|
|
|
| Registros recuperados: 78 | |
|
| |
|
|
| Fontanier, Christophe; Dissard, D.; Ruffine, Livio; Mamo, B.; Ponzevera, Emmanuel; Pelleter, Ewan; Baudin, F.; Roubi, Angelique; Cheron, Sandrine; Boissier, Audrey; Gayet, Nicolas; Bermell-fleury, S.; Pitel, M.; Guyader, Vivien; Lesongeur, Francoise; Savignac, F.. |
| In this preliminary study, we investigate living (stained) foraminifera from the Sea of Marmara. We focus on the faunal composition and geochemical signatures (trace elements, carbon and oxygen stable isotopes) in foraminiferal tests at two deep-sea sites (329 and ~1240 m depth respectively). Documented by ROV observations and sampling, both study areas are heterogeneous (including bacterial mats and carbonate concretions), proximal to cold seeps and consist of dysoxic bottom water (O2<20 µmol/L). The prevailing dysoxia at both study areas restricts foraminiferal diversity to very low values (S<9, H’<0.97). Stress-tolerant species Bolivina vadescens and Globobulimina affinis dominate living faunas at both sites. The highest foraminiferal standing... |
| Tipo: Text |
Palavras-chave: Living (stained) benthic foraminifera; Sea of Marmara; Extreme ecosystems; Trace elements; Stable isotopes. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00416/52774/53646.pdf |
| |
|
|
| Cabrera, I.; Arencibia, G.; Alonso, J. A.; Figueredo, M.; Díaz, N.; Águila, A.. |
| Los problemas de contaminación por elementos trazas y mayores en los sedimentos superficiales de la bahía de Guantánamo constituyen una preocupación de las autoridades locales de la cuenca Guantánamo – Guaso; por tal razón nos dimos a la tarea de estudiar la calidad de las aguas de la ensenada Cerro Guayabo, perteneciente a dicha cuenca, siendo esta una de las más impactadas por el desarrollo salinero en los últimos años. El estudio incluyó una revisión de todos los trabajos de caracterización realizados por otras instituciones en años anteriores, que nos permitió establecer la necesidad de evaluar con profundidad los sedimentos de la zona, pues hasta la fecha el comportamiento de la calidad de las aguas no aportó contaminación significativa. Los... |
| Tipo: Preprint |
Palavras-chave: Trace elements; Trace elements; Http://aims.fao.org/aos/agrovoc/c_7834. |
| Ano: 2010 |
URL: http://hdl.handle.net/1834/3556 |
| |
|
| |
|
|
| Boechat,Cácio Luiz; Quadros,Patricia Dörr de; Giovanella,Patrícia; Brito,Ana Clecia Campos; Carlos,Filipe Selau; Sá,Enilson Luiz Saccol de; Camargo,Flávio Anastácio de Oliveira. |
| ABSTRACT There is a complex interaction between various components of the soil ecosystem, including microbial biomass and soil chemical contaminants such as heavy metals and radionuclides, which may greatly affect the efficiency of bioremediation techniques. The aim of this study was to investigate microbial capacity to change pH, changes in the metal soluble-exchangeable fraction, and effects of initial heavy metal contents on soil samples in microbial solubilization/immobilization capacity. The soil samples used in this study were collected at a known metal-contaminated site. Three highly metal-resistant bacteria were isolated from rhizosphere soil samples collected on weed species identified as Senecio brasiliensis, Senecio leptolobus, and Baccharis... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Trace elements; Bioremediation technology; Rhizosphere; Environmental contamination. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100514 |
| |
|
|
| Silva Filho,Luiz Aníbal; Ker,João Carlos; Fontes,Maurício Paulo Ferreira; Camêlo,Danilo de Lima; Corrêa,Marcelo Metri; Cavalcante,Luis Carlos Duarte; Guimarães,Luciano de Moura. |
| ABSTRACT Ferrimagnetic Fe-oxides are important soil components, which are present in most of the agricultural soils of Brazil. Distinction, origin, and assessment of the influence of these minerals on magnetism and geochemistry is a challenge for mineralogists. This study aimed to characterize mineralogically Fe-rich Rhodic Oxisols ( Latossolos Vermelhos ) originating from several mafic rocks in Brazil, and assess the implications on their magnetic and geochemical properties. We present results on magnetic measurements, chemical dissolutions, X-ray diffractometry, Rietveld refinement, Raman, and Mössbauer spectroscopies of Fe-rich Rhodic Oxisols originating from several mafic rocks. They show that magnetite is inherited from the parent material, and its... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Magnetite; Maghemite; Trace elements; Mafic rocks; Raman spectroscopy. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832019000100411 |
| |
|
|
| Ferreira,Edilene Pereira; Coelho,Ricardo Marques; Valladares,Gustavo Souza; Dias,Laura Milani da Silva; Assis,Ana Carolina Cunha de; Silva,Rafael Cipriano da; Azevedo,Antonio Carlos de; Abreu,Cleide Aparecida de. |
| ABSTRACT Lithological and geomorphological variations determine formation of soils with different mineralogical constitutions and can influence the distribution of potentially toxic elements (PTE). The aim of this study was to determine the contents of PTE and mineralogical assemblages along soil profiles of different classes and parent materials and to investigate the association among these factors in the São Francisco sedimentary basin in the northern part of the state of Minas Gerais (Brazil). Eight soil pedons of different classes that developed from different parent materials (limestone, siltstone, phyllite, alluvial-colluvial sediments, detrital cover, and rhythmite) were studied in two lithotoposequences. Soil morphological, particle-size, and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Parent material; Pedogenesis; Soil minerals; Trace elements. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100519 |
| |
|
| |
|
|
| Bayon, Germain; Birot, Dominique; Bollinger, Claire; Barrat, Jean Alix. |
| We report on an improved method for determining trace element abundances in seawater and other natural waters. The analytical procedure involves co-precipitation on iron hydroxides after addition of a Tm spike, and measurement by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS). The validity of the method was assessed through a series of co-precipitation experiments, using ultra-diluted solutions of a certified rock reference material (BIR-1). Results obtained for four natural water reference materials (NASS-5, CASS-4, SLEW-3, SLRS-4) are in agreement with published working values for rare earth elements, yttrium, vanadium and, when available, for hafnium, zirconium, thorium and scandium. A set of proposed values with uncertainties... |
| Tipo: Text |
Palavras-chave: Seawater; Reference material; ICP-MS; Trace elements; Rare earth elements; Eau de mer; Materiau de reference; ICP-MS; Elements traces; Terres Rares. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14189/18000.pdf |
| |
|
| |
|
|
| Chang, Alice S.; Pichevin, Laetitia; Pedersen, Thomas F.; Gray, Victoria; Ganeshram, Raja. |
| A high-resolution, 55 kyr long record of chalcophile and redox-sensitive trace element accumulation (Ag, Cd, Re, and Mo) from MD02-2515, western Guaymas Basin, is investigated in conjunction with patterns in stratigraphy and productivity. High opal concentrations (~59 wt. %), representing increased diatom production, coincide with laminated sediments and dilute the concentrations of organic carbon (Corg) and metals. A similarity between opal and normalized Corg, Ag, and Cd concentrations suggests delivery to the sediments by diatom export production, while patterns in normalized Re and Mo accumulation suggest a different emplacement mechanism. Although Mo enrichment in organic-rich, laminated sediments typically represents anoxic conditions at other... |
| Tipo: Text |
Palavras-chave: Productivity; Redox; Trace elements; Laminated sediments; Guaymas Basin; Northeast Pacific Ocean. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00294/40566/39461.pdf |
| |
|
|
| Gaspar Júnior, Pascoal José; Centro Universitário de Formiga - UNIFOR-MG; Tomizawa, Márcia Mayumi; Universidade Federal de Lavras; Schwan, Rosane Freitas; Universidade Federal de Lavras; Rinker, Danny Lee; University of Guelph; Dias, Eustáquio Souza; Universidade Federal de Lavras, Departamento de Biologia, Setor de Microbiologia.. |
| The nutritional requirements of A. brasiliensis in culture media were assessed by supplementing a basal medium (g L-1): (glucose, 10, KH2PO4, 1, MgSO4.7H2O, 0.5, [NH4]2SO4, 1, pH 5.5) with CaCl2, trace elements (FeSO4.7H2O; MnCl2.4H2O; ZnSO4.7H2O; CuSO4.5H2O), casein, yeast extract, peptone, B-vitamins or amino acids. Evaluations were based on the mycelial growth in solid or liquid culture (mm day-1 or mg day-1) and visual analysis of the colony. The addition of CaCl2 and trace elements was very important for the major mycelial growth of the fungi. The addition of casein and inositol to the medium did not have a significant effect on growth. The best growth result in solid medium was obtained with the basal medium plus the addition of yeast extract and... |
| Tipo: Crescimento micelial, exigências nutricionais |
Palavras-chave: 2.12.00.00-9 Mushroom; Trace elements; B-vitamins; Amino acids Microbiologia Mushroom; Trace elements; B-vitamins; Amino acids. |
| Ano: 2011 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/7010 |
| |
|
| |
|
|
| Barrat, Jean-alix; Ferrière, L.. |
| Main-group pallasites (MGPs) are meteorites mainly composed of Fe-Ni metal and olivines, the latter being considered as one of the largest sampling of extraterrestrial mantle material available for study on Earth. We analysed the rare earth element (REE) concentrations of olivines from six MGPs to understand better the processes of formation of their parent mantle. All the investigated samples display very low REE abundances, and enrichments in both light REEs and heavy REEs. We interpret the light REE enrichments as a fingerprint of terrestrial contamination. The least contaminated olivines have higher heavy REE enrichments than those inferred for olivines directly crystallised in a magma ocean. Such enrichments in heavy REEs are possible if the mantle of... |
| Tipo: Text |
Palavras-chave: Pallasite; Early solar system; Trace elements; Rare earth elements; Differentiation. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00686/79770/82569.pdf |
| |
|
|
| Ávila,Gonzalo; Gaete,Hernán; Sauvé,Sébastien; Neaman,Alexander. |
| The Aconcagua River basin (Central Chile) is one of the most important agricultural areas in the country. However, several copper (Cu) mining operations are located in the basin. The objective of the study was to determine Cu toxicity for the earthworm Eisenia fetida (Savigny 1826) in the agricultural soils of the basin. We determined the production of cocoons and juveniles of earthworms in the studied soils. The soils differed in the concentrations of organic matter (OM, range 2-6%), pH (range 7.3-8.3), texture (from loamy sand to clay loam), and total Cu concentrations (range 230-960 mg kg-1). Concentrations of Cu and OM in the soils were the variables that determined the earthworms biological response. In contrast, pH and texture did not affect this... |
| Tipo: Journal article |
Palavras-chave: Aconcagua River; Ecological risk assessment; Cu mining; Trace elements. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392009000200015 |
| |
|
| |
|
| |
|
|
| Carlotti, François; Tronczynski, Jacek; Tedetti, Marc; Pagano, Marc; Garnier, Cédric. |
| Recent research on the bioaccumulation of organic and trace element contaminants along trophic food webs suggests that plankton plays a central role as a 'biological pump' for pollutants. The MERITE-HIPPOCAMPE project (oceanographic cruise in April- May 2019) aims at studying the interactions between plankton and contaminants (metallic, organic plastics) at atmosphere/water/biota interfaces via a North-South trans-Mediterranean approach in contrasted areas (primary production, fishing zones, ecoregions, polluted bays). The target contaminants are on the lists of priority pollutants and substances of Regional Conventions (OSPAR) and EU directives (WFD, MSF). The expected results are to provide a better understanding of the transfer processes of contaminants... |
| Tipo: Text |
Palavras-chave: Trace elements; Pcb; Pah; Plankton; Mediterranean Sea. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00599/71132/69447.pdf |
| |
|
|
| Silva,Ygor Jacques Agra Bezerra da; Nascimento,Clístenes Williams Araújo do; Silva,Yuri Jacques Agra Bezerra da; Biondi,Caroline Miranda; Silva,Cinthia Maria Cordeiro Atanázio Cruz. |
| ABSTRACT: Studies regarding background concentrations of rare earth elements (REEs) are scarce and have mainly focused on a limited number of soil types from the northern hemisphere. The aim of this study was to determine REE concentrations in thirty-five benchmark soils of Brazil. Composite soil samples were taken from areas under native vegetation or with minimal anthropogenic influence. Concentrations of La, Ce, Pr, Nd, Sm, Eu, Gd, Yb, Lu, Dy, Er, Ho, Tb, Tm, Y, Sc, and Fe were determined by ICP-OES using a cyclonic spray chamber/nebulizer system after microwave acid digestion. Results were assessed by descriptive statistics, Pearson correlation, and principal component analysis (PCA). Regression analyses among Fe, organic carbon, and REEs were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lanthanides; Scandium; Yttrium; Metals; Trace elements. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100548 |
| |
|
| |
| Registros recuperados: 78 | |
|
|
|
