is the part of the ridge-transform system currently being subducted. The ridge-transform system formerly adjoining the northern end of the Panama fracture zone is likely to have been left-stepping. We use present-day plate motions to design a slab window to fit known variations in igneous composition, hypocentre distribution, and mantle anisotropy. The modeling demonstrates that subduction of ridge segments and resultant slab window development began between 6 and 10 Ma. Cessation of ridge subduction occurred between 1 and 3 Ma, when subduction of the Panama fracture zone is considered to have begun. The slab window is continuing to expand and migrate northeastward below the Central American volcanic arc. The absence of a Wadati-Benioff zone from southeastern Costa Rica through Panama corresponds to the position of the slab window. Within this region, dacitic and rhyolitic volcanic rocks have "adakitic" compositions, and are thought to result from anatexis of the young, buoyant crust which forms the trailing edges of the slabs bounding the window. Basalts in this area were derived from an enriched ocean-island type mantle source, whereas basalts from the rest of the arc, in Nicaragua, El Salvador and Guatemala, are mainly derived from slab-modified depleted mantle, characteristic of

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Team Massachusetts & Central America Solar Decathlon 2015 Final Technical Report

    SciTech Connect

    Lee, Kenneth

    2016-04-29

    Our team was Team MASSCA (Massachusetts and Central America), which was a partnership of Western New England University (WNE) located in Massachusetts USA, The Technological University of Panama (UTP), and Central American Technological University (UNITEC) of Honduras. Together we had a group of 6 faculty members and approximately 30 undergraduate students. Our house is ‘The EASI’ House, which stands for Efficient, Affordable, Solar Innovation. The EASI house is rectangular with two bedrooms and one bath, and offers a total square footage of 680. Based on competition estimates, The EASI house costs roughly $121,000. The EASI house has a 5kW solar system. Faculty and students from all three institutions were represented at the competition in Irvine California. Team MASSCA did well considering this was our first entry in the Solar Decathlon competition. Team MASSCA won the following awards: First Place – Affordability Contest Second Place – Energy Balance Contest. The competition provided a great experience for our students (and faculty as well). This competition provided leadership, endurance, and technical knowledge/skills for our students, and was the single most important hands-on experience during their undergraduate years. We are extremely pleased with the awards we received. At the same time we have learned from our efforts and would do better if we were to compete in the future. Furthermore, as a result of our team’s Inter-Americas collaborative effort, UTP and WNE have partnered to form Team PANAMASS (PANAma and MASSachusetts) and have developed The 3 SMART House for the inaugural Solar Decathlon Latin America & Caribbean competition held in Colombia.

  1. Mantle Xenoliths of Cerro Mercedes, Costa Rica, Central America

    NASA Astrophysics Data System (ADS)

    Lindsay, F. N.; Carr, M. J.; Herzberg, C. T.; Feigenson, M. D.

    2003-12-01

    Mantle peridotite occurs as xenoliths in lavas and bombs at Cerro Mercedes, a Plio-Quaternary potassic alkaline basalt volcano approximately 70 km behind the volcanic front of northern Costa Rica (Tournon and Alvarado, 1997). Mineral exploration led to the first discovery of abundant mantle xenoliths in Central America (Vargas and Alfaro, 1992). The compositions of 71 xenoliths recovered in January 2003 include dunite, harzburgite, lherzolite and olivine websterite. Twenty xenoliths have a diameter of at least 3 cm. The nodules are abundant in basalt outcrops and the rare bombs. In spite of substantial soil development in a rain forest environment, both xenoliths and host lava remain well preserved. Olivine, pyroxenes and spinel are common, plagioclase is present and garnet appears to be absent. There is no obvious shearing or deformation and several pyroxenes are as much as 1 cm in diameter. The mineralogy suggests a relatively shallow upper mantle source, within either the lithosphere or possibly the uppermost asthenosphere. Cerro Mercedes, at latitude 10° 58' N and longitude 82° 21' W, lies along the Rio San Juan, which is locally the border between Nicaragua and Costa Rica, Central America. This location approximately coincides with a boundary between dominantly depleted mantle to the northwest and OIB or Galapagos-like mantle to the southeast. We will use mineralogical data to better define the likely depths and oxidation states of representative nodules and isotopic data to define the type of mantle source.

  2. 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.

  3. 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

  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. The Affect of Drug Trafficking in West Africa on the National Security Interests of the United States of America

    DTIC Science & Technology

    2015-06-12

    Latin America and Asia to end users in North America, Europe, the Middle East, and Asia. The type of illegal substances has expanded from cocaine and...heroin to amphetamine- type stimulants. West Africa is particularly susceptible to influence by transnational criminal organizations (TCOs) due to

  6. 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

  7. 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

  8. 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.

  9. Coughing and fever after surfing in Central America.

    PubMed

    Pongratz, Peter; Laferl, Hermann; Strau, Günther; Stanek, Gerold; Wenisch, Christoph

    2012-11-01

    We report the case of a 19-year-old surfer, returning from Central America, who presented with chronic cough. The X-ray and full blood count, which had been performed in Costa Rica, were without pathology; laboratory parameters showed slightly increased C-reactive protein (59 mg/l). Malaria was excluded by thick smear. Immune serological tests for typhus, paratyphus, brucellosis, rickettsioses, leptospirosis and dengue fever were negative. An ambulant antimicrobial treatment was without any clinical effect. A computer tomography of the thorax showed a solid lesion (30 × 20 mm, middle lobe of the right lung). The patient rejected a bronchoscopic examination. He decided to be treated after his return to Austria. Here, we could substantiate a pulmonal histoplasmosis by a positive immune diffusion test. The patient was successfully treated with itraconazole.

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

    USGS Publications Warehouse

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

    2000-01-01

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

  11. Linkages of Biodiversity and Canopy Lidar Metrics in Central Africa

    NASA Astrophysics Data System (ADS)

    Laporte, N. T.; Horning, N.; Morgan, D.

    2012-12-01

    Central Africa contains the second largest dense humid forest in the world, and one of the largest carbon and biodiversity reservoirs on Earth. With 60% of the forest currently under logging concessions, the Congo basin is poised to undergo extensive land use change. Increases in bushmeat trade, resulting from extensification of logging roads, have already been well documented. From a quantitative standpoint, little is known of the structure of these forests, how logging affects forest biomass or functioning, and how canopy habitat heterogeneity relates to animal species richness or diversity. Here we document, using random forest and MaxEnt, how information from GLAS lidar metrics, ALOS-PalSAR and Landsat imagery, combined with field observations of great ape nest locations ( figure 1) and vegetation types, can be merged to create a map of gorilla and chimpanzee habitat in a region spanning Cameroon, the Republic of Congo, and the Central African Republic. From an initial selection of 48 variables we found the most important for mapping habitat suitability were a combination of PalSAR backscatter, NDVI image texture. Landsat ETM+ top of the atmosphere reflectance and principle component images. While NDVI from ETM+bands was an important predictor of gorilla and chimpanzee nest presence, species-specific differences in habitat use were also identified. Tree canopy height from GLAS was the most important variable predicting chimpanzee nesting habitat, while Landsat ETM+ bands were most important for gorilla nesting habitat. These preliminary results indicate merging field observations with satellite imagery promises to significantly improve our understanding of ape habitat-use at the landscape scale.ombining GLAS lidar metrics, ALOS-PalSAR and Landsat imager with field observations of great ape nest locations for habitat mapping in C. Africa

  12. 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.

  13. Convergent evolution of gigantism in damselflies of Africa and South America? Evidence from nuclear and mitochondrial sequence data.

    PubMed

    Groeneveld, Linn F; Clausnitzer, Viola; Hadrys, Heike

    2007-02-01

    Extreme large body size is rare in modern Zygoptera (damselflies). Only the South and Central American damselfly family Pseudostigmatidae and one African species, Coryphagrion grandis, share the morphological trait of gigantism. By means of phylogenetic analyses using two mitochondrial markers (16S rDNA and ND1) and one nuclear marker (EF1) in combination with an existing morphological data set, we trace the evolution of gigantism in damselflies. Individual and combined data sets were analyzed using the maximum parsimony, minimum evolution and maximum likelihood algorithms. Regardless of the algorithm used and the data set analyzed all principal tree topologies support a monophyly of the damselfly taxa displaying giant body size. This supports the view that the evolution of gigantism in damselflies from Africa and South America is not the result of convergent evolution due to strikingly similar habitat preferences, but rather the result of close genealogical relationship. Because modern odonates evolved before the split of Africa from Gondwanaland, the proposed phylogeny suggests that C. grandis represents a Gondwana relict.

  14. 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…

  15. Geology and petroleum resources of central and east-central Africa

    SciTech Connect

    Peterson, J.A.

    1986-05-01

    The petroleum provinces of central and east-central Africa include the Somali basin, the Ethiopian plateau and rift belt, and the central African rift basins. The western shelf on the Somali basin in the horn of Africa contains a sedimentary cover 1000-10,000 m (3000-3500 ft) thick of Mesozoic and Tertiary marine and continental clastic, carbonate, and evaporite deposits with good reservoir and potentially adequate source rock properties. To date, no commercial oil or gas discoveries have been made. The Ethiopian plateau and rift belt is a high-risk area with minimum potential for commercial petroleum because the Neogene rifting origin of the province has resulted in high geothermal gradients, extensive volcanism, and inadequate marine deposits and petroleum source rocks. The central Africa interior basins are continental craton-rifted depressions of Late Cretaceous and Tertiary age containing as much as 4000 m (13,000 ft) or more of fluvial and lacustrine clastic beds, which inter-tongue with nearshore marine clastic and carbonate beds in the western basins. Since the mid-1970s, approximately 13 oil discoveries have been made in the Upper Nile, Doba-Doseo, and Chad basins. These basins produce from fluvial and lacustrine sandstone reservoirs, sourced by lacustrine organic shale beds of Cretaceous age. The Benue trough is a rifted depression of middle Cretaceous age adjoined on the southwest by the prolific Niger Delta petroleum province. The trough is filled with 6000 m (20,000 ft) or more of clastic and carbonate marine and continental rocks of late Early Cretaceous and early Cenozoic age. Very few exploratory wells have been drilled, and no commercial discoveries have been made although good reservoir and source rocks are present.

  16. Rapid diagnostic tests for neurological infections in central Africa.

    PubMed

    Yansouni, Cedric P; Bottieau, Emmanuel; Lutumba, Pascal; Winkler, Andrea S; Lynen, Lut; Büscher, Philippe; Jacobs, Jan; Gillet, Philippe; Lejon, Veerle; Alirol, Emilie; Polman, Katja; Utzinger, Jürg; Miles, Michael A; Peeling, Rosanna W; Muyembe, Jean-Jacques; Chappuis, François; Boelaert, Marleen

    2013-06-01

    Infections are a leading cause of life-threatening neuropathology worldwide. In central African countries affected by endemic diseases such as human African trypanosomiasis, tuberculosis, HIV/AIDS, and schistosomiasis, delayed diagnosis and treatment often lead to avoidable death or severe sequelae. Confirmatory microbiological and parasitological tests are essential because clinical features of most neurological infections are not specific, brain imaging is seldom feasible, and treatment regimens are often prolonged or toxic. Recognition of this diagnostic bottleneck has yielded major investment in application of advances in biotechnology to clinical microbiology in the past decade. We review the neurological pathogens for which rapid diagnostic tests are most urgently needed in central Africa, detail the state of development of putative rapid diagnostic tests for each, and describe key technical and operational challenges to their development and implementation. Promising field-suitable rapid diagnostic tests exist for the diagnosis of human African trypanosomiasis and cryptococcal meningoencephalitis. For other infections-eg, syphilis and schistosomiasis-highly accurate field-validated rapid diagnostic tests are available, but their role in diagnosis of disease with neurological involvement is still unclear. For others-eg, tuberculosis-advances in research have not yet yielded validated tests for diagnosis of neurological disease.

  17. Intraseasonal atmospheric variability and its interannual modulation in Central Africa

    NASA Astrophysics Data System (ADS)

    Sandjon, Alain Tchakoutio; Nzeukou, Armand; Tchawoua, Clément

    2012-08-01

    The spatial and temporal structures of the intraseasonal atmospheric variability over central Africa is investigated using 2.5° × 2.5° daily outgoing longwave radiation (OLR) and National Centers for Environmental Prediction (NCEP) Reanalysis zonal winds for the period 1980-2010. The study begins with an overview of the Central African rainfall regime, noting in particular the contrast amongst Western and Eastern parts, with different topography and surface conditions features. The annual mean rainfall and OLR over the region revealed a zone of intense convective activity centered on the equator near 30°E, which extends southward and covers almost all the Congo forest. The annual cycle of rainfall reflects the classical bi-annual shift of Inter-Tropical Convergence Zone across the equatorial belt, between 10°S and 10°N. The result of the empirical orthogonal functions (EOFs) analysis has shown that the three leading EOF modes explain about 45 % of total intraseasonal variability. The power spectra of all the three corresponding principal components (PCs) peak around 45-50 days, indicating a Madden-Julian Oscillation (MJO) signal. The first mode exhibits high positive loadings over Northern Congo, the second over Southern Ethiopia and the third over Southwestern Tanzania. The PCs time series revealed less interannual modulation of intraseasonal oscillations for the Congo mode, while Ethiopian and Tanzanian modes exhibit strong interannual variations. Hövmoller plots of OLR, 200 and 850 hPa NCEP zonal winds found the eastward propagating features to be the dominant pattern in all the three times series, but this propagation is less pronounced in the OLR than in the 850 and 200 hpa zonal wind anomalies. An index of MJO strength was built by averaging the 30-50 day power for each day. A plot of MJO indices and El Niño Southern Oscillation (ENSO) cycle confirm a strong interannual modulation of MJO over Eastern central Africa partially linked with the ENSO

  18. Phylogenetic relationship of Hepatozoon blood parasites found in snakes from Africa, America and Asia.

    PubMed

    Haklová, B; Majláthová, V; Majláth, I; Harris, D J; Petrilla, V; Litschka-Koen, T; Oros, M; Peťko, B

    2014-03-01

    The blood parasites from the genus Hepatozoon Miller, 1908 (Apicomplexa: Adeleida: Hepatozoidae) represent the most common intracellular protozoan parasites found in snakes. In the present study, we examined 209 individuals of snakes, from different zoogeographical regions (Africa, America, Asia and Europe), for the occurrence of blood parasites using both molecular and microscopic examination methods, and assess phylogenetic relationships of all Hepatozoon parasites from snakes for the first time. In total, 178 blood smears obtained from 209 individuals, representing 40 species, were examined, from which Hepatozoon unicellular parasites were found in 26 samples (14·6% prevalence). Out of 180 samples tested by molecular method polymerase chain reaction (PCR), the presence of parasites was observed in 21 individuals (prevalence 11·6%): 14 snakes from Africa belonging to six genera (Dendroaspis, Dispholidus, Mehelya, Naja, Philothamnus and Python), five snakes from Asia from the genus Morelia and two snakes from America, from two genera (Coluber and Corallus). The intensity of infection varied from one to 1433 infected cells per 10 000 erythrocytes. Results of phylogenetic analyses (Bayesian and Maximum Likelihood) revealed the existence of five haplotypes divided into four main lineages. The present data also indicate neither geographical pattern of studied Hepatozoon sp., nor congruency in the host association.

  19. First imported Plasmodium ovale malaria in Central America: case report of a Guatemalan soldier and a call to improve its accurate diagnosis.

    PubMed

    Castellanos, María Eugenia; Díaz, Sheilee; Parsons, Emily; Peruski, Leonard F; Enríquez, Fabiola; Ramírez, Juan Luis; Padilla, Norma

    2015-01-01

    The Mesoamerican Ministers of Health have set 2020 as the target for malaria elimination to be achieved in the region. Imported malaria cases are a potential threat to countries attempting elimination or working to prevent resurgence. We report the first imported Plasmodium ovale infection with molecular confirmation in Central America, which occurred in a Guatemalan soldier that had been deployed in Africa. The obstacles for its diagnosis using the standard microscopy technique and the need to improve its detection are discussed.

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

    ERIC Educational Resources Information Center

    Serrano, Jorge A.

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

  2. Pre-Cenozoic tectonic framework of Central America

    SciTech Connect

    Horne, G.S.

    1985-01-01

    Central America (C.A.) lies along the junctions of five crustal plates at the western edge of the Caribbean. Major fault zones divide it into at least three blocks, each of which has experienced a distinct tectonic history. Although the region has been dominated by plate interactions during the Cenozoic, paleogeographic and palinspastic relations among the various blocks is increasingly obscure and conjectural back through the Phanerozoic. Pre-Mesozoic rocks are unknown in southern C.A., but are widespread as metamorphic basement complexes in northern C.A. The Maya basement consists of Precambrian igneous massifs and Lower Paleozoic metasedimentary sequences cut by mid-Paleozoic plutons, unconformably overlain locally by Upper Paleozoic terrestrial-to-marine strata. The Chorotega-Choco basement is a Late Mesozoic ophiolite sequence accreted with Upper Cretaceous and Lower Tertiary deep marine volcanic and sedimentary strata into a forearc subduction complex along the Pacific margin. By contrast, Mesozoic successions on the Maya and Chortis blocks are cratonic and grossly similar, consisting of basal transgressive clastics, one or more thick Lower Cretaceous rudistid limestone units, and fluvial-deltaic terrigenous redbed sequences; sections vary in detail locally, and evaporites are common on the Maya block. The Late Cretaceous along the Maya-Chortis boundary was characterized by plate collision, ophiolite obduction, and sinistral block translation.

  3. 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.

  4. A regional dynamic vegetation-climate model for Central America

    NASA Astrophysics Data System (ADS)

    Snell, R. S.; Cowling, S. A.; Smith, B.

    2009-12-01

    Global vegetation models simulate the distribution of vegetation as a function of climate. Dynamic global vegetation models (DGVMs) are also able to simulate the vegetation shifts in response to climate change, which makes them particularly useful for addressing questions about past and future climate scenarios. However, DGVMs have been criticized for using generic plant functional types (PFTs) and running the models at a coarse grid cell resolution. Regional dynamic vegetation models are able to simulate important landscape variation, since they use a finer resolution and specific PFTs for their region. Regional studies have typically focused on boreal or temperate ecosystems in North America and Europe. We will be presenting the results of applying a dynamic regional vegetation-climate model (LPJ-GUESS) for Central America. Initially, the model was run with the described global PFTs. However, several biomes were very poorly represented. Two PFTs were added: a Tropical Needleleaf Evergreen Tree to improve the simulation of the Mixed Pine-Oak biome, and a Desert Shrub to capture the Xeric Shrublands. The overall distribution of biomes was visually similar, however the Kappa statistic indicated a poor agreement with the potential biome map (overall Kappa = 0.301). The Kappa statistic did improve as we aggregated cell sizes and simplified the biomes (overall Kappa = 0.728). Compared to remote sensing data, the model showed a strong correlation with total LAI (r = 0.75). The poor Kappa statistic is likely due to a combination of factors. The way in which biomes are defined by the author can have a large influence on the level of agreement between simulated and potential vegetation. The Kappa statistic is also limited to comparing individual grid cells and thus, cannot detect overall patterns. Examining those areas which are poorly represented will help to identify future work and improve the representation of vegetation in these ecological models. In particular, the

  5. Petroleum developments in central and southern Africa in 1979

    SciTech Connect

    Rachwal, C.A.; Destefano, E.R.

    1980-11-01

    This review presents developments in petroleum exploration and production during 1979 in 44 countries of central and southern Africa. Petroleum production from 7 countries increased 16.6% to a new record 1,006,846,691 bbl (2.758 million b/d). Nigeria increased production 21% to 845 million, Congo 11.5% to 19 million, and Cameroon 17.6% to 12.5 million bbl. Gabon continued to show a decline in production, off 7.6% at 70.5 million bbl. Surface exploration work decreased 17.5% to 174.9 party-months, though figures on Nigeria are incomplete. Exploration drilling yielded 43 oil and 10 gas wells out of 111 drilled, a 47.7% success rate. Cameroon had 21 and Congo 8 new-field discovery and appraisal wells, up from 11 and 1 respectively in 1978. Development wells numbered 137 of which 86% were successful completions; 45 rigs were operating at year end.

  6. Civil war and the spread of AIDS in Central Africa.

    PubMed

    Smallman-Raynor, M R; Cliff, A D

    1991-08-01

    Using ordinary least squares regression techniques this paper demonstrates, for the first time, that the classic association of war and disease substantially accounts for the presently observed geographical distribution of reported clinical AIDS cases in Uganda. Both the spread of HIV 1 infection in the 1980s, and the subsequent development of AIDS to its 1990 spatial pattern, are shown to be significantly and positively correlated with ethnic patterns of recruitment into the Ugandan National Liberation Army (UNLA) after the overthrow of Idi Amin some 10 years earlier in 1979. This correlation reflects the estimated mean incubation period of 8-10 years for HIV 1 and underlines the need for cognizance of historical factors which may have influenced current patterns of AIDS seen in Central Africa. The findings may have important implications for AIDS forecasting and control in African countries which have recently experienced war. The results are compared with parallel analyses of other HIV hypotheses advanced to account for the reported geographical distribution of AIDS in Uganda.

  7. An 85-ka Paleoclimate Record From Lowland Central America

    NASA Astrophysics Data System (ADS)

    Escobar, J.; Hodell, D. A.; Anselmetti, F. S.; Ariztegui, D.; Brenner, M.; Curtis, J. H.; Gilli, A.; Grzesik, D. A.; Guilderson, T. J.; Müller, A. D.; Bush, M. B.; Correa-Metrio, A.; Kutterolf, S.

    2008-05-01

    Lake sediment cores recovered at seven sites in Lake Peten Itza, northern Guatemala, contain a record of climate change from lowland Central America extending back to ~200 ka. Drill cores at site PI-6 contain a high- resolution record (1 m/ka) for the last ~85 ka. Peten climate generally varied between wetter conditions during interstadials and a drier state during stadials of Marine Isotope Stage (MIS) 3. The most arid periods coincided with Heinrich Events in the North Atlantic and reductions in the strength of meridional overturning circulation. The pattern of clay-gypsum (wet-dry) oscillations during MIS 3 closely resembles the temperature record from Greenland ice cores and North Atlantic marine sediment cores and precipitation proxies from the Cariaco Basin. Previous studies suggested that cool, dry conditions prevailed in the region during the last glacial maximum (LGM) chronozone, ~23 to 18 ka BP. Sedimentologic and palynologic data support a moist climate in the Peten lowlands during this period whenvegetation consisted of a temperate pine-oak forest. This finding contradicts the previous inferences. At the end of the LGM, Peten climate switched abruptly from moist to arid conditions during the so-called "Mystery Period" from 18 to 14.9 ka. Moister conditions prevailed during the warmer Bolling-Allerod (14.7 to 12.8 ka), with the exception of a drier climate, with greater δ18O values between ca. 14.5 and 13.5 ka BP. This drier period in Central America coincided with Meltwater Pulse 1A (14.1- 13.5 ka) (Fairbanks et al., 2005) when a substantial volume of glacial meltwater was introduced to the Gulf of Mexico (e.g. Flower et al., 2004). The greatest δ18O values in Peten Itza occurred at 13.7 ka coinciding with the greatest rate of sea level rise (4.3 cm yr-1) at 13.9 ka. In contrast, sea surface temperature (SST) reconstructions (Lea et al., 2003), color reflectance, and elemental (Fe, Ti) data (Peterson et al., 2000) from Cariaco Basin cores, north of

  8. Forearc sedimentation in Terraba Trough, Costa Rica, Central America

    SciTech Connect

    Yuan, P.B.; Lowe, D.R.

    1987-05-01

    Sedimentary rocks of Terraba Trough, Costa Rica, were deposited in a forearc basin developed at an ocean-ocean convergent boundary. The basin developed in the middle to late Eocene when the Farallon plate began its subduction beneath the Caribbean plate. Shallow-water carbonates of the Brito Formation were deposited on shoals of basement blocks. These were surrounded by deeper marine areas in which volcaniclastics and carbonate debris accumulated. The Brito Formation consists of algal-foraminiferal packstone to grainstone, rudstone, and rare wackestone formed in fore-slope, carbonate buildup, and open platform environments in a warm, tropical sea. The Eocene Brito Formation is overlain by rocks of the upper Oligocene Rio Claro Member of the Terraba Formation. It is composed of rhodolite and bioclastic grainstone deposited in shallow water. A combination of little subsidence, mild volcanism, and possible erosion at about 30 Ma during a global drop of sea level may be responsible for the absence of lower Oligocene rocks in the study area. After the deposition of the Rio Claro Member, the area subsided rapidly to become a trough possibly deeper than 2000 m. Sedimentation took place in deep water from sediment gravity flows. In the early to early middle Miocene, coarser sediments and thicker sand units containing coal fragments became more abundant, suggesting that the basin was gradually filled. This study indicates that the timing and degree of subsidence of the fore-arc basin and the vertical variation in lithology are closely related to the variation in convergence rate between lithospheric plates in this part of Central America and the eastern Pacific.

  9. 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.

  10. 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.

  11. Rural Development in Africa: A Bibliography. (Part I: General, Central, East). Training & Methods Series Number 16.

    ERIC Educational Resources Information Center

    Anderson, Teresa, Comp.; And Others

    Compiled in July, 1971, this bibliography lists approximately 1,950 books, journal articles, and unpublished manuscripts dealing with rural development in Africa generally and in central and east Africa specifically. General entries appear under the following headings: agriculture; economic affairs; bibliography; law; economic and technical…

  12. Paleogeographic and Tectonic Implications of Paleomagnetic Data From Mexico, Central America, Northern South America and Caribbean Arc

    NASA Astrophysics Data System (ADS)

    Urrutia-Fucugauchi, J.; Alva-Valdivia, L.; Goguitchaishvili, A.; Soler-Arechalde, A.; Benammi, M.

    2006-05-01

    Results from recent paleomagnetic studies in Mexico, Cuba, Dominican Republic, El Salvador, Nicaragua and Costa Rica are summarized and discussed in terms of their tectonic and paleogeographic implications. Rock units studied range in age from Jurassic to Neogene. Additionally, we present an updated paleomagnetic database for widely distributed localities from Mexico, Central America, northern South America and the Caribbean. Paleomagnetic constraints are analyzed within a paleogeographic and tectonic framework, which departs from models for continental plate collision of North and South America, including intervening terranes, and subsequent evolution of the Atlantic bordering continental land masses. Most paleoreconstructions imply an allochthonous nature for most of Mexico, Central America and Caribbean. Mesozoic and early Cenozoic evolution of the region has been dominated by Pangea assembly and subsequent drift apart of major continental plates of North and South America following break up of the Pangea supercontinent. Separation of North and South America and opening of the central North Atlantic Ocean permitted development of the Gulf of Mexico and eastward motion of the proto Caribbean plate. Terrane accretion, block rotation and lateral movements are recorded for terranes in Mexico, associated with terrane amalgamation, Gulf of Mexico opening, plate tectonic re-organizations, margin truncation and compression/extensional intra-plate and margin deformation. Paleomagnetic data from the Antilles arc document the occurrence of vertical-axis block rotations, associated with arc development and pull-apart basins. Data from volcanic units in El Salvador do not support occurrence of vertical-axis rotations during the Neogene, as had been proposed for the Central American arc. Paleomagnetic studies provide quantitative information on paleolatitude, latitudinal translations and relative rotations of large and small tectonic blocks, assisting in distinguishing and

  13. IFLA General Conference 1988. Division of Regional Activities. Sections on: Asia and Oceania; Africa; Latin America and the Caribbean; Australia.

    ERIC Educational Resources Information Center

    International Federation of Library Associations, The Hague (Netherlands).

    The eight papers in this collection focus on library activities in various geographical regions, e.g., Asia, Oceania, Africa, Latin America, the Caribbean, and Western Australia: (1) "Future Approaches and Prospects of Computerised Information Network among the Countries of South Asian Association for Regional Cooperation (SAARC)" (Abdullah…

  14. 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... Department trade mission calendar on www.export.gov , the Trade Americas Web page at ( http://export.gov/tradeamericas/tradeevents/trademissions/centralamericajuly2013/index.asp ), and other Internet Web sites,...

  15. Uncertainties in crustal thickness models for data sparse environments: A review for South America and Africa

    NASA Astrophysics Data System (ADS)

    van der Meijde, M.; Fadel, I.; Ditmar, P.; Hamayun, M.

    2015-03-01

    With the recently available high resolution gravity data from the GOCE satellite a whole range of crustal thickness models have been derived. The added value of GOCE is that it provides data globally, including regions that are poorly covered by seismological studies, like large parts of Africa and South America. Potentially these models can provide new insight in crustal structure for these data poor regions. We compare different models of crustal thickness for South America and Africa and attempt to assess the quality of different modelling techniques and the impact of different data sources. We introduce one new global crustal thickness model based on gravity data, DMM-1, and use seven additional, recently published, continental or global crustal thickness models based on gravity or seismological data. All models use different modelling techniques, and either gravity (four models) or seismological data (four models). We will show that significant differences exist between the models but that these cannot be directly related to the used data. Choices made in the selection and parametrization of the various modelling techniques have more impact than using different data sources including data sources of supposed higher quality. The significant differences, up to 28 km, between models can have a major influence on geodynamical analysis for the two continents. We propose that future work should focus on developing a standard for modelling in data sparse environments, and expanding seismological efforts in those regions that are most different between the shown models to verify the actual crustal thickness. Furthermore, the contribution and inclusion of (satellite) gravity data in crustal thickness models should be further explored.

  16. Synthetic Minor NSR Permit: BP America Production Company - Salvador I/II Central Delivery Point

    EPA Pesticide Factsheets

    This page contains the final synthetic minor NSR permit for the BP America Production Company, Salvador I/II Central Delivery Point, located on the Southern Ute Indian Reservation in La Plata County, CO.

  17. Synthetic Minor NSR Permit: BP America Production Company - Wolf Point Central Delivery Point

    EPA Pesticide Factsheets

    This page contains the response to public comments and the final synthetic minor NSR permit for the BP America Production Company, Wolf Point Central Delivery Point, located on the Southern Ute Indian Reservation in La Plata County, CO.

  18. Synthetic Minor NSR Permit: BP America Production Company - Treating Site #8 Central Delivery Point

    EPA Pesticide Factsheets

    This page contains the response to public comments and the final synthetic minor NSR permit for the BP America Production Company, Treating Site #8 Central Delivery Point, located on the Southern Ute Indian Reservation in La Plata County, CO.

  19. Characterization of the Mid Summer Drought in the Central Valley of Costa Rica, Central America

    NASA Astrophysics Data System (ADS)

    Alfaro, E.

    2013-05-01

    The IAS region is characterized by climate features of unique nature, one of them is the Mid-Summer Drought (MSD) or "veranillo", an atmospheric feature rarely observed in other tropical regions. On the Pacific slope of Central America, the precipitation annual cycle is characterized by two rainfall maxima in June and September-October, an extended dry season from November to May, and a secondary precipitation minima during July-August (MSD). Three daily gauge stations records, e.g. La Argentina, Fabio Baudrit and Juan Santamaria, located in the Central Valley of Costa Rica were studied to characterize the MSD from 1937 to 2010. Among the aspects considered are the MSD duration, intensity, timing and seasonal predictability. The modulation of these aspects by climate variability sources as Equatorial Eastern Pacific and Tropical North Atlantic was lately explored, including their interannual and decadal variability. The MSD signal strongly impact social and economic life in the region like energy and the agriculture sector. Additionally, the Central Valley of Costa Rica hosts most of the Costa Rican population with the higher level of exposure and vulnerability to hydro-meteorological hazards.

  20. 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

  1. Qualitative Description of Global Health Nursing Competencies by Nursing Faculty in Africa and the Americas

    PubMed Central

    Wilson, Lynda; Moran, Laura; Zarate, Rosa; Warren, Nicole; Ventura, Carla Aparecida Arena; Tamí-Maury, Irene; Mendes, Isabel Amélia Costa

    2016-01-01

    Abstract Objective: to analyze qualitative comments from four surveys asking nursing faculty to rate the importance of 30 global health competencies for undergraduate nursing programs. Method: qualitative descriptive study that included 591 individuals who responded to the survey in English (49 from Africa and 542 from the Americas), 163 who responded to the survey in Spanish (all from Latin America), and 222 Brazilian faculty who responded to the survey in Portuguese. Qualitative comments were recorded at the end of the surveys by 175 respondents to the English survey, 75 to the Spanish survey, and 70 to the Portuguese survey. Qualitative description and a committee approach guided data analysis. Results: ten new categories of global health competencies emerged from the analysis. Faculty also demonstrated concern about how and when these competencies could be integrated into nursing curricula. Conclusion: the additional categories should be considered for addition to the previously identified global health competencies. These, in addition to the guidance about integration into existing curricula, can be used to guide refinement of the original list of global health competencies. Further research is needed to seek consensus about these competencies and to develop recommendations and standards to guide nursing curriculum development. PMID:27276020

  2. Climate co-variability between South America and Southern Africa at interannual, intraseasonal and synoptic scales

    NASA Astrophysics Data System (ADS)

    Puaud, Yohan; Pohl, Benjamin; Fauchereau, Nicolas; Macron, Clémence; Beltrando, Gérard

    2016-08-01

    This paper investigates and quantifies co-variability between large-scale convection in the South American and Southern African sectors at different timescales (interannual, intraseasonal and synoptic), during the austral summer seasons (November-February) from 1979 to 2012. Multivariate analyses (Canonical Correlation Analysis and Principal Component Analysis) are applied to daily outgoing longwave radiation (OLR, used as a proxy for atmospheric convection) anomalies to extract the principal modes of variability and co-variability in each and between both regions, filtered to consider the appropriate time-scales. At the interannual timescale, results confirm the predominant role of El Niño Southern Oscillation (ENSO), favoring enhanced convection over both southeastern Brazil and northern Argentina on the one hand, and tropical Africa and the western Indian Ocean on the other hand. At the intraseasonal timescale, the leading mode of co-variability is related to modulations of large-scale atmospheric convection over most of South America, and 10 days later, tropical Southern Africa. This mode accounts for the impacts of the Madden-Julian-oscillation (MJO) over these regions: identifying robust co-variability at the intraseasonal timescale between both regions require thus to consider a temporal shift between the two sectors. At the synoptic scale, however, co-variability consists mostly of a synchronous modulation of the large-scale atmospheric convection over the South American and Southern African sectors. This results from the development of concomitant Rossby waves forming a continuous wave train over the South Atlantic in the mid-latitudes, affecting both the South Atlantic and South Indian Convergence Zones. Among the days when convection shows significant anomalies (30 % of the total days in each sector), this synchronous mode occurs about 25 % of the time, individual Rossby waves modulating convection over one single region only during the remaining 75

  3. 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…

  4. Autosomal and mtDNA Markers Affirm the Distinctiveness of Lions in West and Central Africa.

    PubMed

    Bertola, Laura D; Tensen, Laura; van Hooft, Pim; White, Paula A; Driscoll, Carlos A; Henschel, Philipp; Caragiulo, Anthony; Dias-Freedman, Isabela; Sogbohossou, Etotépé A; Tumenta, Pricelia N; Jirmo, Tuqa H; de Snoo, Geert R; de Iongh, Hans H; Vrieling, Klaas

    2015-01-01

    The evolutionary history of a species is key for understanding the taxonomy and for the design of effective management strategies for species conservation. The knowledge about the phylogenetic position of the lion (Panthera leo) in West/Central Africa is largely based on mitochondrial markers. Previous studies using mtDNA only have shown this region to hold a distinct evolutionary lineage. In addition, anthropogenic factors have led to a strong decline in West/Central African lion numbers, thus, the conservation value of these populations is particularly high. Here, we investigate whether autosomal markers are concordant with previously described phylogeographic patterns, and confirm the unique position of the West/Central African lion. Analysis of 20 microsatellites and 1,454 bp of the mitochondrial DNA in 16 lion populations representing the entire geographic range of the species found congruence in both types of markers, identifying four clusters: 1) West/Central Africa, 2) East Africa, 3) Southern Africa and 4) India. This is not in line with the current taxonomy, as defined by the IUCN, which only recognizes an African and an Asiatic subspecies. There are no indications that genetic diversity in West/Central Africa lions is lower than in either East or Southern Africa, however, given this genetic distinction and the recent declines of lion numbers in this region, we strongly recommend prioritization of conservation projects in West/Central Africa. As the current taxonomic nomenclature does not reflect the evolutionary history of the lion, we suggest that a taxonomic revision of the lion is warranted.

  5. Autosomal and mtDNA Markers Affirm the Distinctiveness of Lions in West and Central Africa

    PubMed Central

    Bertola, Laura D.; Tensen, Laura; van Hooft, Pim; White, Paula A.; Driscoll, Carlos A.; Henschel, Philipp; Caragiulo, Anthony; Dias-Freedman, Isabela; Sogbohossou, Etotépé A.; Tumenta, Pricelia N.; Jirmo, Tuqa H.; de Snoo, Geert R.

    2015-01-01

    The evolutionary history of a species is key for understanding the taxonomy and for the design of effective management strategies for species conservation. The knowledge about the phylogenetic position of the lion (Panthera leo) in West/Central Africa is largely based on mitochondrial markers. Previous studies using mtDNA only have shown this region to hold a distinct evolutionary lineage. In addition, anthropogenic factors have led to a strong decline in West/Central African lion numbers, thus, the conservation value of these populations is particularly high. Here, we investigate whether autosomal markers are concordant with previously described phylogeographic patterns, and confirm the unique position of the West/Central African lion. Analysis of 20 microsatellites and 1,454 bp of the mitochondrial DNA in 16 lion populations representing the entire geographic range of the species found congruence in both types of markers, identifying four clusters: 1) West/Central Africa, 2) East Africa, 3) Southern Africa and 4) India. This is not in line with the current taxonomy, as defined by the IUCN, which only recognizes an African and an Asiatic subspecies. There are no indications that genetic diversity in West/Central Africa lions is lower than in either East or Southern Africa, however, given this genetic distinction and the recent declines of lion numbers in this region, we strongly recommend prioritization of conservation projects in West/Central Africa. As the current taxonomic nomenclature does not reflect the evolutionary history of the lion, we suggest that a taxonomic revision of the lion is warranted. PMID:26466139

  6. Are the Maras Overwhelming Governments in Central America

    DTIC Science & Technology

    2006-12-01

    States, 4,000 members in canada, and a large presence in mexico .6 The numbers fluctu- ate—mara membership being dynamic, and gang membership is...better track movements of criminal organizations. Saca proposed a “Plan centroamerica Segura” (central american Security Plan) to the central...2005 where the presidents of all the central american nations were joined by representatives from mexico and the United States. more recently, the

  7. An investigation of MAGSAT and complementary data emphasizing precambrian shields and adjacent areas of West Africa and South America

    NASA Technical Reports Server (NTRS)

    Hastings, D. A. (Principal Investigator)

    1982-01-01

    The problems associated with the use of an interactive magnetic modeling program are reported and a publication summarizing the MAGSAT anomaly results for Africa and the possible tectonic associations of these anomalies is provided. An overview of the MAGSAT scalar anomaly map for Africa suggested a correlation of MAGSAT anomalies with major crustal blocks of uplift or depression and different degrees of regional metamorphism. The strongest MAGSAT anomalies in Africa are closely correlated spatially with major tectonic features. Results indicate that the Bangui anomaly may be caused by a central old Precambrian shield, flanked to the north and south by two relatively young sedimentary basins.

  8. 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.

  9. Lithosphere mechanical behavior inferred from tidal gravity anomalies: a comparison of Africa and South America

    NASA Astrophysics Data System (ADS)

    Mantovani, Marta S. M.; Shukowsky, Wladimir; de Freitas, Silvio R. C.; Brito Neves, Benjamim B.

    2005-02-01

    Earlier studies have shown that the amplitude difference of the M2 gravity tidal component (TGA) between the measured and calculated response for a viscoelastic Earth is significantly correlated to the effective elastic thickness (Te) of the lithosphere. Using a regression equation obtained from a global distribution, data from TGA were integrated with those obtained by other methods (gravity-topography coherence and thermo-mechanical analysis) providing a spatial coverage sufficient to establish regional Te patterns for South America and Africa. A comparison and association between the Te distributions for both continents indicates that for the African plate, the effective elastic thickness map clearly shows a remarkable dichotomy of the Neoproterozoic rocks and reworked older rocks. But for the case of South American plate that is moving faster than the African plate, lower Te values are observed only for areas where extensive tectonics with intense volcanism has acted, suggesting that a colder mantle underlies this continental plate, while a hotter asthenosphere is observed beneath the African plate. This is in part attributed to its relatively slow motion which prevented dissipating the earlier developed high temperature.

  10. GOCE Gradient Tensor Characterization of the Coupled Parana (South America) and Etendeka (Africa) Magmatic Provinces

    NASA Astrophysics Data System (ADS)

    Mariani, Patrizia; Braitenberg, Carla

    2015-03-01

    The Paraná-Etendeka Large Igneous Province (LIP) at the conjugate plate margins of South America and Africa is investigated with GOCE gradients. The LIP is associated to Gondwana breakup, and is asymmetric between the two margins. The study intends to investigate how the lithosphere is affected by continental breakup and what caused the asymmetry, considering that successive spreading is symmetric. The gradients at satellite and surface height are modelled with other geophysical data as seismic profiling, seismic tomography and bore-hole logs. Densities and velocities are modelled with a petrologic model. The residual gravity gradients, reduced of crustal thickness variations and sediments, are continuously high along the Angola and Namibia margin. Inversion shows the high is due to a density increase about 6 km thick with the top at about 23 km depth, placing it above the Moho. It is probable that the densification be due to magmatic intrusions, increasing the volume of the LIP at the African side, which remained trapped in the crust and produced only small volumes of surface basalts. This is true also for the margin of Angola, which in literature is claimed to be void of magmatism along its margin.

  11. 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

  12. Rural Development in Africa: A Bibliography. (Part I: General, Central, East). Training & Methods Series Number 16 (Supplement), March 1973.

    ERIC Educational Resources Information Center

    Anderson, Teresa, Comp.; Strey, Gerry, Comp.

    A supplement to the bibliography of materials dealing with Africa in the Land Tenure Center Library at the University of Wisconsin, this bibliography on rural development in Africa is divided into three major sections as follows: (1) General (400 entries); (2) Central Africa including a general section (2 entries); Cameroon (26 entries); Central…

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

    PubMed

    Kjellstrom, Tord; Crowe, Jennifer

    2011-01-01

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

  14. Central Africa Energy: Utilizing NASA Earth Observations to Explore Flared Gas as an Energy Source Alternative to Biomass in Central Africa

    NASA Technical Reports Server (NTRS)

    Jones, Amber; White, Charles; Castillo, Christopher; Hitimana, Emmanuel; Nguyen, Kenny; Mishra, Shikher; Clark, Walt

    2014-01-01

    Much of Central Africa's economy is centered on oil production. Oil deposits lie below vast amounts of compressed natural gas. The latter is often flared off during oil extraction due to a lack of the infrastructure needed to utilize it for productive energy generation. Though gas flaring is discouraged by many due to its contributions to greenhouse emissions, it represents a waste process and is rarely tracked or recorded in this region. In contrast to this energy waste, roughly 80% of Africa's population lacks access to electricity and in turn uses biomass such as wood for heat and light. In addition to the dangers incurred from collecting and using biomass, the practice commonly leads to ecological change through the acquisition of wood from forests surrounding urban areas. The objective of this project was to gain insight on domestic energy usage in Central Africa, specifically Angola, Gabon, and the Republic of Congo. This was done through an analysis of deforestation, an estimation of gas flared, and a suitability study for the infrastructure needed to realize the natural gas resources. The energy from potential natural gas production was compared to the energy equivalent of the biomass being harvested. A site suitability study for natural gas pipeline routes from flare sites to populous locations was conducted to assess the feasibility of utilizing natural gas for domestic energy needs. Analyses and results were shared with project partners, as well as this project's open source approach to assessing the energy sector. Ultimately, Africa's growth demands energy for its people, and natural gas is already being produced by the flourishing petroleum industry in numerous African countries. By utilizing this gas, Africa could reduce flaring, recuperate the financial and environmental loss that flaring accounts for, and unlock a plentiful domestic energy source for its people. II. Introduction Background Africa is home to numerous burgeoning economies; a

  15. 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.

  16. Developing a Climate Service: Using Hydroclimate Monitoring and Forecasting to Aid Decision Making in Africa and Latin America

    NASA Astrophysics Data System (ADS)

    Wood, E. F.; Sheffield, J.; Fisher, C. K.; Chaney, N.; Wanders, N.

    2015-12-01

    Hydrological and water scarcity predictions have the potential to provide vital information for a variety of needs including water resources management, agricultural and urban water supply, and flood mitigation. In particular, seasonal forecasts of drought risk can enable farmers to make adaptive choices on crop varieties, labor usage, and technology investments. Forecast skill is generally derived from teleconnections with ocean variability specifically sea surface temperature (SST) anomalies and, equally important persistence in the state of the land in terms of soil moisture, snowpack, or streamflow conditions. Short term precipitation forecasts are critical in flood prediction by extending flood prediction lead times beyond the basin travel time, and thus allows for extended warnings. The Global Framework for Climate Services (GFCS) is a UN-wide initiative in which WMO Members and inter- and non- governmental, regional, national and local stakeholders work in partnership to develop targeted climate services. Thus, GFCS offers the potential for hydroclimatologists to develop products (hydroclimatic forecasts) and information services (i.e. product dissemination) to users with the expectation that GFCS will increase the resilience of the society to weather and climate events and to reduce operational costs for economic sectors and regions dependent on water. This presentation will discuss the development of a nascent climate service system focused on hydroclimatic monitoring and forecasting, and initially developed by the authors for Africa and Latin America. Central to this system is the use of satellite remote sensing and hydroclimate forecasts (from days to seasons) in the development of weather and climate information useful for water management in sectors such as flood protection (precipitation and streamflow forecasting) and agriculture (drought and crop forecasting). The elements of this system will be discussed, including the challenges of monitoring and

  17. Mortality in Patients with HIV-1 Infection Starting Antiretroviral Therapy in South Africa, Europe, or North America: A Collaborative Analysis of Prospective Studies

    PubMed Central

    Boulle, Andrew; Schomaker, Michael; May, Margaret T.; Hogg, Robert S.; Shepherd, Bryan E.; Monge, Susana; Keiser, Olivia; Lampe, Fiona C.; Giddy, Janet; Ndirangu, James; Garone, Daniela; Fox, Matthew; Ingle, Suzanne M.; Reiss, Peter; Dabis, Francois; Costagliola, Dominique; Castagna, Antonella; Ehren, Kathrin; Campbell, Colin; Gill, M. John; Saag, Michael; Justice, Amy C.; Guest, Jodie; Crane, Heidi M.; Egger, Matthias; Sterne, Jonathan A. C.

    2014-01-01

    Background High early mortality in patients with HIV-1 starting antiretroviral therapy (ART) in sub-Saharan Africa, compared to Europe and North America, is well documented. Longer-term comparisons between settings have been limited by poor ascertainment of mortality in high burden African settings. This study aimed to compare mortality up to four years on ART between South Africa, Europe, and North America. Methods and Findings Data from four South African cohorts in which patients lost to follow-up (LTF) could be linked to the national population register to determine vital status were combined with data from Europe and North America. Cumulative mortality, crude and adjusted (for characteristics at ART initiation) mortality rate ratios (relative to South Africa), and predicted mortality rates were described by region at 0–3, 3–6, 6–12, 12–24, and 24–48 months on ART for the period 2001–2010. Of the adults included (30,467 [South Africa], 29,727 [Europe], and 7,160 [North America]), 20,306 (67%), 9,961 (34%), and 824 (12%) were women. Patients began treatment with markedly more advanced disease in South Africa (median CD4 count 102, 213, and 172 cells/µl in South Africa, Europe, and North America, respectively). High early mortality after starting ART in South Africa occurred mainly in patients starting ART with CD4 count <50 cells/µl. Cumulative mortality at 4 years was 16.6%, 4.7%, and 15.3% in South Africa, Europe, and North America, respectively. Mortality was initially much lower in Europe and North America than South Africa, but the differences were reduced or reversed (North America) at longer durations on ART (adjusted rate ratios 0.46, 95% CI 0.37–0.58, and 1.62, 95% CI 1.27–2.05 between 24 and 48 months on ART comparing Europe and North America to South Africa). While bias due to under-ascertainment of mortality was minimised through death registry linkage, residual bias could still be present due to differing approaches to and

  18. Forest refugia in Western and Central Africa as 'museums' of Mesozoic biodiversity.

    PubMed

    Murienne, Jérôme; Benavides, Ligia R; Prendini, Lorenzo; Hormiga, Gustavo; Giribet, Gonzalo

    2013-02-23

    The refugial speciation model, or 'species pump', is widely accepted in the context of tropical biogeography and has been advocated as an explanation for present species distributions in tropical Western and Central Africa. In order to test this hypothesis, a phylogeny of the cryptic arachnid order Ricinulei, based on four nuclear and mitochondrial DNA markers, was inferred. This ancient clade of litter-dwelling arthropods, endemic to the primary forests of Western and Central Africa and the Neotropics, might provide insights into the mode and tempo of evolution in Africa. Twenty-six African ricinuleid specimens were sampled from eight countries spanning the distribution of Ricinulei on the continent, and analysed together with Neotropical samples plus other arachnid outgroups. The phylogenetic and molecular dating results suggest that Ricinulei diversified in association with the fragmentation of Gondwana. The early diversification of Ricinoides in Western and Central Africa around 88 (±33) Ma fits old palaeogeographical events better than recent climatic fluctuations. Unlike most recent molecular studies, these results agree with fossil evidence, suggesting that refugia may have acted as 'museums' conserving ancient diversity rather than as engines generating diversity during successive episodes of climatic fluctuation in Africa.

  19. Backed tools in Middle Pleistocene central Africa and their evolutionary significance.

    PubMed

    Barham, Lawrence

    2002-11-01

    The fashioning of stone inserts for composite tools by blunting flakes and blades is a technique usually associated with Late Pleistocene modern humans. Recent reports from two sites in south central Africa (Twin Rivers and Kalambo Falls) suggest that this backed tool technology originated in the later Middle Pleistocene with early or "archaic" Homo sapiens. This paper investigates these claims critically from the perspective of the potential mixing of Middle and Later Stone Age deposits at the two sites and the possible creation of misleading assemblages. The review shows that backed tools form a statistically minor, but technologically significant feature of the early Middle Stone Age of south central Africa. They first appear in the Lupemban industry at approximately 300 ka and remain an element of the Middle Stone Age technological repertoire of the region. Comparisons are made with early backed tool assemblages of east Africa and with the much younger Howiesons Poort industry of southern Africa. The paper concludes that Lupemban tools lack the standardization of the Howiesons Poort backed pieces, but form part of a regionally distinctive and diverse assemblage of heavy and light duty tools. Some modern-like behaviours appear to have emerged by the later Middle Pleistocene in south central Africa.

  20. Forest refugia in Western and Central Africa as ‘museums’ of Mesozoic biodiversity

    PubMed Central

    Murienne, Jérôme; Benavides, Ligia R.; Prendini, Lorenzo; Hormiga, Gustavo; Giribet, Gonzalo

    2013-01-01

    The refugial speciation model, or ‘species pump’, is widely accepted in the context of tropical biogeography and has been advocated as an explanation for present species distributions in tropical Western and Central Africa. In order to test this hypothesis, a phylogeny of the cryptic arachnid order Ricinulei, based on four nuclear and mitochondrial DNA markers, was inferred. This ancient clade of litter-dwelling arthropods, endemic to the primary forests of Western and Central Africa and the Neotropics, might provide insights into the mode and tempo of evolution in Africa. Twenty-six African ricinuleid specimens were sampled from eight countries spanning the distribution of Ricinulei on the continent, and analysed together with Neotropical samples plus other arachnid outgroups. The phylogenetic and molecular dating results suggest that Ricinulei diversified in association with the fragmentation of Gondwana. The early diversification of Ricinoides in Western and Central Africa around 88 (±33) Ma fits old palaeogeographical events better than recent climatic fluctuations. Unlike most recent molecular studies, these results agree with fossil evidence, suggesting that refugia may have acted as ‘museums’ conserving ancient diversity rather than as engines generating diversity during successive episodes of climatic fluctuation in Africa. PMID:23193047

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

    ERIC Educational Resources Information Center

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

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

  2. Criticality of U.S. Military Presence in Central America

    DTIC Science & Technology

    2007-11-02

    authorities ( MACA ), nation assistance/support to counter-insurgency, noncombatant evacuation operations (NEO), peace operations, protection of...FOLs, the U.S. military commitment falls under the execution of Operation Central Skies. Interestingly, military assistance to civil authorities ( MACA

  3. Molecular phylogeny of Trypanosoma cruzi from Central America (Guatemala) and a comparison with South American strains.

    PubMed

    Iwagami, M; Higo, H; Miura, S; Yanagi, T; Tada, I; Kano, S; Agatsuma, T

    2007-12-01

    Molecular phylogenetic analysis was carried out for 21 strains of Trypanosoma cruzi, nine of which were obtained from Guatemala and 12 from South America. Phylogenetic trees were constructed using the nucleotide sequences of two nuclear gene regions, dihydrofolate reductase-thymidylate synthase (DHFR-TS) and trypanothione reductase (TR), and contiguous portions of two mitochondrial genes, cytochrome oxidase subunit II (COII) and reduced nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1). Possible genetic exchange between the rather divergent lineages of T. cruzi II from South America was suggested in the trees of the two nuclear genes. T. cruzi I strains obtained from Guatemala and Colombia were identical in all the genes examined, but other T. cruzi I isolates from South America were rather polymorphic in the DHFR-TS and mitochondrial genes. No genetic exchange was identified between T. cruzi I populations from Central and South America in the present study.

  4. Capacity-Building Programs Under the Dominican Republic-Central America-United States Free Trade Agreement (CAFTA-DR)

    EPA Pesticide Factsheets

    The United States signed the Dominican Republic-Central America-United States Free Trade Agreement (CAFTA-DR) in August 2004 with five Central American countries (Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua) and the Dominican Republic.

  5. Assessment of undiscovered oil and gas resources in Central and South America

    USGS Publications Warehouse

    ,

    2001-01-01

    The U.S. Geological Survey recently completed an assessment of undiscovered conventional oil and gas resources in 130 selected petroleum provinces of the world (USGS, 2000). Of these 130 provinces, 23 are in South America, Central America, and the Caribbean area (fig. 1). The assessed provinces range from established petroleum provinces with long histories of production such as the Maracaibo Basin to frontier provinces with little or no petroleum production such as the Guyana-Suriname Basin. Not all provinces with historic production or potential production were assessed for the USGS 2000 Assessment. At present we are assessing many of the remaining oil and gas provinces in Central and South America. In each province we (1) geologically defined total petroleum systems, (2) defined assessment units within total petroleum systems, and (3) assessed the volume of undiscovered conventional oil and gas in each assessment unit. We defined 26 total petroleum systems and 55 assessment units in the 23 provinces. 

  6. Forecasters Handbook for Central America and Adjacent Waters

    DTIC Science & Technology

    1989-09-01

    Pacific coast, just inland are fertile coastal lowlands for about 25 miles. The coastal Pacific lowlands then give way to the highlands of the southern and...central region, while the north is occupied by the plains of Pet6n. Approximately two-thirds of the country is occupied by highlands with the main...some active, the inland highlands extend from 3500 - 8000 feet in elevation. Very near the western border and at 13,845 feet, the Tajumulco Volcano is

  7. Fine Particulate Pollution and Source Apportionment in the Urban Centers for Africa, Asia and Latin America

    NASA Astrophysics Data System (ADS)

    Guttikunda, S. K.; Johnson, T. M.; Procee, P.

    2004-12-01

    Fossil fuel combustion for domestic cooking and heating, power generation, industrial processes, and motor vehicles are the primary sources of air pollution in the developing country cities. Over the past twenty years, major advances have been made in understanding the social and economic consequences of air pollution. In both industrialized and developing countries, it has been shown that air pollution from energy combustion has detrimental impacts on human health and the environment. Lack of information on the sectoral contributions to air pollution - especially fine particulates, is one of the typical constraints for an effective integrated urban air quality management program. Without such information, it is difficult, if not impossible, for decision makers to provide policy advice and make informed investment decisions related to air quality improvements in developing countries. This also raises the need for low-cost ways of determining the principal sources of fine PM for a proper planning and decision making. The project objective is to develop and verify a methodology to assess and monitor the sources of PM, using a combination of ground-based monitoring and source apportionment techniques. This presentation will focus on four general tasks: (1) Review of the science and current activities in the combined use of monitoring data and modeling for better understanding of PM pollution. (2) Review of recent advances in atmospheric source apportionment techniques (e.g., principal component analysis, organic markers, source-receptor modeling techniques). (3) Develop a general methodology to use integrated top-down and bottom-up datasets. (4) Review of a series of current case studies from Africa, Asia and Latin America and the methodologies applied to assess the air pollution and its sources.

  8. Sedimentary basins on the connugate margins of South America and Africa

    SciTech Connect

    Moore, G.T. )

    1990-05-01

    An Early Cretaceous spreading system formed the South Atlantic by separating South America from Africa along two subparallel major transform fault systems. The distribution of major sedimentary depocenters is controlled by the complex interplay of two factors: the late Mesozoic-Cenozoic cycle of sea-floor spreading and the legacy of a Precambrian collage of ancient cores that comprised western Gondwana. Three spreading modes created this configuration: rift, transform, and subduction. Each produces a different geometry and tectonic framework for the accumulation of sediment. Rifted margins (60%) contain basins that are elongate, form with their depocenter axes inboard of the ocean-continent transition, and rest on a tectonically complex, foundered basement. Transform margins have abrupt ocean-continent transitions. Such margins (30%) may be sediment starved or contain a thick sedimentary section controlled by the volcanic ridges of transform faults. Off Tierra del Fuego, Burdwood Bank is bounded on the north by a fossil (aseismic) subduction zone. The associated basin is an elongate, deformed accretionary prism of sediments on a gently dipping, faulted oceanic plate. The South Atlantic margins are divisible into 68 basins or segments that collectively contain over 33 {times} 106 km{sup 3} of syn- and postbreakup sediments. The South American margin contains 22 {times} 10{sup 6} km{sup 3} in 46 basins, and the African margin, 11 {times} 10{sup 6} km{sup 3} in 22 basins. Over 65% of the basins have a sediment column greater than 5 km with some depocenters that locally exceed 10 km. The source rock quality and character vary along both margins. The top of the oil generation window averages about 3.3 km; however, due to differing thermal histories, individual basins can depart significantly from this average.

  9. Preaxial Polydactyly of the Foot: Variable Expression of Trisomy 13 in a Case from Central Africa

    PubMed Central

    Mbuyi-Musanzayi, Sébastien; Lumaka, Aimé; Yogolelo Asani, Bienvenu; Lubala Kasole, Toni; Lukusa Tshilobo, Prosper; Kalenga Muenze, Prosper; Tshilombo Katombe, François; Devriendt, Koenraad

    2014-01-01

    Trisomy 13 is a chromosomal disorder characterized by a severe clinical picture of multiple congenital anomalies. We here describe the clinical and genetic features and prognosis observed in a newborn with trisomy 13 from Central Africa. He presented the rare feature of preaxial polydactyly of the feet. PMID:25254124

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

    PubMed

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

    2014-02-05

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

  11. 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.…

  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. Drug Cartels and Gangs in Mexico and Central America: A View through the Lens of Counterinsurgency

    DTIC Science & Technology

    2010-06-04

    crime in today’s Central America. First, the institution of an Encomienda system of land ownership, which granted Spanish Conquistadors and upper class...2 Britannica on line, http://www.britannica.com/EBchecked/topic/186567/ encomienda (accessed October 15, 2009). 3 Net Industries, http

  14. A new genus and two new species of Tingidae (Heteroptera) from Central America.

    PubMed

    Montemayor, Sara I

    2008-04-01

    A new genus, Ceratotingis, distributed in Central America, is described to accommodate two new species, C. rafaeli from Panama and C. costarriquense from Costa Rica and to include Macrotingis zeteki from Panama. This paper includes descriptions of the new genus and its species, a redescription of C. zeteki, an identification key, and habitus photographs.

  15. 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

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Office of the Secretary Dominican Republic--Central America--United States Free Trade Agreement; Notice of... Dominican Republic--Central America--United States Free Trade Agreement (CAFTA-DR). On March 26, 2012,...

  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. 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.

  18. 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.

  19. Galapagos-OIB signature in southern Central America: Mantle refertilization by arc-hot spot interaction

    NASA Astrophysics Data System (ADS)

    Gazel, Esteban; Carr, Michael J.; Hoernle, Kaj; Feigenson, Mark D.; Szymanski, David; Hauff, Folkmar; van den Bogaard, Paul

    2009-02-01

    Although most Central American magmas have a typical arc geochemical signature, magmas in southern Central America (central Costa Rica and Panama) have isotopic and trace element compositions with an ocean island basalt (OIB) affinity, similar to the Galapagos-OIB lavas (e.g., Ba/La < 40, La/Yb > 10, 206Pb/204Pb > 18.8). Our new data for Costa Rica suggest that this signature, unusual for a convergent margin, has a relatively recent origin (Late Miocene ˜6 Ma). We also show that there was a transition from typical arc magmas (analogous to the modern Nicaraguan volcanic front) to OIB-like magmas similar to the Galapagos hot spot. The geographic distribution of the Galapagos signature in recent lavas from southern Central America is present landward from the subduction of the Galapagos hot spot tracks (the Seamount Province and the Cocos/Coiba Ridge) at the Middle American Trench. The higher Pb isotopic ratios, relatively lower Sr and Nd isotopic ratios, and enriched incompatible-element signature of central Costa Rican magmas can be explained by arc-hot spot interaction. The isotopic ratios of central Costa Rican lavas require the subducting Seamount Province (Northern Galapagos Domain) component, whereas the isotopic ratios of the adakites and alkaline basalts from southern Costa Rica and Panama are in the geochemical range of the subducting Cocos/Coiba Ridge (Central Galapagos Domain). Geological and geochemical evidence collectively indicate that the relatively recent Galapagos-OIB signature in southern Central America represents a geochemical signal from subducting Galapagos hot spot tracks, which started to collide with the margin ˜8 Ma ago. The Galapagos hot spot contribution decreases systematically along the volcanic front from central Costa Rica to NW Nicaragua.

  20. 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

  1. 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.

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

    USGS Publications Warehouse

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

    2006-01-01

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

  3. 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

  4. Geochemical signatures of the oceanic complexes in southern Central America

    NASA Astrophysics Data System (ADS)

    Gazel, E.; Herzberg, C. T.; Carr, M. J.; Denyer, P.

    2006-12-01

    /204Pb (18.5-19.0) and 207Pb/204Pb (15.53-15.58). Cretaceous oceanic islands show the same 206Pb/204Pb ratios but higher 207Pb/204Pb. Both could be included in the north and central fields of the Galapagos hot-spot. The post-Cretaceous oceanic islands show higher Pb isotopic ratios that reflect a higher HIMU component and could be included in the in the eastern Galapagos Hot-Spot field. Zr/Nb, Nb/Th, Nb/Y, and Zr/Y show that the CLIP rocks are included within the range of the oceanic plateau basalts with primitive and MORB components. The oceanic islands share these components but also include a recycling component (OIB). Santa Elena Nappe trends toward the subduction component (ARC).

  5. [Natural resources of Central America: the origin of the botanical expedition to Guatemala].

    PubMed

    Maldonado Polo, J L

    1995-01-01

    The scientific commission to Central America originated like a continuation of the three big botanical Spanish expeditions being carried out during the reign of Carlos III through the American territories. The presence of the naturalists José Longinos Martínez and José Mociño, and the painter Vicente de la Cerda at the capital of Guatemala was reason of great interest in the "Capitanía General", and it caused great impact on the Enlightened institutions of the time. Friends' of the Country Economical Society and the Consulado of commerce supported the works of the members of the expedition contributing to the institutionalization of the Natural History in Central America.

  6. Resisting violence against women in Central America: the experience of a feminist collective.

    PubMed

    Profitt, N J

    1994-01-01

    This article explores how violence against women was resisted in Central America. It was observed that women in Central America have "developed a feminist critical consciousness of the negative responses to their personal and political transformation." This consciousness served as a bridge between various women groups and movements such as the Women's Collective Pancha Carrasco and other mutual support groups. This paper made clear that any organization addressing the issue of violence against women should take place in a context of a political framework where women can make sense of their resistance. Feminist social work practice should therefore be aimed towards a deeper understanding of the social and political dimensions of women. With this, feminist workers shall be able to create a feminist politics that is rooted on the collectivity of the experiences of women and resistance to abuse and violence.

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

    USGS Publications Warehouse

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

    1957-01-01

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

  8. Atmospheric Transport and Photochemistry of Ozone Over Central Southern Africa During the Southern Africa Fire-Atmosphere Research Initiative

    NASA Technical Reports Server (NTRS)

    Tyson, P. D.; Garstang, M.; Thompson, A. M.; DAbreton, P.; Diab, R. D.; Browell, E. V.

    1997-01-01

    Vertically integrated back and forward trajectories for the 300-200, 700-500 and surface-800 hPa levels are calculated using Pretoria as point of origin for the Southern Africa Fire-Atmosphere Research Initiative (SAFARI) period September-October 1992. The transport fields are then combined to show both horizontal and vertical transport of air to and from Pretoria at the different levels. Air transport patterns in the vertical are linked to the occurrence of absolutely stable layers which are also evident in the 16 ozonesonde profiles recorded at Pretoria during SAFARI. The coherence of the stratification based on dynamical and ozone analysis permits the use of mean ozone profiles with air volume fluxes to interpret the ozone in terms of photochemistry and transport within stable layers. Extensive recirculation across the meridional plane at Pretoria implies that advection of ozone is slow and that photochemistry is responsible for the observed vertical structure over central southern Africa in September and October 1992. Requisite ozone formation rates are supported by model analysis of ozone and ozone precursors measured from SAFARI and Transport and Atmospheric Research Chemistry near the Equator-Atlantic aircraft.

  9. A modeling study of the role of deforestation on the climate of central and eastern Africa

    SciTech Connect

    Semazzi, F.H.M.; Sun, Liqiang; Giorgi, F.

    1997-11-01

    This study assessed the effects of deforestation on the physical climate system of eastern and central Africa. The model used was the regional climate model (RegCM2) developed at the National Center for Atmospheric Research, and customized for the region under study. In the anomaly simulation, the land cover was systematically altered to replace the tropical forest with grass and Savannah cover. The RegCM2 realistically simulated the main features of the climate over eastern and central Africas. It was found that: (1) the rainfall dramatically decreased in 2 subregions, decreased in two subregions, increased in 1 subregion, and remained the same in 1 subregion; (2) rainfall deficit mainly happened during night time over the TF subregion and daytime over the LV subregion; and (3) mean surface air temperature increased over 5 subregions and decreased in 1 subregions. Deforestation also increased the diurnal variation of surface air temperature over one subregion. 12 refs., 2 figs., 3 tabs.

  10. Transition from the Farallon Plate subduction to the collision between South and Central America: Geological evolution of the Panama Isthmus

    NASA Astrophysics Data System (ADS)

    Barat, Flore; Mercier de Lépinay, Bernard; Sosson, Marc; Müller, Carla; Baumgartner, Peter O.; Baumgartner-Mora, Claudia

    2014-05-01

    This paper presents new geological constraints on the collision of southern Central America with South America, and the resulting deformational episodes that have affected the Panama Isthmus since the Late Cretaceous. The Panama Isthmus is located in southwestern Central America, and it represents the zone of contact between the two land masses: Central America and South America. This collision event is still active today. It has resulted in regional uplift since the Late Miocene/Pliocene and is responsible for the Great American Biotic Interchange between South and North America. Depending on the methods of investigation used, and due to the lack of data available, the time when this collision began is still widely debated and poorly constrained. To better constrain this age, we have studied the rock formations and the tectonic deformations in central and eastern Panama that have occurred since the Late Cretaceous. This study presents new rock ages, field-work documentation and analyses, and seismic-line interpretations, and it is complemented by spatial images for the eastern Panama area. During the Middle Eocene, a number of changes suddenly appeared in the geological records that were synchronous with the break-up of southern Central America into two smaller blocks: Chorotega and Chocó. Our main results identify the prevalence of an extensional tectonic regime from the Middle Eocene to the Middle Miocene that caused the formation of horst and graben structures with thick sedimentary basin fills, and a synchronous clockwise block rotation. Here, we propose that these geologic events are associated with the initiation of the oblique collision of southern Central America with South America. The first contact of the southeastern extremity of Central America occurred around 40 Ma to 38 Ma, and then propagated northwestwards. We describe here this long-term collision episode in relation to the history of the Panama Isthmus.

  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. Improving Regional Security in Central America: Military Engagement Options for Nicaragua

    DTIC Science & Technology

    2002-12-01

    peaceful resolution. This group was made up of foreign ministers from Mexico , Venezuela, Colombia, and Panama and was named after Contadora Island, the...from: Martine, George and Guzman, Jose Miguel, UNFPA Country Support Team, Mexico Source: OPS/OMS (1994); CEPAL (1999); OPS-Nicaragua (http...State. Isacson, Adam 1998. Seguridad Cooperativa en Centroamérica. (Cooperative Security in Central America) Diálogo Centro-americano No. 35

  14. Coupled Global-Regional Climate Model Simulations of Future Changes in Hydrology over Central America

    NASA Astrophysics Data System (ADS)

    Oglesby, R. J.; Erickson, D. J.; Hernandez, J. L.; Irwin, D.

    2005-12-01

    Central America covers a relatively small area, but is topographically very complex, has long coast-lines, large inland bodies of water, and very diverse land cover which is both natural and human-induced. As a result, Central America is plagued by hydrologic extremes, especially major flooding and drought events, in a region where many people still barely manage to eke out a living through subsistence. Therefore, considerable concern exists about whether these extreme events will change, either in magnitude or in number, as climate changes in the future. To address this concern, we have used global climate model simulations of future climate change to drive a regional climate model centered on Central America. We use the IPCC `business as usual' scenario 21st century run made with the NCAR CCSM3 global model to drive the regional model MM5 at 12 km resolution. We chose the `business as usual' scenario to focus on the largest possible changes that are likely to occur. Because we are most interested in near-term changes, our simulations are for the years 2010, 2015, and 2025. A long `present-day run (for 2005) allows us to distinguish between climate variability and any signal due to climate change. Furthermore, a multi-year run with MM5 forced by NCEP reanalyses allows an assessment of how well the coupled global-regional model performs over Central America. Our analyses suggest that the coupled model does a credible job simulating the current climate and hydrologic regime, though lack of sufficient observations strongly complicates this comparison. The suite of model runs for the future years is currently nearing completion, and key results will be presented at the meeting.

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

    PubMed

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

    2013-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Amelug, F.; Lebowitz, J.

    2015-12-01

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

  17. 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

  18. Assessment of undiscovered oil and gas resources of the Chad Basin Province, North-Central Africa

    USGS Publications Warehouse

    Brownfield, Michael E.; Schenk, Christopher J.; Charpentier, Ronald R.; Klett, Timothy R.; Cook, Troy A.; Pollastro, Richard M.; Tennyson, Marilyn E.

    2010-01-01

    The Chad Basin Province located in north-central Africa recently was assessed for undiscovered, technically recoverable oil, natural gas, and natural gas liquids resources as part of the U.S. Geological Survey's (USGS) World Oil and Gas Assessment. Using a geology-based assessment methodology, the USGS estimated mean volumes of 2.32 billion barrels of oil, 14.65 trillion cubic feet of natural gas, and 391 million barrels of natural gas liquids.

  19. Assessment of undiscovered oil and gas resources of the Sud Province, north-central Africa

    USGS Publications Warehouse

    Brownfield, M.E.; Klett, T.R.; Schenk, C.J.; Charpentier, R.R.; Cook, T.A.; Pollastro, R.M.; Tennyson, M.E.

    2011-01-01

    The Sud Province located in north-central Africa recently was assessed for undiscovered, technically recoverable oil, natural gas, and natural gas liquids resources as part of the U.S. Geological Survey's (USGS) World Oil and Gas Assessment. Using a geology-based assessment methodology, the USGS estimated mean volumes of 7.31 billion barrels of oil, 13.42 trillion cubic feet of natural gas, and 353 million barrels of natural gas liquids.

  20. 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.

  1. 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

  2. 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.

  3. Africa.

    ERIC Educational Resources Information Center

    Martz, Carlton

    2001-01-01

    This publication explores issues related to Africa. It examines the U.S. response to the Barbary pirate states (Morocco, Algiers, Tunis, Tripoli) in the early 19th century; the current AIDS crisis in Africa; and 14th century Mali and other Islamic lands through the eyes of Ibn Battuta, who traveled throughout the Muslim world. Each article…

  4. Africa.

    ERIC Educational Resources Information Center

    Happel, Sue; Loeb, Joyce

    Although the activities in this unit are designed primarily for students in the intermediate grades, the document's text, illustrations, and bibliographic references are suitable for anyone interested in learning about Africa. Following a brief introduction and map work, the document is arranged into six sections. Section 1 traces Africa's history…

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

    PubMed Central

    Scheffrahn, Rudolf H.

    2016-01-01

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

  6. NASA LCLUC Program: An Integrated Forest Monitoring System for Central Africa

    NASA Technical Reports Server (NTRS)

    Laporte, Nadine; LeMoigne, Jacqueline; Elkan, Paul; Desmet, Olivier; Paget, Dominique; Pumptre, Andrew; Gouala, Patrice; Honzack, Miro; Maisels, Fiona

    2004-01-01

    Central Africa has the second largest unfragmented block of tropical rain forest in the world; it is also one of the largest carbon and biodiversity reservoirs. With nearly one-third of the forest currently allocated for logging, the region is poised to undergo extensive land-use change. Through the mapping of the forests, our Integrated Forest Monitoring System for Central Africa (INFORMS) project aims to monitor habitat alteration, support biodiversity conservation, and promote better land-use planning and forest management. Designed as an interdisciplinary project, its goal is to integrate data acquired from satellites with field observations from forest inventories, wildlife surveys, and socio-economic studies to map and monitor forest resources. This project also emphasizes on collaboration and coordination with international, regional, national, and local partners-including non-profit, governmental, and commercial sectors. This project has been focused on developing remote sensing products for the needs of forest conservation and management, insuring that research findings are incorporated in forest management plans at the national level. The societal impact of INFORMS can be also appreciated through the development of a regional remote sensing network in central Africa. With a regional office in Kinshasa, (www.OSFAC.org), the contribution to the development of forest management plans for 1.5 million hectares of forests in northern Republic of Congo (www.tt-timber.com), and the monitoring of park encroachments in the Albertine region (Uganda and DRC) (www.albertinerift.org).

  7. Migrations of European honey bee lineages into Africa, Asia, and North America during the Oligocene and Miocene

    NASA Astrophysics Data System (ADS)

    Kotthoff, Ulrich; Wappler, Torsten; Engel, Michael

    2013-04-01

    Today honey bees, principally the western honey bee, Apis mellifera, represent a multi-billion dollar agricultural industry. Through the efforts of humans they have become established well outside of their modern native ranges, having been introduced multiple times into the Americas, Australia, New Zealand, New Caledonia, and many areas of Oceania. The native, i.e., non-human influenced, distribution and migration of honey bee species and populations has been a matter of serious and continued debate. Apicultural dogma informs us that the center of origin of honey bees (genus Apis) resides in Asia, with subsequent migration and diversification into Europe and Asia. Recent population genetic studies of the western honey bee, Apis mellifera, slightly modified this received wisdom by suggesting that this species originated in Africa and subsequently reinvaded Eurasia. Research into the historical biogeography of honey bees has ignored entirely the abundant fossil evidence distributed through a variety of Late Paleogene (Oligocene) and Early Neogene (Miocene) deposits, a diversity which is predominantly European in origin, particularly among the most basal species of the genus. We have examined the morphological disparity and affinities of the full living and fossil diversity of honey bees ranging from their earliest origins to the present day. This analysis indicates that honey bees exhibited a greater morphological disparity during the Oligocene and Miocene epochs, a time when the principal lineages were established, and that Apis apparently originated in Europe, spreading from there into Asia, Africa, and North America, with subsequent diversification in the former two regions and extinction in the latter. During the human migrations and colonization honey bees were once again introduced multiple times into the Americas, as well as into Australia and Asia.

  8. 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

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

    PubMed Central

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

    2016-01-01

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

  10. Circulation characteristics of persistent cold spells in central-eastern North America

    NASA Astrophysics Data System (ADS)

    Li, Zhenhua; Manson, Alan H.; Li, Yanping; Meek, Chris

    2017-02-01

    The circulation patterns of persistent cold weather spells with durations longer than 10 days in central-eastern North America (United States and Canada; 32°-52°N, 95°-65°W) are investigated by using NCEP reanalysis data from 1948 to 2014. The criteria for the persistent cold spells are: (1) three-day averaged temperature anomalies for the regional average over the central-eastern United States and Canada must be below the 10th percentile, and (2) such extreme cold spells must last at least 10 days. The circulation patterns associated with these cold spells are examined to find the common signals of these events. The circulation anomaly patterns of these cold spells are categorized based on the El Niño-Southern Oscillation, Arctic Oscillation (AO), and other climate indices. The atmospheric circulation patterns that favor the cold spells are identified through composites of geopotential height maps for the cold spells. Negative AO phases favor persistent cold spells. Phases of sea surface temperature (SST) modes that are associated with warm SSTs in the eastern extratropical Pacific also favor persistent cold events in the study region. Stratospheric polar vortex breakdown alone is not a good predictor for the regional extreme cold spells in central-eastern North America. The meridional dispersions of quasi-stationary Rossby waves in the Pacific-North America sector in terms of cut-off zonal wavenumber modulated by background flow are analyzed to provide insight into the difference in evolution of the cold spells under different mean AO phases. The waveguide for AO > 1 is in a narrow latitudinal band centered on 40°N, whereas the waveguide for AO <-1 is in a broader latitudinal band from 40° to 65°N. The circulation patterns and lower boundary conditions favorable for persistent cold spells identified by this study can be a stepping-stone for improving winter subseasonal forecasting in North America.

  11. Regional Hydrological Response to Climate Change in Mexico and Central America

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    Future changes in precipitation amount and variability are among the most important and serious projected consequences of climate change. Central America (CAM) shows most of its climate variability in precipitation. Thus, the large hydrological response to global warming can have negative consequences on agricultural activities and the ecosystem dynamics in the region. Indeed, Central America is considered to be a climate change hot-spot in the tropics mainly due to a future decrease in precipitation and an increase in precipitation variability as projected by the IPCC models. These coarse resolution general circulation models (GCMs) do not provide climate information at spatial scales appropriate for impacts assessment. A regional climate model PRECIS was used in this study to carry out two experiments: (i) the baseline (present-day) run and (ii) the SRES A2 run, both performed at 25 km horizontal resolution. The low-level circulation in the region around Central America is controlled by the low pressure area in the Pacific (the ITCZ) and the high pressure area (North Atlantic Subtropical High, NASH) in the Atlantic. Changes in the position and magnitude of the ITCZ low and the NASH govern the low-level circulation in the region. The spatial pattern of precipitation over CAM landmass is further modified by the complex topography and the land surface properties. A large reduction in precipitation is projected during the wet season (May-Oct) for eastern Mexico (30% decrease) and the Yucatan Peninsula (40% decrease) under the A2 scenario. A small decrease in precipitation during the wet season is projected for the Caribbean slopes of southern Central America. In general, a decrease in precipitation in these regions is associated with an increase in sea level pressure that indicates extended/intensified NASH in the future scenario. Regions on the Pacific side of the CAM cordillera show up to 20-25% decrease in precipitation in the wet season which is associated with

  12. gis of central africa: a tool for the igcp 470 geological and metallogenic syntheses

    NASA Astrophysics Data System (ADS)

    Milesi, J. P.; Deschamps, Y.; Kampunzu, H.; Nicol, N.; Duguey, E.; Feybesse, J. L.; Le Goff, E.; Lerouge, C.; Leistel, J. M.; Lannez, P.

    2003-04-01

    A GIS concerning the geosciences of the African continent was launched in 1998 by BRGM within the framework of its scientific projects. It aimed to improve the 1:2,000,000-scale synthesis, which is useful for sustainable development, by combining the often-dispersed data concerning the earth sciences (geology, mineral resources and hydrology etc.) in Africa. The African GIS fits between the global syntheses produced by international agencies and the very detailed (1:50,000 to 1:1,000,000-scale) geological and mining plans produced by all the countries. The scale of 1:2,000,000 facilitates analytical comparison of the potential of the regions. The project aims to produce homogenised cross-frontier data integrating the distribution of natural resources into an up-to-date geological framework. These regional digital syntheses (without frontiers) will complement the detailed State documents by improving the interpretation of potential for each country. The GIS of Central Africa started with the construction of (i) a catalogue of available maps (GEOCARTE/GEOMAP) and (ii) a GIS dedicated to the geology and mineral resources. The GEOCARTE/GEOMAP catalogue provides information for 50,000 maps of the entire continent (geological, mineral resource and hydrogeological): type, authors, publication date, scale, format, editors, proprietor etc. A first version (still in progress) of the geological synthesis of Central Africa (from Nigeria to Congo) at 1:2,000,000-scale was constructed and updated by recent publications on geochronology (e.g; Toteu et al., 2001 for the Cameroon). From this simplified, harmonised and geo-referenced geology, new scientific targets occur: e.g. (i) on the structural relationships between Paleoproterozoic and Mesoproterozoic terranes (link with the IGCP 440 project), specially at the frontier between Congo and Central Africa Republic, (Bangui limestone &Liki-Bembien formations on the Equatorial Sheet

  13. Webinar Presentation: Black Carbon and Other Light-absorbing Particles in Snow in Central North America and North China

    EPA Pesticide Factsheets

    This presentation, Black Carbon and Other Light-absorbing Particles in Snow in Central North America and North China, was given at the STAR Black Carbon 2016 Webinar Series: Accounting for Impact, Emissions, and Uncertainty held on Nov. 7, 2016.

  14. 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.

  15. 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.

  16. 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

  17. The Role of Education in Building a Future World Based on Democracy and Development: Regional Perspectives from Africa, Latin America, and South Asia.

    ERIC Educational Resources Information Center

    Woolman, David C.

    This paper begins with a comparative regional survey of the current status of democracy and development in Africa, Latin America, and South Asia. Each region shares a legacy of colonial domination by European powers. The comparative study uses criteria from the basic needs approach. Critical social thought and future visions about democracy and…

  18. [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.

  19. The occurrence of rabies in pre-Columbian Central America: an historical search.

    PubMed

    Vos, A; Nunan, C; Bolles, D; Müller, T; Fooks, A R; Tordo, N; Baer, G M

    2011-10-01

    Rabies is considered one of the oldest infectious diseases known to humans. However, the first written reports on rabies cases in the Americas did not appear until the first decade of the 18th century from Mexico. In an attempt to clarify if the disease was already present in pre-Columbian times, we searched for evidence in the Maya and Aztec cultures. Other sources of information were early manuscripts written by the conquistadors and early explorers. We did not identify any unequivocal direct evidence that the disease rabies was known in pre-Columbian Central America but sufficient circumstantial evidence is available suggesting that (bat) rabies was already present in these early times.

  20. A new hominid from the Upper Miocene of Chad, Central Africa.

    PubMed

    Brunet, Michel; Guy, Franck; Pilbeam, David; Mackaye, Hassane Taisso; Likius, Andossa; Ahounta, Djimdoumalbaye; Beauvilain, Alain; Blondel, Cécile; Bocherens, Hervé; Boisserie, Jean-Renaud; De Bonis, Louis; Coppens, Yves; Dejax, Jean; Denys, Christiane; Duringer, Philippe; Eisenmann, Véra; Fanone, Gongdibé; Fronty, Pierre; Geraads, Denis; Lehmann, Thomas; Lihoreau, Fabrice; Louchart, Antoine; Mahamat, Adoum; Merceron, Gildas; Mouchelin, Guy; Otero, Olga; Pelaez Campomanes, Pablo; Ponce De Leon, Marcia; Rage, Jean-Claude; Sapanet, Michel; Schuster, Mathieu; Sudre, Jean; Tassy, Pascal; Valentin, Xavier; Vignaud, Patrick; Viriot, Laurent; Zazzo, Antoine; Zollikofer, Christoph

    2002-07-11

    The search for the earliest fossil evidence of the human lineage has been concentrated in East Africa. Here we report the discovery of six hominid specimens from Chad, central Africa, 2,500 km from the East African Rift Valley. The fossils include a nearly complete cranium and fragmentary lower jaws. The associated fauna suggest the fossils are between 6 and 7 million years old. The fossils display a unique mosaic of primitive and derived characters, and constitute a new genus and species of hominid. The distance from the Rift Valley, and the great antiquity of the fossils, suggest that the earliest members of the hominid clade were more widely distributed than has been thought, and that the divergence between the human and chimpanzee lineages was earlier than indicated by most molecular studies.

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2012-01-01

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

  3. Meteorological variability and infectious disease in Central Africa: a review of meteorological data quality.

    PubMed

    Heaney, Alexandra; Little, Eliza; Ng, Sophia; Shaman, Jeffrey

    2016-10-01

    Central African countries may bear high climate change-related infectious disease burdens because of preexisting high rates of disease, poor healthcare infrastructure, land use changes, and high environmental change vulnerabilities. However, making connections between climate and infectious diseases in this region is hampered by the paucity of high-quality meteorological data. This review analyzes the sources and quality of meteorological data used to study the interactions between weather and infectious diseases in Central African countries. Results show that 23% of studies used meteorological data that mismatched with the disease spatial scale of interest. Use of inappropriate weather data was most frequently identified in analyses using meteorological station data or gridded data products. These findings have implications for the interpretation of existing analyses and provide guidance for the use of climate data in future analyses of the connections between meteorology and infectious diseases in Central Africa.

  4. 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

  5. Evidence for Pleistocene Population Divergence and Expansion of Anopheles albimanus in Southern Central America

    PubMed Central

    Loaiza, Jose R.; Scott, Marilyn E.; Bermingham, Eldredge; Rovira, Jose; Conn, Jan E.

    2010-01-01

    The micro-geographic structure of Anopheles albimanus was studied in southern Central America using partial sequences of the mtDNA cytochrome oxidase subunit I gene (COI). Analysis of molecular variance supported significant genetic structure between populations from Costa Rica and western Panama versus those from central-eastern Panama (ΦCT = 0.33), whereas the within group divergence was shallow and statistically insignificant (ΦST = 0.08). Furthermore, a statistical parsimony network depicted three divergent groups of haplotypes that were not evenly distributed across the study area. Our findings are in partial agreement with previous studies, yet they do not support physical barriers to gene flow or contemporary isolation by distance in this region. Instead, three co-occurring groups of An. albimanus may be the result of multiple introductions, most likely caused by historical fragmentation and subsequent secondary contact. In addition, the molecular signature of population expansion of An. albimanus was detected in central-eastern Panama approximately 22,000 years ago (95% confidence interval [CI] 10,183–38,169). We hypothesize that the population structure of An. albimanus, as determined by our COI locus analysis, is the result of late Pleistocene climatic changes in northern South America. PMID:20065014

  6. Early and dynamic colonization of Central America drives speciation in Neotropical army ants.

    PubMed

    Winston, Max E; Kronauer, Daniel J C; Moreau, Corrie S

    2017-02-01

    The emergence of the Isthmus of Panama is one of the most important events in recent geological history, yet its timing and role in fundamental evolutionary processes remain controversial. While the formation of the isthmus was complete around 3 million years ago (Ma), recent studies have suggested prior intercontinental biotic exchange. In particular, the possibility of early intermittent land bridges facilitating colonization constitutes a potential mechanism for speciation and colonization before full closure of the isthmus. To test this hypothesis, we employed genomic methods to study the biogeography of the army ant genus Eciton, a group of keystone arthropod predators in Neotropical rainforests. Army ant colonies are unable to disperse across water and are therefore ideally suited to study the biogeographic impact of land bridge formation. Using a reduced representation genome sequencing approach, we show that all strictly Central American lineages of Eciton diverged from their respective South American sister lineage between 4 and 7 Ma, significantly prior to the complete closure of the isthmus. Furthermore, three of the lineage pairs form extensive and coincident secondary contact zones in Costa Rica and Nicaragua, with no evidence of gene flow. Such a discrete and repeated biogeographic pattern indicates at least two waves of army ant dispersal into Central America that were separated by significant genetic divergence times. Thus, by integrating phylogenomic, population genomic and geographic evidence, we show that early colonization of Central America across the emerging Isthmus of Panamá drove parallel speciation in Eciton army ants.

  7. 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.

  8. 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

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

    NASA Astrophysics Data System (ADS)

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

    2011-08-01

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

  10. 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

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

    PubMed

    Crews, Sarah C

    2011-01-01

    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 arikoksp. n., Selenops chamelasp. n., Selenops amonasp. n., Selenops bawekasp. n., Selenops bocacanadensissp. n., Selenops enriquillosp. n, Selenops ixchelsp. n., Selenops huetocatlsp. n., Selenops kalinagosp. n., Selenops oviedosp. n., Selenops morrosp. n., Selenops deniasp. n., Selenops duansp. n., Selenops malinalxochitlsp. n., Selenops oricuajosp. n., Selenops petenajtoysp. n., Selenops guerrerosp. n., Selenops makimakisp. n., Selenops souligasp. n., Selenops wilmotorumsp. n., and Selenops wilsonisp. 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 first time. Almost all species

  12. Reproductive periodicity of the tropical crab Callinectes arcuatus Ordway in Central America

    NASA Astrophysics Data System (ADS)

    DeVries, M. C.; Epifanio, C. E.; Dittel, A. I.

    1983-12-01

    The Gulf of Nicoya, an estuary on the Pacific coast of Central America, contains a large population of the portunid crab Callinectes arcuatus. Results of a 12 month survey indicated that spawning activity occurs throughout the year, but with a distinct peak during the five-month dry season (December-April). Mature females were most prevalent in the upper regions of the gulf during the rainy season and appeared to migrate to the lower gulf to spawn during the dry season. Patterns of spawning and apparent migration differed from those reported in an earlier study of C. arcuatus along the Pacific coast of Mexico.

  13. Abrupt climate oscillations during the last deglaciation in central north america

    PubMed

    Yu; Eicher

    1998-12-18

    Evidence from stable isotopes and a variety of proxies from two Ontario lakes demonstrate that many of the late glacial-to-early Holocene events that are well known from the North Atlantic seaboard, such as the Gerzensee-Killarney Oscillation (also known as the Intra-Allerod Cold Period), Younger Dryas, and Preboreal Oscillation, also occurred in central North America. These results thus imply that climatic forcing acted in the same manner in both regions and that atmospheric circulation played an important role in the propagation of these events.

  14. (Mid-term evaluation of the Central America Rural Electrification Support program)

    SciTech Connect

    Perlack, R.D.

    1990-03-30

    Oak Ridge National Laboratory (ORNL) was requested by Regional Office for Central America and Panama (ROCAP) to conduct a mid-term evaluation of the CARES project. Numerous meetings were held with National Rural Electric Cooperative Association (NRECA) staff, ROCAP staff, and local officials in Guatemala, Honduras, and Belize. In general, the CARES project has been quite successful in a number of key areas as well as in soliciting support from utilities and US Agency for International Development (USAID) Missions. Changes were recommended in the area of report writing and some management activities. It was also recommended that any new activities be considered in the light of the availability of local personnel.

  15. 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

  16. Comparison of Amazon and Central Africa tropical vegetation dynamics using SEVIRI data from 2009 to 2011

    NASA Astrophysics Data System (ADS)

    Tian, Yuhong; Zhou, Liming; Romanov, Peter; Yu, Bob; Ek, Michael

    2013-04-01

    Tropical forests play a crucial role in determining global exchanges of energy, momentum, water, CO2 and other greenhouse gases between the land surface and the atmosphere. Quantifying the areal extent, spatial distribution and vegetation status of tropical forests and their dynamics are essential for studies of climate, carbon cycle and biodiversity. Satellite remote sensing has been an indispensable tool to monitor tropical forests. However, frequent and extensive cloud presence makes mapping and monitoring tropical evergreen forests a challenging task. MODIS and AVHRR vegetation products are spatially and temporally discontinuous and inconsistent or very noisy over many pixels in tropical rainforests. The famous debate about the Amazon forest "green-up" during 2005 dry season drought is an excellent example attributed at least partly to the satellite data quality. Observations from the Spinning Enhanced Visible and Infra-red Imager (SEVIRI), onboard the European Meteosat Second Generation (MSG) satellite, are used in this study to monitor tropical vegetation dynamics. The SEVIRI data used contain observations of land surface at 30-minute time intervals for the year 2009 to 2011. We used top of atmosphere (TOA) reflectance values from the spectral bands of red (0.635um), near-infrared (NIR, 0.81um) and shortwave infrared (SWIR, 1.64 um) and other satellite geometry information to calculate normalized difference vegetation index (NDVI) and land surface water index (LSWI). We generated daily, weekly and monthly NDVI and LSWI based on maximum NDVIs. We examined the pattern of cloud occurrence, precipitation and the seasonality of green vegetation (evergreen forests and savannas) in Amazon and Central Africa. During wet season, Amazon has much less chance to get clear-sky observations than Central Africa. However, during dry season, Amazon and Central Africa have as many as clear-sky observations as other regions. Among different vegetation types, the seasonal cycle

  17. Central southern Africa at the time of the African Humid Period: A new analysis of Holocene palaeoenvironmental and palaeoclimate data.

    NASA Astrophysics Data System (ADS)

    Burrough, Sallie; Thomas, David

    2014-05-01

    The Holocene African Humid Period (c 14.8-5.5 ka) is now recognised in high-resolution records from western Africa as well as in tropical Africa north of the equator. Establishing a clear picture of Holocene environmental changes from palaeodata in central southern Africa is, however, proving both difficult and contentious. This is because in dryland systems in particular it can be difficult to distinguish the effects of sub-millennial scale regional climatic variability from those of major externally-forced global climate changes. We analyse and review existing records for central southern Africa, and neighbouring areas affected by the same climate systems, to attempt to build a clearer spatial picture of regional hydrological system responses during the Holocene. We suggest palaeodata, including new data from Makgadikgadi basin barchan dunes indicate mid-late Holocene aridity following a period of marked hydrological dynamism extending from the early Holocene. We propose that present-day conditions in central southern Africa are relatively stable compared to the early and mid-Holocene and infer that this period of relative stability in the landscape has occurred since ca. 2 ka. We explain Holocene hydrological changes through analysis of changing zonal climatic influences linked to Congo Air Boundary (CAB) and Intertropical Convergence Zone (ITCZ) dynamics, the effects of which filter into the region via complex drainage basin dynamics. It is proposed that, sensu stricto, the AHP was not a spatially uniform feature of early Holocene central southern Africa.

  18. First Early Hominin from Central Africa (Ishango, Democratic Republic of Congo)

    PubMed Central

    Crevecoeur, Isabelle; Skinner, Matthew M.; Bailey, Shara E.; Gunz, Philipp; Bortoluzzi, Silvia; Brooks, Alison S.; Burlet, Christian; Cornelissen, Els; De Clerck, Nora; Maureille, Bruno; Semal, Patrick; Vanbrabant, Yves; Wood, Bernard

    2014-01-01

    Despite uncontested evidence for fossils belonging to the early hominin genus Australopithecus in East Africa from at least 4.2 million years ago (Ma), and from Chad by 3.5 Ma, thus far there has been no convincing evidence of Australopithecus, Paranthropus or early Homo from the western (Albertine) branch of the Rift Valley. Here we report the discovery of an isolated upper molar (#Ish25) from the Western Rift Valley site of Ishango in Central Africa in a derived context, overlying beds dated to between ca. 2.6 to 2.0 Ma. We used µCT imaging to compare its external and internal macro-morphology to upper molars of australopiths, and fossil and recent Homo. We show that the size and shape of the enamel-dentine junction (EDJ) surface discriminate between Plio-Pleistocene and post-Lower Pleistocene hominins, and that the Ishango molar clusters with australopiths and early Homo from East and southern Africa. A reassessment of the archaeological context of the specimen is consistent with the morphological evidence and suggest that early hominins were occupying this region by at least 2 Ma. PMID:24427292

  19. WE-AB-213-04: IAEA Support to Medical Physics in Africa and Latin America: Achievements and Challenges

    SciTech Connect

    Meghzifene, A.

    2015-06-15

    AAPM projects and collaborations in Africa Adam Shulman (AA-SC Chair) The African Affairs Subcommittee (AA-SC) of the AAPM will present a multi-institutional approach to medical physics support in Africa. Current work to increase the quality of care and level of safety for the medical physics practice in Senegal, Ghana, and Zimbabwe will be presented, along with preliminary projects in Nigeria and Botswana. Because the task of addressing the needs of medical physics in countries across Africa is larger than one entity can accomplish on its own, the AA-SC has taken the approach of joining forces with multiple organizations such as Radiating Hope and TreatSafely (NGO’s), the IAEA, companies like BrainLab, Varian and Elekta, medical volunteers and academic institutions such as NYU and Washington University. Elements of current projects include: 1) Distance training and evaluation of the quality of contouring and treatment planning, teaching treatment planning and other subjects, and troubleshooting using modern telecommunications technology in Senegal, Ghana, and Zimbabwe; 2) Assistance in the transition from 2D to 3D in Senegal and Zimbabwe; 3) Assistance in the transition from 3D to IMRT using in-house compensators in Senegal; 4) Modernizing the cancer center in Senegal and increasing safety and; 5) Training on on 3D techniques in Ghana; 6) Assisting a teaching and training radiation oncology center to be built in Zimbabwe; 7) Working with the ISEP Program in Sub-Saharan Africa; 8) Creating instructional videos on linac commissioning; 9) Working on a possible collaboration to train physicists in Nigeria. Building on past achievements, the subcommittee seeks to make a larger impact on the continent, as the number and size of projects increases and more human resources become available. The State of Medical Physics Collaborations and Projects in Latin America Sandra Guzman (Peru) The lack of Medical Physicists (MP) in many Latin American (LA) countries leads to

  20. Five decades of vitamin A studies in the region of Central America and Panama.

    PubMed

    Arroyave, Guillermo; Mejia, Luis A

    2010-03-01

    Vitamin A deficiency in Central America was first identified as a public health problem in the 1950s. It affected primarily children. The main underlying cause was a deficient intake of pre-formed vitamin A, but infection and intestinal parasitism also played important roles. INCAP focused its efforts on overcoming this problem and developed, as a short-term solution, the technology to fortify sugar with vitamin A. Fortification programs were implemented in several Central American countries. Evaluation of these programs revealed a significant impact-not only on vitamin A status, but also on iron nutrition and hematological condition. Longer-term solutions, like increasing the availability and consumption of vitamin A-rich foods, were later suggested and operational tools were developed to assist the countries in the region in the implementation, evaluation and monitoring of their own fortification programs.

  1. D″ shear velocity heterogeneity, anisotropy and discontinuity structure beneath the Caribbean and Central America

    NASA Astrophysics Data System (ADS)

    Garnero, Edward J.; Lay, Thorne

    2003-11-01

    The D″ region in the lowermost mantle beneath the Caribbean and Central America is investigated using shear waves from South American earthquakes recorded by seismic stations in North America. We present a large-scale, composite study of volumetric shear velocity heterogeneity, anisotropy, and the possible presence of a D″ discontinuity in the region. Our data set includes: 328 S( Sdiff)- SKS differential travel times, 300 ScS-S differential travel times, 125 S( Sdiff) and 120 ScS shear wave splitting measurements, and 297 seismograms inspected for Scd, the seismic phase refracted from a high-velocity D″ layer. Broadband digital data are augmented by high-quality digitized analog WWSSN data, providing extensive path coverage in our study area. In all, data from 61 events are utilized. In some cases, a given seismogram can be used for velocity heterogeneity, anisotropy, and discontinuity analyses. Significant mid-mantle structure, possibly associated with the ancient subducted Farallon slab, affects shear wave travel times and must be corrected for to prevent erroneous mapping of D″ shear velocity. All differential times are corrected for contributions from aspherical mantle structure above D″ using a high-resolution tomography model. Travel time analyses demonstrate the presence of pervasive high velocities in D″, with the highest velocities localized to a region beneath Central America, approximately 500-700 km in lateral dimension. Short wavelength variability overprints this general high-velocity background. Corrections are also made for lithospheric anisotropy beneath the receivers. Shear wave splitting analyses of the corrected waveforms reveal D″ anisotropy throughout the study area, with a general correlation with heterogeneity strength. Evidence for Scd arrivals is pervasive across the study area, consistent with earlier work, but there are a few localized regions (100-200 km) lacking clear Scd arrivals, which indicates heterogeneity in the

  2. Oil and gas developments in central and southern Africa in 1981

    SciTech Connect

    McGrew, H.J.

    1982-11-01

    Exploratory activity in central and southern Africa continued to grow during 1981. Geophysical operations reached nearly record levels and the number of wells increased markedly. Oil production suffered from the adverse conditions that existed throughout the world and dropped by a significant amount. New Concession acquisitions occurred in several of the countries in northeast Africa. Elsewhere, the operating companies negotiated new concessions and renewed those that were expiring. In several countries where production has been proven, the operators were assigned exploitation concessions. Seismic crews and marine geophysical vessels were active throughout the countries in this area. A total of 365 party-months of work was done to yield 98,035 km of new lines. A moderate amount of 3-D recording was carried out in connection with field development. Some aeromagnetic work was done, principally in northeast Africa and in Mozambique. Forty-four new fields or pools were discovered by drilling 115 new-field wildcat and exploratory wells. These wells accounted for 1,060,254 ft (323,248 m) of hole. Appraisal and development drilling resulted in 321 wells with a total of 2,533,305 ft (772,349 m) of hole drilled. At year end, 25 exploratory wells were under way or resting, and 49 rigs were active in development drilling. Oil production for the year was 691,995,939 bbl, a decrease of nearly 25% from 1980. Nigeria suffered the greatest drop in production; however, increases were achieved in Cameroon, Congo, and Zaire. The cumulative production from this part of Africa passed the 10 billion bbl mark.

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

    PubMed

    Phillips, Ben L; Puschendorf, Robert

    2013-09-07

    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.

  4. 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.

  5. 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

  6. [Epidemiologic surveillance of the acquired immunodeficiency syndrome in 6 states of Central Africa].

    PubMed

    Merlin, M; Josse, R; Trebucq, A; Mouanda, V; Kouka-Bemba, D

    1988-01-01

    Since 1985, OCEAC, the organization for control of widespread endemic disease in Central Africa, has managed an epidemiological surveillance programme concerning HIV infection and AIDS in six countries of the Sub-Region: Cameroon, Tchad, Central African Republic, Congo, Equatorial Guinea and Gabon. This programme consists in evaluating longitudinally incidence rates of infection and clinical cases, and mortality rates. It is based on a selective strategy using a network of sentinels (hospitals and maternity care consultation centers), completed by cross sectional epidemiological studies. Thanks to this programme high risk groups of population, high risk places and high risk activities have been identified. These observations will be used to plan national prevention programmes on AIDS.

  7. Ocean climate data for user community in West and Central Africa: Needs, opportunities, and challenges

    NASA Technical Reports Server (NTRS)

    Ojo, S. O.

    1992-01-01

    The urgent need to improve data delivery systems needed by scientists studying ocean role in climate and climate characteristics has been manifested in recent years because of the unprecedented climatic events experienced in many parts of the world. Indeed, there has been a striking and growing realization by governments and the general public indicating that national economies and human welfare depend on climate and its variability. In West and Central Africa, for instance climatic events, which have resulted in floods and droughts, have caused a lot of concern to both governments and people of the region. In particular, the droughts have been so widespread that greater awareness and concern have become generated for the need to find solutions to the problems created by the consequences of the climatic events. Particularly in the southern border regions of the Sahara Desert as well as in the Sahel region, the drought episodes considerably reduced food production and led to series of socioeconomic problems, not only in the areas affected by the droughts, but also in the other parts of West Africa. The various climatic variabilities which have caused the climatic events are no doubt related to the ocean-atmosphere interactions. Unfortunately, not much has been done on the understanding of these interactions, particularly as they affect developing countries. Indeed, not much has been done to develop programs which will reflect the general concerns and needs for researching into the ocean-atmosphere systems and their implications on man-environmental systems in many developing countries. This is for example, true of West and Central Africa, where compared with the middle latitude countries, much less is known about the characteristics of the ocean-atmosphere systems and their significance on man-environmental systems of the area.

  8. Tree cover in Central Africa: determinants and sensitivity under contrasted scenarios of global change

    NASA Astrophysics Data System (ADS)

    Aleman, Julie C.; Blarquez, Olivier; Gourlet-Fleury, Sylvie; Bremond, Laurent; Favier, Charly

    2017-01-01

    Tree cover is a key variable for ecosystem functioning, and is widely used to study tropical ecosystems. But its determinants and their relative importance are still a matter of debate, especially because most regional and global analyses have not considered the influence of agricultural practices. More information is urgently needed regarding how human practices influence vegetation structure. Here we focused in Central Africa, a region still subjected to traditional agricultural practices with a clear vegetation gradient. Using remote sensing data and global databases, we calibrated a Random Forest model to correlatively link tree cover with climatic, edaphic, fire and agricultural practices data. We showed that annual rainfall and accumulated water deficit were the main drivers of the distribution of tree cover and vegetation classes (defined by the modes of tree cover density), but agricultural practices, especially pastoralism, were also important in determining tree cover. We simulated future tree cover with our model using different scenarios of climate and land-use (agriculture and population) changes. Our simulations suggest that tree cover may respond differently regarding the type of scenarios, but land-use change was an important driver of vegetation change even able to counterbalance the effect of climate change in Central Africa.

  9. Tree cover in Central Africa: determinants and sensitivity under contrasted scenarios of global change.

    PubMed

    Aleman, Julie C; Blarquez, Olivier; Gourlet-Fleury, Sylvie; Bremond, Laurent; Favier, Charly

    2017-01-30

    Tree cover is a key variable for ecosystem functioning, and is widely used to study tropical ecosystems. But its determinants and their relative importance are still a matter of debate, especially because most regional and global analyses have not considered the influence of agricultural practices. More information is urgently needed regarding how human practices influence vegetation structure. Here we focused in Central Africa, a region still subjected to traditional agricultural practices with a clear vegetation gradient. Using remote sensing data and global databases, we calibrated a Random Forest model to correlatively link tree cover with climatic, edaphic, fire and agricultural practices data. We showed that annual rainfall and accumulated water deficit were the main drivers of the distribution of tree cover and vegetation classes (defined by the modes of tree cover density), but agricultural practices, especially pastoralism, were also important in determining tree cover. We simulated future tree cover with our model using different scenarios of climate and land-use (agriculture and population) changes. Our simulations suggest that tree cover may respond differently regarding the type of scenarios, but land-use change was an important driver of vegetation change even able to counterbalance the effect of climate change in Central Africa.

  10. Tree cover in Central Africa: determinants and sensitivity under contrasted scenarios of global change

    PubMed Central

    Aleman, Julie C.; Blarquez, Olivier; Gourlet-Fleury, Sylvie; Bremond, Laurent; Favier, Charly

    2017-01-01

    Tree cover is a key variable for ecosystem functioning, and is widely used to study tropical ecosystems. But its determinants and their relative importance are still a matter of debate, especially because most regional and global analyses have not considered the influence of agricultural practices. More information is urgently needed regarding how human practices influence vegetation structure. Here we focused in Central Africa, a region still subjected to traditional agricultural practices with a clear vegetation gradient. Using remote sensing data and global databases, we calibrated a Random Forest model to correlatively link tree cover with climatic, edaphic, fire and agricultural practices data. We showed that annual rainfall and accumulated water deficit were the main drivers of the distribution of tree cover and vegetation classes (defined by the modes of tree cover density), but agricultural practices, especially pastoralism, were also important in determining tree cover. We simulated future tree cover with our model using different scenarios of climate and land-use (agriculture and population) changes. Our simulations suggest that tree cover may respond differently regarding the type of scenarios, but land-use change was an important driver of vegetation change even able to counterbalance the effect of climate change in Central Africa. PMID:28134259

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

    PubMed

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

    2013-09-01

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

  12. WE-AB-213-00: Developments in International Medical Physics Collaborations in Africa and Latin America

    SciTech Connect

    2015-06-15

    The African Affairs Subcommittee (AA-SC) of the AAPM will present a multi-institutional approach to medical physics support in Africa. Current work to increase the quality of care and level of safety for the medical physics practice in Senegal, Ghana, and Zimbabwe will be presented, along with preliminary projects in Nigeria and Botswana. Because the task of addressing the needs of medical physics in countries across Africa is larger than one entity can accomplish on its own, the AA-SC has taken the approach of joining forces with multiple organizations such as Radiating Hope and TreatSafely (NGO’s), the IAEA, companies like BrainLab, Varian and Elekta, medical volunteers and academic institutions such as NYU and Washington University. Elements of current projects include: 1) Distance training and evaluation of the quality of contouring and treatment planning, teaching treatment planning and other subjects, and troubleshooting using modern telecommunications technology in Senegal, Ghana, and Zimbabwe; 2) Assistance in the transition from 2D to 3D in Senegal and Zimbabwe; 3) Assistance in the transition from 3D to IMRT using in-house compensators in Senegal; 4) Modernizing the cancer center in Senegal and increasing safety and; 5) Training on on 3D techniques in Ghana; 6) Assisting a teaching and training radiation oncology center to be built in Zimbabwe; 7) Working with the ISEP Program in Sub-Saharan Africa; 8) Creating instructional videos on linac commissioning; 9) Working on a possible collaboration to train physicists in Nigeria. Building on past achievements, the subcommittee seeks to make a larger impact on the continent, as the number and size of projects increases and more human resources become available. The State of Medical Physics Collaborations and Projects in Latin America Sandra Guzman (Peru) The lack of Medical Physicists (MP) in many Latin American (LA) countries leads to recruitment of professionals with incomplete education. In most LA

  13. Lagrangian analysis of moisture sources associated with precipitation in Central America

    NASA Astrophysics Data System (ADS)

    Durán-Quesada, A.; Gimeno, L.; Amador, J.

    2013-05-01

    The moisture sources associated with precipitation in Central America are identified using a Lagrangian methodology based on backward trajectories for the 1980-1999 period. The Caribbean Sea is highlighted as the main source of moisture for Central American precipitation. The Eastern Tropical Pacific is identified as a complementary oceanic source with a marked annual cycle. Moisture recycling is determined to be of importance in terms of local precipitation. The importance of improving the representation of vegetation coverage and land use in the region is pointed out. A remote terrestrial moisture source is identified in northern South America with a peak of intensity in summer. This source is suggested to provide a link between climate in the north of South America and precipitation in the Intra Americas Sea through convective anomalies. The variability of the moisture sources is analysed and the El Niño-Southern Oscillation (ENSO) is found to be the leading variability mode. Forcing from the North Atlantic Oscillation seems to be of importance modulating the Caribbean via the forcing exerted by the NASH. The results suggest that the Madden-Julian Oscillation may play a role in the modulation of precipitation associated with moisture transport through variations in convective activity, the Intertropical Convergence Zone (ITCZ) and the Caribbean Low Level Jet (CLLJ). Low frequency variability is suggested to affect the remote terrestrial source. The contributions to precipitation from the sources are computed. It is found that moisture transported from the sources and recycling may account up to a 80% of the observed precipitation. The CLLJ is found to be the modulator of the regional precipitation by means of the distribution of the regional moisture transport. It is suggested that there may be an important connection between the CLLJ and the ITCZ which may be responsible for the modulation of the regional distribution of precipitation. The response of the

  14. Satellite Estimates of the Direct Radiative Forcing of Biomass Burning Aerosols Over South America and Africa

    NASA Technical Reports Server (NTRS)

    Christopher, Sundar A.; Wang, Min; Kliche, Donna V.; Berendes, Todd; Welch, Ronald M.; Yang, S.K.

    1997-01-01

    Atmospheric aerosol particles, both natural and anthropogenic are important to the earth's radiative balance. Therefore it is important to provide adequate validation information on the spatial, temporal and radiative properties of aerosols. This will enable us to predict realistic global estimates of aerosol radiative effects more confidently. The current study utilizes 66 AVHRR LAC (Local Area Coverage) and coincident Earth Radiation Budget Experiment (ERBE) images to characterize the fires, smoke and radiative forcings of biomass burning aerosols over four major ecosystems of South America.

  15. Epidemiology of lobomycosis-like disease in bottlenose dolphins Tursiops spp. from South America and southern Africa.

    PubMed

    Van Bressem, Marie-Françoise; Simões-Lopes, Paulo C; Félix, Fernando; Kiszka, Jeremy J; Daura-Jorge, Fabio G; Avila, Isabel C; Secchi, Eduardo R; Flach, Leonardo; Fruet, Pedro F; du Toit, Kate; Ott, Paulo H; Elwen, Simon; Di Giacomo, Amanda B; Wagner, Jeanne; Banks, Aaron; Van Waerebeek, Koen

    2015-11-17

    We report on the epidemiology of lobomycosis-like disease (LLD), a cutaneous disorder evoking lobomycosis, in 658 common bottlenose dolphins Tursiops truncatus from South America and 94 Indo-Pacific bottlenose dolphins T. aduncus from southern Africa. Photographs and stranding records of 387 inshore residents, 60 inshore non-residents and 305 specimens of undetermined origin (inshore and offshore) were examined for the presence of LLD lesions from 2004 to 2015. Seventeen residents, 3 non-residents and 1 inshore dolphin of unknown residence status were positive. LLD lesions appeared as single or multiple, light grey to whitish nodules and plaques that may ulcerate and increase in size over time. Among resident dolphins, prevalence varied significantly among 4 communities, being low in Posorja (2.35%, n = 85), Ecuador, and high in Salinas, Ecuador (16.7%, n = 18), and Laguna, Brazil (14.3%, n = 42). LLD prevalence increased in 36 T. truncatus from Laguna from 5.6% in 2007-2009 to 13.9% in 2013-2014, albeit not significantly. The disease has persisted for years in dolphins from Mayotte, Laguna, Salinas, the Sanquianga National Park and Bahía Málaga (Colombia) but vanished from the Tramandaí Estuary and the Mampituba River (Brazil). The geographical range of LLD has expanded in Brazil, South Africa and Ecuador, in areas that have been regularly surveyed for 10 to 35 yr. Two of the 21 LLD-affected dolphins were found dead with extensive lesions in southern Brazil, and 2 others disappeared, and presumably died, in Ecuador. These observations stress the need for targeted epidemiological, histological and molecular studies of LLD in dolphins, especially in the Southern Hemisphere.

  16. Permanent sample plots for natural tropical forests: a rationale with special emphasis on Central Africa.

    PubMed

    Picard, Nicolas; Magnussen, Steen; Banak, Ludovic Ngok; Namkosserena, Salomon; Yalibanda, Yves

    2010-05-01

    Permanent sample plots (PSP), where trees are individually and permanently marked, have received increased interest in Central Africa as a tool to monitor vegetation changes. Although techniques for mounting PSP in tropical forests are well known, their planning still deserves attention. This study aims at defining a rationale for determining the size and number of replicates for setting up PSP in mixed tropical forests. It considers PSP as a sampling plan to estimate a target quantity with its associated margin of error. The target quantity considered here is the stock recovery rate, which is a key parameter for forest management in Central Africa. It is computed separately for each commercial species. The number of trees to monitor for each species defines the margin of error on the stock recovery rate. The size and number of replicated plots is obtained as the solution of an optimization problem that consists in minimizing the margin of error for every species while ensuring that the mounting cost remains below a given threshold. This rationale was applied using the data from the M'Baïki experimental site in the Central African Republic. It showed that the stock recovery rate is a highly variable quantity, and that the typical cost that forest managers are prone to devote to PSP leads to high margins of error. It also showed that the size and number of replicated plots is related to the spatial pattern of trees: clustered or spatially heterogeneous patterns favor many small plots, whereas regular or spatially homogeneous patterns favor few large plots.

  17. 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

  18. The development of the continental margin of eastern North America-conjugate continental margin to West Africa

    USGS Publications Warehouse

    Dillon, William P.; Schlee, J.S.; Klitgord, Kim D.

    1988-01-01

    The continental margin of eastern North America was initiated when West Africa and North America were rifted apart in Triassic-Early Jurassic time. Cooling of the crust and its thinning by rifting and extension caused subsidence. Variation in amounts of subsidence led to formation of five basins. These are listed from south to north. (1) The Blake Plateau Basin, the southernmost, is the widest basin and the one in which the rift-stage basement took longest to form. Carbonate platform deposition was active and persisted until the end of Early Cretaceous. In Late Cretaceous, deposition slowed while subsidence persisted, so a deep water platform was formed. Since the Paleocene the region has undergone erosion. (2) The Carolina Trough is narrow and has relatively thin basement, on the basis of gravity modeling. The two basins with thin basement, the Carolina Trough and Scotian Basin, also show many salt diapirs indicating considerable deposition of salt during their early evolution. In the Carolina Trough, subsidence of a large block of strata above the flowing salt has resulted in a major, active normal fault on the landward side of the basin. (3) The Baltimore Canyon Trough has an extremely thick sedimentary section; synrift and postrift sediments exceed 18 km in thickness. A Jurassic reef is well developed on the basin's seaward side, but post-Jurassic deposition was mainly non-carbonate. In general the conversion from carbonate to terrigenous deposition, characteristics of North American Basins, occurred progressively earlier toward the north. (4) The Georges Bank Basin has a complicated deep structure of sub-basins filled with thick synrift deposits. This may have resulted from some shearing that occurred at this offset of the continental margin. Postrift sediments apparently are thin compared to other basins-only about 8 km. (5) The Scotian Basin, off Canada, contains Jurassic carbonate rocks, sandstone, shale and coal covered by deltaic deposits and Upper

  19. 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

  20. A case of Distributed Continental Collision: Late Cretaceous Intraplate Shortening from Central Europe to North Africa

    NASA Astrophysics Data System (ADS)

    Kley, J.; Voigt, T.; Jaehne, F.

    2008-12-01

    Intraplate thrusting and basin inversion affected west-central Europe in Late Cretaceous time. The timing of this event is fairly well constrained between c. 90 and 65 Ma. The dominantly NW-trending European intraplate structures were often interpreted to have been dextrally transpressive, reflecting a northward push induced by the early collision of the Adria microplate with Europe's southern margin. However, many fault kinematic and other structural data from central Europe indicate dip-slip contraction essentially perpendicular to the main faults, suggesting a push from the southwest. In addition, recent plate reconstructions of the Mediterranean around 85 Ma place Adria far to the southeast and roughly along strike of the central European intraplate structures. The early Alpine nappe stack on Adria's leading edge was still separated from Europe by subducting oceanic lithosphere and had entered a phase of extension after the first orogenic event. All this makes Alpine collision an unlikely cause for intraplate thrusting in Europe. Rather, the timing, kinematics and location of structures suggest that intraplate shortening in Europe was a direct effect of convergence with the Iberian and African plates, with stresses transmitted across the Azores-Gibraltar fracture zone. This hypothesis is supported by structures of Late Cretaceous age indicating SW-NE to S-N shortening in France, Spain (particularly the onset of convergence in the Pyrenees) and northwestern Africa. In contrast to other examples such as the Laramides, intraplate thrusting in this case was not a foreland phenomenon related to a coeval orogen. It does not reflect a transition from subduction to continental collision, but the beginning of convergence across two former transform boundaries. This system which included no strongly thickened and weakened crust was mostly governed by far-field stresses and therefore responded rapidly to plate reorganizations. Specifically, the onset of thrusting

  1. Deep Earthquake Mechanics Inferred From Fault-Plane Orientations in Central South America

    NASA Astrophysics Data System (ADS)

    Warren, L. M.; Biryol, C. B.; Beck, S. L.

    2007-05-01

    To place constraints on the physical mechanisms of deep earthquakes, we analyze the rupture properties of >30 intraslab earthquakes with MW ≥ 5.7 in central South America. For each earthquake, we combine a directivity analysis with mapping of the slip distribution to estimate the rupture vector and identify the fault plane. We can distinguish the fault plane of the focal mechanism for ~1/3 of these earthquakes. At intermediate depths, we test whether earthquakes result from dehydration embrittlement reactivating the steep, trenchward- dipping faults of the outer rise. After accounting for the angle of subduction, the outer-rise faults would be approximately vertical. This prediction disagrees with our identified fault planes between 100-300 km depth, which are all subhorizontal. Subhorizontal faults are consistent with only one of the two failure planes expected from the slab stress field, suggesting that the slab fabric or an isobaric rupture process may also influence fault- plane orientations. The occurrence of exclusively subhorizontal faults at intermediate depths agrees with previous studies in the Tonga-Kermadec and Middle America subduction zones. The similarity in results between the three subduction zones despite large differences in temperature, lithospheric thickness, subduction velocity, and subduction angle suggests that the earthquake-generating mechanism is controlled by pressure rather than temperature or other tectonic parameters. Deeper than 300 km, earthquakes slip along both subhorizontal and subvertical fault planes, in agreement with the ambient stress field.

  2. Deep Earthquake Mechanics Inferred From Fault-Plane Orientations in Central South America

    NASA Astrophysics Data System (ADS)

    Warren, L. M.; Biryol, C. B.; Beck, S. L.

    2007-12-01

    To place constraints on the physical mechanisms of deep earthquakes, we analyze the rupture properties of >30 intraslab earthquakes with MW >5.7 in central South America (15°--25°S). For all earthquakes, we perform a directivity analysis to estimate the rupture vector and identify the fault plane. After comparing the results with synthetics, we can distinguish the fault plane of the focal mechanism for ~1/3 of these earthquakes. For the largest earthquakes, we also invert for the slip distribution on the fault plane. At intermediate depths, we test whether earthquakes result from dehydration embrittlement reactivating the steep, trenchward-dipping faults of the outer rise. After accounting for the angle of subduction, these faults would be approximately vertical. This prediction contrasts with the orientation of faults identified between 100--300 km depth, which are all subhorizontal and instead suggest the creation of a new system of faults. The exclusive occurrence of subhorizontal faults agrees with previous studies in the Tonga-Kermadec and Middle America subduction zones. The similarity in results between the three subduction zones despite large differences in temperature, subduction velocity, and subduction angle suggests that the earthquake-generating mechanism is controlled by pressure rather than tectonic parameters. Deeper than 300 km, earthquakes occur along both subhorizontal and subvertical fault planes.

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  5. Microsatellite analysis supports clonal propagation and reduced divergence of Trypanosoma vivax from asymptomatic to fatally infected livestock in South America compared to West Africa

    PubMed Central

    2014-01-01

    Background Mechanical transmission of the major livestock pathogen Trypanosoma vivax by other biting flies than tsetse allows its spread from Africa to the New World. Genetic studies are restricted to a small number of isolates and based on molecular markers that evolve too slowly to resolve the relationships between American and West African populations and, thus, unable us to uncover the recent history of T. vivax in the New World. Methods T. vivax genetic diversity, population structure and the source of outbreaks was investigated through the microsatellite multiloci (7 loci) genotype (MLGs) analysis in South America (47isolates from Brazil, Venezuela and French Guiana) and West Africa (12 isolates from The Gambia, Burkina Faso, Ghana, Benin and Nigeria). Relationships among MLGs were explored using phylogenetic, principal component and STRUCTURE analyses. Results Although closely phylogenetically related, for the first time, genetic differences were detected between T. vivax isolates from South America (11 genotypes/47 isolates) and West Africa (12 genotypes/12 isolates) with no MLGs in common. Diversity was far greater across West Africa than in South America, where genotypes from Brazil (MLG1-6), Venezuela (MLG7-10) and French Guiana (MLG11) shared similar but not identical allele composition. No MLG was exclusive to asymptomatic (endemic areas) or sick (outbreaks in non-endemic areas) animals, but only MLGs1, 2 and 3 were responsible for severe haematological and neurological disorders. Conclusions Our results revealed closely related genotypes of T. vivax in Brazil and Venezuela, regardless of endemicity and clinical conditions of the infected livestock. The MLGs analysis from T. vivax across SA and WA support clonal propagation, and is consistent with the hypothesis that the SA populations examined here derived from common ancestors recently introduced from West Africa. The molecular markers defined here are valuable to assess the genetic diversity, to

  6. 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

    2016-01-18

    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.

  7. 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

  8. [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)].

  9. 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.

  10. 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.

  11. 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

  12. Comparison of resistance to third-generation cephalosporins in Shigella between Europe-America and Asia-Africa from 1998 to 2012.

    PubMed

    Gu, B; Zhou, M; Ke, X; Pan, S; Cao, Y; Huang, Y; Zhuang, L; Liu, G; Tong, M

    2015-10-01

    We conducted a systematic review to compare resistance to third-generation cephalosporins (TGCs) in Shigella strains between Europe-America and Asia-Africa from 1998 to 2012 based on a literature search of computerized databases. In Asia-Africa, the prevalence of resistance of total and different subtypes to ceftriaxone, cefotaxime and ceftazidime increased markedly, with a total prevalence of resistance up to 14·2% [95% confidence interval (CI) 3·9-29·4], 22·6% (95% CI 4·8-48·6) and 6·2% (95% CI 3·8-9·1) during 2010-2012, respectively. By contrast, resistance rates to these TGCs in Europe-America remained relatively low--less than 1·0% during the 15 years. A noticeable finding was that certain countries both in Europe-America and Asia-Africa, had a rapid rising trend in the prevalence of resistance of S. sonnei, which even outnumbered S. flexneri in some periods. Moreover, comparison between countries showed that currently the most serious problem concerning resistance to these TGCs appeared in Vietnam, especially for ceftriaxone, China, especially for cefotaxime and Iran, especially for ceftazidime. These data suggest that monitoring of the drug resistance of Shigella strains should be strengthened and that rational use of antibiotics is required.

  13. Pediatric Sarcoma in Central America: Outcomes, Challenges and Plans for Improvement

    PubMed Central

    Friedrich, Paola; Ortiz, Roberta; Strait, Kelly; Fuentes, Soad; Gamboa, Yéssica; Arambú, Ingrid; Ah-Chu-Sanchez, María; London, Wendy; Rodríguez-Galindo, Carlos; Antillón-Klussmann, Federico; Báez, Fulgencio

    2012-01-01

    Background Children with cancer in middle-income countries have inferior outcomes to those in high-income countries. The magnitude and drivers for this survival gap are not well understood. We sought to describe patterns of clinical presentation, magnitude of treatment abandonment, and survival in children with sarcoma in Central America. Methods Retrospective review of hospital-based registries from national pediatric oncology referral centers. Patients with newly diagnosed osteosarcoma, Ewing sarcoma (Ewing), rhabdomyosarcoma (RMS), and soft tissue sarcomas (STS) between 1/1/00-12/31/09 were included. Survival analysis was performed using standard definitions of overall and event-free survival (OS and EFS) and with abandonment included as an event (AOS and AEFS). Results A total of 785 new cases of pediatric sarcoma were reported (264 osteosarcoma, 175 Ewing, 240 RMS, and 106 STS). Metastatic disease at presentation was high (osteosarcoma 38%, Ewing 39%, RMS 29% and STS 21%). Treatment abandonment rate was high, particularly among patients with extremity bone sarcomas (osteosarcoma 30%, Ewing 15%, RMS 25% and STS 15%). Of 559 patients experiencing a first event, 59% had either relapse or progressive disease. The 4-year OS was 40% (SE±3%) and EFS was 30% (SE±2%), but further decreased to 31% (SE±2%) and 24% (SE±2%), when abandonment was taken into account. Conclusion High rate of metastases and treatment abandonment, and difficulty with upfront treatment effectiveness are important contributors to poor survival of children with pediatric sarcomas in Central America. Initiatives for early diagnosis, psychosocial support, quality improvement, and multidisciplinary care are warranted to improve outcomes. PMID:22972687

  14. Connections between the Intertropical Convergence Zone and the Caribbean Low Level Jet in Central America

    NASA Astrophysics Data System (ADS)

    Hidalgo, H. G.; Durán-Quesada, A.; Amador, J.; Alfaro, E. J.

    2013-05-01

    This study explores statistical connections between the displacements and strength of the Intertropical Convergence Zone (ITCZ) and the Caribbean Low Level Jet (CLLJ). Indicators of the strength and position of the ITCZ include the latitude (LATC) and longitude (LONC) of the center of mass of precipitation and the mean domain precipitation (Pdomain) in a region bounded by coordinates 10 oS and 25 oN and 100 - 55 oW. The CLLJ was indexed using the average zonal wind velocity at 925 hPa over a region bounded by 7.5 - 12.5 oN and 85 - 75 oW. Preliminary analyses show that there is a strong correlation (0.82) between summer (JJA) LATC and JJA CLLJ index for the period 1979 - 2010; this correlation is lower in other seasons (0.63 for Autumn, 0.20 for Winter and 0.49 for Spring). These correlations were verified in the zonal wind composites at 925 hPa for the 5 lowest and 5 highest years of LATC. LONC does not seem to have the same strong relationship with the CLLJ. At daily level, composites show that precipitation in the Central America region is influenced by Pdomain, LATC, and the CLLJ index. From the comparison between the highest and lowest years of LATC, a strong contrast is observed for the evaporation over the Caribbean and the moisture transport to Central America. Moisture uptake increases significantly for the lowest LATC which corresponds to a stronger CLLJ. Composites of Sea Surface Temperature for the 5 years of highest and lowest LATC show some relationship with ENSO, although there is a disproportionate influence of the 1997-98 El Niño that may be affecting the results. There is however a consistent feature: during years of high LATC, there are warm anomalies in the tropical Atlantic off the coast of Venezuela, that are not present during years of low LATC.

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

    USGS Publications Warehouse

    Shedlock, K.M.

    1999-01-01

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

  16. 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.

  17. 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).

  18. 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.

  19. Spatial variations of effective elastic thickness of the lithosphere in Central America and surrounding regions

    NASA Astrophysics Data System (ADS)

    Jiménez-Díaz, Alberto; Ruiz, Javier; Pérez-Gussinyé, Marta; Kirby, Jon F.; Álvarez-Gómez, José A.; Tejero, Rosa; Capote, Ramón

    2014-04-01

    As a proxy for long-term lithospheric strength, the effective elastic thickness (Te) can be used to understand the relationship between lithospheric rheology and geodynamic evolution of complex tectonic settings. Here we present, for the first time, high-resolution maps of spatial variations of Te in Central America and surrounding regions from the analysis of the coherence between topography and Bouguer gravity anomaly using multitaper and wavelet methods. Regardless of the technical differences between the two methods, there is a good overall agreement in the spatial variations of Te recovered from both methods. Although absolute Te values can vary in both maps, the qualitative Te structure and location of the main Te gradients are very similar. The pattern of the Te variations in Central America and surrounding regions agrees well with the tectonic provinces in the region, and it is closely related to major tectonic boundaries, where the Middle American and Lesser Antilles subduction zones are characterized by a band of high Te on the downgoing slab seaward of the trenches. These high Te values are related to internal loads (and in the case of the southernmost tip of the Lesser Antilles subduction zone also associated with a large amount of sediments) and should be interpreted with caution. Finally, there is a relatively good correlation, despite some uncertainties, between surface heat flow and our Te results for the study area. These results suggest that although this area is geologically complex, the thermal state of the lithosphere has profound influence on its strength, such that Te is strongly governed by thermal structure.

  20. New evidence for hybrid zones of forest and savanna elephants in Central and West Africa.

    PubMed

    Mondol, Samrat; Moltke, Ida; Hart, John; Keigwin, Michael; Brown, Lisa; Stephens, Matthew; Wasser, Samuel K

    2015-12-01

    The African elephant consists of forest and savanna subspecies. Both subspecies are highly endangered due to severe poaching and habitat loss, and knowledge of their population structure is vital to their conservation. Previous studies have demonstrated marked genetic and morphological differences between forest and savanna elephants, and despite extensive sampling, genetic evidence of hybridization between them has been restricted largely to a few hybrids in the Garamba region of northeastern Democratic Republic of Congo (DRC). Here, we present new genetic data on hybridization from previously unsampled areas of Africa. Novel statistical methods applied to these data identify 46 hybrid samples--many more than have been previously identified--only two of which are from the Garamba region. The remaining 44 are from three other geographically distinct locations: a major hybrid zone along the border of the DRC and Uganda, a second potential hybrid zone in Central African Republic and a smaller fraction of hybrids in the Pendjari-Arli complex of West Africa. Most of the hybrids show evidence of interbreeding over more than one generation, demonstrating that hybrids are fertile. Mitochondrial and Y chromosome data demonstrate that the hybridization is bidirectional, involving males and females from both subspecies. We hypothesize that the hybrid zones may have been facilitated by poaching and habitat modification. The localized geography and rarity of hybrid zones, their possible facilitation from human pressures, and the high divergence and genetic distinctness of forest and savanna elephants throughout their ranges, are consistent with calls for separate species classification.

  1. Public health professionals’ perceptions of mental health services in Equatorial Guinea, Central-West Africa

    PubMed Central

    Reuter, Peter Robert; McGinnis, Shannon Marcail; Reuter, Kim Eleanor

    2016-01-01

    Introduction Mental health disorders constitute 13% of global disease burden, the impacts of which are disproportionality felt in sub-Saharan Africa. Equatorial Guinea, located in Central-West Africa, has the highest per-capita investment in healthcare on the African continent, but only two studies have discussed mental health issues in the country and none of have examined the perspective of professionals working in the field. The purpose of this study was to gain a preliminary understanding of Equatoguinean health care professionals' perspectives on the mental health care system. Methods Nine adult participants (directors or program managers) were interviewed in July 2013 in Malabo, Equatorial Guinea from government agencies, aid organizations, hospitals, and pharmacies. Interviews were designed to collect broad information about the mental healthcare system in Equatorial Guinea including the professionals' perspectives and access to resources. This research was reviewed and approved by an ethical oversight committee. Results All individuals interviewed indicated that the mental health system does not currently meet the needs of the community. Professionals cited infrastructural capacity, stigmatization, and a lack of other resources (training programs, knowledgeable staff, medications, data) as key factors that limit the effectiveness of mental healthcare. Conclusion This study provides a preliminary understanding of the existing mental health care needs in the country, highlighting opportunities for enhanced healthcare services. PMID:28293352

  2. Oil and gas developments in central and southern Africa in 1987

    SciTech Connect

    Hartman, J.B.; Walker, T.L.

    1988-10-01

    Significant rightholding changes took place in central and southern Africa during 1987. Angola, Benin, Congo, Gabon, Ghana, Guinea, Guinea Bissau, Mauritania, Seychelles, Somali Republic, Tanzania, Zaire, and Zambia announced awards or acreage open for bidding. Decreases in exploratory rightholdings occurred in Cameroon, Congo, Cote d'Ivoire, Equatorial Guinea, Gabon, Kenya, Namibia, South Africa, and Tanzania. More wells and greater footage were drilled in 1987 than in 1986. Total wells increased by 18% as 254 wells were completed compared to 217 in 1986. Footage drilled during the year increased by 46% as about 1.9 million ft were drilled compared to about 1.3 million ft in 1986. The success rate for exploration wells in 1987 improved slightly to 36% compared to 34% in 1986. Significant discoveries were made in Nigeria, Angola, Congo, and Gabon. Seismic acquisition in 1987 was the major geophysical activity during the year. Total oil production in 1987 was 773 million bbl (about 2.1 million b/d), a decrease of 7%. The decrease is mostly due to a 14% drop in Nigerian production, which comprises 60% of total regional production. The production share of OPEC countries (Nigeria and Gabon) versus non-OPEC countries of 67% remained unchanged from 1986. 24 figs., 5 tabs.

  3. Drug Development and Conservation of Biodiversity in West and Central Africa: Performance of Neurochemical and Radio Receptor Assays of Plant Extracts Drug Discovery for the Central Nervous System

    DTIC Science & Technology

    2004-09-01

    7) Hui, D.; Sao-Xing, C. J. Nat. Prod. 1998, 61, 142-144. (8) Aldrich Libray of 13C and 1H FT NMR spectra 1992, 2, 326A. (9) Kadota, S .; Hui, D...Biodiversity in West and Central Africa: Performance of Neurochemical and Radio Receptor Assays of Plant Extracts Drug Discovery for the Central... s ) and should not be construed as an official Department of the Army position, policy or decision unless so designated by other documentation

  4. Flavor precursors and sensory-active sulfur compounds in alliaceae species native to South Africa and South America.

    PubMed

    Kubec, Roman; Krejčová, Petra; Mansur, Leví; García, Nicolás

    2013-02-13

    Profiles of S-substituted cysteine flavor precursors were determined in 42 Alliaceae species native to South Africa and South America. It was found that the pool of cysteine derivatives present in these plants is remarkably very simple, with S-((methylthio)methyl)cysteine 4-oxide (marasmin) being the principal flavor precursor, typically accounting for 93-100% of the pool. Out of the other cysteine derivatives, only minor quantities of methiin were present in some species. The marasmin-derived thiosulfinate marasmicin (2,4,5,7-tetrathiaoctane 4-oxide), a major sensory-active compound of the freshly disrupted plants, was isolated, and its organoleptic properties were evaluated. Furthermore, sulfur-containing volatiles formed upon boiling of these alliaceous species were studied by GC-MS. The profile of the volatiles formed was relatively simple, with 2,3,5-trithiahexane and 2,4,5,7-tetrathiaoctane being the major components. Despite the traditional belief, ingestion of the marasmin-rich plants was always accompanied by development of a strong "garlic breath". We believe that especially several Tulbaghia species deserve to attract much greater attention from the food industry thanks to their pungent garlicky taste and unusual yet pleasant alliaceous smell.

  5. Comparisons of anemia, thrombocytopenia, and neutropenia at initiation of HIV antiretroviral therapy in Africa, Asia, and the Americas

    PubMed Central

    Firnhaber, Cynthia; Smeaton, Laura; Saukila, Nasinuku; Flanigan, Timothy; Gangakhedkar, Raman; Kumwenda, Johnstone; La Rosa, Alberto; Kumarasamy, Nagalingeswaran; De Gruttola, Victor; Hakim, James Gita; Campbell, Thomas B.

    2010-01-01

    Summary Background Hematological abnormalities are common manifestations of advanced HIV-1 infection that could affect the outcomes of highly-active antiretroviral therapy (HAART). Although most HIV-1-infected individuals live in resource-constrained countries, there is little information about the frequency of hematological abnormalities such as anemia, neutropenia, and thrombocytopenia among individuals with advanced HIV-1 disease. Methods This study compared the prevalence of pre-antiretroviral therapy hematological abnormalities among 1571 participants in a randomized trial of antiretroviral efficacy in Africa, Asia, South America, the Caribbean, and the USA. Potential covariates for anemia, neutropenia, and thrombocytopenia were identified in univariate analyses and evaluated in separate multivariable models for each hematological condition. Results The frequencies of neutropenia (absolute neutrophil count ≤ 1.3 × 109/l), anemia (hemoglobin ≤ 10 g/dl), and thrombocytopenia (platelets ≤ 125 × 109/l) at initiation of antiretroviral therapy were 14%, 12%, and 7%, respectively, and varied by country (p < 0.0001 for each). In multivariable models, anemia was associated with gender, platelet count, and country; neutropenia was associated with CD4+ lymphocyte and platelet counts; and thrombocytopenia was associated with country, gender, and chronic hepatitis B infection. Conclusions Differences in the frequency of pretreatment hematological abnormalities could have important implications for the choice of antiretroviral regimen in resource-constrained settings. PMID:20961784

  6. Oil and gas developments in central and southern Africa in 1984

    SciTech Connect

    Armstrong, A.C.

    1985-10-01

    Key indications are that the industry decline that began in 1982 has bottomed out in central and southern Africa. Seismic in 1984 was up more than 10% from 1983. Wildcatting and total drilling were down slightly, but production posted a 13% increase. The total number of wildcats decreased from 86 in 1983 to 83 in 1984; however, if Nigerian activity is excluded, wildcats actually increased to 71 from 62. Production is up principally because existing fields were expanded and new ones came on stream. It increased from 1.85 million BOPD in 1983 to 2.1 million BOPD in 1984. The increase in development drilling led by Cameroon and Nigeria should result in a continuation of this rise unless world conditions override.

  7. Oil and gas developments in central and southern Africa in 1984

    SciTech Connect

    Armstrong, A.C.

    1985-10-01

    Key indications are that the industry decline that began in 1982 has bottomed out in central and southern Africa. Seismic in 1984 was up more than 10% from 1983. Wildcatting and total drilling were down slightly, but production posted a 13% increase. The total number of wildcats decreased from 86 in 1983 to 83 in 1984; however, if Nigerian activity is excluded, wildcats actually increased to 71 from 62. Production is up principally because existing fields were expanded and new ones came on stream. It increased from 1.85 million BOPD in 1983 to 2.1 million BOPD in 1984. The increase in development drilling led by Cameroon and Nigeria should result in a continuation of this rise unless world conditions override. 31 figures, 7 tables.

  8. Providing care and facing death: nursing during Ebola outbreaks in central Africa.

    PubMed

    Hewlett, Bonnie L; Hewlett, Barry S

    2005-10-01

    Few studies have focused on describing the experiences of health care workers during rapid killing epidemics. In this article, the views and experiences of nurses during three outbreaks of Ebola hemorrhagic fever (EHF) in Central Africa are examined. These three outbreaks occurred in Kikwit, Democratic Republic of Congo (DRC, 1995); Gulu, Uganda (2000-2001); and Republic of Congo (ROC, 2003). Open-ended and semistructured interviews with individuals and small groups were conducted during the outbreaks in Uganda and ROC; data from DRC are extracted from published sources. Three key themes emerged from the interviews: (a) lack of protective gear, basic equipment, and other resources necessary to provide care, especially during the early phases of the outbreaks; (b) stigmatization by family, coworkers, and community; and (c) exceptional commitment to the nursing profession in a context where the lives of the health care workers were in jeopardy.

  9. 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…

  10. Geology and petroleum resources of north-central and northeast Africa

    SciTech Connect

    Peterson, J.A.

    1986-05-01

    In north-central and northeast Africa, important petroleum accumulations exist in the Sirte basin of Libya, the western Sahara region of Algeria, the Pelagian platform offshore from eastern Tunisia, and in the Western Desert basin, Suez graben, and Nile delta in Egypt. Approximately 55 major fields (> 100 million BOE), of which 15 are giants (> 1 billion BOE), have been found in these provinces. Total estimated ultimate production from existing fields in 60 billion bbl of oil and 100 tcf of gas; estimated undiscovered petroleum resources are 26 billion bbl of oil and 93 tcf of gas. The post-Precambrian sedimentary basins of north Africa are related to the development of the Sahara platform during at least four main tectonic episodes (the Caledonian, Hercynian, Laramide, and Alpine cycles). The sedimentary cover of the platform, which includes rocks of all geologic systems, ranges from less than 1000 m (3300 ft) in the south to more than 9000 m (30,000 ft) along the Mediterranean coast. Paleozoic rocks are primarily continental and nearshore marine sandstone and shale, which are important reservoir and source rocks for petroleum in the central and western parts of the Sahara platform. Lower Mesozoic rocks were deposited in a continental and restricted marine environment, and contain thick beds of red beds and evaporites, including salt, which are important seals for oil and gas fields. Upper Mesozoic and Tertiary rocks are related to the development of the Mediterranean Tethys geosyncline and are characterized by numerous transgressive-regressive cycles of the Tethyan seaway. Marine carbonate and shale facies are dominant in the Upper Jurassic, Cretaceous, and lower Tertiary section of northern Libya, eastern Tunisia-Pelagian platform, and northern Egypt. Upper Tertiary beds are continental clastics on most of the platform, except near the Mediterranean.

  11. Central southern Africa at the time of the African Humid Period: a new analysis of Holocene palaeoenvironmental and palaeoclimate data

    NASA Astrophysics Data System (ADS)

    Burrough, S. L.; Thomas, D. S. G.

    2013-11-01

    The Holocene African Humid Period (c 14.8-5.5 ka) is now recognised in high-resolution records from western Africa as well as in tropical Africa north of the equator. Establishing a clear picture of Late Quaternary, including Holocene, environmental changes in central southern Africa is proving both difficult and contentious. This is because in dryland systems in particular it can be difficult to distinguish the effects of sub-millennial scale regional climatic variability from those of major externally-forced global climate changes, and because it is essential to distinguish records of environmental drivers from those of environmental responses. We analyse and review existing records for central southern Africa, and neighbouring areas affected by the same climate systems, to understand the primary controls of regional hydrological systems during the Holocene. We then present new data from Makgadikgadi basin barchan dunes that indicate mid-late Holocene aridity following a period of marked hydrological dynamism extending from the early Holocene. We suggest that present-day conditions in central southern Africa are relatively stable compared to the early and mid-Holocene and infer that this period of relative stability in the landscape has occurred since ca 2 ka. We explain Holocene hydrological changes through analysis of changing zonal climatic influences linked to Congo Air Boundary (CAB) and Intertropical Convergence Zone (ITCZ) dynamics, the effects of which filter into the region via complex drainage basin dynamics. It is proposed that, sensu stricto, the AHP was not a spatially uniform feature of early Holocene central southern Africa.

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

    NASA Astrophysics Data System (ADS)

    Avalos, D.; Gomez, R.

    2012-12-01

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

  13. 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.

  14. An investigation of MAGSAT and complementary data emphasizing precambrian shields and adjacent areas of West Africa and South America

    NASA Technical Reports Server (NTRS)

    Hastings, D. A. (Principal Investigator)

    1983-01-01

    There is lack of acceptance of quantitative crustal models by specialists on regional geology because of the problem of east-west banding on MAGSAT anomaly maps. The possibility of some of the Earth's magnetic field being created in the mantle below the Curie isotherm is discussed as well as the need to remove spherical harmonics of degrees less than 15 from the anomaly map. Two dimensional models were produced for northern South America that might be considered as working models. These models suggest that the presumed Amazon River depression is better developed near Belem and in the upper Amazon basin than in the central Amazon basin. An attempt is proposed for separating the core field from the crustal field using a flat-Earth model.

  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

    ... 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. The... preferential tariff treatment being accorded under the Agreement for certain goods of Costa Rica,...

  16. 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…

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  18. A Volcano Population Index for Estimating Relative Risk With Example Data From Central America

    NASA Astrophysics Data System (ADS)

    Ewert, J. W.; Harpel, C. J.

    2003-12-01

    We have developed a Volcano Population Index (VPI) to make objective comparisons among individual volcanoes of populations that may be subject to volcanic hazards. We used volcano location data from the Smithsonian's Global Volcanism Program (GVP) with the LandScan 2001 gridded global population data base from the Oak Ridge National Laboratory to evaluate population distribution near potentially active volcanoes in Central America. The LandScan database reports global ambient population on a 30- by 30-arc second grid (about 1 km by 1 km). The countries in Central America with volcanoes of Holocene age (<10 ka) are Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama. The VPI is defined as the sum of the population values of all LandScan 2001 cells within 10 km (VPI10) of the coordinates given for each Holocene volcano in the Smithsonian GVP catalog. An analysis of recent evacuations in the region in response to volcanic activity and a global compilation of eruption data by Newhall and Hoblitt (2002) prompted us to also evaluate population within 5 km of Holocene volcanoes and create a 5 km Volcano Population Index (VPI5). The VPI5 is an estimate of the number of people who will almost certainly have to be evacuated and cared for over some time period while an eruption is underway. There will almost always be some volcanic phenomena that adversely affects people within 10 km of the vent, and if an eruption is big enough, acute hazards may easily reach 10 km or more in any direction. We view the VPI10 as an estimate of the number of people who may have to be evacuated and cared for, and we use the VPI10 as the principal population statistic for comparison among individual volcanoes. We calculated the VPI statistics for 75 Central American Holocene volcanoes and report a country by country summary of population within 10 km of Holocene volcanoes that shows the relative exposure to volcano hazards in Central America. We also analyzed the historically

  19. 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.

  20. Geology and total petroleum systems of the West-Central Coastal province (7203), West Africa

    USGS Publications Warehouse

    Brownfield, Michael E.; Charpentier, Ronald R.

    2006-01-01

    The West-Central Coastal Province of the Sub-Saharan Africa Region consists of the coastal and offshore areas of Cameroon, Equatorial Guinea, Gabon, Democratic Republic of the Congo, Republic of the Congo, Angola (including the disputed Cabinda Province), and Namibia. The area stretches from the east edge of the Niger Delta south to the Walvis Ridge. The West-Central Coastal Province includes the Douala, Kribi-Campo, Rio Muni, Gabon, Congo, Kwanza, Benguela, and Namibe Basins, which together form the Aptian salt basin of equatorial west Africa. The area has had significant exploration for petroleum; more than 295 oil fields have been discovered since 1954. Since 1995, several giant oil fields have been discovered, especially in the deep-water area of the Congo Basin. Although many total petroleum systems may exist in the West-Central Coastal Province, only four major total petroleum systems have been defined. The area of the province north of the Congo Basin contains two total petroleum systems: the Melania-Gamba Total Petroleum System, consisting of Lower Cretaceous source and reservoir rocks, and the Azile-Senonian Total Petroleum System, consisting of Albian to Turonian source rocks and Cretaceous reservoir rocks. Two assessment units are defined in the West-Central Coastal Province north of the Congo Basin: the Gabon Subsalt and the Gabon Suprasalt Assessment Units. The Congo Basin contains the Congo Delta Composite Total Petroleum System, consisting of Lower Cretaceous to Tertiary source and reservoir rocks. The Central Congo Delta and Carbonate Platform and the Central Congo Turbidites Assessment Units are defined in the Congo Delta Composite Total Petroleum System. The area south of the Congo Basin contains the Cuanza Composite Total Petroleum System, consisting of Lower Cretaceous to Tertiary source and reservoir rocks. The Cuanza-Namibe Assessment Unit is defined in the Cuanza Composite Total Petroleum System. The U.S. Geological Survey (USGS) assessed the

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

    PubMed Central

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

    1998-01-01

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

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

    PubMed

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

    1998-01-01

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

  3. Interactive effects of grazing, drought, and fire on grassland plant communities in North America and South Africa.

    PubMed

    Koerner, Sally E; Collins, Scott L

    2014-01-01

    Grazing, fire, and climate shape mesic grassland communities. With global change altering all three factors, understanding how grasslands respond to changes in these combined drivers may aid in projecting future changes in grassland ecosystems. We manipulated rainfall and simulated grazing (clipping) in two long-term fire experiments in mesic grasslands in North America (NA) and South Africa (SA). Despite their common drivers, grasslands in NA and SA differ in evolutionary history. Therefore, we expected community structure and production in NA and SA to respond differently to fire, grazing, and drought. Specifically, we hypothesized that NA plant community composition and production would be more responsive than the SA plant communities to changes in the drivers and their interactions, and that despite this expected stability of SA grasslands, drought would be the dominant factor controlling production, but grazing would play the primary role in determining community composition at both sites. Contrary to our hypothesis, NA and SA grasslands generally responded similarly to grazing, drought, and fire. Grazing increased diversity, decreased grass cover and production, and decreased belowground biomass at both sites. Drought alone minimally impacted plant community structure, and we saw similar treatment interactions at the two sites. Drought was not the primary driver of grassland productivity, but instead drought effects were similar to or less than grazing and fire. Even though these grasslands differed in evolutionary history, they responded similarly to our fire, grazing, and climate manipulations. Overall, we found community and ecosystem convergence in NA and SA grasslands. Grazing and fire are as important as climate in controlling mesic grassland ecosystems on both continents.

  4. 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

  5. Mitochondrial DNA variability in Giraffa camelopardalis: consequences for taxonomy, phylogeography and conservation of giraffes in West and central Africa.

    PubMed

    Hassanin, Alexandre; Ropiquet, Anne; Gourmand, Anne-Laure; Chardonnet, Bertrand; Rigoulet, Jacques

    2007-03-01

    The giraffe (Giraffa camelopardalis) still survives in four countries of West and central Africa. The populations of Niger and Cameroon are generally assigned to the subspecies peralta, but those of Chad and the Central African Republic are taxonomically problematic, as they are referred to as either peralta, or antiquorum, or congoensis. In this study, a mitochondrial fragment of 1765 nucleotide sites, covering the complete cytochrome b gene, three transfer RNAs and a large part of the control region, was sequenced to assess the relationships between several populations of giraffe. The phylogenetic analyses performed on the 12 identified haplotypes indicate that northern giraffes constitute a natural group, distinct from that of southern giraffes. Surprisingly, the giraffes of Niger are found to be more closely related to the giraffes of East Africa (subspecies rothschildi and reticulata) than to those of central Africa. We conclude therefore that the subspecies peralta contains only the Niger giraffes, whereas the subspecies antiquorum includes all populations living in Cameroon, Chad, the Central African Republic, and southwestern Sudan. We suggest that the ancestor of the Nigerian giraffe dispersed from East to North Africa during the Quaternary period and thereafter migrated to its current Sahelian distribution in West Africa, in response to the development of the Sahara desert. This hypothesis implies that Lake Mega-Chad acted as a strong geographical barrier during the Holocene, preventing any contact between the subspecies peralta and antiquorum. Our study has direct implications for conservation management, as we show that no subspecies peralta is represented in any European zoos, only in Niger, with a small population of less than 200 individuals.

  6. Intraplate mountain building in response to continent continent collision—the Ancestral Rocky Mountains (North America) and inferences drawn from the Tien Shan (Central Asia)

    NASA Astrophysics Data System (ADS)

    Dickerson, Patricia Wood

    2003-04-01

    The intraplate Ancestral Rocky Mountains of western North America extend from British Columbia, Canada, to Chihuahua, Mexico, and formed during Early Carboniferous through Early Permian time in response to continent-continent collision of Laurentia with Gondwana—the conjoined masses of Africa and South America, including Yucatán and Florida. Uplifts and flanking basins also formed within the Laurentian Midcontinent. On the Gondwanan continent, well inboard from the marginal fold belts, a counterpart structural array developed during the same period. Intraplate deformation began when full collisional plate coupling had been achieved along the continental margin; the intervening ocean had been closed and subduction had ceased—that is, the distinction between upper versus lower plates became moot. Ancestral Rockies deformation was not accompanied by volcanism. Basement shear zones that formed during Mesoproterozoic rifting of Laurentia were reactivated and exerted significant control on the locations, orientations, and modes of displacement on late Paleozoic faults. Ancestral Rocky Mountain uplifts extend as far south as Chihuahua and west Texas (28° to 33°N, 102° to 109°W) and include the Florida-Moyotes, Placer de Guadalupe-Carrizalillo, Ojinaga-Tascotal and Hueco Mountain blocks, as well as the Diablo and Central Basin Platforms. All are cored with Laurentian Proterozoic crystalline basement rocks and host correlative Paleozoic stratigraphic successions. Pre-late Paleozoic deformational, thermal, and metamorphic histories are similar as well. Southern Ancestral Rocky Mountain structures terminate along a line that trends approximately N 40°E (present coordinates), a common orientation for Mesoproterozoic extensional structures throughout southern to central North America. Continuing Tien Shan intraplate deformation (Central Asia) has created an analogous array of uplifts and basins in response to the collision of India with Eurasia, beginning in late

  7. Trypanosoma rangeli genotypes association with Rhodnius prolixus and R. pallescens allopatric distribution in Central America.

    PubMed

    Salazar-Antón, Fernando; Urrea, Daniel Alfonso; Guhl, Felipe; Arévalo, Carolina; Azofeifa, Gabriela; Urbina, Andrea; Blandón-Naranjo, Melissa; Sousa, Octavio E; Zeledón, Rodrigo; Vallejo, Gustavo Adolfo

    2009-12-01

    Previous kDNA polymorphism-based reports have revealed the existence of two Trypanosoma rangeli genotypes (KP1+ and KP1-): SL and SSU rRNA gene polymorphism-based studies have revealed that five genotypes (A-E) are distributed throughout different Latin-American countries. Some evidence has shown that the genotypes' biogeographical distribution is associated with sympatric Rhodnius species. 12 T. rangeli isolates from humans and reservoirs from El Salvador, Guatemala, Honduras, Costa Rica and Panama were characterised by kDNA and mini-exon gene intergene spacer analysis and compared to 12 previously characterised isolates from humans and vectors from Colombia, Guatemala, Honduras and Venezuela. Central American isolates corresponded to genotypes called KP1(+) or lineage A and KP1(-) or lineage C. Such dimorphism was corroborated by randomly amplified polymorphic DNA (RAPD) in 22 selected isolates; a dendrogram was thus produced having two defined branches. One branch grouped KP1(-) or lineage C strains isolated from Rhodnius colombiensis (Colombia), humans (Panama), Procyon lotor and Choloepus hoffmanni (Costa Rica). The other group was formed by KP1(+) or lineage A strains isolated from Rhodnius prolixus (Colombia, Venezuela) and humans (El Salvador, Guatemala, Honduras). These results present evidence that both groups infect different mammals (humans, domestic and silvatic animals) having no association with any particular vertebrate species; however, T. rangeli KP1(+) or (A) strains have been isolated in Central America in areas where R. prolixus circulate (Honduras, El Salvador and Guatemala) and KP1(-) or (C) strains have been isolated in areas where Rhodnius pallescens is the main vector (Panama and Costa Rica) indicating a parasite-vector association. The same lineages circulate in Andean countries (Colombia, Venezuela, Ecuador and Peru), KP1+ being associated with members of the prolixus group (R. prolixus and Rhodnius robustus) and KP1- with members of the

  8. [Optimization of registry of deaths from chronic kidney disease in agricultural communities in Central America].

    PubMed

    Escamilla-Cejudo, José Antonio; Báez, Jorge Lara; Peña, Rodolfo; Luna, Patricia Lorena Ruiz; Ordunez, Pedro

    2016-11-01

    Several Central American countries are seeing continued growth in the number of deaths from chronic kidney disease of nontraditional causes (CKDnT) among farm workers and there is underreporting. This report presents the results of a consensus process coordinated by the Pan American Health Organization/World Health Organization (PAHO/WHO), the United States Centers for Disease Control and Prevention (CDC), and the Latin American Society of Nephrology and Hypertension (SLANH). This consensus seeks to increase the probability of detecting and recording deaths from these causes. There has been recognition of the negative impact of the lack of a standardized instrument and the lack of training in the medical profession for adequate registration of the cause or causes of death. As a result of the consensus, the following has been proposed: temporarily use a code from the Codes for Special Purposes in the International Classification of Diseases (ICD-10); continue to promote use of the WHO international standardized instrument for recording causes and preceding events related to death; increase training of physicians responsible for filling out death certificates; take action to increase the coverage and quality of information on mortality; and create a decision tree to facilitate selection of CKDnT as a specific cause of death, while presenting the role that different regional and subregional mechanisms in the Region of the Americas should play in order to improve CKD and CKDnT mortality records.

  9. 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

  10. 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.

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

    PubMed

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

    2012-06-05

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

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. Characteristics and comprehensiveness of adult HIV care and treatment programmes in Asia-Pacific, sub-Saharan Africa and the Americas: results of a site assessment conducted by the International epidemiologic Databases to Evaluate AIDS (IeDEA) Collaboration

    PubMed Central

    Duda, Stephany N; Farr, Amanda M; Lindegren, Mary Lou; Blevins, Meridith; Wester, C William; Wools-Kaloustian, Kara; Ekouevi, Didier K; Egger, Matthias; Hemingway-Foday, Jennifer; Cooper, David A; Moore, Richard D; McGowan, Catherine C; Nash, Denis

    2014-01-01

    Introduction HIV care and treatment programmes worldwide are transforming as they push to deliver universal access to essential prevention, care and treatment services to persons living with HIV and their communities. The characteristics and capacity of these HIV programmes affect patient outcomes and quality of care. Despite the importance of ensuring optimal outcomes, few studies have addressed the capacity of HIV programmes to deliver comprehensive care. We sought to describe such capacity in HIV programmes in seven regions worldwide. Methods Staff from 128 sites in 41 countries participating in the International epidemiologic Databases to Evaluate AIDS completed a site survey from 2009 to 2010, including sites in the Asia-Pacific region (n=20), Latin America and the Caribbean (n=7), North America (n=7), Central Africa (n=12), East Africa (n=51), Southern Africa (n=16) and West Africa (n=15). We computed a measure of the comprehensiveness of care based on seven World Health Organization-recommended essential HIV services. Results Most sites reported serving urban (61%; region range (rr): 33–100%) and both adult and paediatric populations (77%; rr: 29–96%). Only 45% of HIV clinics that reported treating children had paediatricians on staff. As for the seven essential services, survey respondents reported that CD4+ cell count testing was available to all but one site, while tuberculosis (TB) screening and community outreach services were available in 80 and 72%, respectively. The remaining four essential services – nutritional support (82%), combination antiretroviral therapy adherence support (88%), prevention of mother-to-child transmission (PMTCT) (94%) and other prevention and clinical management services (97%) – were uniformly available. Approximately half (46%) of sites reported offering all seven services. Newer sites and sites in settings with low rankings on the UN Human Development Index (HDI), especially those in the President's Emergency Plan

  17. 60,000 years of interactions between Central and Eastern Africa documented by major African mitochondrial haplogroup L2.

    PubMed

    Silva, Marina; Alshamali, Farida; Silva, Paula; Carrilho, Carla; Mandlate, Flávio; Jesus Trovoada, Maria; Černý, Viktor; Pereira, Luísa; Soares, Pedro

    2015-07-27

    Mitochondrial DNA (mtDNA) haplogroup L2 originated in Western Africa but is nowadays spread across the entire continent. L2 movements were previously postulated to be related to the Bantu expansion, but L2 expansions eastwards probably occurred much earlier. By reconstructing the phylogeny of L2 (44 new complete sequences) we provide insights on the complex net of within-African migrations in the last 60 thousand years (ka). Results show that lineages in Southern Africa cluster with Western/Central African lineages at a recent time scale, whereas, eastern lineages seem to be substantially more ancient. Three moments of expansion from a Central African source are associated to L2: (1) one migration at 70-50 ka into Eastern or Southern Africa, (2) postglacial movements (15-10 ka) into Eastern Africa; and (3) the southward Bantu Expansion in the last 5 ka. The complementary population and L0a phylogeography analyses indicate no strong evidence of mtDNA gene flow between eastern and southern populations during the later movement, suggesting low admixture between Eastern African populations and the Bantu migrants. This implies that, at least in the early stages, the Bantu expansion was mainly a demic diffusion with little incorporation of local populations.

  18. 60,000 years of interactions between Central and Eastern Africa documented by major African mitochondrial haplogroup L2

    PubMed Central

    Silva, Marina; Alshamali, Farida; Silva, Paula; Carrilho, Carla; Mandlate, Flávio; Jesus Trovoada, Maria; Černý, Viktor; Pereira, Luísa; Soares, Pedro

    2015-01-01

    Mitochondrial DNA (mtDNA) haplogroup L2 originated in Western Africa but is nowadays spread across the entire continent. L2 movements were previously postulated to be related to the Bantu expansion, but L2 expansions eastwards probably occurred much earlier. By reconstructing the phylogeny of L2 (44 new complete sequences) we provide insights on the complex net of within-African migrations in the last 60 thousand years (ka). Results show that lineages in Southern Africa cluster with Western/Central African lineages at a recent time scale, whereas, eastern lineages seem to be substantially more ancient. Three moments of expansion from a Central African source are associated to L2: (1) one migration at 70–50 ka into Eastern or Southern Africa, (2) postglacial movements (15–10 ka) into Eastern Africa; and (3) the southward Bantu Expansion in the last 5 ka. The complementary population and L0a phylogeography analyses indicate no strong evidence of mtDNA gene flow between eastern and southern populations during the later movement, suggesting low admixture between Eastern African populations and the Bantu migrants. This implies that, at least in the early stages, the Bantu expansion was mainly a demic diffusion with little incorporation of local populations. PMID:26211407

  19. Seismological Investigations of Crustal and Mantle Structure and Dynamics beneath North-central Africa

    NASA Astrophysics Data System (ADS)

    Lemnifi, A. A.; Liu, K. H.; Gao, S. S.; Reed, C. A.; Yu, Y.

    2015-12-01

    Here we report results of mantle azimuthal anisotropy from shear-wave splitting (SWS) analysis, crustal structure obtained using H-k stacking, and mantle transition zone discontinuity depths beneath the interior of north central Africa, including Libya and adjacent regions using recently available broadband seismic data obtained from stations managed by the Libyan Center for Remote Sensing and Space Science, and those from several other stations at which data are publicly accessible. A total of 583 pairs of high-quality SWS measurements utilizing the PKS, SKKS, and SKS phases demonstrate primarily N-S fast orientations with an average splitting delay time of approximately 1.2 s. An absence of periodic azimuthal variation of the observed splitting parameters indicates the presence of simple anisotropy, and lack of correlation between surficial features and the splitting parameters suggests that the origin of the observed anisotropy is primarily asthenospheric. Receiver function H-k stacking reveals crustal thicknesses ranging from 25 to 36 km, and Vp/Vs measurements ranging from 1.73 to 1.93, suggesting a spatially heterogeneous crustal structure and composition. The apparent depths of the seismic discontinuities (d410 and d660) bordering the mantle transition zone (MTZ) increase beneath Cenozoic volcanoes in central Libya, suggesting lower-than-normal upper mantle velocities. One of the most significant features in the resulting MTZ thickness map is a region in eastern Libya which has a MTZ thickness of about 270 km, indicating a colder than normal MTZ probably associated with subducted slabs.

  20. Legume Diversity Patterns in West Central Africa: Influence of Species Biology on Distribution Models

    PubMed Central

    de la Estrella, Manuel; Mateo, Rubén G.; Wieringa, Jan J.; Mackinder, Barbara; Muñoz, Jesús

    2012-01-01

    Objectives Species Distribution Models (SDMs) are used to produce predictions of potential Leguminosae diversity in West Central Africa. Those predictions are evaluated subsequently using expert opinion. The established methodology of combining all SDMs is refined to assess species diversity within five defined vegetation types. Potential species diversity is thus predicted for each vegetation type respectively. The primary aim of the new methodology is to define, in more detail, areas of species richness for conservation planning. Methodology Using Maxent, SDMs based on a suite of 14 environmental predictors were generated for 185 West Central African Leguminosae species, each categorised according to one of five vegetation types: Afromontane, coastal, non-flooded forest, open formations, or riverine forest. The relative contribution of each environmental variable was compared between different vegetation types using a nonparametric Kruskal-Wallis analysis followed by a post-hoc Kruskal-Wallis Paired Comparison contrast. Legume species diversity patterns were explored initially using the typical method of stacking all SDMs. Subsequently, five different ensemble models were generated by partitioning SDMs according to vegetation category. Ecological modelers worked with legume specialists to improve data integrity and integrate expert opinion in the interpretation of individual species models and potential species richness predictions for different vegetation types. Results/Conclusions Of the 14 environmental predictors used, five showed no difference in their relative contribution to the different vegetation models. Of the nine discriminating variables, the majority were related to temperature variation. The set of variables that played a major role in the Afromontane species diversity model differed significantly from the sets of variables of greatest relative important in other vegetation categories. The traditional approach of stacking all SDMs indicated overall

  1. The role of Pleistocene refugia and rivers in shaping gorilla genetic diversity in central Africa

    PubMed Central

    Anthony, Nicola M.; Johnson-Bawe, Mireille; Jeffery, Kathryn; Clifford, Stephen L.; Abernethy, Kate A.; Tutin, Caroline E.; Lahm, Sally A.; White, Lee J. T.; Utley, John F.; Wickings, E. Jean; Bruford, Michael W.

    2007-01-01

    The role of Pleistocene forest refugia and rivers in the evolutionary diversification of tropical biota has been the subject of considerable debate. A range-wide analysis of gorilla mitochondrial and nuclear variation was used to test the potential role of both refugia and rivers in shaping genetic diversity in current populations. Results reveal strong patterns of regional differentiation that are consistent with refugial hypotheses for central Africa. Four major mitochondrial haplogroups are evident with the greatest divergence between eastern (A, B) and western (C, D) gorillas. Coalescent simulations reject a model of recent east–west separation during the last glacial maximum but are consistent with a divergence time within the Pleistocene. Microsatellite data also support a similar regional pattern of population genetic structure. Signatures of demographic expansion were detected in eastern lowland (B) and Gabon/Congo (D3) mitochondrial haplogroups and are consistent with a history of postglacial expansion from formerly isolated refugia. Although most mitochondrial haplogroups are regionally defined, limited admixture is evident between neighboring haplogroups. Mantel tests reveal a significant isolation-by-distance effect among western lowland gorilla populations. However, mitochondrial genetic distances also correlate with the distance required to circumnavigate intervening rivers, indicating a possible role for rivers in partitioning gorilla genetic diversity. Comparative data are needed to evaluate the importance of both mechanisms of vicariance in other African rainforest taxa. PMID:18077351

  2. Azimuthal anisotropy beneath north central Africa from shear wave splitting analysis

    NASA Astrophysics Data System (ADS)

    Lemnifi, Awad Abdussalam Henish

    This study represents the first multi-station investigation of azimuthal anisotropy beneath the interior of north central Africa, including Libya and adjacent regions, using shear wave splitting (SWS) analysis. Data used in the study include recently available broadband seismic data obtained from 15 stations managed by the Libyan Center for Remote Sensing and Space Science, and those from five other stations at which data are publicly accessible. A total of 583 pairs of high-quality SWS measurements utilizing the PKS, SKKS, and SKS phases demonstrate primarily N-S fast orientations with an average splitting delay time of approximately 1.2 s. An absence of periodic azimuthal variation of the observed splitting parameters indicates the presence of simple anisotropy, and lack of correlation between surficial features and the splitting parameters suggests that the origin of the observed anisotropy is primarily asthenospheric. This conclusion is enhanced by non-periodic azimuthal variation of the splitting parameters observed at one of the stations located near the boundary of areas with different anisotropic properties. This research interprets the observed anisotropy to be the consequence of northward movement of the African plate relative to the asthenosphere toward the Hellenic and Calabrian subduction zones. Local variance in fast orientations may be attributable to flow deflection by the northern edge of the African continental root. The observations provide critical and previously lacking constraints on mantle dynamic models in the vicinity of the convergent boundary between the African and Eurasian plates.

  3. Azimuthal anisotropy beneath north central Africa from shear wave splitting analyses

    NASA Astrophysics Data System (ADS)

    Lemnifi, Awad A.; Liu, Kelly H.; Gao, Stephen S.; Reed, Cory A.; Elsheikh, Ahmed A.; Yu, Youqiang; Elmelade, Abdala A.

    2015-04-01

    This study represents the first multistation investigation of azimuthal anisotropy beneath the interior of north central Africa, including Libya and adjacent regions, using shear wave splitting (SWS) analysis. Data used in the study include recently available broadband seismic data obtained from 15 stations managed by the Libyan Center for Remote Sensing and Space Science, and those from five other stations at which data are publicly accessible. A total of 583 pairs of high-quality SWS measurements utilizing the PKS, SKKS, and SKS phases demonstrate primarily N-S fast orientations with an average splitting delay time of approximately 1.2 s. An absence of periodic azimuthal variation of the observed splitting parameters indicates the presence of simple anisotropy, and lack of correlation between surficial features and the splitting parameters suggests that the origin of the observed anisotropy is primarily asthenospheric. This conclusion is enhanced by nonperiodic azimuthal variation of the splitting parameters observed at one of the stations located near the boundary of areas with different anisotropic properties. We interpret the observed anisotropy to be the consequence of northward movement of the African plate relative to the asthenosphere toward the Hellenic and Calabrian subduction zones. Local variance in fast orientations may be attributable to flow deflection by the northern edge of the African continental root. The observations provide critical and previously lacking constraints on mantle dynamic models in the vicinity of the convergent boundary between the African and Eurasian plates.

  4. Haemosporidian Parasites of Antelopes and Other Vertebrates from Gabon, Central Africa.

    PubMed

    Boundenga, Larson; Makanga, Boris; Ollomo, Benjamin; Gilabert, Aude; Rougeron, Virginie; Mve-Ondo, Bertrand; Arnathau, Céline; Durand, Patrick; Moukodoum, Nancy Diamella; Okouga, Alain-Prince; Delicat-Loembet, Lucresse; Yacka-Mouele, Lauriane; Rahola, Nil; Leroy, Eric; Ba, Cheikh Tidiane; Renaud, Francois; Prugnolle, Franck; Paupy, Christophe

    2016-01-01

    Re-examination, using molecular tools, of the diversity of haemosporidian parasites (among which the agents of human malaria are the best known) has generally led to rearrangements of traditional classifications. In this study, we explored the diversity of haemosporidian parasites infecting vertebrate species (particularly mammals, birds and reptiles) living in the forests of Gabon (Central Africa), by analyzing a collection of 492 bushmeat samples. We found that samples from five mammalian species (four duiker and one pangolin species), one bird and one turtle species were infected by haemosporidian parasites. In duikers (from which most of the infected specimens were obtained), we demonstrated the existence of at least two distinct parasite lineages related to Polychromophilus species (i.e., bat haemosporidian parasites) and to sauropsid Plasmodium (from birds and lizards). Molecular screening of sylvatic mosquitoes captured during a longitudinal survey revealed the presence of these haemosporidian parasite lineages also in several Anopheles species, suggesting a potential role in their transmission. Our results show that, differently from what was previously thought, several independent clades of haemosporidian parasites (family Plasmodiidae) infect mammals and are transmitted by anopheline mosquitoes.

  5. Haemosporidian Parasites of Antelopes and Other Vertebrates from Gabon, Central Africa

    PubMed Central

    Ollomo, Benjamin; Gilabert, Aude; Rougeron, Virginie; Mve-Ondo, Bertrand; Arnathau, Céline; Durand, Patrick; Moukodoum, Nancy Diamella; Okouga, Alain-Prince; Delicat-Loembet, Lucresse; Yacka-Mouele, Lauriane; Rahola, Nil; Leroy, Eric; BA, Cheikh Tidiane; Renaud, Francois; Prugnolle, Franck; Paupy, Christophe

    2016-01-01

    Re-examination, using molecular tools, of the diversity of haemosporidian parasites (among which the agents of human malaria are the best known) has generally led to rearrangements of traditional classifications. In this study, we explored the diversity of haemosporidian parasites infecting vertebrate species (particularly mammals, birds and reptiles) living in the forests of Gabon (Central Africa), by analyzing a collection of 492 bushmeat samples. We found that samples from five mammalian species (four duiker and one pangolin species), one bird and one turtle species were infected by haemosporidian parasites. In duikers (from which most of the infected specimens were obtained), we demonstrated the existence of at least two distinct parasite lineages related to Polychromophilus species (i.e., bat haemosporidian parasites) and to sauropsid Plasmodium (from birds and lizards). Molecular screening of sylvatic mosquitoes captured during a longitudinal survey revealed the presence of these haemosporidian parasite lineages also in several Anopheles species, suggesting a potential role in their transmission. Our results show that, differently from what was previously thought, several independent clades of haemosporidian parasites (family Plasmodiidae) infect mammals and are transmitted by anopheline mosquitoes. PMID:26863304

  6. Polyphase Neoproterozoic orogenesis within the east Africa- Antarctica orogenic belt in central and northern Madagascar

    USGS Publications Warehouse

    Key, R.M.; Pitfield, P.E.J.; Thomas, Ronald J.; Goodenough, K.M.; Waele, D.; Schofield, D.I.; Bauer, W.; Horstwood, M.S.A.; Styles, M.T.; Conrad, J.; Encarnacion, J.; Lidke, D.J.; O'connor, E. A.; Potter, C.; Smith, R.A.; Walsh, G.J.; Ralison, A.V.; Randriamananjara, T.; Rafahatelo, J.-M.; Rabarimanana, M.

    2011-01-01

    Our recent geological survey of the basement of central and northern Madagascar allowed us to re-evaluate the evolution of this part of the East Africa-Antarctica Orogen (EAAO). Five crustal domains are recognized, characterized by distinctive lithologies and histories of sedimentation, magmatism, deformation and metamorphism, and separated by tectonic and/or unconformable contacts. Four consist largely of Archaean metamorphic rocks (Antongil, Masora and Antananarivo Cratons, Tsaratanana Complex). The fifth (Bemarivo Belt) comprises Proterozoic meta-igneous rocks. The older rocks were intruded by plutonic suites at c. 1000 Ma, 820-760 Ma, 630-595 Ma and 560-520 Ma. The evolution of the four Archaean domains and their boundaries remains contentious, with two end-member interpretations evaluated: (1) all five crustal domains are separate tectonic elements, juxtaposed along Neoproterozoic sutures and (2) the four Archaean domains are segments of an older Archaean craton, which was sutured against the Bemarivo Belt in the Neoproterozoic. Rodinia fragmented during the early Neoproterozoic with intracratonic rifts that sometimes developed into oceanic basins. Subsequent Mid- Neoproterozoic collision of smaller cratonic blocks was followed by renewed extension and magmatism. The global 'Terminal Pan-African' event (560-490 Ma) finally stitched together the Mid-Neoproterozoic cratons to form Gondwana. ?? The Geological Society of London 2011.

  7. Mobile pastoralists in Central and West Africa: between conflict, mobile telephony and (im)mobility.

    PubMed

    De Bruijn, M; Amadou, A; Lewa Doksala, E; Sangaré, B

    2016-11-01

    The livelihoods of the Fulani mobile pastoralists in the Sahel, West and Central Africa are characterised by mobility (related to the needs of their animals), extensive social networks, and a focus on social ties as the basis of status and influence ('wealth in people'). The Sahel environment in which many Fulani nomads live has become embroiled in jihadism, conflict, and violence; at the same time, this region has experienced an increase in opportunities to connect through the wireless mobile communication system. This paper analyses the triangle of mobility, communication, and insecurity in order to understand the present-day situation of the nomadic and semi-nomadic Fulani pastoralists and their identity dynamics. The Fulani find themselves caught in between these conflicts, which end their mobility and often lead to the loss of their herds. Will they be able to keep their mobile lifestyle and identity? This article is based on qualitative case studies and the biographical narratives of nomadic and semi-nomadic pastoralists who have lived through conflict and violence in Cameroon, Chad and Mali. These case studies show that, despite the fact that mobile pastoralism has become difficult as a consequence of the conflicts and loss of cattle, the 'mobile' identity is very present and reinforced with the help of mobile telephony, through which social networks and 'wealth in people' are sustained.

  8. Disentangling the relative effects of bushmeat availability on human nutrition in central Africa

    PubMed Central

    Fa, John E.; Olivero, Jesús; Real, Raimundo; Farfán, Miguel A.; Márquez, Ana L.; Vargas, J. Mario; Ziegler, Stefan; Wegmann, Martin; Brown, David; Margetts, Barrie; Nasi, Robert

    2015-01-01

    We studied links between human malnutrition and wild meat availability within the Rainforest Biotic Zone in central Africa. We distinguished two distinct hunted mammalian diversity distributions, one in the rainforest areas (Deep Rainforest Diversity, DRD) containing taxa of lower hunting sustainability, the other in the northern rainforest-savanna mosaic, with species of greater hunting potential (Marginal Rainforest Diversity, MRD). Wild meat availability, assessed by standing crop mammalian biomass, was greater in MRD than in DRD areas. Predicted bushmeat extraction was also higher in MRD areas. Despite this, stunting of children, a measure of human malnutrition, was greater in MRD areas. Structural equation modeling identified that, in MRD areas, mammal diversity fell away from urban areas, but proximity to these positively influenced higher stunting incidence. In DRD areas, remoteness and distance from dense human settlements and infrastructures explained lower stunting levels. Moreover, stunting was higher away from protected areas. Our results suggest that in MRD areas, forest wildlife rational use for better human nutrition is possible. By contrast, the relatively low human populations in DRD areas currently offer abundant opportunities for the continued protection of more vulnerable mammals and allow dietary needs of local populations to be met. PMID:25639588

  9. Disentangling the relative effects of bushmeat availability on human nutrition in central Africa

    NASA Astrophysics Data System (ADS)

    Fa, John E.; Olivero, Jesús; Real, Raimundo; Farfán, Miguel A.; Márquez, Ana L.; Vargas, J. Mario; Ziegler, Stefan; Wegmann, Martin; Brown, David; Margetts, Barrie; Nasi, Robert

    2015-02-01

    We studied links between human malnutrition and wild meat availability within the Rainforest Biotic Zone in central Africa. We distinguished two distinct hunted mammalian diversity distributions, one in the rainforest areas (Deep Rainforest Diversity, DRD) containing taxa of lower hunting sustainability, the other in the northern rainforest-savanna mosaic, with species of greater hunting potential (Marginal Rainforest Diversity, MRD). Wild meat availability, assessed by standing crop mammalian biomass, was greater in MRD than in DRD areas. Predicted bushmeat extraction was also higher in MRD areas. Despite this, stunting of children, a measure of human malnutrition, was greater in MRD areas. Structural equation modeling identified that, in MRD areas, mammal diversity fell away from urban areas, but proximity to these positively influenced higher stunting incidence. In DRD areas, remoteness and distance from dense human settlements and infrastructures explained lower stunting levels. Moreover, stunting was higher away from protected areas. Our results suggest that in MRD areas, forest wildlife rational use for better human nutrition is possible. By contrast, the relatively low human populations in DRD areas currently offer abundant opportunities for the continued protection of more vulnerable mammals and allow dietary needs of local populations to be met.

  10. Computed Tomographic Pattern of Physiological Intracranial Calcifications in a City in Central Africa

    PubMed Central

    Uduma, Uduma Felix; Pius, Fokam; Mathieu, Motah

    2012-01-01

    Objective: Intracranial calcifications underlie certain brain diseases which may be de novo or systemic. But calclfications un-connected to pathologies are classified physiological. Aim: To evaluate physiological intracranial calcifications in Douala with establishment of earliest age range of detection. Materials and Methods: Prospective study of brain computed tomograms was done from April to October 2009 using Schumadzu CT Scan machine. Axial, reconstructed and bone window images as well Hounsfield unit measurements were used for final evaluations. Results were analysed with SSPS 3. Results: 132 patients with 75 males and 57 females were studied and 163 separate calcifications were identified due to co-existent calcifications. The highest calcification was in choroid plexi, constituiting 56.82% of the studied population. This was followed by pineal gland. Both were commonly co-existent with advancing age. These calcifications were first seen at 10-19years. No type of physiological intracranial calcification was seen below age 10. The least calcification of 0.76% of population was in dentate nucleus. Conclusion: No intra-cranial physiological calcifications started earlier than 9years in Douala, a city in Cameroon, Central Africa. PMID:22980109

  11. Plume-subduction interaction in southern Central America: Mantle upwelling and slab melting

    NASA Astrophysics Data System (ADS)

    Gazel, Esteban; Hoernle, Kaj; Carr, Michael J.; Herzberg, Claude; Saginor, Ian; den Bogaard, Paul van; Hauff, Folkmar; Feigenson, Mark; Swisher, Carl

    2011-01-01

    The volcanic front in southern Central America is well known for its Galapagos OIB-like geochemical signature. A comprehensive set of geochemical, isotopic and geochronological data collected on volumetrically minor alkaline basalts and adakites were used to better constrain the mantle and subduction magma components and to test the different models that explain this OIB signature in an arc setting. We report a migration of back-arc alkaline volcanism towards the northwest, consistent with arc-parallel mantle flow models, and a migration towards the southeast in the adakites possibly tracking the eastward movement of the triple junction where the Panama Fracture Zone intersects the Middle America Trench. The adakites major and trace element compositions are consistent with magmas produced by melting a mantle-wedge source metasomatized by slab derived melts. The alkaline magmas are restricted to areas that have no seismic evidence of a subducting slab. The geochemical signature of the alkaline magmas is mostly controlled by upwelling asthenosphere with minor contributions from subduction components. Mantle potential temperatures calculated from the alkaline basalt primary magmas increased from close to ambient mantle (~ 1380-1410 °C) in the Pliocene to ~ 1450 °C in the younger units. The calculated initial melting pressures for these primary magmas are in the garnet stability field (3.0-2.7 GPa). The average final melting pressures range between 2.7 and 2.5 GPa, which is interpreted as the lithosphere-asthenosphere boundary at ~ 85-90 km. We provide a geotectonic model that integrates the diverse observations presented here. The slab detached after the collision of the Galapagos tracks with the arc (~ 10-8 Ma). The detachment allowed hotter asthenosphere to flow into the mantle wedge. This influx of hotter asthenosphere explains the increase in mantle potential temperatures, the northwest migration in the back-arc alkaline lavas that tracks the passage of the

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

    NASA Astrophysics Data System (ADS)

    Audemard, Franck; Zahradnik, Jiri; Assumpção, Marcelo

    2016-11-01

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

  13. Neonatal severe bacterial infection impairment estimates in South Asia, sub-Saharan Africa, and Latin America for 2010

    PubMed Central

    Seale, Anna C.; Blencowe, Hannah; Zaidi, Anita; Ganatra, Hammad; Syed, Sana; Engmann, Cyril; Newton, Charles R.; Vergnano, Stefania; Stoll, Barbara J.; Cousens, Simon N.; Lawn, Joy E.

    2013-01-01

    Background: Survivors of neonatal infections are at risk of neurodevelopmental impairment (NDI), a burden not previously systematically quantified and yet important for program priority setting. Systematic reviews and meta-analyses were undertaken and applied in a three-step compartmental model to estimate NDI cases after severe neonatal bacterial infection in South Asia, sub-Saharan Africa, and Latin America in neonates of >32 wk gestation (or >1,500 g). Methods: We estimated cases of sepsis, meningitis, pneumonia, or no severe bacterial infection from among estimated cases of possible severe bacterial infection ((pSBI) step 1). We applied respective case fatality risks ((CFRs) step 2) and the NDI risk among survivors (step 3). For neonatal tetanus, incidence estimates were based on the estimated deaths, CFRs, and risk of subsequent NDI. Results: For 2010, we estimated 1.7 million (uncertainty range: 1.1–2.4 million) cases of neonatal sepsis, 200,000 (21,000–350,000) cases of meningitis, 510,000 cases (150,000–930,000) of pneumonia, and 79,000 cases (70,000–930,000) of tetanus in neonates >32 wk gestation (or >1,500 g). Among the survivors, we estimated moderate to severe NDI after neonatal meningitis in 23% (95% confidence interval: 19–26%) of survivors, 18,000 (2,700–35,000) cases, and after neonatal tetanus in 16% (6–27%), 4,700 cases (1,700–8,900). Conclusion: Data are lacking for impairment after neonatal sepsis and pneumonia, especially among those of >32 wk gestation. Improved recognition and treatment of pSBI will reduce neonatal mortality. Lack of follow-up data for survivors of severe bacterial infections, particularly sepsis, was striking. Given the high incidence of sepsis, even minor NDI would be of major public health importance. Prevention of neonatal infection, improved case management, and support for children with NDI are all important strategies, currently receiving limited policy attention. PMID:24366464

  14. 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

  15. The effects of buffer strips and bioretention facilities on agricultural productivity and environmental quality in Central Africa

    NASA Astrophysics Data System (ADS)

    Gilroy, Kristin L.; McCuen, Richard H.

    2010-05-01

    SummaryLand degradation is a growing concern in Central Africa as poor management practices continue to cause erosion and increase water runoff in agricultural fields. The implementation of best management practices (BMPs) is needed; however, productivity is often indirectly related to the environmental benefits of such practices and resource constraints often exist. The purpose of this study was to determine the effects of bioretention facilities and buffer strips on environmental quality with productivity and resources as constraints. A water quantity and quality model for an agricultural field in Central Africa was developed. Analyses were conducted to assess the marginal benefits of each BMP, the effect of different BMP combinations on environmental quality and productivity, and the effect of data uncertainty and location uncertainty on model predictions. The results showed that bioretention pits were more effective than buffer strips in increasing environmental quality. Productivity was shown to be directly related to bioretention pits, thus environmental quality can be attained without sacrificing productivity. Data uncertainties resulted in changes in the environmental quality values, but trends remained the same. Guidelines were provided to assist design engineers in developing BMP scenarios that provide the greatest productivity and environmental quality for the constraints involved. The results of this study will bring awareness to the ability of attaining environmental quality without sacrificing productivity as well as the need for accurate data in Central Africa.

  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. 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.

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

    PubMed

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

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

  19. 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.

  20. 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.

  1. 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.

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

    PubMed Central

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

    1988-01-01

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

  3. Rainfall extremes in some selected parts of Central and South America: ENSO and other relationships reexamined

    NASA Astrophysics Data System (ADS)

    Kane, R. P.

    1999-03-01

    El Niños and anti-El Niños (La Niñas) are known to be associated with rainfall extremes in several parts of the globe. However, not all El Niños show good associations. Recently, a finer classification of El Niño events was attempted. It was noticed that Unambiguous ENSOW (El Niño-Southern Oscillation, Warm) events (years when El Niño existed, and the Tahiti minus Darwin pressure difference (T-D) minima and equatorial eastern Pacific sea surface temperature (SST) maxima occurred in the middle of the calendar year) were very well associated with droughts in India and southeast Australia (Tasmania). In addition, C (cold SST, La Niña) events showed reverse effects (excess rains) in these regions. In the present paper, rainfall in selected regions in Central and South America are examined. For the Southern Oscillation Core Region (low latitudes, 155°W-167°E) and for the Gulf-Mexico region, no finer classification was necessary. All El Niños were associated with excess rains and all La Niñas with droughts. As in India and Tasmania, Unambiguous ENSOW years were associated with droughts in some parts of northeast Brazil (Ceara, Rio grande do Norte, Paraiba, Pernambuco) and excess rains in Chile and Peru. C events did not have good associations except in Chile and Peru, where droughts occurred. The effect of El Niños showed some dependence on the month of commencement. In years when El Niños showed no effect, considerable influence of other factors (e.g. Atlantic SST on northeast Brazil rainfall) was noticed. Thus, predictions based on El Niño alone are likely to be erroneous, a fact which should be noted by the mass media. Effects of the recent El Niño of 1997-1998 are discussed.

  4. 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.

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

    PubMed Central

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

    2016-01-01

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

  6. 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.

  7. A new species of Nyanzachoerus (Cetartiodactyla: Suidae) from the late Miocene Toros-Ménalla, Chad, central Africa.

    PubMed

    Boisserie, Jean-Renaud; Souron, Antoine; Mackaye, Hassane Taïsso; Likius, Andossa; Vignaud, Patrick; Brunet, Michel

    2014-01-01

    During the latest Miocene and the early Pliocene, tetraconodontine suids were the most predominant large omnivorous mammals in Africa. Yet, new species were often identified on the grounds of limited evidence, a situation impacting their value for biochronological correlations as well as for environmental and biogeographical reconstructions. The description of the most abundant known collection of craniodental remains attributed to the tetraconodontine Nyanzachoerus helps to improve this situation. These specimens were collected in the upper Miocene deposits at Toros-Ménalla, northern Chad, central Africa, by the Mission Paléoanthropologique Franco-Tchadienne. We compared them with Nyanzachoerus from eastern and southern Africa, using extant species as a reference for patterns of morphological variation. Thanks to a large sample of observations, our work focused as much on craniomandibular morphology as on dental morphology and metrics (improved by an index scoring for the complexity of distal third molars and a detailed investigation of premolar-molar ratios). We recognized two taxa at Toros-Ménalla: Nyanzachoerus khinzir nov. sp. and Ny. cf. australis. We also revised the taxonomic status for other species, including: the restriction of Ny. syrticus to its holotype specimen from Sahabi (Libya), the resurrection of the nomen Ny. tulotos, and the synonymy of Ny. kuseralensis with Ny. waylandi. At Toros-Ménalla, Ny. khinzir was the only suid coexisting with the anthracotheriid Libycosaurus and the hominid Sahelanthropus, whereas Ny. cf. australis was associated with a different, probably younger faunal context. Nyanzachoerus. khinzir, which probably had a diversified diet, supports a latest Miocene biogeographical distinction between central Africa and eastern Africa.

  8. A New Species of Nyanzachoerus (Cetartiodactyla: Suidae) from the Late Miocene Toros-Ménalla, Chad, Central Africa

    PubMed Central

    Boisserie, Jean-Renaud; Souron, Antoine; Mackaye, Hassane Taïsso; Likius, Andossa; Vignaud, Patrick; Brunet, Michel

    2014-01-01

    During the latest Miocene and the early Pliocene, tetraconodontine suids were the most predominant large omnivorous mammals in Africa. Yet, new species were often identified on the grounds of limited evidence, a situation impacting their value for biochronological correlations as well as for environmental and biogeographical reconstructions. The description of the most abundant known collection of craniodental remains attributed to the tetraconodontine Nyanzachoerus helps to improve this situation. These specimens were collected in the upper Miocene deposits at Toros-Ménalla, northern Chad, central Africa, by the Mission Paléoanthropologique Franco-Tchadienne. We compared them with Nyanzachoerus from eastern and southern Africa, using extant species as a reference for patterns of morphological variation. Thanks to a large sample of observations, our work focused as much on craniomandibular morphology as on dental morphology and metrics (improved by an index scoring for the complexity of distal third molars and a detailed investigation of premolar-molar ratios). We recognized two taxa at Toros-Ménalla: Nyanzachoerus khinzir nov. sp. and Ny. cf. australis. We also revised the taxonomic status for other species, including: the restriction of Ny. syrticus to its holotype specimen from Sahabi (Libya), the resurrection of the nomen Ny. tulotos, and the synonymy of Ny. kuseralensis with Ny. waylandi. At Toros-Ménalla, Ny. khinzir was the only suid coexisting with the anthracotheriid Libycosaurus and the hominid Sahelanthropus, whereas Ny. cf. australis was associated with a different, probably younger faunal context. Nyanzachoerus. khinzir, which probably had a diversified diet, supports a latest Miocene biogeographical distinction between central Africa and eastern Africa. PMID:25162699

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

    NASA Astrophysics Data System (ADS)

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

    2012-05-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  11. Miocene Mammals and Central American Seaways: Fauna of the Canal Zone indicates separation of Central and South America during most of the Tertiary.

    PubMed

    Whitmore, F C; Stewart, R H

    1965-04-09

    The presence of Miocene mammals of North American affinity in the Panama Canal Zone indicates that Central America was attached to North America. That this attachment was a broad and stable land mass is shown by the close relation of the Panama Miocene herbivores to the widely distributed Miocene herbivore fauna of North America. A continuous connection existed probably throughout the Tertiary, to the west and north of the isthmian region, but the tectonically active isthmus probably was broken up into an archipelago during most of Tertiary time. Between the islands ran the Strait of Panama; from time to time parts of the isthmian area were connected to the stable land to the west, allowing eastward migration of land animals. The mammals of North American affinity in the Cucaracha Formation were found only a few kilometers from the western end of the San Blas Area, a stable land mass in eastern Panama that was separated from South America by the Bolivar Trough during most of the interval between Oligocene and Pliocene time (16). The Strait of Panama was a less stable barrier than the Bolivar Trough; this being so, it is likely that the San Blas Area was inhabited by land animals of North American rather than South American affinity. Thus, the disappearance of the Bolivar seaway in Pliocene time would have allowed, probably for the first time, mingling of the North and South American mammal faunas.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed

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

    2014-08-01

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

  14. Palaeoecological evidence for Holocene environmental change from the Virunga volcanoes in the Albertine Rift, central Africa

    NASA Astrophysics Data System (ADS)

    McGlynn, Gayle; Mooney, Scott; Taylor, David

    2013-02-01

    This study presents two new, well-dated sedimentary pollen and charcoal records from high-altitude crater sites in the Virunga volcanoes, located in the Albertine Rift, central Africa, currently part of one of the world's most biodiverse areas. Here we argue that Holocene vegetation changes in a ca 8000-year palaeoenvironmental record from a crater swamp at an altitude of 3474 m and a ca 2800-year record from a crater lake at an altitude of 4127 m are linked to variations in both climate and human activity. Climatic changes during the mid- to late Holocene are reflected in the high-altitude sites and more widely in adjacent parts of the Albertine Rift. Vegetation changes, comprising a decline in Ericaceous vegetation at ca 5000 cal yrs BP and subsequent expansion of Afroalpine vegetation, together with a later increase in taxa associated with lower montane forest (particularly Podocarpus), reflect increasing aridity during the mid- to late Holocene. Human-induced environmental change in the Virunga volcanoes is apparent only within the last millennium, despite the long history of human occupation of the area. Both study sites record significant forest clearance at ca 900 cal yrs BP, involving a reduction in lower montane forest taxa and increases in disturbance indicators. Changes in the composition of upper montane forest, and particularly the expansion of Hagenia, are possibly linked to anthropogenic-induced changes in the fire regime, and are apparent from ca 900 cal yrs BP. Human-induced environmental modification from the early part of the last millennium, likely associated with onset of the Late Iron Age, appears to have extended to high altitudes. The importance of natural, long-term climate change as a major cause of environmental change in the Albertine Rift has been eclipsed within the last millennium by human-induced environmental effects.

  15. Patterns in volatile organic compound emissions along a savanna-rainforest gradient in central Africa

    NASA Astrophysics Data System (ADS)

    Klinger, L. F.; Greenburg, J.; Guenther, A.; Tyndall, G.; Zimmerman, P.; M'bangui, M.; Moutsamboté, J.-M.; Kenfack, D.

    1998-01-01

    In temperate regions the chemistry of the lower troposphere is known to be significantly affected by biogenic volatile organic compounds (VOCs) emitted by plants. The chemistry of the lower troposphere over the tropics, however, is poorly understood, in part because of the considerable uncertainties in VOC emissions from tropical ecosystems. Present global VOC models predict that base emissions of isoprene from tropical rainforests are considerably higher than from savannas. These global models of VOC emissions which rely mainly on species inventories are useful, but significant improvement might be made with more ecologically based models of VOC emissions by plants. Ecosystems along a successional transect from woodland savanna to primary rainforest in central Africa were characterized for species composition and vegetation abundance using ground surveys and remotely sensed data. A total of 336 species (mostly trees) at 13 sites were recorded, and 208 of these were measured for VOC emissions at near-optimal light and temperature conditions using a leaf cuvette and hand-held photoionization detector (PID). A subset of 59 species was also sampled using conventional VOC emission techniques in order to validate the PID technique. Results of ecological and VOC emission surveys indicate both phylogenetic and successional patterns along the savanna-rainforest transect. Genera and families of trees which tend to emit isoprene include Lophira, Irvingia, Albizia, Artocarpus, Ficus, Pterocarpus, Caesalpiniaceae, Arecaceae, and Moraceae. Other taxa tend to contain stored VOCs (Annonaceae and Asteraceae). Successional patterns suggest that isoprene emissions are highest in the relatively early successional Isoberlinia forest communities and progressively decrease in the later successional secondary and primary rainforest communities. Stored VOCs appear to increase along the savanna-rainforest succession, but these data are more tentative. These findings are consistent with

  16. Integrating sustainable hunting in biodiversity protection in Central Africa: hot spots, weak spots, and strong spots.

    PubMed

    Fa, John E; Olivero, Jesús; Farfán, Miguel Ángel; Márquez, Ana Luz; Vargas, Juan Mario; Real, Raimundo; Nasi, Robert

    2014-01-01

    Wild animals are a primary source of protein (bushmeat) for people living in or near tropical forests. Ideally, the effect of bushmeat harvests should be monitored closely by making regular estimates of offtake rate and size of stock available for exploitation. However, in practice, this is possible in very few situations because it requires both of these aspects to be readily measurable, and even in the best case, entails very considerable time and effort. As alternative, in this study, we use high-resolution, environmental favorability models for terrestrial mammals (N = 165) in Central Africa to map areas of high species richness (hot spots) and hunting susceptibility. Favorability models distinguish localities with environmental conditions that favor the species' existence from those with detrimental characteristics for its presence. We develop an index for assessing Potential Hunting Sustainability (PHS) of each species based on their ecological characteristics (population density, habitat breadth, rarity and vulnerability), weighted according to restrictive and permissive assumptions of how species' characteristics are combined. Species are classified into five main hunting sustainability classes using fuzzy logic. Using the accumulated favorability values of all species, and their PHS values, we finally identify weak spots, defined as high diversity regions of especial hunting vulnerability for wildlife, as well as strong spots, defined as high diversity areas of high hunting sustainability potential. Our study uses relatively simple models that employ easily obtainable data of a species' ecological characteristics to assess the impacts of hunting in tropical regions. It provides information for management by charting the geography of where species are more or less likely to be at risk of extinction from hunting.

  17. Oil and gas developments in central and southern Africa in 1983

    SciTech Connect

    McGrew, H.J.

    1984-10-01

    All exploratory activity in central and southern Africa decreased in 1983, reflecting world economic conditions and excess productive capacity. Seismic activity has declined sharply from its peak year of 1981. Land operations suffered the greatest drop in 1983, whereas party-months of marine work increased slightly. 3-D recording continued to be used but at a reduced rate compared with 1982. Large aeromagnetic surveys were made in several countries; however, the coverage was less than in 1982. Gravity continues to be used to supplement other geophysical work, but other exploratory techniques are being used infrequently. Total wells drilled dropped from 464 in 1982 to 387 in 1983. Most of the decline was in exploratory drilling, which dropped from 132 to 86 wells. This was reflected in the number of discoveries, which decreased from 48 to 27 while the success rate continued about the same. Development drilling continued at a high level in Cameroon and Congo, whereas in Nigeria the emphasis shifted to the drilling of appraisal wells. In all, 2,937,708 ft (895,643 m) of hole was drilled, a decrease of about 20% from 1982. Oil production of 673,075,667 bbl in 1983 was an increase of 1.7% over 1982's production, bringing cumulative production to over 12 billion bbl. Marked increases in production were recorded in Cabinda, Ivory Coast, and Congo. Production from Nigerian fields continued to dominate this part of the world as they contributed about 67% of the annual production and 75% of the cumulative production. 44 figures, 15 tables.

  18. Genotyping studies of Toxoplasma gondii isolates from Africa revealed that the archetypal clonal lineages predominate as in North America and Europe.

    PubMed

    Velmurugan, G V; Dubey, J P; Su, C

    2008-08-17

    Until recently, Toxoplasma gondii was considered to be clonal with very little genetic variability. Recent studies indicate that T. gondii isolates from Brazil are genetically and biologically different from T. gondii isolates from USA and Europe. However, little is known of the genetics of T. gondii strains from Africa. In this study, we genotyped 19 T. gondii isolates from chickens from six African countries (Egypt, Kenya, Nigeria, Congo, Mali, and Burkina Fasco) using 10 PCR-RFLP markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The results revealed four genotypes. Thirteen isolates belong to the Type III lineage, five isolates have Type II alleles at all loci except apico and they belong to the Type II lineage. One isolate from Nigeria had atypical genotype. In general, these isolates were mostly clonal Type III and II strains that predominate in North American and European. DNA sequencing at several loci for representative isolates confirmed the results of PCR-RFLP genotyping. Taken together with recent studies of T. gondii isolates from Africa, it is clear that the three clonal lineages (Types I, II and III) predominate not only in North America and Europe, but also in Africa.

  19. Effective elastic thickness and crustal thickness variations in west central Africa inferred from gravity data

    SciTech Connect

    Poudjom Djomani, Y.H.; Nnange, J.M.; Ebinger, C.J.

    1995-11-10

    This report uses coherence function analysis of 32,000 gravity and topography points from Cameroon west Africa to determine the relationship between the plate tectonic and flexural rigidity of the lithosphere in terms of the crusts effective elastic thickness.

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

    USGS Publications Warehouse

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

    2000-01-01

    The potential to use ice cores from alpine glaciers in the midlatitudes to reconstruct paleoclimatic records has not been widely recognized. Although excellent paleoclimatic records exist for the polar regions, paleoclimatic ice core records are not common from midlatitude locations. An ice core removed from the Upper Fremont Glacier in Wyoming provides evidence for abrupt climate change during the mid-1800s. Volcanic events (Krakatau and Tambora) identified from electrical conductivity measurements (ECM) and isotopic and chemical data from the Upper Fremont Glacier were reexamined to confirm and refine previous chronological estimates of the ice core. At a depth of 152 m the refined age-depth profile shows good agreement (1736 ± 10 A.D.) with the 14C age date (1729 ± 95 A.D.). The δ18O profile of the Upper Fremont Glacier (UFG) ice core indicates a change in climate known as the Little Ice Age (LIA). However, the sampling interval for δ18O is sufficiently large (20 cm) such that it is difficult to pinpoint the LIA termination on the basis of δ18O data alone. Other research has shown that changes in the δ18O variance are generally coincident with changes in ECM variance. The ECM data set contains over 125,000 data points at a resolution of 1 data point per millimeter of ice core. A 999-point running average of the ECM data set and results from f tests indicates that the variance of the ECM data decreases significantly at about 108 m. At this depth, the age-depth profile predicts an age of 1845 A.D. Results indicate the termination of the LIA was abrupt with a major climatic shift to warmer temperatures around 1845 A.D. and continuing to present day. Prediction limits (error bars) calculated for the profile ages are ±10 years (90% confidence level). Thus a conservative estimate for the time taken to complete the LIA climatic shift to present-day climate is about 10 years, suggesting the LIA termination in alpine regions of central North America may have

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

    SciTech Connect

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

    2000-02-27

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  3. Magmatic evolution of the Sarapiqui Miocene Arc, Costa Rica, Central America

    NASA Astrophysics Data System (ADS)

    Gazel, E.; Alvarado, G. E.; Carr, M. J.; Obando, J.; Alfaro, A.

    2005-12-01

    The Sarapiqui Miocene Arc (22.2-11.4 Ma) is located in the modern back-arc region of northern Costa Rica, Central America. The arc basement is represented by serpentinized peridotites, Albian silicic pelagites, and Paleocene to Middle Eocene turbidites. Magmatic units vary from basalts to rhyolites and include lavas, pyroclastic deposits, and a few subvolcanic bodies. The magmatic evolution of the Sarapiqui Miocene Arc consists of three distinct stages: 1) Jardin Basalts (22.2 Ma) showing a primary tendency with high MgO, Ni, Cr, and Nb, high initial La/Yb ratios, and low Ba/La which increase with the slab fluids addition; 2) Arrepentidos Basaltic-andesites, Chaparron Pyroclasts, Hito Sar Basalts, Boca Tapada Gabro, and Chamorro Andesites, that represent the island arc evolution from 17.2 to 11.4 Ma; and 3) Crucitas Rhyolites (14.3 Ma) characterizated by low TiO2 and very high Ba/La ratios represent non-cogenetic, but contemporaneous felsic magmas produced by remelting of pre-existing intrusives. The REE patterns indicate a plagioclase rich, amphibole bearing source for this last unit. The Zr/Nb ratios (7-36) are evidence of the coalescing of a minor OIB source with a dominant MORB source, both modified by subduction. 87Sr/86Sr correlate positively with Ba/La; however, they are still within the OIB field. An inverse model using the REEs of the mafic units is consistent with a source mantle composition of garnet peridotite. All but one of the units show LILE enrichments and HFSE depletions typical of the island arc environment. The exception is a suite of near primary magmas, included in the Jardin Basalts, which probably originated by decompression melting. The Ba/La and La/Yb ratios of the Sarapiqui Miocene Arc are very similar to those of the modern Northern Costa Rican Arc, suggesting that the subduction fluid composition and the degree of partial melting have not changed significantly in the last 20 Ma.

  4. Active Forearc Response to CO-NZ-CA Triple Junction Migration, Southern Central America

    NASA Astrophysics Data System (ADS)

    Morell, K.; Fisher, D.; Gardner, T. W.

    2007-12-01

    Southeast migration of the CO-NZ-CA triple junction at a rate of ~55 mm/yr results in an abrupt increase in convergence rate, slab thickness and subduction direction within the upper plate of the Central American convergent margin. At the triple junction, an active transform fault (the dextral Panama Fracture Zone) subducts beneath the Caribbean plate at the Middle America Trench, and juxtaposes the thick, orthogonal and shallow subduction of the Cocos plate against the thin, oblique and steeper subduction of the Nazca plate. New bedrock geology, Quaternary mapping and Ar/Ar dates of fluvial and volcanic deposits inboard of the triple junction provide evidence that both the outer and inner forearc of this system is actively responding to the dynamic changes presented by triple junction migration. Our results confirm that the Fila Costeña, a thin-skinned inner forearc thrust belt, is active and likely propagating in concert with triple junction migration. Mapping within the area overriding the Panama Fracture Zone indicates that thrusting develops only in those areas experiencing Cocos subduction; the thrust belt dies out coincident with the on-shore projection of the Panama Fracture Zone, and balanced cross-sections indicate a lateral gradient in the amount of shortening near the termination of the thrust belt. Along-strike variations in drainage basin morphometry suggest that drainage divides of the Fila Costeña are propagating to the southeast with the triple junction, resulting in hook-shaped drainage patterns and asymmetric basin shapes. A survey of a flight of 3-4 fluvial terraces along the Río Chiriquí Viejo indicates recent thrusting along a prominent thrust fault of the Fila Costeña. These terraces are also inset into multiple lahar flows with an upper surface tentatively constrained at ~507 ka based on an Ar/Ar hornblende plateau age. Recent work indicates that this thrust fault displaces surficial lahar deposits, suggesting that it must have become

  5. Comparative susceptibility of three species of Anopheles from Belize, Central America, to Plasmodium falciparum (NF-54).

    PubMed

    Grieco, John P; Achee, Nicole L; Roberts, Donald R; Andre, Richard G

    2005-09-01

    In August of 2000, a comparative susceptibility study was conducted using 3 species of Anopheles mosquitoes from Belize, Central America, and a standard species used in laboratory infection studies, Anopheles stephensi. Test populations were fed human blood infected with cultured Plasmodium falciparum (NF-54 strain) parasites via a membrane feeder. The control species, An. stephensi, exhibited the highest infections, with 73.8% of dissected specimens positive for sporozoites in the salivary glands. The control species also showed heavier sporozoite loads; 74.0% of positive glands having greater than 200 sporozoites. Of species from Belize, Anopheles darlingi was the most susceptibile, e.g., 41.0% of salivary glands were positive, with more than 200 sporozoites per gland. Anopheles vestitipennis had a low salivary gland infection rate (9.3%) and a moderate number of sporozoites in glands (i.e., 85.7% containing 50-250 sporozoites). Anopheles albimanus was the least susceptible species to infection. No specimens of An. albimanus from the Golden Stream population developed sporozoites in the salivary glands, yet 20.7% of dissected specimens had positive midgut infections. The An. albimanus Buena Vista population showed similar results with only a 2.2% salivary gland infection rate and a 21.5% midgut infection rate. Oocysts in An. stephensi increased in size by 20% after day 10. Development peaked at day 12, with a mean oocyst diameter of 58 microm at onset of oocyst differentiation. Oocysts developed more slowly in An. vestitipennis until day 10. After day 10, there was a 53% increase in oocyst development over the previous 10 days. Oocyst differentiation was not observed until day 13 postfeed. As with An. vestitipennis, both populations of An. albimanus showed similar slow rates of oocyst development; however, no dramatic growth increase occurred after day 10. The oocysts in the Golden Stream population exhibited a cessation of growth after day 10, peaking at a mean

  6. The recent apple snails of Africa and Asia (Mollusca: Gastropoda: Ampullariidae: Afropomus, Forbesopomus, Lanistes, Pila, Saulea): a nomenclatural and type catalogue. The apple snails of the Americas: addenda and corrigenda.

    PubMed

    Cowie, Robert H

    2015-03-27

    Ampullariidae are freshwater snails predominantly distributed in humid tropical and sub-tropical habitats in Africa, South and Central America and Asia. This catalogue is concerned only with the non-fossil Old World species, the majority of which are placed in the genera Pila and Lanistes, with a few species in Afropomus, Forbesopomus and Saulea. Pila occurs in Africa and Asia, Lanistes, Afropomus and Saulea only in Africa and Forbesopomus only in Asia. New World taxa were catalogued in a previous publication. The taxonomy of the group is heavily based on shell morphology but the true number of valid taxa remains unknown, pending revisionary work. This catalogue provides the rigorous nomenclatural base for this future work by bringing together all the available and unavailable genus-group and species-group names that have been applied to Recent Asian and African ampullariids, indicating their current nomenclatural status (species, subspecies, synonyms, etc.). Fossil taxa are not included. The catalogue lists 21 published genus-group and 244 published species-group names of Old World ampullariids, excluding 25 names that are incertae sedis and cannot be definitively determined as Old or New World. Of these 265 Old World names, five genus-group and 104 species-group (including 30 infraspecific) names are currently valid. There are 16 genus-group synonyms, 118 species-group synonyms and four species-group homonyms that are not treated as junior synonyms. Also listed are five unavailable family-group, one unavailable genus-group and 18 unavailable species-group names, and a number of unpublished names from museum labels. The catalogue provides bibliographic details for all published names, locations of type material, details of type localities and geographic distributions as far as can be ascertained given the confused state of the taxonomy. The catalogue is a work of nomenclature; it is not a revisionary work of taxonomy. Additional details and corrections to the

  7. Forest pricing and concession policies: Managing the high forest of west and central Africa. World Bank technical paper; Politique de redevances et de concessions forestieres: gestion des futaies en afrique occidentale et centrale

    SciTech Connect

    Grut, M.; Gray, J.A.; Egli, N.

    1993-12-01

    This French edition describes forest revenue systems and concession policies in the tropical moist hardwood forests of West and Central Africa. The paper reviews current issues in silviculture, tenure, concession management, and biological and financial sustainable development. Until the fledgling forestry departments of governments in West and Central Africa are strengthened, the report concludes that a simple system of forest fees should be implemented. The report recommends that such a system emphasize bidding and concession fees.

  8. Genetic diversity, inter-gene pool introgression and nutritional quality of common beans (Phaseolus vulgaris L.) from Central Africa.

    PubMed

    Blair, Matthew W; González, Laura F; Kimani, Paul M; Butare, Louis

    2010-07-01

    The Great Lakes region of Central Africa is a major producer of common beans in Africa. The region is known for high population density and small average farm size. The common bean represents the most important legume crop of the region, grown on over a third of the cultivated land area, and the per capita consumption is among the highest in the world for the food crop. The objective of this study was to evaluate the genetic diversity in a collection of 365 genotypes from the Great Lakes region of Central Africa, including a large group of landraces from Rwanda as well as varieties from primary centers of diversity and from neighboring countries of Central Africa, such as the Democratic Republic of Congo and Uganda, using 30 fluorescently labeled microsatellite markers and automated allele detection. In addition, the landraces were evaluated for their seed iron and zinc concentration to determine if genetic diversity influenced nutritional quality. Principal coordinate and neighbor-joining analyses allowed the separation of the landraces into 132 Andean and 195 Mesoamerican (or Middle American) genotypes with 32 landraces and 6 varieties intermediate between the gene pools and representing inter-gene pool introgression in terms of seed characteristics and alleles. Genetic diversity and the number of alleles were high for the collection, reflecting the preference for a wide range of seed types in the region and no strong commercial class preference, although red, red mottled and brown seeded beans were common. Observed heterozygosity was also high and may be explained by the common practice of maintaining seed and plant mixtures, a coping strategy practiced by Central African farmers to reduce the effects of abiotic and biotic stresses. Finally, nutritional quality differed between the gene pools with respect to seed iron and zinc concentration, while genotypes from the intermediate group were notably high in both minerals. In conclusion, this study has shown that

  9. An investigation of MAGSAT and complementary data emphasizing Precambrian shields and adjacent areas of West Africa and South America

    NASA Technical Reports Server (NTRS)

    Hastings, D. A. (Principal Investigator)

    1982-01-01

    A mineral deposits overlay was prepared to the van der Grinten projection geological world map and coloring of the map was initiated. The Mercator projection version was proofread and some preliminary modeling of MAGSAT anomalies for South America were undertaken.

  10. Geo-risk in Central Africa: integrating multi-hazards and vulnerability to support risk management

    NASA Astrophysics Data System (ADS)

    Kervyn, Francois; Nicolas, d'Oreye; Haventith, Hans-Balder; Kervyn, Matthieu; Caroline, Michellier; Trefon, Theodore; Wolff, Eleonore

    2013-04-01

    In some places, geo-hazards are a major concern for population, the assets, and the economy. This is especially the case in the East African Rift (EAR), where high volcanic and tectonic activities are sometimes coupled with geopolitical issues and dense population as in the Kivu rift area. That area is one of the most densely populated regions of Central Africa and is affected by decades of political instability and subsequent humanitarian crisis. In that region, geo-hazards are poorly assessed despite the numerous recent and historical events. Moreover, the relief of the rift also corresponds in this area to the main political boundaries, which complicates the coordination and the management of geo-hazards monitoring networks and related mitigation measures. Based on the experience acquired through several projects focused on hazard assessment and reinforcement of local monitoring capacity, the GeoRisCA project is addressing the assessment of the global risk related to the major geohazards that affect the region. Taking into account the identified factors, GeoRisCA's objective is to assess the risk from multi geohazards in a region which is subject to many (possibly combined) disasters every year and which could undergo a large impact disaster in the coming years. At regional scale, the high seismicity and the volcanic activity are the most important concerns. Possible eruptions of lethal gas in certain area around Goma, and the large number of reported and likely future mass movements as well as site-specific seismic amplification effects increase the danger at local scale. As both human lives and specific ecosystems are under threat, comprehensive methodologies are required to reliably assess multi geohazards over both short and long terms and to clearly outline and map related risk. These tools are needed by local and regional authorities as well as local and international stakeholders in management and mitigation processes. Developed methodologies in Geo

  11. Hydrological impact of rainwater harvesting in the Modder river basin of central South Africa

    NASA Astrophysics Data System (ADS)

    Welderufael, W. A.; Woyessa, Y. E.; Edossa, D. C.

    2011-05-01

    Along the path of water flowing in a river basin are many water-related human interventions that modify the natural systems. Rainwater harvesting is one such intervention that involves harnessing of water in the upstream catchment. Increased water usage at upstream level is an issue of concern for downstream water availability to sustain ecosystem services. The upstream Modder River basin, located in a semi arid region in the central South Africa, is experiencing intermittent meteorological droughts causing water shortages for agriculture, livestock and domestic purpose. To address this problem a technique was developed for small scale farmers with the objective of harnessing rainwater for crop production. However, the hydrological impact of a wider adoption of this technique by farmers has not been well quantified. In this regard, the SWAT hydrological model was used to simulate the hydrological impact of such practices. The scenarios studied were: (1) Baseline scenario, based on the actual land use of 2000, which is dominated by pasture (combination of natural and some improved grass lands) (PAST); (2) Partial conversion of Land use 2000 (PAST) to conventional agriculture (Agri-CON); and (3) Partial conversion of Land use 2000 (PAST) to in-field rainwater harvesting which was aimed at improving the precipitation use efficiency (Agri-IRWH). SWAT was calibrated using observed daily mean stream flow data of a sub-catchment (419 km2) in the study area. SWAT performed well in simulating the stream flow giving Nash and Sutcliffe (1970) efficiency index of 0.57 for the monthly stream flow calibration. The simulated water balance results showed that the highest peak mean monthly direct flow was obtained on Agri-CON land use (18 mm), followed by PAST (12 mm) and Agri-IRWH land use (9 mm). These were 19 %, 13 % and 11 % of the mean annual rainfall, respectively. The Agri-IRWH scenario reduced direct flow by 38 % compared to Agri-CON. On the other hand it was found that the

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

    SciTech Connect

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

    1990-09-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2015-07-31

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

  15. Design of climate scenarios with application to agriculture and forestry in central and eastern north America. Final report

    SciTech Connect

    Lamb, P.J.; Richman, M.B.

    1996-06-01

    A research program supported by a USEPA cooperative agreement concentrated on statistical and climatological issues related to designing climate scenarios useful for agricultural and forestry in central and eastern North America. Results can be categorized into the areas of statistical techniques for scenario development and evaluation, climate system research, and data set development. A review of the meteorological use of clustering algorithms and an extensive comparison of cluster methods was undertaken. The last major methodological research was development of target analysis, which allows direct incorporation of climate scenarios into a data reduction and pattern matching algorithm. This was tested successfully on GCM output for realistic climate scenarios.

  16. From East Gondwana to Central America: Historical biogeography of the Alstroemeriaceae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Southern South America and Australia/New Zealand share some 15 plant families more or less restricted to them. Understanding these Austral floristic links requires extensive sampling in both regions. For the Alstroemeriaceae, with 189 species in three South American genera, two in an Australian/Tasm...

  17. Synthetic Minor NSR Permit: BP America Production Company - Salvador I/II Central Delivery Point

    EPA Pesticide Factsheets

    This page contains the response to public comments, the final synthetic minor NSR permit, and the administrative record for the BP America Production Company, Salvador I/II CDP, located on the Southern Ute Indian Reservation in La Plata County, CO.

  18. Recent viroid disease outbreaks in greenhouse tomatoes in North and Central America and their management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greenhouse tomato productions in North America have suffered from several high profile viroid disease outbreaks in recent years. In this presentation, I will summarize and briefly describe each of these viroid disease outbreak and their relationship. What are viroids and their transmission through ...

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

    USGS Publications Warehouse

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

    2004-01-01

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

  20. Disease-Bearing Mosquitoes of North and Central America, the West Indies, and the Philippine Islands

    DTIC Science & Technology

    1913-11-01

    April in Old Calabar (Annett). James reports it experimentally positive to malaria, but not found infected in nature, and Christoph<’r 1 says that...frag- ments of aquatic plants. l Boyce, Sir Rubert. The Prevalence , Distribution, and Significance of Stegomyiafasciata in West Africa. Bull. Ento...these mountain or hill streams free of grass and weeds, and the current running strongl.y, did not control certain mosquitoes, and that the prevalence

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

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

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

    SciTech Connect

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

    2004-09-02

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

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

    USGS Publications Warehouse

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

    2012-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    USGS Publications Warehouse

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

    2000-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    USGS Publications Warehouse

    Espinosa, A.F.

    1982-01-01

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

  8. A genome-wide search for type 2 diabetes susceptibility genes in West Africans: the Africa America Diabetes Mellitus (AADM) Study.

    PubMed

    Rotimi, Charles N; Chen, Guanjie; Adeyemo, Adebowale A; Furbert-Harris, Paulette; Parish-Gause, Debra; Zhou, Jie; Berg, Kate; Adegoke, Olufemi; Amoah, Albert; Owusu, Samuel; Acheampong, Joseph; Agyenim-Boateng, Kofi; Eghan, Benjamin A; Oli, Johnnie; Okafor, Godfrey; Ofoegbu, Ester; Osotimehin, Babatunde; Abbiyesuku, Fayeofori; Johnson, Thomas; Rufus, Theresa; Fasanmade, Olufemi; Kittles, Rick; Daniel, Harold; Chen, Yuanxiu; Dunston, Georgia; Collins, Francis S; Guass, Debra

    2004-03-01

    The incidence of type 2 diabetes is growing rapidly, not only in developed countries but also worldwide. We chose to study type 2 diabetes in West Africa, where diabetes is less common than in the U.S., reasoning that in an environment where calories are less abundant, incident cases of type 2 diabetes might carry a proportionately greater genetic component. Through the Africa America Diabetes Mellitus (AADM) study, we carried out a genome-wide linkage analysis of type 2 diabetes in a cohort of 343 affected sibling pairs (691 individuals) enrolled from five West African centers in two countries (Ghana: Accra and Kumasi; Nigeria: Enugu, Ibadan, and Lagos). A total of 390 polymorphic markers were genotyped, and multipoint linkage analysis was conducted using the GENEHUNTER-PLUS and ASM programs. Suggestive evidence of linkage was observed in four regions on three chromosomes (12, 19, and 20). The two largest logarithm of odds scores of 2.63 and 1.92 for chromosomes 20q13.3 and 12q24, respectively, are particularly interesting because these regions have been reported to harbor diabetes susceptibility genes in several other populations and ethnic groups. Given the history of forced migration of West African populations during the slave trade, these results should have considerable relevance to the study of type 2 diabetes in African Americans.

  9. Public health significance of zoonotic bacterial pathogens from bushmeat sold in urban markets of Gabon, Central Africa.

    PubMed

    Bachand, Nicholas; Ravel, André; Onanga, Richard; Arsenault, Julie; Gonzalez, Jean-Paul

    2012-07-01

    Wild animal meat represents an important source of protein for many people in central Africa. Also known as bushmeat, this meat commodity is derived from wild animals hunted under uncontrolled conditions, transported to distant markets under rudimentary or no hygienic methods, and often eviscerated >24 hr after death. Considering the plausible role of wildlife as a reservoir for bacterial zoonotic pathogens, bushmeat may be an important public health risk in Central Africa. This cross-sectional survey served to evaluate the presence of Campylobacter, Salmonella, and Shigella in the muscle tissue of 128 wild animal carcasses from several hunted wildlife species (guenons [Cercopithecus spp.], collared mangabeys [Cercocebus torquatus], gray-cheeked mangabeys [Lophocebus albigena], African crested porcupines [Atherurus africanus], duikers [Cephalophus spp.], and red river hogs [Potamocherus porcus]) sold in two markets of Port-Gentil, Gabon, in July and August 2010. Salmonella was detected from one carcass; no Campylobacter or Shigella was detected. If Campylobacter and Shigella were present, the maximum expected prevalence was estimated at 6% and 1%, respectively. In light of such very low apparent muscle contamination levels, bushmeat likely does not represent a health risk per se with respect to Campylobacter, Salmonella, or Shigella. However, because carcass evisceration and skinning can take place within households prior to consumption, consumers should follow strict hygiene and food safety practices to avoid potential health hazards associated with the handling, preparation, or consumption of bushmeat.

  10. Construction of intensity-duration-frequency (IDF) curves for precipitation with annual maxima data in Rwanda, Central Africa

    NASA Astrophysics Data System (ADS)

    Demarée, G. R.; Van de Vyver, H.

    2013-06-01

    Detailed probabilistic information on the intensity of precipitation in Central Africa is highly needed in order to cope with the risk analysis of natural hazards. In the mountainous areas of Rwanda land slides frequently occur and might cause a heavy toll in human lives. The establishment of Intensity-Duration-Frequency curves for precipitation in Central Africa remains a difficult task as adequate long-term data sets for short aggregation times are usually not available. In 1962 recording raingauges were installed at several stations in Rwanda. According to the climatological procedures in use at that time in Congo, Rwanda and Burundi, maximum monthly and annual precipitation depths for fixed-time durations of 15, 30, 45, 60 and 120 min were determined from the rainfall charts. The data set is completed by the monthly and annual daily precipitation extremes from the non-recording raingauge at the stations. The authors used the dataset to establish the IDF-curves for precipitation at 3 stations in Rwanda having more than 20 yr of operation. The fixed-hour intervals of multiple 15 min require the use of a technique converting data from fixed-time intervals into data of arbitrary starting intervals. Therefore, the van Montfort technique was used.

  11. Changes in Intense Precipitation Events in West Africa and the central U.S. under Global Warming

    SciTech Connect

    Cook, Kerry H.; Vizy, Edward

    2016-02-08

    The purpose of the proposed project is to improve our understanding of the physical processes and large-scale connectivity of changes in intense precipitation events (high rainfall rates) under global warming in West Africa and the central U.S., including relationships with low-frequency modes of variability. This is in response to the requested subject area #2 “simulation of climate extremes under a changing climate … to better quantify the frequency, duration, and intensity of extreme events under climate change and elucidate the role of low frequency climate variability in modulating extremes.” We will use a regional climate model and emphasize an understanding of the physical processes that lead to an intensification of rainfall. The project objectives are as follows: 1. Understand the processes responsible for simulated changes in warm-season rainfall intensity and frequency over West Africa and the Central U.S. associated with greenhouse gas-induced global warming 2. Understand the relationship between changes in warm-season rainfall intensity and frequency, which generally occur on regional space scales, and the larger-scale global warming signal by considering modifications of low-frequency modes of variability. 3. Relate changes simulated on regional space scales to global-scale theories of how and why atmospheric moisture levels and rainfall should change as climate warms.

  12. An updated Bouguer anomaly map of south-central West Africa

    USGS Publications Warehouse

    Hastings, David A.

    1983-01-01

    A new Bouguer gravity anomaly map compiled for western Africa adds data for Ghana, Guinea, and Liberia.The new data add detail to a key part of the Eburnean shield and assist in the development of a model of rifting at the time of the Eburnean orogeny, 2000 million years ago. This model includes a framework for the deposition of the region's mineral deposits. The model and existing field data can be used to guide future minerals exploration in the region.

  13. Accommodation of missing shear strain in the Central Walker Lane, western North America: Constraints from dense GPS measurements

    NASA Astrophysics Data System (ADS)

    Bormann, Jayne M.; Hammond, William C.; Kreemer, Corné; Blewitt, Geoffrey

    2016-04-01

    We present 264 new interseismic GPS velocities from the Mobile Array of GPS for Nevada Transtension (MAGNET) and continuous GPS networks that measure Pacific-North American plate boundary deformation in the Central Walker Lane. Relative to a North America-fixed reference frame, northwestward velocities increase smoothly from ∼4 mm/yr in the Basin and Range province to 12.2 mm/yr in the central Sierra Nevada resulting in a Central Walker Lane deformation budget of ∼8 mm/yr. We use an elastic block model to estimate fault slip and block rotation rates and patterns of deformation from the GPS velocities. Right-lateral shear is distributed throughout the Central Walker Lane with strike-slip rates generally <1.5 mm/yr predicted by the block model, but extension rates are highest near north-striking normal faults found along the Sierra Nevada frontal fault system and in a left-stepping, en-echelon series of asymmetric basins that extend from Walker Lake to Lake Tahoe. Neotectonic studies in the western Central Walker Lane find little evidence of strike-slip or oblique faulting in the asymmetric basins, prompting the suggestion that dextral deformation in this region is accommodated through clockwise block rotations. We test this hypothesis and show that a model relying solely on the combination of clockwise block rotations and normal faulting to accommodate dextral transtensional strain accumulation systematically misfits the GPS data in comparison with our preferred model. This suggests that some component of oblique or partitioned right-lateral fault slip is needed to accommodate shear in the asymmetric basins of the western Central Walker Lane. Present-day clockwise vertical axis rotation rates in the Bodie Hills, Carson Domain, and Mina Deflection are between 1-4°/Myr, lower than published paleomagnetic rotation rates, suggesting that block rotation rates have decreased since the Late to Middle Miocene.

  14. Two Species Previously Confused Under the Concept of Sabethes Tarsopus in Central America (Diptera: Culicidae)

    DTIC Science & Technology

    1992-07-01

    para identificar (PA-ST-02-13); 4.XII.85, 16, 16 genitalia mosquitos en El Salvador. Tesis de Doc- (106617); 5.XII.85, 26, 2d genitalia torado en...Middle America" 7. Costa Rica (CR). distribucion geografica y su importancia en Mosq. Syst. 9:237-287. salud publica. Tesis , licenciado en biologia...Heinemann, S.J. and J.N. Belkin. 1977b. Col- Facultad de Ciencias Biologia. Universidad lection records of the project "Mosquitoes Nacional Autonoma de

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

    PubMed

    Raja, H A; Shearer, C A

    2006-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Adomat, Friederike; Gischler, Eberhard

    2017-01-01

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

  17. Transcontinental arch - a pattern formed by rejuvenation of local features across central North America

    USGS Publications Warehouse

    Carlson, M.P.

    1999-01-01

    The transcontinental Arch has been described by many authors as a feature having significant tectonic influence during the Phanerozoic, although the location, magnitude, and even the timing defining the arch vary greatly among authors. The general trend usually suggested for the Transcontinental Arch is northeast-southwest across the western midcontinent of North America. A series of isopachous and paleogeologic maps was compiled for this study that defines a number of smaller tectonic features - commonly trending northwest-southeast. Six persistent highs and six persistent lows (or sags) are defined that are largely basement controlled and were rejuvenated at various times during the Phanerozoic. These smaller northwest-trending features, when taken collectively and enhanced by the relative downwarping of the adjacent Williston and Anadarko basins, create a platform-like feature - the Transcontinental Arch of the literature. The concept of a Transcontinental Arch is an important reference trend in the geologic history of North America. In both regional and local studies, however, the smaller-scale, transverse features may have had significant control on both tectonic patterns and depositional influence.

  18. Perfluorinated alkyl substances (PFASs) in household dust in Central Europe and North America.

    PubMed

    Karásková, Pavlína; Venier, Marta; Melymuk, Lisa; Bečanová, Jitka; Vojta, Šimon; Prokeš, Roman; Diamond, Miriam L; Klánová, Jana

    2016-09-01

    Concentrations of 20 perfluorinated alkyl substances (PFASs) were measured in dust samples from 41 homes in Canada, the Czech Republic, and United States in the spring-summer of 2013. The most frequently detected compounds were perfluorohexanoic acid (PFHxA) and perfluorooctane sulfonate (PFOS). PFOS and perfluorooctanoic acid (PFOA) had the highest concentrations of PFASs in all countries. PFOS median concentrations for the three countries were between 9.1 and 14.1ng/g, and PFOA medians ranged between 8.2 and 9.3ng/g. In general, concentrations in North America were higher than in the Czech Republic, which is consistent with usage patterns. No differences were found for perfluorooctane sulfonamides/sulfonamidoethanols (FOSA/Es) levels due to the low number of detections. Homologue profiles suggest that the shift from longer to shorter chain PFASs is more advanced in North America than in Europe. Significant relationships were found among individual homologues and between PFAS concentrations in dust and type of floor, number of people living in the house, and building age.

  19. The Tonalá fault in southeastern Mexico: Evidence that the Central America forearc sliver is not being detached?

    NASA Astrophysics Data System (ADS)

    Guzman-Speziale, M.; Molina-Garza, R. S.

    2012-12-01

    The Tonalá fault is a NW-SE oriented feature that flanks the Chiapas Massif on its southwestern side. Several authors coincide that the fault originally developed as a right-lateral structure in the Jurassic, but was reactivated as a left-lateral fault in the Miocene. Seismicity along the fault is low: Only one earthquake with magnitude 5.0 or larger is reported along the Tonalá fault in the years 1964 to present. Fault-plane solutions determined by the Mexican Seismological Survey for earthquakes along the fault show left-lateral, strike-slip faulting. The Tonalá fault lies on the northwestern continuation of the Central America volcanic arc. The volcanic arc is the site of medium-sized (magnitudes up to 6.5) shallow, right-lateral, strike-slip earthquakes. This has led several workers to propose that the forearc sliver is being detached from the Caribbean plate along the arc, moving northward. GPS studies have confirmed relative motion between the Chortis block and the forearc sliver. Recent and current motion along the Tonalá fault is in contradiction with motion and detachment of the forearc sliver along the Central America volcanic arc. Left-lateral motion along it cannot accomodate northwest displacement of the forearc sliver. Motion of the Central America forearc would require NW directed compression between the continental shelf of Chiapas and the forearc itself, which is not observed. Therefore, either another fault (or faults) accomodates right-lateral motion and detachment of the forearc sliver, or the sliver is not being detached and relative motion between the forearc sliver and the Chortis block corresponds to displacement of the latter. We suggest that, as proposed by previous authors, the Tonalá fault is instead part of a fault system that runs from the state of Oaxaca (the Valle Nacional fault), forming an arc concave to the northeast, and running perpendicular to the maximum slope of subduction in the area.

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

    PubMed

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

    2005-06-01

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

  1. [Invasions of Paederus sabaeus (Coleoptera Staphylinidae) in central Africa. 1. Entomological and epidemiological aspects].

    PubMed

    Penchenier, L; Mouchet, J; Cros, B; Legall, P; Cosnefroy, J Y; Quézédé, P; Chandenier, J

    1994-01-01

    In May 1993, at the end of the rainy season, outbreaks of Paederus sabaeus (Coleoptera, Staphylinidae) were recorded in Brazzaville (Congo), Kinshasa (Zaire), Franceville and Libreville (Gabon) and even in Bangui (CAR) at the North of the equator. A short review of previous outbreaks in Africa and on vesicant substances is given by the authors. These beetles are attracted to neon lights and they rest on the walls or on the skin of the occupants. When the insects are crushed on the bare skin their haemolymph liberate pederine and related vesicant components which provocate dermatitis. The insects disappeared spontaneously after three to four weeks.

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

    PubMed Central

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

    2015-01-01

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

  3. Three new species of Pararhabdepyris Gorbatovsky (Hymenoptera, Bethylidae) from Central Africa and the Arabian Peninsula.

    PubMed

    Vargas, Juan M; Azevedo, Celso O

    2016-06-01

    Three new species of Pararhabdepyris are described and illustrated: P. arabo sp. nov. (United Arabian Emirates and Yemen), P. wafrika sp. nov. (Central African Republic), P. ngangu sp. nov. (Central African Republic). The genus is recorded for the first time from the Saharo-Arabian region. A key for all species of the genus is presented.

  4. Two Triatoma dimidiata clades (Chagas disease vector) associated with different habitats in southern Mexico and Central America.

    PubMed

    Tamay-Segovia, Paulino; Alejandre-Aguilar, Ricardo; Martínez, Fernando; Villalobos, Guiehdani; de la Serna, Francisco J Zavala-Díaz; de la Torre, Patricia; Laclette, Juan Pedro; Blum-Domínguez, Selene; Espinoza, Bertha

    2008-03-01

    Triatoma dimidiata is the only reported Chagas disease vector in Campeche, Mexico. The purpose of this study was to determine the genetic variability of vectors from Campeche coastal and rain forest areas and establish a phylogenetic relationship with other T. dimidiata populations by analyzing the internal transcribed spacer-2 (ITS-2) region. The sequence length of samples from Campeche ranged from 469 to 478 basepairs. The ITS-2 variability among the populations enabled us to classify them into two clades with an 18-22 nucleotide difference. The genetic distance (0.042) between them confirms this divergence. Phylogenetic analysis of gene genealogies confirmed these two clades. Furthermore, the population genetic analyses showed two groups with little genetic similarity or migration between them. One group was associated with the tropical forest area and the other group was associated with a mainly coastal distribution. This correlation was also observed when T. dimidiata from other regions of Mexico and Central America were analyzed.

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

    USGS Publications Warehouse

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

    2014-01-01

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

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

    PubMed Central

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

    1992-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1985-05-01

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

  8. Cryptomyrus: a new genus of Mormyridae (Teleostei, Osteoglossomorpha) with two new species from Gabon, West-Central Africa.

    PubMed

    Sullivan, John P; Lavoué, Sébastien; Hopkins, Carl D

    2016-01-01

    We use mitochondrial and nuclear sequence data to show that three weakly electric mormyrid fish specimens collected at three widely separated localities in Gabon, Africa over a 13-year period represent an unrecognized lineage within the subfamily Mormyrinae and determine its phylogenetic position with respect to other taxa. We describe these three specimens as a new genus containing two new species. Cryptomyrus, new genus, is readily distinguished from all other mormyrid genera by a combination of features of squamation, morphometrics, and dental attributes. Cryptomyrus ogoouensis, new species, is differentiated from its single congener, Cryptomyrus ona, new species, by the possession of an anal-fin origin located well in advance of the dorsal fin, a narrow caudal peduncle and caudal-fin lobes nearly as long as the peduncle. In Cryptomyrus ona, the anal-fin origin is located only slightly in advance of the dorsal fin, the caudal peduncle is deep and the caudal-fin lobes considerably shorter than the peduncle. Continued discovery of new taxa within the "Lower Guinea Clade" of Mormyridae highlights the incompleteness of our knowledge of fish diversity in West-Central Africa. We present a revised key to the mormyrid genera of Lower Guinea.

  9. Cryptomyrus: a new genus of Mormyridae (Teleostei, Osteoglossomorpha) with two new species from Gabon, West-Central Africa

    PubMed Central

    Sullivan, John P.; Lavoué, Sébastien; Hopkins, Carl D.

    2016-01-01

    Abstract We use mitochondrial and nuclear sequence data to show that three weakly electric mormyrid fish specimens collected at three widely separated localities in Gabon, Africa over a 13-year period represent an unrecognized lineage within the subfamily Mormyrinae and determine its phylogenetic position with respect to other taxa. We describe these three specimens as a new genus containing two new species. Cryptomyrus, new genus, is readily distinguished from all other mormyrid genera by a combination of features of squamation, morphometrics, and dental attributes. Cryptomyrus ogoouensis, new species, is differentiated from its single congener, Cryptomyrus ona, new species, by the possession of an anal-fin origin located well in advance of the dorsal fin, a narrow caudal peduncle and caudal-fin lobes nearly as long as the peduncle. In Cryptomyrus ona, the anal-fin origin is located only slightly in advance of the dorsal fin, the caudal peduncle is deep and the caudal-fin lobes considerably shorter than the peduncle. Continued discovery of new taxa within the “Lower Guinea Clade” of Mormyridae highlights the incompleteness of our knowledge of fish diversity in West-Central Africa. We present a revised key to the mormyrid genera of Lower Guinea. PMID:27006619

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

    PubMed

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

    2015-01-01

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

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

    PubMed

    Stein, E

    1993-08-01

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

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

    PubMed Central

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

    2011-01-01

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

  13. Trends in health surveillance and joint service delivery for pastoralists in West and Central Africa.

    PubMed

    Abakar, M F; Schelling, E; Béchir, M; Ngandolo, B N; Pfister, K; Alfaroukh, I O; Hassane, H M; Zinsstag, J

    2016-11-01

    In most sub-Saharan African countries, pastoralism represents an important economic resource and contributes significantly to national growth; however, challenges remain, particularly in providing social services to pastoralists (especially health and education) and in avoiding conflict with local sedentary communities and local authorities. All of this takes place while pastoralists try to maintain their mobile lifestyle within a rapidly changing ecosystem. Transdisciplinary approaches, such as 'One Health', which covers both human and animal health, have proven effective in delivering services and reaching mobile pastoralists in remote areas. The pastoralist way of life could be described as being linked to both their livestock and their environment, which makes social science an important element when researching the delivery and adaptation of social services to pastoralists. Early or pre-diagnostic detection of emerging and endemic infectious disease remains a vital aspect of health surveillance targeted at preventing further transmission and spread. Community-based syndromic surveillance, coupled with visual mobile phone technology, adapted to the high levels of illiteracy among nomads, could offer an alternative to existing health surveillance systems. Such an approach could contribute to accelerated reporting, which could in turn lead to targeted intervention among mobile pastoralists in sub-Saharan Africa. Although considerable efforts have been made towards integrating mobile pastoralists into social services, obstacles remain to the adoption of a clear, specific and sustainable policy on pastoralism in sub-Saharan Africa.

  14. Depositional sequence evolution, Paleozoic and early Mesozoic of the central Saharan platform, North Africa

    SciTech Connect

    Sprague, A.R.G. )

    1991-08-01

    Over 30 depositional sequences have been identified in the Paleozoic and lower Mesozoic of the Ghadames basin of eastern Algeria, southern Tunisia, and western Libya. Well logs and lithologic information from more than 500 wells were used to correlate the 30 sequences throughout the basin (total area more than 1 million km{sup 2}). Based on systematic change in the log response of strata in successively younger sequences, five groups of sequences with distinctive characteristics have been identified: Cambro-Ordivician, Upper Silurian-Middle Devonian, Upper Devonian, Carboniferous, and Middle Triassic-Middle Jurassic. Each sequence group is terminated by a major, tectonically enhanced sequence boundary that is immediately overlain (except for the Carboniferous) by a shale-prone interval deposited in response to basin-wide flooding. The four Paleozoic sequence groups were deposited on the Saharan platform, a north facing, clastic-dominated shelf that covered most of North Africa during the Paleozoic. The sequence boundary at the top of the Carboniferous sequence group is one of several Permian-Carboniferous angular unconformities in North Africa related to the Hercynian orogeny. The youngest sequence group (Middle Triassic to Middle Jurassic) is a clastic-evaporite package that onlaps southward onto the top of Paleozoic sequence boundary. The progressive changes from the Cambrian to the Jurassic, in the nature of the Ghadames basin sequences is a reflection of the interplay between basin morphology and tectonics, vegetation, eustasy, climate, and sediment supply.

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

    PubMed Central

    Erwin, Terry L.

    2011-01-01

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

  16. Regional geology of nuclear Central America and petroleum prospects of Belize

    SciTech Connect

    Rao, P.R.; Nair, K.M.; Ramanathan, R.

    1989-03-01

    The subsurface stratigraphy and structural evolution of nuclear Central American are reviewed in the light of new data from Belize. The northern Belize Corozal basin is the southern continuation of the Yucatan platform of Mexico and the eastern extension of the Peten basin of Mexico and Guatemala. The southern Belize basin is contiguous with the Chapayal basin of Guatemala.

  17. Assessment of simulated rainfall and temperature from the regional climate model REMO and future changes over Central Africa

    NASA Astrophysics Data System (ADS)

    Fotso-Nguemo, Thierry C.; Vondou, Derbetini A.; Tchawoua, Clément; Haensler, Andreas

    2016-07-01

    This work investigates spatial and temporal changes in rainfall and temperature over Central Africa, using historical and representative concentration pathways (RCP2.6, RCP4.5 and RCP8.5) of the regional climate model REMO forced by two general climate models: the Europe-wide Consortium Earth System Model (EC-Earth) and the Max Planck Institute-Earth System Model (MPI-ESM). We found that in the present period (1980-2005), the spatial distribution of rainfall is simulated with an annual spatial pattern correlation coefficient (PCC) of 0.76 for REMO driven by EC-Earth and 0.74 for REMO driven by MPI-ESM respectively when compared to CRU data. In terms of temperature, the annual PCC is 0.93 for the two REMO outputs. According to the climatology of Central Africa, we subdivided the study area into five sub-regions, we also noticed that the annual and seasonal PCC depend on the considered sub-region. For the future period (2070-2095), temperature is projected to increase following all the three scenarios. The rainfall amount is projected to decrease by up to 5 mm/day towards the end of the twenty first century under RCP8.5 scenario, and by 1-2 mm/day under RCP4.5 and RCP2.6 scenarios over Equatorial Guinea, Gabon, Congo, north-western Democratic Republic of Congo (DRC) and the Lake Victoria. Significant decrease is predicted to occur mostly in the northern part of the domain under RCP8.5 scenario. However, future rainfall over High Lands of Cameroon, Adamawa Plateau, north-eastern DRC and Atlantic Ocean is projected to increase.

  18. To converge or not to converge in environmental space: testing for similar environments between analogous succulent plants of North America and Africa

    PubMed Central

    Alvarado-Cárdenas, Leonardo O.; Martínez-Meyer, Enrique; Feria, Teresa P.; Eguiarte, Luis E.; Hernández, Héctor M.; Midgley, Guy; Olson, Mark E.

    2013-01-01

    Background and Aims Convergent evolution is invoked to explain similarity between unrelated organisms in similar environments, but most evaluations of convergence analyse similarity of organismal attributes rather than of the environment. This study focuses on the globular succulent plants of the Americas, the cacti, and their counterparts in Africa in the ice-plant, spurge and milkweed families. Though often held up as paragons of convergent morphological evolution, the environmental similarity of these plants has remained largely unexamined from a quantitative perspective. Methods Five hotspots (centres of high species diversity of globular succulents) were selected, two in Mexico and three in South Africa. Their environments were compared using niche modelling tools, randomization tests of niche similarity and multivariate analyses to test for environmental similarity. Key Results Although the sites selected have ‘similar’ but unrelated life forms, almost all our results highlighted more climate differences than similarities between the hotspots. Interprediction of niches within and between continents, a niche equivalence test, and MANOVA results showed significant differences. In contrast, a niche similarity test showed that the comparisons of Cuatrociénegas–Richtersveld, Huizache–Knersvlakte and Huizache–Richtersveld were similar. Conclusions Differences in rainfall and temperature regimes and the potential effect of edaphic factors may be involved in the differences between the hotspots. In addition, differences in structure, morphology and physiology of the globular succulents may coincide with some of the climatic dissimilarities; i.e. given convergence as the evolution of similar morphologies under similar conditions, then it may be that differing environments diagnose inconspicuous morphological differences. Moreover, although fine-scale differences between sites were found, a coarser perspective shows that these sites are clearly similar as

  19. Characteristics of HIV-Infected Children at Enrollment into Care and at Antiretroviral Therapy Initiation in Central Africa

    PubMed Central

    Sinayobye, Jean d’Amour; Nduwimana, Martin; Lelo, Patricia; Nash, Denis

    2017-01-01

    Background Despite the World Health Organization (WHO) regularly updating guidelines to recommend earlier initiation of antiretroviral therapy (ART) in children, timely enrollment into care and initiation of ART in sub-Saharan Africa in children lags behind that of adults. The impact of implementing increasingly less restrictive ART guidelines on ART initiation in Central Africa has not been described. Materials and Methods Data are from the Central Africa International Epidemiologic Databases to Evaluate AIDS (IeDEA) pediatric cohort of 3,426 children (0–15 years) entering HIV care at 15 sites in Burundi, DRC, and Rwanda. Measures include CD4 count, WHO clinical stage, age, and weight-for-age Z score (WAZ), each at enrollment into HIV care and at ART initiation. Changes in the medians or proportions of each measure by year of enrollment and year of ART initiation were assessed to capture potential impacts of changing ART guidelines. Results Median age at care enrollment decreased from 77.2 months in 2004–05 to 30.3 months in 2012–13. The median age at ART initiation (n = 2058) decreased from 83.0 months in 2004–05 to 66.9 months in 2012–13. The proportion of children ≤24 months of age at enrollment increased from 12.7% in 2004–05 to 46.7% in 2012–13, and from 9.6% in 2004–05 to 24.2% in 2012–13 for ART initiation. The median CD4 count at enrollment into care increased from 563 (IQR: 275, 901) in 2004–05 to 660 (IQR: 339, 1071) cells/μl in 2012–13, and the median CD4 count at ART initiation increased from 310 (IQR:167, 600) in 2004–05 to 589 (IQR: 315, 1113) cells/μl in 2012–13. From 2004–05 to 2012–13, median WAZ improved from -2 (IQR: -3.4, -1.1) to -1 (IQR: -2.5, -0.2) at enrollment in care and from -2 (IQR: -3.8, -1.6) to -1 (IQR: -2.6, -0.4) at ART initiation. Discussion and Conclusion Although HIV-infected children ≤24 months of age accounted for half of all children enrolling in care in our cohort during 2012–13, they

  20. Description of two new genera and two new species of Metarbelidae (Lepidoptera, Cossoidea) from the Northeastern Congolian Lowland Forests Ecoregion (Central Africa).

    PubMed

    Lehmann, Ingo

    2014-12-17

    The genera Dianfosseya gen. nov. and Janegoodallia gen. nov. and their single species D. leakeyi sp. nov. and J. davenporti sp. nov. are both described from Isiro, north-eastern Democratic Republic of the Congo, Central Africa (Afrotropical Region). Wing pattern and male genitalia of the new species are depicted and notes on the habitat are presented.

  1. Conference on Resource Sharing in Southern and Central Africa (Dar-es-Salaam, Tanzania, December 16-19, 1985). Final Report.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific and Cultural Organization, Paris (France). General Information Programme.

    This document summarizes the activities of a conference held at the Institute of Finance Management in Tanzania on information resource sharing in Southern and Central Africa. Delegates and observers from Lesotho, Swaziland, Mozambique, Botswana, Zimbabwe, Malawi, Zambia, and Tanzania attended the conference. The 15 participants, 8 sponsored by…

  2. Changing drug markets under new intellectual property regimes: the view from Central America.

    PubMed

    Godoy, Angelina Snodgrass; Cerón, Alejandro

    2011-07-01

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

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

    NASA Technical Reports Server (NTRS)

    Jelacic, A. J. (Principal Investigator)

    1972-01-01

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

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

    PubMed Central

    Cerón, Alejandro

    2011-01-01

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

  5. Molecular diagnosis and species identification of Ehrlichia and Anaplasma infections in dogs from Panama, Central America.

    PubMed

    Santamaria, Annamaria; Calzada, Jose E; Saldaña, Azael; Yabsley, Michael J; Gottdenker, Nicole L

    2014-05-01

    The prevalence and distribution of Anaplasma and Ehrlichia were estimated in 201 symptomatic dogs from Panama by nested PCR and DNA sequencing of the 16S rRNA gene. In total, 163 dogs (70.6%; 163/201) were infected with either Anaplasma or Ehrlichia. On the basis of PCR results, the majority of cases were infected with E. canis (64.2%; 129/201) followed by 21.4% (43/201) with A. platys, whereas 7.5% (15/201) had Anaplasma/Ehrlichia co-infections. Further analyses of 16S rDNA partial sequences show sequence homology with E. canis and A. platys from other countries. Hematology findings from 79 E. canis PCR-positive dogs included anemia (74.7%), thrombocytopenia (81.9%), macroplatelets (29.1%), and leukopenia (6.3%). Among 16 A. platys PCR-positive dogs with available hematology, 62.5% were anemic, 75% had thrombocytopenia, and 100% had macroplatelets. On the basis of E.canis serology (enzyme-linked immunosorbent assay [ELISA]) (n=92 dogs), 30 dogs that were seropositive for E. canis were also PCR-positive, whereas among seronegatives (n=62), 10 were PCR-positive for E. canis. This study provides the first characterization of canine anaplasmosis and ehrlichiosis infections in Panama and is important to veterinary public health and comparative studies of these pathogens in the Americas.

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

    NASA Astrophysics Data System (ADS)

    Mendoza, Blanca; Sánchez de La Peña, Salvador

    2010-08-01

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

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

    DOE PAGES

    Pasyanos, Michael E.

    2015-11-01

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

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

    SciTech Connect

    Pasyanos, Michael E.

    2015-11-01

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

  9. New records of Anacroneuria Klapálek, 1909 (Plecoptera: Perlidae) for Central America.

    PubMed

    Gutiérrez-Fonseca, Pablo E; Alonso-Rodríguez, Aura M; Cornejo, Aydeé; Bailey, Anna Cristina; Maes, Jean-Michel; Ramírez, Alonso

    2015-08-03

    The perlid genus Anacroneuria is the most widely distributed stonefly occurring in the Neotropics. Regional studies of this genus were made early in the last century, whereas local taxonomic and distributional studies have recently increased. In this study, we provide new Central American records for four species of Anacroneuria. Anacroneuria choco Stark & Bersosa 2006, A. costana (Navás 1924), A. hacha Stark 1998, and A. laru Gutiérrez-Fonseca 2015 are newly reported including new range extensions.

  10. Drug resistance associated genetic polymorphisms in Plasmodium falciparum and Plasmodium vivax collected in Honduras, Central America

    PubMed Central

    2011-01-01

    Background In Honduras, chloroquine and primaquine are recommended and still appear to be effective for treatment of Plasmodium falciparum and Plasmodium vivax malaria. The aim of this study was to determine the proportion of resistance associated genetic polymorphisms in P. falciparum and P. vivax collected in Honduras. Methods Blood samples were collected from patients seeking medical attention at the Hospital Escuela in Tegucigalpa from 2004 to 2006 as well as three regional hospitals, two health centres and one regional laboratory during 2009. Single nucleotide polymorphisms in P. falciparum chloroquine resistance transporter (pfcrt), multidrug resistance 1 (pfmdr1), dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) genes and in P. vivax multidrug resistance 1 (pvmdr1) and dihydrofolate reductase (pvdhfr) genes were detected using PCR based methods. Results Thirty seven P. falciparum and 64 P. vivax samples were collected. All P. falciparum infections acquired in Honduras carried pfcrt, pfmdr1, pfdhps and pfdhfr alleles associated with chloroquine, amodiaquine and sulphadoxine-pyrimethamine sensitivity only. One patient with parasites acquired on a Pacific Island had pfcrt 76 T and pfmdr1 86Y alleles. That patient and a patient infected in West Africa had pfdhfr 51I, 59 R and 108 N alleles. Pvmdr1 976 F was found in 7/37 and two copies of pvmdr1 were found in 1/37 samples. Pvdhfr 57 L + 58 R was observed in 2/57 samples. Conclusion The results indicate that P. falciparum from Honduras remain sensitive to chloroquine and sulphadoxine-pyrimethamine. This suggests that chloroquine and sulphadoxine-pyrimethamine should be efficacious for treatment of uncomplicated P. falciparum malaria, supporting current national treatment guidelines. However, genetic polymorphisms associated with chloroquine and sulphadoxine-pyrimethamine tolerance were detected in local P. vivax and imported P. falciparum infections. Continuous monitoring of the prevalence

  11. Adult T-cell leukemia/lymphoma in South and Central America and the Caribbean: systematic search and review.

    PubMed

    Oliveira, Pedro D; de Carvalho, Rebeca F; Bittencourt, Achiléa L

    2017-03-01

    Adult T-cell leukemia/lymphoma (ATL) is caused by the human T-cell lymphotropic virus type 1 (HTLV-1) which is endemic in countries of Caribbean and Central and South America. We performed a systematic search and review to identify publications on ATL in these countries to verify if this disease was getting recognition in these regions as well as the characteristics of the observed cases. The median age of 49.4 years was lower than that referred to in Japan. According to our findings in most Brazilian states and in some other countries, ATL is not being recognized and should be strongly considered in the differential diagnosis of T-cell leukemias/lymphomas. Failure to identify these cases may be due to the unsystematic realization of serology for HTLV-1 and phenotypic identification of non-Hodgkin lymphomas that may result from lack of resources. Detection of ATL cases has been more feasible with cooperation from foreign research centers. A huge effort should be made to improve the surveillance system for ATL diagnosis in most of the South- and Central-American and Caribbean countries, and this attitude should be embraced by public organs to support health professionals in this important task.

  12. Hydro, wind and solar power as a base for a 100% renewable energy supply for South and Central America.

    PubMed

    Barbosa, Larissa de Souza Noel Simas; Bogdanov, Dmitrii; Vainikka, Pasi; Breyer, Christian

    2017-01-01

    Power systems for South and Central America based on 100% renewable energy (RE) in the year 2030 were calculated for the first time using an hourly resolved energy model. The region was subdivided into 15 sub-regions. Four different scenarios were considered: three according to different high voltage direct current (HVDC) transmission grid development levels (region, country, area-wide) and one integrated scenario that considers water desalination and industrial gas demand supplied by synthetic natural gas via power-to-gas (PtG). RE is not only able to cover 1813 TWh of estimated electricity demand of the area in 2030 but also able to generate the electricity needed to fulfil 3.9 billion m3 of water desalination and 640 TWhLHV of synthetic natural gas demand. Existing hydro dams can be used as virtual batteries for solar and wind electricity storage, diminishing the role of storage technologies. The results for total levelized cost of electricity (LCOE) are decreased from 62 €/MWh for a highly decentralized to 56 €/MWh for a highly centralized grid scenario (currency value of the year 2015). For the integrated scenario, the levelized cost of gas (LCOG) and the levelized cost of water (LCOW) are 95 €/MWhLHV and 0.91 €/m3, respectively. A reduction of 8% in total cost and 5% in electricity generation was achieved when integrating desalination and power-to-gas into the system.

  13. Hydro, wind and solar power as a base for a 100% renewable energy supply for South and Central America

    PubMed Central

    Barbosa, Larissa de Souza Noel Simas; Bogdanov, Dmitrii; Vainikka, Pasi; Breyer, Christian

    2017-01-01

    Power systems for South and Central America based on 100% renewable energy (RE) in the year 2030 were calculated for the first time using an hourly resolved energy model. The region was subdivided into 15 sub-regions. Four different scenarios were considered: three according to different high voltage direct current (HVDC) transmission grid development levels (region, country, area-wide) and one integrated scenario that considers water desalination and industrial gas demand supplied by synthetic natural gas via power-to-gas (PtG). RE is not only able to cover 1813 TWh of estimated electricity demand of the area in 2030 but also able to generate the electricity needed to fulfil 3.9 billion m3 of water desalination and 640 TWhLHV of synthetic natural gas demand. Existing hydro dams can be used as virtual batteries for solar and wind electricity storage, diminishing the role of storage technologies. The results for total levelized cost of electricity (LCOE) are decreased from 62 €/MWh for a highly decentralized to 56 €/MWh for a highly centralized grid scenario (currency value of the year 2015). For the integrated scenario, the levelized cost of gas (LCOG) and the levelized cost of water (LCOW) are 95 €/MWhLHV and 0.91 €/m3, respectively. A reduction of 8% in total cost and 5% in electricity generation was achieved when integrating desalination and power-to-gas into the system. PMID:28329023

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

    PubMed Central

    Dorr, Laurence J.

    2011-01-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed Central

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

    2010-01-01

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

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

    ERIC Educational Resources Information Center

    Malkasian, Mark; Davidson, Louise K.

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

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

    ERIC Educational Resources Information Center

    Malkasian, Mark; Davidson, Louise K.

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

  19. High Genetic Diversity of Newcastle Disease Virus in Poultry in West and Central Africa: Cocirculation of Genotype XIV and Newly Defined Genotypes XVII and XVIII

    PubMed Central

    Snoeck, Chantal J.; Owoade, Ademola A.; Couacy-Hymann, Emmanuel; Alkali, Bello R.; Okwen, Mbah P.; Adeyanju, Adeniyi T.; Komoyo, Giscard F.; Nakouné, Emmanuel; Le Faou, Alain

    2013-01-01

    Despite rampant Newcastle disease virus (NDV) outbreaks in Africa for decades, the information about the genetic characteristics of the virulent strains circulating in West and Central Africa is still scarce. In this study, 96 complete NDV fusion gene sequences were obtained from poultry sampled in Cameroon, Central African Republic, Côte d'Ivoire, and Nigeria between 2006 and 2011. Based on rational criteria recently proposed for the classification of NDV strains into classes, genotypes, and subgenotypes, we revisited the classification of virulent strains, in particular those from West and Central Africa, leading to their grouping into genotype XIV and newly defined genotypes XVII and XVIII, each with two subgenotypes. Phylogenetic analyses revealed that several (sub)genotypes are found in almost every country. In Cameroon, most strains were related to vaccine strains, but a single genotype XVII strain was also found. Only three highly similar genotype XVII strains were detected in Central African Republic. Subgenotypes XVIIa, XVIIIa, and XVIIIb cocirculated in Côte d'Ivoire, while subgenotypes XIVa, XIVb, XVIIa, XVIIb, and XVIIIb were found in Nigeria. While these genotypes are so far geographically restricted, local and international trade of domestic and exotic birds may lead to their spread beyond West and Central Africa. A high genetic diversity, mutations in important neutralizing epitopes paired with suboptimal vaccination, various levels of clinical responses of poultry and wild birds to virulent strains, strains with new cleavage sites, and other genetic modifications found in these genotypes tend to undermine and complicate NDV management in Africa. PMID:23658271

  20. Origin and schizophrenia in young refugees and inter-country adoptees from Latin America and East Africa in Sweden: a comparative study

    PubMed Central

    Hollander, Anna-Clara; Almquist, Ylva B.; Rostila, Mikael; Hjern, Anders

    2016-01-01

    Background Migrants’ socioeconomic adversity has been linked to schizophrenia. Aims To investigate whether the more favourable socioeconomic situation of adoptees prevents them from the high risk of schizophrenia found in other migrants. Method Register study in a cohort of refugees and inter-country adoptees aged 16–40 years, born in East Africa (n=8389), Latin America (n=11 572) and 1.2 million native Swedes. Cox-regression models estimated hazard ratios (HRs) of schizophrenia in data from psychiatric care. Results Despite diverse income levels, HRs for schizophrenia were similar for refugees and adoptees, with East Africans having the highest HRs: 5.83 (3.30–10.27) and 5.80 (5.03–6.70), followed by Latin Americans: HRs 3.09 (2.49–3.83) and 2.31 (1.79–2.97), compared with native Swedes. Adjustment for income decreased these risks slightly for refugees, but not for adoptees. Conclusions This study suggests that risk factors associated with origin are more important determinants of schizophrenia than socioeconomic adversity in the country of settlement. Declaration of interest None. Copyright and usage © 2016 The Royal College of Psychiatrists. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence. PMID:27703747

  1. A Survey of Mental Health Research Priorities in Low- and Middle-Income Countries of Africa, Asia, and Latin America and the Caribbean

    PubMed Central

    Sharan, P; Gallo, C; Gureje, O; Lamberte, E; Mari, JJ; Mazzotti, G; Patel, V; Swartz, L; Olifson, S; Levav, I; de Francisco, A; Saxena, S

    2012-01-01

    Background Studies suggest a paucity of and lack of prioritization in mental health research output from low- and middle-income (LAMI) countries. Aims To investigate research priorities in mental health among researchers and other stakeholders in LAMI countries. Method A two-stage design that included enumeration (through literature searches and snowball technique) of researchers and stakeholders in 114 countries of Africa, Asia and Latin America and the Caribbean; and a mail survey on priority research. Results The study revealed broad agreement between researchers and stakeholders and across regions regarding the priorities for mental health research, however, stakeholders did not consider researchers' personal interest as an important criterion for prioritizing research. Studies on epidemiology (burden and risk factors), health systems, and social science were the highest ranked types of needed research. The three prioritized disorders were depression/anxiety, substance use disorders, and psychoses, while prioritized population groups were children and adolescents, women, and persons exposed to violence/trauma. Important criteria for prioritizing research were burden of disease, social justice, and availability of funds. Researchers' and stakeholders' priorities were largely consistent with burden of disease estimates (however, suicide was under-prioritized) and partly congruent with the research projects of the responding researchers. Conclusions The broad agreement found between a large and reasonably representative group of active researchers and stakeholders provides a basis for generating policy and service relevant evidence for global mental health. PMID:19794206

  2. Interpretation of gravity data by the continuous wavelet transform: The case of the Chad lineament (North-Central Africa)

    NASA Astrophysics Data System (ADS)

    Li, Yuanyuan; Braitenberg, Carla; Yang, Yushan

    2013-03-01

    A slightly bended gravity high along the Chad lineament in Central North Africa is analyzed and interpreted by the continuous wavelet transform (CWT) method. We use scale normalization on the continuous wavelet transform, allowing analysis of the gravity field in order to determine the sources at different depths. By focusing on homogenous standard sources, such as sphere or cube, horizontal cylinder or prism, sheet and infinite step, we derive the relationships between the source depth and pseudo-wavenumber. Then the source depth can be recovered from tracing the maximal values of the modulus of the complex wavelet coefficients in the CWT-based scalograms that are function of the pseudo-wavenumber. The studied area includes a central gravity high up to 75 km wide, and a secondary high that occurs at the southern part of the anomaly. The interpretation of the depth slices and vertical sections of the modulus maxima of the complex wavelet coefficients allows recognition of a relatively dense terrane located at middle crustal levels (10-25 km depth). A reasonable geological model derived from the 2.5D gravity forward modelling indicates the presence of high density bodies, probably linked to a buried suture, which were thrusted up into the mid-crust during the Neo-Proterozoic terrane collisions between the Saharan metacraton and the Arabian-Nubian shield. We conclude that the Chad line delineates a first order geological boundary, missing on the geologic maps.

  3. Comparative role of Aedes albopictus and Aedes aegypti in the emergence of Dengue and Chikungunya in central Africa.

    PubMed

    Paupy, Christophe; Ollomo, Benjamin; Kamgang, Basile; Moutailler, Sara; Rousset, Dominique; Demanou, Maurice; Hervé, Jean-Pierre; Leroy, Eric; Simard, Frédéric

    2010-04-01

    Since its discovery in Nigeria in 1991, Aedes albopictus has invaded much of Central Africa, a region where Ae. aegypti also occurs. To assess the relationship between the invasion by Ae. albopictus and the recent emergence of dengue virus (DENV) and chikungunya virus (CHIKV), we undertook vector competence experiments on populations collected from Cameroon and conducted field investigations during concurrent epidemics of DENV and CHIKV in Gabon. Overall, infection and dissemination rates were not significantly different between Ae. albopictus and Ae. aegypti when exposed to titers of 10(8.1) mosquito infectious dose 50/mL and 10(7.5) plaque forming units/mL of DENV type 2 and CHIKV, respectively. Field investigations showed that Ae. albopictus readily bit man, was abundant, and outnumbered Ae. aegypti to a large extent in Gabon, particularly in suburban environments. Nevertheless, Ae. aegypti was predominant in the more urbanized central parts of Libreville. In this city, CHIKV and DENV were detected only in Ae. albopictus. These data strongly suggest that Ae. albopictus acted as the major vector of both viruses in Libreville in 2007, impacting on the epidemiology of DENV and CHIKV in this area.

  4. Linking a sea level pressure anomaly dipole over North America to the central Pacific El Niño

    NASA Astrophysics Data System (ADS)

    Ding, Ruiqiang; Li, Jianping; Tseng, Yu-heng; Sun, Cheng; Zheng, Fei

    2016-10-01

    This study demonstrates the close connection between the north-south dipole pattern of sea level pressure anomalies over northeastern North America to the western tropical North Atlantic, referred to as the North American dipole (NAD), and the central Pacific (CP)-type El Niño a year later. In contrast to other ENSO precursors, such as the North Pacific Oscillation (NPO) and Pacific-North America (PNA) pattern, the NAD appears more closely related to the CP-type El Niño than to the eastern Pacific (EP)-type El Niño, indicating that the NAD may serve as a unique precursor for the CP El Niño. The wintertime NAD induces sea surface temperature anomalies in the northern tropical Atlantic (NTA), which subsequently play an important role in developing the CP El Niño-like pattern in the tropical Pacific over the course of the following year. It appears that the NAD influence on CP El Niño involves air-sea interaction over several major basins, including the subtropical/tropical Pacific and the NTA. Additional analysis indicates that the correlation of either the NAD index or the NPO index with the CP El Niño state a year later depends on the status of the other index. When the wintertime NAD index is of the opposite sign to the simultaneous NPO index, the correlation of the NAD or NPO index with the Niño4 index becomes much weaker.

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

    PubMed

    Pagán, Israel; Holguín, Africa

    2013-01-01

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

  6. Loss of a large grazer impacts savanna grassland plant communities similarly in North America and South Africa.

    PubMed

    Eby, Stephanie; Burkepile, Deron E; Fynn, Richard W S; Burns, Catherine E; Govender, Navashni; Hagenah, Nicole; Koerner, Sally E; Matchett, Katherine J; Thompson, Dave I; Wilcox, Kevin R; Collins, Scott L; Kirkman, Kevin P; Knapp, Alan K; Smith, Melinda D

    2014-05-01

    Large herbivore grazing is a widespread disturbance in mesic savanna grasslands which increases herbaceous plant community richness and diversity. However, humans are modifying the impacts of grazing on these ecosystems by removing grazers. A more general understanding of how grazer loss will impact these ecosystems is hampered by differences in the diversity of large herbivore assemblages among savanna grasslands, which can affect the way that grazing influences plant communities. To avoid this we used two unique enclosures each containing a single, functionally similar large herbivore species. Specifically, we studied a bison (Bos bison) enclosure at Konza Prairie Biological Station, USA and an African buffalo (Syncerus caffer) enclosure in Kruger National Park, South Africa. Within these enclosures we erected exclosures in annually burned and unburned sites to determine how grazer loss would impact herbaceous plant communities, while controlling for potential fire-grazing interactions. At both sites, removal of the only grazer decreased grass and forb richness, evenness and diversity, over time. However, in Kruger these changes only occurred with burning. At both sites, changes in plant communities were driven by increased dominance with herbivore exclusion. At Konza, this was caused by increased abundance of one grass species, Andropogon gerardii, while at Kruger, three grasses, Themeda triandra, Panicum coloratum, and Digitaria eriantha increased in abundance.

  7. Forest pricing and concession policies: Managing the high forest of west and Central Africa. World Bank Technical Paper 143; Politique de redevances et de concessions forestires: gestion des futaies en afrique occidentale et centrale

    SciTech Connect

    Grut, M.; Gray, J.A.; Egli, N.

    1993-12-01

    This French edition of Forest Pricing and Concession Policies: Managing the High Forest of West and Central Africa describes forest revenue systems and concession policies in the tropical moist hardwood forests of West and Central Africa. Virtually all the forests of Africa are publicly owned by central governments or local communities. Revenues from these forests are generally very low due to low forest fees and low collection rates. The lack of concession fees encourages acquisition and waste rather than management and conservation, leading to the allocation of large areas as logging concessions. This paper reviews current issues in silviculture, tenure, concession management, and biological and financial sustainable development. Until the fledgling forestry departments of governments in West and Central Africa are strengthened, the report concludes that a simple system of forest fees should be implemented. The report recommends that such a system emphasize bidding and concession fees. Three specific options in forest pricing are examined for a proposed system; annual concession rent; annual concession rent set by competitive bidding; logging concessions replaced by forest management concessions.

  8. Exploring the diversity of blood-sucking Diptera in caves of Central Africa.

    PubMed

    Obame-Nkoghe, Judicaël; Rahola, Nil; Ayala, Diego; Yangari, Patrick; Jiolle, Davy; Allene, Xavier; Bourgarel, Mathieu; Maganga, Gael Darren; Berthet, Nicolas; Leroy, Eric-Maurice; Paupy, Christophe

    2017-03-21

    Caves house pathogenic microorganisms, some of which are transmitted by blood-sucking arthropods. In Africa, previous studies identified mosquitoes, sand flies and biting midges as the main potential vectors of cave-dwelling pathogens. However, to understand their involvement in pathogen spillover, it is crucial to characterize their diversity, community composition and dynamics. Using CDC light traps, we collected hematophagous Diptera in six caves of Gabon during one-shot or longitudinal sampling, and investigated their species diversity and dynamics in relation with external rainfall. Overall, we identified 68 species of mosquitoes, sand flies and biting midges, including 45 new records for Gabon. The dominant species were: Uranotaenia nigromaculata, Anopheles smithii s.l., Culex. rima group and Culex quasiguiarti for mosquitoes, Spelaeophlebotomus gigas and Spelaeomyia emilii for sand flies and the Culicoides trifasciellus group and Culicoides fulvithorax for biting midges. The survey revealed that species assemblages were cave-specific and included mainly troglophilous and trogloxenous species. Both diversity and abundance varied according to the cave and sampling time, and were significantly associated with rainfall. These associations were modulated by the cave specific environmental conditions. Moreover, the presence of trogloxenous and troglophilous species could be of high significance for pathogen transfers between cave and epigeous hosts, including humans.

  9. Malaria continues to select for sickle cell trait in Central Africa.

    PubMed

    Elguero, Eric; Délicat-Loembet, Lucrèce M; Rougeron, Virginie; Arnathau, Céline; Roche, Benjamin; Becquart, Pierre; Gonzalez, Jean-Paul; Nkoghe, Dieudonné; Sica, Lucas; Leroy, Eric M; Durand, Patrick; Ayala, Francisco J; Ollomo, Benjamin; Renaud, François; Prugnolle, Franck

    2015-06-02

    Sickle cell disease (SCD) is a genetic disorder that poses a serious health threat in tropical Africa, which the World Health Organization has declared a public health priority. Its persistence in human populations has been attributed to the resistance it provides to Plasmodium falciparum malaria in its heterozygous state, called sickle cell trait (SCT). Because of migration, SCT is becoming common outside tropical countries: It is now the most important genetic disorder in France, affecting one birth for every 2,400, and one of the most common in the United States. We assess the strength of the association between SCT and malaria, using current data for both SCT and malaria infections. A total of 3,959 blood samples from 195 villages distributed over the entire Republic of Gabon were analyzed. Hemoglobin variants were identified by using HPLCy (HPLC). Infections by three species of Plasmodium were detected by PCR followed by sequencing of a 201-bp fragment of cytochrome b. An increase of 10% in P. falciparum malaria prevalence is associated with an increase by 4.3% of SCT carriers. An increase of 10 y of age is associated with an increase by 5.5% of SCT carriers. Sex is not associated with SCT. These strong associations show that malaria remains a selective factor in current human populations, despite the progress of medicine and the actions undertaken to fight this disease. Our results provide evidence that evolution is still present in humans, although this is sometimes questioned by scientific, political, or religious personalities.

  10. Detecting recent changes in the demographic parameters of drosophilid populations from western and central Africa

    NASA Astrophysics Data System (ADS)

    Bouiges, Axelle; Yassin, Amir; Ikogou, Maya; Lelarge, Clément; Sikoa, Axelle-Rolande; Mona, Stefano; Veuille, Michel

    2013-07-01

    Previous genetic studies showing evidence of past demographic changes in African drosophilids suggested that these populations had strongly responded to Quaternary climate changes. We surveyed nine species of Zaprionus, a drosophilid genus mostly present in Africa, in forests located between southern Senegal and Gabon. The mitochondrial COI gene showed contrasted levels of sequence variation across species. Populations of the only cosmopolitan species of the genus, Z. indianus, and of its closely related sibling species, Z. africanus, are highly polymorphic and appear to have undergone a continuous population expansion beginning about 130,000 years ago. Five less variable species probably underwent a population expansion beginning only about 20,000-30,000 years ago. One of them, Z. taronus, was significantly structured between forest blocks. The last two species were nearly monomorphic, probably due to infection by Wolbachia. These results are similar to those obtained in three species from the melanogaster subgroup, and may be typical of the responses of African drosophilid populations to glacial cycles.

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  12. Temporal patterns and geographic heterogeneity of Zika virus (ZIKV) outbreaks in French Polynesia and Central America

    PubMed Central

    2017-01-01

    Background Zika virus (ZIKV) transmission has been reported in 67 countries/territories in the Oceania region and the Americas since 2015, prompting the World Health Organization (WHO) to declare ZIKV as a Public Health Emergency of International Concern in February 2016, due to its strong association with medical complications such as microcephaly and Guillain–Barré Syndrome (GBS). However, a substantial gap in knowledge still exists regarding differing temporal pattern and potential of transmission of ZIKV in different regions of the world. Methods We use a phenomenological model to ascertain the temporal patterns and transmission potential of ZIKV in various countries/territories, by fitting the model to Zika case data from Yap Island and French Polynesia in the Oceania region and 11 countries/territories with confirmed case data, namely, Colombia, Ecuador, French Guiana, Guadeloupe, Guatemala, Mexico, Nicaragua, Panama, Puerto Rico, Saint Martin, and Suriname, to pinpoint the waves of infections in each country/territory and to estimate the respective basic reproduction number R0. Results Six of these time series datasets resulted in statistically significant model fit of at least one wave of reported cases, namely that of French Polynesia, Colombia, Puerto Rico, Guatemala, Suriname and Saint Martin. However, only Colombia and Guatemala exhibited two waves of cases while the others had only one wave. Temporal patterns of the second wave in Colombia and the single wave in Suriname are very similar, with the respective turning points separated by merely a week. Moreover, the mean estimates of R0 for Colombia, Guatemala and Suriname, all land-based populations, range between 1.05 and 1.75, while the corresponding mean estimates for R0 of island populations in French Polynesia, Puerto Rico and Saint Martin are significantly lower with a range of 5.70–6.89. We also fit the Richards model to Zika case data from six main archipelagos in French Polynesia

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

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

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

  14. A 3D synoptic model of Central America inferred from gravity data interpretation

    NASA Astrophysics Data System (ADS)

    Alvarado, G.; Fairhead, D.; Goetze, H.-J.; Lahrmann, B.; Leandro, G.; Luecke, O.; Schmidt, S.

    2007-12-01

    Large portions of the Central American Isthmus have served as key areas for the collaborative research program (SFB 574) and its goal to understand orogenic processes at convergent margins, such as the volatile and fluid cycle and the relationships between tectonics and magmatism. Gravity data from both on- and offshore has been gathered from various institutions and has been combined in a homogeneous data set. Due to difficult access to the high mountains the coverage by gravity observations remains rather incomplete mainly in the area of southern Costa Rica and eastern Nicaragua. Station complete Bouguer anomalies, Free Air anomalies and isostatic residual anomalies maps were compiled as a result of the homogenization of gravity field data. First analyses of the gravity field using curvature methods helps to separate density provinces in the crust. A comparison with the geological map shows a good correlation with tectonical units in most of the region and provides possibilities for crustal segmentation. Sources of gravity anomalies were investigated by Euler deconvolution and source point clusters in depths of 10 km and 30 km were obtained. For the first time a 3D density model up to the Central American lithosphere has been compiled by combining the results of curvature and Euler analysis with constraining data e.g. geological maps, seismic profiles, earthquake hypocenters and new results from tomographic modeling and receiver function analysis of the seismological task group of the SFB 574. The in-house software package IGMAS was used for modeling visualization of the model structures and gravity effects (e.g. serpentinization of the oceanic lithosphere at the Pacific side); it helps to identify borders between tectonic blocks e.g. the Chortis block in the north or the Chorotega block in the south of the research area. At a more local scale our 3D modeling works hand in hand with a small scale 3D modeling by Lücke and Alvarado and provides insight into the

  15. Cryptic Genetic Diversity within the Anopheles nili group of Malaria Vectors in the Equatorial Forest Area of Cameroon (Central Africa)

    PubMed Central

    Ndo, Cyrille; Simard, Frédéric; Kengne, Pierre; Awono-Ambene, Parfait; Morlais, Isabelle; Sharakhov, Igor; Fontenille, Didier; Antonio-Nkondjio, Christophe

    2013-01-01

    Background The Anopheles nili group of mosquitoes includes important vectors of human malaria in equatorial forest and humid savannah regions of sub-Saharan Africa. However, it remains largely understudied, and data on its populations’ bionomics and genetic structure are crucially lacking. Here, we used a combination of nuclear (i.e. microsatellite and ribosomal DNA) and mitochondrial DNA markers to explore and compare the level of genetic polymorphism and divergence among populations and species of the group in the savannah and forested areas of Cameroon, Central Africa. Principal Findings All the markers provided support for the current classification within the An. nili group. However, they revealed high genetic heterogeneity within An. nili s.s. in deep equatorial forest environment. Nuclear markers showed the species to be composed of five highly divergent genetic lineages that differed by 1.8 to 12.9% of their Internal Transcribed Spacer 2 (ITS2) sequences, implying approximate divergence time of 0.82 to 5.86 million years. However, mitochondrial data only detected three major subdivisions, suggesting different evolutionary histories of the markers. Conclusions/Significance This study enlightened additional cryptic genetic diversity within An. nili s.s. in the deep equatorial forest environment of South Cameroon, reflecting a complex demographic history for this major vector of malaria in this environment. These preliminary results should be complemented by further studies which will shed light on the distribution, epidemiological importance and evolutionary history of this species group in the African rainforest, providing opportunities for in-depth comparative studies of local adaptation and speciation in major African malaria vectors. PMID:23516565

  16. Disjunct distributions of freshwater snails testify to a central role of the Congo system in shaping biogeographical patterns in Africa

    PubMed Central

    2014-01-01

    Background The formation of the East African Rift System has decisively influenced the distribution and evolution of tropical Africa’s biota by altering climate conditions, by creating basins for large long-lived lakes, and by affecting the catchment and drainage directions of river systems. However, it remains unclear how rifting affected the biogeographical patterns of freshwater biota through time on a continental scale, which is further complicated by the scarcity of molecular data from the largest African river system, the Congo. Results We study these biogeographical patterns using a fossil-calibrated multi-locus phylogeny of the gastropod family Viviparidae. This group allows reconstructing drainage patterns exceptionally well because it disperses very poorly in the absence of existing freshwater connections. Our phylogeny covers localities from major drainage basins of tropical Africa and reveals highly disjunct sister-group relationships between (a) the endemic viviparids of Lake Malawi and populations from the Middle Congo as well as between (b) the Victoria region and the Okavango/Upper Zambezi area. Conclusions The current study testifies to repeated disruptions of the distribution of the Viviparidae during the formation of the East African Rift System, and to a central role of the Congo River system for the distribution of the continent’s freshwater fauna during the late Cenozoic. By integrating our results with previous findings on palaeohydrographical connections, we provide a spatially and temporarily explicit model of historical freshwater biogeography in tropical Africa. Finally, we review similarities and differences in patterns of vertebrate and invertebrate dispersal. Amongst others we argue that the closest relatives of present day viviparids in Lake Malawi are living in the Middle Congo River, thus shedding new light on the origin of the endemic fauna of this rift lake. PMID:24597925

  17. First Report of Outbreaks of the Fall Armyworm Spodoptera frugiperda (J E Smith) (Lepidoptera, Noctuidae), a New Alien Invasive Pest in West and Central Africa.

    PubMed

    Goergen, Georg; Kumar, P Lava; Sankung, Sagnia B; Togola, Abou; Tamò, Manuele

    2016-01-01

    The fall armyworm Spodoptera frugiperda is a prime noctuid pest of maize on the American continents where it has remained confined despite occasional interceptions by European quarantine services in recent years. The pest has currently become a new invasive species in West and Central Africa where outbreaks were recorded for the first time in early 2016. The presence of at least two distinct haplotypes within samples collected on maize in Nigeria and São Tomé suggests multiple introductions into the African continent. Implications of this new threat to the maize crop in tropical Africa are briefly discussed.

  18. First Report of Outbreaks of the Fall Armyworm Spodoptera frugiperda (J E Smith) (Lepidoptera, Noctuidae), a New Alien Invasive Pest in West and Central Africa

    PubMed Central

    Sankung, Sagnia B.; Togola, Abou; Tamò, Manuele

    2016-01-01

    The fall armyworm Spodoptera frugiperda is a prime noctuid pest of maize on the American continents where it has remained confined despite occasional interceptions by European quarantine services in recent years. The pest has currently become a new invasive species in West and Central Africa where outbreaks were recorded for the first time in early 2016. The presence of at least two distinct haplotypes within samples collected on maize in Nigeria and São Tomé suggests multiple introductions into the African continent. Implications of this new threat to the maize crop in tropical Africa are briefly discussed. PMID:27788251

  19. Socioeconomic status as a risk factor for HIV infection in women in East, Central and Southern Africa: a systematic review.

    PubMed

    Wojcicki, Janet Maia

    2005-01-01

    This is a critical, systematic review of the relationship between socioeconomic status (SES) and HIV infection in women in Southern, Central and Eastern Africa. In light of the interest in micro-credit programmes and other HIV prevention interventions structured to empower women through increasing women's access to funds and education, this review examines the epidemiological and public health literature, which ascertains the association between low SES using different measurements of SES and risk of HIV infection in women. Also, given the focus on structural violence and poverty as factors driving the HIV epidemic at a structural/ecological level, as advocated by Paul Farmer and others, this study examines the extent to which differences in SES between individuals in areas with generalized poverty affect risk for SES. Out of 71 studies retrieved, 36 studies met the inclusion criteria including 30 cross-sectional, one case-control and five prospective cohort or nested case-control studies. Thirty-five studies used at least one measurement of female's SES and fourteen also included a measurement of partner's SES. Studies used variables measuring educational level, household income and occupation or employment status at the individual and neighbourhood level to ascertain SES. Of the 36 studies, fifteen found no association between SES and HIV infection, twelve found an association between high SES and HIV infection, eight found an association between low SES and HIV infection and one was mixed. In interpreting these results, this review examines the role of potential confounders and effect modifiers such as history of STDs, number of partners, living in urban or rural areas and time and location of study in sub-Saharan Africa. It is argued that STDs and number of partners are on the causal pathway under investigation between HIV and SES and should not be adjusted as confounders in any analysis. In conclusion, it is argued that in low-income sub-Saharan Africans

  20. Debates in the late Quaternary of central southern Africa: climate change, environmental variability or just plain poor data?

    NASA Astrophysics Data System (ADS)

    Thomas, D. S.; Burrough, S. L.

    2012-12-01

    Quaternary palaeoclimatic/environmental analyses in dryland regions are well-known for the limited range of proxy data sets available, resulting in debates about achieving robust reconstructions (e.g. Butzer 1984, Thomas 1986, Maslin and Christiansen 2007). In some regions, e.g. central southern Africa, this has resulted in reliance on geoproxies: the analysis and dating of depositional landforms and associated sediments. Despite significant advances in geoproxy interpretation and chronometric control, their efficacy remains contentious, not least because of apparent temporal contradictions in reconstructions of past drier and past more humid conditions. Consequently their use has been eschewed in favour of spatially extensive extrapolations from higher-resolution, but geographically-distant, data sets (e.g. Chase and Meadows 2008); an approach not without its own limitations (e.g. Gasse et al. 2008, Thomas and Burrough 2012, Thomas et al. 2012), given the variability in modern terrestrial conditions in dryland regions today. It is therefore highly appropriate to revisit the debates of Butzer (1984) and Thomas (1986) regarding data quality and data extrapolation, but to add in the very relevant characteristic of temporal and spatial environmental variability. Environmental and climatic variability at a range of temporal and spatial scales are significant traits of drylands in southern Africa and worldwide, impacting on ecosystem and geomorphic processes, and human behaviour. It can be hypothesised that while environmental variability has been an important trait of Late Quaternary environments and climate in southern Africa. It has rarely been considered as a viable environmental 'state' when proxy records are analysed and integrated, particularly in the case of spatially extensive geoproxies and in contexts where palaeoenvironment and palaeoclimate are used interchangeably. We present examples where debates over the nature of past changes and quality of datasets

  1. On the added value of the regional climate model REMO in the assessment of climate change signal over Central Africa

    NASA Astrophysics Data System (ADS)

    Fotso-Nguemo, Thierry C.; Vondou, Derbetini A.; Pokam, Wilfried M.; Djomou, Zéphirin Yepdo; Diallo, Ismaïla; Haensler, Andreas; Tchotchou, Lucie A. Djiotang; Kamsu-Tamo, Pierre H.; Gaye, Amadou T.; Tchawoua, Clément

    2017-02-01

    In this paper, the regional climate model REMO is used to investigate the added value of downscaling low resolutions global climate models (GCMs) and the climate change projections over Central Africa. REMO was forced by two GCMs (EC-Earth and MPI-ESM), for the period from 1950 to 2100 under the Representative Concentration Pathway 8.5 scenario. The performance of the REMO simulations for current climate is compared first with REMO simulation driven by ERA-Interim reanalysis, then by the corresponding GCMs in order to determine whether REMO outputs are able to effectively lead to added value at local scale. We found that REMO is generally able to better represent some aspects of the rainfall inter-annual variability, the daily rainfall intensity distribution as well as the intra-seasonal variability of the Central African monsoon, though few biases are still evident. It is also found that the boundary conditions strongly influences the spatial distribution of seasonal 2-m temperature and rainfall. From the analysis of the climate change signal from the present period 1976-2005 to the future 2066-2095, we found that all models project a warming at the end of the twenty-first century although the details of the climate change differ between REMO and the driving GCMs, specifically in REMO where we observe a general decrease in rainfall. This rainfall decrease is associated with delayed onset and anticipated recession of the Central African monsoon and a shortening of the rainy season. Small-scales variability of the climate change signal for 2-m temperature are usually smaller than that of the large-scales climate change part. For rainfall however, small-scales induce change of about 70% compared to the present climate statistics.

  2. Estimativas de possiveis recursos de petroleo e gas na America Central e na America do Sul [Estimates of possible petroleum and gas resources in Central American and South America

    USGS Publications Warehouse

    Schenk, C.S.

    2001-01-01

    O U.S. Geological Survey recentemente completou estimativas de possíveis recursos de petróleo e gás em 130 áreas petrolíferas pré-determinadas no mundo (USGS, 2000). Vinte e três destas áreas ficam na América do Sul, na América Central, e no Caribe (fig. 1). Os resultados estão apresentados na tabela 1. Nas 23 áreas, estimamos um total de 105 BBO e um total de 487 TCFG. A região composta de América Central mais América do Sul ficou em terceiro lugar no mundo em termos de possíveis recursos de petróleo e gás. No primeiro lugar ficou o Oriente Médio e no segundo lugar ficou a antiga União Soviética (USGS, 2000). As áreas com maiores probabilidades de encontrar depósitos gigantes de petróleo e gás se localizam nas áreas do Oceano Atlântico começando com a Bacia de Santos no sul até a Bacia Guyana-Suriname no norte. As possibilidades de existirem depósitos gigantes são maiores nas áreas submersas do mar até profundidades de 3,600 m. Diversos depósitos gigantes de petróleo foram descobertos no mar na Bacia de Campos e ainda podem serem encontrados depósitos similares na Bacia de Campos e suas imediações.

  3. Dust storm off Western Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The impacts of Saharan dust storms reach far beyond Africa. Wind-swept deserts spill airborne dust particles out over the Atlantic Ocean where they can enter trade winds bound for Central and North America and the Caribbean. This Moderate Resolution Imaging Spectroradiometer (MODIS) image shows a dust storm casting an opaque cloud of cloud across the Canary Islands and the Atlantic Ocean west of Africa on June 30, 2002. In general it takes between 5 and 7 days for such an event to cross the Atlantic. The dust has been shown to introduce foreign bacteria and fungi that have damaged reef ecosystems and have even been hypothesized as a cause of increasing occurrences of respiratory complaints in places like Florida, where the amount of Saharan dust reaching the state has been increasing over the past 25 years.

  4. Mapping Biomass for REDD in the Largest Forest of Central Africa: the Democratic Republic of Congo

    NASA Astrophysics Data System (ADS)

    Shapiro, Aurelie; Saatchi, Sassan

    2014-05-01

    With the support of the International Climate Initiative (ICI) of the Federal Ministry of the Environment, Conservation, and Nuclear Security, the implementation of the German Development Bank KfW, the World Wide Fund for Nature (WWF) Germany, the University of California Los Angeles (UCLA) and local DRC partners will produce a national scale biomass map for the entire forest coverage of the Democratic Republic of Congo (DRC) along with feasibility assessments of different forest protection measures within a framework of a REDD+ model project. The « Carbon Map and Model (CO2M&M) » project will produce a national forest biomass map for the DRC, which will enable quantitative assessments of carbon stocks and emissions in the largest forest of the Congo Basin. This effort will support the national REDD (Reducing Emissions from Deforestation and Degradation) program in DRC, which plays a major role in sustainable development and poverty alleviation. This map will be developed from field data, complemented by airborne LiDAR (Light Detection and Ranging) and aerial photos, systematically sampled throughout the forests of the DRC and up-scaled to satellite images to accurately estimate carbon content in all forested areas. The second component of the project is to develop specific approaches for model REDD projects in key landscapes. This project represents the largest LiDAR-derived mapping effort in Africa, under unprecedented logistical constraints, which will provide one of the poorest nations in the world with the richest airborne and satellites derived datasets for analyzing forest structure, biomass and biodiversity.

  5. Malaria continues to select for sickle cell trait in Central Africa

    PubMed Central

    Elguero, Eric; Délicat-Loembet, Lucrèce M.; Rougeron, Virginie; Arnathau, Céline; Roche, Benjamin; Becquart, Pierre; Gonzalez, Jean-Paul; Nkoghe, Dieudonné; Sica, Lucas; Leroy, Eric M.; Durand, Patrick; Ayala, Francisco J.; Ollomo, Benjamin; Renaud, François; Prugnolle, Franck

    2015-01-01

    Sickle cell disease (SCD) is a genetic disorder that poses a serious health threat in tropical Africa, which the World Health Organization has declared a public health priority. Its persistence in human populations has been attributed to the resistance it provides to Plasmodium falciparum malaria in its heterozygous state, called sickle cell trait (SCT). Because of migration, SCT is becoming common outside tropical countries: It is now the most important genetic disorder in France, affecting one birth for every 2,400, and one of the most common in the United States. We assess the strength of the association between SCT and malaria, using current data for both SCT and malaria infections. A total of 3,959 blood samples from 195 villages distributed over the entire Republic of Gabon were analyzed. Hemoglobin variants were identified by using HPLCy (HPLC). Infections by three species of Plasmodium were detected by PCR followed by sequencing of a 201-bp fragment of cytochrome b. An increase of 10% in P. falciparum malaria prevalence is associated with an increase by 4.3% of SCT carriers. An increase of 10 y of age is associated with an increase by 5.5% of SCT carriers. Sex is not associated with SCT. These strong associations show that malaria remains a selective factor in current human populations, despite the progress of medicine and the actions undertaken to fight this disease. Our results provide evidence that evolution is still present in humans, although this is sometimes questioned by scientific, political, or religious personalities. PMID:25941403

  6. Phylogeography, Risk Factors and Genetic History of Hepatitis C Virus in Gabon, Central Africa

    PubMed Central

    Besson, Guillaume; Ndong-Atome, Guy-Roger; Makuwa, Maria; Pouillot, Régis; Nkoghé, Dieudonné; Leroy, Eric; Kazanji, Mirdad

    2012-01-01

    Background The epidemiological and molecular characteristics of hepatitis C virus (HCV) infection in the general population have been poorly investigated in Africa. The aim of this study was to determine the prevalence, genotype distribution and epidemic history of HCV in the Gabonese general population. Methods/Principal Findings A total of 4042 sera collected from adults in 220 villages in all nine administrative areas of the country were screened for antibodies to HCV. HCV NS5B region sequencing was performed for molecular characterization and population genetic analyses. Of 4042 tested sera, 455 (11.2%) were positive. The seroprevalence of HCV varied significantly by administrative area, with the highest rate in Ogooué-Lolo province (20.4%) and the lowest in Ogooué-Maritine province (3.7%). History of parenteral injections, past hospital admission and age over 55 years were independent risk factors for HCV infection (p<0.0001). Phylogenetic analyses showed that 91.9% of the strains were genotype 4 (HCV-4), 5.7% genotype 1 and 2.2% genotype 2. HCV-4 strains were highly heterogeneous, with more than eight subtypes; subtype 4e predominated (57.3%). Coalescence analyses indicated that subtype 4e was the oldest, with an estimated most recent common ancestor of 1702 [95% CI, 1418–1884]. The epidemic profile indicated that it spread exponentially during the first part of the 20th century, probably by iatrogenic transmission. Conclusions/Significance These results confirm the endemicity of HCV subtype 4e in Gabon and show that its spread is due to a cohort effect, with previous, possibly iatrogenic events. More extensive epidemiological studies are needed to better characterize the route of transmission and the dissemination of HCV in Gabon. PMID:22870274

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

    SciTech Connect

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

    1985-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Alvarado, Guillermo E.; Soto, Gerardo J.

    2008-10-01

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

  9. North America - Caribbean plate motion as constrained by provenance of Eocene beds in Central Guatemala

    NASA Astrophysics Data System (ADS)

    Martens, U.; Gutierrez, A.

    2009-12-01

    The continental Subinal Formation of Central Guatemala is composed of red conglomerates and sandstones that outcrop along the Motagua Valley. The geographic distribution of the Subinal basin is elongate and constrained by the faults of the Motagua system. This suggests the basin developed as a trans-extensional feature associated with strike-slip tectonics at the Caribbean-North American plate boundary. Stratigraphic position of the Subinal implies a post-Cretaceous depositional age, possibly Eocene. This chronologic constraint is supported by detrital zircon geochronology by the LA-ICPMS U-Pb method. The presence of eclogite in conglomerate indicates that HP belts of the Guatemala Suture Complex were already exposed at that time. The study of pebbles in conglomerate indicates that the relative abundance of some clast groups correlates with the rock units exposed north, across the San Agustín fault. This implies provenance from the North American plate and minor motion along this fault. We hypothesize that the Subinal basin was formed as an onland response to the opening of the coveal Cayman Trough.

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

    SciTech Connect

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

    1987-09-01

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

  11. Evaluation of historical and future simulations of precipitation and temperature in central Africa from CMIP5 climate models

    NASA Astrophysics Data System (ADS)

    Aloysius, Noel R.; Sheffield, Justin; Saiers, James E.; Li, Haibin; Wood, Eric F.

    2016-01-01

    Global and regional climate change assessments rely heavily on the general circulation model (GCM) outputs such as provided by the Coupled Model Intercomparison Project phase 5 (CMIP5). Here we evaluate the ability of 25 CMIP5 GCMs to simulate historical precipitation and temperature over central Africa and assess their future projections in the context of historical performance and intermodel and future emission scenario uncertainties. We then apply a statistical bias correction technique to the monthly climate fields and develop monthly downscaled fields for the period of 1948-2099. The bias-corrected and downscaled data set is constructed by combining a suite of global observation and reanalysis-based data sets, with the monthly GCM outputs for the 20th century, and 21st century projections for the medium mitigation (representative concentration pathway (RCP)45) and high emission (RCP85) scenarios. Overall, the CMIP5 models simulate temperature better than precipitation, but substantial spatial heterogeneity exists. Many models show limited skill in simulating the seasonality, spatial patterns, and magnitude of precipitation. Temperature projections by the end of the 21st century (2070-2099) show a robust warming between 2 and 4°C across models, whereas precipitation projections vary across models in the sign and magnitude of change (-9% to 27%). Projected increase in precipitation for a subset of models (single model ensemble (SME)) identified based on performance metrics and causal mechanisms are slightly higher compared to the full multimodel ensemble (MME) mean; however, temperature projections are similar between the two ensemble means. For the near-term (2021-2050), neither the historical performance nor choice of models is related to the precipitation projections, indicating that natural variability dominated any signal. With fewer models, the "blind" MME approach will have larger uncertainties in future precipitation projections compared to projections

  12. Medicinal plants use in central Togo (Africa) with an emphasis on the timing

    PubMed Central

    Tchacondo, Tchadjobo; Karou, Simplice D.; Agban, Amégninou; Bako, Mamouda; Batawila, Komlan; Bawa, Moctar L.; Gbeassor, Mensavi; de Souza, Comlan

    2012-01-01

    Background: Plant-based remedies continue to play a key role in the health care of people in Togo; however, there is a lack of published data in medicinal plants and medical practices of the people in the country. Objective: This study was aimed at documenting the plant utilization in the Tem folk medicine in the central region of Togo. Materials and Methods: An ethnobotanical survey was conducted with traditional healers in the central region of Togo using a semi-structured questionnaire. Results: This study demonstrated that local specialists in the central region of Togo tend to agree with each other in terms of the plants used to treat diabetes (ICF = 0.38), infertility, and abdominal pains (ICF = 0.33), but cite a much more diverse groups of plants to treat problems related to arterial hypertension, sickle cell disease, and abscess. They use 144 herbal concoctions made of 72 plants, distributed among 36 botanical families. The Euphorbiaceae family with eight species was best represented in terms of the number of species. The species with the highest use value were Khaya senegalensis (Desr.) A. Juss. (Meliaceae) (UV = 0.36), Anthocleista djalonensis A. Chev. (Gentianaceae) (UV = 0.27), Trichilia emetica Vahl (Meliaceae) (UV = 0.25), and Sarcocephalus latifolius (Sm.) E. A. Bruce (Rubiaceae) (UV = 0.21). They also rely on the timing in the plant processing and the administration of herbal remedies. Conclusion: All these findings are based on empirical observations; laboratory screenings are needed to check the effectiveness of these plants. PMID:22518081

  13. [A French soldier returns from the Central Africa Republic with hepatitis A: Vaccination failure is possible!].

    PubMed

    Ficko, C; Conan, P L; Bigaillon, C; Duron, S; Rapp, C

    2015-01-01

    In stays in tropical countries, the French military, and travelers in general, are exposed to diseases transmitted by the fecal-oral route, some of which are vaccine-preventable. Here we report a 42-yer-old soldier with hepatitis A, which first appeared on his return from a military operation in the Central African Republic. Despite its excellent immunogenicity and a duration of seroprotection extending beyond 20 years in the vast majority of cases, the hepatitis A vaccine can fail. This reminds us of the importance of combining vaccine and non-vaccine prevention in tropical countries, especially in precarious living conditions.

  14. Cancer in HIV-infected Persons from the Caribbean, Central and South America

    PubMed Central

    Fink, Valeria I.; Shepherd, Bryan E.; Cesar, Carina; Krolewiecki, Alejandro; Wehbe, Firas; Cortés, Claudia P.; Crabtree-Ramírez, Brenda; Padgett, Denis; Shafaee, Maryam; Schechter, Mauro; Gotuzzo, Eduardo; Bacon, Melanie; McGowan, Catherine; Cahn, Pedro; Masys, Daniel

    2011-01-01

    Background HIV infected individuals have heightened cancer risk. With the advent of HAART, the frequency of some AIDS defining cancers (ADC) has decreased while certain non-AIDS defining cancers (NADC) are becoming more frequent. Cancers among HIV-infected individuals in Latin American and the Caribbean have not yet been carefully studied. Methods Cancer cases among the Caribbean, Central and South American network for HIV Research (CCASAnet) cohort were identified reviewing clinical records and preexisting databases. Results There were 406 cancers reported: 331 ADC (224 Kaposi´s sarcomas and 98 non Hodgkin lymphomas). Most frequent NADC (n=75) were Hodgkin lymphoma and skin cancers. Seventy-three percent of NADC and 45% of ADC were diagnosed >1 year after HIV diagnosis. 56% of ADC occurred before HAART start. Median time from HAART start until cancer diagnosis was 2.5 years for NADC and 0.5 years for ADC (p=<0.001). Within 3372 HAART starters, 158 were diagnosed with 165 cancers (82.4% ADC); 85 cases were previous to or concomitant with HAART initiation. Incidence of cancer after HAART initiation in 8080 person-years of follow-up was 7.2 per 1000 person-years (95%CI= 5.5–9.3) for ADC and 2.7 (95%CI= 1.8–4.1) for NADC; incidence was higher in the first two months, particularly for ADC (47.6). A pre-HAART ADC was a predictor of mortality after adjusting for age, sex, and CD4 at HAART initiation. Conclusions ADC were the most frequent cancers in this region and were often diagnosed close to HIV diagnosis and HAART start. Incidence of cancer was highest around HAART initiation. PMID:21239992

  15. 21st century projections of snowfall and winter severity across central-eastern North America

    NASA Astrophysics Data System (ADS)

    Notaro, M.; Lorenz, D. J.; Hoving, C.; Schummer, M.

    2014-12-01

    Statistically downscaled climate projections from nine global climate models (GCMs) are used to force a snow accumulation and ablation model (SNOW-17) across the central-eastern North American Landscape Conservation Cooperatives (LCCs) to develop high-resolution projections of snowfall, snow depth, and winter severity index (WSI) by the mid- and late 21st century. Here, we use projections of a cumulative WSI (CWSI) known to influence autumn-winter waterfowl migration to demonstrate the utility of SNOW-17 results. The application of statistically downscaled climate data and a snow model leads to a better representation of lake processes in the Great Lakes Basin, topographic effects in the Appalachian Mountains, and spatial patterns of climatological snowfall, compared to the original GCMs. Annual mean snowfall is simulated to decline across the region, particularly in early winter (December-January), leading to a delay in the mean onset of the snow season. Due to a warming-induced acceleration of snowmelt, the percentage loss in snow depth exceeds that of snowfall. Across the Plains and Prairie Potholes LCC and Upper Midwest and Great Lakes LCC, daily snowfall events are projected to become less common, but more intense. The greatest reductions in the number of days per year with a present snowpack are expected close to the historical position of the -5°C isotherm in DJFM, around 44°N. The CWSI is projected to decline substantially during December-January, leading to increased likelihood of delays in timing and intensity of autumn-winter waterfowl migrations.

  16. Ecological consequences of hydropower development in Central America: Impacts of small dams and water diversion on neotropical stream fish assemblages

    USGS Publications Warehouse

    Anderson, Elizabeth P.; Freeman, Mary C.; Pringle, C.M.

    2006-01-01

    Small dams for hydropower have caused widespread alteration of Central American rivers, yet much of recent development has gone undocumented by scientists and conservationists. We examined the ecological effects of a small hydropower plant (Dona Julia Hydroelectric Center) on two low-order streams (the Puerto Viejo River and Quebradon stream) draining a mountainous area of Costa Rica. Operation of the Dona Julia plant has dewatered these streams, reducing discharge to ~ 10% of average annual flow. This study compared fish assemblage composition and aquatic habitat upstream and downstream of diversion dams on two streams and along a ~ 4 km dewatered reach of the Puerto Viejo River in an attempt to evaluate current instream flow recommendations for regulated Costa Rican streams. Our results indicated that fish assemblages directly upstream and downstream of the dam on the third order Puerto Viejo River were dissimilar, suggesting that the small dam (< 15 in high) hindered movement of fishes. Along the ~ 4 km dewatered reach of the Puerto Viejo River, species count increased with downstream distance from the dam. However, estimated species richness and overall fish abundance were not significantly correlated with downstream distance from the dam. Our results suggested that effects of stream dewatering may be most pronounced for a subset of species with more complex reproductive requirements, classified as equilibrium-type species based on their life-history. In the absence of changes to current operations, we expect that fish assemblages in the Puerto Viejo River will be increasingly dominated by opportunistic-type, colonizing fish species. Operations of many other small hydropower plants in Costa Rica and other parts of Central America mirror those of Doha Julia; the methods and results of this study may be applicable to some of those projects.

  17. Biting patterns and seasonal densities of Anopheles mosquitoes in the Cayo District, Belize, Central America with emphasis on Anopheles darlingi.

    PubMed

    Achee, Nicole L; Grieco, John P; Rejmankova, Eliska; Andre, Richard G; Vanzie, Errol; Polanco, Jorge; Briceno, Ireneo; King, Russell; Roberts, Donald R

    2006-06-01

    The present study utilized an experimental hut to conduct human-baited landing collections for characterizing the all-night biting patterns and seasonal densities of adult Anopheles darlingi in the centrally located Cayo District of Belize, Central America. A total of 25 all-night collections (i.e., sunset to sunrise) were conducted from January 2002 to May 2003, capturing a total of 18,878 An. darlingi females. Anopheles darlingi exhibited a bimodal nightly biting pattern with one predominate peak occurring three h after sunset and a smaller peak occurring one h prior to sunrise. Biting females were collected throughout the night in higher densities indoors (9,611) than outside (9,267) the experimental hut (O:I=1.00:1.04). Seasonal adult collections show An. darlingi densities were highest during the transitional months between the end of the wet and beginning of the dry season (January) and the end of the dry season and beginning of the wet season (May). A total of 2,010 An. darlingi females was captured in 31 two-h, human-baited landing collections performed from January to October 2002. Anopheles darlingi monthly population densities were found to have no significant associations with high or low temperatures, precipitation, or river level. However, qualitative data examination indicates an inverse relationship between river level and An. darlingi adult collections suggesting a disturbance of larval habitats. All-night biting and seasonal distribution patterns for other anopheline species are also described. None of the adult specimens collected throughout the entire study tested positive for Plasmodium spp. infection using the VecTest rapid diagnostic kit.

  18. Holocene Millennial Time Scale Hydrological Changes In Central-east Africa

    NASA Astrophysics Data System (ADS)

    Jolly, D.; Bonnefille, R.; Beaufort, L.

    The Holocene hydrological changes of a tropical swamp is reconstructed using a high resolution pollen record (ca 50 yrs) from the Kuruyange valley (Burundi, Africa, 3°35'S, 29°41'E), at 2000 m elevation. The sequence was dated by 10 radiocarbon dates, allowing reconstruction between ca 12 500 and 1000 cal yr B.P. In the Kuruyange swamp, peat accumulated rapidly at a sedimentation rate varying from 0.73 (prior to 6200 cal yr B.P.) to 1.51 mm/yr (during the late Holocene). A pollen index of water table, based on a ratio of aquatic versus non-aquatic plants has been used in order to test the hypothesis of hydrological constraints on the swampy ecosystem. Eight arid phases are evidenced by the index minima at 12 200, 11 200, 9900, 8600, 6500, 5000, 3400, 1600 cal yr B.P. The good agreement existing between this index and independent data such as (i) low-resolution East-African lake level reconstruct ions (Gillespie et al., 1983) and (ii) ?18O analyses from Arabian Sea (Sirocko et al., 1993) suggests the water table level responds to the monsoon dynamic. The Index varies periodically with a combination of 1/1515, 1/880 and 1/431 years-1 frequencies, revealed by time series analyses (Blackman-Tukey and Maximum Entropy). The extrapolation of the composite curve based on these 3 periodicities show that two major climatic events defined in the high latitudes between 1000 and 660 cal yr B.P. (Medieval Warm Period) and between 500 and 100 cal yr B.P. (Little Ice Age) are recorded in our data and show respectively high and low stands of the water table. Our results support some previous pollen-derived climate estimates in Ethiopia done by Bonnefille and Umer (1994). Moreover, the "1500 year" cycle registered in our data from the tropics, already evidenced in higher latitudes (Wijmstra et al., 1984; Bondet al., 1997; Schulz et al., 1999; Bond et al., 2001) support the hypothesis of strong teleconnections between tropical/subtropical and polar climates during the deglaciation

  19. Disappearing in the Night: An Overview on Trade and Legislation of Night Monkeys in South and Central America.

    PubMed

    Svensson, Magdalena S; Shanee, Sam; Shanee, Noga; Bannister, Flavia B; Cervera, Laura; Donati, Giuseppe; Huck, Maren; Jerusalinsky, Leandro; Juarez, Cecilia P; Maldonado, Angela M; Martinez Mollinedo, Jesus; Méndez-Carvajal, Pedro G; Molina Argandoña, Miguel A; Mollo Vino, Antonietta D; Nekaris, K A I; Peck, Mika; Rey-Goyeneche, Jennifer; Spaan, Denise; Nijman, Vincent

    2016-01-01

    The international trade in night monkeys (Aotus spp.), found throughout Central and South America, has been regulated by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) since 1975. We present a quantitative analysis of this trade from all 9 range countries, over 4 decades, and compare domestic legislation to CITES regulations. Night monkeys were exported from 8 of the 9 habitat countries, totalling 5,968 live individuals and 7,098 specimens, with trade of live individuals declining over time. In terms of species, the most commonly traded was Aotus nancymaae (present in Brazil, Colombia, Peru) followed by A. vociferans (Brazil, Colombia, Ecuador, Peru) and A. zonalis (Colombia, Panama). There was no significant correlation between levels of trade and species' geographic range size or the number of countries in which a species occurs. Five countries have legislation that meets CITES requirements for implementation, whereas the other 4 countries' legislation showed deficiencies. Research conducted in Colombia, Peru, and Brazil suggests significant cross-border trade not captured in official international trade registers. Although international trade has diminished, current trends suggest that populations of rarer species may be under unsustainable pressure. Further research is needed to quantify real trade numbers occurring between habitat countries.

  20. Impact of population expansion on genetic diversity and structure of river otters (Lontra canadensis) in Central North America.

    PubMed

    Brandt, Jessica R; Brandt, Adam L; Ammer, Frank K; Roca, Alfred L; Serfass, Thomas L

    2014-01-01

    Populations of North American river otters (Lontra canadensis) declined throughout large portions of the continent during the early 1900s due to habitat degradation and unregulated trapping. River otters had been extirpated in North Dakota (ND), but the Red River Valley has since been recolonized, with potential source populations including the neighboring states of Minnesota or South Dakota, or the Canadian province of Manitoba (MB). We genotyped 9 microsatellite loci in 121 samples to determine the source population of river otters in the Red River Valley of ND, as well as to assess population structure and diversity of river otters in central North America. Overall, genetic diversity was high, with an average observed heterozygosity of 0.58. Genetic differentiation was low (F ST < 0.05) between river otters in ND and those of Minnesota, suggesting that eastern ND was recolonized by river otters from Minnesota. River otters from MB were genetically distinct from all other sampled populations. Low genetic differentiation (F ST = 0.044) between South Dakota and Louisiana (LA) suggested that reintroductions using LA stock were successful. The genetic distinctiveness of river otters from different geographic regions should be considered when deciding on source populations for future translocations.

  1. Migrants and asylum seekers: policy responses in the United States to immigrants and refugees from Central America and the Caribbean.

    PubMed

    Mcbride, M J

    1999-01-01

    This article analyzes the complex political environment of US immigration and refugee policies in which tensions exist, especially with regard to Central America and the Caribbean. Recommendations for managing it more effectively in the future are discussed. Several western countries, including the US, have implemented stricter restriction policies as a result of the perceived threats to their economies and cultural homogeneity. In general, US immigration policy has addressed both economic concerns and domestic pressures, whereas US refugee policy h