Consulta: subjectFacets:"Speciation"
Registros recuperados: 50
Data/hora: 09/06/2024 06:29:49

Novelty, Adaptive Capacity, and Resilience
Provedor de dados: 7
Autores: 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

Comparison of calling songs in three allopatric populations of Endecous itatibensis (Orthoptera, Phalangopsinae)
Provedor de dados: 76
Autores: 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

Thermosipho spp. Immune System Differences Affect Variation in Genome Size and Geographical Distributions
Provedor de dados: 5
Autores: 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

Genetic diversity, paraphyly and incomplete lineage sorting of mtDNA, ITS2 and microsatellite flanking region in closely related Heliopora species (Octocorallia)
Provedor de dados: 5
Autores: Yasuda, Nina; Taquet, Coralie; Nagai, Satoshi; Fortes, Miguel; Fan, Tung-yung; Harii, Saki; Yoshida, Terutoyo; Sito, Yuta; Nadaoka, Kazuo.
Examining genetic diversity and lineage sorting of different genes in closely related species provide useful information for phylogenetic analyses and ultimately for understanding the origins of biodiversity. In this study, we examined inter- and intraspecific genetic variation in internal transcribed spacer 2 (ITS2), partial mitochondrial gene (mtMutS), and nuclear microsatellite flanking region in two closely related octocoral species (Heliopora coerulea, HC-A and HC-B). These species were recently identified in a population genetic study using microsatellite markers. The two species have different reproductive timing, which ecologically promotes lineage sorting. In this study, we examined whether species boundaries could be detected by the commonly used...
Tipo: Text
Palavras-chave: ITS2; Concerted evolution; MtMutS; Secondary structure; Species identification; Speciation.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00667/77932/80144.pdf

Cycle du mercure en estuaire, baie de Seine et pays de Caux
Provedor de dados: 5
Autores: Laurier, Fabien.
The Seine estuary and its adjacent region Pays de Caux are two significant sources of mercury for coastal marine environments. It is carried through fluvial means for the Seine bay and through karstic fresh water emergences for Pays de Caux's coastal area.  Mercury cycle in the Seine estuary and bay is affected by additional anthropical activities. The estuary's maximal turbidity area acts like a trap and a chemical reactor for fluvial mercury. Within this area, we can confirm: (i) the non conservative behaviour of dissolved mercury; (ii) mercury enrichment of particles when comparing the Seine's and marine environment and we suggest mercury particle redistribution from the organic fraction to the oxyhydroxydes fraction. A large fraction of mercury is...
Tipo: Text
Palavras-chave: Bay of Seine; Pays de Caux; Estuary; Coastal zone; Speciation; Bioavailability; Mercury; Pays de Caux; Seine; Estuaire; Emergence; Zone côtière; Spéciation; Biodisponibilité; Mercure.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/these-1842.pdf

Dispersion larvaire et cycle de vie dans les environnements hydrothermaux profonds : le cas de Rimicaris exoculata et d'espèces proches
Provedor de dados: 5
Autores: Hernandez Avila, Ivan.
Deep-water hydrothermal vent host high-biomass communities based on chemoautotrophy supported by the metabolic activity of free-living and symbiotic bacteria associated to invertebrates, especially megafauna. Knowledge on the mechanisms of dispersal and the life cycle of vent species is essential to our understanding of the vent communities in terms of distribution, structure and temporal variation. In this study, I present some advances regarding the dispersal and life cycle of a dominant species of the Mid-Atlantic Ridge (MAR) vent ecosystems, the alvinocaridid shrimp Rimicaris exoculata, and other related species. The methodological approaches applied include morphological descriptions of larvae, analysis of population biology and reproduction, and...
Tipo: Text
Palavras-chave: Sources hydrothermales profondes; Cycle de vie; Structure de population; Symbiose; Crevettes Alvinocarididae; Deep-water hydrothermal vents; Life cycle; Population structure; Reproduction; Dispersal; Symbiosis; Speciation.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00498/60927/64321.pdf

Spéciation des contaminants métalliques en milieu estuarien : Intérêt de la modélisation et application au cadmium
Provedor de dados: 5
Autores: Gonzalez, Jean-louis; Dange, Catherine; Thouvenin, Benedicte.
In estuarine environment, cadmium has a nonconservative behavior. It 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. This distribution is the result of processes (physical, chemical and biological) which are controlled by many factors (salinity, pH, Eh, nature and concentration of suspended matter, primary production). Geochemical modeling is a very useful approach to understand the dynamics of this type of contaminant, especially in the complex systems which are the estuaries. A speciation model was used to simulate the measurements taken (dissolved and particulate Cd) during various cruises carried out in the...
Tipo: Text
Palavras-chave: Cadmium; Estuary; Speciation; Modeling; Surface complexation; Cadmium; Estuaire; Spéciation; Modélisation; Complexation de surface.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/00480/59120/61749.pdf

The impact of groundwater discharges on mercury partitioning, speciation and bioavailability to mussels in a coastal zone (Reprinted from Marine Chemistry, vol 104, pg 143-155, 2007)
Provedor de dados: 5
Autores: Laurier, Fabien; Cossa, Daniel; Beucher, Charlotte; Breviere, Emily.
The Mussel Watch program conducted along the French coasts for the last 20 years indicates that the highest mercury concentrations in the soft tissue of the blue mussel (Mytilus edulis) occur in animals from the eastern part of Seine Bay on the south coast of the English Channel, the "Pays de Caux". This region is characterized by the presence of intertidal and submarine groundwater discharges, and no particular mercury effluent has been reported in its vicinity. Two groundwater emergence systems in the karstic coastal zone of the Pays de Caux (Etretat and Yport with slow and fast water percolation pathways respectively) were seasonally sampled to study mercury distribution, partitioning and speciation in water. Samples were also collected in the...
Tipo: Text
Palavras-chave: Mussel; Estuaries; Groundwater seepage; Bioavailability; Speciation; Mercury.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-4704.pdf

Mercury sources and transformations in a man-perturbed tidal estuary; the Sinnamary Estuary, French Guiana
Provedor de dados: 5
Autores: Muresan, B; Cossa, Daniel; Coquery, M; Richard, S.
The distribution, partition and speciation of mercury (Hg) were studied along the redox gradient of an anthropogenically perturbed tropical estuary, the Sinnamary Estuary in French Guiana. This system is a partially mixed estuary characterized by an anoxic freshwater end-member, while the marine end member consists of the Amazon Plume. The set up of an artificial oxygenation system in the anoxic freshwater end-member generates sharp gradients of major chemical species (iron, sulfides, etc.) coupled with intense organic matter (OM) turnover. The coexistence of oxygenated waters and dissolved sulfides in an organic rich environment depicts the Upper Sinnamary Estuary (USE: part of Sinnamary Estuary under the tidal influence but upstream of the salt...
Tipo: Text
Palavras-chave: Partitioning; Speciation; Redox; Mercury; Reservoir; Estuary.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4223.pdf

Spatial and temporal distribution of mercury and methylmercury in bivalves from the French coastline
Provedor de dados: 5
Autores: 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

Mercury speciation and exchanges at the air-water interface of a tropical artificial reservoir, French Guiana
Provedor de dados: 5
Autores: 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 &gt; 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 &lt; 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

Observations ultrastructurales sur Ameson nelsoni (Sprague, 1950) microsporidie parasite de la crevette Parapenaeus longirostris Lucas. Consequences taxonomiques.
Provedor de dados: 5
Autores: Loubes, Claude; Maurand, Jean; Comps, Michel; Campillo, Albert.
The sporogony of A. nelsoni is of the apansporoblastic type. Diplocaryons always occur during merogony, never occur during sporogony. Sporoblasts are produced by fission of a multinucleate and elongated plasmodium. Spore morphogenesis begins before the end of the end of the sporoblasts individualization. The polaroplast has a very dense outer area. The genus Ameson is very much like genus Perezia and both are badly classified respectively in the families Nosematidae and Unikaryonidae. The creation of the new family Pereziidae is proposed for both genera.
Tipo: Text
Palavras-chave: MED; Ameson nelsoni; Speciation; Taxonomy.
Ano: 1977
URL: http://archimer.ifremer.fr/doc/1977/publication-1969.pdf

Geographical variation in sound production in the anemonefish Amphiprion akallopisos
Provedor de dados: 5
Autores: 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

Etude de l’influence de la concentration et de la spéciation de trace de cadmium sur la croissance et la physiologie d’une espèce phytoplanctonique
Provedor de dados: 5
Autores: Millour, Mathieu.
The aim of this study is to establish a continuous culture of a diatom (Phaeodactylum tricornutum) in a photobioreactor. As soon as the culture is stable and regulated, increasing cadmium amounts are added to the culture to induce a metal stress in order to study its influence on the production of Volatile Reduced Sulphur Compounds (H2S, OCS, MeSH, DMS and DMDS), and on the production of ligands. In this report, the methods used to assess the continuous culture and to analyse RVSC and other ligands production are described. J This study allowed us to assess cadmium impact on the VRSC and on the production of ligands.
Tipo: Text
Palavras-chave: Photobioréacteur; Phaeodactylum tricornutum; Cadmium; Composés Soufrés Réduits et Volatils; Culture en continu; Spéciation; Complexants.; Photobioreactor; Phaeodactylum tricornutum; Cadmium; Volatile Reduced Sulphur j Compound; Continuous culture; Speciation; Ligands.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00306/41765/40978.pdf

Multiple independent chromosomal fusions accompanied the radiation of the Antarctic teleost genus Trematomus (Notothenioidei:Nototheniidae)
Provedor de dados: 5
Autores: 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

Etude du comportement des éléments traces en milieu estuarien : approche expérimentale et modélisation : Application à l'étude de la spéciation de Cd, Co et Cs dans les estuaires majeurs français (Seine, Loire, Gironde, Rhône)
Provedor de dados: 5
Autores: 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

The impact of groundwater discharges on mercury partitioning, speciation and bioavailability to mussels in a coastal zone
Provedor de dados: 5
Autores: Laurier, Fabien; Cossa, Daniel; Beucher, Charlotte; Breviere, Emily.
The Mussel Watch program conducted along the French coasts for the last 20 years indicates that the highest mercury concentrations in the soft tissue of the blue mussel (Mytilus edulis) occur in animals from the eastern part of Seine Bay on the south coast of the English Channel, the "Pays de Caux". This region is characterized by the presence of intertidal and submarine groundwater discharges, and no particular mercury effluent has been reported in its vicinity. Two groundwater emergence systems in the karstic coastal zone of the Pays de Caux (Etretat and Yport with slow and fast water percolation pathways respectively) were seasonally sampled to study mercury distribution, partitioning and speciation in water. Samples were also collected in the...
Tipo: Text
Palavras-chave: Mussel; Estuaries; Groundwater seepage; Bioavailability; Speciation; Mercury.
Ano: 2007
URL: https://archimer.ifremer.fr/doc/2007/publication-3113.pdf

Total and organic Hg concentrations in cephalopods from the North Eastern Atlantic waters: Influence of geographical origin and feeding ecology
Provedor de dados: 5
Autores: Bustamante, Paco; Lahaye, V; Durnez, C; Churlaud, C; Caurant, Florence.
Total (T-Hg) and organic (O-Hg) mercury concentrations and tissue distribution were examined in 20 species of cephalopods (n = 278) from the north eastern Atlantic waters, i.e. from the Bay of Biscay to the Faroe Islands. Concentrations of T-Hg in whole cephalopods showed elevated variations among species, i.e. from 40 to 3560ng g(-1) dwt, but a low variability within each species (mean CV%=39%). With the exception of oceanic squids, the digestive gland globally displayed higher T-Hg concentrations than the remaining tissues. In contrast, O-Hg concentrations determined in selected species were generally higher in the remaining tissues. Despite higher T-Hg concentrations, the digestive gland weakly contributed to the total body burden of both T-Hg and O-Hg...
Tipo: Text
Palavras-chave: Cuttlefish; Octopus; Squid; Body distribution; Speciation; Bioaccumulation.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1873.pdf

Speciation of dissolved copper within an active hydrothermal edifice on the Lucky Strike vent field (MAR, 37 degrees N)
Provedor de dados: 5
Autores: Sarradin, Pierre-marie; Waeles, M; Bernagout, Solene; Le Gall, Christian; Sarrazin, Jozee; Riso, R.
The objective of this study was to deter-mine the concentrations of different fractions of dissolved copper (after filtration at 0.45 mu m) along the cold part of the hydrothermal fluid-seawater mixing zone on the Tour Eiffel edifice (MAR). Dissolved copper was analyzed by stripping chronopotentiometry (SCP) after chromatographic C-18 extraction. Levels of total dissolved copper (0.03 to 5.15 mu M) are much higher than those reported for deep-sea oceanic waters but in accordance with data previously obtained in this area. Speciation measurements show that the hydrophobic organic fraction (C18Cu) is very low (2 +/- 1%). Dissolved copper is present mainly as inorganic and hydrophilic organic complexes (nonC(18)CU). The distribution of copper along the pH...
Tipo: Text
Palavras-chave: Mid Atlantic Ridge; Hydrothermal vent; Speciation; Dissolved copper.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-5301.pdf

Addressing the measurement of particulate organic and inorganic phosphorus in estuarine and coastal waters
Provedor de dados: 5
Autores: Labry, Claire; Youenou, Agnes; Delmas, Daniel; Michelon, Pascale.
The speciation of particulate phosphorus (TPP) into inorganic (PIP) and organic phosphorus (POP), has been scarcely investigated in suspended particulate matter (SPM), contrary to numerous sediment studies. This work evaluates the actual capacity of methods for TPP, POP and PIP determination in SPM to measure efficiently and specifically each pool. Methods were tested on a range of plankton-associated organic and inorganic P compounds, on microalgal cultures and estuarine samples. Then results are specifically discussed reviewing P speciation in phytoplankton. For TPP analysis, the method of Solorzano and Sharp (1980) is recommended compared with that of Aspila et al. (1976), originally dedicated to sediment, as there is one step less, the protocol is more...
Tipo: Text
Palavras-chave: Phosphorus; Speciation; Waters; Phytoplankton; HTC; CWO.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00149/26046/26385.pdf

Evolutionary processes and cellular functions underlying divergence in Alexandrium minutum
Provedor de dados: 5
Autores: Le Gac, Mickael; Metegnier, Gabriel; Chomerat, Nicolas; Malestroit, Pascale; Quere, Julien; Bouchez, Olivier; Siano, Raffaele; Destombe, Christophe; Guillou, Laure; Chapelle, Annie.
Understanding divergence in the highly dispersive and seemingly homogeneous pelagic environment for organisms living as free drifters in the water column remains a challenge. Here, we analyzed the transcriptome wide mRNA sequences, as well as the morphology of 18 strains of Alexandrium minutum, a dinoflagellate responsible for Harmful Algal Blooms worldwide, to investigate the functional bases of a divergence event. Analysis of the joint site frequency spectrum (JSFS) pointed toward an ancestral divergence in complete isolations followed by a secondary contact resulting in gene flow between the two diverging groups, but heterogeneous across sites. The sites displaying fixed SNPs were associated with a highly restricted gene flow and a strong...
Tipo: Text
Palavras-chave: Dinoflagellates; Harmful algal blooms; Populations Genomics; Pseudocryptic species; Speciation.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00347/45857/45529.pdf

Cryptic diversity within the harmful dinoflagellate Akashiwo sanguinea in coastal Chinese waters is related to differentiated ecological niches
Provedor de dados: 5
Autores: Luo, Zhaohe; Yang, Weidong; Leaw, Chui Pin; Pospelova, Vera; Bilien, Gwenael; Liow, Guat Ru; Lim, Po Teen; Gu, Haifeng.
Blooms of the harmful dinoflagellate Akashiwo sanguinea are responsible for the mass mortality of fish and invertebrates in coastal waters. This cosmopolitan species includes several genetically differentiated clades. Four clonal cultures were established by isolating single cells from Xiamen Harbour (the East China Sea) for morphological and genetic analyses. The cultures displayed identical morphology but were genetically different, thus revealing presence of cryptic diversity in the study area. New details of the apical structure complex of Akashiwo sanguinea were also found. To investigate whether the observed cryptic diversity was related to environmental differentiation, 634 cells were obtained from seasonal water samples collected from 2008 to 2012....
Tipo: Text
Palavras-chave: Biogeography; Cryptic species; Gymnodinium sanguineum; Seasonal occurrence; Speciation.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00386/49771/50355.pdf

Role of particle sorption properties in the behavior and speciation of trace metals in macrotidal estuaries: The cadmium example
Provedor de dados: 5
Autores: 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

Rôle des particules sur le comportement et la spéciation de métaux traces: exemple du cadmium
Provedor de dados: 5
Autores: Gonzalez, Jean-louis; Thouvenin, Benedicte; Dange, Catherine.
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, acidity instrinsic properties and complexation constant) was evaluated using data collected on particles from the Gironde, Loire and Seine estuaries.
Tipo: Text
Palavras-chave: Particles; Speciation; Sorption/desorption; Cadmium; Modeling; Surface properties.
Ano: 2007
URL: https://archimer.ifremer.fr/doc/00480/59152/61781.pdf

Modélisation des contaminants chimiques dans une colonne d'eau. Modèle MOMO (MORGAN+MOCO).
Provedor de dados: 5
Autores: 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

Behaviour of arsenic on the continental shelf off the Gironde estuary: role of phytoplankton in vertical fluxes during spring bloom conditions
Provedor de dados: 5
Autores: Michel, Pierre; Boutier, Bernard; Herbland, Alain; Averty, Bernard; Artigas, Lf; Auger, Dominique; Chartier, E.
The arsenic (As) cycle in the marine environment is known to be sensitive to biological activity. Within the scope of the National Coastal Oceanography Program, we undertook a specific study of the behaviour of this element in a water column on the continental shelf of the Bay of Biscay off the Gironde estuary during two oceanographic cruises conducted in May 1994 and May 1995. Various chemical forms were measured: arsenite (As3), at-senate (As5), monomethylarsenic (MMA), dimethylarsenic (DMA) and dissolved total As after ultraviolet mineralization. The net flux of total As from the Gironde estuary was evaluated as well as its effect on the concentration in surface marine waters. The vertical profiles in the coastal zone during a period of active primary...
Tipo: Text
Palavras-chave: Arsenic; Phytoplankton; Speciation; Gironde plume; Biscay Bay.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/publication-851.pdf

Speciation in Cyprinidae of the Iberic Peninsula.
Provedor de dados: 5
Autores: 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

Variation in the Diacria trispinosa group, new interpretation of colour patterns and description of D. rubecula n. sp. (Pteropoda)
Provedor de dados: 16
Autores: Bontes, B.; Spoel, S. van der.
The development of the initial stages of the colour pattern on the ventral shell side in the eight taxa of the Diacria trispinosa group is studied. A new species: D. rubecula, is split off from D. maculata on the basis of the discriminating value of these initial colour patterns. The relation of the taxa in the group is discussed and their distributions are compared.
Tipo: Article / Letter to the editor
Palavras-chave: Biogeography; Speciation; Pteropods; Colour patterns.
Ano: 1998
URL: http://www.repository.naturalis.nl/record/505347

Historical biogeography of Western Palaearctic pelobatid and pelodytid frogs: a molecular phylogenetic perspective
Provedor de dados: 16
Autores: Veith, M.; Fromhage, L.; Kosuch, J.; Vences, M.
Spadefoot toads (Pelobates) and Parsley frogs (Pelodytes) are an enigmatic group of Western Palaearctic anurans. In the genus Pelobates, a fossorial lifestyle has enforced a conserved bauplan that masks their intraspecific evolutionary history. We used partial sequences of the mitochondrial 16S and 12S rRNA genes to infer a paleobiogeographic scenario of speciation events in these two anuran genera. Based on two alternative, mutually exclusive calibrations of the Iberian-African split within Pelobates (Pb. cultripes and Pb. varaldii), the disjunction of the Betic Cordillera ca. 14-16 million years ago (mya), and the end of the Messinian Salinity crisis 5.33 mya, we inferred alternative scenarios for species evolution within both genera applying...
Tipo: Article / Letter to the editor
Palavras-chave: Phylogeny; Paleobiogeography; Speciation; Regression-based molecular clock; Bayesian molecular dating; Messinian salinity crisis; 16S; 12S; 42.82.
Ano: 2006
URL: http://www.repository.naturalis.nl/record/214531

Contemporary distributions of Panurginus species and subspecies in Europe (Apoidea: Andrenidae: Panurginae)
Provedor de dados: 16
Autores: Pattiny, S.
Contemporary distributions of Panurginus species and subspecies in Europe (Apoidea: Andrenidae: Panurginae)   The largest number of Old World Panurginus Nylander, 1848 species is distributed in the West- Palaearctic. The genus is absent in Africa and rather rare in the East-Palaearctic. Warncke (1972, 1987), who is the main author treating Palaearctic Panurginae in the last decades, subdivided Panurginus into a small number of species, including two principal taxa admitting for each a very large number of subspecies: Panurginus brullei (Lepeletier, 1841) and Panurginus montanus Giraud, 1861. Following recent works, the two latter are in fact complexes of closely related species. In the West-Palaearctic context, distributions of certain species implied in...
Tipo: Article in monograph or in proceedings
Palavras-chave: Panurginae; Biogeography; West-Palaearctic; Speciation; Glaciation; 42.75.
Ano: 2003
URL: http://www.repository.naturalis.nl/record/219862

Biochemical systematics of the leaf mining moth family Nepticulidae (Lepidoptera). III. Allozyme variation patterns in the Ectoedemia subbimaculella group
Provedor de dados: 16
Autores: Menken, Steph B.J.
Gel electrophoretic techniques were used to analyse patterns of variation at 12 genetic loci within and among species of the Ectoedemia subbimaculella group from western Europe. Geographically separated conspecific populations were similar to one another genetically, with the exception of E. subbimaculella where the malate dehydrogenase locus exhibited clinal variation. Genetic differences among species often concerned loci that were monomorphic or slightly polymorphic within populations. Three of the species could not be diagnosed by their allozyme content; allele distribution patterns at some loci suggest that speciation took place recently and did not involve a genetic bottleneck. Phylogenetic trees constructed from allozyme data paralleled closely the...
Tipo: Article / Letter to the editor
Palavras-chave: Allozyme variation; Biochemical genetics; Taxonomy; Speciation; Insecta.
Ano: 1990
URL: http://www.repository.naturalis.nl/record/503975

On present day islands and past distributions
Provedor de dados: 16
Autores: Renema, W.
Southeast Asia, and especially the Philippines-Indonesia-Papua New Guinea Archipelago, harbours the world’s highest marine diversity. This region also had a complex geological history. This raises the question whether these two attributes are related and, if so, how. To locally build high species richness in a region, the balance between speciation/immigration and extinction/exturpation should be positive over at least part of its geologic history.
Tipo: Article / Letter to the editor
Palavras-chave: Islands; Geology; Marine diversity; Speciation; Immigration; Extinction; Exturpation; Phillippines; Indonesia; Papua New Guinea; 42.65; 38.22.
Ano: 2011
URL: http://www.repository.naturalis.nl/record/428070

A new species of Albugo parasitic to Arabidopsis thaliana reveals new evolutionary patterns in white blister rusts (Albuginaceae)
Provedor de dados: 16
Autores: Thines, M.; Choi, Y.-J.; Kemen, E.; Ploch, S.; Holub, E.B.; Shin, H.-D.; Jones, J.D.G.
The obligate biotrophic lineages of the white blister rusts (Albuginales, Oomycota) are of ancient origin compared to the rather recently evolved downy mildews, and sophisticated mechanisms of biotrophy and a high degree of adaptation diversity are to be expected in these organisms. Speciation in the biotrophic Oomycetes is usually thought to be the consequence of host adaptation or geographic isolation. Here we report the presence of two distinct species of Albugo on the model plant Arabidopsis thaliana, Albugo candida and Albugo laibachii, the latter being formally described in this manuscript. Both species may occupy the same host within the same environment, but are nevertheless phylogenetically distinct, as inferred from analyses of both mitochondrial...
Tipo: Article / Letter to the editor
Palavras-chave: Albuginales; Effector gene; Oospore morphology; Phylogeny; Plant pathogen; Speciation.
Ano: 2009
URL: http://www.repository.naturalis.nl/record/532153

Genetics and morphology of the genus Tritetrabdella (Hirudinea, Haemadipsidae) from the mountainous rain forests of Sabah, Borneo, reveal a new species with two new subspecies
Provedor de dados: 16
Autores: Kappes, H.
Blood-feeding terrestrial leeches of the family Haemadipsidae are a notorious part of the invertebrate diversity in Asian and Australian rain forests. All hitherto published records of terrestrial leeches of Borneo belong to the genus Haemadipsa. Here, a second, poorly known haemadipsid genus is reported from Mount Kinabalu and Crocker Range National Park. The individuals were barcoded and compared to sequences available in GenBank. The results show that the genus Tritetrabdella has representatives in the Indochinese and the Sundaic bioregions. All six specimens from Borneo are from a single new Tritetrabdella lineage, T. kinabaluensis spec. nov. Within the Bornean lineage, two groups differing 4-5% in the COI barcoding sequence were identified. Because 1)...
Tipo: Article / Letter to the editor
Palavras-chave: Annelida; Clitellata; Ecological specialization; Genetic distance; Parasite; Phylogeny; Speciation; Tropical mountains; 42.76; 42.64.
Ano: 2013
URL: http://www.repository.naturalis.nl/record/462900

Evolution of species-specific major seminal fluid proteins in placental mammals by gene death and positive selection
Provedor de dados: 16
Autores: Meslin, C.; Laurin, M.; Callebaut, I.; Druart, X.; Monget, P.
The seminal fluid is a complex substance composed of a variety of secreted proteins and has been shown to play an important role in the fertilisation process in mammals and also in Drosophila. Several genes under positive selection have been documented in some rodents and primates. Our study documents this phenomenon in several other mammalian taxa. We study the evolution of genes that encode for 20 proteins that are quantitatively predominant in the seminal fluid of at least one out of seven domestic animal species. We analyse the amino acid composition of these proteins for positive selection and for the presence of pseudogenes. Genes that disappeared through pseudogenisation include KLK2 in cattle, horse and mice. Traces of positive selection are found...
Tipo: Article / Letter to the editor
Palavras-chave: Molecular evolution; Multivariate phylogenetic pairwise comparisons; Reproductive isolation; Speciation; Comparative biology; Pseudogenisation; 42.64; 42.13; 42.70.
Ano: 2015
URL: http://www.repository.naturalis.nl/record/575180

Evaluating methodologies for species delimitation: the mismatch between phenotypes and genotypes in lichenized fungi (Bryoria sect. Implexae, Parmeliaceae)
Provedor de dados: 16
Autores: Boluda, C.G.; Rico, V.J.; Divakar, P.K.; Nadyeina, O.; Myllys, L.; McMullin, R.T.; Zamora, J.C.; Scheidegger, C.; Hawksworth, D.L.
In many lichen-forming fungi, molecular phylogenetic analyses lead to the discovery of cryptic species within traditional morphospecies. However, in some cases, molecular sequence data also questions the separation of phenotypically characterised species. Here we apply an integrative taxonomy approach ‒ including morphological, chemical, molecular, and distributional characters ‒ to re-assess species boundaries in a traditionally speciose group of hair lichens, Bryoria sect. Implexae. We sampled multilocus sequence and microsatellite data from 142 specimens from a broad intercontinental distribution. Molecular data included DNA sequences of the standard fungal markers ITS, IGS, GAPDH, two newly tested loci (FRBi15 and FRBi16), and SSR frequencies from 18...
Tipo: Article / Letter to the editor
Palavras-chave: Chemotypes; Cryptic species; Haplotypes; Incomplete lineage sorting; Integrative taxonomy; Microsatellites; Speciation; Species concepts.
Ano: 2019
URL: http://www.repository.naturalis.nl/record/660277

New species and new records of Ptomaphaginus Portevin from the Sunda region, Southeast Asia (Coleoptera: Leiodidae: Cholevinae)
Provedor de dados: 16
Autores: Schilthuizen, M.; Perreau, M.
This paper aims to fill some gaps in the taxonomic knowledge of the genus Ptomaphaginus for the Sunda region (in insular and peninsular Southeast Asia). We have refrained from a full regional revision. However, we present new distribution records for the following previously described species: Ptomaphaginus murphyi Szymczakowski, 1970 (Malaysia); P. rufus Jeannel, 1936 (Malaysia); P. tarsalis Szymczakowski, 1964 (Sumatra); P. aff. scaphaner Szymczakowski, 1972 (Malaysia, Java); P. sinuatus Schilthuizen, 1984 (Java); P. baliensis Perreau, 1995 (Sumatra). We also name 12 new species: P. anas spec. nov. (Malaysia); P. bryantioides spec. nov. (Borneo); P. caroli spec. nov. (Borneo), P. similipes spec. nov. (Borneo); P. kinabaluensis spec. nov. (Borneo); P....
Tipo: Article / Letter to the editor
Palavras-chave: Cholevidae; Catopidae; Cholevinae; Genitalia; Speciation; Malaysia; Indonesia; Singapore; New species; 42.75.
Ano: 2008
URL: http://www.repository.naturalis.nl/record/261779

Atypical, ventro-ventral copulation position in aphids of the genus Stomaphis Walker, 1870 (Insecta, Hemiptera)
Provedor de dados: 16
Autores: Depa, L.; Kanturski, M.; Taszakowski, A.; Wieczorek, K.
Firm matching of genitals during copulation is of critical importance to effective insemination and thus, gene flow. During the evolution of insects, an effective position during copulation promoted higher fecundity through control over the act of mating or elimination of competitors. Usually during insect copulation, either twisting or flexing of the male abdomen occurs, and genitals remain symmetrically or asymmetrically disposed following changes in the mating position. However, it is always the dorsal side of the male genitalia that makes contact with the ventral side of female abdomen. Here we present the unusual case of a ‘belly-to-belly’ copulation, with symmetrically positioned male genitals and no twisting of the abdomen. During the mating of two...
Tipo: Article / Letter to the editor
Palavras-chave: Aphididae; Dwarfism; Mate guarding; Sexual competition; Speciation; 42.75.
Ano: 2014
URL: http://www.repository.naturalis.nl/record/480053

Mating time of the West Indian fruit fly Anastrepha obliqua (Macquart) (Diptera: Tephritidae) under laboratory conditions
Provedor de dados: 82
Autores: Henning,Frederico; Matioli,Sergio R.
Allochronic reproductive isolation seems to be an important factor in speciation processes in Tephritidae since specific mating times are a widespread feature of its species. The timing of matings of the West Indian fruit fly, Anastrepha obliqua (Macquart) was investigated through group-focal observations, during ten days, under laboratory conditions. The number of observed matings and males exhibiting calling behavior varied significantly according to time of day. Sexual activities seemed to be concentrated in the afternoon period, with the male calling behavior reaching a peak between 3:30p.m. and 4:30p.m., and mating occurred most frequently from 2:00p.m. to 4:30p.m.
Tipo: Info:eu-repo/semantics/report
Palavras-chave: Allochronic isolation; Speciation; Sexual behavior.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2006000100021

Diversity and distribution patterns of Pronophilina butterflies (Lepidoptera: Nymphalidae: Satyrinae) along an altitudinal transect in north-western Ecuador
Provedor de dados: 82
Autores: Pyrcz,Tomasz W; Wojtusiak,Janusz; Garlacz,Rafaa.
Samplings of Pronophilina, a species-rich group of neotropical montane butterflies, were carried out along an elevational transect in Ecuador to assess the effect of altitude on their distribution patterns, diversity and community structure. All diversity indices were significantly correlated with altitude. Maximum diversity expressed in species-richness, Shannon index and Fisher alpha was recorded at 2600 m. Two assemblages of species were identified in the lower (below 2100 m) and upper (above 2300 m) sections of the transect by means of correspondence (CA) and cluster analysis. A comparison of Sørensen similarity coefficients showed lower values, thus higher turnover in the intermediate elevational band. Several closely related morphologically and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Altitudinal spread; Chusquea bamboo; Parapatric species; Speciation; Species- richness.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2009000600003

On the origin and diversification of Venezuelan freshwater fishes: the genus Gephyrocharax (Ostariophysi: Characidae) a case study
Provedor de dados: 83
Autores: Bonilla-Rivero,Ana; López-Rojas,Héctor.
We conducted a phylogeographic analysis of the genus Gephyrocharaxin Venezuela to evaluate geomorphologic evidence for the formation of the country's main watersheds and to establish a biogeographical hypothesis of possible diversification mechanisms of the Neotropical freshwater fish fauna. We assayed eight enzyme systems and general proteins to estimate genetic variability (H, P), intraspecific structuring in several Gephyrocharax valencia and G. venezuelae populations (FIS, FIT, and FST), and a phylogenetic approach for the three species of Gephyrocharax in Venezuela, using Corynopoma riisei as the external group. Fourteen presumptive lociindicate that populations of the three species of Gephyrocharaxanalyzed show a clear genetic inter-specific...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Isoenzymes; Speciation; Venezuela; Vicariance.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000300487

Karyotypic polymorphism and evolution within and between the Liolaemus monticola (Iguanidae) "northern 2n = 38-40" chromosome race populations in central Chile
Provedor de dados: 97
Autores: LAMBOROT,MADELEINE.
Chromosomal genotypes were scored from 359 Liolaemus monticola lizards of the "northern, 2n = 38-40" chromosomal race from 21 locality samples between the Maipo (and one of its tributaries) and the Aconcagua (and one of its tributaries) ribers, plus a sample from the interracial hybridization zone, and some representative locality samples of the "southern 2n = 34" and the "multiple fission 2n = 42-44" chromosomal races for comparisons. The first seven variable chromosomal pairs were coded as Mendelian genotypes and statistically summarized by several clustering and population genetic algorithms. Spatial and temporal differentiation was assessed by chromosome frequencies, chromosomal diversity and heterozygosity. While no differentiation was found for...
Tipo: Journal article
Palavras-chave: Iguanidae; Liolaernus monticola; Chromosomal races; "northern 2n = 38-40" chromosomal race; Population structure; Speciation.
Ano: 2001
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000000017

Biosolids and heavy metals in soils
Provedor de dados: 63
Autores: Silveira,Maria Lucia Azevedo; Alleoni,Luís Reynaldo Ferracciú; Guilherme,Luiz Roberto Guimarães.
The application of sewage sludge or biosolids on soils has been widespread in agricultural areas. However, depending on their characteristics, they may cause increase in heavy metal concentration of treated soils. In general, domestic biosolids have lower heavy metal contents than industrial ones. Origin and treatment method of biosolids may markedly influence their characteristics. The legislation that controls the levels of heavy metal contents in biosolids and the maximum concentrations in soils is still controversial. In the long-term, heavy metal behavior after the and of biosolid application is still unknown. In soils, heavy metals may be adsorbed via specific or non-specific adsorption reactions. Iron oxides and organic matter are the most important...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sewage sludge; Adsorption; Speciation; PH; Organic matter.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000400029

Zinc availability for corn grown on an oxisol amended with flue dust
Provedor de dados: 63
Autores: Santos,Gláucia Cecília Gabrielli dos; Berton,Ronaldo Severiano; Camargo,Otávio Antônio de; Abreu,Mônica Ferreira de.
The costs related to the construction and maintenance of industrial landfills, and the environmental risks that they may represent, have increased the interest of several types of industries in studying the possibility of applying residues to agricultural soils. This study evaluates the efficiency of flue dust as a zinc source for corn, and the zinc availability for corn evaluated by four methods. A greenhouse experiment carried out at Campinas, SP, Brazil, evaluated the effect of two zinc sources (flue dust and zinc sulphate), at three rates (5, 50 and 150 mg dm-3), in one soil (Rhodic Hapludox) under two pH conditions (5.0 and 6.0). The treatments were arranged in a randomized factorial scheme design with three replications. Zinc availability indexes...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: DTPA; Heavy metals; Industrial wastes; Speciation; Soil pH.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162006000600008

Electrochemical attributes and availability of nutrients, toxic elements, and heavy metals in tropical soils
Provedor de dados: 63
Autores: Fontes,Mauricio Paulo Ferreira; Alleoni,Luís Reynaldo Ferracciú.
Electrochemical properties of soils are very important for the understanding of the physico-chemical phenomena which affect soil fertility and the availability of nutrients for plants. This review highlights the electrochemical properties of tropical soils, the behavior and the availability of nutrients, toxic elements and heavy metals in the soil, especially for soils with predominant variable charge minerals. Availability of the elements is related to ionic exchange, solution speciation, and electrostatic and specific adsorptive soil properties. Empirical and surface complexation models are briefly described, and some results of their application in tropical soils are presented. A better understanding of the role of the double diffuse layer of charges...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Electric charge; Adsorption; Model; Ionic exchange; Speciation.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162006000600014

Padrões de distribuição e especiação em Chrysobalanaceae e outras famílias de plantas amazônicas
Provedor de dados: 39
Autores: 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

On the geographical differentiation of Gymnodactylus geckoides Spix, 1825 (Sauria, Gekkonidae): speciation in the Brasilian caatingas
Provedor de dados: 42
Autores: Vanzolini,Paulo Emilio.
The specific concept of G. geckoides was initially ascertained based on a topotypical sample from Salvador, Bahia. Geographic differentiation was studied through the analysis of two meristic characters (tubercles in a paramedian row and fourth toe lamellae) and color pattern of 327 specimens from 23 localities. It is shown that the population from the southernmost locality, Mucugê, is markedly divergent in all characters studied. A Holocene refuge model is proposed to explain the pattern. A decision about the rank to be attributed to the Mucugê population is deferred until more detailed sampling is effected and molecular methods are applied.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Speciation; Holocene refuges; Lizards/ecology; Lizards/systematics.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652004000400005

On Gymnodactylus amarali Barbour, 1925, with the description of a new species (Sauria, Gekkonidae)
Provedor de dados: 42
Autores: 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

Does advertisement call variation coincide with genetic variation in the genetically diverse frog taxon currently known as Leptodactylus fuscus (Amphibia: Leptodactylidae)?
Provedor de dados: 42
Autores: 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

Green speciation of iron using aqueous two-phase system
Provedor de dados: 42
Autores: 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