WorldWideScience

Sample records for mercury-exposed amazonian children

  1. Qualitative assessment of visuospatial errors in mercury-exposed Amazonian children

    DEFF Research Database (Denmark)

    Chevrier, Cécile; Sullivan, Kimberly; White, Roberta F.

    2009-01-01

    In order to better define the effects of methylmercury (MeHg) exposure on neurodevelopment, qualitative error types observed in the responses of exposed children to the Stanford-Binet Copying Test were categorized and quantified using raw data from two studies of 395 Amazonian children aged 7...... mechanisms of observed effects based on convergent evidence of MeHg-related qualitative outcomes in the two studies and (2) to explore possible cultural determinants of test response based on divergent outcomes in the two countries. Multiple linear and logistic regression analyses were performed....../g; this effect appeared to be stronger in the younger children. Risk of committing one or more errors of rotation, simplification or perseveration in the drawings increased with hair-mercury concentration in both cultural settings, providing convergent evidence of specific types of MeHg-related neurocognitive...

  2. Underlying factors associated with anemia in Amazonian children: a population-based, cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Marly A Cardoso

    Full Text Available BACKGROUND: Although iron deficiency is considered to be the main cause of anemia in children worldwide, other contributors to childhood anemia remain little studied in developing countries. We estimated the relative contributions of different factors to anemia in a population-based, cross-sectional survey. METHODOLOGY: We obtained venous blood samples from 1111 children aged 6 months to 10 years living in the frontier town of Acrelândia, northwest Brazil, to estimate the prevalence of anemia and iron deficiency by measuring hemoglobin, erythrocyte indices, ferritin, soluble transferrin receptor, and C-reactive protein concentrations. Children were simultaneously screened for vitamin A, vitamin B(12, and folate deficiencies; intestinal parasite infections; glucose-6-phosphate dehydrogenase deficiency; and sickle cell trait carriage. Multiple Poisson regression and adjusted prevalence ratios (aPR were used to describe associations between anemia and the independent variables. PRINCIPAL FINDINGS: The prevalence of anemia, iron deficiency, and iron-deficiency anemia were 13.6%, 45.4%, and 10.3%, respectively. Children whose families were in the highest income quartile, compared with the lowest, had a lower risk of anemia (aPR, 0.60; 95%CI, 0.37-0.98. Child age (2 pregnancies, 2.01; 1.40-2.87 were positively associated with anemia. Other associated correlates were iron deficiency (2.1; 1.4-3.0, vitamin B(12 (1.4; 1.0-2.2, and folate (2.0; 1.3-3.1 deficiencies, and C-reactive protein concentrations (>5 mg/L, 1.5; 1.1-2.2. CONCLUSIONS: Addressing morbidities and multiple nutritional deficiencies in children and mothers and improving the purchasing power of poorer families are potentially important interventions to reduce the burden of anemia.

  3. Eficácia da vacina Sabin em crianças subnutridas da Amazônia The efficacy of oral polio vaccine in malnourished Amazonian children

    Directory of Open Access Journals (Sweden)

    Klaus E. Stewien

    1985-02-01

    Full Text Available A eficácia da vacina Sabin foi determinada em 106 crianças normais e subnutridas da Amazônia, após a administração de uma e duas doses de vacina oral (trivalente. Após a aplicação de uma dose de vacina, verificou-se que apenas 9% das crianças com subnutrição pregressa (crônica e 43% das crianças normais formaram anticorpos neutralizantes (protetores contra dois ou três tipos de poliovírus (p = 0,04. Após duas doses de vacina, os níveis de imunidade dos dois grupos de crianças estudadas acusaram, respectivamente, 32% e 75% (p = 0,001. Estes resultados mostram que a resposta imunitária à vacina Sabin foi sensivelmente inferior no grupo das crianças subnutridas, do que no das crianças normais. Em decorrência disto, será necessário administrar um número maior de doses de vacina oral àquelas crianças, a fim de que níveis satisfatórios de imunidade contra a poliomielite sejam atingidos em toda a população infantil.Various hypotheses have been proposed to explain the diminished efficacy of the oral polio vaccine in underdeveloped tropical regions. In this study, the influence of mild to moderate chronic malnutrition on the development of antibodies to the 3 types of polioviruses was investigated in Brazilian Amazonian children. Vaccines were administered to 106 normal and stunted children, between 5 to 14 months of age, who were not suffering from acute malnutrition (wasting, in poor peri-urban slum areas of Manaus (AM and São Luis (MA during the National Poliomyelitis Vaccination Campaigns of 1981 and 1982. Two weeks after vaccination, blood was collected by digital puncture and the prevalence of neutralizing antibodies for the 3 types of polioviruses was determined in serum at a dilution of 1:8. In children who had received one dose of the vaccine, 43% of normal children had antibodies to 2 or 3 types of polioviruses, against only 9% of stunted children (p = .04. In children who had received 2 doses of vaccine, 75

  4. Amazonian foods and implications for human biology.

    Science.gov (United States)

    Dufour, Darna L; Piperata, Barbara A; Murrieta, Rui S S; Wilson, Warren M; Williams, Drake D

    2016-07-01

    Diets of subsistence-based Amazonian populations have been linked to local resources, but are changing with market penetration. To review the available data on traditional Amazonian foods and diets and evaluate their implications for human biology as a step toward understanding nutrition transitions in the region. This study used the Human Relations Area Files for information on the diets of Amerindian groups in the Amazon Basin from 1950 to the present, and used other published sources and the authors' own data. Data on food use was identified for only nine groups and dietary intake data for individuals in only three of the groups. A diet based on starchy staples (manioc and plantains) and fish, supplemented with a limited variety of other plant and animal foods, was found. Bitter manioc-based foods were associated with the consumption of cyanogens and fish with the consumption of mercury. Diets of adults appear to be adequate in energy and protein and low in fats. Children's diets were not well documented. Based on the limited available data, Amazonian diets are restricted in variety, but appear to be adequate in energy and protein for adults, but likely insufficiently nutrient-dense for children.

  5. How People Domesticated Amazonian Forests

    Directory of Open Access Journals (Sweden)

    Carolina Levis

    2018-01-01

    Full Text Available For millennia, Amazonian peoples have managed forest resources, modifying the natural environment in subtle and persistent ways. Legacies of past human occupation are striking near archaeological sites, yet we still lack a clear picture of how human management practices resulted in the domestication of Amazonian forests. The general view is that domesticated forests are recognizable by the presence of forest patches dominated by one or a few useful species favored by long-term human activities. Here, we used three complementary approaches to understand the long-term domestication of Amazonian forests. First, we compiled information from the literature about how indigenous and traditional Amazonian peoples manage forest resources to promote useful plant species that are mainly used as food resources. Then, we developed an interdisciplinary conceptual model of how interactions between these management practices across space and time may form domesticated forests. Finally, we collected field data from 30 contemporary villages located on and near archaeological sites, along four major Amazonian rivers, to compare with the management practices synthesized in our conceptual model. We identified eight distinct categories of management practices that contribute to form forest patches of useful plants: (1 removal of non-useful plants, (2 protection of useful plants, (3 attraction of non-human animal dispersers, (4 transportation of useful plants, (5 selection of phenotypes, (6 fire management, (7 planting of useful plants, and (8 soil improvement. Our conceptual model, when ethnographically projected into the past, reveals how the interaction of these multiple management practices interferes with natural ecological processes, resulting in the domestication of Amazonian forest patches dominated by useful species. Our model suggests that management practices became more frequent as human population increased during the Holocene. In the field, we found that

  6. Novel biomarkers of mercury-induced autoimmune dysfunction: a Cross-sectional study in Amazonian Brazil

    Science.gov (United States)

    Motts, Jonathan A.; Shirley, Devon L.; Silbergeld, Ellen K.; Nyland, Jennifer F.

    2014-01-01

    Mercury is an ubiquitous environmental contaminant, causing both neurotoxicity and immunotoxicity. Given its ability to amalgamate gold, mercury is frequently used in small-scale artisanal gold mining. We have previously reported that elevated serum titers of antinuclear autoantibodies (ANA) are associated with mercury exposures of miners in gold mining. The goal of this project was to identify novel serum biomarkers of mercury-induced immunotoxicity and autoimmune dysregulation. We conducted an analysis of serum samples from a cross-sectional epidemiological study on miners working in Amazonian Brazil. In proteomic screening analyses, samples were stratified based on mercury concentrations and ANA titer and a subset of serum samples (N=12) were profiled using Immune Response Biomarker Profiling ProtoArray protein microarray for elevated autoantibodies. Of the up-regulated autoantibodies in the mercury-exposed cohort, potential target autoantibodies were selected based on relevance to pro-inflammatory and macrophage activation pathways. ELISAs were developed to test the entire sample cohort (N=371) for serum titers to the highest of these autoantibodies (anti-glutathione S-transferase alpha, GSTA1) identified in the high mercury/high ANA group. We found positive associations between elevated mercury exposure and up-regulated serum titers of 3760 autoantibodies as identified by ProtoArray. Autoantibodies identified as potential novel biomarkers of mercury-induced immunotoxicity include antibodies to the following proteins: GSTA1, tumor necrosis factor ligand superfamily member 13, linker for activation of T cells, signal peptide peptidase like 2B, stimulated by retinoic acid 13, and interferon induced transmembrane protein. ELISA analyses confirmed that mercury-exposed gold miners had significantly higher serum titers of anti-GSTA1 autoantibody [unadjusted odds ratio = 89.6; 95% confidence interval: 27.2, 294.6] compared to emerald miners (referent population

  7. Tree species richness of upper Amazonian forests

    OpenAIRE

    Gentry, Alwyn H.

    1988-01-01

    Upper Amazonian data for tree species richness in 1-hectare plots are reported. All plants ≥10 cm diameter were censused and identified in six plots in Amazonian Peru and one on the Venezuela-Brazil border. The two plots from the everwet forests near Iquitos, Peru, are the most species-rich in the world, with ≈300 species ≥10 cm diameter in single hectares; all of the Peruvian plots are among the most species-rich ever reported. Contrary to accepted opinion, upper Amazonian forest, and perhap...

  8. Determinants of linear growth from infancy to school-aged years: a population-based follow-up study in urban Amazonian children

    Directory of Open Access Journals (Sweden)

    Lourenço Barbara H

    2012-06-01

    Full Text Available Abstract Background Although linear growth during childhood may be affected by early-life exposures, few studies have examined whether the effects of these exposures linger on during school age, particularly in low- and middle-income countries. Methods We conducted a population-based longitudinal study of 256 children living in the Brazilian Amazon, aged 0.1 y to 5.5 y in 2003. Data regarding socioeconomic and maternal characteristics, infant feeding practices, morbidities, and birth weight and length were collected at baseline of the study (2003. Child body length/height was measured at baseline and at follow-up visits (in 2007 and 2009. Restricted cubic splines were used to construct average height-for-age Z score (HAZ growth curves, yielding estimated HAZ differences among exposure categories at ages 0.5 y, 1 y, 2 y, 5 y, 7 y, and 10 y. Results At baseline, median age was 2.6 y (interquartile range, 1.4 y–3.8 y, and mean HAZ was −0.53 (standard deviation, 1.15; 10.2% of children were stunted. In multivariable analysis, children in households above the household wealth index median were 0.30 Z taller at age 5 y (P = 0.017, and children whose families owned land were 0.34 Z taller by age 10 y (P = 0.023, when compared with poorer children. Mothers in the highest tertile for height had children whose HAZ were significantly higher compared with those of children from mothers in the lowest height tertile at all ages. Birth weight and length were positively related to linear growth throughout childhood; by age 10 y, children weighing >3500 g at birth were 0.31 Z taller than those weighing 2501 g to 3500 g (P = 0.022 at birth, and children measuring ≥51 cm at birth were 0.51 Z taller than those measuring ≤48 cm (P = 0.005. Conclusions Results suggest socioeconomic background is a potentially modifiable predictor of linear growth during the school-aged years. Maternal height and child’s anthropometric characteristics at

  9. Immune function in Amazonian horticulturalists.

    Science.gov (United States)

    Blackwell, Aaron D; Trumble, Benjamin C; Maldonado Suarez, Ivan; Stieglitz, Jonathan; Beheim, Bret; Snodgrass, J Josh; Kaplan, Hillard; Gurven, Michael

    2016-07-01

    Amazonian populations are exposed to diverse parasites and pathogens, including protozoal, bacterial, fungal and helminthic infections. Yet much knowledge of the immune system is based on industrialised populations where these infections are relatively rare. This study examines distributions and age-related differences in 22 measures of immune function for Bolivian forager-horticulturalists and US and European populations. Subjects were 6338 Tsimane aged 0-90 years. Blood samples collected between 2004-2014 were analysed for 5-part blood differentials, C-reactive protein, erythrocyte sedimentation rate (ESR) and total immunoglobulins E, G, A and M. Flow cytometry was used to quantify naïve and non-naïve CD4 and CD8 T cells, natural killer cells, and B cells. Compared to reference populations, Tsimane have elevated levels of most immunological parameters, particularly immunoglobulins, eosinophils, ESR, B cells, and natural killer cells. However, monocytes and basophils are reduced and naïve CD4 cells depleted in older age groups. Tsimane ecology leads to lymphocyte repertoires and immunoglobulin profiles that differ from those observed in industrialised populations. These differences have consequences for disease susceptibility and co-vary with patterns of other life history traits, such as growth and reproduction.

  10. Litter mercury deposition in the Amazonian rainforest

    International Nuclear Information System (INIS)

    Fostier, Anne Hélène; Melendez-Perez, José Javier; Richter, Larissa

    2015-01-01

    The objective of this work was to assess the flux of atmospheric mercury transferred to the soil of the Amazonian rainforest by litterfall. Calculations were based on a large survey of published and unpublished data on litterfall and Hg concentrations in litterfall samples from the Amazonian region. Litterfall based on 65 sites located in the Amazon rainforest averaged 8.15 ± 2.25 Mg ha −1  y −1 . Average Hg concentrations were calculated from nine datasets for fresh tree leaves and ten datasets for litter, and a median concentration of 60.5 ng Hg g −1 was considered for Hg deposition in litterfall, which averaged 49 ± 14 μg m −2  yr −1 . This value was used to estimate that in the Amazonian rainforest, litterfall would be responsible for the annual removing of 268 ± 77 Mg of Hg, approximately 8% of the total atmospheric Hg deposition to land. The impact of the Amazon deforestation on the Hg biogeochemical cycle is also discussed. - Highlights: • Based on published data we estimated the litterfall in the Amazonian rainforest. • All the published data on Hg concentration in leaves and litter from the region and some unpublished data are presented. • We calculated the litter mercury deposition. • We estimated the contribution of dry, wet and litter Hg deposition in the Amazonian rainforest. • We also discussed the impact of Amazon deforestation on the Hg biogeochemical cycle. - The Amazonian rainforest is responsible for removing at least 268 Mg Hg y −1 , 8% of the total atmospheric mercury deposition to land.

  11. Resilience of Amazonian landscapes to agricultural intensification

    NARCIS (Netherlands)

    Jakovac, C.C.

    2015-01-01

    ISBN: 978-94-6257-443-4 Author: Catarina C. Jakovac Title: Resilience of Amazonian landscapes to agricultural intensification Swidden cultivation is the traditional agricultural system in riverine Amazonia, which supports local livelihoods and

  12. The Tsimane' Amazonian Panel Study (TAPS): Nine years (2002-2010) of annual data available to the public.

    Science.gov (United States)

    Leonard, William R; Reyes-García, Victoria; Tanner, Susan; Rosinger, Asher; Schultz, Alan; Vadez, Vincent; Zhang, Rebecca; Godoy, Ricardo

    2015-12-01

    This brief communication contains a description of the 2002-2010 annual panel collected by the Tsimane' Amazonian Panel Study team. The study took place among the Tsimane', a native Amazonian society of forager-horticulturalists. The team tracked a wide range of socio-economic and anthropometric variables from all residents (633 adults ≥16 years; 820 children) in 13 villages along the Maniqui River, Department of Beni. The panel is ideally suited to examine how market exposure and modernization affect the well-being of a highly autarkic population and to examine human growth in a non-Western rural setting. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Pre-LBA Amazonian Region Micrometeorological Experiment (ARME) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — The Amazonian Region Micrometeorological Experiment (ARME) data contain micrometeorological data (climate, interception of precipitation, mircometeorology and soil...

  14. Litter mercury deposition in the Amazonian rainforest.

    Science.gov (United States)

    Fostier, Anne Hélène; Melendez-Perez, José Javier; Richter, Larissa

    2015-11-01

    The objective of this work was to assess the flux of atmospheric mercury transferred to the soil of the Amazonian rainforest by litterfall. Calculations were based on a large survey of published and unpublished data on litterfall and Hg concentrations in litterfall samples from the Amazonian region. Litterfall based on 65 sites located in the Amazon rainforest averaged 8.15 ± 2.25 Mg ha(-1) y(-1). Average Hg concentrations were calculated from nine datasets for fresh tree leaves and ten datasets for litter, and a median concentration of 60.5 ng Hg g(-1) was considered for Hg deposition in litterfall, which averaged 49 ± 14 μg m(-2) yr(-1). This value was used to estimate that in the Amazonian rainforest, litterfall would be responsible for the annual removing of 268 ± 77 Mg of Hg, approximately 8% of the total atmospheric Hg deposition to land. The impact of the Amazon deforestation on the Hg biogeochemical cycle is also discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Voices of Contact: Politics of Language in Urban Amazonian Ecuador

    Science.gov (United States)

    Wroblewski, Michael

    2010-01-01

    This dissertation is a study of diverse linguistic resources and contentious identity politics among indigenous Amazonian Kichwas in the city of Tena, Ecuador. Tena is a rapidly developing Amazonian provincial capital city with a long history of interethnic and interlinguistic contact. In recent decades, the course of indigenous Kichwa identity…

  16. Heterogeneous effects of market integration on sub-adult body size and nutritional status among the Shuar of Amazonian Ecuador.

    Science.gov (United States)

    Urlacher, Samuel S; Liebert, Melissa A; Josh Snodgrass, J; Blackwell, Aaron D; Cepon-Robins, Tara J; Gildner, Theresa E; Madimenos, Felicia C; Amir, Dorsa; Bribiescas, Richard G; Sugiyama, Lawrence S

    2016-07-01

    Market integration (MI)-increasing production for and consumption from a market-based economy-is drastically altering traditional ways of life and environmental conditions among indigenous Amazonian peoples. The effects of MI on the biology and health of Amazonian children and adolescents, however, remain unclear. This study examines the impact of MI on sub-adult body size and nutritional status at the population, regional and household levels among the Shuar of Amazonian Ecuador. Anthropometric data were collected between 2005-2014 from 2164 Shuar (aged 2-19 years) living in two geographic regions differing in general degree of MI. High-resolution household economic, lifestyle and dietary data were collected from a sub-sample of 631 participants. Analyses were performed to investigate relationships between body size and year of data collection, region and specific aspects of household MI. Results from temporal and regional analyses suggest that MI has a significant and overall positive impact on Shuar body size and nutritional status. However, household-level results exhibit nuanced and heterogeneous specific effects of MI underlying these overarching relationships. This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth and health among the Shuar and other indigenous Amazonian populations.

  17. Heterogeneous effects of market integration on subadult body size and nutritional status among the Shuar of Amazonian Ecuador

    Science.gov (United States)

    Urlacher, Samuel S.; Liebert, Melissa A.; Snodgrass, J. Josh; Blackwell, Aaron D.; Cepon-Robins, Tara J.; Gildner, Theresa E.; Madimenos, Felicia C.; Amir, Dorsa; Bribiescas, Richard G.; Sugiyama, Lawrence S.

    2016-01-01

    Background Market integration (MI) – increasing production for and consumption from a market-based economy – is drastically altering traditional ways of life and environmental conditions among indigenous Amazonian peoples. The effects of MI on the biology and health of Amazonian children and adolescents, however, remain unclear. Aim This study examines the impact of MI on subadult body size and nutritional status at the population, regional, and household levels among the Shuar of Amazonian Ecuador. Subjects and Methods Anthropometric data were collected between 2005 and 2014 from 2,164 Shuar (age 2-19 years) living in two geographic regions differing in general degree of MI. High-resolution household economic, lifestyle, and dietary data were collected from a subsample of 631 participants. Analyses were performed to investigate relationships between body size and year of data collection, region, and specific aspects of household MI. Results Results from temporal and regional analyses suggest that MI has a significant and overall positive impact on Shuar body size and nutritional status. However, household-level results exhibit nuanced and heterogeneous specific effects of MI underlying these overarching relationships. Conclusion This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth, and health among the Shuar and other indigenous Amazonian populations. PMID:27230632

  18. Biogeography of Amazonian fishes: deconstructing river basins as biogeographic units

    Directory of Open Access Journals (Sweden)

    Fernando C. P. Dagosta

    2017-09-01

    Full Text Available ABSTRACT Biogeography of Amazonian fishes (2,500 species in vastly disjunct lineages is complex and has so far been approached only partially. Here, we tackle the problem on the basis of the largest database yet on geographical distribution and phylogenetic relationships of Amazonian fishes, including all information available. Distributions of 4,095 species (both Amazonian and outgroups and 84 phylogenetic hypotheses (comprising 549 phylogenetically-informative nodes were compiled, qualified and plotted onto 46 areas (29 Amazonian and 17 non-Amazonian. The database was analyzed with PAE, CADE, BPA and BPA0, yielding largely congruent results and indicating that biogeographic signal is detectable on multiple dimensions of fish distribution, from single species ranges to cladistic congruence. Agreement is especially pronounced in deeper components, such as Trans-Andean, Cis-Andean, Western Amazon and Orinoco basins. Results show that all major Amazonian tributaries, as well as the Amazon basin itself, are non-monophyletic and constitute hybrid sets of heterogeneous biotic partitions. Amazonian drainages should not be assumed a priori as historically cohesive areas, contrary to widespread practice. Our hypothesis allows re-evaluation of broader issues in historical biogeography, such as the predictive power of biogeographic hypotheses, the vicariant/dispersal duality, the significance of widely distributed taxa, and the need for temporal dimension in biogeographic patterns.

  19. Origin and Domestication of Native Amazonian Crops

    Directory of Open Access Journals (Sweden)

    Doriane Picanço-Rodrigues

    2010-01-01

    Full Text Available Molecular analyses are providing new elements to decipher the origin, domestication and dispersal of native Amazonian crops in an expanding archaeological context. Solid molecular data are available for manioc (Manihot esculenta, cacao (Theobroma cacao, pineapple (Ananas comosus, peach palm (Bactris gasipaes and guaraná (Paullinia cupana, while hot peppers (Capsicum spp., inga (Inga edulis, Brazil nut (Bertholletia excelsa and cupuassu (Theobroma grandiflorum are being studied. Emergent patterns include the relationships among domestication, antiquity (terminal Pleistocene to early Holocene, origin in the periphery, ample pre-Columbian dispersal and clear phylogeographic population structure for manioc, pineapple, peach palm and, perhaps, Capsicum peppers. Cacao represents the special case of an Amazonian species possibly brought into domestication in Mesoamerica, but close scrutiny of molecular data suggests that it may also have some incipiently domesticated populations in Amazonia. Another pattern includes the relationships among species with incipiently domesticated populations or very recently domesticated populations, rapid pre- or post-conquest dispersal and lack of phylogeographic population structure, e.g., Brazil nut, cupuassu and guaraná. These patterns contrast the peripheral origin of most species with domesticated populations with the subsequent concentration of their genetic resources in the center of the basin, along the major white water rivers where high pre-conquest population densities developed. Additional molecular genetic analyses on these and other species will allow better examination of these processes and will enable us to relate them to other historical ecological patterns in Amazonia.

  20. Hyperdominance in Amazonian forest carbon cycling.

    Science.gov (United States)

    Fauset, Sophie; Johnson, Michelle O; Gloor, Manuel; Baker, Timothy R; Monteagudo M, Abel; Brienen, Roel J W; Feldpausch, Ted R; Lopez-Gonzalez, Gabriela; Malhi, Yadvinder; ter Steege, Hans; Pitman, Nigel C A; Baraloto, Christopher; Engel, Julien; Pétronelli, Pascal; Andrade, Ana; Camargo, José Luís C; Laurance, Susan G W; Laurance, William F; Chave, Jerôme; Allie, Elodie; Vargas, Percy Núñez; Terborgh, John W; Ruokolainen, Kalle; Silveira, Marcos; Aymard C, Gerardo A; Arroyo, Luzmila; Bonal, Damien; Ramirez-Angulo, Hirma; Araujo-Murakami, Alejandro; Neill, David; Hérault, Bruno; Dourdain, Aurélie; Torres-Lezama, Armando; Marimon, Beatriz S; Salomão, Rafael P; Comiskey, James A; Réjou-Méchain, Maxime; Toledo, Marisol; Licona, Juan Carlos; Alarcón, Alfredo; Prieto, Adriana; Rudas, Agustín; van der Meer, Peter J; Killeen, Timothy J; Marimon Junior, Ben-Hur; Poorter, Lourens; Boot, Rene G A; Stergios, Basil; Torre, Emilio Vilanova; Costa, Flávia R C; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Groot, Nikée; Arets, Eric; Moscoso, Victor Chama; Castro, Wendeson; Coronado, Euridice N Honorio; Peña-Claros, Marielos; Stahl, Clement; Barroso, Jorcely; Talbot, Joey; Vieira, Ima Célia Guimarães; van der Heijden, Geertje; Thomas, Raquel; Vos, Vincent A; Almeida, Everton C; Davila, Esteban Álvarez; Aragão, Luiz E O C; Erwin, Terry L; Morandi, Paulo S; de Oliveira, Edmar Almeida; Valadão, Marco B X; Zagt, Roderick J; van der Hout, Peter; Loayza, Patricia Alvarez; Pipoly, John J; Wang, Ophelia; Alexiades, Miguel; Cerón, Carlos E; Huamantupa-Chuquimaco, Isau; Di Fiore, Anthony; Peacock, Julie; Camacho, Nadir C Pallqui; Umetsu, Ricardo K; de Camargo, Plínio Barbosa; Burnham, Robyn J; Herrera, Rafael; Quesada, Carlos A; Stropp, Juliana; Vieira, Simone A; Steininger, Marc; Rodríguez, Carlos Reynel; Restrepo, Zorayda; Muelbert, Adriane Esquivel; Lewis, Simon L; Pickavance, Georgia C; Phillips, Oliver L

    2015-04-28

    While Amazonian forests are extraordinarily diverse, the abundance of trees is skewed strongly towards relatively few 'hyperdominant' species. In addition to their diversity, Amazonian trees are a key component of the global carbon cycle, assimilating and storing more carbon than any other ecosystem on Earth. Here we ask, using a unique data set of 530 forest plots, if the functions of storing and producing woody carbon are concentrated in a small number of tree species, whether the most abundant species also dominate carbon cycling, and whether dominant species are characterized by specific functional traits. We find that dominance of forest function is even more concentrated in a few species than is dominance of tree abundance, with only ≈1% of Amazon tree species responsible for 50% of carbon storage and productivity. Although those species that contribute most to biomass and productivity are often abundant, species maximum size is also influential, while the identity and ranking of dominant species varies by function and by region.

  1. A Bilingual Experiment in the Amazonian Jungle of Peru

    Science.gov (United States)

    Wise, Mary Ruth

    1971-01-01

    In the Amazonian jungle of Peru 240 Indian leaders representing 20 different South American Indian language groups are successfully teaching their own people to read and write, first in their mother tongue and then in Spanish. (Author/EB)

  2. Access to health care in relation to socioeconomic status in the Amazonian area of Peru

    DEFF Research Database (Denmark)

    Kristiansson, Charlotte; Gotuzzo, Eduardo; Rodriguez, Hugo

    2009-01-01

    in relation to household socioeconomic status for children in two small Amazonian urban communities of Peru; Yurimaguas, Department of Loreto and Moyobamba, Department of San Martin, Peru. METHODS: Cross-sectional study design included household interviews. Caregivers of 780 children aged 6-72 months...... in Yurimaguas and 793 children of the same age in Moyobamba were included in the study. Caregivers were interviewed on health care seeking strategies (public/private sectors; formal/informal providers), and medication for their children in relation to reported symptoms and socio-economic status. Self......-reported symptoms were classified into illnesses based on the IMCI algorithm (Integrated Management of Childhood Ilness). Wealth was used as a proxy indicator for the economic status. Wealth values were generated by Principal Component Analysis using household assets and characteristics. RESULTS: Significantly more...

  3. Placentation in the Amazonian manatee (Trichechus inunguis)

    DEFF Research Database (Denmark)

    Carter, A M; Miglino, M A; Ambrosio, C E

    2008-01-01

    Evidence from several sources supports a close phylogenetic relationship between elephants and sirenians. To explore whether this was reflected in similar placentation, we examined eight delivered placentae from the Amazonian manatee using light microscopy and immunohistochemistry. In addition......, the fetal placental circulation was described by scanning electron microscopy of vessel casts. The manatee placenta was zonary and endotheliochorial, like that of the elephant. The interhaemal barrier comprised maternal endothelium, cytotrophoblasts and fetal endothelium. We found columnar trophoblast...... beneath the chorionic plate and lining lacunae in this region, but there was no trace in the term placenta of haemophagous activity. The gross anatomy of the cord and fetal membranes was consistent with previous descriptions and included a four-chambered allantoic sac, as also found in the elephant...

  4. Correspondence: Rapid tree carbon stock recovery in managed Amazonian forests

    NARCIS (Netherlands)

    Rutishauser, E.; Hérault, B.; Baraloto, C.; Blanc, L.; Descroix, L.; Sotta, E.; Ferreira, J.; Kanashiro, M.; Mazzei, L.; Pena Claros, M.

    2015-01-01

    While around 20% of the Amazonian forest has been cleared for pastures and agriculture, one fourth of the remaining forest is dedicated to wood production [1]. Most of these production forests have been or will be selectively harvested for commercial timber, but recent studies show that even soon

  5. The Amazonian Formative: Crop Domestication and Anthropogenic Soils

    Directory of Open Access Journals (Sweden)

    Manuel Arroyo-Kalin

    2010-03-01

    Full Text Available The emergence of sedentism and agriculture in Amazonia continues to sit uncomfortably within accounts of South American pre-Columbian history. This is partially because deep-seated models were formulated when only ceramic evidence was known, partly because newer data continue to defy simple explanations, and partially because many discussions continue to ignore evidence of pre-Columbian anthropogenic landscape transformations. This paper presents the results of recent geoarchaeological research on Amazonian anthropogenic soils. It advances the argument that properties of two different types of soils, terras pretas and terras mulatas, support their interpretation as correlates of, respectively, past settlement areas and fields where spatially-intensive, organic amendment-reliant cultivation took place. This assessment identifies anthropogenic soil formation as a hallmark of the Amazonian Formative and prompts questions about when similar forms of enrichment first appear in the Amazon basin. The paper reviews evidence for embryonic anthrosol formation to highlight its significance for understanding the domestication of a key Amazonian crop: manioc (Manihot esculenta ssp. esculenta. A model for manioc domestication that incorporates anthropogenic soils outlines some scenarios which link the distribution of its two broader varieties—sweet and bitter manioc—with the widespread appearance of Amazonian anthropogenic dark earths during the first millennium AD.

  6. Fungal community assembly in the Amazonian Dark Earth

    NARCIS (Netherlands)

    Reis Lucheta, Adriano; Souza Cannavan, F.S.; Roesch, L.; Tsai, S.M.; Kuramae, E.E.

    2016-01-01

    Here, we compare the fungal community composition and diversity in Amazonian Dark Earth (ADE) and the respective non-anthropogenic origin adjacent (ADJ) soils from four different sites in Brazilian Central Amazon using pyrosequencing of 18S ribosomal RNA (rRNA) gene. Fungal community composition in

  7. Millennial-scale dynamics of southern Amazonian rain forests.

    Science.gov (United States)

    Mayle, F E; Burbridge, R; Killeen, T J

    2000-12-22

    Amazonian rain forest-savanna boundaries are highly sensitive to climatic change and may also play an important role in rain forest speciation. However, their dynamics over millennial time scales are poorly understood. Here, we present late Quaternary pollen records from the southern margin of Amazonia, which show that the humid evergreen rain forests of eastern Bolivia have been expanding southward over the past 3000 years and that their present-day limit represents the southernmost extent of Amazonian rain forest over at least the past 50,000 years. This rain forest expansion is attributed to increased seasonal latitudinal migration of the Intertropical Convergence Zone, which can in turn be explained by Milankovitch astronomic forcing.

  8. Amazonian Dark Earths: pathways to sustainable development in tropical rainforests?

    Directory of Open Access Journals (Sweden)

    Morgan Schmidt

    2013-04-01

    Full Text Available Fertile dark anthrosols associated with pre-Columbian settlement across the Amazon Basin have sparked wide interest for their potential contribution to sustainable use and management of tropical soils and ecosystems. In the Upper Xingu region of the southern Amazon, research on archaeological settlements and among contemporary descendant populations provides critical new data on the formation and use of anthrosols. These findings provide a basis for describing the variability of soil modifications that result from diverse human activities and a general model for the formation of Amazonian anthrosols. They underscore the potential for indigenous systems of knowledge and resource management to inform efforts for conservation and sustainable development of Amazonian ecosystems.

  9. Fish complementarity is associated to forests in Amazonian streams

    Directory of Open Access Journals (Sweden)

    Carolina Rodrigues Bordignon

    Full Text Available The functional structure of communities is commonly measured by the variability in functional traits, which may demonstrate complementarity or redundancy patterns. In this study, we tested the influence of environmental variables on the functional structure of fish assemblages in Amazonian streams within a deforestation gradient. We calculated six ecomorphological traits related to habitat use from each fish species, and used them to calculate the net relatedness index (NRI and the nearest taxon index (NTI. The set of species that used the habitat differently (complementary or overdispersed assemblages occurred in sites with a greater proportion of forests. The set of species that used the habitat in a similar way (redundant or clustered assemblages occurred in sites with a greater proportion of grasses in the stream banks. Therefore, the deforestation of entire watersheds, which has occurred in many Amazonian regions, may be a central factor for the functional homogenization of fish fauna.

  10. New species of Monostylis Tulasne (Podostemaceae from the Amazonian region

    Directory of Open Access Journals (Sweden)

    Aldalea Sprada Tavares

    2015-06-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2015v28n3p15 Until now, Monostylis Tulasne (Podostemaceae was considered monospecific, containing only M. capillacea Tulasne. However, recent field expeditions and an analysis of samples from the Amazonian region revealed three new species, Monostylis aripuanensis, M. goeldiana and M. paraensis. The present paper provides detailed morphological descriptions, illustrations, habitat data, comparative taxonomic comments and a dichotomous key to the species.

  11. Mosquitoes of eastern Amazonian Ecuador: biodiversity, bionomics and barcodes

    OpenAIRE

    Yvonne-Marie Linton; James E Pecor; Charles H Porter; Luke Brett Mitchell; Andres Garzon-Moreno; Desmond H Foley; David Brooks Pecor; Richard C Wilkerson

    2013-01-01

    Two snapshot surveys to establish the diversity and ecological preferences of mosquitoes (Diptera: Culicidae) in the terra firme primary rain forest surrounding the Tiputini Biodiversity Station in the UNESCO Yasuní Biosphere Reserve of eastern Amazonian Ecuador were carried out in November 1998 and May 1999. The mosquito fauna of this region is poorly known; the focus of this study was to obtain high quality link-reared specimens that could be used to unequivocally confirm species level...

  12. Child stunting is associated with weaker human capital among native Amazonians.

    Science.gov (United States)

    Undurraga, Eduardo A; Behrman, Jere R; Emmett, Susan D; Kidd, Celeste; Leonard, William R; Piantadosi, Steven T; Reyes-García, Victoria; Sharma, Abhishek; Zhang, Rebecca; Godoy, Ricardo A

    2018-01-01

    We assessed associations between child stunting, recovery, and faltering with schooling and human capital skills in a native Amazonian society of horticulturalists-foragers (Tsimane'). We used cross-sectional data (2008) from 1262 children aged 6 to 16 years in 53 villages to assess contemporaneous associations between three height categories: stunted (height-for-age Z score, HAZ-1), and three categories of human capital: completed grades of schooling, test-based academic skills (math, reading, writing), and local plant knowledge. We used annual longitudinal data (2002-2010) from all children (n = 853) in 13 villages to estimate the association between changes in height categories between the first and last years of measure and schooling and academic skills. Stunting was associated with 0.4 fewer completed grades of schooling (∼24% less) and with 13-15% lower probability of showing any writing or math skills. Moderate stunting was associated with ∼20% lower scores in local plant knowledge and 9% lower probability of showing writing skills, but was not associated with schooling or math and writing skills. Compared with nonstunted children, children who became stunted had 18-21% and 15-21% lower probabilities of showing math and writing skills, and stunted children had 0.4 fewer completed grades of schooling. Stunted children who recovered showed human capital outcomes that were indistinguishable from nonstunted children. The results confirm adverse associations between child stunting and human capital skills. Predictors of growth recovery and faltering can affect human capital outcomes, even in a remote, economically self-sufficient society. © 2017 Wiley Periodicals, Inc.

  13. The Mission of the Amazonian Universities in Economic Development and Environmental Preservation.

    Science.gov (United States)

    Lourenco, Jose Seixas

    The Association of Amazonian Universities (UNAMAZ) was created in September 1987 and is involved in a collective effort to find ways to promote the Amazonian region's nonpredatory development, recognizing its limitations and taking into account its potential. With deforestation taking place at ever-increasing speed, it has become necessary to…

  14. Estimating the global conservation status of more than 15,000 Amazonian tree species

    DEFF Research Database (Denmark)

    ter Steege, Hans; Pitman, Nigel C. A.; Killeen, Timothy J.

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree ...

  15. Response to Comment on "persistent effects of pre-Columbian plant domestication on Amazonian forest composition"

    NARCIS (Netherlands)

    Braga Junqueira, Andre; Levis, Carolina; Bongers, Frans; Peña-Claros, Marielos; Clement, Charles Roland; Costa, Flávia R.C.; Steege, Hans Ter

    2017-01-01

    McMichael et al. state that we overlooked the effects of post-Columbian human activities in shaping current floristic patterns in Amazonian forests. We formally show that post- Columbian human influences on Amazonian forests are indeed important, but they have played a smaller role when compared

  16. Environmental change and the carbon balance of Amazonian forests.

    Science.gov (United States)

    Aragão, Luiz E O C; Poulter, Benjamin; Barlow, Jos B; Anderson, Liana O; Malhi, Yadvinder; Saatchi, Sassan; Phillips, Oliver L; Gloor, Emanuel

    2014-11-01

    Extreme climatic events and land-use change are known to influence strongly the current carbon cycle of Amazonia, and have the potential to cause significant global climate impacts. This review intends to evaluate the effects of both climate and anthropogenic perturbations on the carbon balance of the Brazilian Amazon and to understand how they interact with each other. By analysing the outputs of the Intergovernmental Panel for Climate Change (IPCC) Assessment Report 4 (AR4) model ensemble, we demonstrate that Amazonian temperatures and water stress are both likely to increase over the 21st Century. Curbing deforestation in the Brazilian Amazon by 62% in 2010 relative to the 1990s mean decreased the Brazilian Amazon's deforestation contribution to global land use carbon emissions from 17% in the 1990s and early 2000s to 9% by 2010. Carbon sources in Amazonia are likely to be dominated by climatic impacts allied with forest fires (48.3% relative contribution) during extreme droughts. The current net carbon sink (net biome productivity, NBP) of +0.16 (ranging from +0.11 to +0.21) Pg C year(-1) in the Brazilian Amazon, equivalent to 13.3% of global carbon emissions from land-use change for 2008, can be negated or reversed during drought years [NBP = -0.06 (-0.31 to +0.01) Pg C year(-1) ]. Therefore, reducing forest fires, in addition to reducing deforestation, would be an important measure for minimizing future emissions. Conversely, doubling the current area of secondary forests and avoiding additional removal of primary forests would help the Amazonian gross forest sink to offset approximately 42% of global land-use change emissions. We conclude that a few strategic environmental policy measures are likely to strengthen the Amazonian net carbon sink with global implications. Moreover, these actions could increase the resilience of the net carbon sink to future increases in drought frequency. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical

  17. Environmental change and the carbon balance of Amazonian forests

    International Nuclear Information System (INIS)

    Aragao, Luiz E.O.C.; Poulter, Benjamin

    2014-01-01

    Extreme climatic events and land-use change are known to influence strongly the current carbon cycle of Amazonia, and have the potential to cause significant global climate impacts. This review intends to evaluate the effects of both climate and anthropogenic perturbations on the carbon balance of the Brazilian Amazon and to understand how they interact with each other. By analysing the outputs of the Intergovernmental Panel for Climate Change (IPCC) Assessment Report 4 (AR4) model ensemble, we demonstrate that Amazonian temperatures and water stress are both likely to increase over the 21. Century. Curbing deforestation in the Brazilian Amazon by 62% in 2010 relative to the 1990's mean decreased the Brazilian Amazon's deforestation contribution to global land use carbon emissions from 17% in the 1990's and early 2000's to 9% by 2010. Carbon sources in Amazonia are likely to be dominated by climatic impacts allied with forest fires (48.3% relative contribution) during extreme droughts. The current net carbon sink (net biome productivity, NBP) of +0.16 (ranging from +0.11 to +0.21) PgCyear-1 in the Brazilian Amazon, equivalent to 13.3% of global carbon emissions from land-use change for 2008, can be negated or reversed during drought years [NBP=-0.06 (-0.31 to +0.01) PgCyear -1 ]. Therefore, reducing forest fires, in addition to reducing deforestation, would be an important measure for minimizing future emissions. Conversely, doubling the current area of secondary forests and avoiding additional removal of primary forests would help the Amazonian gross forest sink to offset approximately 42% of global land-use change emissions. We conclude that a few strategic environmental policy measures are likely to strengthen the Amazonian net carbon sink with global implications. Moreover, these actions could increase the resilience of the net carbon sink to future increases in drought frequency. (authors)

  18. Medicinal plants of the Achuar (Jivaro) of Amazonian Ecuador: ethnobotanical survey and comparison with other Amazonian pharmacopoeias.

    Science.gov (United States)

    Giovannini, Peter

    2015-04-22

    This paper presents the first ethnobotanical survey conducted among the Achuar (Jivaro), indigenous people living in Amazonian Ecuador and Peru. The aims of this study are: (a) to present and discuss Achuar medicinal plant knowledge in the context of the epidemiology of this population (b) to compare the use of Achuar medicinal plants with the uses reported among the Shuar Jivaro and other Amazonian peoples. The author conducted field research in 9 indigenous villages in the region of Morona Santiago and Pastaza in Ecuador. Semi-structured interviews on local illnesses and herbal remedies were carried out with 82 informants and plant specimens were collected and later identified in Quito. A literature research was conducted on the medicinal species reported by Achuar people during this study. The most reported medicinal plants are species used by the Achuar to treat diarrhoea, parasites infection, fractures, wounds, and snakebites. Informants reported the use of 134 medicinal species for a total of 733 recorded use-reports. Of these 134 species, 44 are reported at least 3 times for one or more specific disease condition for a total of 56 uses. These species are considered a core kit of medicinal plants of the Achuar of Ecuador. Most of these medicinal species are widely used in the Amazon rainforest and in many other parts of Latin America. The author documented a core kit of 44 medicinal plants used among the Achuar of Ecuador and found that this core set of medicinal plants reflects local epidemiological concerns and the pharmacopoeias of the Shuar and other Amazonian groups. These findings suggest that inter-group diffusion of medicinal plant knowledge had a prominent role in the acquisition of current Achuar knowledge of medicinal plants. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Amazonian Buriti oil: chemical characterization and antioxidant potential

    Energy Technology Data Exchange (ETDEWEB)

    Speranza, P.; Oliveira Falcao, A. de; Alves Macedo, J.; Silva, L.H.M. da; Rodrigues, A.M. da C.; Alves Macedo, G.

    2016-07-01

    Buriti oil is an example of an Amazonian palm oil of economic importance. The local population uses this oil for the prevention and treatment of different diseases; however, there are few studies in the literature that evaluate its properties. In this study, detailed chemical and antioxidant properties of Buriti oil were determined. The predominant fatty acid was oleic acid (65.6%) and the main triacylglycerol classes were tri-unsaturated (50.0%) and di-unsaturated-mono-saturated(39.3%) triacylglycerols. The positional distribution of the classes of fatty acids on the triacylglycerol backbone indicated a saturated and unsaturated fatty acid relationship similar in the three-triacylglycerol positions. All tocopherol isomers were present, with a total content of 2364.1 mg·kg−1. α-tocopherol constitutes 48% of the total tocopherol content, followed by γ- tocopherol (45%). Total phenolic (107.0 mg gallic acid equivalent·g−1 oil) and β-carotene (781.6 mg·kg−1) were particularly high in this oil. The highest antioxidant activity against the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) was obtained at an oil concentration of 50 mg·mL−1 (73.15%). The antioxidant activity evaluated by the Oxygen Radical Absorbance Capacity (ORAC) was 95.3 μmol Trolox equivalent·g−1 oil. These results serve to present Buriti oil as an Amazonian resource for cosmetic, food and pharmaceuticals purposes. (Author)

  20. Sustainable development, social organization and environment in the Amazonian Area

    International Nuclear Information System (INIS)

    Vieco, Juan Jose

    2001-01-01

    The effects of the development on the environment and the culture in regions like the Amazonian are one of the most dramatic examples that can be in what refers to the physical disappearance of numerous cultures, as well as of their integration to the national society and their rising loss of cultural identity and the devastating consequences that have had the development politicians on the different Amazon ecosystems. The construction of a sustainable development for the region has to evaluate the different societies that have existed and they exist as for the use, handling and exploitation of the natural resources. This paper will be approached this problem in three Amazon societies: the cacique territory, the tribal societies and the societies in formation in the colonization regions. It will be done an analysis and a critic of the development concept and of the consequences that it has had their application so much in the indigenous towns as in the Amazon ecosystems, as well as their relationship with the current characterization of the Amazonian area

  1. Amazonian functional diversity from forest canopy chemical assembly.

    Science.gov (United States)

    Asner, Gregory P; Martin, Roberta E; Tupayachi, Raul; Anderson, Christopher B; Sinca, Felipe; Carranza-Jiménez, Loreli; Martinez, Paola

    2014-04-15

    Patterns of tropical forest functional diversity express processes of ecological assembly at multiple geographic scales and aid in predicting ecological responses to environmental change. Tree canopy chemistry underpins forest functional diversity, but the interactive role of phylogeny and environment in determining the chemical traits of tropical trees is poorly known. Collecting and analyzing foliage in 2,420 canopy tree species across 19 forests in the western Amazon, we discovered (i) systematic, community-scale shifts in average canopy chemical traits along gradients of elevation and soil fertility; (ii) strong phylogenetic partitioning of structural and defense chemicals within communities independent of variation in environmental conditions; and (iii) strong environmental control on foliar phosphorus and calcium, the two rock-derived elements limiting CO2 uptake in tropical forests. These findings indicate that the chemical diversity of western Amazonian forests occurs in a regionally nested mosaic driven by long-term chemical trait adjustment of communities to large-scale environmental filters, particularly soils and climate, and is supported by phylogenetic divergence of traits essential to foliar survival under varying environmental conditions. Geographically nested patterns of forest canopy chemical traits will play a role in determining the response and functional rearrangement of western Amazonian ecosystems to changing land use and climate.

  2. Pterygium: prevalence and severity in an Amazonian ophthalmic setting, Brazil

    Directory of Open Access Journals (Sweden)

    Sophie Joanna Coutts

    2012-12-01

    Full Text Available OBJECTIVE: This is a cross sectional ophthalmic clinic-based study to estimate the prevalence and severity of pterygium in a selected population in the Amazon Basin, Brazil. METHODS: The study included 225 subjects above 20 years age from three different places of residence of Manaus city (group 1, n=89, river based communities (group 2, n= 116 and indigenous rainforest inhabitants (group 3, n=20. Pterygia was graded 1-4 by torch examination and gender, age and occupation determined. RESULTS: were assessed to have pterygia (grades 2-4 117 people; 52% against 108 control subjects with bilateral disease in 43% of subjects. Prevalence of grades 2-4 increased from 36% in group 1 to 62.5 % in group 2 and 75% in group 3. Of these subjects the percentage with outdoor professions increased across the groups from 31.2% to 67.1 % and 70% respectively. Also subjects of group 2 who worked largely outdoors, showed increasing pterygia severity, from grades 2 at 57% (p=0.0002, grade 3 at 93.3% (p,0.0001 to grade 4 at 100% (p=0.0004 CONCLUSION: Amazonian communities have a high prevalence of pterygia, which correlates to greater outdoor occupation and sun exposure. This study agrees with previous worldwide reports and it is the first study to compare the prevalence of pterygium in rural and urban living in Amazonian in Brazil. This study highlights the public health significance and gross need for intervention studies.

  3. Amazonian indigenous settlement and local development in Pastaza, Ecuador

    Directory of Open Access Journals (Sweden)

    Ruth I. Arias-Gutiérrez

    2016-07-01

    Full Text Available In six Amazonian indigenous communities that call to their selves as membership of nación Kichwa, located in Pastaza province, in Ecuador, it is analyzed the process of inhabitation, population characteristics, how much the territory is enough for food requirements for the indigenous families, and their use of land, to determine important factors to improve strategies for local sustainable development. It is considered important because Ecuador has constitutional protection for plural ethnicity and it is looking for improving a new productivity matrix that let down extraction and contamination and raise another matrix based on knowledge and richness from natural renewable resources. Survey used statistics information, qualitative analysis around reality in process, participant research, documentary analysis, oral history and surveys to leadership and family`s chiefs. Results confirm that communities hold standing their identity and knowledge systems of the Amazonian environment, whose conservation they need. Those are factors to be included in local development strategies that let people become safe from effects of extractives activities that are dangerous for culture and environment, in the geographic and biological diversity of the high Ecuadorian Amazonia.

  4. Spatial trends in leaf size of Amazonian rainforest trees

    Directory of Open Access Journals (Sweden)

    A. C. M. Malhado

    2009-08-01

    Full Text Available Leaf size influences many aspects of tree function such as rates of transpiration and photosynthesis and, consequently, often varies in a predictable way in response to environmental gradients. The recent development of pan-Amazonian databases based on permanent botanical plots has now made it possible to assess trends in leaf size across environmental gradients in Amazonia. Previous plot-based studies have shown that the community structure of Amazonian trees breaks down into at least two major ecological gradients corresponding with variations in soil fertility (decreasing from southwest to northeast and length of the dry season (increasing from northwest to south and east. Here we describe the geographic distribution of leaf size categories based on 121 plots distributed across eight South American countries. We find that the Amazon forest is predominantly populated by tree species and individuals in the mesophyll size class (20.25–182.25 cm2. The geographic distribution of species and individuals with large leaves (>20.25 cm2 is complex but is generally characterized by a higher proportion of such trees in the northwest of the region. Spatially corrected regressions reveal weak correlations between the proportion of large-leaved species and metrics of water availability. We also find a significant negative relationship between leaf size and wood density.

  5. Signs and symptoms of mercury-exposed gold miners.

    Science.gov (United States)

    Bose-O'Reilly, Stephan; Bernaudat, Ludovic; Siebert, Uwe; Roider, Gabriele; Nowak, Dennis; Drasch, Gustav

    2017-03-30

    Gold miners use mercury to extract gold from ore adding liquid mercury to the milled gold-containing ore. This results in a mercury-gold compound, called amalgam. Miners smelt this amalgam to obtain gold, vaporizing it and finally inhaling the toxic mercury fumes. The objective was to merge and analyze data from different projects, to identify typical signs and symptoms of chronic inorganic mercury exposure. Miners and community members from various artisanal small-scale gold mining areas had been examined (Philippines, Mongolia, Tanzania, Zimbabwe, Indonesia). Data of several health assessments were pooled. Urine, blood and hair samples were analyzed for mercury (N = 1252). Questionnaires, standardized medical examinations and neuropsychological tests were used. Participants were grouped into: Controls (N = 209), living in an exposed area (N = 408), working with mercury as panners (N = 181), working with mercury as amalgam burners (N = 454). Chi2 test, linear trend test, Mann-Whitney test, Kruskal-Wallis test, correlation coefficient, Spearman's rho, and analysis of variance tests were used. An algorithm was used to define participants with chronic mercury intoxication. Mean mercury concentrations in all exposed subgroups were elevated and above threshold limits, with amalgam burners showing highest levels. Typical symptoms of chronic metallic mercury intoxication were tremor, ataxia, coordination problems, excessive salivation and metallic taste. Participants from the exposed groups showed poorer results in different neuropsychological tests in comparison to the control group. Fifty-four percent of the high-exposed group (amalgam burners) were diagnosed as being mercury-intoxicated, compared to 0% within the control group (Chi2 p mercury intoxication, with tremor, ataxia and other neurological symptoms together with a raised body burden of mercury was clinically diagnosed in exposed people in artisanal small-scale mining areas. The mercury exposure needs to be urgently reduced. Health care systems need to be prepared for this emerging problem of chronic mercury intoxication among exposed people. Int J Occup Med Environ Health 2017;30(2):249-269. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  6. Composition and diversity of northwestern Amazonian rainforests in a geoecological context

    NARCIS (Netherlands)

    Duivenvoorden, J.F.; Duque, A.J.; Hoorn, C.; Wesselingh, F.P.

    2010-01-01

    The northwestern Amazonian landscape includes most of the representative landscape units that characterize Amazonia, and for this reason it constitutes an excellent place to investigate relationships between the abiotic environment (geology, geomorphology, soils) and biodiversity. In this review we

  7. Pre-LBA Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set presents the principal data from the Anglo-BRazilian Amazonian Climate Observation Study (ABRACOS) (Gash et al. 1996) and provides quality controlled...

  8. Pre-LBA Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: The data set presents the principal data from the Anglo-BRazilian Amazonian Climate Observation Study (ABRACOS) (Gash et al. 1996) and provides quality...

  9. LBA-ECO LC-09 Natural, Infrastructure, and Boundary Features, Amazonian Sites, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set includes 16 zipped archives of shapefiles of cities, rivers and streams, roads, and study area boundaries of several Amazonian study sites:...

  10. LBA-ECO LC-09 Natural, Infrastructure, and Boundary Features, Amazonian Sites, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes 16 zipped archives of shapefiles of cities, rivers and streams, roads, and study area boundaries of several Amazonian study sites: Altamira,...

  11. Unihemispheric slow-wave sleep in the Amazonian dolphin, Inia geoffrensis.

    Science.gov (United States)

    Mukhametov, L M

    1987-08-18

    An electroencephalographic study of sleep in Amazonian dolphins, Inia geoffrensis, revealed that unihemispheric slow-wave sleep is the dominant sleep type in this species, as in the other two dolphin species that were studied earlier.

  12. Food Plants Eaten by Amazonian Manatees (Trichechus inunguis, Mammalia : Sirenia

    Directory of Open Access Journals (Sweden)

    Ioni G. Colares

    2002-03-01

    Full Text Available To determine the feeding habits of the Amazonian manatee Trichechus inunguis in some Central Amazonian rivers and lakes, we compared plant epidermis found in the stomach contents and/or faeces of animals with a reference collection of plants present in the studied areas. Twenty five samples from digestive tracts of animals found dead and 25 faeces samples found floating were analyzed. From these samples, 24 aquatic macrophytes were identified. The Gramineae family was identified in 96% of the samples, Paspalum repens and Echinochloa polystachya being the most abundant in the samples. The second most frequent family was the Pontederiaceae primarily Eichhornia crassipes. During the high water period, the animals showed a more selective diet (eight identified species. In the low water period, when food was more scarce, the animals showed a larger diversity of species in their diet (21 species of plants. Differences in the diet among the two studied areas reflected the physiographics characteristics of the region. Amazonian manatees fed mostly on emergent plants.Para determinar o hábito alimentar do peixe-boi da Amazonia em alguns rios e lagos da Amazonia Central, nós comparamos as epidermes de plantas encontradas nos conteúdos alimentares e/ou fezes de animais com uma coleção de referência de epidermes de plantas presentes nas áreas de estudo. Foram analisadas 25 amostras de trato digestivo de animais encontrados mortos e 25 amostras de fezes . A familia Gramineae foi encontrada em 96% das amostras, com maior ocorrência das espécies Paspalum repens e Echinochloa polystachya. A segunda familia mais freqüente foi Pontederiaceae sendo Eichhornia crassipes a espécie predominante. Durante o período de água cheia, os animais apresentaram uma dieta mais seletiva (oito espécies identificadas. Já na água baixa, com menor oferta de alimentos, os animais apresentam uma maior diversidade de espécies em sua dieta (21 espécies de plantas

  13. Geological control of floristic composition in Amazonian forests.

    Science.gov (United States)

    Higgins, Mark A; Ruokolainen, Kalle; Tuomisto, Hanna; Llerena, Nelly; Cardenas, Glenda; Phillips, Oliver L; Vásquez, Rodolfo; Räsänen, Matti

    2011-11-01

    AIM: Conservation and land-use planning require accurate maps of patterns in species composition and an understanding of the factors that control them. Substantial doubt exists, however, about the existence and determinants of large-area floristic divisions in Amazonia. Here we ask whether Amazonian forests are partitioned into broad-scale floristic units on the basis of geological formations and their edaphic properties. LOCATION: Western and central Amazonia. METHODS: We used Landsat imagery and Shuttle Radar Topography Mission (SRTM) digital elevation data to identify a possible floristic and geological discontinuity of over 300 km in northern Peru. We then used plant inventories and soil sampling to document changes in species composition and soil properties across this boundary. Data were obtained from 138 sites distributed along more than 450 km of road and river. On the basis of our findings, we used broad-scale Landsat and SRTM mosaics to identify similar patterns across western and central Amazonia. RESULTS: The discontinuity identified in Landsat and SRTM data corresponded to a 15-fold change in soil cation concentrations and an almost total change in plant species composition. This discontinuity appears to be caused by the widespread removal of cation-poor surface sediments by river incision to expose cation-rich sediments beneath. Examination of broad-scale Landsat and SRTM mosaics indicated that equivalent processes have generated a north-south discontinuity of over 1500 km in western Brazil. Due to similarities with our study area, we suggest that this discontinuity represents a chemical and ecological limit between western and central Amazonia. MAIN CONCLUSIONS: Our findings suggest that Amazonian forests are partitioned into large-area units on the basis of geological formations and their edaphic properties. The evolution of these units through geological time may provide a general mechanism for biotic diversification in Amazonia. These

  14. Estimating the global conservation status of more than 15,000 Amazonian tree species

    OpenAIRE

    ter Steege, H.; et al., [Unknown; Duivenvoorden, J.F.

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened ...

  15. The perceived benefits of height: strength, dominance, social concern, and knowledge among Bolivian native Amazonians.

    Science.gov (United States)

    Undurraga, Eduardo A; Zebrowitz, Leslie; Eisenberg, Dan T A; Reyes-García, Victoria; Godoy, Ricardo A

    2012-01-01

    Research in industrial countries suggests that, with no other knowledge about a person, positive traits are attributed to taller people and correspondingly, that taller people have slightly better socioeconomic status (SES). However, research in some non-industrialized contexts has shown no correlation or even negative correlations between height and socioeconomic outcomes. It remains unclear whether positive traits remain attributed to taller people in such contexts. To address this question, here we report the results of a study in a foraging-farming society of native Amazonians in Bolivia (Tsimane')--a group in which we have previously shown little association between height and socioeconomic outcomes. We showed 24 photographs of pairs of Tsimane' women, men, boys, and girls to 40 women and 40 men >16 years of age. We presented four behavioral scenarios to each participant and asked them to point to the person in the photograph with greater strength, dominance, social concern, or knowledge. The pairs in the photographs were of the same sex and age, but one person was shorter. Tsimane' women and men attributed greater strength, dominance, and knowledge to taller girls and boys, but they did not attribute most positive traits to taller adults, except for strength, and more social concern only when women assessed other women in the photographs. These results raise a puzzle: why would Tsimane' attribute positive traits to tall children, but not tall adults? We propose three potential explanations: adults' expectations about the more market integrated society in which their children will grow up, height as a signal of good child health, and children's greater variation in the traits assessed corresponding to maturational stages.

  16. The perceived benefits of height: strength, dominance, social concern, and knowledge among Bolivian native Amazonians.

    Directory of Open Access Journals (Sweden)

    Eduardo A Undurraga

    Full Text Available Research in industrial countries suggests that, with no other knowledge about a person, positive traits are attributed to taller people and correspondingly, that taller people have slightly better socioeconomic status (SES. However, research in some non-industrialized contexts has shown no correlation or even negative correlations between height and socioeconomic outcomes. It remains unclear whether positive traits remain attributed to taller people in such contexts. To address this question, here we report the results of a study in a foraging-farming society of native Amazonians in Bolivia (Tsimane'--a group in which we have previously shown little association between height and socioeconomic outcomes. We showed 24 photographs of pairs of Tsimane' women, men, boys, and girls to 40 women and 40 men >16 years of age. We presented four behavioral scenarios to each participant and asked them to point to the person in the photograph with greater strength, dominance, social concern, or knowledge. The pairs in the photographs were of the same sex and age, but one person was shorter. Tsimane' women and men attributed greater strength, dominance, and knowledge to taller girls and boys, but they did not attribute most positive traits to taller adults, except for strength, and more social concern only when women assessed other women in the photographs. These results raise a puzzle: why would Tsimane' attribute positive traits to tall children, but not tall adults? We propose three potential explanations: adults' expectations about the more market integrated society in which their children will grow up, height as a signal of good child health, and children's greater variation in the traits assessed corresponding to maturational stages.

  17. Catch-up growth and growth deficits: Nine-year annual panel child growth for native Amazonians in Bolivia.

    Science.gov (United States)

    Zhang, Rebecca; Undurraga, Eduardo A; Zeng, Wu; Reyes-García, Victoria; Tanner, Susan; Leonard, William R; Behrman, Jere R; Godoy, Ricardo A

    2016-07-01

    Childhood growth stunting is negatively associated with cognitive and health outcomes, and is claimed to be irreversible after age 2. To estimate growth rates for children aged 2-7 who were stunted (sex-age standardised z-score [HAZ] -1) at baseline and tracked annually until age 11; frequency of movement among height categories; and variation in height predicted by early childhood height. This study used a 9-year annual panel (2002-2010) from a native Amazonian society of horticulturalists-foragers (Tsimane'; n = 174 girls; 179 boys at baseline). Descriptive statistics and random-effect regressions were used. This study found some evidence of catch-up growth in HAZ, but persistent height deficits. Children stunted at baseline improved 1 HAZ unit by age 11 and had higher annual growth rates than non-stunted children. Marginally-stunted boys had a 0.1 HAZ units higher annual growth rate than non-stunted boys. Despite some catch up, ∼ 80% of marginally-stunted children at baseline remained marginally-stunted by age 11. The height deficit increased from age 2 to 11. Modest year-to-year movement was found between height categories. The prevalence of growth faltering among the Tsimane' has declined, but hurdles still substantially lock children into height categories.

  18. A marvelous new glassfrog (Centrolenidae, Hyalinobatrachium) from Amazonian Ecuador

    Science.gov (United States)

    Guayasamin, Juan M.; Cisneros-Heredia, Diego F.; Maynard, Ross J.; Lynch, Ryan L.; Culebras, Jaime; Hamilton, Paul S.

    2017-01-01

    Abstract Hyalinobatrachium is a behaviorally and morphologically conserved genus of Neotropical anurans, with several pending taxonomic problems. Using morphology, vocalizations, and DNA, a new species from the Amazonian lowlands of Ecuador is described and illustrated. The new species, Hyalinobatrachium yaku sp. n., is differentiated from all other congenerics by having small, middorsal, dark green spots on the head and dorsum, a transparent pericardium, and a tonal call that lasts 0.27–0.4 s, with a dominant frequency of 5219.3–5329.6 Hz. Also, a mitochondrial phylogeny for the genus is presented that contains the new species, which is inferred as sister to H. pellucidum. Conservation threats to H. yaku sp. n. include habitat destruction and/or pollution mainly because of oil and mining activities. PMID:28769670

  19. Influence of digestive morphology on resource partitioning in Amazonian ungulates.

    Science.gov (United States)

    Bodmer, Richard E

    1991-01-01

    Resource partitioning of diet and habitat use was studied in the entire Amazonian ungulate community of Northeastern Peru, which comprises the red brocket deer (Mazama americana), grey brocket deer (M. gouazoubira), collared peccary (Tayassu tajacu), white-lipped peccary (T. pecari), and lowland tapir (Tapirus terrestris). Each ungulate species partitioned at least one type of resource from every other species. Digestive morphology had a greater influence on resource partitioning of diet than body size. Neither digestive morphology nor body size were related to segregation of habitats. However, species with similar diets partitioned habitats, whereas species with different diets often used the same type of forest. Increases in habitat breadth of ungulates were positively correlated with increases in dietary breadth.

  20. The sustainability search in the Amazonian productive systems

    International Nuclear Information System (INIS)

    Wood, Allan A

    2001-01-01

    Historically the society and the state have a little attention to the Amazonian area and this it continues being one of the regions but marginal of the country. The countries that possess Amazon territory have spread to neglect those lands so far away and unknown. In spite of their margination, the region goes getting paid every time but importance in the nation and the world. The information that it keeps their diversity biotic and cultural it has international recognition; economically it has considerable reservations of minerals, wood and fishes, which are extracted to supply the national and international markets. Politically the region is mentioned by the social conflict and the colonization that it fronts, it also has the only frontiers with Brazil and Peru, in the future, will be built the marginal highway of the forest; connecting to Ecuador with Colombia and Venezuela, opening significant spaces for the trade and the international integration

  1. Drought responses of flood-tolerant trees in Amazonian floodplains.

    Science.gov (United States)

    Parolin, Pia; Lucas, Christine; Piedade, Maria Teresa F; Wittmann, Florian

    2010-01-01

    Flood-tolerant tree species of the Amazonian floodplain forests are subjected to an annual dry period of variable severity imposed when low river-water levels coincide with minimal precipitation. Although the responses of these species to flooding have been examined extensively, their responses to drought, in terms of phenology, growth and physiology, have been neglected hitherto, although some information is found in publications that focus on flooding. The present review examines the dry phase of the annual flooding cycle. It consolidates existing knowledge regarding responses to drought among adult trees and seedlings of many Amazonian floodplain species. Flood-tolerant species display variable physiological responses to dry periods and drought that indicate desiccation avoidance, such as reduced photosynthetic activity and reduced root respiration. However, tolerance and avoidance strategies for drought vary markedly among species. Drought can substantially decrease growth, biomass and photosynthetic activity among seedlings in field and laboratory studies. When compared with the responses to flooding, drought can impose higher seedling mortality and slower growth rates, especially among evergreen species. Results indicate that tolerance and avoidance strategies for drought vary markedly between species. Both seedling recruitment and photosynthetic activity are affected by drought, For many species, the effects of drought can be as important as flooding for survival and growth, particularly at the seedling phase of establishment, ultimately influencing species composition. In the context of climate change and predicted decreases in precipitation in the Amazon Basin, the effects of drought on plant physiology and species distribution in tropical floodplain forest ecosystems should not be overlooked.

  2. Mitochondrial DNA mapping of social-biological interactions in Brazilian Amazonian African-descendant populations

    Directory of Open Access Journals (Sweden)

    Bruno Maia Carvalho

    2008-01-01

    Full Text Available The formation of the Brazilian Amazonian population has historically involved three main ethnic groups, Amerindian, African and European. This has resulted in genetic investigations having been carried out using classical polymorphisms and molecular markers. To better understand the genetic variability and the micro-evolutionary processes acting in human groups in the Brazilian Amazon region we used mitochondrial DNA to investigate 159 maternally unrelated individuals from five Amazonian African-descendant communities. The mitochondrial lineage distribution indicated a contribution of 50.2% from Africans (L0, L1, L2, and L3, 46.6% from Amerindians (haplogroups A, B, C and D and a small European contribution of 1.3%. These results indicated high genetic diversity in the Amerindian and African lineage groups, suggesting that the Brazilian Amazonian African-descendant populations reflect a possible population amalgamation of Amerindian women from different Amazonian indigenous tribes and African women from different geographic regions of Africa who had been brought to Brazil as slaves. The present study partially mapped the historical biological and social interactions that had occurred during the formation and expansion of Amazonian African-descendant communities.

  3. A Miocene hyperdiverse crocodylian community reveals peculiar trophic dynamics in proto-Amazonian mega-wetlands

    Science.gov (United States)

    Salas-Gismondi, Rodolfo; Flynn, John J.; Baby, Patrice; Tejada-Lara, Julia V.; Wesselingh, Frank P.; Antoine, Pierre-Olivier

    2015-01-01

    Amazonia contains one of the world's richest biotas, but origins of this diversity remain obscure. Onset of the Amazon River drainage at approximately 10.5 Ma represented a major shift in Neotropical ecosystems, and proto-Amazonian biotas just prior to this pivotal episode are integral to understanding origins of Amazonian biodiversity, yet vertebrate fossil evidence is extraordinarily rare. Two new species-rich bonebeds from late Middle Miocene proto-Amazonian deposits of northeastern Peru document the same hyperdiverse assemblage of seven co-occurring crocodylian species. Besides the large-bodied Purussaurus and Mourasuchus, all other crocodylians are new taxa, including a stem caiman—Gnatusuchus pebasensis—bearing a massive shovel-shaped mandible, procumbent anterior and globular posterior teeth, and a mammal-like diastema. This unusual species is an extreme exemplar of a radiation of small caimans with crushing dentitions recording peculiar feeding strategies correlated with a peak in proto-Amazonian molluscan diversity and abundance. These faunas evolved within dysoxic marshes and swamps of the long-lived Pebas Mega-Wetland System and declined with inception of the transcontinental Amazon drainage, favouring diversification of longirostrine crocodylians and more modern generalist-feeding caimans. The rise and demise of distinctive, highly productive aquatic ecosystems substantially influenced evolution of Amazonian biodiversity hotspots of crocodylians and other organisms throughout the Neogene. PMID:25716785

  4. Higher Education and Urban Migration for Community Resilience: Indigenous Amazonian Youth Promoting Place-Based Livelihoods and Identities in Peru

    Science.gov (United States)

    Steele, Diana

    2018-01-01

    This paper offers an ethnographic analysis of indigenous Peruvian Amazonian youth pursuing higher education through urban migration to contribute to the resilience of their communities, place-based livelihoods, and indigenous Amazonian identities. Youth and their communities promoted education and migration as powerful tools in the context of…

  5. Carbon Dioxide and Methane Evasion from Amazonian Rivers and Lakes

    Science.gov (United States)

    Melack, J. M.; Barbosa, P.; Schofield, V.; Amaral, J.; Forsberg, B.; Farjalla, V.

    2013-12-01

    Floodplains, with their mosaic of aquatic habitats, constitute the majority of the wetlands of South America. We report 1) estimates of CH4 and CO2 flux from Amazonian floodplain lakes and rivers during low, rising and high water periods, and 2) identify environmental factors regulating these fluxes. We sampled 10 floodplain lakes, 4 tributaries of Solimões River, 6 stations on the Solimões main stem and 1 station on the Madeira, Negro and Amazonas rivers. Diffusive fluxes were measured with static floating chambers. CH4 fluxes were highly variable, with the majority of the values lower than 5 mmol m-2 d-1. For the lakes, no significant differences among the periods were found. CH4 concentration in the water and water temperature were the two main environmental factors regulating the diffusive flux. Our results highlight the importance of considering both the spatial and temporal scales when estimating CH4 fluxes for a region. CO2 fluxes from water to atmosphere ranged between 327 and -21 mmol m-2 d-1, averaging 58 mmol m-2 d-1. We found higher evasion rates in lakes than in rivers. For both systems the lowest rates were found in low water. pH and dissolved oxygen, phosphorous and organic carbon were the main factors correlated to CO2 evasion from the water bodies.

  6. The impact of Amazonian deforestation on Amazon basin rainfall

    Science.gov (United States)

    Spracklen, D. V.; Garcia-Carreras, L.

    2015-11-01

    We completed a meta-analysis of regional and global climate model simulations (n = 96) of the impact of Amazonian deforestation on Amazon basin rainfall. Across all simulations, mean (±1σ) change in annual mean Amazon basin rainfall was -12 ± 11%. Variability in simulated rainfall was not explained by differences in model resolution or surface parameters. Across all simulations we find a negative linear relationship between rainfall and deforestation extent, although individual studies often simulate a nonlinear response. Using the linear relationship, we estimate that deforestation in 2010 has reduced annual mean rainfall across the Amazon basin by 1.8 ± 0.3%, less than the interannual variability in observed rainfall. This may explain why a reduction in Amazon rainfall has not consistently been observed. We estimate that business-as-usual deforestation (based on deforestation rates prior to 2004) would lead to an 8.1 ± 1.4% reduction in annual mean Amazon basin rainfall by 2050, greater than natural variability.

  7. Sexual selection drives speciation in an Amazonian frog

    Science.gov (United States)

    Boul, K.E.; Funk, W.C.; Darst, C.R.; Cannatella, D.C.; Ryan, M.J.

    2007-01-01

    One proposed mechanism of speciation is divergent sexual selection, whereby divergence in female preferences and male signals results in behavioural isolation. Despite the appeal of this hypothesis, evidence for it remains inconclusive. Here, we present several lines of evidence that sexual selection is driving behavioural isolation and speciation among populations of an Amazonian frog (Physalaemus petersi). First, sexual selection has promoted divergence in male mating calls and female preferences for calls between neighbouring populations, resulting in strong behavioural isolation. Second, phylogenetic analysis indicates that populations have become fixed for alternative call types several times throughout the species' range, and coalescent analysis rejects genetic drift as a cause for this pattern, suggesting that this divergence is due to selection. Finally, gene flow estimated with microsatellite loci is an average of 30 times lower between populations with different call types than between populations separated by a similar geographical distance with the same call type, demonstrating genetic divergence and incipient speciation. Taken together, these data provide strong evidence that sexual selection is driving behavioural isolation and speciation, supporting sexual selection as a cause for speciation in the wild. ?? 2006 The Royal Society.

  8. Rapid tree carbon stock recovery in managed Amazonian forests.

    Science.gov (United States)

    Rutishauser, Ervan; Hérault, Bruno; Baraloto, Christopher; Blanc, Lilian; Descroix, Laurent; Sotta, Eleneide Doff; Ferreira, Joice; Kanashiro, Milton; Mazzei, Lucas; d'Oliveira, Marcus V N; de Oliveira, Luis C; Peña-Claros, Marielos; Putz, Francis E; Ruschel, Ademir R; Rodney, Ken; Roopsind, Anand; Shenkin, Alexander; da Silva, Katia E; de Souza, Cintia R; Toledo, Marisol; Vidal, Edson; West, Thales A P; Wortel, Verginia; Sist, Plinio

    2015-09-21

    While around 20% of the Amazonian forest has been cleared for pastures and agriculture, one fourth of the remaining forest is dedicated to wood production. Most of these production forests have been or will be selectively harvested for commercial timber, but recent studies show that even soon after logging, harvested stands retain much of their tree-biomass carbon and biodiversity. Comparing species richness of various animal taxa among logged and unlogged forests across the tropics, Burivalova et al. found that despite some variability among taxa, biodiversity loss was generally explained by logging intensity (the number of trees extracted). Here, we use a network of 79 permanent sample plots (376 ha total) located at 10 sites across the Amazon Basin to assess the main drivers of time-to-recovery of post-logging tree carbon (Table S1). Recovery time is of direct relevance to policies governing management practices (i.e., allowable volumes cut and cutting cycle lengths), and indirectly to forest-based climate change mitigation interventions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Pesticide use and biodiversity conservation in the Amazonian agricultural frontier.

    Science.gov (United States)

    Schiesari, Luis; Waichman, Andrea; Brock, Theo; Adams, Cristina; Grillitsch, Britta

    2013-06-05

    Agricultural frontiers are dynamic environments characterized by the conversion of native habitats to agriculture. Because they are currently concentrated in diverse tropical habitats, agricultural frontiers are areas where the largest number of species is exposed to hazardous land management practices, including pesticide use. Focusing on the Amazonian frontier, we show that producers have varying access to resources, knowledge, control and reward mechanisms to improve land management practices. With poor education and no technical support, pesticide use by smallholders sharply deviated from agronomical recommendations, tending to overutilization of hazardous compounds. By contrast, with higher levels of technical expertise and resources, and aiming at more restrictive markets, large-scale producers adhered more closely to technical recommendations and even voluntarily replaced more hazardous compounds. However, the ecological footprint increased significantly over time because of increased dosage or because formulations that are less toxic to humans may be more toxic to other biodiversity. Frontier regions appear to be unique in terms of the conflicts between production and conservation, and the necessary pesticide risk management and risk reduction can only be achieved through responsibility-sharing by diverse stakeholders, including governmental and intergovernmental organizations, NGOs, financial institutions, pesticide and agricultural industries, producers, academia and consumers.

  10. Mosquitoes of eastern Amazonian Ecuador: biodiversity, bionomics and barcodes

    Directory of Open Access Journals (Sweden)

    Yvonne-Marie Linton

    2013-01-01

    Full Text Available Two snapshot surveys to establish the diversity and ecological preferences of mosquitoes (Diptera: Culicidae in the terra firme primary rain forest surrounding the Tiputini Biodiversity Station in the UNESCO Yasuní Biosphere Reserve of eastern Amazonian Ecuador were carried out in November 1998 and May 1999. The mosquito fauna of this region is poorly known; the focus of this study was to obtain high quality link-reared specimens that could be used to unequivocally confirm species level diversity through integrated systematic study of all life stages and DNA sequences. A total of 2,284 specimens were preserved; 1,671 specimens were link-reared with associated immature exuviae, all but 108 of which are slide mounted. This study identified 68 unique taxa belonging to 17 genera and 27 subgenera. Of these, 12 are new to science and 37 comprise new country records. DNA barcodes [658-bp of the mtDNA cytochrome c oxidase ( COI I gene] are presented for 58 individuals representing 20 species and nine genera. DNA barcoding proved useful in uncovering and confirming new species and we advocate an integrated systematics approach to biodiversity studies in future. Associated bionomics of all species collected are discussed. An updated systematic checklist of the mosquitoes of Ecuador (n = 179 is presented for the first time in 60 years.

  11. Mosquitoes of eastern Amazonian Ecuador: biodiversity, bionomics and barcodes.

    Science.gov (United States)

    Linton, Yvonne-Marie; Pecor, James E; Porter, Charles H; Mitchell, Luke Brett; Garzón-Moreno, Andrés; Foley, Desmond H; Pecor, David Brooks; Wilkerson, Richard C

    2013-01-01

    Two snapshot surveys to establish the diversity and ecological preferences of mosquitoes (Diptera: Culicidae) in the terra firme primary rain forest surrounding the Tiputini Biodiversity Station in the UNESCO Yasuní Biosphere Reserve of eastern Amazonian Ecuador were carried out in November 1998 and May 1999. The mosquito fauna of this region is poorly known; the focus of this study was to obtain high quality link-reared specimens that could be used to unequivocally confirm species level diversity through integrated systematic study of all life stages and DNA sequences. A total of 2,284 specimens were preserved; 1,671 specimens were link-reared with associated immature exuviae, all but 108 of which are slide mounted. This study identified 68 unique taxa belonging to 17 genera and 27 subgenera. Of these, 12 are new to science and 37 comprise new country records. DNA barcodes [658-bp of the mtDNA cytochrome c oxidase (COI) I gene] are presented for 58 individuals representing 20 species and nine genera. DNA barcoding proved useful in uncovering and confirming new species and we advocate an integrated systematics approach to biodiversity studies in future. Associated bionomics of all species collected are discussed. An updated systematic checklist of the mosquitoes of Ecuador (n=179) is presented for the first time in 60 years.

  12. Poor prospects for avian biodiversity in Amazonian oil palm.

    Science.gov (United States)

    Lees, Alexander C; Moura, Nárgila G; de Almeida, Arlete Silva; Vieira, Ima C G

    2015-01-01

    Expansion of oil palm plantations across the humid tropics has precipitated massive loss of tropical forest habitats and their associated speciose biotas. Oil palm plantation monocultures have been identified as an emerging threat to Amazonian biodiversity, but there are no quantitative studies exploring the impact of these plantations on the biome's biota. Understanding these impacts is extremely important given the rapid projected expansion of oil palm cultivation in the basin. Here we investigate the biodiversity value of oil palm plantations in comparison with other dominant regional land-uses in Eastern Amazonia. We carried out bird surveys in oil palm plantations of varying ages, primary and secondary forests, and cattle pastures. We found that oil palm plantations retained impoverished avian communities with a similar species composition to pastures and agrarian land-uses and did not offer habitat for most forest-associated species, including restricted range species and species of conservation concern. On the other hand, the forests that the oil palm companies are legally obliged to protect hosted a relatively species-rich community including several globally-threatened bird species. We consider oil palm to be no less detrimental to regional biodiversity than other agricultural land-uses and that political pressure exerted by large landowners to allow oil palm to count as a substitute for native forest vegetation in private landholdings with forest restoration deficits would have dire consequences for regional biodiversity.

  13. Poor prospects for avian biodiversity in Amazonian oil palm.

    Directory of Open Access Journals (Sweden)

    Alexander C Lees

    Full Text Available Expansion of oil palm plantations across the humid tropics has precipitated massive loss of tropical forest habitats and their associated speciose biotas. Oil palm plantation monocultures have been identified as an emerging threat to Amazonian biodiversity, but there are no quantitative studies exploring the impact of these plantations on the biome's biota. Understanding these impacts is extremely important given the rapid projected expansion of oil palm cultivation in the basin. Here we investigate the biodiversity value of oil palm plantations in comparison with other dominant regional land-uses in Eastern Amazonia. We carried out bird surveys in oil palm plantations of varying ages, primary and secondary forests, and cattle pastures. We found that oil palm plantations retained impoverished avian communities with a similar species composition to pastures and agrarian land-uses and did not offer habitat for most forest-associated species, including restricted range species and species of conservation concern. On the other hand, the forests that the oil palm companies are legally obliged to protect hosted a relatively species-rich community including several globally-threatened bird species. We consider oil palm to be no less detrimental to regional biodiversity than other agricultural land-uses and that political pressure exerted by large landowners to allow oil palm to count as a substitute for native forest vegetation in private landholdings with forest restoration deficits would have dire consequences for regional biodiversity.

  14. Ocurrence of Cryptosporidium spp. in Amazonian manatees (Trichechus inunguis, Natterer, 1883

    Directory of Open Access Journals (Sweden)

    Maria Aparecida da Glória Faustino

    2007-09-01

    Full Text Available The apicomplexa protozoa Cryptosporidium infects several mammals, including terrestrial and aquatic species. In the epidemiology of this infection, the ingestion of water and/or food contamined with oocysts comprises the main mechanism of transmission to susceptible animals. Among the Sirenians, the occurrence of this coccidium has been reported in dugongs (Dugong dugon and Antillean manatee (Trichechus manatus manatus. The present study was conducted with the aim of verifying the occurrence of Cryptosporidium spp. in Amazonian manatee. For this purpose, fecal samples were collected from ten free-ranging Amazonian manatees, two specimens in captivity, and 103 supernatants fecal samples. The samples were processed by the sedimentation method in formol-ether and Kinyoun stain technique for the presence of Cryptosporidium spp.. The positive samples were then submitted to Direct Immunoflorescence Test. The results showed 4.34% (05/115 of positive samples. This is the first report of Cryptosporidium spp. in the Amazonian manatee.

  15. Use of amazonian anthropogenic soils: Comparison between Caboclos communities and Tikunas indigenous group

    International Nuclear Information System (INIS)

    Torres Sanabria, Camilo; Cuartas Ricaurte, Jorge Armando

    2013-01-01

    In general terms, Amazonian soils are infertile and have several constraints for agricultural production. However, use by ancient human societies since pre-columbian times has driven landscape transformation of massive areas and development of anthropogenic soils called Terra Preta do Indio (TP) or Amazonian Dark Earths (ADE). ADE characterization, in terms of fertility and composition, has allowed the development of intensive agricultural activities over time. The current use of ADE for the Brazilian amazon peasants (Caboclos) is different from the indigenous communities in Colombia. The indigenous people in Colombia (Tikunas) no use this type of soils on behalf of cultural restrictions that avoid the use of ancient places. We are comparing the institutional conditions, migrations, social characterization and cultural factors that determine the use/no-use of these soils by the Amazonian societies.

  16. Paleoclimatic Comparisons Between Three Late Quaternary Amazonian Lacustrine Records

    Science.gov (United States)

    Cordeiro, R. C.; Martins, G. S.; Fontes, D.; Turcq, B.; Sifeddine, A.; Seoane, J. S.; Conceição, M. G.; Barbosa, M.; Rodrigues, R. A.; Moreira, L.

    2012-12-01

    In recent years many records made in the cores of ice has shown significant changes in temperature associated with changes in atmospheric composition. The most notable changes occur between the glacials and interglacials cycles. Climatic changes in tropical areas during the global climatic changes is highly debatable. Even today, there are many controversies about the extent of the occurrence of dry weather in the Amazon during glacial periods. In the region of São Gabriel da Cachoeira, polynic diagram of Lagoa da Pata showed that vegetation remained with elements of forest trees, with replacement of elements of cold weather during the last glacial. In Carajás were observed substitution forest to savannah, during the last glacial. We present here a comparison of organic and inorganic geochemical sediment record of tree distinct Amazonian sectors: Morro dos Seis Lagos (AM) is located at 0°17‧9.68″ N and 66°40‧36.18″ W (Lagoa da Pata, LPT V core position) located in the forested upper Rio Negro basin in humid climate area (~3000 mm/yr), Carajás Region at 5°50‧ to 6°35‧ S and 49°30‧ to 52°00‧ situated 800 m high in lateritic crust in south eastern Amazonia (1800mm/yr) and São Benedito Region (PA) at 9°7'0.87"S and 56°16'0.00"W (Lago do Saci, Sac01/05 core position) in south Amazonia with a mean precipitation as Carajás around 1800 mm/yr. A comparison of these records reveals important changes in the environmental history of the Amazonian hydrological regime during the late Quaternary. The results of geochemical analyses reveal three hydrological and climatic regimes from 50,000 cal yr BP until the present. The first phase, between 50,000 until ~25,000 cal yr BP, was characterized by relatively high lake level as suggested by high organic carbon values in Lagoa da Pata and Carajás principally in the beginning of the period. In Saci Lake in the beginning of the record (35,500 cal yr BP) high values of TOC were observed relatively to last

  17. Amazonian Buriti oil: chemical characterization and antioxidant potential

    Directory of Open Access Journals (Sweden)

    Speranza, P.

    2016-06-01

    Full Text Available Buriti oil is an example of an Amazonian palm oil of economic importance. The local population uses this oil for the prevention and treatment of different diseases; however, there are few studies in the literature that evaluate its properties. In this study, detailed chemical and antioxidant properties of Buriti oil were determined. The predominant fatty acid was oleic acid (65.6% and the main triacylglycerol classes were tri-unsaturated (50.0% and di-unsaturated-mono-saturated (39.3% triacylglycerols. The positional distribution of the classes of fatty acids on the triacylglycerol backbone indicated a saturated and unsaturated fatty acid relationship similar in the three-triacylglycerol positions. All tocopherol isomers were present, with a total content of 2364.1 mg·kg−1. α-tocopherol constitutes 48% of the total tocopherol content, followed by γ- tocopherol (45%. Total phenolic (107.0 mg gallic acid equivalent·g−1 oil and β-carotene (781.6 mg·kg−1 were particularly high in this oil. The highest antioxidant activity against the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH was obtained at an oil concentration of 50 mg·mL−1 (73.15%. The antioxidant activity evaluated by the Oxygen Radical Absorbance Capacity (ORAC was 95.3 μmol Trolox equivalent·g−1 oil. These results serve to present Buriti oil as an Amazonian resource for cosmetic, food and pharmaceuticals purposes.El aceite de Buriti es un ejemplo de aceite de palma amazónica de gran importancia económica. La población local utiliza este aceite para la prevención y el tratamiento de diferentes enfermedades; sin embargo, hay pocos estudios científicos que evalúen sus propiedades. En este estudio, se determinaron las propiedades antioxidantes del aceite de Buriti. El ácido graso predominante fue el oleico (65,6 % y las principales clases de triglicéridos fueron tri-insaturadas (50,0 % y Di-insaturados-mono-saturada (39,3 %. La distribución posicional de las

  18. Slow growth rates of Amazonian trees: Consequences for carbon cycling

    Science.gov (United States)

    Vieira, Simone; Trumbore, Susan; Camargo, Plinio B.; Selhorst, Diogo; Chambers, Jeffrey Q.; Higuchi, Niro; Martinelli, Luiz Antonio

    2005-01-01

    Quantifying age structure and tree growth rate of Amazonian forests is essential for understanding their role in the carbon cycle. Here, we use radiocarbon dating and direct measurement of diameter increment to document unexpectedly slow growth rates for trees from three locations spanning the Brazilian Amazon basin. Central Amazon trees, averaging only ≈1mm/year diameter increment, grow half as fast as those from areas with more seasonal rainfall to the east and west. Slow growth rates mean that trees can attain great ages; across our sites we estimate 17-50% of trees with diameter >10 cm have ages exceeding 300 years. Whereas a few emergent trees that make up a large portion of the biomass grow faster, small trees that are more abundant grow slowly and attain ages of hundreds of years. The mean age of carbon in living trees (60-110 years) is within the range of or slightly longer than the mean residence time calculated from C inventory divided by annual C allocation to wood growth (40-100 years). Faster C turnover is observed in stands with overall higher rates of diameter increment and a larger fraction of the biomass in large, fast-growing trees. As a consequence, forests can recover biomass relatively quickly after disturbance, whereas recovering species composition may take many centuries. Carbon cycle models that apply a single turnover time for carbon in forest biomass do not account for variations in life strategy and therefore may overestimate the carbon sequestration potential of Amazon forests. PMID:16339903

  19. Environmental characteristics drive variation in Amazonian understorey bird assemblages.

    Directory of Open Access Journals (Sweden)

    Juliana Menger

    Full Text Available Tropical bird assemblages display patterns of high alpha and beta diversity and, as tropical birds exhibit strong habitat specificity, their spatial distributions are generally assumed to be driven primarily by environmental heterogeneity and interspecific interactions. However, spatial distributions of some Amazonian forest birds are also often restricted by large rivers and other large-scale topographic features, suggesting that dispersal limitation may also play a role in driving species' turnover. In this study, we evaluated the effects of environmental characteristics, topographic and spatial variables on variation in local assemblage structure and diversity of birds in an old-growth forest in central Amazonia. Birds were mist-netted in 72 plots distributed systematically across a 10,000 ha reserve in each of three years. Alpha diversity remained stable through time, but species composition changed. Spatial variation in bird-assemblage structure was significantly related to environmental and topographic variables but not strongly related to spatial variables. At a broad scale, we found bird assemblages to be significantly distinct between two watersheds that are divided by a central ridgeline. We did not detect an effect of the ridgeline per se in driving these patterns, indicating that most birds are able to fly across it, and that differences in assemblage structure between watersheds may be due to unmeasured environmental variables or unique combinations of measured variables. Our study indicates that complex geography and landscape features can act together with environmental variables to drive changes in the diversity and composition of tropical bird assemblages at local scales, but highlights that we still know very little about what makes different parts of tropical forest suitable for different species.

  20. Life history and environment of Cecropia latiloba in Amazonian floodplains.

    Science.gov (United States)

    Parolin, Pia

    2002-06-01

    Cecropia latiloba can be considered to be one of the most efficient colonizers of open areas in the nutrient-rich whitewater floodplains of the Amazon river. Its main strategy to be successful is the high tolerance towards waterlogging and submergence, and the fast vertical growth and reiteration capacity. This, and the tolerance of high irradiation and sediment deposition allow C. latiloba to form large monospecific stands on open sites, and thus the first closed canopy which represents the initial phase of a successional sequence which leads to highly diverse forests. This tree is extremely well adapted to the adverse growth conditions in Amazonian floodplains with prolonged periods of flooding and seedling submergence. The species occurs on the lowest levels in the flooding gradient. Although it belongs to the most often cited species under aspects of taxonomy, species distribution and general descriptions of the ecosystem, little has been published about its ecology. In the present paper the ecological, physiological and phenological characteristics of C. latiloba are described. It is an evergreen species which constantly produces new leaves. With flooding, leaf production is reduced but new leaves are flushed also with prolongued flooding. The peak of flowering and fruiting are in the flooded period. When mature, the fruits are dispersed mainly by water and fish. Seed germination occurs, without dormancy, within 5-13 days after water retreat. In the 7 months before the first flooded period seedlings reach 1 m of height, and height growth increases until 15-20 m are achieved. Photosynthetic assimilation is high, with values of up to 21 mumol CO2 m-2s-1. C. latiloba is a very flood tolerant species, and waterlogged seedlings continuously produce new leaves and adventitious roots.

  1. Thresholds of species loss in Amazonian deforestation frontier landscapes.

    Science.gov (United States)

    Ochoa-Quintero, Jose Manuel; Gardner, Toby A; Rosa, Isabel; Ferraz, Silvio Frosini de Barros; Sutherland, William J

    2015-04-01

    In the Brazilian Amazon, private land accounts for the majority of remaining native vegetation. Understanding how land-use change affects the composition and distribution of biodiversity in farmlands is critical for improving conservation strategies in the face of rapid agricultural expansion. Working across an area exceeding 3 million ha in the southwestern state of Rondônia, we assessed how the extent and configuration of remnant forest in replicate 10,000-ha landscapes has affected the occurrence of a suite of Amazonian mammals and birds. In each of 31 landscapes, we used field sampling and semistructured interviews with landowners to determine the presence of 28 large and medium sized mammals and birds, as well as a further 7 understory birds. We then combined results of field surveys and interviews with a probabilistic model of deforestation. We found strong evidence for a threshold response of sampled biodiversity to landscape level forest cover; landscapes with deforested landscapes many species are susceptible to extirpation following relatively small additional reductions in forest area. In the model of deforestation by 2030 the number of 10,000-ha landscapes under a conservative threshold of 43% forest cover almost doubled, such that only 22% of landscapes would likely to be able to sustain at least 75% of the 35 focal species we sampled. Brazilian law requires rural property owners in the Amazon to retain 80% forest cover, although this is rarely achieved. Prioritizing efforts to ensure that entire landscapes, rather than individual farms, retain at least 50% forest cover may help safeguard native biodiversity in private forest reserves in the Amazon. © 2015 Society for Conservation Biology.

  2. Evolutionary patterns of range size, abundance and species richness in Amazonian angiosperm trees

    Directory of Open Access Journals (Sweden)

    Kyle Dexter

    2016-09-01

    Full Text Available Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. The drivers of this variation are not well understood. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to contribute to explaining the variation. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics; closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species. Our results suggest that phylogenetically correlated intrinsic factors, namely traits of the genera themselves, shape among lineage variation in range size, abundance and species richness. We postulate that tree stature may be one particularly relevant trait. However, other traits may also be relevant, and our study reinforces the need for ambitious compilations of trait data for Amazonian trees. In the meantime, our study shows how large-scale phylogenies can help to elucidate, and contribute to explaining, macroecological and macroevolutionary patterns in hyperdiverse, yet poorly understood regions like the Amazon Basin.

  3. The role of Amazonian anthropogenic soils in shifting cultivation: learning from farmers’ rationales

    NARCIS (Netherlands)

    Braga Junqueira, A.; Almekinders, C.J.M.; Stomph, T.J.; Clement, C.R.; Struik, P.C.

    2016-01-01

    We evaluated farmers’ rationales to understand their decision making in relation to the use of fertile anthropogenic soils, i.e., Amazonian dark earths (ADE), and for dealing with changes in shifting cultivation in Central Amazonia. We analyzed qualitative information from 196 interviews with

  4. Morphology, morphometry and ultrastructure of the Amazonian manatee (Sirenia: Trichechidae spermatozoa

    Directory of Open Access Journals (Sweden)

    Rodrigo S. Amaral

    2010-01-01

    Full Text Available This study describes the morphological, morphometric and ultrastructural characteristics of the Amazonian manatee Trichechus inunguis (Natterer, 1883 spermatozoon. The spermatozoa were obtained from a urine sample of an adult T. inunguis kept in captivity. The spermatozoa were analyzed by light and transmission electron microscopy. The head of Amazonian manatee spermatozoa had a flat oval shape and a well distinguishable midpiece. The mean dimensions of the spermatozoa were: head length, 7.49 ± 0.24 µm; head width, 3.53 ± 0.19 µm; head thickness, 1.61 ± 0.13 µm; midpiece length, 11.36 ± 0.34 µm; flagellum length, 40.91 ± 1.94 µm; total tail length, 52.16 ± 1.06 µm; total spermatozoon length, 60.08 ± 1.40 µm. The Amazonian manatee spermatozoa were similar in shape to other sirenian spermatozoa; however, presenting a different size. This study describes, for the first time, the morphometric and ultrastructural characteristics of the Amazonian manatee spermatozoa, and also demonstrates the possible use of spermatozoa retrieved from urine samples for biological studies.

  5. Legacies of Amazonian dark earths on forest composition, structure and dynamics

    NARCIS (Netherlands)

    Quintero Vallejo, E.M.

    2015-01-01

    Summary

    Amazonian forest is seen as the archetype of pristine forests, untouched by humans, but this romantic view is far from reality. In recent years, there is increasing evidence of long and extensive landscape modification by humans. Processes of permanent inhabitation,

  6. Notes on Amazonian Bittacidae (Mecoptera with the descriptions of two new species

    Directory of Open Access Journals (Sweden)

    Norman D. Penny

    1982-09-01

    Full Text Available New species of Issikiella and Nannobittacus are described and notes are presented on other Amazonian species of Mecoptera.Nova espécie de Issikiella e Nannobittacus são descritas e notas são apresentadas para outras espécies de Mecopteros da Amazônia.

  7. Effects of reduced-impact logging and forest physiognomy on bat populations of lowland Amazonian forest.

    Science.gov (United States)

    Steven J. Presley; Michael R. Willig; Wunderle Jr. Joseph M.; Luis Nélio. Saldanha

    2008-01-01

    1.As human population size increases, demand for natural resources will increase. Logging pressure related to increasing demands continues to threaten remote areas of Amazonian forest. A harvest protocol is required to provide renewable timber resources that meet consumer needs while minimizing negative effects on biodiversity and ecosystem services. Reduced-impact...

  8. Legacies of Amazonian dark earths on forest composition, structure and dynamics

    NARCIS (Netherlands)

    Quintero Vallejo, E.M.

    2015-01-01

    Summary

    Amazonian forest is seen as the archetype of pristine forests, untouched by humans, but this romantic view is far from reality. In recent years, there is increasing evidence of long and extensive landscape modification by humans. Processes of permanent inhabitation,

  9. The development of the Amazonian mega-wetland (Miocene; Brazil, Colombia, Peru, Bolivia)

    NARCIS (Netherlands)

    Hoorn, C.; Wesselingh, F.P.; Hovikoski, J.; Guerrero, J.; Hoorn, C.; Wesselingh, F.P.

    2010-01-01

    The scenery of Western Amazonia once consisted of fluvial systems that originated on the Amazonian Craton and were directed towards the sub-Andean zone and the Caribbean. In the course of the Early Miocene these fluvial systems were largely replaced by lakes, swamps, tidal channels and marginal

  10. Amazonian Dark Earth and its Black Carbon Particles Harbor Different Fungal Abundance and Diversity

    NARCIS (Netherlands)

    Reis Lucheta, Adriano; Souza Cannavan, F.S.; Tsai, S.M.; Kuramae, E.E.

    2017-01-01

    Amazonian Dark Earth (ADE) is a highly fertile soil of anthropogenic origin characterized by higher amount of charred black carbon (BC). ADE is considered a fertility model, however knowledge about the fungal community structure and diversity inhabiting ADE and BC is scarce. Fungal community

  11. Amazonian Dark Earth and plant species from the Amazon region contribute to shape rhizosphere bacterial communities

    NARCIS (Netherlands)

    Barbosa Lima, A.; Souza Cannavan, F.S.; Navarrete, A.A.; Kuramae, E.E.; Teixeira, W.G.; Tsai, S.M.

    2015-01-01

    Amazonian Dark Earths (ADE) or Terra Preta de Índio formed in the past by pre-Columbian populations are highly sustained fertile soils supported by microbial communities that differ from those extant in adjacent soils. These soils are found in the Amazon region and are considered as a model soil

  12. Understanding moisture recycling for atmospheric river management in Amazonian communities

    Science.gov (United States)

    Weng, Wei; Luedeke, Matthias; Zemp, Delphine-Clara; Lakes, Tobia; Pradhan, Prajal; Kropp, Juergen

    2017-04-01

    The invisible atmospheric transports of moisture have recently attracted more research efforts into understanding their structures, processes involved and their function as an ecosystem service. Current attention has been focused on larger scale analysis such as studying global or continental level moisture recycling. Here we applied a water balance model to backtrack the flying river that sustains two local communities in the Colombian and Peruvian Amazon where vulnerable communities rely highly on the rainfall for agricultural practices. By utilising global precipitation (TRMM Multisatillite Precipitation Analysis; TMPA) and evapotranspiration products (Moderate Resolution Imaging Spectroradiometer MODIS, MOD16ET) as input data in the present modelling experiments to compensate the sparse ground observation data in these regions, the moisture recycling process targeting the two amazonian communities which has not yet been explored quantitatively has been shown. The TMPA was selected because of its proved comparativeness with observation data in its precipitation estimations over Amazon regions while the MOD16ET data was chosen for being validated by previous studies in the Amazon basin and for reported good performance. In average, 45.5 % of the precipitation occurring to Caquetá region in Colombia is of terrestrial origin from the South American continent while 48.2% of the total rainfall received by Peruvian Yurimaguas is also from the South American land sources. The spatial distribution of the precipitationsheds (defined previously as the upwind contribution of evapotranspiration to a specific location's precipitation) shows transboundary and transnational shares in the moisture contributors of the precipitation for both regions. An interesting reversed upstream-downstream roles can be observed when the upstream regions in traditional watershed thinking become downstream areas considering precipitationsheds and flying rivers. Strong seasonal variations are

  13. Effects of physical activity at work and life-style on sleep in workers from an Amazonian Extractivist Reserve

    Directory of Open Access Journals (Sweden)

    Andressa Juliane Martins

    2016-10-01

    Full Text Available Physical activity has been recommended as a strategy for improving sleep. Nevertheless, physical effort at work might not be not the ideal type of activity to promote sleep quality. The aim of this study was to evaluate the effects of type of job (low vs. high physical effort and life-style on sleep of workers from an Amazonian Extractivist Reserve, Brazil. A cross-sectional study of 148 low physical activity (factory workers and 340 high physical activity (rubber tappers was conducted between September and November 2011. The workers filled out questionnaires collecting data on demographics (sex, age, occupation, marital status and children, health (reported morbidities, sleep disturbances, musculoskeletal pain and body mass index and life-style (smoking, alcohol use and practice of leisure-time physical activity. Logistic regression models were applied with the presence of sleep disturbances as the primary outcome variable. The prevalence of sleep disturbances among factory workers and rubber tappers was 15.5% and 27.9%, respectively. The following independent variables of the analysis were selected based on a univariate model (p40 years, and having musculoskeletal pain (≥5 symptoms. Rubber tapper work, owing to greater physical effort, pain and musculoskeletal fatigue, was associated with sleep disturbances. Being female and older than 40 years were also predictors of poor sleep. In short, these findings suggest that demanding physical exertion at work may not improve sleep quality.

  14. Spatial and temporal epidemiology of malaria in extra-Amazonian regions of Brazil.

    Science.gov (United States)

    Lorenz, Camila; Virginio, Flávia; Aguiar, Breno S; Suesdek, Lincoln; Chiaravalloti-Neto, Francisco

    2015-10-15

    Mosquitoes, Plasmodium parasites, and humans live in sympatry in some extra-Amazonian regions of Brazil. Recent migrations of people from Amazonia and other countries to extra-Amazonian regions have led to many malaria outbreaks. Lack of relevant expertise among health professionals in non-endemic areas can lead to a neglect of the disease, which can be dangerous given its high fatality rate. Therefore, understanding the spatial and temporal epidemiology of malaria is essential for developing strategies for disease control and elimination. This study aimed to characterize imported (IMP) and autochthonous/introduced (AU/IN) cases in the extra-Amazonian regions and identify risk areas and groups. Epidemiological data collected between 2007 and 2014 were obtained from the Notifiable Diseases Information System of the Ministry of Health (SINAN) and from the Department of the Unified Health System (DATASUS). High malaria risk areas were determined using the Local Indicator of Spatial Association. IMP and AU/IN malaria incidence rates were corrected by Local Empirical Bayesian rates. A total of 6092 malaria cases (IMP: 5416, 88.9 %; AU/IN: 676, 11.1 %) was recorded in the extra-Amazonian regions in 2007-2014. The highest numbers of IMP and AU/IN cases were registered in 2007 (n = 862) and 2010 (n = 149), respectively. IMP cases were more frequent than AU/IN cases in all states except for Espírito Santo. Piauí, Espírito Santo, and Paraná states had high incidences of AU/IN malaria. The majority of infections were by Plasmodium falciparum in northeast and southeast regions, while Plasmodium vivax was the predominant species in the south and mid-west showed cases of dual infection. AU/IN malaria cases were concentrated in the coastal region of Brazil, which contains the Atlantic Forest and hosts the Anopheles transmitters. Several malaria clusters were also associated with the Brazilian Pantanal biome and regions bordering the Amazonian biome. Malaria is widespread

  15. Forest structure and carbon dynamics in Amazonian tropical rain forests.

    Science.gov (United States)

    Vieira, Simone; de Camargo, Plinio Barbosa; Selhorst, Diogo; da Silva, Roseana; Hutyra, Lucy; Chambers, Jeffrey Q; Brown, I Foster; Higuchi, Niro; dos Santos, Joaquim; Wofsy, Steven C; Trumbore, Susan E; Martinelli, Luiz Antonio

    2004-08-01

    Living trees constitute one of the major stocks of carbon in tropical forests. A better understanding of variations in the dynamics and structure of tropical forests is necessary for predicting the potential for these ecosystems to lose or store carbon, and for understanding how they recover from disturbance. Amazonian tropical forests occur over a vast area that encompasses differences in topography, climate, and geologic substrate. We observed large differences in forest structure, biomass, and tree growth rates in permanent plots situated in the eastern (near Santarém, Pará), central (near Manaus, Amazonas) and southwestern (near Rio Branco, Acre) Amazon, which differed in dry season length, as well as other factors. Forests at the two sites experiencing longer dry seasons, near Rio Branco and Santarém, had lower stem frequencies (460 and 466 ha(-1) respectively), less biodiversity (Shannon-Wiener diversity index), and smaller aboveground C stocks (140.6 and 122.1 Mg C ha(-1)) than the Manaus site (626 trees ha(-1), 180.1 Mg C ha(-1)), which had less seasonal variation in rainfall. The forests experiencing longer dry seasons also stored a greater proportion of the total biomass in trees with >50 cm diameter (41-45 vs 30% in Manaus). Rates of annual addition of C to living trees calculated from monthly dendrometer band measurements were 1.9 (Manaus), 2.8 (Santarém), and 2.6 (Rio Branco) Mg C ha(-1) year(-1). At all sites, trees in the 10-30 cm diameter class accounted for the highest proportion of annual growth (38, 55 and 56% in Manaus, Rio Branco and Santarém, respectively). Growth showed marked seasonality, with largest stem diameter increment in the wet season and smallest in the dry season, though this may be confounded by seasonal variation in wood water content. Year-to-year variations in C allocated to stem growth ranged from nearly zero in Rio Branco, to 0.8 Mg C ha(-1) year(-1) in Manaus (40% of annual mean) and 0.9 Mg C ha(-1) year(-1) (33% of

  16. Hypoxic environments as refuge against predatory fish in the Amazonian floodplains

    Directory of Open Access Journals (Sweden)

    MB. Anjos

    Full Text Available Several groups of Amazonian fishes exhibit behavioral, morphological and physiological characteristics that allow occupying hypoxic environments, despite the energetic costs of living in such harsh conditions. One of the supposed advantages of occupying hypoxic habitats would be a lower predation pressure resulting from a lower number of piscivorous fishes in those environments. We tested this hypothesis in an area of the Amazon River floodplain through gill net fishing in normoxic and hypoxic habitats. From the 103 species caught, 38 were classified as piscivores. We found no difference in the number of piscivorous species captured in hypoxic and normoxic habitats (chi2 = 0.23; p = 0.63; df = 1 but piscivorous individuals were more numerous in normoxic than in hypoxic sampling stations (chi2 = 104.4; p < 0.001; df = 1. This indicates that environments submitted to low oxygen conditions may in fact function as refuges against piscivorous fishes in the Amazonian floodplains.

  17. Phenolic constituents and antioxidant activity of geopropolis from two species of amazonian stingless bees

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ellen Cristina Costa da; Muniz, Magno Perea; Nunomura, Rita de Cassia Saraiva, E-mail: ellensilva@yahoo.com.br [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal do Amazonas, Manaus, AM (Brazil); Nunomura, Sergio Massayoshi [Departamento de Produtos Naturais, Instituto Nacional de Pesquisas da Amazonia, Manaus, AM (Brazil); Zilse, Gislene Almeida Carvalho [Departamento de Biodiversidade, Instituto Nacional de Pesquisas da Amazonia, Manaus, AM (Brazil)

    2013-09-01

    We investigated the phenolic constituents and antioxidant activity of geopropolis from two species of stingless Amazonian bees, Melipona interrupta and Melipona seminigra. The chemical investigation of geopropolis from Melipona interrupta led to the isolation of 5,7,4'-trihydroxyflavonone, 3,5,6,7,4'-pentahydroxyflavonol, naringenine-4'-O-{beta}-D-glucopyranoside and myricetin-3-O-{beta}-D-glucopyranoside. Their structures were assigned based on spectroscopic analyses, including two-dimensional NMR techniques. Antioxidant activity of methanol and ethanol extracts of M. interrupta and M. seminigra were measured using the 1,2-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay. This is also the first work reporting the chemical investigation of stingless bee species from the Amazonian region. (author)

  18. Biodiversity, threats and conservation challenges in the Cerrado of Amapá, an Amazonian savanna

    Directory of Open Access Journals (Sweden)

    Karen Mustin

    2017-10-01

    Full Text Available An Amazonian savanna in northern Brazil known as the Cerrado of Amapá is under imminent threat from poor land-use planning, the expansion of large-scale agriculture and other anthropogenic pressures. These savannas house a rich and unique flora and fauna, including endemic plants and animals. However, the area remains under-sampled for most taxa, and better sampling may uncover new species. We estimate that only ~9.16% of these habitats have any kind of protection, and legislative changes threaten to further weaken or remove this protection. Here we present the status of knowledge concerning the biodiversity of the Cerrado of Amapá, its conservation status, and the main threats to the conservation of this Amazonian savanna. To secure the future of these unique and imperilled habitats, we suggest urgent expansion of protected areas, as well as measures that would promote less-damaging land uses to support the local population.

  19. Missing in Amazonian jungle: a case report of skeletal evidence for dismemberment.

    Science.gov (United States)

    Delabarde, Tania; Ludes, Bertrand

    2010-07-01

    This case study presents the results of the recovery and analysis of three sets of disarticulated and incomplete human remains found in Ecuador, within the Amazonian jungle. Recovered body parts sustained extensive sharp force trauma situated on different aspect of the skeleton. The anthropological examination (bone reassembly, biological profile) was followed by a detailed analysis of cut marks, including a basic experimental study on pig bones to demonstrate that dismemberment may have occurred within a certain amount of time after death. Despite the location (deep into the Amazonian jungle) and the perpetrator's actions (dismemberment and dispersion of body parts in a river), forensic work both on the field and in laboratory allowed identification of the victims and the reconstruction of the sequence of events.

  20. Offering offspring as food to cannibals: oviposition strategies of Amazonian poison frogs (Dendrobates ventrimaculatus)

    OpenAIRE

    Poelman, E.H.; Dicke, M.

    2007-01-01

    Species utilizing distinct resources for offspring production often show plasticity in reproductive strategies as a function of resource quality. For species using ephemeral pools, strategies are mainly shaped by a time constraint related to pool stability, resource availability and the colonizing community. We studied reproductive strategies in Amazonian poison frogs (Dendrobates ventrimaculatus) that are characterized by oviposition in distinct, small and resource-limited water bodies in le...

  1. Circadian rhythms constrain leaf and canopy gas exchange in an Amazonian forest

    OpenAIRE

    Doughty, Christopher E.; Goulden, Michael L.; Miller, Scott D.; da Rocha, Humberto R.

    2006-01-01

    We used a controlled-environment leaf gas-exchange system and the micrometeorological technique eddy covariance to determine whether circadian rhythms constrain the rates of leaf and canopy gas exchange in an Amazonian forest over a day. When exposed to continuous and constant light for 20 to 48 hours leaves of eleven of seventeen species reduced their photosynthetic rates and closed their stomata during the normally dark period and resumed active gas exchange during the normally light period...

  2. Chromosome number and karyotype of the endangered Amazonian woody Centrolobium paraense Tul. species

    OpenAIRE

    Nair Dahmer; Maria Teresa Schifino Wittmann; Paulo Emilio Kaminski

    2009-01-01

    Centrolobium paraense Tul., popularly known in Brazil as “pau-rainha”, is a species with a high timberpotential, presently endangered due to deforestation of the Amazonian region and indiscriminate wood extraction. Chromosomenumber and karyotype morphology of this species are presented for the first time. All the individuals of the three populationsanalyzed are diploid, with 2n=2x=20 chromosomes. The chromosomes ranging from ca. 1.7 to 4 μm in size. The karyotypeis composed of three metacentr...

  3. An integrative taxonomy approach unveils unknown and threatened moth species in Amazonian rainforest fragments

    Czech Academy of Sciences Publication Activity Database

    Lamarre, Greg P. A.; Decaëns, T.; Rougerie, R.; Barbut, J.; Dewaard, J. R.; Hebert, P. D. N.; Herbin, D.; Laguerre, M.; Thiaucourt, P.; Martins, M. B.

    2016-01-01

    Roč. 9, č. 5 (2016), s. 475-479 ISSN 1752-458X EU Projects: European Commission(XE) 669609 - Diversity6continents Institutional support: RVO:60077344 Keywords : Amazonian forest * Belém center of endemism * centinelan extinction Subject RIV: EG - Zoology Impact factor: 1.840, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/icad.12187/full

  4. Phylogenetic insights into the diversity of homocytous cyanobacteria from Amazonian rivers.

    Science.gov (United States)

    Genuário, Diego Bonaldo; Vaz, Marcelo Gomes Marçal Vieira; Melo, Itamar Soares de

    2017-11-01

    The Amazon Rainforest holds great tropical biodiversity, mainly because of its favourable climatic conditions. The high temperatures, luminosity and humidity coupled with the nutritional simplicity of cyanobacteria allow undiscovered diversity to flourish within this group of microorganisms. Some efforts to reveal this diversity have been attempted; however, most were focused on the microscopic observation of environmental samples without any genetic information. Very few studies focusing on morphological, ecological and molecular criteria have been conducted, and none have been devoted to homocytous cyanobacteria forms in Amazonia region. Therefore, the genetic relationships amongst strains retrieved from this ecosystem with regard to other environments from Brazil and the world have not been tested and, consequently, the Amazonian strains would naturally be assumed as novel to science. To examine these relationships, cultured homocytous cyanobacteria isolated from two Amazonian rivers (Amazonas and Solimões) were evaluated using a phylogenetic perspective, considering the 16S rRNA gene sequence. A total of eleven homocytous cyanobacterial strains were isolated. Morphologically, they were identified as Pseudanabaena, Leptolyngbya, Planktothrix and Phormidium, but genetically they were included in the typical clusters of Planktothrix, Pseudanabaena, Cephalothrix, Pantanalinema and Alkalinema. These three latter genera have been detected in other Brazilian ecosystems only (Pantanal, Atlantic Rainforest and Pampa), while those remaining have been extensively found in many parts of the world. The data provided here indicate that Amazonian rivers support a homocytous cyanobacterial diversity previously reported from other geographical and ecological environments. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Hydrological pulse regulating the bacterial heterotrophic metabolism between Amazonian mainstems and floodplain lakes

    Science.gov (United States)

    Vidal, Luciana O.; Abril, Gwenäel; Artigas, Luiz F.; Melo, Michaela L.; Bernardes, Marcelo C.; Lobão, Lúcia M.; Reis, Mariana C.; Moreira-Turcq, Patrícia; Benedetti, Marc; Tornisielo, Valdemar L.; Roland, Fabio

    2015-01-01

    We evaluated in situ rates of bacterial carbon processing in Amazonian floodplain lakes and mainstems, during both high water (HW) and low water (LW) phases (p < 0.05). Our results showed that bacterial production (BP) was lower and more variable than bacterial respiration, determined as total respiration. Bacterial carbon demand was mostly accounted by BR and presented the same pattern that BR in both water phases. Bacterial growth efficiency (BGE) showed a wide range (0.2–23%) and low mean value of 3 and 6%, (in HW and LW, respectively) suggesting that dissolved organic carbon was mostly allocated to catabolic metabolism. However, BGE was regulated by BP in LW phase. Consequently, changes in BGE showed the same pattern that BP. In addition, the hydrological pulse effects on mainstems and floodplains lakes connectivity were found for BP and BGE in LW. Multiple correlation analyses revealed that indexes of organic matter (OM) quality (chlorophyll-a, N stable isotopes and C/N ratios) were the strongest seasonal drivers of bacterial carbon metabolism. Our work indicated that: (i) the bacterial metabolism was mostly driven by respiration in Amazonian aquatic ecosystems resulting in low BGE in either high or LW phase; (ii) the hydrological pulse regulated the bacterial heterotrophic metabolism between Amazonian mainstems and floodplain lakes mostly driven by OM quality. PMID:26483776

  6. Geology and insolation-driven climatic history of Amazonian north polar materials on Mars.

    Science.gov (United States)

    Tanaka, Kenneth L

    2005-10-13

    Mariner 9 and Viking spacecraft images revealed that the polar regions of Mars, like those of Earth, record the planet's climate history. However, fundamental uncertainties regarding the materials, features, ages and processes constituting the geologic record remained. Recently acquired Mars Orbiter Laser Altimeter data and Mars Orbiter Camera high-resolution images from the Mars Global Surveyor spacecraft and moderately high-resolution Thermal Emission Imaging System visible images from the Mars Odyssey spacecraft permit more comprehensive geologic and climatic analyses. Here I map and show the history of geologic materials and features in the north polar region that span the Amazonian period (approximately 3.0 Gyr ago to present). Erosion and redeposition of putative circumpolar mud volcano deposits (formed by eruption of liquefied, fine-grained material) led to the formation of an Early Amazonian polar plateau consisting of dark layered materials. Crater ejecta superposed on pedestals indicate that a thin mantle was present during most of the Amazonian, suggesting generally higher obliquity and insolation conditions at the poles than at present. Brighter polar layered deposits rest unconformably on the dark layers and formed mainly during lower obliquity over the past 4-5 Myr (ref. 20). Finally, the uppermost layers post-date the latest downtrend in obliquity <20,000 years ago.

  7. Molecular systematics and phylogeography of Amazonian poison frogs of the genus Dendrobates.

    Science.gov (United States)

    Symula, R; Schulte, R; Summers, K

    2003-03-01

    The study of Amazonian biodiversity requires detailed knowledge of the phylogenetic relationships of closely related taxa distributed across Amazonia. The Amazonian poison frogs of the genus Dendrobates have undergone many taxonomic revisions, but the phylogenetic relationships within this group remain poorly understood. Most previous classifications were based on morphology and skin toxin analyses, with limited use of DNA sequence data. Using mtDNA sequence data from four gene regions (cytochrome b, cytochrome oxidase I, 16S rRNA, and 12S rRNA), we present a molecular phylogenetic analysis of the evolutionary relationships within a representative group of Amazonian Dendrobates. We use the resulting phylogenetic hypothesis to investigate different biogeographic hypotheses concerning genetic divergence and species diversity in Amazonia. The results of the analysis support the presence of ancient paleogeographic barriers to gene flow between eastern and western Amazonia, and indicate substantial genetic divergence between species found in the northern and southern regions of western Amazonia. Copyright 2002 Elsevier Science (USA)

  8. Geology and insolation-driven climatic history of Amazonian north polar materials on Mars

    Science.gov (United States)

    Tanaka, K.L.

    2005-01-01

    Mariner 9 and Viking spacecraft images revealed that the polar regions of Mars, like those of Earth, record the planet's climate history. However, fundamental uncertainties regarding the materials, features, ages and processes constituting the geologic record remained. Recently acquired Mars Orbiter Laser Altimeter data and Mars Orbiter Camera high-resolution images from the Mars Global Surveyor spacecraft and moderately high-resolution Thermal Emission Imaging System visible images from the Mars Odyssey spacecraft permit more comprehensive geologic and climatic analyses. Here I map and show the history of geologic materials and features in the north polar region that span the Amazonian period (???3.0 Gyr ago to present). Erosion and redeposition of putative circumpolar mud volcano deposits (formed by eruption of liquefied, fine-grained material) led to the formation of an Early Amazonian polar plateau consisting of dark layered materials. Crater ejecta superposed on pedestals indicate that a thin mantle was present during most of the Amazonian, suggesting generally higher obliquity and insolation conditions at the poles than at present. Brighter polar layered deposits rest unconformably on the dark layers and formed mainly during lower obliquity over the past 4-5 Myr (ref. 20). Finally, the uppermost layers post-date the latest downtrend in obliquity <20,000 years ago. ?? 2005 Nature Publishing Group.

  9. Estimating the global conservation status of more than 15,000 Amazonian tree species

    Science.gov (United States)

    ter Steege, Hans; Pitman, Nigel C. A.; Killeen, Timothy J.; Laurance, William F.; Peres, Carlos A.; Guevara, Juan Ernesto; Salomão, Rafael P.; Castilho, Carolina V.; Amaral, Iêda Leão; de Almeida Matos, Francisca Dionízia; de Souza Coelho, Luiz; Magnusson, William E.; Phillips, Oliver L.; de Andrade Lima Filho, Diogenes; de Jesus Veiga Carim, Marcelo; Irume, Mariana Victória; Martins, Maria Pires; Molino, Jean-François; Sabatier, Daniel; Wittmann, Florian; López, Dairon Cárdenas; da Silva Guimarães, José Renan; Mendoza, Abel Monteagudo; Vargas, Percy Núñez; Manzatto, Angelo Gilberto; Reis, Neidiane Farias Costa; Terborgh, John; Casula, Katia Regina; Montero, Juan Carlos; Feldpausch, Ted R.; Honorio Coronado, Euridice N.; Montoya, Alvaro Javier Duque; Zartman, Charles Eugene; Mostacedo, Bonifacio; Vasquez, Rodolfo; Assis, Rafael L.; Medeiros, Marcelo Brilhante; Simon, Marcelo Fragomeni; Andrade, Ana; Camargo, José Luís; Laurance, Susan G. W.; Nascimento, Henrique Eduardo Mendonça; Marimon, Beatriz S.; Marimon, Ben-Hur; Costa, Flávia; Targhetta, Natalia; Vieira, Ima Célia Guimarães; Brienen, Roel; Castellanos, Hernán; Duivenvoorden, Joost F.; Mogollón, Hugo F.; Piedade, Maria Teresa Fernandez; Aymard C., Gerardo A.; Comiskey, James A.; Damasco, Gabriel; Dávila, Nállarett; García-Villacorta, Roosevelt; Diaz, Pablo Roberto Stevenson; Vincentini, Alberto; Emilio, Thaise; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Alonso, Alfonso; Dallmeier, Francisco; Ferreira, Leandro Valle; Neill, David; Araujo-Murakami, Alejandro; Arroyo, Luzmila; Carvalho, Fernanda Antunes; Souza, Fernanda Coelho; do Amaral, Dário Dantas; Gribel, Rogerio; Luize, Bruno Garcia; Pansonato, Marcelo Petrati; Venticinque, Eduardo; Fine, Paul; Toledo, Marisol; Baraloto, Chris; Cerón, Carlos; Engel, Julien; Henkel, Terry W.; Jimenez, Eliana M.; Maas, Paul; Mora, Maria Cristina Peñuela; Petronelli, Pascal; Revilla, Juan David Cardenas; Silveira, Marcos; Stropp, Juliana; Thomas-Caesar, Raquel; Baker, Tim R.; Daly, Doug; Paredes, Marcos Ríos; da Silva, Naara Ferreira; Fuentes, Alfredo; Jørgensen, Peter Møller; Schöngart, Jochen; Silman, Miles R.; Arboleda, Nicolás Castaño; Cintra, Bruno Barçante Ladvocat; Valverde, Fernando Cornejo; Di Fiore, Anthony; Phillips, Juan Fernando; van Andel, Tinde R.; von Hildebrand, Patricio; Barbosa, Edelcilio Marques; de Matos Bonates, Luiz Carlos; de Castro, Deborah; de Sousa Farias, Emanuelle; Gonzales, Therany; Guillaumet, Jean-Louis; Hoffman, Bruce; Malhi, Yadvinder; de Andrade Miranda, Ires Paula; Prieto, Adriana; Rudas, Agustín; Ruschell, Ademir R.; Silva, Natalino; Vela, César I. A.; Vos, Vincent A.; Zent, Eglée L.; Zent, Stanford; Cano, Angela; Nascimento, Marcelo Trindade; Oliveira, Alexandre A.; Ramirez-Angulo, Hirma; Ramos, José Ferreira; Sierra, Rodrigo; Tirado, Milton; Medina, Maria Natalia Umaña; van der Heijden, Geertje; Torre, Emilio Vilanova; Vriesendorp, Corine; Wang, Ophelia; Young, Kenneth R.; Baider, Claudia; Balslev, Henrik; de Castro, Natalia; Farfan-Rios, William; Ferreira, Cid; Mendoza, Casimiro; Mesones, Italo; Torres-Lezama, Armando; Giraldo, Ligia Estela Urrego; Villarroel, Daniel; Zagt, Roderick; Alexiades, Miguel N.; Garcia-Cabrera, Karina; Hernandez, Lionel; Huamantupa-Chuquimaco, Isau; Milliken, William; Cuenca, Walter Palacios; Pansini, Susamar; Pauletto, Daniela; Arevalo, Freddy Ramirez; Sampaio, Adeilza Felipe; Valderrama Sandoval, Elvis H.; Gamarra, Luis Valenzuela

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict that most of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century. PMID:26702442

  10. Extremely long-distance seed dispersal by an overfished Amazonian frugivore.

    Science.gov (United States)

    Anderson, Jill T; Nuttle, Tim; Saldaña Rojas, Joe S; Pendergast, Thomas H; Flecker, Alexander S

    2011-11-22

    Throughout Amazonia, overfishing has decimated populations of fruit-eating fishes, especially the large-bodied characid, Colossoma macropomum. During lengthy annual floods, frugivorous fishes enter vast Amazonian floodplains, consume massive quantities of fallen fruits and egest viable seeds. Many tree and liana species are clearly specialized for icthyochory, and seed dispersal by fish may be crucial for the maintenance of Amazonian wetland forests. Unlike frugivorous mammals and birds, little is known about seed dispersal effectiveness of fishes. Extensive mobility of frugivorous fish could result in extremely effective, multi-directional, long-distance seed dispersal. Over three annual flood seasons, we tracked fine-scale movement patterns and habitat use of wild Colossoma, and seed retention in the digestive tracts of captive individuals. Our mechanistic model predicts that Colossoma disperses seeds extremely long distances to favourable habitats. Modelled mean dispersal distances of 337-552 m and maximum of 5495 m are among the longest ever reported. At least 5 per cent of seeds are predicted to disperse 1700-2110 m, farther than dispersal by almost all other frugivores reported in the literature. Additionally, seed dispersal distances increased with fish size, but overfishing has biased Colossoma populations to smaller individuals. Thus, overexploitation probably disrupts an ancient coevolutionary relationship between Colossoma and Amazonian plants.

  11. Life history and environment of Cecropia latiloba in Amazonian floodplains

    Directory of Open Access Journals (Sweden)

    Pia Parolin

    2002-06-01

    Full Text Available Cecropia latiloba can be considered to be one of the most efficient colonizers of open areas in the nutrient-rich whitewater floodplains of the Amazon river. Its main strategy to be successful is the high tolerance towards waterlogging and submergence, and the fast vertical growth and reiteration capacity. This, and the tolerance of high irradiation and sediment deposition allow C. latiloba to form large monospecific stands on open sites, and thus the first closed canopy which represents the initial phase of a successional sequence which leads to highly diverse forests. This tree is extremely well adapted to the adverse growth conditions in Amazonian floodplains with prolongued periods of flooding and seedling submergence. The species occurs on the lowest levels in the flooding gradient. Although it belongs to the most often cited species under aspects of taxonomy, species distribution and general descriptions of the ecosystem, little has been published about its ecology. In the present paper the ecological, physiological and phenological characteristics of C. latiloba are described. It is an evergreen species which constantly produces new leaves. With flooding, leaf production is reduced but new leaves are flushed also with prolongued flooding. The peak of flowering and fruiting are in the flooded period. When mature, the fruits are dispersed mainly by water and fish. Seed germination occurs, without dormancy, within 5-13 days after water retreat. In the 7 months before the first flooded period seedlings reach 1 m of height, and height growth increases until a height of 15-20 m is achieved. Photosynthetic assimilation is high, with values of up to 21 mmol CO2m-2s-1 . C. latiloba is a very flood tolerant species, and waterlogged seedlings continuously produce new leaves and adventitiuos rootsCecropia latiloba puede ser considerada una de las especies colonizadoras más eficientes de áreas abiertas en las llanuras inundadas de agua dulce, rica

  12. Energetic planning in isolated Amazonian communities using geographical information system; Planejamento energetico em regioes isoladas da Amazonia utilizando sistemas de informacoes geograficas

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Arthur [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Programa de Pos-Graduacao de Engenharia Eletrica; Rocha, Brigida R.P.; Monteiro, Jose H.A.; Gaspar, Gabriella C.M. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Dept. de Engenharia Eletrica e de Computacao; Aarao Junior, Raimundo N.N. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Dept. de Engenharia Mecanica

    2004-07-01

    This paper proposes a system of electric planning in isolated Amazonian communities. For those communities, we propose the use of decentralized systems of electric energy with biomass as fuel. We also propose a computer system of electric planning with geographical information systems for its facilities of integrating geographical information, so useful in an Amazonian context. (author)

  13. Biogeography and evolution of Amazonian triatomines (Heteroptera: Reduviidae: implications for Chagas disease surveillance in humid forest ecoregions

    Directory of Open Access Journals (Sweden)

    Fernando Abad-Franch

    2007-10-01

    Full Text Available An ecological-evolutionary classification of Amazonian triatomines is proposed based on a revision of their main contemporary biogeographical patterns. Truly Amazonian triatomines include the Rhodniini, the Cavernicolini, and perhaps Eratyrus and some Bolboderini. The tribe Rhodniini comprises two major lineages (pictipes and robustus. The former gave rise to trans-Andean (pallescens and Amazonian (pictipes species groups, while the latter diversified within Amazonia (robustus group and radiated to neighbouring ecoregions (Orinoco, Cerrado-Caatinga-Chaco, and Atlantic Forest. Three widely distributed Panstrongylus species probably occupied Amazonia secondarily, while a few Triatoma species include Amazonian populations that occur only in the fringes of the region. T. maculata probably represents a vicariant subset isolated from its parental lineage in the Caatinga-Cerrado system when moist forests closed a dry trans-Amazonian corridor. These diverse Amazonian triatomines display different degrees of synanthropism, defining a behavioural gradient from household invasion by adult triatomines to the stable colonisation of artificial structures. Anthropogenic ecological disturbance (driven by deforestation is probably crucial in the onset of the process, but the fact that only a small fraction of species effectively colonises artificial environments suggests a role for evolution at the end of the gradient. Domestic infestation foci are restricted to drier subregions within Amazonia; thus, populations adapted to extremely humid rainforest microclimates may have limited chances of successfully colonising the slightly drier artificial microenvironments. These observations suggest several research avenues, from the use of climate data to map risk areas to the assessment of the synanthropic potential of individual vector species.

  14. Amazonian-aged fluvial system and associated ice-related features in Terra Cimmeria, Mars

    Science.gov (United States)

    Adeli, Solmaz; Hauber, Ernst; Kleinhans, Maarten; Le Deit, Laetitia; Platz, Thomas; Fawdon, Peter; Jaumann, Ralf

    2016-10-01

    The Martian climate throughout the Amazonian is widely believed to have been cold and hyper-arid, very similar to the current conditions. However, ubiquitous evidence of aqueous and glacial activity has been recently reported, including channels that can be tens to hundreds of kilometres long, alluvial and fluvial deposits, ice-rich mantles, and glacial and periglacial landforms. Here we study a ∼340 km-long fluvial system located in the Terra Cimmeria region, in the southern mid-latitudes of Mars. The fluvial system is composed of an upstream catchment system with narrow glaciofluvial valleys and remnants of ice-rich deposits. We observe depositional features including fan-shaped deposits, and erosional features such as scour marks and streamlined islands. At the downstream section of this fluvial system is an outflow channel named Kārūn Valles, which displays a unique braided alluvial fan and terminates on the floor of the Ariadnes Colles basin. Our observations point to surface runoff of ice/snow melt as the water source for this fluvial activity. According to our crater size-frequency distribution analysis the entire fluvial system formed during early to middle Amazonian, between ∼ 1.8-0.2+0.2 Ga to 510-40+40 Ma. Hydraulic modelling indicates that the Kārūn Valles and consequently the alluvial fan formation took place in geologically short-term event(s). We conclude that liquid water was present in Terra Cimmeria during the early to middle Amazonian, and that Mars during that time may have undergone several episodic glacial-related events.

  15. Physical growth of the shuar: Height, Weight, and BMI references for an indigenous amazonian population.

    Science.gov (United States)

    Urlacher, Samuel S; Blackwell, Aaron D; Liebert, Melissa A; Madimenos, Felicia C; Cepon-Robins, Tara J; Gildner, Theresa E; Snodgrass, J Josh; Sugiyama, Lawrence S

    2016-01-01

    Information concerning physical growth among small-scale populations remains limited, yet such data are critical to local health efforts and to foster basic understandings of human life history and variation in childhood development. Using a large dataset and robust modeling methods, this study aims to describe growth from birth to adulthood among the indigenous Shuar of Amazonian Ecuador. Mixed-longitudinal measures of height, weight, and body mass index (BMI) were collected from Shuar participants (n = 2,463; age: 0-29 years). Centile growth curves and tables were created for each anthropometric variable of interest using Generalized Additive Models for Location, Scale, and Shape (GAMLSS). Pseudo-velocity and Lambda-Mu-Sigma curves were generated to further investigate Shuar patterns of growth and to facilitate comparison with United States Center for Disease Control and Prevention and multinational World Health Organization growth references. The Shuar are small throughout life and exhibit complex patterns of growth that differ substantially from those of international references. Similar to other Amazonians, Shuar growth in weight compares more favorably to references than growth in height, resulting in BMI curves that approximate international medians. Several additional characteristics of Shuar development are noteworthy, including large observed variation in body size early in life, significant infant growth faltering, extended male growth into adulthood, and a markedly early female pubertal growth spurt in height. Phenotypic plasticity and genetic selection in response to local environmental factors may explain many of these patterns. Providing a detailed reference of growth for the Shuar and other Amazonian populations, this study possesses direct clinical application and affords valuable insight into childhood health and the ecology of human growth. © 2015 Wiley Periodicals, Inc.

  16. Fish are central in the diet of Amazonian riparians: should we worry about their mercury concentrations?

    International Nuclear Information System (INIS)

    Dorea, Jose G.

    2003-01-01

    The Amazon rain forest extends over an area of 7.8x10 6 km 2 in nine countries. It harbors a diverse human population distributed in dense cities and isolated communities with extreme levels of infrastructure. Amazonian forest people, either autochthons or frontier riparians (ribeirinhos) living in isolated areas, share the same environment for survival and nutritional status. The peculiarities of the hydrological cycle determine disease patterns, agricultural conditions, and food availability. Feeding strategies depend heavily on cassava products and fish. These two foods carry toxic substances such as linamarin (naturally present in cassava) and monomethyl mercury (MMHg) (bioconcentrated in fish flesh) that cause neurotoxic diseases in other parts of the world but not in Amazonia, where neurotoxic cases of food origin are rare and not related to these staples. While cassava detoxification processes may partly explain its safe consumption, the Hg concentrations in Amazonian fish are within traditionally safe limits for this population and contribute to an important metabolic interaction with cassava. The gold rush of the 1970s and 1980s brought large-scale environmental disruption and physical destruction of ecosystems at impact points, along with a heavy discharge of metallic Hg. The discharged Hg has not yet impacted on MMHg concentrations in fish or in hair of fish consumers. Hair Hg concentration, used as a biomarker of fish consumption, indicates that the Amazonian riparians are acquiring an excellent source of protein carrying important nutrients, the lack of which could aggravate their existing health problems. Therefore, in a scenario of insufficient health services and an unhealthy environment, food habits based on fish consumption are part of a successful survival strategy and recommendations for changes are not yet justifiable

  17. Costs and benefits of simulating the hydro-climatological effects of Amazonian deforestation at different resolutions

    Science.gov (United States)

    Khanna, J.; Medvigy, D.

    2013-12-01

    The hydro-climatological effects of Amazonian deforestation have been found to be scale dependent. On one hand GCM studies of deforestation at resolutions >1° and scales 1000 km simulate reduced precipitation over deforested areas, while some observations and RCM studies show an increase in convective activity and precipitation over cleared patches of scales less than 10 km. It is suggested that mesoscale circulations, called ';land breezes', that develop at these small scales of deforestation are responsible for the significant increase in cloud cover and rain. This phenomenon is not captured at the coarse resolution in GCMs. This scale mismatch between GCMs and observed physical processes has to be addressed in modeling studies in order to make realistic inferences for contemporary and future deforestation. One solution is to simulate land breezes in the Amazon at high resolutions exploiting the power of modern high performance computing. But the spatial scales and model resolutions at which mesoscale circulations start to appear and disappear are not well understood. Therefore it is desirable to systematically study the trade off between the computational cost of increased resolution and the resultant information gain. The present study, the first of its kind, formally delves into this problem. The variable resolution Ocean-Land-Atmosphere-Model (OLAM) is used to simulate the hydro-climatic effects of Amazonian deforestation. A cost-benefit analysis is done using different atmospheric initializations to drive the model over a suite of spatial resolutions. High-resolution simulations, informed by the cost-benefit analysis, are performed to estimate the climatically important spatial scales of Amazonian deforestation. Preliminary results from this analysis will be presented.

  18. Elements of metacommunity structure in Amazonian Zygoptera among streams under different spatial scales and environmental conditions.

    Science.gov (United States)

    Brasil, Leandro Schlemmer; Vieira, Thiago Bernardi; de Oliveira-Junior, José Max Barbosa; Dias-Silva, Karina; Juen, Leandro

    2017-05-01

    An important aspect of conservation is to understand the founding elements and characteristics of metacommunities in natural environments, and the consequences of anthropogenic disturbance on these patterns. In natural Amazonian environments, the interfluves of the major rivers play an important role in the formation of areas of endemism through the historical isolation of species and the speciation process. We evaluated elements of metacommunity structure for Zygoptera (Insecta: Odonata) sampled in 93 Amazonian streams distributed in two distinct biogeographic regions (areas of endemism). Of sampled streams, 43 were considered to have experienced negligible anthropogenic impacts, and 50 were considered impacted by anthropogenic activities. Our hypothesis was that preserved ("negligible impact") streams would present a Clementsian pattern, forming clusters of distinct species, reflecting the biogeographic pattern of the two regions, and that anthropogenic streams would present random patterns of metacommunity, due to the loss of more sensitive species and dominance of more tolerant species, which have higher dispersal ability and environmental tolerance. In negligible impact streams, the Clementsian pattern reflected a strong biogeographic pattern, which we discuss considering the areas of endemism of Amazonian rivers. As for communities in human-impacted streams, a biotic homogenization was evident, in which rare species were suppressed and the most common species had become hyper-dominant. Understanding the mechanisms that trigger changes in metacommunities is an important issue for conservation, because they can help create mitigation measures for the impacts of anthropogenic activities on biological communities, and so should be expanded to studies using other taxonomic groups in both tropical and temperate systems, and, wherever possible, at multiple spatial scales.

  19. Natural infection of Lutzomyia tortura with Leishmania (Viannia) naiffi in an Amazonian area of Ecuador.

    Science.gov (United States)

    Kato, Hirotomo; Gomez, Eduardo A; Yamamoto, Yu-ichi; Calvopiña, Manuel; Guevara, Angel G; Marco, Jorge D; Barroso, Paola A; Iwata, Hiroyuki; Hashiguchi, Yoshihisa

    2008-09-01

    Natural infection of sand flies with Leishmania parasites was surveyed in an Amazonian area in Ecuador where leishmaniasis is endemic. Seventy-one female sand flies were dissected and one was positive for Leishmania protozoa. The species of this sand fly was identified as Lutzomyia (Lu.) tortura on the basis of morphologic characteristics. Analysis of the cytochrome b gene sequence identified the parasite as L. (Viannia) naiffi. We report the distribution of L. (V.) naiffi in Ecuador and detection of a naturally infected sand fly in the Ecuadorian Amazon and natural infection of Lu. tortura with Leishmania parasites in the New World.

  20. Sulfur and lead isotope characteristics of the Pontes e Lacerda gold deposits, SW Amazonian Craton Brazil

    International Nuclear Information System (INIS)

    Geraldes, M.C.; Tassinari, C.C.G.; Babinski; M; Iyer, S

    2001-01-01

    This work deals with the characterization of the S and Pb isotope signatures in sulfides from the Pontes e Lacerda mesothermal gold deposits located in the SW sector of Amazonian craton. Stable and radiogenic isotopes have played an important role in the study of ore deposited and hydrothermal processes and they are most useful when can be used together. The purpose of this study is to constrain the sources and the mechanisms of gold deposition in Pontes e Lacerda region which may be a helpful contribution to an exploratory model in the area (au)

  1. Cytogenetic description of the Amazonian brown brocket Mazama nemorivaga (Artiodactyla, Cervidae)

    OpenAIRE

    Fiorillo,Bruno Ferreto; Sarria-Perea,Javier Adolfo; Abril,VanessaVeltrini; Duarte,José Maurício Barbanti

    2013-01-01

    The Amazonian brown brocket Mazama nemorivaga (Cuvier, 1817) is a small to medium-sized deer from the Amazon rainforest and ecotones. The first karyotype described was 2n=67 to 69 + 2-7 B and FN= 69-72, in which all chromosomes were acrocentric and the X chromosome was the only submetacentric chromosome. However, important aspects of the species chromosome evolution were not resolved because of the lack of information on chromosome banding. The G-banding pattern of M. nemorivaga karyotype sho...

  2. Climatic trends in the Amazonian area of Ecuador: Classical and multifractal analyses

    Science.gov (United States)

    Millán, H.; Kalauzi, A.; Llerena, G.; Sucoshañay, J.; Piedra, D.

    The climate evolution and change in the Amazonian area is very important at least at a continental scale involving Latin America where more than 550 million people live. The objective of the present study was to investigate, from an environmental perspective, the climatic trends in the Amazonian area of continental Ecuador. We performed both classical and multifractal analyses of these trends on four climatic variables (maximum and minimum temperature, evaporation and evaporation/precipitation ratio). Data were collected from Puyo meteorological station, Pastaza Province, Ecuador. Data sets covered 31 years (from January 1974 to September 2005). Each time series consisted of 380 months. Piecewise regression analyses with breaking point showed two regimes with a cutoff ranging from t = 80 months (maximum and minimum temperature) to t = 133 months for the evaporation pattern (determination coefficient ≥ 0.979) while the multifractal analyses showed an increasing complexity within each climatic variable. All the considered climatic variables showed an increase since 1974 to approximately 1985. After that some type of smoother increase was observed.

  3. Seed dispersal by macaws shapes the landscape of an Amazonian ecosystem.

    Science.gov (United States)

    Baños-Villalba, Adrián; Blanco, Guillermo; Díaz-Luque, José A; Dénes, Francisco V; Hiraldo, Fernando; Tella, José L

    2017-08-07

    Seed dispersal is one of the most studied plant-animal mutualisms. It has been proposed that the dispersal of many large-seeded plants from Neotropical forests was primarily conducted by extinct megafauna, and currently by livestock. Parrots can transport large fruits using their beaks, but have been overlooked as seed dispersers. We demonstrate that three macaws (Ara ararauna, A. glaucogularis and A. severus) are the main dispersers of the large-seeded motacú palm Attalea princeps, which is the biomass-dominant tree in the Bolivian Amazonian savannas. Macaws dispersed fruits at high rates (75-100% of fruits) to distant (up to 1200 m) perching trees, where they consumed the pulp and discarded entire seeds, contributing to forest regeneration and connectivity between distant forests islands. The spatial distribution of immature palms was positively associated to the proximity to macaws' perching trees and negatively to the proximity to cattle paths. The disperser role of livestock, presumably a substitute for extinct megafauna, had little effect due to soil compaction, trampling and herbivory. Our results underscore the importance of macaws as legitimate, primary dispersers of large-seeded plants at long distances and, specifically, their key role in shaping the landscape structure and functioning of this Amazonian biome.

  4. Enzymes of energy metabolism in hatchlings of amazonian freshwater turtles (Testudines, Podocnemididae

    Directory of Open Access Journals (Sweden)

    WP. Duncan

    Full Text Available The metabolic profiles of selected tissues were analyzed in hatchlings of the Amazonian freshwater turtles Podocnemis expansa, P. unifilis and P. sextuberculata. Metabolic design in these species was judged based on the key enzymes of energy metabolism, with special emphasis on carbohydrate, lipid, amino acid and ketone body metabolism. All species showed a high glycolytic potential in all sampled tissues. Based on low levels of hexokinase, glycogen may be an important fuel for these species. The high lactate dehydrogenase activity in the liver may play a significant role in carbohydrate catabolism, possibly during diving. Oxidative metabolism in P. sextuberculata appears to be designed for the use of lipids, amino acids and ketone bodies. The maximal activities of 3-hydroxyacyl-CoA dehydrogenase, malate dehydrogenase, glutamine dehydrogenase, alanine aminotransferase and succinyl-CoA keto transferase display high aerobic potential, especially in muscle and liver tissues of this species. Although amino acids and ketone bodies may be important fuels for oxidative metabolism, carbohydrates and lipids are the major fuels used by P. expansa and P. unifilis. Our results are consistent with the food habits and lifestyle of Amazonian freshwater turtles. The metabolic design, based on enzyme activities, suggests that hatchlings of P. unifilis and P. expansa are predominately herbivorous, whereas P. sextuberculata rely on a mixed diet of animal matter and vegetation.

  5. Organic matter in the Neoproterozoic cap carbonate from the Amazonian Craton, Brazil

    Science.gov (United States)

    Sousa Júnior, Gustavo R.; Nogueira, Afonso C. R.; Santos Neto, Eugênio V.; Moura, Candido A. V.; Araújo, Bruno Q.; Reis, Francisco de A. M.

    2016-12-01

    Bitumen found in Neoproterozoic carbonates from the southern Amazonian Craton, Brazil, represents a great challenge for its geochemical characterization (origin, thermal maturity and the degree of preservation) within a context of petroleum system. This organic material occurs in the basal Araras Group, considered as a Neoproterozoic cap carbonate, composed of dolostones (Mirassol d'Oeste Formation) overlaid by limestones and shales (Guia Formation). Geochemical analyses in samples of carbonate with bitumen from two open pits (Terconi and Tangará quarries) have shown low to very low total organic carbon content. Analyses of representative samples of Guia and Mirassol d'Oeste formations allowed us to obtain Gas chromatography (GC) traces and diagnostic biomarkers. n-C14 to n-C37 alkane distribution patterns in all samples suggests a major contribution of marine algae. Mid-chain monomethyl alkanes (C14sbnd C25) identified in both sets of samples were also reported in all mid to late Proterozoic oils and source rocks. However, there are significant differences among terpane distribution between the Mirassol d'Oeste and Tangará da Serra regions. The integration of organic geochemistry data and geological information suggests an indigenous origin for studied bitumen, primarily accumulated as hydrocarbon fluids migrated to carbonate rocks with higher porosity and permeability, and afterwards, altered to bitumen or migrabitumen. Although further investigations are required, this work provides a significant contribution to the knowledge about the remnant of this hypothetical Neoproterozoic petroleum system developed in the Southern Amazonian Craton.

  6. Seasonal variation of serum biochemical values of Amazonian snakes (Boa constrictor constrictor kept in captivity

    Directory of Open Access Journals (Sweden)

    Dennis José da Silva Lima

    2012-11-01

    Full Text Available In northern Brazil, the seasons are not well defined compared to the South and Southeast regions, due to a hot and humid equatorial climate with a rainy season, known as the Amazonian winter, and a period with less rain, known as the Amazonian summer. The goal of this study was to evaluate the biochemical variation of serum from the Amazon Boa constrictor by correlating the values with the seasons of the region. A biochemical analysis of the serum was performed (AST, ALT, LDH, ALP, calcium, uric acid, phosphorus, total protein, albumin and globulin using 31 individuals of Boa constrictor constrictor, which were kept in captivity. It was observed that eight of the ten parameters were higher in the winter compared to the summer (total protein, albumin, globulin, ALT, AST, ALP, LDH and calcium. The ALT, AST and calcium values had statistically significant differences for the summer and winter, while the other parameters appear to be influenced by seasonality. This was the first study of snakes kept in captivity that analyzed the serum chemistry profile of Boa constrictor constrictor from the state of Pará, Brazil.

  7. Hydrological pulse regulating the bacterial heterotrophic metabolism between Amazonian mainstems and floodplain lakes

    Directory of Open Access Journals (Sweden)

    Luciana Oliveira Vidal

    2015-09-01

    Full Text Available We evaluated in situ rates of bacterial carbon processing in Amazonian floodplain lakes and mainstems, during both high and low water phases (p < 0.05. Our results showed that Bacterial Production (BP was lower and more variable than Bacterial Respiration (BR, determined as total respiration. Bacterial Carbon Demand (BCD was mostly accounted by BR and presented the same pattern that BR in both water phases. Bacterial growth efficiency showed a wide range (0.2–23% and low mean value of 3 and 6 %, (in high and low water respectively suggesting that dissolved organic carbon (DOC was mostly allocated to catabolic metabolism. However, BGE was regulated by BP in low water phase. Consequently, changes in BGE showed the same pattern that BP. In addition, the hydrological pulse effects on mainstems and floodplains lakes connectivity were found for BP and BGE in low water. Multiple correlation analyses revealed that indexes of organic matter quality (chlorophyll-a, N stable isotopes and C/N ratios were the strongest seasonal drivers of bacterial carbon metabolism. Our work indicated that: (1 the bacterial metabolism was mostly driven by respiration in Amazonian aquatic ecosystems resulting in low BGE in either high and low water phase; (2 the hydrological pulse regulated

  8. Do soil fertilization and forest canopy foliage affect the growth and photosynthesis of Amazonian saplings?

    Directory of Open Access Journals (Sweden)

    Nilvanda dos Santos Magalhães

    2014-02-01

    Full Text Available Most Amazonian soils are highly weathered and poor in nutrients. Therefore, photosynthesis and plant growth should positively respond to the addition of mineral nutrients. Surprisingly, no study has been carried out in situ in the central Amazon to address this issue for juvenile trees. The objective of this study was to determine how photosynthetic rates and growth of tree saplings respond to the addition of mineral nutrients, to the variation in leaf area index of the forest canopy, and to changes in soil water content associated with rainfall seasonality. We assessed the effect of adding a slow-release fertilizer. We determined plant growth from 2010 to 2012 and gas exchange in the wet and dry season of 2012. Rainfall seasonality led to variations in soil water content, but it did not affect sapling growth or leaf gas exchange parameters. Although soil amendment increased phosphorus content by 60 %, neither plant growth nor the photosynthetic parameters were influenced by the addition of mineral nutrients. However, photosynthetic rates and growth of saplings decreased as the forest canopy became denser. Even when Amazonian soils are poor in nutrients, photosynthesis and sapling growth are more responsive to slight variations in light availability in the forest understory than to the availability of nutrients. Therefore, the response of saplings to future increases in atmospheric [CO2] will not be limited by the availability of mineral nutrients in the soil.

  9. Chemical Composition and Antioxidant, Antinociceptive, and Anti-inflammatory Activities of Four Amazonian Byrsonima Species.

    Science.gov (United States)

    Guilhon-Simplicio, Fernanda; Machado, Tallita Marques; do Nascimento, Leandro Flores; Souza, Rayanne da Silva; Koolen, Hector Henrique Ferreira; da Silva, Felipe Moura Araújo; Acho, Leonard Domingo Rosales; Dos Santos, Adair Roberto Soares; Cos, Paul; Pereira, Maria de Meneses; Lima, Emerson Silva

    2017-11-01

    Species of the Byrsonima genus are widely used in Brazil, especially for the treatment of gastrointestinal disorders. However, species from the Amazonian region are still poorly studied. Thus, we studied the antioxidant, antinociceptive, and anti-inflammatory activities of for Amazonian species, Byrsonima crispa, Byrsonima duckeana, Byrsonima garcibarrigae, and Byrsonima incarnata. Phenolic composition was determined by chemical and chromatographic methods. The aqueous extracts were evaluated in DPPH • , ABTS +• , and superoxide (O 2 •- ) tests, LPS-activated macrophage assay, and formalin test. All species contained a high phenolic and flavonoid content. We identified 15 phenolic compounds, including phenolic acids, hydroxycinnamic acids, flavonoids, and catechins. The extracts showed high antioxidant activity and were more active than quercetin at inhibiting nitric oxide release in the LPS-activated macrophage assay. B. duckeana and B. garcibarrigae showed higher in vivo antinociceptive and anti-inflammatory activities. B. garcibarrigae presented significant effect on the early phase of the formalin test, pointing to an antinociceptive mechanism distinct from traditional anti-inflammatory medicines. In conclusion, the pharmacological potential of these species is closely related to their flavonoid-rich chemical composition, which seems to act through antioxidant mechanisms. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  10. Application of lipases to regiospecific interesterification of exotic oils from an Amazonian area.

    Science.gov (United States)

    Speranza, Paula; Ribeiro, Ana Paula Badan; Macedo, Gabriela Alves

    2016-01-20

    Enzymatic interesterification may favor the development of lipid fractions from Amazonian oils with greater application potential. In this study, the Amazonian buriti oil and murumuru fat were subjected to enzymatic interesterification using two lipases in three different enzyme systems: one with a commercial lipase from Thermomyces lanuginosa, a second with the lipase produced by Rhizopus sp., and a third with a mixture of both lipases. The three enzyme systems were able to catalyze the reaction, but the enzymes showed different specificities. The commercial lipase was specific for unsaturated fatty acids, whereas the Rhizopus sp. lipase was specific for both unsaturated fatty acids and the positions sn -1 and sn -3 of the fatty acid on the triacylglycerol. The mixture of both lipases showed no synergistic effect: the results were intermediate between the two enzymes applied alone. Interesterification reduced the levels of trisaturated and triunsaturated triacylglycerols and increased the levels of diunsaturated-monosaturated and monounsaturated-disaturated triacylglycerols. The thermal melting behavior indicated the formation of a single endothermic region with more homogeneous triacylglycerols. The content of the bioactive β-carotene was preserved after the interesterification reaction with all three-enzyme systems. The interesterified lipids obtained, because of the characteristics of the oils, may be applied to the formulation of cosmetics and pharmaceuticals. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Differential expression of a retrotransposable element, Rex6, in Colossoma macropomum fish from different Amazonian environments

    Science.gov (United States)

    Barbosa, Cassiane Martins; Mareco, Edson Assunção; Silva, Maeli Dal Pai; Martins, Cesar; Alves-Costa, Fernanda Antunes

    2014-01-01

    Transposable elements (TEs) are DNA sequences that have the ability to move and replicate within the genomes. TEs can be classified according to their intermediates of transposition, RNA (retrotransposons) or DNA. In some aquatic organisms, it has been observed that environmental factors such as pH, temperature and pollution may stimulate differential transcription and mobilization of retrotransposons. In light of this information, the present study sought to evaluate the expression of Rex6 TE transcripts in Colossoma macropomum, which is a very commercially exploited fish in Brazil. In order to establish a comparative analysis using real-time PCR, the samples were collected from Amazonian rivers with different physical and chemical characteristics (distinguished by clear water and black water). Quantitative RT-PCR analyses revealed a differential pattern of expression between tissues collected from different types of water (clear and black waters). When it came to the hepatic and muscle tissues sampled, the levels of Rex6 transcripts were significantly different between the two Amazonian water types. These results suggest that environmental conditions operate differently in the regulation of Rex6 transcription in C. macropomum, results which have implications in the reshaping of the genome against environmental variations. PMID:25089227

  12. The role of fertile anthropogenic soils in the conservation of native and exotic agrobiodiversity in Amazonian homegardens

    NARCIS (Netherlands)

    Souza, de Nathalia B.; Junqueira, André Braga; Struik, Paul C.; Stomph, Tjeerdjan; Clement, Charles R.

    2017-01-01

    Amazonian dark earths (ADE) are anthropogenic soils mostly created between 500 and 2500 years ago by pre-Columbian populations. ADE are currently used by local people for different agricultural and agroforestry systems. Because of their high fertility they may play an important role in the

  13. BEYOND THE GARDENS: NOTES ON NOMENCLATURE, DISTRIBUTION AND CONSERVATION OF Philodendron melinonii BRONGN. EX REGEL, AN EMBLEMATIC AMAZONIAN AROID

    Directory of Open Access Journals (Sweden)

    Luana S. B. Calazans

    2017-03-01

    Full Text Available Philodendron melinonii is an Amazonian species common in botanical gardens and urban landscaping, however its taxonomy, natural distribution and conservation are barely addressed in the literature. This work presents the nomenclatural history of the species with lectotype designation, a typographical correction and comments on its biogeographic distribution and conservation. Keywords: typification; biogeographic provinces; collection effort; Araceae; Amazonia.

  14. Measurements of soil respiration and simple models dependent on moisture and temperature for an Amazonian southwest tropical forest

    NARCIS (Netherlands)

    Zanchi, F.B.; Rocha, Da H.R.; Freitas, De H.C.; Kruijt, B.; Waterloo, M.J.; Manzi, A.O.

    2009-01-01

    Soil respiration plays a significant role in the carbon cycle of Amazonian tropical forests, although in situ measurements have only been poorly reported and the dependence of soil moisture and soil temperature also weakly understood. This work investigates the temporal variability of soil

  15. Biomass consumption and CO2, CO and main hydrocarbon gas emissions in an Amazonian forest clearing fire

    Science.gov (United States)

    T. G. Soares Neto; J. A. Carvalho; C. A. G. Veras; E. C. Alvarado; R. Gielow; E. N. Lincoln; T. J. Christian; R. J. Yokelson; J. C. Santos

    2009-01-01

    Biomass consumption and CO2, CO and hydrocarbon gas emissions in an Amazonian forest clearing fire are presented and discussed. The experiment was conducted in the arc of deforestation, near the city of Alta Floresta, state of Mato Grosso, Brazil. The average carbon content of dry biomass was 48% and the estimated average moisture content of fresh biomass was 42% on...

  16. Phylogenetic relationships of Amazonian anole lizards (Dactyloa): taxonomic implications, new insights about phenotypic evolution and the timing of diversification.

    Science.gov (United States)

    Prates, Ivan; Rodrigues, Miguel Trefaut; Melo-Sampaio, Paulo Roberto; Carnaval, Ana Carolina

    2015-01-01

    The ecology and evolution of Caribbean anoles are well described, yet little is known about mainland anole species. Lack of phylogenetic information limits our knowledge about species boundaries, morphological evolution, and the biogeography of anoles in South America. To help fill this gap, we provide an updated molecular phylogeny of the Dactyloa (Dactyloidae), with emphasis on the punctata species group. By sampling understudied Amazonian taxa, we (i) assess the phylogenetic placement of the 'odd anole', D. dissimilis; (ii) infer the relationships of the proboscis-bearing D. phyllorhina, testing the hypothesis of independent nasal appendage evolution within the anole radiation; and (iii) examine genetic and dewlap color variation in D. punctata and D. philopunctata. Combining multiple nuclear loci with a review of the fossil record, we also (iv) estimate divergence times within the pleurodont iguanian clade of lizards, including Amazonian representatives of Dactyloa and Norops (Dactyloidae) and of Polychrus (Polychrotidae). We recover the five Dactyloa clades previously referred to as the aequatorialis, heteroderma, latifrons, punctata and roquet species groups, as well as a sixth clade composed of D. dissimilis and the non-Amazonian D. neblinina and D. calimae. We find D. phyllorhina to be nested within the punctata group, suggesting independent evolution of the anole proboscis. We consistently recover D. philopunctata nested within D. punctata, and report limited genetic divergence between distinct dewlap phenotypes. The most recent common ancestor of Dactyloa, Anolis and Norops dates back to the Eocene. Most Amazonian taxa within both Dactyloa and Norops diverged in the Miocene, but some diversification events were as old as the late Eocene and late Oligocene. Amazonian Polychrus diverged in the Pliocene. Our findings have broad implications for anole biogeography, disputing recent suggestions that modern dactyloid genera were present in the Caribbean region

  17. Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

    NARCIS (Netherlands)

    Berton Zanchi, F.; Waterloo, M.J.; Dolman, A.J.; Groenendijk, M.; Kruijt, B.

    2011-01-01

    Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and

  18. The imprint of Late Holocene tectonic reactivation on a megafan landscape in the northern Amazonian wetlands

    Science.gov (United States)

    Rossetti, D. F.; Valeriano, M. M.; Gribel, R.; Cohen, M. C. L.; Tatumi, S. H.; Yee, M.

    2017-10-01

    The modern Amazonian ecosystem outcomes from the complex interplay of different factors performed over the geological history, with tectonics being long speculated as perhaps a fundamental one. Nevertheless, areas where tectonic activity can be fully characterized are still scarce in view of the large dimension of this region. In this work, we investigate the signature of neotectonics in one megafan paleolandform that typifies a large sector of the Negro-Branco basin in northern Amazonia. The approach joined regional morphostructural descriptions of the Viruá megafan surface and the acquisition of topographic, sedimentological, and chronological data focusing on the central sector of the megafan. The results revealed an abundance of rivers that form dendritic, subdendritic, and trellis patterns. These rivers also have numerous straight segments, orthogonal junctions, and orthogonal shifts in courses. Structural lineaments, defined by straight channels and also straight lake margins, are aligned along the NW-SE and NE-SW directions that are coincidental with the main regional structural pattern in Amazonia. This study also led to recognize two large areas of lower topography in the south-central part of the megafan that consist of rectangular depressions parallel to the morphostructural lineaments. A sedimentological survey indicated that cores extracted external to the largest depression have only distributary channel and overbank sand sheet megafan deposits. Optically stimulated luminescence (OSL) ages ranged from 17.5 ± 2.0 to 46.9 ± 3.4 ky and radiocarbon ages ranged from 5.9-5.7 to 20.1-19.6 cal ky BP. In contrast, cores extracted within the depression consisted of fluvial deposits younger than 2.1-1.9 cal ky BP that increased in thickness toward the central part of the depression. We propose that the studied megafan was affected by tectonic reactivation until at least a couple thousand years ago. Tectonics would have produced subsiding areas more prone to

  19. Misalignment of Lava Flows from Topographic Slope Directions Reveals Late Amazonian Deformation at Arsia Mons, Mars

    Science.gov (United States)

    Waring, B. A.; Chadwick, J.; McGovern, P. J., Jr.; Tucker, W.

    2017-12-01

    Arsia Mons is the southernmost of the three large Tharsis Montes near the equator of Mars and one of the largest volcanoes in the solar system. The main edifice of Arsia is about 440 km in diameter, the summit is over 9 km above the surrounding plains and has a pronounced 110 km caldera. Like the other Tharsis volcanoes, Arsia has a large, Late Amazonian glacial deposit on its NW flank. Previous crater retention studies for lava flows on Arsia have shown that the volcano experienced significant volcanic activity in the past 200 Ma. In this study, numerous long (>25 km), thin lava flows on the plains surrounding Arsia were mapped and used as indicators of the topographic slope direction at the time of their emplacement. The azimuthal orientation of each flow was compared with the present-day slope directions on the surrounding plains, derived from Mars Orbiter Laser Altimeter (MOLA) topographic data. The results reveal regions around Arsia where the flows no longer conform to the topography, indicating deformation in the time since the flows where emplaced. In a region of Daedalia Planum to the SE of Arsia, modern slope directions adjacent to 40 long lava flows are consistently misaligned from the paleo-slopes indicated by the lava flow orientations, with an angular offset that averages 7.2° in the clockwise direction. Crater size-frequency measurements for these tilted plains using CraterStats software indicate that the deformation responsible for the misaligned flows took place since 330 ± 10 Ma. Conversely, part of Daedalia Planum to the southwest of Arsia is younger, with a crater retention age of 160 ± 6 Ma, and this area shows no consistent flow-topography misalignments. These observations suggest that extensive regional deformation occurred between the two dates, consistent with other evidence for significant volcanism at Arsia in the Late Amazonian at about 200 Ma. Geophysical modelling using the finite element program COMSOL Multiphysics is planned to

  20. Studying the Effects of Amazonian Land Cover Change on Glacier Mass Balance in the Tropical Andes

    Science.gov (United States)

    Mark, B. G.; Fernandez, A.; Gabrielli, P.; Montenegro, A.; Postigo, J.; Hellstrom, R. A.

    2017-12-01

    Recent research has highlighted several ongoing environmental changes occurring across Tropical South America, including Andean glacier retreat, drought, as well as changes in land-use and land-cover. As the regional climate of the area is mostly characterized by land-ocean interactions, the atmospheric convection in the Amazon, and the effect of the Andes on circulation patterns, it follows that changes in one of those regions may affect the other. Most scholars who have studied the causes of tropical glaciers' fluctuations have not analyzed the linkages with changes in the Amazon with the same attention paid to the influence of Pacific sea surface temperature. Here we study the response of glacier surface mass balance in the Cordillera Blanca, Peru (10°S), to a scenario where the Amazonian rainforest is replaced by savannas. We ran climatic simulations at 2-km spatial resolution utilizing the Weather Research and Forecasting (WRF) model considering two scenarios: (a) control (CRTL), with today's rainforest extent; and (b) land cover change (LCC), where all the rainforest was replaced by savanna. WRF output was in turn ingested into a glacier energy and mass balance (GEMB) model that we validate by reconstructing both the accumulated mass balance from available observations, and the altitudinal distribution of mass balance in the region. Seasonal comparison between CRTL and LCC scenarios indicates that forest replacement by savanna results in more positive glacier mass balance. This shift to more positive mass balance contrasts with a (WRF) modeled rise in the elevation of the freezing line (0°C) between 30 to 120 m for the LCC scenario. Our results are surprising because most previous studies have shown that reducing Amazon forest cover diminishes rainfall and increases temperature, suggesting that glaciers should lose mass. We hypothesize and discuss implications of possible land-atmospheric processes that might drive this tropical glacier response to

  1. Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils

    Directory of Open Access Journals (Sweden)

    L. E. O. C. Aragão

    2009-12-01

    Full Text Available The net primary productivity (NPP of tropical forests is one of the most important and least quantified components of the global carbon cycle. Most relevant studies have focused particularly on the quantification of the above-ground coarse wood productivity, and little is known about the carbon fluxes involved in other elements of the NPP, the partitioning of total NPP between its above- and below-ground components and the main environmental drivers of these patterns. In this study we quantify the above- and below-ground NPP of ten Amazonian forests to address two questions: (1 How do Amazonian forests allocate productivity among its above- and below-ground components? (2 How do soil and leaf nutrient status and soil texture affect the productivity of Amazonian forests? Using a standardized methodology to measure the major elements of productivity, we show that NPP varies between 9.3±1.3 Mg C ha−1 yr−1 (mean±standard error, at a white sand plot, and 17.0±1.4 Mg C ha−1 yr−1 at a very fertile Terra Preta site, with an overall average of 12.8±0.9 Mg C ha−1 yr−1. The studied forests allocate on average 64±3% and 36±3% of the total NPP to the above- and below-ground components, respectively. The ratio of above-ground and below-ground NPP is almost invariant with total NPP. Litterfall and fine root production both increase with total NPP, while stem production shows no overall trend. Total NPP tends to increase with soil phosphorus and leaf nitrogen status. However, allocation of NPP to below-ground shows no relationship to soil fertility, but appears to decrease with the increase of soil clay content.

  2. Diversity and physiological characterization of D-xylose-fermenting yeasts isolated from the Brazilian Amazonian Forest.

    Directory of Open Access Journals (Sweden)

    Raquel M Cadete

    Full Text Available BACKGROUND: This study is the first to investigate the Brazilian Amazonian Forest to identify new D-xylose-fermenting yeasts that might potentially be used in the production of ethanol from sugarcane bagasse hemicellulosic hydrolysates. METHODOLOGY/PRINCIPAL FINDINGS: A total of 224 yeast strains were isolated from rotting wood samples collected in two Amazonian forest reserve sites. These samples were cultured in yeast nitrogen base (YNB-D-xylose or YNB-xylan media. Candida tropicalis, Asterotremella humicola, Candida boidinii and Debaryomyces hansenii were the most frequently isolated yeasts. Among D-xylose-fermenting yeasts, six strains of Spathaspora passalidarum, two of Scheffersomyces stipitis, and representatives of five new species were identified. The new species included Candida amazonensis of the Scheffersomyces clade and Spathaspora sp. 1, Spathaspora sp. 2, Spathaspora sp. 3, and Candida sp. 1 of the Spathaspora clade. In fermentation assays using D-xylose (50 g/L culture medium, S. passalidarum strains showed the highest ethanol yields (0.31 g/g to 0.37 g/g and productivities (0.62 g/L · h to 0.75 g/L · h. Candida amazonensis exhibited a virtually complete D-xylose consumption and the highest xylitol yields (0.55 g/g to 0.59 g/g, with concentrations up to 25.2 g/L. The new Spathaspora species produced ethanol and/or xylitol in different concentrations as the main fermentation products. In sugarcane bagasse hemicellulosic fermentation assays, S. stipitis UFMG-XMD-15.2 generated the highest ethanol yield (0.34 g/g and productivity (0.2 g/L · h, while the new species Spathaspora sp. 1 UFMG-XMD-16.2 and Spathaspora sp. 2 UFMG-XMD-23.2 were very good xylitol producers. CONCLUSIONS/SIGNIFICANCE: This study demonstrates the promise of using new D-xylose-fermenting yeast strains from the Brazilian Amazonian Forest for ethanol or xylitol production from sugarcane bagasse hemicellulosic hydrolysates.

  3. Regional variation in Ascaris lumbricoides and Trichuris trichiura infections by age cohort and sex: effects of market integration among the indigenous Shuar of Amazonian Ecuador.

    Science.gov (United States)

    Gildner, Theresa E; Cepon-Robins, Tara J; Liebert, Melissa A; Urlacher, Samuel S; Madimenos, Felicia C; Snodgrass, J Josh; Sugiyama, Lawrence S

    2016-11-24

    Soil-transmitted helminth (STH) infection peaks during childhood and varies by sex. The impact of market integration (MI) (increasing production for and consumption from a market-based economy) on these infection patterns, however, is unclear. In this study, STH infection is examined by sex and age among indigenous Shuar inhabiting two regions of Amazonian Ecuador: (1) the modestly market-integrated Upano Valley (UV) and (2) the more traditional Cross-Cutucú (CC) region. Kato-Katz fecal smears were examined for parasite presence and infection intensity. Factorial ANOVAs and post hoc simple effects analyses were performed by sex to compare infection intensity between regions and age categories (infant/child, juvenile/adolescent, adult). Significant age and regional differences in Ascaris lumbricoides and Trichuris trichiura infection were detected. Overall, infants/children and juveniles/adolescents displayed higher parasite loads than adults. CC females exhibited higher A. lumbricoides loads than UV females, while the opposite pattern was observed for T. trichiura infection in males. Regional infection patterns varied by sex and parasite species, perhaps due to MI-linked environmental and lifestyle changes. These results have public health implications for the identification of individuals at risk for infection and contribute to ongoing efforts to track changes and alleviate STH infection in indigenous populations undergoing MI.

  4. Tsimane' Amazonian Panel Study (TAPS): the first 5 years (2002-2006) of socioeconomic, demographic, and anthropometric data available to the public.

    Science.gov (United States)

    Leonard, William R; Godoy, Ricardo

    2008-07-01

    The Tsimane' Amazonian Panel Study (TAPS) is making available the first five years (2002-2006, inclusive) of annual socioeconomic, demographic, and anthropometric data available to the public. The information comes from a foraging-farming society of native Amazonians in Bolivia and includes 13 villages, 332 households, and 1985 people who have been tracked annually since 2002. The article provides a brief overview of the data covered and the steps needed to access the data.

  5. Differential Expression of Myogenic Regulatory Factor Genes in the Skeletal Muscles of Tambaqui Colossoma macropomum (Cuvier 1818) from Amazonian Black and Clear Water

    OpenAIRE

    Alves-Costa, F. A.; Barbosa, C. M.; Aguiar, R. C. M.; Mareco, E. A.; Dal-Pai-Silva, M.

    2013-01-01

    Hypothesizing that the Amazonian water system differences would affect the expression of muscle growth-related genes in juvenile tambaqui Colossoma macropomum (Cuvier 1818), this study aimed to analyze the morphometric data and expression of myogenic regulatory factors (MRFs) in the white and red muscle from tambaqui obtained from clear and black Amazonian water systems. All of the MRF transcript levels (myod, myf5, myogenin, and mrf4) were significantly lower in the red muscle from black wat...

  6. The palms in the traditional knowledge of indigenous Amazonian group Aguaruna-Huambisa

    Directory of Open Access Journals (Sweden)

    Fernando Roca Alcázar

    2014-03-01

    Full Text Available The traditional knowledge of indigenous peoples shows a different vision of the world to that of the western society. The knowledge about palms of the Aguaruna-huambisa groups living in the northwestern Peruvian forests express their palm knowledge in a particular way. Many researchers hypothesize that the Aguaruna– huambisa society, due to great botanical knowledge, are able to recognize generic taxa of palms. Scientific botanical knowledge and traditional knowledge lead to divergent perceptions of the Amazonian flora and to different ways to expressing them. The palm generic taxon, SHINKI in aguaruna language, is not recognized, but other generic taxa such as tree, vine and herb clearly appear in the traditional knowledge of this society.

  7. Bioactive properties of Tynanthus panurensis (Bureau) Sanwith bark extract, the Amazonian "clavo huasca".

    Science.gov (United States)

    Morales, Lidia; Acero, Nuria; Galán, Antonio; Perez-García, Carmen; Alguacil, Luis Fernando; Muñoz-Mingarro, Dolores

    2011-09-01

    Tynanthus panurensis (Bureau) Sanwith (Bignoniaceae) is a liana vine used in traditional Amazonian medicine as a tonic and energizer as well as a treatment for rheumatism. These traditional indications prompted this study of the antioxidant and anti-inflammatory activities of T. panurensis bark extract (ETP). Phytochemical analysis of ETP showed the presence of saponins and a high concentration of phenols and flavonoids. A battery of in vitro tests revealed that the extract has free radical-scavenging antioxidant properties and reduces microsomal lipid peroxidation, uric acid synthesis, and tumor necrosis factor-α production. The anti-inflammatory properties of ETP were further confirmed in vivo in a rat carrageenan edema model, in which the extract exhibited a potent activity. These results support the idea that T. panurensis bark extract could be beneficial for treating inflammation and are in agreement with one of the main traditional uses of this plant.

  8. Potential application in biocatalysis of mycelium-bound lipases from Amazonian fungi

    Energy Technology Data Exchange (ETDEWEB)

    Zanotto, Sandra P.; Romano, Israel P.; Lisboa, Lilian U.S.; Duvoisin Junior, Sergio; Lima, Fabiana A.; Silva, Soraya F.; Alburquerque, Patricia M. [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Programa em Biotecnologia e Recursos Naturais da Amazonia. Lab. de Biorganica; Martins, Mayra K. [Centro de Biotecnologia do Amazonas, Manaus, AM (Brazil)

    2009-07-01

    In this study, 212 fungi were isolated from Amazon region plants, aiming to obtain mycelium bound-lipase-producing biocatalysts. These isolates were submitted to hydrolytic and synthetic activity assays. When submitted to the tributyrine substrate test, 87% of the isolates showed hydrolytic activity. Of these, 30% showed good growth in lipase inducing liquid media and were submitted to evaluation of synthetic activity in esterification and transesterification reactions in organic solvents. The nine fungi which had the best synthetic activity were evaluated in the (R, S)-2-octanol resolution reaction, in order to verify the enantioselectivity of mycelium-bound lipases. The isolate UEA{sub 1}15 was the most versatile biocatalyst, showing good performance in esterification reactions (conversion > 90%) and good ability for the resolution of (R, S)-2-octanol (ees 29%; eep 99%; c 22%; E > 200). Thus, this study has demonstrated the great potential of the Amazonian fungi as lipase suppliers for biocatalysts.(author)

  9. Ecological suitability and spatial distribution of five Anopheles species in Amazonian Brazil.

    Science.gov (United States)

    McKeon, Sascha N; Schlichting, Carl D; Povoa, Marinete M; Conn, Jan E

    2013-06-01

    Seventy-six sites characterized in Amazonian Brazil revealed distinct habitat diversification by examining the environmental factors associated with the distribution and abundance of five anopheline species (Diptera: Culicidae) in the subgenus Nyssorhynchus. These included three members of the Albitarsis Complex, Anopheles oryzalimnetes, Anopheles marajoara, Anopheles janconnae; Anopheles triannulatus, and Anopheles goeldii. Anopheles janconnae abundance had a positive correlation to water flow and a negative relationship to sun exposure. Abundance of An. oryzalimentes was associated with water chemistry. Anopheles goeldii larvae were abundant in shaded, more saline waters. Anopheles marajoara and An. triannulatus were negatively associated with available resources, although An. marajoara also showed several local correlations. These analyses suggest An. triannulatus is a habitat generalist, An. oryzalimentes and An. janconnae are specialists, and An. marajoara and An. goeldii could not be easily classified either way. Correlations described herein provide testable hypotheses for future research and identifying habitats for vector control.

  10. The association of genetic markers and malaria infection in the Brazilian Western Amazonian region

    Directory of Open Access Journals (Sweden)

    B Beiguelman

    2003-06-01

    Full Text Available Almost all individuals (182 belonging to an Amazonian riverine population (Portuchuelo, RO, Brazil were investigated for ascertaining data on epidemiological aspects of malaria. Thirteen genetic blood polymorphisms were investigated (ABO, MNSs, Rh, Kell, and Duffy systems, haptoglobins, hemoglobins, and the enzymes glucose-6-phosphate dehydrogenase, glyoxalase, phosphoglucomutase, carbonic anhydrase, red cell acid phosphatase, and esterase D. The results indicated that the Duffy system is associated with susceptibility to malaria, as observed in other endemic areas. Moreover, suggestions also arose indicating that the EsD and Rh loci may be significantly associated with resistance to malaria. If statistical type II errors and sample stratification could be ruled out, hypotheses on the existence of a causal mechanism or an unknown closely linked locus involved in susceptibility to malaria infection may explain the present findings.

  11. Antioxidant Potential and Modulatory Effects of Restructured Lipids from the Amazonian Palms on Liver Cells

    Directory of Open Access Journals (Sweden)

    Andrea de Oliveira Falcão

    2017-01-01

    Full Text Available Enzymatic interesterification is used to manipulate oil and fat in order to obtain improved restructured lipids with desired technological properties. However, with raw materials containing significant amounts of bioactive compounds, the influence of this enzymatic process on the bioactivity of the final product is still not clear. Thus, the aim of this study is to evaluate the antioxidant potential and modulatory effects of two raw materials from the Amazonian area, buriti oil and murumuru fat, before and after lipase interesterification, on human hepatoma cells (HepG2. The results indicate that minor bioactive compounds naturally found in the raw materials and their antioxidant capacity are preserved after enzymatic interesterification, and that the restructured lipids modulate HepG2 endogenous antioxidant enzyme.

  12. Potential application in biocatalysis of mycelium-bound lipases from Amazonian fungi

    International Nuclear Information System (INIS)

    Zanotto, Sandra P.; Romano, Israel P.; Lisboa, Lilian U.S.; Duvoisin Junior, Sergio; Lima, Fabiana A.; Silva, Soraya F.; Alburquerque, Patricia M.

    2009-01-01

    In this study, 212 fungi were isolated from Amazon region plants, aiming to obtain mycelium bound-lipase-producing biocatalysts. These isolates were submitted to hydrolytic and synthetic activity assays. When submitted to the tributyrine substrate test, 87% of the isolates showed hydrolytic activity. Of these, 30% showed good growth in lipase inducing liquid media and were submitted to evaluation of synthetic activity in esterification and transesterification reactions in organic solvents. The nine fungi which had the best synthetic activity were evaluated in the (R, S)-2-octanol resolution reaction, in order to verify the enantioselectivity of mycelium-bound lipases. The isolate UEA 1 15 was the most versatile biocatalyst, showing good performance in esterification reactions (conversion > 90%) and good ability for the resolution of (R, S)-2-octanol (ees 29%; eep 99%; c 22%; E > 200). Thus, this study has demonstrated the great potential of the Amazonian fungi as lipase suppliers for biocatalysts.(author)

  13. Submerged in darkness: adaptations to prolonged submergence by woody species of the Amazonian floodplains.

    Science.gov (United States)

    Parolin, Pia

    2009-01-01

    In Amazonian floodplain forests, >1000 tree species grow in an environment subject to extended annual submergence which can last up to 9 months each year. Water depth can reach 10 m, fully submerging young and also adult trees, most of which reproduce during the flood season. Complete submergence occurs regularly at the seedling or sapling stage for many species that colonize low-lying positions in the flooding gradient. Here hypoxic conditions prevail close to the water surface in moving water, while anaerobic conditions are common in stagnant pools. Light intensities in the floodwater are very low. Despite a lack of both oxygen and light imposed by submergence for several months, most leafed seedlings survive. Furthermore, underwater growth has also been observed in several species in the field and under experimental conditions. The present article assesses how these remarkable plants react to submergence and discusses physiological mechanisms and anatomical adaptations that may explain their success.

  14. Securitization, alterity, and the stateHuman (in)security on an Amazonian frontier.

    Science.gov (United States)

    Brightman, Marc; Grotti, Vanessa

    2014-12-01

    Focusing on the region surrounding the Maroni River, which forms the border between Suriname and French Guiana, we examine how relations between different state and non-state social groups are articulated in terms of security. The region is characterised by multiple "borders" and frontiers of various kinds, the state boundary having the features of an interface or contact zone. Several key collectivities meet in this border zone: native Amazonians, tribal Maroon peoples, migrant Brazilian gold prospectors, and metropolitan French state functionaries. We explore the relationships between these different sets of actors and describe how their mutual encounters center on discourses of human and state security, thus challenging the commonly held view of the region as a stateless zone and showing that the "human security" of citizens from the perspective of the state may compete with locally salient ideas or experiences of well-being.

  15. Chromosome number and karyotype of the endangered Amazonian woody Centrolobium paraense Tul. species

    Directory of Open Access Journals (Sweden)

    Nair Dahmer

    2009-01-01

    Full Text Available Centrolobium paraense Tul., popularly known in Brazil as “pau-rainha”, is a species with a high timberpotential, presently endangered due to deforestation of the Amazonian region and indiscriminate wood extraction. Chromosomenumber and karyotype morphology of this species are presented for the first time. All the individuals of the three populationsanalyzed are diploid, with 2n=2x=20 chromosomes. The chromosomes ranging from ca. 1.7 to 4 μm in size. The karyotypeis composed of three metacentric, three submetacentric (one with a satellite on the short arm, three acrocentric and onesubacrocentric chromosome pairs. Other Centrolobium species and populations should be analyzed in order to assess theextent of intraspecific and interspecific variation in chromosome number and morphology, if any.

  16. The Diversity of Bitter Manioc (Manihot Esculenta Crantz Cultivation in a Whitewater Amazonian Landscape

    Directory of Open Access Journals (Sweden)

    James A. Fraser

    2010-04-01

    Full Text Available While bitter manioc has been one of the most important staple crops in the central Amazon for thousands of years, there have been few studies of its cultivation in the fertile whitewater landscapes of this region. Anthropological research on bitter manioc cultivation in the Amazon has focused almost exclusively on long-fallow shifting cultivation in marginal upland areas of low soil fertility. This has contributed to the persistence of the oversimplified notion that because bitter manioc is well adapted to infertile upland soils; it cannot yield well in alluvial and/or fertile soils. I hypothesized that bitter manioc cultivation would be well adapted to the fertile soils of the whitewater landscapes of the central Amazon because of the centrality of this crop to subsistence in this region. In this article, I examine one such whitewater landscape, the middle Madeira River, Amazonas, Brazil, where smallholders cultivate bitter manioc on fertile Amazonian Dark Earths (ADE and floodplain soils, and on infertile Oxisols and Ultisols. In this region, cultivation on fertile soils tends to be short-cycled, characterised by short fallowing (0–6 years and shorter cropping periods (5–12 months with a predominance of low starch fast maturing “weak” landraces. By contrast, cultivation on infertile soils is normally long-cycled, characterised by longer fallows (>10 years and longer cropping periods (1–3 years with a predominance of high starch slow maturing “strong” landraces. This diversity in bitter manioc cultivation systems (landraces, fallow periods, soils demonstrates that Amazonian farmers have adapted bitter manioc cultivation to the specific characteristics of the landscapes that they inhabit. I conclude that contrary to earlier claims, there are no ecological limitations on growing bitter manioc in fertile soils, and therefore the cultivation of this crop in floodplain and ADE soils would have been possible in the pre-Columbian period.

  17. The role of Amazonian anthropogenic soils in shifting cultivation: learning from farmers' rationales

    Directory of Open Access Journals (Sweden)

    André B. Junqueira

    2016-03-01

    Full Text Available We evaluated farmers' rationales to understand their decision making in relation to the use of fertile anthropogenic soils, i.e., Amazonian dark earths (ADE, and for dealing with changes in shifting cultivation in Central Amazonia. We analyzed qualitative information from 196 interviews with farmers in 21 riverine villages along the Madeira River. In order to decide about crop management options to attain their livelihood objectives, farmers rely on an integrated and dynamic understanding of their biophysical and social environment. Farmers associate fallow development with higher crop yields and lower weed pressure, but ADE is always associated with high yields and high weeding requirements. Amazonian dark earths are also seen as an opportunity to grow different crops and/or grow crops in more intensified management systems. However, farmers often maintain simultaneously intensive swiddens on ADE and extensive swiddens on nonanthropogenic soils. Farmers acknowledge numerous changes in their socioeconomic environment that affect their shifting cultivation systems, particularly their growing interaction with market economies and the incorporation of modern agricultural practices. Farmers considered that shifting cultivation systems on ADE tend to be more prone to changes leading to intensification, and we identified cases, e.g., swiddens used for watermelon cultivation, in which market demand led to overintensification and resulted in ADE degradation. This shows that increasing intensification can be a potential threat to ADE and can undermine the importance of these soils for agricultural production, for the conservation of agrobiodiversity, and for local livelihoods. Given that farmers have an integrated knowledge of their context and respond to socioeconomic and agro-ecological changes in their environment, we argue that understanding farmers' knowledge and rationales is crucial to identify sustainable pathways for the future of ADE and of

  18. Enhanced canopy growth precedes senescence in 2005 and 2010 Amazonian droughts

    KAUST Repository

    Liu, Yi Y.

    2018-04-09

    Unprecedented droughts hit southern Amazonia in 2005 and 2010, causing a sharp increase in tree mortality and carbon loss. To better predict the rainforest\\'s response to future droughts, it is necessary to understand its behavior during past events. Satellite observations provide a practical source of continuous observations of Amazonian forest. Here we used a passive microwave-based vegetation water content record (i.e., vegetation optical depth, VOD), together with multiple hydrometeorological observations as well as conventional satellite vegetation measures, to investigate the rainforest canopy dynamics during the 2005 and 2010 droughts. During the onset of droughts in the wet-to-dry season (May–July) of both years, we found large-scale positive anomalies in VOD, leaf area index (LAI) and enhanced vegetation index (EVI) over the southern Amazonia. These observations are very likely caused by enhanced canopy growth. Concurrent below-average rainfall and above-average radiation during the wet-to-dry season can be interpreted as an early arrival of normal dry season conditions, leading to enhanced new leaf development and ecosystem photosynthesis, as supported by field observations. Our results suggest that further rainfall deficit into the subsequent dry season caused water and heat stress during the peak of 2005 and 2010 droughts (August–October) that exceeded the tolerance limits of the rainforest, leading to widespread negative VOD anomalies over the southern Amazonia. Significant VOD anomalies were observed mainly over the western part in 2005 and mainly over central and eastern parts in 2010. The total area with significant negative VOD anomalies was comparable between these two drought years, though the average magnitude of significant negative VOD anomalies was greater in 2005. This finding broadly agrees with the field observations indicating that the reduction in biomass carbon uptake was stronger in 2005 than 2010. The enhanced canopy growth

  19. Development of a biocompatible magnetic nanofluid by incorporating SPIONs in Amazonian oils

    Science.gov (United States)

    Gaspar, André S.; Wagner, Friedrich E.; Amaral, Vítor S.; Costa Lima, Sofia A.; Khomchenko, Vladimir A.; Santos, Judes G.; Costa, Benilde F. O.; Durães, Luísa

    2017-02-01

    Higher quality magnetic nanoparticles are needed for use as magnetic nanoprobe in medical imaging techniques and cancer therapy. Moreover, the phytochemistry benefits of some Amazonian essential oils have sparked great interest for medical treatments. In this work, a magnetic nanoprobe was developed, allying the biocompatibility and superparamagnetism of iron oxide nanoparticles (SPIONs) with benefits associated with Amazonian oils from Copaiba and Andiroba trees. SPIONs were obtained by two thermal decomposition procedures and different amounts of precursors (iron acetylacetonates). Their characterization was accomplished by Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy (TEM), X-ray diffraction (XRD), Mössbauer spectroscopy and magnetization. The obtained nanoparticles composition and magnetic properties were not affected by the relative proportion of iron(II) and iron(III) in the precursor system. However, when changing the reducing and stabilizing agents the coating layer shows different compositions/relative weight - the more promising SPIONs have a coating mainly composed by oleylamine and an iron oxide:coating wt% ratio of 55:45. Nanoparticles size distributions were very narrow and centred in the average size of 6-7 nm. Cellular assays confirmed the biocompatibility of SPIONs and their effective internalization in human colon cancer cells. Mössbauer/XRD results indicated maghemite as their main iron oxide phase, but traces of magnetite proved to be present. Magnetization saturations of 57 emu/g at 5 K and 42 emu/g at 300 K were achieved. With incorporation of SPIONs into Copaiba and Andiroba essential oils, these values show a 4-fold decrease, but the supermagnetic behaviour is preserved providing the effective formation of a nanofluid.

  20. Impacts of Landscape Context on Patterns of Wind Downfall Damage in a Fragmented Amazonian Landscape

    Science.gov (United States)

    Schwartz, N.; Uriarte, M.; DeFries, R. S.; Gutierrez-Velez, V. H.; Fernandes, K.; Pinedo-Vasquez, M.

    2015-12-01

    Wind is a major disturbance in the Amazon and has both short-term impacts and lasting legacies in tropical forests. Observed patterns of damage across landscapes result from differences in wind exposure and stand characteristics, such as tree stature, species traits, successional age, and fragmentation. Wind disturbance has important consequences for biomass dynamics in Amazonian forests, and understanding the spatial distribution and size of impacts is necessary to quantify the effects on carbon dynamics. In November 2013, a mesoscale convective system was observed over the study area in Ucayali, Peru, a highly human modified and fragmented forest landscape. We mapped downfall damage associated with the storm in order to ask: how does the severity of damage vary within forest patches, and across forest patches of different sizes and successional ages? We applied spectral mixture analysis to Landsat images from 2013 and 2014 to calculate the change in non-photosynthetic vegetation fraction after the storm, and combined it with C-band SAR data from the Sentinel-1 satellite to predict downfall damage measured in 30 field plots using random forest regression. We then applied this model to map damage in forests across the study area. Using a land cover classification developed in a previous study, we mapped secondary and mature forest, and compared the severity of damage in the two. We found that damage was on average higher in secondary forests, but patterns varied spatially. This study demonstrates the utility of using multiple sources of satellite data for mapping wind disturbance, and adds to our understanding of the sources of variation in wind-related damage. Ultimately, an improved ability to map wind impacts and a better understanding of their spatial patterns can contribute to better quantification of carbon dynamics in Amazonian landscapes.

  1. A Molecular Survey of the Diversity of Microbial Communities in Different Amazonian Agricultural Model Systems

    Directory of Open Access Journals (Sweden)

    Acácio A. Navarrete

    2010-05-01

    Full Text Available The processes of land conversion and agricultural intensification are a significant cause of biodiversity loss, with consequent negative effects both on the environment and the sustainability of food production.The anthrosols associated with pre-Colombian settlements in the Amazonian region are examples of how anthropogenic activities may sustain the native populations against harsh tropical environments for human establishment, even without a previous intentionality of anthropic soil formation. In a case study (Model I—“Slash-and-Burn” the community structures detected by automated ribosomal intergenic spacer analysis (ARISA revealed that soil archaeal, bacterial and fungal communities are heterogeneous and each capable of responding differently to environmental characteristics. ARISA data evidenced considerable difference in structure existing between microbial communities in forest and agricultural soils. In a second study (Model II—“Anthropogenic Soil”, the bacterial community structures revealed by terminal restriction fragment length polymorphism (T-RFLP differed among an Amazonian Dark Earth (ADE, black carbon (BC and its adjacent non-anthropogenic oxisoil. The bacterial 16S rRNA gene (OTU richness estimated by pyrosequencing was higher in ADE than BC. The most abundant bacterial phyla in ADE soils and BC were Proteobacteria—24% ADE, 15% BC; Acidobacteria—10% ADE, 21% BC; Actinobacteria—7% ADE, 12% BC; Verrucomicrobia, 8% ADE; 9% BC; Firmicutes—3% ADE, 8% BC. Overall, unclassified bacteria corresponded to 36% ADE, and 26% BC. Regardless of current land uses, our data suggest that soil microbial community structures may be strongly influenced by the historical soil management and that anthrosols in Amazonia, of anthropogenic origins, in addition to their capacity of enhancing crop yields, may also improve microbial diversity, with the support of the black carbon, which may sustain a particular and unique habitat for the

  2. Multi-scale comparisons of tree composition in Amazonian terra firme forests

    Directory of Open Access Journals (Sweden)

    L. Freitas Alvarado

    2009-11-01

    Full Text Available We explored the floristic composition of terra firme forests across Amazonia using 55 plots. Firstly, we examined the floristic patterns using both genus- and species-level data and found that the species-level analysis more clearly distinguishes among forests. Next, we compared the variation in plot floristic composition at regional- and continental-scales, and found that average among-pair floristic similarity and its decay with distance behave similarly at regional- and continental-scales. Nevertheless, geographical distance had different effects on floristic similarity within regions at distances <100 km, where north-western and south-western Amazonian regions showed greater floristic variation than plots of central and eastern Amazonia. Finally, we quantified the role of environmental factors and geographical distance for determining variation in floristic composition. A partial Mantel test indicated that while geographical distance appeared to be more important at continental scales, soil fertility was crucial at regional scales within western Amazonia, where areas with similar soil conditions were more likely to share a high number of species. Overall, these results suggest that regional-scale variation in floristic composition can rival continental-scale differences within Amazonian terra firme forests, and that variation in floristic composition at both scales is influenced by geographical distance and environmental factors, such as climate and soil fertility. To fully account for regional-scale variation in continental studies of floristic composition, future floristic studies should focus on forest types poorly represented at regional scales in current datasets, such as terra firme forests with high soil fertility in north-western Amazonia.

  3. Soil charcoal as long-term pyrogenic carbon storage in Amazonian seasonal forests.

    Science.gov (United States)

    Turcios, Maryory M; Jaramillo, Margarita M A; do Vale, José F; Fearnside, Philip M; Barbosa, Reinaldo Imbrozio

    2016-01-01

    Forest fires (paleo + modern) have caused charcoal particles to accumulate in the soil vertical profile in Amazonia. This forest compartment is a long-term carbon reservoir with an important role in global carbon balance. Estimates of stocks remain uncertain in forests that have not been altered by deforestation but that have been impacted by understory fires and selective logging. We estimated the stock of pyrogenic carbon derived from charcoal accumulated in the soil profile of seasonal forest fragments impacted by fire and selective logging in the northern portion of Brazilian Amazonia. Sixty-nine soil cores to 1-m depth were collected in 12 forest fragments of different sizes. Charcoal stocks averaged 3.45 ± 2.17 Mg ha(-1) (2.24 ± 1.41 Mg C ha(-1) ). Pyrogenic carbon was not directly related to the size of the forest fragments. This carbon is equivalent to 1.40% (0.25% to 4.04%) of the carbon stocked in aboveground live tree biomass in these fragments. The vertical distribution of pyrogenic carbon indicates an exponential model, where the 0-30 cm depth range has 60% of the total stored. The total area of Brazil's Amazonian seasonal forests and ecotones not altered by deforestation implies 65-286 Tg of pyrogenic carbon accumulated along the soil vertical profile. This is 1.2-2.3 times the total amount of residual pyrogenic carbon formed by biomass burning worldwide in 1 year. Our analysis suggests that the accumulated charcoal in the soil vertical profile in Amazonian forests is a substantial pyrogenic carbon pool that needs to be considered in global carbon models. © 2015 John Wiley & Sons Ltd.

  4. Utilization and fate of phosphorus of different sources applied to cohesive soil of Amazonian periphery

    Directory of Open Access Journals (Sweden)

    Marta Jordana Arruda Coelho

    Full Text Available ABSTRACT In the Amazonian region, P is often a primary factor limiting sustainable agrosystems. We compared the efficiencies of local aluminous phosphate (ALP and single superphosphate (SSP under a cover of leguminous residues to determine the fate of P sources in an Amazonian soil with hardsetting characteristics. The experiment followed a randomized block design with four replications and the following treatments: ALPU, i.e. ALP plus urea (U; ALPL, i.e., ALP plus leucaena (L; SSPU, i.e., SSP plus urea; SSPL, i.e., SSP plus leucaena; and BS, i.e., bare soil (without residues. To assess the residual values of the P sources, we used a sequence of crops consisting of maize, cowpea and cassava. Both ALP and SSP exhibited low P efficiency in BS. The greatest amounts of P and N uptake in the plots where P sources and leucaena residues were added, as in those covered with leucaena residue, resulted in higher productivity levels. These differences are important for the adoption of beneficial soil management practices and the use of P sources to enhance efficiency in tropical soils. The use of residues increased the P use efficiency of both P sources, as it enhanced the uptake of both N and soluble P. The replacement of SSP with ALP may be advantageous in the second year of planting with high-demand crops, but the P of the SSP retained in the minus soluble fractions may be available if the SSP is used in P-depleting crops combined with no-tillage underneath a mulch of residues.

  5. Recent (Late Amazonian) enhanced backweathering rates on Mars: Paracratering evidence from gully alcoves

    Science.gov (United States)

    de Haas, Tjalling; Conway, Susan; Krautblatter, Michael

    2016-04-01

    Mars is believed to have been exposed to low planet-wide weathering and denudation since the Noachian period (˜4.1 - 3.7 Ga). However, the widespread occurrence of alcoves at the rim of pristine impact craters suggests locally enhanced recent backweathering rates. Here we derive Late Amazonian backweathering rates from the alcoves of 10 young equatorial and mid-latitude craters, ranging in age from 0.2 to 45 Ma. The enhanced Late Amazonian Martian backweathering rates (10-4 - 10-1 mm yr-1) are approximately one order of magnitude higher than previously reported erosion rates, and are similar to terrestrial rates inferred from Meteor crater and various Arctic and Alpine rock faces, when corrected for age. Alcoves on initially highly fractured and oversteepened crater rims following impact show enhanced backweathering rates that decline over at least 101 - 102 Myr as the crater wall stabilizes. This 'paracratering' backweathering decline with time is analogous to the paraglacial effect observed in rock slopes after deglaciation, but the relaxation time scale of 101 - 102 Myr compared to 10 kyr of the Milankovitch-controlled interglacial duration questions whether a paraglacial steady state is reached on Earth. The backweathering rates on the gullied pole-facing alcoves of the studied mid-latitude craters are much higher (˜2 - 60 times) than those on slopes with other azimuths and those in equatorial craters. The enhanced backweathering rates on gullied crater slopes may result from liquid water acting as a catalyst for backweathering. The decrease in backweathering rates over time might explain the similar size of gullies in young (craters, as alcove growth and sediment supply decrease to low background rates over time.

  6. Enviromental indicators in Amazonian Kichwa Communities from Ecuador for the ellaboration of a sustainable development strategy

    Directory of Open Access Journals (Sweden)

    Ruth Irene Arias Gutiérrez

    2015-02-01

    Full Text Available An environmental diagnosis is made in the Amazonian Kichwa region (Napo and Pastaza provinces, Ecuador for the ellaboration of a sustainable development strategy. The environmental indicators such as the number of cultivated plant species and their use. The use of forest and agricultural products were measured, as well. Qualitative and quantitative research methods, most appropriate for this study, were used. The quantitative methodology consisted in surveying to the residents, the leaders of the six communities and the heads of 64 households scattered around five rural parishes. The main results are collected in a strategic agenda that would boost the ecological sustainability. The communities employ a high number of species directly as food, and a fewer for medical, flavoring and cosmetic use. However, a single use of resources as raw materials is observed. With no the application of science and technology, there is not an orderly and efficient use of resources, which is achieved by establishing links with other universities research projects. It is necessary to replenish and enhance native renewable resources used by the communities, and add value and work on human capital formation for the protection of these resources. Local resources are not reasonably used with a focus on the protection of the environment and the extensive Amazonian biodiversity. There are high rates of illiteracy in the communities. That’s why it is important the development of bio-knowledge through public interventions, which will help sustain the national competitive advantage, based on its natural and biological richness, supported by the development of local production networks and technology generation. A proposed strategy for a sustainable agro-ecological community development was made.

  7. On the vertical distribution of smoke in the Amazonian atmosphere during the dry season

    Directory of Open Access Journals (Sweden)

    F. Marenco

    2016-02-01

    Full Text Available Lidar observations of smoke aerosols have been analysed from six flights of the Facility for Airborne Atmospheric Measurements BAe-146 research aircraft over Brazil during the biomass burning season (September 2012. A large aerosol optical depth (AOD was observed, typically ranging 0.4–0.9, along with a typical aerosol extinction coefficient of 100–400 Mm−1. The data highlight the persistent and widespread nature of the Amazonian haze, which had a consistent vertical structure, observed over a large distance ( ∼ 2200 km during a period of 14 days. Aerosols were found near the surface; but the larger aerosol load was typically found in elevated layers that extended from 1–1.5 to 4–6 km. The measurements have been compared to model predictions with the Met Office Unified Model (MetUM and the ECMWF-MACC model. The MetUM generally reproduced the vertical structure of the Amazonian haze observed with the lidar. The ECMWF-MACC model was also able to reproduce the general features of smoke plumes albeit with a small overestimation of the AOD. The models did not always capture localised features such as (i smoke plumes originating from individual fires, and (ii aerosols in the vicinity of clouds. In both these circumstances, peak extinction coefficients of the order of 1000–1500 Mm−1 and AODs as large as 1–1.8 were encountered, but these features were either underestimated or not captured in the model predictions. Smoke injection heights derived from the Global Fire Assimilation System (GFAS for the region are compatible with the general height of the aerosol layers.

  8. Workplan for Catalyzing Collaboration with Amazonian Universities in the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA)

    Science.gov (United States)

    Brown, I. Foster; Moreira, Adriana

    1997-01-01

    Success of the Large-Scale Biosphere-Atmospheric Experiment in Amazonia (LBA) program depends on several critical factors, the most important being the effective participation of Amazonian researchers and institutions. Without host-county counterparts, particularly in Amazonia, many important studies cannot he undertaken due either to lack of qualified persons or to legal constraints. No less important, the acceptance of the LBA program in Amazonia is also dependent on what LBA can do for improving the scientific expertise in Amazonia. Gaining the active investment of Amazonian scientists in a comprehensive research program is not a trivial task. Potential collaborators are few, particularly where much of the research was to be originally focused - the southern arc of Brazilian Amazonia. The mid-term goals of the LBA Committee on Training and Education are to increase the number of collaborators and to demonstrate that LBA will be of benefit to the region.

  9. Evidence for the control of the geochemistry of Amazonian floodplain sediments by stratification of suspended sediments in the Amazon

    OpenAIRE

    Roddaz, M.; Viers, J.; Moreira Turcq, Patricia; Blondel, C.; Sondag, Francis; Guyot, Jean-Loup; Moreira, L.

    2014-01-01

    Holocene and historical Amazonian floodplain deposits collected from two cores of the "Varzea do Curuai" flooded area (Brazil) were analysed for major and trace element geochemistry as well as Nd-Sr isotopic compositions (21 samples). The TA11 and TA14 cores (110 cm and 270 cm in depth, respectively) were collected at different locations in the Varzea, near a channel inlet connecting the Amazon River to the Varzea and at the centre of the Varzea, respectively. The two cores represent records ...

  10. Two new species in the Matelea stenopetala complex (Apocynaceae, Asclepiadoideae) from the Guiana Shield and Amazonian Brazil

    Science.gov (United States)

    Krings, Alexander; Morillo, Gilberto

    2012-01-01

    Abstract Two new species in the Matelea stenopetala complex (Apocynaceae, Asclepiadoideae) are described from the Guiana Shield and Amazonian Brazil: Matelea brevistipitata Krings & Morillo, sp. nov. and Matelea trichopedicellataKrings & Morillo, sp. nov. The new species belong to a small group of adaxially-pubescent-flowered taxa within the complex, including Matelea hildegardiana and Matelea pakaraimensis. The new species are described and a dichotomous key is provided. PMID:23233816

  11. Conceptions and practices of an integrative treatment for substance use disorders involving Amazonian medicine: traditional healers' perspectives.

    Science.gov (United States)

    Berlowitz, Ilana; Ghasarian, Christian; Walt, Heinrich; Mendive, Fernando; Alvarado, Vanessa; Martin-Soelch, Chantal

    2017-12-18

    The harmful use of psychoactive substances represents one of today's largest public health problems. Yet, in spite of its global relevance, current treatment for substance use disorders (SUDs) is still not entirely successful. The purpose of this study was to investigate alternative treatments and conceptions from traditional Amazonian medicine adapted to SUDs. We conducted semi-structured interviews with 13 practicing experts at a well-established addiction treatment center in the Peruvian Amazon and performed qualitative content analysis on the collected data. Main categories were deductively defined and corresponding subcategories inductively developed. Our findings revealed characteristic features and consequences, causes and antecedents, and treatment methods of SUDs as the main categories. Overall, concepts of disease etiology bore resemblance with contemporary biopsychosocial models of SUDs. The Amazonian therapeutic means however differed markedly from current Western ones. The main methods involved dietary retreats, healing ceremonies, and purging rituals. The integral application of Amazonian methods, as well as their traditional implementation according to prescribed ritual protocols, were emphasized by the experts as crucial for efficacy and safety of treatment delivery. We suggest further scientific attention to these therapies, including clinical studies, for which our results provide conceptual underpinnings. Findings from this research expand the cross-cultural understanding of SUDs and, in the long run, may enhance its treatment options.

  12. Isotopes as validation tools for predictions of the impact of Amazonian deforestation on climate and regional hydrology

    International Nuclear Information System (INIS)

    Henderson-Sellers, A.; Chambers, S.; McGuffie, K.

    2002-01-01

    Isotopic analysis and modelling of the Amazon Basin have both been reported for about thirty years. Isotopic data have been used to explain important characteristics of Amazonian hydrologic cycling by means of simple models. To date there has been no attempt to use isotopic data to evaluate global climate models employed to predict the possible impacts of Amazonian deforestation. This paper reviews the history of isotopic analysis and simulations of deforestation in the Amazon and initiates isotopic evaluation of GCMs. It is shown that one widely reported simulation set gives seasonal transpiration and re-evaporated canopy interception budgets different from those derived from isotopic analysis. It is found that temporal changes (1965 to 1990) in wet season deuterium excess differences between Belem and Manaus are consistent with GCM results only if there has been a relative increase in evaporation from non-fractionating water sources over this period. We propose synergistic future interactions among the climate/hydrological modelling and isotopic analysis communities in order to improve confidence in simulations of Amazonian deforestation. (author)

  13. Chronology of Terra Firme formation in western Amazonia and implications for the diversification of Amazonian biota

    Science.gov (United States)

    Pupim, Fabiano do N.; Sawakushi, André O.; Hartmann, Gelvam A.; Savian, Jairo F.; Kern, Andrea K.; Mineli, Thays D.; Cruz, Francisco W.; Almeida, Renato P.; Grohmann, Carlos H.; Ribas, Camila C.; d'Horta, Fernando M.; Bertassoli, Dailson J.; Marconato, André; Nogueira, Luciana; Lohmann, Lúcia G.

    2017-04-01

    The shift from a large wetland dominated by avulsive channels and flooded forests to the incised transcontinental Amazon River valley (Várzea) bounded by non-flooded forests (Terra Firme) is suggested as one of the main drivers of diversification of the mega diverse Amazonian Biota. Nonetheless, there is no consensus about the timing of this landscape shift, with the current literature suggesting a period that ranges from the Miocene (11 Ma) and the Late Pleistocene (100 ka). This uncertainty may be due to a lack of absolute ages for the sediments forming Terra Firme forest substrates in western Amazonian lowlands. In Brazil, the Içá Formation represents the uppermost fluvial deposits of Terra Firme forests substrates in western Amazonia. Therefore, a reliable chronology for the last depositional stage of the Içá Formation is key for an improved understanding of the formation of the current Terra Firme-Várzea system. Four sediment profiles were sampled along the margins of the Solimões and Içá rivers for Optically Stimulated Luminescence (OSL) dating, geomagnetic excursions, and palynological analysis. OSL dating was performed in twelve samples using a Single Aliquot Regeneration (SAR) protocol in quartz sand grains. The equivalent doses ranged from 47 to 130 Gy (Central Age Model) and the dose rate values ranged from 0.4 to 2.0 Gy/ka. The resulting sediment burial ages range from 48 to 112 ka. Paleomagnetic data were obtained from samples collected at same profiles sampled for OSL dating and results suggest the presence of Post-Blake geomagnetic excursion ( 100 ka). The age of 100 ka for Post-Blake excursion are adopted for the Geomagnetic Instability Time Scale. Pollen assemblage data show a similarity to a more modern flora and the presence of Alnus clearly points towards Pleistocene deposition as it is unknown before in South America. The combined OSL, paleomagnetism and pollen data is a robust geochronological dataset that indicates Late Pleistocene

  14. Calcium fluxes in Hoplosternum littorale (tamoatá exposed to different types of Amazonian waters

    Directory of Open Access Journals (Sweden)

    Bernardo Baldisserotto

    2009-09-01

    Full Text Available Fishes that live in the Amazonian environment may be exposed to several kinds of waters: "black waters", containing high dissolved organic carbon and acidic pH, "white waters", with ten fold higher Ca2+ concentrations than black waters and neutral pH, and "clear waters", with two fold higher Ca2+ concentrations than black waters and also neutral pH. Therefore, the aim of the present study was to analyze Ca2+ fluxes in the facultative air-breather Hoplosternum littorale (tamoatá exposed to different Amazonian waters. Fishes were acclimated in well water (similar to clear water and later placed in individual chambers for Ca2+ fluxes measurements. After 4 h, water from the chambers was replaced by a different type of water. Transfer of tamoatás to ion-poor black or acidic black water resulted in net Ca2+ loss only in the first 2 h of experiment. However, transfer from black or acidic black water to white water led to only net Ca2+ influxes. The results obtained allowed us to conclude that transfer of tamoatás to ion-poor waters (black and acidic black water led to transient net Ca2+ loss, while the amount of Ca2+ in the ion-rich white water seems adequate to prevent Ca2+ loss after transfer. Therefore, transfer of tamoatás between these Amazonian waters does not seem to result in serious Ca2+ disturbance.Os peixes que vivem na Amazônia são expostos a vários tipos de água: águas pretas, contendo grande quantidade de carbono orgânico dissolvido, águas brancas, com concentração de Ca2+ dez vezes maior que as águas pretas e pH neutro, e águas claras, com concentração de Ca2+ duas vezes maior que as águas pretas e pH também neutro. Dessa forma, o objetivo deste trabalho foi analisar o fluxo de Ca2+ no peixe de respiração aérea facultativa Hoplosternum littorale (tamoatá exposto a diferentes tipos de águas amazônicas. Os peixes foram aclimatados em água de poço artesiano (semelhante à água clara e depois colocados

  15. Emplacement and deformation of the A-type Madeira granite (Amazonian Craton, Brazil)

    Science.gov (United States)

    Siachoque, Astrid; Salazar, Carlos Alejandro; Trindade, Ricardo

    2017-04-01

    The Madeira granite is one of the Paleoproterozoic (1.82 Ga) A-type granite intrusions in the Amazonian Craton. It is elongated in the NE-SW direction and is composed of four facies. Classical structural techniques and the anisotropy of magnetic susceptibility (AMS) method were applied to the study of its internal fabric. Magnetic susceptibility measurements, thermomagnetic curves, remanent coercivity spectra, optical microscopy and SEM (scanning electron microscopy) analyses were carried out on the earlier and later facies of the Madeira granite: the rapakivi granite (RG) and the albite granite (AG) respectively. The last one is subdivided into the border albite granite (BAG) and the core albite granite (CAG) subfacies. AMS fabric pattern is controlled by pure magnetite in all facies, despite significant amounts of hematite in the BAG subfacies. Microstructural observations show that in almost all sites, magnetic fabric correlates to magmatic state fabrics that are defined by a weak NE-SW orientation of mafic and felsic silicates. However, strain mechanisms in both subfacies of AG also exhibit evidence for solid-state deformation at high to moderate temperatures. Pegmatite dyke, strike slip fault (SFA-B-C), hydrothermal vein, normal fault (F1-2) and joint (J) structures were observed and their orientation and kinematics is consistent with the magmatic and solid-state structures. Dykes, SFA-C and F1, are usually orientated along the N70°E/40°N plane, which is nearly parallel to the strike of AMS and magmatic foliations. In contrast, veins, SFB, F2 and some J are oriented perpendicular to the N70°E trend. Kinematic analysis in these structures shows evidence for a dextral sense of movement in the system in the brittle regime. The coherent structural pattern for the three facies of Madeira granite suggests that the different facies form a nested pluton. The coherence in orientation and kinematics from magmatic to high-temperature solid-state, and into the brittle

  16. Wood Polymer Composites Technology Supporting the Recovery and Protection of Tropical Forests: The Amazonian Phoenix Project

    Directory of Open Access Journals (Sweden)

    Antonio D. Nobre

    2009-12-01

    Full Text Available The Amazon Rain Forest has attracted worldwide attention due its large scale services to climate and also due to the green house gas emissions arising from deforestation. Contributing to the later and detrimental to the former, timber logging in the region has very low efficiency (only 16% in the production chain. Such timber extraction, often referred to as selective logging, has been claimed as a sustainable extractive industry, because the forest is said to restore itself through regenerative growth. But forest regeneration in the Amazon occurs naturally only in a very limited scale, resulting that large scale, low efficiency logging poses a big treat to the functional integrity of the biome, supplying to the market only a fraction of what it could if done differently. So, instead of extracting big centennial logs from the forests, the Amazonian Phoenix project proposes that large expanses of degraded lands be reforested using pioneer plants species from the forest itself. These plants have the capacity to heal gaps in the canopy, being able to grow and produce woody biomass in very extreme conditions. The idea is to mimic the regenerative dynamics of the natural ecosystem in short cycle agrosilvicultural production areas, utilizing a variety of technologies to transform raw fibers from these fast growth native plants into a variety of materials with high aggregated value. This communication presents the research on natural fibers by the Polymeric Composites Group within the Amazonian Phoenix Project. Sustainable technologies employing materials with good and responsible ecological footprints are important and necessary stimulus for a change in the destructive economical activities present in the Amazon frontiers. The relatively well established wood polymer composites technology, for example, is a good candidate solution. Two research and development fields are proposed: the first one considers production systems with simple and cheap

  17. Diverse Early Life-History Strategies in Migratory Amazonian Catfish: Implications for Conservation and Management.

    Science.gov (United States)

    Hegg, Jens C; Giarrizzo, Tommaso; Kennedy, Brian P

    2015-01-01

    Animal migrations provide important ecological functions and can allow for increased biodiversity through habitat and niche diversification. However, aquatic migrations in general, and those of the world's largest fish in particular, are imperiled worldwide and are often poorly understood. Several species of large Amazonian catfish carry out some of the longest freshwater fish migrations in the world, travelling from the Amazon River estuary to the Andes foothills. These species are important apex predators in the main stem rivers of the Amazon Basin and make up the region's largest fishery. They are also the only species to utilize the entire Amazon Basin to complete their life cycle. Studies indicate both that the fisheries may be declining due to overfishing, and that the proposed and completed dams in their upstream range threaten spawning migrations. Despite this, surprisingly little is known about the details of these species' migrations, or their life history. Otolith microchemistry has been an effective method for quantifying and reconstructing fish migrations worldwide across multiple spatial scales and may provide a powerful tool to understand the movements of Amazonian migratory catfish. Our objective was to describe the migratory behaviors of the three most populous and commercially important migratory catfish species, Dourada (Brachyplatystoma rousseauxii), Piramutaba (Brachyplatystoma vaillantii), and Piraíba (Brachyplatystoma filamentosum). We collected fish from the mouth of the Amazon River and the Central Amazon and used strontium isotope signatures ((87)Sr/(86)Sr) recorded in their otoliths to determine the location of early rearing and subsequent. Fish location was determined through discriminant function classification, using water chemistry data from the literature as a training set. Where water chemistry data was unavailable, we successfully in predicted (87)Sr/(86)Sr isotope values using a regression-based approach that related the geology

  18. Diverse Early Life-History Strategies in Migratory Amazonian Catfish: Implications for Conservation and Management.

    Directory of Open Access Journals (Sweden)

    Jens C Hegg

    Full Text Available Animal migrations provide important ecological functions and can allow for increased biodiversity through habitat and niche diversification. However, aquatic migrations in general, and those of the world's largest fish in particular, are imperiled worldwide and are often poorly understood. Several species of large Amazonian catfish carry out some of the longest freshwater fish migrations in the world, travelling from the Amazon River estuary to the Andes foothills. These species are important apex predators in the main stem rivers of the Amazon Basin and make up the region's largest fishery. They are also the only species to utilize the entire Amazon Basin to complete their life cycle. Studies indicate both that the fisheries may be declining due to overfishing, and that the proposed and completed dams in their upstream range threaten spawning migrations. Despite this, surprisingly little is known about the details of these species' migrations, or their life history. Otolith microchemistry has been an effective method for quantifying and reconstructing fish migrations worldwide across multiple spatial scales and may provide a powerful tool to understand the movements of Amazonian migratory catfish. Our objective was to describe the migratory behaviors of the three most populous and commercially important migratory catfish species, Dourada (Brachyplatystoma rousseauxii, Piramutaba (Brachyplatystoma vaillantii, and Piraíba (Brachyplatystoma filamentosum. We collected fish from the mouth of the Amazon River and the Central Amazon and used strontium isotope signatures ((87Sr/(86Sr recorded in their otoliths to determine the location of early rearing and subsequent. Fish location was determined through discriminant function classification, using water chemistry data from the literature as a training set. Where water chemistry data was unavailable, we successfully in predicted (87Sr/(86Sr isotope values using a regression-based approach that related

  19. Patterns of energy allocation to reproduction in three Amazonian fish species

    Directory of Open Access Journals (Sweden)

    Rodrigo N. dos Santos

    2010-03-01

    Full Text Available The study considered the influence of the hydrological cycle and gonadal development on the accumulation and use of energy in three fish species from an Amazonian flooded area. Fishes were sampled over a 24 hour period at monthly intervals between July 2004 and June 2005 using gillnets of different mesh sizes. Body cavity fat and gonadosomatic indices were determined, as well as energy content of gonads and muscles. Amongst the studied species, different means of energy allocation for reproduction were found: Acestrorhynchus falcirostris allocate energy from body cavity fat to its gonads; Pygocentrus nattereri uses mainly energy accumulated in the muscles for the process of gonadal maturation; and Hoplosternum littorale uses energy accumulated in their muscles and body cavity fat for reproductive processes. It is quite clear that the flood pulse regulates the gain and use of the energy reserves in fishes from the Amazonian floodplain.O presente estudo considerou a influência do ciclo hidrológico e maturação gonadal no acúmulo e utilização da energia em três espécies de peixes, numa área de planície de inundação amazônica. As amostras foram obtidas mensalmente durante o período de julho de 2004 a junho de 2005, utilizando redes de emalhar com vários tamanhos de malhas, durante 24 horas. O índice de gordura cavitária, índice gonadossomático, e teor energético dos músculos e gônadas foram analisados. Dentre as espécies analisadas, foram detectados diferentes padrões de alocação de energia: Acestrorhynchus falcirostris aloca energia das reservas de gordura cavitária para as gônadas; Pygocentrus nattereri utiliza energia dos músculos para este fim e Hoplosternum littorale, além da gordura cavitária, utiliza também energia acumulada nos músculos para realização dos processos reprodutivos. Ficou evidente que o pulso de inundação exerce forte influência no acúmulo e utilização das reservas energéticas dos

  20. Solid state bioreactor production of transglutaminase by Amazonian Bacillus circulans BL32 strain.

    Science.gov (United States)

    de Souza, Claucia Fernanda Volken; Heck, Júlio Xandro; Ayub, Marco Antônio Záchia

    2008-12-01

    In this work, we investigated the production of transglutaminase (TGase) by an Amazonian isolated strain of Bacillus circulans by solid-state cultivation (SSC). Several agro-industrial residues, such as untreated corn grits, milled brewers rice, industrial fibrous soy residue, soy hull, and malt bagasse, were used as substrates for microbial growth and enzyme production. Growth on industrial fibrous soy residue, which is rich in protein and hemicellulose, produced the highest TGase activity (0.74 U g(-1) of dried substrate after 48 h of incubation). A 2(3) central composite design was applied to determine the optimal conditions of aeration, cultivation temperature and inoculum cell concentration to TGase production. The best culture conditions were determined as being 0.6 L air min(-1), 33 degrees C and 10 log (10) CFU g(-1) of dried substrate, respectively. Under the proposed optimized conditions, the model predicted an enzyme production of 1.16 U g(-1) of dried substrate, closely matching the experimental activity of 1.25 U g(-1). Results presented in this work point to the use of this newly isolated B. circulans strain as a potential alternative of microbial source for TGase production by SSC, using inexpensive culture media.

  1. Four species of the new Amazonian sharpshooter Daedaloscarta gen. nov. (Insecta: Hemiptera: Cicadellidae

    Directory of Open Access Journals (Sweden)

    Rodney R. Cavichioli

    2012-12-01

    Full Text Available Four new species, Daedaloscarta erwini sp. nov. (Peru: Loreto, D. maculata sp. nov. (Brazil: Amazonas, D. mene sp. nov. (Ecuador: Orellana, and D. redacta sp. nov. (Brazil: Amazonas are described and placed in the new genus Daedaloscarta gen. nov. Species of the new genus can be readily distinguished from other Cicadellini genera by their: (1 dark brown to black dorsal coloration with contrasting large ivory spots; (2 crown produced and round anteriorly (Figs 1-8; (3 pronotum narrower than transocular width of head, with lateral margins parallel; (4 male pygofer with pair of acute finger-like processes arising at dorsal margin directed inwardly and ventrally; (5 subgenital plates with apical two-thirds very slender; (6 aedeagus very large with shaft elongate, with an unpaired basidorsal, elongate bifurcate basiventral, and paired retrorse lateral processes at midlength of shaft; and (7 paraphyses bifurcate and slender. All known specimens are associated with terra firme or flooded Amazonian forests and were collected by light trapping or insecticidal fogging.

  2. [Aboveground biomass input of Myristicaceae tree species in the Amazonian Forest in Peru].

    Science.gov (United States)

    Ureta Adrianzén, Marisabel

    2015-03-01

    Amazonian forests are a vast storehouse of biodiversity and function as carbon sinks from biomass that accumulates in various tree species. In these forests, the taxa with the greatest contribution of biomass cannot be precisely defined, and the representative distribution of Myristicaceae in the Peruvian Amazon was the starting point for designing the present study, which aimed to quantify the biomass contribution of this family. For this, I analyzed the databases that corresponded to 38 sample units that were previously collected and that were provided by the TeamNetwork and RAINFOR organizations. The analysis consisted in the estimation of biomass using pre-established allometric equations, Kruskal-Wallis sample comparisons, interpolation-analysis maps, and nonparametric multidimensional scaling (NMDS). The results showed that Myristicaceae is the fourth most important biomass contributor with 376.97 Mg/ha (9.92 Mg/ha in average), mainly due to its abundance. Additionally, the family shows a noticeable habitat preference for certain soil conditions in the physiographic units, such is the case of Virola pavonis in "varillales", within "floodplain", or Iryanthera tessmannii and Virola loretensis in sewage flooded areas or "igapo" specifically, and the preference of Virola elongata and irola surinamensis for white water flooded areas or "varzea" edaphic conditions of the physiographic units taken in the study.

  3. Taxonomic and functional composition of arthropod assemblages across contrasting Amazonian forests.

    Science.gov (United States)

    Lamarre, Greg P A; Hérault, Bruno; Fine, Paul V A; Vedel, Vincent; Lupoli, Roland; Mesones, Italo; Baraloto, Christopher

    2016-01-01

    Arthropods represent most of global biodiversity, with the highest diversity found in tropical rain forests. Nevertheless, we have a very incomplete understanding of how tropical arthropod communities are assembled. We conducted a comprehensive mass sampling of arthropod communities within three major habitat types of lowland Amazonian rain forest, including terra firme clay, white-sand and seasonally flooded forests in Peru and French Guiana. We examined how taxonomic and functional composition (at the family level) differed across these habitat types in the two regions. The overall arthropod community composition exhibited strong turnover among habitats and between regions. In particular, seasonally flooded forest habitats of both regions comprised unique assemblages. Overall, 17·7% (26 of 147) of arthropod families showed significant preferences for a particular habitat type. We present a first reproducible arthropod functional classification among the 147 taxa based on similarity among 21 functional traits describing feeding source, major mouthparts and microhabitats inhabited by each taxon. We identified seven distinct functional groups whose relative abundance contrasted strongly across the three habitats, with sap and leaf feeders showing higher abundances in terra firme clay forest. Our novel arthropod functional classification provides an important complement to link these contrasting patterns of composition to differences in forest functioning across geographical and environmental gradients. This study underlines that both environment and biogeographical processes are responsible for driving arthropod taxonomic composition while environmental filtering is the main driver of the variance in functional composition. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

  4. Urinary parameters of Trichechus inunguis (Mammalia, Sirenia: reference values for the Amazonian Manatee

    Directory of Open Access Journals (Sweden)

    TMA. Pantoja

    Full Text Available The Amazonian manatee, Trichechus inunguis (Natterer 1883 is endemic to the Amazon Basin and is currently considered a vulnerable species. In order to establish normality ranges of urinary parameters to help monitor the health of this species in captivity, chemical urinalyses were performed on twelve males and nine females of various age groups. Urine was collected once a month for twelve months in the tanks just after being drained, by placing stainless steel containers under the genital slit of females and applying abdominal massages to males in order to stimulate urination. Quantitative data of glucose, urea, creatinine, uric acid and amylase levels were obtained using colorimetric spectrophotometry. Dip strips were also useful for routine analyses, despite only providing qualitative results. Normal range to glucose levels, regardless of sex or age class, was 3.0 to 3.6 mg.dL-1, coinciding with qualitative values of glucose measured by dip strips. Statistical differences observed in some parameter levels suggest that some urine parameters analysed must take into consideration the sex and the age class of the animal studied, being these differences less remarkable in creatinine and amylase levels. To this last one, statistical difference was detected only in the calve's urine (7.0 to 11.5 mg.dL-1 compared to other age classes samples (4.1 to 5.3 mg.dL-1. The results presented here may be used as comparative data in future research on urinalysis in related species.

  5. Oil palm monoculture induces drastic erosion of an Amazonian forest mammal fauna.

    Science.gov (United States)

    Mendes-Oliveira, Ana Cristina; Peres, Carlos A; Maués, Paula Cristina R de A; Oliveira, Geovana Linhares; Mineiro, Ivo G B; de Maria, Susanne L Silva; Lima, Renata C S

    2017-01-01

    Oil palm monoculture comprises one of the most financially attractive land-use options in tropical forests, but cropland suitability overlaps the distribution of many highly threatened vertebrate species. We investigated how forest mammals respond to a landscape mosaic, including mature oil palm plantations and primary forest patches in Eastern Amazonia. Using both line-transect censuses (LTC) and camera-trapping (CT), we quantified the general patterns of mammal community structure and attempted to identify both species life-history traits and the environmental and spatial covariates that govern species intolerance to oil palm monoculture. Considering mammal species richness, abundance, and species composition, oil palm plantations were consistently depauperate compared to the adjacent primary forest, but responses differed between functional groups. The degree of forest habitat dependency was a leading trait, determining compositional dissimilarities across habitats. Considering both the LTC and CT data, distance from the forest-plantation interface had a significant effect on mammal assemblages within each habitat type. Approximately 87% of all species detected within oil palm were never farther than 1300 m from the forest edge. Our study clearly reinforces the notion that conventional oil palm plantations are extremely hostile to native tropical forest biodiversity, which does not bode well given prospects for oil palm expansion in both aging and new Amazonian deforestation frontiers.

  6. Carbon recovery dynamics following disturbance by selective logging in Amazonian forests

    Science.gov (United States)

    Piponiot, Camille; Sist, Plinio; Mazzei, Lucas; Peña-Claros, Marielos; Putz, Francis E; Rutishauser, Ervan; Shenkin, Alexander; Ascarrunz, Nataly; de Azevedo, Celso P; Baraloto, Christopher; França, Mabiane; Guedes, Marcelino; Honorio Coronado, Eurídice N; d'Oliveira, Marcus VN; Ruschel, Ademir R; da Silva, Kátia E; Doff Sotta, Eleneide; de Souza, Cintia R; Vidal, Edson; West, Thales AP; Hérault, Bruno

    2016-01-01

    When 2 Mha of Amazonian forests are disturbed by selective logging each year, more than 90 Tg of carbon (C) is emitted to the atmosphere. Emissions are then counterbalanced by forest regrowth. With an original modelling approach, calibrated on a network of 133 permanent forest plots (175 ha total) across Amazonia, we link regional differences in climate, soil and initial biomass with survivors’ and recruits’ C fluxes to provide Amazon-wide predictions of post-logging C recovery. We show that net aboveground C recovery over 10 years is higher in the Guiana Shield and in the west (21 ±3 Mg C ha-1) than in the south (12 ±3 Mg C ha-1) where environmental stress is high (low rainfall, high seasonality). We highlight the key role of survivors in the forest regrowth and elaborate a comprehensive map of post-disturbance C recovery potential in Amazonia. DOI: http://dx.doi.org/10.7554/eLife.21394.001 PMID:27993185

  7. Neurotoxic effects of low-level methylmercury contamination in the Amazonian basin

    Energy Technology Data Exchange (ETDEWEB)

    Lebel, J.; Mergler, D.; Lucotte, M.; Larribe, F.; Dolbec, J. [Univ. du Quebec, Montreal, Quebec (Canada); Branches, F. [Santarem, Para (Brazil); Amorim, M. [Univ. Federal do Para (Brazil). Cytogenetic Lab.

    1998-10-01

    Many studies have demonstrated mercury contamination in the Amazonian ecosystem, particularly in fish, a dietary mainstay of populations in this region. The present study focused on potential health effects of this low-level methylmercury exposure. The study was carried out in a village on the Tapajos River, a tributary of the Amazon, on 91 adults inhabitants whose hair mercury levels were inferior to 50 {micro}/g. Performance on a neurofunctional test battery and clinical manifestations of nervous system dysfunction were examined in relation to hair mercury concentrations. Near visual contrast sensitivity and manual dexterity, adjusted for age, decreased significantly with hair mercury levels (P < 0.05), while there was a tendency for muscular fatigue to increase and muscular strength to decrease in women. For the most part, clinical examinations were normal, however, hair mercury levels were significantly higher (P < 0.05) for persons who presented disorganized movements on an alternating movement task and for persons with restricted visual fields. These results suggest dose-dependent nervous system alterations at hair mercury levels below 50 {micro}g/g, previously considered a threshold for clinical effects. The profile of dysfunction in this adult population is consistent with the current knowledge on methylmercury poisoning. The long-term implications of these findings are unknown and need to be addressed.

  8. Vertical stratification of bat assemblages in flooded and unflooded Amazonian forests

    Directory of Open Access Journals (Sweden)

    Maria João Ramos PEREIRA, João Tiago MARQUES, Jorge M. PALMEIRIM

    2010-08-01

    Full Text Available Tropical rainforests usually have multiple strata that results in a vertical stratification of ecological opportunities for animals. We investigated if this stratification influences the way bats use the vertical space in flooded and unflooded forests of the Central Amazon. Using mist-nets set in the canopy (17 to 35 m high and in the understorey (0 to 3 m high we sampled four sites in upland unflooded forests (terra firme, three in forests seasonally flooded by nutrient-rich water (várzea, and three in forests seasonally flooded by nutrient-poor water (igapó. Using rarefaction curves we found that species richness in the understorey and canopy were very similar. An ordination analysis clearly separated the bat assemblages of the canopy from those of the understorey in both flooded and unflooded habitats. Gleaning carnivores were clearly associated with the understorey, whereas frugivores were abundant in both strata. Of the frugivores, Carollinae and some Stenodermatinae were understorey specialists, but several Stenodermatinae mostly used the canopy. The first group mainly includes species that, in general, feed on fruits of understorey shrubs, whereas the second group feed on figs and other canopy fruits. We conclude that vertical stratification in bat communities occurs even within forests with lower canopy heights, such as Amazonian seasonally flooded forests, and that the vertical distribution of bat species is closely related to their diet and foraging behaviour [Current Zoology 56 (4: 469–478, 2010].

  9. Amazonian Plant Natural Products: Perspectives for Discovery of New Antimalarial Drug Leads

    Directory of Open Access Journals (Sweden)

    Lucio H. Freitas-Junior

    2013-08-01

    Full Text Available Plasmodium falciparum and P. vivax malaria parasites are now resistant, or showing signs of resistance, to most drugs used in therapy. Novel chemical entities that exhibit new mechanisms of antiplasmodial action are needed. New antimalarials that block transmission of Plasmodium spp. from humans to Anopheles mosquito vectors are key to malaria eradication efforts. Although P. vivax causes a considerable number of malaria cases, its importance has for long been neglected. Vivax malaria can cause severe manifestations and death; hence there is a need for P. vivax-directed research. Plants used in traditional medicine, namely Artemisia annua and Cinchona spp. are the sources of the antimalarial natural products artemisinin and quinine, respectively. Based on these compounds, semi-synthetic artemisinin-derivatives and synthetic quinoline antimalarials have been developed and are the most important drugs in the current therapeutic arsenal for combating malaria. In the Amazon region, where P. vivax predominates, there is a local tradition of using plant-derived preparations to treat malaria. Here, we review the current P. falciparum and P. vivax drug-sensitivity assays, focusing on challenges and perspectives of drug discovery for P. vivax, including tests against hypnozoites. We also present the latest findings of our group and others on the antiplasmodial and antimalarial chemical components from Amazonian plants that may be potential drug leads against malaria.

  10. Phosphate fertilizers with varying water-solubility applied to Amazonian soils: II. Soil P extraction methods

    International Nuclear Information System (INIS)

    Muraoka, T.; Brasil, E.C.; Scivittaro, W.B.

    2002-01-01

    A pot experiment was carried out under greenhouse conditions at the Centro de Energia Nuclear na Agricultura, Piracicaba (SP, Brazil), to evaluate the phosphorus availability of different phosphate sources in five Amazonian soils. The soils utilized were: medium texture Yellow Latosol, clayey Yellow Latosol, very clayey Yellow Latosol, clayey Red-Yellow Podzolic and very clayey Red-Yellow Podzolic. Four phosphate sources were applied: triple superphosphate, ordinary Yoorin thermophosphate, coarse Yoorin termo-phosphate and North Carolina phosphate rock at P rates of 0, 40, 80 and 120 mg kg -1 soil. The dry matter yield and the amount of P taken up by cowpea and rice were correlated with the extractable P by anionic exchangeable resin, Mehlich-1, Mehlich-3 and Bray-I. The results showed that the extractable P by Mehlich-1 was higher in the soils amended with North Carolina rock phosphate. Irrespective of the phosphorus sources used, the Mehlich-3 extractant showed close correlation with plant response. The Mehlich-3 and Bray-I extractants were more sensitive to soil variations. The Mehlich-3 extractant was more suitable in predicting the P availability to plants in the different soils and phosphorus sources studied. (author)

  11. Phylogenetic impoverishment of Amazonian tree communities in an experimentally fragmented forest landscape.

    Science.gov (United States)

    Santos, Bráulio A; Tabarelli, Marcelo; Melo, Felipe P L; Camargo, José L C; Andrade, Ana; Laurance, Susan G; Laurance, William F

    2014-01-01

    Amazonian rainforests sustain some of the richest tree communities on Earth, but their ecological and evolutionary responses to human threats remain poorly known. We used one of the largest experimental datasets currently available on tree dynamics in fragmented tropical forests and a recent phylogeny of angiosperms to test whether tree communities have lost phylogenetic diversity since their isolation about two decades previously. Our findings revealed an overall trend toward phylogenetic impoverishment across the experimentally fragmented landscape, irrespective of whether tree communities were in 1-ha, 10-ha, or 100-ha forest fragments, near forest edges, or in continuous forest. The magnitude of the phylogenetic diversity loss was low (forest isolation, irrespective of plot location. Analyses based on tree genera that have significantly increased (28 genera) or declined (31 genera) in abundance and basal area in the landscape revealed that increasing genera are more phylogenetically related than decreasing ones. Also, the loss of phylogenetic diversity was greater in tree communities where increasing genera proliferated and decreasing genera reduced their importance values, suggesting that this taxonomic replacement is partially underlying the phylogenetic impoverishment at the landscape scale. This finding has clear implications for the current debate about the role human-modified landscapes play in sustaining biodiversity persistence and key ecosystem services, such as carbon storage. Although the generalization of our findings to other fragmented tropical forests is uncertain, it could negatively affect ecosystem productivity and stability and have broader impacts on coevolved organisms.

  12. Natural selection in the water: freshwater invasion and adaptation by water colour in the Amazonian pufferfish.

    Science.gov (United States)

    Cooke, G M; Chao, N L; Beheregaray, L B

    2012-07-01

    Natural selection and ecological adaptation are ultimately responsible for much of the origin of biodiversity. Yet, the identification of divergent natural selection has been hindered by the spatial complexity of natural systems, the difficulty in identifying genes under selection and their relationship to environment, and the confounding genomic effects of time. Here, we employed genome scans, population genetics and sequence-based phylogeographic methods to identify divergent natural selection on population boundaries in a freshwater invader, the Amazonian pufferfish, Colomesus asellus. We sampled extensively across markedly different hydrochemical settings in the Amazon Basin and use 'water colour' to test for ecological isolation. We distinguish the relative contribution of natural selection across hydrochemical gradients from biogeographic history in the origin and maintenance of population boundaries within a single species and across a complex ecosystem. We show that spatially distinct population structure generated by multiple forces (i.e. water colour and vicariant biogeographic history) can be identified if the confounding effects of genetic drift have not accumulated between selective populations. Our findings have repercussions for studies aimed at identifying engines of biodiversity and assessing their temporal progression in understudied and ecologically complex tropical ecosystems. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  13. Formaldehyde and acetaldehyde exchange during leaf development of the Amazonian deciduous tree species Hymenaea courbaril

    Science.gov (United States)

    Rottenberger, S.; Kuhn, U.; Wolf, A.; Schebeske, G.; Oliva, S. T.; Tavares, T. M.; Kesselmeier, J.

    The effect of leaf age on the formaldehyde (HCHO) and acetaldehyde (CH 3CHO) exchange pattern of the deciduous Amazonian tree species Hymenaea courbaril was investigated under field conditions. Branch enclosure measurements on senescent, young, and mature leaves showed that leaf development had a pronounced impact on the aldehyde exchange behavior with respect to both the direction and the magnitude of the exchange. The emission activity of senescent leaves was associated with a negative CO 2 balance, even during daytime, indicative of a catabolic metabolism and decomposition processes leading to an increased aldehyde production within the leaf. The low exchange rates observed in young leaves were attributed to low stomatal conductance, while in mature leaves stomatal conductance and metabolic activities allowed efficient uptake. Within each leaf class the diurnal variations in the exchange of both aldehyde compounds were found to be mainly dependent on the respective ambient air concentrations. High ambient air concentrations resulted in decreased emission rates of senescent leaves and in enhanced uptake in young and mature leaves. CH 3CHO compensation points decreased from 1.8 to 1.1 ppb with leaf maturation. We provide evidence that leaf-age-dependent variations in the stomatal conductance can account for the major share of differences in the CH 3CHO deposition velocity. The results indicate that leaf surfaces of young and mature leaves may represent an effective additional non-stomatal sink for atmospheric aldehydes.

  14. Response of frugivorous primates to changes in fruit supply in a northern Amazonian forest.

    Science.gov (United States)

    Mourthé, I

    2014-08-01

    Few attempts have been made to understand how spatiotemporal changes in fruit supply influence frugivores in tropical forests. The marked spatiotemporal variation in fruit supply can affect frugivore abundance and distribution, but studies addressing the effects of this variation on primates are scarce. The present study aimed to investigate how the spatiotemporal distribution of fruits influences the local distribution of three frugivorous primates in the eastern part of the Maracá Ecological Station, a highly seasonal Amazonian rainforest. Specifically, it was hypothesised that primate distribution will track changes in fruit supply, resulting that sites with high fruit availability should be heavily used by primates. During a 1-year study, fruit supply (ground fruit surveys) and primate density (line-transects) were monitored in twelve 2 km-long transects at monthly intervals. Fruit supply varied seasonally, being low during the dry season. The density of Ateles belzebuth was positively related to fruit supply during fruit shortage, but Cebus olivaceus and Alouatta macconnelli did not follow the same pattern. The supply of Sapotaceae fruit was an important component determining local distribution of A. belzebuth during the overall fruit shortage. Highly frugivorous primates such as A. belzebuth respond to seasonal decline in fruit supply by congregating at places with high fruit supply in this forest, particularly, those with many individuals of species of Sapotaceae. This study underscores the importance of small-scale spatiotemporal changes of fruit supply as a key component of frugivorous primate ecology in highly seasonal environments.

  15. Unique meteorite from early Amazonian Mars: water-rich basaltic breccia Northwest Africa 7034.

    Science.gov (United States)

    Agee, Carl B; Wilson, Nicole V; McCubbin, Francis M; Ziegler, Karen; Polyak, Victor J; Sharp, Zachary D; Asmerom, Yemane; Nunn, Morgan H; Shaheen, Robina; Thiemens, Mark H; Steele, Andrew; Fogel, Marilyn L; Bowden, Roxane; Glamoclija, Mihaela; Zhang, Zhisheng; Elardo, Stephen M

    2013-02-15

    We report data on the martian meteorite Northwest Africa (NWA) 7034, which shares some petrologic and geochemical characteristics with known martian meteorites of the SNC (i.e., shergottite, nakhlite, and chassignite) group, but also has some unique characteristics that would exclude it from that group. NWA 7034 is a geochemically enriched crustal rock compositionally similar to basalts and average martian crust measured by recent Rover and Orbiter missions. It formed 2.089 ± 0.081 billion years ago, during the early Amazonian epoch in Mars' geologic history. NWA 7034 has an order of magnitude more indigenous water than most SNC meteorites, with up to 6000 parts per million extraterrestrial H(2)O released during stepped heating. It also has bulk oxygen isotope values of Δ(17)O = 0.58 ± 0.05 per mil and a heat-released water oxygen isotope average value of Δ(17)O = 0.330 ± 0.011 per mil, suggesting the existence of multiple oxygen reservoirs on Mars.

  16. Phylogeography and population genetics of the endangered Amazonian manatee, Trichechus inunguis Natterer, 1883 (Mammalia, Sirenia).

    Science.gov (United States)

    Cantanhede, Andréa Martins; Da Silva, Vera Maria Ferreira; Farias, Izeni Pires; Hrbek, Tomas; Lazzarini, Stella Maris; Alves-Gomes, José

    2005-02-01

    We used mitochondrial DNA control region sequences to examine phylogeography and population differentiation of the endangered Amazonian manatee Trichechus inunguis. We observe lack of molecular differentiation among localities and we find weak association between geographical and genetic distances. However, nested clade analysis supports restricted gene flow and/or dispersal with some long-distance dispersal. Although this species has a history of extensive hunting, genetic diversity and effective population sizes are relatively high when compared to the West Indian manatee Trichechus manatus. Patterns of mtDNA haplotype diversity in T. inunguis suggest a genetic disequilibrium most likely explained by demographic expansion resulting from secession of hunting and enforcement of conservation and protective measures. Phylogenetic analysis of T. manatus and T. inunguis haplotypes suggests that T. inunguis is nested within T. manatus, effectively making T. manatus a paraphyletic entity. Paraphyly of T. manatus and recent divergence times of T. inunguis and the three main T. manatus lineages suggest a possible need for a taxonomic re-evaluation of the western Atlantic Trichechus.

  17. Multi-scale comparisons of tree composition in Amazonian terra firme forests

    Science.gov (United States)

    Honorio Coronado, E. N.; Baker, T. R.; Phillips, O. L.; Pitman, N. C. A.; Pennington, R. T.; Vásquez Martínez, R.; Monteagudo, A.; Mogollón, H.; Dávila Cardozo, N.; Ríos, M.; García-Villacorta, R.; Valderrama, E.; Ahuite, M.; Huamantupa, I.; Neill, D. A.; Laurance, W. F.; Nascimento, H. E. M.; Soares de Almeida, S.; Killeen, T. J.; Arroyo, L.; Núñez, P.; Freitas Alvarado, L.

    2009-11-01

    We explored the floristic composition of terra firme forests across Amazonia using 55 plots. Firstly, we examined the floristic patterns using both genus- and species-level data and found that the species-level analysis more clearly distinguishes among forests. Next, we compared the variation in plot floristic composition at regional- and continental-scales, and found that average among-pair floristic similarity and its decay with distance behave similarly at regional- and continental-scales. Nevertheless, geographical distance had different effects on floristic similarity within regions at distances floristic variation than plots of central and eastern Amazonia. Finally, we quantified the role of environmental factors and geographical distance for determining variation in floristic composition. A partial Mantel test indicated that while geographical distance appeared to be more important at continental scales, soil fertility was crucial at regional scales within western Amazonia, where areas with similar soil conditions were more likely to share a high number of species. Overall, these results suggest that regional-scale variation in floristic composition can rival continental-scale differences within Amazonian terra firme forests, and that variation in floristic composition at both scales is influenced by geographical distance and environmental factors, such as climate and soil fertility. To fully account for regional-scale variation in continental studies of floristic composition, future floristic studies should focus on forest types poorly represented at regional scales in current datasets, such as terra firme forests with high soil fertility in north-western Amazonia.

  18. Amazonian palm Oenocarpus bataua ("patawa"): chemical and biological antioxidant activity--phytochemical composition.

    Science.gov (United States)

    Rezaire, A; Robinson, J-C; Bereau, D; Verbaere, A; Sommerer, N; Khan, M K; Durand, P; Prost, E; Fils-Lycaon, B

    2014-04-15

    In French Guiana, "diversity" within the Palm family is obvious since more than 75 species have been identified. Oenocarpus bataua Mart., called "patawa" is well known for its culinary uses whereas literature on its phytochemical composition and biological properties remains poor. This work deals with determining the antioxidant activity of this palm fruit and its polyphenol composition; Euterpe oleracea (açai) used as a reference. It turned out that patawa had a stronger antioxidant activity than açai in TEAC and FRAP tests. A similar activity was observed by DPPH assay whereas in ORAC and KRL tests, that açai showed an antioxidant activity respectively 2.6 and 1.5 fold higher than patawa. Polyphenolic composition, determined by UPLC/MS(n), would imply the presence of anthocyanins, condensed tannins, stilbenes and phenolic acids, well known for their biological activities. These results present patawa fruit as a new amazonian resource for cosmetics, food and pharmaceuticals purposes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Thermokarst, mantling and Late Amazonian Epoch periglacial-revisions in the Argyre region, Mars

    Science.gov (United States)

    Soare, R. J.; Baoini, D.; Conway, S. J.; Dohm, J. M.; Kargel, J. S.

    2015-10-01

    Thermokarst, mantling and Late Amazonian Epoch periglacial-revisions in the Argyre region, Mars R.J. Soare(1), D. Baioni(2), S.J. Conway (3), J.M. Dohm(4)and J.S. Kargel (5)(1) Geography Department, Dawson College, Montreal, Canada H3Z 1A4 rsoare@dawsoncollege.qc.ca.(2) Dipartimento di Scienze della Terra,della Vita e Ambiente, Università di Urbino "Carlo Bo", Campus SOGESTA, 61029 Urbino (PU) Italy. (3) Department of Physical Sciences, Open University, Milton Keynes, United Kingdom, MK7 6AA. (4) The University Museum, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-, Japan.(5) Department of Hydrology & Water Resources, University of Arizona, Tucson, Arizona, USA 85719.1.Introduction Metre to decametre-deep depressions that are rimless, relatively flat-floored, polygonised and scallop-shaped have been widely observed in Utopia Planitia (UP) [e.g. 1-5] and Malea Planum (MP) [6-8]. Although there is some debate about whether the depressions formed by means of sublimation or evaporation, it is commonly believed that the terrain in which the depressions occur is ice-rich.Moreover, most workers assume that this "ice-richness" is derived of a bi-hemispheric, latitudinally-dependent and atmospherically-precipitated mantle that is metres thick [2,4,6-10].

  20. Beings of a Feather: Learning About the Lives of Birds with Amazonian Peoples

    Directory of Open Access Journals (Sweden)

    Kevin Jernigan

    2016-12-01

    Full Text Available This article is a memoir of the author's fieldwork experiences studying traditional knowledge of bird species in the Peruvian Amazon. It describes his growth as a researcher, in light of the practical and methodological challenges of carrying out this kind of work. It also relates how the author's thinking has evolved on questions of current theoretical interest in ethnobiology. The first section outlines how the author came to be interested in this topic while pursuing an ethnobotanical dissertation project. Next, the discussion follows his work with the indigenous Aguaruna and Iquito peoples, learning about and documenting their understandings of the nesting, foraging and reproductive behavior of local avian species. On one hand, he found that local people provided details of these behaviors that match, in many ways, the counts of academic ornithologists. However, local interpretations of why these behaviors take place are often framed by some very different assumptions. The author uses Victor Toledo's tripartite framework of kosmos (overarching belief systems, corpus (cognitive categories, and praxis (set of practices to discuss similarities and differences in Aguaruna, Iquito, and academic ornithology. He also discusses his progression of views on the topic of perspectivism and eventual preference for a theoretical framework favoring a polyontological approach to understanding Amazonian ethnoecology.

  1. Impacts of hydroelectric dams on alluvial riparian plant communities in Eastern Brazilian Amazonian.

    Science.gov (United States)

    Ferreira, Leandro Valle; Cunha, Denise A; Chaves, Priscilla P; Matos, Darley C L; Parolin, Pia

    2013-09-01

    The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity.

  2. Impacts of hydroelectric dams on alluvial riparian plant communities in eastern Brazilian Amazonian

    Directory of Open Access Journals (Sweden)

    LEANDRO VALLE FERREIRA

    2013-09-01

    Full Text Available The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity.

  3. CARBON FIXING CAPACITY OF AMAZONIAN SOILS IN RELATION TO ITS DEGRADATION CONDITIONS

    Directory of Open Access Journals (Sweden)

    Clara Patricia Peña Venegas

    2015-06-01

    Full Text Available Amazonian deforestation and transformation alert about their effects worldwide. One concern is the increase of the Carbon (C levels emitted. Previous works have estimated the fixed C in Amazon forests without including the C stored in soils. Within soil, the organic carbon molecules are highly sensitive to degradation, affecting the natural capacity of soils to fix and store C. The present study evaluates the impact of degradation in the natural capacity of Amazon soils to fix C. Thirty five farms with different typology were selected in Caquetá department which hold the highest deforestation and soil degradation rates in the Colombian Amazon. Soil samples were taken from natural forest relicts, cropping areas and introduced pastures of the farms, in locations with high, intermediate and low soil degradation. Aerial biomass was estimated in pastures with different level of soil degradation. Changes in the labile C stock were estimated from the soil organic carbon and the microbial biomass using substrate induced respiration. Results showed that the main C pool is in the natural forest relicts and the crops of the farms, independently from the size or type of farm sampled. The hills with higher intervention showed the lowest soil C fixation capacities. The soil C fixation capacity was related with changes in the soil microbial composition where conserved soils store preferentially C as fungal biomass while degraded soils store C as bacterial biomass. These estimations contribute to establish the cost of sustainability and soil degradation in the Colombian Amazon.

  4. Facing operational problems in a biodigester in Yuvientsa - Amazonian region of Ecuador

    Energy Technology Data Exchange (ETDEWEB)

    Aragundy, J.

    2007-07-01

    Yuvientsa is a Shuar indigenous community located in the Morona Santiago Province in the southwestern part of the Amazonian region of Ecuador. Two types of alternative energies have being implemented in Yuvientsa to satisfy people's needs. Solar panels provide electricity to the community. A biodigester to treat the school lavatories' brown-water (fecal water) and to provide gas for cooking to the communal kitchen was built as well. During the operational phase the biodigester faced some difficulties as: being perforated by people of the community as started inflating, being fumigated against malaria, and not having enough organic matter to produce biogas. As a result in this time the biodigester did not operate satisfactorily and the community did not believe that it could work and produce biogas. A biodigester should not be built without an awareness campaign or showing a direct benefit to the community that ensures its adequate operation and maintenance. Before constructing the reactor the organic matter source to operate the biodigester should be clearly identified and its amount should be enough. (orig.)

  5. The importance of humin in soil characterisation: A study on Amazonian soils using different fluorescence techniques.

    Science.gov (United States)

    Tadini, Amanda Maria; Nicolodelli, Gustavo; Mounier, Stephane; Montes, Célia Regina; Milori, Débora Marcondes Bastos Pereira

    2015-12-15

    Soil organic matter (SOM) is a complex mixture of molecules with different physicochemical properties, with humic substances (HS) being the main component as it represents around 20-50% of SOM structure. Soil of the Amazon region is considered one of the larger carbon pools of the world; thus, studies of the humic fractions are important for understanding the dynamics of organic matter (OM) in these soils. The aim of this study was to use laser-induced fluorescence spectroscopy (LIFS) and a combination of excitation-emission matrix (EEM) fluorescence with Parallel Factor Analysis (CP/PARAFAC) to assess the characteristics of humin (HU) extracted from Amazonian soils. The results obtained using LIFS showed that there was an increasing gradient of humification degree with depth, the deeper horizon presenting a higher amount of aromatic groups in the structure of HU. From the EEM, the contribution of two fluorophores with similar behaviour in the structures of HU and whole soil was assessed. Additionally, the results showed that the HU fraction might represent a larger fraction of SOM than previously thought: about 80-93% of some Amazon soils. Therefore, HU is an important humic fraction, thus indicating its role in environmental analysis, mainly in soil analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Anthropometric measurements of adolescents from two Amazonian ecosystems: variations according to seasonality.

    Science.gov (United States)

    Silva, Hilton P; Veiga, Gloria V; Kac, Gilberto; Pereira, Rosangela A

    2010-03-01

    This paper aims to describe the nutritional status of Caboclo adolescents living in two areas of the Amazon Basin. Two cross-sectional studies, the first in the dry and the second in the wet season, were carried out in two Amazonian ecosystems: the forest and black water ecosystem, and the floodplain and white water ecosystem. Measurements of weight, stature, arm circumference and triceps, subscapular and suprailiac skinfolds were performed on 247 adolescents (10-19 years of age). Nutritional status was classified using body mass index according to international criteria and the prevalence of underweight and overweight was estimated. Linear mixed effects models were used with the anthropometric measurements as dependent variables and time interval, place of residence, sex, age and stature variation as independent variables. During the wet season, the prevalence of overweight among girls was higher in the forest (42%) than in the floodplain (9%). Longitudinal linear regression models showed that the arm circumference measurement was influenced both by seasonality and location, revealing that the increment between dry and wet seasons was less pronounced in the floodplain. At the time of the study, overweight already constituted a major public health concern among girls living in the forest area. In order to develop adequate public health policies for this important segment of the Amazon population further studies are necessary to investigate the role of environment and seasonality on the growth and nutritional status of adolescents.

  7. Social organization influences the exchange and species richness of medicinal plants in Amazonian homegardens.

    Science.gov (United States)

    2016-03-01

    Medicinal plants provide indigenous and peasant communities worldwide with means to meet their healthcare needs. Homegardens often act as medicine cabinets, providing easily accessible medicinal plants for household needs. Social structure and social exchanges have been proposed as factors influencing the species diversity that people maintain in their homegardens. Here, we assess the association between the exchange of medicinal knowledge and plant material and medicinal plant richness in homegardens. Using Tsimane' Amazonian homegardens as a case study, we explore whether social organization shapes exchanges of medicinal plant knowledge and medicinal plant material. We also use network centrality measures to evaluate people's location and performance in medicinal plant knowledge and plant material exchange networks. Our results suggest that social organization, specifically kinship and gender relations, influences medicinal plant exchange patterns significantly. Homegardens total and medicinal plant species richness are related to gardeners' centrality in the networks, whereby people with greater centrality maintain greater plant richness. Thus, together with agroecological conditions, social relations among gardeners and the culturally specific social structure seem to be important determinants of plant richness in homegardens. Understanding which factors pattern general species diversity in tropical homegardens, and medicinal plant diversity in particular, can help policy makers, health providers, and local communities to understand better how to promote and preserve medicinal plants in situ. Biocultural approaches that are also gender sensitive offer a culturally appropriate means to reduce the global and local loss of both biological and cultural diversity.

  8. Social organization influences the exchange and species richness of medicinal plants in Amazonian homegardens

    Directory of Open Access Journals (Sweden)

    Isabel Díaz-Reviriego

    2016-03-01

    Full Text Available Medicinal plants provide indigenous and peasant communities worldwide with means to meet their healthcare needs. Homegardens often act as medicine cabinets, providing easily accessible medicinal plants for household needs. Social structure and social exchanges have been proposed as factors influencing the species diversity that people maintain in their homegardens. Here, we assess the association between the exchange of medicinal knowledge and plant material and medicinal plant richness in homegardens. Using Tsimane' Amazonian homegardens as a case study, we explore whether social organization shapes exchanges of medicinal plant knowledge and medicinal plant material. We also use network centrality measures to evaluate people's location and performance in medicinal plant knowledge and plant material exchange networks. Our results suggest that social organization, specifically kinship and gender relations, influences medicinal plant exchange patterns significantly. Homegardens total and medicinal plant species richness are related to gardeners' centrality in the networks, whereby people with greater centrality maintain greater plant richness. Thus, together with agroecological conditions, social relations among gardeners and the culturally specific social structure seem to be important determinants of plant richness in homegardens. Understanding which factors pattern general species diversity in tropical homegardens, and medicinal plant diversity in particular, can help policy makers, health providers, and local communities to understand better how to promote and preserve medicinal plants in situ. Biocultural approaches that are also gender sensitive offer a culturally appropriate means to reduce the global and local loss of both biological and cultural diversity.

  9. Aging Perceptions in Tsimane' Amazonian Forager-Farmers Compared With Two Industrialized Societies.

    Science.gov (United States)

    Sorokowski, Piotr; Sorokowska, Agnieszka; Frackowiak, Tomasz; Löckenhoff, Corinna E

    2017-07-01

    Cross-cultural studies suggest that aging attitudes show some variation across societies, but this evidence is mostly drawn from industrialized settings. The limited research record on pre-industrial societies is largely qualitative in nature. The present study targeted this gap by adapting an existing multidimensional measure of aging attitudes for use in traditional populations and administering it to samples from one traditional society and two industrialized societies. We administered the adapted multidimensional measure of aging attitudes to samples from one traditional society (Tsimane' Amazonian forager-farmers in Bolivia, n = 90) and two industrialized societies (the United States, n = 91, and Poland, n = 100). Across societies, aging perceptions were more favorable for respect and wisdom than for other domains of functioning, and women were perceived to be aging less favorably. Further, the Tsimane' reported more positive aging perceptions than the U.S. and Polish samples, especially with regard to memory functioning. Within the Tsimane' sample, there was no evidence of an influence of acculturation on aging perceptions. The present study contributed to our understanding of cross-cultural differences in aging attitudes. Theoretical implications and directions for future research are discussed. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Water contamination from oil extraction activities in Northern Peruvian Amazonian rivers.

    Science.gov (United States)

    Yusta-García, Raúl; Orta-Martínez, Martí; Mayor, Pedro; González-Crespo, Carlos; Rosell-Melé, Antoni

    2017-06-01

    Oil extraction activities in the Northern Peruvian Amazon have generated a long-standing socio-environmental conflict between oil companies, governmental authorities and indigenous communities, partly derived from the discharge of produced waters containing high amounts of heavy metals and hydrocarbons. To assess the impact of produced waters discharges we conducted a meta-analysis of 2951 river water and 652 produced water chemical analyses from governmental institutions and oil companies reports, collected in four Amazonian river basins (Marañon, Tigre, Corrientes and Pastaza) and their tributaries. Produced water discharges had much higher concentrations of chloride, barium, cadmium and lead than are typically found in fresh waters, resulting in the widespread contamination of the natural water courses. A significant number of water samples had levels of cadmium, barium, hexavalent chromium and lead that did not meet Peruvian and international water standards. Our study shows that spillage of produced water in Peruvian Amazon rivers placed at risk indigenous population and wildlife during several decades. Furthermore, the impact of such activities in the headwaters of the Amazon extended well beyond the boundaries of oil concessions and national borders, which should be taken into consideration when evaluating large scale anthropogenic impacts in the Amazon. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Avian Communities in the Amazonian Cangas Vegetation: Biogeographic Affinities, Components of Beta-Diversity and Conservation

    Directory of Open Access Journals (Sweden)

    SÉRGIO H. BORGES

    2017-08-01

    Full Text Available ABSTRACT The Amazonian cangas is a vegetation type distributed as patches of open vegetation embedded in a matrix of tropical forest and that grows over iron-rich soils in the Serra dos Carajás region. To characterize cangas avifauna, we surveyed birds in eight patches varying from 43 to 1,366 hectares. Cangas avifauna has compositional affinities with savannas widespread throughout the Amazon and other biomes, and we estimate that more than 200 bird species occurs in this habitat. Species composition was relatively homogeneous, and the similarity among cangas patches was the dominant component of the beta-diversity. Bird communities in cangas patches exhibited statistically significant nested structure in respect to species richness and patch size. In contrast, the nested site arrangement was not affected by the isolation of patches. Number of species and composition are moderately affected by the area of cangas patches but not by its degree of isolation. To conserve this unique habitat are necessary a strict protection of carefully chosen patches of cangas and an investigation of the conservation value of secondary vegetation recovered by the mining companies.

  12. Wildfires in bamboo-dominated Amazonian forest: impacts on above-ground biomass and biodiversity.

    Directory of Open Access Journals (Sweden)

    Jos Barlow

    Full Text Available Fire has become an increasingly important disturbance event in south-western Amazonia. We conducted the first assessment of the ecological impacts of these wildfires in 2008, sampling forest structure and biodiversity along twelve 500 m transects in the Chico Mendes Extractive Reserve, Acre, Brazil. Six transects were placed in unburned forests and six were in forests that burned during a series of forest fires that occurred from August to October 2005. Normalized Burn Ratio (NBR calculations, based on Landsat reflectance data, indicate that all transects were similar prior to the fires. We sampled understorey and canopy vegetation, birds using both mist nets and point counts, coprophagous dung beetles and the leaf-litter ant fauna. Fire had limited influence upon either faunal or floral species richness or community structure responses, and stems <10 cm DBH were the only group to show highly significant (p = 0.001 community turnover in burned forests. Mean aboveground live biomass was statistically indistinguishable in the unburned and burned plots, although there was a significant increase in the total abundance of dead stems in burned plots. Comparisons with previous studies suggest that wildfires had much less effect upon forest structure and biodiversity in these south-western Amazonian forests than in central and eastern Amazonia, where most fire research has been undertaken to date. We discuss potential reasons for the apparent greater resilience of our study plots to wildfire, examining the role of fire intensity, bamboo dominance, background rates of disturbance, landscape and soil conditions.

  13. Understanding the radar backscattering from flooded and nonflooded Amazonian forests: results from canopy backscatter modeling

    International Nuclear Information System (INIS)

    Wang, Y.; Hess, L.L.; Filoso, S.; Melack, J.M.

    1995-01-01

    To understand the potential of using multiwavelength imaging radars to detect flooding in Amazonian floodplain forests, we simulated the radar backscatter from a floodplain forest with a flooded or nonflooded ground condition at C-, L-, and P-bands. Field measurements of forest structure in the Anavilhanas archipelago of the Negro River, Brazil, were used as inputs to the model. Given the same wavelength or incidence angle, the ratio of backscatter from the flooded forest to that from the nonflooded forest was higher at HH polarization than at VV polarization. Given the same wavelength or polarization, the ratio was larger at small incidence angles than at large incidence angles. Given the same polarization or incidence angle, the ratio was larger at a long wavelength than at a short wavelength. As the surface soil moisture underneath the nonflooded forest increased from 10% to 50% of volumetric moisture, the flooded/nonflooded backscatter ratio decreased; the decreases were small at C- and L-band but large at P-band. When the leaf size was comparable to or larger than the wavelength of C-band, the leaf area index (LAI) had a large effect on the simulated C-band (not L-band or P-band) backscatter from the flooded and nonflooded forests. (author)

  14. Middle Miocene vertebrates from the Amazonian Madre de Dios Subandean Zone, Perú

    Science.gov (United States)

    Antoine, Pierre-Olivier; Roddaz, Martin; Brichau, Stéphanie; Tejada-Lara, Julia; Salas-Gismondi, Rodolfo; Altamirano, Ali; Louterbach, Mélanie; Lambs, Luc; Otto, Thierry; Brusset, Stéphane

    2013-03-01

    A new middle Miocene vertebrate fauna from Peruvian Amazonia is described. It yields the marsupials Sipalocyon sp. (Hathliacynidae) and Marmosa (Micoureus) cf. laventica (Didelphidae), as well as an unidentified glyptodontine xenarthran and the rodents Guiomys sp. (Caviidae), “Scleromys” sp., cf. quadrangulatus-schurmanni-colombianus (Dinomyidae), an unidentified acaremyid, and cf. Microsteiromys sp. (Erethizontidae). Apatite Fission Track provides a detrital age (17.1 ± 2.4 Ma) for the locality, slightly older than its inferred biochronological age (Colloncuran-early Laventan South American Land Mammal Ages: ˜15.6-13.0 Ma). Put together, both the mammalian assemblage and lithology of the fossil-bearing level point to a mixture of tropical rainforest environment and more open habitats under a monsoonal-like tropical climate. The fully fluvial origin of the concerned sedimentary sequence suggests that the Amazonian Madre de Dios Subandean Zone was not part of the Pebas mega-wetland System by middle Miocene times. This new assemblage seems to reveal a previously undocumented “spatiotemporal transition” between the late early Miocene assemblages from high latitudes (Patagonia and Southern Chile) and the late middle Miocene faunas of low latitudes (Colombia, Perú, Venezuela, and ?Brazil).

  15. Wildfires in bamboo-dominated Amazonian forest: impacts on above-ground biomass and biodiversity.

    Science.gov (United States)

    Barlow, Jos; Silveira, Juliana M; Mestre, Luiz A M; Andrade, Rafael B; Camacho D'Andrea, Gabriela; Louzada, Julio; Vaz-de-Mello, Fernando Z; Numata, Izaya; Lacau, Sébastien; Cochrane, Mark A

    2012-01-01

    Fire has become an increasingly important disturbance event in south-western Amazonia. We conducted the first assessment of the ecological impacts of these wildfires in 2008, sampling forest structure and biodiversity along twelve 500 m transects in the Chico Mendes Extractive Reserve, Acre, Brazil. Six transects were placed in unburned forests and six were in forests that burned during a series of forest fires that occurred from August to October 2005. Normalized Burn Ratio (NBR) calculations, based on Landsat reflectance data, indicate that all transects were similar prior to the fires. We sampled understorey and canopy vegetation, birds using both mist nets and point counts, coprophagous dung beetles and the leaf-litter ant fauna. Fire had limited influence upon either faunal or floral species richness or community structure responses, and stems wildfires had much less effect upon forest structure and biodiversity in these south-western Amazonian forests than in central and eastern Amazonia, where most fire research has been undertaken to date. We discuss potential reasons for the apparent greater resilience of our study plots to wildfire, examining the role of fire intensity, bamboo dominance, background rates of disturbance, landscape and soil conditions.

  16. Functional Traits, Flocking Propensity, and Perceived Predation Risk in an Amazonian Understory Bird Community.

    Science.gov (United States)

    Martínez, Ari E; Gomez, Juan P; Ponciano, José Miguel; Robinson, Scott K

    2016-05-01

    Within a community, different species might share similar predation risks, and, thus, the ability of species to signal and interpret heterospecific threat information may determine species' associations. We combined observational, experimental, and phylogenetic approaches to determine the extent to which evolutionary history and functional traits determined flocking propensity and perceived predation risk (response to heterospecific alarm calls) in a lowland Amazonian bird community. We predicted that small birds that feed myopically and out in the open would have higher flocking propensities and account for a higher proportion of positive responses to alarms. Using generalized linear models and the incorporation of phylogeny on data from 56 species, our results suggest that phylogenetic relationships alongside body size, foraging height, vegetation density, and response to alarm calls influence flocking propensity. Conversely, phylogenetic relationships did not influence response to heterospecific alarm calls. Among functional traits, however, foraging strategy, foraging density, and flocking propensity partially explained responses to alarm calls. Our results suggest that flocking propensity and perceived predation risk are positively related and that functional ecological traits and evolutionary history may explain certain species' associations.

  17. Amazonian dark Earth and plant species from the Amazon region contribute to shape rhizosphere bacterial communities.

    Science.gov (United States)

    Barbosa Lima, Amanda; Cannavan, Fabiana Souza; Navarrete, Acacio Aparecido; Teixeira, Wenceslau Geraldes; Kuramae, Eiko Eurya; Tsai, Siu Mui

    2015-05-01

    Amazonian Dark Earths (ADE) or Terra Preta de Índio formed in the past by pre-Columbian populations are highly sustained fertile soils supported by microbial communities that differ from those extant in adjacent soils. These soils are found in the Amazon region and are considered as a model soil when compared to the surrounding and background soils. The aim of this study was to assess the effects of ADE and its surrounding soil on the rhizosphere bacterial communities of two leguminous plant species that frequently occur in the Amazon region in forest sites (Mimosa debilis) and open areas (Senna alata). Bacterial community structure was evaluated using terminal restriction fragment length polymorphism (T-RFLP) and bacterial community composition by V4 16S rRNA gene region pyrosequencing. T-RFLP analysis showed effect of soil types and plant species on rhizosphere bacterial community structure. Differential abundance of bacterial phyla, such as Acidobacteria, Actinobacteria, Verrucomicrobia, and Firmicutes, revealed that soil type contributes to shape the bacterial communities. Furthermore, bacterial phyla such as Firmicutes and Nitrospira were mostly influenced by plant species. Plant roots influenced several soil chemical properties, especially when plants were grown in ADE. These results showed that differences observed in rhizosphere bacterial community structure and composition can be influenced by plant species and soil fertility due to variation in soil attributes.

  18. Fire effects on the composition of a bird community in an Amazonian savanna (Brazil).

    Science.gov (United States)

    Cintra, R; Sanaiotti, T M

    2005-11-01

    The effects of fire on the composition of a bird community were investigated in an Amazonian savanna near Alter-do-Chão, Pará (Brazil). Mist-net captures and visual counts were used to assess species richness and bird abundance pre- and post-fire in an approximately 20 ha area. Visual counts along transects were used to survey birds in an approximately 2000 ha area in a nearby area. Results using the same method of ordination analysis (multidimensional scaling) showed significant effects of fire in the 20 ha and 2000 ha areas and strongly suggest direct effects on bird community composition. However, the effects were different at different spatial scales and/or in different years, indicating that the effects of fire vary spatially and/or temporally. Bird community composition pre-fire was significantly different from that found post-fire. Using multiple regression analysis it was found that the numbers of burned and unburned trees were not significantly related to either bird species richness or bird abundance. Two months after the fire, neither bird species richness nor bird abundance was significantly related to the number of flowering trees (Lafoensia pacari) or fruiting trees (Byrsonima crassifolia). Since fire is an annual event in Alter-do-Chão and is becoming frequent in the entire Amazon, bird community composition in affected areas could be constantly changing in time and space.

  19. Cytogenetic description of the Amazonian brown brocket Mazama nemorivaga (Artiodactyla, Cervidae

    Directory of Open Access Journals (Sweden)

    Bruno Ferreto Fiorillo

    2013-03-01

    Full Text Available The Amazonian brown brocket Mazama nemorivaga (Cuvier, 1817 is a small to medium-sized deer from the Amazon rainforest and ecotones. The first karyotype described was 2n=67 to 69 + 2-7 B and FN= 69-72, in which all chromosomes were acrocentric and the X chromosome was the only submetacentric chromosome. However, important aspects of the species chromosome evolution were not resolved because of the lack of information on chromosome banding. The G-banding pattern of M. nemorivaga karyotype showed the presence of an XX/XY1Y2 sex chromosome system as a product of an X-autosome tandem fusion, which results in a basic 2n=68, FN=70 in females and 2n= 69, FN=70 in males. The fact that this karyotype only differs from that of Capreolus capreolus pygargus (Pallas, 1771; 2n=70, FN=72+B by X-autosome tandem fusion may corroborate the basal condition of M. nemorivaga and its proximity to the ancestral karyotype of the American Odocoileini. A derived karyotype 2n=67, XY1Y2, FN=70 + 3B from the Brazilian state of Mato Grosso (the western Amazon may be evidence of differentiation between western and eastern populations.

  20. Cytogenetic description of the Amazonian brown brocket Mazama nemorivaga (Artiodactyla, Cervidae).

    Science.gov (United States)

    Fiorillo, Bruno Ferreto; Sarria-Perea, Javier Adolfo; Abril, Vanessa Veltrini; Duarte, José Maurício Barbanti

    2013-01-01

    The Amazonian brown brocket Mazama nemorivaga (Cuvier, 1817) is a small to medium-sized deer from the Amazon rainforest and ecotones. The first karyotype described was 2n=67 to 69 + 2-7 B and FN= 69-72, in which all chromosomes were acrocentric and the X chromosome was the only submetacentric chromosome. However, important aspects of the species chromosome evolution were not resolved because of the lack of information on chromosome banding. The G-banding pattern of Mazama nemorivaga karyotype showed the presence of an XX/XY1Y2 sex chromosome system as a product of an X-autosome tandem fusion, which results in a basic 2n=68, FN=70 in females and 2n= 69, FN=70 in males. The fact that this karyotype only differs from that of Capreolus capreolus pygargus (Pallas, 1771; 2n=70, FN=72+B) by X-autosome tandem fusion may corroborate the basal condition of Mazama nemorivaga and its proximity to the ancestral karyotype of the American Odocoileini. A derived karyotype 2n=67, XY1Y2, FN=70 + 3B from the Brazilian state of Mato Grosso (the western Amazon) may be evidence of differentiation between western and eastern populations.

  1. Fire effects on the composition of a bird community in an amazonian Savanna (Brazil

    Directory of Open Access Journals (Sweden)

    R. Cintra

    Full Text Available The effects of fire on the composition of a bird community were investigated in an Amazonian savanna near Alter-do-Chão, Pará (Brazil. Mist-net captures and visual counts were used to assess species richness and bird abundance pre- and post-fire in an approximately 20 ha area. Visual counts along transects were used to survey birds in an approximately 2000 ha area in a nearby area. Results using the same method of ordination analysis (multidimensional scaling showed significant effects of fire in the 20 ha and 2000 ha areas and strongly suggest direct effects on bird community composition. However, the effects were different at different spatial scales and/or in different years, indicating that the effects of fire vary spatially and/or temporally. Bird community composition pre-fire was significantly different from that found post-fire. Using multiple regression analysis it was found that the numbers of burned and unburned trees were not significantly related to either bird species richness or bird abundance. Two months after the fire, neither bird species richness nor bird abundance was significantly related to the number of flowering trees (Lafoensia pacari or fruiting trees (Byrsonima crassifolia. Since fire is an annual event in Alter-do-Chão and is becoming frequent in the entire Amazon, bird community composition in affected areas could be constantly changing in time and space.

  2. Molecular Taxonomy of Anopheles (Nyssorhynchus) benarrochi (Diptera: Culicidae) and Malaria Epidemiology in Southern Amazonian Peru

    Science.gov (United States)

    Conn, Jan E.; Moreno, Marta; Saavedra, Marlon; Bickersmith, Sara A.; Knoll, Elisabeth; Fernandez, Roberto; Vera, Hubert; Burrus, Roxanne G.; Lescano, Andres G.; Sanchez, Juan Francisco; Rivera, Esteban; Vinetz, Joseph M.

    2013-01-01

    Anopheline specimens were collected in 2011 by human landing catch, Shannon and CDC traps from the malaria endemic localities of Santa Rosa and San Pedro in Madre de Dios Department, Peru. Most specimens were either Anopheles (Nyssorhynchus) benarrochi B or An. (Nys.) rangeli, confirmed by polymerase chain reaction-restriction fragment length polymorphism-internal transcribed spacer 2 (PCR-RFLP-ITS2) and, for selected individuals, ITS2 sequences. A few specimens from Lupuna, Loreto Department, northern Amazonian Peru, were also identified as An. benarrochi B. A statistical parsimony network using ITS2 sequences confirmed that all Peruvian An. benarrochi B analyzed were identical to those in GenBank from Putumayo, southern Colombia. Sequences of the mtDNA COI BOLD region of specimens from all three Peruvian localities were connected using a statistical parsimony network, although there were multiple mutation steps between northern and southern Peruvian sequences. A Bayesian inference of concatenated Peruvian sequences of ITS2+COI detected a single clade with very high support for all An. benarrochi B except one individual from Lupuna that was excluded. No samples were positive for Plasmodium by CytB-PCR. PMID:23243107

  3. Leaf-litter amount as a factor in the structure of a ponerine ants community (Hymenoptera, Formicidae, Ponerinae in an eastern Amazonian rainforest, Brazil

    Directory of Open Access Journals (Sweden)

    Alexandro Herbert dos Santos Bastos

    2011-12-01

    Full Text Available Leaf-litter amount as a factor in the structure of a ponerine ants community (Hymenoptera, Formicidae, Ponerinae in an eastern Amazonian rainforest, Brazil. Leaf-litter may be an important factor in structuring ponerine ant communities (Hymenoptera, Formicidae, Ponerinae in tropical rainforests. We specifically examined how leaf-litter affects the structure of a ponerine ant community in primary Amazonian rainforest sites at the Ferreira Penna Scientific Station, Pará, Brazil. A total of 53 species belonging to eight genera of three ponerine tribes were collected with mini-Winkler extractors. The amount of leaf-litter positively affected the abundance and richness of the ponerine ant community, and also influenced species composition. Nearby samples often had low species similarity, especially when adjacent samples differed in the amount of leaf-litter. Leaf-litter availability in Amazonian primary forests is a key factor for distribution of ground-dwelling ponerine species, even at small scales.

  4. Large-scale heterogeneity of Amazonian phenology revealed from 26-year long AVHRR/NDVI time-series

    International Nuclear Information System (INIS)

    Silva, Fabrício B; Shimabukuro, Yosio E; Aragão, Luiz E O C; Anderson, Liana O; Pereira, Gabriel; Cardozo, Franciele; Arai, Egídio

    2013-01-01

    Depiction of phenological cycles in tropical forests is critical for an understanding of seasonal patterns in carbon and water fluxes as well as the responses of vegetation to climate variations. However, the detection of clear spatially explicit phenological patterns across Amazonia has proven difficult using data from the Moderate Resolution Imaging Spectroradiometer (MODIS). In this work, we propose an alternative approach based on a 26-year time-series of the normalized difference vegetation index (NDVI) from the Advanced Very High Resolution Radiometer (AVHRR) to identify regions with homogeneous phenological cycles in Amazonia. Specifically, we aim to use a pattern recognition technique, based on temporal signal processing concepts, to map Amazonian phenoregions and to compare the identified patterns with field-derived information. Our automated method recognized 26 phenoregions with unique intra-annual seasonality. This result highlights the fact that known vegetation types in Amazonia are not only structurally different but also phenologically distinct. Flushing of new leaves observed in the field is, in most cases, associated to a continuous increase in NDVI. The peak in leaf production is normally observed from the beginning to the middle of the wet season in 66% of the field sites analyzed. The phenoregion map presented in this work gives a new perspective on the dynamics of Amazonian canopies. It is clear that the phenology across Amazonia is more variable than previously detected using remote sensing data. An understanding of the implications of this spatial heterogeneity on the seasonality of Amazonian forest processes is a crucial step towards accurately quantifying the role of tropical forests within global biogeochemical cycles. (letter)

  5. Recent and future impacts of climate and land-use changes on the Amazonian ecosystems inferred from an ecosystem model

    Science.gov (United States)

    Zhang, K.; Levine, N. M.; Longo, M.; Moorcroft, P. R.

    2011-12-01

    The impact of drought-induced disturbances and deforestation on the Amazonian ecosystems has been substantial and is predicted to increase due to future land-use and climate changes. The resulting fate of the Amazon forests and the carbon stored within them has important implications for both the future climate of the region and the global climate system. We evaluate the impacts of recent and future climate and land-use changes on the Amazonian ecosystems and the sensitivities of these ecosystems to these changes using the Ecosystem Demography Model 2.1. The model simulation comprises two parts: simulation from 1800 to present day with observed CO2 increase and land use change, and prediction from present day to 2050 driven by changing atmospheric CO2 concentrations and climate under two different land-use scenarios. The model's prediction of present day ecosystem dynamics compares favorably with the field observations and remote sensing-based estimates of biomass, and carbon, water and energy fluxes. Increasing atmospheric CO2 concentrations exert a positive influence on the vegetation productivity in this region. However, land-use change shows the largest impact on the ecosystems and offsets the potential benefits of increasing atmospheric CO2 concentrations in the past decades. Land-use change is also the largest uncertain factor for the future carbon stocks in the Amazon: biomass loss by 2050 under the business-as-usual land-use scenario is double that under the strict governance land-use scenario. Future climate change, especially changes in the spatial pattern of precipitation, also substantially impacts the composition, structure and functioning of Amazonian ecosystems. By coupling the land-use and climate changes, the model predicts that the savanna-like vegetation and seasonal forests will replace many of the current rainforests in the southern and eastern Amazon.

  6. The fate of Amazonian ecosystems over the coming century arising from changes in climate, atmospheric CO2, and land use.

    Science.gov (United States)

    Zhang, Ke; de Almeida Castanho, Andrea D; Galbraith, David R; Moghim, Sanaz; Levine, Naomi M; Bras, Rafael L; Coe, Michael T; Costa, Marcos H; Malhi, Yadvinder; Longo, Marcos; Knox, Ryan G; McKnight, Shawna; Wang, Jingfeng; Moorcroft, Paul R

    2015-02-20

    There is considerable interest in understanding the fate of the Amazon over the coming century in the face of climate change, rising atmospheric CO 2 levels, ongoing land transformation, and changing fire regimes within the region. In this analysis, we explore the fate of Amazonian ecosystems under the combined impact of these four environmental forcings using three terrestrial biosphere models (ED2, IBIS, and JULES) forced by three bias-corrected IPCC AR4 climate projections (PCM1, CCSM3, and HadCM3) under two land-use change scenarios. We assess the relative roles of climate change, CO 2 fertilization, land-use change, and fire in driving the projected changes in Amazonian biomass and forest extent. Our results indicate that the impacts of climate change are primarily determined by the direction and severity of projected changes in regional precipitation: under the driest climate projection, climate change alone is predicted to reduce Amazonian forest cover by an average of 14%. However, the models predict that CO 2 fertilization will enhance vegetation productivity and alleviate climate-induced increases in plant water stress, and, as a result, sustain high biomass forests, even under the driest climate scenario. Land-use change and climate-driven changes in fire frequency are predicted to cause additional aboveground biomass loss and reductions in forest extent. The relative impact of land use and fire dynamics compared to climate and CO 2 impacts varies considerably, depending on both the climate and land-use scenario, and on the terrestrial biosphere model used, highlighting the importance of improved quantitative understanding of all four factors - climate change, CO 2 fertilization effects, fire, and land use - to the fate of the Amazon over the coming century. © 2015 John Wiley & Sons Ltd.

  7. New species of Allopharynx (Digenea: Plagiorchiidae) and other helminths in Uranoscodon superciliosus (Squamata: Tropiduridae) from Amazonian Brazil.

    Science.gov (United States)

    Bursey, Charles R; Goldberg, Stephen R; Vitt, Laurie J

    2005-12-01

    Allopharynx daileyi n. sp. (Digenea: Plagiorchiidae) from the small intestine of the tropidurid lizard Uranoscodon superciliosus from Amazonian Brazil is described and illustrated. Of the 11 currently recognized species of Allopharynx, we consider Allopharynx megorchis Simha, 1961 a synonym of Allopharynx mehrai (Gogate, 1935) Price 1938 and Allopharynx puertoricensis Acholonu, 1976 a synonym of Allopharynx riopedrensis Garcia-Diaz; thus, A. daileyi becomes the 10th species assigned to the genus. The trematode species Mesocoelium monas and 2 species of Nematoda, Africana chabaudi and Cosmocerca vrcibradici, were also present.

  8. Parasitism of the isopod Artystone trysibia in the fish Chaetostoma dermorhynchum from the Tena River (Amazonian region, Ecuador).

    Science.gov (United States)

    Junoy, Juan

    2016-01-01

    The isopod Artystone trysibia Schioedte, 1866 is described by using a collection of specimens that were found parasitizing loricariid fish Chaetostoma dermorhynchum Boulenger, 1887 in the Tena River (Napo province, Ecuador, Amazonian region). Additionally to freshly collected specimens, complementary data of the parasite was obtained from preserved fishes at Ecuadorian museums. This is the first record of A. trysibia in Ecuador, and the most upstream location for the species. The new host fish, Chaetostoma dermorhynchum, is used locally as food. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. A 15-year post evaluation of the fire effects on ant community in an area of Amazonian forest

    OpenAIRE

    Santos, Jean C.; Delabie, Jacques H. C.; Fernandes, G. Wilson

    2008-01-01

    Fire represents an important disturbance to ant communities in areas of fire regime. Otherwise, little is known about the effects of fire on ant communities in areas of non-fire regimes, such as in the Amazonian region. We evaluated the long-term effect of fire on ant species richness in a rain forest (Bacaba Plateau) burned 15-years ago and compare our data with the data of primary unburned forest. A total of 85 ant species distributed in 21 genera and 14 tribes were collected; among them, 7...

  10. Seasonal variations in blood parameters of the Amazonian manatee, Trichechus inunguis

    Directory of Open Access Journals (Sweden)

    Elton P. Colares

    2000-01-01

    Full Text Available Seasonal variations in body weight, food consumption and blood glucose, total lipids, urea, total proteins, albumin and globulins of captive Amazonian manatees, Trichechus inunguis, were determined. Body weight changed significantly along the year, increasing from autumn to spring and decreasing in summer. The mean daily food intake of paragrass remained almost unchanged along the year. Paragrass administered to the manatees showed important variations in crude protein and lipid content along the year. No significant differences in blood parameters were registered between males and females in all seasons. Further, there were no significant differences in blood total proteins, albumin and globulins along the year. On the other hand, significant differences in the mean blood glucose, lipids and urea were registered. An increase in the blood glucose in the spring and summer was observed. Blood urea and lipids levels were positively related to paragrass protein and lipids content. These two correlations suggested that these blood parameters are good indicators of the animal nutritional status in the Amazonian manatee.Variações sasonais no peso do corpo, consumo de alimento e glicose, lípides totais, uréia, proteínas totais, albumina e globulinas do sangue de Peixes bois cativos, Trichechus inunguis, foram determinadas. Houve diferença significativa no peso dos animais ao longo do ano, sendo este aumento entre o outono e a primavera e decresce no verão. O consumo de capim colônia não variou ao longo do ano. A composição de proteína bruta e lipídeos totais de capim colônia dado aos animais mostrou importante variação ao longo do ano. Não foi verificado nenhuma variação nas concentrações dos parâmetros sagüíneos estudados entre os sexos em todas as estações. Também não foi verificado diferenças significativas nas concentrações sangüíneas de proteínas totais, albumina e globulinas ao longo do ano. Por outro lado

  11. Climatic and biotic controls on annual carbon storage in Amazonian ecosystems

    Science.gov (United States)

    Tian, H.; Melillo, J.M.; Kicklighter, D.W.; McGuire, A.D.; Helfrich, J.; Moore, B.; Vorosmarty, C.J.

    2000-01-01

    1 The role of undisturbed tropical land ecosystems in the global carbon budget is not well understood. It has been suggested that inter-annual climate variability can affect the capacity of these ecosystems to store carbon in the short term. In this paper, we use a transient version of the Terrestrial Ecosystem Model (TEM) to estimate annual carbon storage in undisturbed Amazonian ecosystems during the period 1980-94, and to understand the underlying causes of the year-to-year variations in net carbon storage for this region. 2 We estimate that the total carbon storage in the undisturbed ecosystems of the Amazon Basin in 1980 was 127.6 Pg C, with about 94.3 Pg C in vegetation and 33.3 Pg C in the reactive pool of soil organic carbon. About 83% of the total carbon storage occurred in tropical evergreen forests. Based on our model's results, we estimate that, over the past 15 years, the total carbon storage has increased by 3.1 Pg C (+ 2%), with a 1.9-Pg C (+2%) increase in vegetation carbon and a 1.2-Pg C (+4%) increase in reactive soil organic carbon. The modelled results indicate that the largest relative changes in net carbon storage have occurred in tropical deciduous forests, but that the largest absolute changes in net carbon storage have occurred in the moist and wet forests of the Basin. 3 Our results show that the strength of interannual variations in net carbon storage of undisturbed ecosystems in the Amazon Basin varies from a carbon source of 0.2 Pg C/year to a carbon sink of 0.7 Pg C/year. Precipitation, especially the amount received during the drier months, appears to be a major controller of annual net carbon storage in the Amazon Basin. Our analysis indicates further that changes in precipitation combine with changes in temperature to affect net carbon storage through influencing soil moisture and nutrient availability. 4 On average, our results suggest that the undisturbed Amazonian ecosystems accumulated 0.2 Pg C/year as a result of climate

  12. Asymmetric dispersal and colonization success of Amazonian plant-ants queens.

    Directory of Open Access Journals (Sweden)

    Emilio M Bruna

    Full Text Available The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants.We used empirical data and inverse modeling--a technique developed by plant ecologists to model seed dispersal--to quantify and compare the dispersal kernels of queens from three Amazonian ant species that compete for access to host-plants. We found that the modal colonization distance of queens varied 8-fold, with the generalist ant species (Crematogaster laevis having a greater modal distance than two specialists (Pheidole minutula, Azteca sp. that use the same host-plants. However, our results also suggest that queens of Azteca sp. have maximal distances that are four-sixteen times greater than those of its competitors.We found large differences between ant species in both the modal and maximal distance ant queens disperse to find vacant seedlings used to found new colonies. These differences could result from interspecific differences in queen body size, and hence wing musculature, or because queens differ in their ability to identify potential host plants while in flight. Our results provide support for one of the necessary conditions underlying several of the hypothesized mechanisms promoting coexistence in tropical plant-ants. They also suggest that for some ant species limited dispersal capability could pose a significant barrier to the rescue of populations in isolated forest fragments. Finally, we demonstrate that inverse models parameterized with field data are an excellent means of quantifying the dispersal of ant queens.

  13. Reproductive effects on skeletal health in Shuar women of Amazonian Ecuador: a life history perspective.

    Science.gov (United States)

    Madimenos, Felicia C; Snodgrass, J Josh; Liebert, Melissa A; Cepon, Tara J; Sugiyama, Lawrence S

    2012-01-01

    Clinical and epidemiological research suggest that bone mineral density (BMD) in women is shaped by various reproductive factors such as parity and lactation patterns. However, the extent of these effects on BMD remains unclear because of contradictory findings and a focus on industrialized populations. Because fertility patterns in these groups are vastly different than those of women from non-Western, subsistence populations, our current understanding of the reproductive effects on skeletal health is incomplete. Using a life history perspective, this study examines the relationship between reproductive factors and bone density among women from the Indigenous Shuar population, an Amazonian Ecuadorian forager-horticulturalist group. This preliminary, cross-sectional study included 130 premenopausal and postmenopausal women (14-86 years old) from the Morona-Santiago region of Ecuador. Anthropometrics were recorded, as was estimated BMD using a calcaneal ultrasonometer. A reproductive history questionnaire was administered that included questions regarding menarche, parity, lactation patterns, and menopause. Among postmenopausal women, early menarche and greater stature were significantly associated with higher bone density values. Among premenopausal women, few significant relationships between bone values and reproductive variables were documented; effects of lactation appeared to be transient and restored following weaning. Although preliminary and not based on longitudinal data, these findings suggest that the effects of reproduction are transient as the system of calcium homeostasis in premenopausal women efficiently restores the bone loss that results from metabolically active reproductive states. Further, this research suggests that the timing of early life history events may canalize bone density phenotype. Copyright © 2012 Wiley Periodicals, Inc.

  14. Amazonian Triatomine Biodiversity and the Transmission of Chagas Disease in French Guiana: In Medio Stat Sanitas

    Science.gov (United States)

    Flores-Ferrer, Alheli; Blanchet, Denis; Gourbière, Sébastien

    2016-01-01

    The effects of biodiversity on the transmission of infectious diseases now stand as a cornerstone of many public health policies. The upper Amazonia and Guyana shield are hot-spots of biodiversity that offer genuine opportunities to explore the relationship between the risk of transmission of Chagas disease and the diversity of its triatomine vectors. Over 730 triatomines were light-trapped in four geomorphological landscapes shaping French-Guiana, and we determined their taxonomic status and infection by Trypanosoma cruzi. We used a model selection approach to unravel the spatial and temporal variations in species abundance, diversity and infection. The vector community in French-Guiana is typically made of one key species (Panstrongylus geniculatus) that is more abundant than three secondary species combined (Rhodnius pictipes, Panstrongylus lignarius and Eratyrus mucronatus), and four other species that complete the assemblage. Although the overall abundance of adult triatomines does not vary across French-Guiana, their diversity increases along a coastal-inland gradient. These variations unravelled a non-monotonic relationship between vector biodiversity and the risk of transmission of Chagas disease, so that intermediate biodiversity levels are associated with the lowest risks. We also observed biannual variations in triatomine abundance, representing the first report of a biannual pattern in the risk of Chagas disease transmission. Those variations were highly and negatively correlated with the average monthly rainfall. We discuss the implications of these patterns for the transmission of T. cruzi by assemblages of triatomine species, and for the dual challenge of controlling Amazonian vector communities that are made of both highly diverse and mostly intrusive species. PMID:26867025

  15. Amazonian Triatomine Biodiversity and the Transmission of Chagas Disease in French Guiana: In Medio Stat Sanitas.

    Directory of Open Access Journals (Sweden)

    Julie Péneau

    2016-02-01

    Full Text Available The effects of biodiversity on the transmission of infectious diseases now stand as a cornerstone of many public health policies. The upper Amazonia and Guyana shield are hot-spots of biodiversity that offer genuine opportunities to explore the relationship between the risk of transmission of Chagas disease and the diversity of its triatomine vectors. Over 730 triatomines were light-trapped in four geomorphological landscapes shaping French-Guiana, and we determined their taxonomic status and infection by Trypanosoma cruzi. We used a model selection approach to unravel the spatial and temporal variations in species abundance, diversity and infection. The vector community in French-Guiana is typically made of one key species (Panstrongylus geniculatus that is more abundant than three secondary species combined (Rhodnius pictipes, Panstrongylus lignarius and Eratyrus mucronatus, and four other species that complete the assemblage. Although the overall abundance of adult triatomines does not vary across French-Guiana, their diversity increases along a coastal-inland gradient. These variations unravelled a non-monotonic relationship between vector biodiversity and the risk of transmission of Chagas disease, so that intermediate biodiversity levels are associated with the lowest risks. We also observed biannual variations in triatomine abundance, representing the first report of a biannual pattern in the risk of Chagas disease transmission. Those variations were highly and negatively correlated with the average monthly rainfall. We discuss the implications of these patterns for the transmission of T. cruzi by assemblages of triatomine species, and for the dual challenge of controlling Amazonian vector communities that are made of both highly diverse and mostly intrusive species.

  16. Leaf Aging of Amazonian Canopy Trees: Insights to Tropical Ecological Processes and Satellited Detected Canopy Dynamics

    Science.gov (United States)

    Chavana-Bryant, C.; Malhi, Y.; Gerard, F.

    2015-12-01

    Leaf aging is a fundamental driver of changes in leaf traits, thereby, regulating ecosystem processes and remotely-sensed canopy dynamics. Leaf age is particularly important for carbon-rich tropical evergreen forests, as leaf demography (leaf age distribution) has been proposed as a major driver of seasonal productivity in these forests. We explore leaf reflectance as a tool to monitor leaf age and develop a novel spectra-based (PLSR) model to predict age using data from a phenological study of 1,072 leaves from 12 lowland Amazonian canopy tree species in southern Peru. Our results demonstrate monotonic decreases in LWC and Pmass and increase in LMA with age across species; Nmass and Cmassshowed monotonic but species-specific age responses. Spectrally, we observed large age-related variation across species, with the most age-sensitive spectral domains found to be: green peak (550nm), red edge (680-750 nm), NIR (700-850 nm), and around the main water absorption features (~1450 and ~1940 nm). A spectra-based model was more accurate in predicting leaf age (R2= 0.86; %RMSE= 33) compared to trait-based models using single (R2=0.07 to 0.73; %RMSE=7 to 38) and multiple predictors (step-wise analysis; R2=0.76; %RMSE=28). Spectral and trait-based models established a physiochemical basis for the spectral age model. The relative importance of the traits modifying the leaf spectra of aging leaves was: LWC>LMA>Nmass>Pmass,&Cmass. Vegetation indices (VIs), including NDVI, EVI2, NDWI and PRI were all age-dependent. This study highlights the importance of leaf age as a mediator of leaf traits, provides evidence of age-related leaf reflectance changes that have important impacts on VIs used to monitor canopy dynamics and productivity, and proposes a new approach to predicting and monitoring leaf age with important implications for remote sensing.

  17. Amazonian landscapes and the bias in field studies of forest structure and biomass.

    Science.gov (United States)

    Marvin, David C; Asner, Gregory P; Knapp, David E; Anderson, Christopher B; Martin, Roberta E; Sinca, Felipe; Tupayachi, Raul

    2014-12-02

    Tropical forests convert more atmospheric carbon into biomass each year than any terrestrial ecosystem on Earth, underscoring the importance of accurate tropical forest structure and biomass maps for the understanding and management of the global carbon cycle. Ecologists have long used field inventory plots as the main tool for understanding forest structure and biomass at landscape-to-regional scales, under the implicit assumption that these plots accurately represent their surrounding landscape. However, no study has used continuous, high-spatial-resolution data to test whether field plots meet this assumption in tropical forests. Using airborne LiDAR (light detection and ranging) acquired over three regions in Peru, we assessed how representative a typical set of field plots are relative to their surrounding host landscapes. We uncovered substantial mean biases (9-98%) in forest canopy structure (height, gaps, and layers) and aboveground biomass in both lowland Amazonian and montane Andean landscapes. Moreover, simulations reveal that an impractical number of 1-ha field plots (from 10 to more than 100 per landscape) are needed to develop accurate estimates of aboveground biomass at landscape scales. These biases should temper the use of plots for extrapolations of forest dynamics to larger scales, and they demonstrate the need for a fundamental shift to high-resolution active remote sensing techniques as a primary sampling tool in tropical forest biomass studies. The potential decrease in the bias and uncertainty of remotely sensed estimates of forest structure and biomass is a vital step toward successful tropical forest conservation and climate-change mitigation policy.

  18. Production and some properties of crude alkaline proteases of indigenous Central Amazonian rhizobia strains

    Directory of Open Access Journals (Sweden)

    Arlem Nascimento de Oliveira

    2010-10-01

    Full Text Available Two rhizobia strains isolated from soils of the Central Amazonian floodplain produced appreciable quantities of crude alkaline protease extracts with inexpensive carbon and nitrogen sources. These protease crude extracts were optimally active at pH 9.0-11.0. The optimum temperatures were 35 ºC for Rhizobium sp. strain R-986 and 55 ºC for Bradyrhizobium sp. strain R-993. Protease activities in the crude extracts were enhanced in the presence of 5 mM metal ions, such as Na+, Ca2+, Mg2+ and Mn2+. Rhizobia proteases were strongly inhibited by PMSF, a serine-protease inhibitor. The enzymes were active in the presence of surfactants (SDS and Triton X-100 and stable in oxidizing (H2O2 and reducing agents (β-mercaptoethanol, and organic solvents (acetone, hexane, methanol, 1-propanol and toluene.Duas estirpes de rizóbia isoladas de solos de várzea da Amazônia Central produziram grandes quantidades de proteases alcalinas extracelulares, usando fontes baratas de carbono e nitrogênio. Os extratos brutos de proteases foram ativos em pH 9,0-11,0. As temperaturas ótimas foram de 35 ºC para a enzima do Rhizobium R-986 e de 55 ºC para a do Bradyrhizobium R-993. As atividades proteolíticas aumentaram na presença de 5 mM dos íons Na+, Ca2+ , Mg2+ e Mn2+ . As proteases secretadas pelos rizóbios foram fortemente inibidas por PMSF, um inibidor de serina protease. As enzimas foram ativas na presença de surfactantes (SDS e Triton X-100, e estáveis na presença de agentes oxidantes (H2O2 e redutores (β-mercaptoetanol e solventes orgânicos (acetona, hexano, metanol, 1-propanol e tolueno.

  19. Resilient networks of ant-plant mutualists in Amazonian forest fragments.

    Science.gov (United States)

    Passmore, Heather A; Bruna, Emilio M; Heredia, Sylvia M; Vasconcelos, Heraldo L

    2012-01-01

    The organization of networks of interacting species, such as plants and animals engaged in mutualisms, strongly influences the ecology and evolution of partner communities. Habitat fragmentation is a globally pervasive form of spatial heterogeneity that could profoundly impact the structure of mutualist networks. This is particularly true for biodiversity-rich tropical ecosystems, where the majority of plant species depend on mutualisms with animals and it is thought that changes in the structure of mutualist networks could lead to cascades of extinctions. We evaluated effects of fragmentation on mutualistic networks by calculating metrics of network structure for ant-plant networks in continuous Amazonian forests with those in forest fragments. We hypothesized that networks in fragments would have fewer species and higher connectance, but equal nestedness and resilience compared to forest networks. Only one of the nine metrics we compared differed between continuous forest and forest fragments, indicating that networks were resistant to the biotic and abiotic changes that accompany fragmentation. This is partially the result of the loss of only specialist species with one connection that were lost in forest fragments. We found that the networks of ant-plant mutualists in twenty-five year old fragments are similar to those in continuous forest, suggesting these interactions are resistant to the detrimental changes associated with habitat fragmentation, at least in landscapes that are a mosaic of fragments, regenerating forests, and pastures. However, ant-plant mutualistic networks may have several properties that may promote their persistence in fragmented landscapes. Proactive identification of key mutualist partners may be necessary to focus conservation efforts on the interactions that insure the integrity of network structure and the ecosystems services networks provide.

  20. Resilient networks of ant-plant mutualists in Amazonian forest fragments.

    Directory of Open Access Journals (Sweden)

    Heather A Passmore

    Full Text Available The organization of networks of interacting species, such as plants and animals engaged in mutualisms, strongly influences the ecology and evolution of partner communities. Habitat fragmentation is a globally pervasive form of spatial heterogeneity that could profoundly impact the structure of mutualist networks. This is particularly true for biodiversity-rich tropical ecosystems, where the majority of plant species depend on mutualisms with animals and it is thought that changes in the structure of mutualist networks could lead to cascades of extinctions.We evaluated effects of fragmentation on mutualistic networks by calculating metrics of network structure for ant-plant networks in continuous Amazonian forests with those in forest fragments. We hypothesized that networks in fragments would have fewer species and higher connectance, but equal nestedness and resilience compared to forest networks. Only one of the nine metrics we compared differed between continuous forest and forest fragments, indicating that networks were resistant to the biotic and abiotic changes that accompany fragmentation. This is partially the result of the loss of only specialist species with one connection that were lost in forest fragments.We found that the networks of ant-plant mutualists in twenty-five year old fragments are similar to those in continuous forest, suggesting these interactions are resistant to the detrimental changes associated with habitat fragmentation, at least in landscapes that are a mosaic of fragments, regenerating forests, and pastures. However, ant-plant mutualistic networks may have several properties that may promote their persistence in fragmented landscapes. Proactive identification of key mutualist partners may be necessary to focus conservation efforts on the interactions that insure the integrity of network structure and the ecosystems services networks provide.

  1. Photosynthetic responses to light in seedlings of selected Amazonian and Australian rainforest tree species.

    Science.gov (United States)

    Langenheim, J H; Osmond, C B; Brooks, A; Ferrar, P J

    1984-08-01

    Seedlings of the Caesalpinoids Hymenaea courbaril, H. parvifolia and Copaifera venezuelana, emergent trees of Amazonian rainforest canopies, and of the Araucarian conifers Agathis microstachya and A. robusta, important elements in tropical Australian rainforests, were grown at 6% (shade) and 100% full sunlight (sun) in glasshouses. All species produced more leaves in full sunlight than in shade and leaves of sun plants contained more nitrogen and less chlorophyll per unit leaf area, and had a higher specific leaf weight than leaves of shade plants. The photosynthetic response curves as a function of photon flux density for leaves of shade-grown seedlings showed lower compensation points, higher quantum yields and lower respiration rates per unit leaf area than those of sun-grown seedlings. However, except for A. robusta, photosynthetic acclimation between sun and shade was not observed; the light saturated rates of assimilation were not significantly different. Intercellular CO 2 partial pressure was similar in leaves of sun and shade-grown plants, and assimilation was limited more by intrinsic mesophyll factors than by stomata. Comparison of assimilation as a function of intercellular CO 2 partial pressure in sun- and shade-grown Agathis spp. showed a higher initial slope in leaves of sun plants, which was correlated with higher leaf nitrogen content. Assimilation was reduced at high transpiration rates and substantial photoinhibition was observed when seedlings were transferred from shade to sun. However, after transfer, newly formed leaves in A. robusta showed the same light responses as leaves of sun-grown seedlings. These observations on the limited potential for acclimation to high light in leaves of seedlings of rainforest trees are discussed in relation to regeneration following formation of gaps in the canopy.

  2. Optimizing sampling design to deal with mist-net avoidance in Amazonian birds and bats.

    Directory of Open Access Journals (Sweden)

    João Tiago Marques

    Full Text Available Mist netting is a widely used technique to sample bird and bat assemblages. However, captures often decline with time because animals learn and avoid the locations of nets. This avoidance or net shyness can substantially decrease sampling efficiency. We quantified the day-to-day decline in captures of Amazonian birds and bats with mist nets set at the same location for four consecutive days. We also evaluated how net avoidance influences the efficiency of surveys under different logistic scenarios using re-sampling techniques. Net avoidance caused substantial declines in bird and bat captures, although more accentuated in the latter. Most of the decline occurred between the first and second days of netting: 28% in birds and 47% in bats. Captures of commoner species were more affected. The numbers of species detected also declined. Moving nets daily to minimize the avoidance effect increased captures by 30% in birds and 70% in bats. However, moving the location of nets may cause a reduction in netting time and captures. When moving the nets caused the loss of one netting day it was no longer advantageous to move the nets frequently. In bird surveys that could even decrease the number of individuals captured and species detected. Net avoidance can greatly affect sampling efficiency but adjustments in survey design can minimize this. Whenever nets can be moved without losing netting time and the objective is to capture many individuals, they should be moved daily. If the main objective is to survey species present then nets should still be moved for bats, but not for birds. However, if relocating nets causes a significant loss of netting time, moving them to reduce effects of shyness will not improve sampling efficiency in either group. Overall, our findings can improve the design of mist netting sampling strategies in other tropical areas.

  3. Scalar turbulent behavior in the roughness sublayer of an Amazonian forest

    Directory of Open Access Journals (Sweden)

    E. Zahn

    2016-09-01

    Full Text Available An important current problem in micrometeorology is the characterization of turbulence in the roughness sublayer (RSL, where most of the measurements above tall forests are made. There, scalar turbulent fluctuations display significant departures from the predictions of Monin–Obukhov similarity theory (MOST. In this work, we analyze turbulence data of virtual temperature, carbon dioxide, and water vapor in the RSL above an Amazonian forest (with a canopy height of 40 m, measured at 39.4 and 81.6 m above the ground under unstable conditions. We found that dimensionless statistics related to the rate of dissipation of turbulence kinetic energy (TKE and the scalar variance display significant departures from MOST as expected, whereas the vertical velocity variance follows MOST much more closely. Much better agreement between the dimensionless statistics with the Obukhov similarity variable, however, was found for the subset of measurements made at a low zenith angle Z, in the range 0°  <  |Z|  <  20°. We conjecture that this improvement is due to the relationship between sunlight incidence and the “activation–deactivation” of scalar sinks and sources vertically distributed in the forest. Finally, we evaluated the relaxation coefficient of relaxed eddy accumulation: it is also affected by zenith angle, with considerable improvement in the range 0°  <  |Z|  <  20°, and its values fall within the range reported in the literature for the unstable surface layer. In general, our results indicate the possibility of better stability-derived flux estimates for low zenith angle ranges.

  4. Unexpected high diversity of galling insects in the Amazonian upper canopy: the savanna out there.

    Science.gov (United States)

    Julião, Genimar R; Venticinque, Eduardo M; Fernandes, G Wilson; Price, Peter W

    2014-01-01

    A relatively large number of studies reassert the strong relationship between galling insect diversity and extreme hydric and thermal status in some habitats, and an overall pattern of a greater number of galling species in the understory of scleromorphic vegetation. We compared galling insect diversity in the forest canopy and its relationship with tree richness among upland terra firme, várzea, and igapó floodplains in Amazonia, Brazil. The soils of these forest types have highly different hydric and nutritional status. Overall, we examined the upper layer of 1,091 tree crowns. Galling species richness and abundance were higher in terra firme forests compared to várzea and igapó forests. GLM-ANCOVA models revealed that the number of tree species sampled in each forest type was determinant in the gall-forming insect diversity. The ratio between galling insect richness and number of tree species sampled (GIR/TSS ratio) was higher in the terra firme forest and in seasonally flooded igapó, while the várzea presented the lowest GIR/TSS ratio. In this study, we recorded unprecedented values of galling species diversity and abundance per sampling point. The GIR/TSS ratio from várzea was approximately 2.5 times higher than the highest value of this ratio ever reported in the literature. Based on this fact, we ascertained that várzea and igapó floodplain forests (with lower GIA and GIR), together with the speciose terra firme galling community emerge as the gall diversity apex landscape among all biogeographic regions already investigated. Contrary to expectation, our results also support the "harsh environment hypothesis", and unveil the Amazonian upper canopy as similar to Mediterranean vegetation habitats, hygrothermically stressed environments with leaf temperature at lethal limits and high levels of leaf sclerophylly.

  5. Leaf aging of Amazonian canopy trees as revealed by spectral and physiochemical measurements.

    Science.gov (United States)

    Chavana-Bryant, Cecilia; Malhi, Yadvinder; Wu, Jin; Asner, Gregory P; Anastasiou, Athanasios; Enquist, Brian J; Cosio Caravasi, Eric G; Doughty, Christopher E; Saleska, Scott R; Martin, Roberta E; Gerard, France F

    2017-05-01

    Leaf aging is a fundamental driver of changes in leaf traits, thereby regulating ecosystem processes and remotely sensed canopy dynamics. We explore leaf reflectance as a tool to monitor leaf age and develop a spectra-based partial least squares regression (PLSR) model to predict age using data from a phenological study of 1099 leaves from 12 lowland Amazonian canopy trees in southern Peru. Results demonstrated monotonic decreases in leaf water (LWC) and phosphorus (P mass ) contents and an increase in leaf mass per unit area (LMA) with age across trees; leaf nitrogen (N mass ) and carbon (C mass ) contents showed monotonic but tree-specific age responses. We observed large age-related variation in leaf spectra across trees. A spectra-based model was more accurate in predicting leaf age (R 2  = 0.86; percent root mean square error (%RMSE) = 33) compared with trait-based models using single (R 2  = 0.07-0.73; %RMSE = 7-38) and multiple (R 2  = 0.76; %RMSE = 28) predictors. Spectra- and trait-based models established a physiochemical basis for the spectral age model. Vegetation indices (VIs) including the normalized difference vegetation index (NDVI), enhanced vegetation index 2 (EVI2), normalized difference water index (NDWI) and photosynthetic reflectance index (PRI) were all age-dependent. This study highlights the importance of leaf age as a mediator of leaf traits, provides evidence of age-related leaf reflectance changes that have important impacts on VIs used to monitor canopy dynamics and productivity and proposes a new approach to predicting and monitoring leaf age with important implications for remote sensing. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  6. Morphological and physiological adjustments to waterlogging and drought in seedlings of Amazonian floodplain trees.

    Science.gov (United States)

    Parolin, Pia

    2001-08-01

    Plants in central Amazonian floodplains are subjected to waterlogging or complete submersion for 50-270 days every year. Most trees have growth reductions, photosynthetic activity can be reduced for some weeks to months, and leaf fall increases during the high-water period, but leaf flush, flowering and fruiting also occur in waterlogged plants. Whether flooding can trigger the changes in phenology, growth and metabolism of the plants has not yet been established. The aim of this study was to analyse the extent to which waterlogging was directly responsible for morphological, phenological and physiological changes in floodplain seedlings. In two flooding experiments performed at different times of the year, the effects of waterlogging, submersion and drought were tested in seedlings of six species with different growth strategies. One experiment was performed in the period of highest precipitation and rising river levels, and a second experiment in the period of highest river levels and the onset of the period of lowest precipitation. All results were comparable in the two experiments, and the morphological, phenological and physiological responses were linked to the treatments. Height growth and new leaf production were not severely affected in the waterlogged seedlings. All waterlogged plants produced adventitious roots, lenticels and stem hypertrophy. Submersion and drought caused a state of rest, but soon after the water had receded, leaves resprouted. Five to 12 weeks after the end of submersion, the seedlings reached the height of the control plants, showing a high ability to compensate the period of rest induced by submergence. Only the three deciduous species subjected to waterlogging showed a different phenological behaviour in the two experiments, perhaps related to genetically fixed phenological rhythms which are synchronous to those of adult trees in the field.

  7. Mercury Bioaccumulation in the Brazilian Amazonian Tucunares (Cichla sp., Cichlidae, Perciformes

    Directory of Open Access Journals (Sweden)

    Maria Josefina Reyna Kurtz

    2008-08-01

    Full Text Available There are emissions of mercury to the atmosphere, soil and rivers of the Brazilian Amazon stem from many sources. Once in the atmosphere, the metal is oxidized and immediately deposited. In the water, the transformation to methylmercury takes place mostly by the action of microorganisms. The formation of methylmercury increases the dispersion and bioavailability of the element in the aquatic environment. Methylmercury can be assimilated by plankton and enters the food chain. The concentration of mercury increases further up in the trophic levels of the chain and reaches the highest values in carnivorous fishes like tucunare. Therefore, mercury emissions cause the contamination of natural resources and increase risks to the health of regular fish consumers. The objective of this work was to study the bioaccumulation of mercury in tucunares (Cichla sp., top predators of the food chain. The fishes were collected at two locations representative of the Amazonian fluvial ecosystem, in the state of Pará, Brazil, in 1992 and 2001. One location is near a former informal gold mining area. The other is far from the mining area and is considered pristine. Average values of total mercury concentration and accumulation rates for four different collection groups were compared and discussed. Tucunares collected in 2001 presented higher mercury contents and accumulated mercury faster than tucunares collected in 1992 notwithstanding the decline of mining activities in this period. The aggravation of the mercury contamination with time not only in an area where informal gold mining was practiced but also far from this area is confirmed.

  8. Integrating regional and continental scale comparisons of tree composition in Amazonian terra firme forests

    Science.gov (United States)

    Honorio Coronado, E. N.; Baker, T. R.; Phillips, O. L.; Pitman, N. C. A.; Pennington, R. T.; Vásquez Martínez, R.; Monteagudo, A.; Mogollón, H.; Dávila Cardozo, N.; Ríos, M.; García-Villacorta, R.; Valderrama, E.; Ahuite, M.; Huamantupa, I.; Neill, D. A.; Laurance, W. F.; Nascimento, H. E. M.; Soares de Almeida, S.; Killeen, T. J.; Arroyo, L.; Núñez, P.; Freitas Alvarado, L.

    2009-01-01

    We contrast regional and continental-scale comparisons of the floristic composition of terra firme forest in South Amazonia, using 55 plots across Amazonia and a subset of 30 plots from northern Peru and Ecuador. Firstly, we examine the floristic patterns using both genus- or species-level data and find that the species-level analysis more clearly distinguishes different plot clusters. Secondly, we compare the patterns and causes of floristic differences at regional and continental scales. At a continental scale, ordination analysis shows that species of Lecythidaceae and Sapotaceae are gradually replaced by species of Arecaceae and Myristicaceae from eastern to western Amazonia. These floristic gradients are correlated with gradients in soil fertility and to dry season length, similar to previous studies. At a regional scale, similar patterns are found within north-western Amazonia, where differences in soil fertility distinguish plots where species of Lecythidaceae, characteristic of poor soils, are gradually replaced by species of Myristicaceae on richer soils. The main coordinate of this regional-scale ordination correlates mainly with concentrations of available calcium and magnesium. Thirdly, we ask at a regional scale within north-western Amazonia, whether soil fertility or other distance dependent processes are more important for determining variation in floristic composition. A Mantel test indicates that both soils and geographical distance have a similar and significant role in determining floristic similarity across this region. Overall, these results suggest that regional-scale variation in floristic composition can rival continental scale differences within Amazonian terra firme forests, and that variation in floristic composition at both scales is dependent on a range of processes that include both habitat specialisation related to edaphic conditions and other distance-dependent processes. To fully account for regional scale variation in continental

  9. Frugivory in Canopy Plants in a Western Amazonian Forest: Dispersal Systems, Phylogenetic Ensembles and Keystone Plants.

    Science.gov (United States)

    Stevenson, Pablo R; Link, Andrés; González-Caro, Sebastian; Torres-Jiménez, María Fernanda

    2015-01-01

    Frugivory is a widespread mutualistic interaction in which frugivores obtain nutritional resources while favoring plant recruitment through their seed dispersal services. Nonetheless, how these complex interactions are organized in diverse communities, such as tropical forests, is not fully understood. In this study we evaluated the existence of plant-frugivore sub-assemblages and their phylogenetic organization in an undisturbed western Amazonian forest in Colombia. We also explored for potential keystone plants, based on network analyses and an estimate of the amount of fruit going from plants to frugivores. We carried out diurnal observations on 73 canopy plant species during a period of two years. During focal tree sampling, we recorded frugivore identity, the duration of each individual visit, and feeding rates. We did not find support for the existence of sub assemblages, such as specialized vs. generalized dispersal systems. Visitation rates on the vast majority of canopy species were associated with the relative abundance of frugivores, in which ateline monkeys (i.e. Lagothrix and Ateles) played the most important roles. All fruiting plants were visited by a variety of frugivores and the phylogenetic assemblage was random in more than 67% of the cases. In cases of aggregation, the plant species were consumed by only primates or only birds, and filters were associated with fruit protection and likely chemical content. Plants suggested as keystone species based on the amount of pulp going from plants to frugivores differ from those suggested based on network approaches. Our results suggest that in tropical forests most tree-frugivore interactions are generalized, and abundance should be taken into account when assessing the most important plants for frugivores.

  10. Submicron particle mass concentrations and sources in the Amazonian wet season (AMAZE-08)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Q.; Farmer, D. K.; Rizzo, L. V.; Pauliqueivis, T.; Kuwata, Mikinori; Karl, Thomas G.; Guenther, Alex B.; Allan, James D.; Coe, H.; Andreae, M. O.; Poeschl, U.; Jiminez, J. L.; Artaxo, Paulo; Martin, Scot T.

    2015-01-01

    Real-time mass spectra of non-refractory component of submicron aerosol particles were recorded in a tropical rainforest in the central Amazon basin during the wet season of 2008, as a part of the Amazonian Aerosol Characterization Experiment (AMAZE-08). Organic components accounted on average for more than 80% of the non-refractory submicron particle mass concentrations during the period of measurements. Ammonium was present in sufficient quantities to halfway neutralize sulfate. In this acidic, isoprene-dominated, low-NOx environment the high-resolution mass spectra as well as mass closures with ion chromatography measurements did not provide evidence for significant contributions of organosulfate species, at least at concentrations above uncertainty levels. Positive-matrix factorization of the time series of particle mass spectra identified four statistical factors to account for the variance of the signal intensities of the organic constituents: a factor HOA having a hydrocarbon-like signature and identified as regional emissions of primary organic material, a factor OOA-1 associated with fresh production of secondary organic material by a mechanism of BVOC oxidation followed by gas-to-particle conversion, a factor OOA-2 consistent with reactive uptake of isoprene oxidation products, especially epoxydiols by acidic particles, and a factor OOA-3 associated with long range transport and atmospheric aging. The OOA-1, -2, and -3 factors had progressively more oxidized signatures. Diameter-resolved mass spectral markers also suggested enhanced reactive uptake of isoprene oxidation products to the accumulation mode for the OOA-2 factor, and such size partitioning can be indicative of in-cloud process. The campaign-average factor loadings were in a ratio of 1.1:1.0 for the OOA-1 compared to the OOA-2 pathway, suggesting the comparable importance of gas-phase compared to particle-phase (including cloud waters) production pathways of secondary organic material during

  11. The Deep-Sea Microbial Community from the Amazonian Basin Associated with Oil Degradation.

    Science.gov (United States)

    Campeão, Mariana E; Reis, Luciana; Leomil, Luciana; de Oliveira, Louisi; Otsuki, Koko; Gardinali, Piero; Pelz, Oliver; Valle, Rogerio; Thompson, Fabiano L; Thompson, Cristiane C

    2017-01-01

    One consequence of oil production is the possibility of unplanned accidental oil spills; therefore, it is important to evaluate the potential of indigenous microorganisms (both prokaryotes and eukaryotes) from different oceanic basins to degrade oil. The aim of this study was to characterize the microbial response during the biodegradation process of Brazilian crude oil, both with and without the addition of the dispersant Corexit 9500, using deep-sea water samples from the Amazon equatorial margin basins, Foz do Amazonas and Barreirinhas, in the dark and at low temperatures (4°C). We collected deep-sea samples in the field (about 2570 m below the sea surface), transported the samples back to the laboratory under controlled environmental conditions (5°C in the dark) and subsequently performed two laboratory biodegradation experiments that used metagenomics supported by classical microbiological methods and chemical analysis to elucidate both taxonomic and functional microbial diversity. We also analyzed several physical-chemical and biological parameters related to oil biodegradation. The concomitant depletion of dissolved oxygen levels, oil droplet density characteristic to oil biodegradation, and BTEX concentration with an increase in microbial counts revealed that oil can be degraded by the autochthonous deep-sea microbial communities. Indigenous bacteria (e.g., Alteromonadaceae, Colwelliaceae , and Alcanivoracaceae ), archaea (e.g., Halobacteriaceae, Desulfurococcaceae , and Methanobacteriaceae ), and eukaryotic microbes (e.g., Microsporidia, Ascomycota, and Basidiomycota) from the Amazonian margin deep-sea water were involved in biodegradation of Brazilian crude oil within less than 48-days in both treatments, with and without dispersant, possibly transforming oil into microbial biomass that may fuel the marine food web.

  12. Asymmetric Dispersal and Colonization Success of Amazonian Plant-Ants Queens

    Science.gov (United States)

    Bruna, Emilio M.; Izzo, Thiago J.; Inouye, Brian D.; Uriarte, Maria; Vasconcelos, Heraldo L.

    2011-01-01

    Background The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants. Methodology/Principal Findings We used empirical data and inverse modeling—a technique developed by plant ecologists to model seed dispersal—to quantify and compare the dispersal kernels of queens from three Amazonian ant species that compete for access to host-plants. We found that the modal colonization distance of queens varied 8-fold, with the generalist ant species (Crematogaster laevis) having a greater modal distance than two specialists (Pheidole minutula, Azteca sp.) that use the same host-plants. However, our results also suggest that queens of Azteca sp. have maximal distances that are four-sixteen times greater than those of its competitors. Conclusions/Significance We found large differences between ant species in both the modal and maximal distance ant queens disperse to find vacant seedlings used to found new colonies. These differences could result from interspecific differences in queen body size, and hence wing musculature, or because queens differ in their ability to identify potential host plants while in flight. Our results provide support for one of the necessary conditions underlying several of the hypothesized mechanisms promoting coexistence in tropical plant-ants. They also suggest that for some ant species limited dispersal capability could pose a significant barrier to the rescue of populations in isolated forest fragments. Finally, we demonstrate that inverse models parameterized with field data are an excellent means of quantifying the

  13. Visual Inspection after Acetic Acid (VIA) Is Highly Heterogeneous in Primary Cervical Screening in Amazonian Peru

    Science.gov (United States)

    Almonte, Maribel; Ferreccio, Catterina; Luciani, Silvana; Gonzales, Miguel; Delgado, Jose M.; Santos, Carlos; Alvarez, Manuel; Cuzick, Jack; Sasieni, Peter

    2015-01-01

    Background Conventional cytology (Pap) and visual inspection after the application of acetic acid (VIA) are currently used in primary screening in Peru. Studies suggest that the quality of VIA is highly variable. Over 36 000 women were screened with Pap and VIA in the TATI (Tamizaje y Tratamiento Inmediato de Lesiones Cervico-uterinas) project conducted in Amazonian Peru. Within a nested study to compare several screening techniques (C-TATI), a total of 5435 women were additionally screened with liquid-based cytology (LBC) and high-risk human papillomavirus testing (HR-HPV). We investigate the variation of positivity rates of VIA, Pap, LBC and HR-HPV in C-TATI and of VIA in the full TATI intervention. Methods At the screening visit, midwives collected three cervical samples for Pap, LBC and HC2 before performing VIA. The dispersion factor “D” (D = Pearson chi-square value/degrees-of-freedom) was used to measure the variability of tests results. Within C-TATI, the variability of positivity rates of VIA, Pap, LBC and HR-HPV was also graphically assessed with box- and scatter plots by midwife and month of screening. Funnel plots and smoothed scatter plots were used to correlate the variation of VIA by the number of examinations performed by each midwife over the full TATI intervention. Results Consistently over TATI, VIA results were highly variable, independently of the examiner, the time when the test was performed and the number of tests the examiner performed (D>6, p-values25, p-values0.05 for HR-HPV). No evidence for correlation between the number of VIAs done per midwife and the variability of VIA results was observed. Conclusion The lack of over-dispersion for HR-HPV detection suggests that the variable VIA results do not reflect true variation in underlying disease, but a lack of consistency in human judgement. PMID:25635965

  14. Evaluating the nodulation status of leguminous species from the Amazonian forest of Brazil.

    Science.gov (United States)

    de Faria, Sergio M; Diedhiou, Abdala G; de Lima, Haroldo C; Ribeiro, Robson D; Galiana, Antoine; Castilho, Alexandre F; Henriques, João C

    2010-06-01

    Numerous leguminous species are used or have potential uses for timber production, pharmacological products, or land reclamation. Through N(2)-fixation, many leguminous trees contribute to the N-balance of tropical wetlands and rainforests. Therefore, studies of the N(2)-fixation ability of leguminous species appear to be crucial for the better use and conservation of these resources. The global nodulation inventory in the Leguminosae family is constantly being enriched with new records, suggesting the existence of undiscovered nodulated species, especially in tropical natural ecosystems and other hot spots of biodiversity. In this respect, the nodulation of leguminous species from the Amazonian forest of Porto Trombetas (Brazil) was surveyed. Overall, 199 leguminous species from flooded and non-flooded areas, were examined for their nodulation status by combining field observations, seedling inoculations, and screening of N(2)-fixing bacterial strains from the collected nodules. The results revealed a tendency for a higher relative frequency of nodulation in the species from the flooded areas (74%) compared with those from the non-flooded areas (67%). Nodulation was observed in the Caesalpinioideae, Mimosoideae, and Papilionoideae, with 25, 88, and 84% of the examined species in each subfamily, respectively. Of the 137 nodulated leguminous species, 32 including three Caesalpinoideae, 19 Mimosoideae, and 10 Papilionoideae are new records. One new nodulated genus (Cymbosema) was found in the Papilionoideae. Twelve non-nodulating leguminous species were also observed for the first time. The results are discussed based on the systematics of the Leguminosae family and the influence of available nutrients to the legume-bacteria symbiosis.

  15. Leaf level emissions of volatile organic compounds (VOC from some Amazonian and Mediterranean plants

    Directory of Open Access Journals (Sweden)

    A. Bracho-Nunez

    2013-09-01

    Full Text Available Emission inventories defining regional and global biogenic volatile organic compounds (VOC emission strengths are needed to determine the impact of VOC on atmospheric chemistry (oxidative capacity and physics (secondary organic aerosol formation and effects. The aim of this work was to contribute with measurements of tree species from the poorly described tropical vegetation in direct comparison with the quite well-investigated, highly heterogeneous emissions from Mediterranean vegetation. VOC emission from sixteen plant species from the Mediterranean area were compared with twelve plant species from different environments of the Amazon basin by an emission screening at leaf level using branch enclosures. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was the most dominant compound emitted followed by monoterpenes, methanol and acetone. The average loss rates of VOC carbon in relation to the net CO2 assimilation were found below 4% and indicating normal unstressed plant behavior. Most of the Mediterranean species emitted a large variety of monoterpenes, whereas only five tropical species were identified as monoterpene emitters exhibiting a quite conservative emission pattern (α-pinene < limonene < sabinene < ß-pinene. Mediterranean plants showed additional emissions of sesquiterpenes. In the case of Amazonian plants no sesquiterpenes were detected. However, missing of sesquiterpenes may also be due to a lack of sensitivity of the measuring systems. Furthermore, our screening activities cover only 1% of tree species of such tropical areas as estimated based on recent biodiversity reports. Methanol emissions, an indicator of growth, were found to be common in most of the tropical and Mediterranean species. A few species from both ecosystems showed acetone emissions. The observed

  16. Downstream impacts of a Central Amazonian hydroelectric dam on tree growth and mortality in floodplain forests

    Science.gov (United States)

    Resende, A. F. D.; Silva, T. S. F.; Silva, J. D. S.; Piedade, M. T. F.; Streher, A. S.; Ferreira-Ferreira, J.; Schongart, J.

    2017-12-01

    The flood pulse of large Amazonian Rivers is characterized by predictable high- and low-water periods during the annual cycle, and is the main driving force in the floodplains regulating decomposition, nutrient cycles, productivity, life cycles and growth rhythms of floodplains' biota. Over at least 20 millions of years, tree species in these ecosystems developed complex adaptative mechanisms to tolerate flooding, such as the tree species Macrolobium acaciifolium (Fabaceae) and Eschweilera tenuifolia (Lecythidaceae) occupying the lower topographic positions in the floodplain forests along the oligothrophic black-water rivers. Tree growth occurs mainly during terrestrial phase, while during the aquatic phase the anoxic conditions result into a cambial dormancy and formation of annual tree rings. The hydroelectric dam Balbina which was installed in the Uatumã River (central Amazonia) during the 1980s altered significantly the flood pulse regime resulting into higher minimum and lower maximum annual water levels. The suppression of the terrestrial phase caused large-scale mortality of flood-adapted trees growing on the lower topographic positions, as evidenced by radiocarbon dating and cross-dating techniques (dendrochronology). In this study we estimated the extension of dead forests using high resolution ALOS/PALSAR radar images, for their detection along a fluvial distance of more than 280 km downstream of the power plant. Further we analyzed tree growth of 60 living individuals of E. tenuifolia by tree-ring analyses comparing the post- and pre-dam periods. We evaluated the impacts of the altered hydrological regime on tree growth considering ontogenetic effects and the fluvial distance of the trees to the dam. Since the Balbina power plant started operating the associated igapó forests lost about 11% of its cover. We found a significant reduction of tree growth of E. tenuifolia during the post-dam period as a consequence of the increasing aquatic phase duration

  17. Resilient Networks of Ant-Plant Mutualists in Amazonian Forest Fragments

    Science.gov (United States)

    Passmore, Heather A.; Bruna, Emilio M.; Heredia, Sylvia M.; Vasconcelos, Heraldo L.

    2012-01-01

    Background The organization of networks of interacting species, such as plants and animals engaged in mutualisms, strongly influences the ecology and evolution of partner communities. Habitat fragmentation is a globally pervasive form of spatial heterogeneity that could profoundly impact the structure of mutualist networks. This is particularly true for biodiversity-rich tropical ecosystems, where the majority of plant species depend on mutualisms with animals and it is thought that changes in the structure of mutualist networks could lead to cascades of extinctions. Methodology/Principal Findings We evaluated effects of fragmentation on mutualistic networks by calculating metrics of network structure for ant-plant networks in continuous Amazonian forests with those in forest fragments. We hypothesized that networks in fragments would have fewer species and higher connectance, but equal nestedness and resilience compared to forest networks. Only one of the nine metrics we compared differed between continuous forest and forest fragments, indicating that networks were resistant to the biotic and abiotic changes that accompany fragmentation. This is partially the result of the loss of only specialist species with one connection that were lost in forest fragments. Conclusions/Significance We found that the networks of ant-plant mutualists in twenty-five year old fragments are similar to those in continuous forest, suggesting these interactions are resistant to the detrimental changes associated with habitat fragmentation, at least in landscapes that are a mosaic of fragments, regenerating forests, and pastures. However, ant-plant mutualistic networks may have several properties that may promote their persistence in fragmented landscapes. Proactive identification of key mutualist partners may be necessary to focus conservation efforts on the interactions that insure the integrity of network structure and the ecosystems services networks provide. PMID:22912666

  18. Low plant density enhances gene dispersal in the Amazonian understory herb Heliconia acuminata.

    Science.gov (United States)

    Côrtes, Marina C; Uriarte, María; Lemes, Maristerra R; Gribel, Rogério; Kress, W John; Smouse, Peter E; Bruna, Emilio M

    2013-11-01

    In theory, conservation genetics predicts that forest fragmentation will reduce gene dispersal, but in practice, genetic and ecological processes are also dependent on other population characteristics. We used Bayesian genetic analyses to characterize parentage and propagule dispersal in Heliconia acuminata L. C. Richard (Heliconiaceae), a common Amazonian understory plant that is pollinated and dispersed by birds. We studied these processes in two continuous forest sites and three 1-ha fragments in Brazil's Biological Dynamics of Forest Fragments Project. These sites showed variation in the density of H. acuminata. Ten microsatellite markers were used to genotype flowering adults and seedling recruits and to quantify realized pollen and seed dispersal distances, immigration of propagules from outside populations, and reproductive dominance among parents. We tested whether gene dispersal is more dependent on fragmentation or density of reproductive plants. Low plant densities were associated with elevated immigration rates and greater propagule dispersal distances. Reproductive dominance among inside-plot parents was higher for low-density than for high-density populations. Elevated local flower and fruit availability is probably leading to spatially more proximal bird foraging and propagule dispersal in areas with high density of reproductive plants. Nevertheless, genetic diversity, inbreeding coefficients and fine-scale spatial genetic structure were similar across populations, despite differences in gene dispersal. This result may indicate that the opposing processes of longer dispersal events in low-density populations vs. higher diversity of contributing parents in high-density populations balance the resulting genetic outcomes and prevent genetic erosion in small populations and fragments.

  19. Asymmetric dispersal and colonization success of Amazonian plant-ants queens.

    Science.gov (United States)

    Bruna, Emilio M; Izzo, Thiago J; Inouye, Brian D; Uriarte, Maria; Vasconcelos, Heraldo L

    2011-01-01

    The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants. We used empirical data and inverse modeling--a technique developed by plant ecologists to model seed dispersal--to quantify and compare the dispersal kernels of queens from three Amazonian ant species that compete for access to host-plants. We found that the modal colonization distance of queens varied 8-fold, with the generalist ant species (Crematogaster laevis) having a greater modal distance than two specialists (Pheidole minutula, Azteca sp.) that use the same host-plants. However, our results also suggest that queens of Azteca sp. have maximal distances that are four-sixteen times greater than those of its competitors. We found large differences between ant species in both the modal and maximal distance ant queens disperse to find vacant seedlings used to found new colonies. These differences could result from interspecific differences in queen body size, and hence wing musculature, or because queens differ in their ability to identify potential host plants while in flight. Our results provide support for one of the necessary conditions underlying several of the hypothesized mechanisms promoting coexistence in tropical plant-ants. They also suggest that for some ant species limited dispersal capability could pose a significant barrier to the rescue of populations in isolated forest fragments. Finally, we demonstrate that inverse models parameterized with field data are an excellent means of quantifying the dispersal of ant queens.

  20. Diurnal cortisol rhythms in Tsimane' Amazonian foragers: new insights into ecological HPA axis research.

    Science.gov (United States)

    Nyberg, Colleen H

    2012-02-01

    Although a growing body of research has documented important pathways by which the HPA axis mediates the interface between the psychosocial world and individual health, there is a paucity of data from nonwestern populations, particularly from those populations with distinct nutritional and infectious disease ecologies. The specific objectives of this study are: (1) to document variation in diurnal cortisol rhythms among the Tsimane', a remote population in the Bolivian Amazon, (2) to explore this variation by age and by gender, and (3) to compare diurnal rhythms from this study to other population based studies of cortisol conducted in industrialized nations. Salivary cortisol samples were collected twice daily, immediately upon waking and before bed, for three consecutive days from 303 participants (age 1.6-82 years, 1564 samples) in conjunction with the Tsimane' Amazonian Panel Study (TAPS). Cortisol rhythms showed strong age effects across the developmental span, with basal levels and slopes increasing into adulthood, although individuals older than 60 years demonstrated a precipitous flattening of the diurnal slope. Cortisol profiles were elevated in adult females compared to their age-matched male counterparts, and diurnal slopes, as well as mean cortisol concentrations among the Tsimane' were the lowest reported in any population based study of HPA axis function. Although the within-population variation in cortisol profiles was consistent with the established correlates of time of day, age, and sex, the between-population comparisons revealed dramatically lower levels of HPA activity among the Tsimane'. This study provides a benchmark against which to reference cortisol levels from industrialized populations, and expands the range of documented variation in HPA axis function in a nonwestern context. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Indifference to dissonance in native Amazonians reveals cultural variation in music perception.

    Science.gov (United States)

    McDermott, Josh H; Schultz, Alan F; Undurraga, Eduardo A; Godoy, Ricardo A

    2016-07-28

    by biology remains debated. One widely discussed phenomenon is that some combinations of notes are perceived by Westerners as pleasant, or consonant, whereas others are perceived as unpleasant,or dissonant. The contrast between consonance and dissonance is central to Western music and its origins have fascinated scholars since the ancient Greeks. Aesthetic responses to consonance are commonly assumed by scientists to have biological roots, and thus to be universally present in humans. Ethnomusicologists and composers, in contrast, have argued that consonance is a creation of Western musical culture. The issue has remained unresolved, partly because little is known about the extent of cross-cultural variation in consonance preferences. Here we report experiments with the Tsimane'--a native Amazonian society with minimal exposure to Western culture--and comparison populations in Bolivia and the United States that varied in exposure to Western music. Participants rated the pleasantness of sounds. Despite exhibiting Western-like discrimination abilities and Western-like aesthetic responses to familiar sounds and acoustic roughness, the Tsimane' rated consonant and dissonant chords and vocal harmonies as equally pleasant. By contrast, Bolivian city- and town-dwellers exhibited significant preferences for consonance,albeit to a lesser degree than US residents. The results indicate that consonance preferences can be absent in cultures sufficiently isolated from Western music, and are thus unlikely to reflect innate biases or exposure to harmonic natural sounds. The observed variation in preferences is presumably determined by exposure to musical harmony, suggesting that culture has a dominant role in shaping aesthetic responses to music.

  2. Amazonian Triatomine Biodiversity and the Transmission of Chagas Disease in French Guiana: In Medio Stat Sanitas.

    Science.gov (United States)

    Péneau, Julie; Nguyen, Anne; Flores-Ferrer, Alheli; Blanchet, Denis; Gourbière, Sébastien

    2016-02-01

    The effects of biodiversity on the transmission of infectious diseases now stand as a cornerstone of many public health policies. The upper Amazonia and Guyana shield are hot-spots of biodiversity that offer genuine opportunities to explore the relationship between the risk of transmission of Chagas disease and the diversity of its triatomine vectors. Over 730 triatomines were light-trapped in four geomorphological landscapes shaping French-Guiana, and we determined their taxonomic status and infection by Trypanosoma cruzi. We used a model selection approach to unravel the spatial and temporal variations in species abundance, diversity and infection. The vector community in French-Guiana is typically made of one key species (Panstrongylus geniculatus) that is more abundant than three secondary species combined (Rhodnius pictipes, Panstrongylus lignarius and Eratyrus mucronatus), and four other species that complete the assemblage. Although the overall abundance of adult triatomines does not vary across French-Guiana, their diversity increases along a coastal-inland gradient. These variations unravelled a non-monotonic relationship between vector biodiversity and the risk of transmission of Chagas disease, so that intermediate biodiversity levels are associated with the lowest risks. We also observed biannual variations in triatomine abundance, representing the first report of a biannual pattern in the risk of Chagas disease transmission. Those variations were highly and negatively correlated with the average monthly rainfall. We discuss the implications of these patterns for the transmission of T. cruzi by assemblages of triatomine species, and for the dual challenge of controlling Amazonian vector communities that are made of both highly diverse and mostly intrusive species.

  3. Near Infrared Spectroscopy Facilitates Rapid Identification of Both Young and Mature Amazonian Tree Species.

    Directory of Open Access Journals (Sweden)

    Carla Lang

    Full Text Available Precise identification of plant species requires a high level of knowledge by taxonomists and presence of reproductive material. This represents a major limitation for those working with seedlings and juveniles, which differ morphologically from adults and do not bear reproductive structures. Near-infrared spectroscopy (FT-NIR has previously been shown to be effective in species discrimination of adult plants, so if young and adults have a similar spectral signature, discriminant functions based on FT-NIR spectra of adults can be used to identify leaves from young plants. We tested this with a sample of 419 plants in 13 Amazonian species from the genera Protium and Crepidospermum (Burseraceae. We obtained 12 spectral readings per plant, from adaxial and abaxial surfaces of dried leaves, and compared the rate of correct predictions of species with discriminant functions for different combinations of readings. We showed that the best models for predicting species in early developmental stages are those containing spectral data from both young and adult plants (98% correct predictions of external samples, but even using only adult spectra it is still possible to attain good levels of identification of young. We obtained an average of 75% correct identifications of young plants by discriminant equations based only on adults, when the most informative wavelengths were selected. Most species were accurately predicted (75-100% correct identifications, and only three had poor predictions (27-60%. These results were obtained despite the fact that spectra of young individuals were distinct from those of adults when species were analyzed individually. We concluded that FT-NIR has a high potential in the identification of species even at different ontogenetic stages, and that young plants can be identified based on spectra of adults with reasonable confidence.

  4. Carbon economics of LAI drive photosynthesis patterns across an Amazonian precipitation gradient

    Science.gov (United States)

    Flack, Sophie; Williams, Mathew; Meir, Patrick; Malhi, Yadvinder

    2017-04-01

    The Amazon rainforest is an integral part of the terrestrial carbon cycle, yet whilst the physiological response of its plants to water availability is increasingly well quantified, constraints to photosynthesis through adaptive response to precipitation regime have received little attention. We use the Soil Plant Atmosphere model to apportion variation in photosynthesis to individual drivers for plots with detailed measurements of carbon cycling, leaf traits and canopy properties, along an Amazonian mean annual precipitation (MAP) gradient. We hypothesised that leaf area index (LAI) would be the principal driver of variation in photosynthesis. Differences in LAI are predicted to result from economic factors; plants balance the carbon cost of leaf construction and maintenance with assimilation potential, to maximise canopy carbon export. Model analysis showed that LAI was the primary driver of differences in GPP along the precipitation gradient, accounting for 49% of observed variation. Meteorology accounted for 19%, whilst plant traits accounted for only 5%. To explain the observed spatial trends in LAI we undertook model experiments. For each plot the carbon budget was quantified iteratively using the field measured LAI time-series of the other plots, keeping meteorology, soil and plant traits constant. The mean annual LAI achieving maximum photosynthesis and net canopy carbon export increased with MAP, reflecting observed LAI trends. At the driest site, alternative, higher LAI strategies were unsustainable. The carbon cost of leaf construction and maintenance was disproportional to GPP achieved. At high MAP, increased foliar carbon costs were remunerative and GPP was maximised by high LAI. Our evidence therefore suggests that observed LAI trends across the precipitation gradient are driven by carbon economics. Forests LAI response to temporal changes in precipitation reflects trends observed across spatial gradients, identifying LAI as a key mechanism for plant

  5. Abrupt Increases in Amazonian Tree Mortality Due to Drought-Fire Interactions

    Science.gov (United States)

    Brando, Paulo Monteiro; Balch, Jennifer K.; Nepstad, Daniel C.; Morton, Douglas C.; Putz, Francis E.; Coe, Michael T.; Silverio, Divino; Macedo, Marcia N.; Davidson, Eric A.; Nobrega, Caroline C.; hide

    2014-01-01

    Interactions between climate and land-use change may drive widespread degradation of Amazonian forests. High-intensity fires associated with extreme weather events could accelerate this degradation by abruptly increasing tree mortality, but this process remains poorly understood. Here we present, to our knowledge, the first field-based evidence of a tipping point in Amazon forests due to altered fire regimes. Based on results of a large-scale, longterm experiment with annual and triennial burn regimes (B1yr and B3yr, respectively) in the Amazon, we found abrupt increases in fire-induced tree mortality (226 and 462%) during a severe drought event, when fuel loads and air temperatures were substantially higher and relative humidity was lower than long-term averages. This threshold mortality response had a cascading effect, causing sharp declines in canopy cover (23 and 31%) and aboveground live biomass (12 and 30%) and favoring widespread invasion by flammable grasses across the forest edge area (80 and 63%), where fires were most intense (e.g., 220 and 820 kW x m(exp -1)). During the droughts of 2007 and 2010, regional forest fires burned 12 and 5% of southeastern Amazon forests, respectively, compared with less than 1% in nondrought years. These results show that a few extreme drought events, coupled with forest fragmentation and anthropogenic ignition sources, are already causing widespread fire-induced tree mortality and forest degradation across southeastern Amazon forests. Future projections of vegetation responses to climate change across drier portions of the Amazon require more than simulation of global climate forcing alone and must also include interactions of extreme weather events, fire, and land-use change.

  6. Effect of interannual climate variability on carbon storage in Amazonian ecosystems

    Science.gov (United States)

    Tian, H.; Melillo, J.M.; Kicklighter, D.W.; McGuire, David A.; Helfrich, J. V. K.; Moore, B.; Vorosmarty, C.J.

    1998-01-01

    The Amazon Basin contains almost one-half of the world's undisturbed tropical evergreen forest as well as large areas of tropical savanna. The forests account for about 10 per cent of the world's terrestrial primary productivity and for a similar fraction of the carbon stored in land ecosystems, and short-term field measurements suggest that these ecosystems are globally important carbon sinks. But tropical land ecosystems have experienced substantial interannual climate variability owing to frequent El Nino episodes in recent decades. Of particular importance to climate change policy is how such climate variations, coupled with increases in atmospheric CO2 concentration, affect terrestrial carbon storage. Previous model analyses have demonstrated the importance of temperature in controlling carbon storage. Here we use a transient process-based biogeochemical model of terrestrial ecosystems to investigate interannual variations of carbon storage in undisturbed Amazonian ecosystems in response to climate variability and increasing atmospheric CO2 concentration during the period 1980 to 1994. In El Nino years, which bring hot, dry weather to much of the Amazon region, the ecosystems act as a source of carbon to the atmosphere (up to 0.2 petagrams of carbon in 1987 and 1992). In other years, these ecosystems act as a carbon sink (up to 0.7 Pg C in 1981 and 1993). These fluxes are large; they compare to a 0.3 Pg C per year source to the atmosphere associated with deforestation in the Amazon Basin in the early 1990s. Soil moisture, which is affected by both precipitation and temperature, and which affects both plant and soil processes, appears to be an important control on carbon storage.

  7. High Species Richness of Scinax Treefrogs (Hylidae) in a Threatened Amazonian Landscape Revealed by an Integrative Approach

    Science.gov (United States)

    Ferrão, Miquéias; Colatreli, Olavo; de Fraga, Rafael; Kaefer, Igor L.; Moravec, Jiří; Lima, Albertina P.

    2016-01-01

    Rising habitat loss is one of the main drivers of the global amphibian decline. Nevertheless, knowledge of amphibian diversity needed for effective habitat protection is still highly inadequate in remote tropical regions, the greater part of the Amazonia. In this study we integrated molecular, morphological and bioacoustic evidence to evaluate the species richness of the treefrogs genus Scinax over a 1000 km transect across rainforest of the Purus-Madeira interfluve, and along the east bank of the upper Madeira river, Brazilian Amazonia. Analysis revealed that 82% of the regional species richness of Scinax is still undescribed; two nominal species, seven confirmed candidate species, two unconfirmed candidate species, and one deep conspecific lineage were detected in the study area. DNA barcoding based analysis of the 16s rRNA gene indicates possible existence of three discrete species groups within the genus Scinax, in addition to the already-known S. rostratus species Group. Quantifying and characterizing the number of undescribed Scinax taxa on a regional scale, we provide a framework for future taxonomic study in Amazonia. These findings indicate that the level to which Amazonian anura species richness has been underestimated is far greater than expected. Consequently, special attention should be paid both to taxonomic studies and protection of the still-neglected Amazonian Scinax treefrogs. PMID:27806089

  8. PERCEPTIONS AND REPRESENTATIONS OF THE FOREIGN AUTHOR ABOUT AMAZONIAN MAN: AN ANALYSIS UNDER THE CATEGORIES OF GEOGRAPHY

    Directory of Open Access Journals (Sweden)

    Klondy Lúcia de Oliveira Agra

    2013-07-01

    Full Text Available In this article, I analyze, with aid of the concepts guide for the geographical science, two works by Americans over the Brazilian Amazon. Amazon Town of Charles Wagley, and the travel journal of American George E. Hafstad. Works which exposes the Brazilian Amazon and way of life of its people, describing in detail actions, habits, thoughts and beliefs, way of acting man Amazonian descriptions that form a backdrop of compositions and orientations of Amazon to the world. The main objective of this paper is to check the perceptions and representations of foreign researchers to translate Amazon contexts and scenarios to your community, with the help of the notions of space, place, landscape and territory. Interest in the analysis of these materials is due to singular description of Amazonian details that demonstrate the concern of foreign technicians involved with research in the Brazilian Amazon, between the years 1940 to 1950, with reading contexts and scenarios and detailed translation of the analyzed reality to their community, and also by the possibility of observation and demystification of misunderstandings made by these researchers and the rescue of cultural and historical values of this region.

  9. Soil transmitted helminthiasis in indigenous groups. A community cross sectional study in the Amazonian southern border region of Ecuador

    Science.gov (United States)

    Romero-Sandoval, Natalia; Ortiz-Rico, Claudia; Sánchez-Pérez, Héctor Javier; Valdivieso, Daniel; Sandoval, Carlos; Pástor, Jacob; Martín, Miguel

    2017-01-01

    Background Rural communities in the Amazonian southern border of Ecuador have benefited from governmental social programmes over the past 9 years, which have addressed, among other things, diseases associated with poverty, such as soil transmitted helminth infections. The aim of this study was to explore the prevalence of geohelminth infection and several factors associated with it in these communities. Methods This was a cross sectional study in two indigenous communities of the Amazonian southern border of Ecuador. The data were analysed at both the household and individual levels. Results At the individual level, the prevalence of geohelminth infection reached 46.9% (95% CI 39.5% to 54.2%), with no differences in terms of gender, age, temporary migration movements or previous chemoprophylaxis. In 72.9% of households, one or more members were infected. Receiving subsidies and overcrowding were associated with the presence of helminths. Conclusions The prevalence of geohelminth infection was high. Our study suggests that it is necessary to conduct studies focusing on communities, and not simply on captive groups, such as schoolchildren, with the object of proposing more suitable and effective strategies to control this problem. PMID:28292765

  10. Land use and land cover change impacts on the regional climate of non-Amazonian South America: A review

    Science.gov (United States)

    Salazar, Alvaro; Baldi, Germán; Hirota, Marina; Syktus, Jozef; McAlpine, Clive

    2015-05-01

    Land use and land cover change (LUCC) affects regional climate through modifications in the water balance and energy budget. These impacts are frequently expressed by: changes in the amount and frequency of precipitation and alteration of surface temperatures. In South America, most of the studies of the effects of LUCC on the local and regional climate have focused on the Amazon region (54 studies), whereas LUCC within non-Amazonian regions have been largely undermined regardless their potential importance in regulating the regional climate (19 studies). We estimated that 3.6 million km2 of the original natural vegetation cover in non-Amazonian South America were converted into other types of land use, which is about 4 times greater than the historical Amazon deforestation. Moreover, there is evidence showing that LUCC within such fairly neglected ecosystems cause significant reductions in precipitation and increases in surface temperatures, with occasional impacts affecting neighboring or remote areas. We explore the implications of these findings in the context of water security, climatic extremes and future research priorities.

  11. Palaeontological evidence for the last temporal occurrence of the ancient western Amazonian river outflow into the Caribbean.

    Science.gov (United States)

    Aguilera, Orangel; Lundberg, John; Birindelli, Jose; Sabaj Pérez, Mark; Jaramillo, Carlos; Sánchez-Villagra, Marcelo R

    2013-01-01

    Fossil catfishes from fluvio-lacustrine facies of late Miocene Urumaco, early Pliocene Castilletes and late Pliocene San Gregorio formations provide evidence of a hydrographic connection in what is today desert regions of northern Colombia and Venezuela. New discoveries and reevaluation of existing materials leads to the recognition of two new records of the pimelodid Brachyplatystoma cf. vaillantii, and of three distinct doradid taxa: Doraops sp., Rhinodoras sp., and an unidentified third form. The presence of fossil goliath long-whiskered catfishes and thorny catfishes are indicative of the persistence of a fluvial drainage system inflow into the South Caribbean during the Pliocene/Pleistocene boundary, complementary to the previous western Amazonian hydrographic system described from the Middle Miocene Villavieja Formation in central Colombia and Late Miocene Urumaco Formation in northwestern Venezuela. The Pliocene Castilletes and San Gregorio formations potentially represent the last lithostratigraphic units related with an ancient western Amazonian fish fauna and that drainage system in the Caribbean. Alternatively, it may preserve faunas from a smaller, peripheral river basin that was cut off earlier from the Amazon-Orinoco, today found in the Maracaibo basin and the Magdalena Rivers.

  12. Palaeontological evidence for the last temporal occurrence of the ancient western Amazonian river outflow into the Caribbean.

    Directory of Open Access Journals (Sweden)

    Orangel Aguilera

    Full Text Available Fossil catfishes from fluvio-lacustrine facies of late Miocene Urumaco, early Pliocene Castilletes and late Pliocene San Gregorio formations provide evidence of a hydrographic connection in what is today desert regions of northern Colombia and Venezuela. New discoveries and reevaluation of existing materials leads to the recognition of two new records of the pimelodid Brachyplatystoma cf. vaillantii, and of three distinct doradid taxa: Doraops sp., Rhinodoras sp., and an unidentified third form. The presence of fossil goliath long-whiskered catfishes and thorny catfishes are indicative of the persistence of a fluvial drainage system inflow into the South Caribbean during the Pliocene/Pleistocene boundary, complementary to the previous western Amazonian hydrographic system described from the Middle Miocene Villavieja Formation in central Colombia and Late Miocene Urumaco Formation in northwestern Venezuela. The Pliocene Castilletes and San Gregorio formations potentially represent the last lithostratigraphic units related with an ancient western Amazonian fish fauna and that drainage system in the Caribbean. Alternatively, it may preserve faunas from a smaller, peripheral river basin that was cut off earlier from the Amazon-Orinoco, today found in the Maracaibo basin and the Magdalena Rivers.

  13. The 1590-1520 Ma Cachoeirinha magmatic arc and its tectonic implications for the Mesoproterozoic SW Amazonian craton crustal evolution

    Directory of Open Access Journals (Sweden)

    Ruiz Amarildo S.

    2004-01-01

    Full Text Available Isotopic and chemical data of rocks from the Cachoeirinha suite provide new insights on the Proterozoic evolution of the Rio Negro/Juruena Province in SW Amazonian craton. Six U-Pb and Sm-Nd analyses in granitoid rocks of the Cachoeirinha suite yielded ages of 1587-1522 Ma and T DM model ages of 1.88-1.75 Ga (EpsilonNd values of -0.8 to +1.0. In addition, three post-tectonic plutonic rocks yielded U-Pb ages from 1485-1389 Ma (T DM of 1.77-1.74 Ga and EpsilonNd values from -1.3 to +1.7. Variations in major and trace elements of the Cachoeirinha suite rocks indicate fractional crystallization process and magmatic arc geologic setting. These results suggest the following interpretations: (1 The interval of 1590-1520 Ma represents an important magmatic activity in SW Amazonian craton. (2 T DM and arc-related chemical affinity supportthe hypothesis that the rocks are genetically associated with an east-dipping subduction zone under the older (1.79-1.74 Ga continental margin. (3 The 1590-1520 Ma age of intrusive rocks adjacent to an older crust represents similar geological framework along the southern margin of Baltica, corroborating the hypothesis of tectonic relationship at that time.

  14. Differential expression of a retrotransposable element,Rex6, inColossoma macropomumfish from different Amazonian environments.

    Science.gov (United States)

    Barbosa, Cassiane Martins; Mareco, Edson Assunção; Silva, Maeli Dal Pai; Martins, Cesar; Alves-Costa, Fernanda Antunes

    2014-01-01

    Transposable elements (TEs) are DNA sequences that have the ability to move and replicate within the genomes. TEs can be classified according to their intermediates of transposition, RNA (retrotransposons) or DNA. In some aquatic organisms, it has been observed that environmental factors such as pH, temperature and pollution may stimulate differential transcription and mobilization of retrotransposons. In light of this information, the present study sought to evaluate the expression of Rex6 TE transcripts in Colossoma macropomum , which is a very commercially exploited fish in Brazil. In order to establish a comparative analysis using real-time PCR, the samples were collected from Amazonian rivers with different physical and chemical characteristics (distinguished by clear water and black water). Quantitative RT-PCR analyses revealed a differential pattern of expression between tissues collected from different types of water (clear and black waters). When it came to the hepatic and muscle tissues sampled, the levels of Rex6 transcripts were significantly different between the two Amazonian water types. These results suggest that environmental conditions operate differently in the regulation of Rex6 transcription in C. macropomum, results which have implications in the reshaping of the genome against environmental variations.

  15. Humic substances and crude oil induce cytochrome P450 1A expression in the Amazonian fish species Colossoma macropomum (Tambaqui).

    Science.gov (United States)

    Matsuo, Aline Y O; Woodin, Bruce R; Reddy, Christopher M; Val, Adalberto L; Stegeman, John J

    2006-04-15

    Cytochrome P450 1A (CYP1A) induction is used widely as a biomarker of exposure to pollutants, such as petroleum hydrocarbons, yet CYP1A inducibility has been characterized in few tropical fish. Using Western blot analysis, catalytic assay, and immunohistochemistry, we evaluated CYP1A induction in an Amazonian fish (tambaqui; Colossoma macropomum) acclimated to humic substances (HS) and acutely exposed to crude oil. HS are ubiquitous in Amazonian waters, and they are known to affect the bioavailability of pollutants. CYP1A activity was also measured in fish exposed for 10 days to a range of concentrations of HS from both natural and commercial sources. Crude oil induced CYP1A expression in tambaqui, as expected. Exposure to both HS and crude oil resulted in greater levels of CYP1A expression relative to that in fish exposed to petroleum alone. Interestingly, CYP1A induction was also observed in fish exposed to HS alone. Induction by HS was concentration-dependent, and activity was higher in fish exposed to HS from the commercial source than in fish exposed to the HS from the natural source. The use of CYP1A as a biomarker of exposure to pollutants such as petroleum hydrocarbons in fish living in environments rich in humic substances should be considered with caution given that HS themselves induce CYP1A expression. Our results suggest that there may be as yet unknown CYP1A inducing components (aryl hydrocarbon receptor agonists) in humic substances.

  16. Environmental impacts of the production of cast iron in the Amazonian region; O impacto ambiental da producao de ferro-gusa na Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Luczynski, Estanislau; Sauer, Ildo L. [Sao Paulo Univ., SP (Brazil). Inst. de Eletrotecnica e Energia

    1996-12-31

    The environmental problems created in the Brazilian Amazonian region by the use of wood fuel in the cast iron production plants are presented.The problems are related to air pollution, deforestation, soil erosion as well as the extinction of noble types of wood 10 refs., 3 figs., 5 tabs.

  17. Exploring eco-hydrological consequences of the Amazonian ecosystems under climate and land-use changes in the 21st century

    Science.gov (United States)

    Zhang, K.; Castanho, A. D.; Moghim, S.; Bras, R. L.; Coe, M. T.; Costa, M. H.; Levine, N. M.; Longo, M.; McKnight, S.; Wang, J.; Moorcroft, P. R.

    2012-12-01

    Deforestation and drought have imposed regional-scale perturbations onto Amazonian ecosystems and are predicted to cause larger negative impacts on the Amazonian ecosystems and associated regional carbon dynamics in the 21st century. However, global climate models (GCMs) vary greatly in their projections of future climate change in Amazonia, giving rise to uncertainty in the expected fate of the Amazon over the coming century. In this study, we explore the possible eco-hydrological consequences of the Amazonian ecosystems under projected climate and land-use changes in the 21st century using two state-of-the-art terrestrial ecosystem models—Ecosystem Demography Model 2.1(ED2.1) and Integrated Biosphere Simulator model (IBIS)—driven by three representative, bias-corrected climate projections from three IPCC GCMs (NCARPCM1, NCARCCSM3 and HadCM3), coupled with two land-use change scenarios (a business-as-usual and a strict governance scenario). We also analyze the relative roles of climate change, CO2 fertilization, land-use change and fire in driving the projected composition and structure of the Amazonian ecosystems. Our results show that CO2 fertilization enhances vegetation productivity and above-ground biomass (AGB) in the region, while land-use change and fire cause AGB loss and the replacement of forests by the savanna-like vegetation. The impacts of climate change depend strongly on the direction and severity of projected precipitation changes in the region. In particular, when intensified water stress is superimposed on unregulated deforestation, both ecosystem models predict large-scale dieback of Amazonian rainforests.

  18. Spatial Modeling of Flood Duration in Amazonian Floodplains Through Radar Remote Sensing and Generalized Linear Models

    Science.gov (United States)

    Ferreira-Ferreira, J.; Francisco, M. S.; Silva, T. S. F.

    2017-12-01

    Amazon floodplains play an important role in biodiversity maintenance and provide important ecosystem services. Flood duration is the prime factor modulating biogeochemical cycling in Amazonian floodplain systems, as well as influencing ecosystem structure and function. However, due to the absence of accurate terrain information, fine-scale hydrological modeling is still not possible for most of the Amazon floodplains, and little is known regarding the spatio-temporal behavior of flooding in these environments. Our study presents an new approach for spatial modeling of flood duration, using Synthetic Aperture Radar (SAR) and Generalized Linear Modeling. Our focal study site was Mamirauá Sustainable Development Reserve, in the Central Amazon. We acquired a series of L-band ALOS-1/PALSAR Fine-Beam mosaics, chosen to capture the widest possible range of river stage heights at regular intervals. We then mapped flooded area on each image, and used the resulting binary maps as the response variable (flooded/non-flooded) for multiple logistic regression. Explanatory variables were accumulated precipitation 15 days prior and the water stage height recorded in the Mamirauá lake gauging station observed for each image acquisition date, Euclidean distance from the nearest drainage, and slope, terrain curvature, profile curvature, planform curvature and Height Above the Nearest Drainage (HAND) derived from the 30-m SRTM DEM. Model results were validated with water levels recorded by ten pressure transducers installed within the floodplains, from 2014 to 2016. The most accurate model included water stage height and HAND as explanatory variables, yielding a RMSE of ±38.73 days of flooding per year when compared to the ground validation sites. The largest disagreements were 57 days and 83 days for two validation sites, while remaining locations achieved absolute errors lower than 38 days. In five out of nine validation sites, the model predicted flood durations with

  19. Contributions of C3and C4plants to higher trophic levels in an Amazonian savanna.

    Science.gov (United States)

    Magnusson, William E; Carmozina de Araújo, M; Cintra, Renato; Lima, Albertina P; Martinelli, Luiz A; Sanaiotti, Tânia M; Vasconcelos, Heraldo L; Victoria, Reynaldo L

    1999-04-01

    We studied the energy flow from C 3 and C 4 plants to higher trophic levels in a central Amazonian savanna by comparing the carbon stable-isotope ratios of potential food plants to the isotope ratios of species of different consumer groups. All C 4 plants encountered in our study area were grasses and all C 3 plants were bushes, shrubs or vines. Differences in δ 13 C ratios among bushes (x¯ = -30.8, SD = 1.2), vines (x¯ = -30.7, SD = 0.46) and trees (x¯ = -29.7, SD = 1.5) were small. However the mean δ 13 C ratio of dicotyledonous plants (x¯ = -30.4, SD = 1.3) was much more negative than that of the most common grasses (x¯ = -13.4, SD = 0.27). The insect primary consumers had δ 13 C ratios which ranged from a mean of -29.5 (SD = 0.47) for the grasshopper Tropidacris collaris to a mean of -14.7 (SD = 0.56) for a termite (Nasutitermes sp.), a range similar to that of the vegetation. However, the common insectivorous and omnivorous vertebrates had intermediate values for δ 13 C, indicating that carbon from different autotrophic sources mixes rapidly as it moves up the food chain. Despite this mixing, the frogs and lizards generally had higher values of δ 13 C (x¯ = -21.7, SD = 1.6; x¯ = -21.9, SD = 1.8, respectively) than the birds (x¯ = -24.8, SD = 1.8) and the only species of mammal resident in the savanna (x¯ = -25.4), indicating that they are generally more dependent on, or more able to utilise, food chains based on C 4 grasses.

  20. Mushroom tyrosinase inhibitory activity and major fatty acid constituents of Amazonian native flora oils

    Directory of Open Access Journals (Sweden)

    Raquel da Silva Teixeira

    2012-09-01

    Full Text Available In order to treat hyperpigmentation-related problems, there has been a global trend in developing cosmetics claiming to have skin-whitening properties, which act by inhibiting melanin biosynthesis. The objective of this work was to evaluate the in vitro mushroom tyrosinase inhibitory activity of five Amazonian native flora oils, and so to verify the possibility of their incorporation into cosmetic products. In addition, the fatty acid composition of the essential oils was determined by gas chromatography-flame ionisation detection in order to determine the main components of these oils. The tyrosinase inhibitory activity of the tested oils was found to be in the following order: açaí (IA50 = 66.08 µg mL-1 > tucumã > patauá > pracaxi > castanha do Brasil. This study suggests that açaí oil has great potential in the treatment of hyperpigmentation and other related disorders, due to its considerable tyrosinase inhibitory activity.Com o intuito de se tratar problemas dermatológicos de hiperpigmentação, há uma tendência mundial no desenvolvimento de cosméticos que possuam propriedades despigmentantes, os quais agem inibindo a biossíntese de melanina. O objetivo deste trabalho foi avaliar in vitro a atividade de inibição da tirosinase de cogumelo de cinco óleos de plantas nativas da Amazônia e, desta forma, verificar a possibilidade de sua incorporação em produtos cosméticos. Ainda, a composição de ácidos graxos dos óleos foi determinada por cromatografia gasosa com detecção por ionização de chama, no intuito de determinar os principais componentes destes óleos. A atividade de inibição da tirosinase dos óleos testados foi encontrada na seguinte ordem: açaí (IA50 = 66,08 µg mL-1 > tucumã > patauá > pracaxi > castanha do Brasil. Este estudo sugere que o óleo de açaí possui grande potencial para o tratamento da hiperpigmentação cutânea e doenças correlatas, devido à sua considerável atividade de inibi

  1. Ecomorphological patterns of the fishes inhabiting the tide pools of the Amazonian Coastal Zone, Brazil

    Directory of Open Access Journals (Sweden)

    Bruno Eleres Soares

    Full Text Available The present study was based on the identification of the ecomorphological patterns that characterize the fish species found in tide pools in the Amazonian Coastal Zone (ACZ in the Pará State, Brazil. Representatives of 19 species were collected during two field campaigns in 2011. The dominance, residence status, and trophic guild of each species were established, and morphometric data were obtained for up to 10 specimens of each species. A total of 23 ecomorphological attributes related to locomotion, position in the water column, and foraging behavior were calculated for the analysis of ecomorphological distance. Principal Component Analysis (PCA was utilized for the evaluation of ecomorphological attributes that explained the variation among species. Mantel Test was used to correlate the taxonomic distance with species' morphological patterns and a partial Mantel Test to analyze the correlation among trophic guilds and ecomorphological patterns, controlling the effects of taxonomic distance among species. The analyses revealed two principal axes of the variation related to locomotion, correlated with the width of the caudal peduncle and the shape of the anal fin, as well as the influence of taxonomic distance on the ecomorphological characteristics of the different species. The dominant and resident species both presented a reduced capacity for continuous swimming. The two principal axes identified in relation to the position of the fish in the water column were correlated with the position of the eyes, the area of the pelvic fin, and body shape, with evidence of the influence of taxonomic distance on the morphology of the species. PCA grouped species with pelagic habits with benthonic ones. In the case of foraging behavior, the two principal axes formed by the analysis correlated with the size of the mouth, eye size, and the length of the digestive tract. Species of different guilds were grouped together, indicating a weak relationship

  2. Seasonal variation of reactive trace gas profiles in an Amazonian rainforest

    Science.gov (United States)

    Wolff, Stefan; Tsokankunku, Anywhere; Pöhlker, Christopher; Saturno, Jorge; Walter, David; Ditas, Florian; Könemann, Tobias; Ganzeveld, Laurens; de Abreu Sá, Leonardo Deane; Yañez-Serrano, Ana Maria; Ocimar Manzi, Antonio; Souza, Rodrigo; Trebs, Ivonne; Sörgel, Matthias

    2016-04-01

    In 2011, an 80 m high walk up tower for atmospheric research was erected at the ATTO (Amazon Tall Tower Observatory) site (02°08'38.8''S, 58°59'59.5''W) in the remote Amazonian rainforest. The nearly pristine environment allows biosphere-atmosphere studies within an ecosystem far away from large anthropogenic emission sources. Since April 2012 vertical mixing ratio profiles of H2O, CO2 and O3 were measured at 8 different heights between 0.05 m and 79.3 m. During five intensive campaigns (Oct-Dec 2012, Oct-Nov 2013, Mar 2014, Aug-Sep 2014, Oct-Dec 2015) nitric oxide (NO) and nitrogen dioxide (NO2) were also measured. Ozone values exhibit a clear seasonal cycle with lower values in the wet season (Jan-Apr) and higher values the drier seasons (Aug-Nov). The last months of 2015 were strongly influenced by a strong El Niño signal in the Pacific region, leading to much drier conditions and enhanced biomass burning in the Amazon also resulting in an extended period of higher O3 mixing ratios. Back trajectories were used to identify the influence of biomass burning on the formation of O3 at the ATTO site. The burning events were additionally confirmed by aerosol and VOC measurements. By correlating these different measurements we could identify clear seasonal differences regarding sources and sinks of aerosols and trace gases, whereas different regimes of O3 production and destruction within and above the canopy could be detected. NO peaks above canopy in the morning were related to export of below-canopy air that was enriched in NOx and CO2 and depleted in O3. Additional to the detailed concentration measurements, there have also been, O3 flux measurements during this campaign allowing a more detailed analysis of the O3 exchange between atmosphere and the canopy as well as the role of various mechanisms involved in atmosphere-biosphere exchange at the ATTO site.

  3. Lineage divergence detected in the malaria vector Anopheles marajoara (Diptera: Culicidae in Amazonian Brazil

    Directory of Open Access Journals (Sweden)

    Povoa Marinete M

    2010-10-01

    Full Text Available Abstract Background Cryptic species complexes are common among anophelines. Previous phylogenetic analysis based on the complete mtDNA COI gene sequences detected paraphyly in the Neotropical malaria vector Anopheles marajoara. The "Folmer region" detects a single taxon using a 3% divergence threshold. Methods To test the paraphyletic hypothesis and examine the utility of the Folmer region, genealogical trees based on a concatenated (white + 3' COI sequences dataset and pairwise differentiation of COI fragments were examined. The population structure and demographic history were based on partial COI sequences for 294 individuals from 14 localities in Amazonian Brazil. 109 individuals from 12 localities were sequenced for the nDNA white gene, and 57 individuals from 11 localities were sequenced for the ribosomal DNA (rDNA internal transcribed spacer 2 (ITS2. Results Distinct A. marajoara lineages were detected by combined genealogical analysis and were also supported among COI haplotypes using a median joining network and AMOVA, with time since divergence during the Pleistocene (COI sequences at the 3' end were more variable, demonstrating significant pairwise differentiation (3.82% compared to the more moderate 2.92% detected by the Folmer region. Lineage 1 was present in all localities, whereas lineage 2 was restricted mainly to the west. Mismatch distributions for both lineages were bimodal, likely due to multiple colonization events and spatial expansion (~798 - 81,045 ya. There appears to be gene flow within, not between lineages, and a partial barrier was detected near Rio Jari in Amapá state, separating western and eastern populations. In contrast, both nDNA data sets (white gene sequences with or without the retention of the 4th intron, and ITS2 sequences and length detected a single A. marajoara lineage. Conclusions Strong support for combined data with significant differentiation detected in the COI and absent in the nDNA suggest that

  4. Spatial distribution and functional significance of leaf lamina shape in Amazonian forest trees

    Directory of Open Access Journals (Sweden)

    A. C. M. Malhado

    2009-08-01

    Full Text Available Leaves in tropical forests come in an enormous variety of sizes and shapes, each of which can be ultimately viewed as an adaptation to the complex problem of optimising the capture of light for photosynthesis. However, the fact that many different shape "strategies" coexist within a habitat demonstrate that there are many other intrinsic and extrinsic factors involved, such as the differential investment in support tissues required for different leaf lamina shapes. Here, we take a macrogeographic approach to understanding the function of different lamina shape categories. Specifically, we use 106 permanent plots spread across the Amazon rainforest basin to: 1 describe the geographic distribution of some simple metrics of lamina shape in plots from across Amazonia, and; 2 identify and quantify relationships between key environmental parameters and lamina shape in tropical forests. Because the plots are not randomly distributed across the study area, achieving this latter objective requires the use of statistics that can account for spatial auto-correlation. We found that between 60–70% of the 2791 species and 83 908 individual trees in the dataset could be classified as having elliptic leaves (= the widest part of the leaf is on an axis in the middle fifth of the long axis of the leaf. Furthermore, the average Amazonian tree leaf is 2.5 times longer than it is wide and has an entire margin. Contrary to theoretical expectations we found little support for the hypothesis that narrow leaves are an adaptation to dry conditions. However, we did find strong regional patterns in leaf lamina length-width ratios and several significant correlations with precipitation variables suggesting that water availability may be exerting an as yet unrecognised selective pressure on leaf shape of rainforest trees. Some support was found for the hypothesis that narrow leaves are an adaptation to low nutrient soils. Furthermore, we found a strong correlation between

  5. The Northwest Africa 8159 martian meteorite: Expanding the martian sample suite to the early Amazonian

    Science.gov (United States)

    Herd, Christopher D. K.; Walton, Erin L.; Agee, Carl B.; Muttik, Nele; Ziegler, Karen; Shearer, Charles K.; Bell, Aaron S.; Santos, Alison R.; Burger, Paul V.; Simon, Justin I.; Tappa, Michael J.; McCubbin, Francis M.; Gattacceca, Jérôme; Lagroix, France; Sanborn, Matthew E.; Yin, Qing-Zhu; Cassata, William S.; Borg, Lars E.; Lindvall, Rachel E.; Kruijer, Thomas S.; Brennecka, Gregory A.; Kleine, Thorsten; Nishiizumi, Kunihiko; Caffee, Marc W.

    2017-12-01

    the early Amazonian.

  6. Color vision impairment with low-level methylmercury exposure of an Amazonian population - Brazil.

    Science.gov (United States)

    Feitosa-Santana, Claudia; Souza, Givago da Silva; Sirius, Esaú Ventura Pupo; Rodrigues, Anderson Raiol; Cortes, Maria Izabel Tentes; Silveira, Luiz Carlos de Lima; Ventura, Dora Fix

    2018-02-09

    public health policies that will ensure a safer environment for the Amazonian population. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Histological development of the digestive system of the Amazonian pimelodid catfish Pseudoplatystoma punctifer.

    Science.gov (United States)

    Gisbert, E; Moreira, C; Castro-Ruiz, D; Oztürk, S; Fernández, C; Gilles, S; Nuñez, J; Duponchelle, F; Tello, S; Renno, J F; García-Dávila, C; Darias, M J

    2014-11-01

    The organogenesis of the digestive system was described in the Amazonian pimelodid catfish species Pseudoplatystoma punctifer from hatching (3.5 mm total length, TL) to 41 days post-fertilization (dpf) (58.1 mm TL) reared at 28°C. Newly hatched larvae showed a simple digestive tract, which appeared as a straight undifferentiated and unfolded tube lined by a single layer of columnar epithelial cells (future enterocytes). During the endogenous feeding period, comprised between 20 and 96 h post-fertilization (3.5 to 6.1 mm TL), the larval digestive system experienced a fast transformation with the almost complete development and differentiation of most of digestive organs (buccopahrynx, oesophagus, intestine, liver and exocrine pancreas). Yolk reserves were not completely depleted at the onset of exogenous feeding (4 dpf, 6.1 mm TL), and a period of mixed nutrition was observed up to 6 to 7 dpf (6.8 to 7.3 mm TL) when yolk was definitively exhausted. The stomach was the organ that latest achieved its complete differentiation, characterized by the development of abundant gastric glands in the fundic stomach between 10 and 15 dpf (10.9 to 15.8 mm TL) and the formation of the pyloric sphincter at the junction of the pyloric stomach and the anterior intestine at 15 dpf (15.8 mm TL). The above-mentioned morphological and histological features observed suggested the achievement of a digestive system characteristic of P. punctifer juveniles and adults. The ontogeny of the digestive system in P. punctifer followed the same general pattern as in most Siluriform species so far, although some species-specific differences in the timing of differentiation of several digestive structures were noted, which might be related to different reproductive guilds, egg and larval size or even different larval rearing practices. According to present findings on the histological development of the digestive system in P. punctifer, some recommendations regarding the rearing practices of this

  8. Individual health and the visibility of village economic inequality: Longitudinal evidence from native Amazonians in Bolivia.

    Science.gov (United States)

    Undurraga, Eduardo A; Nica, Veronica; Zhang, Rebecca; Mensah, Irene C; Godoy, Ricardo A

    2016-12-01

    Mounting evidence suggests that income inequality is associated with worse individual health. But does the visibility of inequality matter? Using data from a horticultural-foraging society of native Amazonians in Bolivia (Tsimane'), we examined whether village inequality in resources and behaviors with greater cultural visibility is more likely to bear a negative association with health than village inequality in less conspicuous resources. We draw on a nine-year annual panel (2002-2010) from 13 Tsimane' villages for our main analysis, and an additional survey to gauge the cultural visibility of resources. We measured inequality using the Gini coefficient. We tested the robustness of our results using a shorter two-year annual panel (2008-2009) in another 40 Tsimane' villages and an additional measure of inequality (coefficient of variation, CV). Behaviors with low cultural visibility (e.g., household farm area planted with staples) were less likely to be associated with individual health, compared to more conspicuous behaviors (e.g., expenditures in durable goods, consumption of domesticated animals). We find some evidence that property rights and access to resources matter, with inequality of privately-owned resources showing a larger effect on health. More inequality was associated with improved perceived health - maybe due to improved health prospects from increasing wealth - and worse anthropometric indicators. For example, a unit increase in the Gini coefficient of expenditures in durable goods was associated with 0.24 fewer episodes of stress and a six percentage-point lower probability of reporting illness. A one-point increase in the CV of village inequality in meat consumption was associated with a 4 and 3 percentage-point lower probability of reporting illness and being in bed due to illness, and a 0.05 SD decrease in age-sex standardized arm-muscle area. In small-scale, rural societies at the periphery of market economies, nominal economic inequality in

  9. Math skills and market and non-market outcomes: Evidence from an Amazonian society of forager-farmers

    Science.gov (United States)

    Undurraga, Eduardo A.; Behrman, Jere R.; Grigorenko, Elena L.; Schultz, Alan; Yiu, Julie; Godoy, Ricardo A.

    2013-01-01

    Research in industrial nations suggests that formal math skills are associated with improvements in market and non-market outcomes. But do these associations also hold in a highly autarkic setting with a limited formal labor market? We examined this question using observational annual panel data (2008 and 2009) from 1,121 adults in a native Amazonian society of forager-farmers in Bolivia (Tsimane’). Formal math skills were associated with an increase in wealth in durable market goods and in total wealth between data collection rounds, and with improved indicators of own reported perceived stress and child health. These associations did not vary significantly by people’s Spanish skills or proximity to town. We conclude that the positive association between math skills and market and non-market outcomes extends beyond industrial nations to even highly autarkic settings. PMID:24327793

  10. Testing the Beta-Lognormal Model in Amazonian Rainfall Fields Using the Generalized Space q-Entropy

    Directory of Open Access Journals (Sweden)

    Hernán D. Salas

    2017-12-01

    Full Text Available We study spatial scaling and complexity properties of Amazonian radar rainfall fields using the Beta-Lognormal Model (BL-Model with the aim to characterize and model the process at a broad range of spatial scales. The Generalized Space q-Entropy Function (GSEF, an entropic measure defined as a continuous set of power laws covering a broad range of spatial scales, S q ( λ ∼ λ Ω ( q , is used as a tool to check the ability of the BL-Model to represent observed 2-D radar rainfall fields. In addition, we evaluate the effect of the amount of zeros, the variability of rainfall intensity, the number of bins used to estimate the probability mass function, and the record length on the GSFE estimation. Our results show that: (i the BL-Model adequately represents the scaling properties of the q-entropy, S q, for Amazonian rainfall fields across a range of spatial scales λ from 2 km to 64 km; (ii the q-entropy in rainfall fields can be characterized by a non-additivity value, q s a t, at which rainfall reaches a maximum scaling exponent, Ω s a t; (iii the maximum scaling exponent Ω s a t is directly related to the amount of zeros in rainfall fields and is not sensitive to either the number of bins to estimate the probability mass function or the variability of rainfall intensity; and (iv for small-samples, the GSEF of rainfall fields may incur in considerable bias. Finally, for synthetic 2-D rainfall fields from the BL-Model, we look for a connection between intermittency using a metric based on generalized Hurst exponents, M ( q 1 , q 2 , and the non-extensive order (q-order of a system, Θ q, which relates to the GSEF. Our results do not exhibit evidence of such relationship.

  11. Diversity and aspects of the ecology of social wasps (Vespidae, Polistinae in Central Amazonian "terra firme" forest

    Directory of Open Access Journals (Sweden)

    Alexandre Somavilla

    2014-12-01

    Full Text Available Diversity and aspects of the ecology of social wasps (Vespidae, Polistinae in Central Amazonian "terra firme" forest. The knowledge of social wasp richness and biology in the Amazonian region is considered insufficient. Although the Amazonas state is the largest in the region, until now only two brief surveys were conducted there. Considering that the systematic inventory of an area is the first step towards its conservation and wise use, this study presents faunal data on social wasp diversity in a 25 km² area of "terra firme" (upland forest at the Ducke Reserve, Manaus, Amazonas, Brazil. Wasps were collected in the understory, following a protocol of three collectors walking along 60 trails 1,000 m in extension for 16 days between August and October 2010. Methods used were active search of individuals with entomological nets and nest collecting. Fifty-eight species of social wasps, allocated in 13 genera, were recorded; 67% of the collected species belong to Polybia, Agelaia and Mischocyttarus; other genera were represented by only four species or less. The most frequent species in active searches were Agelaia fulvofasciata (DeGeer, 1773, Agelaia testacea (Fabricius, 1804 and Angiopolybia pallens (Lepeletier, 1836. Twelve species were collected in nests. Prior to this study, 65 Polistinae species were deposited at the INPA Collection. Collecting in the study grid, an area not previously sampled for wasps, resulted in an increase of 25% species, and species richness was 86. According to the results, there is evidence that the diversity of social wasps at the Ducke Reserve is even higher, making it one of the richest areas in the Brazilian Amazonia.

  12. Lipase catalyzed interesterification of Amazonian patauá oil and palm stearin for preparation of specific-structured oils.

    Science.gov (United States)

    Speranza, Paula; Ribeiro, Ana Paula Badan; Macedo, Gabriela Alves

    2015-12-01

    This study showed that enzymatic interesterification of Amazonian oils could be an important tool in order to produce new oils with physicochemical properties that improve the applications of these raw materials. Structured oils of Amazonian patauá oil and palm stearin using two lipases were produced in three different enzymatic systems: first, a crude lipase from the fungus Rhizopus sp (a microorganism isolated in our laboratory); second, a commercial lipase; and third, to check any synergistic effect, a mixture of both lipases (Rhizopus sp and commercial). The lipase from Rhizopus sp was specific in the incorporation of oleic acid at the sn-1,3 positions of the triacylglycerol, resulting in an oil richer in saturated fatty acid in the sn-2 position. This enzyme, produced by solid-state fermentation, even though crude, was fatty acid and positional specific and able to operate at low concentration (2.5 %, w/w). In the second enzyme system, the commercial lipase from Thermomyces lanuginosus was not specific in the tested conditions; there was no change in the distribution of saturated and unsaturated fatty acids in the three positions of the triacylglycerol profile, there was only a replacement by the type of fatty acid at the same position. In the third enzyme system, the mixture of both lipases shows no synergic effect. The structured oils retained the concentration of bioactive α- and γ- tocopherol in the three enzyme systems. Triacylglycerol classes and Thermal behavior tests indicated the formation of more homogeneous triacylglycerols, especially the mono and di-unsaturated.

  13. Implications for changes in Anopheles darlingi biting behaviour in three communities in the peri-Iquitos region of Amazonian Peru.

    Science.gov (United States)

    Moreno, Marta; Saavedra, Marlon P; Bickersmith, Sara A; Lainhart, William; Tong, Carlos; Alava, Freddy; Vinetz, Joseph M; Conn, Jan E

    2015-07-30

    Malaria transmission in the peri-Iquitos region of Amazonian Peru has been designated as seasonal and hypo-endemic with recently described hyper-endemic hotspots. Despite relatively recent distribution of long-lasting insecticidal bed nets (LLINs), malaria in Amazonian Peru persists and increased substantially in 2014 compared to previous years. Anopheles darlingi, identified as the main malaria vector, is known for its variable behaviour depending on locality and environment. To evaluate vector biology metrics in relation to seasonality and malaria transmission, mosquito collections were carried out in three localities in the peri-Iquitos region, Loreto, Peru in 2011-2012. Human landing catch (HLC) collection method, Shannon (SHA) and CDC trap types were compared for effectiveness in a neotropical setting. Abundance, human biting rate and entomological inoculation rate (EIR) were measured to provide an updated view of transmission patterns post-LLIN distribution. HLC collected significantly more anopheline mosquitoes than SHA and CDC light traps. Anopheles darlingi was the most prevalent species in all three villages (84% overall). Biting patterns varied depending on trap type, season and village. EIR varied temporally (monthly) and spatially and the highest (2.52) occurred during the 2012 malaria outbreak in Cahuide. Unexpectedly there was a high infection rate (1.47 and 1.75) outside the normal malaria transmission season, coincident with a second local outbreak in Cahuide. The first identification of Anopheles dunhami and Anopheles oswaldoi C in Peru, using molecular markers, is also reported in this study. These data underscore the importance of HLC as the most meaningful collection method for measuring vector biology indices in this region. The highest monthly EIR provides additional evidence of seasonal transmission in riverine localities correlated with high river levels, and An. darlingi as the only contributor to transmission. The trend of an increase in

  14. Apolipoprotein E4 is associated with improved cognitive function in Amazonian forager-horticulturalists with a high parasite burden.

    Science.gov (United States)

    Trumble, Benjamin C; Stieglitz, Jonathan; Blackwell, Aaron D; Allayee, Hooman; Beheim, Bret; Finch, Caleb E; Gurven, Michael; Kaplan, Hillard

    2017-04-01

    The apolipoprotein E4 (E4) allele is present worldwide, despite its associations with higher risk of cardiovascular morbidity, accelerated cognitive decline during aging, and Alzheimer 's disease (AD). The E4 allele is especially prevalent in some tropical regions with a high parasite burden. Equatorial populations also face a potential dual burden of high E4 prevalence combined with parasitic infections that can also reduce cognitive performance. We examined the interactions of E4, parasite burden, and cognitive performance in a traditional, nonindustrialized population of Amazonian forager-horticulturalists ( N = 372) to test whether E4 protects against cognitive decline in environments with a heavy pathogen burden. Contrary to observations in industrial populations, older adult E4 carriers with high parasite burdens either maintained or showed slight improvements in cognitive performance, whereas non-E4 carriers with a high parasite burden showed reduced cognitive performance. Being an E4 carrier is the strongest risk factor to date of AD and cognitive decline in industrial populations; it is associated with greater cognitive performance in individuals facing a high parasite and pathogen load, suggesting advantages to the E4 allele under certain environmental conditions. The current mismatch between postindustrial hygienic lifestyles and active parasite-rich environs may be critical for understanding genetic risk for cognitive aging.-Trumble, B. C., Stieglitz, J., Blackwell, A. D., Allayee, H., Beheim, B., Finch, C. E., Gurven, M., Kaplan, H. Apolipoprotein E4 is associated with improved cognitive function in Amazonian forager-horticulturalists with a high parasite burden. © FASEB.

  15. Observational Evidence for a Decade-long climate optimum near the Hesperian/Amazonian Transition

    Science.gov (United States)

    Parsons, R.; Moore, J. M.; Howard, A. D.

    2012-12-01

    Hesperian to Amazonian-aged valleys (HAVs) are predominantly found in the southern equatorial and mid-latitudes of Mars and form parallel to dendritic networks. These features record a significant warming of the regional/global climate which may have been associated with outflow channel formation and/or a period of alluvial fan deposition in Margaritifer Terra [1]. HAVs are distinct from older valley networks in both their age and morphology and they provide a window into the past climate conditions and potential water sources which formed them. Using quantitative geomorphic analysis we calculate the expected range of timescales, water volumes, precipitation rates and atmospheric conditions which contributed to HAV formation. In Newton crater (40oS, -159oE) we measured valley widths, depths, slopes and alluvial fan volumes. These observations, when combined with a set of terrestrial sediment transport prediction functions [2,3,4,5], allow us to calculate an expected duration of fluvial activity ranging from 0.1 to 10 years for water-filled channel depths ranging between 20 and 130 cm, and median sediment grain size ranging from 1 mm to 10 cm. The water volume required to form a single HAV in Newton crater ranges between 1.8 and 5.7~km3 based on the Darcy-Weisbach equation [6] in combination with the aforementioned range in channel depths, grain sizes and formation timescales. These results imply water runoff rates of between 1 to 10~cm/day over a typical, 300~km2, drainage area. Such a high runoff rate and short formation time suggest a brief, dramatic regional to global climate excursion. The source of water which formed these features remains unclear, but it must have been released at the aforementioned rates, and was widely distributed within each drainage catchment, and regionally over Newton crater and the southern highlands. HAV formation was likely a two-step process involving, first, the deposition of a 10s of meters thick regional snowpack along

  16. Nightly biting cycles of malaria vectors in a heterogeneous transmission area of eastern Amazonian Brazil.

    Science.gov (United States)

    Zimmerman, Robert H; Lounibos, L Philip; Nishimura, Naoya; Galardo, Allan K R; Galardo, Clicia D; Arruda, Mercia E

    2013-07-26

    kurtosis (g2) moments. Anopheles intermedius was usually, but not always, crepuscular in host seeking, and showed moderate mean V values and typically positive skewness and kurtosis. Among sites within villages, significant differences in frequencies of departures from normality (g1 and g2) were detected for An. marajoara and An. darlingi, suggesting that local environments, such as host availability, may affect the shape of biting pattern curves of these two species. Analyses of co-efficients of variation, skewness and kurtosis facilitated quantitative comparisons of host-seeking activity patterns that differ among species, sites, villages, and dates. The variable and heterogeneous nightly host-seeking behaviours of the five exophilic vector species contribute to the maintenance of stable malaria transmission in these Amazonian villages. The abundances of An. darlingi and An. marajoara, their propensities to seek hosts throughout the night, and their ability to adapt host-seeking behaviour to local environments, contribute to their impact as the most important of these vector species.

  17. Changes in the blood parameters of the Amazonian manatee (Trichechus inunguis after long-distance transportation - doi: 10.4025/actascibiolsci.v35i4.20081

    Directory of Open Access Journals (Sweden)

    Talita Laurie Lustosa do Carmo

    2013-07-01

    Full Text Available In this study we report the hematological, biochemical and hormonal parameters in a juvenile male Amazonian manatee measured before transport, immediately after transport, and during adaptation to a new facility. The animal was transported from Manaus, Amazonas, Brazil, to São Paulo, São Paulo, Brazil, (2,733 km within 6 hours. Among all blood parameters analyzed, we observed obvious neutrophilia, lymphopenia, and increases in the neutrophil/lymphocyte ratio and serum glucose and aspartate aminotransferase (AST levels, but these parameters subsequently returned to normal. These results suggest that transport and changes in the environment are temporary stressful events for Amazonian manatees. We, therefore, recommend monitoring the hematological and biochemical parameters before and after translocation to minimize the effects of handling stressors in this species

  18. ’These people aren’t first-class citizens’: Portrayal of Amazonian Indigenous Movements in El Peruano during the Bagua conflict

    OpenAIRE

    Granados Hidalgo, Isabel Nataly

    2015-01-01

    Contrary to the cases of Ecuador and Bolivia, where the indigenous population has managed to constitute successful ethnic movements and political parties, indigenous peoples in Peru have not been able to organize a permanent indigenous movements or to form ethnic parties, which could create and promote their own agendas. The failure of indigenous movement to participate in the public sphere was strikingly visible in the Bagua conflict, a confrontation between Amazonian indigenous movements an...

  19. A trans-Amazonian screening of mtDNA reveals deep intraspecific divergence in forest birds and suggests a vast underestimation of species diversity.

    Directory of Open Access Journals (Sweden)

    Borja Milá

    Full Text Available The Amazonian avifauna remains severely understudied relative to that of the temperate zone, and its species richness is thought to be underestimated by current taxonomy. Recent molecular systematic studies using mtDNA sequence reveal that traditionally accepted species-level taxa often conceal genetically divergent subspecific lineages found to represent new species upon close taxonomic scrutiny, suggesting that intraspecific mtDNA variation could be useful in species discovery. Surveys of mtDNA variation in Holarctic species have revealed patterns of variation that are largely congruent with species boundaries. However, little information exists on intraspecific divergence in most Amazonian species. Here we screen intraspecific mtDNA genetic variation in 41 Amazonian forest understory species belonging to 36 genera and 17 families in 6 orders, using 758 individual samples from Ecuador and French Guiana. For 13 of these species, we also analyzed trans-Andean populations from the Ecuadorian Chocó. A consistent pattern of deep intraspecific divergence among trans-Amazonian haplogroups was found for 33 of the 41 taxa, and genetic differentiation and genetic diversity among them was highly variable, suggesting a complex range of evolutionary histories. Mean sequence divergence within families was the same as that found in North American birds (13%, yet mean intraspecific divergence in Neotropical species was an order of magnitude larger (2.13% vs. 0.23%, with mean distance between intraspecific lineages reaching 3.56%. We found no clear relationship between genetic distances and differentiation in plumage color. Our results identify numerous genetically and phenotypically divergent lineages which may result in new species-level designations upon closer taxonomic scrutiny and thorough sampling, although lineages in the tropical region could be older than those in the temperate zone without necessarily representing separate species. In

  20. Endocarditis - children

    Science.gov (United States)

    ... children; Streptococcus viridians - endocarditis - children; Candida - endocarditis - children; Bacterial endocarditis - children; Infective endocarditis - children; Congenital heart disease - endocarditis - ...

  1. Sibling Composition and Child Educational Attainment: Evidence from Native Amazonians in Bolivia

    Science.gov (United States)

    Zeng, Wu; Undurraga, Eduardo A.; Eisenberg, Dan T. A.; Rubio-Jovel, Karla; Reyes-Garcia; Victoria; Godoy, Ricardo

    2012-01-01

    Evidence from industrial nations suggests that sibling composition is associated with children's educational attainment, particularly if parents face resource constraints. If sibling composition is associated with educational attainment, then those associations should be stronger in poor societies of developing nations. We use data from a…

  2. Paleoclimate modeling of the Amazonian glacial cycles using the new version of the LMD Global Climate Model

    Science.gov (United States)

    Madeleine, J.; Forget, F.; Head, J. W.; Millour, E.; Spiga, A.; Colaitis, A.; Montabone, L.; Montmessin, F.; Maattanen, A. E.

    2011-12-01

    Our study aims at better understanding the Mars climate system through the modeling of the Amazonian glacial cycles with the LMD Global Climate Model. In recent years, many atmospheric measurements by MRO, MGS and MEx, as well as in-situ measurements by the Phoenix lander have revealed the crucial role of various processes in shaping the current climate, such as the radiative effect of water-ice clouds or the scavenging of dust particles by clouds. In parallel, geological evidence for large-scale glaciations has been discovered, and a lot is still to be learned about the origin of the associated geological features. We have been working on developing a new version of the LMD Mars GCM which includes these processes and allows us to assess their impact on the Mars climate system under present-day and past conditions. The processes that are relevant to paleoclimate modeling are the following: - Interactive aerosols: The scavenging of dust particles is made possible by a semi-interactive dust transport scheme which is coupled to the water cycle scheme. The dust particles serve as condensation nuclei for water-ice cloud formation and can be scavenged. Both dust particles and water-ice crystals can scatter radiation depending on their size. - Near-surface convection: A new parameterization of the convection in the boundary layer has been developed and accounts for the turbulent mixing produced by local thermals. This new parameterization may have an impact on ice stability under paleoclimate conditions. - Ice deposition and surface properties: A new soil conduction model allows us to account for the changes in surface thermal inertia due to ice deposition, meaning that the thermal-inertia feedback is active. Also, the coupling between the dust cycle and the water cycle gives access to the amount of dust which is included in the ice deposits, and thereby provides an assessment of the stratigraphy. During the conference, we will revisit our paleoclimate simulations and

  3. Amazonian anthrosols support similar microbial communities that differ distinctly from those extant in adjacent, unmodified soils of the same mineralogy.

    Science.gov (United States)

    Grossman, Julie M; O'Neill, Brendan E; Tsai, Siu Mui; Liang, Biqing; Neves, Eduardo; Lehmann, Johannes; Thies, Janice E

    2010-07-01

    We compared the microbial community composition in soils from the Brazilian Amazon with two contrasting histories; anthrosols and their adjacent non-anthrosol soils of the same mineralogy. The anthrosols, also known as the Amazonian Dark Earths or terra preta, were managed by the indigenous pre-Colombian Indians between 500 and 8,700 years before present and are characterized by unusually high cation exchange capacity, phosphorus (P), and calcium (Ca) contents, and soil carbon pools that contain a high proportion of incompletely combusted biomass as biochar or black carbon (BC). We sampled paired anthrosol and unmodified soils from four locations in the Manaus, Brazil, region that differed in their current land use and soil type. Community DNA was extracted from sampled soils and characterized by use of denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism. DNA bands of interest from Bacteria and Archaea DGGE gels were cloned and sequenced. In cluster analyses of the DNA fingerprints, microbial communities from the anthrosols grouped together regardless of current land use or soil type and were distinct from those in their respective, paired adjacent soils. For the Archaea, the anthrosol communities diverged from the adjacent soils by over 90%. A greater overall richness was observed for Bacteria sequences as compared with those of the Archaea. Most of the sequences obtained were novel and matched those in databases at less than 98% similarity. Several sequences obtained only from the anthrosols grouped at 93% similarity with the Verrucomicrobia, a genus commonly found in rice paddies in the tropics. Sequences closely related to Proteobacteria and Cyanobacteria sp. were recovered only from adjacent soil samples. Sequences related to Pseudomonas, Acidobacteria, and Flexibacter sp. were recovered from both anthrosols and adjacent soils. The strong similarities among the microbial communities present in the anthrosols for

  4. A new morphologically cryptic species of Phyllomedusa (Anura: Phyllomedusidae) from Amazonian forests of northern Peru revealed by DNA sequences.

    Science.gov (United States)

    Castroviejo-Fisher, Santiago; Köhler, Jörn; Riva, Ignacio DE LA; Padial, José M

    2017-05-22

    We describe and name Phyllomedusa chaparroi sp. nov., a medium-sized species (snout-vent length in adult males 67.9-77.5 mm) of monkey frog from Amazonian rainforests of northern Peru. Although morphologically most similar to P. boliviana and P. camba (indistinguishable from the latter in external qualitative and quantitative traits), phylogenetic analysis of combined mitochondrial and nuclear markers place the new species sister to a clade containing P. neildi, P. tarsius, and P. trinitatis. Phyllomedusa chaparroi can be readily differentiated from these species by having a dark reddish-brown iris with indistinct tiny orange spots versus an orange iris with marked dark reticulation found in P. neildi, P. tarsius, and P. trinitatis. Furthermore, genetic distances for a 532 bp sequence of the 16S gene between the new species and its sister species are 2.8-4.1 %, whereas distances are 4.5-5.5 % to the morphologically cryptic P. camba. We briefly discuss the importance of DNA sequences in revealing morphologically cryptic species and modify the content of the P. tarsius species group based on phylogenetic analyses and observations on iris coloration.

  5. The effects of cannibalism on Amazonian poison frog egg and tadpole deposition and survivorship in Heliconia axil pools.

    Science.gov (United States)

    Summers, Kyle

    1999-06-01

    This study investigated the influence of cannibalism on egg and larval mortality, and on the deposition strategies of adults, in a tropical anuran breeding in very small leaf axil pools. Patterns of egg and tadpole deposition and mortality in the Amazonian poison frog, Dendrobates ventrimaculatus, were monitored in rainforest near Pompeya in Sucumbios Province, Ecuador. Oviposition and tadpole deposition typically ocurred in leaf axils of Heliconia plants. Pools typically received more than one oviposition. Egg survivorship was low, and significantly lower when eggs were deposited in pools with large tadpoles, indicating that cannibalism is an important source of mortality. Tadpole survivorship was also associated with the presence of other tadpoles: most pools ended with only one surviving tadpole, regardless of the number of tadpoles deposited in the pool. Egg deposition was signifcantly less likely for pools that had a tadpole in them, suggesting that adults can detect the presence of tadpoles and avoid ovipositing in pools that contain them. This hypothesis was tested with a series of pool choice experiments, which revealed that D. ventrimaculatus avoid placing either eggs or tadpoles into a pool which contains a large tadpole. Several hypotheses which could explain multiple deposition in this species are discussed.

  6. The impact of smoke from forest fires on the spectral dispersion of cloud droplet size distributions in the Amazonian region

    Energy Technology Data Exchange (ETDEWEB)

    Martins, J A [Universidade Tecnologica Federal do Parana, Londrina, PR (Brazil); Silva Dias, M A F [Centro de Previsao de Tempo e Estudos Climaticos, Cachoeira Paulista, SP (Brazil)], E-mail: jmartins@utfpr.edu.br

    2009-01-15

    In this paper, the main microphysical characteristics of clouds developing in polluted and clean conditions in the biomass-burning season of the Amazon region are examined, with special attention to the spectral dispersion of the cloud droplet size distribution and its potential impact on climate modeling applications. The dispersion effect has been shown to alter the climate cooling predicted by the so-called Twomey effect. In biomass-burning polluted conditions, high concentrations of low dispersed cloud droplets are found. Clean conditions revealed an opposite situation. The liquid water content (0.43 {+-} 0.19 g m{sup -3}) is shown to be uncorrelated with the cloud drop number concentration, while the effective radius is found to be very much correlated with the relative dispersion of the size distribution (R{sup 2} = 0.81). The results suggest that an increase in cloud condensation nuclei concentration from biomass-burning aerosols may lead to an additional effect caused by a decrease in relative dispersion. Since the dry season in the Amazonian region is vapor limiting, the dispersion effect of cloud droplet size distributions could be substantially larger than in other polluted regions.

  7. Geology and geophysics of the Vila Nova Greenstone Belt, northeastern portion of the Amazonian Craton, Amapa, Brazil

    International Nuclear Information System (INIS)

    Borghetti, Cristiano; Philipp, Ruy Paulo

    2017-01-01

    A few outcrops and strong weathering conditions prevail in the region of the Vila Nova Greenstone Belt in the southeastern Amapa (Brazil). This paper describes the use of airborne geophysical data for geological and structural analysis during geological mapping. This integration aims to improve the geological and tectonic understanding of this portion of the Amazonian Craton. The magnetometric and gamma-spectrometric qualitative interpretation of the images took place in a Geographic Information System (GIS) environment. Recognition of magnetometric and gamma-ray spectrometric units present in the study area was based on the hierarchical classification of polygons outlined by visual interpretation. The major geological domains and the structural patterns were defined by integration of geophysical data, geological mapping and petrographic analysis. The results allowed the recognition of Archean basement rocks composed of orthogneisses and granitoids of the Tumucumaque Complex, the metavolcano-sedimentary rocks of the Vila Nova Complex and Paleoproterozoic granite massifs. The integration of geophysical and field data resulted in the increase of the geological mapping definition, highlighting the importance of this methodology for recognition of complex structural and lithological fabrics in areas of difficult access and scarce fresh rock outcrops. (author)

  8. Classification of Vegetation over a Residual Megafan Landform in the Amazonian Lowland Based on Optical and SAR Imagery

    Directory of Open Access Journals (Sweden)

    Édipo Henrique Cremon

    2014-11-01

    Full Text Available The origin of large areas dominated by pristine open vegetation that is in sharp contrast with surrounding dense forest within the Amazonian lowland has generally been related to past arid climates, but this is still an issue open for debate. In this paper, we characterize a large open vegetation patch over a residual megafan located in the northern Amazonia. The main goal was to investigate the relationship between this paleolandform and vegetation classes mapped based on the integration of optical and SAR data using the decision tree. Our remote sensing dataset includes PALSAR and TM/Landsat images. Five classes were identified: rainforest; flooded forest; wooded open vegetation; grassy-shrubby open vegetation; and water body. The output map resulting from the integration of PALSAR and TM/Landsat images showed an overall accuracy of 94%. Narrow, elongated and sinuous belts of forest within the open vegetation areas progressively bifurcate into others revealing paleochannels arranged into distributary pattern. Such characteristics, integrated with pre-existing geological information, led us to propose that the distribution of vegetation classes highlight a morphology attributed to a Quaternary megafan developed previous to the modern fluvial tributary system. The characterization of such megafan is important for reconstructing landscape changes associated with the evolution of the Amazon drainage basin.

  9. Predation and predation attempts on red titi monkeys (Callicebus discolor) and equatorial sakis (Pithecia aequatorialis) in Amazonian Ecuador.

    Science.gov (United States)

    de Luna, Ana Gabriela; Sanmiguel, Ramiro; Di Fiore, Anthony; Fernandez-Duque, Eduardo

    2010-08-01

    Anecdotal reports of predation as well as observed predation attempts and rates of animal disappearance provide some of the most relevant data for evaluating the influence that predation risk may have on primate behavioural ecology. Here, we report rates of disappearance from six groups of red titi monkeys (Callicebus discolor) and two groups of equatorial sakis (Pithecia aequatorialis) followed over a period of four and a half years at a lowland site in Amazonian Ecuador. We also describe the first direct observation of a harpy eagle (Harpia harpyja) preying upon a titi monkey, as well as 3 unsuccessful attacks by tayras (Eira barbara) on titi monkeys and 4 unsuccessful attacks by various raptors on sakis. Our data indicate that pitheciid primates may face a wider array of possible predators than previously recognized, and that titi monkeys and sakis are susceptible to different major classes of predators. Our observations also suggest differences in the sex role during predator defence that could be related to the evolution and maintenance of monogamous systems. (c) 2010 S. Karger AG, Basel.

  10. Bradyrhizobium manausense sp. nov., isolated from effective nodules of Vigna unguiculata grown in Brazilian Amazonian rainforest soils.

    Science.gov (United States)

    Silva, Flavia V; De Meyer, Sofie E; Simões-Araújo, Jean L; Barbé, Tatiane da Costa; Xavier, Gustavo R; O'Hara, Graham; Ardley, Julie K; Rumjanek, Norma G; Willems, Anne; Zilli, Jerri E

    2014-07-01

    Root nodule bacteria were trapped within cowpea (Vigna unguiculata) in soils with different cultivation histories collected from the Amazonian rainforest in northern Brazil. Analysis of the 16S rRNA gene sequences of six strains (BR 3351(T), BR 3307, BR 3310, BR 3315, BR 3323 BR and BR 3361) isolated from cowpea nodules showed that they formed a distinct group within the genus Bradyrhizobium, which was separate from previously identified type strains. Phylogenetic analyses of three housekeeping genes (glnII, recA and rpoB) revealed that Bradyrhizobium huanghuaihaiense CCBAU 23303(T) was the most closely related type strain (96% sequence similarity or lower). Chemotaxonomic data, including fatty acid profiles (predominant fatty acids being C16 : 0 and summed feature 8), the slow growth rate and carbon compound utilization patterns supported the assignment of the strains to the genus Bradyrhizobium. The results of DNA-DNA hybridizations, antibiotic resistance and physiological tests differentiated these novel strains from the most closely related species of the genus Bradyrhizobium with validly published names. Symbiosis-related genes for nodulation (nodC) and nitrogen fixation (nifH) grouped the novel strains of the genus Bradyrhizobium together with Bradyrhizobium iriomotense strain EK05(T), with 94% and 96% sequence similarity, respectively. Based on these data, these six strains represent a novel species for which the name Brabyrhizobium manausense sp. nov. (BR 3351(T) = HAMBI 3596(T)), is proposed. © 2014 IUMS.

  11. Chemical characterization and antioxidant activity of Amazonian (Ecuador) Caryodendron orinocense Karst. and Bactris gasipaes Kunth seed oils.

    Science.gov (United States)

    Radice, Matteo; Viafara, Derwin; Neill, David; Asanza, Mercedes; Sacchetti, Gianni; Guerrini, Alessandra; Maietti, Silvia

    2014-01-01

    Nowadays, data concerning the composition of Caryodendron orinocense Karst. (Euphorbiaceae) and Bactris gasipaes Kunth (Arecaceae) seed oils are lacking. In light of this fact, in this paper fatty acids and unsaponifiable fraction composition have been determined using GC-MS, HPLC-DAD (Diode Array Detector), NMR approaches and possible future applications have been preliminary investigated through estimation of antioxidant activity, performed with DPPH test. For C. orinocense linoleic acid (85.59%) was the main component, lauric (33.29%) and myristic (27.76%) acids were instead the most abundant in B. gasipaes. C. orinocense unsaponifiable fraction (8.06%) evidenced a remarkable content of β-sitosterol, campesterol, stigmasterol, squalene and vitamin E (816 ppm). B. gasipaes revealed instead β-sitosterol and squalene as main constituents of unsaponifiable matter (3.01%). Antioxidant capacity evidenced the best performance of C. orinocense seed oil. These preliminary results could be interesting to suggest the improvement of the population's incomes from Amazonian basin. In particular the knowledge of chemical composition of C. orinocense and B. gasipaes oils could be helpful to divulge and valorize these autochthones plants.

  12. Behavioural and seminal characteristics of Santa Ines rams subjected to successive semen collections in the Amazonian region

    Directory of Open Access Journals (Sweden)

    Luiz Fernando S. Rodrigues

    2012-10-01

    Full Text Available The objective of this study was to evaluate the reproductive performance of Santa Ines rams subjected to successive semen collections in an Amazonian climate. Four rams were subjected to successive ejaculations during a maximum period of three hours. This procedure was repeated three times at 15-day intervals. Sexual and behavioural (libido and andrological (testicular and seminal assessments were performed. A total of 81 ejaculates were collected. Libido and semen vigour, volume, appearance and concentration decreased as the ejaculation frequency increased (P<0.05 and sperm motility showed a decreasing trend (P=0.06. The seminal pH increased over the sequence of collections (P<0.05. The only significant differences observed between individual rams were the variable scrotal circumference and the percentages of live sperm and sperm abnormalities (P<0.05. All the parameters of the first ejaculation were within the normal range for this species, which suggests that the local climatic conditions (high temperature and humidity did not affect the behavioural, testicular or seminal parameters of experimental rams. Our findings indicate that the reproductive performance of Santa Ines rams could be affected by the intensification of ejaculation frequency; however, individual male variation needs to be taken into consideration.

  13. Is there a divide between local medicinal knowledge and Western medicine? a case study among native Amazonians in Bolivia.

    Science.gov (United States)

    Calvet-Mir, Laura; Reyes-García, Victoria; Tanner, Susan

    2008-08-18

    Interest in ethnomedicine has grown in the last decades, with much research focusing on how local medicinal knowledge can contribute to Western medicine. Researchers have emphasized the divide between practices used by local medical practitioners and Western doctors. However, researchers have also suggested that merging concepts and practices from local medicinal knowledge and Western science have the potential to improve public health and support medical independence of local people. In this article we study the relations between local and Western medicinal knowledge within a native Amazonian population, the Tsimane'. We used the following methods: 1) participant observation and semi-structured interviews to gather background information, 2) free-listing and pile-sorting to assess whether Tsimane' integrate local medicinal knowledge and Western medicine at the conceptual level, 3) surveys to assess to what extent Tsimane' combine local medicinal knowledge with Western medicine in actual treatments, and 4) a participatory workshop to assess the willingness of Tsimane' and Western medical specialists to cooperate with each other. We found that when asked about medical treatments, Tsimane' do not include Western treatments in their lists, however on their daily practices, Tsimane' do use Western treatments in combination with ethnomedical treatments. We also found that Tsimane' healers and Western doctors express willingness to cooperate with each other and to promote synergy between local and Western medical systems. Our findings contrast with previous research emphasizing the divide between local medical practitioners and Western doctors and suggests that cooperation between both health systems might be possible.

  14. Wood specific gravity and anatomy of branches and roots in 113 Amazonian rainforest tree species across environmental gradients.

    Science.gov (United States)

    Fortunel, Claire; Ruelle, Julien; Beauchêne, Jacques; Fine, Paul V A; Baraloto, Christopher

    2014-04-01

    Wood specific gravity (WSG) is a strong predictor of tree performance across environmental gradients. Yet it remains unclear how anatomical elements linked to different wood functions contribute to variation in WSG in branches and roots across tropical forests. We examined WSG and wood anatomy in white sand, clay terra firme and seasonally flooded forests in French Guiana, spanning broad environmental gradients found throughout Amazonia. We measured 15 traits relating to branches and small woody roots in 113 species representing the 15 most abundant species in each habitat and representative species from seven monophyletic lineages occurring in all habitats. Fiber traits appear to be major determinants of WSG, independent of vessel traits, in branches and roots. Fiber traits and branch and root WSG increased from seasonally flooded species to clay terra firme species and lastly to white sand species. Branch and root wood traits were strongly phylogenetically constrained. Lineages differed in wood design, but exhibited similar variation in wood structure across habitats. We conclude that tropical trees can invest differently in support and transport to respond to environmental conditions. Wind disturbance and drought stress represent significant filters driving tree distribution of Amazonian forests; hence we suggest that biophysical explanations should receive more attention. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  15. Identification and quantification, by HPLC-DAD-MS/MS, of carotenoids and phenolic compounds from the Amazonian fruit Caryocar villosum.

    Science.gov (United States)

    Chisté, Renan Campos; Mercadante, Adriana Zerlotti

    2012-06-13

    The Amazonian region from Brazil has a wide variety of native and wild noncommercially cultivated fruits. This article reports for the first time the composition of carotenoids and phenolic compounds from Caryocar villosum fruit pulp, and, in addition, its proximate composition and antioxidant capacity (ORAC assay) were determined. According to the nutritional composition, water (52%) and lipids (25%) were the major components found in the pulp, and the total energetic value was 291 kcal/100 g. The major phenolic compounds identified by HPLC-DAD-ESI-MS/MS were gallic acid (182.4 μg/g pulp), followed by ellagic acid rhamnoside (107 μg/g pulp) and ellagic acid (104 μg/g pulp). The main carotenoids identified by HPLC-DAD-APCI-MS/MS were all-trans-antheraxanthin (3.4 μg/g pulp), all-trans-zeaxanthin (2.9 μg/g pulp), and a lutein-like carotenoid (2.8 μg/g pulp). The antioxidant capacity of the pulp (3.7 mMol Trolox/100 g pulp) indicates that it can be considered a good peroxyl radical scavenger.

  16. SPECIES DIVERSITY AND COMMUNITY STRUCTURE OF FRUIT-FEEDING BUTTERFLIES (LEPIDOPTERA: NYMPHALIDAE IN AN EASTERN AMAZONIAN FOREST

    Directory of Open Access Journals (Sweden)

    LUCAS PEREIRA MARTINS

    Full Text Available ABSTRACT Deforestation has negative impacts on diversity and community patterns of several taxa. In the eastern Amazon, where much deforestation is predicted for the coming years, forests patches may be essential to maintain the local biodiversity. Despite increasing concerns about the conservation of threatened areas, few studies have been performed to analyze the communities of diversified groups, such as insects, in the eastern Amazon. Here, we investigated species diversity and community structure of fruit-feeding butterflies, a well-known bioindicator group, in a threatened remnant of an eastern Amazonian forest located on Maranhão Island, northeastern Brazil. Fruit-feeding butterflies were sampled monthly for one year. Diversity and evenness indices, richness estimators, rarefaction curve, and rank-abundance plot were used to describe community structure in the study area. We captured 529 fruit-feeding butterflies in four subfamilies, 23 genera and 34 species. The three most abundant species, Hamadryas februa, Hamadryas feronia, and Hermeuptychia cf. atalanta are indicators of disturbed habitats and represented more than half of the collected individuals. Richness estimators revealed that between 87 and 94% of the fruit-feeding butterfly species were sampled, suggesting few additional records would be made for the area. Our results indicate that human-caused disturbances have altered local community patterns and provide baseline data for future research in threatened regions of the eastern Amazon.

  17. pH drop impacts differentially skin and gut microbiota of the Amazonian fish tambaqui (Colossoma macropomum).

    Science.gov (United States)

    Sylvain, François-Étienne; Cheaib, Bachar; Llewellyn, Martin; Gabriel Correia, Tiago; Barros Fagundes, Daniel; Luis Val, Adalberto; Derome, Nicolas

    2016-08-18

    Aquatic organisms are increasingly exposed to lowering of environmental pH due to anthropogenic pressure (e.g. acid rain, acid mine drainages). Such acute variations trigger imbalance of fish-associated microbiota, which in turn favour opportunistic diseases. We used the tambaqui (Colossoma macropomum), an Amazonian fish tolerant to significant pH variation in its natural environment, to assess the response of fish endogenous microbiota to acute short-term acid stress. We exposed 36 specimens of tambaquis to acidic water (pH 4.0) over 2 consecutive weeks and sampled cutaneous mucus, feces and water at 0, 7 &14 days. The 16S RNA hypervariable region V4 was sequenced on Illumina MiSeq. After two weeks of acidic exposure, fecal and skin microbiota taxonomic structures exhibited different patterns: skin microbiota was still exhibiting a significantly disturbed composition whereas fecal microbiota recovered a similar composition to control group, thus suggesting a stronger resilience capacity of the intestinal microbiota than cutaneous microbiota.

  18. Mercury and selenium binding biomolecules in terrestrial mammals (Cervus elaphus and Sus scrofa) from a mercury exposed area.

    Science.gov (United States)

    Ropero, M J Patiño; Fariñas, N Rodríguez; Krupp, E; Mateo, R; Nevado, J J Berzas; Martín-Doimeadios, R C Rodríguez

    2016-06-01

    Mercury (Hg) is likely bound to large biomolecules (e.g. proteins) in living organisms, and in order to assess Hg metabolic pathways and possible toxicological effects, it is essential to study these Hg containing biomolecules. However, the exact nature of most metal binding biomolecules is unknown. Such studies are still in their infancy and information on this topic is scarce because the analysis is challenging, mainly due to their lability upon digestion or extraction from the tissue. New analytical methods that allow complex Hg-biomolecules to be analysed intact are needed and only few very recent studies deal with this approach. Therefore, as an initial step towards the characterization of Hg containing biomolecules, an analytical procedure has been optimised using size-exclusion chromatography (SEC) with inductively coupled plasma mass spectrometry (ICP-MS) detection. We applied this technique to elucidate the distribution and elution profile of Hg and Se, and some physiological important elements such as Fe, Ni, Zn and Cu, to assess metal binding profiles in liver and kidney samples of red deer (Cervus elaphus) and wild boar (Sus scrofa) who roam freely within the largest Hg mining district on Earth, Almadén in Spain. Elemental fractionation profiles of the extracts from different tissues were obtained using two different SEC columns (BioSep-SEC-S2000 GL 300-1kDa and Superdex 75 10/300 GL 70-3kDa). Similar profiles of Hg were observed in red deer and wild boar; however, significant differences were evident for liver and kidney. Moreover, the profiles of Se showed a single peak at high-medium molecular weight in all investigated tissues, while co-elution of Hg with Fe, Ni, Zn and Cu was observed. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Preservation of Late Amazonian Mars ice and water-related deposits in a unique crater environment in Noachis Terra: Age relationships between lobate debris tongues and gullies

    Science.gov (United States)

    Morgan, Gareth A.; Head, James W.; Marchant, David R.

    2011-01-01

    The Amazonian period of Mars has been described as static, cold, and dry. Recent analysis of high-resolution imagery of equatorial and mid-latitude regions has revealed an array of young landforms produced in association with ice and liquid water; because near-surface ice in these regions is currently unstable, these ice-and-water-related landforms suggest one or more episodes of martian climate change during the Amazonian. Here we report on the origin and evolution of valley systems within a degraded crater in Noachis Terra, Asimov Crater. The valleys have produced a unique environment in which to study the geomorphic signals of Amazonian climate change. New high-resolution images reveal Hesperian-aged layered basalt with distinctive columnar jointing capping interior crater fill and providing debris, via mass wasting, for the surrounding annular valleys. The occurrence of steep slopes (>20°), relatively narrow (sheltered) valleys, and a source of debris have provided favorable conditions for the preservation of shallow-ice deposits. Detailed mapping reveals morphological evidence for viscous ice flow, in the form of several lobate debris tongues (LDT). Superimposed on LDT are a series of fresh-appearing gullies, with typical alcove, channel, and fan morphologies. The shift from ice-rich viscous-flow formation to gully erosion is best explained as a shift in martian climate, from one compatible with excess snowfall and flow of ice-rich deposits, to one consistent with minor snow and gully formation. Available dating suggests that the climate transition occurred >8 Ma, prior to the formation of other small-scale ice-rich flow features identified elsewhere on Mars that have been interpreted to have formed during the most recent phases of high obliquity. Taken together, these older deposits suggest that multiple climatic shifts have occurred over the last tens of millions of years of martian history.

  20. Simulation of the Unexpected Photosynthetic Seasonality in Amazonian Evergreen Forests by Using an Improved Diffuse Fraction-Based Light Use Efficiency Model

    Science.gov (United States)

    Yan, Hao; Wang, Shao-Qiang; da Rocha, Humberto R.; Rap, Alexandru; Bonal, Damien; Butt, Nathalie; Coupe, Natalia Restrepo; Shugart, Herman H.

    2017-11-01

    Understanding the mechanism of photosynthetic seasonality in Amazonian evergreen forests is critical for its formulation in global climate and carbon cycle models. However, the control of the unexpected photosynthetic seasonality is highly uncertain. Here we use eddy-covariance data across a network of Amazonian research sites and a novel evapotranspiration (E) and two-leaf-photosynthesis-coupled model to investigate links between photosynthetic seasonality and climate factors on monthly scales. It reproduces the GPP seasonality (R2 = 0.45-0.69) with a root-mean-square error (RMSE) of 0.67-1.25 g C m-2 d-1 and a Bias of -0.03-1.04 g C m-2 d-1 for four evergreen forest sites. We find that the proportion of diffuse and direct sunlight governs the photosynthetic seasonality via their interaction with sunlit and shaded leaves, supported by a proof that canopy light use efficiency (LUE) has a strong linear relationship with the fraction of diffuse sunlight for Amazonian evergreen forests. In the transition from dry season to rainy season, incident total radiation (Q) decreased while LUE and diffuse fraction increased, which produced the large seasonal increase ( 34%) in GPP of evergreen forests. We conclude that diffuse radiation is an important environmental driver of the photosynthetic seasonality in tropical Amazon forests yet depending on light utilization by sunlit and shaded leaves. Besides, the GPP model simulates the precipitation-dominated GPP seasonality (R2 = 0.40-0.69) at pasture and savanna sites. These findings present an improved physiological method to relate light components with GPP in tropical Amazon.

  1. The synergistic use of models and observations: understanding the mechanisms behind observed biomass dynamics at 14 Amazonian field sites and the implications for future biomass change

    Science.gov (United States)

    Levine, N. M.; Galbraith, D.; Christoffersen, B. J.; Imbuzeiro, H. A.; Restrepo-Coupe, N.; Malhi, Y.; Saleska, S. R.; Costa, M. H.; Phillips, O.; Andrade, A.; Moorcroft, P. R.

    2011-12-01

    The Amazonian rainforests play a vital role in global water, energy and carbon cycling. The sensitivity of this system to natural and anthropogenic disturbances therefore has important implications for the global climate. Some global models have predicted large-scale forest dieback and the savannization of Amazonia over the next century [Meehl et al., 2007]. While several studies have demonstrated the sensitivity of dynamic global vegetation models to changes in temperature, precipitation, and dry season length [e.g. Galbraith et al., 2010; Good et al., 2011], the ability of these models to accurately reproduce ecosystem dynamics of present-day transitional or low biomass tropical forests has not been demonstrated. A model-data intercomparison was conducted with four state-of-the-art terrestrial ecosystem models to evaluate the ability of these models to accurately represent structure, function, and long-term biomass dynamics over a range of Amazonian ecosystems. Each modeling group conducted a series of simulations for 14 sites including mature forest, transitional forest, savannah, and agricultural/pasture sites. All models were run using standard physical parameters and the same initialization procedure. Model results were compared against forest inventory and dendrometer data in addition to flux tower measurements. While the models compared well against field observations for the mature forest sites, significant differences were observed between predicted and measured ecosystem structure and dynamics for the transitional forest and savannah sites. The length of the dry season and soil sand content were good predictors of model performance. In addition, for the big leaf models, model performance was highest for sites dominated by late successional trees and lowest for sites with predominantly early and mid-successional trees. This study provides insight into tropical forest function and sensitivity to environmental conditions that will aid in predictions of the

  2. The effects of local medicinal knowledge and hygiene on helminth infections in an Amazonian society.

    Science.gov (United States)

    Tanner, Susan; Chuquimia-Choque, Maria E; Huanca, Tomás; McDade, Thomas W; Leonard, William R; Reyes-García, Victoria

    2011-03-01

    Social science has long recognized the importance of understanding how interactions between culture and behavior shape disease patterns, especially in resource-poor areas where individuals draw on multiple medical treatments to maintain health. While global health programs aimed at controlling high infection rates of soil-transmitted helminthes among indigenous groups often acknowledge the value of local culture, little research has been able to examine this value. This study investigates the association between parental ethnomedical knowledge, parental biomedical knowledge, and household sanitation behavior and childhood soil-transmitted helminth infections among a group of foragers-farmers in the Bolivian Amazon (Tsimane'). During 2007, a parasitological survey was completed for 329 children (≤ 16 years of age) from 109 households in combination with a comprehensive survey of both of the child's parents to assess biomedical and ethnomedical knowledge and household sanitary environment. Soil-transmitted helminthes were found to be common with 67% of sample positive for hookworm species. Indices that capture a household's relative state of risky and preventive hygienic behavior were significantly associated with risk of hookworm infection. Mother's but not father's ethnomedical knowledge was also negatively associated with a child's probability of being positive for hookworm infection. The effect was stronger for young children and boys. Like many rural populations, Tsimane' actively draw upon multiple medical systems to respond to health challenges. Integration into markets and national societies is likely to affect local medical systems by increasing the use of biomedicine as formal education prioritizes biomedical over ethnomedical systems. This study underscores the value of considering both ethnomedical knowledge systems and household hygiene in public health campaigns to treat and control soil-transmitted helminths. There is no question that providing

  3. Interpreting participatory Fuzzy Cognitive Maps as complex networks in the social-ecological systems of the Amazonian forests

    Science.gov (United States)

    Varela, Consuelo; Tarquis, Ana M.; Blanco-Gutiérrez, Irene; Estebe, Paloma; Toledo, Marisol; Martorano, Lucieta

    2015-04-01

    Social-ecological systems are linked complex systems that represent interconnected human and biophysical processes evolving and adapting across temporal and spatial scales. In the real world, social-ecological systems pose substantial challenges for modeling. In this regard, Fuzzy Cognitive Maps (FCMs) have proven to be a useful method for capturing the functioning of this type of systems. FCMs are a semi-quantitative type of cognitive map that represent a system composed of relevant factors and weighted links showing the strength and direction of cause-effects relationships among factors. Therefore, FCMs can be interpreted as complex system structures or complex networks. In this sense, recent research has applied complex network concepts for the analysis of FCMs that represent social-ecological systems. Key to FCM the tool is its potential to allow feedback loops and to include stakeholder knowledge in the construction of the tool. Also, previous research has demonstrated their potential to represent system dynamics and simulate the effects of changes in the system, such as policy interventions. For illustrating this analysis, we have developed a series of participatory FCM for the study of the ecological and human systems related to biodiversity conservation in two case studies of the Amazonian region, the Bolivia lowlands of Guarayos and the Brazil Tapajos National forest. The research is carried out in the context of the EU project ROBIN1 and it is based on the development of a series of stakeholder workshops to analyze the current state of the socio-ecological environment in the Amazonian forest, reflecting conflicts and challenges for biodiversity conservation and human development. Stakeholders included all relevant actors in the local case studies, namely farmers, environmental groups, producer organizations, local and provincial authorities and scientists. In both case studies we illustrate the use of complex networks concepts, such as the adjacency

  4. Interethnic Interaction, Strategic Bargaining Power, and the Dynamics of Cultural Norms : A Field Study in an Amazonian Population.

    Science.gov (United States)

    Bunce, John Andrew; McElreath, Richard

    2017-12-01

    Ethnic groups are universal and unique to human societies. Such groups sometimes have norms of behavior that are adaptively linked to their social and ecological circumstances, and ethnic boundaries may function to protect that variation from erosion by interethnic interaction. However, such interaction is often frequent and voluntary, suggesting that individuals may be able to strategically reduce its costs, allowing adaptive cultural variation to persist in spite of interaction with out-groups with different norms. We examine five mechanisms influencing the dynamics of ethnically distinct cultural norms, each focused on strategic individual-level choices in interethnic interaction: bargaining, interaction-frequency-biased norm adoption, assortment on norms, success-biased interethnic social learning, and childhood socialization. We use Bayesian item response models to analyze patterns of norm variation and interethnic interaction in an ethnically structured Amazonian population. We show that, among indigenous Matsigenka, interethnic education with colonial Mestizos is more strongly associated with Mestizo-typical norms than even extensive interethnic experience in commerce and wage labor is. Using ethnographic observations, we show that all five of the proposed mechanisms of norm adoption may contribute to this effect. However, of these mechanisms, we argue that changes in relative bargaining power are particularly important for ethnic minorities wishing to preserve distinctive norms while engaging in interethnic interaction in domains such as education. If this mechanism proves applicable in a range of other ethnographic contexts, it would constitute one cogent explanation for when and why ethnically structured cultural variation can either persist or erode given frequent, and often mutually beneficial, interethnic interaction.

  5. Modeling Disease Vector Occurrence when Detection Is Imperfect: Infestation of Amazonian Palm Trees by Triatomine Bugs at Three Spatial Scales

    Science.gov (United States)

    Abad-Franch, Fernando; Ferraz, Gonçalo; Campos, Ciro; Palomeque, Francisco S.; Grijalva, Mario J.; Aguilar, H. Marcelo; Miles, Michael A.

    2010-01-01

    Background Failure to detect a disease agent or vector where it actually occurs constitutes a serious drawback in epidemiology. In the pervasive situation where no sampling technique is perfect, the explicit analytical treatment of detection failure becomes a key step in the estimation of epidemiological parameters. We illustrate this approach with a study of Attalea palm tree infestation by Rhodnius spp. (Triatominae), the most important vectors of Chagas disease (CD) in northern South America. Methodology/Principal Findings The probability of detecting triatomines in infested palms is estimated by repeatedly sampling each palm. This knowledge is used to derive an unbiased estimate of the biologically relevant probability of palm infestation. We combine maximum-likelihood analysis and information-theoretic model selection to test the relationships between environmental covariates and infestation of 298 Amazonian palm trees over three spatial scales: region within Amazonia, landscape, and individual palm. Palm infestation estimates are high (40–60%) across regions, and well above the observed infestation rate (24%). Detection probability is higher (∼0.55 on average) in the richest-soil region than elsewhere (∼0.08). Infestation estimates are similar in forest and rural areas, but lower in urban landscapes. Finally, individual palm covariates (accumulated organic matter and stem height) explain most of infestation rate variation. Conclusions/Significance Individual palm attributes appear as key drivers of infestation, suggesting that CD surveillance must incorporate local-scale knowledge and that peridomestic palm tree management might help lower transmission risk. Vector populations are probably denser in rich-soil sub-regions, where CD prevalence tends to be higher; this suggests a target for research on broad-scale risk mapping. Landscape-scale effects indicate that palm triatomine populations can endure deforestation in rural areas, but become rarer in

  6. Changing patterns of fire occurrence in proximity to forest edges, roads and rivers between NW Amazonian countries

    Directory of Open Access Journals (Sweden)

    D. Armenteras

    2017-06-01

    Full Text Available Tropical forests in NW Amazonia are highly threatened by the expansion of the agricultural frontier and subsequent deforestation. Fire is used, both directly and indirectly, in Brazilian Amazonia to propagate deforestation and increase forest accessibility. Forest fragmentation, a measure of forest degradation, is also attributed to fire occurrence in the tropics. However, outside the Brazilian Legal Amazonia the role of fire in increasing accessibility and forest fragmentation is less explored. In this study, we compared fire regimes in five countries that share this tropical biome in the most north-westerly part of the Amazon Basin (Venezuela, Colombia, Ecuador, Peru and Brazil. We analysed spatial differences in the timing of peak fire activity and in relation to proximity to roads and rivers using 12 years of MODIS active fire detections. We also distinguished patterns of fire in relation to forest fragmentation by analysing fire distance to the forest edge as a measure of fragmentation for each country. We found significant hemispheric differences in peak fire occurrence with the highest number of fires in the south in 2005 vs. 2007 in the north. Despite this, both hemispheres are equally affected by fire. We also found difference in peak fire occurrence by country. Fire peaked in February in Colombia and Venezuela, whereas it peaked in September in Brazil and Peru, and finally Ecuador presented two fire peaks in January and October. We confirmed the relationship between fires and forest fragmentation for all countries and also found significant differences in the distance between the fire and the forest edge for each country. Fires were associated with roads and rivers in most countries. These results can inform land use planning at the regional, national and subnational scales to minimize the contribution of road expansion and subsequent access to the Amazonian natural resources to fire occurrence and the associated deforestation and

  7. When roads appear jaguars decline: Increased access to an Amazonian wilderness area reduces potential for jaguar conservation.

    Directory of Open Access Journals (Sweden)

    Santiago Espinosa

    Full Text Available Roads are a main threat to biodiversity conservation in the Amazon, in part, because roads increase access for hunters. We examine how increased landscape access by hunters may lead to cascading effects that influence the prey community and abundance of the jaguar (Panthera onca, the top Amazonian terrestrial predator. Understanding such ecological effects originating from anthropogenic actions is essential for conservation and management of wildlife populations in areas undergoing infrastructure development. Our study was conducted in Yasuní Biosphere Reserve, the protected area with highest potential for jaguar conservation in Ecuador, and an area both threatened by road development and inhabited by indigenous groups dependent upon bushmeat. We surveyed prey and jaguar abundance with camera traps in four sites that differed in accessibility to hunters and used site occupancy and spatially explicit capture-recapture analyses to evaluate prey occurrence and estimate jaguar density, respectively. Higher landscape accessibility to hunters was linked with lower occurrence and biomass of game, particularly white-lipped peccary (Tayassu pecari and collared peccary (Pecari tajacu, the primary game for hunters and prey for jaguars. Jaguar density was up to 18 times higher in the most remote site compared to the most accessible site. Our results provide a strong case for the need to: 1 consider conservation of large carnivores and other wildlife in policies about road construction in protected areas, 2 coordinate conservation initiatives with local governments so that development activities do not conflict with conservation objectives, and 3 promote development of community-based strategies for wildlife management that account for the needs of large carnivores.

  8. Evaluation of in vivo solid phase microextraction for minimally invasive analysis of nonvolatile phytochemicals in Amazonian plants.

    Science.gov (United States)

    Musteata, Florin Marcel; Sandoval, Manuel; Ruiz-Macedo, Juan C; Harrison, Kathleen; McKenna, Dennis; Millington, William

    2016-08-24

    Although solid phase microextraction (SPME) has been used extensively for fingerprinting volatile compounds emitted by plants, there are very few such reports for direct insertion SPME. In this research, direct contact of SPME probes with the interstitial fluid of plants was investigated as a method for phytochemical analysis. Medicinal plants from the Amazon have been the source of numerous drugs used in western medicine. However, a large number of species used in traditional medicine have not been characterized chemically, partly due to the difficulty of field work. In this project, the phytochemical composition of plants from several genera was fingerprinted by combining convenient field sampling by solid phase microextraction (SPME) with laboratory analysis by LC-MS. The new method was compared with classical sampling followed by liquid extraction (LE). SPME probes were prepared by coating stainless steel wires with a mixture of polyacrylonitrile and either RP-amide or HS-F5 silica particles. Sampling was performed by inserting the microextraction probes into various tissues of living plants in their natural environment. After in vivo extraction, the probes were sealed under vacuum and refrigerated until analyzed. The probes were desorbed in mobile phase and analyzed on a Waters Acquity UPLC with triple quadrupole mass spectrometer in positive ion mode. Twenty Amazonian plant species were sampled and unique metabolomic fingerprints were obtained. In addition, quantitative analysis was performed for previously identified compounds in three species. Comparison of the fingerprints obtained by in vivo SPME with those obtained by LE showed that 27% of the chromatographic features were unique to SPME, 57% were unique to LE, and 16% were common to both methods. In vivo SPME caused minimal damage to the plants, was much faster than traditional liquid extraction, and provided unique fingerprints for all investigated plants. SPME revealed unique chromatographic

  9. When roads appear jaguars decline: Increased access to an Amazonian wilderness area reduces potential for jaguar conservation.

    Science.gov (United States)

    Espinosa, Santiago; Celis, Gerardo; Branch, Lyn C

    2018-01-01

    Roads are a main threat to biodiversity conservation in the Amazon, in part, because roads increase access for hunters. We examine how increased landscape access by hunters may lead to cascading effects that influence the prey community and abundance of the jaguar (Panthera onca), the top Amazonian terrestrial predator. Understanding such ecological effects originating from anthropogenic actions is essential for conservation and management of wildlife populations in areas undergoing infrastructure development. Our study was conducted in Yasuní Biosphere Reserve, the protected area with highest potential for jaguar conservation in Ecuador, and an area both threatened by road development and inhabited by indigenous groups dependent upon bushmeat. We surveyed prey and jaguar abundance with camera traps in four sites that differed in accessibility to hunters and used site occupancy and spatially explicit capture-recapture analyses to evaluate prey occurrence and estimate jaguar density, respectively. Higher landscape accessibility to hunters was linked with lower occurrence and biomass of game, particularly white-lipped peccary (Tayassu pecari) and collared peccary (Pecari tajacu), the primary game for hunters and prey for jaguars. Jaguar density was up to 18 times higher in the most remote site compared to the most accessible site. Our results provide a strong case for the need to: 1) consider conservation of large carnivores and other wildlife in policies about road construction in protected areas, 2) coordinate conservation initiatives with local governments so that development activities do not conflict with conservation objectives, and 3) promote development of community-based strategies for wildlife management that account for the needs of large carnivores.

  10. Satellite Images Combined with Field Data Reveal Negative Changes in the Distribution of Babassu Palms after Clearing off Amazonian Forests

    Science.gov (United States)

    Mitja, D.; Delaître, E.; Santos, A. M.; Miranda, I.; Coelho, R. F. R.; Macedo, D. J.; Demagistri, L.; Petit, M.

    2018-02-01

    When the Amazonian rain forest is cut to create pasture, some of the original vegetal species survive clearing, even expressing their ability to invade agro-systems. It is true of the babassu palm, which can be considered, paradoxically, a natural resource by the "Interstate Movement of Babassu Fruit Breaker Women" or as native weed by land owners-farmers. To manage potential conflict of land uses, we study here the current density of this palm tree in different habitats, based on a combination of field data and remote sensing data. Firstly, we checked that the field survey methodology (i.e., counting free-trunk palm trees over 20 cm in circumference) provides density values compatible with those stemming from satellite images interpretation. We can see then that, a PA-Benfica Brazilian territory revealed an average density of the babassu lower in pastures (2.86 ind/ha) than in the dense forest (4.72 ind/ha) from which they originate and than in fallow land (4.31 ind/ha). We analyze in detail density data repartition in three habitats and we discuss results from the literature on the density of this palm tree versus its resilience at different developmental stages after forest clearing, depending on anthropogenic—or not—factors, including solar radiation, fire, weeding, clear cutting, burying fruit, and competition with forage grass. All these results can be exploited for the design of future management plans for the babassu palm and we think that the linked methodology and interdisciplinary approach can be extended to others palms and trees species in similar problematic issues.

  11. Microphysical variability of vigorous Amazonian deep convection observed by CloudSat, and relevance for cloud-resolving model

    Science.gov (United States)

    Dodson, J. B.; Taylor, P. C.

    2017-12-01

    The number and varieties of both satellite cloud observations and cloud simulations are increasing rapidly. This create a challenge in identifying the best methods for quantifying the physical processes associated with deep convection, and then comparing convective observations with simulations. The use of satellite simulators in conjunction with model output is an increasingly popular method of comparison studies. However, the complexity of deep convective systems renders simplistic comparison metrics hazardous, possibly resulting is misleading or even contradicting conclusions. To investigate this, CloudSat observations of Amazonian deep convective cores (DCCs) and associated anvils are compared and contrasted with output from cloud resolving models in a manner that both highlights microphysical proprties of observed convection, and displays the effects of microphysical parameterizations on allowing robust comparisons. First, contoured frequency by altitude diagrams (CFAD) are calculated from the reflectivity fields of DCCs observed by CloudSat. This reveals two distinct modes of hydrometeor variability in the high level cloud region, with one dominated by snow and aggregates, and the other by large graupel and hail. Second, output from the superparameterized Community Atmospheric Model (SP-CAM) data are processed with the Quickbeam radar simulator to produce CFADs which can be compared with the observed CFADs. Two versions of SP-CAM are used, with one (version 4) having single-moment microphysics which excludes graupel/hail, and the other (version 5) a double-moment scheme with graupel. The change from version 4 to 5 improves the reflectivity CFAD, even without corresponding changes to non-hydrometeor fields such as vertical velocity. However, it does not produce a realistic double hydrometeor mode. Finally, the influences of microphysics are further tested in the System for Atmospheric Modeling (SAM), which allows for higher control over model parameters than

  12. Intensive trapping of blood-fed Anopheles darlingi in Amazonian Peru reveals unexpectedly high proportions of avian blood-meals.

    Directory of Open Access Journals (Sweden)

    Marta Moreno

    2017-02-01

    Full Text Available Anopheles darlingi, the main malaria vector in the Neotropics, has been considered to be highly anthropophilic. However, many behavioral aspects of this species remain unknown, such as the range of blood-meal sources. Barrier screens were used to collect resting Anopheles darlingi mosquitoes from 2013 to 2015 in three riverine localities (Lupuna, Cahuide and Santa Emilia in Amazonian Peru. Overall, the Human Blood Index (HBI ranged from 0.58-0.87, with no significant variation among years or sites. Blood-meal analysis revealed that humans are the most common blood source, followed by avian hosts (Galliformes-chickens and turkeys, and human/Galliforme mixed-meals. The Forage Ratio and Selection Index both show a strong preference for Galliformes over humans in blood-fed mosquitoes. Our data show that 30% of An. darlingi fed on more than one host, including combinations of dogs, pigs, goats and rats. There appears to be a pattern of host choice in An. darlingi, with varying proportions of mosquitoes feeding only on humans, only on Galliformes and some taking mixed-meals of blood (human plus Galliforme, which was detected in the three sites in different years, indicating that there could be a structure to these populations based on blood-feeding preferences. Mosquito age, estimated in two localities, Lupuna and Cahuide, ranged widely between sites and years. This variation may reflect the range of local environmental factors that influence longevity or possibly potential changes in the ability of the mosquito to transmit the parasite. Of 6,204 resting An. darlingi tested for Plasmodium infection, 0.42% were infected with P. vivax. This study provides evidence for the first time of the usefulness of barrier screens for the collection of blood-fed resting mosquitoes to calculate the Human Blood Index (HBI and other blood-meal sources in a neotropical malaria endemic setting.

  13. Heterogeneous movement of insectivorous Amazonian birds through primary and secondary forest: A case study using multistate models with radiotelemetry data

    Science.gov (United States)

    Hines, James; Powell, Luke L.; Wolfe, Jared D.; Johnson, Erik l.; Nichols, James D.; Stouffer, Phillip C.

    2015-01-01

    Given rates of deforestation, disturbance, and secondary forest accumulation in tropical rainforests, there is a great need to quantify habitat use and movement among different habitats. This need is particularly pronounced for animals most sensitive to disturbance, such as insectivorous understory birds. Here we use multistate capture–recapture models with radiotelemetry data to determine the successional stage at which within-day movement probabilities of Amazonian birds in secondary forest are similar to those in primary forest. We radio-tracked three common understory insectivore species in primary and secondary forest at the Biological Dynamics of Forest Fragments project near Manaus, Brazil: two woodcreepers, Glyphorynchus spirurus (n = 19) andXiphorhynchus pardalotus (n = 18), and the terrestrial antthrush Formicarius colma(n = 19). Forest age was a strong predictor of fidelity to a given habitat. All three species showed greater fidelity to primary forest than to 8–14-year-old secondary forest, indicating the latter’s relatively poor quality. The two woodcreeper species used 12–18-year-old secondary forest in a manner comparable to continuous forest, but F. colmaavoided moving even to 27–31-year-old secondary forest—the oldest at our site. Our results suggest that managers concerned with less sensitive species can assume that forest reserves connected by 12–18-year-old secondary forest corridors are effectively connected. On the other hand, >30 years are required after land abandonment before secondary forest serves as a primary forest-like conduit for movement by F. colma; more sensitive terrestrial insectivores may take longer still.

  14. Parameterization of Leaf-Level Gas Exchange for Plant Functional Groups From Amazonian Seasonal Tropical Rain Forest

    Science.gov (United States)

    Domingues, T. F.; Berry, J. A.; Ometto, J. P.; Martinelli, L. A.; Ehleringer, J. R.

    2004-12-01

    Plant communities exert strong influence over the magnitude of carbon and water cycling through ecosystems by controlling photosynthetic gas exchange and respiratory processes. Leaf-level gas exchange fluxes result from a combination of physiological properties, such as carboxylation capacity, respiration rates and hydraulic conductivity, interacting with environmental drivers such as water and light availability, leaf-to-air vapor pressure deficit, and temperature. Carbon balance models concerned with ecosystem-scale responses have as a common feature the description of eco-physiological properties of vegetation. Here we focus on the parameterization of ecophysiological gas-exchange properties of plant functional groups from a pristine Amazonian seasonally dry tropical rain forest ecosystem (FLONA-Tapajós, Santarém, PA, Brazil). The parameters were specific leaf weight, leaf nitrogen content, leaf carbon isotope ratio, maximum photosynthetic assimilation rate, photosynthetic carboxylation capacity, dark respiration rates, and stomatal conductance to water vapor. Our plant functional groupings were lianas at the top of the canopy, trees at the top of the canopy, mid-canopy trees and undestory trees. Within the functional groups, we found no evidence that leaves acclimated to seasonal changes in precipitation. However, there were life-form dependent distinctions when a combination of parameters was included. Top-canopy lianas were statistically different from top-canopy trees for leaf carbon isotope ratio, maximum photosynthetic assimilation rate, and stomatal conductance to water vapor, suggesting that lianas are more conservative in the use of water, causing a stomatal limitation on photosynthetic assimilation. Top-canopy, mid canopy and understory groupings were distinct for specific leaf weight, leaf nitrogen content, leaf carbon isotope ratio, maximum photosynthetic assimilation rate, and photosynthetic carboxylation capacity. The recognition that plant

  15. Is there a divide between local medicinal knowledge and Western medicine? a case study among native Amazonians in Bolivia

    Directory of Open Access Journals (Sweden)

    Calvet-Mir Laura

    2008-08-01

    Full Text Available Abstract Background Interest in ethnomedicine has grown in the last decades, with much research focusing on how local medicinal knowledge can contribute to Western medicine. Researchers have emphasized the divide between practices used by local medical practitioners and Western doctors. However, researchers have also suggested that merging concepts and practices from local medicinal knowledge and Western science have the potential to improve public health and support medical independence of local people. In this article we study the relations between local and Western medicinal knowledge within a native Amazonian population, the Tsimane'. Methods We used the following methods: 1 participant observation and semi-structured interviews to gather background information, 2 free-listing and pile-sorting to assess whether Tsimane' integrate local medicinal knowledge and Western medicine at the conceptual level, 3 surveys to assess to what extent Tsimane' combine local medicinal knowledge with Western medicine in actual treatments, and 4 a participatory workshop to assess the willingness of Tsimane' and Western medical specialists to cooperate with each other. Results We found that when asked about medical treatments, Tsimane' do not include Western treatments in their lists, however on their daily practices, Tsimane' do use Western treatments in combination with ethnomedical treatments. We also found that Tsimane' healers and Western doctors express willingness to cooperate with each other and to promote synergy between local and Western medical systems. Conclusion Our findings contrast with previous research emphasizing the divide between local medical practitioners and Western doctors and suggests that cooperation between both health systems might be possible.

  16. Impacts of selective logging on inbreeding and gene flow in two Amazonian timber species with contrasting ecological and reproductive characteristics.

    Science.gov (United States)

    Vinson, C C; Kanashiro, M; Harris, S A; Boshier, D H

    2015-01-01

    Selective logging in Brazil allows for the removal of up to 90% of trees above 50 cm diameter of a given timber species, independent of a species' life history characteristics or how quickly it will recover. The genetic and demographic effects of selective logging on two Amazonian timber species (Dipteryx odorata Leguminosae, Jacaranda copaia Bignoniaceae) with contrasting ecological and reproductive characteristics were assessed in the same forest. Genetic diversity and gene flow were characterized by genotyping adults and seed sampled before and after logging, using hypervariable microsatellite markers. Overall, there were no short-term genetic impacts on the J. copaia population, with commercial application of current Brazilian forest management regulations. In contrast, for D. Odorata, selective logging showed a range of genetic impacts, with a 10% loss of alleles, and reductions in siring by pollen from trees within the 546-ha study area (23-11%) and in the number of pollen donors per progeny array (2.8-1.6), illustrating the importance of the surrounding landscape. Asynchrony in flowering between D. odorata trees led to trees with no breeding partners, which could limit the species reproduction and regeneration under current regulations. The results are summarized with other published studies from the same site and the implications for forest management discussed. The different types and levels of impacts associated with each species support the idea that ecological and genetic information by species, ecological guild or reproductive group is essential in helping to derive sustainable logging guidelines for tropical forests. © 2014 John Wiley & Sons Ltd.

  17. A successful case of biological invasion: the fish Cichla piquiti, an Amazonian species introduced into the Pantanal, Brazil

    Directory of Open Access Journals (Sweden)

    EK. Resende

    Full Text Available The "tucunaré", Cichla piquiti, an exotic Amazonian fish has become established along the left bank of the Paraguay River in the Pantanal. It was introduced by escaping from culture ponds in the Upper Piquiri River and spread downstream, along the lateral flooded areas of that river, continuing through the clear waters of the left bank of the Paraguay River and reaching south as far as the Paraguai Mirim and Negrinho rivers. Adult spawners have been found in the region, meaning that it is a self-sustained population. Reproduction occurs in the period of low waters. They were found feeding on fishes of lentic environments belonging to the families Characidae, Cichlidae and Loricariidae. Until the end of 2004, its distribution was restricted to the left bank of the Paraguay River, but in March 2005, some specimens were found on the right bank, raising a question for the future: what will be the distribution area of the tucunaré in the Pantanal? Information about its dispersion is increasing: it is known to be in the Tuiuiú Lake, Pantanal National Park and in the Bolivian Pantanal, all of them on the right bank of the Paraguay River. The hypothesis that the "tucunaré" could not cross turbid waters, such as in the Paraguay River, was refuted by these recent findings. Possibly, the tucunaré's capacity to lay more than one batch of eggs in a reproductive period, as well as its care of eggs and young, lead them to establish themselves successfully in new environments, as has been observed in the Pantanal and other localities.

  18. Differential repetitive DNA composition in the centromeric region of chromosomes of Amazonian lizard species in the family Teiidae.

    Science.gov (United States)

    Carvalho, Natalia D M; Carmo, Edson; Neves, Rogerio O; Schneider, Carlos Henrique; Gross, Maria Claudia

    2016-01-01

    Differences in heterochromatin distribution patterns and its composition were observed in Amazonian teiid species. Studies have shown repetitive DNA harbors heterochromatic blocks which are located in centromeric and telomeric regions in Ameiva ameiva (Linnaeus, 1758), Kentropyx calcarata (Spix, 1825), Kentropyx pelviceps (Cope, 1868), and Tupinambis teguixin (Linnaeus, 1758). In Cnemidophorus sp.1, repetitive DNA has multiple signals along all chromosomes. The aim of this study was to characterize moderately and highly repetitive DNA sequences by C ot1-DNA from Ameiva ameiva and Cnemidophorus sp.1 genomes through cloning and DNA sequencing, as well as mapping them chromosomally to better understand its organization and genome dynamics. The results of sequencing of DNA libraries obtained by C ot1-DNA showed that different microsatellites, transposons, retrotransposons, and some gene families also comprise the fraction of repetitive DNA in the teiid species. FISH using C ot1-DNA probes isolated from both Ameiva ameiva and Cnemidophorus sp.1 showed these sequences mainly located in heterochromatic centromeric, and telomeric regions in Ameiva ameiva, Kentropyx calcarata, Kentropyx pelviceps, and Tupinambis teguixin chromosomes, indicating they play structural and functional roles in the genome of these species. In Cnemidophorus sp.1, C ot1-DNA probe isolated from Ameiva ameiva had multiple interstitial signals on chromosomes, whereas mapping of C ot1-DNA isolated from the Ameiva ameiva and Cnemidophorus sp.1 highlighted centromeric regions of some chromosomes. Thus, the data obtained showed that many repetitive DNA classes are part of the genome of Ameiva ameiva, Cnemidophorus sp.1, Kentroyx calcarata, Kentropyx pelviceps, and Tupinambis teguixin, and these sequences are shared among the analyzed teiid species, but they were not always allocated at the same chromosome position.

  19. A successful case of biological invasion: the fish Cichla piquiti, an Amazonian species introduced into the Pantanal, Brazil.

    Science.gov (United States)

    Resende, E K; Marques, D K S; Ferreira, L K S G

    2008-11-01

    The 'tucunaré', Cichla piquiti, an exotic Amazonian fish has become established along the left bank of the Paraguay River in the Pantanal. It was introduced by escaping from culture ponds in the Upper Piquiri River and spread downstream, along the lateral flooded areas of that river, continuing through the clear waters of the left bank of the Paraguay River and reaching south as far as the Paraguai Mirim and Negrinho rivers. Adult spawners have been found in the region, meaning that it is a self-sustained population. Reproduction occurs in the period of low waters. They were found feeding on fishes of lentic environments belonging to the families Characidae, Cichlidae and Loricariidae. Until the end of 2004, its distribution was restricted to the left bank of the Paraguay River, but in March 2005, some specimens were found on the right bank, raising a question for the future: what will be the distribution area of the tucunaré in the Pantanal? Information about its dispersion is increasing: it is known to be in the Tuiuiú Lake, Pantanal National Park and in the Bolivian Pantanal, all of them on the right bank of the Paraguay River. The hypothesis that the 'tucunaré' could not cross turbid waters, such as in the Paraguay River, was refuted by these recent findings. Possibly, the tucunaré's capacity to lay more than one batch of eggs in a reproductive period, as well as its care of eggs and young, lead them to establish themselves successfully in new environments, as has been observed in the Pantanal and other localities.

  20. Physiological impacts and bioaccumulation of dietary Cu and Cd in a model teleost: The Amazonian tambaqui (Colossoma macropomum).

    Science.gov (United States)

    Giacomin, Marina; Vilarinho, Gisele C; Castro, Katia F; Ferreira, Márcio; Duarte, Rafael M; Wood, Chris M; Val, Adalberto L

    2018-03-19

    Increasing anthropogenic activities in the Amazon have led to elevated metals in the aquatic environment. Since fish are the main source of animal protein for the Amazonian population, understanding metal bioaccumulation patterns and physiological impacts is of critical importance. Juvenile tambaqui, a local model species, were exposed to chronic dietary Cu (essential, 500 μg Cu/g food) and Cd (non-essential, 500 μg Cd/g food). Fish were sampled at 10-14, 18-20 and 33-36 days of exposure and the following parameters were analyzed: growth, voluntary food consumption, conversion efficiency, tissue-specific metal bioaccumulation, ammonia and urea-N excretion, O 2 consumption, P crit , hypoxia tolerance, nitrogen quotient, major blood plasma ions and metabolites, gill and gut enzyme activities, and in vitro gut fluid transport. The results indicate no ionoregulatory impacts of either of the metal-contaminated diets at gill, gut, or plasma levels, and no differences in plasma cortisol or lactate. The Cd diet appeared to have suppressed feeding, though overall tank growth was not affected. Bioaccumulation of both metals was observed. Distinct tissue-specific and time-specific patterns were seen. Metal burdens in the edible white muscle remained low. Overall, physiological impacts of the Cu diet were minimal. However dietary Cd increased hypoxia tolerance, as evidenced by decreased P crit , increased time to loss of equilibrium, a lack of plasma glucose elevation, decreased plasma ethanol, and decreased NQ during hypoxia. Blood O 2 transport characteristics (P 50 , Bohr coefficient, hemoglobin, hematocrit) were unaffected, suggesting that tissue level changes in metabolism accounted for the greater hypoxia tolerance in tambaqui fed with a Cd-contaminated diet. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Changing patterns of fire occurrence in proximity to forest edges, roads and rivers between NW Amazonian countries

    Science.gov (United States)

    Armenteras, Dolors; Barreto, Joan Sebastian; Tabor, Karyn; Molowny-Horas, Roberto; Retana, Javier

    2017-06-01

    Tropical forests in NW Amazonia are highly threatened by the expansion of the agricultural frontier and subsequent deforestation. Fire is used, both directly and indirectly, in Brazilian Amazonia to propagate deforestation and increase forest accessibility. Forest fragmentation, a measure of forest degradation, is also attributed to fire occurrence in the tropics. However, outside the Brazilian Legal Amazonia the role of fire in increasing accessibility and forest fragmentation is less explored. In this study, we compared fire regimes in five countries that share this tropical biome in the most north-westerly part of the Amazon Basin (Venezuela, Colombia, Ecuador, Peru and Brazil). We analysed spatial differences in the timing of peak fire activity and in relation to proximity to roads and rivers using 12 years of MODIS active fire detections. We also distinguished patterns of fire in relation to forest fragmentation by analysing fire distance to the forest edge as a measure of fragmentation for each country. We found significant hemispheric differences in peak fire occurrence with the highest number of fires in the south in 2005 vs. 2007 in the north. Despite this, both hemispheres are equally affected by fire. We also found difference in peak fire occurrence by country. Fire peaked in February in Colombia and Venezuela, whereas it peaked in September in Brazil and Peru, and finally Ecuador presented two fire peaks in January and October. We confirmed the relationship between fires and forest fragmentation for all countries and also found significant differences in the distance between the fire and the forest edge for each country. Fires were associated with roads and rivers in most countries. These results can inform land use planning at the regional, national and subnational scales to minimize the contribution of road expansion and subsequent access to the Amazonian natural resources to fire occurrence and the associated deforestation and carbon emissions.

  2. Female Empowerment of Amazonian Riverine Beneficiaries of the Bolsa Família Program

    Directory of Open Access Journals (Sweden)

    Thamyris Maués dos Santos

    2017-06-01

    Full Text Available Today, policies of combat to poverty prioritize women as owners in programs of income transference, among them, Bolsa Família Program. Considering that women empowerment is influenced by this social policy, this research aimed to identify the dimensions of the process of empowerment achieved by riparian women, beneficiary of the program. The research was performed at Combú Island, Belém do Pará. Four riparian mothers took part in the study. For data collection, the Sociodemographic Inventory and semi structured interviews were used. As procedure of organization of information, content analysis was used. The categories, which appeared from the beneficiary perceptions were adapted from literature and defined as economic, family, social and psychological empowerment. The results showed that after the entrance in BFP the notion of a owned income and bigger control of resources were obtained by a parcel of the participants, providing a partial economic empowerment. The befit increased the purchase power, and gave to these women grater management over family decision-making. The ownership of the program’s card made them to feel benefited when following-up children, providing social visibility to these mothers, when not depending completely of the husbands’ intermediation. Lastly, the benefit generated in the participants a feeling of stability, for having money, security for the family monthly needs. The empowerment that riparian women achieved shows that they passed to interfere in the dynamics and providing of the family before the lack or not of their husbands’ income.

  3. A New 13 Million Year Old Gavialoid Crocodylian from Proto-Amazonian Mega-Wetlands Reveals Parallel Evolutionary Trends in Skull Shape Linked to Longirostry

    Science.gov (United States)

    Salas-Gismondi, Rodolfo; Flynn, John J.; Baby, Patrice; Tejada-Lara, Julia V.; Claude, Julien; Antoine, Pierre-Olivier

    2016-01-01

    Gavialoid crocodylians are the archetypal longirostrine archosaurs and, as such, understanding their patterns of evolution is fundamental to recognizing cranial rearrangements and reconstructing adaptive pathways associated with elongation of the rostrum (longirostry). The living Indian gharial Gavialis gangeticus is the sole survivor of the group, thus providing unique evidence on the distinctive biology of its fossil kin. Yet phylogenetic relationships and evolutionary ecology spanning ~70 million-years of longirostrine crocodylian diversification remain unclear. Analysis of cranial anatomy of a new proto-Amazonian gavialoid, Gryposuchus pachakamue sp. nov., from the Miocene lakes and swamps of the Pebas Mega-Wetland System reveals that acquisition of both widely separated and protruding eyes (telescoped orbits) and riverine ecology within South American and Indian gavialoids is the result of parallel evolution. Phylogenetic and morphometric analyses show that, in association with longirostry, circumorbital bone configuration can evolve rapidly for coping with trends in environmental conditions and may reflect shifts in feeding strategy. Our results support a long-term radiation of the South American forms, with taxa occupying either extreme of the gavialoid morphospace showing preferences for coastal marine versus fluvial environments. The early biogeographic history of South American gavialoids was strongly linked to the northward drainage system connecting proto-Amazonian wetlands to the Caribbean region. PMID:27097031

  4. Differential Expression of Myogenic Regulatory Factor Genes in the Skeletal Muscles of Tambaqui Colossoma macropomum (Cuvier 1818) from Amazonian Black and Clear Water.

    Science.gov (United States)

    Alves-Costa, F A; Barbosa, C M; Aguiar, R C M; Mareco, E A; Dal-Pai-Silva, M

    2013-01-01

    Hypothesizing that the Amazonian water system differences would affect the expression of muscle growth-related genes in juvenile tambaqui Colossoma macropomum (Cuvier 1818), this study aimed to analyze the morphometric data and expression of myogenic regulatory factors (MRFs) in the white and red muscle from tambaqui obtained from clear and black Amazonian water systems. All of the MRF transcript levels (myod, myf5, myogenin, and mrf4) were significantly lower in the red muscle from black water fish in comparison to clear water fish. However, in white muscle, only the myod transcript level was significantly decreased in the black water tambaqui. The changes in MRFs gene expression in muscle fibers of tambaqui from black water system provide relevant information about the environmental influence as that of water systems on gene expression of muscle growth related genes in the C. macropomum. Our results showed that the physical and chemical water characteristics change the expression of genes that promote muscle growth, and these results may be also widely applicable to future projects that aim to enhance muscle growth in fish that are of substantial interest to the aquaculture.

  5. Differential Expression of Myogenic Regulatory Factor Genes in the Skeletal Muscles of Tambaqui Colossoma macropomum (Cuvier 1818 from Amazonian Black and Clear Water

    Directory of Open Access Journals (Sweden)

    F. A. Alves-Costa

    2013-01-01

    Full Text Available Hypothesizing that the Amazonian water system differences would affect the expression of muscle growth-related genes in juvenile tambaqui Colossoma macropomum (Cuvier 1818, this study aimed to analyze the morphometric data and expression of myogenic regulatory factors (MRFs in the white and red muscle from tambaqui obtained from clear and black Amazonian water systems. All of the MRF transcript levels (myod, myf5, myogenin, and mrf4 were significantly lower in the red muscle from black water fish in comparison to clear water fish. However, in white muscle, only the myod transcript level was significantly decreased in the black water tambaqui. The changes in MRFs gene expression in muscle fibers of tambaqui from black water system provide relevant information about the environmental influence as that of water systems on gene expression of muscle growth related genes in the C. macropomum. Our results showed that the physical and chemical water characteristics change the expression of genes that promote muscle growth, and these results may be also widely applicable to future projects that aim to enhance muscle growth in fish that are of substantial interest to the aquaculture.

  6. Recycling of Amazonian detrital zircons in the Mixteco terrane, southern Mexico: Paleogeographic implications during Jurassic-Early Cretaceous and Paleogene times

    Science.gov (United States)

    Silva-Romo, Gilberto; Mendoza-Rosales, Claudia Cristina; Campos-Madrigal, Emiliano; Morales-Yáñez, Axél; de la Torre-González, Alam Israel; Nápoles-Valenzuela, Juan Ivan

    2018-04-01

    In the northeastern Mixteco terrane of southern Mexico, in the Ixcaquixtla-Atzumba region, the recycling of Amazonian detrital zircons records the paleogeography during the Mesozoic period in the context of the breakup of Pangea, a phenomenon that disarticulated the Sanozama-La Mora paleo-river. The clastic units of southern Mexico in the Ayuquila, Otlaltepec and Zapotitlán Mesozoic basins, as well as in the Atzumba Cenozoic basin, are characterized by detrital zircon contents with ages specific to the Amazonian craton, ranging between 3040 and 1278 Ma. The presence of zircons of Amazonian affinity suggests a provenance by recycling from carrier units such as the La Mora Formation or the Ayú Complex. In the area, the Ayú and Acatlán complexes form the Cosoltepec block, a paleogeographic element that during Early Cretaceous time acted as the divide between the slopes of the paleo-Gulf of Mexico and the paleo-Pacific Ocean. The sedimentological characteristics of the Jurassic-Cenozoic clastic successions in the Ixcaquixtla-Atzumba region denote relatively short transport in braided fluvial systems and alluvial fans. In this way, several basins are recognized around the Cosoltepec block. At the southeastern edge of the Cosoltepec block, the Ayuquila and Tecomazúchil formations accumulated in the Ayuquila continental basin on the paleo-Pacific Ocean slope. On the other hand, within the paleo-Gulf of Mexico slope, in the Otlaltepec continental basin, the Piedra Hueca and the Otlaltepec formations accumulated. The upper member of the Santa Lucía Formation accumulated in a transitional environment on the southwestern shoulder of the Zapotitlán basin, as well as on the paleo-Gulf of Mexico slope. In the Ayuquila basin, a marine transgression is recognized that advanced from south to north during the Late Jurassic. At the northeastern edge of the Cosoltepec block, we propose that the Santa Lucía formation attests to a transgression from the paleo-Gulf of Mexico

  7. The influence of the Amazonian floodplain ecosystems on the trace element dynamics of the Amazon River mainstem (Brazil).

    Science.gov (United States)

    Viers, Jérôme; Barroux, Guénaël; Pinelli, Marcello; Seyler, Patrick; Oliva, Priscia; Dupré, Bernard; Boaventura, Geraldo Resende

    2005-03-01

    productivity of floodplain ecosystems, a first order approximation of trace element storage (permanent or temporary) in the vegetation of these floodplains was made. It was found that floodplain-mainstem elemental fluxes make a significant contribution to the dissolved flux of the Amazon River. This study is part of the Brazilian_French joint research program Hybam (Hydrology and Geochemistry of the Amazonian Basin).

  8. Systematics and biogeography of the Neotropical genus Mabuya, with special emphasis on the Amazonian skink Mabuya nigropunctata (Reptilia, Scincidae).

    Science.gov (United States)

    Miralles, A; Carranza, S

    2010-03-01

    Phylogenetic analyses using up to 1532 base pairs (bp) of mitochondrial DNA from 106 specimens of Neotropical Mabuya, including 18 of the 19 recognized South American and Mesoamerican species, indicate that most species of the genus are monophyletic, including M. nigropunctata that had previously been reported to be paraphyletic. The present results shows that this species includes three highly divergent and largely allopatric lineages restricted to occidental, meridional, and oriental Amazonia. Our dataset demonstrates that previous claims regarding the paraphyletic status of M. nigropunctata and the phylogenetic relationships within this species complex based on the analysis of three mitochondrial and four nuclear genes (approx. 5000bp) were erroneous and resulted from two contaminated cytochrome b sequences. The phylogenetic results indicate that diversification in the Neotropical genus Mabuya started approximately in the Middle Miocene (15.5-13.4Ma). The divergence dates estimated for the Mabuya nigropunctata species complex suggest that the major cladogenetic events that produced the three main groups (occidental (oriental+meridional)) occurred during the Late Miocene. These estimations show that diversification within the M. nigropunctata species complex was not triggered by the climatic changes that occurred during the Pleistocene, as has been suggested by several authors. Rather, our data support the hypothesis that the late tertiary (essentially Miocene epoch) was a period that played a very important role in the generation of biological diversity in the Amazonian forests. Speciation between Mabuyacarvalhoi, endemic to the coastal mountain range of Venezuela, and M. croizati, restricted to the Guiana Shield, occurred during the Middle Miocene and may have been as the result of a vicariant event produced by the formation of the present day Orinoco river drainage basin and the consequent appearance of the Llanos del Orinoco, which acted as a barrier to

  9. Ion and acid-base balance in three species of Amazonian fish during gradual acidification of extremely soft water.

    Science.gov (United States)

    Wilson, R W; Wood, C M; Gonzalez, R J; Patrick, M L; Bergman, H L; Narahara, A; Val, A L

    1999-01-01

    Sensitivity to acid water was assessed in three species of Amazonian fish that encounter naturally acidic blackwaters to differing degrees in the wild: tambaqui (Colossoma macropomum), matrincha (Brycon erythropterum), and tamoatá (Hoplosternum littorale), in decreasing order of occurrence in blackwater. Fish were exposed to a graded reduction in water pH, from pH 6 to 5 to 4 to 3.5, followed by return to pH 6. Fish were exposed to each new pH for 24 h. During these exposures, net transfers of ions (Na+, K+, Cl-, and Ca2+) and acid-base equivalents to and from the external water were used as physiological indicators of acid tolerance. Exposure to pH 5 had a minimal effect on net ion fluxes. Significant net losses of all ions (except Ca2+) were recorded in all three species during the first few hours of exposure to pH 4. However, ion balance was usually restored within 18 h at pH 4. Exposure to pH 3.5 caused even greater ion losses in all three species and proved to be acutely lethal to tamoatá. Matrincha sustained irreversible physiological damage at pH 3.5, as ion fluxes did not recover following return to pH 6 and there was some mortality. Tambaqui suffered the least ionoregulatory disturbances at pH 3.5 and was the only species to make a full recovery on return to pH 6. In all species, there was a tendency for ammonia excretion to increase at low water pH, but even at pH 3.5, there was no significant net uptake of acid from the water. Overall, there was a strong relationship between the magnitude of ionic disturbances and the lethality of exposure to low pH. The relative insensitivity of the ionoregulatory system of tambaqui to low pH indicates that this is a feature of fish native to blackwater systems rather than one that is common to all Amazon fish.

  10. Investigating copper toxicity in the tropical fish cardinal tetra (Paracheirodon axelrodi) in natural Amazonian waters: Measurements, modeling, and reality

    Energy Technology Data Exchange (ETDEWEB)

    Crémazy, Anne, E-mail: acremazy@zoology.ubc.ca [Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Wood, Chris M. [Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Smith, D. Scott [Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, ON N2L 3C5 (Canada); Ferreira, Márcio S. [Laboratory of Ecophysiology and Molecular Evolution, National Institute for Amazonian Research, Manaus, AM (Brazil); Johannsson, Ora E.; Giacomin, Marina [Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Val, Adalberto L. [Laboratory of Ecophysiology and Molecular Evolution, National Institute for Amazonian Research, Manaus, AM (Brazil)

    2016-11-15

    Highlights: • Copper toxicity to a tropical fish varied greatly in different Amazonian waters. • The biotic ligand model could not capture this variability. • Possible physiological protection was offered by natural organic matter. • Care must be used in applying BLM to fish in tropical waters. - Abstract: Copper at high concentrations is an ionoregulatory toxicant in fish and its toxicity is known to be strongly modulated by the water chemistry. The toxicity of Cu to the tropical fish cardinal tetra (Paracheirodon axelrodi) was investigated in waters from two major rivers of the Amazon watershed: the Rio Negro (filtered <0.45 μm, pH 5.6, DOC = 8.4 mg L{sup −1}, Na = 33 μM, Ca = 8 μM) and the Rio Solimões (filtered <0.45 μm, pH 6.7, DOC = 2.8 mg L{sup −1}, Na = 185 μM, Ca = 340 μM), as well as in a natural “reference water” (groundwater) which was almost DOC-free (pH 6.0, DOC = 0.34 mg L{sup −1}, Na = 53 μM, Ca = 5 μM). Acute 96-h mortality, Cu bioaccumulation and net flux rates of Na{sup +}, Cl{sup −}, K{sup +} and total ammonia were determined in P. axelrodi exposed in each water. Copper speciation in each water was determined by two thermodynamic models and by potentiometry, and its toxicity was predicted based on the biotic ligand model (BLM) framework. Our results indicate that high Na{sup +} loss is the main mode of toxic action of Cu in P. axelrodi, in accordance with general theory. Cardinal tetra showed a particularly high ability to tolerate Cu and to maintain Na{sup +} balance, similar to the ability of this and other endemic Rio Negro species to tolerate low pH and ion-poor conditions. Cu toxicity was lower in Rio Negro than in the other two waters tested, and the free [Cu{sup 2+}] at the LC50, as determined by any of the three speciation methods tested, was approximately 10-fold higher. This variation could not be captured by a realistic set of BLM parameters. At least in part, this observation may be due to gill

  11. Responses of an Amazonian teleost, the tambaqui (Colossoma macropomum), to low pH in extremely soft water.

    Science.gov (United States)

    Wood, C M; Wilson, R W; Gonzalez, R J; Patrick, M L; Bergman, H L; Narahara, A; Val, A L

    1998-01-01

    Our goal was to compare the internal physiological responses to acid challenge in an acidophilic tropical teleost endemic to dilute low-pH waters with those in nonacidophilic temperate species such as salmonids, which have been the subjects of most previous investigations. The Amazonian tambaqui (Colossoma macropomum), which migrates between circumneutral water and dilute acidic "blackwater" of the Rio Negro, was exposed to a graded low-pH and recovery regime in representative soft water (Na+ = 15, Cl- = 16, Ca2+ = 20 mumol L-1). Fish were fitted with arterial catheters for repetitive blood sampling. Water pH was altered from 6.5 (control) to 5.0, 4.0, 3.0, and back to 6.5 (recovery) on successive days. Some deaths occurred at pH 3.0. Throughout the regime, there were no disturbances of blood gases (O2 and CO2 tensions and contents) or lactate levels, and only very minor changes in acid-base status of plasma and red cells. However, erythrocytic guanylate and adenylate levels increased at pH's less than or equal to 5.0. Down to pH 4.0, plasma glucose, cortisol, and total ammonia levels remained constant, but all increased at pH 3.0, denoting a stress response. Plasma Na+ and Cl- levels declined and plasma protein concentration increased at pH 3.0, indicative of ionoregulatory and fluid volume disturbance, and neither recovered upon return to pH 6.5. Cortisol and ammonia elevations also persisted. Transepithelial potential changed progressively from highly negative values (inside) at pH 6.5 to highly positive values at pH 3.0; these alterations were fully reversible. Experimental elevations in water calcium levels drove the transepithelial potential positive at circumneutral pH, attenuated or prevented changes in transepithelial potential at low pH, and reduced Na+ and Cl- loss rates to the water during acute low-pH challenges. In general, tambaqui exhibited responses to low pH that were qualitatively similar but quantitatively more resistant than those previously

  12. Anemia and Iron Deficiency in School Children, Adolescents, and Adults: A Community-Based Study in Rural Amazonia

    Science.gov (United States)

    Ferreira, Marcelo U.; da Silva-Nunes, Mônica; Bertolino, Carla N.; Malafronte, Rosely S.; Muniz, Pascoal T.; Cardoso, Marly A.

    2007-01-01

    We investigated the prevalence and risk factors of anemia and iron deficiency in 398 rural Amazonians aged 5–90 years in Acre, Brazil. Anemia and iron deficiency were diagnosed in 16% and 19% of the population, respectively. Anemia was likely to have multiple causes; although nearly half of anemic school children and women had altered iron status indicators, only 19.7% of overall anemia was attributable to iron deficiency. Geo-helminth infection and a recent malaria episode were additional factors affecting iron status indicators in this population. PMID:17194861

  13. Do attention deficit/hyperactivity disorder symptoms exist among Brazilian indigenous children?

    Directory of Open Access Journals (Sweden)

    Paulo Verlaine Borges e Azevêdo

    Full Text Available Abstract The validity of the clinical constructs of attention deficit hyperactivity disorder (ADHD has been generalized for all human populations of different cultures worldwide. Yet important population groups have yet to be adequately studied so as to definitively confirm this generalization. Objective: To investigate the presence of symptoms of ADHD in children living within an indigenous community. Methods: We performed interviews in a bid to screen for symptoms of ADHD among settlement-dwelling indigenous children of the Karajá ethnic group in the Brazilian Amazonian Region. Results: Three narratives are presented highlighting the classical symptomatological triad of ADHD: inattentiveness, hyperactivity and impulsiveness. Conclusions: Some of ADHD's major characteristics, described in the most common disease classification worldwide, are clearly described by children of this population. We concluded that ADHD symptoms are present in this population which diverges greatly in cultural issues compared to the Western world

  14. Feeding habits of Sotalia fluviatilis in the Amazonian Estuary = Hábitos alimentares de Sotalia fluviatilis no estuário amazônico

    Directory of Open Access Journals (Sweden)

    Sandra Beltrán-Pedreros

    2006-10-01

    Full Text Available In this paper we present an analysis of the fifty S. fluviatilis feeding habits in the Amazonian Estuary. Animals were bycaught by the artisanal fishing fleet between 1996 and 2001. Feeding habits were analyzed by prey occurrence frequency (%F and number percentage and stomachs contents preys similarity between marine and freshwater fishspecies present in the Amazonian Estuary. Thirteen fish species were identified (%F= 86.6, the most significant families were Sciaenidae (32%, Trichiuridae (26% e Ariidae (16%, and four crustaceans species (%F=26. S. fluviatilis feeding habits did not differ bygender and in general, calves had higher prey diversity than juveniles and adults. The similarity was high (0.89 between estuarine S. fluviatilis feeding habits and the fishes speciespresent in the Amazonian Estuary when the environment is mostly marine.Objetivou-se descrever e analisar os hábitos alimentares de 50 golfinhos Sotalia fluviatilis capturados acidentalmente na frota pesqueira artesanal do Estuário Amazônico entre 1996 e 2001. As presas foram identificadas e calculadas a freqüência de ocorrência e numérica; testada a similaridade entre a diversidade de presas dos conteúdos e a diversidade de peixes marinhos e de água doce do estuário e, comparados os hábitos alimentares por sexo e categoria de maturidade. Ocorreram 13 espécies de peixes (86,6% onde as famíliasSciaenidae (32%, Trichiuridae (26% e Ariidae (16% foram mais representativas e, quatro espécies de crustáceos (26%. A espécie não apresentou diferenças nos hábitos alimentares entre sexos, mas, os filhotes tiveram maior diversidade de presas que jovens e adultos.Finalmente, houve maior similaridade (0.89 entre a diversidade de presas de S. fluviatilis e as espécies de peixes quando o estuário apresenta características marinhas.

  15. Thermal structure of the Poraquê lake, Central Amazonian, Brazil - doi: 10.4025/actascibiolsci.v33i2.5150 Thermal structure of the Poraquê lake, Central Amazonian, Brazil - doi: 10.4025/actascibiolsci.v33i2.5150

    Directory of Open Access Journals (Sweden)

    Fabio Marques Aprile

    2011-05-01

    Full Text Available Thermal gradient of a Central Amazonian lake was studied to establish a link between seasonal variations in the water level, temperature, suspended particulate matter (SPM and thermal stratification. Bimonthly measurements of temperature and PAR radiation were made at 0.25 m intervals from the surface to bottom from February 2004 to July 2006. Daily occurs full vertical mixing of the water column, and classic thermal stratification was not observed in the period. The effect of the winds associated to flood-pulse and the penetrative convection, transported the turbulent kinetic energy (TKE into the lake mixing the column of water. This phenomenon was more expressive in the rainfall seasons when is generally higher contributing to the circulation of the water. The limit of the euphotic zone ranged from 1.36 to 1.77 m in the period studied. The results of the transmission curves for the sampling sites showed that, in general, less than 0.01% of the surface light reached the bottom. The trend curve developed can facilitate the understanding of the limnological and ecological processes in lentic systems of whitewaters of the Central Amazonian.Thermal gradient of a Central Amazonian lake was studied to establish a link between seasonal variations in the water level, temperature, suspended particulate matter (SPM and thermal stratification. Bimonthly measurements of temperature and PAR radiation were made at 0.25 m intervals from the surface to bottom from February 2004 to July 2006. Daily occurs full vertical mixing of the water column, and classic thermal stratification was not observed in the period. The effect of the winds associated to flood-pulse and the penetrative convection, transported the turbulent kinetic energy (TKE into the lake mixing the column of water. This phenomenon was more expressive in the rainfall seasons when is generally higher contributing to the circulation of the water. The limit of the euphotic zone ranged from 1.36 to 1

  16. Human modification of a large meandering Amazonian river: genesis, ecological and economic consequences of the Masisea cutoff on the central Ucayali, Peru.

    Science.gov (United States)

    Coomes, Oliver T; Abizaid, Christian; Lapointe, Michel

    2009-05-01

    Evidence is mounting regarding the significant extent and scope of long-term human modification of "pristine nature" in the neotropics. In Amazonia, recent studies point to the landscape imprint of human activity that has transformed the forests, savannas, soils, and waterways of the basin. In this report, we describe a massive meander cutoff in the Peruvian Amazon along the Ucayali River--the fifth-longest river in the Amazon basin--that was triggered by small-scale human actions and resulted in significant ecological and economic consequences for the region. The modern case of the Masisea cutoff-near the Amazonian port city of Pucallpa, Peru (285,000 inhabitants)-indicates that humans using simple tools can play a major role in transforming large meandering rivers and their floodplains.

  17. Richness and composition of macrophyte assemblages in four Amazonian lakes - doi: 10.4025/actascibiolsci.v35i3.11602

    Directory of Open Access Journals (Sweden)

    Sidinei Magela Thomaz

    2013-08-01

    Full Text Available Aquatic macrophytes are an important component in the structure of lakes in Neotropical floodplains, for example, because they support a high diversity of invertebrates and vertebrates. In this paper, we tested whether or not the variability of macrophyte assemblages is lower in spatially close quadrats than among quadrats of different lakes. The study was carried in four lakes in a large Amazonian floodplain (Purus river, where floating meadows were investigated. A total of 49 taxa of macrophytes were found. Five species dominated and three species were rare. Taxa richness, composition and beta diversity differed more between than within lakes. Because high beta diversity was found among the lakes, they should be considered individually important for maintaining the gamma diversity of macrophytes within the Purus River floodplain, and this should be considered in plans of lake management.  

  18. A study of the hydrothermal alteration in Paleoproterozoic volcanic centers, São Félix do Xingu region, Amazonian Craton, Brazil, using short-wave infrared spectroscopy

    Science.gov (United States)

    da Cruz, Raquel Souza; Fernandes, Carlos Marcello Dias; Villas, Raimundo Netuno Nobre; Juliani, Caetano; Monteiro, Lena Virgínia Soares; de Almeida, Teodoro Isnard Ribeiro; Lagler, Bruno; de Carvalho Carneiro, Cleyton; Misas, Carlos Mario Echeverri

    2015-10-01

    Hypogene hydrothermal minerals have been identified by short-wave infrared spectroscopy in hydrothermally altered rocks from the Sobreiro and Santa Rosa formations, which belong to a Paleoproterozoic volcano-plutonic system in Amazonian craton. Three clay minerals are spectrally recognized: montmorillonite, kaolinite, and illite. The integration of these data with those available in the literature, including gold occurrences, suggests that those rocks are hydrothermal products of both volcanic thermal sources and later crustal intrusions, as evidenced by variable styles of propylitic, sericitic, potassic, and intermediate argillic alteration. The influence of meteoric fluids is emphasized. This low cost exploratory technique, which can be applied to hand samples, seems to be promising in the separation of hydrothermally altered volcano-plutonic centers in regions submitted to severe weathering conditions, in addition to aid elaborating models for prospecting mineral deposits.

  19. Influence of the natural Rio Negro water on the toxicological effects of a crude oil and its chemical dispersion to the Amazonian fish Colossoma macropomum.

    Science.gov (United States)

    Sadauskas-Henrique, Helen; Braz-Mota, Susana; Duarte, Rafael Mendonça; de Almeida-Val, Vera Maria Fonseca

    2016-10-01

    The increment in crude oil exploitation over the last decades has considerably increased the risk of polycyclic aromatic hydrocarbon (PAH) contamination to Amazonian aquatic environments, especially for the black water environments such as the Rio Negro. The present work was designed to evaluate the acute toxicity of the Urucu crude oil (CO), the chemically dispersed Urucu crude oil (CO + D), and the dispersant alone (D) to the Amazonian fish Colossoma macropomum. Acute toxicity tests were performed, using a more realistic approach, where fish were acclimated to both groundwater (GW), used as internal control, and natural Rio Negro water (RNW) and exposed to CO, CO + D and D. Then, biomarkers such as ethoxyresorufin-O-deethylase (EROD), superoxide dismutase (SOD), lipid peroxidation (LPO), serum sorbitol dehydrogenase (s-SDH) in liver, DNA damage in blood cells, and the presence of the benzo[a]pyrene-type, pyrene-type, and naphthalene-type metabolites in fish bile were assessed. Fish exposed to CO and CO + D, at both water types tested, presented increased biomarker responses and higher PAH-type metabolites in the bile. However, fish exposed to these treatments after the acclimation to RNW increased the levels of LPO, s-SDH (hepatotoxicity), DNA damage in blood cells (genotoxicity), and benzo[a]pyrene-type metabolites when compared to fish in GW. Our data suggests that some physicochemical properties of Rio Negro water (i.e., presence of natural organic matter (NOM)) might cause mild chemical stress responses in fish, which can make it more susceptible to oxidative stress following exposure to crude oil, particularly to those chemically dispersed.

  20. Study of ice-related flow features around Tanaica Montes, Mars: Implications for late amazonian debris-covered glaciation

    Science.gov (United States)

    Sinha, Rishitosh K.; Vijayan, S.; Bharti, Rajiv R.

    2017-11-01

    reflectors with the surrounding plains when a permittivity of ice (3.2) is assumed and the radargram is depth-corrected, we infer that some of the portions of LDA flow units have preserved ice in their subsurface up to ∼300-500 m depth. Crater size frequency distribution of craters counted on LDA surface indicates that the best-fit age is ∼110 Ma. In addition, the LDA surfaces exhibit different best-fit ages for different types of crater morphologies (bowl-shaped, ring-mold and infilled craters) included in the crater count statistics. Together, these observations and the interpretations suggest that most, if not all, of the LDAs in the study region are like classical LDAs mapped in other regions of Mars (e.g. along the mid-latitude dichotomy boundary and eastern Hellas region). These results indicate that a widespread accumulation and preservation of ice has occurred during the Late Amazonian as suggested in previous studies.

  1. EFFECT OF FALLOW LAND, CULTIVATED PASTURE AND ABANDONED PASTURE ON SOIL FERTILITY IN TWO DEFORESTED AMAZONIAN REGIONS

    Directory of Open Access Journals (Sweden)

    J.A DIEZ

    1997-01-01

    Full Text Available The effect of two practices adopted by settlers (abandoned pasture and fallow land on soil fertility of two deforested Amazonian regions (Belém-Pará and Ariquemes-Rondônia was studied. Whenever possible, cultivated pasture, over similar time periods in both cases and in natural forest, were employed as soil fertility reference standards. Nutrient dynamics was studied using the electroultra-filtration technique. In general, deforestation, as practiced in these areas, has a degrading effect on soil fertility. The effect of burning normally leads to a pH rise caused by ash. This usually yields a favorable transitory effect, improving soil fertility conditions, however not sufficient for plant needs, as inferred from the low P and K levels. Cattle excrements, improved the K level for cultivated pastures. Qualitative differences related to N were observed between cultivated pasture and both, fallow land or abandoned pasture. In the first, a certain recovery of available N levels was detected, mainly affecting the EUF-Norg fraction. On the other hand, a regeneration of organic compounds, in the fallow land and the abandoned pasture, closely related to those existing in the natural forest, was verified. This is mainly due to the presence of a higher proportion of NO3-_N and, consequently, a EUF-Norg/EUF-NO3- ratio close to 1.Comparou-se o efeito de duas práticas de manejo, ou seja, o abandono da pastagem e o pousio, sobre a fertilidade do solo de duas regiões desmatadas da Amazônia (Belém-Pará e Ariquemes-Rondônia. Quando possível, pastagens cultivadas por períodos semelhantes e florestas nativas foram usadas como padrões da fertilidade do solo. A dinâmica dos nutrientes foi estuda pela técnica da eletroultrafiltração (EUF. De um modo geral, o desmatamento, como praticado nessas regiões, tem efeito degradador sobre a fertilidade do solo. A queima da biomassa vegetal normalmente leva a um aumento do pH causado pelas cinzas, resultando

  2. Resilience of Amazonian forests

    NARCIS (Netherlands)

    Monteiro Flores, B.

    2016-01-01

    The Amazon has recently been portrayed as a resilient forest system based on quick recovery of biomass after human disturbance. Yet with climate change, the frequency of droughts and wildfires may increase, implying that parts of this massive forest may shift into a savanna state. Although the

  3. The PIATAM MAR I Project and its environmental and social management of the Amazonian coastal zone; O Projeto PIATAM MAR I e a gestao ambiental e social da zona costeira amazonica

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Edson R.S.P. da; Miranda, Fernando P. de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Geoquimica]. E-mails: ercunha@petrobras.com.br; fmiranda@cenpes.petrobras.com.br; Souza Filho, Pedro Walfir Martins [Universidade Federal do Para (UFPA), Belem, PA (Brazil)]. E-mail: walfir@ufpa.br; Sales, Maria E. da C. [Museu Paraense Emilio Goeldi (MPEG), Belem, PA (Brazil)]. E-mail: bia@museu-goeldi.br; Landau, Luiz [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto Alberto Luiz Coimbra de Pos-Graduacao e Pesquisa de Engenharia (COPPE)]. E-mail: landau@lamce.ufrj.br

    2004-07-01

    PETROBRAS is carrying out applied research as an aid to environmental management and systematic monitoring of the complex Amazonian ecosystem. This effort is contemplated in Western Amazonia by projects PIATAM II, PIATAM III, and Cognitus I. PIATAM MAR I was recently extended the scientific benefits of this initiative to the Amazonian coast. Data acquired up to now in this region are stored in different Institutions using distinct structures and formats. Such a circumstance is a hindrance to their application in a multidisciplinary fashion for mapping environmental sensitivity to oil spills along the shoreline therefore, the prime objective of PIATAM MAR I is to consolidate in digital form environmental information available in Eastern Amazonia, in order to allow the integrated geographic analysis of this data set. Such a procedure will make feasible the construction of environmental sensitivity maps tailored to the unique conditions of the Amazonian coast (high tides, huge fluvial discharge, and mangrove development for thousands of kilometers). The research will offer the conceptual basis for systematic monitoring by PETROBRAS in the region, aiming at avoiding environmental damage to nature and society caused by oil spills. (author)

  4. Analysis of the potential use of palm oil biodiesel for power generation in Amazonian remote systems; Analise do potencial do biodiesel de dende para geracao eletrica em sistemas isolados da Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Anamelia Medeiros

    2008-07-01

    This paper aims to analyze the potential of palm-oil biodiesel production and consumption in remote Amazonian systems (not connected to the national grid), taking into account economic, social and environmental impacts of this biofuel alternative. Through a detailed analysis of remote systems and in particular the examination of the national subside called 'Combustible Consumption Account', the study presents potential scenarios of biodiesel demand for electricity generation in the region, considering also the generation and grid connections projects in forthcoming years. Definition of current and future quantities of biodiesel needed to maintain thermal production in this system defines the Biodiesel investment necessities in remote Amazonian states (Acre, Amapa, Amazonas, Para, Rondonia, Roraima). Possibility of using biodiesel made progress with the launch of the National Program of Production and Use of Biodiesel (PNPB) in 2004. Although African Palm-oil trees adapt very well Amazonian soil, wide adoption of this specie as raw material for biodiesel production shows some barriers, like raise of palm oil price in global market, palm tree long maturation time and attractive price for conventional diesel in the region. Even if using palmoil biodiesel result in obvious significant social and environmental benefits, these benefits tend not to compensate the inefficiency of the market and, thus, expand the biofuel production in the Northern Region. (author)

  5. Health and demography of native Amazonians: historical perspective and current status Saúde e demografia de povos indígenas amazônicos: perspectiva histórica e situação atual

    Directory of Open Access Journals (Sweden)

    Warren M. Hern

    1991-12-01

    Full Text Available Native Amazonians have been the victims of two massive historical assaults, one at the time of the Conquest and the other during the Twentieth century. Due to epidemic disease and environmental destruction, many tribes have gone from contact to displacement, decimation, and extinction in a single generation. Deculturation and the construction of large development projects have had catastrophic effects on native populations. In many ways, native Amazonians have experienced a reverse of the "Epidemiologic Transition". Paradoxically, one of the effects of cultural disruption for some native Amazonians has been the loss of cultural controls on fertility with the result that high fertility has become a major health problem. Combined with rapid growth of non-indigenous Amazonian populations, deforestation, and urbanization, native Amazonians face grave obstacles to long-term survival.Os nativos da Amazônia foram vítimas de dois grandes ataques históricos: um na época da Conquista e outro durante o século XX. Devido a doenças epidêmicas e à destruição ambiental, inúmeras tribos passaram a vivenciar problemas de deslocamentos, dizimação e extinção em uma única geração. A aculturação e a construção de grandes projetos desenvolvimentistas tiveram efeitos catastróficos sobre as populações indígenas. Em diversos aspectos, os nativos da Amazônia sofreram uma "Transição Epidemiológica". Paradoxalmente, um dos efeitos da dilaceração cultural para alguns dos nativos da Amazônia foi a perda de controles culturais sobre a fecundidade, fazendo com que a elevada fecundidade se tornasse um importante problema de saúde. Com o rápido crescimento de populações amazônicas não indígenas, o desmatamento e a urbanização, os nativos da Amazônia enfrentam sérios obstáculos para a sua sobrevivência a longo prazo.

  6. Biogeography of squirrel monkeys (genus Saimiri): South-central Amazon origin and rapid pan-Amazonian diversification of a lowland primate.

    Science.gov (United States)

    Lynch Alfaro, Jessica W; Boubli, Jean P; Paim, Fernanda P; Ribas, Camila C; Silva, Maria Nazareth F da; Messias, Mariluce R; Röhe, Fabio; Mercês, Michelle P; Silva Júnior, José S; Silva, Claudia R; Pinho, Gabriela M; Koshkarian, Gohar; Nguyen, Mai T T; Harada, Maria L; Rabelo, Rafael M; Queiroz, Helder L; Alfaro, Michael E; Farias, Izeni P

    2015-01-01

    The squirrel monkey, Saimiri, is a pan-Amazonian Pleistocene radiation. We use statistical phylogeographic methods to create a mitochondrial DNA-based timetree for 118 squirrel monkey samples across 68 localities spanning all Amazonian centers of endemism, with the aim of better understanding (1) the effects of rivers as barriers to dispersal and distribution; (2) the area of origin for modern Saimiri; (3) whether ancestral Saimiri was a lowland lake-affiliated or an upland forest taxa; and (4) the effects of Pleistocene climate fluctuation on speciation. We also use our topology to help resolve current controversies in Saimiri taxonomy and species relationships. The Rondônia and Inambari centers in the southern Amazon were recovered as the most likely areas of origin for Saimiri. The Amazon River proved a strong barrier to dispersal, and squirrel monkey expansion and diversification was rapid, with all speciation events estimated to occur between 1.4 and 0.6Ma, predating the last three glacial maxima and eliminating climate extremes as the main driver of squirrel monkey speciation. Saimiri expansion was concentrated first in central and western Amazonia, which according to the "Young Amazon" hypothesis was just becoming available as floodplain habitat with the draining of the Amazon Lake. Squirrel monkeys also expanded and diversified east, both north and south of the Amazon, coincident with the formation of new rivers. This evolutionary history is most consistent with a Young Amazon Flooded Forest Taxa model, suggesting Saimiri has always maintained a lowland wetlands niche and was able to greatly expand its range with the transition from a lacustrine to a riverine system in Amazonia. Saimiri vanzolinii was recovered as the sister group to one clade of Saimiri ustus, discordant with the traditional Gothic vs. Roman morphological division of squirrel monkeys. We also found paraphyly within each of the currently recognized species: S. sciureus, S. ustus, and S

  7. Three years of vertically resolved CO2/CH4/CO measurements at the tallest tower in the Amazon - Amazonian Tall Tower Observatory (ATTO, Brazil)

    Science.gov (United States)

    Valentin Lavrič, Jošt; Winderlich, Jan; Walter, David; Chi, Xuguang; Andreae, Meinrat O.; Heimann, Martin

    2015-04-01

    The 330 m-tall tower that is currently in its final phase of construction at the Amazonian Tall Tower Observatory (ATTO, Brazil; 2° 08'S, 59° 00'W), is the counterpart of the 304 m-tall tower of the Zotino Tall Tower Observatory tower (ZOTTO), located in central Siberia (Russia; 60° 48'N, 89° 21'E). The ATTO tall tower will extend above the atmospheric surface layer and the nocturnal stable boundary layer, and aims at delivering ground breaking findings that will be the basis for improved climate models. While awaiting the completion of the tall tower, a number of campaign or continuous pilot measurements are taking place on the ATTO site at and around the currently tallest Amazonian tower and mast (80 m a.g.l.). Since March 2012, we run continuous high precision CO2/CH4/CO measurements in an air-conditioned container at the foot of the 80 m tower. The sample air inlets are installed at five levels; 79, 53, 38, 24, and 4 m a.g.l. Two frequently calibrated CRDS analyzers (G1301 and G1302; Picarro Inc., USA) are used for measuring CO2/CH4 and CO/CO2, respectively. Even if due to proximity of our measurements to the canopy (~ 35 m a.g.l.) the data is influenced by local sources and sinks, it still provides a valuable insight into the diurnal and seasonal variations of the measured gas species. Additionally, the data set has proven to be also interesting combined with the parameters that are measured by other groups at the site in parallel either continuously or during intensive observation periods (e.g. VOCs, reactive trace gases, aerosols). A first analysis of the available data is presented. Our work was performed within the frame of the German-Brazilian project ATTO and supported by the federal government agencies BMBF and MCT (Grant number BMBF 01LB1001A). We acknowledge the fundamental support by the Max Planck Society, INPA and UEA. Special thanks go to the Amazonas State SDS/CEUC-RDS Uatumã.

  8. Attenuation of adjuvant-induced arthritis in rats by phonophoresis with an aqueous gel of the Amazonian plant Elaeoluma nuda (Sapotaceae).

    Science.gov (United States)

    Merini, Lilian Regiani; Furtado, Silvânia da Conceição; de Oliveira, Marcelo Miguel Brito; Carneiro, Ana Lúcia Basílio; Boechat, Antonio Luiz; Barcellos, José Fernando Marques

    2014-02-01

    Various species of the genus Pouteria (Elaeoluma) are used by the native population of Brazil because of, among other factors, their anti-inflammatory properties. The anti-inflammatory properties of the extract of the Amazonian plant Elaeoluma nuda were recently identified in prospective pharmacological studies. The objective of this study was to assess the anti-inflammatory effect of phonophoresis with aqueous gel extract of E. nuda in rat adjuvant-induced arthritis. Arthritis was induced in Lewis rats with an adjuvant. Phonophoresis with E. nuda gel was then administered daily and the results compared with those obtained with phonophoresis of diclofenac diethylammonium gel and ultrasound therapy without phonophoresis. Arthritis in the different groups was evaluated by plethysmometry. Proinflammatory cytokines TNF-α and IL-1α were quantified by cytometric bead array (CBA). The effect of phonophoresis of aqueous gel with E. nuda extract on arthritis in rats' paws (a 33% reduction compared with the controls) was the same as that produced by phonophoresis with diclofenac diethylammonium. Ultrasound therapy without phonophoresis produced no significant effect on the 21st day of therapy. There was a significant reduction in TNF-α and IL-1α levels in the group treated with phonophoresis with E. nuda gel (p=0.0042; p=0.0003, respectively). Our results demonstrate the anti-inflammatory effect of phonophoresis with E. nuda gel on cytokines TNF-α, IL-1α and adjuvant-induced arthritis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. A phytochemical-rich diet may explain the absence of age-related decline in visual acuity of Amazonian hunter-gatherers in Ecuador.

    Science.gov (United States)

    London, Douglas S; Beezhold, Bonnie

    2015-02-01

    Myopia is absent in undisturbed hunter-gatherers but ubiquitous in modern populations. The link between dietary phytochemicals and eye health is well established, although transition away from a wild diet has reduced phytochemical variety. We hypothesized that when larger quantities and greater variety of wild, seasonal phytochemicals are consumed in a food system, there will be a reduced prevalence of degenerative-based eye disease as measured by visual acuity. We compared food systems and visual acuity across isolated Amazonian Kawymeno Waorani hunter-gatherers and neighboring Kichwa subsistence agrarians, using dietary surveys, dietary pattern observation, and Snellen Illiterate E visual acuity examinations. Hunter-gatherers consumed more food species (130 vs. 63) and more wild plants (80 vs. 4) including 76 wild fruits, thereby obtaining larger variety and quantity of phytochemicals than agrarians. Visual acuity was inversely related to age only in agrarians (r = -.846, P .05). This unusual absence of juvenile-onset vision problems may be related to local, organic, whole food diets of subsistence food systems isolated from modern food production. Our results suggest that intake of a wider variety of plant foods supplying necessary phytochemicals for eye health may help maintain visual acuity and prevent degenerative eye conditions as humans age. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Direct analysis of psychoactive tryptamine and harmala alkaloids in the Amazonian botanical medicine ayahuasca by liquid chromatography-electrospray ionization-tandem mass spectrometry.

    Science.gov (United States)

    McIlhenny, Ethan H; Pipkin, Kelly E; Standish, Leanna J; Wechkin, Hope A; Strassman, Rick; Barker, Steven A

    2009-12-18

    A direct injection/liquid chromatography-electrospray ionization-tandem mass spectrometry procedure has been developed for the simultaneous quantitation of 11 compounds potentially found in the increasingly popular Amazonian botanical medicine and religious sacrament ayahuasca. The method utilizes a deuterated internal standard for quantitation and affords rapid detection of the alkaloids by a simple dilution assay, requiring no extraction procedures. Further, the method demonstrates a high degree of specificity for the compounds in question, as well as low limits of detection and quantitation despite using samples for analysis that had been diluted up to 200:1. This approach also appears to eliminate potential matrix effects. Method bias for each compound, examined over a range of concentrations, was also determined as was inter- and intra-assay variation. Its application to the analysis of three different ayahuasca preparations is also described. This method should prove useful in the study of ayahuasca in clinical and ethnobotanical research as well as in forensic examinations of ayahuasca preparations.

  11. In vitro and in vivo antimalarial activity and cytotoxicity of extracts, fractions and a substance isolated from the Amazonian plant Tachia grandiflora (Gentianaceae

    Directory of Open Access Journals (Sweden)

    Luiz Francisco Rocha e Silva

    2013-06-01

    Full Text Available Tachia sp. are used as antimalarials in the Amazon Region and in vivo antimalarial activity of a Tachia sp. has been previously reported. Tachia grandiflora Maguire and Weaver is an Amazonian antimalarial plant and herein its cytotoxicity and antimalarial activity were investigated. Spectral analysis of the tetraoxygenated xanthone decussatin and the iridoid aglyone amplexine isolated, respectively, from the chloroform fractions of root methanol and leaf ethanol extracts was performed. In vitro inhibition of the growth of Plasmodium falciparum Welch was evaluated using optical microscopy on blood smears. Crude extracts of leaves and roots were inactive in vitro. However, chloroform fractions of the root and leaf extracts [half-maximal inhibitory concentration (IC50 = 10.5 and 35.8 µg/mL, respectively] and amplexine (IC50= 7.1 µg/mL were active in vitro. Extracts and fractions were not toxic to type MRC-5 human fibroblasts (IC50> 50 µg/mL. Water extracts of the roots of T. grandiflora administered by mouth were the most active extracts in the Peters 4-day suppression test in Plasmodium berghei-infected mice. At 500 mg/kg/day, these extracts exhibited 45-59% inhibition five to seven days after infection. T. grandiflora infusions, fractions and isolated substance have potential as antimalarials.

  12. Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

    Directory of Open Access Journals (Sweden)

    Antônio Ocimar Manzi

    2011-04-01

    Full Text Available Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and groundwater chemistry and soil CO2 respiration were studied in forests on sandy soils, whereas drought sensitivity of poorly-drained valley soils was investigated in an artificial drainage experiment. Slightly changes in litter decomposition or water chemistry were observed as a consequence of artificial drainage. Riparian plots did experience higher litter decomposition rates than campina forest. In response to a permanent lowering of the groundwater level from 0.1 m to 0.3 m depth in the drainage plot, topsoil carbon and nitrogen contents decreased substantially. Soil CO2 respiration decreased from 3.7±0.6 µmol m-2 s-1 before drainage to 2.5±0.2 and 0.8±0.1 µmol m-2 s-1 eight and 11 months after drainage, respectively. Soil respiration in the control plot remained constant at 3.7±0.6 µmol m-2 s-1. The above suggests that more frequent droughts may affect topsoil carbon and nitrogen content and soil respiration rates in the riparian ecosystem, and may induce a transition to less diverse campinarana or short-statured campina forest that covers areas with strongly-leached sandy soil.

  13. Assessment of Spatial Interpolation Methods to Map the Bathymetry of an Amazonian Hydroelectric Reservoir to Aid in Decision Making for Water Management

    Directory of Open Access Journals (Sweden)

    Marcelo Curtarelli

    2015-02-01

    Full Text Available The generation of reliable information for improving the understanding of hydroelectric reservoir dynamics is fundamental for guiding decision-makers to implement best management practices. In this way, we assessed the performance of different interpolation algorithms to map the bathymetry of the Tucuruí hydroelectric reservoir, located in the Brazilian Amazon, as an aid to manage and operate Amazonian reservoirs. We evaluated three different deterministic and one geostatistical algorithms. The performance of the algorithms was assessed through cross-validation and Monte Carlo Simulation. Finally, operational information was derived from the bathymetric grid with the best performance. The results showed that all interpolation methods were able to map important bathymetric features. The best performance was obtained with the geostatistical method (RMSE = 0.92 m. The information derived from the bathymetric map (e.g., the level-area and level-volume diagram and the three-dimensional grid will allow for optimization of operational monitoring of the Tucuruí hydroelectric reservoir as well as the development of three-dimensional modeling studies.

  14. Condition factor variations over time and trophic position among four species of Characidae from Amazonian floodplain lakes: effects of an anomalous drought.

    Science.gov (United States)

    Tribuzy-Neto, I A; Conceição, K G; Siqueira-Souza, F K; Hurd, L E; Freitas, C E C

    2017-08-17

    The effects of extreme droughts on freshwater fish remain unknown worldwide. In this paper, we estimated the condition factor, a measure of relative fitness based on the relationship of body weight to length, in four fish species representing two trophic levels (omnivores and piscivores) from Amazonian floodplain lakes for three consecutive years: 2004, 2005 (an anomalous drought year), and 2006. The two omnivores, Colossoma macropomum and Mylossoma duriventre, exhibited trends consistent with their life cycles in 2004 and 2006: high values during the hydrologic seasons of high water, receding water, and low water, with a drop following reproduction following the onset of rising water. However during the drought year of 2005 the condition factor was much lower than normal during receding and low water seasons, probably as a result of an abnormal reduction in resource availability in a reduced habitat. The two piscivorous piranhas, Serrasalmus spilopleura and S. elongatus, maintained relatively stable values of condition factor over the hydrologic cycles of all three years, with no apparent effect of the drought, probably because the reduction in habitat is counterbalanced by the resulting increase in relative prey density. We suggest that if predictions of increasing drought in the Amazon are correct, predatory species may benefit, at least in the short run, while omnivores may be negatively affected.

  15. Characterization of acetylcholinesterase from the brain of the Amazonian tambaqui (Colossoma macropomum) and in vitro effect of organophosphorus and carbamate pesticides.

    Science.gov (United States)

    Assis, Caio Rodrigo Dias; Castro, Patrícia Fernandes; Amaral, Ian Porto Gurgel; Carvalho, Elba Verônica Matoso Maciel; Carvalho, Luiz Bezerra; Bezerra, Ranilson Souza

    2010-10-01

    In the present study, acetylcholinesterase (AChE) from the brain of the Amazonian fish tambaqui (Colossoma macropomum) was partially characterized and its activity was assayed in the presence of five organophosphates (dichlorvos, diazinon, chlorpyrifos, and tetraethyl pyrophosphate [TEPP]) and two carbamates (carbaryl and carbofuran) insecticides. Optimal pH and temperature were 7.0 to 8.0 and 45°C, respectively. The enzyme retained approximately 70% of activity after incubation at 50°C for 30 min. The insecticide concentration capable of inhibiting half of the enzyme activity (IC50) for dichlorvos, chlorpyrifos, and TEPP were calculated as 0.04 µmol/L, 7.6 µmol/L, and 3.7 µmol/L, respectively. Diazinon and temephos did not inhibit the enzyme. The IC50 values for carbaryl and carbofuran were estimated as 33.8 µmol/L and 0.92 µmol/L, respectively. These results suggest that AChE from the juvenile C. macropomum brain could be used as an alternative biocomponent of organophosphorus and carbamate biosensors in routine pesticide screening in the environment. Environ. Toxicol. Chem. 2010;29:2243-2248. © 2010 SETAC.

  16. Molecular and morphological differentiation between two Miocene-divergent lineages of Amazonian shrimps, with the description of a new species (Decapoda, Palaemonidae, Palaemon

    Directory of Open Access Journals (Sweden)

    Fabrício Carvalho

    2014-11-01

    Full Text Available Palaemon carteri (Gordon, 1935 and P. ivonicus (Holthuis, 1950 are morphologically similar species of South American freshwater shrimps. Past studies have questioned the taxonomic status of both species, which are supposed to have partially sympatric geographic distributions in the Amazon basin. We analyzed a 550 bp fragment of the mitochondrial 16S rRNA gene from these Amazonian Palaemon species as well as from 11 palaemonids as the outgroup. Additionally, we checked diagnostic characters of the genus and family as well as other morphological characters that have been little explored before. Palaemon carteri and P. ivonicus are allocated in two sister lineages, with wide genetic divergence and little morphological differentiation. The divergence time between these lineages was estimated as approximately 10 million years ago. Both molecular and morphological data support the taxonomic validity of both Palaemon carteri and P. ivonicus, refuting the hypothesis of synonymy. In addition, a new species, Palaemon yuna sp. n., closely related to P. ivonicus, is described. Our findings indicate that these species can be differentiated using the projection of the anterolateral margin and anterolateral spine of the first antennular segment, shape of the rostrum, and relative size of the appendix masculina.

  17. Physiological response and performance of tambaqui fed with diets supplemented with Amazonian nut Respostas fisiológicas e desempenho do tambaqui alimentado com dietas suplementadas com castanha da Amazônia

    Directory of Open Access Journals (Sweden)

    Marcio Quara de Carvalho Santos

    2010-10-01

    Full Text Available The present study evaluated the effectiveness of Amazonian nut (Bertholletia excelsa as an alternative source of vegetal protein in tambaqui (Colossoma macropomum diet. Performance and physiological status of fish fed for 60 days were evaluated. Four experimental isonitrogenous diets with 36% crude protein were formulated with increasing levels of nut meal (0, 10, 20 and 30%. Results showed the same growth performance for fish fed with diet with different levels of Amazonian nut than that without this ingredient (control. Analysis of physiological parameters (hematocrit, erythrocyte number, hemoglobin concentration, hematimetric indexes, total plasma protein and plasma glucose corroborate these results, with no significant differences among treatments. Therefore, adding up to 30% of Amazonian nut in tambaqui diet there is no negative effect on physiological homeostasis and growth performance, indicating that the Amazonian nut is a promising alternative dietary protein source ingredient for tambaqui.Este estudo avaliou a eficácia da farinha de castanha da Amazônia (Bertholletia excelsa como fonte alternativa de proteína vegetal na dieta do tambaqui (Colossoma macropomum. Para isso, foram avaliados o desempenho e o estado fisiológico dos peixes alimentados durante 60 dias. Foram formuladas quatro dietas experimentais isoproteicas com 36% proteína bruta, com níveis crescentes de farinha de castanha (0, 10, 20 e 30%. Os resultados mostraram que os diferentes níveis de castanha da Amazônia mantiveram o mesmo desempenho zootécnico obtido para os peixes alimentados com dieta sem esse ingrediente (controle. Esses resultados são corroborados pela análise dos parâmetros fisiológicos: hematócrito, número de eritrócitos, concentração de hemoglobina, índices hematimétricos, proteínas plasmáticas totais e glicose plasmática, os quais não demonstraram diferenças significativas relacionadas aos diferentes tratamentos. Portanto, até 30

  18. Paleoproterozoic high-sulfidation mineralization in the Tapajós gold province, Amazonian Craton, Brazil: geology, mineralogy, alunite argon age, and stable-isotope constraints

    Science.gov (United States)

    Juliani, Caetano; Rye, Robert O.; Nunes, Carmen M.D.; Snee, Lawrence W.; Correa, Rafael H.; Monteiro, Lena V.S.; Bettencourt, Jorge S.; Neumann, Rainer; Neto, Arnaldo A.

    2005-01-01

    The Brazilian Tapajós gold province contains the first evidence of high-sulfidation gold mineralization in the Amazonian Craton. The mineralization appears to be in large nested calderas. The Tapajós–Parima (or Ventuari–Tapajós) geological province consists of a metamorphic, igneous, and sedimentary sequence formed during a 2.10 to 1.87 Ga ocean−continent orogeny. The high-sulfidation mineralization with magmatic-hydrothermal alunite is related to hydrothermal breccias hosted in a rhyolitic volcanic ring complex that contains granitic stocks ranging in age from 1.89 to 1.87 Ga. Cone-shaped hydrothermal breccias, which flare upward, contain vuggy silica and have an overlying brecciated cap of massive silica; the deposits are located in the uppermost part of a ring-structure volcanic cone. Drill cores of one of the hydrothermal breccias contain alunite, natroalunite, pyrophyllite, andalusite, quartz, rutile, diaspore, woodhouseite–svanbergite, kaolinite, and pyrite along with inclusions of enargite–luzonite, chalcopyrite, bornite, and covellite. The siliceous core of this alteration center is surrounded by advanced argillic and argillic alteration zones that grade outward into large areas of propylitically altered rocks with sericitic alteration assemblages at depth. Several occurrences and generations of alunite are observed. Alunite is disseminated in the advanced argillic haloes that envelop massive and vuggy silica or that underlie the brecciated silica cap. Coarse-grained alunite also occurs in branching veins and locally is partly replaced by a later generation of fine-grained alunite. Silicified hydrothermal breccias associated with the alunite contain an estimated reserve of 30 tonnes of gold in rock that grades up to 4.5 g t−1 Au. Seven alunite samples gave 40Ar/39Ar ages of 1.869 to 1.846 Ga, with various degrees of apparent minor Ar loss. Stable isotopic data require a magmatic-hydrothermal origin for the alunite, typical for high

  19. Thermal structure of the Poraquê lake, Central Amazonian, Brazil = Estrutura térmica do lago Poraquê, Amazônia Central, Brasil

    Directory of Open Access Journals (Sweden)

    Fabio Marques Aprile

    2011-04-01

    Full Text Available Thermal gradient of a Central Amazonian lake was studied to establish a link between seasonal variations in the water level, temperature, suspended particulate matter (SPM and thermal stratification. Bimonthly measurements of temperature and PAR radiation were made at 0.25 m intervals from the surface to bottom from February 2004 to July 2006. Daily occurs full vertical mixing of the water column, and classic thermal stratification was not observed in the period. The effect of the winds associated to flood-pulse and the penetrativeconvection, transported the turbulent kinetic energy (TKE into the lake mixing the column of water. This phenomenon was more expressive in the rainfall seasons when is generally higher contributing to the circulation of the water. The limit of the euphotic zone ranged from 1.36 to 1.77 m in the period studied. The results of the transmission curves for the sampling sites showed that, in general, less than 0.01% of the surface light reached the bottom. The trend curve developed can facilitate the understanding of the limnological and ecological processes in lentic systems of whitewaters of the Central Amazonian.Foi estudado o gradiente térmico de um lago da Amazônia Central para estabelecer associação entre variações sazonais no nível de água, temperatura, material em suspensão e estratificação térmica. Bimestralmente, foram medidas a temperatura e a radiação luminosada superfície ao fundo do lago no período entre fevereiro de 2004 e julho de 2006. Ocorreu completa mistura vertical diária da coluna de água, não sendo observada estratificação térmica clássica no período. A energia cinética turbulenta (ECT proveniente da ação dos ventos em associação com o pulso de inundação foi responsável pela mistura da coluna de água. Esse fenômeno foi mais expressivo no período chuvoso, quando a ECT é geralmente mais alta, contribuindo para a circulação da água. A extensão da zona euf

  20. Sinopse das espécies de Marlierea Cambess. (Myrtaceae na Amazônia brasileira Sinopse of the species of Marlierea Cambess. (Myrtaceae in Amazonian Brazil

    Directory of Open Access Journals (Sweden)

    Alessandro Silva do Rosário

    2006-03-01

    Full Text Available O estudo de Marlierea Cambess. na Amazônia Brasileira tem como principal objetivo atualizar os dados sobre a morfologia e taxonomia das espécies da região, bem como fornecer subsídios para esclarecer a separação de Marlierea de Myrcia DC. ex Guill., conforme sugerem alguns autores. Na Amazônia Brasileira, Marlierea está representada por 11 espécies (Marlierea bipennis (O. Berg McVaugh, M. caudata McVaugh, M. ensiformis McVaugh, M. ferruginea (Poir. McVaugh, M. mcvaughii B. Holst, M. scytophylla Diels, M. spruceana O. Berg, M. subulata McVaugh, M. summa McVaugh, M. umbraticola (Kunth O. Berg e M. velutina McVaugh e uma mal conhecida (M. obumbrans (O. Berg Nied., habitando principalmente áreas de formações florestais. O gênero se caracteriza pelo hábito arbóreo ou arbustivo; folhas opostas (exceto em M. velutina que pode apresentar folhas opostas e/ou alternas; as inflorescências em panículas (de fascículos, racemos, cimeiras ou dicásios; botões florais geralmente fechados, abertura irregular do cálice, em 4-5 lobos, pétalas freqüentemente ausentes. Os Estados do Amazonas e Pará representam os dois principais centros de distribuição dessas espécies, sendo M. spruceana e M. umbraticola as espécies mais comuns. Marlierea obumbrans será melhor estudada posteriormente, devido apresentar sua delimitação taxonômica confusa entre Myrcia e Marlierea.A morphological study of Marlierea Cambess. occurring in Amazonian Brazil was carried out in order to obtain a better understanding of the morphology and taxonomy of all species in the region and to provide data to elucidate the taxonomic segregation of Marlierea from the morphologically similar Myrcia DC. ex Guill. In Amazonian Brazil, Marlierea is represented by 11, primarily forest, species (Marlierea bipennis (O. Berg McVaugh, M. caudata McVaugh, M. ensiformis McVaugh, M. ferruginea (Poir. McVaugh, M. mcvaughii B. Holst, M. scytophylla Diels, M. spruceana O. Berg, M

  1. Activity and abundance of methane-oxidizing bacteria in secondary forest and manioc plantations of Amazonian Dark Earth and their adjacent soils

    Directory of Open Access Journals (Sweden)

    Amanda eBarbosa Lima

    2014-10-01

    Full Text Available The oxidation of atmospheric CH4 in upland soils is mostly mediated by uncultivated groups of microorganisms that have been identified solely by molecular markers, such as the sequence of the pmoA gene encoding the β-subunit of the particulate methane monooxygenase enzyme. The objective of this work was to compare the activity and diversity of methanotrophs in Amazonian Dark Earth soil (ADE, Hortic Anthrosol and their adjacent non-anthropic soil. Secondly, the effect of land use in the form of manioc cultivation was examined by comparing secondary forest and plantation soils. CH4 oxidation potentials were measured and the structure of the methanotroph communities assessed by qPCR and amplicon pyrosequencing of pmoA genes. The oxidation potentials at low CH4 concentrations (10 ppm of volume were relatively high in all the secondary forest sites of both ADE and adjacent soils. CH4 oxidation by the ADE soil only recently converted to a manioc plantation was also relatively high. In contrast, both the adjacent soils used for manioc cultivation and the ADE soil with a long history of agriculture displayed lower CH4 uptake rates. Amplicon pyrosequencing of pmoA genes indicated that USCα, Methylocystis and the tropical upland soil cluster (TUSC were the dominant groups depending on the site. By qPCR analysis it was found that USCα pmoA genes, which are believed to belong to atmospheric CH4 oxidizers, were more abundant in ADE than adjacent soil. USCα pmoA genes were abundant in both forested and cultivated ADE soil, but were below the qPCR detection limit in manioc plantations of adjacent soil. The results indicate that ADE soils can harbor high abundances of atmospheric CH4 oxidizers and are potential CH4 sinks, but as in other upland soils this activity can be inhibited by the conversion of forest to agricultural plantations.

  2. Geology, petrology, U-Pb (SHRIMP) geochronology of the Morrinhos granite - Paragua terrane, SW Amazonian craton: implications for the magmatic evolution of the San Ignacio orogeny

    Energy Technology Data Exchange (ETDEWEB)

    Franca, Ohana; Ruiz, Amarildo Salina; Sousa, Maria Zelia Aguiar de, E-mail: ohana.geo@gmail.com, E-mail: asruiz@gmail.com, E-mail: mzaguiar@terra.com.br [Universidade Federal de Mato Grosso (UFMT), Cuiaba, MT (Brazil). Instituto de Ciencias Exatas e da Terra. Dept. de Geologia Geral; Batata, Maria Elisa Froes, E-mail: elisabatata@bol.com.br [Universidade Federal de Mato Grosso (UFMT), Cuiaba, MT (Brazil). Grupo de Pesquisa em Evolucao Crustal e Tectonica; Lafon, Jean-Michel [Universidade Federal do Para (GEOCIAM/UFPA), Belem, PR (Brazil). Inst. Nacional de Cencia e Tecnologia de Geociencias da Amazonia

    2014-09-15

    Morrinhos granite is a batholith body that is slightly elongated in the NNW direction and approximately 1,140 km{sup 2} long; it is located in the municipality of Vila Bela da Santissima Trindade of the state of Mato Grosso, Brazil, in the Paragua Terrane, Rondonian-San Ignacio Province, in the SW portion of the Amazonian Craton. This intrusion displays a compositional variation from tonalite to monzogranite, has a medium to coarse inequigranular texture and is locally porphyritic; biotite is the predominant mafic in one of the facies, and hornblende is predominant in the other, with both metamorphosed into the green schist facies. The studied rocks characterize an intermediate to acidic sequence that was formed by a subalkaline magmatism; the series is alkali-calcic to metaluminous to slightly peraluminous, and the rocks evolved through fractioned crystallization mechanisms. The structural data show two deformation phases represented by penetrative foliation (S{sub 1}) and open folds (D{sub 2}), and both phases were most likely related to the San Ignacio Orogeny. The geochronological (U-Pb SHRIMP) and isotopic (Sm-Nd) investigations of these rocks indicated a crystallization age of 1350±12Ma, T{sub DM} of approximately 1.77 Ga and εNd{sub (1.35}) with a negative value of -2.57, suggesting that their generation was related to a partial melting process of a Paleoproterozoic (Statherian) continental crust. The results herein indicate that the Morrinhos granite was generated in a continental magmatic arc in a late- to post-orogenic stage of the San Ignacio Orogeny, and it can be recognized as belonging to the Pensamiento Intrusive Suite. (author)

  3. Myrcia splendens (Sw.) DC. (syn. M. fallax (Rich.) DC.) (Myrtaceae) Essential Oil from Amazonian Ecuador: A Chemical Characterization and Bioactivity Profile.

    Science.gov (United States)

    Scalvenzi, Laura; Grandini, Alessandro; Spagnoletti, Antonella; Tacchini, Massimo; Neill, David; Ballesteros, José Luis; Sacchetti, Gianni; Guerrini, Alessandra

    2017-07-12

    In this study, we performed the chemical characterization of Myrcia splendens (Sw.) DC. (Myrtaceae) essential oil from Amazonian Ecuador and the assessment of its bioactivity in terms of cytotoxic, antibacterial, and antioxidant activity as starting point for possible applicative uses. M. splendens essential oil, obtained by hydro-distillation, was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Flame Ionization Detector (GC-FID): the major components were found to be trans -nerolidol (67.81%) and α-bisabolol (17.51%). Furthermore, we assessed the cytotoxic activity against MCF-7 (breast), A549 (lung) human tumor cell lines, and HaCaT (human keratinocytes) non-tumor cell line through 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2- H -tetrazolium bromide (MTT) test: promising results in terms of selectivity and efficacy against the MCF-7 cell line (IC 50 of 5.59 ± 0.13 μg/mL at 48 h) were obtained, mainly due to α-bisabolol. Furthermore, antibacterial activity against Gram positive and negative bacteria were performed through High Performance Thin Layer Chromatography (HPTLC) bioautographic assay and microdilution method: trans -nerolidol and β-cedren-9-one were the main molecules responsible for the low antibacterial effects against human pathogens. Nevertheless, interesting values of Minimum Inhibitory Concentration (MIC) were noticeable against phytopathogen strains. Radical scavenging activity performed by HPTLC bioautographic and spectrophotometric 1,1-diphenyl-2-picrylhydrazyl (DPPH) approaches were negligible. In conclusion, the essential oil revealed a good potential for plant defense and anti-cancer applications.

  4. A new species of Amazonian snouted treefrog (Hylidae: Scinax) with description of a novel species-habitat association for an aquatic breeding frog

    Science.gov (United States)

    de Fraga, Rafael; Moravec, Jiří; Kaefer, Igor L.; Lima, Albertina P.

    2018-01-01

    The genus Scinax is one of the most specious genera of treefrogs of the family Hylidae. Despite the high number of potential new species of Scinax revealed in recent studies, the rate of species descriptions for Amazonia has been low in the last decade. A potential cause of this low rate may be the existence of morphologically cryptic species. Describing new species may not only impact the taxonomy and systematics of a group of organisms but also benefit other fields of biology. Ecological studies conducted in megadiverse regions, such as Amazonia, often meet challenging questions concerning insufficient knowledge of organismal alpha taxonomy. Due to that, detecting species-habitat associations is dependent on our ability to properly identify species. In this study, we first provide a description of a new species (including its tadpoles) of the genus Scinax distributed along heterogeneous landscapes in southern Amazonia; and secondly assess the influence of environmental heterogeneity on the new species’ abundance and distribution. Scinax ruberoculatus sp. nov. differs from all nominal congeners by its small size (SVL 22.6–25.9 mm in males and 25.4–27.5 mm in females), by having a dark brown spot on the head and scapular region shaped mainly like the moth Copiopteryx semiramis (or a human molar in lateral view, or a triangle), bicolored reddish and grey iris, snout truncate in dorsal view, bilobate vocal sac in males, by its advertisement call consisting of a single pulsed note with duration of 0.134–0.331 s, 10–23 pulses per note, and dominant frequency 1,809–1,895 Hz. Both occurrence and abundance of the new species are significantly influenced by silt content in the soil. This finding brings the first evidence that edaphic factors influence species-habitat association in Amazonian aquatic breeding frogs. PMID:29441233

  5. The Effect of Aerosol-Cloud-Vegetation Interactions and Intraseasonal Meteorological Variability on Warm Cloud Development during the Amazonian Biomass Burning Season

    Science.gov (United States)

    Ten Hoeve, J. E.; Remer, L. A.; Jacobson, M. Z.

    2009-12-01

    The effect of aerosols on the hydrological cycle remains one of the largest uncertainties in our climate system. Biomass burning, from both deforestation and annual agricultural burning, is the largest anthropogenic source of these aerosols in the Southern Hemisphere. Biomass burning aerosols have competing effects on clouds: Depending on the level of aerosol loading and the background cloud characteristics, biomass burning aerosols have been shown in observational studies to invigorate or inhibit cloud formation and/or growth through microphysical and absorptive pathways, respectively. Many of these previous studies have employed all days during the Amazonian burning season months of August through October to formulate aerosol-cloud correlations, assuming relatively constant meteorological conditions exist throughout these months. This study investigates how intraseasonal trends of precipitable water vapor and aerosol loading between August and October impact these aerosol-cloud correlations. Other factors affecting aerosol-cloud relationships, such as atmospheric stability, are also investigated. This study is focused on a small 3 degree NE x 4 degree WE region in Rondonia, Brazil that encompasses extensive, contiguous areas of both forested and deforested land. High resolution aerosol, cloud, water vapor, and atmospheric profile data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra and Aqua satellites, as well as aerosol and water vapor data from the Aerosol Robotic Network (AERONET), are used collectively to explore the effect of aerosols on water vapor loading and warm cloud development over the Amazon. The difference in aerosol effects on the local hydrological cycle over forested and deforested areas is also examined. This final exercise provides insight into the relationship between aerosols, land-atmosphere processes, and warm clouds.

  6. Targeting of Gold Deposits in Amazonian Exploration Frontiers using Knowledge- and Data-Driven Spatial Modeling of Geophysical, Geochemical, and Geological Data

    Science.gov (United States)

    Magalhães, Lucíola Alves; Souza Filho, Carlos Roberto

    2012-03-01

    This paper reports the application of weights-of-evidence, artificial neural networks, and fuzzy logic spatial modeling techniques to generate prospectivity maps for gold mineralization in the neighborhood of the Amapari Au mine, Brazil. The study area comprises one of the last Brazilian mineral exploration frontiers. The Amapari mine is located in the Maroni-Itaicaiúnas Province, which regionally hosts important gold, iron, manganese, chromite, diamond, bauxite, kaolinite, and cassiterite deposits. The Amapari Au mine is characterized as of the orogenic gold deposit type. The highest gold grades are associated with highly deformed rocks and are concentrated in sulfide-rich veins mainly composed of pyrrhotite. The data used for the generation of gold prospectivity models include aerogeophysical and geological maps as well as the gold content of stream sediment samples. The prospectivity maps provided by these three methods showed that the Amapari mine stands out as an area of high potential for gold mineralization. The prospectivity maps also highlight new targets for gold exploration. These new targets were validated by means of detailed maps of gold geochemical anomalies in soil and by fieldwork. The identified target areas exhibit good spatial coincidence with the main soil geochemical anomalies and prospects, thus demonstrating that the delineation of exploration targets by analysis and integration of indirect datasets in a geographic information system (GIS) is consistent with direct prospecting. Considering that work of this nature has never been developed in the Amazonian region, this is an important example of the applicability and functionality of geophysical data and prospectivity analysis in regions where geologic and metallogenetic information is scarce.

  7. Myrcia splendens (Sw. DC. (syn. M. fallax (Rich. DC. (Myrtaceae Essential Oil from Amazonian Ecuador: A Chemical Characterization and Bioactivity Profile

    Directory of Open Access Journals (Sweden)

    Laura Scalvenzi

    2017-07-01

    Full Text Available In this study, we performed the chemical characterization of Myrcia splendens (Sw. DC. (Myrtaceae essential oil from Amazonian Ecuador and the assessment of its bioactivity in terms of cytotoxic, antibacterial, and antioxidant activity as starting point for possible applicative uses. M. splendens essential oil, obtained by hydro-distillation, was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS and Gas Chromatography-Flame Ionization Detector (GC-FID: the major components were found to be trans-nerolidol (67.81% and α-bisabolol (17.51%. Furthermore, we assessed the cytotoxic activity against MCF-7 (breast, A549 (lung human tumor cell lines, and HaCaT (human keratinocytes non-tumor cell line through 3-(4,5-dimethyl-2-thiazolyl-2,5-diphenyl-2-H-tetrazolium bromide (MTT test: promising results in terms of selectivity and efficacy against the MCF-7 cell line (IC50 of 5.59 ± 0.13 μg/mL at 48 h were obtained, mainly due to α-bisabolol. Furthermore, antibacterial activity against Gram positive and negative bacteria were performed through High Performance Thin Layer Chromatography (HPTLC bioautographic assay and microdilution method: trans-nerolidol and β-cedren-9-one were the main molecules responsible for the low antibacterial effects against human pathogens. Nevertheless, interesting values of Minimum Inhibitory Concentration (MIC were noticeable against phytopathogen strains. Radical scavenging activity performed by HPTLC bioautographic and spectrophotometric 1,1-diphenyl-2-picrylhydrazyl (DPPH approaches were negligible. In conclusion, the essential oil revealed a good potential for plant defense and anti-cancer applications.

  8. Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models.

    Science.gov (United States)

    Johnson, Michelle O; Galbraith, David; Gloor, Manuel; De Deurwaerder, Hannes; Guimberteau, Matthieu; Rammig, Anja; Thonicke, Kirsten; Verbeeck, Hans; von Randow, Celso; Monteagudo, Abel; Phillips, Oliver L; Brienen, Roel J W; Feldpausch, Ted R; Lopez Gonzalez, Gabriela; Fauset, Sophie; Quesada, Carlos A; Christoffersen, Bradley; Ciais, Philippe; Sampaio, Gilvan; Kruijt, Bart; Meir, Patrick; Moorcroft, Paul; Zhang, Ke; Alvarez-Davila, Esteban; Alves de Oliveira, Atila; Amaral, Ieda; Andrade, Ana; Aragao, Luiz E O C; Araujo-Murakami, Alejandro; Arets, Eric J M M; Arroyo, Luzmila; Aymard, Gerardo A; Baraloto, Christopher; Barroso, Jocely; Bonal, Damien; Boot, Rene; Camargo, Jose; Chave, Jerome; Cogollo, Alvaro; Cornejo Valverde, Fernando; Lola da Costa, Antonio C; Di Fiore, Anthony; Ferreira, Leandro; Higuchi, Niro; Honorio, Euridice N; Killeen, Tim J; Laurance, Susan G; Laurance, William F; Licona, Juan; Lovejoy, Thomas; Malhi, Yadvinder; Marimon, Bia; Marimon, Ben Hur; Matos, Darley C L; Mendoza, Casimiro; Neill, David A; Pardo, Guido; Peña-Claros, Marielos; Pitman, Nigel C A; Poorter, Lourens; Prieto, Adriana; Ramirez-Angulo, Hirma; Roopsind, Anand; Rudas, Agustin; Salomao, Rafael P; Silveira, Marcos; Stropp, Juliana; Ter Steege, Hans; Terborgh, John; Thomas, Raquel; Toledo, Marisol; Torres-Lezama, Armando; van der Heijden, Geertje M F; Vasquez, Rodolfo; Guimarães Vieira, Ima Cèlia; Vilanova, Emilio; Vos, Vincent A; Baker, Timothy R

    2016-12-01

    Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basin-wide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs. © 2016 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  9. Effects of copper and cadmium on ion transport and gill metal binding in the Amazonian teleost tambaqui (Colossoma macropomum) in extremely soft water.

    Science.gov (United States)

    Matsuo, Aline Y O; Wood, Chris M; Val, Adalberto L

    2005-09-30

    Metal toxicity in fish is expected to be most severe in soft waters because of the low availability of cations (particularly Ca(2+)) to out-compete the metal forms for binding sites on the gills. Natural waters in the Amazon basin are typically soft due to regional geochemistry, but few studies have focused on metal toxicity in fish native to the basin. We assessed the ionoregulatory effects of waterborne copper (Cu) and cadmium (Cd) on tambaqui (Colossoma macropomum) in extremely soft water (10 micromoll(-1) Ca(2+)). Tambaqui had a very high tolerance to Cu (50-400 microgl(-1)), as indicated by a complete lack of inhibition of Na(+) uptake and an ability to gradually recover over 6h from elevated diffusive Na(+) losses caused by Cu. The insensitivity of active Na(+) influx to Cu further supports the notion that Amazonian fish may have a unique Na(+) transport system. Addition of 5-10 mgCl(-1) of dissolved organic matter (DOM) did not prevent initial (0-3h) negative Na(+) balance in tambaqui exposed to Cu. Exposure to 40 mgCl(-1) DOM prevented Na(+) losses in tambaqui even at 400 microgl(-1) Cu, probably because most Cu was complexed to DOM. Tambaqui exposed to waterborne Cd (10-80 microgl(-1)) experienced an average of 42% inhibition in whole body Ca(2+) uptake relative to controls within 3h of exposure to the metal. Inhibition of Ca(2+) uptake increased over time and, at 24h, Ca(2+) uptake was suppressed by 51% and 91% in fish exposed to 10 and 80 microgl(-1) Cd, respectively. Previous acclimation of fish to either elevated [Ca(2+)] or elevated [DOM] proved to be very effective in protecting against acute short-term metal accumulation at the gills of tambaqui in soft water (in the absence of the protective agent during metal exposure), suggesting a conditioning effect on gill metal binding physiology.

  10. Biochemical and behavioral responses of the Amazonian fish Colossoma macropomum to crude oil: the effect of oil layer on water surface.

    Science.gov (United States)

    Kochhann, Daiani; Meyersieck Jardim, Manoela; Valdez Domingos, Fabíola Xochilt; Val, Adalberto Luis

    2015-01-01

    The largest Brazilian terrestrial province of petroleum mining is located at the margins of Urucu River, Amazonas. Mined crude oil is transported along 400 km across Solimões River to be refined in Manaus. Thus, the main goal of this study was to evaluate the effects of crude oil exposure on biochemical, physiological and behavioral parameters of juveniles of the Amazonian fish tambaqui (Colossoma macropomum). The toxicity of water-soluble and insoluble oil fractions and the influence of a layer formed by the oil on the water surface from low and high concentrations of crude oil were analyzed. The results showed a strong physical effect of oil at the water surface and a significant effect on fish behavior. Swimming time and response to alarm substance decreased when fish was exposed for just one day to water insoluble fraction, and remain lower after 30 days of exposure, compared to control. Chronic exposure to water insoluble fraction of the inert oil also affected these two parameters. Critical swimming velocity decreased in fish exposed to both crude and inert oil water insoluble fraction. These reductions are possibly related to a decrease in aerobic capacity. Only exposure to high concentrations of petroleum water-soluble fractions induced transient alterations of the analyzed parameters. The exposure of fish to low and high concentrations of water insoluble fraction of Urucu oil caused a reduction of responses to alarm substance, spontaneous swimming activity and swimming capacity (Ucrit), decreased activity of acetylcholinesterase, and increased activity of alkaline phosphatase. Severe hypertrophy of lamellar epithelium and extensive lamellar fusion of the gills were also observed. Overall, these results show significant behavioral and physiological changes caused by the oil layer on the water surface, which means that toxicity of petroleum produced by its chemical components is, in fact, in this fish species, enhanced by the presence of an oil phase as a

  11. [Tuberculosis in Amazonian municipalities of the Brazil-Colombia-Peru-Venezuela border: epidemiological situation and risk factors associated with treatment default].

    Science.gov (United States)

    Belo, Elsia Nascimento; Orellana, Jesem Douglas Yamall; Levino, Antônio; Basta, Paulo Cesar

    2013-11-01

    To describe the epidemiological situation and the incidence of tuberculosis and to investigate the factors associated with treatment default in the Amazonian municipalities located in the northern Brazilian international border. This retrospective study employed sociodemographic, clinical, and epidemiological tuberculosis data recorded in the Brazilian Notifiable Diseases Information System (SINAN) between 2001 and 2010. Logistic regression was used to identify factors associated with treatment default. Tuberculosis affected mostly indigenous peoples (51.9%), males (57.9%), and people aged 25-44 years (31.4%). The predominant clinical presentation was pulmonary (89.7%), yet in 24.5% of the cases the patients did not undergo sputum smear microscopy, and only half received supervised treatment. In 70.0% of the cases notified, patients were discharged as cured. Treatment default was recorded in 10.0% of the patients. Of all deaths, 4.1% were by tuberculosis and other causes, and 1.7% by multidrug-resistant tuberculosis. The average incidence by race/color was greater among indigenous peoples, ranging from 202.3/100 000 in 2001 to 65.6/100 000 in 2010. Treatment default was associated with failure to perform the follow-up smear at the second, fourth, and sixth months (OR = 11.9, 95%CI: 7.4-19.0); with resuming treatment after default (OR = 3.0, 95%CI: 1.5-5.9); and with living in specific subregions, particularly the Alto Solimões region (OR = 6.7, 95%CI: 4.6-9.8). The present results show a high incidence of tuberculosis in the Amazon portion of the northern Brazilian international border, especially among indigenous peoples. Considering the socio-cultural specificities of these populations and the poor tuberculosis control in this area, the authors of the study conclude that the integration of different national health systems is both necessary and urgent.

  12. Trace element distribution in heart tissue sections studied by nuclear microscopy is changed in Coxsackie virus B3 myocarditis in methyl mercury-exposed mice.

    Science.gov (United States)

    Ilbäck, N G; Lindh, U; Wesslén, L; Fohlman, J; Friman, G

    2000-01-01

    Methyl mercury (MeHg) has been shown to change Coxsackie virus type B3 (CB3) myocarditis in a direction compatible with the development of chronic disease. Murine models of CB3 myocarditis closely mimic the pathogenesis in humans. There are also indications that metals, such as mercury, and trace elements may interact and adversely affect viral replication and development of inflammatory lesions. The effects of low-dose MeHg exposure on myocardial trace element distribution, as determined by means of nuclear microscopy, was studied in CB3 myocarditis. Balb/c mice were fed a MeHg-containing diet (3.9 mg/kg diet) for 12 wk prior to infection. Areas of inflammatory lesions in the myocardium were identified by traditional histologic examination, and serial tissue sections in these selected areas were used for immune histology (macrophages), in situ hybridization of virus genomes, and nuclear microscopy of tissue trace element distribution. Areas with no inflammation or virus were compared with areas of ongoing inflammation and viral replication. In the inflammatory lesions of MeHg-exposed mice as compared to nonexposed mice, the myocardial contents of calcium (Ca), manganese (Mn), and iron (Fe) were significantly increased, whereas the zinc (Zn) content was decreased. The increased Ca and decreased Zn contents in the inflamed heart may partly explain a more severe disease in MeHg-exposed individuals. Although not significant in the present study, with a limited number of mice, the inflammatory and necrotic lesions in the ventricular myocardium on d 7 of the infection was increased by 50% (from 2.2% to 3.3% of the tissue section area) in MeHg-exposed mice and, also, there was a tendency of increased persistence of virus with MeHg exposure. No increased MeHg uptake, either in the inflammatory lesions or in the areas of noninflamed heart tissue in infected mice, could be detected. The present results indicate that a "competition" exists between potentially toxic heavy metals from the environment/diet and important trace elements in the body and that a disturbed trace element balance adversely influences the development of pathophysiologic changes in inflammatory heart disease.

  13. Children's Learning

    Science.gov (United States)

    Siegler, Robert S.

    2005-01-01

    A new field of children's learning is emerging. This new field differs from the old in recognizing that children's learning includes active as well as passive mechanisms and qualitative as well as quantitative changes. Children's learning involves substantial variability of representations and strategies within individual children as well as…

  14. Geomorphic record of Noachian, Hesperian and Amazonian materials and deposits preserved within Asimov Crater, Mars: A cross-sectional view of the role of volatiles through martian history

    Science.gov (United States)

    Morgan, G. A.; Head, J. W.; Marchant, D. R.

    2010-12-01

    We describe the geomorphic record preserved within the highly degraded 80 km diameter Asimov impact crater located within Noachis Terra. The crater has been significantly in-filled since its formation in the Noachian, presumably by sedimentary materials similar to units identified elsewhere in Noachian aged craters. In this case the fill is unusual in that there is an annulus of disconnected valleys adjacent to the interior flanks of the crater wall. High-resolution images reveal that Hesperian-aged layered basalt with distinctive columnar jointing caps the interior crater fill and provides a source of debris that via mass wasting, accumulates in the surrounding annular valleys. Models for the formation of the valleys need to account for the removal of large volumes of crater fill material from below the basaltic cap. One distinct possibility is that the fill material originally contained high proportions of volatiles that have since been lost to the atmosphere. We explore this model and others and investigate the surrounding regions to place further constraints on valley formation. The occurrence of steep slopes (>20 °), relatively narrow (sheltered) valleys, and a source of debris have provided favorable conditions for the preservation of late Amazonian shallow-ice deposits. Detailed mapping reveals morphological evidence for viscous ice flow, in the form of several lobate debris tongues (LDT). Superimposed on LDT are a series of fresh-appearing gullies, with typical alcove, channel, and fan morphologies. The shift from ice-rich viscous-flow formation to gully erosion is best explained as a shift in martian climate, from one compatible with excess snowfall and flow of ice-rich deposits, to one consistent with minor snowfall and gully formation. Available dating suggests that the climate transition occurred >8 Ma, prior to the formation of other small-scale ice-rich flow features identified elsewhere on Mars that have been interpreted to have formed during the

  15. Contributions to the petrography, geochemistry and geochronology (U-Pb and Sm-Nd) of the Paleoproterozoic effusive rocks from Iricoume Group, Amazonian Craton, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Suelen Nonata de Souza; Nascimento, Rielva Solimairy Campelo do, E-mail: suelen-marques@hotmail.com, E-mail: rielva@ufam.edu.br [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Inst. de Geociencias; Souza, Valmir da Silva; Dantas, Elton Luiz, E-mail: vsouza@unb.br, E-mail: elton@unb.br [Universidade de Brasilia (UnB), DF (Brazil). Inst. de Geociencias; Valerio, Cristovao da Silva, E-mail: cristovao@igeo.ufrr.br [Universidade Federal de Roraima (UFRR), Boa Vista, RR (Brazil). Inst. de Geociencias

    2014-07-01

    The southernmost region of the Guyana shield, Amazonian craton, hosts large record of Paleoproterozoic effusive rocks of the Iricoume Group. They present remarkably well-preserved igneous textures and structures. The SiO{sub 2} contents reveal a bimodal association marked by a compositional gap between acid (SiO{sub 2} > 67 wt%) and intermediate (SiO{sub 2} < 57.7 wt%) rocks. The acid effusive rocks are rhyolites to rhyodacites with high SiO{sub 2}, alkali, Rb, Zr, Nb + Ta, La + Ce and 104 Ga/Al content and low Fe{sub 2}O{sub 3tot}, TiO{sub 2}, CaO, Sr and Co content. They exhibit subalkaline, metaluminous-to-peraluminous compositions, and geochemically compatible to A-type magmatism emplaced in post-collisional to within-plate tectonic settings. The intermediate rocks are andesitic/basalt to andesite relatively high contents of TiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3total}, MgO, CaO, Sr and Co; low SiO{sub 2}, K{sub 2}O, Rb, Zr, Nb + Ta, La + Ce. They have subalkaline and metaluminous geochemical composition and plot on within-plate basalt field. The acid rocks crystallized at 1882 ± 11 Ma in U-Pb analyses for LA-MC-ICPMS zircon data. The Sm-Nd isotopic data on all rocks reveal a Nd TDM model ages between 2.59 and 2.16 Ga and ε{sub Nd}(t) values between -5.78 and 0.03, indicate that the magmatic evolution was related to the reworking of older Paleoproterozoic at the Rhyacian-Siderian period, continental crust (Transamazonian crust-forming event) with some mixing with a limited amount mantle-derived magmas or with contamination by Archean crust. The petrographic, geochemical and geochronological data presented in this paper suggest a within-plate to post-collisional tectonic setting for the Iricoume volcanism, involving lower crust uplift and generation of basalt magma in an extensional regime. (author)

  16. Effects of copper and cadmium on ion transport and gill metal binding in the Amazonian teleost tambaqui (Colossoma macropomum) in extremely soft water

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, Aline Y.O. [Laboratory of Ecophysiology and Molecular Evolution, National Institute for Research in the Amazon (INPA), Av. Andre Araujo, 2936 Aleixo, Manaus, Amazonas 69083-000 (Brazil)]. E-mail: matsuoaline@aol.com; Wood, Chris M. [Department of Biology, McMaster University, 1280 Main St. West, Hamilton, Ont., L8S 4K1 (Canada); Val, Adalberto L. [Laboratory of Ecophysiology and Molecular Evolution, National Institute for Research in the Amazon (INPA), Av. Andre Araujo, 2936 Aleixo, Manaus, Amazonas 69083-000 (Brazil)

    2005-09-30

    Metal toxicity in fish is expected to be most severe in soft waters because of the low availability of cations (particularly Ca{sup 2+}) to out-compete the metal forms for binding sites on the gills. Natural waters in the Amazon basin are typically soft due to regional geochemistry, but few studies have focused on metal toxicity in fish native to the basin. We assessed the ionoregulatory effects of waterborne copper (Cu) and cadmium (Cd) on tambaqui (Colossoma macropomum) in extremely soft water (10 {mu}mol l{sup -1} Ca{sup 2+}). Tambaqui had a very high tolerance to Cu (50-400 {mu}g l{sup -1}), as indicated by a complete lack of inhibition of Na{sup +} uptake and an ability to gradually recover over 6 h from elevated diffusive Na{sup +} losses caused by Cu. The insensitivity of active Na{sup +} influx to Cu further supports the notion that Amazonian fish may have a unique Na{sup +} transport system. Addition of 5-10 mg C l{sup -1} of dissolved organic matter (DOM) did not prevent initial (0-3 h) negative Na{sup +} balance in tambaqui exposed to Cu. Exposure to 40 mg C l{sup -1} DOM prevented Na{sup +} losses in tambaqui even at 400 {mu}g l{sup -1} Cu, probably because most Cu was complexed to DOM. Tambaqui exposed to waterborne Cd (10-80 {mu}g l{sup -1}) experienced an average of 42% inhibition in whole body Ca{sup 2+} uptake relative to controls within 3 h of exposure to the metal. Inhibition of Ca{sup 2+} uptake increased over time and, at 24 h, Ca{sup 2+} uptake was suppressed by 51% and 91% in fish exposed to 10 and 80 {mu}g l{sup -1} Cd, respectively. Previous acclimation of fish to either elevated [Ca{sup 2+}] or elevated [DOM] proved to be very effective in protecting against acute short-term metal accumulation at the gills of tambaqui in soft water (in the absence of the protective agent during metal exposure), suggesting a conditioning effect on gill metal binding physiology.

  17. Risk assessment of environmental exposure to mercury in the urban area of Alta Floresta, Mato Grosso State - Amazonian basin - Brazil; Avaliacao do risco potencial para a saude humana da exposicao ao mercurio na area urbana de Alta Floresta, Mato Grosso - Bacia Amazonica - Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Hacon, Sandra de Souza

    1996-07-01

    Mercury contamination in the Amazon basin is a consequence of the intensive and extensive use of metallic Hg in gold mining activities which use the amalgamation process. Mercury vapor is the main form of Hg released in the Amazonian ecosystem. However, some studies have shown that enhanced biotransformation of inorganic mercury into organic Hg is occurring. These two forms of Hg have some properties in common but differ in toxicity and metabolic behavior. Knowledge of the fate and transport of Hg in the Amazon basin is especially important for the assessment of the extent of contamination, as well as the characterization of exposed groups. the present study attempts to evaluate the Hg exposure scenario as well as to assess the quantitative risk (from Hg emission) for workers in gold-dealers' shops and for the general population in the urban area of Alta Floresta. The way that are was populated and the regional and local economy history, particularly in connection with the commercialization of gold in the region, are important factors in the study of the exposure scenario in Alta Floresta. Assessment of exposure pathways has shown that the adult and infant populations of Alta Floresta are exposed to low dose levels of Hg. Fish consumed locally shows high concentrations of Hg, ranging from 0,5 to 3,6 mg/kg. However, due to the low consumption of fish by the general population this exposure pathway has little effect on the health of the general public. Fishermen and their families are those most at risk from Hg intoxication. Workers in gold shops are another critical group, in relation to exposure to Hg vapor. As for the infant population, above 4 years old, inhalation of Hg vapor is the main source of the exposure, one exception being to children of fishermen whose pattern of fish consumption is similar to their parents. These are the two groups at risk from fish ingestion. Infants between 1 and 4 years of age are the group most likely to suffer adverse effects

  18. Pancreatitis - children

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007679.htm Pancreatitis - children To use the sharing features on this page, please enable JavaScript. Pancreatitis in children occurs when the pancreas becomes swollen ...

  19. Intussusception - children

    Science.gov (United States)

    ... Viral infection Englarged lymph node in the intestine Polyp or tumor The reason for the problem is more likely to be found in older children. Intussusception can affect both children and adults. However, ...

  20. Children's Health

    Science.gov (United States)

    Your child's health includes physical, mental and social well-being. Most parents know the basics of keeping children healthy, like offering ... for children to get regular checkups with their health care provider. These visits are a chance to ...

  1. Epilepsy - children

    Science.gov (United States)

    Seizure disorder - children; Convulsion - childhood epilepsy; Medically refractory childhood epilepsy; Anticonvulsant - childhood epilepsy; Antiepileptic drug - childhood epilepsy; AED - childhood epilepsy

  2. Lipid profile and cardiovascular risk in two Amazonian populations Perfil lipídico e risco cardiovascular em amazônidas

    Directory of Open Access Journals (Sweden)

    Claudine Maria Alves Feio

    2003-12-01

    Full Text Available OBJECTIVE: To compare the lipid profiles and coronary heart disease risks of 2 Brazilian Amazonian populations as follows: a riverside population (village of Vigia and an urban population (city of Belém in the state of Pará. METHODS: Fifty individuals controlled for age and sex were assessed in each region, and the major risk factors for coronary heart disease were analyzed. RESULTS: According to the National Cholesterol Education Program (NCEP III and using the Framingham score, both populations had the same absolute risk of events (Vigia = 5.4 ± 1 vs Belém = 5.7 ± 1, although the population of Vigia had a lower consumption of saturated fat (POBJETIVO: Comparar o perfil lipídico e risco coronariano de uma população ribeirinha (Vigia ao de uma população urbana (Belém. MÉTODOS: Foram avaliados 50 indivíduos de cada região, controlados por idade e sexo, examinando-se os principais fatores de risco para a doença coronariana. RESULTADOS: Segundo o Programa Nacional de Educação sobre o Colesterol (NCEP III e determinando-se o escore de Framingham, ambas as populações expressaram o mesmo risco absoluto de eventos (Vigia 5,4 ± 1 vs. Belém 5,7 ± 1, a despeito da população de Vigia apresentar menor consumo de gordura saturada (p<0,0001, maior de mono e poliinsaturada (p<0,03, além de menores valores do índice de massa corpórea (25,4±0,6 vs. 27,6±0,7kg/m², p<0,02, da prega biceptal (18,6±1,1 vs. 27,5±1,3mm, p<0,0001 e triceptal (28,7±1,2 vs. 37,3±1,7mm, p<0,002, de colesterol total (205±5 vs. 223±6mg/dL, p< 0,03 e triglicérides (119 ± 9 vs. 177±18mg/dL, p<0,005, não diferindo no HDL-c (46±1 vs. 46±1mg/dL, LDL-c (135 ± 4 vs. 144 ± 5mg/dL e pressão arterial (PAS 124 ± 3 vs. 128 ± 3mmHg; PAD 80 ± 2 vs. 82 ± 2mmHg. CONCLUSÃO: A população ribeirinha e urbana da Amazônia apresentaram risco cardiovascular semelhante. Entretanto, a marcante diferença entre as variáveis estudadas sugere que devam ser aplicadas

  3. Likeable children, uneasy children

    DEFF Research Database (Denmark)

    Anderson, Sally Dean

    2014-01-01

    Drawing on fieldwork in small-town schools with children of Muslim background whose families came to Denmark as United Nation refugees, the chapter explores how pedagogical ideologies of school-based peer sociability inflect children’s experiences of ‘being Muslim.’ Danish provincial schools......, with their permanent classes, emphasis on class-based sociability, and particular understandings of what constitutes religion, represent a particular context for children’s school experiences. An analysis of two contrasting cases reveals that participation in peer sociability in and beyond school tends to erase...

  4. Sesquiterpenes of Amazonian Piper species*

    OpenAIRE

    SANTOS, Alberdan S; ANDRADE, Eloisa H. A; ZOGHBI, Maria das Graças B; LUZ, Arnaldo I. R; MAIA, José G. S

    1998-01-01

    The essential oils from leaves and thin branches of Piper amapense, Piper ducket and Piper bartlingianum were analysed by GC/MS and all volatile compounds were identified as sesquiterpenes. The main constitutents identified in the oil of P. amapense were trans-caryophyllene (25.0%), caryophyllene oxide (17.0%) and β-selinene (15.0%). The oil of P. duckei was dominated by trans-caryophyllene (23.5%), caryophyllene oxide (18.4%), β-eudesmol (9.4%) and a-eudesmol (9.1%). The major components fou...

  5. Gastroesophageal reflux disease - children

    Science.gov (United States)

    Peptic esophagitis - children; Reflux esophagitis - children; GERD - children; Heartburn - chronic - children; Dyspepsia - GERD - children ... GERD. Certain factors can lead to GERD in children, including: Birth defects, such as hiatal hernia , a ...

  6. Life history, immune function, and intestinal helminths: Trade-offs among immunoglobulin E, C-reactive protein, and growth in an Amazonian population.

    Science.gov (United States)

    Blackwell, Aaron D; Snodgrass, J Josh; Madimenos, Felicia C; Sugiyama, Lawrence S

    2010-01-01

    Infection with helminths is associated with shifts in host immunity, including increased production of immunoglobulin E (IgE) and reduced inflammation. Given limited energy budgets, these shifts may involve changes in energy allocation toward competing demands. Here we test for potential trade-offs between growth, IgE, and the inflammatory marker C-reactive protein (CRP). Dried blood spots and anthropometrics were collected from 162 Shuar forager-horticulturalists from a village in southeastern Ecuador. Enzyme-linked immunosorbent assays (ELISAs) were used to measure IgE and CRP. Relationships among IgE, CRP, and anthropometrics were examined in three groups: children aged 2-7 years (n = 63), children aged 8-15 (n = 61), and adults over age 18 (n = 37). Geometric mean IgE was 1,196 IU ml⁻¹ while geometric mean CRP was 1.33 mg l⁻¹. In children, IgE and CRP were negatively correlated (r = -0.21, P = 0.02, df = 122). Controlling for fat stores and age, IgE was associated with lower stature in children (t = -2.04, P = 0.04, df = 109), and adults (t = -3.29, P < 0.01, df = 33). In children there was a significant interaction between age and CRP, such that in younger children CRP was associated with shorter stature, but in older children was associated with greater stature (t = 2.15, P = 0.04, df = 109). These results suggest that infection with helminths may have hidden costs associated with immunological changes, and that these costs may ultimately affect growth and other life history parameters. © 2010 Wiley-Liss, Inc.

  7. Heart failure in children - overview

    Science.gov (United States)

    Congestive heart failure - children; Cor pulmonale - children; Cardiomyopathy - children; CHF - children; Congenital heart defect - heart failure in children; Cyanotic heart disease - heart failure in children; Birth ...

  8. Metallogenetic systems associated with granitoid magmatism in the Amazonian Craton: An overview of the present level of understanding and exploration significance

    Science.gov (United States)

    Bettencourt, Jorge Silva; Juliani, Caetano; Xavier, Roberto P.; Monteiro, Lena V. S.; Bastos Neto, Artur C.; Klein, Evandro L.; Assis, Rafael R.; Leite, Washington Barbosa, Jr.; Moreto, Carolina P. N.; Fernandes, Carlos Marcello Dias; Pereira, Vitor Paulo

    2016-07-01

    The Amazonian Craton hosts world-class metallogenic provinces with a wide range of styles of primary precious, rare, base metal, and placer deposits. This paper provides a synthesis of the geological database with regard to granitoid magmatic suites, spatio temporal distribution, tectonic settings, and the nature of selected mineral deposits. The Archean Carajás Mineral Province comprises greenstone belts (3.04-2.97 Ga), metavolcanic-sedimentary units (2.76-2.74 Ga), granitoids (3.07-2.84 Ga) formed in a magmatic arc and syn-collisional setting, post-orogenic A2-type granites as well as gabbros (ca. 2.74 Ga), and anorogenic granites (1.88 Ga). Archean iron oxide-Cu-Au (IOCG) deposits were synchronous or later than bimodal magmatism (2.74-2.70 Ga). Paleoproterozoic IOCG deposits, emplaced at shallow-crustal levels, are enriched with Nb-Y-Sn-Be-U. The latter, as well as Sn-W and Au-EGP deposits are coeval with ca. 1.88 Ga A2-type granites. The Tapajós Mineral Province includes a low-grade meta-volcano-sedimentary sequence (2.01 Ga), tonalites to granites (2.0-1.87 Ga), two calc-alkaline volcanic sequences (2.0-1.95 Ga to 1.89-1.87 Ga) and A-type rhyolites and granites (1.88 Ga). The calc-alkaline volcanic rocks host epithermal Au and base metal mineralization, whereas Cu-Au and Cu-Mo ± Au porphyry-type mineralization is associated with sub-volcanic felsic rocks, formed in two continental magmatic arcs related to an accretionary event, resulting from an Andean-type northwards subduction. The Alta Floresta Gold Province consists of Paleoproterozoic plutono-volcanic sequences (1.98-1.75 Ga), generated in ocean-ocean orogenies. Disseminated and vein-type Au ± Cu and Au + base metal deposits are hosted by calc-alkaline I-type granitic intrusions (1.98 Ga, 1.90 Ga, and 1.87 Ga) and quartz-feldspar porphyries (ca. 1.77 Ga). Timing of the gold deposits has been constrained between 1.78 Ga and 1.77 Ga and linked to post-collisional Juruena arc felsic magmatism (e.g., Col

  9. The influence of particles recycling on the geochemistry of sediments in a large tropical dam lake in the Amazonian region, Brazil

    Science.gov (United States)

    Fonseca, Rita; Pinho, Catarina; Oliveira, Manuela

    2016-12-01

    As a result of over-erosion of soils, the fine particles, which contain the majority of nutrients, are easily washed away from soils, which become deficient in a host of components, accumulating in lakes. On one hand, the accumulation of nutrients-rich sediments are a problem, as they affect the quality of the overlying water and decrease the water storage capacity of the system; on the other hand, sediments may constitute an important resource, as they are often extremely rich in organic and inorganic nutrients in readily available forms. In the framework of an extensive work on the use of rock related materials to enhance the fertility of impoverish soils, this study aimed to evaluate the role on the nutrients cycle, of particles recycling processes from the watershed to the bottom of a large dam reservoir, at a wet tropical region under high weathering conditions. The study focus on the mineralogical transformations that clay particles undergo from the soils of the drainage basin to their final deposition within the reservoir and their influence in terms of the geochemical characteristics of sediments. We studied the bottom sediments that accumulate in two distinct seasonal periods in Tucuruí reservoir, located in the Amazonian Basin, Brazil, and soils from its drainage basin. The surface layers of sediments in twenty sampling points with variable depths, are representative of the different morphological sections of the reservoir. Nineteen soil samples, representing the main soil classes, were collected near the margins of the reservoir. Sediments and soils were subjected to the same array of physical, mineralogical and geochemical analyses: (1) texture, (2) characterization and semi-quantification of the clay fraction mineralogy and (3) geochemical analysis of the total concentration of major elements, organic compounds (organic C and nitrogen), soluble fractions of nutrients (P and K), exchangeable fractions (cation exchange capacity, exchangeable bases and

  10. Hydroelectric reservoir inundation (Rio Madeira Basin, Amazon) and changes in traditional lifestyle: impact on growth and neurodevelopment of pre-school children.

    Science.gov (United States)

    Marques, Rejane C; Dórea, José G; McManus, Concepta; Leão, Renata S; Brandão, Katiane G; Marques, Rayson C; Vieira, Igor H Ito; Guimarães, Jean-Remy D; Malm, Olaf

    2011-04-01

    To assess the dependence on fish consumption of families and its impact on nutritional status and neurodevelopment of pre-school children. Cross-sectional study that measured children's hair mercury (HHg) as an indicator of family fish consumption, growth (anthropometric Z-scores, WHO standards) and neurological (Gesell developmental scores (GDS)) development. Traditional living conditions among families residing in the area adjacent to the Samuel Dam (Western Amazon) hydroelectric reservoir. Two hundred and forty-nine pre-school children (1-59 months of age) from families transitioning from the traditional Amazonian lifestyle. Family fish consumption was significantly correlated with children's HHg concentration (Spearman's r=0.246, P85), multiple regression analysis showed that fish consumption (as HHg) had no impact on GDS, but that some variables did interact significantly with specific domains (motor and language development). The study showed that the families' shift in fish consumption had no negative impact on the growth of young children and that ensuing methylmercury exposure has not been a noticeable neurodevelopmental hindrance.

  11. uninfected children

    African Journals Online (AJOL)

    To bridge the management gap between nutritional rehabilitation for severe acute malnutrition (SAM) and chronic malnutrition, ... Chronically malnourished children with superimposed SAM benefit from the use of RUTF as much as children without ... France), an energy-dense lipid paste made of peanut butter, milk powder ...

  12. 1.88 Ga São Gabriel AMCG association in the southernmost Uatumã-Anauá Domain: Petrological implications for post-collisional A-type magmatism in the Amazonian Craton

    Science.gov (United States)

    Valério, Cristóvão da Silva; Macambira, Moacir José Buenano; Souza, Valmir da Silva; Dantas, Elton Luiz; Nardi, Lauro Valentim Stoll

    2018-02-01

    In the southernmost Uatumã-Anauá Domain, central Amazonian craton (Brazil), crop out 1.98 Ga basement inliers represented by (meta)leucosyenogranites and amphibolites (Igarapé Canoas Suite), 1.90-1.89 Ga high-K calc-alkaline granitoids (Água Branca Suite), a 1.88-1.87 Ga alkali-calcic A-type volcano-plutonic system (Iricoumé-Mapuera), Tonian SiO2-satured alkaline granitoids, 1.45-1.25 Ga orthoderived metamorphic rocks (Jauaperi Complex) and Orosirian-Upper Triassic mafic intrusions. New data on petrography, multielementar geochemistry, in situ zircon U-Pb ages and Nd and Hf isotopes of alkali-calcic A-type granites (São Gabriel Granite, Mapuera Suite) and related rocks are indicative of a 1.89-1.87 Ga volcano-plutonic system integrated to the São Gabriel AMCG association. Its magmatic evolution was controlled by the fractional crystallization combined with magma mixing and cumulation processes. Nd isotope values (εNdt values = - 3.71 to + 0.51 and Nd TDM model age = 2.44 to 2.12 Ga) and U-Pb inherited zircon crystals (2115 ± 22 Ma; 2206 ± 21 Ma; 2377 ± 17 Ma, 2385 ± 17 Ma) of the São Gabriel system indicate a large participation of Siderian-Rhyacian crust (granite-greenstones and granulites) and small contribution of Rhyacian mantelic magma. εHft values (+ 5.2 to - 5.8) and Hf TDM ages (3.27-2.14 Ga) also point to contribution of Paleoarchean-Rhyacian crustal melts and small participation of Siderian-Rhyacian mantle melts. Residual melts from the lower crust have been mixed with basaltic melts generated by partial melting of the subcontinental lithospheric mantle (peridotite) in a post-collisional setting at 1.89-1.87 Ga. The mafic melts of such a mixture could have been originated through partial melting of residual ocean plate fragments (eclogites) which ascended onto a residual mantle wedge (hornblende peridotite) and melted it, resulting in modified basaltic magma which, by underplating, led heat to the anatexis of the lower continental crust

  13. Floristic composition and diversity of Amazonian rainforest bryophytes in the state of Acre, Brazil Composição florística e diversidade de briófitas em floresta no estado do Acre, Brasil

    Directory of Open Access Journals (Sweden)

    Denise Pinheiro da Costa

    2003-01-01

    Full Text Available Bryophyte diversity in Amazonian Brazil is high, presently recorded at 514 species distributed among 36 families and 89 genera. Comparisions of species richness among the Amazonian states of Brazil suggests that the bryoflora of Acre is still underestimated, presently recorded at 106 species distributed among 33 families and 63 genera. After two field trips, the diversity increased 50% showing that the bryoflora is still poorly known. Collection data and comments on morphology, ecology and distribution are given for sixty-two species of bryophytes collected in the state of Acre, Brazil, which are new (fifty-two species or interesting floristic records (ten species. Microlejeunea crenulifolia (Gottsche Steph. and Stictolejeunea balfourdii Mitt. are new records for Brazil and fifty species are new records for Acre.A diversidade de briófitas na região Amazônica brasileira é alta, sendo citado atualmente, 514 espécies, em 36 famílias e 89 gêneros. Comparações entre a riqueza de espécies dos estados da Amazônia brasileira sugerem que a brioflora do Acre ainda é subestimada, contando atualmente com 106 espécies, distribuídas em 33 famílias e 63 gêneros. Após duas excursões científicas, a diversidade para o estado aumentou em 50 %, demonstrando que a brioflora ainda é pouco conhecida. Dados sobre a morfologia, ecologia e distribuição geográfica são apresentados para sessenta e duas espécies de briófitas coletadas no estado do Acre, Brasil, as quais são registros florísticos novos (cinquenta e duas espécies ou interessantes (dez espécies. Microlejeunea crenulifolia (Gottsche Steph. e Stictolejeunea balfourdii Mitt. são citadas pela primeira vez para o Brasil e cinquenta espécies são novas ocorrências para o estado do Acre.

  14. Street children

    Directory of Open Access Journals (Sweden)

    Rončević Nevenka

    2013-01-01

    Full Text Available According to UNICEF, street child is any child under the age of 18 for whom the street has become home and/or source of income and which is not adequately protected or supervised by adult, responsible person. It has been estimated that there are between 100 and 150 million street children worldwide. Life and work on the street have long term and far-reaching consequences for development and health of these children. By living and working in the street, these children face the highest level of risk. Street children more often suffer from the acute illness, injuries, infection, especially gastrointestinal, acute respiratory infections and sexually transmitted diseases, inadequate nutrition, mental disorders, and drug abuse. They are more often victims of abuse, sexual exploitation, trafficking; they have higher rate of adolescent pregnancy than their peers from poor families. Street children and youth have higher rates of hospitalization and longer hospital stay due to seriousness of illness and delayed health care. Street children/youth are reluctant to seek health care, and when they try, they face many barriers. Street children are invisible to the state and their number in Serbia is unknown. Recently, some non­governmental organizations from Belgrade, Novi Sad and Nis have recognized this problem and tried to offer some help to street children, by opening drop­in centers, but this is not enough. To solve this problem, an engagement of the state and the whole community is necessary, and primary responsibility lies in health, social and educational sector. The best interests of the child must serve as a basic guideline in all activities aimed at improving health, quality of life and rights of children involved in the life and work in the street.

  15. Geology and geophysics of the Vila Nova Greenstone Belt, northeastern portion of the Amazonian Craton, Amapa, Brazil; Geologia e geofisica do greenstone belt Vila Nova, porcao NE do Craton Amazonico, Amapa, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Borghetti, Cristiano; Philipp, Ruy Paulo, E-mail: cborghetti@terra.com.br, E-mail: ruy.philipp@ufrgs.br [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre (Brazil)

    2017-01-15

    A few outcrops and strong weathering conditions prevail in the region of the Vila Nova Greenstone Belt in the southeastern Amapa (Brazil). This paper describes the use of airborne geophysical data for geological and structural analysis during geological mapping. This integration aims to improve the geological and tectonic understanding of this portion of the Amazonian Craton. The magnetometric and gamma-spectrometric qualitative interpretation of the images took place in a Geographic Information System (GIS) environment. Recognition of magnetometric and gamma-ray spectrometric units present in the study area was based on the hierarchical classification of polygons outlined by visual interpretation. The major geological domains and the structural patterns were defined by integration of geophysical data, geological mapping and petrographic analysis. The results allowed the recognition of Archean basement rocks composed of orthogneisses and granitoids of the Tumucumaque Complex, the metavolcano-sedimentary rocks of the Vila Nova Complex and Paleoproterozoic granite massifs. The integration of geophysical and field data resulted in the increase of the geological mapping definition, highlighting the importance of this methodology for recognition of complex structural and lithological fabrics in areas of difficult access and scarce fresh rock outcrops. (author)

  16. Phlebotominae sand flies (Diptera: Psychodidae): potential vectors of American cutaneous leishmaniasis agents in the area associated with the Santo Antônio Hydroelectric System in Western Amazonian Brazil.

    Science.gov (United States)

    Galardo, Allan Kardec Ribeiro; Galardo, Clícia Denis; Silveira, Guilherme Abbad; Ribeiro, Kaio Augusto Nabas; Hijjar, Andréa Valadão; Oliveira, Liliane Leite; Dos Santos, Thiago Vasconcelos

    2015-01-01

    An entomological study was conducted as part of a vector-monitoring program in the area associated with the Santo Antônio hydroelectric system in State of Rondônia, Western Amazonian Brazil. Fourteen sampling sites were surveyed to obtain data on the potential vectors of Leishmania spp. in the area. Sand flies were collected from 2011 to 2014 during the months of January/February (rainy season), May/June (dry season), and September/October (intermediary season) using light traps arranged in three vertical strata (0.5, 1, and 20m). A total of 7,575 individuals belonging to 62 species/subspecies were collected. The five most frequently collected sand flies were Psychodopygus davisi (Root) (36.67%), Trichophoromyia ubiquitalis (Mangabeira) (8.51%), Nyssomyia umbratilis (Ward & Fraiha) (6.14%), Bichromomyia flaviscutellata (Mangabeira) (5.74%), and Psychodopygus complexus (Mangabeira) (5.25%). These species have been implicated in the transmission of American cutaneous leishmaniasis agents in the Brazilian Amazon region and described as potential vectors of this disease in the study area. Additional surveillance is needed, especially in areas where these five species of sand fly are found.

  17. Phlebotominae sand flies (Diptera: Psychodidae: potential vectors of American cutaneous leishmaniasis agents in the area associated with the Santo Antônio Hydroelectric System in Western Amazonian Brazil

    Directory of Open Access Journals (Sweden)

    Allan Kardec Ribeiro Galardo

    2015-06-01

    Full Text Available INTRODUCTION: An entomological study was conducted as part of a vector-monitoring program in the area associated with the Santo Antônio hydroelectric system in State of Rondônia, Western Amazonian Brazil. METHODS: Fourteen sampling sites were surveyed to obtain data on the potential vectors of Leishmania spp. in the area. Sand flies were collected from 2011 to 2014 during the months of January/February (rainy season, May/June (dry season, and September/October (intermediary season using light traps arranged in three vertical strata (0.5, 1, and 20m. RESULTS : A total of 7,575 individuals belonging to 62 species/subspecies were collected. The five most frequently collected sand flies were Psychodopygus davisi (Root (36.67%, Trichophoromyia ubiquitalis (Mangabeira (8.51%, Nyssomyia umbratilis (Ward & Fraiha (6.14%, Bichromomyia flaviscutellata (Mangabeira (5.74%, and Psychodopygus complexus (Mangabeira (5.25%. These species have been implicated in the transmission of American cutaneous leishmaniasis agents in the Brazilian Amazon region and described as potential vectors of this disease in the study area. CONCLUSIONS: Additional surveillance is needed, especially in areas where these five species of sand fly are found.

  18. Difficult Children

    DEFF Research Database (Denmark)

    Christensen, Else

    The purpose of this paper is to put focus on families and children who have had contact to the social service department because of problems related children’s well-being, health or development. Problems that are recognized by the families themselves and by the authorities as problems that put...... the family in a poor position regarding the children’s well-being, health and development, but not so severe that the child is to be placed out of home. The paper concentrates attention on differences between families with and without contact to the social service department for reasons related to the child....... Especially on children and their development in social relations to children at the same age, on how the mothers experience their child and on the parent’s resources concerning health, education and job situation. The paper presents results from the first two data collections (1996 and 1999) in a prospective...

  19. Chronic Pancreatitis in Children

    Science.gov (United States)

    ... Information Children/Pediatric Chronic Pancreatitis in Children Chronic Pancreatitis in Children What symptoms would my child have? ... will develop diabetes in adolescence. Who gets chronic pancreatitis? Those at risk for chronic pancreatitis are children ...

  20. Pneumonia - children - community acquired

    Science.gov (United States)

    Bronchopneumonia - children; Community-acquired pneumonia - children; CAP - children ... Viruses are the most common cause of pneumonia in infants and children. Ways your child can get CAP include: Bacteria and viruses living in the nose, sinuses, or mouth may spread ...

  1. A 15-year post evaluation of the fire effects on ant community in an area of Amazonian forest Uma avaliação após 15 anos do efeito do fogo sobre a comunidade de formiga em uma área de floresta amazônica

    OpenAIRE

    Jean C. Santos; Jacques H. C. Delabie; G. Wilson Fernandes

    2008-01-01

    Fire represents an important disturbance to ant communities in areas of fire regime. Otherwise, little is known about the effects of fire on ant communities in areas of non-fire regimes, such as in the Amazonian region. We evaluated the long-term effect of fire on ant species richness in a rain forest (Bacaba Plateau) burned 15-years ago and compare our data with the data of primary unburned forest. A total of 85 ant species distributed in 21 genera and 14 tribes were collected; among them, 7...

  2. Children's Rights.

    Science.gov (United States)

    Schlene, Vickie J.

    1992-01-01

    Provides a sampling of citations in the ERIC database on children's rights. Includes human rights education, United Nations' conventions, state takeovers of local school districts, and federal law as it affects student rights. Covers child abuse, corporal punishment, child welfare, and child advocacy. (DK)

  3. Wild Children

    Science.gov (United States)

    Trotman, Helen

    2010-01-01

    In this article, the author, a Forest School Leader with Shropshire Wildlife Trust, shows how nature is the best teacher. She describes a new approach to out-of-classroom learning during which qualified leaders use simple challenges and achievable tasks to encourage child-initiated learning in the great outdoors. At Forest School, children are…

  4. Perceptions of Amazonian deforestation in the British and Brazilian media Percepções do desmatamento da Amazônia na mídia Britânica e Brasileira

    Directory of Open Access Journals (Sweden)

    Richard J. Ladle

    2010-01-01

    Full Text Available The Amazon rainforest stretches across more than six million square kilometers and nine countries. Of the original forest area it is thought that 18 per cent has been cleared, mainly for farming purposes. In Brazil, the main drivers of deforestation are beef ranching and soya production that together occupy more than 75 per cent of newly deforested land. The situation in the Amazon illustrates a fundamental dilemma facing environmentalists around the world: how to reconcile economic development with biodiversity conservation. In this paper the representation of this dilemma in the British and Brazilian news media is assessed. The results indicate that there were far more articles referring to deforestation in the Brazilian press (816 Brazilian to 29 UK but that many of these make no mention of what factors are responsible for deforestation. The patterns of representation of the proximate (direct causes of Amazonian deforestation were very similar in the two countries, with soya and beef cattle ranching commanding the most press attention. The ultimate (indirect causes of deforestation, however, are treated very differently, with the Brazilian media seemingly far more aware of the role of economic development needs than the UK press. Interestingly, the role of international demand for soya, beef, and forest products in driving deforestation was highlighted primarily in the UK press. These findings are critically discussed in the context of media influence on public understandings of Amazonian deforestation.A floresta Amazônica abrange mais de 6 milhões de km² e engloba 9 países. Acredita-se que 18% da superficie florestal já tenha sido desmatada principalmente para usos agropecuários. No Brasil, a pecuária e a produção de soja encabeçam as causas do desmatamento, sendo estes responsáveis por 75% das terras desmatadas. A situação da Amazônia ilustra o principal dilema que enfrentam os ambientalistas em todo o mundo: como permitir um

  5. Redes sociais, capital social e governança ambiental no Território Portal da Amazônia Social networks, social capital and environmental governance in the Amazonian Gateway Territory

    Directory of Open Access Journals (Sweden)

    Frédéric Mertens

    2011-01-01

    actors from the Amazonian Gateway Territory. The analysis identified 3384 dialogue relationships. Each actor has an average of 6,7 dialogue partners. The analysis of the structural characteristics of the dialogue network was used to build indicators of social capital of the bonding type, based on the mapping of the organization among actors from the same municipalities, and bridging type, based on the identification of relationships among actors from different municipalities. At the municipal level, the distribution of the two types of social capital allowed the characterization of groups of actors according to their differing participation in the environmental governance of the Territory. At the territorial level, the connectivity pattern among the 16 municipalities exhibits a balance between the two types of social capital and reveals the potential of communication and organization among actors, as demonstrated through the example of the local Agenda 21 projects. These results demonstrate how social network analysis can contribute to the definition (or re-definition of the territories frontiers in order to include a set of municipalities whose cohesion is based on effective social relationships. We also propose governance actions for the Amazonian Gateway aiming at strengthening dialogue processes, reducing conflicts and promoting the sustainable use of natural resources in the Amazon.

  6. BMI gain and insulin resistance among school-aged children: a population-based longitudinal study in the Brazilian Amazon.

    Science.gov (United States)

    Lourenço, Barbara H; Gimeno, Suely G A; Cardoso, Marly A

    2014-12-14

    Investigation of the determinants of metabolic outcomes associated with non-communicable diseases is increasingly important in developing countries, but such parameters have not been explored extensively during childhood. The present study assessed the impact of weight gain, measured as BMI-for-age Z-scores, on glucose and insulin concentrations, homeostasis model assessment index of insulin resistance (HOMA-IR) values, and systolic and diastolic blood pressure during school years among Amazonian children. A population-based prospective study of 696 children aged >4 to ≤ 10 years with complete anthropometric information at baseline (51% females and 86% of mixed race) was carried out; 411 children had data on metabolic parameters after a median follow-up period of 2.0 years (range 1.7-2.6 years). During follow-up, there was a significant increase in the proportion of overweight children (BMI-for-age Z-score >1) from 10.1 to 15.8% (P= 0.003). In linear regression models adjusted for the child's sex, age, race/ethnicity, baseline household wealth, birth weight and pubertal development stage, for each unit of BMI-for-age Z-score variation during follow-up, an increase of 8.58 (95% CI 7.68, 9.60) pmol/l in fasting plasma insulin concentrations and 1.47 (95% CI 1.30, 1.66) in HOMA-IR values was observed. There was no significant impact of weight gain on glucose concentrations and systolic and diastolic blood pressure. In conclusion, we found evidence that an increase in BMI during a 2-year period affected insulin resistance during school years. Considering the significant increase in overweight in this age group, special attention should be paid to monitoring increases in BMI in children from the Brazilian Amazon.

  7. Geology, petrology, U-Pb (shrimp geochronology of the Morrinhos granite -Paraguá terrane, SW Amazonian craton: implications for the magmatic evolution of the San Ignácio orogeny

    Directory of Open Access Journals (Sweden)

    Ohana França

    Full Text Available Morrinhos granite is a batholith body that is slightly elongated in the NNW direction and approximately 1,140 km2 long; it is located in the municipality of Vila Bela da Santíssima Trindade of the state of Mato Grosso, Brazil, in the Paraguá Terrane, Rondonian-San Ignácio Province, in the SW portion of the Amazonian Craton. This intrusion displays a compositional variation from tonalite to monzogranite, has a medium to coarse inequigranular texture and is locally porphyritic; biotite is the predominant mafic in one of the facies, and hornblende is predominant in the other, with both metamorphosed into the greenschist facies. The studied rocks characterize an intermediate to acidic sequence that was formed by a subalkaline magmatism; the series is alkali-calcic to metaluminous to slightly peraluminous, and the rocks evolved through fractioned crystallization mechanisms. The structural data show two deformation phases represented by penetrative foliation (S1 and open folds (D2, and both phases were most likely related to the San Ignácio Orogeny. The geochronological (U-Pb SHRIMP and isotopic (Sm-Nd investigations of these rocks indicated a crystallization age of 1350 ± 12 Ma, TDMof approximately 1.77 Ga and εNd(1.35with a negative value of -2.57, suggesting that their generation was related to a partial melting process of a Paleoproterozoic (Statherian continental crust. The results herein indicate that the Morrinhos granite was generated in a continental magmatic arc in a late- to post-orogenic stage of the San Ignácio Orogeny, and it can be recognized as belonging to the Pensamiento Intrusive Suite.

  8. Catadoras de caranguejo e saberes tradicionais na conservação de manguezais da Amazônia brasileira Crab pickers and traditional knowledge in the conservation of brazilian Amazonian mangroves

    Directory of Open Access Journals (Sweden)

    Denise Machado

    2007-08-01

    Full Text Available A catação de caranguejo (Ucides cordatus desenvolvida por mulheres caboclas em áreas do litoral norte da região amazônica, precisamente no nordeste paraense, possibilita a análise da problemática ambiental e relações de gênero a partir de uma abordagem antropológica sobre uma parcela da população tradicional amazônica. Quanto à questão ambiental, é tratada em termos de conservação, manejo e conhecimento de recursos ambientais. Evidenciou-se que a pesca desenvolvida nas áreas de manguezais na vila de Guarajubal é feita artesanalmente e direcionada à captura e beneficiamento do caranguejo, com o trabalho decisivo das mulheres a partir da maior demanda nos centros urbanos próximos. O trabalho das catadoras lhes possibilita manifestarem-se em relação aos problemas ambientais, ainda que no contexto local.The crab (Ucides cordatus picking, done by cabocla women in Northeast Pará of the North Coastal Amazon Region, permits the analysis of the environmental question and of gender relations from an anthropological approach on a specific Amazonian traditional population. The environmental question is dealt with in terms of conservation, handling and knowledge about environmental resources. Evidence shows that crab picking is an artisan activity developed in mangrove swamp areas near the town of Guarajubal in which catching and doing product betterment of the crab are women's work, stimulated by the growing demand from nearby urban centers. The work of the catadoras (pickers allows them to manifest their opinions in relation to the environmental problems, albeit in the local context.

  9. Children's Stereotypes of Overweight Children

    Science.gov (United States)

    Penny, Helen; Haddock, Geoffrey

    2007-01-01

    The aim of the present study was to assess the content, favourability and generality of perceptions held about overweight children. The research also addressed whether anti-fat biases change with age and whether they result from a strong association between overweight and bad behaviour, a weak association between overweight and good behaviour or…

  10. Prenatal care and childbirth assistance in Amazonian women before and after the Pacific Highway Construction (2003-2011): a cross-sectional study.

    Science.gov (United States)

    Guimarães, Andréia S; Mantovani, Saulo A S; Oliart-Guzmán, Humberto; Martins, Antonio C; Filgueira-Júnior, José Alcântara; Santos, Ana Paula; Braña, Athos Muniz; Branco, Fernando Luís Cunha Castelo; Pereira, Thasciany Moraes; Delfino, Breno Matos; Ramalho, Alanderson A; Oliveira, Cristieli S M; Araújo, Thiago S; de Lara Estrada, Carlos Hermogenes Manrique; Arróspide, Nancy; Muniz, Pascoal T; Codeço, Cláudia T; da Silva-Nunes, Mônica

    2016-07-13

    Attention to prenatal care and child delivery is important for the health of women and children, but in the Amazon these indicators tend to be historically unfavorable, in part by geographical and political isolation. In 2003 both Brazilian and Peru governments have finished paving an international road connecting remotes areas in the Brazilian Amazon to the Pacific coast in Peru. The situation of prenatal care and child delivery with mothers of children under 5 years old living in the urban area of Assis Brasil, Acre was assessed in two cross-sectional studies performed in 2003 and 2011, corresponding to the period before and after the Pacific highway construction. In 2003, most mothers were of black/Afro-American ethnicity, or "pardos" (the offspring of a Caucasian with a African descendant) (77.69 %), had more than 4 years of schooling (73.40 %) and had a mean age of 22.18 years. In 2011, the number of as a migration of indigenous women increased from 0 to 14.40 % of the respondents, because of migration from communities along the rivers to urban areas, with no other significant changes in maternal characteristics. No significant improvement in childbirth assistance was noticed between 1997 and 2011; only the percentage of in-hospital vaginal deliveries performed by doctors increased from 17.89 to 66.26 % (p prenatal care was associated with white ethnicity in 2003, and higher socioeconomic level and white ethnicity in 2011, while the higher number of prenatal visits was associated with higher maternal education and higher socioeconomic levels in 2011. Vaginal child delivery at a hospital facility was associated with maternal age in 2003, and year of birth, being of white ethnicity and higher level of education in 2011. The indicators of prenatal care and child delivery were below the national average, showing that geographical isolation still affects women's health care in the Amazon, despite the construction of the highway and governmental health protocols

  11. in Children

    Directory of Open Access Journals (Sweden)

    Monika Jabłońska-Jesionowska

    2016-12-01

    Full Text Available Introduction. Chronic rhinitis in children may have different causes, both local – with changes being present only in the nasalcavity – or systemic, with nasal congestion as one of the symptoms of a bigger clinical picture.Aim. the aim of this study was to draw attention to a very rare congenital cause of chronic rhinitis in children – which is hypohidrotic ectodermal dysplasia.Material and methods. A 6-month-old boy was admitted to the department of pediatric otolaryngology of Warsaw medicalUniversity due to chronic nasal obstruction present from birth. Clinical investigation included anterior and posterior rhinoscopy and fiberoscopy of nasopharynx. the mri was also performed before admission. Complete blood count, serum iron level,serum thyroid hormones and level of igG, igA, igm were examined to exclude anaemia, ozaena and hypothyroidism. Antinuclear antibodies (AnA and antineutrophil cytoplasmic antibodies (AnCA tests were also ordered to exclude granulomatosiswith polyangiitis. next, a mucosal biopsy of the nasal cavity was performed to exclude primary ciliary dyskinesia. Allergic pricktests were also performed.Results. After genetic tests, hypohidrotic ectodermal dysplasia was diagnosed.Conclusions. 1. every case of chronic nasal congestion in children requires not only adequate treatment, but also thoroughclinical investigation. 2. nasal obstruction may be due to local causes, systemic diseases and genetic disorders. 3. hypohidroticectodermal dysplasia is a very rare genetic disorder that causes severe, even life threatening symptoms, one of which is chronicrhinitis.

  12. Ptosis - infants and children

    Science.gov (United States)

    Blepharoptosis - children; Congenital ptosis; Eyelid drooping - children; Eyelid drooping - amblyopia; Eyelid drooping - astigmatism ... Ptosis in infants and children is often due to a problem with the muscle that raises the eyelid. A nerve problem in the eyelid can ...

  13. Treating Children and Adolescents

    Science.gov (United States)

    ... Children and Adolescents Go Back Treating Children and Adolescents Email Print + Share For the most part, the ... tailored, based upon the child's weight. Children and adolescents are moving through a period of physical and ...

  14. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging ... the limitations of Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a branch ...

  15. Intestinal Polyps (in Children)

    Science.gov (United States)

    ... these inherited conditions. What are the symptoms of polyps? Children with polyps usually pass blood in the stools. ... to have another colonoscopy. Children that have several polyps, or children whose families have special polyposis syndromes, may need ...

  16. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... What are the limitations of Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is ... this time is PET/MRI. top of page What are some common uses of the procedure? Children's ( ...

  17. Divorce: Helping Children Cope.

    Science.gov (United States)

    Cook, Alicia S.; McBride, Jean

    1982-01-01

    Examines children's reactions to the divorce process and explores ways in which adults can promote growth and adjustment in children of divorce. Suggests ways in which parents, teachers, and counselors can help children. (RC)

  18. Hodgkin lymphoma - children

    Science.gov (United States)

    ... children; Hodgkin disease - children; Cancer - Hodgkin lymphoma - children; Childhood Hodgkin lymphoma ... of cancer is unknown. But, certain factors may play a role in ... Common early childhood infections also may increase the risk.

  19. Cow's milk and children

    Science.gov (United States)

    Milk and children; Cow's milk allergy - children; Lactose intolerance - children ... You may have heard that cow's milk should not be given to babies younger than 1 year old. This is because cow's milk doesn't provide enough of ...

  20. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging uses ... limitations of Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a branch of ...

  1. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging uses small ... of Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a branch of medical ...

  2. Children's (Pediatric) Nuclear Medicine

    Science.gov (United States)

    ... Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging uses small amounts ... Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a branch of medical imaging ...

  3. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging uses small amounts ... Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a branch of medical imaging ...

  4. Magmatic microgranular enclaves of the northeast of Mato Grosso, Brazil, SE Amazonian Craton: Insights into the magmatism of the Uatumã Supergroup on the basis of field and petrological data

    Science.gov (United States)

    Tarelow Neto, João; Pierosan, Ronaldo; Barros, Márcia Aparecida de Sant'Ana; Chemale, Farid, Jr.; Santos, Fernanda Silva

    2017-10-01

    Felsic and mafic microgranular enclaves occurs hosted in Paleoproterozoic felsic volcanic and plutonic rocks of the Iriri Group and Rio Dourado Intrusive Suite that crop out in the northeast of the Brazilian state of Mato Grosso as part of the Uatumã Supergroup in the SE Amazonian Craton. The volcanic rocks consist of dacites, rhyolites and ignimbrites of the Iriri Group among which dacites yielded a crystallization age of 1895 ± 7 Ma. The granitoids are composed of syenogranites, and monzogranites along with subordinate granodiorites. The granite pluton of syenogranite composition belongs to the Rio Dourado Intrusive Suite and was previously dated at 1876 ± 39 Ma. Mafic enclaves show petrographic features that suggest magma mingling processes and may be classified as olivine-clinopyroxene gabbro, clinopyroxene-hornblende gabbro, biotite-clinopyroxene diorite, biotite-hornblende diorite, and biotite-quartz diorite. Geochemical patterns of dioritic enclaves fit with those of the mafic rocks of the Santa Inês Intrusive Suite and suggest that they are comagmatic. The felsic enclaves consist of quartz monzonites, monzogranites and quartz-rich granitoids, with geochemical patterns and ages compatible with those of the Iriri Group. U-Pb dating of a granodioritic enclave hosted by a syenogranite of the Rio Dourado Intrusive Suite yielded three distinct ages: a Paleoproterozoic magmatic age around 1.87 Ga; a Paleoproterozoic inherited age of 2001 ± 7 Ma; and Neoarchean inherited ages ranging from 2512 to 2767 Ma. The felsic enclaves may have been derived from crustal melts, and contain restitic zircon grains, or chilled margins with zircon removed from the wall rocks. The recognition of diverse geochemical patterns of felsic and mafic enclaves suggests that the study area can represent the top of a shallow complex magma chamber that experienced a number of different replenishment events from diverse sources. The mafic enclaves and their coeval enclosing volcanic rocks

  5. First description of reproductive behavior of the Amazonian damselfly Chalcopteryx rutilans (Rambur (Odonata, Polythoridae Primeira descrição do comportamento reprodutivo da libélula amazônica Chalcopteryx rutilans (Rambur (Odonata, Polythoridae

    Directory of Open Access Journals (Sweden)

    Daniela C. Resende

    2010-01-01

    Full Text Available Polythoridae comprise a widespread group of species in the New World tropics, but little is known about their behavior or life history. Here, we described the reproductive behavior of Amazonian Chalchopteryx rutilans, using mark-recapture techniques. Males were resident and territorial, though we found disputes (complex flight manoeuvres to be rare. Trunks (rotting wood were important to male persistence in sites, as these are the locations preferred by females for oviposition. The mating system of C. rutilans may be comparable to the resource limitation category, described by Conrad & Pritchard (1992, where males cannot control female access to oviposition sites. So, female choice becomes important and apparently, the observed displays (in which males flash the coppery coloration of their hind wings may be related to attraction of females to territories, as in a lek system.A família Polythoridae compreende diversas espécies tropicais, das quais muito pouco se conhece sobre o comportamento ou história de vida. Neste trabalho, nós descrevemos o comportamento reprodutivo da espécie amazônica Calchopteryx rutilans, utilizando técnica de marcação e recaptura. Os machos foram residentes e territorialistas, apesar das disputas (que envolvem manobras de vôo complexas serem raras. A ocorrência de troncos caídos sobre os igarapés foi importante para a persistência dos machos nos territórios, uma vez que as fêmeas utilizam estes locais para postura dos ovos. O sistema de acasalamento de C. rutilans parece similar ao "sistema com limitação de recurso", descrito por Conrad & Pritchard (1992, onde os machos não são capazes de controlar o acesso das fêmeas aos recursos de oviposição. Nestes casos, as fêmeas podem escolher os machos e, aparentemente, as freqüentes exibições dos machos (mostrando a coloração interna cobreada de suas asas podem estar relacionadas à atração de fêmeas aos territórios, semelhante ao sistema tipo

  6. Immunizing Children

    Directory of Open Access Journals (Sweden)

    Geraldine Jody Macdonald

    2014-11-01

    Full Text Available This article addresses the complex contexts within which Canadian health professionals engage in immunizing children and focuses on the Canadian practice guidelines and current scientific evidence that direct Canadian health professional competencies. The article begins by presenting two current global vaccine initiatives and links these to immunization in Canada. A selected literature review identifies current best immunization practices. With the purpose of promoting quality improvement, three key Canadian immunization competencies for health professional are highlighted: communication with parents, including those who are experiencing vaccine hesitancy; administration of immunizing agents; and documentation of immunizations. Health professionals are encouraged to reflect on immunization competencies and ensure evidence-based practices underpin vaccine delivery in their primary care settings.

  7. Evidence for Late Amazonian explosive volcanism in the Tharsis Region of Mars: Photogeology of the "Stealth" radar feature and discovery of a dune field among the lava flows west of Arsia Mons

    Science.gov (United States)

    Edgett, Kenneth S.; Butler, Bryan J.; Zimbelman, James R.; Hamilton, Victoria E.

    1996-10-01

    INTRODUCTION: Extensive volcanic ash deposits blanketing the youngest geomorphic units on Mars would imply that major explosive volcanic events occurred relatively late in martian history. Discovery of the radar "Stealth" region that extends westward of Arsia and Pavonis Montes has led to the conclusion that the surfaces with "Stealth" characteristics are mantled by fine-grained volcanic ash [1-3]. In our present study, we have examined data sets that further illuminate the nature and origin of "Stealth": maps of albedo, thermal inertia, and rock abundance derived from Viking Thermal Infrared Mapper (IRTM) data [4-6], plus Viking images that range in resolution from 15 to 200 m/pixel. RADAR STEALTH: The Stealth region was discovered in bistatic 3.5-cm radar observations [1]. It is defined as a region in which the backscatter cross section at normal incidence is very low (nearly zero, or below the 1-sigma noise value) [2]. "Stealth" is likely caused by the presence of an extremely underdense surface material containing no scatterers to some depth [1]. Stealth is at least 2 to 3 m thick, and might be 7 to 15 m thick [1-3]. The Stealth feature extends more than 2,000 km along the equator between Arsia Mons and Nicholson Crater, and it appears to be part of a region of generally low radar signal return that extends from Pavonis Mons westward to the Elysium Basin [2]. STEALTH IN RELATION TO GEOLOGIC FEATURES: To be observed from Earth, the radar Stealth area must consist of a material that is physically on top of (and therefore younger than) the lava flows, craters, and other features seen in the western equatorial Tharsis region. The youngest units overlain by Stealth are among the youngest on Mars (Late Amazonian). For example, Stealth overlies the Medusae Fossae Formation (units "Amu" and "Amm" in map by Scott and Tanaka [7]), which consists of gently undulating smooth and wind-sculpted (yardangs) surfaces interpreted by some to be volcanic ash deposits [8, 9

  8. Hábitos alimentares de Sotalia fluviatilis no estuário amazônico - DOI: 10.4025/actascibiolsci.v28i4.173 Feeding habits of Sotalia fluviatilis in the Amazonian Estuary- DOI: 10.4025/actascibiolsci.173

    Directory of Open Access Journals (Sweden)

    Sandra Beltrán Pedreros

    2007-11-01

    Full Text Available Objetivou-se descrever e analisar os hábitos alimentares de 50 golfinhos Sotalia fluviatilis capturados acidentalmente na frota pesqueira artesanal do Estuário Amazônico entre 1996 e 2001. As presas foram identificadas e calculadas a freqüência de ocorrência e numérica; testada a similaridade entre a diversidade de presas dos conteúdos e a diversidade de peixes marinhos e de água doce do estuário e, comparados os hábitos alimentares por sexo e categoria de maturidade. Ocorreram 13 espécies de peixes (86,6% onde as famílias Sciaenidae (32%, Trichiuridae (26% e Ariidae (16% foram mais representativas e, quatro espécies de crustáceos (26%. A espécie não apresentou diferenças nos hábitos alimentares entre sexos, mas, os filhotes tiveram maior diversidade de presas que jovens e adultos. Finalmente, houve maior similaridade (0.89 entre a diversidade de presas de S. fluviatilis e as espécies de peixes quando o estuário apresenta características marinhas.In this paper we present an analysis of the fifty S. fluviatilis feeding habits in the Amazonian Estuary. Animals were bycaught by the artisanal fishing fleet between 1996 and 2001. Feeding habits were analyzed by prey occurrence frequency (%F and number percentage and stomachs contents preys similarity between marine and freshwater fish species present in the Amazonian Estuary. Thirteen fish species were identified (%F= 86.6, the most significant families were Sciaenidae (32%, Trichiuridae (26% e Ariidae (16%, and four crustaceans species (%F=26. S. fluviatilis feeding habits did not differ by gender and in general, calves had higher prey diversity than juveniles and adults. The similarity was high (0.89 between estuarine S. fluviatilis feeding habits and the fishes species present in the Amazonian Estuary when the environment is mostly marine.

  9. Why Children Misbehave

    OpenAIRE

    Telep, Valya Goodwin, 1955-

    2009-01-01

    This series of lessons was prepared for parents like you - parents who want to do a better job of disciplining their children. The lessons were especially written for parents of preschool children, ages two to six, but some of the discipline methods are appropriate for older children, too. This lesson focuses on why children misbehavior.

  10. Children Solve Problems.

    Science.gov (United States)

    De Bono, Edward

    A group of children were presented with several tasks, including the invention of a sleep machine and a machine to weigh elephants. The tasks were chosen to involve the children in coping with problems of a distinct character. A study of the children's drawings and interpretations shows that children's thinking ability is not very different from…

  11. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... in the body. jaundice in newborns and older children. epilepsy . location, anatomy and function of the thyroid gland. ... General Nuclear Medicine Children's (Pediatric) CT (Computed Tomography) Epilepsy Images related to Children's (Pediatric) Nuclear Medicine Videos related to Children's (Pediatric) ...

  12. Full quantification of selenium species by RP and AF-ICP-qMS with on-line isotope dilution in serum samples from mercury-exposed people supplemented with selenium-enriched yeast

    DEFF Research Database (Denmark)

    Li, Yu-Feng; Hu, Liang; Li, Bai

    2011-01-01

    Accurate determination of selenium (Se) species in biological samples is a critical issue because Se commonly occurs at low levels and in diverse species. The method for the full quantification of Se species in serum samples was proposed through combined ion-pair reverse-phase (RP) chromatography...

  13. Torture in children.

    Science.gov (United States)

    Quiroga, Jose

    2009-01-01

    This is a review article that studies the problem of torture in children. Torture in children is a significant worldwide problem, but there are no official or reliable independent statistics to measure the magnitude of the problem. The definition of torture in the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment applies to adults and children. The Convention on the Rights of the Child defines children as "every human being below the age of eighteen years". Torture in children happens during peace times and during political violence and war conflicts. The majority of torture victims happen during peace times. The high-risk groups are impoverished children living in the street, children deprived of parental care, children in conflict with the law, and children in detention. During political violence and war the high risk children are the children detained during political violence, child soldiers, children internally displaced in refugee camps, detained children during the war against terrorism and children tortured by peacekeeping forces. The perpetrators of torture in children are the members of the same forces that torture adults, generally the police, civil police, security guards trained by police, prison guards, and military forces. The paper identifies some preventive measure and develops recommendations for action at the local, national and international level.

  14. Rb-Sr geochronology and geochemical characteristics of mafic dikes in the Nova Lacerda and Conquista D'Oeste region, Mato Grosso, SW Amazonian Craton; Geocronologia Rb-Sr e caracteristicas geoquimicas dos diques maficos da regiao de Nova Lacerda e Conquista D'Oeste (MT), porcao sudoeste do Craton Amazonico

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Paulo Cesar Correa da; Matos, Joao Batista de [Universidade Federal de Mato Grosso (UFMT), Cuiaba, MT (Brazil). Dept. de Recursos Minerais; Grupo de Pesquisas em Evolucao Crustal e Metalogenia Guapore, Cuiaba, MT (Brazil)], e-mail: pccorrea@ufmt.br, e-mail: jmatos@cpd.ufmt.br; Girardi, Vicente Antonio Vitorio [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias. Dept. de Mineralogia e Geotectonica], e-mail: girardi@usp.br; Ruiz, Amarildo Salina [Universidade Federal de Mato Grosso (UFMT), Cuiaba, MT (Brazil). Dept. de Geologia Geral; Grupo de Pesquisas em Evolucao Crustal e Metalogenia Guapore, Cuiaba, MT (Brazil)], e-mail: asruiz@rc.unesp.br

    2009-07-01

    In the Nova Lacerda and Conquista D'Oeste regions, Mato Grosso State, SW part of the Amazonian Craton, mafic dikes trending NNW intrude the Nova Lacerda Granite (1462{+-}12 Ma), within the Jauru Domain, in the Rondonia-San Ignacio Province (1.55 - 1.3 Ga). The mafic swarm comprises diabases, metadiabases and amphibolites. Metadiabases originated from uralitization of diabases. These rocks have tholeiitic affinity and predominant basaltic composition. Some samples are andesi-basalts. The ages of diabases and metabasites are 1380 {+-} 32 Ma and 1330 {+-} 120 Ma respectively. Geochemical data indicate that the compositional variation of diabases and metadiadases is due to fractional crystallization of evolved tholeiitic magmas. The origin of the basaltic magmas is related to a heterogeneous mantle source. (author)

  15. Pinhão-Manso: Uma Alternativa para Produção de Biodiesel na Agricultura Familiar da Amazônia Brasileira. = Jatropha curcas: An alternative for biodiesel production in the Brazilian Amazonian family agriculture.

    Directory of Open Access Journals (Sweden)

    José Maria Arcanjo Alves

    2008-07-01

    fertile soils, such as those in the Amazonian savannah. There are various studies in progress dedicated to this culture in Roraima state, and through these studies, it may be achieved a possibility to develop feasible production technologies that could be adopted by family agriculture. That would show a promising alternative for job creation and better income, fostering the recovering and protection of modified areas, and promoting the organization of native fruit and annual cultures consortiums.

  16. Paleoproterozoic (~1.88Ga felsic volcanism of the Iricoumé Group in the Pitinga Mining District area, Amazonian Craton, Brazil: insights in ancient volcanic processes from field and petrologic data

    Directory of Open Access Journals (Sweden)

    Ronaldo Pierosan

    2011-09-01

    Full Text Available The Iricoumé Group correspond to the most expressive Paleoproterozoic volcanism in the Guyana Shield, Amazonian craton. The volcanics are coeval with Mapuera granitoids, and belong to the Uatumã magmatism. They have U-Pb ages around 1880 Ma, and geochemical signatures of α-type magmas. Iricoumé volcanics consist of porphyritic trachyte to rhyolite, associated to crystal-rich ignimbrites and co-ignimbritic fall tuffs and surges. The amount and morphology of phenocrysts can be useful to distinguish lava (flow and dome from hypabyssal units. The morphology of ignimbrite crystals allows the distinction between effusive units and ignimbrite, when pyroclasts are obliterated. Co-ignimbritic tuffs are massive, and some show stratifications that suggest deposition by current traction flow. Zircon and apatite saturation temperatures vary from 799°C to 980°C, are in agreement with most temperatures of α-type melts and can be interpreted as minimum liquidus temperature. The viscosities estimation for rhyolitic and trachytic compositions yield values close to experimentally determined melts, and show a typical exponential decay with water addition. The emplacement of Iricoumé volcanics and part of Mapuera granitoids was controlled by ring-faults in an intracratonic environment. A genesis related to the caldera complex setting can be assumed for the Iricoumé-Mapuera volcano-plutonic association in the Pitinga Mining District.O Grupo Iricoumé corresponde ao mais expressivo vulcanismo Paleoproterozóico do Escudo das Guianas, craton Amazônico. As rochas vulcânicas são coexistentes com os granitóides Mapuera, e pertencem ao magmatismo Uatumã. Possuem idades U-Pb em torno 1888 Ma, e assinaturas geoquímicas de magmas tipo-A. As vulcânicas do Iricoumé consistem de traquitos a riolitos porfiríticos, associados a ignimbritos ricos em cristal e tufos co-ignimbríticos de queda e surge. A quantidade e a morfologia dos fenocristais podem ser

  17. Invasão de áreas de savana intra-amazônicas por Digitonthophagus gazella (Fabricius, 1787 (Insecta: Coleoptera: Scarabaeidae Invasion of intra-Amazonian savannas by the dung beetle Digintonthophagus gazella (Fabricius, 1787 (Insecta: Coleoptera: Scarabaeidae

    Directory of Open Access Journals (Sweden)

    Rodrigo Augusto Matavelli

    2008-01-01

    Full Text Available Neste estudo, foi avaliada a invasão da comunidade de Scarabaeinae detritívoros de uma savana amazônica pela espécie africana Digitonthophagus gazella (Fabricius 1787. O estudo foi realizado nas proximidades da vila de Alter do Chão (2º 31' S e 55º 00' W, localizada a aproximadamente 36 km a sudoeste de Santarém, Pará, Brasil. Vinte e duas áreas de savanas de 3,75 ha (250 x 150 m distribuídas em 30.000 ha foram amostradas, no período de 21 de julho a 13 de agosto de 2003, utilizando 66 armadilhas de queda com três tipos de iscas (fezes bovinas, fezes humanas e carcaças. Foram encontrados indivíduos de D. gazella em quatro das vinte e duas áreas amostradas. Procurou-se explicar a presença da espécie nas áreas de savana através de análises de regressão logística, onde as variáveis explicativas foram: ocorrência de queimada nos últimos seis anos, diversidade e abundância total de Scarabaeidae nativos presentes na área, abundância de Canthon sp.1, (espécie de Scarabaeidae mais abundante na região. Exceto pela abundância total de indivíduos de Scarabaeidae nativos, nenhuma das variáveis bióticas e abióticas tiveram efeito estatisticamente significativo na presença do D. gazella. Estes resultados podem ser explicados por: (a algum fator ainda não analisado, relacionado à invasão da área pelo D. gazella; (b Não houve tempo para a dispersão e estabelecimento da espécie em todas as áreas; (c A comunidade nativa de Scarabaeinae apresenta resistência à invasão pelo D. gazella.This work aimed to verify the invasion of the dung beetles community from intra-Amazonian savanna by the African species Digitonthophagus gazella (Fabricius 1787. The research was carried out near Alter do Chão village (2º 31' S; 55º 00' W, 36 Km Southwest of Santarém, Pará, Brazil. Twenty two areas were sampled, from 21 July to 13 August 2003, using 66 baited pitfall traps (cattle dung, human faeces and carcass bait. D. gazella

  18. Caracterização e análise estrutural da hidroxisodalita sintetizada a partir de amostras de solo amazônico Characterization and structural analysis hydroxysodalite synthesized from Amazonian soil samples

    Directory of Open Access Journals (Sweden)

    V. A. A. de Freitas

    2011-09-01

    Full Text Available As zeólitas desde sua descoberta, na forma natural, vêm promovendo grande interesse em aplicações tecnológicas como peneiras moleculares, trocadores iônicos, catalisadores e, principalmente, adsorventes. As zeólitas sintéticas geralmente são preparadas com soluções aquosas saturadas de sais de aluminatos e silicatos. Mas, rejeito industrial do processo de beneficiamento de caulim tem sido empregado para sintetizar zeólita A e hidroxisodalita, devido a razão equimolar Si/Al. Nesse trabalho foi sintetizado a zeólita do tipo hidroxisodalita [Na6(AlSiO46 .8H2O] a partir da fração fina de duas amostras de solo amazônico - rico em caulinita [Al2Si2O5(OH4] que é basicamente composta de Al e Si - usando o método hidrotermal. A caracterização por espectrofotometria de absorção no infravermelho com transformada de Fourier, análise termogravimétrica e térmica diferencial e difração de raios X confirmaram que as amostras in natura são majoritariamente compostas por caulinita com 69 a 71% de abundância. O refinamento estrutural de Rietveld mostrou que o produto da síntese é constituída de uma fase cristalina de hidroxisodalita de estrutura cúbica (grupo espacial , #218 com parâmetros de rede a = 0,88468 e 0,88594 nm. Os dados ajustados permitiram estimar o tamanho médio dos cristalitos d = 57 nm (ambas amostras e a área superficial S = 44 e 41 m².g-1.Zeolites since their discovery in natural form have promoted a great interest in technological applications as molecular sieves, ion exchangers, catalysts, and especially adsorbents. The synthetic zeolites are usually prepared with saturated aqueous solutions of salts of aluminates, and silicates. But the process of industrial waste processing kaolin has been used to synthesize zeolite A and hydroxysodalite due to equimolar Si/Al ratio. In this work zeolite type hydroxysodalite, Na6[Si6Al6 O4]6.8H2O was synthesized from the fine fraction of two samples from Amazonian soil

  19. Tolerância de Himatanthus sucuuba Wood. (Apocynaceae ao alagamento na Amazônia Central Tolerance of Himatanthus sucuuba Wood. (Apocynaceae to the flooding regime in the Central Amazonian

    Directory of Open Access Journals (Sweden)

    Cristiane Ferreira

    2005-09-01

    Full Text Available Himatanthus sucuuba é uma espécie arbórea de reputado valor fitoterápico, que coloniza regiões de várzea e de terra firme na Amazônia Central. Objetivou-se verificar durante quatro meses, em casa de vegetação, a germinação e o desenvolvimento inicial de plântulas da espécie, oriundas de sementes dos dois diferentes ecossistemas. Não houve diferença significativa em relação ao peso de matéria seca de sementes da várzea e da terra firme. Entretanto, a taxa de germinação da espécie variou de acordo com o substrato e o local de procedência das sementes. No substrato areia+serragem (não-alagado a germinação da espécie foi alta, independente do ambiente (várzea 94% e terra firme 91%. No substrato constituído apenas por água (alagado, as sementes provenientes da várzea tiveram a maior taxa de germinação (96% e de formação de plântulas (84%, quando relacionadas às da terra firme, que apresentaram taxa de germinação de 64%, e nenhuma das sementes germinadas formou plântulas. Neste tratamento foi verificado o apodrecimento da radícula poucos dias após sua emissão, indicando que as sementes oriundas da várzea apresentam características adaptativas ao ambiente inundado em relação às da mesma espécie oriundas da terra firme.Himatanthus sucuuba is a tree species with known phytotherapic value which colonizes both white-water floodplains (várzea and upland forests (terra firme in Central Amazonian. The objective of this study was to compare germination and initial seedling development from seeds collected in both the ecosystems. There was no significant difference between dry seed mass, but in a four month period in a glasshouse in Manaus, Brazil, germination rate differed according to the substrate and origin of the seeds. In the substrate sand + sawdust (non-flooded germination rate was high, independent of seed origin (várzea 94% and terra firme 91%. In the substrate constituted only by water (flooded, the

  20. Western Amazonian Ateleutina (Hymenoptera, Ichneumonidae, Cryptinae

    Directory of Open Access Journals (Sweden)

    Santiago Bordera

    2012-10-01

    Full Text Available Ateleutina is a small subtribe of Cryptinae (Ichneumonidae composed of two genera: Ateleute Förster and Tamaulipeca Kasparyan. Neither of the genera includes species described from South America. In this article five new species of Ateleute (A. ashaninka sp. n. and A. amarakaeri from Peru, A. shuar sp. n. from Ecuador and Peru, and A. huaorani sp. n. and A. kichua sp. n. from Ecuador and three new species of Tamaulipeca (T. bora sp. n. from Ecuador and Peru, T. candoshi sp. n. from Ecuador and T. matses sp. n. from Peru are described and illustrated from Western Amazonia. Identification keys to the known South American species of the genera are provided.

  1. A new medicinal plant from Amazonian Ecuador.

    Science.gov (United States)

    van Asdall, W

    1983-12-01

    Dalbergaria tessmanii, a shrub of the Gesneriaceae locally abundant in the tropical forests of Ecuador, is variously ethnomedicinally employed. For example, none of several Shuar (Jívaro) herbal healers know or use it, but the one Shuar Shaman consulted extols its importance in reducing vaginal bleeding. Although Mestizo native consultants from the provincial capital of Morona-Santiago report its use in alleviating heart problems, those from Pastaza Province employ it to reduce menstrual flow. The Lowland Quechua apparently use it for this purpose as well. This plant has apparently not yet been chemically examined. Its reported use in several different cultural context suggest that it should be phytochemically investigated.

  2. Understanding Colombian Amazonian white sand forests

    NARCIS (Netherlands)

    Peñuela-Mora, M.C.

    2014-01-01

    Although progress has been made in studies on white sand forests in the Amazon, there is still a considerable gap in our knowledge of the unique species composition of white sand forests and their structure and dynamics, especially in Western Amazon. This thesis aims to fill this gap by addressing

  3. Constraining Amazonian Methane Emission from Wetlands

    Science.gov (United States)

    Boesch, Hartmut; Parker, Robert; Webb, Alex; Wilson, Chris; Chipperfield, Martyn; Gloor, Emanuel; Feng, Liang; Palmer, Paul

    2017-04-01

    The Amazon Basin contains large wetland ecosystems which are important sources of methane (CH4). Spaceborne observations provide detailed information about the spatio-temporal distributions of atmospheric methane over the Amazon Basin which will provide a strong constrain on the underlying emissions and their year to year variations. Methane observations from space are available from the Japanese GOSAT instrument since 2009. We use the proxy retrieval method which provides much greater coverage over the Amazon region compared to so-called Full-Physics methods due to their lower sensitivity to thin clouds. Validation of GOSAT retrieval over the Amazon using the ground-based TCCON network is currently not possible due to a lack of data and we have used routine aircraft profiles to show that GOSAT columns are sufficiently accurate for estimating surface flux for the region. Using a variational flux inverse system together with the 3-D atmospheric chemical transport model TOMCAT, we infer surface fluxes for the Amazon region from GOSAT observations which are used to analyse the spatial distribution of methane wetlands emissions as well as annual variations in emissions with a focus on periods 2011/2012 and 2013/14 which are characterized by large variations in rainfall.

  4. Impact of Amazonian deforestation on atmospheric chemistry

    NARCIS (Netherlands)

    Ganzeveld, L.N.; Lelieveld, J.

    2004-01-01

    A single-column chemistry and climate model has been used to study the impact of deforestation in the Amazon Basin on atmospheric chemistry. Over deforested areas, daytime ozone deposition generally decreases strongly except when surface wetness decreases through reduced precipitation, whereas

  5. Phylogenetic diversity of Amazonian tree communities

    NARCIS (Netherlands)

    Honorio Coronado, E.N.; Dexter, K.G.; Pennington, R.T.; Chave, Jérôme; Lewis, S.L.; Alexiades, M.N.; Alvarez, Esteban; Alves de Oliveira, Atila; Amaral, J.L.; Araujo-Murakami, Alejandro; Arets, E.J.M.M.

    2015-01-01

    Aim: To examine variation in the phylogenetic diversity (PD) of tree communities across geographical and environmental gradients in Amazonia. Location: Two hundred and eighty-three c. 1 ha forest inventory plots from across Amazonia. Methods: We evaluated PD as the total phylogenetic branch

  6. Amazonian volcanism inside Valles Marineris on Mars

    Czech Academy of Sciences Publication Activity Database

    Brož, Petr; Hauber, E.; Wray, J. J.; Michael, G.

    2017-01-01

    Roč. 473, September (2017), s. 122-130 ISSN 0012-821X Institutional support: RVO:67985530 Keywords : Mars * Valles Marineris * volcanism * scoria cone * hydrothermal activity Subject RIV: DC - Siesmology, Volcanology, Earth Structure OBOR OECD: Volcanology Impact factor: 4.409, year: 2016

  7. Tonsillectomies and children

    Science.gov (United States)

    Children and tonsillectomies ... many parents wonder if it is wise for children to have the tonsils taken out. Tonsillectomy may be recommended if your child has any of the following: Difficulty swallowing Obstructed ...

  8. Children and Dietary Supplements

    Science.gov (United States)

    ... Clinical Digest for health professionals Children and Dietary Supplements Share: September 2012 © Matthew Lester Research has shown that many children use herbs and other dietary supplements. However, there are little data available on their ...

  9. Healthy Lifestyle: Children's Health

    Science.gov (United States)

    Healthy Lifestyle Children's health You want your child to eat healthy foods, but do you know which nutrients ... 15, 2017 Original article: http://www.mayoclinic.org/healthy-lifestyle/childrens-health/in-depth/nutrition-for-kids/art- ...

  10. Separation anxiety in children

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001542.htm Separation anxiety in children To use the sharing features on this page, ... to test their independence. To get over separation anxiety, children need to: Feel safe in their home. Trust ...

  11. Children and TV Violence

    Science.gov (United States)

    ... Facts for Families Guide Facts for Families - Vietnamese TV Violence and Children No. 13; Updated December 2014 ... violent. Hundreds of studies of the effects of TV violence on children and teenagers have found that ...

  12. Cough in Children

    Science.gov (United States)

    ... Library ▸ Allergy Library ▸ Cough in children TTR Share | Cough in Children This article has been reviewed by ... MD, FAAAAI As a parent, hearing your child cough may make you feel uneasy. Yet an occasional ...

  13. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... patient story here Images × Image Gallery Radiologist and patient consultation. View full size with caption Related Articles and Media General Nuclear Medicine Children's (Pediatric) CT (Computed Tomography) Epilepsy Images related to Children's (Pediatric) Nuclear Medicine ...

  14. Controversial Books for Children.

    Science.gov (United States)

    Hoffman, La Vinia Jean

    1979-01-01

    Discusses children's books which have caused controversies pertaining to ethnic stereotyping, labeling, sex instruction, and offensive language, and maintains that controversy is beneficial in that it keeps librarians aware of children's interests. (FM)

  15. Cancer immunotherapy in children

    Science.gov (United States)

    More often than not, cancer immunotherapies that work in adults are used in modified ways in children. Seldom are new therapies developed just for children, primarily because of the small number of pediatric patients relative to the adult cancer patient

  16. Traveling with children

    Science.gov (United States)

    ... not suit the child's needs. Small crackers, unsugared cereals, and string cheese make good snacks. Some children can eat fruit without problems. Cookies and sugared cereals make for sticky children. When flying with babies ...

  17. Cold medicines and children

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000942.htm Cold medicines and children To use the sharing features on ... children younger than age 4. About OTC Cold Medicines Cold medicines do not cure or shorten a ...

  18. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... used in children with cancer, epilepsy and back pain. top of page What does the equipment look ... being recorded. Though nuclear imaging itself causes no pain, children may experience some discomfort from having to ...

  19. Children, Time, and Play

    DEFF Research Database (Denmark)

    Elkind, David; Rinaldi, Carla; Flemmert Jensen, Anne

    Proceedings from the conference "Children, Time, and Play". Danish University of Education, January 30th 2003.......Proceedings from the conference "Children, Time, and Play". Danish University of Education, January 30th 2003....

  20. Sleepwalking and children

    Science.gov (United States)

    ... event. It is most often triggered by poor sleep habits. In children, sleepwalking starts between ages 6 and 12. It occurs more often in boys than girls. Children outgrow ... to stick to a bedtime routine may help reduce the problem.