Polycyclic aromatic hydrocarbons (PAHs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil): Sources and depositional history

Located in southeastern Brazil, the Santos Estuary has the most important industrial and urban population area of South America. Since the 1950`s, increased urbanization and industrialization near the estuary margins has caused the degradation of mangroves and has increased the discharge of sewage and industrial effluents. The main objectives of this work were to determine the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment cores in order to investigate the input of these substances in the last 50 years. The PAHs analyses indicated multiple sources of these compounds (oil and pyrolitic origin), basically anthropogenic contributions from biomass, coal and fossil fuels combustion. The distribution of PAHs in the cores was associated with the formation and development of Cubatao industrial complex and the Santos harbour, waste disposal, world oil crisis and the pollution control program, which results in the decrease of organic pollutants input in this area. (C) 2011 Elsevier Ltd. All rights reserved.

Different lead sources in an abandoned uranium mine (Urgeirica - Central Portugal) and its environment impact - isotopic evidence

Different lead sources were identified in a large uranium tailings deposit (5Mton) in the Central Region of Portugal using lead isotopic ratios obtained by ICP-QMS. These ratios helped to clarify the different sources of Pb within the tailings deposit and the impact of the tailings on the surroundings. Ten depth profiles were used for isotopic characterization of the tailings deposit; the lead background signature was evaluated in seven regional rocks (granites) and was defined as being 28 +/- 1 mg kg(-1) for Pb bulk concentration and with isotopic ratios of 1.264(2) for Pb-206/Pb-207 and 1.962(7) for Pb-208/Pb-206. In order to understand Pb isotope distribution within the tailings deposit, simple mixing/mass balance models were used to fit experimental data, involving: (1) the background component; (2) uranium ores (pitchblende) characterized by the ratios Pb-206/Pb-207 of 1.914(3) and Pb-208/Pb-206 of 1.235(2); and (3) an unknown Pb source (named 'Fonte 5') characterized by the ratios Pb-206/Pb-207 of 3.079(7) and Pb-208/Pb-206 of 0.715(1). This unknown source showed high radiogenic ratios found in the water of some tailings depth profiles located in a very specific position in the dump. In terms of isotopic characterization, 69% of the deposit material resulted from the background source, 25% from uranium minerals and only 6% from other uranium mines in the region. Finally, the environment impact revealed that the pollution was focused only in the beginning of the stream and not in the surroundings, nor in the groundwater system. The lead in the water was found only in colloidal form with a clear pitchblende signature. Those data revealed possible remobilization phenomena along the bedside and margins of the watercourse.

Investigating South American biogeographic history using patterns of skull shape variation on Cerdocyon thous (Mammalia: Canidae)

Patterns of geographic variation of the canid Cerdocyon thous have historically been obscured by its remarkable intraspecific morphological variability. The observed distribution is highly associated with phytophysiognomy, a feature considered highly dynamic along geological time. In the present study, we tested whether vegetation distribution during the Holocene Glacial Maximum of South America (HGM) explains the patterns of morphological variation within Cerdocyon thous. The species was divided in groups according to paleohabitats that could support their presence during the HGM, and then tested for differences in skull morphometrics. The results obtained demonstrate that the climatic changes during the HGM influenced the population structure of this species, resulting in the establishment of geographical groups with different degrees of morphological cohesion. Higher morphological cohesion found in the Northern group might be explained by the marked discontinuity between its geographical range and the rest of the species`distribution. The Eastern and Southern morphological divergence is less striking and, although this could be related to past vegetation distribution, the disappearance of those barriers leads to a population structure that could be slowly breaking down. (C) 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 77-84.

Convergent Adaptations: Bitter Manioc Cultivation Systems in Fertile Anthropogenic Dark Earths and Floodplain Soils in Central Amazonia

Shifting cultivation in the humid tropics is incredibly diverse, yet research tends to focus on one type: long-fallow shifting cultivation. While it is a typical adaptation to the highly-weathered nutrient-poor soils of the Amazonian terra firme, fertile environments in the region offer opportunities for agricultural intensification. We hypothesized that Amazonian people have developed divergent bitter manioc cultivation systems as adaptations to the properties of different soils. We compared bitter manioc cultivation in two nutrient-rich and two nutrient-poor soils, along the middle Madeira River in Central Amazonia. We interviewed 249 farmers in 6 localities, sampled their manioc fields, and carried out genetic analysis of bitter manioc landraces. While cultivation in the two richer soils at different localities was characterized by fast-maturing, low-starch manioc landraces, with shorter cropping periods and shorter fallows, the predominant manioc landraces in these soils were generally not genetically similar. Rather, predominant landraces in each of these two fertile soils have emerged from separate selective trajectories which produced landraces that converged for fast-maturing low-starch traits adapted to intensified swidden systems in fertile soils. This contrasts with the more extensive cultivation systems found in the two poorer soils at different localities, characterized by the prevalence of slow-maturing high-starch landraces, longer cropping periods and longer fallows, typical of previous studies. Farmers plant different assemblages of bitter manioc landraces in different soils and the most popular landraces were shown to exhibit significantly different yields when planted in different soils. Farmers have selected different sets of landraces with different perceived agronomic characteristics, along with different fallow lengths, as adaptations to the specific properties of each agroecological micro-environment. These findings open up new avenues for research and debate concerning the origins, evolution, history and contemporary cultivation of bitter manioc in Amazonia and beyond.

The construction of the African perspective: a history of the General History of Africa project (Unesco)

This article analyzes the construction of the African perspective in the General History of Africa project (GHA), focusing on the period between 1965 and 1979. With the participation of over two hundred international experts under the auspices of Unesco, this was one of the greatest intellectual projects of the twentieth century. Based on primary sources, this analysis emphasizes the internal conflicts involved in the construction of the African perspective as a hegemonic line of thought in the GHA. Two critical moments of the project were found in the investigation: the controversial years (1972-78), and the pragmatic years (1978-82). As a result of these disputes, theoretical and methodological parameters were constructed, in addition to eight volumes of material published in the 1980s, and recently republished in Brazil.

Geochronological constraints on the age of a Permo-Triassic impact event: U-Pb and Ar-40/Ar-39 results for the 40 km Araguainha structure of central Brazil

Impact cratering has been a fundamental geological process in Earth history with major ramifications for the biosphere. The complexity of shocked and melted rocks within impact structures presents difficulties for accurate and precise radiogenic isotope age determination, hampering the assessment of the effects of an individual event in the geological record. We demonstrate the utility of a multi-chronometer approach in our study of samples from the 40 km diameter Araguainha impact structure of central Brazil. Samples of uplifted basement granite display abundant evidence of shock deformation, but U/Pb ages of shocked zircons and the Ar-40/Ar-39 ages of feldspar from the granite largely preserve the igneous crystallization and cooling history. Mixed results are obtained from in situ Ar-40/Ar-39 spot analyses of shocked igneous biotites in the granite, with deformation along kink-bands resulting in highly localized, partial resetting in these grains. Likewise, spot analyses of perlitic glass from pseudotachylitic breccia samples reflect a combination of argon inheritance from wall rock material, the age of the glass itself, and post-impact devitrification. The timing of crater formation is better assessed using samples of impact-generated melt rock where isotopic resetting is associated with textural evidence of melting and in situ crystallization. Granular aggregates of neocrystallized zircon form a cluster of ten U-Pb ages that yield a "Concordia" age of 247.8 +/- 3.8 Ma. The possibility of Pb loss from this population suggests that this is a minimum age for the impact event. The best evidence for the age of the impact comes from the U-Th-Pb dating of neocrystallized monazite and Ar-40/Ar-39 step heating of three separate populations of post-impact, inclusion-rich quartz grains that are derived from the infill of miarolitic cavities. The Pb-206/U-238 age of 254.5 +/- 3.2 Ma (2 sigma error) and Pb-208/Th-232 age of 255.2 +/- 4.8 Ma (2 sigma error) of monazite, together with the inverse, 18 point isochron age of 254 +/- 10 Ma (MSWD = 0.52) for the inclusion-rich quartz grains yield a weighted mean age of 254.7 +/- 2.5 Ma (0.99%, 2 sigma error) for the impact event. The age of the Araguainha crater overlaps with the timing of the Permo-Triassic boundary, within error, but the calculated energy released by the Araguainha impact is insufficient to be a direct cause of the global mass extinction. However, the regional effects of the Araguainha impact event in the Parana-Karoo Basin may have been substantial. (C) 2012 Elsevier Ltd. All rights reserved.

Dental health in Northern Chile's Atacama oases: Evaluating the Middle Horizon (AD 500-1000) impact on local diet

As one of the few areas apt for horticulture in Northern Chile's arid landscape, the prehistory of the Atacama oases is deeply enmeshed with that of the inter-regional networks that promoted societal development in the south central Andes. During the Middle Horizon (AD 5001000), local populations experienced a cultural apex associated with a substantial increase in inter-regional interaction, population density, and quantity and quality of mortuary assemblages. Here, we test if this cultural peak affected dietary practices equally among the distinct local groups of this period. We examine caries prevalence and the degree of occlusal wear in four series recovered from three cemeteries. Our results show a reduction in the prevalence of caries for males among an elite subsample from Solcor 3 and the later Coyo 3 cemeteries. Dental wear tends to increase over time with the Late Middle Horizon/Late Intermediate Period cemetery of Quitor 6 showing a higher average degree of wear. When considered in concert with archaeological information, we concluded that the Middle Horizon was marked by dietary variability wherein some populations were able to obtain better access to protein sources (e.g., camelid meat). Not all members of Atacameno society benefited from this, as we note that this dietary change only affected men. Our results suggest that the benefits brought to the San Pedro oases during the Middle Horizon were not equally distributed among local groups and that social status, relationship to the Tiwanaku polity, and interment in particular cemeteries affected dietary composition. Am J Phys Anthropol, 2012. (C) 2012 Wiley Periodicals, Inc.

Astrobiology in Brazil: early history and perspectives

This review reports the Brazilian history in astrobiology, as well as the first delineation of a vision of the future development of the field in the country, exploring its abundant biodiversity, highly capable human resources and state-of-the-art facilities, reflecting the last few years of stable governmental investments in science, technology and education, all conditions providing good perspectives on continued and steadily growing funding for astrobiology-related research. Brazil is growing steadily and fast in terms of its worldwide economic power, an effect being reflected in different areas of the Brazilian society, including industry, technology, education, social care and scientific production. In the field of astrobiology, the country has had some important landmarks, more intensely after the First Brazilian Workshop on Astrobiology in 2006. The history of astrobiology in Brazil, however, is not so recent and had its first occurrence in 1958. Since then, researchers carried out many individual initiatives across the country in astrobiology-related fields, resulting in an ever growing and expressive scientific production. The number of publications, including articles and theses, has particularly increased in the last decade, but still counting with the effort of researchers working individually. That scenario started to change in 2009, when a formal group of Brazilian researchers working with astrobiology was organized, aiming at congregating the scientific community interested in the subject and to promote the necessary interactions to achieve a multidisciplinary work, receiving facilities and funding from the University de Sao Paulo and other funding agencies. Received 29 February 2012, accepted 17 May 2012, first published online 18 July 2012

Factors controlling water-column respiration in rivers of the central and southwestern Amazon Basin

We examined the factors controlling the variability in water-column respiration rates in Amazonian rivers. Our objectives were to determine the relationship between respiration rates and the in situ concentrations of the size classes of organic carbon (OC), and the biological source (C-3 and C-4 plants and phytoplankton) of organic matter (OM) supporting respiration. Respiration was measured along with OC size fractions and dissolved oxygen isotopes (delta O-18-O-2) in rivers of the central and southwestern Amazon Basin. Rates ranged from 0.034 mu mol O-2 L-1 h(-1) to 1.78 mu mol O-2 L-1 h(-1), and were four-fold higher in rivers with evidence of photosynthetic production (demonstrated by delta O-18-O-2<24.2 parts per thousand) as compared to rivers lacking such evidence (delta O-18-O-2>24.2 parts per thousand; 1.35 +/- 0.22 vs. 0.30 +/- 0.29 mu mol L-1 h(-1)). Rates were likely elevated in the former rivers, which were all sampled during low water, due to the stimulation of heterotrophic respiration via the supply of a labile, algal-derived substrate and/or the occurrence of autotrophic respiration. The organic composition of fine particulate OM (FPOM) of these rivers is consistent with a phytoplankton origin. Multiple linear regression analysis indicates that [FPOC], C:N-FPOC ratios, and [O-2] account for a high amount of the variability in respiration rates (r(2) = 0.80). Accordingly, FPOC derived from algal sources is associated with elevated respiration rates. The delta C-13 of respiration-derived CO2 indicates that the role of phytoplankton, C-3 plants, and C-4 grasses in supporting respiration is temporally and spatially variable. Future scaling work is needed to evaluate the significance of phytoplankton production to basin-wide carbon cycling.

Aerosol and precipitation chemistry measurements in a remote site in Central Amazonia: the role of biogenic contribution

In this analysis a 3.5 years data set of aerosol and precipitation chemistry, obtained in a remote site in Central Amazonia (Balbina, (1A degrees 55' S, 59A degrees 29' W, 174 m a.s.l.), about 200 km north of Manaus) is discussed. Aerosols were sampled using stacked filter units (SFU), which separate fine (d < 2.5 mu m) and coarse mode (2.5 mu m < d < 10.0 mu m) aerosol particles. Filters were analyzed for particulate mass (PM), Equivalent Black Carbon (BCE) and elemental composition by Particle Induced X-Ray Emission (PIXE). Rainwater samples were collected using a wet-only sampler and samples were analyzed for pH and ionic composition, which was determined using ionic chromatography (IC). Natural sources dominated the aerosol mass during the wet season, when it was predominantly of natural biogenic origin mostly in the coarse mode, which comprised up to 81% of PM10. Biogenic aerosol from both primary emissions and secondary organic aerosol dominates the fine mode in the wet season, with very low concentrations (average 2.2 mu g m(-3)). Soil dust was responsible for a minor fraction of the aerosol mass (less than 17%). Sudden increases in the concentration of elements as Al, Ti and Fe were also observed, both in fine and coarse mode (mostly during the April-may months), which we attribute to episodes of Saharan dust transport. During the dry periods, a significant contribution to the fine aerosols loading was observed, due to the large-scale transport of smoke from biomass burning in other portions of the Amazon basin. This contribution is associated with the enhancement of the concentration of S, K, Zn and BCE. Chlorine, which is commonly associated to sea salt and also to biomass burning emissions, presented higher concentration not only during the dry season but also for the April-June months, due to the establishment of more favorable meteorological conditions to the transport of Atlantic air masses to Central Amazonia. The chemical composition of rainwater was similar to those ones observed in other remote sites in tropical forests. The volume-weighted mean (VWM) pH was 4.90. The most important contribution to acidity was from weak organic acids. The organic acidity was predominantly associated with the presence of acetic acid instead of formic acid, which is more often observed in pristine tropical areas. Wet deposition rates for major species did not differ significantly between dry and wet season, except for NH4+, citrate and acetate, which had smaller deposition rates during dry season. While biomass burning emissions were clearly identified in the aerosol component, it did not present a clear signature in rainwater. The biogenic component and the long-range transport of sea salt were observed both in aerosols and rainwater composition. The results shown here indicate that in Central Amazonia it is still possible to observe quite pristine atmospheric conditions, relatively free of anthropogenic influences.

Postnatal longitudinal evaluation of children diagnosed with prenatal hydronephrosis: insights in natural history and referral pattern

Objectives Clinical significance and management of prenatal hydronephrosis (PNH) are sources of debate. Existing studies are flawed with biased cohorts or inconsistent follow-up. We aimed to evaluate the incidence of pathology in a large cohort of PNH and assess the biases and outcomes of this population. Methods We reviewed 1034 charts of fetuses with PNH. Records of delivered offspring were reviewed at a pediatric center and analyzed with respect to prenatal and postnatal pathology and management. Results Prenatal resolution of hydronephrosis occurred in 24.7% of pregnancies. On first postnatal ultrasound, some degree of dilatation was present in 80%, 88% and 95% of mild, moderate and severe PNH cases, respectively. At the end of follow-up, hydronephrosis persisted in 10%, 25% and 72% of children, respectively. Incidence of vesicoureteral reflux did not correlate with severity of PNH. Children with postnatal workup had more severe PNH than those without. Conclusions Despite prenatal resolution totalizing 25%, pelvic dilatation persisted on first postnatal imaging in most cases, thus justifying postnatal ultrasound evaluation. Whereas most mild cases resolved spontaneously, a quarter of moderate and more than half of severe cases required surgery. Patients with postnatal imaging and referral had more severe PNH, which could result in overestimation of pathology. (c) 2012 John Wiley & Sons, Ltd.

Investigation of the Goias Alkaline Province, Central Brazil: Application of gravity and magnetic methods

We investigate the strong magnetic and gravity anomalies of the Goias Alkaline Province (GAP), a region of Late Cretaceous alkaline magmatism along the northern border of the Parana Basin, Brazil. The alkaline complexes (eight of which are present in outcrops, two others inferred from magnetic signals) are characterized by a series of small intrusions forming almost circular magnetic and gravimetric anomalies varying from -4000 to +6000 nT and from -10 to +40 mGal, respectively. We used the Aneuler method and Analytical Signal Amplitude to obtain depth and geometry for mapped sources from the magnetic anomaly data. These results were used as the reference models in the 3D gravity inversion. The 3D inversion results show that the alkaline intrusions have depths of 10-12 km. The intrusions in the northern GAP follow two alignments and have different sizes. In the anomaly magnetic map, dominant guidelines correlate strongly with the extensional regimes that correlate with the rise of alkaline magmatism. The emplacement of these intrusions marks mechanical discontinuities and zones of weakness in the upper crust. According to the 3D inversion results, those intrusions are located within the upper crust (from the surface to 18 km depth) and have spheres as the preferable geometry. Such spherical shapes are more consistent with magmatic chambers instead of plug intrusions. The Registro do Araguaia anomaly (similar to 15 by 25 km) has a particular magnetic signature that indicates that the top is deeper than 1500 m. North of this circular anomaly are lineaments with structural indices indicating contacts on their edges and dikes/sills in the interiors. Results of 3D inversion of magnetic and gravity data suggest that the Registro do Araguaia is the largest body in the area, reaching 18 km depth and indicating a circular layered structure. (C) 2011 Elsevier Ltd. All rights reserved.

U-Pb zircon ages of orthogneisses and supracrustal rocks of the Cariris Velhos belt: Onset of Neoproterozoic rifting in the Borborema Province, NE Brazil

New geochronological and geochemical constraints on Precambrian sedimentary and volcanic successions exposed in the western part of the Central Domain of the Borborema Province, NE Brazil, indicate the presence of two distinct tectono-stratigraphic complexes: Riacho Gravata and Sao Caetano. Both complexes and associated orthogneisses are referred in the literature as the Cariris Velhos belt, having depositional, extrusive, or intrusive ages within the interval 985-913 Ma. The Riacho Gravata complex consists of bimodal (but mostly felsic) volcanic and volcanoclastic rocks, muscovite+/-graphite schists, quartzites, and marble with local occurrences of banded-iron-formation. The Sao Caetano complex mainly consists of metagreywackes, marbles, calc-silicate rocks, and rare meta-mafic rocks. Meta-mafic rocks from both complexes have geochemical signatures similar to those of continental flood basalts, with epsilon Nd (1.0 Ga) values ranging from -1.0 to -2.8. Felsic volcanic rocks from the Riacho Gravata complex show epsilon Nd (1.0 Ga) values ranging from -1.0 to -7.4 and geochemical signatures similar to A(2)-type granitoids. New SHRIMP U-Pb zircon data from felsic volcanic rocks within the Riacho Gravata complex yielded ages of 1091 +/- 13 Ma and 996 +/- 13 Ma. In contrast, meta-graywackes from the Sao Caetano complex show a maximum deposition age of ca. 806 Ma in the northern part and ca. 862 Ma in the southern part of the outcrop area. The orthogneisses show epsilon Nd (1.0 Ga) values ranging from 1.0 to -4.2 with U/Pb TIMS and SHRIMP ages ranging from 960 to 926 Ma and geochemical signatures of A(2)-type granitoids. The data reported in this paper suggest at least two periods of extension within the Central Domain of the Borborema Province, the first starts ca. 1091 Ma with magmatism and deposition, creating the Riacho Gravata basin and continued intrusion of A-type granites to 920 Ma. A second rift event, which reactivated old faults, generated a basin with a maximum deposition age of ca. 806 Ma. Furthermore, the oldest granitoids cutting these metasedimentary rocks have crystallization ages of ca. 600 Ma. This suggests that the second rift event could be early Brasiliano in age. The resulting Sao Caetano basin received detritus from a variety of sources, although detritus from the Riacho Gravata complex dominated. Deposition ages of the Riacho Gravata and the Sao Caetano complexes are coeval with deposits in other basins of the Borborema Province (Riacho do Tigre in the Central Domain; Macurure and Maranco in the Sergipano Belt of the Southern domain). The Macaubas Group from SE Brazil and its counterparts in Africa, the Zadanian and Mayumbian Groups, in the western edge of the Congo Craton are also coeval. Closure of the Riacho Gravata and Sao Caetano basins occurred during the Brasiliano convergence (705-600 Ma). During the last stage of convergence, ca. 612 Ma, pull-apart basins were created and filled; final basin closure took place 605-592 Ma, after deposition ceased. (C) 2011 Elsevier B.V. All rights reserved.

When size makes a difference: allometry, life-history and morphological evolution of capuchins (Cebus) and squirrels (Saimiri) monkeys (Cebinae, Platyrrhini)

Abstract Background How are morphological evolution and developmental changes related? This rather old and intriguing question had a substantial boost after the 70s within the framework of heterochrony (changes in rates or timing of development) and nowadays has the potential to make another major leap forward through the combination of approaches: molecular biology, developmental experimentation, comparative systematic studies, geometric morphometrics and quantitative genetics. Here I take an integrated approach combining life-history comparative analyses, classical and geometric morphometrics applied to ontogenetic series to understand changes in size and shape which happen during the evolution of two New World Monkeys (NWM) sister genera. Results Cebus and Saimiri share the same basic allometric patterns in skull traits, a result robust to sexual and ontogenetic variation. If adults of both genera are compared in the same scale (discounting size differences) most differences are small and not statistically significant. These results are consistent using both approaches, classical and geometric Morphometrics. Cebus is a genus characterized by a number of peramorphic traits (adult-like) while Saimiri is a genus with paedomorphic (child like) traits. Yet, the whole clade Cebinae is characterized by a unique combination of very high pre-natal growth rates and relatively slow post-natal growth rates when compared to the rest of the NWM. Morphologically Cebinae can be considered paedomorphic in relation to the other NWM. Geometric morphometrics allows the precise separation of absolute size, shape variation associated with size (allometry), and shape variation non-associated with size. Interestingly, and despite the fact that they were extracted as independent factors (principal components), evolutionary allometry (those differences in allometric shape associated with intergeneric differences) and ontogenetic allometry (differences in allometric shape associated with ontogenetic variation within genus) are correlated within these two genera. Furthermore, morphological differences produced along these two axes are quite similar. Cebus and Saimiri are aligned along the same evolutionary allometry and have parallel ontogenetic allometry trajectories. Conclusion The evolution of these two Platyrrhini monkeys is basically due to a size differentiation (and consequently to shape changes associated with size). Many life-history changes are correlated or may be the causal agents in such evolution, such as delayed on-set of reproduction in Cebus and larger neonates in Saimiri.