Relative roles of biogenic emissions and Saharan dust as ice nuclei in the Amazon basin

Some aerosol particles, known as ice nuclei, can initiate ice formation in clouds, thereby influencing precipitation, cloud dynamics and the amount of incoming and outgoing solar radiation. In the absence of biomass burning, aerosol mass concentrations in the Amazon basin are low(1). Tropical forests emit primary biological particles directly into the atmosphere; secondary organic aerosols form from the emission and oxidation of biogenic gases(2). In addition, particles derived from biomass burning in central Africa, marine aerosols, and windblown dust from North Africa(3-5) often reach the central part of the Amazon basin during the wet season. The contribution of these aerosol sources to ice nucleation in the region is uncertain. Here we present observations of the concentration and elemental composition of ice nuclei in the Amazon basin during the wet season. Using transmission electron microscopy combined with energy-dispersive X-ray spectroscopy, we show that ice nuclei are primarily composed of carbonaceous material and dust. We show that biological particles dominate the carbonaceous fraction, whereas import of Saharan dust explains the intermittent appearance of dust-containing nuclei. We conclude that ice-nucleus concentration and abundance can be explained almost entirely by local emissions of biological particles supplemented by import of Saharan dust. Using a simple model, we tentatively suggest that the contribution of local biological particles to ice nucleation is increased at higher atmospheric temperatures, whereas the contribution of dust particles is increased at lower temperatures.

Closing the Clymene ocean and bending a Brasiliano belt: Evidence for the Cambrian formation of Gondwana, southeast Amazon craton

We report new paleomagnetic and geochronological data from Ediacaran rift-drift carbonates in the Paraguai belt at the southern end of the suture zone between the Amazon craton and the Sao Francisco and Rio de Plata cratons, South America. Early thrusting resulted in remagnetization ca. 528 +/- 36 Ma or later; the mean age is established by (40)Ar/(39)Ar encapsulation dating of mixed authigenic and detrital illite from remagnetized carbonates from the unmetamorphosed fold-thrust belt. This remagnetization overlaps with a 525 Ma Gondwana reference pole. Metamorphic illite from the slate belt yields (40)Ar/(39)Ar ages of 496-484 Ma, the timing of peak regional metamorphism. Oroclinal bending of the Paraguai belt was caused by a 90 degrees clockwise rotation of the east-west limb after ca. 528 Ma, probably reflecting the irregular margin of the southeast Amazon craton. The age of the Paraguai belt overlaps with that of the Pampean orogeny farther south along the western margin of the Rio de Plata craton, suggesting a coeval closure for the Clymene ocean separating the Amazon craton from the Sao Francisco and Rio de Plata cratons.

Morphology and composition of gold in a lateritic profile, Fazenda Pison ""Garimpo"", Amazon, Brazil

This study describes the morphological evolution of gold grains in a lateritic weathering profile in an equatorial rainforest climate. Primary sources of gold are quartz veins associated with shallow granophyric intrusion. Gold grains were found in fresh ore, saprolite, transition zones, ferruginous duricrust, red latosol, and yellow latosol. Irregularly shaped grains predominate, with smaller proportions of dendritic and prismatic forms. Gold grains are weathered in the uppermost 10 m of the regolith. Mean gold grain size is maximum in the duricrust (> 125 mu m) and decreases progressively upward into the yellow latosol (<90 mu m). Voids and corrosion pits appear on grain surfaces, and progressive rounding is observed from the bottom of the profile to the top. Gold grains can be classified as either homogeneous or zoned with respect to their chemical composition. Homogeneous grains contain 2-15% Ag (mean 8.3%). Zoned grains have more variable Ag contents; grain cores have means of approximately 10% or 23% Ag, with Ag-poor zones of approximately 3.7% Ag along internal discontinuities and/or outer rims. Formation of Ag-poor rims is due to preferential depletion of silver. Processes responsible for duricrust formation may preserve some grains as large aggregates, but subsequent transformation into latosol further modifies them. (c) 2007 Elsevier Ltd. All rights reserved.

Forensisk undersökning av Amazon Kindle

Detta arbete har genomförts i samarbete med Försvarsmakten och behandlar vilka möjligheter som finns för forensiska undersökningar av e-boksläsaren Amazon Kindle. I arbetets litteraturstudie beskrivs hur tidigare forskning inom ämnet är kraftigt begränsad. Arbetet syftar därför till att besvara hur data kan extraheras från en Kindle, vilka data av forensiskt intresse en Kindle kan innehålla, var denna information lagras och om detta skiljer sig åt mellan olika modeller och firmware-versioner samt om det är nog att undersöka endast den del av minnet som är tillgänglig för användaren eller om ytterligare privilegier för att komma åt hela minnesarean bör införskaffas. För att göra detta fylls tre olika modeller av Kindles med information. Därefter tas avbilder på dem, dels på endast användarpartitionen och dels på dess fullständiga minnesarea efter att en privilegie-eskalering har utförts. Inhämtad data analyseras och resultatet presenteras. Resultatet visar att information av forensiskt intresse så som anteckningar, besökta webbsidor och dokument kan återfinnas, varför det finns ett värde i att utföra forensiska undersökningar på Amazon Kindles. Skillnader råder mellan vilken information som kan återfinnas och var den lagras på de olika enheterna. Enheterna har fyra partitioner varav endast en kan kommas åt utan privilegie-eskalering, varför det finns en fördel med att inhämta avbilder av hela minnesarean. Utöver ovanstående presenteras en metod för att förbipassera en enhets kodlås och därigenom få fullständig åtkomst till den även om den är låst.

Predicting Amazon Deforestation through the deterninants of demand for agricultural land

This paper develops a model of deforestation pressure in the Amazon. It is based on the determinants of demand for agricultural land, i.e. the interactions between population dynamics, urbanization and the growth of local markets, land prices, and government spending and policies. The mo deI is estimated using data from the period 1970 - 1985, and predictions for the period 1985 - 2010 are made under explicit assumptions about the underlying factors of deforestation. The predictions indicate that economic growth in the Amazon is likely to continue at high rates even if the federal government abandons its aggressive development policy. Deforestation will be much smaller if they do, though, since the active development policies tend to promote wasteful use of land.

Análise paramétrica não-linear à esbelteza de pilares em betão armado em relação aos efeitos de 2ª ordem de acordo com o EC2

Esta dissertação tem como principal objectivo comparar os métodos propostos pelo Eurocódigo 2, através de uma análise paramétrica dos efeitos de segunda ordem em pilares de betão armado. Os métodos estudados foram o método simplificado baseado na Curvatura Nominal e o Método Geral. Através da comparação destes dois métodos verificou-se se o dimensionamento efectuado para o primeiro método é correcto e se encontra do lado da segurança. Para este efeito são analisado noventa e seis pórticos, onde setenta e dois são pórticos simples e vinte e quatro são pórticos parede. Todos os pórticos apresentam uma estrutura simples, constituída por dois elementos verticais, pilar ou parede, e um elemento horizontal, viga. Os noventa e seis pórticos são divididos em dois grupos. Um grupo em que a ligação entre pilar viga é rotulada e o outro grupo onde a ligação é rígida. Dentro de cada grupo é definido oito conjuntos de pórticos cuja diferença reside na percentagem de carga que cada um dos elementos verticais recebe, sendo estas características iguais para os dois grupos. Cada conjunto é constituído por seis pórticos em que é variada a esbelteza. Em todos os modelos analisados manteve-se as mesmas características de materiais e acções. Efectuou-se um primeiro dimensionamento através do método baseado na curvatura nominal, onde obteve-se os esforços e armaduras, que serão utilizados para a modelação no método geral. Este método geral, consiste numa análise não linear, e é efectuado num programa de análise não linear de elementos finitos, Atena. A modelação efectuou-se da seguinte forma: aplicou-se numa primeira fase a totalidade da carga vertical aplicada à estrutura de forma incremental, e quando esta atingiu a carga de dimensionamento, aplicou-se a carga horizontal também de forma incremental até ao colapso da estrutura. De acordo com os resultados obtidos, pode concluir-se que o dimensionamento efectuado pelo método simplificado está do lado da segurança, sendo em alguns casos em que possui pilares esbeltos demasiado conservativo, onde obteve-se mais 200% de carga horizontal.

Thermal Decomposition Kinetics of Humic Substances Extracted from Mid-Rio Negro (Amazon Basin) Soil Samples

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Kinetic Analysis of Gill (Na+,K+)-ATPase Activity in Selected Ontogenetic Stages of the Amazon River Shrimp, (Decapoda, Palaemonidae): Interactions at ATP- and Cation-Binding Sites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The Predation of Artemia Nauplii by the Larvae of the Amazon River Prawn, Macrobrachium amazonicum (Heller, 1862), is Affected by Prey Density, Time of Day, and Ontogenetic Development

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

ECONOMIC ANALYSIS of AMAZON RIVER PRAWN FARMING TO THE MARKETS FOR LIVE BAIT and JUVENILES IN PANTANAL, BRAZIL

The implementation of a hypothetical aquaculture facility with hatchery, nursery and grow-out earthen ponds for raising the Amazon River Prawn Macrobrachium amazonicum in the Pantanal was considered. Eight larviculture cycles per year were projected: four to produce post-larvae for stocking in grow-out bait ponds, and four to stock nursery tanks to sell juveniles as seed to grow-out farms, which produce prawns for human consumption. Annual production would be 146,880 dozen bait prawns and 2,938 thousand juveniles. The assumed sale prices were US$ 1.38 per dozen baits and US$ 15.39 per thousand juveniles. The net present value was US$ 555,890.79, internal rate of return was 48% per year, payback period was 2.4 years and benefit-cost ratio was 3.90. The breakeven price to cover total costs per dozen baits was US$ 0.70 and per thousand juveniles was US$ 17.00, indicating that the selling price assumed for juveniles in base scenario is not realistic. Net return was US$ 84,773.80. The results indicate that this activity would be a lucrative and attractive investment in the Pantanal.

Effect of Urucu oil (Brazilian Amazon) on the biomass of the aquatic macrophyte Eichhornia crassipes (Mart.) Solms (Pontederiaceae)

Os rios e lagos de várzea da província petrolífera de Urucu, na Amazônia Central, são amplamente colonizados por macrófitas aquáticas, que podem ser afetadas por acidentes durante a exploração e o transporte de petróleo. Entre as macrófitas, a espécie flutuante Eichhornia crassipes (aguapé) ocorre abundantemente na região; OBJETIVO: O objetivo desse estudo foi verificar o efeito de diferentes dosagens do petróleo de Urucu (0; 0,5; 1,5 e 3,0 L.m-2) na biomassa viva e morta de E. crassipes e em algumas características físicas e químicas da água; MÉTODOS: O experimento teve oitenta e quatro dias de duração. A cada sete dias foi determinada a biomassa (viva e morta) de E. crassipes e os valores de temperatura, pH, condutividade elétrica e oxigênio dissolvido da água; RESULTADOS: A dosagem de 0,5 L.m-2 foi suficiente para causar mortalidade parcial (48%) em E. crassipes após trinta e cinco dias de exposição ao petróleo. A dosagem de 3,0 L.m-2 causou mortalidade total (100%) em E. crassipes em oitenta e quatro dias de exposição. A decomposição do petróleo e da biomassa morta de E. crassipes provocam a redução do oxigênio dissolvido e do pH, e aumento da condutividade elétrica e de fósforo total na água; CONCLUSÕES: Nós concluímos que um derramamento de petróleo pode provocar mortalidade total em uma população de uma espécie de macrófita, mas não em uma outra. Isto pode alterar a diversidade de espécies de macrófitas na região impactada. No caso de Eichhornia crassipes e Pistia stratiotes, um derramamento de petróleo de Urucu pode favorecer E. crassipes, a espécie menos sensível ao petróleo.

Effect of intensification on grow out of the Amazon River prawn, Macrobrachium amazonicum

The effects of intensification on growth, survival, productivity, population structure, and distribution of harvested biomass in individual size classes of Macrobrachium amazonicum in semi-intensive culture were evaluated. Postlarvae (0.01 g) were stocked in 12 ponds at densities of 10, 20, 40, and 80/m(2) (three replicates per treatment) and raised for 5.5 mo. Average individual weight significantly decreased and productivity significantly increased as stocking density increased (P < 0.001), while survival was not affected (P > 0.05). Prawn mean weight at harvest ranged from 3.6 (80/m(2)) to 7.0 g (10/m(2)). Average survival ranged from 65.5% (40/m(2)) to 72.8% (20/m(2)), while productivity ranged from 508 (10/m(2)) to 2051 kg/ha (80/m(2)). Harvested biomass showed a clear bimodal distribution in individual size classes indicating the occurrence of heterogeneous growth, which may affect management and market strategies. Harvested biomass of prawns weighing more than 7 g (the best market size) increases for stocking densities up to 40/m(2) and stabilizes between 40 and 80/m(2). Growth reduction was associated with a decreasing frequency and average weight of green claw 1 and green claw 2 male morphotypes and adult females as density increased. Thus, the distribution of male morphotypes and sexually mature females are affected by density-dependent factors. Results suggest that prawn density plays an important role on M. amazonicum grow-out phase, as has been demonstrated for other species of the genus Macrobrachium. M. amazonicum tolerates grow-out intensification and may be raised in both semi-intensive and intensive systems stocked at very high densities yielding high productivity.

Effect of density on population development in the Amazon River prawn Macrobrachium amazonicum

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ontogenetic Variation in Ammonia Excretion during the Early Life Stages of the Amazon River Prawn, Macrobrachium amazonicum

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Protein requirements for Blue-fronted Amazon (Amazona aestiva) growth

The objective of this study was to evaluate the protein requirements for hand-rearing Blue-fronted Amazon parrots (Amazona aestiva). Forty hatchlings were fed semi-purified diets containing one of four (as-fed basis) protein levels: 13%, 18%, 23% and 28%. The experiment was carried out in a randomized block design with the initial weight of the nestling as the blocking factor and 10 parrots per protein level. Regression analysis was used to determine relationships between protein level and biometric measurements. The data indicated that 13% crude protein supported nestling growth with 18% being the minimum tested level required for maximum development. The optimal protein concentration for maximum weight gain was 24.4% (p = 0.08; r(2) = 0.25), tail length 23.7% (p = 0.09; r(2) = 0.19), wing length 23.0% (p = 0.07; r(2) = 0.17), tarsus length 21.3% (p = 0.06; r(2) = 0.10) and tarsus width 21.4% (p = 0.07; r(2) = 0.09). Tarsus measurements were larger in males (p < 0.05), indicating that sex must be considered when studying developing psittacines. These results were obtained using a highly digestible protein and a diet with moderate metabolizable energy levels.