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METALS IN SEDIMENTS FROM THE SHELF-SLOPE INTERFACE OFF THE POTIGUAR BASIN OFFSHORE OIL EXPLORATION AREA, NE BRAZIL. Marine sediments collected in November 2009 and July 2011 at depths ranging from 150 m to 2,000 m in the Potiguar Basin, northeastern Brazil, were analyzed for their main sedimentological characteristics (contents of carbon, nitrogen and their stable isotopes) and metals (Al, Fe, Mn, As, Cr, Cu, Ni, Pb, V and Zn) concentrations and their spatial distribution. Sediments were relatively rich in organic matter (C-org: 0.21% to 0.56%) and metals concentrations increased with depth, suggesting an accumulation of fine and terrigenous sediments eroded and transported from the continental shelf to the slope region. Metals concentrations were higher than those observed in coarser shelf sediments, because of sorting of fine-grained sediments. Iron (Fe), Cr and Cu distribution, although presenting this general pattern, also suggests some changes along the transport. Fe and Cr, probably in discrete minerals, are less affected by accumulation in deeper sediments. The high enrichment in Cu, however, suggests additional sources directly to slope sediments, probably by biological productivity and deposition through the water column. The concentrations of all metals are lower or fall close to the lowest range of concentrations reported for slope sediments from other marine regions worldwide and no evidence of anthropogenic contribution was evident.

https://doi.org/10.21577/0100-4042.20170959

Mercury concentrations in coastal Elasmobranchs (Hypanus guttatus and Rhizoprionodon porosus) and human exposure in Pernambuco, Northeastern Brazil
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JULIO, TAINÁ G.

; MOURA, VICTOR L.

; LACERDA, LUIZ D.

; LESSA, ROSÂNGELA P.T.

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2022, Volume 94 Supl. 4 elocation e20220045

Resumo: En | Texto: En | PDF: En

Abstract Elasmobranchs are long-lived predatory fish that show high Hg concentrations generally reflecting environmental levels, notwithstanding they are widely consumed in Brazil increasing Hg exposure to humans. This study reports on Hg concentrations in largely consumed sharks (Rhizoprionodon porosus) and rays (Hypanus guttatus) from the Pernambuco coast, NE Brazil and the risk associated with their consumption. Muscle tissue concentrations of Hg in H. guttatus and R. porosus varied from 40 to 1,020 ng.g-1 w.w. (median = 125; mean = 124 ± 48 ng.g-1 w.w.) in sharks and from 129 to 2,130 ng.g-1 w.w. (median = 976; mean = 919 ± 139 ng.g-1 w.w.) in rays. Concentrations of Hg positively correlated with size in sharks, but not in rays. Concentrations reflect the local environmental contamination of a large urban center and industrial park concentrated in a short extension of mangrove-dominated coastline (50 km) and are higher compared to other Brazilian sites where Hg concentrations in these species have been reported. Sharks had a risk coefficient (HQ) range of 0.04 to 1.1, not surpassing the reference level of exposure. On the other hand, rays’ HQ ranged from 0.14 to 2.3, and exceeds the reference level of exposure and suggests adverse effects to consumers.

https://doi.org/10.1590/0001-3765202220220045

The Program for Biodiversity Research in Brazil: The role of regional networks for biodiversity knowledge, dissemination, and conservation
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ROSA, CLARISSA

; BACCARO, FABRICIO

; CRONEMBERGER, CECILIA

; HIPÓLITO, JULIANA

; BARROS, CLAUDIA FRANCA

; RODRIGUES, DOMINGOS DE JESUS

; NECKEL-OLIVEIRA, SELVINO

; OVERBECK, GERHARD E.

; DRECHSLER-SANTOS, ELISANDRO RICARDO

; ANJOS, MARCELO RODRIGUES DOS

; FERREGUETTI, ÁTILLA C.

; AKAMA, ALBERTO

; MARTINS, MARLÚCIA BONIFÁCIO

; TOMAS, WALFRIDO MORAES

; SANTOS, SANDRA APARECIDA

; FERREIRA, VANDA LÚCIA

; CUNHA, CATIA NUNES DA

; PENHA, JERRY

; PINHO, JOÃO BATISTA DE

; SALIS, SUZANA MARIA

; DORIA, CAROLINA RODRIGUES DA COSTA

; PILLAR, VALÉRIO D.

; PODGAISKI, LUCIANA R.

; MENIN, MARCELO

; BÍGIO, NARCÍSIO COSTA

; ARAGÓN, SUSAN

; MANZATTO, ANGELO GILBERTO

; VÉLEZ-MARTIN, EDUARDO

; SILVA, ANA CAROLINA BORGES LINS E

; IZZO, THIAGO JUNQUEIRA

; MORTATI, AMANDA FREDERICO

; GIACOMIN, LEANDRO LACERDA

; ALMEIDA, THAÍS ELIAS

; ANDRÉ, THIAGO

; SILVEIRA, MARIA AUREA PINHEIRO DE ALMEIDA

; SILVEIRA, ANTÔNIO LAFFAYETE PIRES DA

; MESSIAS, MARILUCE REZENDE

; MARQUES, MARCIA C.M.

; PADIAL, ANDRE ANDRIAN

; MARQUES, RENATO

; BITAR, YOUSZEF O.C.

; SILVEIRA, MARCOS

; MORATO, ELDER FERREIRA

; PAGOTTO, RUBIANI DE CÁSSIA

; STRUSSMANN, CHRISTINE

; MACHADO, RICARDO BOMFIM

; AGUIAR, LUDMILLA MOURA DE SOUZA

; FERNANDES, GERALDO WILSON

; OKI, YUMI

; NOVAIS, SAMUEL

; FERREIRA, GUILHERME BRAGA

; BARBOSA, FLÁVIA RODRIGUES

; OCHOA, ANA C.

; MANGIONE, ANTONIO M.

; GATICA, AILIN

; CARRIZO, MARÍA CELINA

; RETTA, LUCÍA MARTINEZ

; JOFRÉ, LAURA E.

; CASTILLO, LUCIANA L.

; NEME, ANDREA M.

; RUEDA, CARLA

; TOLEDO, JOSÉ JULIO DE

; GRELLE, CARLOS EDUARDO VIVEIROS

; VALE, MARIANA M.

; VIEIRA, MARCUS VINICIUS

; CERQUEIRA, RUI

; HIGASHIKAWA, EMÍLIO MANABU

; MENDONÇA, FERNANDO PEREIRA DE

; GUERREIRO, QUÊZIA LEANDRO DE MOURA

; BANHOS, AUREO

; HERO, JEAN-MARC

; KOBLITZ, RODRIGO

; COLLEVATTI, ROSANE GARCIA

; SILVEIRA, LUÍS FÁBIO

; VASCONCELOS, HERALDO L.

; VIEIRA, CECÍLIA RODRIGUES

; COLLI, GUARINO RINALDI

; CECHIN, SONIA ZANINI

; SANTOS, TIAGO GOMES DOS

; FONTANA, CARLA S.

; JARENKOW, JOÃO A.

; MALABARBA, LUIZ R.

; RUEDA, MARTA P.

; ARAUJO, PUBLIO A.

; PALOMO, LUCAS

; ITURRE, MARTA C.

; BERGALLO, HELENA GODOY

; MAGNUSSON, WILLIAM E.

Anais da Academia Brasileira de Ciências

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2021, Volume 93 Nº 2 elocation e20201604

Resumo: En | Texto: En | PDF: En

Abstract The Program for Biodiversity Research (PPBio) is an innovative program designed to integrate all biodiversity research stakeholders. Operating since 2004, it has installed long-term ecological research sites throughout Brazil and its logic has been applied in some other southern-hemisphere countries. The program supports all aspects of research necessary to understand biodiversity and the processes that affect it. There are presently 161 sampling sites (see some of them at Supplementary Appendix), most of which use a standardized methodology that allows comparisons across biomes and through time. To date, there are about 1200 publications associated with PPBio that cover topics ranging from natural history to genetics and species distributions. Most of the field data and metadata are available through PPBio web sites or DataONE. Metadata is available for researchers that intend to explore the different faces of Brazilian biodiversity spatio-temporal variation, as well as for managers intending to improve conservation strategies. The Program also fostered, directly and indirectly, local technical capacity building, and supported the training of hundreds of undergraduate and graduate students. The main challenge is maintaining the long-term funding necessary to understand biodiversity patterns and processes under pressure from global environmental changes.

https://doi.org/10.1590/0001-3765202120201604 1034 downloads

Selection indexes for Nellore production system in the Brazilian Pantanal
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Portes, Juliana Varchaki

; Menezes, Gilberto Romeiro de Oliveira

; Silva, Luiz Otávio Campos da

; MacNeil, Michael D.

; Abreu, Urbano Gomes Pinto de

; Lacerda, Viviane Vasconcelos de

; Braccini Neto, José

Revista Brasileira de Zootecnia

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2021, Volume 50 elocation e20200264

Resumo: En | Texto: En | PDF: En

ABSTRACT The objective was to develop selection indexes for Nellore cattle raised in full-cycle production system in the Brazilian Pantanal. The resulting offspring are retained as replacements or sold at two years of age. Preliminary analyses explored effects of scale on economic values (EV). However, given the available data, these effects were very small. Presented herein are results from a simulated system consisting of 5,000 cows with all animals maintained on pasture as is typical in Pantanal. The EV were determined by approximating the partial derivatives of the profit function, changing one trait at a time, by one unit, while keeping the other traits constant. Traits in the breeding objective were mature cow weight, direct and maternal weaning weight, postweaning average daily gain, subcutaneous fat depth, longissimus muscle area, and stayability. Economic values were calculated on the basis of number of animals (per head), number of animal units, and arroba of carcasss weight. Regardless of the basis, maternal weaning weight and subcutaneous fat depth made negligible contributions to the breeding objective. Proportions of variation in the breeding objectives (per head, per animal unit, per arroba) explained by cow weight, direct weaning weight, postweaning average daily gain, stayability, and longissimus muscle area were: 13, 13, 17; 6, 1, 5; 3, 3, 4; 67, 67, 61; and 11, 17, 13, respectively. These indexes may aid Nellore breeders in their selection decisions, thus facilitating the genetic progress and increased productivity and profitability of Pantanal herds.

https://doi.org/10.37496/rbz5020200264 157 downloads

Spatial and Temporal Effects of Decommissioning a Zinc Smelter on the Sediment Quality of an Estuary System: Sepetiba Bay, Rio de Janeiro, Brazil
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Gonçalves, Rodrigo A.

; Oliveira, Douglas F.

; Rezende, Carlos Eduardo

; Almeida, Phelipe

; Lacerda, Luiz D. de

; Gama, Bernardo A. P. da

; Godoy, José Marcus

Journal of the Brazilian Chemical Society

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Abr 2020, Volume 31 Nº 4 Páginas 683 - 693

Resumo: En | Texto: En | PDF: En

Sepetiba Bay, Rio de Janeiro, Brazil, was home to a zinc smelter until its shutdown in 1998, and during 2011 the remains of the smelter were decommissioned. This study investigates the impact of decommissioning on metal concentrations in the bottom sediments of the bay. In addition to Zn and Cd, Cr, Cu, Ni and Pb are also quantified. The results show that over these 15 years, Cd and Zn concentrations have decreased by 100 and 70%, respectively. Temporal effects are also studied by applying five dated 210Pb cores, which are validated using the Zn and Cd profiles. The observed decrease in the Zn concentration in oysters is correlated with its reduction in the sediment. It was possible to verify the impact of Cr, Cu, Ni and Pb on the sediment quality due to the remaining metallurgical industries in the Sepetiba Bay basin.

https://doi.org/10.21577/0103-5053.20190232 303 downloads

Phosphorus and suspended matter retention in mangroves affected by shrimp farm effluents in NE Brazil
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MARINS, ROZANE V.

; LACERDA, LUIZ D.

; ARAÚJO, ISABEL CRISTINA S.

; FONSECA, LOUIZE V.

; SILVA, FRANCISCO A.T.F.

Anais da Academia Brasileira de Ciências

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2020, Volume 92 Nº 3 elocation e20200758

Resumo: En | Texto: En | PDF: En

Abstract This study compares two mangroves with different land uses in the Jaguaribe River estuary, harboring large shrimp farms, and in the more pristine Pacotí River estuary. Normalized Difference Vegetation Index (NDVI) was used to compare the overall health of the forests. Measures of suspended matter (TSS), total (TP), particulate (PartP) and soluble reactive phosphorus (SRP) in the inflow and outflow waters of tidal channels draining the mangroves were performed during tidal cycles. NDVI varied from 0.65 in the Jaguaribe estuary to 0.85 in the Pacotí, suggesting the impact of shrimp farm effluents on mangrove canopy cover. The shrimp farm influenced site showed 10 times larger absolute ∑P (TP + PartP + SRP) = 1.2-5.2 kg.hr-1) flux than the pristine site (∑P = 0.22 kg.hr-1). Tidal balances showed smaller retentions of the total influx: 28-54%; 44-45%; 38-65% and 8-53% for TSS; TP; SRP; and PartP respectively, in the shrimp farm influenced site to over 93% of the total tidal input of TSS and all P fractions in the pristine mangrove. This suggests that mangrove phosphorus accumulation is decreased in the forest with lower NDVI and limits mangrove’s potential as a natural barrier to the nutrient transport to adjacent estuarine and coastal waters.

https://doi.org/10.1590/0001-3765202020200758 578 downloads

Mercury and methylmercury in carapace of the marine turtle Caretta caretta, in northeastern Brazil and its potential for environmental monitoring
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RODRIGUEZ, CÉSAR AUGUSTO B.

; BEZERRA, MOISES F.

; REZENDE, CARLOS EDUARDO DE

; BASTOS, WANDERLEY R.

; LACERDA, LUIZ D. DE

Anais da Academia Brasileira de Ciências

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2019, Volume 91 Nº 2 elocation e20180672

Resumo: En | Texto: En | PDF: En

Abstract: The present work tests the use of carapace fragments of the marine turtle Caretta caretta as a tool for environmental biomonitoring of mercury (Hg) and to evaluate the influence of biological and ecological factors in Hg concentrations. Samples of carapace fragments were obtained during the nesting season of 2012 and 2016 and were analyzed for their total-Hg and methyl-Hg concentrations and the isotopic composition of carbon and nitrogen (δ15N and δ13C). Seventy-six females were sampled, with an average size of 87.1 to 107 cm of curved carapace length (CCL). The results showed a wide variation in total Hg concentrations (3.3 – 1,672 ng g-1) and low concentrations of methyl-Hg, not showing any pattern of accumulation among the individuals. The isotopic composition of δ15N and δ13C suggests that the individuals sampled belong to a high trophic level but did not present any relationship with the Hg concentrations. It suggests that, at least with the existing results, and unlike other turtle species, carapace fragments of C. caretta cannot yet be used in environmental monitoring.

https://doi.org/10.1590/0001-3765201920180672 1027 downloads

Limnology of the largest multi-use artificial reservoir in NE Brazil: The Castanhão Reservoir, Ceará State
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LACERDA, LUIZ D.

; SANTOS, JANAÍNA A.

; MARINS, ROZANE V.

; SILVA, FRANCISCO A.T.F. DA

Anais da Academia Brasileira de Ciências

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Ago 2018, Volume 90 Nº 2 Páginas 2073 - 2096

Resumo: En | Texto: En | PDF: En

Abstract This work reviews the limnology of the largest multi-use reservoir in NE Brazil, the Castanhão Reservoir in Ceará State, during 5 years of an extended drought when the reservoir’s volume decreased from 88% to about 30%. Major physical and chemical parameters of the water column, phytoplankton community, trophic state and sediment geochemistry were monitored, as well as the impact from extensive aquaculture. Water quality of the full reservoir was maintained due to hydrodynamics, which transport nutrients to the hypolimnion of a stratified water column, rendering an oligotrophic state to the reservoir, notwithstanding the large nutrient inputs from aquaculture and irrigated agriculture. However, with the extension of the drought period, the reservoir volume reduced, decreasing water depth leading to breaking of the thermocline due to wind forcing, and mixing the entire water column. This increased turbidity, nutrient availability and primary productivity, also changed phytoplankton functional groups. As a result, at the end of the monitoring period, when the reservoir attained its lowest volume, its trophic state became eutrophic. Under a scenario of climate change, where annual precipitation is decreasing, human uses of reservoirs in the semiarid should be very restricted to maintain water quality proper for human use.

https://doi.org/10.1590/0001-3765201820180085 1347 downloads

Monitoring structures with optical fibers: infiltration detection
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MARCONCIN, LILIANE R.

; MACHADO, ROBERTO D.

; LACERDA, LUIZ A. DE

; AUFLEGER, MARKUS

Anais da Academia Brasileira de Ciências

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Abr 2018, Volume 90 Nº 2 Páginas 1865 - 1872

Resumo: En | Texto: En | PDF: En

ABSTRACT The use of sensors and optical fibers for monitoring structures is continuously growing. Strains, displacements, accelerations, temperatures are just a few of the monitoring possibilities. In the case of dam structures, concrete face rockfill dams constitute a type of structures where the monitoring of water infiltrations is of particular interest. In large structures of this type, opening of slab joints is a common effect of general strain distributions, but crack formation may also occur as a result of high compressive stresses, during and after the reservoir filling stage. In this context, this paper verifies, experimentally, the applicability and the response of a distributed fiber optic monitoring system in the identification of infiltration spots and its potential sizes. The experimental tests confirm the technical feasibility of detecting infiltrations, but did not show clear evidence of their sizes.

https://doi.org/10.1590/0001-3765201820170144 1230 downloads

10.

Highly prevalence of vitamin D deficiency among Brazilian women of reproductive age
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Lopes, Vinicius Medina

; Lopes, Joaquim Roberto Costa

; Brasileiro, Jean Pierre Barguil

; Oliveira, Ingrid de

; Lacerda, Ricardo Peclat

; Andrade, Marcos Renato Dib

; Tierno, Natália Ivet Zavattiero

; Souza, Roberto Costa Cavalcante de

; Motta, Luiz Augusto Casulari Roxo da

Archives of Endocrinology and Metabolism

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Fev 2017, Volume 61 Nº 1 Páginas 21 - 27

Resumo: En | Texto: En | PDF: En

ABSTRACT Objective Vitamin D has several metabolic functions and possible reproductive functions. This study aimed to determine the prevalence of vitamin D deficiency among Brazilian women of reproductive age, and to evaluate the relationship between serum 25-hydroxyvitamin D [25(OH)D] concentrations and infertility causes. Subjects and methods This retrospective cross-sectional study evaluated data from a private Brazilian assisted reproduction center that were collected between January 1 and May 5, 2012. Serum 25(OH)D concentrations were measured and compared for infertile and fertile women. Concentrations of 25(OH)D that were < 20 ng/mL were defined as deficiency and concentrations of 21-30 ng/mL were defined as hypovitaminosis D. Results Among the 369 evaluated women, 81.1% exhibited hypovitaminosis D and 32.0% exhibited deficiency. The infertile and control patients did not exhibit any significant differences in the prevalence of vitamin D deficiency (30.2% vs. 35%, respectively; p = 0.33) or in the mean 25(OH)D concentrations (24.3 ± 7.9 ng/mL vs. 23.8 ± 8.7 ng/mL, respectively; p = 0.51). Furthermore, there were no significant differences in the mean 25(OH)D concentrations among subgroups of patients with single infertility factors, or between these subgroups and the control group. Conclusions A high proportion of Brazilian women of reproductive age exhibited vitamin D deficiency, regardless of their fertility status. Thus, it may be useful to evaluate this population for vitamin D deficiency, although future studies are needed to determine whether this deficiency might affect the outcomes of treatments for infertility.

https://doi.org/10.1590/2359-3997000000216 2632 downloads

11.

Mangroves Response to Climate Change: A Review of Recent Findings on Mangrove Extension and Distribution
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Godoy, Mario D.P.

; Lacerda, Luiz D. de

Anais da Academia Brasileira de Ciências

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Jun 2015, Volume 87 Nº 2 Páginas 651 - 667

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Manguezais funcionam como proteção natural para a linha da costa em casos de erosão e inundação, provendo importantes serviços ambientais. Devido à distribuição geográfica desse habitat na interface continente-oceano, é muito provável que sofra sérios impactos oriundos das mudanças climáticas, potencializados por atividades humanas na zona costeira. Esse trabalho revisa os resul tados de estudos realizados nos últimos 25 anos sobre as respostas observadas dos manguezais às alterações ambientais causadas tanto por alterações climáticas. Foram levados em consideração 104 estudos de caso e de modelagem no mundo todo. A maioria desses estudos foi publicada depois do ano 2000 como um reflexo do relatório publicado pelo IPCC em 1997. Apesar de muitos estudos mostrarem uma diminuição global da área de manguezais no mundo devido à pressão antrópica direta, vários outros mostraram que, localmente, uma variedade de habitats de manguezal está se expandindo como uma resposta à mudança climática global. Em todo o mundo, uma migração em direção aos polos está ampliando os limites latitudinais de manguezais devido a invernos mais quentes, e a diminuição de eventos de baixas temperaturas extremas, enquanto nas baixas planícies costeiras os manguezais estão migrando continente adentro devido ao aumento do nível do mar, como observado para o litoral nordeste brasileiro. Levando em consideração apenas as alterações climáticas globais, os manguezais irão exibir uma resposta positiva na maior parte de sua área de distribuição. Em algumas áreas, no entanto, como ilhas oceânicas baixas, como no oceano pacífico e no Caribe, e zonas costeiras restritas, como no litoral sudeste do Brasil, os manguezais mais provavelmente não sobreviverão.

Mangroves function as a natural coastline protection for erosion and inundation, providing important environmental services. Due to their geographical distribution at the continent-ocean interface, the mangrove habitat may suffer heavy impacts from global climate change, maximized by local human activities occurring in a given coastal region. This review analyzed the literature published over the last 25 years, on the documented response of mangroves to environmental change caused by global climate change, taking into consideration 104 case studies and predictive modeling, worldwide. Most studies appeared after the year 2000, as a response to the 1997 IPCC report. Although many reports showed that the world's mangrove area is decreasing due to direct anthropogenic pressure, several others, however, showed that in a variety of habitats mangroves are expanding as a response to global climate change. Worldwide, pole ward migration is extending the latitudinal limits of mangroves due to warmer winters and decreasing the frequency of extreme low temperatures, whereas in low-lying coastal plains, mangroves are migrating landward due to sea level rise, as demonstrated for the NE Brazilian coast. Taking into consideration climate change alone, mangroves in most areas will display a positive response. In some areas however, such as low-lying oceanic islands, such as in the Pacific and the Caribbean, and constrained coastlines, such as the SE Brazilian coast, mangroves will most probably not survive.

https://doi.org/10.1590/0001-3765201520150055 14696 downloads

12.

Evaluating sedimentation rates in the estuary and shelf region of the Paraíba do Sul River, Southeastern Brazil
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Wanderley, Cristiana V. A.

; Godoy, José Marcus

; Godoy, Maria Luiza D. P.

; Rezende, Carlos Eduardo

; Lacerda, Luiz D.

; Moreira, Isabel

; Carvalho, Zenildo L.

Journal of the Brazilian Chemical Society

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Jan 2014, Volume 25 Nº 1 Páginas 50 - 64

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Este estudo é uma avaliação das taxas de sedimentação na região do delta do Rio Paraíba do Sul e sua correlação com a forte erosão que ocorre em Atafona, Rio de Janeiro. Os resultados obtidos são baseados 14 testemunhos de sedimentos, com um total de aproximadamente 540 amostras, coletados em janeiro de 2010 e fevereiro de 2011. Os inventários de 210Pb nos pontos de amostragem ao sul da desembocadura do Rio Paraíba do Sul foram maiores do que aqueles observados para os pontos de coleta na região norte e central, o que sugere que os sedimentos são transportados ao longo da costa com as correntes nesta direção. Os resultados da datação 210Pb foram validados com base na variação de concentração elementar ao longo de dois dos testemunhos. Concentrações de Cd e Zn aumentaram significativamente em 1982 e atingindo valores máximos (0,5 mg kg-1 e 139 mg kg-1, respectivamente) em 1984. Estes máximos correspondem ao acidente da indústria Cia Paraibuna de Metais, que ocorreu em 1982.

This study aims to evaluate sedimentation rates in the Paraíba do Sul estuary and its shelf regions. These sedimentation rates were correlated with strong erosion occurring in Atafona, Rio de Janeiro. The results were based on four transects, from which 14 sediment cores with approximately 540 sediment samples were collected in January 2010 and February 2011. At sampling points south of the Paraíba do Sul River (PSR) mouth, 210Pb inventories were higher than those at the northern and central sampling locations, suggesting that sediment is transported southward by the alongshore current. The 210Pb dating results were validated based on the elemental concentration variation throughout two of the sediment cores. Heavy metal concentrations, such as Cd and Zn, increased significantly in 1982 and reached maximum values (0.5 mg kg-1 and 139 mg kg-1, respectively) in 1984. These maxima correspond to the Cia Paraibuna de Metais industry accident, which occurred in 1982.

https://doi.org/10.5935/0103-5053.20130268 2096 downloads

13.

Pluriannual watershed discharges of hg into a tropical semi-arid estuary of the Jaguaribe river, NE Brazil
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Lacerda, Luiz D.

; Dias, Francisco J. S.

; Marins, Rozane V.

; Soares, Talita M.

; Godoy, José Marcos O.

; Godoy, Maria Luiza D. P.

Journal of the Brazilian Chemical Society

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Nov 2013, Volume 24 Nº 11 Páginas 1719 - 1731

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Fluxos de Hg foram determinados entre 2005 e 2009 nas estações seca e chuvosa no estuário do Rio Jaguaribe, que desagua no Oceano Atlântico Equatorial, NE do Brasil. Na estação chuvosa a massa d'água no estuário apresenta um curto tempo de residência no estuário (0,8 dias), quatro vezes menor que na seca (3,1 dias). As concentrações e fluxos de Hg dissolvido (< 0,7 µm) e particulado foram maiores na interface rio/estuário que na estuário/mar, acumulando Hg particulado na região estuarina. A exportação de Hg particulado (1,8 a 12,6 mg s-1) ao oceano ocorreu sob chuva extrema, enquanto a exportação de Hg dissolvido foi quase zero na estação chuvosa e de até 0,45 mg s-1 na seca. Como a lixiviação continental no semiárido é afetada por mudanças climáticas globais e dos usos da terra, um aumento da acumulação de Hg particulado nos estuários e uma maior exportação de Hg dissolvido para o oceano é esperada.

Mercury fluxes were measured during the dry and rainy seasons (2005 to 2009) at the Jaguaribe River estuary, which discharges into the Equatorial Atlantic Ocean in NE Brazil. During rainy periods, the water masses exhibited a short residence time within the estuary (0.8 days). During dry periods, seawater choked the fluvial discharge, resulting in longer residence times (3.1 days). Dissolved (< 0.7 µm) and particulate Hg concentrations and fluxes were greater from the river to the estuary than from the estuary to the sea, producing accumulated particulate Hg in the estuary. Particulate Hg export (1.8 to 12.6 mg s-1) to the ocean occurred during extremely rainy periods, while dissolved Hg export was practically nonexistent during rainy periods and increased up to 0.45 mg s-1 during dry periods. Because continental runoff in semi-arid regions is affected by land use and global climate changes, the increasing accumulation of particulate Hg in the estuaries and increasing export of dissolved Hg to the ocean are expected.

https://doi.org/10.5935/0103-5053.20130216 1419 downloads

14.

Contrast sensitivity of pattern transient VEP components: contribution from M and P pathways
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Souza, Givago S.

; Gomes, Bruno D.

; Lacerda, Eliza Maria C.B.

; Saito, Cézar A.

; Silva Filho, Manoel da

; Silveira, Luiz Carlos L.

Psychology & Neuroscience

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2013, Volume 6 Nº 2 Páginas 191 - 198

Resumo: En | Texto: En | PDF: En

The purpose of this study was to compare contrast sensitivity estimated from transient visual evoked potentials (VEPs) elicited by achromatic pattern-reversal and pattern-onset/offset modes. The stimuli were 2-cpd, achromatic horizontal gratings presented either as a 1 Hz pattern reversal or a 300 ms onset/700 ms offset stimulus. Contrast thresholds were estimated by linear regression to amplitudes of VEP components vs. the logarithm of the stimulus contrasts, and these regressions were extrapolated to the zero amplitude level. Contrast sensitivity was defined as the inverse of contrast threshold. For pattern reversal, the relation between the P100 amplitude and log of the stimulus contrast was best described by two separate linear regressions. For the N135 component, a single straight line was sufficient. In the case of pattern onset/offset for both the C1 and C2 components, single straight lines described their amplitude vs. log contrast relations in the medium-to-low contrast range. Some saturation was observed for C2 components. The contrast sensitivity estimated from the low-contrast limb of the P100, from the N135, and from the C2 were all similar but higher than those obtained from the high-contrast limb of the P100 and C1 data, which were also similar to each other. With 2 cpd stimuli, a mechanism possibly driven by the M pathway appeared to contribute to the P100 component at medium-to-low contrasts and to the N135 and C2 components at all contrast levels, whereas another mechanism, possibly driven by the P and M pathways, appeared to contribute to the P100 component at high contrast and C1 component at all contrast levels.

https://doi.org/10.3922/j.psns.2013.2.07 2167 downloads

15.

Mercury in the sea turtle Chelonia mydas (Linnaeus, 1958) from Ceará coast, NE Brazil
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Bezerra, Moisés F.

; Lacerda, Luiz D.

; Costa, Breno G.B.

; Lima, Eduardo H.S.M.

Anais da Academia Brasileira de Ciências

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Mar 2012, Volume 84 Nº 1 Páginas 123 - 128

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

As concentrações de Hg em fragmentos de carapaça de Chelonia mydas no litoral do Ceará, nordeste do Brasil, são reportadas. Concentrações variaram de <0,34 a 856,6 ng.g -1 em peso seco, e foram maiores (média de 154,8 ng.g -1 em peso seco) em indivíduos juvenis (n = 22), enquanto que as menores concentrações (média de 2,5 ng.g -1 em peso seco) foram observadas em indivíduos adultos/sub-adultos (n = 3). Houve uma correlação negativa significativa entre tamanho do animal e concentração de Hg provavelmente devido a diferença de dieta entre juvenis e sub-adultos/adultos. Fragmentos de carapaça, que constituem substratos não-invasivos e não letais, podem ser importantes para fins de monitoramento ambiental dessas espécies ameaçadas de extinção.

Mercury concentrations in carapace fragments of the green turtle Chelonia mydas from the Ceará coast in NE Brazil are reported. Concentrations varied from <0.34 to 856.6 ng.g -1 d.w., and were highest (average of 154.8 ng.g -1 d.w.) in juveniles (n = 22), whereas lowest concentrations (average of 2.5 ng.g -1 d.w.) were observed in adult/sub-adult animals (n = 3). There was a significant negative correlation between animal size and Hg concentration probably due to different diets between juveniles and sub-adults/adults. Carapace fragments, which are non-invasive, non-lethal substrates, may be of importance for monitoring purposes of these generally endangered species.

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