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Registros recuperados: 51
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A new species of Albugo parasitic to Arabidopsis thaliana reveals new evolutionary patterns in white blister rusts (Albuginaceae) Naturalis
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
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Addressing the measurement of particulate organic and inorganic phosphorus in estuarine and coastal waters ArchiMer
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
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Analytical methods for mercury speciation in several matrixes: a review IPB - Escola Superior Agrária
Ramalhosa, Elsa; Río-Segade, Susana.
Mercury is one of the hazardous contaminants that may be present in the environment. Moreover, its toxicological effects are strongly dependent on the chemical form of the element, being the organic species the most toxic. In spite of this, the determination of mercury compounds in environmental samples, such as water, soils, sediments and biological matrixes, is of great importance. This review examines the current state of the sample treatments that have been developed, during the last 18 years (1990-2007),previous to separation and detection of mercury compounds, namely acid lixiviation, distillation,alkaline digestion and supercritical fluid extraction, as well as of the chromatographic techniques (gas chromatography and high performance liquid...
Tipo: Article Palavras-chave: Mercury; Speciation; Analytical methods; Gas chromatography; Liquid chromatography.
Ano: 2008 URL: http://hdl.handle.net/10198/3605
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Atypical, ventro-ventral copulation position in aphids of the genus Stomaphis Walker, 1870 (Insecta, Hemiptera) Naturalis
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
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Behaviour of arsenic on the continental shelf off the Gironde estuary: role of phytoplankton in vertical fluxes during spring bloom conditions ArchiMer
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
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Biochemical systematics of the leaf mining moth family Nepticulidae (Lepidoptera). III. Allozyme variation patterns in the Ectoedemia subbimaculella group Naturalis
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
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Biosolids and heavy metals in soils Scientia Agricola
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
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Comparison of calling songs in three allopatric populations of Endecous itatibensis (Orthoptera, Phalangopsinae) Iheringia, Sér. Zool.
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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Contemporary distributions of Panurginus species and subspecies in Europe (Apoidea: Andrenidae: Panurginae) Naturalis
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
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Cryptic diversity within the harmful dinoflagellate Akashiwo sanguinea in coastal Chinese waters is related to differentiated ecological niches ArchiMer
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
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Cycle du mercure en estuaire, baie de Seine et pays de Caux ArchiMer
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
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Dispersion larvaire et cycle de vie dans les environnements hydrothermaux profonds : le cas de Rimicaris exoculata et d'espèces proches ArchiMer
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
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Diversity and distribution patterns of Pronophilina butterflies (Lepidoptera: Nymphalidae: Satyrinae) along an altitudinal transect in north-western Ecuador Neotropical Entomology
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
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Does advertisement call variation coincide with genetic variation in the genetically diverse frog taxon currently known as Leptodactylus fuscus (Amphibia: Leptodactylidae)? Anais da ABC (AABC)
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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Electrochemical attributes and availability of nutrients, toxic elements, and heavy metals in tropical soils Scientia Agricola
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
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Especiação redox de cromo em solo acidentalmente contaminado com solução sulfocrômica. Repositório Alice
MATOS, W. O.; NÓBREGA, J. de A.; SOUZA, G. B. de; NOGUEIRA, A. R. de A..
Determination of Cr(VI) and Cr(III) was studied in soil samples accidentally contaminated with sulphochromic solution. Molecular absorption spectrophotometry based on the diphenylcarbazide method was used for the determination of Cr(VI) after its alkaline extraction. The total chromium concentration was determined using ICP OES. The quantification of Cr(III) was accomplished by subtracting the Cr(VI) concentration from the total chromium concentration. Regardless of the known contamination of the soil samples by sulphochromic solution, concentrations of Cr(VI) were below the detection limit. Addition and recovery experiments for Cr(VI) in soil samples with and without organic matter indicated its influence on the reduction of Cr(VI) to Cr(III).
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Chromium: Redox; Speciation; Solo.
Ano: 2008 URL: http://www.alice.cnptia.embrapa.br/handle/doc/48502
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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 ArchiMer
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
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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) ArchiMer
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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Evaluating methodologies for species delimitation: the mismatch between phenotypes and genotypes in lichenized fungi (Bryoria sect. Implexae, Parmeliaceae) Naturalis
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
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Evolution of species-specific major seminal fluid proteins in placental mammals by gene death and positive selection Naturalis
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
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