WorldWideScience

Sample records for ecological speciation meets

  1. Advances in Ecological Speciation: an integrative approach.

    Science.gov (United States)

    Faria, Rui; Renaut, Sebastien; Galindo, Juan; Pinho, Catarina; Melo-Ferreira, José; Melo, Martim; Jones, Felicity; Salzburger, Walter; Schluter, Dolph; Butlin, Roger

    2014-02-01

    The role of natural selection in promoting reproductive isolation has received substantial renewed interest within the last two decades. As a consequence, the study of ecological speciation has become an extremely productive research area in modern evolutionary biology. Recent innovations in sequencing technologies offer an unprecedented opportunity to study the mechanisms involved in ecological speciation. Genome scans provide significant insights but have some important limitations; efforts are needed to integrate them with other approaches to make full use of the sequencing data deluge. An international conference 'Advances in Ecological Speciation' organized by the University of Porto (Portugal) aimed to review current progress in ecological speciation. Using some of the examples presented at the conference, we highlight the benefits of integrating ecological and genomic data and discuss different mechanisms of parallel evolution. Finally, future avenues of research are suggested to advance our knowledge concerning the role of natural selection in the establishment of reproductive isolation during ecological speciation. © 2013 John Wiley & Sons Ltd.

  2. How Facilitation May Interfere with Ecological Speciation

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    P. Liancourt

    2012-01-01

    Full Text Available Compared to the vast literature linking competitive interactions and speciation, attempts to understand the role of facilitation for evolutionary diversification remain scarce. Yet, community ecologists now recognize the importance of positive interactions within plant communities. Here, we examine how facilitation may interfere with the mechanisms of ecological speciation. We argue that facilitation is likely to (1 maintain gene flow among incipient species by enabling cooccurrence of adapted and maladapted forms in marginal habitats and (2 increase fitness of introgressed forms and limit reinforcement in secondary contact zones. Alternatively, we present how facilitation may favour colonization of marginal habitats and thus enhance local adaptation and ecological speciation. Therefore, facilitation may impede or pave the way for ecological speciation. Using a simple spatially and genetically explicit modelling framework, we illustrate and propose some first testable ideas about how, when, and where facilitation may act as a cohesive force for ecological speciation. These hypotheses and the modelling framework proposed should stimulate further empirical and theoretical research examining the role of both competitive and positive interactions in the formation of incipient species.

  3. Investigating ecological speciation in non-model organisms

    DEFF Research Database (Denmark)

    Foote, Andrew David

    2012-01-01

    Background: Studies of ecological speciation tend to focus on a few model biological systems. In contrast, few studies on non-model organisms have been able to infer ecological speciation as the underlying mechanism of evolutionary divergence. Questions: What are the pitfalls in studying ecological...... speciation in non-model organisms that lead to this bias? What alternative approaches might redress the balance? Organism: Genetically differentiated types of the killer whale (Orcinus orca) exhibiting differences in prey preference, habitat use, morphology, and behaviour. Methods: Review of the literature...... on killer whale evolutionary ecology in search of any difficulty in demonstrating causal links between variation in phenotype, ecology, and reproductive isolation in this non-model organism. Results: At present, we do not have enough evidence to conclude that adaptive phenotype traits linked to ecological...

  4. Parasites Promote and When Might They Constrain Ecological Speciation?

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    Anssi Karvonen

    2012-01-01

    Full Text Available Research on speciation and adaptive radiation has flourished during the past decades, yet factors underlying initiation of reproductive isolation often remain unknown. Parasites represent important selective agents and have received renewed attention in speciation research. We review the literature on parasite-mediated divergent selection in context of ecological speciation and present empirical evidence for three nonexclusive mechanisms by which parasites might facilitate speciation: reduced viability or fecundity of immigrants and hybrids, assortative mating as a pleiotropic by-product of host adaptation, and ecologically-based sexual selection. We emphasise the lack of research on speciation continuums, which is why no study has yet made a convincing case for parasite driven divergent evolution to initiate the emergence of reproductive isolation. We also point interest towards selection imposed by single versus multiple parasite species, conceptually linking this to strength and multifariousness of selection. Moreover, we discuss how parasites, by manipulating behaviour or impairing sensory abilities of hosts, may change the form of selection that underlies speciation. We conclude that future studies should consider host populations at variable stages of the speciation process, and explore recurrent patterns of parasitism and resistance that could pinpoint the role of parasites in imposing the divergent selection that initiates ecological speciation.

  5. Synergy between Allopatry and Ecology in Population Differentiation and Speciation

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    Yann Surget-Groba

    2012-01-01

    Full Text Available The general diversity pattern of the Caribbean anole radiation has been described in detail; however, the actual mechanisms at the origin of their diversification remain controversial. In particular, the role of ecological speciation, and the relative importance of divergence in allopatry and in parapatry, is debated. We describe the genetic structure of anole populations across lineage contact zones and ecotones to investigate the effect of allopatric divergence, natural selection, and the combination of both factors on population differentiation. Allopatric divergence had no significant impact on differentiation across the lineage boundary, while a clear bimodality in genetic and morphological characters was observed across an ecotone within a single lineage. Critically, the strongest differentiation was observed when allopatry and ecology act together, leading to a sharp reduction in gene flow between two lineages inhabiting different habitats. We suggest that, for Caribbean anoles to reach full speciation, a synergistic combination of several historical and ecological factors may be requisite.

  6. Phylogenetic niche conservatism and the evolutionary basis of ecological speciation.

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    Pyron, R Alexander; Costa, Gabriel C; Patten, Michael A; Burbrink, Frank T

    2015-11-01

    Phylogenetic niche conservatism (PNC) typically refers to the tendency of closely related species to be more similar to each other in terms of niche than they are to more distant relatives. This has been implicated as a potential driving force in speciation and other species-richness patterns, such as latitudinal gradients. However, PNC has not been very well defined in most previous studies. Is it a pattern or a process? What are the underlying endogenous (e.g. genetic) and exogenous (e.g. ecological) factors that cause niches to be conserved? What degree of similarity is necessary to qualify as PNC? Is it possible for the evolutionary processes causing niches to be conserved to also result in niche divergence in different habitats? Here, we revisit these questions, codifying a theoretical and operational definition of PNC as a mechanistic evolutionary process resulting from several factors. We frame this both from a macroevolutionary and population-genetic perspective. We discuss how different axes of physical (e.g. geographic) and environmental (e.g. climatic) heterogeneity interact with the fundamental process of PNC to produce different outcomes of ecological speciation. We also review tests for PNC, and suggest ways that these could be improved or better utilized in future studies. Ultimately, PNC as a process has a well-defined mechanistic basis in organisms, and future studies investigating ecological speciation would be well served to consider this, and frame hypothesis testing in terms of the processes and expected patterns described herein. The process of PNC may lead to patterns where niches are conserved (more similar than expected), constrained (divergent within a limited subset of available niches), or divergent (less similar than expected), based on degree of phylogenetic relatedness between species. © 2014 Cambridge Philosophical Society.

  7. Assortative flocking in crossbills and implications for ecological speciation.

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    Smith, Julie W; Sjoberg, Stephanie M; Mueller, Matthew C; Benkman, Craig W

    2012-10-22

    How reproductive isolation is related to divergent natural selection is a central question in speciation. Here, we focus on several ecologically specialized taxa or 'call types' of red crossbills (Loxia curvirostra complex), one of the few groups of birds providing much evidence for ecological speciation. Call types differ in bill sizes and feeding capabilities, and also differ in vocalizations, such that contact calls provide information on crossbill phenotype. We found that two call types of red crossbills were more likely to approach playbacks of their own call type than those of heterotypics, and that their propensity to approach heterotypics decreased with increasing divergence in bill size. Although call similarity also decreased with increasing divergence in bill size, comparisons of responses to familiar versus unfamiliar call types indicate that the decrease in the propensity to approach heterotypics with increasing divergence in bill size was a learned response, and not a by-product of calls diverging pleiotropically as bill size diverged. Because crossbills choose mates while in flocks, assortative flocking could lead indirectly to assortative mating as a by-product. These patterns of association therefore provide a mechanism by which increasing divergent selection can lead to increasing reproductive isolation.

  8. Ecological niche partitioning between Anopheles gambiae molecular forms in Cameroon: the ecological side of speciation

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    Fotsing Jean-Marie

    2009-05-01

    Full Text Available Abstract Background Speciation among members of the Anopheles gambiae complex is thought to be promoted by disruptive selection and ecological divergence acting on sets of adaptation genes protected from recombination by polymorphic paracentric chromosomal inversions. However, shared chromosomal polymorphisms between the M and S molecular forms of An. gambiae and insufficient information about their relationship with ecological divergence challenge this view. We used Geographic Information Systems, Ecological Niche Factor Analysis, and Bayesian multilocus genetic clustering to explore the nature and extent of ecological and chromosomal differentiation of M and S across all the biogeographic domains of Cameroon in Central Africa, in order to understand the role of chromosomal arrangements in ecological specialisation within and among molecular forms. Results Species distribution modelling with presence-only data revealed differences in the ecological niche of both molecular forms and the sibling species, An. arabiensis. The fundamental environmental envelope of the two molecular forms, however, overlapped to a large extent in the rainforest, where they occurred in sympatry. The S form had the greatest niche breadth of all three taxa, whereas An. arabiensis and the M form had the smallest niche overlap. Correspondence analysis of M and S karyotypes confirmed that molecular forms shared similar combinations of chromosomal inversion arrangements in response to the eco-climatic gradient defining the main biogeographic domains occurring across Cameroon. Savanna karyotypes of M and S, however, segregated along the smaller-scale environmental gradient defined by the second ordination axis. Population structure analysis identified three chromosomal clusters, each containing a mixture of M and S specimens. In both M and S, alternative karyotypes were segregating in contrasted environments, in agreement with a strong ecological adaptive value of

  9. How common is ecological speciation in plant-feeding insects? A 'Higher' Nematinae perspective

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    Nyman Tommi

    2010-09-01

    Full Text Available Abstract Background Ecological speciation is a process in which a transiently resource-polymorphic species divides into two specialized sister lineages as a result of divergent selection pressures caused by the use of multiple niches or environments. Ecology-based speciation has been studied intensively in plant-feeding insects, in which both sympatric and allopatric shifts onto novel host plants could speed up diversification. However, while numerous examples of species pairs likely to have originated by resource shifts have been found, the overall importance of ecological speciation in relation to other, non-ecological speciation modes remains unknown. Here, we apply phylogenetic information on sawflies belonging to the 'Higher' Nematinae (Hymenoptera: Tenthredinidae to infer the frequency of niche shifts in relation to speciation events. Results Phylogenetic trees reconstructed on the basis of DNA sequence data show that the diversification of higher nematines has involved frequent shifts in larval feeding habits and in the use of plant taxa. However, the inferred number of resource shifts is considerably lower than the number of past speciation events, indicating that the majority of divergences have occurred by non-ecological allopatric speciation; based on a time-corrected analysis of sister species, we estimate that a maximum of c. 20% of lineage splits have been triggered by a change in resource use. In addition, we find that postspeciational changes in geographic distributions have led to broad sympatry in many species having identical host-plant ranges. Conclusion Our analysis indicates that the importance of niche shifts for the diversification of herbivorous insects is at present implicitly and explicitly overestimated. In the case of the Higher Nematinae, employing a time correction for sister-species comparisons lowered the proportion of apparent ecology-based speciation events from c. 50-60% to around 20%, but such corrections are

  10. Pollinator-driven ecological speciation in plants: new evidence and future perspectives.

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    Van der Niet, Timotheüs; Peakall, Rod; Johnson, Steven D

    2014-01-01

    The hypothesis that pollinators have been important drivers of angiosperm diversity dates back to Darwin, and remains an important research topic today. Mounting evidence indicates that pollinators have the potential to drive diversification at several different stages of the evolutionary process. Microevolutionary studies have provided evidence for pollinator-mediated floral adaptation, while macroevolutionary evidence supports a general pattern of pollinator-driven diversification of angiosperms. However, the overarching issue of whether, and how, shifts in pollination system drive plant speciation represents a critical gap in knowledge. Bridging this gap is crucial to fully understand whether pollinator-driven microevolution accounts for the observed macroevolutionary patterns. Testable predictions about pollinator-driven speciation can be derived from the theory of ecological speciation, according to which adaptation (microevolution) and speciation (macroevolution) are directly linked. This theory is a particularly suitable framework for evaluating evidence for the processes underlying shifts in pollination systems and their potential consequences for the evolution of reproductive isolation and speciation. This Viewpoint paper focuses on evidence for the four components of ecological speciation in the context of plant-pollinator interactions, namely (1) the role of pollinators as selective agents, (2) floral trait divergence, including the evolution of 'pollination ecotypes', (3) the geographical context of selection on floral traits, and (4) the role of pollinators in the evolution of reproductive isolation. This Viewpoint also serves as the introduction to a Special Issue on Pollinator-Driven Speciation in Plants. The 13 papers in this Special Issue range from microevolutionary studies of ecotypes to macroevolutionary studies of historical ecological shifts, and span a wide range of geographical areas and plant families. These studies further illustrate

  11. Pollinator-driven ecological speciation in plants: new evidence and future perspectives

    Science.gov (United States)

    Van der Niet, Timotheüs; Peakall, Rod; Johnson, Steven D.

    2014-01-01

    Background The hypothesis that pollinators have been important drivers of angiosperm diversity dates back to Darwin, and remains an important research topic today. Mounting evidence indicates that pollinators have the potential to drive diversification at several different stages of the evolutionary process. Microevolutionary studies have provided evidence for pollinator-mediated floral adaptation, while macroevolutionary evidence supports a general pattern of pollinator-driven diversification of angiosperms. However, the overarching issue of whether, and how, shifts in pollination system drive plant speciation represents a critical gap in knowledge. Bridging this gap is crucial to fully understand whether pollinator-driven microevolution accounts for the observed macroevolutionary patterns. Testable predictions about pollinator-driven speciation can be derived from the theory of ecological speciation, according to which adaptation (microevolution) and speciation (macroevolution) are directly linked. This theory is a particularly suitable framework for evaluating evidence for the processes underlying shifts in pollination systems and their potential consequences for the evolution of reproductive isolation and speciation. Scope This Viewpoint paper focuses on evidence for the four components of ecological speciation in the context of plant-pollinator interactions, namely (1) the role of pollinators as selective agents, (2) floral trait divergence, including the evolution of ‘pollination ecotypes‘, (3) the geographical context of selection on floral traits, and (4) the role of pollinators in the evolution of reproductive isolation. This Viewpoint also serves as the introduction to a Special Issue on Pollinator-Driven Speciation in Plants. The 13 papers in this Special Issue range from microevolutionary studies of ecotypes to macroevolutionary studies of historical ecological shifts, and span a wide range of geographical areas and plant families. These studies

  12. Genetic tests for ecological and allopatric speciation in anoles on an island archipelago.

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    Thorpe, Roger S; Surget-Groba, Yann; Johansson, Helena

    2010-04-29

    From Darwin's study of the Galapagos and Wallace's study of Indonesia, islands have played an important role in evolutionary investigations, and radiations within archipelagos are readily interpreted as supporting the conventional view of allopatric speciation. Even during the ongoing paradigm shift towards other modes of speciation, island radiations, such as the Lesser Antillean anoles, are thought to exemplify this process. Geological and molecular phylogenetic evidence show that, in this archipelago, Martinique anoles provide several examples of secondary contact of island species. Four precursor island species, with up to 8 mybp divergence, met when their islands coalesced to form the current island of Martinique. Moreover, adjacent anole populations also show marked adaptation to distinct habitat zonation, allowing both allopatric and ecological speciation to be tested in this system. We take advantage of this opportunity of replicated island coalescence and independent ecological adaptation to carry out an extensive population genetic study of hypervariable neutral nuclear markers to show that even after these very substantial periods of spatial isolation these putative allospecies show less reproductive isolation than conspecific populations in adjacent habitats in all three cases of subsequent island coalescence. The degree of genetic interchange shows that while there is always a significant genetic signature of past allopatry, and this may be quite strong if the selection regime allows, there is no case of complete allopatric speciation, in spite of the strong primae facie case for it. Importantly there is greater genetic isolation across the xeric/rainforest ecotone than is associated with any secondary contact. This rejects the development of reproductive isolation in allopatric divergence, but supports the potential for ecological speciation, even though full speciation has not been achieved in this case. It also explains the paucity of anole species

  13. Genetic Coupling of Female Mate Choice with Polygenic Ecological Divergence Facilitates Stickleback Speciation.

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    Bay, Rachael A; Arnegard, Matthew E; Conte, Gina L; Best, Jacob; Bedford, Nicole L; McCann, Shaugnessy R; Dubin, Matthew E; Chan, Yingguang Frank; Jones, Felicity C; Kingsley, David M; Schluter, Dolph; Peichel, Catherine L

    2017-11-06

    Ecological speciation with gene flow is widespread in nature [1], but it presents a conundrum: how are associations between traits under divergent natural selection and traits that contribute to assortative mating maintained? Theoretical models suggest that genetic mechanisms inhibiting free recombination between loci underlying these two types of traits (hereafter, "genetic coupling") can facilitate speciation [2-4]. Here, we perform a direct test for genetic coupling by mapping both divergent traits and female mate choice in a classic model of ecological speciation: sympatric benthic and limnetic threespine stickleback (Gasterosteus aculeatus). By measuring mate choice in F2 hybrid females, we allowed for recombination between loci underlying assortative mating and those under divergent ecological selection. In semi-natural mating arenas in which females had access to both benthic and limnetic males, we found that F2 females mated with males similar to themselves in body size and shape. In addition, we found two quantitative trait loci (QTLs) associated with female mate choice that also predicted female morphology along the benthic-limnetic trait axis. Furthermore, a polygenic genetic model that explains adaptation to contrasting benthic and limnetic feeding niches [5] also predicted F2 female mate choice. Together, these results provide empirical evidence that genetic coupling of assortative mating with traits under divergent ecological selection helps maintain species in the face of gene flow, despite a polygenic basis for adaptation to divergent environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Mechanisms by Which Phenotypic Plasticity Affects Adaptive Divergence and Ecological Speciation.

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    Nonaka, Etsuko; Svanbäck, Richard; Thibert-Plante, Xavier; Englund, Göran; Brännström, Åke

    2015-11-01

    Phenotypic plasticity is the ability of one genotype to produce different phenotypes depending on environmental conditions. Several conceptual models emphasize the role of plasticity in promoting reproductive isolation and, ultimately, speciation in populations that forage on two or more resources. These models predict that plasticity plays a critical role in the early stages of speciation, prior to genetic divergence, by facilitating fast phenotypic divergence. The ability to plastically express alternative phenotypes may, however, interfere with the early phase of the formation of reproductive barriers, especially in the absence of geographic barriers. Here, we quantitatively investigate mechanisms under which plasticity can influence progress toward adaptive genetic diversification and ecological speciation. We use a stochastic, individual-based model of a predator-prey system incorporating sexual reproduction and mate choice in the predator. Our results show that evolving plasticity promotes the evolution of reproductive isolation under diversifying environments when individuals are able to correctly select a more profitable habitat with respect to their phenotypes (i.e., adaptive habitat choice) and to assortatively mate with relatively similar phenotypes. On the other hand, plasticity facilitates the evolution of plastic generalists when individuals have a limited capacity for adaptive habitat choice. We conclude that plasticity can accelerate the evolution of a reproductive barrier toward adaptive diversification and ecological speciation through enhanced phenotypic differentiation between diverging phenotypes.

  15. The role of ecology in speciation by sexual selection: a systematic empirical review.

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    Scordato, Elizabeth S C; Symes, Laurel B; Mendelson, Tamra C; Safran, Rebecca J

    2014-01-01

    Theoretical and empirical research indicates that sexual selection interacts with the ecological context in which mate choice occurs, suggesting that sexual and natural selection act together during the evolution of premating reproductive isolation. However, the relative importance of natural and sexual selection to speciation remains poorly understood. Here, we applied a recent conceptual framework for examining interactions between mate choice divergence and ecological context to a review of the empirical literature on speciation by sexual selection. This framework defines two types of interactions between mate choice and ecology: internal interactions, wherein natural and sexual selection jointly influence divergence in sexual signal traits and preferences, and external interactions, wherein sexual selection alone acts on traits and preferences but ecological context shapes the transmission efficacy of sexual signals. The objectives of this synthesis were 3-fold: to summarize the traits, ecological factors, taxa, and geographic contexts involved in studies of mate choice divergence; to analyze patterns of association between these variables; and to identify the most common types of interactions between mate choice and ecological factors. Our analysis revealed that certain traits are consistently associated with certain ecological factors. Moreover, among studies that examined a divergent sexually selected trait and an ecological factor, internal interactions were more common than external interactions. Trait-preference associations may thus frequently be subject to both sexual and natural selection in cases of divergent mate choice. Our results highlight the importance of interactions between sexual selection and ecology in mate choice divergence and suggest areas for future research. © The American Genetic Association. 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Niche divergence builds the case for ecological speciation in skinks of the Plestiodon skiltonianus species complex

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    Wogan, Guinevere O.U.; Richmond, Jonathan Q.

    2015-01-01

    Adaptation to different thermal environments has the potential to cause evolutionary changes that are sufficient to drive ecological speciation. Here, we examine whether climate-based niche divergence in lizards of the Plestiodon skiltonianus species complex is consistent with the outcomes of such a process. Previous work on this group shows that a mechanical sexual barrier has evolved between species that differ mainly in body size and that the barrier may be a by-product of selection for increased body size in lineages that have invaded xeric environments; however, baseline information on niche divergence among members of the group is lacking. We quantified the climatic niche using mechanistic physiological and correlative niche models and then estimated niche differences among species using ordination techniques and tests of niche overlap and equivalency. Our results show that the thermal niches of size-divergent, reproductively isolated morphospecies are significantly differentiated and that precipitation may have been as important as temperature in causing increased shifts in body size in xeric habitats. While these findings alone do not demonstrate thermal adaptation or identify the cause of speciation, their integration with earlier genetic and behavioral studies provides a useful test of phenotype–environment associations that further support the case for ecological speciation in these lizards.

  17. The contribution of post-copulatory mechanisms to incipient ecological speciation in sticklebacks.

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    Kaufmann, Joshka; Eizaguirre, Christophe; Milinski, Manfred; Lenz, Tobias L

    2015-01-01

    Ecology can play a major role in species diversification. As individuals are adapting to contrasting habitats, reproductive barriers may evolve at multiple levels. While pre-mating barriers have been extensively studied, the evolution of post-mating reproductive isolation during early stages of ecological speciation remains poorly understood. In diverging three-spined stickleback ecotypes from two lakes and two rivers, we observed differences in sperm traits between lake and river males. Interestingly, these differences did not translate into ecotype-specific gamete precedence for sympatric males in competitive in vitro fertilization experiments, potentially owing to antagonistic compensatory effects. However, we observed indirect evidence for impeded development of inter-ecotype zygotes, possibly suggesting an early stage of genetic incompatibility between ecotypes. Our results show that pre-zygotic post-copulatory mechanisms play a minor role during this first stage of ecotype divergence, but suggest that genetic incompatibilities may arise at early stages of ecological speciation. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  18. Magadi tilapia ecological specialization: filling the early gap in the speciation continuum.

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    Pinho, Catarina; Faria, Rui

    2016-04-01

    Cichlid fish are well known for their high speciation rates, which are usually accompanied by spectacular and rapid diversification in eco-morphological and secondary sexual traits. This is best illustrated by the famous repeated explosive radiations in the African Great Lakes Tanganyika, Malawi and Victoria, each lake harbouring several hundreds of mostly endemic species. Correspondingly, cichlids diversified very rapidly in many other lakes across their range. Although the larger radiations, unparalleled in vertebrates, are certainly the most intriguing, they are also the most intricate and difficult to address because of their complex nature. This is where smaller, simpler systems may prove to be the most useful. In this issue of Molecular Ecology, Kavembe et al. (2016) report very recent genetic diversification accompanied by ecological specialization in cichlids of the small and ecologically extreme Lake Magadi, in Kenya. Combining geometric morphometrics, stable isotope analysis, population genomics using RADSeq data and coalescent-based modelling techniques, the authors characterize the eco-morphological differences between genetically distinct populations of Magadi tilapia (Alcolapia grahami), which are consistent with the different environmental conditions they experience, and infer their history of divergence. The simplicity of the focal system and the use of a multidisciplinary approach make this work particularly important for our understanding of the early stages of speciation, in both cichlids and other organisms. © 2016 John Wiley & Sons Ltd.

  19. Larval Performance in the Context of Ecological Diversification and Speciation in Lycaeides Butterflies

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    Cynthia F. Scholl

    2012-01-01

    Full Text Available The role of ecology in diversification has been widely investigated, though few groups have been studied in enough detail to allow comparisons of different ecological traits that potentially contribute to reproductive isolation. We investigated larval performance within a species complex of Lycaeides butterflies. Caterpillars from seven populations were reared on five host plants, asking if host-specific, adaptive larval traits exist. We found large differences in performance across plants and fewer differences among populations. The patterns of performance are complex and suggest both conserved traits (i.e., plant effects across populations and more recent dynamics of local adaptation, in particular for L. melissa that has colonized an exotic host. We did not find a relationship between oviposition preference and larval performance, suggesting that preference did not evolve to match performance. Finally, we put larval performance within the context of several other traits that might contribute to ecologically based reproductive isolation in the Lycaeides complex. This larger context, involving multiple ecological and behavioral traits, highlights the complexity of ecological diversification and emphasizes the need for detailed studies on the strength of putative barriers to gene flow in order to fully understand the process of ecological speciation.

  20. Ecological speciation by temporal isolation in a population of the stonefly Leuctra hippopus (Plecoptera, Leuctridae).

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    Boumans, Louis; Hogner, Silje; Brittain, John; Johnsen, Arild

    2017-03-01

    Stream dwelling invertebrates are ideal candidates for the study of ecological speciation as they are often adapted to particular environmental conditions within a stream and inhabit only certain reaches of a drainage basin, separated by unsuitable habitat. We studied an atypical population of the stonefly Leuctra hippopus at a site in central Norway, the Isterfoss rapids, in relation to three nearby and two remote conspecific populations. Adults of this population emerge about a month earlier than those of nearby populations, live on large boulders emerging from the rapids, and are short-lived. This population also has distinct morphological features and was studied earlier during the period 1975-1990. We reassessed morphological distinctness with new measurements and added several analyses of genetic distinctness based on mitochondrial and nuclear sequence markers, as well as AFLP fingerprinting and SNPs mined from RAD sequences. The Isterfoss population is shown to be most closely related to its geographical neighbors, yet clearly morphologically and genetically distinct and homogeneous. We conclude that this population is in the process of sympatric speciation, with temporal isolation being the most important direct barrier to gene flow. The shift in reproductive season results from the particular temperature and water level regime in the Isterfoss rapids. The distinct adult body shape and loss of flight are hypothesized to be an adaptation to the unusual habitat. Ecological diversification on small spatial and temporal scales is one of the likely causes of the high diversity of aquatic insects.

  1. Does niche divergence accompany allopatric divergence in Aphelocoma jays as predicted under ecological speciation? Insights from tests with niche models.

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    McCormack, John E; Zellmer, Amanda J; Knowles, L Lacey

    2010-05-01

    The role of ecology in the origin of species has been the subject of long-standing interest to evolutionary biologists. New sources of spatially explicit ecological data allow for large-scale tests of whether speciation is associated with niche divergence or whether closely related species tend to be similar ecologically (niche conservatism). Because of the confounding effects of spatial autocorrelation of environmental variables, we generate null expectations for niche divergence for both an ecological-niche modeling and a multivariate approach to address the question: do allopatrically distributed taxa occupy similar niches? In a classic system for the study of niche evolution--the Aphelocoma jays--we show that there is little evidence for niche divergence among Mexican Jay (A. ultramarina) lineages in the process of speciation, contrary to previous results. In contrast, Aphelocoma species that exist in partial sympatry in some regions show evidence for niche divergence. Our approach is widely applicable to the many cases of allopatric lineages in the beginning stages of speciation. These results do not support an ecological speciation model for Mexican Jay lineages because, in most cases, the allopatric environments they occupy are not significantly more divergent than expected under a null model.

  2. The role of ecological divergence in speciation between intertidal and subtidal Scoloplos armiger (Polychaeta, Orbiniidae)

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    Kruse, Inken; Strasser, Matthias; Thiermann, Frank

    2004-02-01

    The concept of ecological speciation implies that habitat differences may split a species by strong selection and rapid adaptation even under sympatric conditions. Studies on the polychaete Scoloplos armiger in the Wadden Sea (North Sea) indicate sibling species existing in sympatry: the intertidal 'Type I' with holobenthic development out of egg cocoons and the subtidal 'Type S' producing pelagic larvae. In the current study, Types I and S are compared in habitat-related traits of reproductive timing and physiological response to hypoxia and sulphide. Spawnings of Type I and Type S recorded over six years overlap in spring and both appear to be triggered by a rise in seawater temperature above 5 °C. Type S exhibits an additional autumn spawning (at seawater temperatures around 10 °C) which was previously unknown and is absent in Type I. The overall abundance of pelagic larvae in the Wadden Sea is higher in spring than in autumn. Tolerance of both sulphide and hypoxia was lower in Type S than in Type I. This correlates with a 5 to 10-fold lower sulphide concentration in the subtidal compared to the intertidal habitat. Physiological tolerance and divergence in developmental mode appear as traits which may have led to reproductive isolation between Type I and Type S. Their role in allopatric and sympatric speciation scenarios in S. armiger is discussed. Since the pelagic dispersal mode has been neglected so far, a reassessment of population dynamics models for S. armiger is suggested.

  3. Historical contingency and ecological determinism interact to prime speciation in sticklebacks, Gasterosteus.

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    Taylor, E B; McPhail, J D

    2000-01-01

    Historical contingency and determinism are often cast as opposing paradigms under which evolutionary diversification operates. It may be, however, that both factors act together to promote evolutionary divergence, although there are few examples of such interaction in nature. We tested phylogenetic predictions of an explicit historical model of divergence (double invasions of freshwater by marine ancestors) in sympatric species of three-spined sticklebacks (Gasterosteus aculeatus) where determinism has been implicated as an important factor driving evolutionary novelty. Microsatellite DNA variation at six loci revealed relatively low genetic variation in freshwater populations, supporting the hypothesis that they were derived by colonization of freshwater by more diverse marine ancestors. Phylogenetic and genetic distance analyses suggested that pairs of sympatric species have evolved multiple times, further implicating determinism as a factor in speciation. Our data also supported predictions based on the hypothesis that the evolution of sympatric species was contingent upon 'double invasions' of postglacial lakes by ancestral marine sticklebacks. Sympatric sticklebacks, therefore, provide an example of adaptive radiation by determinism contingent upon historical conditions promoting unique ecological interactions, and illustrate how contingency and determinism may interact to generate geographical variation in species diversity PMID:11133026

  4. Speciation and ecological risk of heavy metals and metalloid in the sediments of Zhalong Wetland in China

    International Nuclear Information System (INIS)

    Ye, H.; Zang, S.; Xiao, H.; Zhang, L.

    2015-01-01

    A total of 271 sediments samples from the Zhalong Wetland were analyzed for concentration and distribution of Hg, Cd, As, Cu, Pb, Zn, Cr, and Zn; their speciation according to the modified European Community Bureau of Reference sequential extraction procedures and their ecological risk based on Lars Hakanson’s potential ecological risk assessment and risk assessment code were made. The results can be summarized as the followings: (1) Concentrations of all metals measured were above soil background values of Songnen Plain, and their spatial distributions were distinctly different. The concentrations of metals (except Pb) were high in the east, followed by the north, and were relatively low in the core zone and south. The concentration of Pb was high in the north, south, and west, compared with low concentration in the core zone and east. (2) The dominant proportion of Pb, Zn, and Cr was in the residual fraction, suggesting that they were environmental stable. The concentrations of Cu and As in the reducible fraction, the concentration of Cd in the acid soluble fraction, and the concentration of Hg in the oxidizable fraction were relatively high, indicating they had greater environmental effects. (3) The evaluation of the ecological risk showed that Cd, Hg, and As had relatively high ecological risk index, especially the ecological risk of Cd should be paid attention to. In general, the ecological risk of the heavy metals and metalloid by zone was experimental zone >buffering zone>ecological tourism zone>core zone.

  5. Speciation analysis of arsenic, chromium and selenium in aquatic media. Proceedings of a final research coordination meeting

    International Nuclear Information System (INIS)

    2007-03-01

    The initiation of the Coordinated Research Project (CRP) on Development and Validation of Speciation Analysis using Nuclear Techniques resulted from the recognition that knowledge of total element concentration does not provide adequate information to understand the effects of trace and heavy metals observed in the environment and in living systems. Their toxicity, bioavailability, physiological and metabolic processes, mobility and distribution are greatly dependent on the specific chemical form of the element. Speciation analysis has yet to be developed to its full potential for biochemical, clinical and environmental investigations and still more work is needed in the near future. Seven participants from seven countries participated in this CRP covering a range of analytical techniques including GC, HPLC, AAS, and ICP-MS. The first Research Coordination Meeting (RCM) of the Coordinated Research Project on the Development and Validation of Speciation Analysis using Nuclear Techniques was held at the Reactor Centre of the Jozef Stefan Institute, Podgorica (near Ljubljana), Slovenia, 20-23 June 2001. The second RCM was held at the Technical University of Vienna, 18-22 November 2002, where, in addition to the participants, two external researchers could present their views and experience in the field. The last RCM was held in Vienna, 26-29 April 2004, and this publication is a summary of the results achieved and presented at this last RCM. The participants have developed several new procedures for the reliable analysis of As, Cr, and Se species, mainly in aquatic media. A new instrument was designed and several recommendations for speciation analysis were issued. It is hoped that this publication will make a contribution to enhancing the awareness of the importance of speciation analysis and add to the reliability of speciation results in Member State laboratories

  6. Ecological hybrid speciation in central-European species of Bolboschoenus: genetic and morphological evaluation

    Czech Academy of Sciences Publication Activity Database

    Píšová, Soňa; Hroudová, Zdenka; Chumová, Zuzana; Fér, T.

    2017-01-01

    Roč. 89, č. 1 (2017), s. 17-39 ISSN 0032-7786 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : AFLP * Bolboschoenus * central Europe * speciation * model-based clustering * morfometrics Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 3.000, year: 2016

  7. Little ecological divergence associated with speciation in two African rain forest tree genera

    NARCIS (Netherlands)

    Couvreur, T.L.P.; Porter-Morgan, H.; Wieringa, J.J.; Chatrou, L.W.

    2011-01-01

    Background - The tropical rain forests (TRF) of Africa are the second largest block of this biome after the Amazon and exhibit high levels of plant endemism and diversity. Two main hypotheses have been advanced to explain speciation processes that have led to this high level of biodiversity:

  8. Meeting ecological and societal needs for freshwater

    Science.gov (United States)

    Baron, Jill S.; Poff, N.L.; Angermeier, P.L.; Dahm, Clifford N.; Gleick, P.H.; Hairston, N.G.; Jackson, R.B.; Johnston, C.A.; Richter, B.D.; Steinman, A.D.

    2002-01-01

    efforts, using well-grounded ecological principles as guidelines; (5) Maintain and protect the remaining freshwater ecosystems that have high integrity; and (6) Recognize the dependence of human society on naturally functioning ecosystems.

  9. Ancient tetraploidy and slow molecular evolution in Scaphiophryne: ecological correlates of speciation mode in Malagasy relict amphibians.

    Science.gov (United States)

    Vences, Miguel; Aprea, Gennaro; Capriglione, Teresa; Andreone, Franco; Odierna, Gaetano

    2002-01-01

    Karyotypes of three microhylid frog species of the Malagasy relict genus Scaphiophryne were studied: Scaphiophryne gottlebei, S. madagascariensis and S. spinosa. The latter two showed a plesiomorphic ranoid karyotype of 2n = 26. In contrast, tetraploidy was demonstrated in S. gottlebei, which constitutes an exceptional state among Malagasy amphibians. A combination of different banding techniques and of rDNA-FISH provided evidence for allopolyploidy in the species and for a completed subsequent functional and structural diploidization. Phylogenetic analysis of mitochondrial 16S rDNA sequences revealed a significant deceleration of nucleotide substitution rates in Scaphiophryne. The tetraploidy of S. gottlebei probably occurred early in their radiation. Ecological and behavioural patterns of Scaphiophryne probably favoured intraspecific gene flow and hybridization events, thereby leading to slow molecular substitution rates and to allopolyploid chromosome speciation in S. gottlebei.

  10. Temporal, spatial and ecological dynamics of speciation among amphi-Beringian small mammals

    Science.gov (United States)

    Hope, Andrew G.; Takebayashi, Naoki; Galbreath, Kurt E.; Talbot, Sandra L.; Cook, Joseph A.

    2013-01-01

    Quaternary climate cycles played an important role in promoting diversification across the Northern Hemisphere, although details of the mechanisms driving evolutionary change are still poorly resolved. In a comparative phylogeographical framework, we investigate temporal, spatial and ecological components of evolution within a suite of Holarctic small mammals. We test a hypothesis of simultaneous divergence among multiple taxon pairs, investigating time to coalescence and demographic change for each taxon in response to a combination of climate and geography.

  11. Influences of organic carbon speciation on hyporheic corridor biogeochemistry and microbial ecology.

    Science.gov (United States)

    Stegen, James C; Johnson, Tim; Fredrickson, James K; Wilkins, Michael J; Konopka, Allan E; Nelson, William C; Arntzen, Evan V; Chrisler, William B; Chu, Rosalie K; Fansler, Sarah J; Graham, Emily B; Kennedy, David W; Resch, Charles T; Tfaily, Malak; Zachara, John

    2018-02-08

    The hyporheic corridor (HC) encompasses the river-groundwater continuum, where the mixing of groundwater (GW) with river water (RW) in the HC can stimulate biogeochemical activity. Here we propose a novel thermodynamic mechanism underlying this phenomenon and reveal broader impacts on dissolved organic carbon (DOC) and microbial ecology. We show that thermodynamically favorable DOC accumulates in GW despite lower DOC concentration, and that RW contains thermodynamically less-favorable DOC, but at higher concentrations. This indicates that GW DOC is protected from microbial oxidation by low total energy within the DOC pool, whereas RW DOC is protected by lower thermodynamic favorability of carbon species. We propose that GW-RW mixing overcomes these protections and stimulates respiration. Mixing models coupled with geophysical and molecular analyses further reveal tipping points in spatiotemporal dynamics of DOC and indicate important hydrology-biochemistry-microbial feedbacks. Previously unrecognized thermodynamic mechanisms regulated by GW-RW mixing may therefore strongly influence biogeochemical and microbial dynamics in riverine ecosystems.

  12. Change of heavy metal speciation, mobility, bioavailability, and ecological risk during potassium ferrate treatment of waste-activated sludge.

    Science.gov (United States)

    Yu, Ming; Zhang, Jian; Tian, Yu

    2018-05-01

    The effects of potassium ferrate treatment on the heavy metal concentrations, speciation, mobility, bioavailability, and environmental risk in waste-activated sludge (WAS) at various dosages of potassium ferrate and different treatment times were investigated. Results showed that the total concentrations of all metals (except Cd) were decreased slightly after treatment and the order of metal concentrations in WAS and treated waste-activated sludge (TWAS) was Mg > Zn > Cu > Cr > Pb > Ni > Cd. Most heavy metals in WAS remained in TWAS after potassium ferrate treatment with metal residual rates over 67.8% in TWAS. The distribution of metal speciation in WAS was affected by potassium ferrate treatment. The bioavailability and the mobility of heavy metals (except Mg) in TWAS were mitigated, compared to those in WAS. Meanwhile, the environmental risk of heavy metals (except Pb and Cu) was alleviated after potassium ferrate treatment.

  13. Big questions, big science: meeting the challenges of global ecology.

    Science.gov (United States)

    Schimel, David; Keller, Michael

    2015-04-01

    Ecologists are increasingly tackling questions that require significant infrastucture, large experiments, networks of observations, and complex data and computation. Key hypotheses in ecology increasingly require more investment, and larger data sets to be tested than can be collected by a single investigator's or s group of investigator's labs, sustained for longer than a typical grant. Large-scale projects are expensive, so their scientific return on the investment has to justify the opportunity cost-the science foregone because resources were expended on a large project rather than supporting a number of individual projects. In addition, their management must be accountable and efficient in the use of significant resources, requiring the use of formal systems engineering and project management to mitigate risk of failure. Mapping the scientific method into formal project management requires both scientists able to work in the context, and a project implementation team sensitive to the unique requirements of ecology. Sponsoring agencies, under pressure from external and internal forces, experience many pressures that push them towards counterproductive project management but a scientific community aware and experienced in large project science can mitigate these tendencies. For big ecology to result in great science, ecologists must become informed, aware and engaged in the advocacy and governance of large ecological projects.

  14. Population genetics meets ecological genomics and community ecology in Cornus Florida

    Science.gov (United States)

    Understanding evolutionary/ecological consequences of alien pests on native forests is important to conservation. Cornus florida L. subsp. florida is an ecologically important understory tree in forests of the eastern United States but faces heavy mortality from dogwood anthracnose. Understanding ge...

  15. Speciation of heavy metals in different grain sizes of Jiaozhou Bay sediments: Bioavailability, ecological risk assessment and source analysis on a centennial timescale.

    Science.gov (United States)

    Kang, Xuming; Song, Jinming; Yuan, Huamao; Duan, Liqin; Li, Xuegang; Li, Ning; Liang, Xianmeng; Qu, Baoxiao

    2017-09-01

    Heavy metal contamination is an essential indicator of environmental health. In this work, one sediment core was used for the analysis of the speciation of heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) in Jiaozhou Bay sediments with different grain sizes. The bioavailability, sources and ecological risk of heavy metals were also assessed on a centennial timescale. Heavy metals were enriched in grain sizes of Pb > Cd > Zn > Cu >Ni > Cr > As. Enrichment factors (EF) indicated that heavy metals in Jiaozhou Bay presented from no enrichment to minor enrichment. The potential ecological risk index (RI) indicated that Jiaozhou Bay had been suffering from a low ecological risk and presented an increasing trend since 1940s owing to the increase of anthropogenic activities. The source analysis indicated that natural sources were primary sources of heavy metals in Jiaozhou Bay and anthropogenic sources of heavy metals presented an increasing trend since 1940s. The principal component analysis (PCA) indicated that Cr, Mn, Ni, Cu and Pb were primarily derived from natural sources and that Zn and Cd were influenced by shipbuilding industry. Mn, Cu, Zn and Pb may originate from both natural and anthropogenic sources. As may be influenced by agricultural activities. Moreover, heavy metals in sediments of Jiaozhou Bay were clearly influenced by atmospheric deposition and river input. Copyright © 2017. Published by Elsevier Inc.

  16. Options for meeting the ecological Reserve for a raised Clanwilliam ...

    African Journals Online (AJOL)

    A recent evaluation of the potential raising of Clanwilliam Dam included an assessment of whether the operation of the dam would meet the flow quality and quantity requirements for the protection of the downstream river and its estuary, taking Olifants/Doring River basin-level considerations into account. The implications of ...

  17. VARIATION IN SPECIES DIVERSITY AND SHELL SHAPE IN HAWAIIAN LAND SNAILS: IN SITU SPECIATION AND ECOLOGICAL RELATIONSHIPS.

    Science.gov (United States)

    Cowie, Robert H

    1995-12-01

    The native land-snail fauna of the Hawaiian islands was investigated from a combined perspective of ecological and historical, vicariant, and dispersalist biogeography. There were more than 750 described, valid species; almost all were endemic to the archipelago, many to single islands. Path analysis showed that island area, per se, had the strongest influence on numbers of species. Island altitude and number of plant communities, both strongly related to area and both dimensions of habitat diversity, also had major influences. The influence of island age was complex. A direct effect, older islands having more species, was more than counterbalanced by the strong indirect effects of age on area and altitude: older islands are smaller and lower, and smaller, lower islands had fewer species. Distance of an island from a source of colonization was of minor importance. Species richness thus appears to be related almost exclusively to evolutionary radiation in situ and not to an equilibrium between immigration and extinction. Islands need not be extremely isolated for evolutionary radiation to be more important than immigration/extinction dynamics in determining species richness, but isolation is a relative term dependent on the dispersal abilities of the organisms in question. Numbers of recorded species were also strongly correlated with collecting effort on each island, a result that stands as a warning to others involved in such studies. Numbers of species in different families were not evenly distributed across islands. Notably, Kauai had more amastrids and helicinids and fewer achatinellids than predicted; Oahu had more amastrids but fewer pupillids and succineids than predicted; Hawaii exhibited the opposite pattern from Oahu. These patterns may partly reflect the vagaries of collecting/describing effort, but some may be due to the combined effects of historical factors and competitive exclusion. The distribution of shell height/diameter was bimodal with a

  18. The role of ecologic diversification in sibling speciation of Empidonax flycatchers (Tyrannidae): multigene evidence from mtDNA.

    Science.gov (United States)

    Johnson, N K; Cicero, C

    2002-10-01

    Avian genera characterized by sibling species with distinctive habitat preferences present an evolutionary enigma in view of the more commonplace occurrence of syntopic congeners that differ strikingly in colour and pattern. No existing theory has explained the evolutionary background that led to these differences. Here we propose that great phenotypic similarity among some groups of sibling species limits their coexistence and that clues to their radiation can be seen in patterns of geographical occurrence. To illustrate our thesis we focused on the New World flycatcher genus Empidonax, a group of 15 species notorious for their great phenotypic similarity. Using 3069 base pairs of mitochondrial DNA from four genes, we produced a complete molecular phylogeny that identified four clades, three of which represent close relatives. The fourth clade includes only E. virescens, which apparently has no close living relatives. The majority of species, including many distant relatives, are completely (58.1%) or essentially (6.7%) allopatric in breeding distribution and exhibit striking ecological segregation into distinctive climate-vegetation zones. Even where ranges overlap, occupancy of the same habitat by different species is rare. Phylogenetic and distributional patterns in Empidonax suggest a peripatric model of stepwise colonization and then range expansion of small groups of pioneers during glacial periods into initially enlarging, distinctive habitats destined to be widespread during interglacials. Vicariance is not indicated in the absence of barriers of appropriate age and geographical position. Rapoport's rule that northern species have larger ranges than southern species is strongly supported.

  19. Meeting report: GSC M5 roundtable at the 13th International Society for Microbial Ecology meeting in Seattle, WA, USA August 22-27, 2010

    Science.gov (United States)

    Gilbert, Jack A.; Meyer, Folker; Knight, Rob; Field, Dawn; Kyrpides, Nikos; Yilmaz, Pelin; Wooley, John

    2010-01-01

    This report summarizes the proceedings of the Metagenomics, Metadata, Metaanalysis, Models and Metainfrastructure (M5) Roundtable at the 13th International Society for Microbial Ecology Meeting in Seattle, WA, USA August 22-27, 2010. The Genomic Standards Consortium (GSC) hosted this meeting as a community engagement exercise to describe the GSC to the microbial ecology community during this important international meeting. The roundtable included five talks given by members of the GSC, and was followed by audience participation in the form of a roundtable discussion. This report summarizes this event. Further information on the GSC and its range of activities can be found at http://www.gensc.org. PMID:21304725

  20. Meeting report: GSC M5 roundtable at the 13th International Society for Microbial Ecology meeting in Seattle, WA, USA August 22-27, 2010.

    Science.gov (United States)

    Gilbert, Jack A; Meyer, Folker; Knight, Rob; Field, Dawn; Kyrpides, Nikos; Yilmaz, Pelin; Wooley, John

    2010-12-15

    This report summarizes the proceedings of the Metagenomics, Metadata, Metaanalysis, Models and Metainfrastructure (M5) Roundtable at the 13th International Society for Microbial Ecology Meeting in Seattle, WA, USA August 22-27, 2010. The Genomic Standards Consortium (GSC) hosted this meeting as a community engagement exercise to describe the GSC to the microbial ecology community during this important international meeting. The roundtable included five talks given by members of the GSC, and was followed by audience participation in the form of a roundtable discussion. This report summarizes this event. Further information on the GSC and its range of activities can be found at http://www.gensc.org.

  1. Evolution: sympatric speciation the eusocial way

    DEFF Research Database (Denmark)

    Boomsma, Jacobus Jan; Nash, David Richard

    2014-01-01

    Sympatric speciation normally requires particular conditions of ecological niche differentiation. However, ant social parasites have been suspected to arise sympatrically, because (dis)loyalty to eusocial kin-structures induces disruptive selection for dispersal and inbreeding. A new study docume...

  2. Neutral Models with Generalised Speciation

    NARCIS (Netherlands)

    Haegeman, Bart; Etienne, Rampal S.

    Hubbell's neutral theory claims that ecological patterns such as species abundance distributions can be explained by a stochastic model based on simple assumptions. One of these assumptions, the point mutation assumption, states that every individual has the same probability to speciate. Etienne et

  3. Report on the consultants' meeting to: Outline a co-ordinated research project on trace element speciation to enhance technology transfer in this field by the development of suitable methodologies and/or the production of suitably characterised reference materials

    International Nuclear Information System (INIS)

    2001-01-01

    In the environment and in man, the total concentration of a given element in a sample is almost always comprised of two or more discrete chemical forms. The toxicological or nutritive impact of the element in the sample in the environment or when ingested by man will be dependent upon the properties of its individual components. Therefore, in order to make meaningful benefit or risk assessment statements, it is essential to have a knowledge of the forms and relative amounts of an element in a given matrix. When the analyte in question is only present at total concentrations at the trace level (mg.kg -1 ) or below, the problems involved in obtaining this information become much more complex. The term trace metal speciation has been coined to refer to the determination of the chemical forms and quantities of an analyte present in a sample at the trace (and ultra trace) level. Even at such relatively low levels, the presence or absence of specific forms of an analyte can have serious consequences in terms of trade, health and environmental management. In light of the PPAS External Reviewers' Report of the Consultants' Meeting on Analytical Quality Control Services (October 1997, Vienna) which recommended that characterisation of chemical species should be undertaken in AQCS reference materials, the Agency decided to convene a consultants' meeting specifically to advise it on the importance of trace metal speciation, the state of the art and the value of a CRP to address aspects of speciation in order to facilitate technology transfer and equip member states with appropriate tools to meet the challenges posed. Five scientists, recognised as experts in the field of trace metal speciation were identified and invited to the Agency's headquarters to act as consultants. The meeting was held at the Vienna International Centre from 23rd to 26th November 1998. The first day of the meeting was given over to presentations from the consultants on various aspects of trace element

  4. Self-consistent approach for neutral community models with speciation

    NARCIS (Netherlands)

    Haegeman, Bart; Etienne, Rampal S.

    Hubbell's neutral model provides a rich theoretical framework to study ecological communities. By incorporating both ecological and evolutionary time scales, it allows us to investigate how communities are shaped by speciation processes. The speciation model in the basic neutral model is

  5. Hitchhiking to speciation.

    Directory of Open Access Journals (Sweden)

    Daven C Presgraves

    Full Text Available The modern evolutionary synthesis codified the idea that species exist as distinct entities because intrinsic reproductive barriers prevent them from merging together. Understanding the origin of species therefore requires understanding the evolution and genetics of reproductive barriers between species. In most cases, speciation is an accident that happens as different populations adapt to different environments and, incidentally, come to differ in ways that render them reproductively incompatible. As with other reproductive barriers, the evolution and genetics of interspecific hybrid sterility and lethality were once also thought to evolve as pleiotripic side effects of adaptation. Recent work on the molecular genetics of speciation has raised an altogether different possibility-the genes that cause hybrid sterility and lethality often come to differ between species not because of adaptation to the external ecological environment but because of internal evolutionary arms races between selfish genetic elements and the genes of the host genome. Arguably one of the best examples supporting a role of ecological adaptation comes from a population of yellow monkey flowers, Mimulus guttatus, in Copperopolis, California, which recently evolved tolerance to soil contaminants from copper mines and simultaneously, as an incidental by-product, hybrid lethality in crosses with some off-mine populations. However, in new work, Wright and colleagues show that hybrid lethality is not a pleiotropic consequence of copper tolerance. Rather, the genetic factor causing hybrid lethality is tightly linked to copper tolerance and spread to fixation in Copperopolis by genetic hitchhiking.

  6. Magic cues versus magic preferences in speciation

    NARCIS (Netherlands)

    Maan, Martine E.; Seehausen, Ole

    Question: How does divergent natural selection lead to divergence in mating traits and the evolution of reproductive isolation? Background: Ecological speciation of non-allopatric taxa usually requires the evolution of an association between selective mating and the traits underlying ecological

  7. Ecology

    Science.gov (United States)

    Ternjej, Ivancica; Mihaljevic, Zlatko

    2017-10-01

    Ecology is a science that studies the mutual interactions between organisms and their environment. The fundamental subject of interest in ecology is the individual. Topics of interest to ecologists include the diversity, distribution and number of particular organisms, as well as cooperation and competition between organisms, both within and among ecosystems. Today, ecology is a multidisciplinary science. This is particularly true when the subject of interest is the ecosystem or biosphere, which requires the knowledge and input of biologists, chemists, physicists, geologists, geographists, climatologists, hydrologists and many other experts. Ecology is applied in a science of restoration, repairing disturbed sites through human intervention, in natural resource management, and in environmental impact assessments.

  8. Speciation analysis of radionuclides in the environment. NKS-B speciation project report 2007

    Energy Technology Data Exchange (ETDEWEB)

    Xiaolin Hou (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Aldahan, A. (Uppsala Univ., Dept. of Earth Science, Uppsala (Sweden)); Possnert, G. (Uppsala Univ., Tandem Lab., Uppsala (Sweden)); Lujaniene, G. (Institute of Physics, Vilnius (Lithuania)); Lehto, J. (Univ. of Helsinki, Dept. of Chemistry, Helsinki (Finland)); Salbu, B. (Norwegian Univ. of Life Sciences (UMB), AAs (Norway))

    2008-07-15

    This report describes the work carried out under the NUK-B project SPECIATION 2007. In 2007, the project partners had two meeting in April and November, organized a NUK seminar on speciation and hot particles. SPECIATION 2007 t mainly focused on two issues on speciation (1) further development of speciation methods for radionuclides, and (2) investigation of speciation of radionuclides in environment. The report summarized the work done in partners labs, which includes: (1) Further development on the speciation of 129I and 127I in water samples; (2) Speciation method for 129I and 127I in air; (3) Dynamic system for fractionation of Pu and Am in soil and sediment; (4) Investigation on Re-absorption of Pu during the fractionation of Pu in soil and sediment; (5) Speciation of 129I in North Sea surface water; (6) Partition of 137Cs and 129I in the Nordic lake sediment, pore-water and lake water; (7) Sequential extraction of Pu in soil, sediment and concrete samples, (8) Pu sorption to Mn and Fe oxides in the geological materials, (10) Investigation of the adsorbed species of lanthanides and actinides on clays surfaces. In addition, two review articles on the speciation of plutonium and iodine in environmental are planned to be submitted to an international journal for publication. (au)

  9. Speciation analysis of radionuclides in the environment. NKS-B speciation project report 2007

    International Nuclear Information System (INIS)

    Hou, Xiaolin; Aldahan, A.; Possnert, G.; Lujaniene, G.; Lehto, J.; Salbu, B.

    2008-07-01

    This report describes the work carried out under the NUK-B project SPECIATION 2007. In 2007, the project partners had two meeting in April and November, organized a NUK seminar on speciation and hot particles. SPECIATION 2007 t mainly focused on two issues on speciation (1) further development of speciation methods for radionuclides, and (2) investigation of speciation of radionuclides in environment. The report summarized the work done in partners labs, which includes: (1) Further development on the speciation of 129I and 127I in water samples; (2) Speciation method for 129I and 127I in air; (3) Dynamic system for fractionation of Pu and Am in soil and sediment; (4) Investigation on Re-absorption of Pu during the fractionation of Pu in soil and sediment; (5) Speciation of 129I in North Sea surface water; (6) Partition of 137Cs and 129I in the Nordic lake sediment, pore-water and lake water; (7) Sequential extraction of Pu in soil, sediment and concrete samples, (8) Pu sorption to Mn and Fe oxides in the geological materials, (10) Investigation of the adsorbed species of lanthanides and actinides on clays surfaces. In addition, two review articles on the speciation of plutonium and iodine in environmental are planned to be submitted to an international journal for publication. (au)

  10. The neutral theory of biodiversity with random fission speciation

    NARCIS (Netherlands)

    Etienne, Rampal S.; Haegeman, Bart

    The neutral theory of biodiversity and biogeography emphasizes the importance of dispersal and speciation to macro-ecological diversity patterns. While the influence of dispersal has been studied quite extensively, the effect of speciation has not received much attention, even though it was already

  11. Ecology

    International Nuclear Information System (INIS)

    Kalusche, D.

    1978-01-01

    The book turns to the freshment, the teacher, for preparation of ecological topics for lessons, but also to pupils of the secondary stage II, and the main course ecology. The book was knowingly held simple with the restriction to: the ecosystem and its abiotic basic functions, simple articles on population biology, bioceonotic balance ith the questions of niche formation and the life form types coherent with it, of the substance and energy household, the production biology and space-wise and time-wise differentations within an ecological system form the main points. A central role in the volume is given to the illustrations. Their variety is to show and deepen the coherences shown. (orig./HP) [de

  12. Conference Proceedings: Seed Ecology III - The Third International Society for Seed Science Meeting on Seeds and the Environment - "Seeds and Change"; June 20-June 24, 2010; Salt Lake City, Utah, USA

    Science.gov (United States)

    Rosemary Pendleton; Susan Meyer; Bitsy Schultz

    2010-01-01

    Seed Ecology III was held in Salt Lake City, Utah in June 2010, sharing the latest research on all aspects of seed ecology. Our meeting was organized around the theme "Seeds and Change." We welcomed contributions in any area of seed ecology. Our agenda also aimed to create bridges between seed ecology and plant conservation, restoration ecology, and global...

  13. Ecology and distribution of two sympatric, closely related sponge species, Halichondria panicea (Pallas, 1766) and H. bowerbanki Burton, 1930 (Porifera, Demospongiae), with remarks on their speciation

    NARCIS (Netherlands)

    Vethaak, A.D.; Cronie, R.J.A.; Soest, van R.W.M.

    1982-01-01

    North Atlantic coastal waters harbour two closely related sympatric sponges belonging to the genus Halichondria, viz. H. panicea and H. bowerbanki. From the study of their littoral and sublittoral microdistribution and ecology in the Oosterschelde area (= Eastern Scheldt, S.W. part of The

  14. Genomics meets applied ecology : Characterizing habitat quality for sloths in a tropical agro-ecosystem

    NARCIS (Netherlands)

    Fountain, Emily D; Kang, Jung Koo; Tempel, Douglas J; Palsbøll, Per J; Pauli, Jonathan N; Peery, M Zachariah

    Understanding how habitat quality in heterogeneous landscapes governs the distribution and fitness of individuals is a fundamental aspect of ecology. While mean individual fitness is generally considered a key to assessing habitat quality, a comprehensive understanding of habitat quality in

  15. Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

    OpenAIRE

    Sobolev, Konstantin

    2003-01-01

    The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA) cement helps to improve its ecologi...

  16. Cancer: an emergent property of disturbed resource-rich environments? Ecology meets personalized medicine.

    Science.gov (United States)

    Ducasse, Hugo; Arnal, Audrey; Vittecoq, Marion; Daoust, Simon P; Ujvari, Beata; Jacqueline, Camille; Tissot, Tazzio; Ewald, Paul; Gatenby, Robert A; King, Kayla C; Bonhomme, François; Brodeur, Jacques; Renaud, François; Solary, Eric; Roche, Benjamin; Thomas, Frédéric

    2015-07-01

    For an increasing number of biologists, cancer is viewed as a dynamic system governed by evolutionary and ecological principles. Throughout most of human history, cancer was an uncommon cause of death and it is generally accepted that common components of modern culture, including increased physiological stresses and caloric intake, favor cancer development. However, the precise mechanisms for this linkage are not well understood. Here, we examine the roles of ecological and physiological disturbances and resource availability on the emergence of cancer in multicellular organisms. We argue that proliferation of 'profiteering phenotypes' is often an emergent property of disturbed, resource-rich environments at all scales of biological organization. We review the evidence for this phenomenon, explore it within the context of malignancy, and discuss how this ecological framework may offer a theoretical background for novel strategies of cancer prevention. This work provides a compelling argument that the traditional separation between medicine and evolutionary ecology remains a fundamental limitation that needs to be overcome if complex processes, such as oncogenesis, are to be completely understood.

  17. Abstracts of papers of international meeting 'Ecological status of territories contaminated by radionuclides'

    International Nuclear Information System (INIS)

    Konoplya, E.F.

    1995-04-01

    The collection contains the results of investigations implemented on the territories of Belarus, Ukraine and Russia within the realization of the Chernobyl Ecological Science Network: dynamics of radionuclides migration in the environment, state of phytocenosis, metabolic and genetic effects of the Chernobyl catastrophe

  18. Abstracts of papers of International Meeting 'Ecological status of territories polluted by radionuclides'

    International Nuclear Information System (INIS)

    1995-04-01

    The collection contains the results of investigations implemented on the territories of Belarus, Ukraine and Russia within the realization of Chernobyl Ecological Science Network: dynamics of radionuclides migration in the environment, state of plant community on the areas polluted by radionuclides, biological changes of biocenoses, metabolic and genetic effects of Chernobyl catastrophe (author)

  19. Long-term ecological reflections: writers, philosophers, and scientists meet in the forest.

    Science.gov (United States)

    Jonathan Thompson

    2008-01-01

    Over the past 7 years, a strong collaboration has emerged between the H.J. Andrews Experimental Forest ecosystem research group and the Spring Creek Project for Ideas, Nature, and the Written Word, an independently funded program for nature writing based in the Department of Philosophy, Oregon State University. The program is called Long-Term Ecological Reflections and...

  20. Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

    Directory of Open Access Journals (Sweden)

    Konstantin Sobolev

    2003-01-01

    Full Text Available The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA cement helps to improve its ecological compatibility. HVMA cement technology is based on the intergrinding of portland cement clinker, gypsum, mineral additives, and a special complex admixture. This new method increases the compressive strength of ordinary cement, improves durability of the cement-based materials, and - at the same time - uses inexpensive natural mineral additives or industrial by-products. This improvement leads to a reduction of energy consumption per unit of the cement produced. Higher strength, better durability, reduction of pollution at the clinker production stage, and decrease of landfill area occupied by industrial by-products, all provide ecological advantages for HVMA cement.

  1. Genomics of Rapid Incipient Speciation in Sympatric Threespine Stickleback.

    Directory of Open Access Journals (Sweden)

    David A Marques

    2016-02-01

    Full Text Available Ecological speciation is the process by which reproductively isolated populations emerge as a consequence of divergent natural or ecologically-mediated sexual selection. Most genomic studies of ecological speciation have investigated allopatric populations, making it difficult to infer reproductive isolation. The few studies on sympatric ecotypes have focused on advanced stages of the speciation process after thousands of generations of divergence. As a consequence, we still do not know what genomic signatures of the early onset of ecological speciation look like. Here, we examined genomic differentiation among migratory lake and resident stream ecotypes of threespine stickleback reproducing in sympatry in one stream, and in parapatry in another stream. Importantly, these ecotypes started diverging less than 150 years ago. We obtained 34,756 SNPs with restriction-site associated DNA sequencing and identified genomic islands of differentiation using a Hidden Markov Model approach. Consistent with incipient ecological speciation, we found significant genomic differentiation between ecotypes both in sympatry and parapatry. Of 19 islands of differentiation resisting gene flow in sympatry, all were also differentiated in parapatry and were thus likely driven by divergent selection among habitats. These islands clustered in quantitative trait loci controlling divergent traits among the ecotypes, many of them concentrated in one region with low to intermediate recombination. Our findings suggest that adaptive genomic differentiation at many genetic loci can arise and persist in sympatry at the very early stage of ecotype divergence, and that the genomic architecture of adaptation may facilitate this.

  2. Meeting of the IUFRO Working Party “Ecological and Population Genetics”

    CERN Document Server

    1985-01-01

    When we consider the main object of forestry, the tree, it immediately becomes clear why experimental population geneticists have been so hesitant in making this object a primary concern of their research. Trees are very long-living organisms with generation intervals frequently exceeding those of their investigators by multiples. They virtually exclude, therefore, application of the classical methods of population genetics since these are based on observing genetic structures over generations. This situation, where the limits set to observation are so severe, particularly requires close cooperation between theory and experiment. It also requires careful consideration of results obtained for organisms other than trees, in order to gain additional insights by comparing the results for trees with those for other organisms. Yet, the greatest challenge to population and ecological genetics probably originates from the fact that forests are very likely to be the most complex ecosystems of all, even in some cases w...

  3. Ecophysiology Tracks Phylogeny and Meets Ecological Models in an Iberian Gecko.

    Science.gov (United States)

    Rato, C; Carretero, M A

    2015-01-01

    Because fitness of ectotherms, including reptiles, is highly dependent on temperature and water availability, the study of ecophysiological traits, such as preferred temperature (T p) and water loss rates (WLRs), may provide mechanistic evidence on the restricting factors to the species ranges. The Moorish gecko, Tarentola mauritanica, is a species complex with a circum-Mediterranean distribution. In the Iberian Peninsula, two sister parapatric forms of the complex, known as the Iberian and the European clades, are found. Ecological models previously performed using presence records and bioclimatic variables suggest niche divergence between both lineages correlated with precipitation rather than with temperature. In this study, we test this correlative hypothesis using ecophysiological evidence. In the laboratory, we analyzed the T p and WLRs for 84 adult males from seven distinct populations ascribed to one of the two lineages present in Iberia. Specifically, we evaluated the existence of trait conservatism versus adaptation among populations, lineages, or both. In addition, we tested for a trade-off between water and thermal traits and assessed whether climate regime of sampling localities had any influence on the ecophysiological patterns found. We found that T p is quite conserved at both the population and lineage levels and independent from body size. In contrast, water loss experiments revealed some variation among populations, but the regression analysis failed to detect correlation between T p and WLR at any level. Overall, the European lineage displayed a trend for higher water loss and was more diverse among populations when compared with the Iberian lineage. The lack of correspondence between ecophysiological traits and local climatic conditions favors phylogenetic signal versus adaptation. This suggests divergent evolutionary responses to the environment, mainly acting on water ecology, in both lineages, which may account for the differences in their

  4. Arsenic speciation results

    Data.gov (United States)

    U.S. Environmental Protection Agency — Linear combination fitting results of synchrotron data to determine arsenic speciation in soil samples. This dataset is associated with the following publication:...

  5. Chemical Speciation - General Information

    Science.gov (United States)

    This page includes general information about the Chemical Speciation Network that is not covered on the main page. Commonly visited documents, including calendars, site lists, and historical files for the program are listed here

  6. Searching for speciation genes

    DEFF Research Database (Denmark)

    Holt, Benjamin George; Côté, Isabelle M; Emerson, Brent C

    2011-01-01

    Closely related species that show clear phenotypic divergence, but without obvious geographic barriers, can provide opportunities to study how diversification can occur when opportunities for allopatric speciation are limited. We examined genetic divergence in the coral reef fish genus Hypoplectrus...

  7. Uranium speciation in plants

    International Nuclear Information System (INIS)

    Guenther, A.; Bernhard, G.; Geipel, G.; Reich, T.; Rossberg, A.; Nitsche, H.

    2003-01-01

    Detailed knowledge of the nature of uranium complexes formed after the uptake by plants is an essential prerequisite to describe the migration behavior of uranium in the environment. This study focuses on the determination of uranium speciation after uptake of uranium by lupine plants. For the first time, time-resolved laser-induced fluorescence spectroscopy and X-ray absorption spectroscopy were used to determine the chemical speciation of uranium in plants. Differences were detected between the uranium speciation in the initial solution (hydroponic solution and pore water of soil) and inside the lupine plants. The oxidation state of uranium did not change and remained hexavalent after it was taken up by the lupine plants. The chemical speciation of uranium was identical in the roots, shoot axis, and leaves and was independent of the uranium speciation in the uptake solution. The results indicate that the uranium is predominantly bound as uranyl(VI) phosphate to the phosphoryl groups. Dandelions and lamb's lettuce showed uranium speciation identical to lupine plants. (orig.)

  8. Mosquitoes meet microfluidics: High-throughput microfluidic tools for insect-parasite ecology in field conditions

    Science.gov (United States)

    Prakash, Manu; Mukundarajan, Haripriya

    2013-11-01

    A simple bite from an insect is the transmission mechanism for many deadly diseases worldwide--including malaria, yellow fever, west nile and dengue. Very little is known about how populations of numerous insect species and disease-causing parasites interact in their natural habitats due to a lack of measurement techniques. At present, vector surveillance techniques involve manual capture by using humans as live bait, which is hard to justify on ethical grounds. Individual mosquitoes are manually dissected to isolate salivary glands to detect sporozites. With typical vector infection rates being very low even in endemic areas, it is almost impossible to get an accurate picture of disease distribution, in both space and time. Here we present novel high-throughput microfluidic tools for vector surveillance, specifically mosquitoes. A two-dimensional high density array with baits provide an integrated platform for multiplex PCR for detection of both vector and parasite species. Combining techniques from engineering and field ecology, methods and tools developed here will enable high-throughput measurement of infection rates for a number of diseases in mosquito populations in field conditions. Pew Foundation.

  9. Five species, many genotypes, broad phenotypic diversity: When agronomy meets functional ecology.

    Science.gov (United States)

    Prieto, Ivan; Litrico, Isabelle; Violle, Cyrille; Barre, Philippe

    2017-01-01

    Current ecological theory can provide insight into the causes and impacts of plant domestication. However, just how domestication has impacted intraspecific genetic variability (ITV) is unknown. We used 50 ecotypes and 35 cultivars from five grassland species to explore how selection drives functional trait coordination and genetic differentiation. We quantified the extent of genetic diversity among different sets of functional traits and determined how much genetic diversity has been generated within populations of natural ecotypes and selected cultivars. In general, the cultivars were larger (e.g., greater height, faster growth rates) and had larger and thinner leaves (greater SLA). We found large (average 63%) and trait-dependent (ranging from 14% for LNC to 95.8% for growth rate) genetic variability. The relative extent of genetic variability was greater for whole-plant than for organ-level traits. This pattern was consistent within ecotypes and within cultivars. However, ecotypes presented greater ITV variability. The results indicated that genetic diversity is large in domesticated species with contrasting levels of heritability among functional traits and that selection for high yield has led to indirect selection of some associated leaf traits. These findings open the way to define which target traits should be the focus in selection programs, especially in the context of community-level selection. © 2017 Botanical Society of America.

  10. Patterns of plant speciation in the Cape floristic region.

    Science.gov (United States)

    van der Niet, Timotheüs; Johnson, Steven D

    2009-04-01

    Plant species have accumulated in the Cape region of southern Africa to a much greater degree than in areas of equivalent size in the rest of the subcontinent. Although this could be a consequence simply of lower extinction rates in the Cape, most researchers have invoked high rates of ecological speciation, driven by unique aspects of the Cape environment, as the primary explanation for this richness. To assess these ideas, we analyzed the frequencies of ecological shifts among 188 sister species pairs obtained from molecular phylogenies of eight Cape clades. Ecological shifts were evident in 80% of sister species pairs, with general habitat, pollinator, and fire-survival strategy shifts being especially frequent. Contrary to an established idea that shifts in soil type are frequently associated with speciation of Cape taxa, these shifts were relatively rare, occurring in just 17% of species pairs. More cases of sister species divergence are accompanied solely by floral than by vegetative diversification, suggesting an important role for pollinator-driven speciation. In an analysis of two large orchid genera that have radiated in both the Cape and the rest of southern Africa, the frequency of ecological shifts (general habitat, soil type, altitude and flowering time), did not differ between sister species pairs in the Cape region and those outside it. Despite suggestions that Cape plants tend to have small range sizes and show fine-scale patterns of speciation, range size did not differ significantly between species in the Cape and those outside it. We conclude that ecological speciation is likely to have been important for radiation of the Cape flora, but there is no evidence as yet for special "Cape" patterns of ecological speciation.

  11. Genomics meets applied ecology: Characterizing habitat quality for sloths in a tropical agroecosystem.

    Science.gov (United States)

    Fountain, Emily D; Kang, Jung Koo; Tempel, Douglas J; Palsbøll, Per J; Pauli, Jonathan N; Zachariah Peery, M

    2018-01-01

    Understanding how habitat quality in heterogeneous landscapes governs the distribution and fitness of individuals is a fundamental aspect of ecology. While mean individual fitness is generally considered a key to assessing habitat quality, a comprehensive understanding of habitat quality in heterogeneous landscapes requires estimates of dispersal rates among habitat types. The increasing accessibility of genomic approaches, combined with field-based demographic methods, provides novel opportunities for incorporating dispersal estimation into assessments of habitat quality. In this study, we integrated genomic kinship approaches with field-based estimates of fitness components and approximate Bayesian computation (ABC) procedures to estimate habitat-specific dispersal rates and characterize habitat quality in two-toed sloths (Choloepus hoffmanni) occurring in a Costa Rican agricultural ecosystem. Field-based observations indicated that birth and survival rates were similar in a sparsely shaded cacao farm and adjacent cattle pasture-forest mosaic. Sloth density was threefold higher in pasture compared with cacao, whereas home range size and overlap were greater in cacao compared with pasture. Dispersal rates were similar between the two habitats, as estimated using ABC procedures applied to the spatial distribution of pairs of related individuals identified using 3,431 single nucleotide polymorphism and 11 microsatellite locus genotypes. Our results indicate that crops produced under a sparse overstorey can, in some cases, constitute lower-quality habitat than pasture-forest mosaics for sloths, perhaps because of differences in food resources or predator communities. Finally, our study demonstrates that integrating field-based demographic approaches with genomic methods can provide a powerful means for characterizing habitat quality for animal populations occurring in heterogeneous landscapes. © 2017 John Wiley & Sons Ltd.

  12. Defining ecological and economical hydropoweroperations: a framework for managing dam releasesto meet multiple conflicting objectives

    Science.gov (United States)

    Irwin, Elise R.

    2014-01-01

    Hydroelectric dams are a flexible source of power, provide flood control, and contribute to the economic growth of local communities through real-estate and recreation. Yet the impoundment of rivers can alter and fragment miles of critical riverine habitat needed for other competing needs such as downstream consumptive water use, fish and wildlife population viability, or other forms of recreation. Multiple conflicting interests can compromise progressive management especially with recognized uncertainties related to whether management actions will fulfill the objectives of policy makers, resource managers and/or facility owners. Decision analytic tools were used in a stakeholder-driven process to develop and implement a template for evaluation and prediction of the effects of water resource management of multiple-use systems under the context provided by R.L. Harris Dam on the Tallapoosa River, Alabama, USA. The approach provided a transparent and structured framework for decision-making and incorporated both existing and new data to meet multiple management objectives. Success of the template has been evaluated by the stakeholder governing body in an adaptive resource management framework since 2005 and is ongoing. Consequences of management of discharge at the dam were evaluated annually relative to stakeholder satisfaction to allow for adjustment of both management scenarios and objectives. This template can be applied to attempt to resolve conflict inherent in many dam-regulated systems where management decisions impact diverse values of stakeholders.

  13. Differential survival between visual environments supports a role of divergent sensory drive in cichlid fish speciation

    NARCIS (Netherlands)

    Maan, Martine E.; Seehausen, Ole; Groothuis, Ton G. G.

    Identifying the selective forces that initiate ecological speciation is a major challenge in evolutionary biology. Sensory drive has been implicated in speciation in various taxa, largely based on phenotype-environment correlations and signatures of selection in sensory genes. Here, we present a

  14. Mimetic Divergence and the Speciation Continuum in the Mimic Poison Frog Ranitomeya imitator

    DEFF Research Database (Denmark)

    Twomey, Evan; Vestergaard, Jacob Schack; Venegas, Pablo J.

    2016-01-01

    While divergent ecological adaptation can drive speciation, understanding the factors that facilitate or constrain this process remains a major goal in speciation research. Here, we study two mimetic transition zones in the poison frog Ranitomeya imitator, a species that has undergone a Mullerian...

  15. Self-consistent approach for neutral community models with speciation

    Science.gov (United States)

    Haegeman, Bart; Etienne, Rampal S.

    2010-03-01

    Hubbell’s neutral model provides a rich theoretical framework to study ecological communities. By incorporating both ecological and evolutionary time scales, it allows us to investigate how communities are shaped by speciation processes. The speciation model in the basic neutral model is particularly simple, describing speciation as a point-mutation event in a birth of a single individual. The stationary species abundance distribution of the basic model, which can be solved exactly, fits empirical data of distributions of species’ abundances surprisingly well. More realistic speciation models have been proposed such as the random-fission model in which new species appear by splitting up existing species. However, no analytical solution is available for these models, impeding quantitative comparison with data. Here, we present a self-consistent approximation method for neutral community models with various speciation modes, including random fission. We derive explicit formulas for the stationary species abundance distribution, which agree very well with simulations. We expect that our approximation method will be useful to study other speciation processes in neutral community models as well.

  16. Sexual selection and magic traits in speciation with gene flow

    Directory of Open Access Journals (Sweden)

    Maria R. SERVEDIO, Michael KOPP

    2012-06-01

    Full Text Available The extent to which sexual selection is involved in speciation with gene flow remains an open question and the subject of much research. Here, we propose that some insight can be gained from considering the concept of magic traits (i.e., traits involved in both reproductive isolation and ecological divergence. Both magic traits and other, “non-magic”, traits can contribute to speciation via a number of specific mechanisms. We argue that many of these mechanisms are likely to differ widely in the extent to which they involve sexual selection. Furthermore, in some cases where sexual selection is present, it may be prone to inhibit rather than drive speciation. Finally, there are a priori reasons to believe that certain categories of traits are much more effective than others in driving speciation. The combination of these points suggests a classification of traits that may shed light on the broader role of sexual selection in speciation with gene flow. In particular, we suggest that sexual selection can act as a driver of speciation in some scenarios, but may play a negligible role in potentially common categories of magic traits, and may be likely to inhibit speciation in common categories of non-magic traits [Current Zoology 58 (3: 507–513, 2012].

  17. Meeting

    Indian Academy of Sciences (India)

    July 1989 No.19 Newsletter of the Indian Academy of Sciences. 55th Annual. Meeting ... in the world, keeping alive atthe same time his research interests, abreast .... theory made a comeback with many new ideas and with the success of the ...

  18. Speciation of long-lived radionuclides in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Xiaolin Hou

    2008-11-15

    This project started in November 2005 and ended in November 2008, the work and research approaches are summarized in this report. This project studied the speciation of radionuclides in environment. A number of speciation analytical methods are developed for determination of species of 129I, 99Tc, isotopes of Pu, and 237Np in seawater, fresh water, soil, sediment, vegetations, and concrete. The developed methods are used for the investigation of the chemical speciation of these radionuclides as well as their environmental behaviours, especially in Danish environment. In addition the speciation of Pu isotopes in waste samples from the decommissioning of Danish nuclear facilities is also investigated. The report summarizes these works completed in this project. Through this research project, a number of research papers have been published in the scientific journals, the research results has also been presented in the Nordic and international conference/meeting and communicated to international colleagues. Some publications are also enclosed to this report. (au)

  19. Chemical speciation of long-lived radionuclides in the environment

    International Nuclear Information System (INIS)

    Xiaolin Hou

    2008-11-01

    This project started in November 2005 and ended in November 2008, the work and research approaches are summarized in this report. This project studied the speciation of radionuclides in environment. A number of speciation analytical methods are developed for determination of species of 129 I, 99 Tc, isotopes of Pu, and 237 Np in seawater, fresh water, soil, sediment, vegetations, and concrete. The developed methods are used for the investigation of the chemical speciation of these radionuclides as well as their environmental behaviours, especially in Danish environment. In addition the speciation of Pu isotopes in waste samples from the decommissioning of Danish nuclear facilities is also investigated. The report summarizes these works completed in this project. Through this research project, a number of research papers have been published in the scientific journals, the research results has also been presented in the Nordic and international conference/meeting and communicated to international colleagues. Some publications are also enclosed to this report. (au)

  20. Speciation driven by hybridization and chromosomal plasticity in a wild yeast.

    Science.gov (United States)

    Leducq, Jean-Baptiste; Nielly-Thibault, Lou; Charron, Guillaume; Eberlein, Chris; Verta, Jukka-Pekka; Samani, Pedram; Sylvester, Kayla; Hittinger, Chris Todd; Bell, Graham; Landry, Christian R

    2016-01-11

    Hybridization is recognized as a powerful mechanism of speciation and a driving force in generating biodiversity. However, only few multicellular species, limited to a handful of plants and animals, have been shown to fulfil all the criteria of homoploid hybrid speciation. This lack of evidence could lead to the interpretation that speciation by hybridization has a limited role in eukaryotes, particularly in single-celled organisms. Laboratory experiments have revealed that fungi such as budding yeasts can rapidly develop reproductive isolation and novel phenotypes through hybridization, showing that in principle homoploid speciation could occur in nature. Here, we report a case of homoploid hybrid speciation in natural populations of the budding yeast Saccharomyces paradoxus inhabiting the North American forests. We show that the rapid evolution of chromosome architecture and an ecological context that led to secondary contact between nascent species drove the formation of an incipient hybrid species with a potentially unique ecological niche.

  1. Heavy metal speciation and their accumulation in sediments of Lake ...

    African Journals Online (AJOL)

    UFUOMA

    Key words: Heavy metals, chemical speciation, sediments, Burullus, Lake. INTRODUCTION ..... fuel for use in internal combustion engines and in making batteries. ..... (Tuner, 1989). According to this model, human risk assessment was .... 593 - 594. Hökanson L (1980). "Ecological Risk Index for Aquatic Pollution. Control.

  2. The reality and importance of founder speciation in evolution.

    Science.gov (United States)

    Templeton, Alan R

    2008-05-01

    A founder event occurs when a new population is established from a small number of individuals drawn from a large ancestral population. Mayr proposed that genetic drift in an isolated founder population could alter the selective forces in an epistatic system, an observation supported by recent studies. Carson argued that a period of relaxed selection could occur when a founder population is in an open ecological niche, allowing rapid population growth after the founder event. Selectable genetic variation can actually increase during this founder-flush phase due to recombination, enhanced survival of advantageous mutations, and the conversion of non-additive genetic variance into additive variance in an epistatic system, another empirically confirmed prediction. Templeton combined the theories of Mayr and Carson with population genetic models to predict the conditions under which founder events can contribute to speciation, and these predictions are strongly confirmed by the empirical literature. Much of the criticism of founder speciation is based upon equating founder speciation to an adaptive peak shift opposed by selection. However, Mayr, Carson and Templeton all modeled a positive interaction of selection and drift, and Templeton showed that founder speciation is incompatible with peak-shift conditions. Although rare, founder speciation can have a disproportionate importance in adaptive innovation and radiation, and examples are given to show that "rare" does not mean "unimportant" in evolution. Founder speciation also interacts with other speciation mechanisms such that a speciation event is not a one-dimensional process due to either selection alone or drift alone. (c) 2008 Wiley Periodicals, Inc.

  3. Interaction between Digestive Strategy and Niche Specialization Predicts Speciation Rates across Herbivorous Mammals.

    Science.gov (United States)

    Tran, Lucy A P

    2016-04-01

    Biotic and abiotic factors often are treated as mutually exclusive drivers of diversification processes. In this framework, ecological specialists are expected to have higher speciation rates than generalists if abiotic factors are the primary controls on species diversity but lower rates if biotic interactions are more important. Speciation rate is therefore predicted to positively correlate with ecological specialization in the purely abiotic model but negatively correlate in the biotic model. In this study, I show that the positive relationship between ecological specialization and speciation expected from the purely abiotic model is recovered only when a species-specific trait, digestive strategy, is modeled in the terrestrial, herbivorous mammals (Mammalia). This result suggests a more nuanced model in which the response of specialized lineages to abiotic factors is dependent on a biological trait. I also demonstrate that the effect of digestive strategy on the ecological specialization-speciation rate relationship is not due to a difference in either the degree of ecological specialization or the speciation rate between foregut- and hindgut-fermenting mammals. Together, these findings suggest that a biological trait, alongside historical abiotic events, played an important role in shaping mammal speciation at long temporal and large geographic scales.

  4. Shaping the future of marine socio-ecological systems research: when early-career researchers meet the seniors

    NARCIS (Netherlands)

    Drakou, Evangelia G.; Kermagoret, Charlène; Comte, Adrien; Trapman, Brita; Rice, Jake C.

    2017-01-01

    As the environmental issues facing our planet change, scientific efforts need to inform the sustainable management of marine resources by adopting a socio-ecological systems approach. Taking the symposium on “Understanding marine socio-ecological systems: including the human dimension in Integrated

  5. Extensive range overlap between heliconiine sister species: evidence for sympatric speciation in butterflies?

    Science.gov (United States)

    Rosser, Neil; Kozak, Krzysztof M; Phillimore, Albert B; Mallet, James

    2015-06-30

    Sympatric speciation is today generally viewed as plausible, and some well-supported examples exist, but its relative contribution to biodiversity remains to be established. We here quantify geographic overlap of sister species of heliconiine butterflies, and use age-range correlations and spatial simulations of the geography of speciation to infer the frequency of sympatric speciation. We also test whether shifts in mimetic wing colour pattern, host plant use and climate niche play a role in speciation, and whether such shifts are associated with sympatry. Approximately a third of all heliconiine sister species pairs exhibit near complete range overlap, and analyses of the observed patterns of range overlap suggest that sympatric speciation contributes 32%-95% of speciation events. Müllerian mimicry colour patterns and host plant choice are highly labile traits that seem to be associated with speciation, but we find no association between shifts in these traits and range overlap. In contrast, climatic niches of sister species are more conserved. Unlike birds and mammals, sister species of heliconiines are often sympatric and our inferences using the most recent comparative methods suggest that sympatric speciation is common. However, if sister species spread rapidly into sympatry (e.g. due to their similar climatic niches), then assumptions underlying our methods would be violated. Furthermore, although we find some evidence for the role of ecology in speciation, ecological shifts did not show the associations with range overlap expected under sympatric speciation. We delimit species of heliconiines in three different ways, based on "strict and " "relaxed" biological species concepts (BSC), as well as on a surrogate for the widely-used "diagnostic" version of the phylogenetic species concept (PSC). We show that one reason why more sympatric speciation is inferred in heliconiines than in birds may be due to a different culture of species delimitation in the two

  6. Arsenic Speciation in Groundwater: Role of Thioanions

    Science.gov (United States)

    The behavior of arsenic in groundwater environments is fundamentally linked to its speciation. Understanding arsenic speciation is important because chemical speciation impacts reactivity, bioavailability, toxicity, and transport and fate processes. In aerobic environments arsen...

  7. Adaptive divergence with gene flow in incipient speciation of Miscanthus floridulus / sinensis complex (Poaceae)

    KAUST Repository

    Huang, Chao-Li; Ho, Chuan-Wen; Chiang, Yu-Chung; Shigemoto, Yasumasa; Hsu, Tsai-Wen; Hwang, Chi-Chuan; Ge, Xue-Jun; Chen, Charles; Wu, Tai-Han; Chou, Chang-Hung; Huang, Hao-Jen; Gojobori, Takashi; Osada, Naoki; Chiang, Tzen-Yuh

    2014-01-01

    Young incipient species provide ideal materials for untangling the process of ecological speciation in the presence of gene flow. The Miscanthus floridulus/sinensis complex exhibits diverse phenotypic and ecological differences despite recent divergence (approximately 1.59million years ago). To elucidate the process of genetic differentiation during early stages of ecological speciation, we analyzed genomic divergence in the Miscanthus complex using 72 randomly selected genes from a newly assembled transcriptome. In this study, rampant gene flow was detected between species, estimated as M=3.36x10(-9) to 1.20x10(-6), resulting in contradicting phylogenies across loci. Nevertheless, beast analyses revealed the species identity and the effects of extrinsic cohesive forces that counteracted the non-stop introgression. As expected, early in speciation with gene flow, only 3-13 loci were highly diverged; two to five outliers (approximately 2.78-6.94% of the genome) were characterized by strong linkage disequilibrium, and asymmetrically distributed among ecotypes, indicating footprints of diversifying selection. In conclusion, ecological speciation of incipient species of Miscanthus probably followed the parapatric model, whereas allopatric speciation cannot be completely ruled out, especially between the geographically isolated northern and southern M.sinensis, for which no significant gene flow across oceanic barriers was detected. Divergence between local ecotypes in early-stage speciation began at a few genomic regions under the influence of natural selection and divergence hitchhiking that overcame gene flow.

  8. Adaptive divergence with gene flow in incipient speciation of Miscanthus floridulus / sinensis complex (Poaceae)

    KAUST Repository

    Huang, Chao-Li

    2014-11-11

    Young incipient species provide ideal materials for untangling the process of ecological speciation in the presence of gene flow. The Miscanthus floridulus/sinensis complex exhibits diverse phenotypic and ecological differences despite recent divergence (approximately 1.59million years ago). To elucidate the process of genetic differentiation during early stages of ecological speciation, we analyzed genomic divergence in the Miscanthus complex using 72 randomly selected genes from a newly assembled transcriptome. In this study, rampant gene flow was detected between species, estimated as M=3.36x10(-9) to 1.20x10(-6), resulting in contradicting phylogenies across loci. Nevertheless, beast analyses revealed the species identity and the effects of extrinsic cohesive forces that counteracted the non-stop introgression. As expected, early in speciation with gene flow, only 3-13 loci were highly diverged; two to five outliers (approximately 2.78-6.94% of the genome) were characterized by strong linkage disequilibrium, and asymmetrically distributed among ecotypes, indicating footprints of diversifying selection. In conclusion, ecological speciation of incipient species of Miscanthus probably followed the parapatric model, whereas allopatric speciation cannot be completely ruled out, especially between the geographically isolated northern and southern M.sinensis, for which no significant gene flow across oceanic barriers was detected. Divergence between local ecotypes in early-stage speciation began at a few genomic regions under the influence of natural selection and divergence hitchhiking that overcame gene flow.

  9. Speciation environments and centres of diversity in southern Africa. I. Conceptual framework

    Directory of Open Access Journals (Sweden)

    E. R. Robinson

    1982-10-01

    Full Text Available A knowledge of the nature and distribution of the environments where speciation (micro-evolution is or has been rapid would help explain plant distributions and give insight into the mechanisms of plant evolution. Before southern African speciation environments can be identified and described, a number of basic theoretical concepts have to be clarified. In this paper the major taxonomic, systematic, floristic, ecological and evolutionary ideas pertinent to speciation environments are reviewed and discussed. Despite many publications about species concepts, species diversity, modes of speciation and the relationship between environments and genetic variability within taxa, it is still not possible to make predictions about the kinds of environments that favour speciation.

  10. Review: Speciation in the myrtle family (Myrtaceae: rapid and slow models

    Directory of Open Access Journals (Sweden)

    PUDJI WIDODO

    2007-01-01

    Full Text Available Speciation or formation of new species is a process which may take very long time. When a new species is really formed from a previous species is still unknown exactly. However, sometimes when populations no longer interbreed, they are thought to be separate species. As natural selection, if populations adapt the occupying different environments, they will diverge into races, subspecies, and finally separate species. There are some models of speciation such as geographical, polyploidy, chromosomal, and ecological speciation. However, in the myrtle family (Myrtaceae they can be grouped into two big models of speciation namely the rapid and slow speciation. This review points out that hybridization is a major factor affecting Myrtaceae, although evolution activities were also approved by the fact that some fossil pollens have been found in Antartica

  11. Speciation analysis of radionuclides

    International Nuclear Information System (INIS)

    Salbu, B.

    2010-01-01

    Full text: Naturally occurring and artificially produced radionuclides in the environment can be present in different physico-chemical forms (i. e. radionuclide species) varying in size (nominal molecular mass), charge properties and valence, oxidation state, structure and morphology, density, complexing ability etc. Low molecular mass (LMM) species are believed to be mobile and potentially bioavailable, while high molecular mass (HMM) species such as colloids, polymers, pseudocolloids and particles are considered inert. Due to time dependent transformation processes such as mobilization of radionuclide species from solid phases or interactions of mobile and reactive radionuclide species with components in soils and sediments, however, the original distribution of radionuclides deposited in ecosystems will change over time and influence the ecosystem behaviour. To assess the environmental impact from radionuclide contamination, information on radionuclide species deposited, interactions within affected ecosystems and the time-dependent distribution of radionuclide species influencing mobility and biological uptake is essential. The development of speciation techniques to characterize radionuclide species in waters, soils and sediments should therefore be essential for improving the prediction power of impact and risk assessment models. The present paper reviews fractionation techniques which should be utilised for radionuclide speciation purposes. (author)

  12. Society of Environmental Toxicology and Chemistry 15th annual meeting: Abstract book. Ecological risk: Science, policy, law, and perception

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    The purpose of this conference was to provide a forum for exchange of state-of-the-art information on the ecological risks of toxic chemicals. Presentations covered research in the following areas: environmental transport; monitoring; pollution sources; analysis; remediation; policies; environmental effects; and biological effects. Individual papers have been processed separately for inclusion in the appropriate data bases

  13. Earthworms as Invasive Species in Latin America — the 2nd Latin American Meeting on Oligochaeta (Earthworm) Ecology and Taxonomy

    Science.gov (United States)

    Grizelle Gonzalez

    2006-01-01

    This special issue is based on scientific contributions presented at the 2nd Latin American Symposium of Earthworm Ecology and Taxonomy (ELAETAO, for its Spanish acronym) held in San Juan, Puerto Rico November 14-18, 2005. The first of these symposia was organized by George G. Brown and Klaus D. Sautter and held at Londrina, Brazil from December 1-3, 2003.The objective...

  14. Electrophysiology Meets Ecology: Investigating How Vision is Tuned to the Life Style of an Animal using Electroretinography.

    Science.gov (United States)

    Stowasser, Annette; Mohr, Sarah; Buschbeck, Elke; Vilinsky, Ilya

    2015-01-01

    Students learn best when projects are multidisciplinary, hands-on, and provide ample opportunity for self-driven investigation. We present a teaching unit that leads students to explore relationships between sensory function and ecology. Field studies, which are rare in neurobiology education, are combined with laboratory experiments that assess visual properties of insect eyes, using electroretinography (ERG). Comprised of nearly one million species, insects are a diverse group of animals, living in nearly all habitats and ecological niches. Each of these lifestyles puts different demands on their visual systems, and accordingly, insects display a wide array of eye organizations and specializations. Physiologically relevant differences can be measured using relatively simple extracellular electrophysiological methods that can be carried out with standard equipment, much of which is already in place in most physiology laboratories. The teaching unit takes advantage of the large pool of locally available species, some of which likely show specialized visual properties that can be measured by students. In the course of the experiments, students collect local insects or other arthropods of their choice, are guided to formulate hypotheses about how the visual system of "their" insects might be tuned to the lifestyle of the species, and use ERGs to investigate the insects' visual response dynamics, and both chromatic and temporal properties of the visual system. Students are then guided to interpret their results in both a comparative physiological and ecological context. This set of experiments closely mirrors authentic research and has proven to be a popular, informative and highly engaging teaching tool.

  15. Climate-induced forest dieback as an emergent global phenomenon: Organized oral session at the Ecological Society of America/Society of Ecological Restoration Joint Meeting; San Jose, California, 5-10 August 2007

    Science.gov (United States)

    Allen, Craig D.; Breshears, David D.

    2007-01-01

    An organized oral session at the annual meeting of the Ecological Society of America in San Jose, Calif., posed this question: Is climate-induced drought stress triggering increasing rates and unusual patterns of forest die-off at a global scale? Twenty-nine researchers representing five continents reported on patterns, mechanisms, and projections of forest mortality.Observations include widespread forest dieback or reductions in tree cover and biodiversity in response to drought and warmer temperatures in the African Sahel (Patrick Gonzalez, The Nature Conservancy), Mediterranean and alpine Europe (Jorge Castro, Universidad de Granada), and Argentinean Patagonia (Thomas Kitzberger, Universidad Nacional del Comahue). In contrast, although much Eucalyptus mortality has resulted from recent droughts in Australia, warming trends have been less pronounced in the Southern Hemisphere and it is unclear if contemporary climate-induced tree mortality differs from previous historical drought impacts (Rod Fensham, Queensland Herbarium).

  16. 75 FR 8338 - EPA Science Advisory Board Staff Office Notification of a Meeting of the Ecological Effects...

    Science.gov (United States)

    2010-02-24

    ... previously provided advice on the analytical blueprint for this study. EPA's Office of Air and Radiation (OAR... information on access or services for individuals with disabilities, please contact Ms. Sanzone at (202) 343... meeting, to give EPA as much time as possible to process your request. Dated: February 18, 2010. Vanessa T...

  17. Divergence with gene flow across a speciation continuum of Heliconius butterflies.

    Science.gov (United States)

    Supple, Megan A; Papa, Riccardo; Hines, Heather M; McMillan, W Owen; Counterman, Brian A

    2015-09-24

    A key to understanding the origins of species is determining the evolutionary processes that drive the patterns of genomic divergence during speciation. New genomic technologies enable the study of high-resolution genomic patterns of divergence across natural speciation continua, where taxa pairs with different levels of reproductive isolation can be used as proxies for different stages of speciation. Empirical studies of these speciation continua can provide valuable insights into how genomes diverge during speciation. We examine variation across a handful of genomic regions in parapatric and allopatric populations of Heliconius butterflies with varying levels of reproductive isolation. Genome sequences were mapped to 2.2-Mb of the H. erato genome, including 1-Mb across the red color pattern locus and multiple regions unlinked to color pattern variation. Phylogenetic analyses reveal a speciation continuum of pairs of hybridizing races and incipient species in the Heliconius erato clade. Comparisons of hybridizing pairs of divergently colored races and incipient species reveal that genomic divergence increases with ecological and reproductive isolation, not only across the locus responsible for adaptive variation in red wing coloration, but also at genomic regions unlinked to color pattern. We observe high levels of divergence between the incipient species H. erato and H. himera, suggesting that divergence may accumulate early in the speciation process. Comparisons of genomic divergence between the incipient species and allopatric races suggest that limited gene flow cannot account for the observed high levels of divergence between the incipient species. Our results provide a reconstruction of the speciation continuum across the H. erato clade and provide insights into the processes that drive genomic divergence during speciation, establishing the H. erato clade as a powerful framework for the study of speciation.

  18. X exceptionalism in Caenorhabditis speciation.

    Science.gov (United States)

    Cutter, Asher D

    2017-11-13

    Speciation genetics research in diverse organisms shows the X-chromosome to be exceptional in how it contributes to "rules" of speciation. Until recently, however, the nematode phylum has been nearly silent on this issue, despite the model organism Caenorhabditis elegans having touched most other topics in biology. Studies of speciation with Caenorhabditis accelerated with the recent discovery of species pairs showing partial interfertility. The resulting genetic analyses of reproductive isolation in nematodes demonstrate key roles for the X-chromosome in hybrid male sterility and inviability, opening up new understanding of the genetic causes of Haldane's rule, Darwin's corollary to Haldane's rule, and enabling tests of the large-X effect hypothesis. Studies to date implicate improper chromatin regulation of the X-chromosome by small RNA pathways as integral to hybrid male dysfunction. Sexual transitions in reproductive mode to self-fertilizing hermaphroditism inject distinctive molecular evolutionary features into the speciation process for some species. Caenorhabditis also provides unique opportunities for analysis in a system with XO sex determination that lacks a Y-chromosome, sex chromosome-dependent sperm competition differences and mechanisms of gametic isolation, exceptional accessibility to the development process and rapid experimental evolution. As genetic analysis of reproductive isolation matures with investigation of multiple pairs of Caenorhabditis species and new species discovery, nematodes will provide a powerful complement to more established study organisms for deciphering the genetic basis of and rules to speciation. © 2017 John Wiley & Sons Ltd.

  19. Differential Survival between Visual Environments Supports a Role of Divergent Sensory Drive in Cichlid Fish Speciation.

    Science.gov (United States)

    Maan, Martine E; Seehausen, Ole; Groothuis, Ton G G

    2017-01-01

    Identifying the selective forces that initiate ecological speciation is a major challenge in evolutionary biology. Sensory drive has been implicated in speciation in various taxa, largely based on phenotype-environment correlations and signatures of selection in sensory genes. Here, we present a reciprocal transplant experiment revealing species differences in performance in alternative visual environments, consistent with speciation by divergent sensory drive. The closely related cichlids Pundamilia pundamilia and Pundamilia nyererei inhabit different visual environments in Lake Victoria and show associated differences in visual system properties. Mimicking the two light environments in the laboratory, we find a substantial reduction in survival of both species when reared in the other species' visual environment. This implies that the observed differences in Pundamilia color vision are indeed adaptive and substantiates the implicit assumption in sensory drive speciation models that divergent environmental selection is strong enough to drive divergence in sensory properties.

  20. CHURCH, Category, and Speciation

    Directory of Open Access Journals (Sweden)

    Rinderknecht Jakob Karl

    2018-01-01

    Full Text Available The Roman Catholic definition of “church”, especially as applied to groups of Protestant Christians, creates a number of well-known difficulties. The similarly complex category, “species,” provides a model for applying this term so as to neither lose the centrality of certain examples nor draw a hard boundary to rule out border cases. In this way, it can help us to more adequately apply the complex ecclesiology of the Second Vatican Council. This article draws parallels between the understanding of speciation and categorization and the definition of Church since the council. In doing so, it applies the work of cognitive linguists, including George Lakoff, Zoltan Kovecses, Giles Fauconnier and Mark Turner on categorization. We tend to think of categories as containers into which we sort objects according to essential criteria. However, categories are actually built inductively by making associations between objects. This means that natural categories, including species, are more porous than we assume, but nevertheless bear real meaning about the natural world. Taxonomists dispute the border between “zebras” and “wild asses,” but this distinction arises out of genetic and evolutionary reality; it is not merely arbitrary. Genetic descriptions of species has also led recently to the conviction that there are four species of giraffe, not one. This engagement will ground a vantage point from which the Council‘s complex ecclesiology can be more easily described so as to authentically integrate its noncompetitive vision vis-a-vis other Christians with its sense of the unique place held by Catholic Church.

  1. Cancer: beyond speciation.

    Science.gov (United States)

    Vincent, Mark D

    2011-01-01

    A good account of the nature of cancer should provide not only a description of its consistent features, but also how they arise, how they are maintained, why conventional chemotherapy succeeds, and fails, and where to look for better targets. Cancer was once regarded as enigmatic and inexplicable; more recently, the "mutation theory," based on random alterations in a relatively small set of proto-oncogenes and tumor suppressor genes, has enjoyed widespread acceptance. The "mutation theory," however, is noticeable for its failure to explain the basis of differential chemosensitivity, for providing a paucity of targets, especially druggable ones, and for justifying the development of targeted therapies with, in general, disappointingly abbreviated clinical benefit. Furthermore, this theory has mistakenly predicted a widespread commonality of consistent genetic abnormalities across the range of cancers, whereas the opposite, that is, roiling macrogenomic instability, is generally the rule. In contrast, concerning what actually is consistent, that is, the suite of metabolic derangements common to virtually all, especially aggressive, cancers, the "Mutation Theory" has nothing to say. Other hypotheses merit serious consideration "aneuploidy theories" posit whole-genome instability and imbalance as causally responsible for the propagation of the tumor. Another approach, that is, "derepression atavism," suggests cancer results from the release of an ancient survival program, characterized by the emergence of remarkably primitive features such as unicellularity, fermentation, and immortality; existential goals are served by heuristic genomic instability coupled with host-to-tumor biomass interconversion, mediated by the Warburg effect, a major component of the program. Carcinogenesis is here seen as a process of de-speciation; however, genomic nonrestabilization raises issues as to where on the tree of life cancers belong, as a genuinely alternative modus vivendi

  2. CONCAWE effluent speciation project

    Energy Technology Data Exchange (ETDEWEB)

    Leonards, P.; Comber, M.; Forbes, S.; Whale, G.; Den Haan, K.

    2010-09-15

    In preparation for the implementation of the EU REACH regulation, a project was undertaken to transfer the high-resolution analytical method for determining hydrocarbon blocks in petroleum products by comprehensive two-dimensional gas chromatography (GCxGC) to a laboratory external to the petroleum industry (Institute for Environmental Studies (IVM) of the VU University of Amsterdam). The method was validated and used for the analysis of petroleum hydrocarbons extracted from refinery effluents. The report describes the technology transfer and the approaches used to demonstrate the successful transfer and application of the GCxGC methodology from analysing petroleum products to the quantitative determination of hydrocarbon blocks in refinery effluents. The report describes all the methods used for all the determinations on the effluent samples along with an overview of the results obtained which are presented in summary tables and graphs. These data have significantly improved CONCAWE's knowledge of what refineries emit in their effluents. A total of 111 Effluent Discharge Samples from 105 CONCAWE refineries in Europe were obtained in the period June 2008 to March 2009. These effluents were analysed for metals, standard effluent parameters (including COD, BOD), oil in water, BTEX and volatile organic compounds. The hydrocarbon speciation determinations and other hydrocarbon analyses are also reported. The individual refinery analytical results are included into this report, coded as per the CONCAWE system. These data will be, individually, communicated to companies and refineries. The report demonstrates that it is feasible to conduct a research programme to investigate the fate and effects of hydrocarbon blocks present in discharged refinery effluents.

  3. Risks and chances of an ecologically oriented energy industry. Revised version of the speech of the Hessian Minister for Environment, Energy and Federal Issues, Joschka Fischer (Die Gruenen), on the occasion of the IZE communication meeting 1992

    International Nuclear Information System (INIS)

    Kukuck, H.A.

    1994-01-01

    During the 1992 'Discussion Day' of the IZE, held under the motto 'Energy and Environment: Public Relations in the field of tension between economy and ecology', Joschka Fischer, the environment minister of Hessen, delivered an address that met with great attention. It resulted in a lively discussion of his theses with the attendants of the meeting. (orig./UA) [de

  4. Sympatric Speciation in Threespine Stickleback: Why Not?

    Directory of Open Access Journals (Sweden)

    Daniel I. Bolnick

    2011-01-01

    Full Text Available Numerous theoretical models suggest that sympatric speciation is possible when frequency-dependent interactions such as intraspecific competition drive disruptive selection on a trait that is also subject to assortative mating. Here, I review recent evidence that both conditions are met in lake populations of threespine stickleback (Gasterosteus aculeatus. Nonetheless, sympatric speciation appears to be rare or absent in stickleback. If stickleback qualitatively fit the theoretical requirements for sympatric speciation, why do they not undergo sympatric speciation? I present simulations showing that disruptive selection and assortative mating in stickleback, though present, are too weak to drive speciation. Furthermore, I summarize empirical evidence that disruptive selection in stickleback drives other forms of evolutionary diversification (plasticity, increased trait variance, and sexual dimorphism instead of speciation. In conclusion, core assumptions of sympatric speciation theory seem to be qualitatively reasonable for stickleback, but speciation may nevertheless fail because of (i quantitative mismatches with theory and (ii alternative evolutionary outcomes.

  5. The shape and temporal dynamics of phylogenetic trees arising from geographic speciation.

    Science.gov (United States)

    Pigot, Alex L; Phillimore, Albert B; Owens, Ian P F; Orme, C David L

    2010-12-01

    Phylogenetic trees often depart from the expectations of stochastic models, exhibiting imbalance in diversification among lineages and slowdowns in the rate of lineage accumulation through time. Such departures have led to a widespread perception that ecological differences among species or adaptation and subsequent niche filling are required to explain patterns of diversification. However, a key element missing from models of diversification is the geographical context of speciation and extinction. In this study, we develop a spatially explicit model of geographic range evolution and cladogenesis, where speciation arises via vicariance or peripatry, and explore the effects of these processes on patterns of diversification. We compare the results with those observed in 41 reconstructed avian trees. Our model shows that nonconstant rates of speciation and extinction are emergent properties of the apportioning of geographic ranges that accompanies speciation. The dynamics of diversification exhibit wide variation, depending on the mode of speciation, tendency for range expansion, and rate of range evolution. By varying these parameters, the model is able to capture many, but not all, of the features exhibited by birth-death trees and extant bird clades. Under scenarios with relatively stable geographic ranges, strong slowdowns in diversification rates are produced, with faster rates of range dynamics leading to constant or accelerating rates of apparent diversification. A peripatric model of speciation with stable ranges also generates highly unbalanced trees typical of bird phylogenies but fails to produce realistic range size distributions among the extant species. Results most similar to those of a birth-death process are reached under a peripatric speciation scenario with highly volatile range dynamics. Taken together, our results demonstrate that considering the geographical context of speciation and extinction provides a more conservative null model of

  6. Behavioural divergence, interfertility and speciation: a review.

    Science.gov (United States)

    Pillay, Neville; Rymer, Tasmin L

    2012-11-01

    Behavioural compatibility between mates is fundamental for maintaining species boundaries and is achieved through appropriate communication between males and females. A breakdown in communication will lead to behavioural divergence and reduced interfertility. In this review, we summarise the current knowledge on male signals and female perception of these signals, integrating the literature from several taxa. We advocate that signaller-perceiver coevolution, which is usually under strong stabilising selection to enable mating, forms the basis of species-specific mate recognition systems. The mechanisms (phylogeny, geography, ecology, biology) shaping signaller-perceiver systems are briefly discussed to demonstrate the factors underpinning the evolution of signaller-perceiver couplings. Since divergence and diversification of communication systems is driven by changes in the mechanical properties of sensory pathways and morphology of sensory organs, we highlight signal modalities (auditory, olfactory, visual, tactile) and their importance in communication, particularly in mate selection. Next, using available examples and generating a stylised model, we suggest how disruption (biological, ecological, stochastic) of signaller-perceiver systems drives behavioural divergence and consequently results in reduced interfertility and speciation. Future studies should adopt an integrative approach, combining multiple parameters (phylogeny, adaptive utility of communication systems, genetics and biomechanical/biochemical properties of signals and perception) to explore how disruption of signaller-perceiver systems results in behavioural divergence and reduced interfertility. Finally, we question the impact that rapid environmental change will have on disruption of communication systems, potentially interfering with signaller-perceiver couplings. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Ecosystem ecology meets adaptive management: food web response to a controlled flood on the Colorado River, Glen Canyon

    Science.gov (United States)

    Cross, Wyatt F.; Baxter, Colden V.; Donner, Kevin C.; Rosi-Marshall, Emma J.; Kennedy, Theodore A.; Hall, Robert O.; Wellard Kelly, Holly A.; Rogers, R. Scott

    2011-01-01

    Large dams have been constructed on rivers to meet human demands for water, electricity, navigation, and recreation. As a consequence, flow and temperature regimes have been altered, strongly affecting river food webs and ecosystem processes. Experimental high-flow dam releases, i.e., controlled floods, have been implemented on the Colorado River, USA, in an effort to reestablish pulsed flood events, redistribute sediments, improve conditions for native fishes, and increase understanding of how dam operations affect physical and biological processes. We quantified secondary production and organic matter flows in the food web below Glen Canyon dam for two years prior and one year after an experimental controlled flood in March 2008. Invertebrate biomass and secondary production declined significantly following the flood (total biomass, 55% decline; total production, 56% decline), with most of the decline driven by reductions in two nonnative invertebrate taxa, Potamopyrgus antipodarum and Gammarus lacustris. Diatoms dominated the trophic basis of invertebrate production before and after the controlled flood, and the largest organic matter flows were from diatoms to the three most productive invertebrate taxa (P. antipodarum, G. lacustris, and Tubificida). In contrast to invertebrates, production of rainbow trout (Oncorhynchus mykiss) increased substantially (194%) following the flood, despite the large decline in total secondary production of the invertebrate assemblage. This counterintuitive result is reconciled by a post-flood increase in production and drift concentrations of select invertebrate prey (i.e., Chironomidae and Simuliidae) that supported a large proportion of trout production but had relatively low secondary production. In addition, interaction strengths, measured as species impact values, were strongest between rainbow trout and these two taxa before and after the flood, demonstrating that the dominant consumer—resource interactions were not

  8. [Speciation and Risk Characteristics of Heavy Metals in the Sediments of the Yangtze Estuary].

    Science.gov (United States)

    Yin, Su; Feng, Cheng-hong; Li, Yang-yang; Yin, Li-feng; Shen, Zhen-yao

    2016-03-15

    Based on the investigation on the distribution of total contents and speciation of 8 heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) in the surface sediments at 14 typical sites of the Yangtze Estuary during three hydrological seasons ( wet, normal, and dry seasons) , this study applied equilibrium partitioning approach to build the sediment quality guidelines (SQGs) of the Yangtze Estuary, and assessed ecological risks of the heavy metals. The relationship between ecological risk and speciation of heavy metals was also revealed. The results showed that, except for Cd, the residual fraction was the main speciation of heavy metals, especially for As, Cr and Hg, their residual fraction proportions were all over 90%. The sediment quality guidelines of the Yangtze Estuary for As, Cd, Cr, Cu, Hg, Ni, Pb, Zn were 43.29, 0.672, 79.65, 19.08, 0.569, 339.09, 30.87, 411.36 µg · g⁻¹, respectively. Cu had the highest ecological risk to aquatic organisms. The upstream of Yangtze Estuary was mainly affected by Yangtze River runoff, where the risks were relatively high in wet season and relatively low in normal and dry seasons. However, the downstream of the estuary was mainly affected by municipal sewage of cities like Shanghai, where the risks were relatively high, especially in normal and dry seasons. There were three different relationships between the ecological risks and speciation of the eight heavy metals.

  9. Molecular evidence of cryptic speciation in the "cosmopolitan" excavating sponge Cliona celata (Porifera, Clionaidae)

    NARCIS (Netherlands)

    Xavier, J.R.; Rachello-Dolmen, P.G.; Parra-Velandia, F.; Schönberg, C.H.L.; Breeuwer, J.A.J.; van Soest, R.W.M.

    2010-01-01

    Over the past several decades molecular tools have shown an enormous potential to aid in the clarification of species boundaries in the marine realm, particularly in morphologically simple groups. In this paper we report a case of cryptic speciation in an allegedly cosmopolitan and ecologically

  10. Genetic linkage of distinct adaptive traits in sympatrically speciating crater lake cichlid fish

    Czech Academy of Sciences Publication Activity Database

    Fruciano, C.; Franchini, C.; Kováčová, Viera; Elmer, K.R.; Henning, F.; Meyer, A.

    2016-01-01

    Roč. 7, SEP2016 (2016), č. článku 12736. ISSN 2041-1723 R&D Projects: GA ČR GA13-06264S Institutional support: RVO:68081707 Keywords : rna-seq * ecological speciation * geometric morphometrics * morphological variation Subject RIV: BO - Biophysics Impact factor: 12.124, year: 2016

  11. Distributed and dynamic modelling of hydrology, phosphorus and ecology in the Hampshire Avon and Blashford Lakes: evaluating alternative strategies to meet WFD standards.

    Science.gov (United States)

    Whitehead, P G; Jin, L; Crossman, J; Comber, S; Johnes, P J; Daldorph, P; Flynn, N; Collins, A L; Butterfield, D; Mistry, R; Bardon, R; Pope, L; Willows, R

    2014-05-15

    The issues of diffuse and point source phosphorus (P) pollution in the Hampshire Avon and Blashford Lakes are explored using a catchment model of the river system. A multibranch, process based, dynamic water quality model (INCA-P) has been applied to the whole river system to simulate water fluxes, total phosphorus (TP) and soluble reactive phosphorus (SRP) concentrations and ecology. The model has been used to assess impacts of both agricultural runoff and point sources from waste water treatment plants (WWTPs) on water quality. The results show that agriculture contributes approximately 40% of the phosphorus load and point sources the other 60% of the load in this catchment. A set of scenarios have been investigated to assess the impacts of alternative phosphorus reduction strategies and it is shown that a combined strategy of agricultural phosphorus reduction through either fertiliser reductions or better phosphorus management together with improved treatment at WWTPs would reduce the SRP concentrations in the river to acceptable levels to meet the EU Water Framework Directive (WFD) requirements. A seasonal strategy for WWTP phosphorus reductions would achieve significant benefits at reduced cost. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. The role of male contest competition over mates in speciation

    Directory of Open Access Journals (Sweden)

    Anna QVARNSTRÖM, Niclas VALLIN, Andreas RUDH

    2012-06-01

    Full Text Available Research on the role of sexual selection in the speciation process largely focuses on the diversifying role of mate choice. In particular, much attention has been drawn to the fact that population divergence in mate choice and in the male traits subject to choice directly can lead to assortative mating. However, male contest competition over mates also constitutes an important mechanism of sexual selection. We review recent empirical studies and argue that sexual selection through male contest competition can affect speciation in ways other than mate choice. For example, biases in aggression towards similar competitors can lead to disruptive and negative frequency-dependent selection on the traits used in contest competition in a similar way as competition for other types of limited resources. Moreover, male contest abilities often trade-off against other abilities such as parasite resistance, protection against predators and general stress tolerance. Populations experiencing different ecological conditions should therefore quickly diverge non-randomly in a number of traits including male contest abilities. In resource based breeding systems, a feedback loop between competitive ability and habitat use may lead to further population divergence. We discuss how population divergence in traits used in male contest competition can lead to the build up of reproductive isolation through a number of different pathways. Our main conclusion is that the role of male contest competition in speciation remains largely scientifically unexplored [Current Zoology 58 (3: 490–506, 2012].

  13. Aspects of speciation in foodstuffs

    International Nuclear Information System (INIS)

    Crews, Helen M.

    2001-01-01

    Food is the primary source of trace elements for humans and it is now generally accepted that the bioavailability of a given element and its behaviour in the body depends upon its chemical form. This point was illustrated with the example of arsenic speciation in fish in which bioaccumulation takes place in the marine food chain, however, the species of arsenic ingested by man when the fish is consumed are not toxic. It was pointed out that species information will be vital in deciding upon realistic average dietary requirements for trace elements, particularly because both deficiency or excess of an element can have detrimental consequences on an individual's health. Two examples of speciation studies with food (Cd and Se) were presented and the importance of the use of label technology which will allow studies of target analytes at physiological levels, was stressed

  14. MODELING MONOMETHYLMERCURY AND TRIBUTYLTIN SPECIATION WITH EPA'S GEOCHEMICAL SPECIATION MODEL MINTEQA2

    Science.gov (United States)

    Given the complexity of the various, simultaneous (and competing) equilibrium reactions governing the speciation of ionic species in aquatic systems, EPA has developed and distributed the geochemical speciation model MINTEQA2 (Brown and Allison, 1987, Allison et al., 1991; Hydrog...

  15. Riverscape genetics identifies replicated ecological divergence across an Amazonian ecotone.

    Science.gov (United States)

    Cooke, Georgina M; Landguth, Erin L; Beheregaray, Luciano B

    2014-07-01

    Ecological speciation involves the evolution of reproductive isolation and niche divergence in the absence of a physical barrier to gene flow. The process is one of the most controversial topics of the speciation debate, particularly in tropical regions. Here, we investigate ecologically based divergence across an Amazonian ecotone in the electric fish, Steatogenys elegans. We combine phylogenetics, genome scans, and population genetics with a recently developed individual-based evolutionary landscape genetics approach that incorporates selection. This framework is used to assess the relative contributions of geography and divergent natural selection between environments as biodiversity drivers. We report on two closely related and sympatric lineages that exemplify how divergent selection across a major Amazonian aquatic ecotone (i.e., between rivers with markedly different hydrochemical properties) may result in replicated ecologically mediated speciation. The results link selection across an ecological gradient with reproductive isolation and we propose that assortative mating based on water color may be driving the divergence. Divergence resulting from ecologically driven selection highlights the importance of considering environmental heterogeneity in studies of speciation in tropical regions. Furthermore, we show that framing ecological speciation in a spatially explicit evolutionary landscape genetics framework provides an important first step in exploring a wide range of the potential effects of spatial dependence in natural selection. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  16. Uranium speciation in Fernald soils

    International Nuclear Information System (INIS)

    Morris, D.E.; Conradson, S.D.; Tait, C.D.; Chisholm-Brause, C.J.; Berg, J.; Musgrave, J.

    1992-01-01

    This report details progress made from January 1 to May 31, 1992 in this analytical support task to determine the speciation of uranium in contaminated soil samples from the Fernald Environmental Management Project site under the auspices of the Uranium in Soils Integrated Demonstration funded through the US DOE's Office of Technology Development. The authors' efforts have focused on characterization of soil samples collected by S.Y. Lee (Oak Ridge National Laboratory) from five locales at the Fernald site. These were chosen to sample a broad range of uranium source terms. On the basis of x-ray absorption spectroscopy data, they have determined that the majority of uranium (> 80--90%) exists in the hexavalent oxidation state for all samples examined. This is a beneficial finding from the perspective of remediation, because U(VI) species are more soluble in general than uranium species in other oxidation states. Optical luminescence data from many of the samples show the characteristic structured yellow-green emission from the uranyl (UO 2 2+ ) moiety. The luminescence data also suggest that much of the uranium in these soils is present as well-crystallized UO 2 2+ species. Some clear spectroscopic distinctions have been noted for several samples that illustrate significant differences in the speciation (1) from site to site, (2) within different horizons at the same site, and (3) within different size fractions of the soils in the same horizon at the same site. This marked heterogeneity in uranyl speciation suggests that several soil washing strategies may be necessary to reduce the total uranium concentrations within these soils to regulatory limits

  17. Speciation of Pb in industrially polluted soils

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Ottosen, Lisbeth M.; Pedersen, Anne Juul

    2006-01-01

    This study was aimed at elucidating the importance of original Pb-speciation versus soil-characteristics to mobility and distribution of Pb in industrially polluted soils. Ten industrially polluted Danish surface soils were characterized and Pb speciation was evaluated through SEM-EDX studies...

  18. [Ecology and ecologies].

    Science.gov (United States)

    Valera, Luca

    2011-01-01

    Ecology (from the Greek words οιχοσ, "house" and λογια "study of") is the science of the "house", since it studies the environments where we live. There are three main ways of thinking about Ecology: Ecology as the study of interactions (between humans and the environment, between humans and living beings, between all living beings, etc.), Ecology as the statistical study of interactions, Ecology as a faith, or rather as a science that requires a metaphysical view. The history of Ecology shows us how this view was released by the label of "folk sense" to gain the epistemological status of science, a science that strives to be interdisciplinary. So, the aim of Ecology is to study, through a scientific methodology, the whole natural world, answering to very different questions, that arise from several fields (Economics, Biology, Sociology, Philosophy, etc.). The plurality of issues that Ecology has to face led, during the Twentieth-century, to branch off in several different "ecologies". As a result, each one of these new approaches chose as its own field a more limited and specific portion of reality.

  19. Speciation on a local geographic scale: the evolution of a rare rock outcrop specialist in Mimulus.

    Science.gov (United States)

    Ferris, Kathleen G; Sexton, Jason P; Willis, John H

    2014-08-05

    Speciation can occur on both large and small geographical scales. In plants, local speciation, where small populations split off from a large-ranged progenitor species, is thought to be the dominant mode, yet there are still few examples to verify speciation has occurred in this manner. A recently described morphological species in the yellow monkey flowers, Mimulus filicifolius, is an excellent candidate for local speciation because of its highly restricted geographical range. Mimulus filicifolius was formerly identified as a population of M. laciniatus due to similar lobed leaf morphology and rocky outcrop habitat. To investigate whether M. filicifolius is genetically divergent and reproductively isolated from M. laciniatus, we examined patterns of genetic diversity in ten nuclear and eight microsatellite loci, and hybrid fertility in M. filicifolius and its purported close relatives: M. laciniatus, M. guttatus and M. nasutus. We found that M. filicifolius is genetically divergent from the other species and strongly reproductively isolated from M. laciniatus. We conclude that M. filicifolius is an independent rock outcrop specialist despite being morphologically and ecologically similar to M. laciniatus, and that its small geographical range nested within other wide-ranging members of the M. guttatus species complex is consistent with local speciation. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  20. 15. ESRF users meeting

    Energy Technology Data Exchange (ETDEWEB)

    Fotis C, Kafatos; Ulrich, K.U.; Weib, S.; Rossberg, A.; Scheinost, A.C.; Foerstendorf, H.; Zanker, H.; Meyerheim, H.L.; Sander, D.; Popescu, R.; Kirschner, J.; Robach, O.; Ferrer, S.; Lyman, P.F.; Shneerson, V.L.; Fung, R.; Harder, R.J.; Parihar, S.S.; Johnson-Steigelman, H.T.; Lu, E.D.; Saldin, D.K.; Eastwood, D.S.; Atkinson, D.; Tanner, B.K.; Hase, T.P.A.; Van Kampen, M.; Hjorvarsson, B.; Brown, S.; Thompson, P.; Konovalov, O.; Saint-Martin, E.; Daillant, J.; Luzet, D.; Szlachetko, J.; Barrett, R.; Berset, M.; Dousse, J.C.; Fennane, K.; Hoszowska, J.; Kubala-Kukus, A.; Pajek, M.; Szlachetko, M.; Monaco, A.; Chumakov, A.; Crichton, W.; Van Buerck, I.; Wortmann, G.; Meyer, A.; Ponkratz, U.; Ruffer, R.; Sakurai, Y.; Hiraoka, N.; Itou, M.; Buslaps, T.; Honkimki, V.; Maeno, Y.; Collart, E.; Shukla, A.; Rueff, J.P.; Leininger, Ph.; Ishii, H.; Cai, Y.; Cheong, S.W.; Martins, R.M.S.; Schell, N.; Beckers, M.; Silva, R.; Braz Fernandes, F.M.; Acapito, F.; Seta, M. de; Capelini, G.; Giorgi, M.; Schorr, G.; Geandier, G.; Alves Marques, M.; Barros Marquesa, M.I. de; Cabaco, M.I.; Gaspara, A.M.; Marques, M.P.M.; Amado, A.M.; Amorim da Costa, A.M.; Bruneseaux, F.; Weisbecker, P.; Brandao, M.J.; Aeby-Gautier, E.; Simmonds, H.; Lei, C.; Das, A.; Trolley, D.; Thomas, H.E.; Macdonald, J.E.; Wiegart, L.; Tolan, M.; Struth, B.; Petukhov, A.V.; Thijssen, J.H.J.; Hart, D.C.; Imhof, A.; Van Blaaderen, A.; Dolbnya, I.P.; Snigirev, A.; Mossaid, A.; Snigireva, I.; Reconditi, M.; Brunello, E

    2005-07-01

    This document gathers the posters presented on the one day and a half long plenary meeting workshop. This meeting workshop is a privileged forum where ESRF users can exchange their views on the latest scientific and technical development involving synchrotron radiation. One poster deals with the investigation of colloid composition and uranium bond structure to see whether the migration of contaminants from abandoned mines could be stimulated or attenuated by colloids. Another poster is dedicated to the investigation of the uranium speciation in covered mine tailings by a combination of micro-spectroscopic and wet chemical approaches. 2 posters deal with the contribution of synchrotron radiation to radiotherapy.

  1. 15. ESRF users meeting

    International Nuclear Information System (INIS)

    Fotis C, Kafatos; Ulrich, K.U.; Weib, S.; Rossberg, A.; Scheinost, A.C.; Foerstendorf, H.; Zanker, H.; Meyerheim, H.L.; Sander, D.; Popescu, R.; Kirschner, J.; Robach, O.; Ferrer, S.; Lyman, P.F.; Shneerson, V.L.; Fung, R.; Harder, R.J.; Parihar, S.S.; Johnson-Steigelman, H.T.; Lu, E.D.; Saldin, D.K.; Eastwood, D.S.; Atkinson, D.; Tanner, B.K.; Hase, T.P.A.; Van Kampen, M.; Hjorvarsson, B.; Brown, S.; Thompson, P.; Konovalov, O.; Saint-Martin, E.; Daillant, J.; Luzet, D.; Szlachetko, J.; Barrett, R.; Berset, M.; Dousse, J.C.; Fennane, K.; Hoszowska, J.; Kubala-Kukus, A.; Pajek, M.; Szlachetko, M.; Monaco, A.; Chumakov, A.; Crichton, W.; Van Buerck, I.; Wortmann, G.; Meyer, A.; Ponkratz, U.; Ruffer, R.; Sakurai, Y.; Hiraoka, N.; Itou, M.; Buslaps, T.; Honkimki, V.; Maeno, Y.; Collart, E.; Shukla, A.; Rueff, J.P.; Leininger, Ph.; Ishii, H.; Cai, Y.; Cheong, S.W.; Martins, R.M.S.; Schell, N.; Beckers, M.; Silva, R.; Braz Fernandes, F.M.; Acapito, F.; Seta, M. de; Capelini, G.; Giorgi, M.; Schorr, G.; Geandier, G.; Alves Marques, M.; Barros Marquesa, M.I. de; Cabaco, M.I.; Gaspara, A.M.; Marques, M.P.M.; Amado, A.M.; Amorim da Costa, A.M.; Bruneseaux, F.; Weisbecker, P.; Brandao, M.J.; Aeby-Gautier, E.; Simmonds, H.; Lei, C.; Das, A.; Trolley, D.; Thomas, H.E.; Macdonald, J.E.; Wiegart, L.; Tolan, M.; Struth, B.; Petukhov, A.V.; Thijssen, J.H.J.; Hart, D.C.; Imhof, A.; Van Blaaderen, A.; Dolbnya, I.P.; Snigirev, A.; Mossaid, A.; Snigireva, I.; Reconditi, M.; Brunello, E.

    2005-01-01

    This document gathers the posters presented on the one day and a half long plenary meeting workshop. This meeting workshop is a privileged forum where ESRF users can exchange their views on the latest scientific and technical development involving synchrotron radiation. One poster deals with the investigation of colloid composition and uranium bond structure to see whether the migration of contaminants from abandoned mines could be stimulated or attenuated by colloids. Another poster is dedicated to the investigation of the uranium speciation in covered mine tailings by a combination of micro-spectroscopic and wet chemical approaches. 2 posters deal with the contribution of synchrotron radiation to radiotherapy

  2. Synergistic selection between ecological niche and mate preference primes diversification.

    Science.gov (United States)

    Boughman, Janette W; Svanbäck, Richard

    2017-01-01

    The ecological niche and mate preferences have independently been shown to be important for the process of speciation. Here, we articulate a novel mechanism by which ecological niche use and mate preference can be linked to promote speciation. The degree to which individual niches are narrow and clustered affects the strength of divergent natural selection and population splitting. Similarly, the degree to which individual mate preferences are narrow and clustered affects the strength of divergent sexual selection and assortative mating between diverging forms. This novel perspective is inspired by the literature on ecological niches; it also explores mate preferences and how they may contribute to speciation. Unlike much comparative work, we do not search for evolutionary patterns using proxies for adaptation and sexual selection, but rather we elucidate how ideas from niche theory relate to mate preference, and how this relationship can foster speciation. Recognizing that individual and population niches are conceptually and ecologically linked to individual and population mate preference functions will significantly increase our understanding of rapid evolutionary diversification in nature. It has potential to help solve the difficult challenge of testing the role of sexual selection in the speciation process. We also identify ecological factors that are likely to affect individual niche and individual mate preference in synergistic ways and as a consequence to promote speciation. The ecological niche an individual occupies can directly affect its mate preference. Clusters of individuals with narrow, differentiated niches are likely to have narrow, differentiated mate preference functions. Our approach integrates ecological and sexual selection research to further our understanding of diversification processes. Such integration may be necessary for progress because these processes seem inextricably linked in the natural world. © 2016 The Author(s). Evolution

  3. US EPA's SPECIATE 4.4 Database: Development and Uses

    Science.gov (United States)

    SPECIATE is the U.S. Environmental Protection Agency’s (EPA) repository of volatile organic gas and particulate matter (PM) speciation profiles of air pollution sources. EPA released SPECIATE 4.4 in early 2014 and, in total, the SPECIATE 4.4 database includes 5,728 PM, volatile o...

  4. Speciation Analysis of Radionuclides in the Environment - NSK-B SPECIATION project report 2009

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Aldahan, Ala; Possnert, Göran

    . Speciation of radionuclides in soils and sediments includes: Sequential extraction of radionuclides in sediments and of trace elements in soil samples. Sequential extraction of radionuclides in aerosols and particles has also been performed. Further-more, sorption experiments have been performed......, sediments, particles); and (3) Intercomparison excise for speciation analysis of radionu-clides in soil and sediment. This report summarizes the work completed in the project partners’ laboratories, Method developments include: Development of an rapid and in-suit separation method for the speciation...... analysis of 129I in seawater samples; Development of a simple method for the speciation analysis of 129I in fresh water and seawater samples; Development of an on-line HPLC-ICP-MS method for the direct speciation analysis of 127I in water and leachate samples; Speciation of radionuclides in water includes...

  5. Molecular Phylogenetics of the Serranid Subfamily Epinephelinae: Speciation and Biogeography in a Nearshore Marine Fish Clade

    OpenAIRE

    Craig, Matthew T,

    2005-01-01

    The processes that shape present day distributions of marine organisms have remained a central topic in evolutionary biology, conservation biology, and ecology. In this thesis, genetic data from mitochondrial and nuclear genes were used to create a phylogenetic hypothesis for the groupers of the subfamily Epinephelinae as a means of evaluating the current taxonomy of the group and the geography of speciation in marine organisms. The molecular phylogenetic hypothesis presented in Chap...

  6. Metal and proton toxicity to lake zooplankton: A chemical speciation based modelling approach

    Czech Academy of Sciences Publication Activity Database

    Stockdale, A.; Tipping, E.; Lofts, S.; Fott, J.; Garmo, Ø.; Hruška, Jakub; Keller, B.; Löfgren, S.; Maberlyh, S.; Majer, V.; Nierzwicki-Bauer, S. A.; Persson, G.; Schartau, A.; Thackeray, S. J.; Valois, A.; Vrba, Jaroslav; Walseng, B.; Yan, N.

    2014-01-01

    Roč. 186, MAR (2014), s. 115-125 ISSN 0269-7491 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA ČR GA206/07/1200 Institutional support: RVO:67179843 ; RVO:60077344 Keywords : chemical speciation * bioavailability * recovery * crustacean zooplankton * lakes Subject RIV: EH - Ecology, Behaviour Impact factor: 4.143, year: 2014

  7. Speciation analysis of radionuclides in the environment - NSK-B SPECIATION project report 2009

    International Nuclear Information System (INIS)

    Hou, X.; Aldahan, A.; Possnert, G.; Lujaniene, G.; Lehto, J.; Skipperud, L.; Lind, O.C.; Salbu, B.

    2009-10-01

    The second stage of the NKS-B project SPECIATION was complemented in 2008-2009, which mainly focus on three aspects: (1) Further improvement and development of methods for speciation analysis of radionuclides; (2) Investigation of speciation of some radionuclides in the environment (water, sediments, particles); and (3) Intercomparison excise for speciation analysis of radionuclides in soil and sediment. This report summarizes the work completed in the project partners' laboratories. Method developments include: Development of an rapid and in-suit separation method for the speciation analysis of 129I in seawater samples; Development of a simple method for the speciation analysis of 129I in fresh water and seawater samples; Development of an on-line HPLC-ICP-MS method for the direct speciation analysis of 127I in water and leachate samples; Speciation of radionuclides in water includes: Speciation of 129I and 127I in time-series precipitation samples collected in Denmark 2001-2006 and its application for the investigation of geochemistry and atmospheric chemistry of iodine, Speciation of radionuclides in Ob and Yenisey Rivers, and Speciation of 129I and 127I in Lake Heimdalen water. Speciation of radionuclides in soils and sediments includes: Sequential extraction of radionuclides in sediments and of trace elements in soil samples. Sequential extraction of radionuclides in aerosols and particles has also been performed. Furthermore, sorption experiments have been performed to investigate the association of Pu, Am and Cs with different geological materials. The intercomparison exercises included sequential extraction of Pu, 137Cs, U, Th, and 129I in one soil and one sediment standard reference materials (NIST-4354, IAEA-375) and Pu in sediment collected from the Lake Heimdalen, Norway. (author)

  8. Speciation analysis of radionuclides in the environment - NSK-B SPECIATION project report 2009

    Energy Technology Data Exchange (ETDEWEB)

    Hou, X. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Aldahan, A. (Uppsala Univ., Dept. of Earth Science (Sweden)); Possnert, G. (Uppsala Univ., Tandem Lab. (Sweden)); Lujaniene, G. (Univ. of Helsinki, Lab. of Radiochemistry (Finland)); Lehto, J. (Institute of Physics (Lithuania)); Skipperud, L.; Lind, O.C.; Salbu, B. (Norwegian Univ. of Life Sciences, Isotope Lab., AAs (Norway))

    2009-10-15

    The second stage of the NKS-B project SPECIATION was complemented in 2008-2009, which mainly focus on three aspects: (1) Further improvement and development of methods for speciation analysis of radionuclides; (2) Investigation of speciation of some radionuclides in the environment (water, sediments, particles); and (3) Intercomparison excise for speciation analysis of radionuclides in soil and sediment. This report summarizes the work completed in the project partners' laboratories. Method developments include: Development of an rapid and in-suit separation method for the speciation analysis of 129I in seawater samples; Development of a simple method for the speciation analysis of 129I in fresh water and seawater samples; Development of an on-line HPLC-ICP-MS method for the direct speciation analysis of 127I in water and leachate samples; Speciation of radionuclides in water includes: Speciation of 129I and 127I in time-series precipitation samples collected in Denmark 2001-2006 and its application for the investigation of geochemistry and atmospheric chemistry of iodine, Speciation of radionuclides in Ob and Yenisey Rivers, and Speciation of 129I and 127I in Lake Heimdalen water. Speciation of radionuclides in soils and sediments includes: Sequential extraction of radionuclides in sediments and of trace elements in soil samples. Sequential extraction of radionuclides in aerosols and particles has also been performed. Furthermore, sorption experiments have been performed to investigate the association of Pu, Am and Cs with different geological materials. The intercomparison exercises included sequential extraction of Pu, 137Cs, U, Th, and 129I in one soil and one sediment standard reference materials (NIST-4354, IAEA-375) and Pu in sediment collected from the Lake Heimdalen, Norway. (author)

  9. Biodiversity in Benthic Ecology

    DEFF Research Database (Denmark)

    Friberg, Nikolai; Carl, J. D.

    Foreword: This proceeding is based on a set of papers presented at the second Nordic Benthological Meeting held in Silkeborg, November 13-14, 1997. The main theme of the meeting was biodiversity in benthic ecology and the majority of contributions touch on this subject. In addition, the proceeding...... contains papers which cover other themes thus continuing with the spirit of the meetings in the Nordic Benthological Society (NORBS) by being an open forum for exchanging knowledge on all aspects of benthic ecology. Overall, we feel the proceeding contains a wide selection of very interesting papers...... representing the state-of-the-art of benthic ecology research within, and to a lesser degree, outside the Nordic countries. We wish to thank all the authors for their inspirational contributions to the proceeding, but we feel that a special thanks is due to the invited speakers for their readiness to produce...

  10. Radionuclide speciation in the environment: a review

    International Nuclear Information System (INIS)

    Moulin, V.; Moulin, C.

    2001-01-01

    Speciation determination is of prime importance to explain and evaluate the mobility, the toxicity and the risk resulting from the presence of trace elements in natural systems, in particular in the case of radionuclides, in the framework of environment and waste management purposes. The present paper will then focus more specifically on the physico-chemical speciation of radionuclides, and more particularly of actinides, in the environment, with emphasis on the behavior in solution: from a chemical point of view (with important ligands including colloidal phases) using experimental data and speciation calculations, as well as from a more technical point of view (with analytical methods for in situ speciation determination and thermodynamic data determination). A review of recent papers (mainly from CEA) is presented. (orig.)

  11. Pb speciation results in amended soils

    Data.gov (United States)

    U.S. Environmental Protection Agency — The dataset shows the distribution of Pb phases resulting from various amendments to change Pb speciation. This dataset is associated with the following publication:...

  12. Speciation of radionuclides in the environment

    International Nuclear Information System (INIS)

    Gunten, H.R. von; Benes, P.

    1994-02-01

    Methods for the determination of the speciation of radionuclides in aerosols, in aquatic solutions, in sediments, soils and rocks are reviewed. At present, most of the results about speciation are deduced from model calculations, model experiments, and separation of species (forms) of radionuclides, e.g., by sequential extraction procedures. Methods of direct determination of speciation of radionuclides (e.g. by laser induced spectroscopy) are in general not yet sensitive enough for a measurement of the very low concentrations of radionuclides in the environment. The methodological part of this paper is followed by a review of the very abundant literature about speciation of important radionuclides in the environment, i.e. in the atmosphere, hydrosphere and lithosphere. The review does not include the biosphere. Literature up to spring 1993 is included (with a few more recent additions). (author)

  13. Dearborn GC-MS organic speciation data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Ambient particulate matter organic speciation data from July - August, 2011. This dataset is associated with the following publication: Lynam, M., T. Dvonch, J....

  14. Aerosol Chemical Speciation Monitor (ACSM) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Thomas B. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-08-15

    The Aerodyne Aerosol Chemical Speciation Monitor (ACSM) measures particle mass loading and chemical composition in real time for non-refractory sub-micron aerosol particles. The ACSM is designed for long-term unattended deployment and routine monitoring applications.

  15. Detecting cryptic speciation in the widespread and morphologically conservative carpet chameleon (Furcifer lateralis) of Madagascar.

    Science.gov (United States)

    Florio, A M; Ingram, C M; Rakotondravony, H A; Louis, E E; Raxworthy, C J

    2012-07-01

    Species delimitation within recently evolved groups can be challenging because species may be difficult to distinguish morphologically. Following the General Lineage Concept, we apply a multiple evidence approach to assess species limits within the carpet chameleon Furcifer lateralis, which is endemic to Madagascar and exported in large numbers for the pet trade. Cryptic speciation within F. lateralis was considered likely because this species (1) has a vast distribution, (2) occupies exceptionally diverse habitats and (3) exhibits subtle regional differences in morphology. Phylogenetic trees reconstructed using nuclear and mitochondrial genes recovered three well-supported clades corresponding with geography. Morphological results based on canonical variates analysis show that these clades exhibit subtle differences in head casque morphology. Ecological niche modelling results found that these phylogenetic groups also occupy unique environmental space and exhibit patterns of regional endemism typical of other endemic reptiles. Combined, our findings provide diverse yet consistent evidence for the existence of three species. Consequently, we elevate the subspecies F. lateralis major to species rank and name a new species distributed in northern and western Madagascar. Initial ecological divergence, associated with speciation of F. lateralis in humid eastern habitat, fits the Ecographic Constraint model for species diversification in Madagascar. By contrast, the second speciation event provides some support for the Riverine Barrier model, with the Mangoky River possibly causing initial isolation between species. These findings thus support two contrasting models of speciation within closely related species and demonstrate the utility of applying a combined-evidence approach for detecting cryptic speciation. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  16. Translating ecology, physiology, biochemistry and population genetics research to meet the challenge of tick and tick-borne diseases in North America

    Science.gov (United States)

    Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal population...

  17. Abstracts of papers of international meeting `Ecological status of territories contaminated by radionuclides`; Tezisy dokladov mezhdunarodnogo rabochego soveshchaniya `Ehkologicheskij status zagryaznennykh radionuklidami territorij`

    Energy Technology Data Exchange (ETDEWEB)

    Konoplya, E F [ed.; Natsyyanal` naya akadehmiya navuk Belarusi, Minsk (Belarus)

    1995-04-01

    The collection contains the results of investigations implemented on the territories of Belarus, Ukraine and Russia within the realization of the Chernobyl Ecological Science Network: dynamics of radionuclides migration in the environment, state of phytocenosis, metabolic and genetic effects of the Chernobyl catastrophe.

  18. Research on the chemical speciation of actinides

    International Nuclear Information System (INIS)

    Jung, Euo Chang; Park, K. K.; Cho, H. R.

    2012-04-01

    A demand for the safe and effective management of spent nuclear fuel and radioactive waste generated from nuclear power plant draws increasing attention with the growth of nuclear power industry. The objective of this project is to establish the basis of research on the actinide chemistry by using highly sensitive and advanced laser-based spectroscopic systems. Researches on the chemical speciation of actinides are prerequisite for the development of technologies related to nuclear fuel cycles, especially, such as the safe management of high level radioactive wastes and the chemical examination of irradiated nuclear fuels. For supporting these technologies, laser-based spectroscopies have been applied for the chemical speciation of actinide in aqueous solutions and the quantitative analysis of actinide isotopes in spent nuclear fuels. In this report, results on the following subjects have been summarized. Development of TRLFS technology for the chemical speciation of actinides, Development of laser-induced photo-acoustic spectroscopy (LPAS) system, Application of LIBD technology to investigate dynamic behaviors of actinides dissolution reactions, Development of nanoparticle analysis technology in groundwater using LIBD, Chemical speciation of plutonium complexes by using a LWCC system, Development of LIBS technology for the quantitative analysis of actinides, Evaluation on the chemical reactions between actinides and humic substances, Spectroscopic speciation of uranium-ligand complexes in aqueous solution, Chemical speciation of actinides adsorbed on metal oxides surfaces

  19. Research on the chemical speciation of actinides

    International Nuclear Information System (INIS)

    Jung, Euo Chang; Park, K. K.; Cho, H. R.

    2010-04-01

    A demand for the safe and effective management of spent nuclear fuel and radioactive waste generated from nuclear power plant draws increasing attention with the growth of nuclear power industry. The objective of this project is to establish the basis of research on the actinide chemistry by using advanced laser-based highly sensitive spectroscopic systems. Researches on the chemical speciation of actinides are prerequisite for the development of technologies related to nuclear fuel cycles, especially, such as the safe management of high level radioactive wastes and the chemical examination of irradiated nuclear fuels. For supporting these technologies, laser-based spectroscopies have been performed for the chemical speciation of actinide in an aqueous solutions and the quantitative analysis of actinide isotopes in spent nuclear fuels. In this report, results on the following subjects have been summarized. (1) Development of TRLFS technology for chemical speciation of actinides, (2) Development of LIBD technology for measuring solubility of actinides, (3) Chemical speciation of plutonium complexes by using a LWCC system, (4) Development of LIBS technology for the quantitative analysis of actinides, (5) Development of technology for the chemical speciation of actinides by CE, (6) Evaluation on the chemical reactions between actinides and humic substances, (7) Chemical speciation of actinides adsorbed on metal oxides surfaces, (8) Determination of actinide source terms of spent nuclear fuel

  20. Ecological opportunity and the adaptive diversification of lineages.

    Science.gov (United States)

    Wellborn, Gary A; Langerhans, R Brian

    2015-01-01

    The tenet that ecological opportunity drives adaptive diversification has been central to theories of speciation since Darwin, yet no widely accepted definition or mechanistic framework for the concept currently exists. We propose a definition for ecological opportunity that provides an explicit mechanism for its action. In our formulation, ecological opportunity refers to environmental conditions that both permit the persistence of a lineage within a community, as well as generate divergent natural selection within that lineage. Thus, ecological opportunity arises from two fundamental elements: (1) niche availability, the ability of a population with a phenotype previously absent from a community to persist within that community and (2) niche discordance, the diversifying selection generated by the adaptive mismatch between a population's niche-related traits and the newly encountered ecological conditions. Evolutionary response to ecological opportunity is primarily governed by (1) spatiotemporal structure of ecological opportunity, which influences dynamics of selection and development of reproductive isolation and (2) diversification potential, the biological properties of a lineage that determine its capacity to diversify. Diversification under ecological opportunity proceeds as an increase in niche breadth, development of intraspecific ecotypes, speciation, and additional cycles of diversification that may themselves be triggered by speciation. Extensive ecological opportunity may exist in depauperate communities, but it is unclear whether ecological opportunity abates in species-rich communities. Because ecological opportunity should generally increase during times of rapid and multifarious environmental change, human activities may currently be generating elevated ecological opportunity - but so far little work has directly addressed this topic. Our framework highlights the need for greater synthesis of community ecology and evolutionary biology, unifying

  1. Selfish X chromosomes and speciation.

    Science.gov (United States)

    Patten, Manus M

    2017-12-27

    In two papers published at about the same time almost thirty years ago, Frank (Evolution, 45, 1991a, 262) and Hurst and Pomiankowski (Genetics, 128, 1991, 841) independently suggested that divergence of meiotic drive systems-comprising genes that cheat meiosis and genes that suppress this cheating-might provide a general explanation for Haldane's rule and the large X-effect in interspecific hybrids. Although at the time, the idea was met with skepticism and a conspicuous absence of empirical support, the tide has since turned. Some of the clearest mechanistic explanations we have for hybrid male sterility involve meiotic drive systems, and several other cases of hybrid sterility are suggestive of a role for meiotic drive. In this article, I review these ideas and their descendants and catalog the current evidence for the meiotic drive model of speciation. In addition, I suggest that meiotic drive is not the only intragenomic conflict to involve the X chromosome and contribute to hybrid incompatibility. Sexually and parentally antagonistic selection pressures can also pit the X chromosome and autosomes against each other. The resulting intragenomic conflicts should lead to co-evolution within populations and divergence between them, thus increasing the likelihood of incompatibilities in hybrids. I provide a sketch of these ideas and interpret some empirical patterns in the light of these additional X-autosome conflicts. © 2017 John Wiley & Sons Ltd.

  2. Summaries of the Idaho National Engineering Laboratory Site ecological studies information meeting held at Idaho Falls, July 10--11, 1975

    International Nuclear Information System (INIS)

    Markham, O.D.

    1976-04-01

    Brief summaries are presented for 30 papers that discuss the ecology of plants, wild animals, and birds on the Idaho National Engineering Laboratory site. Eleven of the papers report the results of studies on the diffusion of radioactive wastes in the environment and measurements of the content of various radionuclides in the tissues of animals and plants, soil, waste water leaching ponds, and aquifers. Two papers discuss the diffusion of chemical effluents in the environment

  3. Liquid phase microextraction for the analysis of trace elements and their speciation

    International Nuclear Information System (INIS)

    Hu, Bin; He, Man; Chen, Beibei; Xia, Linbo

    2013-01-01

    Trace/ultra-trace elements and their speciation analysis in complex matrices usually require sample preparation procedures to achieve sample clean-up and analyte preconcentration. Sample preparation is often the bottleneck in trace elements and their speciation analysis which has a direct impact on accuracy, precision and limits of detection and is often the rate-determining step of the analytical process. Recent trends in sample preparation include miniaturization, automation, high-throughput performance and reduction in solvent/sample consumption and operation time. Liquid-phase microextraction (LPME) technique as a novel and promising alternative in sample preparation can meet these requirements and has become a very efficient sample preparation technique. This review updates the state of art of LPME for trace elements and their speciation analysis and discusses its promising prospects. The major thrust of the article highlights the applications of LPME including single-drop microextraction (SDME), hollow fiber-liquid phase microextraction (HF-LPME), dispersive liquid liquid microextraction (DLLME) and solidified floating organic drop microextraction (SFODME) to the fields of elemental and their speciation analysis by atomic spectrometry-based methods, especially inductively coupled plasma mass spectrometry. General and specific concepts, different extraction formats and characteristics of LPME are described and compared, along with examples of recent innovations and applications presented to demonstrate its potential for trace elements and their speciation analysis in biological and environmental fields. Moreover, the application potential and an outlook on the combination of LPME and atomic spectrometry-based techniques for inorganic analysis are commentated. - Highlights: • The state of art of LPME for trace elements and their speciation analysis is updated. • Different extraction formats of LPME are described. • The application potential and future

  4. Speciation distribution and mass balance of copper and zinc in urban rain, sediments, and road runoff.

    Science.gov (United States)

    Zuo, Xiaojun; Fu, Dafang; Li, He

    2012-11-01

    Heavy metal pollution in road runoff had caused widespread concern since the last century. However, there are little references on metal speciation in multiple environmental media (e.g., rain, road sediments, and road runoff). Our research targeted the investigation of metal speciation in rain, road sediments, and runoff; the analysis of speciation variation and mass balance of metals among rain, road sediments, and runoff; the selection of main factors by principal component analysis (PCA); and the establishment of equation to evaluate the impact of rain and road sediments to metals in road runoff. Sequential extraction procedure contains five steps for the chemical fractionation of metals. Flame atomic absorption spectrometry (Shimadzu, AA-6800) was used to determine metal speciation concentration, as well as the total and dissolved fractions. The dissolved fractions for both Cu and Zn were dominant in rain. The speciation distribution of Zn was different from that of Cu in road sediments, while speciation distribution of Zn is similar to that of Cu in runoff. The bound to carbonates for both Cu and Zn in road sediments were prone to be dissolved by rain. The levels of Cu and Zn in runoff were not obviously influenced by rain, but significantly influenced by road sediments. The masses for both Cu and Zn among rain, road sediments, and road runoff approximately meet the mass balance equation for all rainfall patterns. Five principal factors were selected for metal regression equation based on PCA, including rainfall, average rainfall intensity, antecedent dry periods, total suspended particles, and temperature. The established regression equations could be used to predict the effect of road runoff on receiving environments.

  5. The genetic signature of recent speciation in manta rays (Manta alfredi and M. birostris).

    Science.gov (United States)

    Kashiwagi, Tom; Marshall, Andrea D; Bennett, Michael B; Ovenden, Jennifer R

    2012-07-01

    Manta rays have been taxonomically revised as two species, Manta alfredi and M. birostris, on the basis of morphological and meristic data, yet the two species occur in extensive mosaic sympatry. We analysed the genetic signatures of the species boundary using a portion of the nuclear RAG1 (681 base pairs), mitochondrial CO1 (574 bp) and ND5 genes (1188 bp). The assay with CO1 sequences, widely used in DNA barcoding, failed to distinguish the two species. The two species were clearly distinguishable, however, with no shared RAG1 or ND5 haplotypes. The species were reciprocally monophyletic for RAG1, but paraphyletic for ND5 sequences. Qualitative evidence and statistical inferences using the 'Isolation-with-Migration models' indicated that these results were better explained with post-divergence gene flow in the recent past rather than incomplete lineage sorting with zero gene flow since speciation. An estimate of divergence time was less than 0.5 Ma with an upper confidence limit of within 1 Ma. Recent speciation of highly mobile species in the marine environment is of great interest, as it suggests that speciation may have occurred in the absence of long-term physical barriers to gene flow. We propose that the ecologically driven forces such as habitat choice played a significant role in speciation in manta rays. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Molecular ecology of aquatic microbes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Abstracts of reports are presented from a meeting on Molecular Ecology of Aquatic Microbes. Topics included: opportunities offered to aquatic ecology by molecular biology; the role of aquatic microbes in biogeochemical cycles; characterization of the microbial community; the effect of the environment on aquatic microbes; and the targeting of specific biological processes.

  7. Speciation of zinc in contaminated soils

    International Nuclear Information System (INIS)

    Stephan, Chadi H.; Courchesne, Francois; Hendershot, William H.; McGrath, Steve P.; Chaudri, Amar M.; Sappin-Didier, Valerie; Sauve, Sebastien

    2008-01-01

    The chemical speciation of zinc in soil solutions is critical to the understanding of its bioavailability and potential toxic effects. We studied the speciation of Zn in soil solution extracts from 66 contaminated soils representative of a wide range of field conditions in both North America and Europe. Within this dataset, we evaluated the links among the dissolved concentrations of zinc and the speciation of Zn 2+ , soil solution pH, total soil Zn, dissolved organic matter (DOM), soil organic matter (SOM) and the concentrations of different inorganic anions. The solid-liquid partitioning coefficient (K d ) for Zn ranged from 17 to 13,100 L kg -1 soil. The fraction of dissolved Zn bound to DOM varied from 60% to 98% and the soil solution free Zn 2+ varied from 40% to 60% of the labile Zn. Multiple regression equations to predict free Zn 2+ , dissolved Zn and the solid-liquid partitioning of Zn are given for potential use in environmental fate modeling and risk assessment. The multiple regressions also highlight some of the most important soil properties controlling the solubility and chemical speciation of zinc in contaminated soils. - We studied the relationships among the chemical speciation of Zn in soil solution extracts from 66 contaminated soils and various physicochemical properties of the soils

  8. Speciation by Symbiosis: the Microbiome and Behavior.

    Science.gov (United States)

    Shropshire, J Dylan; Bordenstein, Seth R

    2016-03-31

    Species are fundamental units of comparison in biology. The newly discovered importance and ubiquity of host-associated microorganisms are now stimulating work on the roles that microbes can play in animal speciation. We previously synthesized the literature and advanced concepts of speciation by symbiosis with notable attention to hybrid sterility and lethality. Here, we review recent studies and relevant data on microbes as players in host behavior and behavioral isolation, emphasizing the patterns seen in these analyses and highlighting areas worthy of additional exploration. We conclude that the role of microbial symbionts in behavior and speciation is gaining exciting traction and that the holobiont and hologenome concepts afford an evolving intellectual framework to promote research and intellectual exchange between disciplines such as behavior, microbiology, genetics, symbiosis, and speciation. Given the increasing centrality of microbiology in macroscopic life, microbial symbiosis is arguably the most neglected aspect of animal and plant speciation, and studying it should yield a better understanding of the origin of species. Copyright © 2016 Shropshire and Bordenstein.

  9. Mechanisms of rapid sympatric speciation by sex reversal and sexual selection in cichlid fish.

    Science.gov (United States)

    Lande, R; Seehausen, O; van Alphen, J J

    2001-01-01

    Mechanisms of speciation in cichlid fish were investigated by analyzing population genetic models of sexual selection on sex-determining genes associated with color polymorphisms. The models are based on a combination of laboratory experiments and field observations on the ecology, male and female mating behavior, and inheritance of sex-determination and color polymorphisms. The models explain why sex-reversal genes that change males into females tend to be X-linked and associated with novel colors, using the hypothesis of restricted recombination on the sex chromosomes, as suggested by previous theory on the evolution of recombination. The models reveal multiple pathways for rapid sympatric speciation through the origin of novel color morphs with strong assortative mating that incorporate both sex-reversal and suppressor genes. Despite the lack of geographic isolation or ecological differentiation, the new species coexists with the ancestral species either temporarily or indefinitely. These results may help to explain different patterns and rates of speciation among groups of cichlids, in particular the explosive diversification of rock-dwelling haplochromine cichlids.

  10. Speciation from photon to ion detection

    International Nuclear Information System (INIS)

    Moulin, C.

    2001-01-01

    New analytical techniques allowing to perform speciation in the framework of the nuclear fuel cycle are more and more needed. Among them, several laser-based analytical techniques present several advantages (non intrusive). Hence, Thermal Lensing (TL)/Photoacoustic (LIPAS), Time Resolved selective, sensitive Laser-Induced Fluorescence (TRLIF) have been used for actinides/lanthanides interaction and speciation studies in inorganic and organic matrices, Laser Ablation-Optical Emission Spectroscopy (LA-OES or LIBS) for direct studies on solids, liquids,... where in situ measurements (elemental or isotopic) are mandatory. In complementary to these photon-based methods, new ion detection methods such as ElectroSpray-Mass Spectrometry (ES-MS) seems promising for speciation studies. Principle, advantages and limitations as well as results obtained and trends for these different methods will be presented. (author)

  11. Anaerobic Digestion Alters Copper and Zinc Speciation.

    Science.gov (United States)

    Legros, Samuel; Levard, Clément; Marcato-Romain, Claire-Emmanuelle; Guiresse, Maritxu; Doelsch, Emmanuel

    2017-09-19

    Anaerobic digestion is a widely used organic waste treatment process. However, little is known on how it could alter the speciation of contaminants in organic waste. This study was focused on determining the influence of anaerobic digestion on the speciation of copper and zinc, two metals that generally occur at high concentration in organic waste. Copper and zinc speciation was investigated by X-ray absorption spectroscopy in four different raw organic wastes (predigestion) and their digested counterparts (postdigestion, i.e., digestates). The results highlighted an increase in the digestates of the proportion of amorphous or nanostructured copper sulfides as well as amorphous or nanostructured zinc sulfides and zinc phosphate as compared to raw waste. We therefore suggest that the environmental fate of these elements would be different when spreading either digestates or raw waste on cropland.

  12. Loss of speciation rate will impoverish future diversity

    OpenAIRE

    Rosenzweig, Michael L.

    2001-01-01

    Human activities have greatly reduced the amount of the earth's area available to wild species. As the area they have left declines, so will their rates of speciation. This loss of speciation will occur for two reasons: species with larger geographical ranges speciate faster; and loss of area drives up extinction rates, thus reducing the number of species available for speciation. Theory predicts steady states in species diversity, and fossils suggest that these have t...

  13. The development of chemical speciation analysis

    International Nuclear Information System (INIS)

    Martin, R.; Santana, J.L.; Lima, L.; De La Rosa, D.; Melchor, K.

    2003-01-01

    The knowledge of many metals species on the environmental, its bioaccumulation, quantification and its effect in human body has been studied by a wide researchers groups in the last two decades. The development of speciation analysis has an vertiginous advance close to the developing of novel analytical techniques. Separation and quantification at low level is a problem that's has been afford by a coupling of high resolution chromatographic techniques like HPLC and HRGC with a specific method of detection (ICP-MS or CV-AAS). This methodological approach make possible the success in chemical speciation nowadays

  14. Incidence and Speciation of Candida Species among Non-gravid ...

    African Journals Online (AJOL)

    This study investigated the incidence and speciation of Candida species among non-gravid young females, using commercially available chromogenic Candida speciation media (CHROM agar) for the identification/speciation of medically important yeast and yeastlike organisms in a routine clinical mycology laboratory.

  15. EPAs SPECIATE 4.4 Database: Development and Uses

    Science.gov (United States)

    SPECIATE is the U.S. Environmental Protection Agency’s (EPA) repository of source category-specific particulate matter (PM), volatile organic gas, and other gas speciation profiles of air pollutant emissions. Abt Associates, Inc. developed SPECIATE 4.4 through a collaborat...

  16. Rapid neo-sex chromosome evolution and incipient speciation in a major forest pest.

    Science.gov (United States)

    Bracewell, Ryan R; Bentz, Barbara J; Sullivan, Brian T; Good, Jeffrey M

    2017-11-17

    Genome evolution is predicted to be rapid following the establishment of new (neo) sex chromosomes, but it is not known if neo-sex chromosome evolution plays an important role in speciation. Here we combine extensive crossing experiments with population and functional genomic data to examine neo-XY chromosome evolution and incipient speciation in the mountain pine beetle. We find a broad continuum of intrinsic incompatibilities in hybrid males that increase in strength with geographic distance between reproductively isolated populations. This striking progression of reproductive isolation is coupled with extensive gene specialization, natural selection, and elevated genetic differentiation on both sex chromosomes. Closely related populations isolated by hybrid male sterility also show fixation of alternative neo-Y haplotypes that differ in structure and male-specific gene content. Our results suggest that neo-sex chromosome evolution can drive rapid functional divergence between closely related populations irrespective of ecological drivers of divergence.

  17. Speciation, Divergence, and the Origin of Gryllus rubens: Behavior, Morphology, and Molecules

    Directory of Open Access Journals (Sweden)

    David A. Gray

    2011-05-01

    Full Text Available The last 25 years or so has seen a huge resurgence of interest in speciation research. This has coincided with the development and widespread use of new tools in molecular genetics, especially DNA sequencing, to inform ecological and evolutionary questions. Here I review about a decade of work on the sister species of field crickets Gryllus texensis and G. rubens. This work has included analysis of morphology, behavior, and the mitochondrial DNA molecule. The molecular work in particular has dramatically re-shaped my interpretation of the speciational history of these taxa, suggesting that rather than ‘sister’ species we should consider these taxa as ‘mother-daughter’ species with G. rubens derived from within a subset of ancestral G. texensis.

  18. Summary and perspective on evolutionary ecology of fishes

    Czech Academy of Sciences Publication Activity Database

    Mehner, T.; Freyhof, J.; Reichard, Martin

    2011-01-01

    Roč. 25, č. 3 (2011), s. 547-556 ISSN 0269-7653 R&D Projects: GA ČR GA206/09/0815 Institutional research plan: CEZ:AV0Z60930519 Keywords : non-model systems * ecological speciation * behavioural interactions * local adaptation Subject RIV: EG - Zoology Impact factor: 2.453, year: 2011

  19. Actinide speciation in the environment

    International Nuclear Information System (INIS)

    Choppin, G.R.

    2007-01-01

    Nuclear test explosions and nuclear reactor wastes and accidents have released large amounts of radioactivity into the environment. Actinide ions in waters often are not in a state of thermodynamic equilibrium and their solubility and migration behavior is related to the form in which the nuclides are introduced into the aquatic system. Chemical speciation, oxidation state, redox reactions, and sorption characteristics are necessary in predicting solubility of the different actinides, their migration behaviors and their potential effects on marine biota. The most significant of these variables is the oxidation state of the metal ion as the simultaneous presence of more than one oxidation state for some actinides in a solution complicates actinide environmental behavior. Both Np(V)O 2 + and Pu(V)O 2 + , the most significant soluble states in natural oxic waters, are relatively noncomplexing and resistant to hydrolysis and subsequent precipitation. The solubility of NpO 2 + can be as high as 10 -4 M while that of PuO 2 + is much more limited by reduction to the insoluble tetravalent species, Pu(OH) 4 , (pK sp ≥56) but which can be present in the pentavalent form in aqautic phases as colloidal material. The solubility of hexavalent UO 2 2+ in sea water is relatively high due to formation of carbonate complexes. The insoluble trivalent americium hydroxocarbonate, Am(OH)(CO 3 ) is the limiting species for the solubility of Am(III) in sea water. Thorium(IV) is present as Th(OH) 4 , in colloidal form. The chemistry of actinide ions in the environment is reviewed to show the spectrum of reactions that can occur in natural waters which must be considered in assessing the environmental behavior of actinides. Much is understood about sorption of actinides on surfaces, the mode of migration of actinides in such waters and the potential effects of these radioactive species on marine biota, but much more understanding of the behavior of the actinides in the environment is

  20. Controlled ecological life support systems; Proceedings of Workshop II of the 26th COSPAR Plenary Meeting, Toulouse, France, June 30-July 11, 1986

    Science.gov (United States)

    Macelroy, R. D. (Editor); Smernoff, D. T. (Editor)

    1987-01-01

    The present conference on the development status of Controlled Ecological Life Support Systems (CELSSs) discusses food production and gas exchange with the Spirulina blue-green alga, biomass recycling for greater energy efficiency in algal culture CELSSs, algal proteins for food processing in a CELSS, a CELSS with photosynthetic N2-fixing cyanobacteria, the NASA CELSS program, and vapor compression ditillation and membrane technology for water revitalization. Also discussed are a fundamental study of CELSS gas monitoring, the application of catalytic wet oxidation to CELSS, a large-scale perspective on ecosystems, Japanese CELSS research activities, the use of potatoes in bioregenerative life-support, wheat production in controlled environments, and a trickle water and feeding system in plant culture.

  1. How does male–male competition generate negative frequency-dependent selection and disruptive selection during speciation?

    Science.gov (United States)

    Border, Shana E

    2018-01-01

    Abstract Natural selection has been shown to drive population differentiation and speciation. The role of sexual selection in this process is controversial; however, most of the work has centered on mate choice while the role of male–male competition in speciation is relatively understudied. Here, we outline how male–male competition can be a source of diversifying selection on male competitive phenotypes, and how this can contribute to the evolution of reproductive isolation. We highlight how negative frequency-dependent selection (advantage of rare phenotype arising from stronger male–male competition between similar male phenotypes compared with dissimilar male phenotypes) and disruptive selection (advantage of extreme phenotypes) drives the evolution of diversity in competitive traits such as weapon size, nuptial coloration, or aggressiveness. We underscore that male–male competition interacts with other life-history functions and that variable male competitive phenotypes may represent alternative adaptive options. In addition to competition for mates, aggressive interference competition for ecological resources can exert selection on competitor signals. We call for a better integration of male–male competition with ecological interference competition since both can influence the process of speciation via comparable but distinct mechanisms. Altogether, we present a more comprehensive framework for studying the role of male–male competition in speciation, and emphasize the need for better integration of insights gained from other fields studying the evolutionary, behavioral, and physiological consequences of agonistic interactions. PMID:29492042

  2. Radiating on oceanic islands: patterns and processes of speciation in the land snail genus Theba (Risso 1826.

    Directory of Open Access Journals (Sweden)

    Carola Greve

    Full Text Available Island radiations have played a major role in shaping our current understanding of allopatric, sympatric and parapatric speciation. However, the fact that species divergence correlates with island size emphasizes the importance of geographic isolation (allopatry in speciation. Based on molecular and morphological data, we investigated the diversification of the land snail genus Theba on the two Canary Islands of Lanzarote and Fuerteventura. Due to the geological history of both islands, this study system provides ideal conditions to investigate the interplay of biogeography, dispersal ability and differentiation in generating species diversity. Our analyses demonstrated extensive cryptic diversification of Theba on these islands, probably driven mainly by non-adaptive allopatric differentiation and secondary gene flow. In a few cases, we observed a complete absence of gene flow among sympatrically distributed forms suggesting an advanced stage of speciation. On the Jandía peninsula genome scans suggested genotype-environment associations and potentially adaptive diversification of two closely related Theba species to different ecological environments. We found support for the idea that genetic differentiation was enhanced by divergent selection in different environments. The diversification of Theba on both islands is therefore best explained by a mixture of non-adaptive and adaptive speciation, promoted by ecological and geomorphological factors.

  3. Radiating on oceanic islands: patterns and processes of speciation in the land snail genus Theba (Risso 1826).

    Science.gov (United States)

    Greve, Carola; Gimnich, France; Hutterer, Rainer; Misof, Bernhard; Haase, Martin

    2012-01-01

    Island radiations have played a major role in shaping our current understanding of allopatric, sympatric and parapatric speciation. However, the fact that species divergence correlates with island size emphasizes the importance of geographic isolation (allopatry) in speciation. Based on molecular and morphological data, we investigated the diversification of the land snail genus Theba on the two Canary Islands of Lanzarote and Fuerteventura. Due to the geological history of both islands, this study system provides ideal conditions to investigate the interplay of biogeography, dispersal ability and differentiation in generating species diversity. Our analyses demonstrated extensive cryptic diversification of Theba on these islands, probably driven mainly by non-adaptive allopatric differentiation and secondary gene flow. In a few cases, we observed a complete absence of gene flow among sympatrically distributed forms suggesting an advanced stage of speciation. On the Jandía peninsula genome scans suggested genotype-environment associations and potentially adaptive diversification of two closely related Theba species to different ecological environments. We found support for the idea that genetic differentiation was enhanced by divergent selection in different environments. The diversification of Theba on both islands is therefore best explained by a mixture of non-adaptive and adaptive speciation, promoted by ecological and geomorphological factors.

  4. The ecological economics: An ecological economics

    International Nuclear Information System (INIS)

    Castiblanco R, Carmenza

    2007-01-01

    Ecological Economics arise as a scientific discipline aimed to integrate concepts of economics, ecology, thermodynamics, ethic and other natural and social sciences in order to incorporate a biophysical and integrated perspective of the inter dependences between economies and environment, from a plural conception and a methodology beyond disciplines. Ecological Economics studies the black box of economic processes usually excluded of the traditional economics: thermodynamics and ecology. Although it is relatively a new field of study, it has been strengthening its theoretical framework with scientific basis and analytic principles that lead to its identification as a new discipline that show a whole new paradigm. The scope of this article is to show the conceptual and methodological bases, the main founders, approaches and central debates of this new discipline. This brief introduction is a preamble to the papers of the meeting Ecological Economics: a perspective for Colombia included in this number, that took place on September 22 - 27 of 2007, at the National University of Colombia at Bogota. During tree days national and international experts, professors, researchers, workers of environmental sector and people interested on environmental issues joined together to know the conceptual and methodological achievements reached of this discipline; as well as to analyse and evaluate the environmental problems of the country, from the systemic, interdisciplinary and general perspective that it promotes

  5. Incipient speciation driven by hypertrophied lips in Midas cichlid fishes?

    Science.gov (United States)

    Machado-Schiaffino, Gonzalo; Kautt, Andreas F; Torres-Dowdall, Julian; Baumgarten, Lukas; Henning, Frederico; Meyer, Axel

    2017-04-01

    Sympatric speciation has been debated in evolutionary biology for decades. Although it has gained in acceptance recently, still only a handful of empirical examples are seen as valid (e.g. crater lake cichlids). In this study, we disentangle the role of hypertrophied lips in the repeated adaptive radiations of Nicaraguan crater lake cichlid fish. We assessed the role of disruptive selection and assortative mating during the early stages of divergence and found a functional trade-off in feeding behaviour between thick- and thin-lipped ecotypes, suggesting that this trait is a target of disruptive selection. Thick-lipped fish perform better on nonevasive prey at the cost of a poorer performance on evasive prey. Using enclosures in the wild, we found that thick-lipped fish perform significantly better in rocky than in sandy habitats. We found almost no mixed pairs during two breeding seasons and hence significant assortative mating. Genetic differentiation between ecotypes seems to be related to the time since colonization, being subtle in L. Masaya (1600 generations ago) and absent in the younger L. Apoyeque (<600 generations ago). Genome-wide differentiation between ecotypes was higher in the old source lakes than in the young crater lakes. Our results suggest that hypertrophied lips might be promoting incipient sympatric speciation through divergent selection (ecological divergence in feeding performance) and nonrandom mating (assortative mating) in the young Nicaraguan crater lakes. Nonetheless, further manipulative experiments are needed in order to confirm the role of hypertrophied lips as the main cue for assortative mating. © 2017 John Wiley & Sons Ltd.

  6. Electrochemical metal speciation in colloidal dispersions

    NARCIS (Netherlands)

    Wonders, J.H.A.M.

    1995-01-01

    The term "heavy metals" is connected with toxicity. They form strong complexes with enzymes, other proteins and DNA in living organisms, which causes dysfunctioning and hence poisoning. In combination with the uptake mechanism of the organism, speciation of heavy metal determines the

  7. ARSENIC SPECIATION ANALYSIS IN HUMAN SALIVA

    Science.gov (United States)

    Background: Determination of arsenic species in human saliva is potentially useful for biomonitoring of human exposure to arsenic and for studying arsenic metabolism. However, there is no report on the speciation analysis of arsenic in saliva. Methods: Arsenic species in saliva ...

  8. Biogeochemical speciation of Fe in ocean water

    NARCIS (Netherlands)

    Hiemstra, T.; Riemsdijk, van W.H.

    2006-01-01

    The biogeochemical speciation of Fe in seawater has been evaluated using the consistent Non-Ideal Competitive Adsorption model (NICA¿Donnan model). Two types of data sets were used, i.e. Fe-hydroxide solubility data and competitive ligand equilibration/cathodic stripping voltammetry (CLE/CSV) Fe

  9. Biosensor for metal analysis and speciation

    Science.gov (United States)

    Aiken, Abigail M.; Peyton, Brent M.; Apel, William A.; Petersen, James N.

    2007-01-30

    A biosensor for metal analysis and speciation is disclosed. The biosensor comprises an electron carrier immobilized to a surface of an electrode and a layer of an immobilized enzyme adjacent to the electrode. The immobilized enzyme comprises an enzyme having biological activity inhibited by a metal to be detected by the biosensor.

  10. The speciation of iodine in the environment

    International Nuclear Information System (INIS)

    Bulman, R.A.

    1986-01-01

    The speciation of iodine in the environment is discussed under the following topics: (i) sea surface to atmosphere, (ii) chemistry in bulk seawater, (iii) iodine in rocks, (iv) iodine in soils, (v) iodine in plants and (vi) iodine in solidified wastes. (author)

  11. Chemical Speciation and Quantitative Evaluation of Heavy Metal Pollution Hazards in Two Army Shooting Range Backstop Soils.

    Science.gov (United States)

    Islam, Mohammad Nazrul; Nguyen, Xuan Phuc; Jung, Ho-Young; Park, Jeong-Hun

    2016-02-01

    The chemical speciation and ecological risk assessment of heavy metals in two shooting range backstop soils in Korea were studied. Both soils were highly contaminated with Cd, Cu, Pb, and Sb. The chemical speciation of heavy metals reflected the present status of contamination, which could help in promoting management practices. We-rye soil had a higher proportion of exchangeable and carbonate bound metals and water-extractable Cd and Sb than the Cho-do soil. Bioavailable Pb represented 42 % of the total Pb content in both soils. A significant amount of Sb was found in the two most bioavailable fractions, amounting to ~32 % in the soil samples, in good agreement with the batch leaching test using water. Based on the values of ecological risk indices, both soils showed extremely high potential risk and may represent serious environmental problems.

  12. Polarographic validation of chemical speciation models

    International Nuclear Information System (INIS)

    Duffield, J.R.; Jarratt, J.A.

    2001-01-01

    It is well established that the chemical speciation of an element in a given matrix, or system of matrices, is of fundamental importance in controlling the transport behaviour of the element. Therefore, to accurately understand and predict the transport of elements and compounds in the environment it is a requirement that both the identities and concentrations of trace element physico-chemical forms can be ascertained. These twin requirements present the analytical scientist with considerable challenges given the labile equilibria, the range of time scales (from nanoseconds to years) and the range of concentrations (ultra-trace to macro) that may be involved. As a result of this analytical variability, chemical equilibrium modelling has become recognised as an important predictive tool in chemical speciation analysis. However, this technique requires firm underpinning by the use of complementary experimental techniques for the validation of the predictions made. The work reported here has been undertaken with the primary aim of investigating possible methodologies that can be used for the validation of chemical speciation models. However, in approaching this aim, direct chemical speciation analyses have been made in their own right. Results will be reported and analysed for the iron(II)/iron(III)-citrate proton system (pH 2 to 10; total [Fe] = 3 mmol dm -3 ; total [citrate 3- ] 10 mmol dm -3 ) in which equilibrium constants have been determined using glass electrode potentiometry, speciation is predicted using the PHREEQE computer code, and validation of predictions is achieved by determination of iron complexation and redox state with associated concentrations. (authors)

  13. Historical ecology meets conservation and evolutionary genetics: a secondary contact zone between Carabus violaceus (Coleoptera, Carabidae populations inhabiting ancient and recent woodlands in north-western Germany

    Directory of Open Access Journals (Sweden)

    Andrea Matern

    2011-05-01

    Full Text Available Only very few cases have documented that an increase in connectivity after a period of fragmentation in ecological time has had an effect on the distribution, genetic structure and morphology of stenotopic species. In this study we present an example of clinal variability in a woodland ground beetle as a result of changes in the connectivity of a landscape during the last two centuries. The study area hosts both the nominate form C. violaceus s. str. and the subspecies C. v. purpurascens, which is ranked as a distinct species by some authors. We studied 12 Carabus violaceus populations from a 30 km transect of ancient and recent forests in north-western Germany. We analyzed three polymorphic enzyme loci, classified the elytron sculpture and measured the shape of the aedeagus tip of the specimens. C. violaceus showed secondary gradients both in allozyme markers and morphometric characters in our study area. A genetic differentiation of 16% between the populations is high but lies within the range of intraspecific variability in habitat specialists of the genus Carabus. Populations had no significant deficit of heterozygotes. We found many hybrid populations in terms of morphological properties. This study highlights the conservation value of ancient woodland and the consequences of landscape connectivity and defragmentation on the genetic setting of a ground beetle. Moreover, it shows that differences in the external shape of male genitalia do not prevent gene flow within the genus Carabus. Thus, the establishment of species status should not exclusively be based on this property.

  14. Evolution and ecology meet molecular genetics: adaptive phenotypic plasticity in two isolated Negev desert populations of Acacia raddiana at either end of a rainfall gradient

    Science.gov (United States)

    Ward, David; Shrestha, Madan K.; Golan-Goldhirsh, Avi

    2012-01-01

    Background and Aims The ecological, evolutionary and genetic bases of population differentiation in a variable environment are often related to the selection pressures that plants experience. We compared differences in several growth- and defence-related traits in two isolated populations of Acacia raddiana trees from sites at either end of an extreme environmental gradient in the Negev desert. Methods We used random amplified polymorphic DNA (RAPD) to determine the molecular differences between populations. We grew plants under two levels of water, three levels of nutrients and three levels of herbivory to test for phenotypic plasticity and adaptive phenotypic plasticity. Key Results The RAPD analyses showed that these populations are highly genetically differentiated. Phenotypic plasticity in various morphological traits in A. raddiana was related to patterns of population genetic differentiation between the two study sites. Although we did not test for maternal effects in these long-lived trees, significant genotype × environment (G × E) interactions in some of these traits indicated that such plasticity may be adaptive. Conclusions The main selection pressure in this desert environment, perhaps unsurprisingly, is water. Increased water availability resulted in greater growth in the southern population, which normally receives far less rain than the northern population. Even under the conditions that we defined as low water and/or nutrients, the performance of the seedlings from the southern population was significantly better, perhaps reflecting selection for these traits. Consistent with previous studies of this genus, there was no evidence of trade-offs between physical and chemical defences and plant growth parameters in this study. Rather, there appeared to be positive correlations between plant size and defence parameters. The great variation in several traits in both populations may result in a diverse potential for responding to selection pressures in

  15. Triatominae as a model of morphological plasticity under ecological pressure

    Directory of Open Access Journals (Sweden)

    Dujardin JP

    1999-01-01

    Full Text Available The use of biochemical and genetic characters to explore species or population relationships has been applied to taxonomic questions since the 60s. In responding to the central question of the evolutionary history of Triatominae, i.e. their monophyletic or polyphyletic origin, two important questions arise (i to what extent is the morphologically-based classification valid for assessing phylogenetic relationships? and (ii what are the main mechanisms underlying speciation in Triatominae? Phenetic and genetic studies so far developed suggest that speciation in Triatominae may be a rapid process mainly driven by ecological factors.

  16. Allochronic speciation, secondary contact, and reproductive character displacement in periodical cicadas (Hemiptera: Magicicada spp.): genetic, morphological, and behavioural evidence.

    Science.gov (United States)

    Cooley, J R; Simon, C; Marshall, D C; Slon, K; Ehrhardt, C

    2001-03-01

    Periodical cicadas have proven useful in testing a variety of ecological and evolutionary hypotheses because of their unusual life history, extraordinary abundance, and wide geographical range. Periodical cicadas provide the best examples of synchronous periodicity and predator satiation in the animal kingdom, and are excellent illustrations of habitat partitioning (by the three morphologically distinct species groups), incipient species (the year classes or broods), and cryptic species (a newly discovered 13-year species, Magicicada neotredecim). They are particularly useful for exploring questions regarding speciation via temporal isolation, or allochronic speciation. Recently, data were presented that provided strong support for an instance of allochronic speciation by life-cycle switching. This speciation event resulted in the formation of a new 13-year species from a 17-year species and led to secondary contact between two formerly separated lineages, one represented by the new 13-year cicadas (and their 17-year ancestors), and the other represented by the pre-existing 13-year cicadas. Allozyme frequency data, mitochondrial DNA (mtDNA), and abdominal colour were shown to be correlated genetic markers supporting the life-cycle switching/allochronic speciation hypothesis. In addition, a striking pattern of reproductive character displacement in male call pitch and female pitch preference between the two 13-year species was discovered. In this paper we report a strong association between calling song pitch and mtDNA haplotype for 101 individuals from a single locality within the M. tredecim/M. neotredecim contact zone and a strong association between abdomen colour and mtDNA haplotype. We conclude by reviewing proposed mechanisms for allochronic speciation and reproductive character displacement.

  17. AQUATIC PLANT SPECIATION AFFECTED BY DIVERSIFYING SELECTION OF ORGANELLE DNA REGIONS(1).

    Science.gov (United States)

    Kato, Syou; Misawa, Kazuharu; Takahashi, Fumio; Sakayama, Hidetoshi; Sano, Satomi; Kosuge, Keiko; Kasai, Fumie; Watanabe, Makoto M; Tanaka, Jiro; Nozaki, Hisayoshi

    2011-10-01

    Many of the genes that control photosynthesis are carried in the chloroplast. These genes differ among species. However, evidence has yet to be reported revealing the involvement of organelle genes in the initial stages of plant speciation. To elucidate the molecular basis of aquatic plant speciation, we focused on the unique plant species Chara braunii C. C. Gmel. that inhabits both shallow and deep freshwater habitats and exhibits habitat-based dimorphism of chloroplast DNA (cpDNA). Here, we examined the "shallow" and "deep" subpopulations of C. braunii using two nuclear DNA (nDNA) markers and cpDNA. Genetic differentiation between the two subpopulations was measured in both nDNA and cpDNA regions, although phylogenetic analyses suggested nuclear gene flow between subpopulations. Neutrality tests based on Tajima's D demonstrated diversifying selection acting on organelle DNA regions. Furthermore, both "shallow" and "deep" haplotypes of cpDNA detected in cultures originating from bottom soils of three deep environments suggested that migration of oospores (dormant zygotes) between the two habitats occurs irrespective of the complete habitat-based dimorphism of cpDNA from field-collected vegetative thalli. Therefore, the two subpopulations are highly selected by their different aquatic habitats and show prezygotic isolation, which represents an initial process of speciation affected by ecologically based divergent selection of organelle genes. © 2011 Phycological Society of America.

  18. Hybridization and genome evolution I: The role of contingency during hybrid speciation

    Directory of Open Access Journals (Sweden)

    Fabrice EROUKHMANOFF, Richard I. BAILEY, Glenn-Peter SæTRE

    2013-10-01

    Full Text Available Homoploid hybrid speciation (HHS involves the recombination of two differentiated genomes into a novel, functional one without a change in chromosome number. Theoretically, there are numerous ways for two parental genomes to recombine. Hence, chance may play a large role in the formation of a hybrid species. If these genome combinations can evolve rapidly following hybridization and sympatric situations are numerous, recurrent homoploid hybrid speciation is a possibility. We argue that three different, but not mutually exclusive, types of contingencies could influence this process. First, many of these “hopeful monsters” of recombinant parent genotypes would likely have low fitness. Only specific combinations of parental genomic contributions may produce viable, intra-fertile hybrid species able to accommodate potential constraints arising from intragenomic conflict. Second, ecological conditions (competition, geography of the contact zones or the initial frequency of both parent species might favor different outcomes ranging from sympatric coexistence to the formation of hybrid swarms and ultimately hybrid speciation. Finally, history may also play an important role in promoting or constraining recurrent HHS if multiple hybridization events occur sequentially and parental divergence or isolation differs along this continuum. We discuss under which conditions HHS may occur multiple times in parallel and to what extent recombination and selection may fuse the parent genomes in the same or different ways. We conclude by examining different approaches that might help to solve this intriguing evolutionary puzzle [Current Zoology 59 (5: 667-674, 2013]. 

  19. Early events in speciation: Cryptic species of Drosophila aldrichi.

    Science.gov (United States)

    Castro Vargas, Cynthia; Richmond, Maxi Polihronakis; Ramirez Loustalot Laclette, Mariana; Markow, Therese Ann

    2017-06-01

    Understanding the earliest events in speciation remains a major challenge in evolutionary biology. Thus identifying species whose populations are beginning to diverge can provide useful systems to study the process of speciation. Drosophila aldrichi , a cactophilic fruit fly species with a broad distribution in North America, has long been assumed to be a single species owing to its morphological uniformity. While previous reports either of genetic divergence or reproductive isolation among different D. aldrichi strains have hinted at the existence of cryptic species, the evolutionary relationships of this species across its range have not been thoroughly investigated. Here we show that D. aldrichi actually is paraphyletic with respect to its closest relative, Drosophila wheeleri , and that divergent D. aldrichi lineages show complete hybrid male sterility when crossed. Our data support the interpretation that there are at least two species of D. aldrichi, making these flies particularly attractive for studies of speciation in an ecological and geographical context.

  20. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    Landscape ecology is an interdisciplinary field of research and practice that deals with the mutual association between the spatial configuration and ecological functioning of landscapes, exploring and describing processes involved in the differentiation of spaces within landscapes......, and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... pattern analysis and ecological interaction of land units. The landscape is seen as a holon: an assemblage of interrelated phenomena, both cultural and biophysical, that together form a complex whole. Enduring challenges to landscape ecology include the need to develop a systematic approach able...

  1. Trace element speciation in the environment

    International Nuclear Information System (INIS)

    Heumann, Klaus G.

    2001-01-01

    The production of methylated heavy metal species in the ocean was reviewed and shown to be correlated with biological parameters demonstrating them to be of biogenic origin. Methods for the determination of the species were discussed. The potential for the use of isotopic spiking either in 'species specific' or 'non-species specific' formats was identified as a valuable tool in the struggle for accuracy, specificity and precision in speciation analysis. The value of using a size exclusion chromatographic method in conjunction with non-species specific spiking IDMS was highlighted with an example illustrating the molecular mass fractions associated with halogenated species from a humic sample. Additional recommendations that the Agency might wish to consider when evaluating its potential role as a service to Member States engaged in speciation activities are also given

  2. Speciation and zoogeography of amphibian in Sundaland

    Directory of Open Access Journals (Sweden)

    Nia Kurniawan

    2015-12-01

    Full Text Available Sundaland is an interesting area to be explored based on its geological history, topography, and climate. Sundaland consists of Penisular Malaysia, Sumatra, Borneo, and Java which experienced some emergence and submergence process in the past. During 1981-2015, most of research in Sundaland found that amphibian family in Sundaland was dominated by Bufonidae, Ranidae, Microhylidae, Megophrydae, Rachophoridae, and Dicroglossidae which experienced lot of speciation in its history. Among of 4 major islands in Sundaland, Borneo has the highest number of species diversity, then Peninsular Malaysia, Sumatra, and Java. During those years, Sumatra and Java got least concern by researcher. Therefore, it is suggested for further study to explore more in Sumatra and Java. Keywords: Sundaland, amphibian, speciation, zoogeography.

  3. Speciation studies of cobalt in sea water

    International Nuclear Information System (INIS)

    Toteja, R.S.D.; Sudersanan, M.; Iyer, R.K.

    1995-01-01

    Recent results on the speciation of cobalt in simulated and actual sea water is reported using ion exchangers. The influence of magnesium ions in affecting the composition of ion exchangers and subsequent interpretation of the results is discussed. The results indicated that Co +2 may predominate in both the simulated and actual sea water and the presence of other constituents in sea water does not affect the nature of complex species present. (author). 2 refs., 3 tabs., 1 fig

  4. Tungsten Speciation in Firing Range Soils

    Science.gov (United States)

    2011-01-01

    satisfactorily, such as: which tungsten mineral phase is present in soil and to what extent is adsorption important in regu- lating soil solution concentrations... soil solution rather than discrete mineral phases. Information provided in this report will assist the following organizations in future decision...the soil solution ERDC TR-11-1 43 must affect tungsten speciation in other ways. The precipitation of soil minerals also would limit tungsten

  5. The genetics of speciation by reinforcement.

    Directory of Open Access Journals (Sweden)

    Daniel Ortiz-Barrientos

    2004-12-01

    Full Text Available Reinforcement occurs when natural selection strengthens behavioral discrimination to prevent costly interspecies matings, such as when matings produce sterile hybrids. This evolutionary process can complete speciation, thereby providing a direct link between Darwin's theory of natural selection and the origin of new species. Here, by examining a case of speciation by reinforcement in Drosophila,we present the first high-resolution genetic study of variation within species for female mating discrimination that is enhanced by natural selection. We show that reinforced mating discrimination is inherited as a dominant trait, exhibits variability within species, and may be influenced by a known set of candidate genes involved in olfaction. Our results show that the genetics of reinforced mating discrimination is different from the genetics of mating discrimination between species, suggesting that overall mating discrimination might be a composite phenomenon, which in Drosophila could involve both auditory and olfactory cues. Examining the genetics of reinforcement provides a unique opportunity for both understanding the origin of new species in the face of gene flow and identifying the genetic basis of adaptive female species preferences, two major gaps in our understanding of speciation.

  6. First passage time to allopatric speciation.

    Science.gov (United States)

    Yamaguchi, Ryo; Iwasa, Yoh

    2013-12-06

    Allopatric speciation is a mechanism to evolve reproductive isolation; it is caused by the accumulation of genetic differences between populations while they are geographically isolated. Here, we studied a simple stochastic model for the time until speciation caused by geographical isolation in fragmented populations that experience recurrent but infrequent migration between subpopulations. We assumed that mating incompatibility is controlled by a number of loci that behave as neutral characters in the accumulation of novel mutations within each population. Genetic distance between populations was defined as the number of incompatibility-controlling loci that differ between them. Genetic distance increases through the separate accumulation of mutations in different populations, but decreases after a successful migration event followed by genetic mixing between migrants and residents. We calculated the time to allopatric speciation, which occurs when the genetic distance exceeds a specified threshold. If the number of invasive individuals relative to the resident population is not very large, diffusion approximation provides an accurate prediction. There is an intermediate optimal rate of migration that maximizes the rate of species creation by recurrent invasion and diversification. We also examined cases that involved more than two populations.

  7. Arsenic speciation and sorption in natural environments

    Science.gov (United States)

    Campbell, Kate M.; Nordstrom, D. Kirk

    2014-01-01

    Aqueous arsenic speciation, or the chemical forms in which arsenic exists in water, is a challenging, interesting, and complicated aspect of environmental arsenic geochemistry. Arsenic has the ability to form a wide range of chemical bonds with carbon, oxygen, hydrogen, and sulfur, resulting in a large variety of compounds that exhibit a host of chemical and biochemical properties. Besides the intriguing chemical diversity, arsenic also has the rare capacity to capture our imaginations in a way that few elements can duplicate: it invokes images of foul play that range from sinister to comedic (e.g., “inheritance powder” and arsenic-spiked elderberry wine). However, the emergence of serious large-scale human health problems from chronic arsenic exposure in drinking water has placed a high priority on understanding environmental arsenic mobility, toxicity, and bioavailability, and chemical speciation is key to these important questions. Ultimately, the purpose of arsenic speciation research is to predict future occurrences, mitigate contamination, and provide successful management of water resources.

  8. Hierarchical structure of ecological and non-ecological processes of differentiation shaped ongoing gastropod radiation in the Malawi Basin.

    Science.gov (United States)

    Van Bocxlaer, Bert

    2017-09-13

    Ecological processes, non-ecological processes or a combination of both may cause reproductive isolation and speciation, but their specific roles and potentially complex interactions in evolutionary radiations remain poorly understood, which defines a central knowledge gap at the interface of microevolution and macroevolution. Here I examine genome scans in combination with phenotypic and environmental data to disentangle how ecological and non-ecological processes contributed to population differentiation and speciation in an ongoing radiation of Lanistes gastropods from the Malawi Basin. I found a remarkable hierarchical structure of differentiation mechanisms in space and time: neutral and mutation-order processes are older and occur mainly between regions, whereas more recent adaptive processes are the main driver of genetic differentiation and reproductive isolation within regions. The strongest differentiation occurs between habitats and between regions, i.e. when ecological and non-ecological processes act synergistically. The structured occurrence of these processes based on the specific geographical setting and ecological opportunities strongly influenced the potential for evolutionary radiation. The results highlight the importance of interactions between various mechanisms of differentiation in evolutionary radiations, and suggest that non-ecological processes are important in adaptive radiations, including those of cichlids. Insight into such interactions is critical to understanding large-scale patterns of organismal diversity. © 2017 The Author(s).

  9. Speciation below ground: Tempo and mode of diversification in a radiation of endogean ground beetles.

    Science.gov (United States)

    Andújar, Carmelo; Pérez-González, Sergio; Arribas, Paula; Zaballos, Juan P; Vogler, Alfried P; Ribera, Ignacio

    2017-11-01

    Dispersal is a critical factor determining the spatial scale of speciation, which is constrained by the ecological characteristics and distribution of a species' habitat and the intrinsic traits of species. Endogean taxa are strongly affected by the unique qualities of the below-ground environment and its effect on dispersal, and contrasting reports indicate either high dispersal capabilities favoured by small body size and mediated by passive mechanisms, or low dispersal due to restricted movement and confinement inside the soil. We studied a species-rich endogean ground beetle lineage, Typhlocharina, including three genera and more than 60 species, as a model for the evolutionary biology of dispersal and speciation in the deep soil. A time-calibrated molecular phylogeny generated from >400 individuals was used to delimit candidate species, to study the accumulation of lineages through space and time by species-area-age relationships and to determine the geographical structure of the diversification using the relationship between phylogenetic and geographic distances across the phylogeny. Our results indicated a small spatial scale of speciation in Typhlocharina and low dispersal capacity combined with sporadic long distance, presumably passive dispersal events that fuelled the speciation process. Analysis of lineage growth within Typhlocharina revealed a richness plateau correlated with the range of distribution of lineages, suggesting a long-term species richness equilibrium mediated by density dependence through limits of habitat availability. The interplay of area- and age-dependent processes ruling the lineage diversification in Typhlocharina may serve as a general model for the evolution of high species diversity in endogean mesofauna. © 2017 John Wiley & Sons Ltd.

  10. Study of the impact of environmental bacteria ob uranium speciation in order to engage bioremediation process

    International Nuclear Information System (INIS)

    Untereiner, G.

    2008-11-01

    Uranium is both a radiological and a chemical toxic. Its concentration in the environment is low except when human activities have caused pollution. Uranium is a heavy reactive element, and thus it is easily complexed with soil component like minerals or organic molecules. These different complexes can be more or less bioavailable for microorganisms and plants, and then get in the human food chain. The knowledge and the understanding of transfer mechanisms and also the fate of toxic elements in the biosphere are a key issue to estimate health and ecological hazards. The knowledge of the speciation is very important for bioremediation processes. Here, we focused on the microorganisms effects onto uranium speciation in environment. Bacteria can accumulate and/or transform uranium depending on the initial form of the element. Thus, its bioavailability could be changed. The species used in this work are Cupriavidus metallidurans CH34, which is an environmental bacteria with a high resistance to heavy metal, Deinococcus radiodurans R1, which is known for his radiological resistance, and Rhodopseudomonas palustris, which is a purple photo-trophic bacteria capable of degrading aromatic compounds. Two forms of uranium were used with these bacteria, a mineral one, uranyl carbonate, and an organic one, uranyl citrate. In a first step, the growth media were modified in order to stabilize uranium complexes thanks to a simulation program. Then, the capacity of the bacteria to accumulate or transform uranium was studied. We saw a difference between minimal inhibition concentrations of these two speciation which is due to a difference between phosphate bioavailability. No accumulation was observed with environmental pH but uranium precipitation was observed with acidic pH (pH 1). Uranium speciation seemed to be well controlled in the growth media and the precipitates were uranyl phosphate. (author)

  11. Thermodynamics proposes, kinetics decides, speciation dares: speciation of actinides in biological media

    International Nuclear Information System (INIS)

    Ansoborlo, E.

    2005-06-01

    After having recalled the content and purpose of his research thesis, the author proposes a detailed overview of the research works he performed thereafter in the field of the speciation of actinides at the level of the organism entry gates and in target tissues. These works therefore concern four important areas of research in radioprotection: bio-kinetic, toxicology, decorporation, and dosimetry studies. The author outlines how speciation studies can be useful for these different areas, and to better understand and describe, and therefore foresee, the biokinetics and toxicity of radionuclides

  12. Electrospray mass spectrometry for actinides and lanthanide speciation

    International Nuclear Information System (INIS)

    Moulin, C.; Amekraz, B.; Colette, S.; Doizi, D.; Jacopin, C.; Lamouroux, C.; Plancque, G.

    2006-01-01

    Electrospray mass spectrometry (ES-MS) is a new speciation technique that has the great interest to be able to probe the element, the ligand and the complex in order to reach the speciation. This paper will focus on the use of ES-MS for the speciation of actinides/lanthanides on several systems of interest in various fields such as the interaction between DTPA (decorporant) and europium, HEBP and uranium, BTP (new extracting agent) and lanthanides with comparison with known chemistry as well as whenever possible with other speciation techniques

  13. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    , and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... to translate positivist readings of the environment and hermeneutical perspectives on socioecological interaction into a common framework or terminology....

  14. Rapid allopatric speciation in logperch darters (Percidae: Percina).

    Science.gov (United States)

    Near, Thomas J; Benard, Michael F

    2004-12-01

    Theory predicts that clades diversifying via sympatric speciation will exhibit high diversification rates. However, the expected rate of diversification in clades characterized by allopatric speciation is less clear. Previous studies have documented significantly higher speciation rates in freshwater fish clades diversifying via sympatric versus allopatric modes, leading to suggestions that the geographic pattern of speciation can be inferred solely from knowledge of the diversification rate. We tested this prediction using an example from darters, a clade of approximately 200 species of freshwater fishes endemic to eastern North America. A resolved phylogeny was generated using mitochondrial DNA gene sequences for logperches, a monophyletic group of darters composed of 10 recognized species. Divergence times among logperch species were estimated using a fossil calibrated molecular clock in centrarchid fishes, and diversification rates in logperches were estimated using several methods. Speciation events in logperches are recent, extending from 4.20 +/- 1.06 million years ago (mya) to 0.42 +/- 0.22 mya, with most speciation events occurring in the Pleistocene. Diversification rates are high in logperches, at some nodes exceeding rates reported for well-studied adaptive radiations such as Hawaiian silverswords. The geographic pattern of speciation in logperches was investigated by examining the relationship between degree of sympatry and the absolute age of the contrast, with the result that diversification in logperches appears allopatric. The very high diversification rate observed in the logperch phylogeny is more similar to freshwater fish clades thought to represent examples of sympatric speciation than to clades representing allopatric speciation. These results demonstrate that the geographic mode of speciation for a clade cannot be inferred from the diversification rate. The empirical observation of high diversification rates in logperches demonstrates that

  15. Sexual imprinting on ecologically divergent traits leads to sexual isolation in sticklebacks.

    Science.gov (United States)

    Kozak, Genevieve M; Head, Megan L; Boughman, Janette W

    2011-09-07

    During sexual imprinting, offspring learn parental phenotypes and then select mates who are similar to their parents. Imprinting has been thought to contribute to the process of speciation in only a few rare cases; this is despite imprinting's potential to generate assortative mating and solve the problem of recombination in ecological speciation. If offspring imprint on parental traits under divergent selection, these traits will then be involved in both adaptation and mate preference. Such 'magic traits' easily generate sexual isolation and facilitate speciation. In this study, we show that imprinting occurs in two ecologically divergent stickleback species (benthics and limnetics: Gasterosteus spp.). Cross-fostered females preferred mates of their foster father's species. Furthermore, imprinting is essential for sexual isolation between species; isolation was reduced when females were raised without fathers. Daughters imprinted on father odour and colour during a critical period early in development. These traits have diverged between the species owing to differences in ecology. Therefore, we provide the first evidence that imprinting links ecological adaptation to sexual isolation between species. Our results suggest that imprinting may facilitate the evolution of sexual isolation during ecological speciation, may be especially important in cases of rapid diversification, and thus play an integral role in the generation of biodiversity.

  16. Complementary arsenic speciation methods: A review

    Energy Technology Data Exchange (ETDEWEB)

    Nearing, Michelle M., E-mail: michelle.nearing@rmc.ca; Koch, Iris, E-mail: koch-i@rmc.ca; Reimer, Kenneth J., E-mail: reimer-k@rmc.ca

    2014-09-01

    The toxicity of arsenic greatly depends on its chemical form and oxidation state (speciation) and therefore accurate determination of arsenic speciation is a crucial step in understanding its chemistry and potential risk. High performance liquid chromatography with inductively coupled mass spectrometry (HPLC–ICP-MS) is the most common analysis used for arsenic speciation but it has two major limitations: it relies on an extraction step (usually from a solid sample) that can be incomplete or alter the arsenic compounds; and it provides no structural information, relying on matching sample peaks to standard peaks. The use of additional analytical methods in a complementary manner introduces the ability to address these disadvantages. The use of X-ray absorption spectroscopy (XAS) with HPLC–ICP-MS can be used to identify compounds not extracted for HPLC–ICP-MS and provide minimal processing steps for solid state analysis that may help preserve labile compounds such as those containing arsenic-sulfur bonds, which can degrade under chromatographic conditions. On the other hand, HPLC–ICP-MS is essential in confirming organoarsenic compounds with similar white line energies seen by using XAS, and identifying trace arsenic compounds that are too low to be detected by XAS. The complementary use of electrospray mass spectrometry (ESI–MS) with HPLC–ICP-MS provides confirmation of arsenic compounds identified during the HPLC–ICP-MS analysis, identification of unknown compounds observed during the HPLC–ICP-MS analysis and further resolves HPLC–ICP-MS by identifying co-eluting compounds. In the complementary use of HPLC–ICP-MS and ESI–MS, HPLC–ICP-MS helps to focus the ESI–MS selection of ions. Numerous studies have shown that the information obtained from HPLC–ICP-MS analysis can be greatly enhanced by complementary approaches. - Highlights: • HPLC–ICP-MS is the most common method used for arsenic speciation. • HPLC limitations include

  17. Plutonium Speciation, Solubilization and Migration in Soils

    International Nuclear Information System (INIS)

    Neu, M.; Runde, W.

    1999-01-01

    This report summarizes research completed in the first half of a three-year project. As outlined in the authors' proposal they are focusing on (1) characterizing the plutonium at an actinide contaminated site, RFETS, including determining the origin, dispersion, and speciation of the plutonium, (2) studying environmentally important plutonium complexes, primarily hydroxides and carbonates, and (3) examining the interactions of plutonium species with manganese minerals. In the first year the authors focused on site based studies. This year they continue to characterize samples from the RFETS, study the formation and structural and spectroscopic features of environmentally relevant Pu species, and begin modeling the environmental behavior of plutonium

  18. Speciation of arsenic in biological samples.

    Science.gov (United States)

    Mandal, Badal Kumar; Ogra, Yasumitsu; Anzai, Kazunori; Suzuki, Kazuo T

    2004-08-01

    Speciation of arsenicals in biological samples is an essential tool to gain insight into its distribution in tissues and its species-specific toxicity to target organs. Biological samples (urine, hair, fingernail) examined in the present study were collected from 41 people of West Bengal, India, who were drinking arsenic (As)-contaminated water, whereas 25 blood and urine samples were collected from a population who stopped drinking As contaminated water 2 years before the blood collection. Speciation of arsenicals in urine, water-methanol extract of freeze-dried red blood cells (RBCs), trichloroacetic acid treated plasma, and water extract of hair and fingernail was carried out by high-performance liquid chromatography (HPLC)-inductively coupled argon plasma mass spectrometry (ICP MS). Urine contained arsenobetaine (AsB, 1.0%), arsenite (iAs(III), 11.3), arsenate (iAs(V), 10.1), monomethylarsonous acid (MMA(III), 6.6), monomethylarsonic acid (MMA(V), 10.5), dimethylarsinous acid (DMA(III), 13.0), and dimethylarsinic acid (DMA(V), 47.5); fingernail contained iAs(III) (62.4%), iAs(V) (20.2), MMA(V) (5.7), DMA(III) (8.9), and DMA(V) (2.8); hair contained iAs(III) (58.9%), iAs(V) (34.8), MMA(V) (2.9), and DMA(V) (3.4); RBCs contained AsB (22.5%) and DMA(V) (77.5); and blood plasma contained AsB (16.7%), iAs(III) (21.1), MMA(V) (27.1), and DMA(V) (35.1). MMA(III), DMA(III), and iAs(V) were not found in any plasma and RBCs samples, but urine contained all of them. Arsenic in urine, fingernails, and hair are positively correlated with water As, suggesting that any of these measurements could be considered as a biomarker to As exposure. Status of urine and exogenous contamination of hair urgently need speciation of As in these samples, but speciation of As in nail is related to its total As (tAs) concentration. Therefore, total As concentrations of nails could be considered as biomarker to As exposure in the endemic areas.

  19. Speciation of arsenic in biological samples

    International Nuclear Information System (INIS)

    Mandal, Badal Kumar; Ogra, Yasumitsu; Anzai, Kazunori; Suzuki, Kazuo T.

    2004-01-01

    Speciation of arsenicals in biological samples is an essential tool to gain insight into its distribution in tissues and its species-specific toxicity to target organs. Biological samples (urine, hair, fingernail) examined in the present study were collected from 41 people of West Bengal, India, who were drinking arsenic (As)-contaminated water, whereas 25 blood and urine samples were collected from a population who stopped drinking As contaminated water 2 years before the blood collection. Speciation of arsenicals in urine, water-methanol extract of freeze-dried red blood cells (RBCs), trichloroacetic acid treated plasma, and water extract of hair and fingernail was carried out by high-performance liquid chromatography (HPLC)-inductively coupled argon plasma mass spectrometry (ICP MS). Urine contained arsenobetaine (AsB, 1.0%), arsenite (iAs III , 11.3), arsenate (iAs V , 10.1), monomethylarsonous acid (MMA III , 6.6), monomethylarsonic acid (MMA V , 10.5), dimethylarsinous acid (DMA III , 13.0), and dimethylarsinic acid (DMA V , 47.5); fingernail contained iAs III (62.4%), iAs V (20.2), MMA V (5.7), DMA III (8.9), and DMA V (2.8); hair contained iAs III (58.9%), iAs V (34.8), MMA V (2.9), and DMA V (3.4); RBCs contained AsB (22.5%) and DMA V (77.5); and blood plasma contained AsB (16.7%), iAs III (21.1), MMA V (27.1), and DMA V (35.1). MMA III , DMA III , and iAs V were not found in any plasma and RBCs samples, but urine contained all of them. Arsenic in urine, fingernails, and hair are positively correlated with water As, suggesting that any of these measurements could be considered as a biomarker to As exposure. Status of urine and exogenous contamination of hair urgently need speciation of As in these samples, but speciation of As in nail is related to its total As (tAs) concentration. Therefore, total As concentrations of nails could be considered as biomarker to As exposure in the endemic areas

  20. Complementary arsenic speciation methods: A review

    International Nuclear Information System (INIS)

    Nearing, Michelle M.; Koch, Iris; Reimer, Kenneth J.

    2014-01-01

    The toxicity of arsenic greatly depends on its chemical form and oxidation state (speciation) and therefore accurate determination of arsenic speciation is a crucial step in understanding its chemistry and potential risk. High performance liquid chromatography with inductively coupled mass spectrometry (HPLC–ICP-MS) is the most common analysis used for arsenic speciation but it has two major limitations: it relies on an extraction step (usually from a solid sample) that can be incomplete or alter the arsenic compounds; and it provides no structural information, relying on matching sample peaks to standard peaks. The use of additional analytical methods in a complementary manner introduces the ability to address these disadvantages. The use of X-ray absorption spectroscopy (XAS) with HPLC–ICP-MS can be used to identify compounds not extracted for HPLC–ICP-MS and provide minimal processing steps for solid state analysis that may help preserve labile compounds such as those containing arsenic-sulfur bonds, which can degrade under chromatographic conditions. On the other hand, HPLC–ICP-MS is essential in confirming organoarsenic compounds with similar white line energies seen by using XAS, and identifying trace arsenic compounds that are too low to be detected by XAS. The complementary use of electrospray mass spectrometry (ESI–MS) with HPLC–ICP-MS provides confirmation of arsenic compounds identified during the HPLC–ICP-MS analysis, identification of unknown compounds observed during the HPLC–ICP-MS analysis and further resolves HPLC–ICP-MS by identifying co-eluting compounds. In the complementary use of HPLC–ICP-MS and ESI–MS, HPLC–ICP-MS helps to focus the ESI–MS selection of ions. Numerous studies have shown that the information obtained from HPLC–ICP-MS analysis can be greatly enhanced by complementary approaches. - Highlights: • HPLC–ICP-MS is the most common method used for arsenic speciation. • HPLC limitations include

  1. Community Ecology

    CERN Document Server

    1988-01-01

    This book presents the proceedings of a workshop on community ecology organized at Davis, in April, 1986, sponsored by the Sloan Foundation. There have been several recent symposia on community ecology (Strong et. al., 1984, Diamond and Case, 1987) which have covered a wide range of topics. The goal of the workshop at Davis was more narrow: to explore the role of scale in developing a theoretical approach to understanding communities. There are a number of aspects of scale that enter into attempts to understand ecological communities. One of the most basic is organizational scale. Should community ecology proceed by building up from population biology? This question and its ramifications are stressed throughout the book and explored in the first chapter by Simon Levin. Notions of scale have long been important in understanding physical systems. Thus, in understanding the interactions of organisms with their physical environment, questions of scale become paramount. These more physical questions illustrate the...

  2. Dynamic speciation analysis and bioavailability of metals in aquatic systems

    NARCIS (Netherlands)

    Leeuwen, van H.P.; Town, R.M.; Buffle, J.; Cleven, R.F.M.J.; Davison, W.; Puy, J.; Riemsdijk, van W.H.; Sigg, L.

    2005-01-01

    Dynamic metal speciation analysis in aquatic ecosystems is emerging as a powerful basis for development of predictions of bioavailability and reliable risk assessment strategies. A given speciation sensor is characterized by an effective time scale or kinetic window that defines the measurable metal

  3. What do we need to know about speciation?

    NARCIS (Netherlands)

    Butlin, Roger; Debelle, Allan; Kerth, Claudius; Snook, Rhonda R.; Beukeboom, Leo W.; Castillo Cajas, Ruth; Diao, Wenwen; Maan, Martine E.; Paolucci, Silvia; Weissing, Franz J.; van de Zande, Louis; Hoikkala, Anneli; Geuverink, Elzemiek; Jennings, Jackson; Kankare, Maaria; Knott, K. Emily; Tyukmaeva, Venera I.; Zoumadakis, Christos; Ritchie, Michael G.; Barker, Daniel; Immonen, Elina; Kirkpatrick, Mark; Noor, Mohamed; Macias Garcia, Constantino; Schmitt, Thomas; Schilthuizen, Menno

    Speciation has been a major focus of evolutionary biology research in recent years, with many important advances. However, some of the traditional organising principles of the subject area no longer provide a satisfactory framework, such as the classification of speciation mechanisms by geographical

  4. Speciation imperatives for waste management and environmental pollution

    International Nuclear Information System (INIS)

    Wymer, R.G.

    2001-01-01

    This paper addresses speciation requirements in the context of problems produced by nuclear energy and nuclear weapons production. These problems are primarily in the areas of waste management, material contamination, and environmental pollution. They pose difficult and important measurement and speciation challenges. Examples of speciation requirements in the context of national and international regulations are presented to exemplify and make quantitative the types of problems posed by waste management, material contamination, and environmental pollution. The importance of identifying species present in the natural environment as well as in wastes from chemical and physical processing and from waste management activities and accidental releases is addressed. Differing speciation requirements for macro and micro concentrations of species are discussed. The role of speciation in modelling studies is discussed. (author)

  5. Invasion ecology meets parasitology: Advances and challenges

    Directory of Open Access Journals (Sweden)

    Robert Poulin

    2017-12-01

    Full Text Available Biological invasions threaten the diversity and functioning of native ecosystems, and the rate at which species are being introduced to new areas shows no sign of slowing down. Parasites play roles in biological invasions, for instance when native parasites interact with exotic hosts, or when parasites themselves are introduced to new areas. However, publication trends show clearly that research on parasitism in the context of biological invasions is lagging far behind research on biological invasions in general. The different articles in this special issue of International Journal for Parasitology–Parasites and Wildlife on ‘Invasions’ address various aspects of the interface between parasitology and invasion biology, including how invasive free-living species lose or gain parasites on the invasion front as they move away from their site of introduction, how these invasive species affect the dynamics of native parasites, and how exotic parasites become established and impact native hosts. Together, they highlight the challenges facing researchers in this area, and set the agenda for the next few years of research. Keywords: alien species, Biological invasions, Enemy release, Non-natives, Parasites

  6. Invasion ecology meets parasitology: Advances and challenges

    OpenAIRE

    Robert Poulin

    2017-01-01

    Biological invasions threaten the diversity and functioning of native ecosystems, and the rate at which species are being introduced to new areas shows no sign of slowing down. Parasites play roles in biological invasions, for instance when native parasites interact with exotic hosts, or when parasites themselves are introduced to new areas. However, publication trends show clearly that research on parasitism in the context of biological invasions is lagging far behind research on biological ...

  7. The rate test of speciation: estimating the likelihood of non-allopatric speciation from reproductive isolation rates in Drosophila.

    Science.gov (United States)

    Yukilevich, Roman

    2014-04-01

    Among the most debated subjects in speciation is the question of its mode. Although allopatric (geographical) speciation is assumed the null model, the importance of parapatric and sympatric speciation is extremely difficult to assess and remains controversial. Here I develop a novel approach to distinguish these modes of speciation by studying the evolution of reproductive isolation (RI) among taxa. I focus on the Drosophila genus, for which measures of RI are known. First, I incorporate RI into age-range correlations. Plots show that almost all cases of weak RI are between allopatric taxa whereas sympatric taxa have strong RI. This either implies that most reproductive isolation (RI) was initiated in allopatry or that RI evolves too rapidly in sympatry to be captured at incipient stages. To distinguish between these explanations, I develop a new "rate test of speciation" that estimates the likelihood of non-allopatric speciation given the distribution of RI rates in allopatry versus sympatry. Most sympatric taxa were found to have likely initiated RI in allopatry. However, two putative candidate species pairs for non-allopatric speciation were identified (5% of known Drosophila). In total, this study shows how using RI measures can greatly inform us about the geographical mode of speciation in nature. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  8. Relative Bioavailability and Bioaccessability and Speciation of ...

    Science.gov (United States)

    Background: Assessment of soil arsenic (As) bioavailability may profoundly affect the extent of remediation required at contaminated sites by improving human exposure estimates. Because small adjustments in soil As bioavailability estimates can significantly alter risk assessments and remediation goals, convenient, rapid, reliable, and inexpensive tools are needed to determine soil As bioavailability. Objectives: We evaluated inexpensive methods for assessing As bioavailability in soil as a means to improve human exposure estimates and potentially reduce remediation costs. Methods: Nine soils from residential sites affected by mining or smelting activity and two National Institute of Standards and Technology standard reference materials were evaluated for As bioavailability, bioaccessibility, and speciation. Arsenic bioavailability was determined using an in vivo mouse model, and As bioaccessibility was determined using the Solubility/Bioavailability Research Consortium in vitro assay. Arsenic speciation in soil and selected soil physicochemical properties were also evaluated to determine whether these parameters could be used as predictors of As bio¬availability and bioaccessibility. Results: In the mouse assay, we compared bioavailabilities of As in soils with that for sodium arsenate. Relative bioavailabilities (RBAs) of soil As ranged from 11% to 53% (mean, 33%). In vitro soil As bioaccessibility values were strongly correlated with soil As RBAs (R

  9. Uranium(VI) speciation by spectroscopy

    International Nuclear Information System (INIS)

    Meinrath, G.

    1997-01-01

    The application of UV-Vis and time-resolved laser-induced fluorescence (TRLF) spectroscopies to direct of uranium(VI) in environmental samples offers various prospects that have, however, serious limitations. While UV-Vis spectroscopy is probably not sensitive enough to detect uranium(VI) species in the majority of environmental samples, TRLFS is principially able to speciate uranium(VI) at very low concentration levels in the nanomol range. Speciation by TRLFS can be based on three parameters: excitation spectrum, emission spectrum and lifetime of the fluorescence emission process. Due to quenching effects, the lifetime may not be expected to be as characteristics as, e.g., the emission spectrum. Quenching of U(VI) fluorescence by reaction with organic substances, inorganic ions and formation of carbonate radicals is one important limiting factor in the application of U(VI) fluorescence spectroscopy. Fundamental photophysical criteria are illustrated using UV-Vis and fluorescence spectra of U(VI) hydrolysis and carbonato species as examples. (author)

  10. Resolving uncertainty in chemical speciation determinations

    Science.gov (United States)

    Smith, D. Scott; Adams, Nicholas W. H.; Kramer, James R.

    1999-10-01

    Speciation determinations involve uncertainty in system definition and experimentation. Identification of appropriate metals and ligands from basic chemical principles, analytical window considerations, types of species and checking for consistency in equilibrium calculations are considered in system definition uncertainty. A systematic approach to system definition limits uncertainty in speciation investigations. Experimental uncertainty is discussed with an example of proton interactions with Suwannee River fulvic acid (SRFA). A Monte Carlo approach was used to estimate uncertainty in experimental data, resulting from the propagation of uncertainties in electrode calibration parameters and experimental data points. Monte Carlo simulations revealed large uncertainties present at high (>9-10) and low (monoprotic ligands. Least-squares fit the data with 21 sites, whereas linear programming fit the data equally well with 9 sites. Multiresponse fitting, involving simultaneous fluorescence and pH measurements, improved model discrimination. Deconvolution of the excitation versus emission fluorescence surface for SRFA establishes a minimum of five sites. Diprotic sites are also required for the five fluorescent sites, and one non-fluorescent monoprotic site was added to accommodate the pH data. Consistent with greater complexity, the multiresponse method had broader confidence limits than the uniresponse methods, but corresponded better with the accepted total carboxylic content for SRFA. Overall there was a 40% standard deviation in total carboxylic content for the multiresponse fitting, versus 10% and 1% for least-squares and linear programming, respectively.

  11. Chromium fractionation and speciation in natural waters.

    Science.gov (United States)

    Pereira, Catarinie Diniz; Techy, João Gabriel; Ganzarolli, Edgard Moreira; Quináia, Sueli Pércio

    2012-05-01

    It is common for leather industries to dump chromium-contaminated effluent into rivers and other bodies of water. Thus, it is crucial to know the impacts caused by this practice to the environment. A study on chromium partitioning and speciation, with determination at trace levels, was carried out in a potentially contaminated creek. Chromium fractionation and speciation was performed using a flow-injection preconcentration system and detection by flame atomic absorption spectrometry. High levels of this element were found in the particulate material (449-9320 mg kg(-1)), which indicates its compatibility with this fraction. The concentration of Cr(iii) in the water samples collected ranged from 5.2-105.2 μg L(-1). Cr(vi) was always below of the DL (0.3 μg L(-1)). Chromium accumulation observed in the sediment (873-1691 mg kg(-1)) may confirm contamination due to the long term release of contaminated effluents in the creek.

  12. Speciation of animal fat: Needs and challenges.

    Science.gov (United States)

    Hsieh, Yun-Hwa Peggy; Ofori, Jack Appiah

    2017-05-24

    The use of pork fat is a concern for Muslims and Jews, who for religious reasons avoid consuming anything that is pig-derived. The use of bovine materials, including beef fat, is prohibited in Hinduism and may also pose a risk of carrying the infectious agent for bovine spongiform encephalopathy. Vegetable oils are sometimes adulterated with animal fat or pork fat with beef fat for economic gain. The development of methods to determine the species origin of fat has therefore become a priority due to the complex and global nature of the food trade, which creates opportunities for the fraudulent use of these animal fats as food ingredients. However, determining the species origin of fats in processed foods or composite blends is an arduous task as the adulterant has a composition that is very similar to that of the original fat or oil. This review examines some of the methods that have been developed for fat speciation, including both fat-based and DNA-based methods, their shortcomings, and the need for additional alternatives. Protein-based methods, specifically immunoassays targeting residual proteins in adipose tissue, that are being explored by researchers as a new tool for fat speciation will also be discussed.

  13. Assessing models of speciation under different biogeographic scenarios; An empirical study using multi-locus and RNA-seq analyses

    Science.gov (United States)

    Edwards, Taylor; Tollis, Marc; Hsieh, PingHsun; Gutenkunst, Ryan N.; Liu, Zhen; Kusumi, Kenro; Culver, Melanie; Murphy, Robert W.

    2016-01-01

    Evolutionary biology often seeks to decipher the drivers of speciation, and much debate persists over the relative importance of isolation and gene flow in the formation of new species. Genetic studies of closely related species can assess if gene flow was present during speciation, because signatures of past introgression often persist in the genome. We test hypotheses on which mechanisms of speciation drove diversity among three distinct lineages of desert tortoise in the genus Gopherus. These lineages offer a powerful system to study speciation, because different biogeographic patterns (physical vs. ecological segregation) are observed at opposing ends of their distributions. We use 82 samples collected from 38 sites, representing the entire species' distribution and generate sequence data for mtDNA and four nuclear loci. A multilocus phylogenetic analysis in *BEAST estimates the species tree. RNA-seq data yield 20,126 synonymous variants from 7665 contigs from two individuals of each of the three lineages. Analyses of these data using the demographic inference package ∂a∂i serve to test the null hypothesis of no gene flow during divergence. The best-fit demographic model for the three taxa is concordant with the *BEAST species tree, and the ∂a∂i analysis does not indicate gene flow among any of the three lineages during their divergence. These analyses suggest that divergence among the lineages occurred in the absence of gene flow and in this scenario the genetic signature of ecological isolation (parapatric model) cannot be differentiated from geographic isolation (allopatric model).

  14. Sympatric ecological divergence associated with a color polymorphism

    OpenAIRE

    Kusche, Henrik; Elmer, Kathryn R.; Meyer, Axel

    2015-01-01

    Background Color polymorphisms are a conspicuous feature of many species and a way to address broad ecological and evolutionary questions. Three potential major evolutionary fates of color polymorphisms are conceivable over time: maintenance, loss, or speciation. However, the understanding of color polymorphisms and their evolutionary implications is frequently impaired by sex-linkage of coloration, unknown inheritance patterns, difficulties in phenotypic characterization, and a lack of evolu...

  15. Ecological macroeconomics

    DEFF Research Database (Denmark)

    Røpke, Inge

    2013-01-01

    by a more theoretical debate and increased interaction between the heterodox schools of ecological economics and post-Keynesian economics. In addition, both the degrowth community and the research community organized around sustainable transitions of socio-technical systems have contributed to discussions...... on how to reconcile environmental and social concerns. Based on this broad variety of pieces in a jigsaw puzzle, a new ecological macroeconomics is emerging, but the contours are still vague. This chapter seeks to outline some of this topography and to add a few pieces of its own by highlighting the need...... to shift resources from consumption to investment and describing the role of consumer-citizens in such a change. The chapter starts by identifying the problems and challenges for an ecological macroeconomics. The next section outlines some of the shortcomings of traditional macroeconomics...

  16. EPA’s SPECIATE 4.4 Database:Development and Uses

    Science.gov (United States)

    SPECIATE is the U.S. Environmental Protection Agency's (EPA)repository of volatile organic gas and particulate matter (PM) speciation profiles for air pollution sources. EPA released SPECIATE 4.4 in early 2014 and, in total, the SPECIATE 4.4 database includes 5,728 PM, VOC, total...

  17. Extensive gene flow over Europe and possible speciation

    Energy Technology Data Exchange (ETDEWEB)

    VINCENOT, Dr. LUCIE [Centre d’Ecologie Fonctionnelle et Evolutive Montpellier, France; NARA, Dr. KAZUHIDE [Department of Natural Environmental Studies, The University of Tokyo, Japan; STHULTZ, CHRISTOPHER [Centre d’Ecologie Fonctionnelle et Evolutive Montpellier, France; Labbe, Jessy L [ORNL; DUBOIS, MARIE-PIERRE [Centre d’Ecologie Fonctionnelle et Evolutive Montpellier, France; TEDERSOO, LEHO [University of Tartu, Estonia; Martin, Francis [INRA, Nancy, France; SELOSSE, Dr. MARC-ANDRE [Centre d’Ecologie Fonctionnelle et Evolutive Montpellier, France

    2012-01-01

    Biogeographical patterns and large-scale genetic structure have been little studied in ectomycorrhizal (EM) fungi, despite the ecological and economic importance of EM symbioses. We coupled population genetics and phylogenetic approaches to understand spatial structure in fungal populations on a continental scale. Using nine microsatellite markers, we characterized gene flow among 16 populations of the widespread EM basidiomycete Laccaria amethystina over Europe (i.e. over 2900 km). We also widened our scope to two additional populations from Japan (104 km away) and compared them with European populations through microsatellite markers and multilocus phylogenies, using three nuclear genes (NAR, G6PD and ribosomal DNA) and two mitochondrial ribosomal genes. European L. amethystina populations displayed limited differentiation (average FST = 0.041) and very weak isolation by distance (IBD). This panmictic European pattern may result from effective aerial dispersal of spores, high genetic diversity in populations and mutualistic interactions with multiple hosts that all facilitate migration. The multilocus phylogeny based on nuclear genes confirmed that Japanese and European specimens were closely related but clustered on a geographical basis. By using microsatellite markers, we found that Japanese populations were strongly differentiated from the European populations (FST = 0.416), more than expected by extrapolating the European pattern of IBD. Population structure analyses clearly separated the populations into two clusters, i.e. European and Japanese clusters. We discuss the possibility of IBD in a continuous population (considering some evidence for a ring species over the Northern Hemisphere) vs. an allopatric speciation over Eurasia, making L. amethystina a promising model of intercontinental species for future studies.

  18. Ecological modeling for forest management in the Shawnee National Forest

    Science.gov (United States)

    Richard G. Thurau; J.F. Fralish; S. Hupe; B. Fitch; A.D. Carver

    2008-01-01

    Land managers of the Shawnee National Forest in southern Illinois are challenged to meet the needs of a diverse populace of stakeholders. By classifying National Forest holdings into management units, U.S. Forest Service personnel can spatially allocate resources and services to meet local management objectives. Ecological Classification Systems predict ecological site...

  19. Speciation issues in food control - are we ready?

    International Nuclear Information System (INIS)

    Sloth, J.J.; Hedegaard, R.V.; Julshamn, K.; Trier, X.T.; Larsen, E.H.

    2009-01-01

    Full text: Our understanding of the mechanisms of biological activities and biotransformation of trace elements has improved during recent years with the help of chemical speciation studies. However, the most important practical application of elemental speciation is in the area of toxicology. Toxicological knowledge on the individual chemical elemental species should lead to more specific legislation of hazardous substances. Presently, European legislation concerning food safety is based on total element concentrations expressed as maximum limits. The lecture focuses on the present situation for speciation in food control and discusses the latest and expected future developments within this area. (author)

  20. NICKEL SPECIATION OF URBAN PARTICULATE MATTER

    Energy Technology Data Exchange (ETDEWEB)

    Kevin C. Galbreath; Charlene R. Crocker; Carolyn M. Nyberg; Frank E. Huggins; Gerald P. Huffman

    2003-10-01

    A four-step sequential Ni extraction method, summarized in Table AB-1, was evaluated for identifying and quantifying the Ni species occurring in urban total suspended particulate (TSP) matter and fine particulate matter (<10 {micro}m [PM{sub 10}] and <2.5 {micro}m [PM{sub 2.5}] in aerodynamic diameter). The extraction method was originally developed for quantifying soluble, sulfidic, elemental, and oxidic forms of Ni that may occur in industrial atmospheres. X-ray diffraction (XRD) and x-ray absorption fine structure (XAFS) spectroscopy were used to evaluate the Ni species selectivity of the extraction method. Uncertainties in the chemical speciation of Ni in urban PM{sub 10} and PM{sub 2.5} greatly affect inhalation health risk estimates, primarily because of the large variability in acute, chronic, and cancer-causing effects for different Ni compounds.

  1. Selenium speciation from farm to faeces

    International Nuclear Information System (INIS)

    Larsen, E.H.; Kapolna, E.; Hillestroem, P.R.; Laursen, K.; Budek, A.; Husted, S.; Buegel, S.

    2009-01-01

    Full text:The content and speciation of Se were studied in food crops originating from organic and conventional cultivation schemes. Additionally, carrots and onions were biofortified and intrinsically labelled using foliar spraying with isotopically enriched 77 SeO 3 -2 . HPLC-ICPMS and HPLC-ESIMS/MS analysis revealed that Se was mainly metabolized to 77 SeMet and to Me 77 SeCys, also in carrot. The 77 Se plants were processed to food (50 μg 77 Se/d) for a human intervention study. The isotopic enrichment by 77 Se as well as 67 Zn and 65 Cu in urine and faeces was determined by ICP(DRC)MS and the mineral absorption rates estimated. (author)

  2. Chemical speciation of radionuclides migrating in groundwaters

    International Nuclear Information System (INIS)

    Robertson, D.; Schilk, A.; Abel, K.; Lepel, E.; Thomas, C.; Pratt, S.; Cooper, E.; Hartwig, P.; Killey, R.

    1994-04-01

    In order to more accurately predict the rates and mechanisms of radionuclide migration from low-level waste disposal facilities via groundwater transport, ongoing studies are being conducted at field sites at Chalk River Laboratories to identify and characterize the chemical speciation of mobile, long-lived radionuclides migrating in groundwaters. Large-volume water sampling techniques are being utilized to separate and concentrate radionuclides into particular, cationic, anionic, and nonionic chemical forms. Most radionuclides are migrating as soluble, anionic species that appear to be predominantly organoradionuclide complexes. Laboratory studies utilizing anion exchange chromatography have separated several anionically complexed radionuclides, e.g., 60 Co and 106 Ru, into a number of specific compounds or groups of compounds. Further identification of the anionic organoradionuclide complexes is planned utilizing high resolution mass spectrometry. Large-volume ultra-filtration experiments are characterizing the particulate forms of radionuclides being transported in these groundwaters

  3. Sex chromosomes and speciation in Drosophila

    Science.gov (United States)

    Presgraves, Daven C.

    2010-01-01

    Two empirical rules suggest that sex chromosomes play a special role in speciation. The first is Haldane's rule— the preferential sterility and inviability of species hybrids of the heterogametic (XY) sex. The second is the disproportionately large effect of the X chromosome in genetic analyses of hybrid sterility. Whereas the causes of Haldane's rule are well established, the causes of the ‘large X-effect’ have remained controversial. New genetic analyses in Drosophila confirm that the X is a hotspot for hybrid male sterility factors, providing a proximate explanation for the large X-effect. Several other new findings— on faster X evolution, X chromosome meiotic drive, and the regulation of the X chromosome in the male-germline— provide plausible evolutionary explanations for the large X-effect. PMID:18514967

  4. Speciation of actinides in marine waters

    International Nuclear Information System (INIS)

    Roberts, R.A.

    1984-01-01

    The oxidation state distribution of plutonium in seawater, pore water from marine sediments, and a series of model solutions similar to seawater was measured using a TTA solvent extraction technique and α liquid scintillation counting methods. Electromigration was used to compare migration behavior of americium in 0.7M NaCl solutions (pH 6.5 to 8.0) with the behavior calculated from predicted speciation. In all pH 8 solutions studied, Pu(VI) was rapidly reduced to Pu(V). In 0.7M NaCl, pH 8.0, and artifical seawater (no organics), the Pu(V) formed was stable. In real seawater (with organic components), a rapid reduction of Pu(VI) to Pu(IV) was also observed. The Pu(V) formed in seawater was metastable; a very slow reduction to Pu(IV) occurred. This reduction was catalyzed by light. Humic acid (obtained from marine sediments from the Bahama Islands), was added to 0.7M NaCl, pH 8.0 solutions to determine its effect on Pu redox reactions. The effect was similar to the reductions in seawater. Increasing the humic acid concentration decreased the amount of Pu(V) which was formed and favored the IV state. The americium electromigration experiments showed a +0.12 net charge for the Am complexes formed in 0.7M NaCl solutions from pH 7.0 to 8.0. This value was smaller than the charge of +0.94 calculated from predicted speciation

  5. Ecological concepts

    International Nuclear Information System (INIS)

    1986-01-01

    This volume contains three critical contributions on the application of modern technology from the ethical point of view. The peaceful use of nuclear power is rejected as a technical error, which is overwhelming humanity. Ethical bases of a preventive technological policy and ecological aims are developed for the 21st century, in economy, technology, politics, and consciousness. (HSCH) [de

  6. Information Ecology

    DEFF Research Database (Denmark)

    Christiansen, Ellen Tove

    2006-01-01

    in the 1960ties, and chosen here because it integrates cultural and psychological trajectories in a theory of living settings. The pedagogical-didactical paradigm comprises three distinct information ecologies, named after their intended outcome: the problem-setting, the exploration-setting, and the fit...

  7. saosakwe@yahoo.com Chemical Speciation and Mobility of Some

    African Journals Online (AJOL)

    Michael Horsfall

    ABSTRACT: The mobility of some heavy metals (Fe, Co, Ni and Mn) in soils around ... Sampling and Analysis: Soil samples were collected ..... Speciation Studies of trace elements levels in .... Characterization of Radioactive Particles in the.

  8. Pb Speciation Data to Estimate Lead Bioavailability to Quail

    Data.gov (United States)

    U.S. Environmental Protection Agency — Linear combination fitting data for lead speciation of soil samples evaluated through an in-vivo/in-vitro correlation for quail exposure. This dataset is associated...

  9. Speciation of arsenic and mercury in feed: why and how?

    DEFF Research Database (Denmark)

    Hedegaard, Rikke Susanne Vingborg; Sloth, Jens Jørgen

    2011-01-01

    The understanding of the mechanisms of biological activities and biotransformation of trace elements such as arsenic and mercury has improved during recent years with the help of chemical speciation studies. However, the most important practical application of elemental speciation is in the area ...... in feed as well as initiatives for the establishment of standardized methods for determination of inorganic arsenic and methylmercury are presented.......The understanding of the mechanisms of biological activities and biotransformation of trace elements such as arsenic and mercury has improved during recent years with the help of chemical speciation studies. However, the most important practical application of elemental speciation is in the area...... of toxicology. Toxicological knowledge on the individual trace element species can lead to more specific legislation of hazardous substances found in feed. Examples here are arsenic, where the inorganic forms are the most toxic, and mercury, where the organic form methylmercury is more toxic than inorganic...

  10. Speciation and Persistence of Dimethoate in the Aquatic Environment

    African Journals Online (AJOL)

    Speciation and Persistence of Dimethoate in the Aquatic Environment: Characterization in Terms of a Rate Model that Takes Into Account Hydrolysis, Photolysis, Microbial Degradation and Adsorption of the Pesticide by Colloidal and Sediment Particles.

  11. Speciation and internal dosimetry: from chemical species to dosimetric models

    International Nuclear Information System (INIS)

    Paquet, F.; Frelon, S.; Cote, G.; Madic, C.

    2004-01-01

    Speciation studies refer to the distribution of species in a particular sample or matrix. These studies are necessary to improve the description, understanding and prediction of trace element kinetics and toxicity. In case of internal contamination with radionuclides, speciation studies could help to improve both the biokinetic and dosimetric models for radionuclides. There are different methods to approach the speciation of radionuclide in a biological system, depending on the degree of accuracy needed and the level of uncertainties accepted. Among them, computer modelling and experimental determination are complementary approaches. This paper describes what is known about speciation of actinides in blood, GI-tract, liver and skeleton and of their consequences in terms of internal dosimetry. The conclusion is that such studies provide very valuable data and should be targeted in the future on some specific tissues and biomolecules. (authors)

  12. The contribution of chemical speciation to internal dosimetry

    International Nuclear Information System (INIS)

    Paquet, F.; Frelon, S.; Cote, G.; Madic, C.

    2003-01-01

    Speciation studies refer to the distribution of species in a particular sample or matrix. These studies are necessary to improve the description, understanding and prediction of trace element kinetics and toxicity. In the case of internal contamination with radionuclides, speciation studies could help to improve both the biokinetic and dosimetric models for radionuclides. There are different methods to approach the speciation of radionuclides in a biological system, depending on the degree of accuracy needed and the level of uncertainties accepted. Among them, computer modelling and experimental determination are complementary approaches. This paper describes what is known about speciation of actinides in blood, GI tract, liver and skeleton and of their consequences in terms of internal dosimetry. The conclusion is that such studies provide very valuable data and should be targeted in the future on some specific tissues and biomolecules. (author)

  13. Genomic support for speciation and specificity of baculoviruses

    NARCIS (Netherlands)

    Jakubowska, A.K.

    2010-01-01

    Keywords: baculovirus, insects, speciation, genomics, phylogeny, host specificity

    The Baculoviridae comprise a large family of double-stranded DNA viruses infecting
    arthropods. In this thesis two baculoviruses, Leucoma salicis nucleopolyhedrovirus
    (LesaNPV) and Agrotis

  14. Speciation and the Latitudinal Diversity Gradient: Insights from the Global Distribution of Endemic Fish.

    Science.gov (United States)

    Hanly, Patrick J; Mittelbach, Gary G; Schemske, Douglas W

    2017-06-01

    The nearly universal pattern that species richness increases from the poles to the equator (the latitudinal diversity gradient [LDG]) has been of intense interest since its discovery by early natural-history explorers. Among the many hypotheses proposed to explain the LDG, latitudinal variation in (1) productivity, (2) time and area available for diversification, and (3) speciation and/or extinction rates have recently received the most attention. Because tropical regions are older and were formerly more widespread, these factors are often intertwined, hampering efforts to distinguish their relative contributions to the LDG. Here we examine the global distribution of endemic lake fishes to determine how lake age, area, and latitude each affect the probability of speciation and the extent of diversification occurring within a lake. We analyzed the distribution of endemic fishes worldwide (1,933 species and subspecies from 47 families in 2,746 lakes) and find that the probability of a lake containing an endemic species and the total number of endemics per lake increase with lake age and area and decrease with latitude. Moreover, the geographic locations of endemics in 34 of 41 families are found at lower latitudes than those of nonendemics. We propose that the greater diversification of fish at low latitudes may be driven in part by ecological opportunities promoted by tropical climates and by the coevolution of species interactions.

  15. The use of geochemical speciation modelling to predict the impact of uranium to freshwater biota

    International Nuclear Information System (INIS)

    Markich, S.J.; Brown, P.L.; Jeffree, R.A.

    1996-01-01

    Uranium is the prime potential contaminant in mine waste waters that may be released from the Ranger Uranium Mine (RUM) into the receiving waters of the Magela Creek, Alligator Rivers Region, Northern Australia. The potential ecological impact of the migration of uranium, that would result from an elevation in its concentration above background, in the Magela Creek downstream of the RUM, has been experimentally investigated by integrating biomonitoring with geochemical speciation modelling. The freshwater bivalve Velesunio angasi, abundant throughout the Magela Creek catchment, was exposed to a variety of uranium concentrations in a synthetic Magela Creek water, at four pH levels (5.0, 5.3, 5.5 and 6.0), in the presence (3.05 and 7.50 mg l -1 ) and absence of a model fulvic acid (FA), and its behavioural response was measured. Speciation modelling, using the HARPHRQ code, provided evidence that UO 2+ 2 and UO 2 OH + are the uranium species most responsible (ca. 96%) for eliciting an adverse behavioural response when UO 2+ 2 is assigned twice the toxic effect of UO 2 OH + . This finding rejects the notion that biota respond specifically to the sum total of inorganic uranyl species. (orig.)

  16. Electrochemical metal speciation in natural and model polyelectrolyte systems

    OpenAIRE

    Hoop, van den, M.A.G.T.

    1994-01-01

    The purpose of the research described in this thesis was to examine the applicability of electro-analytical techniques in obtaining information on the speciation of metals, i.e. their distribution over different physico-chemical forms, in aquatic systems containing charged macromolecules. In chapter 1 a general introduction is given to (i) metal speciation in aquatic systems, (ii) (bio)polyelectrolytes and their counterion distributions and (iii) electrochemical ...

  17. How humans drive speciation as well as extinction

    DEFF Research Database (Denmark)

    Bull, Joseph William; Maron, M.

    2016-01-01

    influence upon divergence in microorganisms. Even if human activities resulted in no net loss of species diversity by balancing speciation and extinction rates, this would probably be deemed unacceptable. We discuss why, based upon ‘no net loss’ conservation literature— considering phylogenetic diversity...... and other metrics, risk aversion, taboo trade-offs and spatial heterogeneity. We conclude that evaluating speciation alongside extinction could result in more nuanced understanding of biosphere trends, clarifying what it is we actually value about biodiversity....

  18. Along the speciation continuum: Quantifying intrinsic and extrinsic isolating barriers across five million years of evolutionary divergence in California jewelflowers.

    Science.gov (United States)

    Christie, Kyle; Strauss, Sharon Y

    2018-05-01

    Understanding the relative roles of intrinsic and extrinsic reproductive barriers, and their interplay within the geographic context of diverging taxa, remains an outstanding challenge in the study of speciation. We conducted a comparative analysis of reproductive isolation in California Jewelflowers (Streptanthus, s.l., Brassicaceae) by quantifying potential barriers to gene flow at multiple life history stages in 39 species pairs spanning five million years of evolutionary divergence. We quantified nine potential pre- and postzygotic barriers and explored patterns of reproductive isolation in relation to genetic distance. Intrinsic postzygotic isolation was initially weak, increased at intermediate genetic distances, and reached a threshold characterized by complete genetic incompatibility. Climatic niche differences were strong at shallow genetic distances, and species pairs with overlapping ranges showed slight but appreciable phenological isolation, highlighting the potential for ecological barriers to contribute to speciation. Geographic analyses suggest that speciation is not regionally allopatric in the California Jewelflowers, as recently diverged taxa occur in relatively close proximity and display substantial range overlap. Young pairs are characterized by incomplete intrinsic postzygotic isolation, suggesting that extrinsic barriers or fine-scale spatial segregation are more important early in the divergence process than genetic incompatibilities. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

  19. Variation in Linked Selection and Recombination Drive Genomic Divergence during Allopatric Speciation of European and American Aspens.

    Science.gov (United States)

    Wang, Jing; Street, Nathaniel R; Scofield, Douglas G; Ingvarsson, Pär K

    2016-07-01

    Despite the global economic and ecological importance of forest trees, the genomic basis of differential adaptation and speciation in tree species is still poorly understood. Populus tremula and Populus tremuloides are two of the most widespread tree species in the Northern Hemisphere. Using whole-genome re-sequencing data of 24 P. tremula and 22 P. tremuloides individuals, we find that the two species diverged ∼2.2-3.1 million years ago, coinciding with the severing of the Bering land bridge and the onset of dramatic climatic oscillations during the Pleistocene. Both species have experienced substantial population expansions following long-term declines after species divergence. We detect widespread and heterogeneous genomic differentiation between species, and in accordance with the expectation of allopatric speciation, coalescent simulations suggest that neutral evolutionary processes can account for most of the observed patterns of genetic differentiation. However, there is an excess of regions exhibiting extreme differentiation relative to those expected under demographic simulations, which is indicative of the action of natural selection. Overall genetic differentiation is negatively associated with recombination rate in both species, providing strong support for a role of linked selection in generating the heterogeneous genomic landscape of differentiation between species. Finally, we identify a number of candidate regions and genes that may have been subject to positive and/or balancing selection during the speciation process. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  20. Political ecology

    International Nuclear Information System (INIS)

    Strohm, H.

    1979-01-01

    Using facts and examples, this didactically structures textbook gives an insight into the extent and consequences of the damage to the environment, with the subjects - fundamentals of ecology; - population and food problems; - the energy problem; - economic growth; scarcity of resources, recycling; - ground, water, and air pollution, - city and traffic problems; - work protection and medical care; - political alternatives and 'soft technologies'. The analysis of the political and economic reasons is combined with social and technical alternatives from which demands to be made and measures to be taken can be derived for individuals, citizens' interest groups, political groups and trade unions. Teaching models intend to help teachers to work on specific problems of ecology. (orig.) [de

  1. Wasteland ecologies

    DEFF Research Database (Denmark)

    Hoag, Colin Brewster; Bertoni, Filippo; Bubandt, Nils Ole

    2018-01-01

    landscapes, this article argues, are the result of unheralded multispecies collaboration that can be traced empirically by attending ethnographically to multispecies forms of “gain-making,” the ways in which humans and other species leverage difference to find economic and ecological opportunity....... in the 1970s, when prevailing perceptions were that the entire mining area was a polluted wasteland, the AFLD Fasterholt waste and recycling plant has since changed in response to new EU waste management regulations, as well as the unexpected proliferation of non-human life in the area. Based on field...... research at this site—an Anthropocene landscape in the heartland of an EU-configured welfare state — this article is a contribution to the multispecies ethnography and political ecology of wastelands. We argue that “waste” is a co-species, biopolitical happening — a complex symbolic, political, biological...

  2. Marine ecology

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Studies on marine ecology included marine pollution; distribution patterns of Pu and Am in the marine waters, sediments, and organisms of Bikini Atoll and the influence of physical, chemical, and biological factors on their movements through marine biogeochemical systems; transfer and dispersion of organic pollutants from an oil refinery through coastal waters; transfer of particulate pollutants, including sediments dispersed during construction of offshore power plants; and raft culture of the mangrove oysters

  3. Terrestrial ecology

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The main effort of the Terrestrial Ecology Division has been redirected to a comprehensive study of the Espiritu Santo Drainage Basin located in northeastern Puerto Rico. The general objective are to provide baseline ecological data for future environmental assessment studies at the local and regional levels, and to provide through an ecosystem approach data for the development of management alternatives for the wise utilization of energy, water, and land resources. The interrelationships among climate, vegetation, soils, and man, and their combined influence upon the hydrologic cycle will be described and evaluated. Environmental management involves planning and decision making, and both require an adequate data base. At present, little is known about the interworkings of a complete, integrated system such as a drainage basin. A literature survey of the main research areas confirmed that, although many individual ecologically oriented studies have been carried out in a tropical environment, few if any provide the data base required for environmental management. In view of rapidly changing socio-economic conditions and natural resources limitations, management urgently requires data from these systems: physical (climatological), biological, and cultural. This integrated drainage basin study has been designed to provide such data. The scope of this program covers the hydrologic cycle as it is affected by the interactions of the physical, biological, and cultural systems

  4. Integrative analyses unveil speciation linked to host plant shift in Spialia butterflies.

    Science.gov (United States)

    Hernández-Roldán, Juan L; Dapporto, Leonardo; Dincă, Vlad; Vicente, Juan C; Hornett, Emily A; Šíchová, Jindra; Lukhtanov, Vladimir A; Talavera, Gerard; Vila, Roger

    2016-09-01

    Discovering cryptic species in well-studied areas and taxonomic groups can have profound implications in understanding eco-evolutionary processes and in nature conservation because such groups often involve research models and act as flagship taxa for nature management. In this study, we use an array of techniques to study the butterflies in the Spialia sertorius species group (Lepidoptera, Hesperiidae). The integration of genetic, chemical, cytogenetic, morphological, ecological and microbiological data indicates that the sertorius species complex includes at least five species that differentiated during the last three million years. As a result, we propose the restitution of the species status for two taxa often treated as subspecies, Spialia ali (Oberthür, 1881) stat. rest. and Spialia therapne (Rambur, 1832) stat. rest., and describe a new cryptic species Spialia rosae Hernández-Roldán, Dapporto, Dincă, Vicente & Vila sp. nov. Spialia sertorius (Hoffmannsegg, 1804) and S. rosae are sympatric and synmorphic, but show constant differences in mitochondrial DNA, chemical profiles and ecology, suggesting that S. rosae represents a case of ecological speciation involving larval host plant and altitudinal shift, and apparently associated with Wolbachia infection. This study exemplifies how a multidisciplinary approach can reveal elusive cases of hidden diversity. © 2016 John Wiley & Sons Ltd.

  5. Molecular evidence of cryptic speciation in the "cosmopolitan" excavating sponge Cliona celata (Porifera, Clionaidae).

    Science.gov (United States)

    Xavier, J R; Rachello-Dolmen, P G; Parra-Velandia, F; Schönberg, C H L; Breeuwer, J A J; van Soest, R W M

    2010-07-01

    Over the past several decades molecular tools have shown an enormous potential to aid in the clarification of species boundaries in the marine realm, particularly in morphologically simple groups. In this paper we report a case of cryptic speciation in an allegedly cosmopolitan and ecologically important species-the excavating sponge Cliona celata (Clionaidae, Hadromerida). In the Northeast Atlantic and Mediterranean C. celata displays a discontinuous distribution of its putative growth stages (boring, encrusting, and massive) leading us to investigate its specific status. Phylogenetic reconstructions of mitochondrial (COI, Atp8) and nuclear (28S) gene fragments revealed levels of genetic diversity and divergence compatible with interspecific relationships. We therefore demonstrate C. celata as constituting a species complex comprised of at least four morphologically indistinct species, each showing a far more restricted distribution: two species on the Atlantic European coasts and two on the Mediterranean and adjacent Atlantic coasts (Macaronesian islands). Our results provide further confirmation that the different morphotypes do indeed constitute either growth stages or ecologically adapted phenotypes as boring and massive forms were found in two of the four uncovered species. We additionally provide an overview of the cases of cryptic speciation which have been reported to date within the Porifera, and highlight how taxonomic crypsis may confound scientific interpretation and hamper biotechnological advancement. Our work together with previous studies suggests that overconservative systematic traditions but also morphological stasis have led to genetic complexity going undetected and that a DNA-assisted taxonomy may play a key role in uncovering the hidden diversity in this taxonomic group. Copyright 2010 Elsevier Inc. All rights reserved.

  6. Speciation of Metals and Assessment of Contamination in Surface Sediments from Daya Bay, South China Sea

    Directory of Open Access Journals (Sweden)

    Jie Yang

    2014-12-01

    Full Text Available The contents, speciation, source factors and potential ecological risks of the selected metals (Cr, Ni, Cu, Pb, Zn, Cd and As were analyzed in surface sediments from Daya Bay (DYB. The results show that, with the exception of Pb, metal concentrations have decreased at all sites over the past decade. The distribution features of these concentrations represent a ring shape that descends from shore to bay by varying degrees. Speciation analysis showed that Cr, Ni, Cu, Zn and As exist mainly in the residual fraction and, thus, are of low bioavailability, while Cd and Pb were found to be abundant in the non-residual fraction and, thus, have high potential mobility. The ratio of heavy metals in non-residual form in descending order is Pb (78.83%, Cd (78.65%, Cu (48.54%, Zn (48.10%, Ni (38.31%, Cr (28.43% and As (27.76%. The ratio of Pb content is the highest, meaning the highest mobility of Pb. The metals’ potential ecological risks to the environment were also assessed using the methods of the mean effect range-median quotient and the criteria of risk assessment code. The results showed that Cd presents the highest risk, and Pb and Cu are generally considered to be medium risks in the sub-basins of Daya Bay. The principal component analysis (PCA revealed that natural coastal weathering and erosion of rock caused the highest input, followed by mariculture and industrial wastewater and, finally, domestic sewage discharge.

  7. Uranium Speciation and Bioavailability in Aquatic Systems: An Overview

    Directory of Open Access Journals (Sweden)

    Scott J. Markich

    2002-01-01

    Full Text Available The speciation of uranium (U in relation to its bioavailability is reviewed for surface waters (fresh- and seawater and their sediments. A summary of available analytical and modeling techniques for determining U speciation is also presented. U(VI is the major form of U in oxic surface waters, while U(IV is the major form in anoxic waters. The bioavailability of U (i.e., its ability to bind to or traverse the cell surface of an organism is dependent on its speciation, or physicochemical form. U occurs in surface waters in a variety of physicochemical forms, including the free metal ion (U4+ or UO22+ and complexes with inorganic ligands (e.g., uranyl carbonate or uranyl phosphate, and humic substances (HS (e.g., uranyl fulvate in dissolved, colloidal, and/or particulate forms. Although the relationship between U speciation and bioavailability is complex, there is reasonable evidence to indicate that UO22+ and UO2OH+ are the major forms of U(VI available to organisms, rather than U in strong complexes (e.g., uranyl fulvate or adsorbed to colloidal and/or particulate matter. U(VI complexes with inorganic ligands (e.g., carbonate or phosphate and HS apparently reduce the bioavailability of U by reducing the activity of UO22+ and UO2OH+. The majority of studies have used the results from thermodynamic speciation modeling to support these conclusions. Time-resolved laser-induced fluorescence spectroscopy is the only analytical technique able to directly determine specific U species, but is limited in use to freshwaters of low pH and ionic strength. Nearly all of the available information relating the speciation of U to its bioavailability has been derived using simple, chemically defined experimental freshwaters, rather than natural waters. No data are available for estuarine or seawater. Furthermore, there are no available data on the relationship between U speciation and bioavailability in sediments. An understanding of this relationship has been

  8. Are sympatrically speciating Midas cichlid fish special? Patterns of morphological and genetic variation in the closely related species Archocentrus centrarchus.

    Science.gov (United States)

    Fruciano, Carmelo; Franchini, Paolo; Raffini, Francesca; Fan, Shaohua; Meyer, Axel

    2016-06-01

    Established empirical cases of sympatric speciation are scarce, although there is an increasing consensus that sympatric speciation might be more common than previously thought. Midas cichlid fish are one of the few substantiated cases of sympatric speciation, and they formed repeated radiations in crater lakes. In contrast, in the same environment, such radiation patterns have not been observed in other species of cichlids and other families of fish. We analyze morphological and genetic variation in a cichlid species (Archocentrus centrarchus) that co-inhabits several crater lakes with the Midas species complex. In particular, we analyze variation in body and pharyngeal jaw shape (two ecologically important traits in sympatrically divergent Midas cichlids) and relate that to genetic variation in mitochondrial control region and microsatellites. Using these four datasets, we analyze variation between and within two Nicaraguan lakes: a crater lake where multiple Midas cichlids have been described and a lake where the source population lives. We do not observe any within-lake clustering consistent across morphological traits and genetic markers, suggesting the absence of sympatric divergence in A. centrarchus. Genetic differentiation between lakes was low and morphological divergence absent. Such morphological similarity between lakes is found not only in average morphology, but also when analyzing covariation between traits and degree of morphospace occupation. A combined analysis of the mitochondrial control region in A. centrarchus and Midas cichlids suggests that a difference between lineages in the timing of crater lake colonization cannot be invoked as an explanation for the difference in their levels of diversification. In light of our results, A. centrarchus represents the ideal candidate to study the genomic differences between these two lineages that might explain why some lineages are more likely to speciate and diverge in sympatry than others.

  9. Molecular activation analysis for chemical speciation studies

    International Nuclear Information System (INIS)

    Chai-Chifang

    1998-01-01

    The term of Molecular Activation Analysis (MAA) refers to an activation analysis method that is able to provide information about the chemical species of elements in system of interests, though its definition has remained to be assigned. Its development is strongly stimulated by the urgent need to know the chemical species of elements, because the total concentrations are often without any meaning when assessing health or environmental risks of trace elements.In practice, the MAA is a combination of conventional instrumental or radiochemical activation analysis and physical, chemical or biochemical separation techniques. The MAA is able to play a particular role in speciation studies. However, the critical point in the MAA is that it is not permitted to change the primitive chemical species of elements in systems, or the change has to be under control; in the meantime it is not allowed to form the 'new artifact' originally not present in systems. Some practical examples of MAA for chemical species research performed recently in our laboratory will be presented as follows: Chemical species of platinum group elements in sediment; Chemical species of iodine in marine algae; Chemical species of mercury in human tissues; Chemical species of selenium in corn; Chemical species of rare earth elements in natural plant, etc. The merits and limitations of MAA will be described as well. (author)

  10. Graphic Ecologies

    Directory of Open Access Journals (Sweden)

    Brook Weld Muller

    2014-12-01

    Full Text Available This essay describes strategic approaches to graphic representation associated with critical environmental engagement and that build from the idea of works of architecture as stitches in the ecological fabric of the city. It focuses on the building up of partial or fragmented graphics in order to describe inclusive, open-ended possibilities for making architecture that marry rich experience and responsive performance. An aphoristic approach to crafting drawings involves complex layering, conscious absence and the embracing of tension. A self-critical attitude toward the generation of imagery characterized by the notion of ‘loose precision’ may lead to more transformative and environmentally responsive architectures.

  11. Industrial ecology.

    Science.gov (United States)

    Patel, C K

    1992-01-01

    Industrial ecology addresses issues that will impact future production, use, and disposal technologies; proper use of the concept should reduce significantly the resources devoted to potential remediation in the future. This cradle-to-reincarnation production philosophy includes industrial processes that are environmentally sound and products that are environmentally safe during use and economically recyclable after use without adverse impact on the environment or on the net cost to society. This will require an industry-university-government round table to set the strategy and agenda for progress. PMID:11607254

  12. Speciation needs in relation with environmental and biological purposes

    International Nuclear Information System (INIS)

    Moulin, V.; Ansoborlo, E.; Bion, L.; Doizi, D.; Moulin, C.; Cote, G.; Madic, C.; Van Der Lee, J.

    2004-01-01

    Radionuclides can occur in the environment either through chronic releases of nuclear facilities, or due to incidents or accidents. In order to study their behaviour in the environment (migration, retention, transfer, and in human organisms (metabolism, retention, excretion), it is of prime importance to know their solution chemistry, and more particularly thermodynamic constants, which will allow to determine their speciation. In fact, speciation governs the migration, the bioavailability and the toxicity of elements. Moreover, this knowledge is also of great interest for decorporation or decontamination purposes. In this framework, a CEA working group on speciation has been created in order to share data both on thermodynamic constants and on speciation analytical methods, interesting chemists, environmentalists and biologists. It has been focused, in a first time, on actinides, namely Th, U, Pu, Am, Np, taking into account their most important oxidation states occurring in environmental or biological environments: Th(IV), U(IV, VI), Pu(III, IV, VI), Am(III), Np(IV, V). A particular attention was devoted to the choice of ligands (inorganic and organic) for being the most representative of environmental and biological media. The thermodynamic database used is BASSIST for Base Applied to Speciation in Solution and at Interfaces and Solubility (developed by CEA), in interaction with the code JCHESS. Different examples will be then presented on the selection of data (thermodynamic constants, ligands of interest) through benchmark exercises (case of U(VI), Am(III), Pu(IV)) which will show the lacks or weakness of knowledge. Speciation diagrams will support these discussions. Moreover, analytical methods to determine thermodynamic constants or direct speciation will also be presented and discussed. (author)

  13. Guidelines for terms related to chemical speciations and fractionation of elements : definitions, structural aspects, and methodological approaches (IUPAC Recommendations 2000)

    NARCIS (Netherlands)

    Templeton, D.M.; Ariese, F.; Cornelis, R.; Danielsson, L.G.; Muntau, H.; Leeuwen, van H.P.; Lobínski, R.

    2000-01-01

    This paper presents definitions of concepts related to speciation of elements, more particularly speciation analysis and chemical species. Fractionation is distinguished from speciation analysis, and a general outline of fractionation procedures is given. We propose a categorization of species

  14. Inferring speciation modes in a clade of Iberian chafers from rates of morphological evolution in different character systems

    Directory of Open Access Journals (Sweden)

    Ahrens Dirk

    2009-09-01

    Full Text Available Abstract Background Studies of speciation mode based on phylogenies usually test the predicted effect on diversification patterns or on geographical distribution of closely related species. Here we outline an approach to infer the prevalent speciation mode in Iberian Hymenoplia chafers through the comparison of the evolutionary rates of morphological character systems likely to be related to sexual or ecological selection. Assuming that mitochondrial evolution is neutral and not related to measured phenotypic differences among the species, we contrast hypothetic outcomes of three speciation modes: 1 geographic isolation with subsequent random morphological divergence, resulting in overall change proportional to the mtDNA rate; 2 sexual selection on size and shape of the male intromittent organs, resulting in an evolutionary rate decoupled to that of the mtDNA; and 3 ecological segregation, reflected in character systems presumably related to ecological or biological adaptations, with rates decoupled from that of the mtDNA. Results The evolutionary rate of qualitative external body characters was significantly correlated to that of the mtDNA both for the overall root-to-tip patristic distances and the individual inter-node branches, as measured with standard statistics and the randomization of a global comparison metric (the z-score. The rate of the body morphospace was significantly correlated to that of the mtDNA only for the individual branches, but not for the patristic distances, while that of the paramere outline was significantly correlated with mtDNA rates only for the patristic distances but not for the individual branches. Conclusion Structural morphological characters, often used for species recognition, have evolved at a rate proportional to that of the mtDNA, with no evidence of directional or stabilising selection according to our measures. The change in body morphospace seems to have evolved randomly at short term, but the overall

  15. Pollinator-Driven Speciation in Sexually Deceptive Orchids

    Directory of Open Access Journals (Sweden)

    Shuqing Xu

    2012-01-01

    Full Text Available Pollinator-mediated selection has been suggested to play a major role for the origin and maintenance of the species diversity in orchids. Sexually deceptive orchids are one of the prime examples for rapid, pollinator-mediated plant radiations, with many species showing little genetic differentiation, lack of postzygotic barriers, but strong prezygotic reproductive isolation. These orchids mimic mating signals of female insects and employ male insects as pollinators. This kind of sexual mimicry leads to highly specialised pollination and provides a good system for investigating the process of pollinator-driven speciation. Here, we summarise the knowledge of key processes of speciation in this group of orchids and conduct a meta-analysis on traits that contribute to species differentiation, and thus potentially to speciation. Our study suggests that pollinator shift through changes in floral scent is predominant among closely related species in sexually deceptive orchids. Such shifts can provide a mechanism for pollinator-driven speciation in plants, if the resulting floral isolation is strong. Furthermore, changes in floral scent in these orchids are likely controlled by few genes. Together these factors suggest speciation in sexually deceptive orchids may happen rapidly and even in sympatry, which may explain the remarkable species diversity observed in this plant group.

  16. Speciation and Health Risks of Atmospheric Nanoparticulates

    Science.gov (United States)

    Nguyen, Kennedy

    Exposure to air pollution causes several adverse health effects such as asthma, respiratory disease, cardiovascular disease, cancer, and premature death; and the San Joaquin Valley is one of the most heavily polluted regions in the US. The mountains that surround the valley allow air pollution, including particulate matter, to remain stagnant, prolonging the exposure of valley populations to it. The primary sources of particulate matter for this region are aluminosilicate dust from agricultural activities, and soot emissions from diesel trucks and vehicular traffic. A substantial fraction of emitted material is nanoparticulate matter (testing in cell culture studies, and correlation of particulate properties and sources with their negative health impacts. These results can help identify the sources of air pollution to prioritize for mitigation for the greatest health benefit. In addition, further chemical speciation can help monitor the results of such mitigation efforts. Here, natural particulate matter samples from Merced and Fresno, two cities in the San Joaquin Valley, were analyzed. Ultrafine particles present were 40 to 50 nm in diameter and mostly composed of aluminum, silicon, oxygen, and iron hydroxide. XAS data confirmed the presence of the aluminosilicate as smectite clay and the iron hydroxide as ferrihydrite. Furthermore, a chemical speciation study investigated industrial emissions of air particulate matter. Samples were analyzed using electron microscopy for elemental composition and size distribution, and found to contain fine metal particulates (lead and iron) that can lead to lung inflammation. From characterization data, in order to create a simplified proxy particle system for cell culture studies, amorphous silica particles were synthesized using a modified Stober Synthesis and coated with iron hydroxide. A range of iron hydroxide concentrations (0.06 to 1.63 mmol of iron per gram of silica) were used to test the effect of iron contamination on

  17. Study of Np speciation in citrate medium

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, L.; Den Auwer, C.; Ansoborlo, E.; Moisy, P. [CEA Valrho - DEN/DRCP/SCPS, Bagnols sur Ceze (France); Cote, G. [ENSP - LECA, UMR 7575, Paris (France)

    2007-07-01

    In the framework of the French Environmental Nuclear Toxicology program, additional experiments related to the decorporation of actinides are planned. Decorporation is the removal or release from target organs (bones, liver, kidney..), tissues or cells of radioactive material previously incorporated in them, using chelating agents or other administrated pharmaceutical agents. The contradictory data on the neptunium complexation behaviour within blood and its transfer to target organs, as well as the inefficiency of therapeutic treatments, led us to study the complexation of this element with biological constituents. Within this purpose, the in vitro behaviour of Np(IV) and Np(V) in simple media simulating biological fluids was studied. This study was more specifically focused on the behaviour of neptunium with citrate ion, which is an essential component in a number of metalloenzyme active sites. In order to determine the speciation of this system, spectrophotometry was more particularly used. Concerning the complexation phenomenon, the existence of several complexes of Np(V) with various acido-basic forms of the citrate anion was observed; regarding Np(IV), complexes with Cit{sup 3-} have been observed. From the quantitative study of these equilibria, the values of the absolute constants for the complexation of Np(IV) and Np(V) with citrate were determined. Concerning the stability of neptunium towards oxydo-reduction, it was confirmed that Np(VI) was very quickly reduced to Np(V) by the citrate anions, whereas Np(IV) was stable. In the case of Np(V), it was observed that, depending on the pH and the citrate concentration, Np(V) was unstable and was reduced to Np(IV). The E-pH diagrams, constructed using the stability constants determined in this study, showed that this instability was due to the Np(V) disproportionation. (orig.)

  18. Voltammetric Investigation Of Hydrothermal Iron Speciation

    Directory of Open Access Journals (Sweden)

    Charlotte eKleint

    2016-05-01

    Full Text Available Hydrothermal vent fluids are highly enriched in iron (Fe compared to ambient seawater, and organic ligands may play a role in facilitating the transport of some hydrothermal Fe into the open ocean. This is important since Fe is a limiting micronutrient for primary production in large parts of the world`s surface ocean. We have investigated the concentration and speciation of Fe in several vent fluid and plume samples from the Nifonea vent field, Coriolis Troughs, New Hebrides Island Arc, South Pacific Ocean using competitive ligand exchange - adsorptive cathodic stripping voltammetry (CLE - AdCSV with salicylaldoxime (SA as the artificial ligand. Our results for total dissolved Fe (dFe in the buoyant hydrothermal plume samples showed concentrations up to 3.86 µM dFe with only a small fraction between 1.1% and 11.8% being chemically labile. Iron binding ligand concentrations ([L] were found in µM level with strong conditional stability constants up to log K[L],Fe3+ of 22.9. Within the non-buoyant hydrothermal plume above the Nifonea vent field, up to 84.7% of the available Fe is chemically labile and [L] concentrations up to 97 nM were measured. [L] was consistently in excess of Felab, indicating that all available Fe is being complexed, which in combination with high Felab values in the non-buoyant plume, signifies that a high fraction of hydrothermal dFe is potentially being transported away from the plume into the surrounding waters, contributing to the global oceanic Fe budget.

  19. Microimaging and tomography with chemical speciation

    Energy Technology Data Exchange (ETDEWEB)

    Rau, C. E-mail: rau@esrf.fr; Somogyi, A.; Simionovici, A

    2003-01-01

    Materials science deals with the study of the morphology of samples, their chemical composition and the relation between both. One general problem is the preservation of the sample throughout the different analyses, like it is often the case for classical chemical analysis. Destruction-free chemical speciation in three dimensions with micrometer resolution can be achieved by combining X-ray spectroscopy and imaging techniques. Highly brilliant radiation is needed for this purpose available at 3rd generation synchrotrons such as the ESRF. X-ray absorption near-edge spectroscopy (XANES) is a non-destructive well-known and established technique in chemistry. By scanning the X-ray energy in the vicinity (50-100 eV) of the absorption edge of an element, information can be obtained about the oxidation state of the probed atoms. The (conventional) technique mainly employed until now applies to homogeneous, specifically prepared flat samples where the measured signal can be considered as the average over the whole irradiated volume. This restriction for samples is partially released when the XANES method is combined with imaging techniques. 2D resolved data is acquired using area detectors or by scanning with a focussed beam. X-ray absorption tomography is a method of choice for investigating the 3D structure of objects and its dual energy version is used for getting information about the 3D distribution of a given element within the sample. Although the combination of XANES and tomography seems to be a natural extension of dual-energy tomography, in practice several experimental problems have to be overcome in order to obtain useable data. In the following we describe the results of XANES imaging and tomography obtained measuring a phantom sample of pure molybdenum compounds using a FreLoN 2000 camera system at the ESRF undulator beamline ID22. This system allowed making volume resolved distinctions between different oxidation states with spatial resolution in the

  20. Media Ecology

    Directory of Open Access Journals (Sweden)

    Marina Ašković

    2015-05-01

    Full Text Available Does the trend in which electronic media are gradually becoming extension of human body have to move towards full enslavement of a human and his personality, or the same human will unpredictably, with the aid of his personal media literacy, exit the whirls of media and technological censorships? Personality crisis is closely related to the crisis of language no matter how contradicted to global ideology of transnational transhumanism it may seem. Considering the fact that recent media presentations of the world are based on commercialization of environmentalism, philosophical and aesthetic thought appears as an important subject of ecology. As media mediates, the scenery of civilized living increasingly becomes more appealing even though it derives from commercial and political background. Consequently, the future of humanity depends by large on the philosophy of media. Media have to truly ecologise returning the humanum to its essence making it into the extension of the natural world.

  1. Ecological Ethics

    International Nuclear Information System (INIS)

    Oughton, Deborah

    2013-01-01

    Deborah Oughton started with a view of the work in progress by the ICRP TG 94 on ethics, from the historical context and the principles-based ethics in RP, to continue with an overview of the ethical theories and with the main area of elaboration which concerns the common values, to conclude with considerations about the implementation in different area such as biomedicine, nuclear safety and workers, ecological aspects, and environmental health and society. By reading again the ICRP and IAEA publications on the ethical aspects in the protection of environment from the effects of ionizing radiation, the presentation covers the various and different cultures within the history of environmental ethics, the perception of Nature and the theories of environmental ethics, in particular by focusing on anthropocentrism, biocentrism and ecocentrism, as philosophical worldwide views, and on conservation, biodiversity, sustainability, environmental justice and human dignity, as primary principles of environmental protection. The influence of western Christianity, with a view of man dominating over every creeping thing on earth, and of the non-western ideas, the human perception of Nature has been analyzed and discussed to conclude that, in reality then, the anthropocentrism, biocentrism and ecocentrism, as reflected in many cultures and religions, they all support the need to protect the environment and to recognise and preserve the diversity. Three challenges were then discussed in the presentation: the ecosystem approach and ecological economics, for example in the case of Fukushima by asking what is the economic cost of marine contamination; the ecosystem changes with attention to what harms, as in the case of the environment in the contaminated areas around Chernobyl; and the environmental consequences of remediation, which can be considered a source of controversy for environmental ethics and policy

  2. Simultaneous speciation of trace elements using chemical separation and neutron activation

    International Nuclear Information System (INIS)

    Chatt, A.

    2003-01-01

    Speciation neutron activation analysis (SNAA) is a sophisticated analytical technique which can be developed for studying the simultaneous speciation of a number of elements in a variety of matrices. The advantages of SNAA are demonstrated with typical examples such as (i) arsenic speciation in sea foods and water, and simultaneous speciation of (ii) arsenic, antimony and selenium in water, (iii) chlorine, bromine and iodine in fish, (iv) lanthanides in simulated vitrified waste, and (v) trace elements bound to proteins. (author)

  3. ISSEBETS 2009. 7. International Symposium on Speciation of Elements in Biological, Environmental and Toxicological Sciences

    International Nuclear Information System (INIS)

    2009-01-01

    The 7th ISSEBETS was held in August 2009 in city of Eger, Hungary. The main topics were: speciation of essential and toxic elements in food, in traditional drugs, designing functional foods through applied speciation, metallomics and metalloproteomics, metal species in health and disease, cycling of elemental species in the environment, speciation related regulations and legislation, metal environmental, bioremediation, quality assurance of speciation analysis. (S.I.)

  4. Meeting Disorders.

    Science.gov (United States)

    Yager, Joel; Katzman, Jeffrey W

    2017-12-01

    Although meetings are central to organizational work, considerable time devoted to meetings in Academic Health Centers appears to be unproductively spent. The primary purposes of this article are to delineate and describe Meeting Disorders, pathological processes resulting in these inefficient and ineffective scenarios, and Meeting Fatigue Disorder (MFD), a clinical syndrome. The paper also offers preliminary approaches to remedies. The authors integrate observations made during tens of thousands of hours in administrative meetings in academic medical settings with information in the literature regarding the nature, causes and potential interventions for dysfunctional groups and meetings. Meeting Disorders, resulting from distinct pathologies of leadership and organization, constitute prevalent subgroups of the bureaucrapathologies, pathological conditions caused by dysfunctional bureaucratic processes that generate excesses of wasted time, effort, and other resources. These disorders also generate frustration and demoralization among participants, contributing to professional burnout. Meeting Fatigue Disorder (MFD) is a subjective condition that develops in individuals who overdose on these experiences and may reflect one manifestation of burnout. Meeting disorders and Meeting Fatigue Disorder occur commonly in bureaucratic life. Resources and potential remedies are available to help ameliorate their more deleterious effects.

  5. Ecological stability of landscape - ecological infrastructure - ecological management

    International Nuclear Information System (INIS)

    1992-01-01

    The Field Workshop 'Ecological Stability of Landscape - Ecological Infrastructure - Ecological Management' was held within a State Environmental Programme financed by the Federal Committee for the Environment. The objectives of the workshop were to present Czech and Slovak approaches to the ecological stability of the landscape by means of examples of some case studies in the field, and to exchange ideas, theoretical knowledge and practical experience on implementing the concept of ecological infrastructure in landscape management. Out of 19 papers contained in the proceedings, 3 items were inputted to the INIS system. (Z.S.)

  6. Towards accounting for dissolved iron speciation in global ocean models

    Directory of Open Access Journals (Sweden)

    A. Tagliabue

    2011-10-01

    Full Text Available The trace metal iron (Fe is now routinely included in state-of-the-art ocean general circulation and biogeochemistry models (OGCBMs because of its key role as a limiting nutrient in regions of the world ocean important for carbon cycling and air-sea CO2 exchange. However, the complexities of the seawater Fe cycle, which impact its speciation and bioavailability, are simplified in such OGCBMs due to gaps in understanding and to avoid high computational costs. In a similar fashion to inorganic carbon speciation, we outline a means by which the complex speciation of Fe can be included in global OGCBMs in a reasonably cost-effective manner. We construct an Fe speciation model based on hypothesised relationships between rate constants and environmental variables (temperature, light, oxygen, pH, salinity and assumptions regarding the binding strengths of Fe complexing organic ligands and test hypotheses regarding their distributions. As a result, we find that the global distribution of different Fe species is tightly controlled by spatio-temporal environmental variability and the distribution of Fe binding ligands. Impacts on bioavailable Fe are highly sensitive to assumptions regarding which Fe species are bioavailable and how those species vary in space and time. When forced by representations of future ocean circulation and climate we find large changes to the speciation of Fe governed by pH mediated changes to redox kinetics. We speculate that these changes may exert selective pressure on phytoplankton Fe uptake strategies in the future ocean. In future work, more information on the sources and sinks of ocean Fe ligands, their bioavailability, the cycling of colloidal Fe species and kinetics of Fe-surface coordination reactions would be invaluable. We hope our modeling approach can provide a means by which new observations of Fe speciation can be tested against hypotheses of the processes present in governing the ocean Fe cycle in an

  7. The United States Regional Association of the International Association for Landscape Ecology

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    Abstracts are presented from a meeting on landscape ecology. Topics include: conservation, climatic change, forest management, aquatic, wetland, rural and urban landscapes, land use, and biodiversity.

  8. The United States Regional Association of the International Association for Landscape Ecology

    Energy Technology Data Exchange (ETDEWEB)

    1993-06-01

    Abstracts are presented from a meeting on landscape ecology. Topics include: conservation, climatic change, forest management, aquatic, wetland, rural and urban landscapes, land use, and biodiversity.

  9. The EU network on trace element speciation in full swing

    DEFF Research Database (Denmark)

    Cornelis, R.; Camara, C.; Ebdon, L.

    2000-01-01

    health and hygiene. The network covers a number of important issues including organotin compounds, chromium and nickel species, chemical characterisation of environmental and industrial particulate samples, risk assessment, selenium and a series of other essential and toxic elements in food, as well......The EC-funded thematic network 'Speciation 21' links scientists in analytical chemistry working in method development for the chemical speciation of trace elements, and potential users from industry and representatives of legislative agencies, in the field of environment, food and occupational...

  10. Speciation of Long-Lived Radionuclides in the Environment

    DEFF Research Database (Denmark)

    Hou, Xiaolin

    , isotopes of Pu, and 237Np in seawater, fresh water, soil, sediment, vegetations, and concrete. The developed methods are used for the investigation of the chemical speciation of these radionuclides as well as their environmental behaviours, especially in Danish environment. In addition the speciation of Pu...... isotopes in waste samples from the decommissioning of Danish nuclear facilities is also investigated. The report summarizes these works completed in this project. Through this research project, a number of research papers have been published in the scientific journals, the research results has also been...

  11. Individual-based modeling of ecological and evolutionary processes

    Science.gov (United States)

    DeAngelis, Donald L.; Mooij, Wolf M.

    2005-01-01

    Individual-based models (IBMs) allow the explicit inclusion of individual variation in greater detail than do classical differential-equation and difference-equation models. Inclusion of such variation is important for continued progress in ecological and evolutionary theory. We provide a conceptual basis for IBMs by describing five major types of individual variation in IBMs: spatial, ontogenetic, phenotypic, cognitive, and genetic. IBMs are now used in almost all subfields of ecology and evolutionary biology. We map those subfields and look more closely at selected key papers on fish recruitment, forest dynamics, sympatric speciation, metapopulation dynamics, maintenance of diversity, and species conservation. Theorists are currently divided on whether IBMs represent only a practical tool for extending classical theory to more complex situations, or whether individual-based theory represents a radically new research program. We feel that the tension between these two poles of thinking can be a source of creativity in ecology and evolutionary theory.

  12. Niche divergence facilitated by fine-scale ecological partitioning in a recent cichlid fish adaptive radiation.

    Science.gov (United States)

    Ford, Antonia G P; Rüber, Lukas; Newton, Jason; Dasmahapatra, Kanchon K; Balarin, John D; Bruun, Kristoffer; Day, Julia J

    2016-12-01

    Ecomorphological differentiation is a key feature of adaptive radiations, with a general trend for specialization and niche expansion following divergence. Ecological opportunity afforded by invasion of a new habitat is thought to act as an ecological release, facilitating divergence, and speciation. Here, we investigate trophic adaptive morphology and ecology of an endemic clade of oreochromine cichlid fishes (Alcolapia) that radiated along a herbivorous trophic axis following colonization of an isolated lacustrine environment, and demonstrate phenotype-environment correlation. Ecological and morphological divergence of the Alcolapia species flock are examined in a phylogenomic context, to infer ecological niche occupation within the radiation. Species divergence is observed in both ecology and morphology, supporting the importance of ecological speciation within the radiation. Comparison with an outgroup taxon reveals large-scale ecomorphological divergence but shallow genomic differentiation within the Alcolapia adaptive radiation. Ancestral morphological reconstruction suggests lake colonization by a generalist oreochromine phenotype that diverged in Lake Natron to varied herbivorous morphologies akin to specialist herbivores in Lakes Tanganyika and Malawi. © 2016 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

  13. STAFF MEETING

    CERN Document Server

    2003-01-01

    I should like to invite all members of the CERN Personnel to a meeting on Wednesday 25th June 2003 at 11.00 hrs - Auditorium, bldg. 500 to give a report on the outcome of the June Meetings of Council and its Committees. Closed-circuit transmission of the meeting will be available in the AB Auditorium (Prévessin), the AB Auditorium (Meyrin - bldg. 6), the IT Auditorium (bldg. 31) and the AT Auditorium (bldg. 30). Luciano Maiani Director General

  14. Phenotypic disparity in Iberian short-horned grasshoppers (Acrididae): the role of ecology and phylogeny.

    Science.gov (United States)

    García-Navas, Vicente; Noguerales, Víctor; Cordero, Pedro J; Ortego, Joaquín

    2017-05-04

    The combination of model-based comparative techniques, disparity analyses and ecomorphological correlations constitutes a powerful method to gain insight into the evolutionary mechanisms that shape morphological variation and speciation processes. In this study, we used a time-calibrated phylogeny of 70 Iberian species of short-horned grasshoppers (Acrididae) to test for patterns of morphological disparity in relation to their ecology and phylogenetic history. Specifically, we examined the role of substrate type and level of ecological specialization in driving different aspects of morphological evolution (locomotory traits, chemosensitive organs and cranial morphology) in this recent radiation. We found a bimodal distribution of locomotory attributes corresponding to the two main substrate type guilds (plant vs. ground); plant-perching species tend to exhibit larger wings and thicker femora than those that remain on the ground. This suggests that life form (i.e., substrate type) is an important driving force in the evolution of morphological traits in short-horned grasshoppers, irrespective of ancestry. Substrate type and ecological specialization had no significant influence on head shape, a trait that showed a strong phylogenetic conservatism. Finally, we also found a marginal significant association between the length of antennae and the level of ecological specialization, suggesting that the development of sensory organs may be favored in specialist species. Our results provide evidence that even in taxonomic groups showing limited morphological and ecological disparity, natural selection seems to play a more important role than genetic drift in driving the speciation process. Overall, this study suggests that morphostatic radiations should not necessarily be considered as "non-adaptive" and that the speciation process can bind both adaptive divergence mechanisms and neutral speciation processes related with allopatric and/or reproductive isolation.

  15. Indigenous Ecological Knowledge and Modern Western Ecological ...

    African Journals Online (AJOL)

    Indigenous knowledge is often dismissed as 'traditional and outdated', and hence irrelevant to modern ecological assessment. This theoretical paper critically examines the arguments advanced to elevate modern western ecological knowledge over indigenous ecological knowledge, as well as the sources and uses of ...

  16. Ecological palaeoecology: a missing link between ecology and evolution

    Directory of Open Access Journals (Sweden)

    Rull, V.

    2014-12-01

    Full Text Available Palaeoecology is more than a palaeoenvironmental discipline; it is a science that is well-suited for supplying the empirical evidence necessary to test ecological hypotheses and contributes to our understanding of the interface of ecology and evolution. A critical time frame in palaeoecology is the often-overlooked Q-time dimension (centuries to millennia, which tends to be the most appropriate time dimension to examine ecology–evolution interactions. This paper discusses these topics from a conceptual perspective and provides examples of the contributions of palaeoecology to the study of ecology–evolution interactions. It also admonishes researchers about the threats of overlooking palaeoecology. Specifically, this paper argues that the neglect of palaeoecology may result in the loss of empirical support for ecology and its interactions with evolution as DNA-based phylogenetic and phylogeographic studies become more and more prevalent. The main concepts discussed are the time continuum, the notion of ecological palaeoecology and the empirical nature of palaeoecology in the face of more hypothetical approaches. More practically speaking, several examples are provided that highlight the utility of ecological palaeoecology for understanding a variety of processes, including ecological succession, community– environment equilibria, community assembly, biotic responses to environmental change, speciation and extinction, and biodiversity conservation. The ecology–evolution interface is analysed using two processes in which these disciplines interact intensively: ecological succession and long-range migration. This work concludes that both ecological palaeoecology (including ancient DNA records and DNA-based phylogenetics and phylogeography are needed to better understand the biosphere ecologically and the processes occurring at the ecology–evolution interface.La paleoecología es más que una disciplina ambiental, ya que proporciona las

  17. Gypsophila bermejoi G. López: A possible case of speciation repressed by bioclimatic factors.

    Science.gov (United States)

    de Luis, Miguel; Bartolomé, Carmen; García Cardo, Óscar; Álvarez-Jiménez, Julio

    2018-01-01

    Gypsophila bermejoi G. López is an allopolyploid species derived from the parental G. struthium L. subsp. struthium and G. tomentosa L. All these plants are gypsophytes endemic to the Iberian Peninsula of particular ecological, evolutionary and biochemical interest. In this study, we present evidence of a possible repression on the process of G. bermejoi speciation by climatic factors. We modelled the ecological niches of the three taxa considered here using a maximum entropy approach and employing a series of bioclimatic variables. Subsequently, we projected these models onto the geographical space of the Iberian Peninsula in the present age and at two past ages: the Last Glacial Maximum and the mid-Holocene period. Furthermore, we compared these niches using the statistical method devised by Warren to calculate their degree of overlap. We also evaluated the evolution of the bioclimatic habitat suitability at those sites were the soil favors the growth of these species. Both the maximum entropy model and the degree of overlap indicated that the ecological behavior of the hybrid differs notably from that of the parental species. During the Last Glacial Maximum, the two parental species appear to take refuge in the western coastal strip of the Peninsula, a region in which there are virtually no sites where G. bermejoi could potentially be found. However, in the mid-Holocene period the suitability of G. bermejoi to sites with favorable soils shifts from almost null to a strong adaptation, a clear change in this tendency. These results suggest that the ecological niches of hybrid allopolyploids can be considerably different to those of their parental species, which may have evolutionary and ecologically relevant consequences. The data obtained indicate that certain bioclimatic variables may possibly repress the processes by which new species are formed. The difference in the ecological niche of G. bermejoi with respect to its parental species prevented it from

  18. Logic Meeting

    CERN Document Server

    Tugué, Tosiyuki; Slaman, Theodore

    1989-01-01

    These proceedings include the papers presented at the logic meeting held at the Research Institute for Mathematical Sciences, Kyoto University, in the summer of 1987. The meeting mainly covered the current research in various areas of mathematical logic and its applications in Japan. Several lectures were also presented by logicians from other countries, who visited Japan in the summer of 1987.

  19. Electrochemical metal speciation in natural and model polyelectrolyte systems

    NARCIS (Netherlands)

    Hoop, van den M.A.G.T.

    1994-01-01

    The purpose of the research described in this thesis was to examine the applicability of electro-analytical techniques in obtaining information on the speciation of metals, i.e. their distribution over different physico-chemical forms, in aquatic systems containing charged macromolecules.

  20. Speciation and determination of priority metals in sediments of Oyun ...

    African Journals Online (AJOL)

    This work was carried out to determine the concentrations, bioavailability and mobility of priority metals in sediments of Oyun River, Sango, Ilorin, Nigeria. The river sediments were sampled at six selected locations and the samples were analyzed for some certain priority metals to determine the concentration, speciation and ...

  1. Speciation and phase separation of water in quartz (A review ...

    African Journals Online (AJOL)

    By sp3-hybridization of electron bonds, the water molecule exhibits a tetrahedral charged structure, leading to various water point defects in the form of substitution of ... The formation of combined defect [SiO4]-H2O-M+ [M3+O4] upon water speciation (M+ is metallic ion), is an indication of the presence of hydrous species.

  2. Comparative Studies of the Speciation Patterns of Nickel and ...

    African Journals Online (AJOL)

    Results of speciation stdies of nickel and chromium in wastewater, surface and groundwater systems using flame atomic absorption spectrometry (FAAS), graphite furnace atomic absorption spectrometry (GFAAS) and differential pulse adsorptive cathodic stripping voltammetry (DPAdCSV) are presented. Dimethylglyoxime ...

  3. Fractionation, characterization and speciation of heavy metals in ...

    African Journals Online (AJOL)

    Speciation of heavy metals in soils determines the availability for metals for plant uptake and potential for contamination of groundwater following application of composts to agricultural lands. Methods used to characterize heavy metals in solid phase of composts and compost amended soils include physical fractionation ...

  4. Behavioural isolation may facilitate homoploid hybrid speciation in cichlid fish

    NARCIS (Netherlands)

    Selz, O. M.; Thommen, R.; Maan, M. E.; Seehausen, O.

    Hybrid speciation is constrained by the homogenizing effects of gene flow from the parental species. In the absence of post-mating isolation due to structural changes in the genome, or temporal or spatial premating isolation, another form of reproductive isolation would be needed for homoploid

  5. The molecular basis of speciation: from patterns to processes, rules ...

    Indian Academy of Sciences (India)

    male; large X-effect; meiotic drive; genomic conflict. Abstract. The empirical study of speciation has brought us closer to unlocking the origins of life's vast diversity. By examining recently formed species, a number of general patterns, or rules, ...

  6. Mitochondrial Recombination and Introgression during Speciation by Hybridization.

    Science.gov (United States)

    Leducq, Jean-Baptiste; Henault, Mathieu; Charron, Guillaume; Nielly-Thibault, Lou; Terrat, Yves; Fiumera, Heather L; Shapiro, B Jesse; Landry, Christian R

    2017-08-01

    Genome recombination is a major source of genotypic diversity and contributes to adaptation and speciation following interspecies hybridization. The contribution of recombination in these processes has been thought to be largely limited to the nuclear genome because organelles are mostly uniparentally inherited in animals and plants, which prevents recombination. Unicellular eukaryotes such as budding yeasts do, however, transmit mitochondria biparentally, suggesting that during hybridization, both parents could provide alleles that contribute to mitochondrial functions such as respiration and metabolism in hybrid populations or hybrid species. We examined the dynamics of mitochondrial genome transmission and evolution during speciation by hybridization in the natural budding yeast Saccharomyces paradoxus. Using population-scale mitochondrial genome sequencing in two endemic North American incipient species SpB and SpC and their hybrid species SpC*, we found that both parental species contributed to the hybrid mitochondrial genome through recombination. We support our findings by showing that mitochondrial recombination between parental types is frequent in experimental crosses that recreate the early step of this speciation event. In these artificial hybrids, we observed that mitochondrial genome recombination enhances phenotypic variation among diploid hybrids, suggesting that it could play a role in the phenotypic differentiation of hybrid species. Like the nuclear genome, the mitochondrial genome can, therefore, also play a role in hybrid speciation. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Heavy metal speciation and their accumulation in sediments of Lake ...

    African Journals Online (AJOL)

    Several sediment samples in Lake Burullus have been affected by the discharges of heavy metals through different drains. The study aimed to analyze the chemical speciation of these metals. In particular, the chemical forms of Cd, Cu, Fe, Mn, Pb and Zn in sediments collected in spring season were studied using a ...

  8. Mercury speciation with fluorescent gold nanocluster as a probe.

    Science.gov (United States)

    Yang, Jian-Yu; Yang, Ting; Wang, Xiao-Yan; Chen, Ming-Li; Yu, Yong-Liang; Wang, Jian-Hua

    2018-05-11

    Fluorescent nanoparticles are widely used for sensing biologically significant species. However, it is rarely reported for the discrimination or speciation of metal species. In this work, we report for the first time the speciation of mercury (Hg 2+ ) and methylmercury (CH 3 Hg + ) by taking advantage of the fluorescence feature of folic acid-capped gold nanoclusters (FA-AuNCs). FA-Au NCs exhibit an average size of 2.08±0.15 nm and a maximum emission at λ ex /λ em = 280/440 nm with a quantum yield of 27.3%. It is interesting that Hg 2+ causes a significant quench on the fluorescence of FA-Au NCs, whereas CH 3 Hg + leads to a remarkable fluorescence enhancement. Based on this discriminative fluorescent response between Hg 2+ and CH 3 Hg + , a novel nanosensor for the speciation of CH 3 Hg + and Hg 2+ was developed, providing limits of detection (LOD) of 28 nM for Hg 2+ and 25 nM for CH 3 Hg + within 100-1000 nM. This sensing system is highly selective to mercury. Its practical applications were further demonstrated by the analysis of CH 3 Hg + and the speciation of mercury (CH 3 Hg + and Hg 2+ ) in environmental water and fish samples.

  9. Geometry, charge distribution, and surface speciation of phosphate on goethite.

    NARCIS (Netherlands)

    Rahnemaie, R.; Hiemstra, T.; Riemsdijk, van W.H.

    2007-01-01

    The surface speciation of phosphate has been evaluated with surface complexation modeling using an interfacial charge distribution (CD) approach based on ion adsorption and ordering of interfacial water. In the CD model, the charge of adsorbed ions is distributed over two electrostatic potentials in

  10. Speciation of Fe in Fe-modified zeolite catalysts

    Czech Academy of Sciences Publication Activity Database

    Smoláková, L.; Grygar, Tomáš; Čapek, L.; Schneeweiss, Oldřich; Zbořil, R.

    2010-01-01

    Roč. 647, č. 1 (2010), s. 8-19 ISSN 1572-6657 Institutional research plan: CEZ:AV0Z40320502; CEZ:AV0Z20410507 Keywords : solid state speciation * Fe2O3 * heterogeneous catalysts Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.732, year: 2010

  11. Speciation Studies of Some Toxic Metal Complexes of Glycylglycine ...

    African Journals Online (AJOL)

    NICO

    mixtures apart from its established utility in understanding ... Chemical speciation of metals is important for an understand- ... Titrations with differ- ent ratios (1:2.5, 1:3.5 and 1:5) of metal-ligand were performed with 0.4 mol L–1 sodium hydroxide solution. The mixtures obtained from PG and water are non-ideal due.

  12. Speciation of Candida isolates obtained from diarrheal stool

    Directory of Open Access Journals (Sweden)

    Beena Uppal

    2016-01-01

    Conclusion Candida diarrhea was mostly seen in individuals younger than 12 years, most commonly caused by C. krusei. Resistance to fluconazole was high. A rising resistance to amphotericin B is alarming. Speciation of Candida is important to see the difference in antifungal susceptibility in different species.

  13. FINE PARTICULATE MATTER (PM) AND ORGANIC SPECIATION OF FIREPLACE EMISSIONS

    Science.gov (United States)

    This paper presents a summary of fireplace particle size and organic speciation data gathered to date in an on-going project. Tests are being conducted in a residential wood combustion (RWC) laboratory on three factory-built fireplaces. RWC wood smoke particles <10?m (PM10) con...

  14. Speciation of Zinc Mixed Ligand Complexes in Salt Water Systems ...

    African Journals Online (AJOL)

    Speciation of Zinc Mixed Ligand Complexes in Salt Water Systems. ... method has been used to study heavy metal interaction in model lake water in KNO3 ... is of no consequential effect because in its normal state, the [OH-] of the lake water is ...

  15. Speciation and bioavailability of copper in Lake Tjeukemeer

    NARCIS (Netherlands)

    Verweij, W.

    1991-01-01

    Chapter 1: introduction

    In this thesis an account is given of a research project dealing with the chemical speciation and bioavailability of copper in Lake Tjeukemeer, a lake in the north of the Netherlands. The reason for the initiation of this project was a lack of

  16. Distribution and Speciation of Mercury in Mine Waste Dumps

    Czech Academy of Sciences Publication Activity Database

    Hojdová, Maria; Navrátil, Tomáš; Rohovec, Jan

    2008-01-01

    Roč. 80, č. 3 (2008), s. 237-241 ISSN 0007-4861 R&D Projects: GA AV ČR(CZ) KJB300130615 Institutional research plan: CEZ:AV0Z30130516 Keywords : mercury * mine waste * mercury speciation * thermo-desorption analysis Subject RIV: DD - Geochemistry Impact factor: 0.609, year: 2008

  17. Speciation and migration of 129I in soil profiles

    DEFF Research Database (Denmark)

    Luo, Maoyi; Hou, Xiaolin; Zhou, Weijian

    2013-01-01

    A method has been developed for speciation analysis of ultra low level 129I in soil using sequential extraction combined with coprecipitation for separation of carrier free iodine and AMS measurement of 129I. Two loess profiles collected from northwest China were analyzed for species of 129I...

  18. Phytotoxicity and bioavailablity of nickel: chemical speciation and bioaccumulation

    NARCIS (Netherlands)

    Weng, L.P.; Lexmond, T.M.; Wolthoorn, A.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2003-01-01

    The effect of pH on the bioaccumulation of nickel (Ni) by plants is opposite when using a nutrient solution or a soil as a growing medium. This paradox can be understood if the pH effect on the bioaccumulation, on the chemical speciation in the soil solution, and on the binding to the soil of Ni are

  19. Effects of conversion of mangroves into gei wai ponds on accumulation, speciation and risk of heavy metals in intertidal sediments.

    Science.gov (United States)

    Li, Rongyu; Qiu, Guo Yu; Chai, Minwei; Shen, Xiaoxue; Zan, Qijie

    2018-06-23

    Mangroves are often converted into gei wai ponds for aquaculture, but how such conversion affects the accumulation and behavior of heavy metals in sediments is not clear. The present study aims to quantify the concentration and speciation of heavy metals in sediments in different habitats, including gei wai pond, mangrove marsh dominated by Avicennia marina and bare mudflat, in a mangrove nature reserve in South China. The results showed that gei wai pond acidified the sediment and reduced its electronic conductivity and total organic carbon (TOC) when compared to A. marina marsh and mudflat. The concentrations of Cd, Cu, Zn and Pb at all sediment depths in gei wai pond were lower than the other habitats, indicating gei wai pond reduced the fertility and the ability to retain heavy metals in sediment. Gei wai pond sediment also had a lower heavy metal pollution problem according to multiple evaluation methods, including potential ecological risk coefficient, potential ecological risk index, geo-accumulation index, mean PEL quotients, pollution load index, mean ERM quotients and total toxic unit. Heavy metal speciation analysis showed that gei wai pond increased the transfer of the immobilized fraction of Cd and Cr to the mobilized one. According to the acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) analysis, the conversion of mangroves into gei wai pond reduced values of ([SEM] - [AVS])/f oc , and the role of TOC in alleviating heavy metal toxicity in sediment. This study demonstrated the conversion of mangrove marsh into gei wai pond not only reduced the ecological purification capacity on heavy metal contamination, but also enhanced the transfer of heavy metals from gei wai pond sediment to nearby habitats.

  20. An advanced concept that promises ecological and economic viability

    Science.gov (United States)

    Wright, B. R.; Sedgwick, T. A.; Urie, D. M.

    1976-01-01

    The actuality of supersonic commercial service being provided by Concorde is demonstrating to the world the advantages offered by supersonic travel for both business and recreation. Public acceptance will gradually and persistently stimulate interest to proceed with a second generation design that meets updated economic and ecological standards. It is estimated that this concept could operate profitably on world-wide routes with a revenue structure based upon economy fares. Airplanes will meet all present day ecological requirements regarding noise and emissions.

  1. Diversity along a speciation continuum : ecology and morphology of northern European whitefish (Coregonus lavaretus)

    OpenAIRE

    Siwertsson, Anna

    2012-01-01

    Papers 1 and 4 of this thesis are not available in Munin: 1. Anna Siwertsson, Rune Knudsen and Per-Arne Amundsen: 'Temporal stability in gill raker numbers of subarctic European whitefish populations', Advances in Limnology (2012), vol. 63:229-240. Available at http://www.schweizerbart.de/papers/adv_limnology/detail/63/77932/Temporal_stability_ingill_raker_numbers_of_subarct 4. Anna Siwertsson, Rune Knudsen, Colin Adams and Per-Arne Amundsen: 'Replicated morphological divergence supports inci...

  2. Mitochondrial Capture Misleads about Ecological Speciation in the Daphnia pulex Complex

    Czech Academy of Sciences Publication Activity Database

    Marková, Silvia; Dufresne, F.; Manca, M.; Kotlík, Petr

    2013-01-01

    Roč. 8, č. 7 (2013) E-ISSN 1932-6203 R&D Projects: GA AV ČR KJB600450901 Institutional support: RVO:67985904 Keywords : genomic DNA * lactate dehydrogenase * mitochondrial DNA Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.534, year: 2013

  3. Comment on "Neutral ecological theory reveals isolation and rapid speciation in a biodiversity hot spot"

    NARCIS (Netherlands)

    Etienne, RS; Latimer, AM; Silander, JA; Cowling, RM

    2006-01-01

    Latimer et at. (Reports, 9 September 2005, p. 1722) used an approximate likelihood function to estimate parameters of Hubbell's neutral model of biodiversity. Reanalysis with the exact likelihood not only yields different estimates but also shows that two similar likelihood maxima for very different

  4. Speciation of trace elements in the environmental studies

    International Nuclear Information System (INIS)

    Reddy, A.V.R.

    2012-01-01

    Elements present at trace levels, often referred as trace elements, play an important role in the environment and in the functioning of life on our planet. Trace elements in environment present as free metal ions or incorporated into colloids or attached to particulate matter or exist in different physical and chemical forms. It is well established that some elements are highly toxic and some are essential, but can become toxic at higher doses. It is also now known that the forms of elements (speciation) and their amounts are more important than the chemical dose of the elements as their interaction depends on different species. For example, Cr(VI) ions are considered far more toxic than Cr(III), whereas As(III) is more toxic than As(V). Similarly, in the case of mercury, both methylmercury and inorganic mercury are toxic but they show different levels of toxicity. Thus the adverse effects depend on the nature of species of the elements and therefore speciation studies are of paramount importance in many areas like toxicology, environmental chemistry and geochemisty. In view of this, speciation studies is a challenge to analytical chemists as the measurement methodologies have to be carefully developed, validated and applied. The grand challenge is to obtain quality data ensuring traceability, as the data obtained will be used in modeling for predicting the environmental impacts. In this talk importance of speciation and challenges to environmental analytical chemists will be discussed along with the following three speciation studies on Cr, U and Hg which were carried out in our laboratories

  5. Purex process modelling - do we really need speciation data?

    International Nuclear Information System (INIS)

    Taylor, R.J.; May, I.

    2001-01-01

    The design of reprocessing flowsheets has become a complex process requiring sophisticated simulation models, containing both chemical and engineering features. Probably the most basic chemical data needed is the distribution of process species between solvent and aqueous phases at equilibrium, which is described by mathematical algorithms. These algorithms have been constructed from experimentally determined distribution coefficients over a wide range of conditions. Distribution algorithms can either be empirical fits of the data or semi-empirical equations, which describe extraction as functions of process variables such as temperature, activity coefficients, uranium loading, etc. Speciation data is not strictly needed in the accumulation of distribution coefficients, which are simple ratios of analyte concentration in the solvent phase to that in the aqueous phase. However, as we construct process models of increasing complexity, speciation data becomes much more important both to raise confidence in the model and to understand the process chemistry at a more fundamental level. UV/vis/NIR spectrophotometry has been our most commonly used speciation method since it is a well-established method for the analysis of actinide ion oxidation states in solution at typical process concentrations. However, with the increasing availability to actinide science of more sophisticated techniques (e.g. NMR; EXAFS) complementary structural information can often be obtained. This paper will, through examples, show how we have used spectrophotometry as a primary tool in distribution and kinetic experiments to obtain data for process models, which are then validated through counter-current flowsheet trials. It will also discuss how spectrophotometry and other speciation methods are allowing us to study the link between molecular structure and extraction behaviour, showing how speciation data really is important in PUREX process modelling. (authors)

  6. Sex chromosomes and speciation in birds and other ZW systems.

    Science.gov (United States)

    Irwin, Darren E

    2018-02-14

    Theory and empirical patterns suggest a disproportionate role for sex chromosomes in evolution and speciation. Focusing on ZW sex determination (females ZW, males ZZ; the system in birds, many snakes, and lepidopterans), I review how evolutionary dynamics are expected to differ between the Z, W and the autosomes, discuss how these differences may lead to a greater role of the sex chromosomes in speciation and use data from birds to compare relative evolutionary rates of sex chromosomes and autosomes. Neutral mutations, partially or completely recessive beneficial mutations, and deleterious mutations under many conditions are expected to accumulate faster on the Z than on autosomes. Sexually antagonistic polymorphisms are expected to arise on the Z, raising the possibility of the spread of preference alleles. The faster accumulation of many types of mutations and the potential for complex evolutionary dynamics of sexually antagonistic traits and preferences contribute to a role for the Z chromosome in speciation. A quantitative comparison among a wide variety of bird species shows that the Z tends to have less within-population diversity and greater between-species differentiation than the autosomes, likely due to both adaptive evolution and a greater rate of fixation of deleterious alleles. The W chromosome also shows strong potential to be involved in speciation, in part because of its co-inheritance with the mitochondrial genome. While theory and empirical evidence suggest a disproportionate role for sex chromosomes in speciation, the importance of sex chromosomes is moderated by their small size compared to the whole genome. © 2018 John Wiley & Sons Ltd.

  7. Simultaneous speciation neutron activation analysis for trace elements

    International Nuclear Information System (INIS)

    Chatt, A.; Kiceniuk, J.W.; Menendez Sanchez, W.; Bottaro, C.

    2006-01-01

    Among the various forms of neutron activation technique being developed in our laboratory, much emphasis has been placed over the last ten years or so on the development of simultaneous speciation neutron activation analysis (SSNAA). This technique can now be used for the simultaneous determination of various species of a number of elements. Almost all speciation techniques consist of two steps. The first step involves the separation of species from the sample followed by the second step of element-specific detection. A number of characteristic features of NAA, which other techniques normally do not possess, can be advantageously exploited in SSNAA. For example, SSNAA can be used for: (i) multielement speciation with high specificity, (ii) speciation of chemically dissimilar elements such as Cd, Mn and Se, (iii) speciation of elements such as Cl, Br and I which are rather difficult to determine by most other techniques, etc. We have developed SSNAA methods for assaying various arsenic species, namely As(III), As(V), dimethyl arsonic acid (DMA), monomethylarsinic acid (MMA), arsenobetaine (AsB), organically bound arsenic (OBAs), and lipid-soluble arsenic (LSAs) in marine fish samples. We have extended these methods to include simultaneous determination of various species of As, Sb and Se in water. We have also developed SSNAA methods employing biochemical techniques for the simultaneous separation, preconcentration and characterization of metalloproteins and protein-bound trace element species of As, Br, Cd, Cu, Mn, Se, and Zn. We have developed methods for the simultaneous separation and characterization of organohalogen compounds in fish. An overview of the SSNAA methods being developed in our laboratory will be presented. (author)

  8. Introduction to special issue on the ecology of clonal plants

    Czech Academy of Sciences Publication Activity Database

    Gross, K. L.; Herben, T.; Klimešová, Jitka

    2017-01-01

    Roč. 52, 3-4 (2017), s. 265-267 ISSN 1211-9520 Institutional support: RVO:67985939 Keywords : Introduction to special issue * clonal plants * clonal meeting Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.017, year: 2016

  9. Multimodal Student Interaction Online: An Ecological Perspective

    Science.gov (United States)

    Berglund, Therese Ornberg

    2009-01-01

    This article describes the influence of tool and task design on student interaction in language learning at a distance. Interaction in a multimodal desktop video conferencing environment, FlashMeeting, is analyzed from an ecological perspective with two main foci: participation rates and conversational feedback strategies. The quantitative…

  10. Economics, Ethics, Ecology: Roots of Productive Conservation.

    Science.gov (United States)

    Jeske, Walter E., Ed.

    Forty-seven articles represent most of the papers presented at the annual meeting of the Soil Conservation Society of America. The conference addressed the facts and values from economics, ethics, and ecology as they pertain to critical issues in land and water conservation in North America. Part I includes discussions of economic realities,…

  11. Ecological partitioning and diversity in tropical planktonic foraminifera

    Directory of Open Access Journals (Sweden)

    Seears Heidi A

    2012-04-01

    Full Text Available Abstract Background Ecological processes are increasingly being viewed as an important mode of diversification in the marine environment, where the high dispersal potential of pelagic organisms, and a lack of absolute barriers to gene flow may limit the occurrence of allopatric speciation through vicariance. Here we focus on the potential role of ecological partitioning in the diversification of a widely distributed group of marine protists, the planktonic foraminifera. Sampling was conducted in the tropical Arabian Sea, during the southwest (summer monsoon, when pronounced environmental conditions result in a strong disparity in temperature, salinity and productivity between distinct northern and southern water masses. Results We uncovered extensive genetic diversity within the Arabian Sea planktonic foraminifera, identifying 13 morphospecies, represented by 20 distinct SSU rRNA genetic types. Several morphospecies/genetic types displayed non-random biogeographical distributions, partitioning between the northern and southern water masses, giving a strong indication of independent ecological adaptations. Conclusions We propose sea-surface primary productivity as the main factor driving the geographical segregation of Arabian Sea planktonic foraminifera, during the SW monsoon, with variations in symbiotic associations possibly playing a role in the specific ecological adaptations observed. Our findings suggest that ecological partitioning could be contributing to the high levels of 'cryptic' genetic diversity observed within the planktonic foraminifera, and support the view that ecological processes may play a key role in the diversification of marine pelagic organisms.

  12. A global phylogeny of leafmining Ectoedemia moths (Lepidoptera: Nepticulidae): exploring host plant family shifts and allopatry as drivers of speciation.

    Science.gov (United States)

    Doorenweerd, Camiel; van Nieukerken, Erik J; Menken, Steph B J

    2015-01-01

    Host association patterns in Ectoedemia (Lepidoptera: Nepticulidae) are also encountered in other insect groups with intimate plant relationships, including a high degree of monophagy, a preference for ecologically dominant plant families (e.g. Fagaceae, Rosaceae, Salicaceae, and Betulaceae) and a tendency for related insect species to feed on related host plant species. The evolutionary processes underlying these patterns are only partly understood, we therefore assessed the role of allopatry and host plant family shifts in speciation within Ectoedemia. Six nuclear and mitochondrial DNA markers with a total aligned length of 3692 base pairs were used to infer phylogenetic relationships among 92 species belonging to the subgenus Ectoedemia of the genus Ectoedemia, representing a thorough taxon sampling with a global coverage. The results support monophyletic species groups that are congruent with published findings based on morphology. We used the obtained phylogeny to explore host plant family association and geographical distribution to investigate if host shifts and allopatry have been instrumental in the speciation of these leafmining insects. We found that, even though most species within species groups commonly feed on plants from one family, shifts to a distantly related host family have occasionally occurred throughout the phylogeny and such shifts are most commonly observed towards Betulaceae. The largest radiations have occurred within species groups that feed on Fagaceae, Rosaceae, and Salicaceae. Most species are restricted to one of the seven global biogeographic regions, but within species groups representatives are commonly found in different biogeographic regions. Although we find general patterns with regard to host use and biogeography, there are differences between clades that suggest that different drivers of speciation, and perhaps drivers that we did not examine, have shaped diversity patterns in different clades.

  13. August Meeting

    African Journals Online (AJOL)

    chifaou.amzat

    2011-10-19

    Oct 19, 2011 ... rural hometowns, where they unite with their rural-based colleagues for ... extent have they empowered the women-folk in the public sphere? ...... It would be safe, therefore, for one to conceptualise the 'August Meeting'.

  14. Public meetings

    CERN Multimedia

    Staff Association

    2014-01-01

    You were hundreds of persons to participate in our information meetings of October 3 and 6 2014, and we thank you for your participation! The full presentation is available here. A summary of the topics is available here (in french).

  15. Public meetings

    CERN Multimedia

    Staff Association

    2017-01-01

    Do you have questions about the elections to the Staff Council, 2017 MERIT exercise, EVE and School, LD to IC exercise, CHIS, the Pension Fund… Come get informed and ask your questions at our public meetings. These public meetings are also an opportunity to get the more information on current issues. Benefit from this occasion to get the latest news and to discuss with the representatives of the statutory body that is the Staff Association!

  16. Ecological divergence and conservatism: spatiotemporal patterns of niche evolution in a genus of livebearing fishes (Poeciliidae: Xiphophorus).

    Science.gov (United States)

    Culumber, Zachary W; Tobler, Michael

    2016-02-19

    Ecological factors often have a strong impact on spatiotemporal patterns of biodiversity. The integration of spatial ecology and phylogenetics allows for rigorous tests of whether speciation is associated with niche conservatism (constraints on ecological divergence) or niche divergence. We address this question in a genus of livebearing fishes for which the role of sexual selection in speciation has long been studied, but in which the potential role of ecological divergence during speciation has not been tested. By combining reconstruction of ancestral climate tolerances and disparity indices, we show that the earliest evolutionary split in Xiphophorus was associated with significant divergence for temperature variables. Niche evolution and present day niches were most closely associated with each species' geographic distribution relative to a biogeographic barrier, the Trans-Mexican Volcanic Belt. Tests for similarity of the environmental backgrounds of closely related species suggested that the relative importance of niche conservatism and divergence during speciation varied among the primary clades of Xiphophorus. Closely related species in the two swordtail clades exhibited higher levels of niche overlap than expected given environmental background similarity indicative of niche conservatism. In contrast, almost all species of platyfish had significantly divergent niches compared to environmental backgrounds, which is indicative of niche divergence. The results suggest that the relative importance of niche conservatism and divergence differed among the clades of Xiphophorus and that traits associated with niche evolution may be more evolutionarily labile in the platyfishes. Our results ultimately suggest that the taxonomic scale of tests for conservatism and divergence could greatly influence inferences of their relative importance in the speciation process.

  17. [Progress and prospects on evaluation of ecological restoration: a review of the 5th World Conference on Ecological Restoration].

    Science.gov (United States)

    Ding, Jing-Yi; Zhao, Wen-Wu

    2014-09-01

    The 5th World Conference on Ecological Restoration was held in Madison, Wisconsin, USA on October 6-11, 2013. About 1200 delegates from more than 50 countries attended the conference, and discussed the latest developments in different thematic areas of ecological restoration. Discussions on evaluation of ecological restoration were mainly from three aspects: The construction for evaluation indicator system of ecological restoration; the evaluation methods of ecological restoration; monitoring and dynamic evaluation of ecological restoration. The meeting stressed the importance of evaluation in the process of ecological restoration and concerned the challenges in evaluation of ecological restoration. The conference had the following enlightenments for China' s research on evaluation of ecological restoration: 1) Strengthening the construction of comprehensive evaluation indicators system and focusing on the multi-participation in the evaluation process. 2) Paying more attentions on scale effect and scale transformation in the evaluation process of ecological restoration. 3) Expanding the application of 3S technology in assessing the success of ecological restoration and promoting the dynamic monitoring of ecological restoration. 4) Carrying out international exchanges and cooperation actively, and promoting China's international influence in ecological restoration research.

  18. ENVIRONMENTAL PHILOSOPHY AND ECOLOGICAL CULTURE

    Directory of Open Access Journals (Sweden)

    Kalimat M. Alilova

    2017-01-01

    Full Text Available Aim. The aim of the research is to study environmental problems related to the decline of culture, the importance of philosophy in overcoming private and personal interests as well as the unilateral approach of man in his relationship to nature. The study shows how philosophy can participate in the formation of ecological culture, a new ecological consciousness in man, while ecological culture is called upon to resist technocratic stereotypes and the course of history was aimed at preventing the biosphere from becoming deserted. Discussion. On the basis of the analysis of literary sources, we used the method of socio-cultural and socio-natural approaches based on the possibility of philosophy to introduce a new life into culture, new ecological values and new ecological principles. To solve these problems, environmental philosophy develops new theories. Representatives of different cultures, ethnic groups, nations, religions must learn to coexist with each other. We consider philosophy as a means of teaching rapprochement between peoples and creating new opportunities for understanding and improving the environmental situation. Cultural development makes it possible to assess the level of a man’s knowledge of nature, himself and the world around him. Ecological culture is a way of connecting man with nature on the basis of deeper knowledge and understanding. Philosophy says that you cannot move away from nature and be lauded over it since this will destroy culture. Rational doctrines tend to put a person above other living beings so the synthesis of philosophy with culture can have a positive ecological meaning. Conclusion. The findings obtained can be recommended for practical use in schools, starting from primary school, as well as in secondary special educational institutions and universities. It is necessary to work on the motivation and values of people, develop a common and ecological culture. Only a cultured person can move from

  19. Effects of Particle Size on Chemical Speciation and Bioavailability of Copper to Earthworms ( Eisenia fetida ) Exposed to Copper Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    J Unrine; O Tsyusko; S Hunyadi; J Judy; P Bertsch

    2011-12-31

    To investigate the role of particle size on the oxidation, bioavailability, and adverse effects of manufactured Cu nanoparticles (NPs) in soils, we exposed the earthworm Eisenia fetida to a series of concentrations of commercially produced NPs labeled as 20- to 40-nm or <100-nm Cu in artificial soil media. Effects on growth, mortality, reproduction, and expression of a variety of genes associated with metal homeostasis, general stress, and oxidative stress were measured. We also used X-ray absorption spectroscopy and scanning X-ray fluorescence microscopy to characterize changes in chemical speciation and spatial distribution of the NPs in soil media and earthworm tissues. Exposure concentrations of Cu NPs up to 65 mg kg{sup -1} caused no adverse effects on ecologically relevant endpoints. Increases in metallothionein expression occurred at concentrations exceeding 20 mg kg-1 of Cu NPs and concentrations exceeding 10 mg kg{sup -1} of CuSO{sub 4} Based on the relationship of Cu tissue concentration to metallothionein expression level and the spatial distribution and chemical speciation of Cu in the tissues, we conclude that Cu ions and oxidized Cu NPs were taken up by the earthworms. This study suggests that oxidized Cu NPs may enter food chains from soil but that adverse effects in earthworms are likely to occur only at relatively high concentrations (>65 mg Cu kg{sup -1} soil).

  20. Towards improving the ethics of ecological research.

    Science.gov (United States)

    Crozier, G K D; Schulte-Hostedde, Albrecht I

    2015-06-01

    We argue that the ecological research community should develop a plan for improving the ethical consistency and moral robustness of the field. We propose a particular ethics strategy--specifically, an ongoing process of collective ethical reflection that the community of ecological researchers, with the cooperation of applied ethicists and philosophers of biology, can use to address the needs we identify. We suggest a particular set of conceptual (in the form of six core values--freedom, fairness, well being, replacement, reduction, and refinement) and analytic (in the forms of decision theoretic software, 1000Minds) tools that, we argue, collectively have the resources to provide an empirically grounded and conceptually complete foundation for an ethics strategy for ecological research. We illustrate our argument with information gathered from a survey of ecologists conducted at the 2013 meeting of the Canadian Society of Ecology and Evolution.

  1. Ecological niche dimensionality and the evolutionary diversification of stick insects.

    Directory of Open Access Journals (Sweden)

    Patrik Nosil

    Full Text Available The degree of phenotypic divergence and reproductive isolation between taxon pairs can vary quantitatively, and often increases as evolutionary divergence proceeds through various stages, from polymorphism to population differentiation, ecotype and race formation, speciation, and post-speciational divergence. Although divergent natural selection promotes divergence, it does not always result in strong differentiation. For example, divergent selection can fail to complete speciation, and distinct species pairs sometimes collapse ('speciation in reverse'. Widely-discussed explanations for this variability concern genetic architecture, and the geographic arrangement of populations. A less-explored possibility is that the degree of phenotypic and reproductive divergence between taxon pairs is positively related to the number of ecological niche dimensions (i.e., traits subject to divergent selection. Some data supporting this idea stem from laboratory experimental evolution studies using Drosophila, but tests from nature are lacking. Here we report results from manipulative field experiments in natural populations of herbivorous Timema stick insects that are consistent with this 'niche dimensionality' hypothesis. In such insects, divergent selection between host plants might occur for cryptic colouration (camouflage to evade visual predation, physiology (to detoxify plant chemicals, or both of these niche dimensions. We show that divergent selection on the single niche dimension of cryptic colouration can result in ecotype formation and intermediate levels of phenotypic and reproductive divergence between populations feeding on different hosts. However, greater divergence between a species pair involved divergent selection on both niche dimensions. Although further replication of the trends reported here is required, the results suggest that dimensionality of selection may complement genetic and geographic explanations for the degree of

  2. Meeting Mid-Year Meeting

    Indian Academy of Sciences (India)

    23 Newsletter of the Indian Academy of ScienCE. 57th Annual. Meeting ... Srinivas, Institute for Social and Economic. Change ... "Quantum mechanics and statistical mechanics of anyons" .... Special Issue on Geomagnetic Methods and.

  3. U(IV) fluorescence spectroscopy. A new speciation tool

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, Susanne; Brendler, Vinzenz [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes; Steudtner, Robin [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology

    2017-06-01

    We combined absorption and fluorescence spectroscopy to study the speciation of U(IV) in solution in concentrations down to 10{sup -6} M uranium. With our time-resolved laser-induced fluorescence setup we could determine the fluorescence decay time of U(IV) in perchloric as well as in chloric acid with 2.6 ± 0.3 ns at room temperature and 148.4 ± 6.5 ns at liquid nitrogen temperature. For the U(IV) sulfate system, we observed a bathochromic shift and a peak shape modification in the fluorescence spectra with increasing sulfate concentration in solution. Thus, the potential of U(IV) fluorescence for speciation analysis could be proven.

  4. Determining uranium speciation in Fernald soils by molecular spectroscopic methods

    International Nuclear Information System (INIS)

    Allen, P.G.; Berg, J.M.; Crisholm-Brause, C.J.; Conradson, S.D.; Donohoe, R.J.; Morris, D.E.; Musgrave, J.A.; Tait, C.D.

    1994-07-01

    This progress report describes new experimental results and interpretations for data collected from October 1, 1992, through September 30, 1993, as part of the Characterization Task of the Uranium in Soils Integrated Demonstration of the Office of Technology Development, Office of Environmental Restoration and Waste Management of the US Department of Energy. X-ray absorption, optical luminescence, and Raman vibrational spectroscopies were used to determine uranium speciation in contaminated soils from the US DOE's former uranium production facility at Fernald, Ohio. These analyses were carried out both before and after application of one of the various decontamination technologies being developed within the Integrated Demonstration. This year the program focused on characterization of the uranium speciation remaining in the soils after decontamination treatment. X-ray absorption and optical luminescence spectroscopic data were collected for approximately 40 Fernald soil samples, which were treated by one or more of the decontamination technologies

  5. Speciation of Fe in ambient aerosol and cloudwater

    Energy Technology Data Exchange (ETDEWEB)

    Siefert, Ronald Lyn [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    1996-08-15

    Atmospheric iron (Fe) is thought to play an important role in cloudwater chemistry (e.g., S(IV) oxidation, oxidant production, etc.), and is also an important source of Fe to certain regions of the worlds oceans where Fe is believed to be a rate-limiting nutrient for primary productivity. This thesis focuses on understanding the chemistry, speciation and abundance of Fe in cloudwater and aerosol in the troposphere, through observations of Fe speciation in the cloudwater and aerosol samples collected over the continental United States and the Arabian Sea. Different chemical species of atmospheric Fe were measured in aerosol and cloudwater samples to help assess the role of Fe in cloudwater chemistry.

  6. Pu speciation in actual and simulated aged wastes

    Energy Technology Data Exchange (ETDEWEB)

    Lezama-pacheco, Juan S [Los Alamos National Laboratory; Conradson, Steven D [Los Alamos National Laboratory

    2008-01-01

    X-ray Absorption Fine Structure Spectroscopy (XAFS) at the Pu L{sub II/III} edge was used to determine the speciation of this element in (1) Hanford Z-9 Pu crib samples, (2) deteriorated waste resins from a chloride process ion-exchange purification line, and (3) the sediments from two Waste Isolation Pilot Plant Liter Scale simulant brine systems. The Pu speciation in all of these samples except one is within the range previously displayed by PuO{sub 2+x-2y}(OH){sub y}{center_dot}zH{sub 2}O compounds, which is expected based on the putative thermodynamic stability of this system for Pu equilibrated with excess H{sub 2}O and O{sub 2} under environmental conditions. The primary exception was a near neutral brine experiment that displayed evidence for partial substitution of the normal O-based ligands with Cl{sup -} and a concomitant expansion of the Pu-Pu distance relative to the much more highly ordered Pu near neighbor shell in PuO{sub 2}. However, although the Pu speciation was not necessarily unusual, the Pu chemistry identified via the history of these samples did exhibit unexpected patterns, the most significant of which may be that the presence of the Pu(V)-oxo species may decrease rather than increase the overall solubility of these compounds. Several additional aspects of the Pu speciation have also not been previously observed in laboratory-based samples. The molecular environmental chemistry of Pu is therefore likely to be more complicated than would be predicted based solely on the behavior of PuO{sub 2} under laboratory conditions.

  7. Speciation and gene flow between snails of opposite chirality.

    Directory of Open Access Journals (Sweden)

    Angus Davison

    2005-09-01

    Full Text Available Left-right asymmetry in snails is intriguing because individuals of opposite chirality are either unable to mate or can only mate with difficulty, so could be reproductively isolated from each other. We have therefore investigated chiral evolution in the Japanese land snail genus Euhadra to understand whether changes in chirality have promoted speciation. In particular, we aimed to understand the effect of the maternal inheritance of chirality on reproductive isolation and gene flow. We found that the mitochondrial DNA phylogeny of Euhadra is consistent with a single, relatively ancient evolution of sinistral species and suggests either recent "single-gene speciation" or gene flow between chiral morphs that are unable to mate. To clarify the conditions under which new chiral morphs might evolve and whether single-gene speciation can occur, we developed a mathematical model that is relevant to any maternal-effect gene. The model shows that reproductive character displacement can promote the evolution of new chiral morphs, tending to counteract the positive frequency-dependent selection that would otherwise drive the more common chiral morph to fixation. This therefore suggests a general mechanism as to how chiral variation arises in snails. In populations that contain both chiral morphs, two different situations are then possible. In the first, gene flow is substantial between morphs even without interchiral mating, because of the maternal inheritance of chirality. In the second, reproductive isolation is possible but unstable, and will also lead to gene flow if intrachiral matings occasionally produce offspring with the opposite chirality. Together, the results imply that speciation by chiral reversal is only meaningful in the context of a complex biogeographical process, and so must usually involve other factors. In order to understand the roles of reproductive character displacement and gene flow in the chiral evolution of Euhadra, it will be

  8. SOME SPECIATION STUDIES IN FOODSTUFF BY ATOMIC ABSORPTION SPECTROMETRY

    OpenAIRE

    Gücer, S

    2000-01-01

    There has been increasing interest in speciation studies of essentialelements in foods. The main limitation of this studies, their levels in foodsamples and the difficulties for the determination in their own differentforms without any changes in their original forms.Atomic Absorption Spectrometry (AAS) coupled with separation methodswould be outline in this presentation. Analytical scheme was given for tea, olive and garlic samples forManganese, Magnesium and Selenium respectively. Activated...

  9. Speciation of cadmium mixed ligand complexes in salt water lakes ...

    African Journals Online (AJOL)

    The experimentally determined shifts in half-wave potentials are used to compute several formation constants. At the natural [CO32-] of 0.5 M in the lake, the main contributor to the speciation of cadmium is [Cd(CO3Cl2)]2-. At high [Cd2+], the DPASV detects the presence of free Cd2+ ions, hence, potential polluting effect, ...

  10. Ecologies of Learning, Ecologies of Creativity

    DEFF Research Database (Denmark)

    Høyrup, Helene

    in the light of the new Danish school reform. How can different learning institutions contribute to a “joint” ecology of learning? What would the benefits be from this in terms of young people’s literacies? On what theoretical basis can such an ecology and co-creation take place? And what kind of didactics...

  11. Public meeting

    CERN Multimedia

    HR Department

    2010-01-01

    Dear Colleagues, I am pleased to invite you to a public meeting which will be held on Thursday 11 November 2010 at 2:30 p.m., in the Main Auditorium (welcome coffee from 2 p.m.) In this meeting Sigurd Lettow, Director for Administration and General Infrastructure will present the Management’s proposals towards restoring full funding of the Pension Fund. The meeting will follow discussions which took place with the Staff Association, at the Standing Concertation Committee (CCP) of 1 November 2010 and will be held with the Members States, at the Tripartite Employment Conditions Forum (TREF) of 4 November 2010. You will be able to attend this presentation in the Main Auditorium or via the webcast. The Management will also be available to reply to your questions on this subject. Best regards, Anne-Sylvie Catherin

  12. ACCU Meeting

    CERN Multimedia

    PH Department

    2010-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 December 2010 at 9:15 a.m. in room 60-6-002 Chairperson's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on services from GS department The CERN Ombuds The new account management system Crèche progress + Restaurants Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Chairperson in writing or by e-mail to Michael.Hauschild@cern.ch   Michael Hauschild (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): ...

  13. ACCU Meeting

    CERN Multimedia

    PH Department

    2011-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 March 2011 At 9:15 a.m. in room 60-6-002   Chairperson's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on services from GS department Update on Safety at CERN The new account management system Users’ Office news Any Other Business Agenda for the next meeting   Anyone wishing to raise any points under item 10 is invited to send them to the Chairperson in writing or by e-mail to Michael.Hauschild@cern.ch Michael Hauschild (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria G. Walzel (76592) Belgium ...

  14. ACCU MEETING

    CERN Multimedia

    PH Department

    2010-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 September 2010 at 9:15 a.m. in Room 60-6-002 Chairperson’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on services from GS Department An update on Safety at CERN The CERN Summer Student program Bringing Library services to users Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Chairperson in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): ...

  15. ACCU Meeting

    CERN Multimedia

    PH Department

    2010-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 June 2010 At 9:15 a.m. in room 60-6-002 Chairperson’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on services from GS department CERN Global Network An update on Safety at CERN Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairperson in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria G. Walzel (76592) ...

  16. Speciation, in the nuclear fuel cycle by spectroscopic techniques

    International Nuclear Information System (INIS)

    Colette, S.; Plancque, G.; Allain, F.; Lamouroux, C.; Steiner, V.; Amekraz, B.; Moulin, C.

    2000-01-01

    New analytical techniques allowing to perform speciation in the framework of the nuclear fuel cycle are more and more needed. They have to be selective (since matrix encountered are very complex), sensitive (in order to work at representative concentration and below solubility limit), as well as non intrusive (in order to keep the image of the real solution). Among them, laser-based analytical techniques present these advantages together with the possibility to perform remote measurements via fiber optics. Hence, Time-Resolved Laser-Induced Fluorescence (TRLIF) has been used for actinides/lanthanides interaction and speciation studies in inorganic and organic matrices from the reprocessing to waste storage. Moreover, new ion detection methods such as Electro-Spray - Mass Spectrometry (ES-MS) seems promising for speciation studies. Hence, it is the first time that it is possible to directly couple a liquid at atmospheric pressure to a mass detection working at reduced pressure with a soft mode of ionisation that should allow to give informations on chemical species present. Principle, advantages and limitations as well as results obtained with the use of TRLIF and ES-MS on different systems of interest including actinides, lanthanides, fission products in interaction with simple organic molecules to very complex structure will be presented and discussed. (authors)

  17. Speciation, in the nuclear fuel cycle by spectroscopic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Colette, S.; Plancque, G.; Allain, F.; Lamouroux, C.; Steiner, V.; Amekraz, B.; Moulin, C. [CEA/Saclay, Dept, des Procedes d' Enrichissement (DPE), 91 - Gif-sur-Yvette (France)

    2000-07-01

    New analytical techniques allowing to perform speciation in the framework of the nuclear fuel cycle are more and more needed. They have to be selective (since matrix encountered are very complex), sensitive (in order to work at representative concentration and below solubility limit), as well as non intrusive (in order to keep the image of the real solution). Among them, laser-based analytical techniques present these advantages together with the possibility to perform remote measurements via fiber optics. Hence, Time-Resolved Laser-Induced Fluorescence (TRLIF) has been used for actinides/lanthanides interaction and speciation studies in inorganic and organic matrices from the reprocessing to waste storage. Moreover, new ion detection methods such as Electro-Spray - Mass Spectrometry (ES-MS) seems promising for speciation studies. Hence, it is the first time that it is possible to directly couple a liquid at atmospheric pressure to a mass detection working at reduced pressure with a soft mode of ionisation that should allow to give informations on chemical species present. Principle, advantages and limitations as well as results obtained with the use of TRLIF and ES-MS on different systems of interest including actinides, lanthanides, fission products in interaction with simple organic molecules to very complex structure will be presented and discussed. (authors)

  18. Metal accumulation by stream bryophytes, related to chemical speciation

    Energy Technology Data Exchange (ETDEWEB)

    Tipping, E. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)], E-mail: et@ceh.ac.uk; Vincent, C.D.; Lawlor, A.J.; Lofts, S. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)

    2008-12-15

    Metal accumulation by aquatic bryophytes was investigated using data for headwater streams of differing chemistry. The Windermere Humic Aqueous Model (WHAM) was applied to calculate chemical speciation, including competitive proton and metal interactions with external binding sites on the plants. The speciation modelling approach gives smaller deviations between observed and predicted bryophyte contents of Cu, Zn, Cd and Pb than regressions based on total filtered metal concentrations. If all four metals, and Ni, are considered together, the WHAM predictions are superior at the 1% level. Optimised constants for bryophyte binding by the trace metals are similar to those for humic substances and simple carboxylate ligands. Bryophyte contents of Na, Mg and Ca are approximately explained by binding at external sites, while most of the K is intracellular. Oxide phases account for some of the Al, and most of the Mn, Fe and Co. - Speciation modelling can be used to interpret the accumulation of Ni, Cu, Zn, Cd and Pb by bryophytes, supporting its use to quantify trace metal bioavailability in the field.

  19. Staff meeting

    CERN Document Server

    2006-01-01

    I would like to invite all members of the CERN Personnel to a meeting on Thursday 18 January 2007 at 3:00 p.m. Main Auditorium (bldg.. 500) to convey my best wishes for the new year, to review CERN's activities during 2006 and to present the perspectives for this special year of the LHC start-up. Closed-circuit transmission of the meeting will be available in the Council Chamber and in the AB Auditorium (Meyrin), the AB Auditorium (Prévessin), the IT Auditorium (bldg.. 31) and the AT Auditorium (bldg.. 30). Simultaneous translation into English will be available in the main Auditorium. Robert AYMAR

  20. Scientific meetings

    International Nuclear Information System (INIS)

    1973-01-01

    One of the main aims of the IAEA is to foster the exchange of scientific and technical information and one of the main ways of doing this is to convene international scientific meetings. They range from large international conferences bringing together several hundred scientists, smaller symposia attended by an average of 150 to 250 participants and seminars designed to instruct rather than inform, to smaller panels and study groups of 10 to 30 experts brought together to advise on a particular programme or to develop a set of regulations. The topics of these meetings cover every part of the Agency's activities and form a backbone of many of its programmes. (author)

  1. STAFF MEETING

    CERN Multimedia

    Robert Aymar

    2005-01-01

    I would like to invite all members of the CERN Personnel to a meeting on Thursday 12 January 2006 at 4:00 p.m. - Main Auditorium (bldg. 500) to convey my best wishes for the new year, to review CERN's activities during 2005 and to present the perspectives for this coming year. Closed-circuit transmission of the meeting will be available in the Council Chamber and in the AB Auditorium (Meyrin), the AB Auditorium (Prévessin), the IT Auditorium (bldg. 31) and the AT Auditorium (bldg. 30). A simultaneous translation into English will be available in the main Auditorium. Best wishes for the festive season Robert AYMAR

  2. STAFF MEETING

    CERN Multimedia

    2004-01-01

    I would like to invite all members of the CERN Personnel to a meeting on Tuesday 13 January 2004 at 4:00 p.m. - Main Auditorium (bldg. 500) to convey my best wishes for the new year and to present a perspective of CERN's future activities. Closed-circuit transmission of the meeting will be available in the Council Chamber and in the AB Auditorium (Meyrin), the AB Auditorium (Prévessin), the IT Auditorium (bldg. 31) and the AT Auditorium (bldg. 30). A simultaneous translation into English will be available in the main Auditorium. Robert AYMAR

  3. Public meetings

    CERN Multimedia

    Staff Association

    2014-01-01

      Public meetings : Come and talk about your future employment conditions !   The Staff Association will come and present the results of our survey on the 2015 five-yearly review. Following the survey, the topics discussed, will be contract policy, recognition of merit (MARS), working time arrangements and family policy. After each meeting and around a cup of coffee or tea you will be able to continue the discussions. Do not hesitate to join us, the five-yearly review, it is with YOU!

  4. Introduction. Antarctic ecology: from genes to ecosystems. Part 2. Evolution, diversity and functional ecology.

    Science.gov (United States)

    Rogers, Alex D; Murphy, Eugene J; Johnston, Nadine M; Clarke, Andrew

    2007-12-29

    The Antarctic biota has evolved over the last 100 million years in increasingly isolated and cold conditions. As a result, Antarctic species, from micro-organisms to vertebrates, have adapted to life at extremely low temperatures, including changes in the genome, physiology and ecological traits such as life history. Coupled with cycles of glaciation that have promoted speciation in the Antarctic, this has led to a unique biota in terms of biogeography, patterns of species distribution and endemism. Specialization in the Antarctic biota has led to trade-offs in many ecologically important functions and Antarctic species may have a limited capacity to adapt to present climate change. These include the direct effects of changes in environmental parameters and indirect effects of increased competition and predation resulting from altered life histories of Antarctic species and the impacts of invasive species. Ultimately, climate change may alter the responses of Antarctic ecosystems to harvesting from humans. The unique adaptations of Antarctic species mean that they provide unique models of molecular evolution in natural populations. The simplicity of Antarctic communities, especially from terrestrial systems, makes them ideal to investigate the ecological implications of climate change, which are difficult to identify in more complex systems.

  5. Health and ecological implications of radioactively contaminated environments

    International Nuclear Information System (INIS)

    Weinberg, A.

    1991-01-01

    This paper summarizes the 26th Annual Meeting of NCRP, which entails a strictly scientific meeting dealing with sources, doses, and derived health and ecological effects; and second, a quite different meeting that dealt with remedial measures. These measures, as many of the speakers suggested, often have little to do with human health, as revealed by scientific findings, but have much to do with the way a liberal democracy responds to technological hazard in this Age of Anxiety

  6. Taoism and Deep Ecology.

    Science.gov (United States)

    Sylvan, Richard; Bennett, David

    1988-01-01

    Contrasted are the philosophies of Deep Ecology and ancient Chinese. Discusses the cosmology, morality, lifestyle, views of power, politics, and environmental philosophies of each. Concludes that Deep Ecology could gain much from Taoism. (CW)

  7. Information Assurance Cyber Ecology

    National Research Council Canada - National Science Library

    Jorgensen, Jane

    2003-01-01

    .... The goals of the Cyber Ecology project were to: (1) enable and demonstrate the discovery of noel IA technologies for the detection and mitigation of damage due to cyber attack through the application of ecological models, (2...

  8. Forest Fire Ecology.

    Science.gov (United States)

    Zucca, Carol; And Others

    1995-01-01

    Presents a model that integrates high school science with the needs of the local scientific community. Describes how a high school ecology class conducted scientific research in fire ecology that benefited the students and a state park forest ecologist. (MKR)

  9. Microbial Interactions and the Ecology and Evolution of Hawaiian Drosophilidae

    Directory of Open Access Journals (Sweden)

    Timothy eO'Connor

    2014-12-01

    Full Text Available Adaptive radiations are characterized by an increased rate of speciation and expanded range of habitats and ecological niches exploited by those species. The Hawaiian Drosophilidae is a classic adaptive radiation; a single ancestral species colonized Hawaii approximately 25 million years ago and gave rise to two monophyletic lineages, the Hawaiian Drosophila and the genus Scaptomyza. The Hawaiian Drosophila are largely saprophagous and rely on approximately 40 endemic plant families and their associated microbes to complete development. Scaptomyza are even more diverse in host breadth. While many species of Scaptomyza utilize decomposing plant substrates, some species have evolved to become herbivores, parasites on spider egg masses, and exploit microbes on living plant tissue. Understanding the origin of the ecological diversity encompassed by these nearly 700 described species has been a challenge. The central role of microbes in drosophilid ecology suggests bacterial and fungal associates may have played a role in the diversification of the Hawaiian Drosophilidae. Here we synthesize recent ecological and microbial community data from the Hawaiian Drosophilidae to examine the forces that may have led to this adaptive radiation. We propose that the evolutionary success of the Hawaiian Drosophilidae is due to a combination of factors, including adaptation to novel ecological niches facilitated by microbes.

  10. Quantification of ecological debt

    International Nuclear Information System (INIS)

    Martinez Alier, Joan

    2005-01-01

    The discussion about ecological debt is important keeping in mind historical foreign trade, where natural resources exploitation and primary production exported didn't assessment the ecological damage or the environmental values of the interchange. This essay shows the debate of ecological debt on greenhouse emission, enterprise environmental debit, unequal international trade, toxic waste export, and b io piracy ; in order to present the necessity of a new ecological and equitable world economy

  11. Atmospheric speciation of mercury in two contrasting Southeastern US airsheds

    Science.gov (United States)

    Gabriel, Mark C.; Williamson, Derek G.; Brooks, Steve; Lindberg, Steve

    Simultaneous measurement of gaseous elemental, reactive gaseous, and fine particulate mercury took place in Tuscaloosa AL, (urban airshed) and Cove Mountain, TN (non-urban airshed) during the summers of 2002 and 2003. The objective of this research was to (1) summarize the temporal distribution of each mercury specie at each site and compare to other speciation data sets developed by other researchers and (2) provide insight into urban and non-urban mercury speciation effects using various statistical methods. Average specie concentrations were as follows: 4.05 ng m -3 (GEM), 13.6 pg m -3 (RGM), 16.4 pg m -3 (Hg-p) for Tuscaloosa; 3.20 ng m -3 (GEM), 13.6 pg m -3 (RGM), 9.73 pg m -3 (Hg-p) for Cove Mountain. As a result of urban airshed impacts, short periods of high concentration for all mercury species was common in Tuscaloosa. At Cove Mountain a consistent mid-day rise and evening drop for mercury species was found. This pattern was primarily the result of un-impacted physical boundary layer movement, although, other potential impacts were ambient photochemistry and air-surface exchange of mercury. Meteorological parameters that are known to heavily impact mercury speciation were similar for the study period for Tuscaloosa and Cove Mountain except for wind speed (m s -1), which was higher at Cove Mountain. For both sites statistically significant ( p<0.0001), inverse relationships existed between wind speed and Hg 0 concentration. A weaker windspeed-Hg 0 correlation existed for Tuscaloosa. By analyzing Hg concentration—wind speed magnitude change at both sites it was found that wind speed at Cove Mountain had a greater influence on Hg 0 concentration variability than Tuscaloosa by a factor of 3. Using various statistical tests, we concluded that the nature of Tuscaloosa's atmospheric mercury speciation was the result of typical urban airshed impacts. Cove Mountain showed atmospheric mercury speciation characteristics indicative of a non-urban area along with

  12. Crisis meeting

    CERN Multimedia

    Staff Association

    2014-01-01

      To all CERN staff: your rights are at risk ! We invite you to come to a crisis meeting on Wednesday 2nd April at 10:30 a.m., Auditorium, Main Building, Meyrin site. Your presence is crucial, we are ALL concerned !

  13. Crisis meeting

    CERN Multimedia

    Staff Association

    2015-01-01

    To all CERN staff: your rights are at risk! We invite you to come to a crisis meeting on Thursday 7th May 2015 at 9 a.m., Auditorium, Main Building, Meyrin site. Your presence is crucial, we are ALL concerned!

  14. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2002-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 4 December 2002 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Fellows, Associates and Summer Student Programmes Particle Data Book distribution Revoking Computer accounts Equipment insurance on site Reports from ACCU representatives on other committees Users' Office news Any Other Business Dates for meetings in 2003 Agenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch   ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (74837...

  15. ACCU MEETING

    CERN Multimedia

    Chris Onions (Secretary)

    2001-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 5 December 2001 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 2. Adoption of the agenda 3. Minutes of the previous meeting 4. Matters arising 5. News from the CERN Management 6. Housing 7. Restaurant Surveillance Committee 8. Users' Office news 9. Election of ACCU chairman 10. Any Other Business 11. Dates for meetings in 2002 12. Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria  W. Adam  (71661) Belgium  G. Wilquet  (74664) Bulgaria  R. Tzenov  (77958) Czech Republic  P. Závada&am...

  16. ACCU MEETING

    CERN Multimedia

    Chris Onions (Secretary)

    2001-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 5 December 2001 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 2. Adoption of the agenda 3. Minutes of the previous meeting 4. Matters arising 5. News from the CERN Management 6. Housing 7. Restaurant Surveillance Committee 8. Users' Office news 9. Election of ACCU chairman 10. Any Other Business 11. Dates for meetings in 2002 12. Agenda for the next meetingAnyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland A. Kiiskinen (79387) Fr...

  17. ACCU MEETING

    CERN Multimedia

    2000-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 December 2000 At 10 a.m. in the 6th floor Conference Room, Main Building Chairman's remarks Adoption of the agenda News from the CERN Management Minutes of the previous meeting Matters arising Equal Opportunities at CERN The Summer Student programme CERN Programme for Physics High School Teachers Users' Office News Any Other Business Dates for Meetings in 2001 Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets) :   Austria G. Neuhofer (74094) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958)...

  18. ACCU MEETING

    CERN Multimedia

    Chris Onions (Secretary)

    2000-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 December 2000 At 10 a.m. in the 6th floor Conference Room, Main Building Chairman's remarks Adoption of the agenda News from the CERN Management Minutes of the previous meeting Matters arising Equal Opportunities at CERN The Summer Student programme CERN Programme for Physics High School Teachers Users' Office News Any Other Business Dates for Meetings in 2001 Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets) : Austria G. Neuhofer (74094) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Re...

  19. ACCU Meeting

    CERN Multimedia

    PH Department

    2011-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 15 June 2011 At 9:15 a.m. in room 60-6-002 Chairperson’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on services from GS department Update on Safety at CERN Reports from ACCU representatives on other Committees a. Scientific Information Policy Board (SIPB) b. IT Service Review Meeting (ITSRM) c. GS User Commission Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairperson in writing or by e-mail to Michael.Hauschild@cern.ch Michael Hauschild (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in bra...

  20. Ecological restoration [book review

    Science.gov (United States)

    Eric J. Gustafson

    2010-01-01

    Ecological restoration has increased in prominence in recent years as environmental policies have slowed the rate of environmental degradation in many parts of the world and practitioners have looked for active ways to reverse the damage. Because of the vast number of types and contexts of degraded ecological systems, the field of ecological restoration is still very...

  1. The importance of element speciation in water analysis - a plea for further investigations

    International Nuclear Information System (INIS)

    Frimmel, F.H.; Gremm, T.

    1994-01-01

    Water analysis is dominated by parameters given in laws and recommendations concerning water quality. Speciation has been broadly neglected. This might be due to the difficulties in defining speciation and in determining species at low concentrations. This paper addresses the physical, chemical and biological approaches to speciation and gives examples for methods which are suited for species determination in aquatic systems. Metals and non-metallic elements are covered as well. It is obvious that speciation is a key for understanding the function of aquatic ecosystems and their technical utilization. (orig.)

  2. The Secondary Contact Zone of Phylogenetic Lineages of the Philaenus spumarius (Hemiptera: Aphrophoridae): An Example of Incomplete Allopatric Speciation

    Science.gov (United States)

    Lis, Agata; Maryańska-Nadachowska, Anna; Lachowska-Cierlik, Dorota; Kajtoch, Łukasz

    2014-01-01

    Abstract Previous studies on the phylogeography of the meadow spittlebug Philaenus spumarius (L.) (Hemiptera: Aphrophoridae) suggest the existence of a contact zone of its main phylogenetic lineages along mountain chains in Europe and western Asia. This study presents a detailed examination of the population genetics of P. spumarius within the Carpathian Mountains. The main objective was to determine whether the populations inhabiting that area consist of individuals belonging to different genetic units and whether the observed pattern could be an example of secondary contact zone which formed after incomplete allopatric speciation. Specimens from six transects across the Carpathian arc were examined. The mitochondrial phylogeography of the meadow spittlebug in the examined area clearly shows that individuals from both main clades meet and mix there. Representatives of all three main EF1-α clades were also found. The present distribution of the main clades with a zone of overlap along the mountain ranges may suggest that these phylogenetic lineages form a young hybrid zone. Moreover, a limited number of individuals were shown to possess heteroplasmic mitochondrial DNA, which gives additional support to intraspecific hybridization. P. spumarius could be used in future work as an excellent model species in investigating population genetics, intraspecific hybridization, and speciation in progress. PMID:25500280

  3. The secondary contact zone of phylogenetic lineages of the Philaenus spumarius (Hemiptera: Aphrophoridae): an example of incomplete allopatric speciation.

    Science.gov (United States)

    Lis, Agata; Maryańska-Nadachowska, Anna; Lachowska-Cierlik, Dorota; Kajtoch, Lukasz

    2014-01-01

    Previous studies on the phylogeography of the meadow spittlebug Philaenus spumarius (L.) (Hemiptera: Aphrophoridae) suggest the existence of a contact zone of its main phylogenetic lineages along mountain chains in Europe and western Asia. This study presents a detailed examination of the population genetics of P. spumarius within the Carpathian Mountains. The main objective was to determine whether the populations inhabiting that area consist of individuals belonging to different genetic units and whether the observed pattern could be an example of secondary contact zone which formed after incomplete allopatric speciation. Specimens from six transects across the Carpathian arc were examined. The mitochondrial phylogeography of the meadow spittlebug in the examined area clearly shows that individuals from both main clades meet and mix there. Representatives of all three main EF1-α clades were also found. The present distribution of the main clades with a zone of overlap along the mountain ranges may suggest that these phylogenetic lineages form a young hybrid zone. Moreover, a limited number of individuals were shown to possess heteroplasmic mitochondrial DNA, which gives additional support to intraspecific hybridization. P. spumarius could be used in future work as an excellent model species in investigating population genetics, intraspecific hybridization, and speciation in progress. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  4. The secondary contact zone of phylogenetic lineages of the Philaenus spumarius (Hemiptera: Aphrophoridae: Cercopidae): an example of incomplete allopatric speciation.

    Science.gov (United States)

    Lis, Agata; Maryańska-Nadachowska, Anna; Lachowska-Cierlik, Dorota; Kajtoch, Łukasz

    2014-01-01

    Previous studies on the phylogeography of the meadow spittlebug Philaenus spumarius (L.) (Hemiptera: Aphrophoridae: Cercopidae) suggest the existence of a contact zone of its main phylogenetic lineages along mountain chains in Europe and western Asia. This study presents a detailed examination of the population genetics of P. spumarius within the Carpathian Mountains. The main objective was to determine whether the populations inhabiting that area consist of individuals belonging to different genetic units and whether the observed pattern could be an example of secondary contact zone which formed after incomplete allopatric speciation. Specimens from six transects across the Carpathian arc were examined. The mitochondrial phylogeography of the meadow spittlebug in the examined area clearly shows that individuals from both main clades meet and mix there. Representatives of all three main EF1-α clades were also found. The present distribution of the main clades with a zone of overlap along the mountain ranges may suggest that these phylogenetic lineages form a young hybrid zone. Moreover, a limited number of individuals were shown to possess heteroplasmic mitochondrial DNA, which gives additional support to intraspecific hybridization. P. spumarius could be used in future work as an excellent model species in investigating population genetics, intraspecific hybridization, and speciation in progress. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  5. Philosophy of ecology

    CERN Document Server

    Brown, Bryson; Peacock, Kent A

    2011-01-01

    The most pressing problems facing humanity today - over-population, energy shortages, climate change, soil erosion, species extinctions, the risk of epidemic disease, the threat of warfare that could destroy all the hard-won gains of civilization, and even the recent fibrillations of the stock market - are all ecological or have a large ecological component. in this volume philosophers turn their attention to understanding the science of ecology and its huge implications for the human project. To get the application of ecology to policy or other practical concerns right, humanity needs a clear and disinterested philosophical understanding of ecology which can help identify the practical lessons of science. Conversely, the urgent practical demands humanity faces today cannot help but direct scientific and philosophical investigation toward the basis of those ecological challenges that threaten human survival. This book will help to fuel the timely renaissance of interest in philosophy of ecology that is now oc...

  6. Public meetings

    CERN Multimedia

    Staff Association

    2012-01-01

    MARS PENSIONS CONTRACT POLICY GENERAL INFORMATION   PUBLIC MEETINGS COME AND BE INFORMED! Public meetings Monday 15 Oct. 2 pm Amphi IT, 31-3-004 Meyrin Wednesday 17 Oct. 10 am Amphi BE, 864-1-D02 Prévessin Thursday 18 Oct. 10 am Salle du Conseil/ Council Chamber 503-1-001 Meyrin Thursday 18 Oct. 2 pm Filtration Plant, 222-R-001(in English) Meyrin   Overview of the topics to be discussed Recognition of Merit – MARS Outcome of last exercise 2007 to 2012 : lessons learned Pension Fund Capital preservation policy : what is it ? Contract policy LC2IC statistics SA proposal General information CVI 2013 Voluntary programmes (PRP, SLS)  

  7. Staff meeting

    CERN Multimedia

    2007-01-01

    I would like to invite all members of the CERN Personnel to a meeting on Wednesday 16 January 2008 at 3:00 p.m. Main Auditorium (bldg 500) to convey my best wishes for the new year, to review CERN’s activities during 2007 and to present the perspectives for 2008, the year of the LHC start-up. Closed-circuit transmission of the meeting will be available in the Council Chamber and in the AB Auditorium (Meyrin), the AB Auditorium (Prévessin), the IT Auditorium (Bldg. 31) and the AT Auditorium (Bldg. 30). Simultaneous translation into English will be available in the main Auditorium. Best wishes for the festive season! Robert AYMAR

  8. Distribution, speciation, environmental risk, and source identification of heavy metals in surface sediments from the karst aquatic environment of the Lijiang River, Southwest China.

    Science.gov (United States)

    Xu, Daoquan; Wang, Yinghui; Zhang, Ruijie; Guo, Jing; Zhang, Wei; Yu, Kefu

    2016-05-01

    The distribution and speciation of several heavy metals, i.e., As, Cd, Cr, Cu, Hg, Pb, and Zn, in surface sediments from the karst aquatic environment of the Lijiang River, Southwest China, were studied comparatively. The mean contents of Cd, Cu, Hg, Pb, and Zn were 1.72, 38.07, 0.18, 51.54, and 142.16 mg/kg, respectively, which were about 1.5-6 times higher than their corresponding regional sediment background values. Metal speciation obtained by the optimized BCR protocol highlighted the bioavailable threats of Cd, Cu, and Zn, which were highly associated with the exchangeable fraction (the labile phase). Hierarchical cluster analysis indicated that in sediments, As and Cr were mainly derived from natural and industrial sources, whereas fertilizer application might lead to the elevated level of Cd. Besides, Cu, Hg, Pb, and Zn were related to traffic activities. The effects-based sediment quality guidelines (SQGs) showed that Hg, Pb, and Zn could pose occasional adverse effects on sediment-dwelling organisms. However, based on the potential ecological risk assessment (PER) and risk assessment code (RAC), Cd was the most outstanding pollutant and posed the highest ecological hazard and bioavailable risk among the selected metals. Moreover, the metal partitioning between water and sediments was quantified through the calculation of the pseudo-partitioning coefficient (K P), and result implied that the sediments in this karst aquatic environment cannot be used as stable repositories for the metal pollutants.

  9. Meeting information

    Science.gov (United States)

    The 1986 Ocean Sciences Meeting of the American Geophysical Union and the American Society of Limnology and Oceanography (ASLO) will be held January 13-17, 1986, in New Orleans, La., at the Fairmont Hotel. Co-sponsoring societies are the Acoustical Society of America (ASA), the American Meteorological Society (AMS), the Marine Technology Society (MTS), and the Institute of Electrical and Electronics Engineers, Oceanic Engineering Society (OES).

  10. ACCU Meeting

    CERN Multimedia

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 March 2004 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 6. The PH Department 2. Adoption of the agenda 7. Reports from ACCU representatives on other committees 3. Minutes of the previous meeting 8. Users' Office news 4. News from the CERN Management 9. Any Other Business 5. Matters arising 10. Agenda for the next meeting Anyone wishing to raise any points under item 9 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Norway H. Helstrup (73601) Belgium G. Wilquet (74664) Poland Z. Hajduk (75917) Bulgaria R. Tsenov (79573) Portugal P. Bordalo (74704) Czech Republic P. Závada ...

  11. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 March 2004 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting News from the CERN Management Matters arising The PH Department Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 9 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark P. Hansen (75941) Finland E. Tuominen (71534) France F. Bauer (71247) L. Serin...

  12. ACCU MEETING

    CERN Multimedia

    Chris Onions/EP (Secretary)

    2001-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 June 2001 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda News from the CERN Management Minutes of the previous meeting Matters arising EP Space management Cars Housing EDH from the User's point of view VRVS Users' Office News Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland A. Kiiskinen (79387) France M. Déj...

  13. ACCU Meeting

    CERN Document Server

    Chris Onions

    2006-01-01

    DRAFT Agenda of the meeting to be held on Wednesday 8 March 2006 At 9:15 a.m. in Room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Proposal for a centralised access control service Report from PH Space Management Policy Board Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under Item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives on ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) ...

  14. ACCU MEETING

    CERN Document Server

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 5 December 2007 at 9:15 a.m. in room 60-6-002 1.\tChairman’s remarks7.\tEmergency Services at CERN 2.\tAdoption of the agenda\t8.\tThe Meyrin Tram project 3.\tMinutes of the previous meeting9.\tReports from ACCU representatives on other committees 4.\tMatters arising10.\tUsers’ Office news 5.\tNews from the CERN Management11.\tElection of ACCU Chair 6. LHC 2008 start-up events 6.\tLogistics and transport at CERN 12.\tAny Other Business 13.\tAgenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Aust...

  15. ACCU MEETING

    CERN Multimedia

    PH Department

    2008-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 11 June 2008 At 9:15 a.m. in Room 60-6-002 1.\tChairman’s remarks 2.\tAdoption of the agenda 3.\tMinutes of the previous meeting 4.\tMatters arising 5.\tNews from the CERN Management 6.\tAn update on safety at CERN 7.\tChildcare initiative 8.\tReports from ACCU representatives on other committees 9.\tUsers’ Office news 10.\tAny Other Business 11.\tAgenda for the next meeting Anyone wishing to raise any points under Item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium C. Vander Velde (71539) Bulgaria Czech Republic P. Závada (75...

  16. ACCU meeting

    CERN Document Server

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 5 December 2007 At 9:15 a.m. in room 60-6-002 1.\tChairman’s remarks 2.\tAdoption of the agenda 3.\tMinutes of the previous meeting 4.\tMatters arising 5.\tNews from the CERN Management 6.\tLHC 2008 start-up events 7.\tEmergency Services at CERN 8.\tThe Meyrin Tram project 9.\tReports from ACCU representatives on other committees 10.\tUsers’ Office news 11.\tElection of ACCU Chair 12.\tAny Other Business 13.\tAgenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilq...

  17. ACCU MEETING

    CERN Document Server

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 June 2004 at 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Update on CERN's 50th anniversary celebrations Report from the EPOG (European Particle Physics Outreach Group) Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark P. Hansen (75941...

  18. ACCU Meeting

    CERN Document Server

    Chris Onions

    2005-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 7 September 2005 At 9:15 a.m. in room 60-6-002 Chairman’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Logistics at CERN Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K. Lassila-Perini (79354) France F. Bauer S. Laplace...

  19. ACCU Meeting

    CERN Document Server

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 September 2004 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management The Visits Service Lifetime of Computer Accounts Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark P. Hansen (75941) Finland K. Lassila-Perini (79354) France F. Bauer (7...

  20. ACCU MEETING

    CERN Document Server

    2006-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 September 2006 at 9:15 a.m. in room 60-6-002 1.     Chairman's remarks 2.     Adoption of the agenda 3.     Minutes of the previous meeting 4.     Matters arising 5.     News from the CERN Management 6.     Report on Fellows and Associates programme 7.     Overview of safety at CERN 8.     Reports from ACCU representatives on other committees 9.     Users' Office news 10.  Any Other Business 11.  Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets):Austria W. Adam  (71661) Belgium G. Wilquet (74664) Bulgaria ...

  1. ACCU Meeting

    CERN Document Server

    Chris Onions

    2005-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 7 December 2005 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Closure of computer accounts upon CERN contract expiry Reports from ACCU representatives on other committees Users' Office news Election of ACCU Chair Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets). Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) ...

  2. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2005-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 June 2005 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Logistics at CERN Open Access Publishing Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K. Lassila-Perini ...

  3. ACCU Meeting

    CERN Document Server

    Chris Onions

    2006-01-01

    DRAFT Agendafor the meeting to be held on Wednesday 8 March 2006At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Proposal for a centralised access control service Report from PH Space Management Policy Board Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Fin...

  4. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2005-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 March 2005 At 9:15 a.m. in room 160-1-009 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Purchasing procedures at CERN Reports from ACCU representatives on other committees Users' Office news CERN Clubs Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K. Las...

  5. ACCU MEETING

    CERN Document Server

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 12 September 2007 at 9:15 a.m. in room 60-6-002 1.\tChairman’s remarks7.\tCar sharing pilot project 2.\tAdoption of the agenda\t8.\tReports from ACCU representatives on other committees 3.\tMinutes of the previous meeting9.\tUsers’ Office newss 4.\tMatters arising10.\tAny Other Business 5.\tNews from the CERN Management11.\tAgenda for the next meeting 6.\tLogistics and transport at CERN Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria\tW. Adam (71661)NorwayG. Løvhøiden (73176)Belgium\tG. Wilquet (74664)PolandM. Witek (78967)...

  6. ACCU MEETING

    CERN Multimedia

    PH Department

    2008-01-01

    DRAFT Agenda for the meeting to be heldon Wednesday 5 March 2008 At 9:15 a.m. in room 60-6-002 Chairman’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management An update on Safety at CERN The CERN Ombudsperson proposal Childcare initiative Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to mailto:Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) BelgiumnC. Vander Velde (71539) Bulgaria Czech Republic P. Závada (75877) Denm...

  7. ACCU MEETING

    CERN Document Server

    2006-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 December 2006 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Safety at CERN Car sharing pilot project CERN Public Web Sites and Intranet Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria   Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finl...

  8. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 December 2004 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting The effects of the reorganization of CERN's structure, one year on Matters arising News from the CERN Management Computer Security The new CERN Dosimeter Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark P. Hansen (7594...

  9. ACCU MEETING

    CERN Multimedia

    2006-01-01

    DRAFT Agenda of the meeting to be held on Wednesday 6 September 2006 at 9:15 a.m. in Room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on Fellows and Associates Programme Overview of safety at CERN Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under Item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K....

  10. ACCU meeting

    CERN Document Server

    PH Department

    2008-01-01

    DRAFT Agenda for the meeting to be heldon Wednesday 5 March 2008 At 9:15 a.m. in room 60-6-002 Chairman’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management An update on Safety at CERN The CERN Ombudsperson proposal Childcare initiative Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to mailto:Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) BelgiumnC. Vander Velde (71539) Bulgaria Czech Republic P. Závada (75877) Denm...

  11. ACCU MEETING

    CERN Document Server

    PH Department

    2008-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 September 2008 At 9:15 a.m. in Room 60-6-002 Chairman’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management An update on Safety at CERN Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 9 is invited to send them to the Chairman in writing or by e-mail to mailto:Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria, W. Adam (71661) Belgium, C. Vander Velde (71539) Bulgaria Czech Republic, P. Závada (75877) Denmark, J.B. Hansen (...

  12. ACCU MEETING

    CERN Document Server

    Chris Onions

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 13 June 2007 at 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Dosimetry at CERN Status of collaborative tools at CERN Reports from ACCU representatives on other committees Users' Office newss Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K. Lassila-Perini (7935...

  13. ACCU Meeting

    CERN Document Server

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 7 March 2007 at 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Car-sharing pilot project Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 9 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K. Lassila-Perini (79354) France F. Kunne S. ...

  14. ACCU MEETING

    CERN Multimedia

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 13 June 2007 at 9:15 a.m. in room 60-6-002 1.\tChairman’s remarks 6.\tDosimetry at CERN 2.\tAdoption of the agenda 7.\tStatus of collaborative tools at CERN 3.\tMinutes of the previous meeting 8.\tReports from ACCU representatives on other committees 4.\tMatters arising 9.\tUsers’ Office newss 5.\tNews from the CERN Management 10.\tAny Other Business 11.\tAgenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Norway G. Løvhøiden (73176) Belgium G. Wilquet (74664) Poland M. Witek (78967) Bulgaria Portugal...

  15. ACCU Meeting

    CERN Document Server

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 September 2004 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management The Visits Service Lifetime of Computer Accounts Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark P. Hansen (75941) Finland K. Lassila-Perini (79354) France F. Bauer (...

  16. ACCU Meeting

    CERN Multimedia

    2006-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 December 2006 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Safety at CERN Car sharing pilot project CERN Public Web Sites and Intranet Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria   Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finl...

  17. ACCU Meeting

    CERN Multimedia

    PH Department

    2008-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 11 June 2008 At 9:15 a.m. in room 60-6-002 Chairman’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management An update on Safety at CERN Childcare initiative Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to mailto:Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria - W. Adam (71661) Belgium - C. Vander Velde (71539) Bulgaria Czech Republic - P. Závada (75877) Denmark - J.B. Hansen...

  18. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 December 2004 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting The effects of the reorganization of CERN's structure, one year on Matters arising News from the CERN Management Computer Security The new CERN Dosimeter Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark P. Hansen (75941) Finl...

  19. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 June 2004 at 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Update on CERN's 50th anniversary celebrations Report from the EPOG (European Particle Physics Outreach Group) Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark P. Hansen (75941) Finlan...

  20. ACCU MEETING

    CERN Document Server

    PH Department

    2008-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 3 December 2008 at 9:15 a.m. in Room 60-6-002 1.\tChairman’s remarks 2.\tAdoption of the agenda 3.\tMinutes of the previous meeting 4.\tMatters arising 5.\tNews from the CERN Management 6.\tReport from the new Director-General 7.\tReport on the Fellows and Associates programme 8.\tAn update on Safety at CERN 9.\tReports from ACCU representatives on other committees 10.\tUsers’ Office news 11.\tAny Other Business 12.\tAgenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium C. ...

  1. ACCU MEETING

    CERN Document Server

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 12 September 2007 at 9:15 a.m. in room 60-6-002 1.\tChairman’s remarks6.\tLogistics and transport at CERN2.\tAdoption of the agenda\t7.\tCar sharing pilot project3.\tMinutes of the previous meeting8.\tReports from ACCU representatives on other committees4.\tMatters arising9.\tUsers’ Office newss5.\tNews from the CERN Management10.\tAny Other Business11.\tAgenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria\tW. Adam (71661)NorwayG. Løvhøiden (73176)Belgium\tG. Wilquet (74664)PolandM. Witek (78967)Bulgaria\tPortugalP...

  2. ACCU Meeting

    CERN Document Server

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 7 March 2007 at 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Car-sharing pilot project Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 9 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K. Lassila-Perini (79354) France F. Kunne S. La...

  3. ACCU MEETING

    CERN Multimedia

    Chris Onions (Secretary)

    2001-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 June 2001 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda News from the CERN Management Minutes of the previous meeting Matters arising Logistics and Self-service stores EP Space management follow-up How to improve IT User Support? Users' Office News Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Roger.Jones@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland A. Kiis...

  4. ACCU MEETING

    CERN Multimedia

    Chris Onions (Secretary)

    2001-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 12 September 2001 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda News from the CERN Management Minutes of the previous meeting Matters arising Logistics and Self-service stores EP Space management follow-up How to improve IT User Support? Users' Office News Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Roger.Jones@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland A. Kiiskin...

  5. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2001-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 7 March 2001 At 9:15 a.m. in the 6th floor Conference Room, Main Building Chairman's remarks Adoption of the agenda News from the CERN Management Minutes of the previous meeting Matters arising Video-conferencing/recording Fellows programme Operational Circular No. 6 EP Space management Update on Computing Issues Users' Office News Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary)  ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic...

  6. ACCU Meeting

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 September 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 7. Equal Opportunities Commission 2. Adoption of the agenda 8. Registration plans for portables 3. Minutes of the previous meeting 9. Reports from ACCU representatives on other committees 4. Matters arising 10. Users' Office news 5. News from the CERN Management 11. Any Other Business 6. The Press Office 12. Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Norway H. Helstrup (73601) Belgium G. Wilquet (74664) Poland Z. Hajduk (75917) Bulgar...

  7. ACCU MEETING

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 5 March 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 7. Equipment insurance on site 2. Adoption of the agenda,8. ACCU reporting mechanisms in the different countries 3. Minutes of the previous meeting9. Reports from ACCU representatives on other committees 4. Matters arising10. Users' Office news 5. News from the CERN Management11. Any Other Business 6. CHIS news and follow-up of survey12. Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661)NorwayH. Helstrup (73601) Belgium G. Wilquet (74664) Poland Z. Hajduk (7591...

  8. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2002-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 11 September 2002 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Health Insurance Questionnaire Host States Relations Service Update on EP Space management Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland E. Tuominen (71534) France F. Bauer (71247) L. Serin (...

  9. ACCU MEETING

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 December 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 8. Report from IT division on Computing matters 2. Adoption of the agenda 9. Young Particle Physicists Association 3. Minutes of the previous meeting 10. Reports from ACCU representatives on other committees 4. Matters arising 11. Users' Office news 5. News from the CERN Management 12. Election of the ACCU Chair 6. Report from the new Director-General 13. Any Other Business 7. CERN's 50th anniversary 14. Agenda for the next meeting Anyone wishing to raise any points under item 13 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Ada...

  10. ACCU MEETING

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 5 March 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 7. Equipment insurance on site 2. Adoption of the agenda 8. ACCU reporting mechanisms in the different countries 3. Minutes of the previous meeting 9. Reports from ACCU representatives on other committees 4. Matters arising 10. Users' Office news 5. News from the CERN Management 11. Any Other Business 6. Health Insurance news and follow-up of survey 12. Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Norway H. Helstrup (73601) Belgium G. Wil...

  11. ACCU MEETING

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 11 June 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 7. Reports from ACCU representatives 2. Adoption of the agenda on other committees 3. Minutes of the previous meeting 8. Users' Office news 4. Matters arising 9. Any Other Business 5. News from the CERN Management 10. Agenda for the next meeting 6. Property Protection at CERN Anyone wishing to raise any points under item 9 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Norway H. Helstrup (73601) Belgium G. Wilquet (74664) Poland Z. Hajduk (75917) Bulgaria R. Tsenov (74837) Portugal P. Bordalo (74704) Czech Republic ...

  12. ACCU Meeting

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 September 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 8. Registration plans for portables 2. Adoption of the agenda 9. Reports from ACCU representatives 3. Minutes of the previous meeting on other committees 4. Matters arising 10. Users' Office news 5. News from the CERN Management 11. Any Other Business 6. The Press Office 12. Agenda for the next meeting 7. Equal Opportunities Commission Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): AustriaW. Adam (71661) Norway H. Helstrup (73601) Belgium G. Wilquet (74664) Poland Z. Hajduk (75917) Bulgari...

  13. ACCU MEETING

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 December 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 8. Report from IT division on Computing matters 2. Adoption of the agenda 9. Young Particle Physicists Association 3. Minutes of the previous meeting 10. Reports from ACCU representatives on other committees 4. Matters arising 11. Users' Office news 5. News from the CERN Management 12. Election of the ACCU Chair 6. Report from the new Director-General 13. Any Other Business 7. CERN's 50th anniversary 14. Agenda for the next meeting Anyone wishing to raise any points under item 13 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (716...

  14. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2002-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 March 2002 At 9:15 a.m. in the Council Chamber Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Follow-up on Space Management Users' Desktop needs PIE procedures Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland E. Tuominen (71534) France F. Bauer L. Serin (712...

  15. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2002-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 12 June 2002 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management PIE procedures CERN Cars EP Electronics Advisory Board Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch   ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland E. Tuominen (71534) France F. Bauer (71247) L. Serin (71143) Germany H. Kroha...

  16. ACCU MEETING

    CERN Multimedia

    2000-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 13 September 2000 At 10 a.m. in the 6th floor Conference Room, Main Building 1. Chairman's remarks 2. Adoption of the agenda 3. News from the CERN Management 4. Minutes of the previous meeting 5. Matters arising 6. Report from the Scientific Information Policy Board 7. Report from ETT Division: The Press Office 8. Update on Computing Issues 9. Users' Office News 10. Any Other Business 11. Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Bryan Pattison (Secretary). ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets) : Austria G. Neuhofer (74094) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Z vada (75...

  17. ACCU MEETING

    CERN Multimedia

    Bryan Pattison

    2000-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 13 September 2000 At 10 a.m. in the 6th floor Conference Room, Main Building1. Chairman's remarks2. Adoption of the agenda3. News from the CERN Management4. Minutes of the previous meeting5. Matters arising6. Report from the Scientific Information Policy Board7. Report from ETT Division: The Press Office8. Update on Computing Issues9. Users' Office News10. Any Other Business11. Agenda for the next meetingAnyone wishing to raise any points under item 10 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail toBryan Pattison(Secretary).ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets) :Austria G. Neuhofer (74094)Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958)Czech Republic P. Závada (75877)Den...

  18. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2002-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 12 June 2002 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management PIE procedures CERN Cars EP Electronics Advisory Board Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch   ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland E. Tuominen (71534) France F. Bauer (71247) L. Serin (71143) Germany H. Kroha ...

  19. ACCU MEETING

    CERN Multimedia

    PH Department

    2009-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 11 March 2009 At 9:15 a.m. in room 60-6-002 Chairman’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management The CERN Press Office An update on Safety at CERN The Burotel project Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to mailto:Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria G. Walzel () Belgium C. Vander Velde (71539) Bulgaria Czech Republic P. Závada (75877) Denmark...

  20. ACCU MEETING

    CERN Multimedia

    PH Department

    2010-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 March 2010 At 9:15 a.m. in room 60-6-002 Chairperson’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on services from GS department An update on Safety at CERN Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives on ACCU are (CERN internal telephone numbers in brackets): Austria G. Walzel (76592) Belgium C. Vander Velde (Chairperson) (71539) Bulgaria Czech Republic S. Nemecek (71144) ...

  1. ACCU MEETING

    CERN Multimedia

    PH Department

    2011-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 7 September 2011 at 9:15 a.m. in room 60-6-002   Chairperson's remarks Adoption of the agenda      Minutes of the previous meeting Matters arising       News from the CERN Management Report on services from GS department Report on new CHIS rules Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 9 is invited to send them to the Chairperson in writing or by e-mail to Michael.Hauschild@cern.ch Michael Hauschild (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria M. Jeitler (76307) Belgium C. Vander Velde (Chairperson)...

  2. ACCU MEETING

    CERN Multimedia

    PH Department

    2009-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 September 2009 At 9:15 a.m. in room 60-6-002 1.\tChairman’s remarks 2.\tAdoption of the agenda 3.\tMinutes of the previous meeting 4.\tMatters arising 5.\tNews from the CERN Management 6.\tCode of conduct 7.\tEqual Opportunities at CERN 8.\tAn update on safety at CERN 9.\tThe CERN shuttle service 10.\tReports from ACCU representatives on other committees 11.\tUsers’ Office news 12.\tOther business 13.\tAgenda of the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Chairman in writing or by e-mail to mailto:Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives on ACCU are (CERN internal telephone numbers in brackets): Austria G. Walzel (76592) Belgium C. Vander Velde (71539) Bulgaria Czech Re...

  3. ACCU MEETING

    CERN Multimedia

    PH Department

    2009-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 June 2009At 9:15 a.m. in room 60-6-002 Chairman’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management CERN Social Services User services in GS Department An update on Safety at CERN Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to mailto:Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria - G. Walzel (76592) Belgium - C. Vander Velde (71539) Bulgaria Czech Republic - P. Závada (7587...

  4. ACCU Meeting

    CERN Multimedia

    Chris Onions

    DRAFT Agenda for the meeting to be held on Wednesday 9 December 2009 At 9:15 a.m. in Room 60-6-002 Chairman’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Restaurant No. 1 extension An update on Safety at CERN Reports from ACCU representatives on other committees Users’ Office news Election of the ACCU Chair Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria G. Walzel (76592) Belgium C. Vander Velde (71539) Bulgaria Czech Republic P. Záv...

  5. ACCU MEETING

    CERN Multimedia

    PH Department

    2009-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 September 2009 At 9:15 a.m. in room 60-6-002 1.\tChairman’s remarks 2.\tAdoption of the agenda 3.\tMinutes of the previous meeting 4.\tMatters arising 5.\tNews from the CERN Management 6.\tCode of Conduct 7.\tEqual Opportunities at CERN 8.\tAn update on Safety at CERN 9.\tThe CERN shuttle service 10.\tReports from ACCU representatives on other committees 11.\tUsers’ Office news 12.\tAny Other Business 13.\tAgenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Chairman in writing or by e-mail to mailto:Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria G. Walzel (76592) Belgium C. Vander Velde (71539) Bulgaria Cze...

  6. ACCU MEETING

    CERN Multimedia

    PH Department

    2009-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 11 March 2009 At 9:15 a.m. in room 60-6-002 1.\tChairman’s remarks 2.\tAdoption of the agenda 3.\tMinutes of the previous meeting 4.\tMatters arising 5.\tNews from the CERN Management 6.\tThe CERN Press Office 7.\tAn update on Safety at CERN 8.\tThe Burotel project 9.\tReports from ACCU representatives on other committees 10.\tUsers’ Office news 11.\tAny Other Business 12.\tAgenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to mailto:Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria G. Walzel () Belgium C. Vander Velde (71539) Bulgaria C...

  7. ACCU Meeting

    CERN Document Server

    Chris Onions

    2006-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 14 June 2006 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Car sharing pilot project The CERN Document Server : the portal to Open Access Videoconferencing and collaborative tools at CERN Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (7...

  8. ACCU Meeting

    CERN Document Server

    Chris Onions

    2006-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 14 June 2006 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Car sharing pilot project The CERN Document Server : the portal to Open Access Videoconferencing and collaborative tools at CERN Reports from ACCU representatives on other committees Users'Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) ...

  9. Using ecological production functions to link ecological ...

    Science.gov (United States)

    Ecological production functions (EPFs) link ecosystems, stressors, and management actions to ecosystem services (ES) production. Although EPFs are acknowledged as being essential to improve environmental management, their use in ecological risk assessment has received relatively little attention. Ecological production functions may be defined as usable expressions (i.e., models) of the processes by which ecosystems produce ES, often including external influences on those processes. We identify key attributes of EPFs and discuss both actual and idealized examples of their use to inform decision making. Whenever possible, EPFs should estimate final, rather than intermediate, ES. Although various types of EPFs have been developed, we suggest that EPFs are more useful for decision making if they quantify ES outcomes, respond to ecosystem condition, respond to stressor levels or management scenarios, reflect ecological complexity, rely on data with broad coverage, have performed well previously, are practical to use, and are open and transparent. In an example using pesticides, we illustrate how EPFs with these attributes could enable the inclusion of ES in ecological risk assessment. The biggest challenges to ES inclusion are limited data sets that are easily adapted for use in modeling EPFs and generally poor understanding of linkages among ecological components and the processes that ultimately deliver the ES. We conclude by advocating for the incorporation into E

  10. Potential application of SERS for arsenic speciation in biological matrices.

    Science.gov (United States)

    Yang, Mingwei; Matulis, Shannon; Boise, Lawrence H; McGoron, Anthony J; Cai, Yong

    2017-08-01

    Speciation of arsenic is usually carried out using chromatography-based methods coupled with spectroscopic determination; however, the inevitable procedures involving sample preparation and separation could potentially alter the integrity of the arsenic metabolites present in biological samples. Surface-enhanced Raman spectroscopy (SERS) could be a promising alternative for providing a reliable arsenic analysis under the influence of a cellular matrix. A method for arsenic speciation using SERS in cellular matrix was developed in this study and four arsenicals were selected, including arsenite (As III ), arsenate (As V ), monomethylarsonic acid (MMA V ) and dimethylarsinic acid (DMA V ). Silver nanoparticles in the form of colliodal suspension with different surface charges, i.e., coated with citrate (AgNPs-Citrate) and spermine (AgNPs-Spermine) were employed as SERS substrates. Adsorption of arsenicals on nanoparticles in colloidal suspensions and the cellular matrix and the pH, size, and zeta potential of the colloidal suspensions were investigated for a better understanding of the SERS signal response of arsenicals in the colloidal suspensions or under the influence of cellular matrix. Arsenicals showed substantially different SERS responses in the two colloidal suspensions, mainly because of the distinct difference in the interaction between the arsenicals and the nanoparticles. Arsenic speciation in cell lysate could be successfully carried out in AgNPs-Spermine suspension, while AgNPs-Citrate could not yield significant SERS signals under the experimental conditions. This study proved that AgNPs-Spermine colloidal suspension could be a promising SERS substrate for studying arsenic metabolism in a biological matrix, reducing the bias caused by traditional techniques that involve sample extraction and pretreatment.

  11. Nickel speciation in cement-stabilized/solidified metal treatment filtercakes

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Amitava, E-mail: reroy@lsu.edu [J. Bennett Johnston, Sr., Center for Advanced Microstructures and Devices, Louisiana State University, Baton Rouge, LA 70806, USA (United States); Stegemann, Julia A., E-mail: j.stegemann@ucl.ac.uk [Centre for Resource Efficiency & the Environment, Department of Civil, Environmental & Geomatic Engineering, University College London, Chadwick Building, Gower Street, London WC1E 6BT, UK (United Kingdom)

    2017-01-05

    Highlights: • XAS shows the same Ni speciation in untreated and stabilized/solidified filtercake. • Ni solubility is the same for untreated and stabilized/solidified filtercake. • Leaching is controlled by pH and physical encapsulation for all binders. - Abstract: Cement-based stabilization/solidification (S/S) is used to decrease environmental leaching of contaminants from industrial wastes. In this study, two industrial metal treatment filtercakes were characterized by X-ray diffractometry (XRD), thermogravimetric and differential thermogravimetric analysis (TG/DTG) and Fourier transform infrared (FTIR); speciation of nickel was examined by X-ray absorption (XAS) spectroscopy. Although the degree of carbonation and crystallinity of the two untreated filtercakes differed, α-nickel hydroxide was identified as the primary nickel-containing phase by XRD and nickel K edge XAS. XAS showed that the speciation of nickel in the filtercake was unaltered by treatment with any of five different S/S binder systems. Nickel leaching from the untreated filtercakes and all their stabilized/solidified products, as a function of pH in the acid neutralization capacity test, was essentially complete below pH ∼5, but was 3–4 orders of magnitude lower at pH 8–12. S/S does not respeciate nickel from metal treatment filtercakes and any reduction of nickel leaching by S/S is attributable to pH control and physical mechanisms only. pH-dependent leaching of Cr, Cu and Ni is similar for the wastes and s/s products, except that availability of Cr, Cu and Zn at decreased pH is reduced in matrices containing ground granulated blast furnace slag.

  12. Miscibility and Speciation in the Water/carbon Dioxide System

    Science.gov (United States)

    Abramson, E.; Bollengier, O.; Brown, J. M.

    2017-12-01

    We have been exploring fluid-fluid solubilities and speciation in mixed systems of CO2-H2O. Fluid-fluid immiscibility extends to the highest pressures and temperatures yet explored (7 GPa, 700K). In this region, commonly used COH fluid models agree neither with the data nor among themselves. The range of immiscibility is extended by addition of NaCl, but miscibility limits determined in preliminary experiments are not as expected from extrapolation of lower pressure (linked to an observed change in speciation as CO2(aq) reacts with water. The identity of the newly formed species is, as of the writing of this abstract, unknown, but presumed to be either H2CO3 or HCO3-. A reasonable match between the observed equilibria and an application of HKF theory suggests that the new species is, indeed, HCO3-, but with a Raman frequency shifted from that found in the dilute aqueous solution. Application of HKF theory to the CO2(f)-CO2(aq) equilibrium suffers from an incompatibility of the usual formulation of the theory with known molar volumes of CO2(f) at higher pressures. On the basis of these studies we conclude that models of CO2-H2O fluids must take into account major changes in speciation, and that simple equations-of-state, of a few fitted parameters, will not afford an adequate description of such fluids. "First principles" models, tested against real data, seem more likely to yield the desired results. This statement extends as well to the calculation of the dielectric constants of these mixed fluids, the basis of ionic solution chemistry. Further, semi-empirical formulations of solution thermodynamics, which function well at pressures of kbars, ought to be re-worked for use over larger pressure ranges.

  13. Genetic evidence for hybrid trait speciation in heliconius butterflies.

    Directory of Open Access Journals (Sweden)

    Camilo Salazar

    2010-04-01

    Full Text Available Homoploid hybrid speciation is the formation of a new hybrid species without change in chromosome number. So far, there has been a lack of direct molecular evidence for hybridization generating novel traits directly involved in animal speciation. Heliconius butterflies exhibit bright aposematic color patterns that also act as cues in assortative mating. Heliconius heurippa has been proposed as a hybrid species, and its color pattern can be recreated by introgression of the H. m. melpomene red band into the genetic background of the yellow banded H. cydno cordula. This hybrid color pattern is also involved in mate choice and leads to reproductive isolation between H. heurippa and its close relatives. Here, we provide molecular evidence for adaptive introgression by sequencing genes across the Heliconius red band locus and comparing them to unlinked wing patterning genes in H. melpomene, H. cydno, and H. heurippa. 670 SNPs distributed among 29 unlinked coding genes (25,847bp showed H. heurippa was related to H. c. cordula or the three species were intermixed. In contrast, among 344 SNPs distributed among 13 genes in the red band region (18,629bp, most showed H. heurippa related with H. c. cordula, but a block of around 6,5kb located in the 3' of a putative kinesin gene grouped H. heurippa with H. m. melpomene, supporting the hybrid introgression hypothesis. Genealogical reconstruction showed that this introgression occurred after divergence of the parental species, perhaps around 0.43Mya. Expression of the kinesin gene is spatially restricted to the distal region of the forewing, suggesting a mechanism for pattern regulation. This gene therefore constitutes the first molecular evidence for adaptive introgression during hybrid speciation and is the first clear candidate for a Heliconius wing patterning locus.

  14. Modelling interaction of deep groundwaters with bentonite and radionuclide speciation

    International Nuclear Information System (INIS)

    Wanner, H.

    1986-04-01

    In the safety analysis recently reported for a potential Swiss high-level waste repository, radionuclide speciation and solubility limits are calculated for expected granitic groundwater conditions. With the objective of deriving a more realistic description of radionuclide release from the near-field, an investigation has been initiated to quantitatively specify the chemistry of the near-field. In the Swiss case, the main components of the near-field are the glass waste-matrix, a thick steel canister horizontally emplaced in a drift, and a backfill of highly compacted sodium bentonite. This report describes a thermodynamic model which is used to estimate the chemical composition of the pore water in compacted sodium bentonite. Solubility limits and speciation of important actinides and the fission product technetium in the bentonite pore water are then calculated. The model is based on available experimental data on the interaction of sodium bentonite and groundwater and represents means of extrapolation from laboratory data to repository conditions. The modelled composition of the pore water of compacted sodium bentonite, as well as the various compositions resulting from the long-term extrapolation, are used to estimate radionuclide solubilities in the near-field of a deep repository. From the chemical point of view, calcium bentonite seems to be more stable than sodium bentonite in the presence of Swiss Reference Groundwater. Since the effect of calcium bentonite on the groundwater chemical composition will be considerably less marked than that of sodium bentonite, especially with respect to key parameters for the nuclide speciation like carbonate concentration and pH, the use of calcium bentonite instead of sodium bentonite will improve the reliability in the prediction of source terms for radionuclide transport in the geosphere. (author)

  15. 76 FR 365 - Exposure Modeling Public Meeting

    Science.gov (United States)

    2011-01-04

    ... classification for ecological risk assessments using aerial photography and GIS data. Dermal contact, movement... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2009-0879; FRL-8860-5] Exposure Modeling Public Meeting AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY: An Exposure Modeling...

  16. Trace metal speciation: Finally, correctly addressing trace metal issues

    International Nuclear Information System (INIS)

    Donard, O.F.X.

    2001-01-01

    The history of the development of trace metal speciation was discussed and the reasons behind the relatively slow widespread acceptance of its importance were presented. Partially, this was due to the lack of availability of commercial instrumentation and partly to the drive towards improving sensitivity in analytical chemistry which had focused attention on total concentration determinations. The sophistication and control of analytical instrumentation is now such that the spotlight must be turned onto the chemical species of an element present in a sample since this is what governs its behaviour in the biosphere. Indeed, several companies are currently considering the introduction of instrumentation specifically designed for metal species determination

  17. WHATIF-AQ, Geochem Speciation and Saturation of Aqueous Solution

    International Nuclear Information System (INIS)

    Nielsen, Ole John; Jensen, Bror Skytte

    1988-01-01

    1 - Description of program or function: WHATIF-AQ is part of a family of programs for calculations of geochemistry in the near-field of radioactive waste with temperature gradients. The program calculates speciation and saturation indices for an aqueous solution at temperatures in the range 0 - 125 degrees C. The chemical equilibrium is determined by solving a set of nonlinear equations consisting of the equilibrium constant and mass balance constraints. 2 - Method of solution: The set of equations is solved using a generalized Newton-Raphson technique

  18. Chemical speciation and transformation of mercury in contaminated sediments

    OpenAIRE

    Drott, Andreas

    2009-01-01

    Biomagnification of mercury (Hg) in aquatic food webs occurs almost exclusively as mono-methyl Hg (MeHg). In this thesis, the influence of chemical speciation and environmental conditions on transformations of inorganic Hg (HgII) and MeHg was studied at eight sites in Sweden with Hg contaminated sediments. The source of contamination was either Hg0(l) or phenyl-Hg, and total Hg concentrations ranged between 1.0-1100 nmol g-1. The environmental conditions, e.g. salinity, temperature climate, p...

  19. Evolution of blind beetles in isolated aquifers: a test of alternative modes of speciation

    NARCIS (Netherlands)

    Leys, R.; Nes, van E.H.; Watts, C.H.; Cooper, S.J.B.; Humphreys, W.F.; Hogendoorn, K.

    2012-01-01

    Evidence is growing that not only allopatric but also sympatric speciation can be important in the evolution of species. Sympatric speciation has most convincingly been demonstrated in laboratory experiments with bacteria, but field-based evidence is limited to a few cases. The recently discovered

  20. Comparison of analytical charge-form and equilibrium thermodynamic speciation of certain radionuclides

    International Nuclear Information System (INIS)

    Jenne, E.A.; Cowan, C.E.; Robertson, D.E.

    1984-01-01

    Calculating trace element speciation with a thermodynamic model is often challenged on the basis that the existing thermodynamic data are not sufficiently reliable. Water quality data and corresponding analytical charge-form speciation analysis were available for radionuclides occurring in a low-level radioactive groundwater. This offered an opportunity for comparing the results of an equilibrium thermodynamic model with the results of analytical charge-form speciation. The charge-form speciation was determined using the Battelle Large Volume Water Sampler, which contains consecutive layers of cation resin, anion resin and activated aluminum oxide for retention of cationic, anionic and non-ionic dissolved chemical species, respectively. The thermodynamic speciation of Cs, Cr, Fe, I, Mn, Mo, Na, and Zn was calculated using the MINTEQ geochemical model. Ce, Co, Tc, Np, Pm, and Sb were speciated by hand calculation. Excellent agreement between the analytically determined charge-form and the thermodynamic speciation was observed for 54 Mn, 144 Ce, 131 I, 24 Na, 137 Cs, 99 Mo, 99 Tc, 151 Pm, 239 Np. Organic complexation by natural and/or synthetic organics in the waters may be important in the speciation of 65 An, 60 Co, 131 I, 59 Fe and possibly 51 Cr. Both 124 Sb and 125 Sb appeared to be in redox disequilibria with the groundwater. 29 references, 2 tables

  1. Recent Developments in the Speciation and Determination of Mercury Using Various Analytical Techniques

    Directory of Open Access Journals (Sweden)

    Lakshmi Narayana Suvarapu

    2015-01-01

    Full Text Available This paper reviews the speciation and determination of mercury by various analytical techniques such as atomic absorption spectrometry, voltammetry, inductively coupled plasma techniques, spectrophotometry, spectrofluorometry, high performance liquid chromatography, and gas chromatography. Approximately 126 research papers on the speciation and determination of mercury by various analytical techniques published in international journals since 2013 are reviewed.

  2. Influence of EDDS on metal speciation in soil extracts: Measurement and mechanistic multicomponent modeling

    NARCIS (Netherlands)

    Koopmans, G.F.; Schenkeveld, W.D.C.; Song, J.; Luo, Y.; Japenga, J.; Temminghoff, E.J.M.

    2008-01-01

    The use of the [S,S]-isomer of EDDS to enhance phytoextraction has been proposed for the remediation of heavy metal contaminated soils. Speciation of metals in soil solution in the presence of EDDS and dissolved organic matter (DOM) received, however, almost no attention, whereas metal speciation

  3. Chemical speciation of L-glutamine complexes with Co(II), Ni(II) and ...

    African Journals Online (AJOL)

    The trend in the variation of stability constants of the complexes with mole fraction of the surfactant is attributed to the compartmentalization of complexation equilibria. Distribution of species and effect of influential parameters on chemical speciation have also been presented. KEY WORDS: Chemical speciation, complex ...

  4. EPA’s SPECIATE 4.4 Database - Development and Uses

    Science.gov (United States)

    SPECIATE is the EPA's repository of TOG, PM, and Other Gases speciation profiles of air pollution sources. It includes weight fractions of both organic species and PM and provides data in consistent units. Species include metals, ions, elements, and organic and inorganic compound...

  5. Overview of receptor-based source apportionment studies for speciated atmospheric mercury

    OpenAIRE

    Cheng, I.; Xu, X.; Zhang, L.

    2015-01-01

    Receptor-based source apportionment studies of speciated atmospheric mercury are not only concerned with source contributions but also with the influence of transport, transformation, and deposition processes on speciated atmospheric mercury concentrations at receptor locations. Previous studies applied multivariate receptor models including principal components analysis and positive matrix factorization, and back trajectory receptor models including potential source contri...

  6. HPLC inorganic arsenic speciation analysis of samples containing high sulfuric acid and iron levels

    NARCIS (Netherlands)

    Gonzalez-Contreras, P.A.; Gerrits, I.P.A.M.; Weijma, J.; Buisman, C.J.N.

    2011-01-01

    To monitor the oxidation of arsenite to arsenate in oxidizing and bioleaching reactors, speciation analysis of the inorganic arsenic compounds is required. Existing arsenic speciation analysis techniques are based on the use of liquid chromatography columns coupled to detector equipment such as

  7. Speciation analysis of 129I in seawater using coprecipitation and accelerator mass spectrometry and its applications

    DEFF Research Database (Denmark)

    Xing, Shan; Hou, Xiaolin; Aldahan, Ala

    2017-01-01

    Speciation analysis of long-lived 129I in seawater can provide useful information on the source of water masses. This paper presents an improved method for speciation analysis of 129I based on coprecipitation of iodide as AgI with Ag2SO3 and AgCl. By adding a small amount of 127I carrier...

  8. Ecological approach in constructing residential areas

    Directory of Open Access Journals (Sweden)

    Bogdanović Ružica

    2004-01-01

    Full Text Available As a concept sustainable development has evolved over the past two decades from a concept closely associated with the biophysical environment to become much more complex, embracing social, cultural, economic political and esthetic phenomenon, which are invariably in mutual interaction, so they influence sustainability of natural environment. The very notion of "sustainable" we are meeting today in almost all significance areas of human activities. Contemporary planning, projecting and building techniques undoubtedly implied integration of goals of environmental prevention with goals of socio-economic development, all with respecting the esthetic standards. This paper represents experience from foreign praxis. Project defines and resolves objectives from social, economical, morphological and ecological aspects. Most important is aspect of Ecological Optimisation, which consists of main components: energy use optimization, water concept, exemplary waste management concept and ecological soil management.

  9. Staff meeting

    CERN Multimedia

    2007-01-01

    Dear Colleagues, 2007 is a very special year for CERN. I would like to review the status of our activities with you, and I invite you to a presentation on Wednesday 27 June 2007 at 3:00 p.m. Main Auditorium (bldg. 500) Closed-circuit transmission of the meeting will be available in the Council Chamber and in the AB Auditorium (Meyrin), the AB Auditorium (Prévessin), the IT Auditorium (bldg. 31) and the AT Auditorium (bldg. 30). Simultaneous translation into English will be available in the Main Auditorium. Robert AYMAR

  10. Public meetings

    CERN Multimedia

    Staff Association

    2014-01-01

      MARS 2015 FIVE YEARLY REVIEW CONTRACT POLICY PENSION FUND GENERAL INFORMATION   COME AND BE INFORMED! PUBLIC MEETINGS Friday 3rd October at 10 am Amphi BE, 864-1-D02 Prévessin Friday 3rd October at 2 pm Salle du Conseil / Council Chamber, 503-1-001 (in English) Meyrin Monday 6th October at 10 am Kjell Johnsen Auditorium, 30-7-018 Meyrin Monday 6th October at 2 pm Salle du Conseil / Council Chamber, 503-1-001 Meyrin  

  11. Mutualistic interactions drive ecological niche convergence in a diverse butterfly community.

    Science.gov (United States)

    Elias, Marianne; Gompert, Zachariah; Jiggins, Chris; Willmott, Keith

    2008-12-02

    Ecological communities are structured in part by evolutionary interactions among their members. A number of recent studies incorporating phylogenetics into community ecology have upheld the paradigm that competition drives ecological divergence among species of the same guild. However, the role of other interspecific interactions, in particular positive interactions such as mutualism, remains poorly explored. We characterized the ecological niche and inferred phylogenetic relationships among members of a diverse community of neotropical Müllerian mimetic butterflies. Müllerian mimicry is one of the best studied examples of mutualism, in which unpalatable species converge in wing pattern locally to advertize their toxicity to predators. We provide evidence that mutualistic interactions can drive convergence along multiple ecological axes, outweighing both phylogeny and competition in shaping community structure. Our findings imply that ecological communities are adaptively assembled to a much greater degree than commonly suspected. In addition, our results show that phenotype and ecology are strongly linked and support the idea that mimicry can cause ecological speciation through multiple cascading effects on species' biology.

  12. Mutualistic interactions drive ecological niche convergence in a diverse butterfly community.

    Directory of Open Access Journals (Sweden)

    Marianne Elias

    2008-12-01

    Full Text Available Ecological communities are structured in part by evolutionary interactions among their members. A number of recent studies incorporating phylogenetics into community ecology have upheld the paradigm that competition drives ecological divergence among species of the same guild. However, the role of other interspecific interactions, in particular positive interactions such as mutualism, remains poorly explored. We characterized the ecological niche and inferred phylogenetic relationships among members of a diverse community of neotropical Müllerian mimetic butterflies. Müllerian mimicry is one of the best studied examples of mutualism, in which unpalatable species converge in wing pattern locally to advertize their toxicity to predators. We provide evidence that mutualistic interactions can drive convergence along multiple ecological axes, outweighing both phylogeny and competition in shaping community structure. Our findings imply that ecological communities are adaptively assembled to a much greater degree than commonly suspected. In addition, our results show that phenotype and ecology are strongly linked and support the idea that mimicry can cause ecological speciation through multiple cascading effects on species' biology.

  13. Review of speciation and solubility of radionuclides in the near and far field. Pt. 2

    International Nuclear Information System (INIS)

    Smith-Briggs, J.L.

    1992-01-01

    This report represents Part 2 in a series of three reports which review the speciation and solubility of radionuclides in the near and far field. Part 2 is a general bibliography from 1978 to 1991. This report contains the bibliography for the review of speciation and solubility radionuclides in the near and far field from 1978 to 1991. The importance of the solubility and speciation of radionuclides in relation to the safety assessment of the repository is discussed. Solubility is defined, both theoretically and pragmatically, and the factors which influence solubility and speciation are discussed. The literature search was performed using the INIS database. The UKAEA RECAP database, the NIREX report bibliography and a list of DOE reports provided by the DOE were also used. The bibliography is divided into five sections, solubility and speciation experimental data, basic thermodynamic data, solubility limiting solid phases, experimental design and review and overview articles. Some references appear in more than one section. (Author)

  14. Floral traits and pollination ecology of European Arum hybrids.

    Science.gov (United States)

    Chartier, Marion; Liagre, Suzanne; Weiss-Schneeweiss, Hanna; Kolano, Bozena; Bessière, Jean-Marie; Schönenberger, Jürg; Gibernau, Marc

    2016-02-01

    Hybridisation is common in plants and can affect the genetic diversity and ecology of sympatric parental populations. Hybrids may resemble the parental species in their ecology, leading to competition and/or gene introgression; alternatively, they may diverge from the parental phenotypes, possibly leading to the colonisation of new ecological niches and to speciation. Here, we describe inflorescence morphology, ploidy levels, pollinator attractive scents, and pollinator guilds of natural hybrids of Arum italicum and A. maculatum (Araceae) from a site with sympatric parental populations in southern France to determine how these traits affect the hybrid pollination ecology. Hybrids were characterised by inflorescences with a size and a number of flowers more similar to A. italicum than to A. maculatum. In most cases, hybrid stamens were purple, as in A. maculatum, and spadix appendices yellow, as in A. italicum. Hybrid floral scent was closer to that of A. italicum, but shared some compounds with A. maculatum and comprised unique compounds. Also, the pollinator guild of the hybrids was similar to that of A. italicum. Nevertheless, the hybrids attracted a high proportion of individuals of the main pollinator of A. maculatum. We discuss the effects of hybridisation in sympatric parental zones in which hybrids exhibit low levels of reproductive success, the establishment of reproductive barriers between parental species, the role of the composition of floral attractive scents in the differential attraction of pollinators and in the competition between hybrids and their parental species, and the potential of hybridisation to give rise to new independent lineages.

  15. Does density-dependent diversification mirror ecological competitive exclusion?

    Directory of Open Access Journals (Sweden)

    Melanie J Monroe

    Full Text Available Density-dependence is a term used in ecology to describe processes such as birth and death rates that are regulated by the number of individuals in a population. Evolutionary biologists have borrowed the term to describe decreasing rates of species accumulation, suggesting that speciation and extinction rates depend on the total number of species in a clade. If this analogy with ecological density-dependence holds, diversification of clades is restricted because species compete for limited resources. We hypothesize that such competition should not only affect numbers of species, but also prevent species from being phenotypically similar. Here, we present a method to detect whether competitive interactions between species have ordered phenotypic traits on a phylogeny, assuming that competition prevents related species from having identical trait values. We use the method to analyze clades of birds and mammals, with body size as the phenotypic trait. We find no sign that competition has prevented species from having the same body size. Thus, since body size is a key ecological trait and competition does not seem to be responsible for differences in body size between species, we conclude that the diversification slowdown that is prevalent in these clades is unlikely due to the ecological interference implied by the term density dependence.

  16. Between Design and Ecology

    DEFF Research Database (Denmark)

    Bjørn, Mona Chor

    such vegetation, based on concepts and theories in plant community ecology. If these communities are based on local forbs there is a continuum in anthropogenic intervention from designed and intensively maintained to semi-natural herbaceous vegetation. Results from a large field experiment show that, after three...... colonised by grasses and eventually woody species. This thesis adds useful basic knowledge in plant community ecology and species-specific growth, which are relevant to research and planning in landscape architecture and ecology....

  17. Development of Ecological Buildings

    Directory of Open Access Journals (Sweden)

    Andrius Keizikas

    2011-04-01

    Full Text Available The article presents research on ecological buildings and their influence on the constructional sphere. The aim of the paper is to reveal the essence of ecological architecture showing substantial progress and its potential to stimulate architectural and technological growth. The article also describes relations between the ideas of ecological buildings and the ‘passive house’ concepts and aspects of development as well as describes the possibilities of improving building sustainability and energy efficiency. Article in Lithuanian

  18. ACCU MEETING

    CERN Document Server

    PH Department

    2008-01-01

    DRAFT Agenda for the meetingto be held on Wednesday 3 December 2008 at 9:15 a.m.in Room 60-6-002 1.\tChairman’s remarks 2.\tAdoption of the agenda 3.\tMinutes of the previous meeting 4.\tMatters arising 5.\tNews from the CERN Management 6.\tReport from the new Director-General 7.\tReport on the Fellows and Associates programme 8.\tAn update on Safety at CERN 9.\tReports from ACCU representatives on other committees 10.\tUsers’ Office news 11.\tAny Other Business 12.\tAgenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium C. Va...

  19. Dynamics in artifact ecologies

    DEFF Research Database (Denmark)

    Bødker, Susanne; Klokmose, Clemens Nylandsted

    2012-01-01

    We increasingly interact with multiple interactive artifacts with overlapping capabilities during our daily activities. It has previously been shown that the use of an interactive artifact cannot be understood in isolation, but artifacts must be understood as part of an artifact ecology, where...... artifacts influence the use of others. Understanding this interplay becomes more and more essential for interaction design as our artifact ecologies grow. This paper continues a recent discourse on artifact ecologies. Through interviews with iPhone users, we demonstrate that relationships between artifacts...... in artifact ecologies cannot be understood as static, instead they evolve dynamically over time. We provide activity theory-based concepts to explain these dynamics....

  20. Ecological risk assessment

    National Research Council Canada - National Science Library

    Suter, Glenn W; Barnthouse, L. W. (Lawrence W)

    2007-01-01

    Ecological risk assessment is commonly applied to the regulation of chemicals, the remediation of contaminated sites, the monitoring of importation of exotic organisms, the management of watersheds...

  1. Chemical ecology of fungi.

    Science.gov (United States)

    Spiteller, Peter

    2015-07-01

    Fungi are widespread in nature and have conquered nearly every ecological niche. Fungi occur not only in terrestrial but also in freshwater and marine environments. Moreover, fungi are known as a rich source of secondary metabolites. Despite these facts, the ecological role of many of these metabolites is still unknown and the chemical ecology of fungi has not been investigated systematically so far. This review intends to present examples of the various chemical interactions of fungi with other fungi, plants, bacteria and animals and to give an overview of the current knowledge of fungal chemical ecology.

  2. Uranium speciation in biofilms studies by laser fluorescence techniques

    International Nuclear Information System (INIS)

    Arnold, Thuro; Grossmann, Kay; Baumann, Nils

    2010-01-01

    Biofilms may immobilize toxic heavy metals in the environment and thereby influence their migration behaviour. The mechanisms of these processes are currently not understood, because the complexity of such biofilms creates many discrete geochemical microenvironments which may differ from the surrounding bulk solution in their bacterial diversity, their prevailing geochemical properties, e.g. pH and dissolved oxygen concentration, the presence of organic molecules, e.g. metabolites, and many more, all of which may affect metal speciation. To obtain such information, which is necessary for performance assessment studies or the development of new cost-effective strategies for cleaning waste waters, it is very important to develop new non-invasive methods applicable to study the interactions of metals within biofilm systems. Laser fluorescence techniques have some superior features, above all very high sensitivity for fluorescent heavy metals. An approach combining confocal laser scanning microscopy and laser-induced fluorescence spectroscopy for study of the interactions of biofilms with uranium is presented. It was found that coupling these techniques furnishes a promising tool for in-situ non-invasive study of fluorescent heavy metals within biofilm systems. Information on uranium speciation and uranium redox states can be obtained.

  3. Quantifying variation in speciation and extinction rates with clade data.

    Science.gov (United States)

    Paradis, Emmanuel; Tedesco, Pablo A; Hugueny, Bernard

    2013-12-01

    High-level phylogenies are very common in evolutionary analyses, although they are often treated as incomplete data. Here, we provide statistical tools to analyze what we name "clade data," which are the ages of clades together with their numbers of species. We develop a general approach for the statistical modeling of variation in speciation and extinction rates, including temporal variation, unknown variation, and linear and nonlinear modeling. We show how this approach can be generalized to a wide range of situations, including testing the effects of life-history traits and environmental variables on diversification rates. We report the results of an extensive simulation study to assess the performance of some statistical tests presented here as well as of the estimators of speciation and extinction rates. These latter results suggest the possibility to estimate correctly extinction rate in the absence of fossils. An example with data on fish is presented. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  4. Iron(III) citrate speciation in aqueous solution.

    Science.gov (United States)

    Silva, Andre M N; Kong, XiaoLe; Parkin, Mark C; Cammack, Richard; Hider, Robert C

    2009-10-28

    Citrate is an iron chelator and it has been shown to be the major iron ligand in the xylem sap of plants. Furthermore, citrate has been demonstrated to be an important ligand for the non-transferrin bound iron (NTBI) pool occurring in the plasma of individuals suffering from iron-overload. However, ferric citrate chemistry is complicated and a definitive description of its aqueous speciation at neutral pH remains elusive. X-Ray crystallography data indicates that the alcohol function of citrate (Cit4-) is involved in Fe(III) coordination and that deprotonation of this functional group occurs upon complex formation. The inability to include this deprotonation in the affinity constant calculations has been a major source of divergence between various reports of iron(III)-citrate affinity constants. However the recent determination of the alcoholic pKa of citric acid (H4Cit) renders the reassessment of the ferric citrate system possible. The aqueous speciation of ferric citrate has been investigated by mass spectrometry and EPR spectroscopy. It was observed that the most relevant species are a monoiron dicitrate species and dinuclear and trinuclear oligomeric complexes, the relative concentration of which depends on the solution pH value and the iron : citric acid molar ratio. Spectrophotometric titration was utilized for affinity constant determination and the formation constant for the biologically relevant [Fe(Cit)2]5- is reported for the first time.

  5. Metal speciation: survey of environmental methods of analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mach, M.H.; Nott, B.; Scott, J.W.; Maddalone, R.F.; Whiddon, N.T. [TRW, Redondo Beach, CA (United States). Chemistry Technology Dept.

    1996-07-01

    As part of a recent task under the EPRI Analytical Methods Qualification Program (RP 1851), TRW has surveyed the methods available for monitoring metal species in typical utility aqueous discharge streams. Methods for determining the individual species of these metals can become important in a regulatory sense as the EPA transitions to assessment of environmental risk based on bioavailability. For example, EPA considers methyl mercury and Cr(VI) much more toxic to the aquatic environment than inorganic mercury or Cr(III). The species of a given element can also differ in their transport and bioaccumulation. Methods for speciation generally include a selective separation step followed by standard metals analysis. Speciation, therefore, is mainly derived from the separation step and not from the method of final quantisation. Examples of separation/analysis include: selective extraction followed by graphite furnace atomic absorption or ICP-MS; separation by GC followed by metals detection; chelation and/or direct separation by LC followed by UV measurement or metals detection; and ion chromatography with conductivity, UV, or metals detection. There are a number of sampling issues associated with metal species such as stabilization (maintaining oxidation state), absorption, and filtration that need to be addressed in order to obtain and maintain a representative sample for analysis. 45 refs., 1 tab.

  6. Selenium speciation from food source to metabolites: a critical review

    Energy Technology Data Exchange (ETDEWEB)

    Dumont, Emmie; Vanhaecke, Frank; Cornelis, Rita [Ghent University, Department of Analytical Chemistry, Ghent (Belgium)

    2006-08-15

    Especially in the last decade, a vast number of papers on Se and its role in health issues have been published. This review gives a brief, critical overview of the main analytical findings reported in these papers. Of particular interest is the Se content in different food sources worldwide and the extent to which their consumption is reflected in the Se content of human tissues and body fluids. Several food sources, both natural (Brazil nuts, garlic, Brassica juncea) and Se-enriched (yeast-based supplements), are discussed as to origin, characteristics, Se metabolism and impact of their consumption on the human body. The continuous development of new and improvement of existing analytical techniques has provided different powerful tools to unravel the Se species and their function. An up-to-date literature study on Se speciation analysis is given, illustrating how analytical chemistry in its different facets aids in the identification of Se compounds and provides insight into the complete metabolic pathway of Se throughout the human body. This review includes a detailed image of the current state-of-the-art of Se speciation analysis in these food sources and in human tissues and body fluids. (orig.)

  7. Allopatric speciation within a cryptic species complex of Australasian octopuses.

    Science.gov (United States)

    Amor, Michael D; Norman, Mark D; Cameron, Hayley E; Strugnell, Jan M

    2014-01-01

    Despite extensive revisions over recent decades, the taxonomy of benthic octopuses (Family Octopodidae) remains in a considerable flux. Among groups of unresolved status is a species complex of morphologically similar shallow-water octopods from subtropical Australasia, including: Allopatric populations of Octopus tetricus on the eastern and western coasts of Australia, of which the Western Australian form is speculated to be a distinct or sub-species; and Octopus gibbsi from New Zealand, a proposed synonym of Australian forms. This study employed a combination of molecular and morphological techniques to resolve the taxonomic status of the 'tetricus complex'. Phylogenetic analyses (based on five mitochondrial genes: 12S rRNA, 16S rRNA, COI, COIII and Cytb) and Generalised Mixed Yule Coalescent (GMYC) analysis (based on COI, COIII and Cytb) distinguished eastern and Western Australian O. tetricus as distinct species, while O. gibbsi was found to be synonymous with the east Australian form (BS = >97, PP = 1; GMYC p = 0.01). Discrete morphological differences in mature male octopuses (based on sixteen morphological traits) provided further evidence of cryptic speciation between east (including New Zealand) and west coast populations; although females proved less useful in morphological distinction among members of the tetricus complex. In addition, phylogenetic analyses suggested populations of octopuses currently treated under the name Octopus vulgaris are paraphyletic; providing evidence of cryptic speciation among global populations of O. vulgaris, the most commercially valuable octopus species worldwide.

  8. Speciation and migration of 129I in soil profiles

    International Nuclear Information System (INIS)

    Luo, Maoyi; Hou, Xiaolin; Zhou, Weijian; He, Chaohui; Chen, Ning; Liu, Qi; Zhang, Luoyuan

    2013-01-01

    A method has been developed for speciation analysis of ultra low level 129 I in soil using sequential extraction combined with coprecipitation for separation of carrier free iodine and AMS measurement of 129 I. Two loess profiles collected from northwest China were analyzed for species of 129 I and 127 I. Similar partitioning of 129 I and 127 I was observed in the loess profiles, the distribution of iodine isotopes followed an order of organic > leachable > reducible > residue. The 129 I concentrations and 129 I/ 127 I ratios decreased exponentially with the depth, and 2 orders of magnitude lower in the deepest layer (60 and 90 cm) compared with the top layer, indicating a significant contribution of anthropogenic input in the upper layer, and high retention of 129 I in soil. The mobility of 129 I in different fractions decreased in an order of leachable > organic > oxides > residue. The results suggest that migration of iodine downwards in the soil profile is a slow process; the oxides and residue are the less mobile fractions of iodine. Highlights: ► 129 I concentration decreases exponentially with the depth of soil profile. ► The mobility of 129 I in fractions decreases: leachable > organic > oxides > residue. ► Iodine shows less mobility in oxides and residue fractions. ► High organic soil content can effectively reduce the migration of 129 I in the environment. ► Carrier free iodine AMS is an effective method for natural 129 I speciation analysis in the environment

  9. Allopatric Speciation within a Cryptic Species Complex of Australasian Octopuses

    Science.gov (United States)

    Amor, Michael D.; Norman, Mark D.; Cameron, Hayley E.; Strugnell, Jan M.

    2014-01-01

    Despite extensive revisions over recent decades, the taxonomy of benthic octopuses (Family Octopodidae) remains in a considerable flux. Among groups of unresolved status is a species complex of morphologically similar shallow-water octopods from subtropical Australasia, including: Allopatric populations of Octopus tetricus on the eastern and western coasts of Australia, of which the Western Australian form is speculated to be a distinct or sub-species; and Octopus gibbsi from New Zealand, a proposed synonym of Australian forms. This study employed a combination of molecular and morphological techniques to resolve the taxonomic status of the ‘tetricus complex’. Phylogenetic analyses (based on five mitochondrial genes: 12S rRNA, 16S rRNA, COI, COIII and Cytb) and Generalised Mixed Yule Coalescent (GMYC) analysis (based on COI, COIII and Cytb) distinguished eastern and Western Australian O. tetricus as distinct species, while O. gibbsi was found to be synonymous with the east Australian form (BS = >97, PP = 1; GMYC p = 0.01). Discrete morphological differences in mature male octopuses (based on sixteen morphological traits) provided further evidence of cryptic speciation between east (including New Zealand) and west coast populations; although females proved less useful in morphological distinction among members of the tetricus complex. In addition, phylogenetic analyses suggested populations of octopuses currently treated under the name Octopus vulgaris are paraphyletic; providing evidence of cryptic speciation among global populations of O. vulgaris, the most commercially valuable octopus species worldwide. PMID:24964133

  10. Evaluation of mercury speciation by EPA (Draft) Method 29

    Energy Technology Data Exchange (ETDEWEB)

    Laudal, D.L.; Heidt, M.K. [Energy & Environmental Research Center, Grand Forks, ND (United States); Nott, B. [Electric Power Research Institute, Palo Alto, CA (United States)

    1995-11-01

    The 1990 Clean Air Act Amendments require that the U.S. Environmental protection Agency (EPA) assess the health risks associated with mercury emissions. Also, the law requires a separate assessment of health risks posed by the emission of 189 tract chemicals (including mercury) for electric utility steam-generating units. In order to conduct a meaningful assessment of health and environmental effects, we must have, among other things, a reliable and accurate method to measure mercury emissions. In addition, the rate of mercury deposition and the type of control strategies used may depend upon the type of mercury emitted (i.e., whether it is in the oxidized or elemental form). It has been speculated that EPA (Draft) Method 29 can speciate mercury by selective absorption; however, this claim has yet to be proven. The Electric Power Research Institute (EPRI) and the U.S. Department of Energy (DOE) have contracted with the Energy & Environmental Research Center (EERC) at University of North Dakota to evaluate EPA (Draft) Method 29 at the pilot-scale level. The objective of the work is to determine whether EPA (Draft) Method 29 can reliably quantify and speciate mercury in the flue gas from coal-fired boilers.

  11. AN ANALYTICAL METHOD FOR CHEMICAL SPECIATION OF SELENIUM IN SOIL

    Directory of Open Access Journals (Sweden)

    Constantin Luca

    2010-10-01

    Full Text Available Selenium is an essential microelement, sometimes redoubtable, through its beneficial role - risk depending on its concentration in the food chain, at low dose is an important nutrient in the life of humans and animals, contrary at high doses, it becomes toxic. Selenium may be find itself in the environment (soil, sediment, water in many forms (oxidized, reduced, organometallic which determine their mobility and toxicity. Determination of chemical speciation (identification of different chemical forms provides much more complete information for a better understanding of the behavior and the potential impact on the environment. In this work we present the results of methodological research on the extraction of sequential forms of selenium in the soil and the coupling of analytical methods capable of identifying very small amounts of selenium in soils An efficient scheme of sequential extractions forms of selenium (SES consisting in atomic absorption spectrometry coupled with hydride generation (HGAAS has been developed into five experimental steps, detailed in the paper. This operational scheme has been applied to the analysis of chemical speciation in the following areas: the Bărăgan Plain and Central Dobrogea of Romania.

  12. Technetium Inventory, Distribution, and Speciation in Hanford Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rapko, Brian M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pegg, Ian L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-11-13

    The purpose of this report is three fold: 1) assemble the available information regarding Tc inventory, distribution between phases, and speciation in Hanford’s 177 storage tanks into a single, detailed, comprehensive assessment; 2) discuss the fate (distribution/speciation) of Tc once retrieved from the storage tanks and processed into final waste forms; and 3) discuss/document in less detail the available data on the inventory of Tc in other “pools” such as the vadose zone below inactive cribs and trenches, below single-shell tanks (SSTs) that have leaked, and in the groundwater below the Hanford Site. This report was revised in September 2014 to add detail and correct inaccuracies in Section 5.0 on the fate of technetium (Tc) recycle from the off-gas systems downstream of the low-activity waste (LAW) melters back to the melters, based on several reports that were not found in the original literature search on the topic. The newly provided reports, from experts active in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) glass studies, the Vitreous State Laboratory at The Catholic University of America (VSL) melter and off-gas system demonstrations and overall WTP systems analysis, were not originally found on electronic databases commonly searched. The major revisions to Section 5.0 also required changes to Section 7.0 (Summary and Conclusions) and this executive summary.

  13. Triassic-Jurassic pteridosperms of Australasia: speciation, diversity and decline

    Energy Technology Data Exchange (ETDEWEB)

    Pattemore, G. A.; Rigby, J. F.; Playford, G.

    2015-07-01

    Pteridosperms are preserved abundantly in the Gondwanan Triassic, with many species exhibiting consider- able morphological variation that has been attributed to a hybridization model of speciation. This is an improbable explanation given that hybridization is very rare in gymnosperms. Allopatric speciation resulting from geographic and climatic provincialism is a more likely explanation for the morphological diversity which is well represented in Anisian Norian (Middle and Upper Triassic) floras of Australasia and elsewhere in Gondwana. Most specimens are distributed among three families: Umkomasiaceae, Peltaspermaceae and Matatiellaceae. These families, together with other possibly pteridospermous genera, are reviewed herein. Diversity in these families apparently declined by the Rhaetian and they did not persist into the Gondwanan post-Triassic. Australasian post-Triassic strata contain remarkably different floral assemblages to those of the Triassic. No fructifications are clearly pteridospermous and no remains show any obvious relationship with pteridosperms of the Gondwanan Triassic. Caytonialean fructifications are not known in Australasian strata; however, associated foliage has been reported from the Eastern Gondwanan Upper Triassic through Middle Jurassic including Australia. Much fern-like foliage, claimed to be pteridospermous from the Lower Jurassic through Eocene of Eastern Gondwana, lacks supporting evidence of such affiliation. (Author)

  14. Savannah River Ecology Laboratory. Annual technical progress report of ecological research

    International Nuclear Information System (INIS)

    Smith, M.H.

    1996-01-01

    The Savannah River Ecology Laboratory (SREL) is a research unit of the University of Georgia (UGA). The overall mission of the Laboratory is to acquire and communicate knowledge of ecological processes and principles. SREL conducts basic and applied ecological research, as well as education and outreach programs, under a contract with the U.S. Department of Energy (DOE) at the Savannah River Site (SRS) near Aiken, South Carolina. Significant accomplishments were made during the past year in the areas of research, education and service. The Laboratory's research mission was fulfilled with the publication of two books and 143 journal articles and book chapters by faculty, technical and students, and visiting scientists. An additional three books and about 80 journal articles currently are in press. Faculty, technician and students presented 193 lectures, scientific presentations, and posters to colleges and universities, including minority institutions. Dr. J Vaun McArthur organized and conducted the Third Annual SREL Symposium on the Environment: New Concepts in Strewn Ecology: An Integrative Approach. Dr. Michael Newman conducted a 5-day course titled Quantitative Methods in Ecotoxicology, and Dr. Brian Teppen of The Advanced Analytical Center for Environmental Sciences (AACES) taught a 3-day short course titled Introduction to Molecular Modeling of Environmental Systems. Dr. I. Lehr Brisbin co-hosted a meeting of the Crocodile Special Interest Group. Dr. Rebecca Sharitz attended four symposia in Japan during May and June 1996 and conducted meetings of the Executive Committee and Board of the International Association for Ecology (ENTECOL)

  15. Savannah River Ecology Laboratory. Annual technical progress report of ecological research

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.H.

    1996-07-31

    The Savannah River Ecology Laboratory (SREL) is a research unit of the University of Georgia (UGA). The overall mission of the Laboratory is to acquire and communicate knowledge of ecological processes and principles. SREL conducts basic and applied ecological research, as well as education and outreach programs, under a contract with the U.S. Department of Energy (DOE) at the Savannah River Site (SRS) near Aiken, South Carolina. Significant accomplishments were made during the past year in the areas of research, education and service. The Laboratory`s research mission was fulfilled with the publication of two books and 143 journal articles and book chapters by faculty, technical and students, and visiting scientists. An additional three books and about 80 journal articles currently are in press. Faculty, technician and students presented 193 lectures, scientific presentations, and posters to colleges and universities, including minority institutions. Dr. J Vaun McArthur organized and conducted the Third Annual SREL Symposium on the Environment: New Concepts in Strewn Ecology: An Integrative Approach. Dr. Michael Newman conducted a 5-day course titled Quantitative Methods in Ecotoxicology, and Dr. Brian Teppen of The Advanced Analytical Center for Environmental Sciences (AACES) taught a 3-day short course titled Introduction to Molecular Modeling of Environmental Systems. Dr. I. Lehr Brisbin co-hosted a meeting of the Crocodile Special Interest Group. Dr. Rebecca Sharitz attended four symposia in Japan during May and June 1996 and conducted meetings of the Executive Committee and Board of the International Association for Ecology (ENTECOL).

  16. Arsenic speciation in biological environmental samples of aquatic ecosystems by using HPLC-ICP-MS; Speciation von Arsen in biologischen Umweltproben aus aquatischen Oekosystemen mittels HPLC-ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Falk, K.

    1999-09-01

    The physicochemical forms of arsenic (arsenic species) which are present in the environment vary significantly with respect to toxicity, bioavailability, stability and transport behaviour. Therefore, it is necessary for an assessment of the toxic potential to humans and the environment to investigate not only the total arsenic concentrations but also to differentiate the single species. By that the knowledge about ecological correlations and pathways will be increased. The present thesis reports the results of a Ph.D. study on the development and optimisation of analytical methods for arsenic speciation and their application to biological samples from different aquatic ecosystems in Germany. The method development included separation of 12 naturally occurring arsenic species by high-performance liquid chromatography (HPLC) followed by an arsenic selective detection by inductively coupled plasma-mass spectrometry (ICP-MS). The arsenic species As (III), As (V), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AB), arsenocholine (AC), trimethylarsine oxid (TMAO) and tetramethylarsonium (Tetra) were separated with ion-exchange chromatography, whereas reversed-phase chromatography was used for the separation of four arsenosugars. Because of the partly low arsenic concentration in biological samples a very good detection power was required. Therefore, an HPLC-ICP-MS system was tested with different nebulizers. Using the high efficiency nebulizer HHPN (Hydraulic High Pressure Nebulizer), detection limits in the low pg-range could be achieved. The developed analytical methods were applied to arsenic speciation in four marine matrices, which are representative of different trophic levels in the food chain. All samples originated from an ecosystem in the North Sea.

  17. Neither nature nor environment: Systemic operationalism and ecologism

    International Nuclear Information System (INIS)

    Gomez E, Luis F

    2009-01-01

    Nature is a complex concept that some critics have found as one of the roots of the current crisis of orthodox modernity. Because of this, we think ecologism should develop a theory where it does not play a pivotal role. Here, we propose systemic operationalism as a theoretical basis for ecologism since it seems to meet this requirement without having to replace it with terms such as environment which appears to keep some of the problems critics see in the concept of nature.

  18. Meeting Venus

    Science.gov (United States)

    Sterken, Christiaan; Aspaas, Per Pippin

    2013-06-01

    On 2-3 June 2012, the University of Tromsoe hosted a conference about the cultural and scientific history of the transits of Venus. The conference took place in Tromsoe for two very specific reasons. First and foremost, the last transit of Venus of this century lent itself to be observed on the disc of the Midnight Sun in this part of Europe during the night of 5 to 6 June 2012. Second, several Venus transit expeditions in this region were central in the global enterprise of measuring the scale of the solar system in the eighteenth century. The site of the conference was the Nordnorsk Vitensenter (Science Centre of Northern Norway), which is located at the campus of the University of Tromsoe. After the conference, participants were invited to either stay in Tromsoe until the midnight of 5-6 June, or take part in a Venus transit voyage in Finnmark, during which the historical sites Vardoe, Hammerfest, and the North Cape were to be visited. The post-conference program culminated with the participants observing the transit of Venus in or near Tromsoe, Vardoe and even from a plane near Alta. These Proceedings contain a selection of the lectures delivered on 2-3 June 2012, and also a narrative description of the transit viewing from Tromsoe, Vardoe and Alta. The title of the book, Meeting Venus, refers the title of a play by the Hungarian film director, screenwriter and opera director Istvan Szabo (1938-). The autobiographical movie Meeting Venus (1991) directed by him is based on his experience directing Tannhauser at the Paris Opera in 1984. The movie brings the story of an imaginary international opera company that encounters a never ending series of difficulties and pitfalls that symbolise the challenges of any multicultural and international endeavour. As is evident from the many papers presented in this book, Meeting Venus not only contains the epic tales of the transits of the seventeenth, eighteenth and nineteenth centuries, it also covers the conference

  19. Public meetings

    CERN Multimedia

    Staff Association

    2013-01-01

    MARS SURVEY 5YR 2015 GENERAL INFORMATION ELECTIONS 2013   COME AND BE INFORMED! Public meetings Tuesday 1st Oct. 10 am Amphi IT, 31-3-004 Meyrin Tuesday 1st Oct. 2 pm Council Chamber, 503-1-001 Meyrin Friday 4 Oct. 10 am Amphi BE, 864-1-D02 Prévessin Monday 7 Oct. 2 pm Council Chamber, 503-1-001 (in English) Meyrin Tuesday 8 Oct. 10 am Amphi Kjell Johnsen, 30-7-018 Meyrin   Overview of the topics to be discussed Recognition of Merit – MARS Outcome of last exercise 2007 to 2013: lessons learned Survey: five-yearly review, give us your opinion General information CVI 2014 Voluntary programmes (PRP, SLS) Elections 2013 Renewal of the Staff Council 2014 - 2015  

  20. Meetings and Meeting Modeling in Smart Environments

    NARCIS (Netherlands)

    Nijholt, Antinus; op den Akker, Hendrikus J.A.; Heylen, Dirk K.J.

    In this paper we survey our research on smart meeting rooms and its relevance for augmented reality meeting support and virtual reality generation of meetings in real time or off-line. The research reported here forms part of the European 5th and 6th framework programme projects multi-modal meeting

  1. Meetings and meeting modeling in smart surroundings

    NARCIS (Netherlands)

    op den Akker, Hendrikus J.A.; Heylen, Dirk K.J.; Nijholt, Antinus; Nishida, T.

    2004-01-01

    In this paper we survey our research on smart meeting rooms and its relevance for augmented reality meeting support and virtual reality generation of meetings in real-time or off-line. Intelligent real-time and off-line generation requires understanding of what is going on during a meeting. The

  2. Workshop meeting

    International Nuclear Information System (INIS)

    Veland, Oeystein

    2004-04-01

    1-2 September 2003 the Halden Project arranged a workshop on 'Innovative Human-System Interfaces and their Evaluation'. This topic is new in the HRP 2003-2005 programme, and it is important to get feedback from member organizations to the work that is being performed in Halden. It is also essential that relevant activities and experiences in this area from the member organizations are shared with the Halden staff and other HRP members. Altogether 25 persons attended the workshop. The workshop had a mixture of presentations and discussions, and was chaired by Dominique Pirus of EDF, France. Day one focused on the HRP/IFE activities on Human-System Interface design, including Function-oriented displays, Ecological Interface Design, Task-oriented displays, as well as work on innovative display solutions for the oil and gas domain. There were also presentations of relevant work in France, Japan and the Czech Republic. The main focus of day two was the verification and validation of human-system interfaces, with presentations of work at HRP on Human-Centered Validation, Criteria-Based System Validation, and Control Room Verification and Validation. The chairman concluded that it was a successful workshop, although one could have had more time for discussions. The Halden Project got valuable feedback and viewpoints on this new topic during the workshop, and will consider all recommendations related to the future work in this area. (Author)

  3. Nuclear and plastid haplotypes suggest rapid diploid and polyploid speciation in the N Hemisphere Achillea millefolium complex (Asteraceae

    Directory of Open Access Journals (Sweden)

    Guo Yan-Ping

    2012-01-01

    Full Text Available Abstract Background Species complexes or aggregates consist of a set of closely related species often of different ploidy levels, whose relationships are difficult to reconstruct. The N Hemisphere Achillea millefolium aggregate exhibits complex morphological and genetic variation and a broad ecological amplitude. To understand its evolutionary history, we study sequence variation at two nuclear genes and three plastid loci across the natural distribution of this species complex and compare the patterns of such variations to the species tree inferred earlier from AFLP data. Results Among the diploid species of A. millefolium agg., gene trees of the two nuclear loci, ncpGS and SBP, and the combined plastid fragments are incongruent with each other and with the AFLP tree likely due to incomplete lineage sorting or secondary introgression. In spite of the large distributional range, no isolation by distance is found. Furthermore, there is evidence for intragenic recombination in the ncpGS gene. An analysis using a probabilistic model for population demographic history indicates large ancestral effective population sizes and short intervals between speciation events. Such a scenario explains the incongruence of the gene trees and species tree we observe. The relationships are particularly complex in the polyploid members of A. millefolium agg. Conclusions The present study indicates that the diploid members of A. millefolium agg. share a large part of their molecular genetic variation. The findings of little lineage sorting and lack of isolation by distance is likely due to short intervals between speciation events and close proximity of ancestral populations. While previous AFLP data provide species trees congruent with earlier morphological classification and phylogeographic considerations, the present sequence data are not suited to recover the relationships of diploid species in A. millefolium agg. For the polyploid taxa many hybrid links and

  4. Modelling metal speciation in the Scheldt Estuary: Combining a flexible-resolution transport model with empirical functions

    Energy Technology Data Exchange (ETDEWEB)

    Elskens, Marc [Vrije Universiteit Brussel, Analytical, Pleinlaan 2, BE-1050 Brussels (Belgium); Gourgue, Olivier [Université catholique de Louvain, Institute of Mechanics, Materials and Civil Engineering (IMMC), 4 Avenue G. Lemaître, bte L4.05.02, BE-1348 Louvain-la-Neuve (Belgium); Université catholique de Louvain, Georges Lemaître Centre for Earth and Climate Research (TECLIM), Place Louis Pasteur 2, bte L4.03.08, BE-1348 Louvain-la-Neuve (Belgium); Baeyens, Willy [Vrije Universiteit Brussel, Analytical, Pleinlaan 2, BE-1050 Brussels (Belgium); Chou, Lei [Université Libre de Bruxelles, Biogéochimie et Modélisation du Système Terre (BGéoSys) —Océanographie Chimique et Géochimie des Eaux, Campus de la Plaine —CP 208, Boulevard du Triomphe, BE-1050 Brussels (Belgium); Deleersnijder, Eric [Université catholique de Louvain, Institute of Mechanics, Materials and Civil Engineering (IMMC), 4 Avenue G. Lemaître, bte L4.05.02, BE-1348 Louvain-la-Neuve (Belgium); Université catholique de Louvain, Earth and Life Institute (ELI), Georges Lemaître Centre for Earth and Climate Research (TECLIM), Place Louis Pasteur 2, bte L4.03.08, BE-1348 Louvain-la-Neuve (Belgium); Leermakers, Martine [Vrije Universiteit Brussel, Analytical, Pleinlaan 2, BE-1050 Brussels (Belgium); and others

    2014-04-01

    Predicting metal concentrations in surface waters is an important step in the understanding and ultimately the assessment of the ecological risk associated with metal contamination. In terms of risk an essential piece of information is the accurate knowledge of the partitioning of the metals between the dissolved and particulate phases, as the former species are generally regarded as the most bioavailable and thus harmful form. As a first step towards the understanding and prediction of metal speciation in the Scheldt Estuary (Belgium, the Netherlands), we carried out a detailed analysis of a historical dataset covering the period 1982–2011. This study reports on the results for two selected metals: Cu and Cd. Data analysis revealed that both the total metal concentration and the metal partitioning coefficient (K{sub d}) could be predicted using relatively simple empirical functions of environmental variables such as salinity and suspended particulate matter concentration (SPM). The validity of these functions has been assessed by their application to salinity and SPM fields simulated by the hydro-environmental model SLIM. The high-resolution total and dissolved metal concentrations reconstructed using this approach, compared surprisingly well with an independent set of validation measurements. These first results from the combined mechanistic-empirical model approach suggest that it may be an interesting tool for risk assessment studies, e.g. to help identify conditions associated with elevated (dissolved) metal concentrations. - Highlights: • Empirical functions were designed for assessing metal speciation in estuarine water. • The empirical functions were implemented in the hydro-environmental model SLIM. • Validation was carried out in the Scheldt Estuary using historical data 1982–2011. • This combined mechanistic-empirical approach is useful for risk assessment.

  5. Genetic variability, local selection and demographic history: genomic evidence of evolving towards allopatric speciation in Asian seabass.

    Science.gov (United States)

    Wang, Le; Wan, Zi Yi; Lim, Huan Sein; Yue, Gen Hua

    2016-08-01

    Genomewide analysis of genetic divergence is critically important in understanding the genetic processes of allopatric speciation. We sequenced RAD tags of 131 Asian seabass individuals of six populations from South-East Asia and Australia/Papua New Guinea. Using 32 433 SNPs, we examined the genetic diversity and patterns of population differentiation across all the populations. We found significant evidence of genetic heterogeneity between South-East Asian and Australian/Papua New Guinean populations. The Australian/Papua New Guinean populations showed a rather lower level of genetic diversity. FST and principal components analysis revealed striking divergence between South-East Asian and Australian/Papua New Guinean populations. Interestingly, no evidence of contemporary gene flow was observed. The demographic history was further tested based on the folded joint site frequency spectrum. The scenario of ancient migration with historical population size changes was suggested to be the best fit model to explain the genetic divergence of Asian seabass between South-East Asia and Australia/Papua New Guinea. This scenario also revealed that Australian/Papua New Guinean populations were founded by ancestors from South-East Asia during mid-Pleistocene and were completely isolated from the ancestral population after the last glacial retreat. We also detected footprints of local selection, which might be related to differential ecological adaptation. The ancient gene flow was examined and deemed likely insufficient to counteract the genetic differentiation caused by genetic drift. The observed genomic pattern of divergence conflicted with the 'genomic islands' scenario. Altogether, Asian seabass have likely been evolving towards allopatric speciation since the split from the ancestral population during mid-Pleistocene. © 2016 John Wiley & Sons Ltd.

  6. Host-symbiont co-speciation and reductive genome evolution in gut symbiotic bacteria of acanthosomatid stinkbugs

    Directory of Open Access Journals (Sweden)

    Kamagata Yoichi

    2009-01-01

    Full Text Available Abstract Background Host-symbiont co-speciation and reductive genome evolution have been commonly observed among obligate endocellular insect symbionts, while such examples have rarely been identified among extracellular ones, the only case reported being from gut symbiotic bacteria of stinkbugs of the family Plataspidae. Considering that gut symbiotic communities are vulnerable to invasion of foreign microbes, gut symbiotic associations have been thought to be evolutionarily not stable. Stinkbugs of the family Acanthosomatidae harbor a bacterial symbiont in the midgut crypts, the lumen of which is completely sealed off from the midgut main tract, thereby retaining the symbiont in the isolated cryptic cavities. We investigated histological, ecological, phylogenetic, and genomic aspects of the unique gut symbiosis of the acanthosomatid stinkbugs. Results Phylogenetic analyses showed that the acanthosomatid symbionts constitute a distinct clade in the γ-Proteobacteria, whose sister groups are the obligate endocellular symbionts of aphids Buchnera and the obligate gut symbionts of plataspid stinkbugs Ishikawaella. In addition to the midgut crypts, the symbionts were located in a pair of peculiar lubricating organs associated with the female ovipositor, by which the symbionts are vertically transmitted via egg surface contamination. The symbionts were detected not from ovaries but from deposited eggs, and surface sterilization of eggs resulted in symbiont-free hatchlings. The symbiont-free insects suffered retarded growth, high mortality, and abnormal morphology, suggesting important biological roles of the symbiont for the host insects. The symbiont phylogeny was generally concordant with the host phylogeny, indicating host-symbiont co-speciation over evolutionary time despite the extracellular association. Meanwhile, some local host-symbiont phylogenetic discrepancies were found, suggesting occasional horizontal symbiont transfers across the host

  7. Ecological analyses and applications

    International Nuclear Information System (INIS)

    Brocksen, R.W.

    1977-01-01

    Progress is reported on the following: analysis of ecological impacts of construction and operation of nuclear power plants; fossil energy environmental project; ecological analysis of geothermal energy development; HUD modular integrated utility systems; expansion of uranium enrichment facilities at Portsmouth; environmental standard review plans; environmental assessment of cooling reservoirs; and analysis of fish impingement at power plants in the southeastern United States

  8. Ecology and economy

    International Nuclear Information System (INIS)

    Menard, M.; Bischoff, J.

    1980-01-01

    The green movement challenges workers' unions and socialists. Who are the 'Greens', and what do they want. Where do their theoretical fundamentals come from. Will an ecological economy be able to function. Are the 'Greens' leftists or dreamers fighting against progress. Arguments for trade unionists and socialists in the ecological controversy. (orig.) [de

  9. Ecological analyses and applications

    International Nuclear Information System (INIS)

    Kroodsma, R.L.; Craig, R.B.; Hildebrand, S.G.

    1978-01-01

    Progress is reported on the following: assessment of nuclear power plants; ecological analysis of uranium mining, milling, and fuel fabrication; environmental impact statements concerning uranium enrichment facilities; site evaluations for storage of radioactive wastes; ecological analysis of geothermal energy development; enhanced oil recovery; environmental monitoring plan for modular integrated utility systems; and fossil energy environmental project

  10. Terrestrial Ecology Guide.

    Science.gov (United States)

    Morrison, James W., Ed.; Hall, James A., Ed.

    This collection of study units focuses on the study of the ecology of land habitats. Considered are such topics as map reading, field techniques, forest ecosystem, birds, insects, small mammals, soils, plant ecology, preparation of terrariums, air pollution, photography, and essentials of an environmental studies program. Each unit contains…

  11. Children's Ecology Books.

    Science.gov (United States)

    Lussenhop, Martha

    Selected for this listing of children's books are fiction and non-fiction books which add to an understanding of ecology, broadly considered here as the study of the interrelationships of organisms to each other and their environment. General ecology, natural resources, man and his environment, evolution and adaptation, appreciation, survival,…

  12. Predictive systems ecology.

    Science.gov (United States)

    Evans, Matthew R; Bithell, Mike; Cornell, Stephen J; Dall, Sasha R X; Díaz, Sandra; Emmott, Stephen; Ernande, Bruno; Grimm, Volker; Hodgson, David J; Lewis, Simon L; Mace, Georgina M; Morecroft, Michael; Moustakas, Aristides; Murphy, Eugene; Newbold, Tim; Norris, K J; Petchey, Owen; Smith, Matthew; Travis, Justin M J; Benton, Tim G

    2013-11-22

    Human societies, and their well-being, depend to a significant extent on the state of the ecosystems that surround them. These ecosystems are changing rapidly usually in response to anthropogenic changes in the environment. To determine the likely impact of environmental change on ecosystems and the best ways to manage them, it would be desirable to be able to predict their future states. We present a proposal to develop the paradigm of predictive systems ecology, explicitly to understand and predict the properties and behaviour of ecological systems. We discuss the necessary and desirable features of predictive systems ecology models. There are places where predictive systems ecology is already being practised and we summarize a range of terrestrial and marine examples. Significant challenges remain but we suggest that ecology would benefit both as a scientific discipline and increase its impact in society if it were to embrace the need to become more predictive.

  13. Spatial ecology across scales.

    Science.gov (United States)

    Hastings, Alan; Petrovskii, Sergei; Morozov, Andrew

    2011-04-23

    The international conference 'Models in population dynamics and ecology 2010: animal movement, dispersal and spatial ecology' took place at the University of Leicester, UK, on 1-3 September 2010, focusing on mathematical approaches to spatial population dynamics and emphasizing cross-scale issues. Exciting new developments in scaling up from individual level movement to descriptions of this movement at the macroscopic level highlighted the importance of mechanistic approaches, with different descriptions at the microscopic level leading to different ecological outcomes. At higher levels of organization, different macroscopic descriptions of movement also led to different properties at the ecosystem and larger scales. New developments from Levy flight descriptions to the incorporation of new methods from physics and elsewhere are revitalizing research in spatial ecology, which will both increase understanding of fundamental ecological processes and lead to tools for better management.

  14. What is dental ecology?

    Science.gov (United States)

    Cuozzo, Frank P; Sauther, Michelle L

    2012-06-01

    Teeth have long been used as indicators of primate ecology. Early work focused on the links between dental morphology, diet, and behavior, with more recent years emphasizing dental wear, microstructure, development, and biogeochemistry, to understand primate ecology. Our study of Lemur catta at the Beza Mahafaly Special Reserve, Madagascar, has revealed an unusual pattern of severe tooth wear and frequent tooth loss, primarily the result of consuming a fallback food for which these primates are not dentally adapted. Interpreting these data was only possible by combining our areas of expertise (dental anatomy [FC] and primate ecology [MS]). By integrating theoretical, methodological, and applied aspects of both areas of research, we adopted the term "dental ecology"-defined as the broad study of how teeth respond to the environment. Specifically, we view dental ecology as an interpretive framework using teeth as a vehicle for understanding an organism's ecology, which builds upon earlier work, but creates a new synthesis of anatomy and ecology that is only possible with detailed knowledge of living primates. This framework includes (1) identifying patterns of dental pathology and tooth use-wear, within the context of feeding ecology, behavior, habitat variation, and anthropogenic change, (2) assessing ways in which dental development and biogeochemical signals can reflect habitat, environmental change and/or stress, and (3) how dental microstructure and macro-morphology are adapted to, and reflect feeding ecology. Here we define dental ecology, provide a short summary of the development of this perspective, and place our new work into this context. Copyright © 2012 Wiley Periodicals, Inc.

  15. A multi-technique investigation of copper and zinc distribution, speciation and potential bioavailability in biosolids

    International Nuclear Information System (INIS)

    Donner, E.; Ryan, C.G.; Howard, D.L.; Zarcinas, B.; Scheckel, K.G.; McGrath, S.P.; Jonge, M.D. de; Paterson, D.; Naidu, R.; Lombi, E.

    2012-01-01

    The use of biosolids in agriculture continues to be debated, largely in relation to their metal contents. Our knowledge regarding the speciation and bioavailability of biosolids metals is still far from complete. In this study, a multi-technique approach was used to investigate copper and zinc speciation and partitioning in one contemporary and two historical biosolids used extensively in previous research and field trials. Using wet chemistry and synchrotron spectroscopy techniques it was shown that copper/zinc speciation in the biosolids was largely equivalent despite the biosolids being derived from different countries over a 50 year period. Furthermore, copper speciation was consistently dominated by sorption to organic matter whereas Zn partitioned mainly to iron oxides. These data suggest that the results of historical field trials are still relevant for modern biosolids and that further risk assessment studies should concentrate particularly on Cu as this metal is associated with the mineralisable biosolids fraction. - Highlights: ► Complementary techniques were used to investigate Cu and Zn speciation in biosolids. ► Historic and contemporary biosolids with differing metal contents were examined. ► Similarities in Cu/Zn speciation were observed irrespective of biosolids provenance. ► Key binding environments identified were organic matter for Cu and Fe oxides for Zn. ► Similarities show historic field trial results are still relevant for biosolids management. - Historic and contemporary biosolids show similarities in Cu/Zn speciation despite having very different total Zn/Cu contents.

  16. Airborne Vertical Profiling of Mercury Speciation near Tullahoma, TN, USA

    Directory of Open Access Journals (Sweden)

    Steve Brooks

    2014-08-01

    Full Text Available Atmospheric transport and in situ oxidation are important factors influencing mercury concentrations at the surface and wet and dry deposition rates. Contributions of both natural and anthropogenic processes can significantly impact burdens of mercury on local, regional and global scales. To address these key issues in atmospheric mercury research, airborne measurements of mercury speciation and ancillary parameters were conducted over a region near Tullahoma, Tennessee, USA, from August 2012 to June 2013. Here, for the first time, we present vertical profiles of Hg speciation from aircraft for an annual cycle over the same location. These airborne measurements included gaseous elemental mercury (GEM, gaseous oxidized mercury (GOM and particulate bound mercury (PBM, as well as ozone (O3, sulfur dioxide (SO2, condensation nuclei (CN and meteorological parameters. The flights, each lasting ~3 h, were conducted typically one week out of each month to characterize seasonality in mercury concentrations. Data obtained from 0 to 6 km altitudes show that GEM exhibited a relatively constant vertical profile for all seasons with an average concentration of 1.38 ± 0.17 ng∙m−3. A pronounced seasonality of GOM was observed, with the highest GOM concentrations up to 120 pg∙m−3 in the summer flights and lowest (0–20 pg∙m−3 in the winter flights. Vertical profiles of GOM show the maximum levels at altitudes between 2 and 4 km. Limited PBM measurements exhibit similar levels to GOM at all altitudes. HYSPLIT back trajectories showed that the trajectories for elevated GOM (>70 pg∙m−3 or PBM concentrations (>30 pg∙m−3 were largely associated with air masses coming from west/northwest, while events with low GOM (<20 pg∙m−3 or PBM concentrations (<5 pg∙m−3 were generally associated with winds from a wider range of wind directions. This is the first set of speciated mercury vertical profiles collected in a single location over the course

  17. Speciated Elemental and Isotopic Characterization of Atmospheric Aerosols - Recent Advances

    Science.gov (United States)

    Shafer, M.; Majestic, B.; Schauer, J.

    2007-12-01

    Detailed elemental, isotopic, and chemical speciation analysis of aerosol particulate matter (PM) can provide valuable information on PM sources, atmospheric processing, and climate forcing. Certain PM sources may best be resolved using trace metal signatures, and elemental and isotopic fingerprints can supplement and enhance molecular maker analysis of PM for source apportionment modeling. In the search for toxicologically relevant components of PM, health studies are increasingly demanding more comprehensive characterization schemes. It is also clear that total metal analysis is at best a poor surrogate for the bioavailable component, and analytical techniques that address the labile component or specific chemical species are needed. Recent sampling and analytical developments advanced by the project team have facilitated comprehensive characterization of even very small masses of atmospheric PM. Historically; this level of detail was rarely achieved due to limitations in analytical sensitivity and a lack of awareness concerning the potential for contamination. These advances have enabled the coupling of advanced chemical characterization to vital field sampling approaches that typically supply only very limited PM mass; e.g. (1) particle size-resolved sampling; (2) personal sampler collections; and (3) fine temporal scale sampling. The analytical tools that our research group is applying include: (1) sector field (high-resolution-HR) ICP-MS, (2) liquid waveguide long-path spectrophotometry (LWG-LPS), and (3) synchrotron x-ray absorption spectroscopy (sXAS). When coupled with an efficient and validated solubilization method, the HR-ICP-MS can provide quantitative elemental information on over 50 elements in microgram quantities of PM. The high mass resolution and enhanced signal-to-noise of HR-ICP-MS significantly advance data quality and quantity over that possible with traditional quadrupole ICP-MS. The LWG-LPS system enables an assessment of the soluble

  18. Selenium speciation influences bioaccumulation in Limnodynastes peronii tadpoles

    Energy Technology Data Exchange (ETDEWEB)

    Lanctôt, C.M., E-mail: c.lanctot@griffith.edu.au [Central Queensland University, School of Medical and Applied Sciences, Gladstone, QLD 4680 (Australia); Australian Rivers Institute, School of Environment, Griffith University, Southport, QLD 4215 (Australia); Melvin, S.D., E-mail: s.melvin@griffith.edu.au [Australian Rivers Institute, School of Environment, Griffith University, Southport, QLD 4215 (Australia); Cresswell, T., E-mail: tom.cresswell@ansto.gov.au [Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia)

    2017-06-15

    Highlights: • Differences in SeIV and SeVI bioaccumulation and biodistribution were assessed. • Limnodynastes peronii tadpoles accumulated more selenite than selenate. • Selenium depuration kinetics was similar for both forms. • Tadpoles accumulated Se predominantly in the digestive and excretory organs. - Abstract: Despite being essential for animal health and fitness, Se has a relatively narrow range between deficiency and toxicity, and excess Se can cause a variety of adverse effects in aquatic organisms. Amphibians are particularly vulnerable to contaminants during larval aquatic life stage, because they can accumulate toxic ions through various routes including skin, gills, lungs and digestive tract. Few attempts have been made to understand the tissue-specific accumulation of trace elements, including the impacts of chemical speciation in developing amphibian larvae. We used radiolabelled {sup 75}Se to explore the biokinetics and tissue distributions of the two dominant forms occurring in surface waters, selenite (SeIV) and selenate (SeVI). Tadpoles of the native Australian frog Limnodynastes peronii were exposed to Se in both forms, and live-animal gamma spectroscopy was used to track accumulation and retention over time. Tissue biodistributions were also quantified at the end of the uptake and depuration phases. Results showed the bioconcentration of SeIV to be 3 times greater compared to SeVI, but rates of elimination were similar for both forms. This suggests a change of Se speciation within the organism prior to excretion. Depuration kinetics were best described by a one-phase exponential decay model, and tadpoles retained approximately 19% of the accumulated Se after 12 days of depuration in clean water. Selenium bioaccumulation was greatest in digestive and excretory organs, as well as the eye, which may directly relate to previously reported Se-induced impairments. Results demonstrate how the use of radiotracing techniques can significantly

  19. Speciation and bioavailability of lead in complementary medicines

    International Nuclear Information System (INIS)

    Bolan, S.; Naidu, R.; Kunhikrishnan, A.; Seshadri, B.; Ok, Y.S.; Palanisami, T.; Dong, M.; Clark, I.

    2016-01-01

    Complementary medicines have associated risks which include toxic heavy metal(loid) and pesticide contamination. The objective of this study was to examine the speciation and bioavailability of lead (Pb) in selected complementary medicines. Six herbal and six ayurvedic medicines were analysed for: (i) total heavy metal(loid) contents including arsenic (As), cadmium (Cd), Pb and mercury (Hg); (ii) speciation of Pb using sequential fractionation and extended x-ray absorption fine structure (EXAFS) techniques; and (iii) bioavailability of Pb using a physiologically-based in vitro extraction test (PBET). The daily intake of Pb through the uptake of these medicines was compared with the safety guidelines for Pb. The results indicated that generally ayurvedic medicines contained higher levels of heavy metal(loid)s than herbal medicines with the amount of Pb much higher than the other metal(loid)s. Sequential fractionation indicated that while organic-bound Pb species dominated the herbal medicines, inorganic-bound Pb species dominated the ayurvedic medicines. EXAFS data indicated the presence of various Pb species in ayurvedic medicines. This implies that Pb is derived from plant uptake and inorganic mineral input in herbal and ayurvedic medicines, respectively. Bioavailability of Pb was higher in ayurvedic than herbal medicines, indicating that Pb added as a mineral therapeutic input is more bioavailable than that derived from plant uptake. There was a positive relationship between soluble Pb fraction and bioavailability indicating that solubility is an important factor controlling bioavailability. The daily intake values for Pb as estimated by total and bioavailable metal(loid) contents are likely to exceed the safe threshold level in certain ayurvedic medicines. This research demonstrated that Pb toxicity is likely to result from the regular intake of these medicines which requires further investigation. - Highlights: • Pb species in complementary medicines was

  20. Rapid sympatric ecological differentiation of crater lake cichlid fishes within historic times

    Directory of Open Access Journals (Sweden)

    Harrod Chris

    2010-05-01

    Full Text Available Abstract Background After a volcano erupts, a lake may form in the cooled crater and become an isolated aquatic ecosystem. This makes fishes in crater lakes informative for understanding sympatric evolution and ecological diversification in barren environments. From a geological and limnological perspective, such research offers insight about the process of crater lake ecosystem establishment and speciation. In the present study we use genetic and coalescence approaches to infer the colonization history of Midas cichlid fishes (Amphilophus cf. citrinellus that inhabit a very young crater lake in Nicaragua-the ca. 1800 year-old Lake Apoyeque. This lake holds two sympatric, endemic morphs of Midas cichlid: one with large, hypertrophied lips (~20% of the total population and another with thin lips. Here we test the associated ecological, morphological and genetic diversification of these two morphs and their potential to represent incipient speciation. Results Gene coalescence analyses [11 microsatellite loci and mitochondrial DNA (mtDNA sequences] suggest that crater lake Apoyeque was colonized in a single event from the large neighbouring great lake Managua only about 100 years ago. This founding in historic times is also reflected in the extremely low nuclear and mitochondrial genetic diversity in Apoyeque. We found that sympatric adult thin- and thick-lipped fishes occupy distinct ecological trophic niches. Diet, body shape, head width, pharyngeal jaw size and shape and stable isotope values all differ significantly between the two lip-morphs. The eco-morphological features pharyngeal jaw shape, body shape, stomach contents and stable isotopes (δ15N all show a bimodal distribution of traits, which is compatible with the expectations of an initial stage of ecological speciation under disruptive selection. Genetic differentiation between the thin- and thick-lipped population is weak at mtDNA sequence (FST = 0.018 and absent at nuclear