Genome sequencing of cells that live inside glass cages reveals their past history

One-quarter of the total primary production on earth is contributed by diatoms1. These are photosynthetic, unicellular algae with ornamented silica shells found in all aquatic and moist environments. They form the base of energy-efficient food webs that support all aquatic life forms. More than 250 genera of living diatoms, with as many as 100,000 species are known2. Fossil diatoms are known as early as the Cretaceous, 144–65 m.y. ago3. In India, deposits of diatoms occur in Rajasthan and are known as ‘multani mitti’. Multani mitti or Indian Fuller’s earth or diatomaceous earth as it is called in the West, is applied as a paste on the surface of the skin for 15–20 min and then washed-off. This leaves the skin feeling smooth, soft, moist and rejuvenated. Diatomaceous earth is now being used in the formulation of soaps, cleansing products, face powders and skincare preparations. Diatomaceous earth is a mineral material consisting mainly of siliceous fragments of various species of fossilized remains of diatoms.

Control of shrinkage and swelling of expansive soils

Fly ashes are used to improve the properties of expansive soils. The paper brings out the effect of two different fly ashes containig different lime contents on shrinkage and swelling behaviour of expansive Indian Black cotton soil. Since the specific gravities of the fly ashes are considerably different,Void ratio at shrinkage limit and % of swelling are used to describe the shrinkage and swell behaviour of soils. Both fly ashes increase the shrinkage void ratio and decrease the % swell of the soil. While high lime fly ash is more effective in increasing the shrinkage void ratio, low lime flyash is more effective in reducing the swelling. Lime content which causes floculation of soil particle, is responsible for the differences.

Caracterização de solos sob diferentes ambientes na região Sul do Amazonas

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Comportamento do mercúrio em perfis de solos do sítio Ilha de Terra-Caxiuanã, Pará

ABSTRACT: Behavior of mercury in soil profiles with archaeological black earth (ABE) and surroundings area (SA) from Sítio Ilha de Terra, Caxiuanã, can provide information on anthropogenic activity of the Amazonian habitat. The samples of ABE and SA soil profiles were submitted to mineralogical chemical (total and sequential) analysis. The data show that the Hg occurs mainly in goethite and kaolinite in the two soil profiles. The highest concentrations of Hg and Fe are observed in the SA profile. These results indicate that the prehistoric human occupation contributed to the decrease of the concentration of Hg in soil ABE from Caxiuanã.

Comportamento do arsênio em perfis de solos do Sítio Ilha de Terra de Caxiuanã-Pará

Concentrações de arsênio em perfis de solos com terra preta arqueológica (TPA) e solos de área adjacente (AD) do Sítio Ilha de Terra, Caxiuanã, no Estado do Pará, região Amazônica, podem dar informações sobre as atividades antropogênicas dos habitantes dessa região. Análises químicas e mineralógicas foram realizadas nas amostras desses perfis. Os dados obtidos mostram que as concentrações do Fe e As aumentam com a profundidade dos perfis de solos, enquanto que as concentrações de matéria orgânica (MO) decrescem; as concentrações mais elevadas de Fe e As são observadas no perfil AD. Esses resultados indicam interações entre Fe e As e sugerem que a MO nos solos promove a dissolução da goethita e lixiviação do Fe e As no perfil TPA.

Mineralogia e geoquímica de perfis de solo com Terra Preta Arqueológica de Bom Jesus do Tocantins, sudeste da Amazônia

A comparação de dados morfológicos, mineralógicos e químicos de solo com horizontes antrópicos - Terra Preta Arqueológica (TPA) com Argissolos adjacentes permitiu identificar os principais processos responsáveis pela formação da TPA em um sítio arqueológico no Município de Bom Jesus do Tocantins, sudeste do Estado do Pará. A similaridade entre os dados dos horizontes subsuperficiais do solo com TPA e solos adjacentes indica que o horizonte antrópico do solo TPA foi provavelmente desenvolvido a partir de um horizonte similar aos Argissolos adjacentes com posterior transformação pedogenética através da introdução de materiais orgânicos e inorgânicos por antigas colonizações humanas, resultando no espessamento do horizonte superficial e em concentrações maiores de CaO e P₂O₅ (teores totais), Zn (teor traço), P e Zn disponível (teores disponíveis), além de Ca e Mg trocáveis (teores trocáveis) em relação aos Argissolos adjacentes. Além disso, essa intervenção antrópica antiga também provocou modificações no horizonte subsuperficial do Argissolo com TPA, como concentrações altas de P₂O₅ e principalmente P disponível. O Soil Taxonomy e o Sistema Brasileiro de Classificação de Solos (SiBCS) são adequados para a identificação de solo com horizonte antrópico (p.exe. TPA), uma vez que priorizam nas ordens do solo os principais processos pedogenéticos atuantes na formação do solo, relacionados aos horizontes subsuperficiais, além das transformações pedogenéticas posteriores no horizonte superficial. Contudo, este trabalho recomenda o acréscimo de alguns atributos diagnósticos como quantidade de artefatos cerâmicos e líticos, P₂O₅, P e Zn disponíveis, C orgânico, Ca²++ Mg²⁺ (teores trocáveis), CTC e índice de saturação por bases no horizonte superficial para o agrupamento e distinção dos diversos tipos de solos antrópicos antigos da Amazônia.

Metodologia geofísica aplicada à pesquisa de salvamento arqueológico nos sítios Bittencourt, Jambuaçu e Jaburu, Estado do Pará

Este trabalho apresenta os resultados da aplicação de métodos geofísicos no salvamento arqueológico em três sítios no estado do Pará: Bittencourt, localizado em Abaetetuba; Jambuaçu, localizado em Moju; e Jaburu, localizado em Almeirim. Os métodos utilizados foram Magnetometria, Cintilometria e Radar de Penetração no Solo (GPR). As medidas magnéticas foram utilizadas para indicar os locais para escavação. O GPR foi usado para confirmar as anomalias detectadas pelas medidas magnéticas e proporcionou a diminuição de erros cometidos quando se identificam anomalias magnéticas que não são causadas por feições arqueológicas. As medidas de cintilometria foram usadas para tentar mapear os solos de Terra Preta Arqueológica (TPA) através da radiação gama natural do solo. Os locais indicados para escavação pela magnetometria e GPR possibilitaram a descoberta de materiais arqueológicos como cerâmica, louça, lítico e ferro. Os resultados obtidos com a cintilometria foram satisfatórios, mostrando haver relação entre as medidas mais baixas de cintilometria e as áreas com maior espessura de TPA. A metodologia geofísica utilizada demonstrou eficiência e rapidez sem causar impactos destrutivos nos sítios.

Variabilidade espacial de atributos físicos de solos antropogênico e não antropogênico na região de Manicoré, AM

Better knowledge of the anthropogenic soils can help create future scenarios for the Amazon region through information that supports the sustainable planning. The aim of this study was to evaluate the spatial variability of soil physical anthropogenic and not anthropogenic in the region of Manipur, AM. In the study area we selected two, one with no anthropogenic soils (native forest) and another with anthropogenic soils (black earth archaeological). In each area, we established a grid measuring 70 x 70 m and the soils were sampled at the points of intersection of the grid with regular spacing of 10 by 10 feet, making a total of 64 sampling points in each landscape. Soil samples were collected at a depth from 0.0 to 0.10 I did the analyzes physical (texture, bulk density, macroporosity, microporososidade, porosity and aggregate stability). Then, the data were subjected to descriptive statistics and geostatistics. It was found that the anthropogenic and non-anthropogenic soils showed different behaviors in relation ace their spatial structures. The spatial variability that prevailed in anthropogenic and non-anthropogenic soil was moderate and weak indicating that these soils are strongly linked to changes in the soil by extrinsic factors. The soil was observed anthropogenic best results for total porosity, microporosity and bulk density, showing superior characteristics compared for agronomic soil not anthropogenic. And the range of values found in the above two areas were used in the mesh, showing greater spatial continuity in these environments.

Caracterização de solos sob diferentes usos na região sul do Amazonas

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

Características de atributos do solo em ambientes da região Sul do estado do Amazonas

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Planktic foraminiferal Mg/Ca and oxygen isotopes, plus estimated d18Oseawater and ice volume corrected d18Oseawater for the past 35000 years of sediment core GeoB10069-3

Evidence from geologic archives suggests that there were large changes in the tropical hydrologic cycle associated with the two prominent northern hemisphere deglacial cooling events, Heinrich Stadial 1 (HS1; ~19 to 15 kyr BP; kyr BP = 1000 yr before present) and the Younger Dryas (~12.9 to 11.7 kyr BP). These hydrologic shifts have been alternatively attributed to high and low latitude origin. Here, we present a new record of hydrologic variability based on planktic foraminifera-derived d18O of seawater (d18Osw) estimates from a sediment core from the tropical Eastern Indian Ocean, and using 12 additional d18Osw records, construct a single record of the dominant mode of tropical Eastern Equatorial Pacific and Indo-Pacific Warm Pool (IPWP) hydrologic variability. We show that deglacial hydrologic shifts parallel variations in the reconstructed interhemispheric temperature gradient, suggesting a strong response to variations in the Atlantic Meridional Overturning Circulation and the attendant heat redistribution. A transient model simulation of the last deglaciation suggests that hydrologic changes, including a southward shift in the Intertropical Convergence Zone (ITCZ) which likely occurred during these northern hemisphere cold events, coupled with oceanic advection and mixing, resulted in increased salinity in the Indonesian region of the IPWP and the eastern tropical Pacific, which is recorded by the d18Osw proxy. Based on our observations and modeling results we suggest the interhemispheric temperature gradient directly controls the tropical hydrologic cycle on these time scales, which in turn mediates poleward atmospheric heat transport.

AMS 14C dating points, isotopic compositions, Mg/Ca ratios and sea surface temperatures of sediment cores GeoB10029-4 and GeoB10038-4

Quantifying the spatial and temporal sea surface temperature (SST) and salinity changes of the Indo-Pacific Warm Pool is essential to understand the role of this region in connection with abrupt climate changes particularly during the last deglaciation. In this study we reconstruct SST and seawater d18O of the tropical eastern Indian Ocean for the past 40,000 years from two sediment cores (GeoB 10029-4, 1°30'S, 100°08'E, and GeoB 10038-4, 5°56'S, 103°15'E) retrieved offshore Sumatra. Our results show that annual mean SSTs increased about 2-3 °C at 19,000 years ago and exhibited southern hemisphere-like timing and pattern during the last deglaciation. Our SST records together with other Mg/Ca-based SST reconstructions around Indonesia do not track the monsoon variation since the last glacial period, as recorded by terrestrial monsoon archives. However, the spatial SST heterogeneity might be a result of changing monsoon intensity that shifts either the annual mean SSTs or the seasonality of G. ruber towards the warmer or the cooler season at different locations. Seawater d18O reconstructions north of the equator suggest fresher surface conditions during the last glacial and track the northern high-latitude climate change during the last deglaciation. In contrast, seawater ?18O records south of the equator do not show a significant difference between the last glacial period and the Holocene, and lack Bølling-Allerød and Younger Dryas periods suggestive of additional controls on annual mean surface hydrology in this part of the Indo-Pacific Warm Pool.