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| Registros recuperados: 51 | |
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| Prance,Ghillean T. |
| Neste trabalho são apresentados padrões de distribuição geográfica de espécies de Chrysobalanaceae, Caryocaraceae, Dichapetalaceae e Lecythidaceae. Seis padrões são discutidos: espécies amplamente distribuidas, polimórficas (ochlospecies) onde a variabilidade morfológica não conduzia a especiação; distribuição disjunta onde a diferenciação em espécie não ocorreu; especiação através de separação histórica tal como isolamento durante o Pleistoceno; generos com grupos de espécies muito relacionadas, que não podem ser subdivididos em subgeneros; utilizou-se diagramas de isolinhas de espécies para determinar o centro de diversidade dos gêneros; e, espécies de savanas que inicialmente tinham distribuição contínua e que atualmente são isoladas. A análise de... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Distribution patterns; Speciation; Disjunct distribution; Refugia. |
| Ano: 1987 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33061987000300003 |
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| CAMPOS,RAQUEL A.; PATRÍCIO,PAMELA R.; VARGAS,SILVIA JULIANA R.; SILVA,LUIS HENRIQUE M. DA; HESPANHOL,MARIA C.. |
| Abstract Fe(II) and Fe(III) have distinct chemical and biological functions. Consequently, it is more important to determine the fraction of both oxidation state that knowing the total iron concentration in a sample. However, green methods for iron speciation are still limited. This work uses aqueous two-phase system, a safe alternative to liquid–liquid extraction, to perform the chemical speciation of iron. This method is based on the reaction of Fe(II) with 1,10-phenanthroline extractant, forming a complex of Fe(II)-phenanthroline that concentrates in the top phase of the system. The Fe(III) specie concentrated in the bottom phase of the system. Iron speciation was affected by the electrolyte nature, macromolecule type, quantity of phenanthroline added,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aqueous two-phase system; Flame atomic absorption spectrometry; Iron; Speciation; Green chemistry. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000501929 |
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| Vanzolini,Paulo Emilio. |
| Gymnodactylus amarali Barbour, 1925, was previously considered to be a subspecies of G. geckoides, with a wide distribution in the Brasilian cerrados. Examination of a specimen from Alto Parnaíba, Maranhão, near the type locality (Engenheiro Dodt, Piauí), indicates that it is a proper species, apparently limited to the upper Parnaíba basin. The form previously identified as G. geckoides amarali is described as a new species, G. carvalhoi, type locality Ipueiras, State of Tocantins, thus diagnosed: color pattern plain or, more often, with moderately contrasted ocelli; dorsal tubercles in 13 - 16 poorly organized longitudinal rows (mode 14, 72%); 31 - 49 tubercles in a paramedian row; 17 - 22 transverse rows of ventral scales; 13 - 18 infradigital lamellae... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Speciation; Lizards/systematics. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652005000400003 |
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| HEYER,W. RONALD; REID,YANA R.. |
| The frog Leptodactylus fuscus is found throughout much of South America in open and disturbed habitats. Previous study of genetic differentiation in L. fuscus demonstrated that there was lack of genetic exchange among population units consistent with multiple species, rather than a single species. We examine advertisement vocalizations of L. fuscus to determine whether call variation coincides with genetic differentiation. Calls were analyzed for 32 individual frogs from 25 localities throughout the distributional range of L. fuscus. Although there is variation in calls among geographic samples, call variation is not concordant with genetic variation or geographic distance and the call variation observed is less than that typically found among other... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Advertisement calls; Leptodactylus fuscus; Speciation. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652003000100006 |
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| Santos,Lisia Maria Gobbo; Jacob,Silvana do Couto. |
| The Graphite furnace atomic absorption spectrometry (GF AAS) was the technique chosen by the inorganic contamination laboratory (INCQ/ FIOCRUZ) to be validated and applied in routine analysis for arsenic detection and quantification. The selectivity, linearity, sensibility, detection, and quantification limits besides accuracy and precision parameters were studied and optimized under Stabilized Temperature Platform Furnace (STPF) conditions. The limit of detection obtained was 0.13 µg.L-1 and the limit of quantification was 1.04 µg.L-1, with an average precision, for total arsenic, less than 15% and an accuracy of 96%. To quantify the chemical species As(III) and As(V), an ion-exchange resin (Dowex 1X8, Cl- form) was used and the physical-chemical... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Arsenic; Water; Graphite furnace atomic absorption spectrometry; Speciation; Validation. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612009000100019 |
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| Allen, Craig R; U.S. Geological Survey, Nebraska Cooperative Fish and Wildlife Research Unit; allencr@unl.edu; Holling, C. S.; Department of Zoology, University of Florida; holling@zoo.ufl.edu. |
| We present a conceptual framework that explores some of the forces creating innovation and novelty in complex systems. Understanding the sources of variability and novelty may help us better understand complex systems. Understanding complex phenomena such as invasions, migration, and nomadism may provide insight into the structure of ecosystems and other complex systems, and aid our attempts to cope with and mitigate these phenomena, in the case of invasions, and better understand and or predict them. Our model is broadly applicable to ecological theory, including community ecology, resilience, restoration, and policy. Characterizing the link between landscape change and the composition of species communities may help policymakers in their decision-making... |
| Tipo: Peer-Reviewed Insight |
Palavras-chave: Adaptation; Cross-scale; Extinction; Innovation; Invasion; Speciation. |
| Ano: 2010 |
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| Zefa,Edison. |
| Three isolated populations of the cricket Endecous itatibensis Rehn, 1918 had been analyzed to test the hypothesis of divergence in the calling song estridulation and to discuss its implications in the speciation process. The song registers were obtained from specimens in Corumbataí, Piraciacaba and Itatiba cities, state of São Paulo, Brazil. In the three analyzed populations, calling songs are composed by pairs of notes. Specimens from Corumbataí emit composed phrases with 3 to 18 pairs of notes, while those of Piracicaba and Itatiba have 1 to 3 pairs of notes. Inter- and intrapopulational variability in the frequencies of acoustic signals were detected. While recording the calling songs, other stridulations were registered, possibly from species of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cricket; Bioacoustics; Acoustic competition; Stridulation; Speciation. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212006000100002 |
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| Parmentier, E; Lagardere, Jean-paul; Vandewalle, P; Fine, M. |
| Because of pelagic-larval dispersal, coral-reef fishes are distributed widely with minimal genetic differentiation between populations. Amphiprion akallopisos, a clownfish that uses sound production to defend its anemone territory, has a wide but disjunct distribution in the Indian Ocean. We compared sounds produced by these fishes from populations in Madagascar and Indonesia, a distance of 6500 km. Differentiation of agonistic calls into distinct types indicates a complexity not previously recorded in fishes' acoustic communication. Moreover, various acoustic parameters, including peak frequency, pulse duration, number of peaks per pulse, differed between the two populations. The geographic comparison is the first to demonstrate 'dialects' in a marine... |
| Tipo: Text |
Palavras-chave: Speciation; Dialect; Geographic variation; Pomacentridae; Sound production. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-3630.pdf |
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| Almaca, Carlos. |
| Coming from Oriental Asia and Siberia, the Cyprinidae reached the Iberic Peninsula probably at the end of the Oligocene. Their populations bore speciation processes which led to the formation of a fauna rich in endemic species and subspecies. Populations of two of the genera Barbus and Pseudophoxinus reached Northwestern African forming there several endemic species. Concerning the speciation forms, it is probable that the allopatric form, whether by foundation effect or by subdivision, played an important part. Pyrenees and Mediterranean Sea settled probably efficient barriers for the Iberic Cyprinidae isolation. The present geographical repartition of Cyprinidae in Iberic Peninsula suggests that altitude lines and glaciations which reached the north of... |
| Tipo: Text |
Palavras-chave: Portugal; Spain; Cyprinidae; Biogeography; Speciation. |
| Ano: 1976 |
URL: http://archimer.ifremer.fr/doc/1976/publication-1997.pdf |
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| Briant, Nicolas; Chouvelon, Tiphaine; Martinez, Laura; Brach-papa, Christophe; Chiffoleau, Jean-francois; Savoye, N.; Sonke, J.; Knoery, Joel. |
| Marine mercury (Hg) concentrations have been monitored in the French coastline for the last half a century using bivalves. The analyses presented in this study concerned 192 samples of bivalves (mussels: Mytilus edulis and Mytilus galloprovincialis and oysters: Crassostrea gigas and Isognomon alatus) from 77 sampling stations along the French coast and in the French Antilles sea. The goals of this study were to assess MeHg levels in various common bivalves from French coastline, and to identify possible geographic, taxonomic or temporal variations of concentrations. We show that the evolution of methylmercury (MeHg) concentrations covary with total mercury (HgT) concentrations. Moreover, in most of the study sites, HgT concentrations have not decreased... |
| Tipo: Text |
Palavras-chave: Mercury; Methylmercury; France; Bivalves; Speciation. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00353/46465/46398.pdf |
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| Muresan Paslaru, Bogdan; Cossa, Daniel; Richard, S; Burban, B. |
| The distribution and speciation of mercury (Hg) in air, rain, and surface waters from the artificial tropical lake of Petit-Saut in French Guiana were investigated during the 2003/04 period. In the air, total gaseous mercury (TGM) at the dam station averaged 12 +/- 2 pmol m(-3) of which > 98% was gaseous elemental mercury (GEM). GEM distribution depicted a day-night cycling with high concentrations (up to 15 pmol m(-3)) at dawn and low concentrations (down to 5 pmol m(-3)) at nightfall. Reactive gaseous mercury (RGM) represented < 1% of the GEM with a mean concentration of 4 3 fmol m(-3). Diel RGM variations were negatively related to GEM. In the rain, the sum of all Hg species in the unfiltered (HgTUNF) averaged 16 +/- 112 pmol L-1. Temporal... |
| Tipo: Text |
Palavras-chave: Fluxes; Speciation; Mercury; Artificial reservoir; Atmosphere. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3329.pdf |
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| Dange, Catherine. |
| Most of trace elements have a non conservative behavior in estuarine environments. It is the case of cadmium, cobalt and caesium for which the fate in estuarine and coastal zones is largely controlled by their distribution between water and suspended particles, which generally have high residence times or can be definitely deposited in these areas. Metallic contaminants and radionuclides can be present under various species : dissolved (mineral and organic complexes), colloidal and particulate forms (adsorbed, precipitated) or integrated by various mechanisms in the organisms. Such distributions are the result of processes (physical, chemical, biological) which are controlled by many factors (ionic strengh, pH, Eh, major cations concentration, nature and... |
| Tipo: Text |
Palavras-chave: Modeling; French estuaries; Caesium; Cobalt; Cadmium; Radionuclides; Trace metals; Speciation; Modélisation; Estuaires français; Cesium; Cobalt; Cadmium; Radionucléides; Métal trace; Speciation. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/these-183.pdf |
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| Haverkamp, Thomas H. A.; Geslin, Claire; Lossouarn, Julien; Podosokorskaya, Olga A.; Kublanov, Ilya; Nesbo, Camilla L.. |
| Thermosipho species inhabit thermal environments such as marine hydrothermal vents, petroleum reservoirs, and terrestrial hot springs. A 16S rRNA phylogeny of available Thermosipho spp. sequences suggested habitat specialists adapted to living in hydrothermal vents only, and habitat generalists inhabiting oil reservoirs, hydrothermal vents, and hotsprings. Comparative genomics of 15 Thermosipho genomes separated them into three distinct species with different habitat distributions: The widely distributed T. africanus and the more specialized, T. melanesiensis and T. affectus. Moreover, the species can be differentiated on the basis of genome size (GS), genome content, and immune system composition. For instance, the T. africanus genomes are largest and... |
| Tipo: Text |
Palavras-chave: Extremophiles; Hydrothermal vents; Mobile DNA; Speciation; Thermotogae; Vitamine B-12. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00478/58934/61503.pdf |
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| Thouvenin, Benedicte; Gonzalez, Jean-louis. |
| Within the framework of the "Contaminants cycle and modeling" project of the BE department ("Biogeochemistry and Ecotoxicology") in Ifremer, two chemical contaminant modeling software were developed between 1998 and 2011 (Gonzalez JL, 2017): the MORGAN model (Model behavior of ORGANic contaminants in an aquatic environment) and the MOCO model (Surface Complexation MOdel for metallic COntaminants). These two models had been brought together in a single "zero-dimensional" software (known as MOMO), which made it possible to simulate the various processes affecting the behavior of chemical contaminants in a homogeneous mass of water (biodegradation, adsorption/desorption, photolysis, hydrolysis, volatilization, surface complexation, cation exchange,... |
| Tipo: Text |
Palavras-chave: Modelisation; Biogeochimie; Contaminants métalliques et organiques; Spéciation; Modeling; Biochemical; Trace metals - organic contaminants; Speciation. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00686/79771/82993.pdf |
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| Auvinet, Juliette; Graça, Paula; Dettai, Agnès; Amores, Angel; Postlethwait, John H.; Detrich, H. William; Ozouf-costaz, Catherine; Coriton, Olivier; Higuet, Dominique. |
| Background Chromosomal rearrangements are thought to be an important driving force underlying lineage diversification, but their link to speciation continues to be debated. Antarctic teleost fish of the family Nototheniidae (Notothenioidei) diversified in a changing environmental context, which led to ecological, morphological, and genetic differentiation among populations. In addition, extensive chromosomal repatterning accompanied species divergence in several clades. The most striking karyotypic changes involved the recent species radiation (about 10 My) of the genus Trematomus, with chromosomal pair numbers ranging between 29 and 12. These dramatic reductions in chromosome number resulted mostly from large-scale chromosome fusions. Multiple centric... |
| Tipo: Text |
Palavras-chave: BAC-FISH; Chromosomal painting; Chromosomal rearrangements; Chromosomal structural units; Chromosomal synteny; Nototheniidae; Speciation. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00615/72731/71831.pdf |
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| Gonzalez, Jean-louis; Thouvenin, Benedicte; Dange, Catherine; Chiffoleau, Jean-francois; Boutier, Bernard. |
| The role of particles in the fate and speciation of trace metals in macrotidal estuaries was studied using a surface complexation model (MOCO). Cadmium was selected as the target metal contaminant due to its reactivity in estuaries: cadmium behavior is mainly controlled by heterogeneous processes (sorption/desorption) related to salinity and suspended matter gradients. Various scenarios of suspended matter distribution according to salinity were simulated. The impact of surface properties (specific surface area, density of surface sites, acido-basic properties, and complexation constant) was evaluated using data collected on particles from the Gironde, Loire, and Seine estuaries. Our results show that particle surface properties, evaluated on the basis... |
| Tipo: Text |
Palavras-chave: Turbidity maximum; Speciation; Sorption; Particles; Modeling; Macrotidal estuaries; Cadmium. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2005.pdf |
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| Registros recuperados: 51 | |
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