Myxomatosis in Australia and Europe: a model for emerging infectious diseases.
Kerr, Peter J
2012-03-01
Myxoma virus is a poxvirus naturally found in two American leporid (rabbit) species (Sylvilagus brasiliensis and Sylvilagus bachmani) in which it causes an innocuous localised cutaneous fibroma. However, in European rabbits (Oryctolagus cuniculus) the same virus causes the lethal disseminated disease myxomatosis. The introduction of myxoma virus into the European rabbit population in Australia in 1950 initiated the best known example of what happens when a novel pathogen jumps into a completely naïve new mammalian host species. The short generation time of the rabbit and their vast numbers in Australia meant evolution could be studied in real time. The carefully documented emergence of attenuated strains of virus that were more effectively transmitted by the mosquito vector and the subsequent selection of rabbits with genetic resistance to myxomatosis is the paradigm for pathogen virulence and host-pathogen coevolution. This natural experiment was repeated with the release of a separate strain of myxoma virus in France in 1952. The subsequent spread of the virus throughout Europe and its coevolution with the rabbit essentially paralleled what occurred in Australia. Detailed molecular studies on myxoma virus have dissected the role of virulence genes in the pathogenesis of myxomatosis and when combined with genomic data and reverse genetics should in future enable the understanding of the molecular evolution of the virus as it adapted to its new host. This review describes the natural history and evolution of myxoma virus together with the molecular biology and experimental pathogenesis studies that are informing our understanding of evolution of emerging diseases. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.
The effect of selection environment on the probability of parallel evolution.
Bailey, Susan F; Rodrigue, Nicolas; Kassen, Rees
2015-06-01
Across the great diversity of life, there are many compelling examples of parallel and convergent evolution-similar evolutionary changes arising in independently evolving populations. Parallel evolution is often taken to be strong evidence of adaptation occurring in populations that are highly constrained in their genetic variation. Theoretical models suggest a few potential factors driving the probability of parallel evolution, but experimental tests are needed. In this study, we quantify the degree of parallel evolution in 15 replicate populations of Pseudomonas fluorescens evolved in five different environments that varied in resource type and arrangement. We identified repeat changes across multiple levels of biological organization from phenotype, to gene, to nucleotide, and tested the impact of 1) selection environment, 2) the degree of adaptation, and 3) the degree of heterogeneity in the environment on the degree of parallel evolution at the gene-level. We saw, as expected, that parallel evolution occurred more often between populations evolved in the same environment; however, the extent of parallel evolution varied widely. The degree of adaptation did not significantly explain variation in the extent of parallelism in our system but number of available beneficial mutations correlated negatively with parallel evolution. In addition, degree of parallel evolution was significantly higher in populations evolved in a spatially structured, multiresource environment, suggesting that environmental heterogeneity may be an important factor constraining adaptation. Overall, our results stress the importance of environment in driving parallel evolutionary changes and point to a number of avenues for future work for understanding when evolution is predictable. © The Author 2015. 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.
Host Genetic Variation Does Not Determine Spatio-Temporal Patterns of European Bat 1 Lyssavirus.
Troupin, Cécile; Picard-Meyer, Evelyne; Dellicour, Simon; Casademont, Isabelle; Kergoat, Lauriane; Lepelletier, Anthony; Dacheux, Laurent; Baele, Guy; Monchâtre-Leroy, Elodie; Cliquet, Florence; Lemey, Philippe; Bourhy, Hervé
2017-11-01
The majority of bat rabies cases in Europe are attributed to European bat 1 lyssavirus (EBLV-1), circulating mainly in serotine bats (Eptesicus serotinus). Two subtypes have been defined (EBLV-1a and EBLV-1b), each associated with a different geographical distribution. In this study, we undertake a comprehensive sequence analysis based on 80 newly obtained EBLV-1 nearly complete genome sequences from nine European countries over a 45-year period to infer selection pressures, rates of nucleotide substitution, and evolutionary time scale of these two subtypes in Europe. Our results suggest that the current lineage of EBLV-1 arose in Europe ∼600 years ago and the virus has evolved at an estimated average substitution rate of ∼4.19×10-5 subs/site/year, which is among the lowest recorded for RNA viruses. In parallel, we investigate the genetic structure of French serotine bats at both the nuclear and mitochondrial level and find that they constitute a single genetic cluster. Furthermore, Mantel tests based on interindividual distances reveal the absence of correlation between genetic distances estimated between viruses and between host individuals. Taken together, this indicates that the genetic diversity observed in our E. serotinus samples does not account for EBLV-1a and -1b segregation and dispersal in Europe. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Emms, David M; Covshoff, Sarah; Hibberd, Julian M; Kelly, Steven
2016-07-01
C4 photosynthesis is considered one of the most remarkable examples of evolutionary convergence in eukaryotes. However, it is unknown whether the evolution of C4 photosynthesis required the evolution of new genes. Genome-wide gene-tree species-tree reconciliation of seven monocot species that span two origins of C4 photosynthesis revealed that there was significant parallelism in the duplication and retention of genes coincident with the evolution of C4 photosynthesis in these lineages. Specifically, 21 orthologous genes were duplicated and retained independently in parallel at both C4 origins. Analysis of this gene cohort revealed that the set of parallel duplicated and retained genes is enriched for genes that are preferentially expressed in bundle sheath cells, the cell type in which photosynthesis was activated during C4 evolution. Furthermore, functional analysis of the cohort of parallel duplicated genes identified SWEET-13 as a potential key transporter in the evolution of C4 photosynthesis in grasses, and provides new insight into the mechanism of phloem loading in these C4 species. C4 photosynthesis, gene duplication, gene families, parallel evolution. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Range-wide parallel climate-associated genomic clines in Atlantic salmon
Stanley, Ryan R. E.; Wringe, Brendan F.; Guijarro-Sabaniel, Javier; Bourret, Vincent; Bernatchez, Louis; Bentzen, Paul; Beiko, Robert G.; Gilbey, John; Clément, Marie; Bradbury, Ian R.
2017-01-01
Clinal variation across replicated environmental gradients can reveal evidence of local adaptation, providing insight into the demographic and evolutionary processes that shape intraspecific diversity. Using 1773 genome-wide single nucleotide polymorphisms we evaluated latitudinal variation in allele frequency for 134 populations of North American and European Atlantic salmon (Salmo salar). We detected 84 (4.74%) and 195 (11%) loci showing clinal patterns in North America and Europe, respectively, with 12 clinal loci in common between continents. Clinal single nucleotide polymorphisms were evenly distributed across the salmon genome and logistic regression revealed significant associations with latitude and seasonal temperatures, particularly average spring temperature in both continents. Loci displaying parallel clines were associated with several metabolic and immune functions, suggesting a potential basis for climate-associated adaptive differentiation. These climate-based clines collectively suggest evidence of large-scale environmental associated differences on either side of the North Atlantic. Our results support patterns of parallel evolution on both sides of the North Atlantic, with evidence of both similar and divergent underlying genetic architecture. The identification of climate-associated genomic clines illuminates the role of selection and demographic processes on intraspecific diversity in this species and provides a context in which to evaluate the impacts of climate change. PMID:29291123
Emms, David M.; Covshoff, Sarah; Hibberd, Julian M.; Kelly, Steven
2016-01-01
C4 photosynthesis is considered one of the most remarkable examples of evolutionary convergence in eukaryotes. However, it is unknown whether the evolution of C4 photosynthesis required the evolution of new genes. Genome-wide gene-tree species-tree reconciliation of seven monocot species that span two origins of C4 photosynthesis revealed that there was significant parallelism in the duplication and retention of genes coincident with the evolution of C4 photosynthesis in these lineages. Specifically, 21 orthologous genes were duplicated and retained independently in parallel at both C4 origins. Analysis of this gene cohort revealed that the set of parallel duplicated and retained genes is enriched for genes that are preferentially expressed in bundle sheath cells, the cell type in which photosynthesis was activated during C4 evolution. Furthermore, functional analysis of the cohort of parallel duplicated genes identified SWEET-13 as a potential key transporter in the evolution of C4 photosynthesis in grasses, and provides new insight into the mechanism of phloem loading in these C4 species. Key words: C4 photosynthesis, gene duplication, gene families, parallel evolution. PMID:27016024
Bouwstra, R J; Koch, G; Heutink, R; Harders, F; van der Spek, A; Elbers, A R; Bossers, A
2015-07-02
Phylogenetic analysis of highly pathogenic avian influenza A(H5N8) virus strains causing outbreaks in Dutch poultry farms in 2014 provides evidence for separate introduction of the virus in four outbreaks in farms located 16-112 km from each other and for between-farm transmission between the third and fourth outbreak in farms located 550 m from each other. In addition, the analysis showed that all European and two Japanese H5N8 virus strains are very closely related and seem to originate from a calculated common ancestor, which arose between July and September 2014. Our findings suggest that the Dutch outbreak virus strain 'Ter Aar' and the first German outbreak strain from 2014 shared a common ancestor. In addition, the data indicate that the Dutch outbreak viruses descended from an H5N8 virus that circulated around 2009 in Asia, possibly China, and subsequently spread to South Korea and Japan and finally also to Europe. Evolution of the virus seemed to follow a parallel track in Japan and Europe, which supports the hypothesis that H5N8 virus was exchanged between migratory wild waterfowl at their breeding grounds in Siberia and from there was carried by migrating waterfowl to Europe.
Making sense of Islamic creationism in Europe.
Hameed, Salman
2015-05-01
Islamic creationism has been noted as a serious concern in Europe. There have been reports of boycotts of university evolution lectures and, in one extreme case, even a threat of violence. While religious objections are indeed at play in some cases, our understanding of the rise of Islamic creationism should also take into account socioeconomic disparities and its impact on education for Muslim minorities in Europe. Furthermore, the broader narrative of rejection of evolution in Europe, for some Muslims, may be bound up in reactions to the secular culture and in the formation of their own minority religious identity. On the other hand, the stories of Muslim rejection of evolution in media end up reinforcing the stereotype of Muslims as "outsiders" and a threat to the European education system. A nuanced understanding of this dynamic may benefit those who support both the propagation of good science and favor cultural pluralism. © The Author(s) 2014.
Similar traits, different genes? Examining convergent evolution in related weedy rice populations
USDA-ARS?s Scientific Manuscript database
Convergent phenotypic evolution may or may not be associated with parallel genotypic evolution. Agricultural weeds have repeatedly been selected for weed-adaptive traits such as rapid growth, increased seed dispersal and dormancy, thus providing an ideal system for the study of parallel evolution. H...
Validation of neoclassical bootstrap current models in the edge of an H-mode plasma.
Wade, M R; Murakami, M; Politzer, P A
2004-06-11
Analysis of the parallel electric field E(parallel) evolution following an L-H transition in the DIII-D tokamak indicates the generation of a large negative pulse near the edge which propagates inward, indicative of the generation of a noninductive edge current. Modeling indicates that the observed E(parallel) evolution is consistent with a narrow current density peak generated in the plasma edge. Very good quantitative agreement is found between the measured E(parallel) evolution and that expected from neoclassical theory predictions of the bootstrap current.
Hanson, Marta; Pomata, Gianna
2017-03-01
This essay deals with the medical recipe as an epistemic genre that played an important role in the cross-cultural transmission of knowledge. The article first compares the development of the recipe as a textual form in Chinese and European premodern medical cultures. It then focuses on the use of recipes in the transmission of Chinese pharmacology to Europe in the second half of the seventeenth century. The main sources examined are the Chinese medicinal formulas translated—presumably—by the Jesuit Michael Boym and published in Specimen Medicinae Sinicae (1682), a text that introduced Chinese pulse medicine to Europe. The article examines how the translator rendered the Chinese formulas into Latin for a European audience. Arguably, the translation was facilitated by the fact that the recipe as a distinct epistemic genre had developed, with strong parallels, in both Europe and China. Building on these parallels, the translator used the recipe as a shared textual format that would allow the transfer of knowledge between the two medical cultures.
Population structure and cultural geography of a folktale in Europe
Ross, Robert M.; Greenhill, Simon J.; Atkinson, Quentin D.
2013-01-01
Despite a burgeoning science of cultural evolution, relatively little work has focused on the population structure of human cultural variation. By contrast, studies in human population genetics use a suite of tools to quantify and analyse spatial and temporal patterns of genetic variation within and between populations. Human genetic diversity can be explained largely as a result of migration and drift giving rise to gradual genetic clines, together with some discontinuities arising from geographical and cultural barriers to gene flow. Here, we adapt theory and methods from population genetics to quantify the influence of geography and ethnolinguistic boundaries on the distribution of 700 variants of a folktale in 31 European ethnolinguistic populations. We find that geographical distance and ethnolinguistic affiliation exert significant independent effects on folktale diversity and that variation between populations supports a clustering concordant with European geography. This pattern of geographical clines and clusters parallels the pattern of human genetic diversity in Europe, although the effects of geographical distance and ethnolinguistic boundaries are stronger for folktales than genes. Our findings highlight the importance of geography and population boundaries in models of human cultural variation and point to key similarities and differences between evolutionary processes operating on human genes and culture. PMID:23390109
SOVCAN STAR: An international satellite system
NASA Astrophysics Data System (ADS)
Skatchkov, Valery A.
SOVCAN STAR is a Russian-Canadian cooperative venture company formed to manufacture, test, launch and operate a Ku-band satellite system. Drawing on the more than twenty years communications satellite experience of the founding companies, the SOVCAN STAR satellites are being designed to be competitive and cost effective. They will be equipped with 24 transponders and four steerable antennas. The design allows the operators to switch individual transponders between the various antenna coverage beams. These satellites will offer a high degree of operational flexibility and performance. The SOVCAN STAR strategy is to develop a network of satellites in parallel with the growth and evolution of the traffic requirements. Such an approach minimizes the technical, schedule and program risks while at the same time significantly reduces the financial exposure. The first SOVCAN STAR satellite will be commissioned in 1996 and operated at 14 deg W. The beams will be aligned to North America and Europe offering International service between Canada, the Eastern U.S.A., Europe, Russia and the Western C.I.S. Republics. The second SOVCAN STAR satellite will be commissioned a year later and operated at 145 deg E. This satellite will cover the Western Pacific Ocean, Eastern Asia and Australasia.
Emms, David M.; Covshoff, Sarah; Hibberd, Julian M.; ...
2016-03-24
C4 photosynthesis is considered one of the most remarkable examples of evolutionary convergence in eukaryotes. However, it is unknown whether the evolution of C4 photosynthesis required the evolution of new genes. Genome-wide gene-tree species-tree reconciliation of seven monocot species that span two origins of C4 photosynthesis revealed that there was significant parallelism in the duplication and retention of genes coincident with the evolution of C4 photosynthesis in these lineages. Specifically, 21 orthologous genes were duplicated and retained independently in parallel at both C4 origins. Analysis of this gene cohort revealed that the set of parallel duplicated and retained genes ismore » enriched for genes that are preferentially expressed in bundle sheath cells, the cell type in which photosynthesis was activated during C4 evolution. Moreover, functional analysis of the cohort of parallel duplicated genes identified SWEET-13 as a potential key transporter in the evolution of C4 photosynthesis in grasses, and provides new insight into the mechanism of phloem loading in these C4 species.« less
Long-term trends in emissions and transboundary transport of acidifying air pollution in Europe
DOE Office of Scientific and Technical Information (OSTI.GOV)
Berge, E.; Bartnicki, J.; Olendrzynski, K.
1999-09-01
The time evolution of the atmospheric emissions and depositions of sulphur and nitrogen compounds in Europe have been studied in this paper. Source-receptor matrices, which quantify the transboundary transport between the European countries, are presented. The temporal evolution of exceedances of the critical loads have also been analyzed. The present (1995) emission and deposition levels are also presented. The database utilized in this study is the one presently employed under the 1979 Geneva Convention on Long Range Transboundary Air Pollution. The emission data reported to EMEP indicate that the European sulfur emissions declined by approximately 50% during the period 1980--1995.more » Larger reductions were found in the area of the Former Soviet Union and western Europe than in central eastern Europe. For oxidized and reduced nitrogen the overall European reductions were approximately 15% from 1980 to 1995. Both oxidized and reduced nitrogen emissions fell more in eastern Europe than in western Europe.« less
Enzmann, Peter-Joachim; Castric, Jeannette; Bovo, Giuseppe; Thiery, Richard; Fichtner, Dieter; Schütze, Heike; Wahli, Thomas
2010-02-24
The fish pathogenic rhabdovirus infectious hematopoietic necrosis virus (IHNV) causes substantial losses in European aquaculture. IHNV was first detected in Europe in 1987 and has since undergone considerable spread. Phylogenetic analyses of the full G-gene sequences of 73 isolates obtained from 4 countries in Europe (France, n = 18; Italy, 9; Switzerland, 4; Germany, 42) enable determination of the evolution of the virus in Europe since the first detection, and identification of characteristic changes within the G-genes of European strains. Further, the database allows us to analyse the pathways of distribution in Europe over time. The results suggest that in most of the recent cases, spread of IHNV was related to trade of infected fish. The data further demonstrate that knowledge of the sequence is required to determine the source of infections in farms.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Emms, David M.; Covshoff, Sarah; Hibberd, Julian M.
C4 photosynthesis is considered one of the most remarkable examples of evolutionary convergence in eukaryotes. However, it is unknown whether the evolution of C4 photosynthesis required the evolution of new genes. Genome-wide gene-tree species-tree reconciliation of seven monocot species that span two origins of C4 photosynthesis revealed that there was significant parallelism in the duplication and retention of genes coincident with the evolution of C4 photosynthesis in these lineages. Specifically, 21 orthologous genes were duplicated and retained independently in parallel at both C4 origins. Analysis of this gene cohort revealed that the set of parallel duplicated and retained genes ismore » enriched for genes that are preferentially expressed in bundle sheath cells, the cell type in which photosynthesis was activated during C4 evolution. Moreover, functional analysis of the cohort of parallel duplicated genes identified SWEET-13 as a potential key transporter in the evolution of C4 photosynthesis in grasses, and provides new insight into the mechanism of phloem loading in these C4 species.« less
Modernisation of Higher Education in Europe: Access, Retention and Employability. Eurydice Brief
ERIC Educational Resources Information Center
Crosier, David; Horvath, Anna; Kerpanova, Viera; Kocanova, Daniela; Riihelainen, Jari
2015-01-01
The information in this Eurydice Brief is drawn from the report, "Modernisation of higher education in Europe 2014: access, retention and employability." The report is the second in a series examining the evolution of the European Commission's modernisation agenda for higher education in Europe. Information for the report was gathered…
Gascoyne, D M; Heritage, J; Hawkey, P M; Turner, A; van Klingeren, B
1991-08-01
High level tetracycline resistant strains of Neisseria gonorrhoeae (TRNG) have been shown to carry a 40.6 kb (25.2 MDa) conjugative plasmid with a Class M tetracycline resistance determinant. Restriction endonuclease analysis mapping showed that there were at least two different TRNG plasmid types which were found in geographically distinct locations. The physical maps of these two plasmids were compared to a gonococcal conjugative plasmid which did not encode tetracycline resistance. The plasmid type which is endemic in the Netherlands was found to be closely related to the gonococcal conjugative plasmid, which supports the established hypothesis that the 40.6 kb plasmid has evolved by transposition of the TetM determinant into the conjugative plasmid. The plasmid found in the United States has either evolved by substantial divergent evolution or it results from a different transposition event. In the UK there have been isolations of TRNGs carrying either of the two plasmid types reflecting a flow of people both across the Atlantic and in Europe. It is possible that further TetM-containing plasmids will be found in N. gonorrhoeae paralleling the family of TEM beta-lactamase encoding plasmids already described.
Ferchaud, Anne-Laure; Hansen, Michael M
2016-01-01
Heterogeneous genomic divergence between populations may reflect selection, but should also be seen in conjunction with gene flow and drift, particularly population bottlenecks. Marine and freshwater three-spine stickleback (Gasterosteus aculeatus) populations often exhibit different lateral armour plate morphs. Moreover, strikingly parallel genomic footprints across different marine-freshwater population pairs are interpreted as parallel evolution and gene reuse. Nevertheless, in some geographic regions like the North Sea and Baltic Sea, different patterns are observed. Freshwater populations in coastal regions are often dominated by marine morphs, suggesting that gene flow overwhelms selection, and genomic parallelism may also be less pronounced. We used RAD sequencing for analysing 28 888 SNPs in two marine and seven freshwater populations in Denmark, Europe. Freshwater populations represented a variety of environments: river populations accessible to gene flow from marine sticklebacks and large and small isolated lakes with and without fish predators. Sticklebacks in an accessible river environment showed minimal morphological and genomewide divergence from marine populations, supporting the hypothesis of gene flow overriding selection. Allele frequency spectra suggested bottlenecks in all freshwater populations, and particularly two small lake populations. However, genomic footprints ascribed to selection could nevertheless be identified. No genomic regions were consistent freshwater-marine outliers, and parallelism was much lower than in other comparable studies. Two genomic regions previously described to be under divergent selection in freshwater and marine populations were outliers between different freshwater populations. We ascribe these patterns to stronger environmental heterogeneity among freshwater populations in our study as compared to most other studies, although the demographic history involving bottlenecks should also be considered in the interpretation of results. © 2015 John Wiley & Sons Ltd.
Manousaki, Tereza; Hull, Pincelli M; Kusche, Henrik; Machado-Schiaffino, Gonzalo; Franchini, Paolo; Harrod, Chris; Elmer, Kathryn R; Meyer, Axel
2013-02-01
The study of parallel evolution facilitates the discovery of common rules of diversification. Here, we examine the repeated evolution of thick lips in Midas cichlid fishes (the Amphilophus citrinellus species complex)-from two Great Lakes and two crater lakes in Nicaragua-to assess whether similar changes in ecology, phenotypic trophic traits and gene expression accompany parallel trait evolution. Using next-generation sequencing technology, we characterize transcriptome-wide differential gene expression in the lips of wild-caught sympatric thick- and thin-lipped cichlids from all four instances of repeated thick-lip evolution. Six genes (apolipoprotein D, myelin-associated glycoprotein precursor, four-and-a-half LIM domain protein 2, calpain-9, GTPase IMAP family member 8-like and one hypothetical protein) are significantly underexpressed in the thick-lipped morph across all four lakes. However, other aspects of lips' gene expression in sympatric morphs differ in a lake-specific pattern, including the magnitude of differentially expressed genes (97-510). Generally, fewer genes are differentially expressed among morphs in the younger crater lakes than in those from the older Great Lakes. Body shape, lower pharyngeal jaw size and shape, and stable isotopes (δ(13)C and δ(15)N) differ between all sympatric morphs, with the greatest differentiation in the Great Lake Nicaragua. Some ecological traits evolve in parallel (those related to foraging ecology; e.g. lip size, body and head shape) but others, somewhat surprisingly, do not (those related to diet and food processing; e.g. jaw size and shape, stable isotopes). Taken together, this case of parallelism among thick- and thin-lipped cichlids shows a mosaic pattern of parallel and nonparallel evolution. © 2012 Blackwell Publishing Ltd.
Kimmel, Charles B.; Cresko, William A.; Phillips, Patrick C.; Ullmann, Bonnie; Currey, Mark; von Hippel, Frank; Kristjánsson, Bjarni K.; Gelmond, Ofer; McGuigan, Katrina
2014-01-01
Evolution of similar phenotypes in independent populations is often taken as evidence of adaptation to the same fitness optimum. However, the genetic architecture of traits might cause evolution to proceed more often toward particular phenotypes, and less often toward others, independently of the adaptive value of the traits. Freshwater populations of Alaskan threespine stickleback have repeatedly evolved the same distinctive opercle shape after divergence from an oceanic ancestor. Here we demonstrate that this pattern of parallel evolution is widespread, distinguishing oceanic and freshwater populations across the Pacific Coast of North America and Iceland. We test whether this parallel evolution reflects genetic bias by estimating the additive genetic variance– covariance matrix (G) of opercle shape in an Alaskan oceanic (putative ancestral) population. We find significant additive genetic variance for opercle shape and that G has the potential to be biasing, because of the existence of regions of phenotypic space with low additive genetic variation. However, evolution did not occur along major eigenvectors of G, rather it occurred repeatedly in the same directions of high evolvability. We conclude that the parallel opercle evolution is most likely due to selection during adaptation to freshwater habitats, rather than due to biasing effects of opercle genetic architecture. PMID:22276538
Molecular pathways to parallel evolution: I. Gene nexuses and their morphological correlates.
Zuckerkandl, E
1994-12-01
Aspects of the regulatory interactions among genes are probably as old as most genes are themselves. Correspondingly, similar predispositions to changes in such interactions must have existed for long evolutionary periods. Features of the structure and the evolution of the system of gene regulation furnish the background necessary for a molecular understanding of parallel evolution. Patently "unrelated" organs, such as the fat body of a fly and the liver of a mammal, can exhibit fractional homology, a fraction expected to become subject to quantitation. This also seems to hold for different organs in the same organism, such as wings and legs of a fly. In informational macromolecules, on the other hand, homology is indeed all or none. In the quite different case of organs, analogy is expected usually to represent attenuated homology. Many instances of putative convergence are likely to turn out to be predominantly parallel evolution, presumably including the case of the vertebrate and cephalopod eyes. Homology in morphological features reflects a similarity in networks of active genes. Similar nexuses of active genes can be established in cells of different embryological origins. Thus, parallel development can be considered a counterpart to parallel evolution. Specific macromolecular interactions leading to the regulation of the c-fos gene are given as an example of a "controller node" defined as a regulatory unit. Quantitative changes in gene control are distinguished from relational changes, and frequent parallelism in quantitative changes is noted in Drosophila enzymes. Evolutionary reversions in quantitative gene expression are also expected. The evolution of relational patterns is attributed to several distinct mechanisms, notably the shuffling of protein domains. The growth of such patterns may in part be brought about by a particular process of compensation for "controller gene diseases," a process that would spontaneously tend to lead to increased regulatory and organismal complexity. Despite the inferred increase in gene interaction complexity, whose course over evolutionary time is unknown, the number of homology groups for the functional and structural protein units designated as domains has probably remained rather constant, even as, in some of its branches, evolution moved toward "higher" organisms. In connection with this process, the question is raised of parallel evolution within the purview of activating and repressing master switches and in regard to the number of levels into which the hierarchies of genic master switches will eventually be resolved.
Evolving binary classifiers through parallel computation of multiple fitness cases.
Cagnoni, Stefano; Bergenti, Federico; Mordonini, Monica; Adorni, Giovanni
2005-06-01
This paper describes two versions of a novel approach to developing binary classifiers, based on two evolutionary computation paradigms: cellular programming and genetic programming. Such an approach achieves high computation efficiency both during evolution and at runtime. Evolution speed is optimized by allowing multiple solutions to be computed in parallel. Runtime performance is optimized explicitly using parallel computation in the case of cellular programming or implicitly taking advantage of the intrinsic parallelism of bitwise operators on standard sequential architectures in the case of genetic programming. The approach was tested on a digit recognition problem and compared with a reference classifier.
Atkinson, Quentin D; Gray, Russell D
2005-08-01
In The Descent of Man (1871), Darwin observed "curious parallels" between the processes of biological and linguistic evolution. These parallels mean that evolutionary biologists and historical linguists seek answers to similar questions and face similar problems. As a result, the theory and methodology of the two disciplines have evolved in remarkably similar ways. In addition to Darwin's curious parallels of process, there are a number of equally curious parallels and connections between the development of methods in biology and historical linguistics. Here we briefly review the parallels between biological and linguistic evolution and contrast the historical development of phylogenetic methods in the two disciplines. We then look at a number of recent studies that have applied phylogenetic methods to language data and outline some current problems shared by the two fields.
Collective Landmarks for Deep Time: A New Tool for Evolution Education
ERIC Educational Resources Information Center
Delgado, Cesar
2014-01-01
Evolution is a fundamental, organising concept in biology, yet there is widespread resistance to evolution among US students and there are rising creationist challenges in Europe. Resistance to evolution is linked to lack of understanding of the age of the Earth. An understanding of deep time is thus essential for effective biology education.…
JPRS Report Science & Technology Europe.
1992-10-22
Potatoes for More Sugar [Frankfurt/Main FRANKFURTER ALLEGEMEINE, 12 Aug 92] 26 COMPUTERS French Devise Operating System for Parallel, Failure...Tolerant and Real-Time Systems [Munich COMPUTER WOCHE, 5 Jun 92] 27 Germany Markets External Mass Memory for IBM-Compatible Parallel Interfaces...Infrared Detection System [Thierry Lucas; Paris L’USINE NOUVELLE TECHNOLOGIES, 16 Jul 92] 28 Streamlined ACE Fighter Airplane Approved [Paris AFP
Networks of lexical borrowing and lateral gene transfer in language and genome evolution
List, Johann-Mattis; Nelson-Sathi, Shijulal; Geisler, Hans; Martin, William
2014-01-01
Like biological species, languages change over time. As noted by Darwin, there are many parallels between language evolution and biological evolution. Insights into these parallels have also undergone change in the past 150 years. Just like genes, words change over time, and language evolution can be likened to genome evolution accordingly, but what kind of evolution? There are fundamental differences between eukaryotic and prokaryotic evolution. In the former, natural variation entails the gradual accumulation of minor mutations in alleles. In the latter, lateral gene transfer is an integral mechanism of natural variation. The study of language evolution using biological methods has attracted much interest of late, most approaches focusing on language tree construction. These approaches may underestimate the important role that borrowing plays in language evolution. Network approaches that were originally designed to study lateral gene transfer may provide more realistic insights into the complexities of language evolution. PMID:24375688
Many-to-one form-to-function mapping weakens parallel morphological evolution.
Thompson, Cole J; Ahmed, Newaz I; Veen, Thor; Peichel, Catherine L; Hendry, Andrew P; Bolnick, Daniel I; Stuart, Yoel E
2017-11-01
Evolutionary ecologists aim to explain and predict evolutionary change under different selective regimes. Theory suggests that such evolutionary prediction should be more difficult for biomechanical systems in which different trait combinations generate the same functional output: "many-to-one mapping." Many-to-one mapping of phenotype to function enables multiple morphological solutions to meet the same adaptive challenges. Therefore, many-to-one mapping should undermine parallel morphological evolution, and hence evolutionary predictability, even when selection pressures are shared among populations. Studying 16 replicate pairs of lake- and stream-adapted threespine stickleback (Gasterosteus aculeatus), we quantified three parts of the teleost feeding apparatus and used biomechanical models to calculate their expected functional outputs. The three feeding structures differed in their form-to-function relationship from one-to-one (lower jaw lever ratio) to increasingly many-to-one (buccal suction index, opercular 4-bar linkage). We tested for (1) weaker linear correlations between phenotype and calculated function, and (2) less parallel evolution across lake-stream pairs, in the many-to-one systems relative to the one-to-one system. We confirm both predictions, thus supporting the theoretical expectation that increasing many-to-one mapping undermines parallel evolution. Therefore, sole consideration of morphological variation within and among populations might not serve as a proxy for functional variation when multiple adaptive trait combinations exist. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.
Evolution method and ``differential hierarchy'' of colored knot polynomials
NASA Astrophysics Data System (ADS)
Mironov, A.; Morozov, A.; Morozov, And.
2013-10-01
We consider braids with repeating patterns inside arbitrary knots which provides a multi-parametric family of knots, depending on the "evolution" parameter, which controls the number of repetitions. The dependence of knot (super)polynomials on such evolution parameters is very easy to find. We apply this evolution method to study of the families of knots and links which include the cases with just two parallel and anti-parallel strands in the braid, like the ordinary twist and 2-strand torus knots/links and counter-oriented 2-strand links. When the answers were available before, they are immediately reproduced, and an essentially new example is added of the "double braid", which is a combination of parallel and anti-parallel 2-strand braids. This study helps us to reveal with the full clarity and partly investigate a mysterious hierarchical structure of the colored HOMFLY polynomials, at least, in (anti)symmetric representations, which extends the original observation for the figure-eight knot to many (presumably all) knots. We demonstrate that this structure is typically respected by the t-deformation to the superpolynomials.
Parallel evolution of sexual isolation in sticklebacks.
Boughman, Janette Wenrick; Rundle, Howard D; Schluter, Dolph
2005-02-01
Mechanisms of speciation are not well understood, despite decades of study. Recent work has focused on how natural and sexual selection cause sexual isolation. Here, we investigate the roles of divergent natural and sexual selection in the evolution of sexual isolation between sympatric species of threespine sticklebacks. We test the importance of morphological and behavioral traits in conferring sexual isolation and examine to what extent these traits have diverged in parallel between multiple, independently evolved species pairs. We use the patterns of evolution in ecological and mating traits to infer the likely nature of selection on sexual isolation. Strong parallel evolution implicates ecologically based divergent natural and/or sexual selection, whereas arbitrary directionality implicates nonecological sexual selection or drift. In multiple pairs we find that sexual isolation arises in the same way: assortative mating on body size and asymmetric isolation due to male nuptial color. Body size and color have diverged in a strongly parallel manner, similar to ecological traits. The data implicate ecologically based divergent natural and sexual selection as engines of speciation in this group.
NASA Astrophysics Data System (ADS)
Couvidat, Florian; Bessagnet, Bertrand; Garcia-Vivanco, Marta; Real, Elsa; Menut, Laurent; Colette, Augustin
2018-01-01
A new aerosol module was developed and integrated in the air quality model CHIMERE. Developments include the use of the Model of Emissions and Gases and Aerosols from Nature (MEGAN) 2.1 for biogenic emissions, the implementation of the inorganic thermodynamic model ISORROPIA 2.1, revision of wet deposition processes and of the algorithms of condensation/evaporation and coagulation and the implementation of the secondary organic aerosol (SOA) mechanism H2O and the thermodynamic model SOAP. Concentrations of particles over Europe were simulated by the model for the year 2013. Model concentrations were compared to the European Monitoring and Evaluation Programme (EMEP) observations and other observations available in the EBAS database to evaluate the performance of the model. Performances were determined for several components of particles (sea salt, sulfate, ammonium, nitrate, organic aerosol) with a seasonal and regional analysis of results. The model gives satisfactory performance in general. For sea salt, the model succeeds in reproducing the seasonal evolution of concentrations for western and central Europe. For sulfate, except for an overestimation of sulfate in northern Europe, modeled concentrations are close to observations and the model succeeds in reproducing the seasonal evolution of concentrations. For organic aerosol, the model reproduces with satisfactory results concentrations for stations with strong modeled biogenic SOA concentrations. However, the model strongly overestimates ammonium nitrate concentrations during late autumn (possibly due to problems in the temporal evolution of emissions) and strongly underestimates summer organic aerosol concentrations over most of the stations (especially in the northern half of Europe). This underestimation could be due to a lack of anthropogenic SOA or biogenic emissions in northern Europe. A list of recommended tests and developments to improve the model is also given.
Neglected diseases amid wealth in the United States and Europe.
Hotez, Peter
2009-01-01
Neglected tropical diseases are not exclusive to low-income countries. In the United States, such infections account for a sizable but largely hidden disease burden among minority populations living in poverty and among people of African descent in particular. Similar infections also occur in Europe. As efforts to control neglected tropical diseases expand throughout Africa, parallel efforts should also target poor and forgotten people in wealthy nations.
Agriculture of the Soviet Union and Eastern Europe.
ERIC Educational Resources Information Center
Stebelsky, Ihor
1985-01-01
Food production in the Soviet Union and Eastern Europe is described; the opportunities and limitations of the region's land resources for agriculture are examined; and the evolution of the institutional structures of agriculture are discussed. Recent developments to improve the food supply are outlined. (RM)
Parallel Evolution of Polydactyly Traits in Chinese and European Chickens.
Zhang, Zebin; Nie, Changsheng; Jia, Yaxiong; Jiang, Runshen; Xia, Haijian; Lv, Xueze; Chen, Yu; Li, Junying; Li, Xianyao; Ning, Zhonghua; Xu, Guiyun; Chen, Jilan; Yang, Ning; Qu, Lujiang
2016-01-01
Polydactyly is one of the most common hereditary congenital limb malformations in chickens and other vertebrates. The zone of polarizing activity regulatory sequence (ZRS) is critical for the development of polydactyly. The causative mutation of polydactyly in the Silkie chicken has been mapped to the ZRS; however, the causative mutations of other chicken breeds are yet to be established. To understand whether the same mutation decides the polydactyly phenotype in other chicken breeds, we detected the single-nucleotide polymorphism in 26 different chicken breeds, specifically, 24 Chinese indigenous breeds and 2 European breeds. The mutation was found to have fully penetrated chickens with polydactyly in China, indicating that it is causative for polydactyly in Chinese indigenous chickens. In comparison, the mutation showed no association with polydactyly in Houdan chickens, which originate from France, Europe. Based on the different morphology of polydactyly in Chinese and European breeds, we assumed that the trait might be attributable to different genetic foundations. Therefore, we subsequently performed genome-wide association analysis (GWAS) to locate the region associated with polydactyly. As a result, a ~0.39 Mb genomic region on GGA2p was identified. The region contains six candidate genes, with the causative mutation found in Chinese indigenous breeds also being located in this region. Our results demonstrate that polydactyly in chickens from China and Europe is caused by two independent mutation events that are closely located in the chicken genome.
Liu, Shenglin; Hansen, Michael M; Jacobsen, Magnus W
2016-10-01
We analysed 81 whole genome sequences of threespine sticklebacks from Pacific North America, Greenland and Northern Europe, representing 16 populations. Principal component analysis of nuclear SNPs grouped populations according to geographical location, with Pacific populations being more divergent from each other relative to European and Greenlandic populations. Analysis of mitogenome sequences showed Northern European populations to represent a single phylogeographical lineage, whereas Greenlandic and particularly Pacific populations showed admixture between lineages. We estimated demographic history using a genomewide coalescence with recombination approach. The Pacific populations showed gradual population expansion starting >100 Kya, possibly reflecting persistence in cryptic refuges near the present distributional range, although we do not rule out possible influence of ancient admixture. Sharp population declines ca. 14-15 Kya were suggested to reflect founding of freshwater populations by marine ancestors. In Greenland and Northern Europe, demographic expansion started ca. 20-25 Kya coinciding with the end of the Last Glacial Maximum. In both regions, marine and freshwater populations started to show different demographic trajectories ca. 8-9 Kya, suggesting that this was the time of recolonization. In Northern Europe, this estimate was surprisingly late, but found support in subfossil evidence for presence of several freshwater fish species but not sticklebacks 12 Kya. The results demonstrate distinctly different demographic histories across geographical regions with potential consequences for adaptive processes. They also provide empirical support for previous assumptions about freshwater populations being founded independently from large, coherent marine populations, a key element in the Transporter Hypothesis invoked to explain the widespread occurrence of parallel evolution across freshwater stickleback populations. © 2016 John Wiley & Sons Ltd.
Convergent and parallel evolution in life habit of the scallops (Bivalvia: Pectinidae)
2011-01-01
Background We employed a phylogenetic framework to identify patterns of life habit evolution in the marine bivalve family Pectinidae. Specifically, we examined the number of independent origins of each life habit and distinguished between convergent and parallel trajectories of life habit evolution using ancestral state estimation. We also investigated whether ancestral character states influence the frequency or type of evolutionary trajectories. Results We determined that temporary attachment to substrata by byssal threads is the most likely ancestral condition for the Pectinidae, with subsequent transitions to the five remaining habit types. Nearly all transitions between life habit classes were repeated in our phylogeny and the majority of these transitions were the result of parallel evolution from byssate ancestors. Convergent evolution also occurred within the Pectinidae and produced two additional gliding clades and two recessing lineages. Furthermore, our analysis indicates that byssal attaching gave rise to significantly more of the transitions than any other life habit and that the cementing and nestling classes are only represented as evolutionary outcomes in our phylogeny, never as progenitor states. Conclusions Collectively, our results illustrate that both convergence and parallelism generated repeated life habit states in the scallops. Bias in the types of habit transitions observed may indicate constraints due to physical or ontogenetic limitations of particular phenotypes. PMID:21672233
Parallel independent evolution of pathogenicity within the genus Yersinia
Reuter, Sandra; Connor, Thomas R.; Barquist, Lars; Walker, Danielle; Feltwell, Theresa; Harris, Simon R.; Fookes, Maria; Hall, Miquette E.; Petty, Nicola K.; Fuchs, Thilo M.; Corander, Jukka; Dufour, Muriel; Ringwood, Tamara; Savin, Cyril; Bouchier, Christiane; Martin, Liliane; Miettinen, Minna; Shubin, Mikhail; Riehm, Julia M.; Laukkanen-Ninios, Riikka; Sihvonen, Leila M.; Siitonen, Anja; Skurnik, Mikael; Falcão, Juliana Pfrimer; Fukushima, Hiroshi; Scholz, Holger C.; Prentice, Michael B.; Wren, Brendan W.; Parkhill, Julian; Carniel, Elisabeth; Achtman, Mark; McNally, Alan; Thomson, Nicholas R.
2014-01-01
The genus Yersinia has been used as a model system to study pathogen evolution. Using whole-genome sequencing of all Yersinia species, we delineate the gene complement of the whole genus and define patterns of virulence evolution. Multiple distinct ecological specializations appear to have split pathogenic strains from environmental, nonpathogenic lineages. This split demonstrates that contrary to hypotheses that all pathogenic Yersinia species share a recent common pathogenic ancestor, they have evolved independently but followed parallel evolutionary paths in acquiring the same virulence determinants as well as becoming progressively more limited metabolically. Shared virulence determinants are limited to the virulence plasmid pYV and the attachment invasion locus ail. These acquisitions, together with genomic variations in metabolic pathways, have resulted in the parallel emergence of related pathogens displaying an increasingly specialized lifestyle with a spectrum of virulence potential, an emerging theme in the evolution of other important human pathogens. PMID:24753568
Ecology and evolution of rabies virus in Europe.
Bourhy, H; Kissi, B; Audry, L; Smreczak, M; Sadkowska-Todys, M; Kulonen, K; Tordo, N; Zmudzinski, J F; Holmes, E C
1999-10-01
The evolution of rabies viruses of predominantly European origin was studied by comparing nucleotide sequences of the nucleoprotein and glycoprotein genes, and by typing isolates using RFLP. Phylogenetic analysis of the gene sequence data revealed a number of distinct groups, each associated with a particular geographical area. Such a pattern suggests that rabies virus has spread westwards and southwards across Europe during this century, but that physical barriers such as the Vistula river in Poland have enabled localized evolution. During this dispersal process, two species jumps took place - one into red foxes and another into raccoon dogs, although it is unclear whether virus strains are preferentially adapted to particular animal species or whether ecological forces explain the occurrence of the phylogenetic groups.
Parallel evolution of auditory genes for echolocation in bats and toothed whales.
Shen, Yong-Yi; Liang, Lu; Li, Gui-Sheng; Murphy, Robert W; Zhang, Ya-Ping
2012-06-01
The ability of bats and toothed whales to echolocate is a remarkable case of convergent evolution. Previous genetic studies have documented parallel evolution of nucleotide sequences in Prestin and KCNQ4, both of which are associated with voltage motility during the cochlear amplification of signals. Echolocation involves complex mechanisms. The most important factors include cochlear amplification, nerve transmission, and signal re-coding. Herein, we screen three genes that play different roles in this auditory system. Cadherin 23 (Cdh23) and its ligand, protocadherin 15 (Pcdh15), are essential for bundling motility in the sensory hair. Otoferlin (Otof) responds to nerve signal transmission in the auditory inner hair cell. Signals of parallel evolution occur in all three genes in the three groups of echolocators--two groups of bats (Yangochiroptera and Rhinolophoidea) plus the dolphin. Significant signals of positive selection also occur in Cdh23 in the Rhinolophoidea and dolphin, and Pcdh15 in Yangochiroptera. In addition, adult echolocating bats have higher levels of Otof expression in the auditory cortex than do their embryos and non-echolocation bats. Cdh23 and Pcdh15 encode the upper and lower parts of tip-links, and both genes show signals of convergent evolution and positive selection in echolocators, implying that they may co-evolve to optimize cochlear amplification. Convergent evolution and expression patterns of Otof suggest the potential role of nerve and brain in echolocation. Our synthesis of gene sequence and gene expression analyses reveals that positive selection, parallel evolution, and perhaps co-evolution and gene expression affect multiple hearing genes that play different roles in audition, including voltage and bundle motility in cochlear amplification, nerve transmission, and brain function.
SPH simulation of free surface flow over a sharp-crested weir
NASA Astrophysics Data System (ADS)
Ferrari, Angela
2010-03-01
In this paper the numerical simulation of a free surface flow over a sharp-crested weir is presented. Since in this case the usual shallow water assumptions are not satisfied, we propose to solve the problem using the full weakly compressible Navier-Stokes equations with the Tait equation of state for water. The numerical method used consists of the new meshless Smooth Particle Hydrodynamics (SPH) formulation proposed by Ferrari et al. (2009) [8], that accurately tracks the free surface profile and provides monotone pressure fields. Thus, the unsteady evolution of the complex moving material interface (free surface) can been properly solved. The simulations involving about half a million of fluid particles have been run in parallel on two of the most powerful High Performance Computing (HPC) facilities in Europe. The validation of the results has been carried out analysing the pressure field and comparing the free surface profiles obtained with the SPH scheme with experimental measurements available in literature [18]. A very good quantitative agreement has been obtained.
Early evolution of Tubulogenerina during the Paleogene of Europe
Gibson, T.G.; Barbin, V.; Poignant, A.; Sztrakos, K.
1991-01-01
The early evolution of Tubulogenerina took place in Europe where eight species occur in lower Eocene to uppermost Oligocene or lower Miocene strata. Species diversity within Tubulogenerina dropped significantly in the early Oligocne; only a single species persisted from the late Eocene, and it became extinct before the end of the early Oligocene. Morphologic changes during the European phylogeny of Tubulogenerina include (1) the development of costate and more complex tubulopore ornamentation, and (2) the change from a single elongated apertural slit with a single toothplate to multiple apertures and toothplates. Three new Tubulogenerina species are described. -from Authors
NASA Astrophysics Data System (ADS)
Shackleton, J. R.; Cooke, M. L.
2005-12-01
The Sant Corneli Anticline is a well-exposed example of a fault-cored fold whose hydrologic evolution and structural development are directly linked. The E-W striking anticline is ~ 5 km wide with abrupt westerly plunge, and formed in response to thrusting associated with the upper Cretaceous to Miocene collision of Iberia with Europe. The fold's core of fractured carbonates contains a variety of west dipping normal faults with meter to decameter scale displacement and abundant calcite fill. This carbonate unit is capped by a marl unit with low angle, calcite filled normal faults. The marl unit is overlain by clastic syn-tectonic strata whose sedimentary architecture records limb rotation during the evolution of the fold. The syn-tectonic strata contain a variety of joint sets that record the stresses before, during, and possibly after fold growth. Faulting in the marl and calcite-filled joints in the syn-tectonic strata suggest that normal faults within the carbonate core of the fold eventually breached the overlying marl unit. This breach may have connected the joints of the syn-tectonic strata to the underlying carbonate reservoir and eliminated previous compartmentalization of fluids. Furthermore, breaching of the marl units probably enhanced joint formation in the overlying syn-tectonic strata. Future geochemical studies of calcite compositions in the three units will address this hypothesis. Preliminary mapping of joint sets in the syn-tectonic strata reveal a multistage history of jointing. Early bed-perpendicular joints healed by calcite strike NE-SW, parallel to normal faults in the underlying carbonates, and may be related to an early regional extensional event. Younger healed bed-perpendicular joints cross cut the NE-SW striking set, and are closer to N-S in strike: these joints are interpreted to represent the initial stages of folding. Decameter scale, bed perpendicular, unfilled fractures that are sub-parallel to strike probably represent small joints and faults that formed in response to outer arc extension during folding. Many filled, late stage joints strike sub-parallel to, and increase in frequency near, normal faults and transverse structures observed in the carbonate fold core. This suggests that faulting in the underlying carbonates and marls significantly affected the joint patterns in the syn-tectonic strata. Preliminary three-dimensional finite element restorations using Dynel have allowed us to test our hypotheses and constrain the timing of jointing and marl breach.
Zhu, Lei; Yin, Qiuyuan; Irwin, David M; Zhang, Shuyi
2015-01-01
Bats are an ideal mammalian group for exploring adaptations to fasting due to their large variety of diets and because fasting is a regular part of their life cycle. Mammals fed on a carbohydrate-rich diet experience a rapid decrease in blood glucose levels during a fast, thus, the development of mechanisms to resist the consequences of regular fasts, experienced on a daily basis, must have been crucial in the evolution of frugivorous bats. Phosphoenolpyruvate carboxykinase 1 (PEPCK1, encoded by the Pck1 gene) is the rate-limiting enzyme in gluconeogenesis and is largely responsible for the maintenance of glucose homeostasis during fasting in fruit-eating bats. To test whether Pck1 has experienced adaptive evolution in frugivorous bats, we obtained Pck1 coding sequence from 20 species of bats, including five Old World fruit bats (OWFBs) (Pteropodidae) and two New World fruit bats (NWFBs) (Phyllostomidae). Our molecular evolutionary analyses of these sequences revealed that Pck1 was under purifying selection in both Old World and New World fruit bats with no evidence of positive selection detected in either ancestral branch leading to fruit bats. Interestingly, however, six specific amino acid substitutions were detected on the ancestral lineage of OWFBs. In addition, we found considerable evidence for parallel evolution, at the amino acid level, between the PEPCK1 sequences of Old World fruit bats and New World fruit bats. Test for parallel evolution showed that four parallel substitutions (Q276R, R503H, I558V and Q593R) were driven by natural selection. Our study provides evidence that Pck1 underwent parallel evolution between Old World and New World fruit bats, two lineages of mammals that feed on a carbohydrate-rich diet and experience regular periods of fasting as part of their life cycle.
Irwin, David M.; Zhang, Shuyi
2015-01-01
Bats are an ideal mammalian group for exploring adaptations to fasting due to their large variety of diets and because fasting is a regular part of their life cycle. Mammals fed on a carbohydrate-rich diet experience a rapid decrease in blood glucose levels during a fast, thus, the development of mechanisms to resist the consequences of regular fasts, experienced on a daily basis, must have been crucial in the evolution of frugivorous bats. Phosphoenolpyruvate carboxykinase 1 (PEPCK1, encoded by the Pck1 gene) is the rate-limiting enzyme in gluconeogenesis and is largely responsible for the maintenance of glucose homeostasis during fasting in fruit-eating bats. To test whether Pck1 has experienced adaptive evolution in frugivorous bats, we obtained Pck1 coding sequence from 20 species of bats, including five Old World fruit bats (OWFBs) (Pteropodidae) and two New World fruit bats (NWFBs) (Phyllostomidae). Our molecular evolutionary analyses of these sequences revealed that Pck1 was under purifying selection in both Old World and New World fruit bats with no evidence of positive selection detected in either ancestral branch leading to fruit bats. Interestingly, however, six specific amino acid substitutions were detected on the ancestral lineage of OWFBs. In addition, we found considerable evidence for parallel evolution, at the amino acid level, between the PEPCK1 sequences of Old World fruit bats and New World fruit bats. Test for parallel evolution showed that four parallel substitutions (Q276R, R503H, I558V and Q593R) were driven by natural selection. Our study provides evidence that Pck1 underwent parallel evolution between Old World and New World fruit bats, two lineages of mammals that feed on a carbohydrate-rich diet and experience regular periods of fasting as part of their life cycle. PMID:25807515
Rohner, Patrick T; Blanckenhorn, Wolf U; Puniamoorthy, Nalini
2016-06-01
Sexual size dimorphism (SSD) arises when the net effects of natural and sexual selection on body size differ between the sexes. Quantitative SSD variation between taxa is common, but directional intraspecific SSD reversals are rare. We combined micro- and macroevolutionary approaches to study geographic SSD variation in closely related black scavenger flies. Common garden experiments revealed stark intra- and interspecific variation: Sepsis biflexuosa is monomorphic across the Holarctic, while S. cynipsea (only in Europe) consistently exhibits female-biased SSD. Interestingly, S. neocynipsea displays contrasting SSD in Europe (females larger) and North America (males larger), a pattern opposite to the geographic reversal in SSD of S. punctum documented in a previous study. In accordance with the differential equilibrium model for the evolution of SSD, the intensity of sexual selection on male size varied between continents (weaker in Europe), whereas fecundity selection on female body size did not. Subsequent comparative analyses of 49 taxa documented at least six independent origins of male-biased SSD in Sepsidae, which is likely caused by sexual selection on male size and mediated by bimaturism. Therefore, reversals in SSD and the associated changes in larval development might be much more common and rapid and less constrained than currently assumed. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.
Qian, Yamin; Fang, Tao; Shen, Bin; Zhang, Shuyi
2014-01-01
Frugivorous and nectarivorous bats rely largely on hepatic glycogenesis and glycogenolysis for postprandial blood glucose disposal and maintenance of glucose homeostasis during short time starvation, respectively. The glycogen synthase 2 encoded by the Gys2 gene plays a critical role in liver glycogen synthesis. To test whether the Gys2 gene has undergone adaptive evolution in bats with carbohydrate-rich diets in relation to their insect-eating sister taxa, we sequenced the coding region of the Gys2 gene in a number of bat species, including three Old World fruit bats (OWFBs) (Pteropodidae) and two New World fruit bats (NWFBs) (Phyllostomidae). Our results showed that the Gys2 coding sequences are highly conserved across all bat species we examined, and no evidence of positive selection was detected in the ancestral branches leading to OWFBs and NWFBs. Our explicit convergence test showed that posterior probabilities of convergence between several branches of OWFBs, and the NWFBs were markedly higher than that of divergence. Three parallel amino acid substitutions (Q72H, K371Q, and E666D) were detected among branches of OWFBs and NWFBs. Tests for parallel evolution showed that two parallel substitutions (Q72H and E666D) were driven by natural selection, while the K371Q was more likely to be fixed randomly. Thus, our results suggested that the Gys2 gene has undergone parallel evolution on amino acid level between OWFBs and NWFBs in relation to their carbohydrate metabolism.
1990-09-01
decrease in average consumer prices , to think of Europe 1992 as a starting date or a point of departure for what some have called the largest...overall The European Community’s four consumer prices . executive institutions-- Commission, Parliament, Council of Ministers and Court In 1985, the...of the draft, but also for may want to skim Chapter One and go to the extra effort he put forth to ensure that Chapter Two’s discussion on parallel
NASA Astrophysics Data System (ADS)
Kan, Guangyuan; He, Xiaoyan; Ding, Liuqian; Li, Jiren; Hong, Yang; Zuo, Depeng; Ren, Minglei; Lei, Tianjie; Liang, Ke
2018-01-01
Hydrological model calibration has been a hot issue for decades. The shuffled complex evolution method developed at the University of Arizona (SCE-UA) has been proved to be an effective and robust optimization approach. However, its computational efficiency deteriorates significantly when the amount of hydrometeorological data increases. In recent years, the rise of heterogeneous parallel computing has brought hope for the acceleration of hydrological model calibration. This study proposed a parallel SCE-UA method and applied it to the calibration of a watershed rainfall-runoff model, the Xinanjiang model. The parallel method was implemented on heterogeneous computing systems using OpenMP and CUDA. Performance testing and sensitivity analysis were carried out to verify its correctness and efficiency. Comparison results indicated that heterogeneous parallel computing-accelerated SCE-UA converged much more quickly than the original serial version and possessed satisfactory accuracy and stability for the task of fast hydrological model calibration.
Integrating Remote and Social Sensing Data for a Scenario on Secure Societies in Big Data Platform
NASA Astrophysics Data System (ADS)
Albani, Sergio; Lazzarini, Michele; Koubarakis, Manolis; Taniskidou, Efi Karra; Papadakis, George; Karkaletsis, Vangelis; Giannakopoulos, George
2016-08-01
In the framework of the Horizon 2020 project BigDataEurope (Integrating Big Data, Software & Communities for Addressing Europe's Societal Challenges), a pilot for the Secure Societies Societal Challenge was designed considering the requirements coming from relevant stakeholders. The pilot is focusing on the integration in a Big Data platform of data coming from remote and social sensing.The information on land changes coming from the Copernicus Sentinel 1A sensor (Change Detection workflow) is integrated with information coming from selected Twitter and news agencies accounts (Event Detection workflow) in order to provide the user with multiple sources of information.The Change Detection workflow implements a processing chain in a distributed parallel manner, exploiting the Big Data capabilities in place; the Event Detection workflow implements parallel and distributed social media and news agencies monitoring as well as suitable mechanisms to detect and geo-annotate the related events.
ERIC Educational Resources Information Center
MOGUEROU, PHILIPPE
2005-01-01
In this article, we discuss the recent evolutions of science and engineering doctoral and postdoctoral education in Europe. Indeed, Ph.Ds are crucial to the conduct of research and innovation in the national innovation systems, as they provide a large amount of input into creating the competitive advantage, notably through basic research. First,…
DeFaveri, Jacquelin; Shikano, Takahito; Shimada, Yukinori; Goto, Akira; Merilä, Juha
2011-06-01
Examples of parallel evolution of phenotypic traits have been repeatedly demonstrated in threespine sticklebacks (Gasterosteus aculeatus) across their global distribution. Using these as a model, we performed a targeted genome scan--focusing on physiologically important genes potentially related to freshwater adaptation--to identify genetic signatures of parallel physiological evolution on a global scale. To this end, 50 microsatellite loci, including 26 loci within or close to (<6 kb) physiologically important genes, were screened in paired marine and freshwater populations from six locations across the Northern Hemisphere. Signatures of directional selection were detected in 24 loci, including 17 physiologically important genes, in at least one location. Although no loci showed consistent signatures of selection in all divergent population pairs, several outliers were common in multiple locations. In particular, seven physiologically important genes, as well as reference ectodysplasin gene (EDA), showed signatures of selection in three or more locations. Hence, although these results give some evidence for consistent parallel molecular evolution in response to freshwater colonization, they suggest that different evolutionary pathways may underlie physiological adaptation to freshwater habitats within the global distribution of the threespine stickleback. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
Csiki-Sava, Zoltán; Buffetaut, Eric; Ősi, Attila; Pereda-Suberbiola, Xabier; Brusatte, Stephen L.
2015-01-01
Abstract The Late Cretaceous was a time of tremendous global change, as the final stages of the Age of Dinosaurs were shaped by climate and sea level fluctuations and witness to marked paleogeographic and faunal changes, before the end-Cretaceous bolide impact. The terrestrial fossil record of Late Cretaceous Europe is becoming increasingly better understood, based largely on intensive fieldwork over the past two decades, promising new insights into latest Cretaceous faunal evolution. We review the terrestrial Late Cretaceous record from Europe and discuss its importance for understanding the paleogeography, ecology, evolution, and extinction of land-dwelling vertebrates. We review the major Late Cretaceous faunas from Austria, Hungary, France, Spain, Portugal, and Romania, as well as more fragmentary records from elsewhere in Europe. We discuss the paleogeographic background and history of assembly of these faunas, and argue that they are comprised of an endemic ‘core’ supplemented with various immigration waves. These faunas lived on an island archipelago, and we describe how this insular setting led to ecological peculiarities such as low diversity, a preponderance of primitive taxa, and marked changes in morphology (particularly body size dwarfing). We conclude by discussing the importance of the European record in understanding the end-Cretaceous extinction and show that there is no clear evidence that dinosaurs or other groups were undergoing long-term declines in Europe prior to the bolide impact. PMID:25610343
Dufresnes, Christophe; Bertholet, Youna; Wassef, Jérôme; Ghali, Karim; Savary, Romain; Pasteur, Baptiste; Brelsford, Alan; Rozenblut-Kościsty, Beata; Ogielska, Maria; Stöck, Matthias; Perrin, Nicolas
2014-12-01
Occasional XY recombination is a proposed explanation for the sex-chromosome homomorphy in European tree frogs. Numerous laboratory crosses, however, failed to detect any event of male recombination, and a detailed survey of NW-European Hyla arborea populations identified male-specific alleles at sex-linked loci, pointing to the absence of XY recombination in their recent history. Here, we address this paradox in a phylogeographic framework by genotyping sex-linked microsatellite markers in populations and sibships from the entire species range. Contrasting with postglacial populations of NW Europe, which display complete absence of XY recombination and strong sex-chromosome differentiation, refugial populations of the southern Balkans and Adriatic coast show limited XY recombination and large overlaps in allele frequencies. Geographically and historically intermediate populations of the Pannonian Basin show intermediate patterns of XY differentiation. Even in populations where X and Y occasionally recombine, the genetic diversity of Y haplotypes is reduced below the levels expected from the fourfold drop in copy numbers. This study is the first in which X and Y haplotypes could be phased over the distribution range in a species with homomorphic sex chromosomes; it shows that XY-recombination patterns may differ strikingly between conspecific populations, and that recombination arrest may evolve rapidly (<5000 generations). © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.
Gaut, Brandon S
2015-07-01
In this commentary, I make inferences about the level of repeatability and constraint in the evolutionary process, based on two sets of replicated experiments. The first experiment is crop domestication, which has been replicated across many different species. I focus on results of whole-genome scans for genes selected during domestication and ask whether genes are, in fact, selected in parallel across different domestication events. If genes are selected in parallel, it implies that the number of genetic solutions to the challenge of domestication is constrained. However, I find no evidence for parallel selection events either between species (maize vs. rice) or within species (two domestication events within beans). These results suggest that there are few constraints on genetic adaptation, but conclusions must be tempered by several complicating factors, particularly the lack of explicit design standards for selection screens. The second experiment involves the evolution of Escherichia coli to thermal stress. Unlike domestication, this highly replicated experiment detected a limited set of genes that appear prone to modification during adaptation to thermal stress. However, the number of potentially beneficial mutations within these genes is large, such that adaptation is constrained at the genic level but much less so at the nucleotide level. Based on these two experiments, I make the general conclusion that evolution is remarkably flexible, despite the presence of epistatic interactions that constrain evolutionary trajectories. I also posit that evolution is so rapid that we should establish a Speciation Prize, to be awarded to the first researcher who demonstrates speciation with a sexual organism in the laboratory. © The Author 2015. 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.
GPU-Based Point Cloud Superpositioning for Structural Comparisons of Protein Binding Sites.
Leinweber, Matthias; Fober, Thomas; Freisleben, Bernd
2018-01-01
In this paper, we present a novel approach to solve the labeled point cloud superpositioning problem for performing structural comparisons of protein binding sites. The solution is based on a parallel evolution strategy that operates on large populations and runs on GPU hardware. The proposed evolution strategy reduces the likelihood of getting stuck in a local optimum of the multimodal real-valued optimization problem represented by labeled point cloud superpositioning. The performance of the GPU-based parallel evolution strategy is compared to a previously proposed CPU-based sequential approach for labeled point cloud superpositioning, indicating that the GPU-based parallel evolution strategy leads to qualitatively better results and significantly shorter runtimes, with speed improvements of up to a factor of 1,500 for large populations. Binary classification tests based on the ATP, NADH, and FAD protein subsets of CavBase, a database containing putative binding sites, show average classification rate improvements from about 92 percent (CPU) to 96 percent (GPU). Further experiments indicate that the proposed GPU-based labeled point cloud superpositioning approach can be superior to traditional protein comparison approaches based on sequence alignments.
ERIC Educational Resources Information Center
Bianchini, Paolo
2011-01-01
Between the eighteenth and nineteenth centuries a new method for the provision of popular education emerged in Europe. The Sardinian Kingdom represents a good example of this evolution: in 1729, Piedmont was the first state in Europe to launch a "modern" educational policy with the creation of a public school system. Education was…
Predictable transcriptome evolution in the convergent and complex bioluminescent organs of squid
Pankey, M. Sabrina; Minin, Vladimir N.; Imholte, Greg C.; Suchard, Marc A.; Oakley, Todd H.
2014-01-01
Despite contingency in life’s history, the similarity of evolutionarily convergent traits may represent predictable solutions to common conditions. However, the extent to which overall gene expression levels (transcriptomes) underlying convergent traits are themselves convergent remains largely unexplored. Here, we show strong statistical support for convergent evolutionary origins and massively parallel evolution of the entire transcriptomes in symbiotic bioluminescent organs (bacterial photophores) from two divergent squid species. The gene expression similarities are so strong that regression models of one species’ photophore can predict organ identity of a distantly related photophore from gene expression levels alone. Our results point to widespread parallel changes in gene expression evolution associated with convergent origins of complex organs. Therefore, predictable solutions may drive not only the evolution of novel, complex organs but also the evolution of overall gene expression levels that underlie them. PMID:25336755
Experimental evolution reveals hidden diversity in evolutionary pathways.
Lind, Peter A; Farr, Andrew D; Rainey, Paul B
2015-03-25
Replicate populations of natural and experimental organisms often show evidence of parallel genetic evolution, but the causes are unclear. The wrinkly spreader morph of Pseudomonas fluorescens arises repeatedly during experimental evolution. The mutational causes reside exclusively within three pathways. By eliminating these, 13 new mutational pathways were discovered with the newly arising WS types having fitnesses similar to those arising from the commonly passaged routes. Our findings show that parallel genetic evolution is strongly biased by constraints and we reveal the genetic bases. From such knowledge, and in instances where new phenotypes arise via gene activation, we suggest a set of principles: evolution proceeds firstly via pathways subject to negative regulation, then via promoter mutations and gene fusions, and finally via activation by intragenic gain-of-function mutations. These principles inform evolutionary forecasting and have relevance to interpreting the diverse array of mutations associated with clinically identical instances of disease in humans.
Jones, Ryan J. R.; Shinde, Aniketa; Guevarra, Dan; ...
2015-01-05
There are many energy technologies require electrochemical stability or preactivation of functional materials. Due to the long experiment duration required for either electrochemical preactivation or evaluation of operational stability, parallel screening is required to enable high throughput experimentation. We found that imposing operational electrochemical conditions to a library of materials in parallel creates several opportunities for experimental artifacts. We discuss the electrochemical engineering principles and operational parameters that mitigate artifacts int he parallel electrochemical treatment system. We also demonstrate the effects of resistive losses within the planar working electrode through a combination of finite element modeling and illustrative experiments. Operationmore » of the parallel-plate, membrane-separated electrochemical treatment system is demonstrated by exposing a composition library of mixed metal oxides to oxygen evolution conditions in 1M sulfuric acid for 2h. This application is particularly important because the electrolysis and photoelectrolysis of water are promising future energy technologies inhibited by the lack of highly active, acid-stable catalysts containing only earth abundant elements.« less
Doshi, Shivang; Ray, David; Stein, Karen; Zhang, Jie; Koduru, Prasad; Fogt, Franz; Wellman, Axel; Wat, Ricky; Mathews, Charles
2016-01-06
Identification of alterations in ALK gene and development of ALK-directed therapies have increased the need for accurate and efficient detection methodologies. To date, research has focused on the concordance between the two most commonly used technologies, fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC). However, inter-test concordance reflects only one, albeit important, aspect of the diagnostic process; laboratories, hospitals, and payors must understand the cost and workflow of ALK rearrangement detection strategies. Through literature review combined with interviews of pathologists and laboratory directors in the U.S. and Europe, a cost-impact model was developed that compared four alternative testing strategies-IHC only, FISH only, IHC pre-screen followed by FISH confirmation, and parallel testing by both IHC and FISH. Interviews were focused on costs of reagents, consumables, equipment, and personnel. The resulting model showed that testing by IHC alone cost less ($90.07 in the U.S., $68.69 in Europe) than either independent or parallel testing by both FISH and IHC ($441.85 in the U.S. and $279.46 in Europe). The strategies differed in cost of execution, turnaround time, reimbursement, and number of positive results detected, suggesting that laboratories must weigh the costs and the clinical benefit of available ALK testing strategies.
Doshi, Shivang; Ray, David; Stein, Karen; Zhang, Jie; Koduru, Prasad; Fogt, Franz; Wellman, Axel; Wat, Ricky; Mathews, Charles
2016-01-01
Identification of alterations in ALK gene and development of ALK-directed therapies have increased the need for accurate and efficient detection methodologies. To date, research has focused on the concordance between the two most commonly used technologies, fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC). However, inter-test concordance reflects only one, albeit important, aspect of the diagnostic process; laboratories, hospitals, and payors must understand the cost and workflow of ALK rearrangement detection strategies. Through literature review combined with interviews of pathologists and laboratory directors in the U.S. and Europe, a cost-impact model was developed that compared four alternative testing strategies—IHC only, FISH only, IHC pre-screen followed by FISH confirmation, and parallel testing by both IHC and FISH. Interviews were focused on costs of reagents, consumables, equipment, and personnel. The resulting model showed that testing by IHC alone cost less ($90.07 in the U.S., $68.69 in Europe) than either independent or parallel testing by both FISH and IHC ($441.85 in the U.S. and $279.46 in Europe). The strategies differed in cost of execution, turnaround time, reimbursement, and number of positive results detected, suggesting that laboratories must weigh the costs and the clinical benefit of available ALK testing strategies. PMID:26838801
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fishman, N.; Prazmowska, A.J.; Heith, H.
2006-01-15
The demand for coal in war-torn Europe after VE Day gave coalmining trade unions unprecedented bargaining leverage. Miners' incomes had been depressed throughout the interwar period, and they were now anxious to recover their past high wages and improve their conditions. In several key European countries, Communists were prominent among the leadership of mining trade unions. Communist miners' leaders Willi Agatz, Edward Gierek and Arthur Horner each faced unprecedented opportunities and challenges at the onset of the Cold War in 1948, as they sought to fuse their parallel identities as committed and influential Communists and as conscientious trade union negotiatorsmore » in these newly advantageous circumstances. Each of these three 'revolutionary' trade unionists pursued strategies that revived the position of miners, without undermining the potential for economic recovery in their respective countries - for which an uninterrupted supply of coal remained critical. A comparative study of the personal and political experiences of the three Communist miners' leaders enhances our understanding of the evolution of Communist trade unionism in the early postwar period.« less
NASA Astrophysics Data System (ADS)
Lopez-Sanchez, Marco A.; Marcos, Alberto; Martínez, Francisco J.; Iriondo, Alexander; Llana-Fúnez, Sergio
2015-06-01
The Vivero fault is crustal-scale extensional shear zone parallel to the Variscan orogen in the Iberian massif belt with an associated dip-slip movement toward the hinterland. To constrain the timing of the extension accommodated by this structure, we performed zircon U-Pb LA-ICP-MS geochronology in several deformed plutons: some of them emplaced syntectonically. The different crystallization ages obtained indicate that the fault was active at least between 303 ± 2 and 287 ± 3 Ma, implying a minimum tectonic activity of 16 ± 5 Ma along the fault. The onset of the faulting is established to have occurred later than 314 ± 2 Ma. The geochronological data confirm that the Vivero fault postdates the main Variscan deformation events in the NW of the Iberian massif and that the extension direction of the Late Carboniferous-Early Permian crustal-scale extensional shear zones along the Ibero-Armorican Arc was consistently perpendicular to the general arcuate trend of the belt in SW Europe.
Genomics of parallel adaptation at two timescales in Drosophila
Begun, David J.
2017-01-01
Two interesting unanswered questions are the extent to which both the broad patterns and genetic details of adaptive divergence are repeatable across species, and the timescales over which parallel adaptation may be observed. Drosophila melanogaster is a key model system for population and evolutionary genomics. Findings from genetics and genomics suggest that recent adaptation to latitudinal environmental variation (on the timescale of hundreds or thousands of years) associated with Out-of-Africa colonization plays an important role in maintaining biological variation in the species. Additionally, studies of interspecific differences between D. melanogaster and its sister species D. simulans have revealed that a substantial proportion of proteins and amino acid residues exhibit adaptive divergence on a roughly few million years long timescale. Here we use population genomic approaches to attack the problem of parallelism between D. melanogaster and a highly diverged conger, D. hydei, on two timescales. D. hydei, a member of the repleta group of Drosophila, is similar to D. melanogaster, in that it too appears to be a recently cosmopolitan species and recent colonizer of high latitude environments. We observed parallelism both for genes exhibiting latitudinal allele frequency differentiation within species and for genes exhibiting recurrent adaptive protein divergence between species. Greater parallelism was observed for long-term adaptive protein evolution and this parallelism includes not only the specific genes/proteins that exhibit adaptive evolution, but extends even to the magnitudes of the selective effects on interspecific protein differences. Thus, despite the roughly 50 million years of time separating D. melanogaster and D. hydei, and despite their considerably divergent biology, they exhibit substantial parallelism, suggesting the existence of a fundamental predictability of adaptive evolution in the genus. PMID:28968391
Bai, Haihua; Guo, Xiaosen; Zhang, Dong; Narisu, Narisu; Bu, Junjie; Jirimutu, Jirimutu; Liang, Fan; Zhao, Xiang; Xing, Yanping; Wang, Dingzhu; Li, Tongda; Zhang, Yanru; Guan, Baozhu; Yang, Xukui; Yang, Zili; Shuangshan, Shuangshan; Su, Zhe; Wu, Huiguang; Li, Wenjing; Chen, Ming; Zhu, Shilin; Bayinnamula, Bayinnamula; Chang, Yuqi; Gao, Ying; Lan, Tianming; Suyalatu, Suyalatu; Huang, Hui; Su, Yan; Chen, Yujie; Li, Wenqi; Yang, Xu; Feng, Qiang; Wang, Jian; Yang, Huanming; Wang, Jun; Wu, Qizhu; Yin, Ye; Zhou, Huanmin
2014-11-05
Mongolians have played a significant role in modern human evolution, especially after the rise of Genghis Khan (1162[?]-1227). Although the social cultural impacts of Genghis Khan and the Mongolian population have been well documented, explorations of their genome structure and genetic imprints on other human populations have been lacking. We here present the genome of a Mongolian male individual. The genome was de novo assembled using a total of 130.8-fold genomic data produced from massively parallel whole-genome sequencing. We identified high-confidence variation sets, including 3.7 million single nucleotide polymorphisms (SNPs) and 756,234 short insertions and deletions. Functional SNP analysis predicted that the individual has a pathogenic risk for carnitine deficiency. We located the patrilineal inheritance of the Mongolian genome to the lineage D3a through Y haplogroup analysis and inferred that the individual has a common patrilineal ancestor with Tibeto-Burman populations and is likely to be the progeny of the earliest settlers in East Asia. We finally investigated the genetic imprints of Mongolians on other human populations using different approaches. We found varying degrees of gene flows between Mongolians and populations living in Europe, South/Central Asia, and the Indian subcontinent. The analyses demonstrate that the genetic impacts of Mongolians likely resulted from the expansion of the Mongolian Empire in the 13th century. The genome will be of great help in further explorations of modern human evolution and genetic causes of diseases/traits specific to Mongolians. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
The role of Bh4 in parallel evolution of hull colour in domesticated and weedy rice.
Vigueira, C C; Li, W; Olsen, K M
2013-08-01
The two independent domestication events in the genus Oryza that led to African and Asian rice offer an extremely useful system for studying the genetic basis of parallel evolution. This system is also characterized by parallel de-domestication events, with two genetically distinct weedy rice biotypes in the US derived from the Asian domesticate. One important trait that has been altered by rice domestication and de-domestication is hull colour. The wild progenitors of the two cultivated rice species have predominantly black-coloured hulls, as does one of the two U.S. weed biotypes; both cultivated species and one of the US weedy biotypes are characterized by straw-coloured hulls. Using Black hull 4 (Bh4) as a hull colour candidate gene, we examined DNA sequence variation at this locus to study the parallel evolution of hull colour variation in the domesticated and weedy rice system. We find that independent Bh4-coding mutations have arisen in African and Asian rice that are correlated with the straw hull phenotype, suggesting that the same gene is responsible for parallel trait evolution. For the U.S. weeds, Bh4 haplotype sequences support current hypotheses on the phylogenetic relationship between the two biotypes and domesticated Asian rice; straw hull weeds are most similar to indica crops, and black hull weeds are most similar to aus crops. Tests for selection indicate that Asian crops and straw hull weeds deviate from neutrality at this gene, suggesting possible selection on Bh4 during both rice domestication and de-domestication. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.
Solé, Floréal; Amson, Eli; Borths, Matthew; Vidalenc, Dominique; Morlo, Michael; Bastl, Katharina
2015-01-01
We describe a new large-sized species of hypercarnivorous hyainailourine–Kerberos langebadreae gen. & sp. nov.–from the Bartonian (MP16) locality of Montespieu (Tarn, France). These specimens consist of a skull, two hemimandibles and several hind limb elements (fibula, astragalus, calcaneum, metatarsals, and phalanges). Size estimates suggest K. langebadreae may have weighed up to 140 kg, revealing this species as the largest carnivorous mammal in Europe at that time. Besides its very large size, K. langebadreae possesses an interesting combination of primitive and derived features. The distinctive skull morphology of K. langebadreae reflects a powerful bite force. The postcranial elements, which are rarely associated with hyainailourine specimens, indicate an animal capable of a plantigrade stance and adapted for terrestrial locomotion. We performed the first phylogenetic analysis of hyainailourines to determine the systematic position of K. langebadreae and to understand the evolution of the group that includes other massive carnivores. The analysis demonstrates that Hemipsalodon, a North American taxon, is a hyainailourine and is closely related to European Paroxyaena. Based on this analysis we hypothesize the biogeographic history of the Hyainailourinae. The group appeared in Africa with a first migration to Europe during the Bartonian that likely included the ancestors of Kerberos, Paroxyaena and Hemipsalodon, which further dispersed into North America at this time. We propose that the hyainailourines dispersed into Europe also during the Priabonian. These migrants have no ecological equivalent in Europe during these intervals and likely did not conflict with the endemic hyaenodont proviverrines. The discovery of K. langebadreae shows that large body size appears early in the evolution of hyainailourines. Surprisingly, the late Miocene Hyainailouros shares a more recent common ancestor with small-bodied hyainailourines (below 15 kg). Finally, our study supports a close relationship between the Hyainailourinae and Apterodontinae and we propose the new clade: Hyainailouridae. PMID:26398622
Genetic and developmental basis for parallel evolution and its significance for hominoid evolution.
Reno, Philip L
2014-01-01
Greater understanding of ape comparative anatomy and evolutionary history has brought a general appreciation that the hominoid radiation is characterized by substantial homoplasy.(1-4) However, little consensus has been reached regarding which features result from repeated evolution. This has important implications for reconstructing ancestral states throughout hominoid evolution, including the nature of the Pan-Homo last common ancestor (LCA). Advances from evolutionary developmental biology (evo-devo) have expanded the diversity of model organisms available for uncovering the morphogenetic mechanisms underlying instances of repeated phenotypic change. Of particular relevance to hominoids are data from adaptive radiations of birds, fish, and even flies demonstrating that parallel phenotypic changes often use similar genetic and developmental mechanisms. The frequent reuse of a limited set of genes and pathways underlying phenotypic homoplasy suggests that the conserved nature of the genetic and developmental architecture of animals can influence evolutionary outcomes. Such biases are particularly likely to be shared by closely related taxa that reside in similar ecological niches and face common selective pressures. Consideration of these developmental and ecological factors provides a strong theoretical justification for the substantial homoplasy observed in the evolution of complex characters and the remarkable parallel similarities that can occur in closely related taxa. Thus, as in other branches of the hominoid radiation, repeated phenotypic evolution within African apes is also a distinct possibility. If so, the availability of complete genomes for each of the hominoid genera makes them another model to explore the genetic basis of repeated evolution. © 2014 Wiley Periodicals, Inc.
Cancer heterogeneity: converting a limitation into a source of biologic information.
Rübben, Albert; Araujo, Arturo
2017-09-08
Analysis of spatial and temporal genetic heterogeneity in human cancers has revealed that somatic cancer evolution in most cancers is not a simple linear process composed of a few sequential steps of mutation acquisitions and clonal expansions. Parallel evolution has been observed in many early human cancers resulting in genetic heterogeneity as well as multilineage progression. Moreover, aneuploidy as well as structural chromosomal aberrations seems to be acquired in a non-linear, punctuated mode where most aberrations occur at early stages of somatic cancer evolution. At later stages, the cancer genomes seem to get stabilized and acquire only few additional rearrangements. While parallel evolution suggests positive selection of driver mutations at early stages of somatic cancer evolution, stabilization of structural aberrations at later stages suggests that negative selection takes effect when cancer cells progressively lose their tolerance towards additional mutation acquisition. Mixing of genetically heterogeneous subclones in cancer samples reduces sensitivity of mutation detection. Moreover, driver mutations present only in a fraction of cancer cells are more likely to be mistaken for passenger mutations. Therefore, genetic heterogeneity may be considered a limitation negatively affecting detection sensitivity of driver mutations. On the other hand, identification of subclones and subclone lineages in human cancers may lead to a more profound understanding of the selective forces which shape somatic cancer evolution in human cancers. Identification of parallel evolution by analyzing spatial heterogeneity may hint to driver mutations which might represent additional therapeutic targets besides driver mutations present in a monoclonal state. Likewise, stabilization of cancer genomes which can be identified by analyzing temporal genetic heterogeneity might hint to genes and pathways which have become essential for survival of cancer cell lineages at later stages of cancer evolution. These genes and pathways might also constitute patient specific therapeutic targets.
Genetic adaptations of the plateau zokor in high-elevation burrows.
Shao, Yong; Li, Jin-Xiu; Ge, Ri-Li; Zhong, Li; Irwin, David M; Murphy, Robert W; Zhang, Ya-Ping
2015-11-25
The plateau zokor (Myospalax baileyi) spends its entire life underground in sealed burrows. Confronting limited oxygen and high carbon dioxide concentrations, and complete darkness, they epitomize a successful physiological adaptation. Here, we employ transcriptome sequencing to explore the genetic underpinnings of their adaptations to this unique habitat. Compared to Rattus norvegicus, genes belonging to GO categories related to energy metabolism (e.g. mitochondrion and fatty acid beta-oxidation) underwent accelerated evolution in the plateau zokor. Furthermore, the numbers of positively selected genes were significantly enriched in the gene categories involved in ATPase activity, blood vessel development and respiratory gaseous exchange, functional categories that are relevant to adaptation to high altitudes. Among the 787 genes with evidence of parallel evolution, and thus identified as candidate genes, several GO categories (e.g. response to hypoxia, oxygen homeostasis and erythrocyte homeostasis) are significantly enriched, are two genes, EPAS1 and AJUBA, involved in the response to hypoxia, where the parallel evolved sites are at positions that are highly conserved in sequence alignments from multiple species. Thus, accelerated evolution of GO categories, positive selection and parallel evolution at the molecular level provide evidences to parse the genetic adaptations of the plateau zokor for living in high-elevation burrows.
Linguistics: evolution and language change.
Bowern, Claire
2015-01-05
Linguists have long identified sound changes that occur in parallel. Now novel research shows how Bayesian modeling can capture complex concerted changes, revealing how evolution of sounds proceeds. Copyright © 2015 Elsevier Ltd. All rights reserved.
Vitamin D Deficiency in Europeans Today and in Viking Settlers of Greenland.
Göring, H; Koshuchowa, S
2016-12-01
The vast majority of the Earth's population lives between the 20th and 40th parallel north and south. It seems that right here humans have found the best living conditions relating not only to temperature and food recourses, but also to UV radiation necessary for the production of vitamin D by human skin. An exception to this general rule is Europe. Nearly half a billion people live between the 40th and 60th parallel north of the equator despite the fact that the amounts of UV radiation there are much lower. Moreover, since the time of the Vikings, there has always been a part of the European population that lived even further north than the 60th parallel (the northern parts of Europe, including Greenland). In this work, we present the potential role that vitamin D deficiency might have played in the extinction of the Vikings of Greenland. We analyze factors that contribute to the discrepancy between the theoretical distribution of areas with vitamin D deficiency and today's reality, like the impact of civilization, religious traditions, as well as vitamin D supplementation in food products and as a biologically active dietary additive. The global migration of people on a scale and speed never seen before is now even more important for this discrepancy.
Qi, Delin; Chao, Yan; Guo, Songchang; Zhao, Lanying; Li, Taiping; Wei, Fulei; Zhao, Xinquan
2012-01-01
Schizothoracine fishes distributed in the water system of the Qinghai-Tibetan plateau (QTP) and adjacent areas are characterized by being highly adaptive to the cold and hypoxic environment of the plateau, as well as by a high degree of diversity in trophic morphology due to resource polymorphisms. Although convergent and parallel evolution are prevalent in the organisms of the QTP, it remains unknown whether similar evolutionary patterns have occurred in the schizothoracine fishes. Here, we constructed for the first time a tentative molecular phylogeny of the schizothoracine fishes based on the complete sequences of the cytochrome b gene. We employed this molecular phylogenetic framework to examine the evolution of trophic morphologies. We used Pagel's maximum likelihood method to estimate the evolutionary associations of trophic morphologies and food resource use. Our results showed that the molecular and published morphological phylogenies of Schizothoracinae are partially incongruent with respect to some intergeneric relationships. The phylogenetic results revealed that four character states of five trophic morphologies and of food resource use evolved at least twice during the diversification of the subfamily. State transitions are the result of evolutionary patterns including either convergence or parallelism or both. Furthermore, our analyses indicate that some characters of trophic morphologies in the Schizothoracinae have undergone correlated evolution, which are somewhat correlated with different food resource uses. Collectively, our results reveal new examples of convergent and parallel evolution in the organisms of the QTP. The adaptation to different trophic niches through the modification of trophic morphologies and feeding behaviour as found in the schizothoracine fishes may account for the formation and maintenance of the high degree of diversity and radiations in fish communities endemic to QTP. PMID:22470515
Delling, Bo; Palm, Stefan; Palkopoulou, Eleftheria; Prestegaard, Tore
2014-01-01
Presence of sympatric populations may reflect local diversification or secondary contact of already distinct forms. The Baltic cisco (Coregonus albula) normally spawns in late autumn, but in a few lakes in Northern Europe sympatric autumn and spring- or winter-spawners have been described. So far, the evolutionary relationships and taxonomic status of these main life history forms have remained largely unclear. With microsatellites and mtDNA sequences, we analyzed extant and extinct spring- and autumn-spawners from a total of 23 Swedish localities, including sympatric populations. Published sequences from Baltic ciscoes in Germany and Finland, and Coregonus sardinella from North America were also included together with novel mtDNA sequences from Siberian C. sardinella. A clear genetic structure within Sweden was found that included two population assemblages markedly differentiated at microsatellites and apparently fixed for mtDNA haplotypes from two distinct clades. All sympatric Swedish populations belonged to the same assemblage, suggesting parallel evolution of spring-spawning rather than secondary contact. The pattern observed further suggests that postglacial immigration to Northern Europe occurred from at least two different refugia. Previous results showing that mtDNA in Baltic cisco is paraphyletic with respect to North American C. sardinella were confirmed. However, the inclusion of Siberian C. sardinella revealed a more complicated pattern, as these novel haplotypes were found within one of the two main C. albula clades and were clearly distinct from those in North American C. sardinella. The evolutionary history of Northern Hemisphere ciscoes thus seems to be more complex than previously recognized. PMID:25540695
Delling, Bo; Palm, Stefan; Palkopoulou, Eleftheria; Prestegaard, Tore
2014-11-01
Presence of sympatric populations may reflect local diversification or secondary contact of already distinct forms. The Baltic cisco (Coregonus albula) normally spawns in late autumn, but in a few lakes in Northern Europe sympatric autumn and spring- or winter-spawners have been described. So far, the evolutionary relationships and taxonomic status of these main life history forms have remained largely unclear. With microsatellites and mtDNA sequences, we analyzed extant and extinct spring- and autumn-spawners from a total of 23 Swedish localities, including sympatric populations. Published sequences from Baltic ciscoes in Germany and Finland, and Coregonus sardinella from North America were also included together with novel mtDNA sequences from Siberian C. sardinella. A clear genetic structure within Sweden was found that included two population assemblages markedly differentiated at microsatellites and apparently fixed for mtDNA haplotypes from two distinct clades. All sympatric Swedish populations belonged to the same assemblage, suggesting parallel evolution of spring-spawning rather than secondary contact. The pattern observed further suggests that postglacial immigration to Northern Europe occurred from at least two different refugia. Previous results showing that mtDNA in Baltic cisco is paraphyletic with respect to North American C. sardinella were confirmed. However, the inclusion of Siberian C. sardinella revealed a more complicated pattern, as these novel haplotypes were found within one of the two main C. albula clades and were clearly distinct from those in North American C. sardinella. The evolutionary history of Northern Hemisphere ciscoes thus seems to be more complex than previously recognized.
ERIC Educational Resources Information Center
Eder, Erich; Turic, Katharina; Milasowszky, Norbert; Van Adzin, Katherine; Hergovich, Andreas
2011-01-01
The present study is the first to investigate the relationships between a multiple set of paranormal beliefs and the acceptance of evolution, creationism, and intelligent design, respectively, in Europe. Using a questionnaire, 2,129 students at secondary schools in Vienna (Austria) answered the 26 statements of the Revised Paranormal Belief Scale…
ERIC Educational Resources Information Center
Hutchinson, E. M.; And Others
This course was held to review research and investigations undertaken in Europe, their significance for the practice of adult education, and the possibility of cooperative action in the future. Delegates reached conclusions calling for the general review of European adult education, bibliographic services, general and joint research, cooperation,…
[On the evolution of scientific thought].
de Micheli, Alfredo; Iturralde Torres, Pedro
2015-01-01
The Nominalists of the XIV century, precursors of modern science, thought that science's object was not the general, vague and indeterminate but the particular, which is real and can be known directly. About the middle of the XVII Century the bases of the modern science became established thanks to a revolution fomented essentially by Galileo, Bacon and Descartes. During the XVIII Century, parallel to the development of the great current of English Empiricism, a movement of scientific renewal also arose in continental Europe following the discipline of the Dutch Physicians and of Boerhaave. In the XIX Century, Claude Bernard dominated the scientific medicine but his rigorous determinism impeded him from taking into account the immense and unforeseeable field of the random. Nowadays, we approach natural science and medicine, from particular groups of facts; that is, from the responses of Nature to specific questions, but not from the general laws. Furthermore, in recent epistemology, the concept that experimental data are not pure facts, but rather, facts interpreted within a hermeneutical context has been established. Finally a general tendency to retrieve philosophical questions concerning the understanding of essence and existence can frequently be seen in scientific inquiry. In the light of the evolution of medical thought, it is possible to establish the position of scientific medicine within the movement of ideas dominating in our time. Copyright © 2014 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.
Experimental evolution reveals hidden diversity in evolutionary pathways
Lind, Peter A; Farr, Andrew D; Rainey, Paul B
2015-01-01
Replicate populations of natural and experimental organisms often show evidence of parallel genetic evolution, but the causes are unclear. The wrinkly spreader morph of Pseudomonas fluorescens arises repeatedly during experimental evolution. The mutational causes reside exclusively within three pathways. By eliminating these, 13 new mutational pathways were discovered with the newly arising WS types having fitnesses similar to those arising from the commonly passaged routes. Our findings show that parallel genetic evolution is strongly biased by constraints and we reveal the genetic bases. From such knowledge, and in instances where new phenotypes arise via gene activation, we suggest a set of principles: evolution proceeds firstly via pathways subject to negative regulation, then via promoter mutations and gene fusions, and finally via activation by intragenic gain-of-function mutations. These principles inform evolutionary forecasting and have relevance to interpreting the diverse array of mutations associated with clinically identical instances of disease in humans. DOI: http://dx.doi.org/10.7554/eLife.07074.001 PMID:25806684
In Planta Recapitulation of Isoprene Synthase Evolution from Ocimene Synthases.
Li, Mingai; Xu, Jia; Algarra Alarcon, Alberto; Carlin, Silvia; Barbaro, Enrico; Cappellin, Luca; Velikova, Violeta; Vrhovsek, Urska; Loreto, Francesco; Varotto, Claudio
2017-10-01
Isoprene is the most abundant biogenic volatile hydrocarbon compound naturally emitted by plants and plays a major role in atmospheric chemistry. It has been proposed that isoprene synthases (IspS) may readily evolve from other terpene synthases, but this hypothesis has not been experimentally investigated. We isolated and functionally validated in Arabidopsis the first isoprene synthase gene, AdoIspS, from a monocotyledonous species (Arundo donax L., Poaceae). Phylogenetic reconstruction indicates that AdoIspS and dicots isoprene synthases most likely originated by parallel evolution from TPS-b monoterpene synthases. Site-directed mutagenesis demonstrated invivo the functional and evolutionary relevance of the residues considered diagnostic for IspS function. One of these positions was identified by saturating mutagenesis as a major determinant of substrate specificity in AdoIspS able to cause invivo a dramatic change in total volatile emission from hemi- to monoterpenes and supporting evolution of isoprene synthases from ocimene synthases. The mechanism responsible for IspS neofunctionalization by active site size modulation by a single amino acid mutation demonstrated in this study might be general, as the very same amino acidic position is implicated in the parallel evolution of different short-chain terpene synthases from both angiosperms and gymnosperms. Based on these results, we present a model reconciling in a unified conceptual framework the apparently contrasting patterns previously observed for isoprene synthase evolution in plants. These results indicate that parallel evolution may be driven by relatively simple biophysical constraints, and illustrate the intimate molecular evolutionary links between the structural and functional bases of traits with global relevance. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Tuning and History: A Personal Overview
ERIC Educational Resources Information Center
Isaacs, Ann Katherine
2017-01-01
The text places Tuning History in the context of the rapidly developing international collaboration among historians which began in Europe in 1989, with the ECTS Pilot project, and continued, from 2000 on, with the European History Networks (for research and for curriculum development) working in parallel and in collaboration with Tuning, in…
1993-01-05
its own destiny in its own capable and industrious hands and will build the type of free and independent Bulgaria for which our apostles dreamed and...privatization. (5) Finally, we need to develop a new private sector, the true embryo of the market economy. It will develop separately or in parallel with
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Commission des Communautes Europeennes (Luxembourg).
The following papers are included in this volume: "Technological Change: The Future of Training and Work" (Lord Young of Graffham); "L'Education, la Formation et l'Evolution Technologique dans l'Industrie" (Mathias Hinterscheid); "Education, Training, and Technological Change in Industry" (Philippe Meyer);…
ERIC Educational Resources Information Center
Oppedisano, Veruska; Turati, Gilberto
2015-01-01
This paper provides evidence on the sources of differences in inequality in educational scores and their evolution over time in four European countries. Using Programme for International Student Assessment data from the 2000 and the 2006 waves, the paper shows that inequality decreased in Germany and Spain (two "decentralised" schooling…
Liu, Zhen; Qi, Fei-Yan; Zhou, Xin; Ren, Hai-Qing; Shi, Peng
2014-09-01
Echolocation is a sensory system whereby certain mammals navigate and forage using sound waves, usually in environments where visibility is limited. Curiously, echolocation has evolved independently in bats and whales, which occupy entirely different environments. Based on this phenotypic convergence, recent studies identified several echolocation-related genes with parallel sites at the protein sequence level among different echolocating mammals, and among these, prestin seems the most promising. Although previous studies analyzed the evolutionary mechanism of prestin, the functional roles of the parallel sites in the evolution of mammalian echolocation are not clear. By functional assays, we show that a key parameter of prestin function, 1/α, is increased in all echolocating mammals and that the N7T parallel substitution accounted for this functional convergence. Moreover, another parameter, V1/2, was shifted toward the depolarization direction in a toothed whale, the bottlenose dolphin (Tursiops truncatus) and a constant-frequency (CF) bat, the Stoliczka's trident bat (Aselliscus stoliczkanus). The parallel site of I384T between toothed whales and CF bats was responsible for this functional convergence. Furthermore, the two parameters (1/α and V1/2) were correlated with mammalian high-frequency hearing, suggesting that the convergent changes of the prestin function in echolocating mammals may play important roles in mammalian echolocation. To our knowledge, these findings present the functional patterns of echolocation-related genes in echolocating mammals for the first time and rigorously demonstrate adaptive parallel evolution at the protein sequence level, paving the way to insights into the molecular mechanism underlying mammalian echolocation. © The Author 2014. 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.
Parallel Evolution of Sperm Hyper-Activation Ca2+ Channels.
Cooper, Jacob C; Phadnis, Nitin
2017-07-01
Sperm hyper-activation is a dramatic change in sperm behavior where mature sperm burst into a final sprint in the race to the egg. The mechanism of sperm hyper-activation in many metazoans, including humans, consists of a jolt of Ca2+ into the sperm flagellum via CatSper ion channels. Surprisingly, all nine CatSper genes have been independently lost in several animal lineages. In Drosophila, sperm hyper-activation is performed through the cooption of the polycystic kidney disease 2 (pkd2) Ca2+ channel. The parallels between CatSpers in primates and pkd2 in Drosophila provide a unique opportunity to examine the molecular evolution of the sperm hyper-activation machinery in two independent, nonhomologous calcium channels separated by > 500 million years of divergence. Here, we use a comprehensive phylogenomic approach to investigate the selective pressures on these sperm hyper-activation channels. First, we find that the entire CatSper complex evolves rapidly under recurrent positive selection in primates. Second, we find that pkd2 has parallel patterns of adaptive evolution in Drosophila. Third, we show that this adaptive evolution of pkd2 is driven by its role in sperm hyper-activation. These patterns of selection suggest that the evolution of the sperm hyper-activation machinery is driven by sexual conflict with antagonistic ligands that modulate channel activity. Together, our results add sperm hyper-activation channels to the class of fast evolving reproductive proteins and provide insights into the mechanisms used by the sexes to manipulate sperm behavior. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
In Planta Recapitulation of Isoprene Synthase Evolution from Ocimene Synthases
Li, Mingai; Xu, Jia; Algarra Alarcon, Alberto; Carlin, Silvia; Barbaro, Enrico; Cappellin, Luca; Velikova, Violeta; Vrhovsek, Urska; Loreto, Francesco; Varotto, Claudio
2017-01-01
Abstract Isoprene is the most abundant biogenic volatile hydrocarbon compound naturally emitted by plants and plays a major role in atmospheric chemistry. It has been proposed that isoprene synthases (IspS) may readily evolve from other terpene synthases, but this hypothesis has not been experimentally investigated. We isolated and functionally validated in Arabidopsis the first isoprene synthase gene, AdoIspS, from a monocotyledonous species (Arundo donax L., Poaceae). Phylogenetic reconstruction indicates that AdoIspS and dicots isoprene synthases most likely originated by parallel evolution from TPS-b monoterpene synthases. Site-directed mutagenesis demonstrated invivo the functional and evolutionary relevance of the residues considered diagnostic for IspS function. One of these positions was identified by saturating mutagenesis as a major determinant of substrate specificity in AdoIspS able to cause invivo a dramatic change in total volatile emission from hemi- to monoterpenes and supporting evolution of isoprene synthases from ocimene synthases. The mechanism responsible for IspS neofunctionalization by active site size modulation by a single amino acid mutation demonstrated in this study might be general, as the very same amino acidic position is implicated in the parallel evolution of different short-chain terpene synthases from both angiosperms and gymnosperms. Based on these results, we present a model reconciling in a unified conceptual framework the apparently contrasting patterns previously observed for isoprene synthase evolution in plants. These results indicate that parallel evolution may be driven by relatively simple biophysical constraints, and illustrate the intimate molecular evolutionary links between the structural and functional bases of traits with global relevance. PMID:28637270
Long-range dispersal moved Francisella tularensis into Western Europe from the East.
Dwibedi, Chinmay; Birdsell, Dawn; Lärkeryd, Adrian; Myrtennäs, Kerstin; Öhrman, Caroline; Nilsson, Elin; Karlsson, Edvin; Hochhalter, Christian; Rivera, Andrew; Maltinsky, Sara; Bayer, Brittany; Keim, Paul; Scholz, Holger C; Tomaso, Herbert; Wittwer, Matthias; Beuret, Christian; Schuerch, Nadia; Pilo, Paola; Hernández Pérez, Marta; Rodriguez-Lazaro, David; Escudero, Raquel; Anda, Pedro; Forsman, Mats; Wagner, David M; Larsson, Pär; Johansson, Anders
2016-12-01
For many infections transmitting to humans from reservoirs in nature, disease dispersal patterns over space and time are largely unknown. Here, a reversed genomics approach helped us understand disease dispersal and yielded insight into evolution and biological properties of Francisella tularensis , the bacterium causing tularemia. We whole-genome sequenced 67 strains and characterized by single-nucleotide polymorphism assays 138 strains, collected from individuals infected 1947-2012 across Western Europe. We used the data for phylogenetic, population genetic and geographical network analyses. All strains ( n =205) belonged to a monophyletic population of recent ancestry not found outside Western Europe. Most strains ( n =195) throughout the study area were assigned to a star-like phylogenetic pattern indicating that colonization of Western Europe occurred via clonal expansion. In the East of the study area, strains were more diverse, consistent with a founder population spreading from east to west. The relationship of genetic and geographic distance within the F. tularensis population was complex and indicated multiple long-distance dispersal events. Mutation rate estimates based on year of isolation indicated null rates; in outbreak hotspots only, there was a rate of 0.4 mutations/genome/year. Patterns of nucleotide substitution showed marked AT mutational bias suggestive of genetic drift. These results demonstrate that tularemia has moved from east to west in Europe and that F. tularensis has a biology characterized by long-range geographical dispersal events and mostly slow, but variable, replication rates. The results indicate that mutation-driven evolution, a resting survival phase, genetic drift and long-distance geographical dispersal events have interacted to generate genetic diversity within this species.
Monitoring Data-Structure Evolution in Distributed Message-Passing Programs
NASA Technical Reports Server (NTRS)
Sarukkai, Sekhar R.; Beers, Andrew; Woodrow, Thomas S. (Technical Monitor)
1996-01-01
Monitoring the evolution of data structures in parallel and distributed programs, is critical for debugging its semantics and performance. However, the current state-of-art in tracking and presenting data-structure information on parallel and distributed environments is cumbersome and does not scale. In this paper we present a methodology that automatically tracks memory bindings (not the actual contents) of static and dynamic data-structures of message-passing C programs, using PVM. With the help of a number of examples we show that in addition to determining the impact of memory allocation overheads on program performance, graphical views can help in debugging the semantics of program execution. Scalable animations of virtual address bindings of source-level data-structures are used for debugging the semantics of parallel programs across all processors. In conjunction with light-weight core-files, this technique can be used to complement traditional debuggers on single processors. Detailed information (such as data-structure contents), on specific nodes, can be determined using traditional debuggers after the data structure evolution leading to the semantic error is observed graphically.
Proton core-beam system in the expanding solar wind: Hybrid simulations
NASA Astrophysics Data System (ADS)
Hellinger, Petr; Trávníček, Pavel M.
2011-11-01
Results of a two-dimensional hybrid expanding box simulation of a proton beam-core system in the solar wind are presented. The expansion with a strictly radial magnetic field leads to a decrease of the ratio between the proton perpendicular and parallel temperatures as well as to an increase of the ratio between the beam-core differential velocity and the local Alfvén velocity creating a free energy for many different instabilities. The system is indeed most of the time marginally stable with respect to the parallel magnetosonic, oblique Alfvén, proton cyclotron and parallel fire hose instabilities which determine the system evolution counteracting some effects of the expansion and interacting with each other. Nonlinear evolution of these instabilities leads to large modifications of the proton velocity distribution function. The beam and core protons are slowed with respect to each other and heated, and at later stages of the evolution the two populations are not clearly distinguishable. On the macroscopic level the instabilities cause large departures from the double adiabatic prediction leading to an efficient isotropization of effective proton temperatures in agreement with Helios observations.
Parallel Evolution of Sperm Hyper-Activation Ca2+ Channels
Phadnis, Nitin
2017-01-01
Abstract Sperm hyper-activation is a dramatic change in sperm behavior where mature sperm burst into a final sprint in the race to the egg. The mechanism of sperm hyper-activation in many metazoans, including humans, consists of a jolt of Ca2+ into the sperm flagellum via CatSper ion channels. Surprisingly, all nine CatSper genes have been independently lost in several animal lineages. In Drosophila, sperm hyper-activation is performed through the cooption of the polycystic kidney disease 2 (pkd2) Ca2+ channel. The parallels between CatSpers in primates and pkd2 in Drosophila provide a unique opportunity to examine the molecular evolution of the sperm hyper-activation machinery in two independent, nonhomologous calcium channels separated by > 500 million years of divergence. Here, we use a comprehensive phylogenomic approach to investigate the selective pressures on these sperm hyper-activation channels. First, we find that the entire CatSper complex evolves rapidly under recurrent positive selection in primates. Second, we find that pkd2 has parallel patterns of adaptive evolution in Drosophila. Third, we show that this adaptive evolution of pkd2 is driven by its role in sperm hyper-activation. These patterns of selection suggest that the evolution of the sperm hyper-activation machinery is driven by sexual conflict with antagonistic ligands that modulate channel activity. Together, our results add sperm hyper-activation channels to the class of fast evolving reproductive proteins and provide insights into the mechanisms used by the sexes to manipulate sperm behavior. PMID:28810709
Human population dynamics in Europe over the Last Glacial Maximum.
Tallavaara, Miikka; Luoto, Miska; Korhonen, Natalia; Järvinen, Heikki; Seppä, Heikki
2015-07-07
The severe cooling and the expansion of the ice sheets during the Last Glacial Maximum (LGM), 27,000-19,000 y ago (27-19 ky ago) had a major impact on plant and animal populations, including humans. Changes in human population size and range have affected our genetic evolution, and recent modeling efforts have reaffirmed the importance of population dynamics in cultural and linguistic evolution, as well. However, in the absence of historical records, estimating past population levels has remained difficult. Here we show that it is possible to model spatially explicit human population dynamics from the pre-LGM at 30 ky ago through the LGM to the Late Glacial in Europe by using climate envelope modeling tools and modern ethnographic datasets to construct a population calibration model. The simulated range and size of the human population correspond significantly with spatiotemporal patterns in the archaeological data, suggesting that climate was a major driver of population dynamics 30-13 ky ago. The simulated population size declined from about 330,000 people at 30 ky ago to a minimum of 130,000 people at 23 ky ago. The Late Glacial population growth was fastest during Greenland interstadial 1, and by 13 ky ago, there were almost 410,000 people in Europe. Even during the coldest part of the LGM, the climatically suitable area for human habitation remained unfragmented and covered 36% of Europe.
Human population dynamics in Europe over the Last Glacial Maximum
Tallavaara, Miikka; Luoto, Miska; Korhonen, Natalia; Järvinen, Heikki; Seppä, Heikki
2015-01-01
The severe cooling and the expansion of the ice sheets during the Last Glacial Maximum (LGM), 27,000–19,000 y ago (27–19 ky ago) had a major impact on plant and animal populations, including humans. Changes in human population size and range have affected our genetic evolution, and recent modeling efforts have reaffirmed the importance of population dynamics in cultural and linguistic evolution, as well. However, in the absence of historical records, estimating past population levels has remained difficult. Here we show that it is possible to model spatially explicit human population dynamics from the pre-LGM at 30 ky ago through the LGM to the Late Glacial in Europe by using climate envelope modeling tools and modern ethnographic datasets to construct a population calibration model. The simulated range and size of the human population correspond significantly with spatiotemporal patterns in the archaeological data, suggesting that climate was a major driver of population dynamics 30–13 ky ago. The simulated population size declined from about 330,000 people at 30 ky ago to a minimum of 130,000 people at 23 ky ago. The Late Glacial population growth was fastest during Greenland interstadial 1, and by 13 ky ago, there were almost 410,000 people in Europe. Even during the coldest part of the LGM, the climatically suitable area for human habitation remained unfragmented and covered 36% of Europe. PMID:26100880
de Lombera-Hermida, Arturo; Bargalló, Amèlia; Terradillos-Bernal, Marcos; Huguet, Rosa; Vallverdú, Josep; García-Antón, Maria-Dolores; Mosquera, Marina; Ollé, Andreu; Sala, Robert; Carbonell, Eudald; Rodríguez-Álvarez, Xosé-Pedro
2015-05-01
This paper presents the lithic assemblages documented at Sima del Elefante (TE) and their importance in the context of the Early and Middle Pleistocene human occupation of Europe. We also study changes in human behaviour within the context of the palaeoenvironmental evolution of the Sierra de Atapuerca. This site has characteristics that are of great value for the study of human evolution. The lower levels of TE (Units TE7-TE14) are an essential reference for understanding the early stages of the colonization of Europe. The TE9c level has provided stone tools (Mode 1), faunal remains, and human fossils dated to 1.22 Ma (millions of years ago). Moreover, this is one of the few European sites with a stratigraphic sequence that includes remains of human occupations predating the Jaramillo subchron (Early Pleistocene) and from the Late Middle Pleistocene (Units TE18-TE19). Despite this, the presence of archaeologically sterile units (TE15-17) prevents us from establishing a continuous relationship between the Early and Middle Pleistocene human settlements and, consequently, between their technological and behavioural differences. We can, however compare the technological and palaeoeconomic strategies adopted by different species of hominins during two key phases of the occupation of Europe. Copyright © 2015 Elsevier Ltd. All rights reserved.
Assessment of the pharmacogenomics educational environment in Southeast Europe.
Pisanu, Claudia; Tsermpini, Evangelia-Eirini; Mavroidi, Eirini; Katsila, Theodora; Patrinos, George P; Squassina, Alessio
2014-01-01
Pharmacogenomics aims to use the information derived from an individual's genomic profile in the context of individualizing medical treatment modalities. However, currently, pharmacogenomics education is not uniformly provided to health care professionals. This study investigates the status of pharmacogenomics education in Southeast Europe. University websites served as information sources in order to investigate the discrepancies in pharmacogenomics education in Southeast Europe. In parallel, a survey was conducted at the University of Cagliari (Italy) to test pharmacogenomics knowledge and understanding among specialists, residents and undergraduate students. Our study shows that pharmacogenomics knowledge is not uniformly spread in universities in Southeast Europe and provides the basis for the harmonization of pharmacogenomics education that would directly impact on a smoother integration of pharmacogenomics into mainstream medical practice. Also, a considerable gap in pharmacogenomics education was obvious between the group of specialists and the groups of residents and undergraduate students. Pharmacogenomics education as well as the continuous enrichment of pharmacogenomics knowledge for health care professionals are fundamental approaches toward personalized medicine. Ideally, pharmacogenomics should be taught as a stand-alone course or at least in the context of genetics courses that already exist in universities in Southeast Europe. © 2014 S. Karger AG, Basel.
Mitochondrial gene rearrangements confirm the parallel evolution of the crab-like form.
Morrison, C L; Harvey, A W; Lavery, S; Tieu, K; Huang, Y; Cunningham, C W
2002-01-01
The repeated appearance of strikingly similar crab-like forms in independent decapod crustacean lineages represents a remarkable case of parallel evolution. Uncertainty surrounding the phylogenetic relationships among crab-like lineages has hampered evolutionary studies. As is often the case, aligned DNA sequences by themselves were unable to fully resolve these relationships. Four nested mitochondrial gene rearrangements--including one of the few reported movements of an arthropod protein-coding gene--are congruent with the DNA phylogeny and help to resolve a crucial node. A phylogenetic analysis of DNA sequences, and gene rearrangements, supported five independent origins of the crab-like form, and suggests that the evolution of the crab-like form may be irreversible. This result supports the utility of mitochondrial gene rearrangements in phylogenetic reconstruction. PMID:11886621
USDA-ARS?s Scientific Manuscript database
The anthropogenic evolution of chernozems as a result of plowing and the creation of forest shelterbelts on three meadow-steppe areas of forest-steppe were studied. It was established, that in all areas there are similar patterns, caused by the transformation of virgin soils into arable soils and vi...
ERIC Educational Resources Information Center
Méndez García, María del Carmen
2017-01-01
The Council of Europe's "Autobiography of Intercultural Encounter" (AIE) is a tool to develop intercultural competence (IC) in education by encouraging users to reflect upon and learn from momentous intercultural encounters they have experienced face to face. Its parallel resource, the "Autobiography of Intercultural Encounters…
Crustal movements in Europe observed with EUROPE and IVS-T2 VLBI networks
NASA Astrophysics Data System (ADS)
Zubko, N.; Poutanen, M.
2011-07-01
The comparative analysis of the EUROPE and IVS-T2 geodetic VLBI sessions has been performed. The main purpose of both campaigns is to observe and accurately determine the VLBI station coordinates and their time evolution. In this analysis our interest is to understand the influence of network configuration on the estimated parameters and, also, how much the results of these two campaigns are consistent. We have used the VieVS software developing at Vienna University of Technology to analyze the EUROPE and IVS-T2 sessions of 2002-2009. We have analyzed the difference of crustal movements obtained with these two networks and the effect of network configuration and station selection. The EPN (EUREF permanent GNSS Network) and IGS (International GNSS Service) networks can be used to compare the results.
Waterfalls drive parallel evolution in a freshwater goby
Kano, Yuichi; Nishida, Shin; Nakajima, Jun
2012-01-01
Waterfalls may affect fish distribution and genetic structure within drainage networks even to the extent of leading evolutionary events. Here, parallel evolution was studied by focusing on waterfall and the landlocked freshwater goby Rhinogobius sp. YB (YB), which evolved from amphidromous R. brunneus (BR). The fish fauna was surveyed at 30 sites in 11 rivers on Iriomote Island, Japan, the geography of which was characterized by terraces/tablelands with many waterfalls. We found that all YB individuals were distributed only above waterfalls (height 6.8–58.7 m), whereas BR, and other fishes, were mostly distributed below waterfalls. Mitochondrial DNA analysis showed that every YB local population above the waterfall was independently evolved from BR. In contrast, cluster analysis of nine morphological characters, such as fin color and body pattern, showed that the morphology of YB individuals held a similarity beyond the genetic divergence, suggesting parallel evolution has occurred relating to their morphology. Genetic distance between each YB local population and BR was significantly correlated with waterfall height (r2 = 0.94), suggesting that the waterfalls have been heightened due to the constant geological erosion and that their height represents the isolation period of YB local populations from BR (ca. 11,000–88,000 years). Each local population of BR was once landlocked in upstream by waterfall formation, consequently evolving to YB in each site. Although the morphology of YB had a high degree of similarity among local populations, finer scale analysis showed that the morphology of YB was significantly correlated with the genetic distance from BR. Consequently, there could be simultaneous multiple phases of allopatric/parallel evolution of the goby due to variations in waterfall height on this small island. PMID:22957183
A Balanced Mixture of Antagonistic Pressures Promotes the Evolution of Parallel Movement
NASA Astrophysics Data System (ADS)
Demšar, Jure; Štrumbelj, Erik; Lebar Bajec, Iztok
2016-12-01
A common hypothesis about the origins of collective behaviour suggests that animals might live and move in groups to increase their chances of surviving predator attacks. This hypothesis is supported by several studies that use computational models to simulate natural evolution. These studies, however, either tune an ad-hoc model to ‘reproduce’ collective behaviour, or concentrate on a single type of predation pressure, or infer the emergence of collective behaviour from an increase in prey density. In nature, prey are often targeted by multiple predator species simultaneously and this might have played a pivotal role in the evolution of collective behaviour. We expand on previous research by using an evolutionary rule-based system to simulate the evolution of prey behaviour when prey are subject to multiple simultaneous predation pressures. We analyse the evolved behaviour via prey density, polarization, and angular momentum. Our results suggest that a mixture of antagonistic external pressures that simultaneously steer prey towards grouping and dispersing might be required for prey individuals to evolve dynamic parallel movement.
Huang, Shan; Eronen, Jussi T; Janis, Christine M; Saarinen, Juha J; Silvestro, Daniele; Fritz, Susanne A
2017-02-22
Because body size interacts with many fundamental biological properties of a species, body size evolution can be an essential component of the generation and maintenance of biodiversity. Here we investigate how body size evolution can be linked to the clade-specific diversification dynamics in different geographical regions. We analyse an extensive body size dataset of Neogene large herbivores (covering approx. 50% of the 970 species in the orders Artiodactyla and Perissodactyla) in Europe and North America in a Bayesian framework. We reconstruct the temporal patterns of body size in each order on each continent independently, and find significant increases of minimum size in three of the continental assemblages (except European perissodactyls), suggesting an active selection for larger bodies. Assessment of trait-correlated birth-death models indicates that the common trend of body size increase is generated by different processes in different clades and regions. Larger-bodied artiodactyl species on both continents tend to have higher origination rates, and both clades in North America show strong links between large bodies and low extinction rate. Collectively, our results suggest a strong role of species selection and perhaps of higher-taxon sorting in driving body size evolution, and highlight the value of investigating evolutionary processes in a biogeographic context. © 2017 The Author(s).
Eronen, Jussi T.; Janis, Christine M.; Saarinen, Juha J.
2017-01-01
Because body size interacts with many fundamental biological properties of a species, body size evolution can be an essential component of the generation and maintenance of biodiversity. Here we investigate how body size evolution can be linked to the clade-specific diversification dynamics in different geographical regions. We analyse an extensive body size dataset of Neogene large herbivores (covering approx. 50% of the 970 species in the orders Artiodactyla and Perissodactyla) in Europe and North America in a Bayesian framework. We reconstruct the temporal patterns of body size in each order on each continent independently, and find significant increases of minimum size in three of the continental assemblages (except European perissodactyls), suggesting an active selection for larger bodies. Assessment of trait-correlated birth-death models indicates that the common trend of body size increase is generated by different processes in different clades and regions. Larger-bodied artiodactyl species on both continents tend to have higher origination rates, and both clades in North America show strong links between large bodies and low extinction rate. Collectively, our results suggest a strong role of species selection and perhaps of higher-taxon sorting in driving body size evolution, and highlight the value of investigating evolutionary processes in a biogeographic context. PMID:28202809
Alexander, Jake M
2013-09-22
A topic of great current interest is the capacity of populations to adapt genetically to rapidly changing climates, for example by evolving the timing of life-history events, but this is challenging to address experimentally. I use a plant invasion as a model system to tackle this question by combining molecular markers, a common garden experiment and climatic niche modelling. This approach reveals that non-native Lactuca serriola originates primarily from Europe, a climatic subset of its native range, with low rates of admixture from Asia. It has rapidly refilled its climatic niche in the new range, associated with the evolution of flowering phenology to produce clines along climate gradients that mirror those across the native range. Consequently, some non-native plants have evolved development times and grow under climates more extreme than those found in Europe, but not among populations from the native range as a whole. This suggests that many plant populations can adapt rapidly to changed climatic conditions that are already within the climatic niche space occupied by the species elsewhere in its range, but that evolution to conditions outside of this range is more difficult. These findings can also help to explain the prevalence of niche conservatism among non-native species.
Influence of solar variability on the occurrence of central European weather types from 1763 to 2009
NASA Astrophysics Data System (ADS)
Schwander, Mikhaël; Rohrer, Marco; Brönnimann, Stefan; Malik, Abdul
2017-09-01
The impact of solar variability on weather and climate in central Europe is still not well understood. In this paper we use a new time series of daily weather types to analyse the influence of the 11-year solar cycle on the tropospheric weather of central Europe. We employ a novel, daily weather type classification over the period 1763-2009 and investigate the occurrence frequency of weather types under low, moderate, and high solar activity level. Results show a tendency towards fewer days with westerly and west-southwesterly flow over central Europe under low solar activity. In parallel, the occurrence of northerly and easterly types increases. For the 1958-2009 period, a more detailed view can be gained from reanalysis data. Mean sea level pressure composites under low solar activity also show a reduced zonal flow, with an increase of the mean blocking frequency between Iceland and Scandinavia. Weather types and reanalysis data show that the 11-year solar cycle influences the late winter atmospheric circulation over central Europe with colder (warmer) conditions under low (high) solar activity.
Long-range dispersal moved Francisella tularensis into Western Europe from the East
Dwibedi, Chinmay; Birdsell, Dawn; Lärkeryd, Adrian; Myrtennäs, Kerstin; Öhrman, Caroline; Nilsson, Elin; Karlsson, Edvin; Hochhalter, Christian; Rivera, Andrew; Maltinsky, Sara; Bayer, Brittany; Keim, Paul; Scholz, Holger C.; Tomaso, Herbert; Wittwer, Matthias; Beuret, Christian; Schuerch, Nadia; Pilo, Paola; Hernández Pérez, Marta; Rodriguez-Lazaro, David; Escudero, Raquel; Anda, Pedro; Forsman, Mats; Wagner, David M.; Larsson, Pär
2016-01-01
For many infections transmitting to humans from reservoirs in nature, disease dispersal patterns over space and time are largely unknown. Here, a reversed genomics approach helped us understand disease dispersal and yielded insight into evolution and biological properties of Francisella tularensis, the bacterium causing tularemia. We whole-genome sequenced 67 strains and characterized by single-nucleotide polymorphism assays 138 strains, collected from individuals infected 1947-2012 across Western Europe. We used the data for phylogenetic, population genetic and geographical network analyses. All strains (n=205) belonged to a monophyletic population of recent ancestry not found outside Western Europe. Most strains (n=195) throughout the study area were assigned to a star-like phylogenetic pattern indicating that colonization of Western Europe occurred via clonal expansion. In the East of the study area, strains were more diverse, consistent with a founder population spreading from east to west. The relationship of genetic and geographic distance within the F. tularensis population was complex and indicated multiple long-distance dispersal events. Mutation rate estimates based on year of isolation indicated null rates; in outbreak hotspots only, there was a rate of 0.4 mutations/genome/year. Patterns of nucleotide substitution showed marked AT mutational bias suggestive of genetic drift. These results demonstrate that tularemia has moved from east to west in Europe and that F. tularensis has a biology characterized by long-range geographical dispersal events and mostly slow, but variable, replication rates. The results indicate that mutation-driven evolution, a resting survival phase, genetic drift and long-distance geographical dispersal events have interacted to generate genetic diversity within this species. PMID:28348839
Wu, Qizhu; Yin, Ye; Zhou, Huanmin
2014-01-01
Mongolians have played a significant role in modern human evolution, especially after the rise of Genghis Khan (1162[?]–1227). Although the social cultural impacts of Genghis Khan and the Mongolian population have been well documented, explorations of their genome structure and genetic imprints on other human populations have been lacking. We here present the genome of a Mongolian male individual. The genome was de novo assembled using a total of 130.8-fold genomic data produced from massively parallel whole-genome sequencing. We identified high-confidence variation sets, including 3.7 million single nucleotide polymorphisms (SNPs) and 756,234 short insertions and deletions. Functional SNP analysis predicted that the individual has a pathogenic risk for carnitine deficiency. We located the patrilineal inheritance of the Mongolian genome to the lineage D3a through Y haplogroup analysis and inferred that the individual has a common patrilineal ancestor with Tibeto-Burman populations and is likely to be the progeny of the earliest settlers in East Asia. We finally investigated the genetic imprints of Mongolians on other human populations using different approaches. We found varying degrees of gene flows between Mongolians and populations living in Europe, South/Central Asia, and the Indian subcontinent. The analyses demonstrate that the genetic impacts of Mongolians likely resulted from the expansion of the Mongolian Empire in the 13th century. The genome will be of great help in further explorations of modern human evolution and genetic causes of diseases/traits specific to Mongolians. PMID:25377941
Hepatitis E Virus Genotype 4 Outbreak, Italy, 2011
Garbuglia, Anna R.; Scognamiglio, Paola; Petrosillo, Nicola; Mastroianni, Claudio Maria; Sordillo, Pasquale; Gentile, Daniele; La Scala, Patrizia; Girardi, Enrico
2013-01-01
During 2011, 5 persons in the area of Lazio, Italy were infected with a monophyletic strain of hepatitis E virus that showed high sequence homology with isolates from swine in China. Detection of this genotype in Italy parallels findings in other countries in Europe, signaling the possible spread of strains new to Western countries. PMID:23260079
1987-11-24
of the assortment of manufactured parts for partial and complete frames, as well as abutments , support walls, and bridgehead construction...Uniform Series II Generation based on anticipated spans; and • Increased effectiveness of prefabrication for steel and masonry bridge construction...support structures and abutments . Parallel to and on an equal par with standard primary construction trades already cited, the scientific-technical
The Self-Perceptions of Young Men as Singers in Singaporean Pre-University Schools
ERIC Educational Resources Information Center
Freer, Patrick K.; Tan, Leonard
2014-01-01
The persistence of young men in choral singing activity has been widely studied in North America, with emerging parallel research in Europe (Freer, 2013; Harrison & Welch, 2012). There has been little such research in Asia. This study, of 12 young men enrolled in Singapore's pre-university schools, collected both written narratives and drawn…
Crystal MD: The massively parallel molecular dynamics software for metal with BCC structure
NASA Astrophysics Data System (ADS)
Hu, Changjun; Bai, He; He, Xinfu; Zhang, Boyao; Nie, Ningming; Wang, Xianmeng; Ren, Yingwen
2017-02-01
Material irradiation effect is one of the most important keys to use nuclear power. However, the lack of high-throughput irradiation facility and knowledge of evolution process, lead to little understanding of the addressed issues. With the help of high-performance computing, we could make a further understanding of micro-level-material. In this paper, a new data structure is proposed for the massively parallel simulation of the evolution of metal materials under irradiation environment. Based on the proposed data structure, we developed the new molecular dynamics software named Crystal MD. The simulation with Crystal MD achieved over 90% parallel efficiency in test cases, and it takes more than 25% less memory on multi-core clusters than LAMMPS and IMD, which are two popular molecular dynamics simulation software. Using Crystal MD, a two trillion particles simulation has been performed on Tianhe-2 cluster.
Teaching and Learning: Highlighting the Parallels between Education and Participatory Evaluation.
ERIC Educational Resources Information Center
Vanden Berk, Eric J.; Cassata, Jennifer Coyne; Moye, Melinda J.; Yarbrough, Donald B.; Siddens, Stephanie K.
As an evaluation team trained in educational psychology and committed to participatory evaluation and its evolution, the researchers have found the parallel between evaluator-stakeholder roles in the participatory evaluation process and educator-student roles in educational psychology theory to be important. One advantage then is that the theories…
New Parallel Algorithms for Landscape Evolution Model
NASA Astrophysics Data System (ADS)
Jin, Y.; Zhang, H.; Shi, Y.
2017-12-01
Most landscape evolution models (LEM) developed in the last two decades solve the diffusion equation to simulate the transportation of surface sediments. This numerical approach is difficult to parallelize due to the computation of drainage area for each node, which needs huge amount of communication if run in parallel. In order to overcome this difficulty, we developed two parallel algorithms for LEM with a stream net. One algorithm handles the partition of grid with traditional methods and applies an efficient global reduction algorithm to do the computation of drainage areas and transport rates for the stream net; the other algorithm is based on a new partition algorithm, which partitions the nodes in catchments between processes first, and then partitions the cells according to the partition of nodes. Both methods focus on decreasing communication between processes and take the advantage of massive computing techniques, and numerical experiments show that they are both adequate to handle large scale problems with millions of cells. We implemented the two algorithms in our program based on the widely used finite element library deal.II, so that it can be easily coupled with ASPECT.
Parallel genetic origins of pelvic reduction in vertebrates
Shapiro, Michael D.; Bell, Michael A.; Kingsley, David M.
2006-01-01
Despite longstanding interest in parallel evolution, little is known about the genes that control similar traits in different lineages of vertebrates. Pelvic reduction in stickleback fish (family Gasterosteidae) provides a striking example of parallel evolution in a genetically tractable system. Previous studies suggest that cis-acting regulatory changes at the Pitx1 locus control pelvic reduction in a population of threespine sticklebacks (Gasterosteus aculeatus). In this study, progeny from intergeneric crosses between pelvic-reduced threespine and ninespine (Pungitius pungitius) sticklebacks also showed severe pelvic reduction, implicating a similar genetic origin for this trait in both genera. Comparative sequencing studies in complete and pelvic-reduced Pungitius revealed no differences in the Pitx1 coding sequences, but Pitx1 expression was absent from the prospective pelvic region of larvae from pelvic-reduced parents. A much more phylogenetically distant example of pelvic reduction, loss of hindlimbs in manatees, shows a similar left–right size bias that is a morphological signature of Pitx1-mediated pelvic reduction in both sticklebacks and mice. These multiple lines of evidence suggest that changes in Pitx1 may represent a key mechanism of morphological evolution in multiple populations, species, and genera of sticklebacks, as well as in distantly related vertebrate lineages. PMID:16945911
Protons and alpha particles in the expanding solar wind: Hybrid simulations
NASA Astrophysics Data System (ADS)
Hellinger, Petr; Trávníček, Pavel M.
2013-09-01
We present results of a two‒dimensional hybrid expanding box simulation of a plasma system with three ion populations, beam and core protons, and alpha particles (and fluid electrons), drifting with respect to each other. The expansion with a strictly radial magnetic field leads to a decrease of the ion perpendicular to parallel temperature ratios as well as to an increase of the ratio between the ion relative velocities and the local Alfvén velocity creating a free energy for many different instabilities. The system is most of the time marginally stable with respect to kinetic instabilities mainly due to the ion relative velocities; these instabilities determine the system evolution counteracting some effects of the expansion. Nonlinear evolution of these instabilities leads to large modifications of the ion velocity distribution functions. The beam protons and alpha particles are decelerated with respect to the core protons and all the populations are cooled in the parallel direction and heated in the perpendicular one. On the macroscopic level, the kinetic instabilities cause large departures of the system evolution from the double adiabatic prediction and lead to perpendicular heating and parallel cooling rates which are comparable to the heating rates estimated from the Helios observations.
Jeukens, Julie; Bittner, David; Knudsen, Rune; Bernatchez, Louis
2009-01-01
In the past 40 years, there has been increasing acceptance that variation in levels of gene expression represents a major source of evolutionary novelty. Gene expression divergence is therefore likely to be involved in the emergence of incipient species, namely, in a context of adaptive radiation. In the lake whitefish species complex (Coregonus clupeaformis), previous microarray experiments have led to the identification of candidate genes potentially implicated in the parallel evolution of the limnetic dwarf lake whitefish, which is highly distinct from the benthic normal lake whitefish in life history, morphology, metabolism, and behavior, and yet diverged from it only approximately 15,000 years before present. The aim of the present study was to address transcriptional divergence for six candidate genes among lake whitefish and European whitefish (Coregonus lavaretus) species pairs, as well as lake cisco (Coregonus artedi) and vendace (Coregonus albula). The main goal was to test the hypothesis that parallel phenotypic adaptation toward the use of the limnetic niche in coregonine fishes is accompanied by parallelism in candidate gene transcription as measured by quantitative real-time polymerase chain reaction. Results obtained for three candidate genes, whereby parallelism in expression was observed across all whitefish species pairs, provide strong support for the hypothesis that divergent natural selection plays an important role in the adaptive radiation of whitefish species. However, this parallelism in expression did not extend to cisco and vendace, thereby infirming transcriptional convergence between limnetic whitefish species and their limnetic congeners for these genes. As recently proposed (Lynch 2007a. The evolution of genetic networks by non-adaptive processes. Nat Rev Genet. 8:803-813), these results may suggest that convergent phenotypic evolution can result from nonadaptive shaping of genome architecture in independently evolved coregonine lineages.
Reflections on the evolution of health technology assessment in Europe.
Sorenson, Corinna; Chalkidou, Kalipso
2012-01-01
Health technology assessment (HTA) has assumed an increasing role in health systems in recent years, with many countries establishing agencies or programmes to evaluate health technology and other interventions to inform policy decisions and clinical practice. This paper reflects upon its development and evolution in Europe over the last decade, with a focus on England, France, Germany and Sweden. In particular, we explore how HTA has evolved over time as well as its impact on policy and practice. While countries share many of the same objectives, there are differences in the way HTA agencies and programmes are organised, operate, and influence decision making. Despite these differences, all systems are faced with opportunities and challenges related to stakeholder involvement and acceptance, the suitability and transparency of assessment requirements and methods, balancing evidence and values in decision making, and demonstrating impact. © Cambridge University Press 2012
NASA Technical Reports Server (NTRS)
Zerefos, Christos S.; Balis, Dimitrios S.; Bais, Alkiviadis F.; Ziomas, Ioannis C.; Tourpali, Kleareti; Meleti, Chariklea; Tzoumaka, Paraskevi; Mantis, Homer T.; Repapis, Christos C.; Fioletov, Vitali E.
1994-01-01
The evolution of ozone anomalies over the middle and high latitudes of the Northern Hemisphere during the winter 1991-1992 is studied in this work. The largest monthly mean negative deviations in the middle latitudes of the Northern Hemisphere were about 10 percent in November and December, and up to 20 percent in January, February, and March over Eurasian territories, and much smaller over the Canadian sector. At the end of January, on individual days, total ozone values of 190-210 D.U. were observed over Eastern Europe and European part of Russia, that is 40-45 percent below normal. On the whole, the 1991-1992 winter was one of the most anomalous over all the period of ozone observations. Finally, an attempt is made to quantify the contribution of transport in the ozone layer changes over Europe during this period.
Closed depressions in the European loess belt - Natural or anthropogenic origin?
NASA Astrophysics Data System (ADS)
Kołodyńska-Gawrysiak, Renata; Poesen, Jean
2017-07-01
Closed depressions (CDs) are typical geomorphological features of the loess belt in Europe. CDs have been reported in several regions of the European loess belt, where they are described as hollows, mardeles, wymoki, crovuri, bludtsa and zapadiny. The natural and anthropogenic origins of CDs are debated in literature. Moreover, no comprehensive review of the geomorphic properties or the evolution of these depressions exists. Therefore this paper reviews the characteristics of CDs in the European loess belt and attempts to better understand their genesis based on detailed case studies. The main morphometric features as well as sediment deposits within CDs in several sub-regions of Europe were analysed and compared. Morphometric properties of CDs from the West European and East European loess belt were investigated through a comparison of CDs from two representative regions, i.e. East Poland and Central Belgium. In both study areas, CDs under cropland are similar. However, a comparison of morphological features of CDs under forest, revealed clear differences, suggesting a different origin of CDs from both regions. Infilled sediments in CDs show various litho-genetical features in different regions of the European loess belt. The morphometric features, ages and stratigraphy of infillings clearly indicate that both anthropogenic and natural processes have shaped these landforms within the loess belt of Europe. CDs observed in Eastern Europe may have a very different origin than those documented in Western Europe. Detailed analysis of CDs in Poland and in neighbouring regions of East Europe, suggest that CDs are natural landforms: thermokarst, deflation and dissolution of loess are reported as probable genetic processes. In contrast, several studies in Western Europe indicate a dominant anthropogenic origin (i.e. digging of calcareous loess or marls, bomb and mining craters, collapse of underground limestone quarries), although CDs formed by natural processes (i.e. piping, dissolution of limestone and salt lenses below the loess cover) are reported as well. CDs act as important archives, allowing one to reconstruct both natural and anthropogenic processes operating in the past. As CDs store most sediments eroded within their catchment they provide ideal sediment traps to assess long-term erosion rates in these environments which have hitherto been under-researched. More research is needed to unravel the genesis and evolution of these depressions to better understand the importance of the Late Glacial and Holocene stages for the morphogenesis of the loess belt in Europe.
Thorpe, Roger S; Barlow, Axel; Malhotra, Anita; Surget-Groba, Yann
2015-03-01
Global warming will impact species in a number of ways, and it is important to know the extent to which natural populations can adapt to anthropogenic climate change by natural selection. Parallel microevolution within separate species can demonstrate natural selection, but several studies of homoplasy have not yet revealed examples of widespread parallel evolution in a generic radiation. Taking into account primary phylogeographic divisions, we investigate numerous quantitative traits (size, shape, scalation, colour pattern and hue) in anole radiations from the mountainous Lesser Antillean islands. Adaptation to climatic differences can lead to very pronounced differences between spatially close populations with all studied traits showing some evidence of parallel evolution. Traits from shape, scalation, pattern and hue (particularly the latter) show widespread evolutionary parallels within these species in response to altitudinal climate variation greater than extreme anthropogenic climate change predicted for 2080. This gives strong evidence of the ability to adapt to climate variation by natural selection throughout this radiation. As anoles can evolve very rapidly, it suggests anthropogenic climate change is likely to be less of a conservation threat than other factors, such as habitat loss and invasive species, in this, Lesser Antillean, biodiversity hot spot. © 2015 John Wiley & Sons Ltd.
Manpower of neurologists in the post-socialist countries of Central and Eastern Europe.
Lisnic, V; Grisold, W; Müller, E
2008-11-01
Manpower of neurologists from the post-socialist countries of Central and Eastern Europe differs very much from the number of neurologists in most of the countries of Western Europe. With the enlargement of the European Union (EU), it is necessary to consider the tendencies of manpower evolution amongst the 'new' European countries to be able to consider future developments, particularly in regard to education and migration. A survey was performed to study distribution and tendencies to migrate amongst neurologists from the post-socialist countries of Central and Eastern Europe. The number of neurologists per 10,000 inhabitants varies from one country to another, but is higher in the countries of Central and Eastern Europe than in most Western European countries. There are almost no available positions for neurologists in Eastern Europe, and the majority of neurologists are keen to migrate to EU countries -- for further education and for financial reasons. The number of neurologists in the 'reforming and transition' countries is considerably higher than in the countries of the EU. Many neurologists from these countries would like to migrate to countries of the EU or USA, but the existing barriers are difficult to overcome.
Iberian-Europe convergence: evolution of the Cretaceous and Eocene basins in Pyrenees and Provence
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muller, J.; Ducassel, L.; Guieu, G.
1988-08-01
During Cretaceous time the geodynamic evolution of Northern and Western Pyrenean basins was related to scissors-shaped rifting which evolved as a passive margin filled by thick flysch deposits. In Provence, the carbonate platform was marked since the late Albian by the arrival of significant detrital flows originated from an uplifted Paleozoic block situated in the Gulf of Lion. In Provence the northward migration of the basin from Cenomanian to Eocene and Oligocene indicates the growing of the Gulf of Lion-South Provence crustal uplift and its northward displacement. The Cretaceous opening of the western Pyrenean, Parentis, and Bay of Biscay basinsmore » is synchronous with the first stages of compression in the Gulf of Lion. These features are induced by the rotation of Iberia. During the Eocene the compression, resulting from the Iberian-Europe convergence, affected nearly the whole Pyrenean-Provencal area. In the southern part of the Pyrenees east of the Pamplona fault, the successive dislocations of carbonate platforms, migration of reefs, and filling of foreland basins became the signature of the intracontinental subduction of Iberia. The transform fault pattern, still well preserved in spite of the Eocene compression, prevents any important strike-slip movement between Europe and Iberia, especially along the so-called North Pyrenean fault zone, which shows several discontinuities in the western part of Pyrenees. The final evolution of Gulf of Lion crustal uplift generated a gliding of its cover (Provence overthrusts) and, during Oligocene, the opening of the Ligurian-Provencal basin by a propagating rift process.« less
Parallel evolution of mound-building and grass-feeding in Australian nasute termites.
Arab, Daej A; Namyatova, Anna; Evans, Theodore A; Cameron, Stephen L; Yeates, David K; Ho, Simon Y W; Lo, Nathan
2017-02-01
Termite mounds built by representatives of the family Termitidae are among the most spectacular constructions in the animal kingdom, reaching 6-8 m in height and housing millions of individuals. Although functional aspects of these structures are well studied, their evolutionary origins remain poorly understood. Australian representatives of the termitid subfamily Nasutitermitinae display a wide variety of nesting habits, making them an ideal group for investigating the evolution of mound building. Because they feed on a variety of substrates, they also provide an opportunity to illuminate the evolution of termite diets. Here, we investigate the evolution of termitid mound building and diet, through a comprehensive molecular phylogenetic analysis of Australian Nasutitermitinae. Molecular dating analysis indicates that the subfamily has colonized Australia on three occasions over the past approximately 20 Myr. Ancestral-state reconstruction showed that mound building arose on multiple occasions and from diverse ancestral nesting habits, including arboreal and wood or soil nesting. Grass feeding appears to have evolved from wood feeding via ancestors that fed on both wood and leaf litter. Our results underscore the adaptability of termites to ancient environmental change, and provide novel examples of parallel evolution of extended phenotypes. © 2017 The Author(s).
The genomics of selection in dogs and the parallel evolution between dogs and humans.
Wang, Guo-dong; Zhai, Weiwei; Yang, He-chuan; Fan, Ruo-xi; Cao, Xue; Zhong, Li; Wang, Lu; Liu, Fei; Wu, Hong; Cheng, Lu-guang; Poyarkov, Andrei D; Poyarkov, Nikolai A; Tang, Shu-sheng; Zhao, Wen-ming; Gao, Yun; Lv, Xue-mei; Irwin, David M; Savolainen, Peter; Wu, Chung-I; Zhang, Ya-ping
2013-01-01
The genetic bases of demographic changes and artificial selection underlying domestication are of great interest in evolutionary biology. Here we perform whole-genome sequencing of multiple grey wolves, Chinese indigenous dogs and dogs of diverse breeds. Demographic analysis show that the split between wolves and Chinese indigenous dogs occurred 32,000 years ago and that the subsequent bottlenecks were mild. Therefore, dogs may have been under human selection over a much longer time than previously concluded, based on molecular data, perhaps by initially scavenging with humans. Population genetic analysis identifies a list of genes under positive selection during domestication, which overlaps extensively with the corresponding list of positively selected genes in humans. Parallel evolution is most apparent in genes for digestion and metabolism, neurological process and cancer. Our study, for the first time, draws together humans and dogs in their recent genomic evolution.
Phylogeny of the TRAF/MATH domain.
Zapata, Juan M; Martínez-García, Vanesa; Lefebvre, Sophie
2007-01-01
The TNF-receptor associated factor (TRAF) domain (TD), also known as the meprin and TRAF-C homology (MATH) domain is a fold of seven anti-parallel p-helices that participates in protein-protein interactions. This fold is broadly represented among eukaryotes, where it is found associated with a discrete set of protein-domains. Virtually all protein families encompassing a TRAF/MATH domain seem to be involved in the regulation of protein processing and ubiquitination, strongly suggesting a parallel evolution of the TRAF/MATH domain and certain proteolysis pathways in eukaryotes. The restricted number of living organisms for which we have information of their genetic and protein make-up limits the scope and analysis of the MATH domain in evolution. However, the available information allows us to get a glimpse on the origins, distribution and evolution of the TRAF/MATH domain, which will be overviewed in this chapter.
The modern temperature-accelerated dynamics approach
Zamora, Richard J.; Uberuaga, Blas P.; Perez, Danny; ...
2016-06-01
Accelerated molecular dynamics (AMD) is a class of MD-based methods used to simulate atomistic systems in which the metastable state-to-state evolution is slow compared with thermal vibrations. Temperature-accelerated dynamics (TAD) is a particularly efficient AMD procedure in which the predicted evolution is hastened by elevating the temperature of the system and then recovering the correct state-to-state dynamics at the temperature of interest. TAD has been used to study various materials applications, often revealing surprising behavior beyond the reach of direct MD. This success has inspired several algorithmic performance enhancements, as well as the analysis of its mathematical framework. Recently, thesemore » enhancements have leveraged parallel programming techniques to enhance both the spatial and temporal scaling of the traditional approach. Here, we review the ongoing evolution of the modern TAD method and introduce the latest development: speculatively parallel TAD.« less
Crimean-Congo hemorrhagic fever virus in ticks collected from livestock in Albania.
Papa, Anna; Velo, Enkeleda; Kadiaj, Perparim; Tsioka, Katerina; Kontana, Anastasia; Kota, Majlinda; Bino, Silvia
2017-10-01
Albania is a Balkan country endemic for Crimean-Congo hemorrhagic fever (CCHF). It was shown previously that CCHF virus (CCHFV) sequences from Albanian patients cluster into Europe 1 clade. Aim of the present study was to test for CCHFV ticks collected in several regions of Albania, and to determine the genetic lineage(s) of the CCHFV strains in relation with their geographic distribution. A total of 726 ticks (366 Hyalomma marginatum, 349 Rhipicephalus bursa and 11 Rhipicephalus sanguineus) collected from livestock during 2007-2014 were included in the study. Thirty of 215 (13.9%) tick pools were positive for CCHFV. Lineage Europe 1 was detected in H. marginatum ticks collected in the endemic region of Albania, while lineage Europe 2 was detected mainly in R. bursa ticks in various regions of the country. Both genetic lineages were detected in the CCHF endemic area (northeastern Albania), while only Europe 2 lineage was detected in the south of the country. A higher genetic diversity was seen among Europe 2 than Europe 1 Albanian sequences (mean distance 3.7% versus 1%), suggesting a longer evolution of AP92-like strains (Europe 2) in their tick hosts. The present study shows that besides CCHFV lineage Europe 1, lineage Europe 2 is also present in Albania. Combined with results from recent studies, it is concluded that lineage Europe 2 is widely spread in the Balkans and Turkey, and is associated mainly with R. bursa ticks (at least in this region). Its pathogenicity and impact to the public health remain to be elucidated. Copyright © 2017 Elsevier B.V. All rights reserved.
Pursuing Darwin’s curious parallel: Prospects for a science of cultural evolution
2017-01-01
In the past few decades, scholars from several disciplines have pursued the curious parallel noted by Darwin between the genetic evolution of species and the cultural evolution of beliefs, skills, knowledge, languages, institutions, and other forms of socially transmitted information. Here, I review current progress in the pursuit of an evolutionary science of culture that is grounded in both biological and evolutionary theory, but also treats culture as more than a proximate mechanism that is directly controlled by genes. Both genetic and cultural evolution can be described as systems of inherited variation that change over time in response to processes such as selection, migration, and drift. Appropriate differences between genetic and cultural change are taken seriously, such as the possibility in the latter of nonrandomly guided variation or transformation, blending inheritance, and one-to-many transmission. The foundation of cultural evolution was laid in the late 20th century with population-genetic style models of cultural microevolution, and the use of phylogenetic methods to reconstruct cultural macroevolution. Since then, there have been major efforts to understand the sociocognitive mechanisms underlying cumulative cultural evolution, the consequences of demography on cultural evolution, the empirical validity of assumed social learning biases, the relative role of transformative and selective processes, and the use of quantitative phylogenetic and multilevel selection models to understand past and present dynamics of society-level change. I conclude by highlighting the interdisciplinary challenges of studying cultural evolution, including its relation to the traditional social sciences and humanities. PMID:28739929
Pursuing Darwin's curious parallel: Prospects for a science of cultural evolution.
Mesoudi, Alex
2017-07-24
In the past few decades, scholars from several disciplines have pursued the curious parallel noted by Darwin between the genetic evolution of species and the cultural evolution of beliefs, skills, knowledge, languages, institutions, and other forms of socially transmitted information. Here, I review current progress in the pursuit of an evolutionary science of culture that is grounded in both biological and evolutionary theory, but also treats culture as more than a proximate mechanism that is directly controlled by genes. Both genetic and cultural evolution can be described as systems of inherited variation that change over time in response to processes such as selection, migration, and drift. Appropriate differences between genetic and cultural change are taken seriously, such as the possibility in the latter of nonrandomly guided variation or transformation, blending inheritance, and one-to-many transmission. The foundation of cultural evolution was laid in the late 20th century with population-genetic style models of cultural microevolution, and the use of phylogenetic methods to reconstruct cultural macroevolution. Since then, there have been major efforts to understand the sociocognitive mechanisms underlying cumulative cultural evolution, the consequences of demography on cultural evolution, the empirical validity of assumed social learning biases, the relative role of transformative and selective processes, and the use of quantitative phylogenetic and multilevel selection models to understand past and present dynamics of society-level change. I conclude by highlighting the interdisciplinary challenges of studying cultural evolution, including its relation to the traditional social sciences and humanities.
Liu, June; Cattadori, Isabella M.; Sim, Derek G.; Eden, John-Sebastian; Read, Andrew F.
2017-01-01
ABSTRACT The coevolution of myxoma virus (MYXV) and wild European rabbits in Australia and Europe is a paradigm for the evolution of a pathogen in a new host species. Genomic analyses have identified the mutations that have characterized this evolutionary process, but defining causal mutations in the pathways from virulence to attenuation and back to virulence has not been possible. Using reverse genetics, we examined the roles of six selected mutations found in Australian field isolates of MYXV that fall in known or potential virulence genes. Several of these mutations occurred in genes previously identified as virulence genes in whole-gene knockout studies. Strikingly, no single or double mutation among the mutations tested had an appreciable impact on virulence. This suggests either that virulence evolution was defined by amino acid changes other than those analyzed here or that combinations of multiple mutations, possibly involving epistatic interactions or noncoding sequences, have been critical in the ongoing evolution of MYXV virulence. In sum, our results show that single-gene knockout studies of a progenitor virus can have little power to predict the impact of individual mutations seen in the field. The genetic determinants responsible for this canonical case of virulence evolution remain to be determined. IMPORTANCE The species jump of myxoma virus (MYXV) from the South American tapeti to the European rabbit populations of Australia and Europe is a canonical example of host-pathogen coevolution. Detailed molecular studies have identified multiple genes in MYXV that are critical for virulence, and genome sequencing has revealed the evolutionary history of MYXV in Australia and Europe. However, it has not been possible to categorically identify the key mutations responsible for the attenuation of or reversion to virulence during this evolutionary process. Here we use reverse genetics to examine the role of mutations in viruses isolated early and late in the Australian radiation of MYXV. Surprisingly, none of the candidate mutations that we identified as likely having roles in attenuation proved to be important for virulence. This indicates that considerable caution is warranted when interpreting the possible role of individual mutations during virulence evolution. PMID:28768866
Teachers' Cultural Maps: Asia as a "Tricky Sort of Subject Matter" in Curriculum Inquiry
ERIC Educational Resources Information Center
Salter, Peta
2014-01-01
The refocussing of Australia-Asia relations is manifest in a combination of national policy moves in Australia. Parallel shifts have been made in Europe, the United States, Canada and New Zealand. In Australia, the curricular response to this shift has become known as "Asia literacy." This study is drawn from a wider project that…
NASA Astrophysics Data System (ADS)
Dielforder, Armin; Frasca, Gianluca; Ford, Mary
2017-04-01
The European plate was affected by contractional deformation events in Late Cretaceous time. This is recorded by inception of thrusting and foreland basin subsidence in the Pyrenean realm, and inversion of Mesozoic rift systems in the interior of the European plate. It is widely accepted that the plate-wide deformation resulted from the onset of NE-directed convergence of Africa-Iberia relative to Europe, and a strong mechanical coupling of the plates, which allowed the transfer of stresses far into Europe. Geological data from both the Pyrenean orogen and the interior of the European plate indicate, however, that these conditions persisted only for 15-20 Myr and that Europe experienced a plate-wide stress relaxation during Paleocene time. Although a slow down in plate convergence between Africa and Europe and North Atlantic continental rifting were proposed as potential causes for the stress relaxation, the subject has remained controversial. In particular, none of the mechanisms seem to be suitable to explain the required changes in the mechanical coupling of Iberian and European plates and the associated stress transfer. Here we propose a new model for the Upper Cretaceous to Paleocene tectonic evolution of the European plate, which takes the temporal evolution of the Pyrenean plate boundary fault into account. Based on plate reconstructions, geological field-data, and restored cross-sections we argue that the plate boundary fault initiated during the Upper Cretaceous within the exhumed mantle domain situated between the rifted margins of the Iberian and European plates. At the transition from the Late Cretaceous to Paleocene, the mantle domain was closed and the rifted margins collided. This evolution was associated with a substantial change in the fault rheology leading to an overall decrease in the plate coupling force. During Paleocene time, the plate coupling force was efficiently balanced by the gravitational push of the European plate, leading to a near neutral stress state in the upper plate and the observed plate-wide stress relaxation in Europe. This study is part of the Orogen research program and conducted in close collaboration with the BRGM (Bureau de Recherches Géologiques et Minières), the CNRS (Centre National de la Recherche Scientifique), and Total.
Eronen, Jussi T.; Janis, Christine M.; Chamberlain, C. Page; Mulch, Andreas
2015-01-01
Patterns of late Palaeogene mammalian evolution appear to be very different between Eurasia and North America. Around the Eocene–Oligocene (EO) transition global temperatures in the Northern Hemisphere plummet: following this, European mammal faunas undergo a profound extinction event (the Grande Coupure), while in North America they appear to pass through this temperature event unscathed. Here, we investigate the role of surface uplift to environmental change and mammalian evolution through the Palaeogene (66–23 Ma). Palaeogene regional surface uplift in North America caused large-scale reorganization of precipitation patterns, particularly in the continental interior, in accord with our combined stable isotope and ecometric data. Changes in mammalian faunas reflect that these were dry and high-elevation palaeoenvironments. The scenario of Middle to Late Eocene (50–37 Ma) surface uplift, together with decreasing precipitation in higher-altitude regions of western North America, explains the enigma of the apparent lack of the large-scale mammal faunal change around the EO transition that characterized western Europe. We suggest that North American mammalian faunas were already pre-adapted to cooler and drier conditions preceding the EO boundary, resulting from the effects of a protracted history of surface uplift. PMID:26041349
Prehistoric land use and Neolithisation in Europe in the context of regional climate events
NASA Astrophysics Data System (ADS)
Lemmen, C.; Wirtz, K. W.; Gronenborn, D.
2009-04-01
We present a simple, adaptation-driven, spatially explicit model of pre-Bronze age socio-technological change, called the Global Land Use and Technological Evolution Simulator (GLUES). The socio-technological realm is described by three characteristic traits: available technology, subsistence style ratio, and economic diversity. Human population and culture develop in the context of global paleoclimate and regional paleoclimate events. Global paleoclimate is derived from CLIMBER-2 Earth System Model anomalies superimposed on the IIASA temperature and precipitation database. Regional a forcing is provided by abrupt climate deteriorations from a compilation of 138 long-term high-resolution climate proxy time series from mostly terrestrial and near-shore archives. The GLUES simulator provides for a novel way to explore the interplay between climate, climate change, and cultural evolution both on the Holocene timescale as well as for short-term extreme event periods. We sucessfully simulate the migration of people and the diffusion of Neolithic technology from the Near East into Europe in the period 12000-4000 a BP. We find good agreement with recent archeological compilations of Western Eurasian Neolithic sites. No causal relationship between climate events and cultural evolution could be identified, but the speed of cultural development is found to be modulated by the frequency of climate events. From the demographic evolution and regional ressource consumption, we estimate regional land use change and prehistoric greenhouse gas emissions.
Creationism as a Misconception: Socio-Cognitive Conflict in the Teaching of Evolution
ERIC Educational Resources Information Center
Foster, Colin
2012-01-01
This position paper argues that students' understanding and acceptance of evolution may be supported, rather than hindered, by classroom discussion of creationism. Parallels are drawn between creationism and other scientific misconceptions, both of the scientific community in the past and of students in the present. Science teachers frequently…
NASA Technical Reports Server (NTRS)
Keskinen, M. J.; Chaturvedi, P. K.; Ossakow, S. L.
1992-01-01
The 2D nonlinear evolution of the ionization-driven adiabatic auroral arc instability is studied. We find: (1) the adiabatic auroral arc instability can fully develop on time scales of tens to hundreds of seconds and on spatial scales of tens to hundreds of kilometers; (2) the evolution of this instability leads to nonlinear 'hook-shaped' conductivity structures: (3) this instability can lead to parallel current filamentation over a wide range of scale sizes; and (4) the k-spectra of the density, electric field, and parallel current develop into inverse power laws in agreement with satellite observations. Comparison with mesoscale auroral phenomenology and current filamentation structures is made.
Kerr, Peter J.; Cattadori, Isabella M.; Fitch, Adam; Geber, Adam; Liu, June; Sim, Derek G.; Boag, Brian; Ghedin, Elodie
2017-01-01
The co-evolution of myxoma virus (MYXV) and the European rabbit occurred independently in Australia and Europe from different progenitor viruses. Although this is the canonical study of the evolution of virulence, whether the genomic and phenotypic outcomes of MYXV evolution in Europe mirror those observed in Australia is unknown. We addressed this question using viruses isolated in the United Kingdom early in the MYXV epizootic (1954–1955) and between 2008–2013. The later UK viruses fell into three distinct lineages indicative of a long period of separation and independent evolution. Although rates of evolutionary change were almost identical to those previously described for MYXV in Australia and strongly clock-like, genome evolution in the UK and Australia showed little convergence. The phenotypes of eight UK viruses from three lineages were characterized in laboratory rabbits and compared to the progenitor (release) Lausanne strain. Inferred virulence ranged from highly virulent (grade 1) to highly attenuated (grade 5). Two broad disease types were seen: cutaneous nodular myxomatosis characterized by multiple raised secondary cutaneous lesions, or an amyxomatous phenotype with few or no secondary lesions. A novel clinical outcome was acute death with pulmonary oedema and haemorrhage, often associated with bacteria in many tissues but an absence of inflammatory cells. Notably, reading frame disruptions in genes defined as essential for virulence in the progenitor Lausanne strain were compatible with the acquisition of high virulence. Combined, these data support a model of ongoing host-pathogen co-evolution in which multiple genetic pathways can produce successful outcomes in the field that involve both different virulence grades and disease phenotypes, with alterations in tissue tropism and disease mechanisms. PMID:28253375
Kerr, Peter J; Cattadori, Isabella M; Rogers, Matthew B; Fitch, Adam; Geber, Adam; Liu, June; Sim, Derek G; Boag, Brian; Eden, John-Sebastian; Ghedin, Elodie; Read, Andrew F; Holmes, Edward C
2017-03-01
The co-evolution of myxoma virus (MYXV) and the European rabbit occurred independently in Australia and Europe from different progenitor viruses. Although this is the canonical study of the evolution of virulence, whether the genomic and phenotypic outcomes of MYXV evolution in Europe mirror those observed in Australia is unknown. We addressed this question using viruses isolated in the United Kingdom early in the MYXV epizootic (1954-1955) and between 2008-2013. The later UK viruses fell into three distinct lineages indicative of a long period of separation and independent evolution. Although rates of evolutionary change were almost identical to those previously described for MYXV in Australia and strongly clock-like, genome evolution in the UK and Australia showed little convergence. The phenotypes of eight UK viruses from three lineages were characterized in laboratory rabbits and compared to the progenitor (release) Lausanne strain. Inferred virulence ranged from highly virulent (grade 1) to highly attenuated (grade 5). Two broad disease types were seen: cutaneous nodular myxomatosis characterized by multiple raised secondary cutaneous lesions, or an amyxomatous phenotype with few or no secondary lesions. A novel clinical outcome was acute death with pulmonary oedema and haemorrhage, often associated with bacteria in many tissues but an absence of inflammatory cells. Notably, reading frame disruptions in genes defined as essential for virulence in the progenitor Lausanne strain were compatible with the acquisition of high virulence. Combined, these data support a model of ongoing host-pathogen co-evolution in which multiple genetic pathways can produce successful outcomes in the field that involve both different virulence grades and disease phenotypes, with alterations in tissue tropism and disease mechanisms.
NASA Astrophysics Data System (ADS)
Maneva, Yana; Poedts, Stefaan
2017-04-01
The electromagnetic fluctuations in the solar wind represent a zoo of plasma waves with different properties, whose wavelengths range from largest fluid scales to the smallest dissipation scales. By nature the power spectrum of the magnetic fluctuations is anisotropic with different spectral slopes in parallel and perpendicular directions with respect to the background magnetic field. Furthermore, the magnetic field power spectra steepen as one moves from the inertial to the dissipation range and we observe multiple spectral breaks with different slopes in parallel and perpendicular direction at the ion scales and beyond. The turbulent dissipation of magnetic field fluctuations at the sub-ion scales is believed to go into local ion heating and acceleration, so that the spectral breaks are typically associated with particle energization. The gained energy can be in the form of anisotropic heating, formation of non-thermal features in the particle velocity distributions functions, and redistribution of the differential acceleration between the different ion populations. To study the relation between the evolution of the anisotropic turbulent spectra and the particle heating at the ion and sub-ion scales we perform a series of 2.5D hybrid simulations in a collisionless drifting proton-alpha plasma. We neglect the fast electron dynamics and treat the electrons as an isothermal fluid electrons, whereas the protons and a minor population of alpha particles are evolved in a fully kinetic manner. We start with a given wave spectrum and study the evolution of the magnetic field spectral slopes as a function of the parallel and perpendicular wave¬numbers. Simultaneously, we track the particle response and the energy exchange between the parallel and perpendicular scales. We observe anisotropic behavior of the turbulent power spectra with steeper slopes along the dominant energy-containing direction. This means that for parallel and quasi-parallel waves we have steeper spectral slope in parallel direction, whereas for highly oblique waves the dissipation occurs predominantly in perpendicular direction and the spectral slopes are steeper across the background magnetic field. The value of the spectral slopes depends on the angle of propagation, the spectral range, as well as the plasma properties. In general the dissipation is stronger at small scales and the corresponding spectral slopes there are steeper. For parallel and quasi-parallel propagation the prevailing energy cascade remains along the magnetic field, whereas for initially isotropic oblique turbulence the cascade develops mainly in perpendicular direction.
A Parallel Genetic Algorithm for Automated Electronic Circuit Design
NASA Technical Reports Server (NTRS)
Lohn, Jason D.; Colombano, Silvano P.; Haith, Gary L.; Stassinopoulos, Dimitris; Norvig, Peter (Technical Monitor)
2000-01-01
We describe a parallel genetic algorithm (GA) that automatically generates circuit designs using evolutionary search. A circuit-construction programming language is introduced and we show how evolution can generate practical analog circuit designs. Our system allows circuit size (number of devices), circuit topology, and device values to be evolved. We present experimental results as applied to analog filter and amplifier design tasks.
Genetic Parallel Programming: design and implementation.
Cheang, Sin Man; Leung, Kwong Sak; Lee, Kin Hong
2006-01-01
This paper presents a novel Genetic Parallel Programming (GPP) paradigm for evolving parallel programs running on a Multi-Arithmetic-Logic-Unit (Multi-ALU) Processor (MAP). The MAP is a Multiple Instruction-streams, Multiple Data-streams (MIMD), general-purpose register machine that can be implemented on modern Very Large-Scale Integrated Circuits (VLSIs) in order to evaluate genetic programs at high speed. For human programmers, writing parallel programs is more difficult than writing sequential programs. However, experimental results show that GPP evolves parallel programs with less computational effort than that of their sequential counterparts. It creates a new approach to evolving a feasible problem solution in parallel program form and then serializes it into a sequential program if required. The effectiveness and efficiency of GPP are investigated using a suite of 14 well-studied benchmark problems. Experimental results show that GPP speeds up evolution substantially.
Tobler, Ray; Hermisson, Joachim; Schlötterer, Christian
2015-07-01
Thermal stress is a pervasive selective agent in natural populations that impacts organismal growth, survival, and reproduction. Drosophila melanogaster exhibits a variety of putatively adaptive phenotypic responses to thermal stress in natural and experimental settings; however, accompanying assessments of fitness are typically lacking. Here, we quantify changes in fitness and known thermal tolerance traits in replicated experimental D. melanogaster populations following more than 40 generations of evolution to either cyclic cold or hot temperatures. By evaluating fitness for both evolved populations alongside a reconstituted starting population, we show that the evolved populations were the best adapted within their respective thermal environments. More strikingly, the evolved populations exhibited increased fitness in both environments and improved resistance to both acute heat and cold stress. This unexpected parallel response appeared to be an adaptation to the rapid temperature changes that drove the cycling thermal regimes, as parallel fitness changes were not observed when tested in a constant thermal environment. Our results add to a small, but growing group of studies that demonstrate the importance of fluctuating temperature changes for thermal adaptation and highlight the need for additional work in this area. © 2015 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.
EARLINET observations of the Eyjafjallajökull ash plume over Europe
NASA Astrophysics Data System (ADS)
Pappalardo, Gelsomina; Amodeo, Aldo; Ansmann, Albert; Apituley, Arnoud; Alados Arboledas, Lucas; Balis, Dimitris; Böckmann, Christine; Chaikovsky, Anatoli; Comeron, Adolfo; D'Amico, Giuseppe; De Tomasi, Ferdinando; Freudenthaler, Volker; Giannakaki, Elina; Giunta, Aldo; Grigorov, Ivan; Gustafsson, Ove; Gross, Silke; Haeffelin, Martial; Iarlori, Marco; Kinne, Stefan; Linné, Holger; Madonna, Fabio; Mamouri, Rodanthi; Mattis, Ina; McAuliffe, Michael; Molero, Francisco; Mona, Lucia; Müller, Detlef; Mitev, Valentin; Nicolae, Doina; Papayannis, Alexandros; Perrone, Maria Rita; Pietruczuk, Aleksander; Pujadas, Manuel; Putaud, Jean-Philippe; Ravetta, Francois; Rizi, Vincenzo; Serikov, Ilya; Sicard, Michael; Simeonov, Valentin; Spinelli, Nicola; Stebel, Kerstin; Trickl, Thomas; Wandinger, Ulla; Wang, Xuan; Wagner, Frank; Wiegner, Matthias
2010-10-01
EARLINET, the European Aerosol Research Lidar NETwork, established in 2000, is the first coordinated lidar network for tropospheric aerosol study on the continental scale. The network activity is based on scheduled measurements, a rigorous quality assurance program addressing both instruments and evaluation algorithms, and a standardised data exchange format. At present, the network includes 27 lidar stations distributed over Europe. EARLINET performed almost continuous measurements since 15 April 2010 in order to follow the evolution of the volcanic plume generated from the eruption of the Eyjafjallajökull volcano, providing the 4-dimensional distribution of the volcanic ash plume over Europe. During the 15-30 April period, volcanic particles were detected over Central Europe over a wide range of altitudes, from 10 km down to the local planetary boundary layer (PBL). Until 19 April, the volcanic plume transport toward South Europe was nearly completely blocked by the Alps. After 19 April volcanic particles were transported to the south and the southeast of Europe. Descending aerosol layers were typically observed all over Europe and intrusion of particles into the PBL was observed at almost each lidar site that was affected by the volcanic plume. A second event was observed over Portugal and Spain (6 May) and then over Italy on 9 May 2010. The volcanic plume was then observed again over Southern Germany on 11 May 2010.
[Reform of public health in Central Europe during the 18th century].
Kapronczay, Károly
2010-01-01
Author outlines the history of making and of development of public health during the period of enlightenment in Central Europe, with special regards on the Habsurg Empire, on Poland and on Russia. This development--including the foundation or reforms of medical education--was highly influenced by the ideas of the enlightened absolutism and by other international trends of the age as well. The detailed analysis of the factors shaping the history of public health in the three rather different countries shows an interesing parallelism regarding main issues. While re-organization of public health in all these countries was initiated and directed by the government and shaped according to western models, it was strongly influenced by local possibilities, culture and history.
Spatio-temporal seasonal drought patterns in Europe from 1950 to 2015
NASA Astrophysics Data System (ADS)
Spinoni, Jonathan; Naumann, Gustavo; Vogt, Jürgen
2016-04-01
Drought is one of the natural disasters with severe impacts in Europe, not only in areas which frequently experience water scarcity such as the Mediterranean, but also in temperate or continental climates such as Central and Eastern Europe and even in cold regions such as Scandinavia and Iceland. In this study the spatio-temporal patterns of seasonal meteorological droughts in Europe between 1950 and 2015 are investigated using the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI). Since the focus is on the analysis of seasonal drought trends, indicators were calculated for 3 monthly accumulation periods. The input variables of precipitation and temperature were derived from E-OBS grids (v11-v12) at a spatial resolution of 0.25°x0.25°. Seasonal trends of drought frequency and severity were analyzed for moderate (SPI or SPEI <-1.0) and extreme (SPI or SPEI <-2.0) events during the periods 1950-2015 and 1981-2015. For the moderate events, results of the SPI analysis (precipitation driven) demonstrate a significant tendency towards less frequent and severe droughts in Northern Europe and Russia, especially in winter and spring; oppositely, an increasing trend is visible in Southern Europe, mainly in spring and summer. According to the SPEI analysis (precipitation and temperature driven) Northern Europe shows wetting patterns, while Southern and Eastern Europe show a more remarkable drying tendency, especially in summer and autumn for drought frequency and in every season for drought severity. The evolution towards drier conditions is more relevant from 1981 onwards, both in terms of frequency and severity. This is especially true for Central Europe in spring, for the Mediterranean in summer, and for Eastern Europe in autumn. Extreme events follow similar patterns, but in autumn no spatially coherent trend can be found.
Parallel Evolution of Copy-Number Variation across Continents in Drosophila melanogaster.
Schrider, Daniel R; Hahn, Matthew W; Begun, David J
2016-05-01
Genetic differentiation across populations that is maintained in the presence of gene flow is a hallmark of spatially varying selection. In Drosophila melanogaster, the latitudinal clines across the eastern coasts of Australia and North America appear to be examples of this type of selection, with recent studies showing that a substantial portion of the D. melanogaster genome exhibits allele frequency differentiation with respect to latitude on both continents. As of yet there has been no genome-wide examination of differentiated copy-number variants (CNVs) in these geographic regions, despite their potential importance for phenotypic variation in Drosophila and other taxa. Here, we present an analysis of geographic variation in CNVs in D. melanogaster. We also present the first genomic analysis of geographic variation for copy-number variation in the sister species, D. simulans, in order to investigate patterns of parallel evolution in these close relatives. In D. melanogaster we find hundreds of CNVs, many of which show parallel patterns of geographic variation on both continents, lending support to the idea that they are influenced by spatially varying selection. These findings support the idea that polymorphic CNVs contribute to local adaptation in D. melanogaster In contrast, we find very few CNVs in D. simulans that are geographically differentiated in parallel on both continents, consistent with earlier work suggesting that clinal patterns are weaker in this species. © The Author 2016. 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.
Messinian age and savannah environment of the possible hominin Graecopithecus from Europe.
Böhme, Madelaine; Spassov, Nikolai; Ebner, Martin; Geraads, Denis; Hristova, Latinka; Kirscher, Uwe; Kötter, Sabine; Linnemann, Ulf; Prieto, Jérôme; Roussiakis, Socrates; Theodorou, George; Uhlig, Gregor; Winklhofer, Michael
2017-01-01
Dating fossil hominids and reconstructing their environments is critically important for understanding human evolution. Here we date the potentially oldest hominin, Graecopithecus freybergi from Europe and constrain the environmental conditions under which it thrived. For the Graecopithecus-bearing Pikermi Formation of Attica/Greece, a saline aeolian dust deposit of North African (Sahara) provenance, we obtain an age of 7.37-7.11 Ma, which is coeval with a dramatic cooling in the Mediterranean region at the Tortonian-Messinian transition. Palaeobotanic proxies demonstrate C4-grass dominated wooded grassland-to-woodland habitats of a savannah biome for the Pikermi Formation. Faunal turnover at the Tortonian-Messinian transition led to the spread of new mammalian taxa along with Graecopithecus into Europe. The type mandible of G. freybergi from Pyrgos (7.175 Ma) and the single tooth (7.24 Ma) from Azmaka (Bulgaria) represent the first hominids of Messinian age from continental Europe. Our results suggest that major splits in the hominid family occurred outside Africa.
Rowland, Julia H; Kent, Erin E; Forsythe, Laura P; Loge, Jon Håvard; Hjorth, Lars; Glaser, Adam; Mattioli, Vittorio; Fosså, Sophie D
2013-06-01
The growing number of cancer survivors worldwide has led to of the emergence of diverse survivorship movements in the United States and Europe. Understanding the evolution of cancer survivorship within the context of different political and health care systems is important for identifying the future steps that need to be taken and collaborations needed to promote research among and enhance the care of those living after cancer. The authors first review the history of survivorship internationally and important related events in both the United States and Europe. Lessons learned from survivorship research are then broadly discussed, followed by examination of the infrastructure needed to sustain and advance this work, including platforms for research, assessment tools, and vehicles for the dissemination of findings. Future perspectives concern the identification of collaborative opportunities for investigators in Europe and the United States to accelerate the pace of survivorship science going forward. Copyright © 2013 American Cancer Society.
Messinian age and savannah environment of the possible hominin Graecopithecus from Europe
Spassov, Nikolai; Ebner, Martin; Geraads, Denis; Hristova, Latinka; Kirscher, Uwe; Kötter, Sabine; Linnemann, Ulf; Prieto, Jérôme; Roussiakis, Socrates; Theodorou, George; Uhlig, Gregor; Winklhofer, Michael
2017-01-01
Dating fossil hominids and reconstructing their environments is critically important for understanding human evolution. Here we date the potentially oldest hominin, Graecopithecus freybergi from Europe and constrain the environmental conditions under which it thrived. For the Graecopithecus-bearing Pikermi Formation of Attica/Greece, a saline aeolian dust deposit of North African (Sahara) provenance, we obtain an age of 7.37–7.11 Ma, which is coeval with a dramatic cooling in the Mediterranean region at the Tortonian-Messinian transition. Palaeobotanic proxies demonstrate C4-grass dominated wooded grassland-to-woodland habitats of a savannah biome for the Pikermi Formation. Faunal turnover at the Tortonian-Messinian transition led to the spread of new mammalian taxa along with Graecopithecus into Europe. The type mandible of G. freybergi from Pyrgos (7.175 Ma) and the single tooth (7.24 Ma) from Azmaka (Bulgaria) represent the first hominids of Messinian age from continental Europe. Our results suggest that major splits in the hominid family occurred outside Africa. PMID:28531204
Parallel dynamics between non-Hermitian and Hermitian systems
NASA Astrophysics Data System (ADS)
Wang, P.; Lin, S.; Jin, L.; Song, Z.
2018-06-01
We reveals a connection between non-Hermitian and Hermitian systems by studying the connection between a family of non-Hermitian and Hermitian Hamiltonians based on exact solutions. In general, for a dynamic process in a non-Hermitian system H , there always exists a parallel dynamic process governed by the corresponding Hermitian conjugate system H†. We show that a linear superposition of the two parallel dynamics is exactly equivalent to the time evolution of a state under a Hermitian Hamiltonian H , and we present the relations between {H ,H ,H†} .
MEvoLib v1.0: the first molecular evolution library for Python.
Álvarez-Jarreta, Jorge; Ruiz-Pesini, Eduardo
2016-10-28
Molecular evolution studies involve many different hard computational problems solved, in most cases, with heuristic algorithms that provide a nearly optimal solution. Hence, diverse software tools exist for the different stages involved in a molecular evolution workflow. We present MEvoLib, the first molecular evolution library for Python, providing a framework to work with different tools and methods involved in the common tasks of molecular evolution workflows. In contrast with already existing bioinformatics libraries, MEvoLib is focused on the stages involved in molecular evolution studies, enclosing the set of tools with a common purpose in a single high-level interface with fast access to their frequent parameterizations. The gene clustering from partial or complete sequences has been improved with a new method that integrates accessible external information (e.g. GenBank's features data). Moreover, MEvoLib adjusts the fetching process from NCBI databases to optimize the download bandwidth usage. In addition, it has been implemented using parallelization techniques to cope with even large-case scenarios. MEvoLib is the first library for Python designed to facilitate molecular evolution researches both for expert and novel users. Its unique interface for each common task comprises several tools with their most used parameterizations. It has also included a method to take advantage of biological knowledge to improve the gene partition of sequence datasets. Additionally, its implementation incorporates parallelization techniques to enhance computational costs when handling very large input datasets.
ERIC Educational Resources Information Center
Scott, Mark
2004-01-01
Throughout the 1990s, Europe's rural areas increasingly embraced local action and local development solutions to face the challenge of the continued re-structuring of the agricultural industry. In parallel, in both the EU and the UK, a policy discourse has emerged which envisages a fundamental shift in support policies for rural areas from a…
Constraints in cancer evolution.
Venkatesan, Subramanian; Birkbak, Nicolai J; Swanton, Charles
2017-02-08
Next-generation deep genome sequencing has only recently allowed us to quantitatively dissect the extent of heterogeneity within a tumour, resolving patterns of cancer evolution. Intratumour heterogeneity and natural selection contribute to resistance to anticancer therapies in the advanced setting. Recent evidence has also revealed that cancer evolution might be constrained. In this review, we discuss the origins of intratumour heterogeneity and subsequently focus on constraints imposed upon cancer evolution. The presence of (1) parallel evolution, (2) convergent evolution and (3) the biological impact of acquiring mutations in specific orders suggest that cancer evolution may be exploitable. These constraints on cancer evolution may help us identify cancer evolutionary rule books, which could eventually inform both diagnostic and therapeutic approaches to improve survival outcomes. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.
Methodes iteratives paralleles: Applications en neutronique et en mecanique des fluides
NASA Astrophysics Data System (ADS)
Qaddouri, Abdessamad
Dans cette these, le calcul parallele est applique successivement a la neutronique et a la mecanique des fluides. Dans chacune de ces deux applications, des methodes iteratives sont utilisees pour resoudre le systeme d'equations algebriques resultant de la discretisation des equations du probleme physique. Dans le probleme de neutronique, le calcul des matrices des probabilites de collision (PC) ainsi qu'un schema iteratif multigroupe utilisant une methode inverse de puissance sont parallelises. Dans le probleme de mecanique des fluides, un code d'elements finis utilisant un algorithme iteratif du type GMRES preconditionne est parallelise. Cette these est presentee sous forme de six articles suivis d'une conclusion. Les cinq premiers articles traitent des applications en neutronique, articles qui representent l'evolution de notre travail dans ce domaine. Cette evolution passe par un calcul parallele des matrices des PC et un algorithme multigroupe parallele teste sur un probleme unidimensionnel (article 1), puis par deux algorithmes paralleles l'un mutiregion l'autre multigroupe, testes sur des problemes bidimensionnels (articles 2--3). Ces deux premieres etapes sont suivies par l'application de deux techniques d'acceleration, le rebalancement neutronique et la minimisation du residu aux deux algorithmes paralleles (article 4). Finalement, on a mis en oeuvre l'algorithme multigroupe et le calcul parallele des matrices des PC sur un code de production DRAGON ou les tests sont plus realistes et peuvent etre tridimensionnels (article 5). Le sixieme article (article 6), consacre a l'application a la mecanique des fluides, traite la parallelisation d'un code d'elements finis FES ou le partitionneur de graphe METIS et la librairie PSPARSLIB sont utilises.
Age of the Association between Helicobacter pylori and Man
Bond, Robert P.; Nieuwoudt, Martin; Soodyall, Himla; Schlebusch, Carina M.; Bernhöft, Steffi; Hale, James; Suerbaum, Sebastian; Mugisha, Lawrence; van der Merwe, Schalk W.; Achtman, Mark
2012-01-01
When modern humans left Africa ca. 60,000 years ago (60 kya), they were already infected with Helicobacter pylori, and these bacteria have subsequently diversified in parallel with their human hosts. But how long were humans infected by H. pylori prior to the out-of-Africa event? Did this co-evolution predate the emergence of modern humans, spanning the species divide? To answer these questions, we investigated the diversity of H. pylori in Africa, where both humans and H. pylori originated. Three distinct H. pylori populations are native to Africa: hpNEAfrica in Afro-Asiatic and Nilo-Saharan speakers, hpAfrica1 in Niger-Congo speakers and hpAfrica2 in South Africa. Rather than representing a sustained co-evolution over millions of years, we find that the coalescent for all H. pylori plus its closest relative H. acinonychis dates to 88–116 kya. At that time the phylogeny split into two primary super-lineages, one of which is associated with the former hunter-gatherers in southern Africa known as the San. H. acinonychis, which infects large felines, resulted from a later host jump from the San, 43–56 kya. These dating estimates, together with striking phylogenetic and quantitative human-bacterial similarities show that H. pylori is approximately as old as are anatomically modern humans. They also suggest that H. pylori may have been acquired via a single host jump from an unknown, non-human host. We also find evidence for a second Out of Africa migration in the last 52,000 years, because hpEurope is a hybrid population between hpAsia2 and hpNEAfrica, the latter of which arose in northeast Africa 36–52 kya, after the Out of Africa migrations around 60 kya. PMID:22589724
Rapid evolution of phenology during range expansion with recent climate change.
Lustenhouwer, Nicky; Wilschut, Rutger A; Williams, Jennifer L; van der Putten, Wim H; Levine, Jonathan M
2018-02-01
Although climate warming is expected to make habitat beyond species' current cold range edge suitable for future colonization, this new habitat may present an array of biotic or abiotic conditions not experienced within the current range. Species' ability to shift their range with climate change may therefore depend on how populations evolve in response to such novel environmental conditions. However, due to the recent nature of thus far observed range expansions, the role of rapid adaptation during climate change migration is only beginning to be understood. Here, we evaluated evolution during the recent native range expansion of the annual plant Dittrichia graveolens, which is spreading northward in Europe from the Mediterranean region. We examined genetically based differentiation between core and edge populations in their phenology, a trait that is likely under selection with shorter growing seasons and greater seasonality at northern latitudes. In parallel common garden experiments at range edges in Switzerland and the Netherlands, we grew plants from Dutch, Swiss, and central and southern French populations. Population genetic analysis following RAD-sequencing of these populations supported the hypothesized central France origins of the Swiss and Dutch range edge populations. We found that in both common gardens, northern plants flowered up to 4 weeks earlier than southern plants. This differentiation in phenology extended from the core of the range to the Netherlands, a region only reached from central France over approximately the last 50 years. Fitness decreased as plants flowered later, supporting the hypothesized benefits of earlier flowering at the range edge. Our results suggest that native range expanding populations can rapidly adapt to novel environmental conditions in the expanded range, potentially promoting their ability to spread. © 2017 John Wiley & Sons Ltd.
Towards physical principles of biological evolution
NASA Astrophysics Data System (ADS)
Katsnelson, Mikhail I.; Wolf, Yuri I.; Koonin, Eugene V.
2018-03-01
Biological systems reach organizational complexity that far exceeds the complexity of any known inanimate objects. Biological entities undoubtedly obey the laws of quantum physics and statistical mechanics. However, is modern physics sufficient to adequately describe, model and explain the evolution of biological complexity? Detailed parallels have been drawn between statistical thermodynamics and the population-genetic theory of biological evolution. Based on these parallels, we outline new perspectives on biological innovation and major transitions in evolution, and introduce a biological equivalent of thermodynamic potential that reflects the innovation propensity of an evolving population. Deep analogies have been suggested to also exist between the properties of biological entities and processes, and those of frustrated states in physics, such as glasses. Such systems are characterized by frustration whereby local state with minimal free energy conflict with the global minimum, resulting in ‘emergent phenomena’. We extend such analogies by examining frustration-type phenomena, such as conflicts between different levels of selection, in biological evolution. These frustration effects appear to drive the evolution of biological complexity. We further address evolution in multidimensional fitness landscapes from the point of view of percolation theory and suggest that percolation at level above the critical threshold dictates the tree-like evolution of complex organisms. Taken together, these multiple connections between fundamental processes in physics and biology imply that construction of a meaningful physical theory of biological evolution might not be a futile effort. However, it is unrealistic to expect that such a theory can be created in one scoop; if it ever comes to being, this can only happen through integration of multiple physical models of evolutionary processes. Furthermore, the existing framework of theoretical physics is unlikely to suffice for adequate modeling of the biological level of complexity, and new developments within physics itself are likely to be required.
NASA Astrophysics Data System (ADS)
Burke, Ariane; Kageyama, Masa; Latombe, Guilllaume; Fasel, Marc; Vrac, Mathieu; Ramstein, Gilles; James, Patrick M. A.
2017-05-01
The extent to which climate change has affected the course of human evolution is an enduring question. The ability to maintain spatially extensive social networks and a fluid social structure allows human foragers to ;map onto; the landscape, mitigating the impact of ecological risk and conferring resilience. But what are the limits of resilience and to which environmental variables are foraging populations sensitive? We address this question by testing the impact of a suite of environmental variables, including climate variability, on the distribution of human populations in Western Europe during the Last Glacial Maximum (LGM). Climate variability affects the distribution of plant and animal resources unpredictably, creating an element of risk for foragers for whom mobility comes at a cost. We produce a model of habitat suitability that allows us to generate predictions about the probable distribution of human populations and discuss the implications of these predictions for the structure of human populations and their social and cultural evolution during the LGM.
Dedouit, Fabrice; Duchesne, Sylvie; Mokrane, Fatima-Zohra; Gendrot, Véronique; Gérard, Patrice; Dabernat, Henri; Crubézy, Éric; Telmon, Norbert
2016-01-01
The evolution of funeral practices from the Middle Ages through the Modern era in Europe is generally seen as a process of secularization. The study, through imaging and autopsy, of two mummies, five lead urns containing hearts, and more than six hundred skeletons of nobles and clergymen from a Renaissance convent in Brittany has led us to reject this view. In addition to exceptional embalming, we observed instances in which hearts alone had been extracted, a phenomenon that had never before been described, and brains alone as well, and instances in which each spouse's heart had been placed on the other's coffin. In some identified cases we were able to establish links between the religious attitudes of given individuals and either ancient Medieval practices or more modern ones generated by the Council of Trent. All of these practices, which were a function of social status, were rooted in religion. They offer no evidence of secularization whatsoever. PMID:28030554
Molecular Epidemiology and Evolution of European Bat Lyssavirus 2.
McElhinney, Lorraine M; Marston, Denise A; Wise, Emma L; Freuling, Conrad M; Bourhy, Hervé; Zanoni, Reto; Moldal, Torfinn; Kooi, Engbert A; Neubauer-Juric, Antonie; Nokireki, Tiina; Müller, Thomas; Fooks, Anthony R
2018-01-05
Bat rabies cases in Europe are mainly attributed to two lyssaviruses, namely European Bat Lyssavirus 1 (EBLV-1) and European Bat Lyssavirus 2 (EBLV-2). Prior to the death of a bat worker in Finland in 1985, very few bat rabies cases were reported. Enhanced surveillance in the two subsequent years (1986-1987) identified 263 cases (more than a fifth of all reported cases to date). Between 1977 and 2016, 1183 cases of bat rabies were reported, with the vast majority (>97%) being attributed to EBLV-1. In contrast, there have been only 39 suspected cases of EBLV-2, of which 34 have been confirmed by virus typing and presently restricted to just two bat species; Myotis daubentonii and Myotis dasycneme . The limited number of EBLV-2 cases in Europe prompted the establishment of a network of European reference laboratories to collate all available viruses and data. Despite the relatively low number of EBLV-2 cases, a large amount of anomalous data has been published in the scientific literature, which we have here reviewed and clarified. In this review, 29 EBLV-2 full genome sequences have been analysed to further our understanding of the diversity and molecular evolution of EBLV-2 in Europe. Analysis of the 29 complete EBLV-2 genome sequences clearly corroborated geographical relationships with all EBLV-2 sequences clustering at the country level irrespective of the gene studied. Further geographical clustering was also observed at a local level. There are high levels of homogeneity within the EBLV-2 species with nucleotide identities ranging from 95.5-100% and amino acid identities between 98.7% and 100%, despite the widespread distribution of the isolates both geographically and chronologically. The mean substitution rate for EBLV-2 across the five concatenated genes was 1.65 × 10 -5 , and evolutionary clock analysis confirms the slow evolution of EBLV-2 both between and within countries in Europe. This is further supported by the first detailed EBLV-2 intra-roost genomic analysis whereby a relatively high sequence homogeneity was found across the genomes of three EBLV-2 isolates obtained several years apart (2007, 2008, and 2014) from M. daubentonii at the same site (Stokesay Castle, Shropshire, UK).
Parallel programming with Easy Java Simulations
NASA Astrophysics Data System (ADS)
Esquembre, F.; Christian, W.; Belloni, M.
2018-01-01
Nearly all of today's processors are multicore, and ideally programming and algorithm development utilizing the entire processor should be introduced early in the computational physics curriculum. Parallel programming is often not introduced because it requires a new programming environment and uses constructs that are unfamiliar to many teachers. We describe how we decrease the barrier to parallel programming by using a java-based programming environment to treat problems in the usual undergraduate curriculum. We use the easy java simulations programming and authoring tool to create the program's graphical user interface together with objects based on those developed by Kaminsky [Building Parallel Programs (Course Technology, Boston, 2010)] to handle common parallel programming tasks. Shared-memory parallel implementations of physics problems, such as time evolution of the Schrödinger equation, are available as source code and as ready-to-run programs from the AAPT-ComPADRE digital library.
Transformation and diversification in early mammal evolution.
Luo, Zhe-Xi
2007-12-13
Evolution of the earliest mammals shows successive episodes of diversification. Lineage-splitting in Mesozoic mammals is coupled with many independent evolutionary experiments and ecological specializations. Classic scenarios of mammalian morphological evolution tend to posit an orderly acquisition of key evolutionary innovations leading to adaptive diversification, but newly discovered fossils show that evolution of such key characters as the middle ear and the tribosphenic teeth is far more labile among Mesozoic mammals. Successive diversifications of Mesozoic mammal groups multiplied the opportunities for many dead-end lineages to iteratively evolve developmental homoplasies and convergent ecological specializations, parallel to those in modern mammal groups.
Fox, Charles W; Wagner, James D; Cline, Sara; Thomas, Frances Ann; Messina, Frank J
2009-05-01
Independent populations subjected to similar environments often exhibit convergent evolution. An unresolved question is the frequency with which such convergence reflects parallel genetic mechanisms. We examined the convergent evolution of egg-laying behavior in the seed-feeding beetle Callosobruchus maculatus. Females avoid ovipositing on seeds bearing conspecific eggs, but the degree of host discrimination varies among geographic populations. In a previous experiment, replicate lines switched from a small host to a large one evolved reduced discrimination after 40 generations. We used line crosses to determine the genetic architecture underlying this rapid response. The most parsimonious genetic models included dominance and/or epistasis for all crosses. The genetic architecture underlying reduced discrimination in two lines was not significantly different from the architecture underlying differences between geographic populations, but the architecture underlying the divergence of a third line differed from all others. We conclude that convergence of this complex trait may in some cases involve parallel genetic mechanisms.
Fang, Lu; Shen, Bin; Irwin, David M; Zhang, Shuyi
2014-10-01
Glycogen synthase, which catalyzes the synthesis of glycogen, is especially important for Old World (Pteropodidae) and New World (Phyllostomidae) fruit bats that ingest high-carbohydrate diets. Glycogen synthase 1, encoded by the Gys1 gene, is the glycogen synthase isozyme that functions in muscles. To determine whether Gys1 has undergone adaptive evolution in bats with carbohydrate-rich diets, in comparison to insect-eating sister bat taxa, we sequenced the coding region of the Gys1 gene from 10 species of bats, including two Old World fruit bats (Pteropodidae) and a New World fruit bat (Phyllostomidae). Our results show no evidence for positive selection in the Gys1 coding sequence on the ancestral Old World and the New World Artibeus lituratus branches. Tests for convergent evolution indicated convergence of the sequences and one parallel amino acid substitution (T395A) was detected on these branches, which was likely driven by natural selection.
Co-evolution of upstream waves and accelerated ions at parallel shocks
NASA Astrophysics Data System (ADS)
Fujimoto, M.; Sugiyama, T.
2016-12-01
Shock waves in space plasmas have been considered as the agents for various particle acceleration phenomena. The basic idea behind shock acceleration is that particles are accelerated as they move back-and-forth across a shock front. Detailed studies of ion acceleration at the terrestrial bow shock have been performed, however, the restricted maximum energies attained prevent a straight-forward application of obtained knowledge to more energetic astrophysical situations. Here we show by a large-scale self-consistent particle simulation that the co-evolution of magnetic turbulence and accelerated ion population is the foundation for continuous operation of shock acceleration to ever higher energies. Magnetic turbulence is created by ions reflected back upstream of a parallel shock front. The co-evolution arises because more energetic ions excite waves of longer wavelengths, and because longer wavelength modes are capable of scattering (in the upstream) and reflecting (at the shock front) more energetic ions. Via carefully designed numerical experiments, we show very clearly that this picture is true.
Bartels, Melissa; French, Roy; Graybosch, Robert A; Tatineni, Satyanarayana
2016-05-01
An infectious cDNA clone of Triticum mosaic virus (TriMV) (genus Poacevirus; family Potyviridae) was used to establish three independent lineages in wheat to examine intra-host population diversity levels within protein 1 (P1) and coat protein (CP) cistrons over time. Genetic variation was assessed at passages 9, 18 and 24 by single-strand conformation polymorphism, followed by nucleotide sequencing. The founding P1 region genotype was retained at high frequencies in most lineage/passage populations, while the founding CP genotype disappeared after passage 18 in two lineages. We found that rare TriMV genotypes were present only transiently and lineages followed independent evolutionary trajectories, suggesting that genetic drift dominates TriMV evolution. These results further suggest that experimental populations of TriMV exhibit lower mutant frequencies than that of Wheat streak mosaic virus (genus Tritimovirus; family Potyviridae) in wheat. Nevertheless, there was evidence for parallel evolution at a synonymous site in the TriMV CP cistron. Published by Elsevier Inc.
Schmitt, Paul J; Agarwal, Nitin; Prestigiacomo, Charles J
2012-01-01
Military explorations of the practical role of simulators have served as a driving force for much of the virtual reality technology that we have today. The evolution of 3-dimensional and virtual environments from the early flight simulators used during World War II to the sophisticated training simulators in the modern military followed a path that virtual surgical and neurosurgical devices have already begun to parallel. By understanding the evolution of military simulators as well as comparing and contrasting that evolution with current and future surgical simulators, it may be possible to expedite the development of appropriate devices and establish their validity as effective training tools. As such, this article presents a historical perspective examining the progression of neurosurgical simulators, the establishment of effective and appropriate curricula for using them, and the contributions that the military has made during the ongoing maturation of this exciting treatment and training modality. Copyright © 2012. Published by Elsevier Inc.
Milk, social acceptance of a new food in Europe: Catalonia, 19th-20th centuries.
Nicolau-Nos, Roser; Pujol-Andreu, Josep; Hernández, Ismael
2010-01-01
In this article we analyse the time course of the consumption of fresh milk in different regions of Europe between the 1870s and 1930s. Working from the case of Catalonia, we affirm that the increasing consumption of milk in that period must be especially linked to the spreading of new scientific knowledge in microbiology and nutrition that followed Pasteur's discoveries. We particularly highlight the information dissemination activities in this direction carried out by health sector professionals (medical doctors and pharmacists), governing local institutions and the milk industry. The initiatives developed by these groups changed people's preferences--fresh milk became accepted as a necessary food-stuff, and demand for it increased. However, the evolution of consumption was not the same in all regions of Europe due to their different environmental and agronomic conditions.
Phylogeographic history of grey wolves in Europe
2010-01-01
Background While it is generally accepted that patterns of intra-specific genetic differentiation are substantially affected by glacial history, population genetic processes occurring during Pleistocene glaciations are still poorly understood. In this study, we address the question of the genetic consequences of Pleistocene glaciations for European grey wolves. Combining our data with data from published studies, we analysed phylogenetic relationships and geographic distribution of mitochondrial DNA haplotypes for 947 contemporary European wolves. We also compared the contemporary wolf sequences with published sequences of 24 ancient European wolves. Results We found that haplotypes representing two haplogroups, 1 and 2, overlap geographically, but substantially differ in frequency between populations from south-western and eastern Europe. A comparison between haplotypes from Europe and other continents showed that both haplogroups are spread throughout Eurasia, while only haplogroup 1 occurs in contemporary North American wolves. All ancient wolf samples from western Europe that dated from between 44,000 and 1,200 years B.P. belonged to haplogroup 2, suggesting the long-term predominance of this haplogroup in this region. Moreover, a comparison of current and past frequencies and distributions of the two haplogroups in Europe suggested that haplogroup 2 became outnumbered by haplogroup 1 during the last several thousand years. Conclusions Parallel haplogroup replacement, with haplogroup 2 being totally replaced by haplogroup 1, has been reported for North American grey wolves. Taking into account the similarity of diets reported for the late Pleistocene wolves from Europe and North America, the correspondence between these haplogroup frequency changes may suggest that they were associated with ecological changes occurring after the Last Glacial Maximum. PMID:20409299
Experimental evolution and the dynamics of adaptation and genome evolution in microbial populations.
Lenski, Richard E
2017-10-01
Evolution is an on-going process, and it can be studied experimentally in organisms with rapid generations. My team has maintained 12 populations of Escherichia coli in a simple laboratory environment for >25 years and 60 000 generations. We have quantified the dynamics of adaptation by natural selection, seen some of the populations diverge into stably coexisting ecotypes, described changes in the bacteria's mutation rate, observed the new ability to exploit a previously untapped carbon source, characterized the dynamics of genome evolution and used parallel evolution to identify the genetic targets of selection. I discuss what the future might hold for this particular experiment, briefly highlight some other microbial evolution experiments and suggest how the fields of experimental evolution and microbial ecology might intersect going forward.
Nothing in the History of Spanish "Anis" Makes Sense, Except in the Light of Evolution
ERIC Educational Resources Information Center
Delgado, Juan Antonio; Palma, Ricardo Luis
2011-01-01
We describe, discuss and illustrate a metaphoric parallel between the history of the most famous Spanish liqueur, "Anis del Mono" ("Anis" of the Monkey), and the evolution of living organisms in the light of Darwinian theory and other biological hypotheses published subsequent to Charles Darwin's "Origin of Species." Also, we report the use of a…
Numerical study of the vortex tube reconnection using vortex particle method on many graphics cards
NASA Astrophysics Data System (ADS)
Kudela, Henryk; Kosior, Andrzej
2014-08-01
Vortex Particle Methods are one of the most convenient ways of tracking the vorticity evolution. In the article we presented numerical recreation of the real life experiment concerning head-on collision of two vortex rings. In the experiment the evolution and reconnection of the vortex structures is tracked with passive markers (paint particles) which in viscous fluid does not follow the evolution of vorticity field. In numerical computations we showed the difference between vorticity evolution and movement of passive markers. The agreement with the experiment was very good. Due to problems with very long time of computations on a single processor the Vortex-in-Cell method was implemented on the multicore architecture of the graphics cards (GPUs). Vortex Particle Methods are very well suited for parallel computations. As there are myriads of particles in the flow and for each of them the same equations of motion have to be solved the SIMD architecture used in GPUs seems to be perfect. The main disadvantage in this case is the small amount of the RAM memory. To overcome this problem we created a multiGPU implementation of the VIC method. Some remarks on parallel computing are given in the article.
Mukherjee, Krishanu; Campos, Henry; Kolaczkowski, Bryan
2013-03-01
RNA interference (RNAi) is a eukaryotic molecular system that serves two primary functions: 1) gene regulation and 2) protection against selfish elements such as viruses and transposable DNA. Although the biochemistry of RNAi has been detailed in model organisms, very little is known about the broad-scale patterns and forces that have shaped RNAi evolution. Here, we provide a comprehensive evolutionary analysis of the Dicer protein family, which carries out the initial RNA recognition and processing steps in the RNAi pathway. We show that Dicer genes duplicated and diversified independently in early animal and plant evolution, coincident with the origins of multicellularity. We identify a strong signature of long-term protein-coding adaptation that has continually reshaped the RNA-binding pocket of the plant Dicer responsible for antiviral immunity, suggesting an evolutionary arms race with viral factors. We also identify key changes in Dicer domain architecture and sequence leading to specialization in either gene-regulatory or protective functions in animal and plant paralogs. As a whole, these results reveal a dynamic picture in which the evolution of Dicer function has driven elaboration of parallel RNAi functional pathways in animals and plants.
Eronen, Jussi T; Janis, Christine M; Chamberlain, C Page; Mulch, Andreas
2015-06-22
Patterns of late Palaeogene mammalian evolution appear to be very different between Eurasia and North America. Around the Eocene-Oligocene (EO) transition global temperatures in the Northern Hemisphere plummet: following this, European mammal faunas undergo a profound extinction event (the Grande Coupure), while in North America they appear to pass through this temperature event unscathed. Here, we investigate the role of surface uplift to environmental change and mammalian evolution through the Palaeogene (66-23 Ma). Palaeogene regional surface uplift in North America caused large-scale reorganization of precipitation patterns, particularly in the continental interior, in accord with our combined stable isotope and ecometric data. Changes in mammalian faunas reflect that these were dry and high-elevation palaeoenvironments. The scenario of Middle to Late Eocene (50-37 Ma) surface uplift, together with decreasing precipitation in higher-altitude regions of western North America, explains the enigma of the apparent lack of the large-scale mammal faunal change around the EO transition that characterized western Europe. We suggest that North American mammalian faunas were already pre-adapted to cooler and drier conditions preceding the EO boundary, resulting from the effects of a protracted history of surface uplift. © 2015 The Author(s) Published by the Royal Society. All rights reserved.
1991-01-30
GDR [POLITYKA 8 Dec] 16 Border Treaty, Future German Relations Viewed [GAZETA WYBORCZA 14 Nov] 18 Senator Favors Silesian Bridge-Building Role ...Slovak history was a part until 1918 . We could find parallels here to illuminate many an effort by the current Slovak political leadership. In some... Romanians , and others, on the other side. The constant pressure did not cease until after the Austro-Hungarian settlement in 1867. The Hapsburgs of Vienna
JPRS Report, Science & Technology, Europe.
1991-04-30
processor in collaboration with Intel . The processor , christened Touchstone, will be used as the core of a parallel computer with 2,000 processors . One of...ELECTRONIQUE HEBDO in French 24 Jan 91 pp 14-15 [Article by Claire Remy: "Everything Set for Neural Signal Processors " first paragraph is ELECTRONIQUE...paving the way for neural signal processors in so doing. The principal advantage of this specific circuit over a neuromimetic software program is
Blocking the spread of nuclear weapons. American and European perspectives
DOE Office of Scientific and Technical Information (OSTI.GOV)
Smith, G.C.; Holst, J.J.
1986-01-01
This volume is the product of separate but parallel studies undertaken by two panels of experts-one from the United States, the other from Western Europe-on new approaches to preventing the proliferation of nuclear weapons to additional countries. Neither panel sounded a doomsday alarm; each concluded that the chances for controlling proliferation lie in good part on building on the sound foundation of existing policies and institutional structures. Among the other conclusions derived from the parallel studies: The threat of nuclear proliferation is a specific, definable danger in a limited number of countries. The incentives that appear to make nuclear weaponsmore » an interesting option to some states must be understood, and potential proliferators must be persuaded that their acquisition will not lead to national security. Effective persuasion is more likely to come from non-nuclear weapon nations. Europe and the United States must collaborate in engaging such third-party persuaders in this endeavor. The panels' intensive examination of the six states of greatest near-term concern leads to the conclusion that the uneasy status quo will probably prevail for the next several years, yet these are volatile situations. The nature of the threat demands an extraordinary degree of international collaboration.« less
An explicit plate kinematic model for the orogeny in the southern Uralides
NASA Astrophysics Data System (ADS)
Görz, Ines; Hielscher, Peggy
2010-10-01
The Palaeozoic Uralides formed in a three plate constellation between Europe, Siberia and Kazakhstan-Tarim. Starting from the first plate tectonic concepts, it was controversially discussed, whether the Uralide orogeny was the result of a relative plate motion between Europe and Siberia or between Europe and Kazakhstan. In this study, we use a new approach to address this problem. We perform a structural analysis on the sphere, reconstruct the positions of the Euler poles of the relative plate rotation Siberia-Europe and Tarim-Europe and describe Uralide structures by their relation to small circles about the two Euler poles. Using this method, changes in the strike of tectonic elements that are caused by the spherical geometry of the Earth's surface are eliminated and structures that are compatible with one of the relative plate motions can be identified. We show that only two Euler poles controlled the Palaeozoic tectonic evolution in the whole West Siberian region, but that they acted diachronously in different regions. We provide an explicit model describing the tectonism in West Siberia by an Euler pole, a sense of rotation and an approximate rotation angle. In the southern Uralides, Devonian structures resulted from a plate rotation of Siberia with respect to Europe, while the Permian structures were caused by a relative plate motion of Kazakhstan-Tarim with respect to Europe. The tectonic pause in the Carboniferous period correlates with a reorganization of the plate kinematics.
Severe Autumn storms in future Western Europe with a warmer Atlantic Ocean
NASA Astrophysics Data System (ADS)
Baatsen, Michiel; Haarsma, Reindert J.; Van Delden, Aarnout J.; de Vries, Hylke
2015-08-01
Simulations with a very high resolution (~25 km) global climate model indicate that more severe Autumn storms will impact Europe in a warmer future climate. The observed increase is mainly attributed to storms with a tropical origin, especially in the later part of the twentyfirst century. As their genesis region expands, tropical cyclones become more intense and their chances of reaching Europe increase. This paper investigates the properties and evolution of such storms and clarifies the future changes. The studied tropical cyclones feature a typical evolution of tropical development, extratropical transition and a re-intensification. A reduction of the transit area between regions of tropical and extratropical cyclogenesis increases the probability of re-intensification. Many of the modelled storms exhibit hybrid properties in a considerable part of their life cycle during which they exhibit the hazards of both tropical and extratropical systems. In addition to tropical cyclones, other systems such as cold core extratropical storms mainly originating over the Gulf Stream region also increasingly impact Western Europe. Despite their different history, all of the studied storms have one striking similarity: they form a warm seclusion. The structure, intensity and frequency of storms in the present climate are compared to observations using the MERRA and IBTrACS datasets. Damaging winds associated with the occurrence of a sting jet are observed in a large fraction of the cyclones during their final stage. Baroclinic instability is of great importance for the (re-)intensification of the storms. Furthermore, so-called atmospheric rivers providing tropical air prove to be vital for the intensification through diabatic heating and will increase considerably in strength in the future, as will the associated flooding risks.
Parallel evolution of image processing tools for multispectral imagery
NASA Astrophysics Data System (ADS)
Harvey, Neal R.; Brumby, Steven P.; Perkins, Simon J.; Porter, Reid B.; Theiler, James P.; Young, Aaron C.; Szymanski, John J.; Bloch, Jeffrey J.
2000-11-01
We describe the implementation and performance of a parallel, hybrid evolutionary-algorithm-based system, which optimizes image processing tools for feature-finding tasks in multi-spectral imagery (MSI) data sets. Our system uses an integrated spatio-spectral approach and is capable of combining suitably-registered data from different sensors. We investigate the speed-up obtained by parallelization of the evolutionary process via multiple processors (a workstation cluster) and develop a model for prediction of run-times for different numbers of processors. We demonstrate our system on Landsat Thematic Mapper MSI , covering the recent Cerro Grande fire at Los Alamos, NM, USA.
Weng, Jing-Ke; Noel, Joseph P.
2013-01-01
Early plants began colonizing the terrestrial earth approximately 450 million years ago. Their success on land has been partially attributed to the evolution of specialized metabolic systems from core metabolic pathways, the former yielding structurally and functionally diverse chemicals to cope with a myriad of biotic and abiotic ecological pressures. Over the past two decades, functional genomics, primarily focused on flowering plants, has begun cataloging the biosynthetic players underpinning assorted classes of plant specialized metabolites. However, the molecular mechanisms enriching specialized metabolic pathways during land plant evolution remain largely unexplored. Selaginella is an extant lycopodiophyte genus representative of an ancient lineage of tracheophytes. Notably, the lycopodiophytes diverged from euphyllophytes over 400 million years ago. The recent completion of the whole-genome sequence of an extant lycopodiophyte, S. moellendorffii, provides new genomic and biochemical resources for studying metabolic evolution in vascular plants. 400 million years of independent evolution of lycopodiophytes and euphyllophytes resulted in numerous metabolic traits confined to each lineage. Surprisingly, a cadre of specialized metabolites, generally accepted to be restricted to seed plants, have been identified in Selaginella. Initial work suggested that Selaginella lacks obvious catalytic homologs known to be involved in the biosynthesis of well-studied specialized metabolites in seed plants. Therefore, these initial functional analyses suggest that the same chemical phenotypes arose independently more commonly than anticipated from our conventional understanding of the evolution of metabolism. Notably, the emergence of analogous and homologous catalytic machineries through convergent and parallel evolution, respectively, seems to have occurred repeatedly in different plant lineages. PMID:23717312
Long waves in parallel flow in Hele-Shaw cells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zeybek, M.; Yortsos, Y.C.
1991-09-09
The evolution of fluid interfaces in parallel flow in Hele-Shaw cells is studied theoretically and experimentally in the limit of large capillary number. It is shown that such interfaces support wave motion, the amplitude of which for long waves is governed by a set of Korteweg--de Vries and Airy equations. Experiments conducted in a long Hele-Shaw cell validate the theory in the symmetric case.
Extent of QTL Reuse During Repeated Phenotypic Divergence of Sympatric Threespine Stickleback.
Conte, Gina L; Arnegard, Matthew E; Best, Jacob; Chan, Yingguang Frank; Jones, Felicity C; Kingsley, David M; Schluter, Dolph; Peichel, Catherine L
2015-11-01
How predictable is the genetic basis of phenotypic adaptation? Answering this question begins by estimating the repeatability of adaptation at the genetic level. Here, we provide a comprehensive estimate of the repeatability of the genetic basis of adaptive phenotypic evolution in a natural system. We used quantitative trait locus (QTL) mapping to discover genomic regions controlling a large number of morphological traits that have diverged in parallel between pairs of threespine stickleback (Gasterosteus aculeatus species complex) in Paxton and Priest lakes, British Columbia. We found that nearly half of QTL affected the same traits in the same direction in both species pairs. Another 40% influenced a parallel phenotypic trait in one lake but not the other. The remaining 10% of QTL had phenotypic effects in opposite directions in the two species pairs. Similarity in the proportional contributions of all QTL to parallel trait differences was about 0.4. Surprisingly, QTL reuse was unrelated to phenotypic effect size. Our results indicate that repeated use of the same genomic regions is a pervasive feature of parallel phenotypic adaptation, at least in sticklebacks. Identifying the causes of this pattern would aid prediction of the genetic basis of phenotypic evolution. Copyright © 2015 by the Genetics Society of America.
Three-dimensional Hybrid Simulation Study of Anisotropic Turbulence in the Proton Kinetic Regime
NASA Astrophysics Data System (ADS)
Vasquez, Bernard J.; Markovskii, Sergei A.; Chandran, Benjamin D. G.
2014-06-01
Three-dimensional numerical hybrid simulations with particle protons and quasi-neutralizing fluid electrons are conducted for a freely decaying turbulence that is anisotropic with respect to the background magnetic field. The turbulence evolution is determined by both the combined root-mean-square (rms) amplitude for fluctuating proton bulk velocity and magnetic field and by the ratio of perpendicular to parallel wavenumbers. This kind of relationship had been considered in the past with regard to interplanetary turbulence. The fluctuations nonlinearly evolve to a turbulent phase whose net wave vector anisotropy is usually more perpendicular than the initial one, irrespective of the initial ratio of perpendicular to parallel wavenumbers. Self-similar anisotropy evolution is found as a function of the rms amplitude and parallel wavenumber. Proton heating rates in the turbulent phase vary strongly with the rms amplitude but only weakly with the initial wave vector anisotropy. Even in the limit where wave vectors are confined to the plane perpendicular to the background magnetic field, the heating rate remains close to the corresponding case with finite parallel wave vector components. Simulation results obtained as a function of proton plasma to background magnetic pressure ratio β p in the range 0.1-0.5 show that the wave vector anisotropy also weakly depends on β p .
Musical emotions: Functions, origins, evolution
NASA Astrophysics Data System (ADS)
Perlovsky, Leonid
2010-03-01
Theories of music origins and the role of musical emotions in the mind are reviewed. Most existing theories contradict each other, and cannot explain mechanisms or roles of musical emotions in workings of the mind, nor evolutionary reasons for music origins. Music seems to be an enigma. Nevertheless, a synthesis of cognitive science and mathematical models of the mind has been proposed describing a fundamental role of music in the functioning and evolution of the mind, consciousness, and cultures. The review considers ancient theories of music as well as contemporary theories advanced by leading authors in this field. It addresses one hypothesis that promises to unify the field and proposes a theory of musical origin based on a fundamental role of music in cognition and evolution of consciousness and culture. We consider a split in the vocalizations of proto-humans into two types: one less emotional and more concretely-semantic, evolving into language, and the other preserving emotional connections along with semantic ambiguity, evolving into music. The proposed hypothesis departs from other theories in considering specific mechanisms of the mind-brain, which required the evolution of music parallel with the evolution of cultures and languages. Arguments are reviewed that the evolution of language toward becoming the semantically powerful tool of today required emancipation from emotional encumbrances. The opposite, no less powerful mechanisms required a compensatory evolution of music toward more differentiated and refined emotionality. The need for refined music in the process of cultural evolution is grounded in fundamental mechanisms of the mind. This is why today's human mind and cultures cannot exist without today's music. The reviewed hypothesis gives a basis for future analysis of why different evolutionary paths of languages were paralleled by different evolutionary paths of music. Approaches toward experimental verification of this hypothesis in psychological and neuroimaging research are reviewed.
Using hybridization networks to retrace the evolution of Indo-European languages.
Willems, Matthieu; Lord, Etienne; Laforest, Louise; Labelle, Gilbert; Lapointe, François-Joseph; Di Sciullo, Anna Maria; Makarenkov, Vladimir
2016-09-06
Curious parallels between the processes of species and language evolution have been observed by many researchers. Retracing the evolution of Indo-European (IE) languages remains one of the most intriguing intellectual challenges in historical linguistics. Most of the IE language studies use the traditional phylogenetic tree model to represent the evolution of natural languages, thus not taking into account reticulate evolutionary events, such as language hybridization and word borrowing which can be associated with species hybridization and horizontal gene transfer, respectively. More recently, implicit evolutionary networks, such as split graphs and minimal lateral networks, have been used to account for reticulate evolution in linguistics. Striking parallels existing between the evolution of species and natural languages allowed us to apply three computational biology methods for reconstruction of phylogenetic networks to model the evolution of IE languages. We show how the transfer of methods between the two disciplines can be achieved, making necessary methodological adaptations. Considering basic vocabulary data from the well-known Dyen's lexical database, which contains word forms in 84 IE languages for the meanings of a 200-meaning Swadesh list, we adapt a recently developed computational biology algorithm for building explicit hybridization networks to study the evolution of IE languages and compare our findings to the results provided by the split graph and galled network methods. We conclude that explicit phylogenetic networks can be successfully used to identify donors and recipients of lexical material as well as the degree of influence of each donor language on the corresponding recipient languages. We show that our algorithm is well suited to detect reticulate relationships among languages, and present some historical and linguistic justification for the results obtained. Our findings could be further refined if relevant syntactic, phonological and morphological data could be analyzed along with the available lexical data.
Influence of equilibrium shear flow in the parallel magnetic direction on edge localized mode crash
DOE Office of Scientific and Technical Information (OSTI.GOV)
Luo, Y.; Xiong, Y. Y.; Chen, S. Y., E-mail: sychen531@163.com
2016-04-15
The influence of the parallel shear flow on the evolution of peeling-ballooning (P-B) modes is studied with the BOUT++ four-field code in this paper. The parallel shear flow has different effects in linear simulation and nonlinear simulation. In the linear simulations, the growth rate of edge localized mode (ELM) can be increased by Kelvin-Helmholtz term, which can be caused by the parallel shear flow. In the nonlinear simulations, the results accord with the linear simulations in the linear phase. However, the ELM size is reduced by the parallel shear flow in the beginning of the turbulence phase, which is recognizedmore » as the P-B filaments' structure. Then during the turbulence phase, the ELM size is decreased by the shear flow.« less
Convergent Evolution of Human-Isolated H7N9 Avian Influenza A Viruses.
Xiang, Dan; Shen, Xuejuan; Pu, Zhiqing; Irwin, David M; Liao, Ming; Shen, Yongyi
2018-05-05
Avian influenza A virus H7N9 has caused 5 epidemic waves of human infections in China since 2013. Avian influenza A viruses may face strong selection to adapt to novel conditions when establishing themselves in humans. In this study, we sought to determine whether adaptive evolution had occurred in human-isolated H7N9 viruses. We evaluated all available genomes of H7N9 avian influenza A virus. Maximum likelihood trees were separately reconstructed for all 8 genes. Signals of positive selection and convergent evolution were then detected on branches that lead to changes in host tropism (from avian to human). We found that 3 genes had significant signals of positive selection (all of them P < .05). In addition, we detected 34 sites having significant signals for parallel evolution in 8 genes (all of them P < .05), including 7 well-known sites (Q591K, E627K, and D701N in PB2 gene; R156K, V202A, and L244Q in HA; and R289K in NA) that play roles in crossing species barriers for avian influenza A viruses. Our study suggests that, during infection in humans, H7N9 viruses have undergone adaptive evolution to adapt to their new host environment and that the sites where parallel evolution occurred might play roles in crossing species barriers and respond to the new selection pressures arising from their new host environments.
NASA Astrophysics Data System (ADS)
Ferrando, N.; Gosálvez, M. A.; Cerdá, J.; Gadea, R.; Sato, K.
2011-03-01
Presently, dynamic surface-based models are required to contain increasingly larger numbers of points and to propagate them over longer time periods. For large numbers of surface points, the octree data structure can be used as a balance between low memory occupation and relatively rapid access to the stored data. For evolution rules that depend on neighborhood states, extended simulation periods can be obtained by using simplified atomistic propagation models, such as the Cellular Automata (CA). This method, however, has an intrinsic parallel updating nature and the corresponding simulations are highly inefficient when performed on classical Central Processing Units (CPUs), which are designed for the sequential execution of tasks. In this paper, a series of guidelines is presented for the efficient adaptation of octree-based, CA simulations of complex, evolving surfaces into massively parallel computing hardware. A Graphics Processing Unit (GPU) is used as a cost-efficient example of the parallel architectures. For the actual simulations, we consider the surface propagation during anisotropic wet chemical etching of silicon as a computationally challenging process with a wide-spread use in microengineering applications. A continuous CA model that is intrinsically parallel in nature is used for the time evolution. Our study strongly indicates that parallel computations of dynamically evolving surfaces simulated using CA methods are significantly benefited by the incorporation of octrees as support data structures, substantially decreasing the overall computational time and memory usage.
[Swine influenza virus: evolution mechanism and epidemic characterization--a review].
Qi, Xian; Lu, Chengping
2009-09-01
Pigs may play an important role in the evolution and ecology of influenza A virus. The tracheal epithelium of pigs contain both SA alpha 2,6 Gal and SA alpha 2,3 Gal receptors and can be infected with swine, human and avian viruses, therefore, pigs have been considered as an intermediate host for the adaptation of avian influenza viruses to humans or as mixing vessels for the generation of genetically reassortant viruses. Evolution patterns among swine influenza viruses including evolution of host adaptation, antigenic drift and genetic reassortment, and the latter is the main one. Unlike human influenza viruses, swine viruses have different epizootiological patterns in different areas of world, which is enzootic and geographic dependence. Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: H1N1, H3N2, and H1N2, and these include classical swine H1N1, avian-like H1N1, human-like H3N2, reassortant H3N2 and various genotype H1N2 viruses. In Europe, North America and China, influenza A viruses circulating in pigs are distinct in the genetic characteristics and genetic sources. Since 1979, three subtypes, avian-like H1N1, reassortant H1N2 and H3N2 viruses, have been co-circulating in European swine. Before 1998, classical H1N1 viruses were the exclusive cause of swine influenza in North America. However, after that, three triple-reassortant H1N2, H3N2 and H1N1 viruses with genes of human, swine and avian virus began to emerge in pigs. Genetically, the pandemic viruses emerging in human, so called influenza A (H1N1) viruses, contain genes from both Europe and North American SIV lineages. SIV is not the same as Europe and the United States in the prevalence and genetic background in China, mainly classical swine H1N1 and human-like H3N2 type virus. However, in recent years, SIV from Europe and North America have been introduced into Chinese pig herds, so more attention should be given on the evolutionary of SIV in China. Worldwide, more than 50 cases of SIV infection in human have been documented since the 1970s, which indicate that SIV is also an important zoonosis, and the potential of SIV as human pandemic virus or genes donator. In view of SIV in the importance of ecology, as well as a potential threat to human public health, it is recommended to start as soon as possible regular surveillance, paying close attention to its prevalence and molecular evolution. At the same time, we should establish the surveillance network of the whole influenza virus (including human and animal influenza virus) in China, ecologically mastering the prevalence and evolution of influenza viruses, which is of great significance for the protection of animal health and the prevention of human pandemic.
The European University in the Context of Logic of Integration
ERIC Educational Resources Information Center
Kotlyarov, Igor V.; Kostjukevich, Svetlana V.
2011-01-01
Many contemporary historians debate and ponder whether modern universities represent a unique creation of the high Middle Ages in Europe, or a simple evolution of schools and academies of classical antiquity. Policymakers, though, could also benefit from addressing this question because in order to find appropriate solutions to reforming…
A systemic approach for modeling biological evolution using Parallel DEVS.
Heredia, Daniel; Sanz, Victorino; Urquia, Alfonso; Sandín, Máximo
2015-08-01
A new model for studying the evolution of living organisms is proposed in this manuscript. The proposed model is based on a non-neodarwinian systemic approach. The model is focused on considering several controversies and open discussions about modern evolutionary biology. Additionally, a simplification of the proposed model, named EvoDEVS, has been mathematically described using the Parallel DEVS formalism and implemented as a computer program using the DEVSLib Modelica library. EvoDEVS serves as an experimental platform to study different conditions and scenarios by means of computer simulations. Two preliminary case studies are presented to illustrate the behavior of the model and validate its results. EvoDEVS is freely available at http://www.euclides.dia.uned.es. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Wilke, Thomas; Wagner, Bernd; Albrecht, Christian; Levkov, Zlatko; Francke, Alexander; Hauffe, Torsten; Cvetkoska, Aleksandra; Jovanovska, Elena; Zhang, Xiaosen; Reed, Jane M.; Wagner-Cremer, Friederike; Stelbrink, Björn; Viehberg, Finn
2015-04-01
Ancient Lake Ohrid on the Balkan Peninsula constitutes the oldest and most biodiverse lake in Europe. The processes generating this extraordinary species richness with a high share of endemic taxa, however, are poorly understood. In order to unravel the geological and biological history of the lake and to study, among others, the influence of major geological and environmental events on the evolution of endemic taxa, an international research initiative - the SCOPSCO project - was launched. The project combines sedimentological, tephro-stratigraphical, seismic and paleontological (diatoms, mollusks, ostracods) studies of lake sediment cores with molecular-dating and empirical modelling approaches applied to extant taxa. Preliminary analyses of sediment core and borehole logging data from drill sites with a maximum penetration depth of 569 m below lake floor and an overall recovery of > 95 % indicate that Lake Ohrid is roughly 1.3 to 1.5 My old. Intriguingly, these data fully reinforce the results of molecular clock analyses conducted prior to the drilling operation. Moreover, the combined geological and biological studies suggest that the extraordinary biodiversity in Lake Ohrid is largely driven by 1) the long and continuous existence of the lake, 2) the lack of catastrophic events (e.g., desiccation, full glaciation or salinization) during its lifetime potentially causing massive extinctions, 3) the high buffer capacity of the lake to environmental change and/or the high resilience of its taxa, and 4) distinct turnovers in species composition over time promoting frequency dependent selection. The cumulative effect of these factors, in turn, resulted in overall low extinction rates and continuous speciation and radiation events. These findings not only shed new light on patterns and processes of evolution in Europe's oldest lake, they also show that data from sediment cores can contribute to a better understanding of the driving forces of biotic evolution. Moreover, Lake Ohrid appears to be a first class example for studying the link between geological and biological evolution in highly isolated ecosystems over comparatively long time scales.
NASA Astrophysics Data System (ADS)
Wang, Miaomiao; Tan, Chengxuan; Meng, Jing; Yang, Baicun; Li, Yuan
2017-08-01
Characterization and evolution of the cracking mode in shale formation is significant, as fracture networks are an important element in shale gas exploitation. In this study we determine the crack modes and evolution in anisotropic shale under cyclic loading using the acoustic emission (AE) parameter-analysis method based on the average frequency and RA (rise-time/amplitude) value. Shale specimens with bedding-plane orientations parallel and perpendicular to the axial loading direction were subjected to loading cycles with increasing peak values until failure occurred. When the loading was parallel to the bedding plane, most of the cracks at failure were shear cracks, while tensile cracks were dominant in the specimens that were loaded normal to the bedding direction. The evolution of the crack mode in the shale specimens observed in the loading-unloading sequence except for the first cycle can be divided into three stages: (I) no or several cracks (AE events) form as a result of the Kaiser effect, (II) tensile and shear cracks increase steadily at nearly equal proportions, (III) tensile cracks and shear cracks increase abruptly, with more cracks forming in one mode than in the other. As the dominant crack motion is influenced by the bedding, the failure mechanism is discussed based on the evolution of the different crack modes. Our conclusions can increase our understanding of the formation mechanism of fracture networks in the field.
Pumping ions: rapid parallel evolution of ionic regulation following habitat invasions.
Lee, Carol Eunmi; Kiergaard, Michael; Gelembiuk, Gregory William; Eads, Brian Donovan; Posavi, Marijan
2011-08-01
Marine to freshwater colonizations constitute among the most dramatic evolutionary transitions in the history of life. This study examined evolution of ionic regulation following saline-to-freshwater transitions in an invasive species. In recent years, the copepod Eurytemora affinis has invaded freshwater habitats multiple times independently. We found parallel evolutionary shifts in ion-motive enzyme activity (V-type H(+) ATPase, Na(+) /K(+) -ATPase) across independent invasions and in replicate laboratory selection experiments. Freshwater populations exhibited increased V-type H(+) ATPase activity in fresh water (0 PSU) and declines at higher salinity (15 PSU) relative to saline populations. This shift represented marked evolutionary increases in plasticity. In contrast, freshwater populations displayed reduced Na(+) /K(+) -ATPase activity across all salinities. Most notably, modifying salinity alone during laboratory selection experiments recapitulated the evolutionary shifts in V-type H(+) ATPase activity observed in nature. Maternal and embryonic acclimation could not account for the observed shifts in enzyme activity. V-type H(+) ATPase function has been hypothesized to be critical for freshwater and terrestrial adaptations, but evolution of this enzyme function had not been previously demonstrated in the context of habitat transitions. Moreover, the speed of these evolutionary shifts was remarkable, within a few generations in the laboratory and a few decades in the wild. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
NASA Astrophysics Data System (ADS)
Yang, Chang; Xiao, Fuliang; He, Yihua; Liu, Si; Zhou, Qinghua; Guo, Mingyue; Zhao, Wanli
2018-03-01
During the 13-14 November 2012 storm, Van Allen Probe A simultaneously observed a 10 h period of enhanced chorus (including quasi-parallel and oblique propagation components) and relativistic electron fluxes over a broad range of L = 3-6 and magnetic local time = 2-10 within a complete orbit cycle. By adopting a Gaussian fit to the observed wave spectra, we obtain the wave parameters and calculate the bounce-averaged diffusion coefficients. We solve the Fokker-Planck diffusion equation to simulate flux evolutions of relativistic (1.8-4.2 MeV) electrons during two intervals when Probe A passed the location L = 4.3 along its orbit. The simulating results show that chorus with combined quasi-parallel and oblique components can produce a more pronounced flux enhancement in the pitch angle range ˜45°-80°, consistent well with the observation. The current results provide the first evidence on how relativistic electron fluxes vary under the drive of almost continuously distributed chorus with both quasi-parallel and oblique components within a complete orbit of Van Allen Probe.
McGlothlin, Joel W; Chuckalovcak, John P; Janes, Daniel E; Edwards, Scott V; Feldman, Chris R; Brodie, Edmund D; Pfrender, Michael E; Brodie, Edmund D
2014-11-01
Members of a gene family expressed in a single species often experience common selection pressures. Consequently, the molecular basis of complex adaptations may be expected to involve parallel evolutionary changes in multiple paralogs. Here, we use bacterial artificial chromosome library scans to investigate the evolution of the voltage-gated sodium channel (Nav) family in the garter snake Thamnophis sirtalis, a predator of highly toxic Taricha newts. Newts possess tetrodotoxin (TTX), which blocks Nav's, arresting action potentials in nerves and muscle. Some Thamnophis populations have evolved resistance to extremely high levels of TTX. Previous work has identified amino acid sites in the skeletal muscle sodium channel Nav1.4 that confer resistance to TTX and vary across populations. We identify parallel evolution of TTX resistance in two additional Nav paralogs, Nav1.6 and 1.7, which are known to be expressed in the peripheral nervous system and should thus be exposed to ingested TTX. Each paralog contains at least one TTX-resistant substitution identical to a substitution previously identified in Nav1.4. These sites are fixed across populations, suggesting that the resistant peripheral nerves antedate resistant muscle. In contrast, three sodium channels expressed solely in the central nervous system (Nav1.1-1.3) showed no evidence of TTX resistance, consistent with protection from toxins by the blood-brain barrier. We also report the exon-intron structure of six Nav paralogs, the first such analysis for snake genes. Our results demonstrate that the molecular basis of adaptation may be both repeatable across members of a gene family and predictable based on functional considerations. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Väliranta, M.; Salonen, J. S.; Heikkilä, M.; Amon, L.; Helmens, K.; Klimaschewski, A.; Kuhry, P.; Kultti, S.; Poska, A.; Shala, S.; Veski, S.; Birks, H. H.
2015-01-01
Holocene summer temperature reconstructions from northern Europe based on sedimentary pollen records suggest an onset of peak summer warmth around 9,000 years ago. However, pollen-based temperature reconstructions are largely driven by changes in the proportions of tree taxa, and thus the early-Holocene warming signal may be delayed due to the geographical disequilibrium between climate and tree populations. Here we show that quantitative summer-temperature estimates in northern Europe based on macrofossils of aquatic plants are in many cases ca. 2 °C warmer in the early Holocene (11,700–7,500 years ago) than reconstructions based on pollen data. When the lag in potential tree establishment becomes imperceptible in the mid-Holocene (7,500 years ago), the reconstructed temperatures converge at all study sites. We demonstrate that aquatic plant macrofossil records can provide additional and informative insights into early-Holocene temperature evolution in northernmost Europe and suggest further validation of early post-glacial climate development based on multi-proxy data syntheses. PMID:25858780
SARS-CoV related Betacoronavirus and diverse Alphacoronavirus members found in western old-world.
Ar Gouilh, Meriadeg; Puechmaille, Sébastien J; Diancourt, Laure; Vandenbogaert, Mathias; Serra-Cobo, Jordi; Lopez Roïg, Marc; Brown, Paul; Moutou, François; Caro, Valérie; Vabret, Astrid; Manuguerra, Jean-Claude
2018-04-01
The emergence of SARS-CoV and MERS-CoV, triggered the discovery of a high diversity of coronaviruses in bats. Studies from Europe have shown that coronaviruses circulate in bats in France but this reflects only a fraction of the whole diversity. In the current study the diversity of coronaviruses circulating in western Europe was extensively explored. Ten alphacoronaviruses in eleven bat species belonging to the Miniopteridae, Vespertilionidae and Rhinolophidae families and, a SARS-CoV-related Betacoronavirus in Rhinolophus ferrumequinum were identified. The diversity and prevalence of bat coronaviruses presently reported from western Europe is much higher than previously described and includes a SARS-CoV sister group. This diversity demonstrates the dynamic evolution and circulation of coronaviruses in this species. That said, the identified coronaviruses were consistently associated with a particular bat species or genus, and these relationships were maintained no matter the geographic location. The observed phylogenetic grouping of coronaviruses from the same species in Europe and Asia, emphasizes the role of host/pathogen coevolution in this group. Copyright © 2018 Elsevier Inc. All rights reserved.
The HIV Epidemic: High-Income Countries
Vermund, Sten H.; Leigh-Brown, Andrew J.
2012-01-01
The HIV epidemic in higher-income nations is driven by receptive anal intercourse, injection drug use through needle/syringe sharing, and, less efficiently, vaginal intercourse. Alcohol and noninjecting drug use increase sexual HIV vulnerability. Appropriate diagnostic screening has nearly eliminated blood/blood product-related transmissions and, with antiretroviral therapy, has reduced mother-to-child transmission radically. Affected subgroups have changed over time (e.g., increasing numbers of Black and minority ethnic men who have sex with men). Molecular phylogenetic approaches have established historical links between HIV strains from central Africa to those in the United States and thence to Europe. However, Europe did not just receive virus from the United States, as it was also imported from Africa directly. Initial introductions led to epidemics in different risk groups in Western Europe distinguished by viral clades/sequences, and likewise, more recent explosive epidemics linked to injection drug use in Eastern Europe are associated with specific strains. Recent developments in phylodynamic approaches have made it possible to obtain estimates of sequence evolution rates and network parameters for epidemics. PMID:22553497
Suggestion, persuasion and work: Psychotherapies in communist Europe.
Marks, Sarah
2018-01-01
This article traces what recent research and primary sources tell us about psychotherapy in Communist Europe, and how it survived both underground and above the surface. In particular, I will elaborate on the psychotherapeutic techniques that were popular across the different countries and language cultures of the Soviet sphere, with a particular focus upon the Cold War period. This article examines the literature on the mixed fortunes of psychoanalysis and group therapies in the region. More specifically, it focuses upon the therapeutic modalities such as work therapy, suggestion and rational therapy, which gained particular popularity in the Communist countries of Central and Eastern Europe. The latter two approaches had striking similarities with parallel developments in behavioural and cognitive therapies in the West. In part, this was because clinicians on both sides of the 'iron curtain' drew upon shared European traditions from the late nineteenth and early twentieth centuries. Nevertheless, this article argues that in the Soviet sphere, those promoting these approaches appropriated socialist thought as a source of inspiration and justification, or at the very least, as a convenient political shield.
Suggestion, persuasion and work: Psychotherapies in communist Europe
Marks, Sarah
2018-01-01
Abstract This article traces what recent research and primary sources tell us about psychotherapy in Communist Europe, and how it survived both underground and above the surface. In particular, I will elaborate on the psychotherapeutic techniques that were popular across the different countries and language cultures of the Soviet sphere, with a particular focus upon the Cold War period. This article examines the literature on the mixed fortunes of psychoanalysis and group therapies in the region. More specifically, it focuses upon the therapeutic modalities such as work therapy, suggestion and rational therapy, which gained particular popularity in the Communist countries of Central and Eastern Europe. The latter two approaches had striking similarities with parallel developments in behavioural and cognitive therapies in the West. In part, this was because clinicians on both sides of the ‘iron curtain’ drew upon shared European traditions from the late nineteenth and early twentieth centuries. Nevertheless, this article argues that in the Soviet sphere, those promoting these approaches appropriated socialist thought as a source of inspiration and justification, or at the very least, as a convenient political shield. PMID:29527126
Bartke, Stephan; Hagemann, Nina; Harries, Nicola; Hauck, Jennifer; Bardos, Paul
2018-04-01
A deliberate expert-based scenario approach is applied to better understand the likely determinants of the evolution of the market for nanoparticles use in remediation in Europe until 2025. An initial set of factors had been obtained from a literature review and was complemented by a workshop and key-informant interviews. In further expert engaging formats - focus groups, workshops, conferences, surveys - this initial set of factors was condensed and engaged experts scored the factors regarding their importance for being likely to influence the market development. An interaction matrix was obtained identifying the factors being most active in shaping the market development in Europe by 2025, namely "Science-Policy-Interface" and "Validated information on nanoparticle application potential". Based on these, potential scenarios were determined and development of factors discussed. Conclusions are offered on achievable interventions to enhance nanoremediation deployment. Copyright © 2017 Elsevier B.V. All rights reserved.
History of bioengineering techniques for erosion control in rivers in Western Europe.
Evette, Andre; Labonne, Sophie; Rey, Freddy; Liebault, Frederic; Jancke, Oliver; Girel, Jacky
2009-06-01
Living plants have been used for a very long time throughout the world in structures against soil erosion, as traces have been found dating back to the first century BC. Widely practiced in Western Europe during the eighteenth and nineteenth centuries, bioengineering was somewhat abandoned in the middle of the twentieth century, before seeing a resurgence in recent times. Based on an extensive bibliography, this article examines the different forms of bioengineering techniques used in the past to manage rivers and riverbanks, mainly in Europe. We compare techniques using living material according to their strength of protection against erosion. Many techniques are described, both singly and in combination, ranging from tree planting or sowing seeds on riverbanks to dams made of fascine or wattle fences. The recent appearance of new materials has led to the development of new techniques, associated with an evolution in the perception of riverbanks.
Gehring, Walter J
2014-01-01
In this review, the evolution of vision is retraced from its putative origins in cyanobacteria to humans. Circadian oscillatory clocks, phototropism, and phototaxis require the capability to detect light. Photosensory proteins allow us to reconstruct molecular phylogenetic trees. The evolution of animal eyes leading from an ancestral prototype to highly complex image forming eyes can be deciphered on the basis of evolutionary developmental genetic experiments and comparative genomics. As all bilaterian animals share the same master control gene, Pax6, and the same retinal and pigment cell determination genes, we conclude that the different eye-types originated monophyletically and subsequently diversified by divergent, parallel, or convergent evolution. © 2012 Wiley Periodicals, Inc.
Evolution: bats, radar, and science (The Remote Sensing Award Lecture)
NASA Technical Reports Server (NTRS)
Atlas, David
1991-01-01
A parallel is drawn between the evolution of the bat and the evolution of the science and technology of radar and remote sensing to illustrate the importance of the role of Darwinian processes in the culture and practice of science and technology, and thus in the survival of their vitality. The lecture touches on several themes of interest to the science community, such as the relation between basic and applied science and engineering; research in academia, industry, and government laboratories; elite scientists; and the survival of a scientific institution.
Workshop - "Physics for Health in Europe"
None
2018-05-16
2-4 February 2010 at CERN This event will be will be available live via the Webcast Service and transmitted in parallel to: IT auditorium, Salle Anderssen 40-S2-A01(Tuesday 2nd February) BE auditorium (all day), Salle 40-S2-01 (only between 08:00- 14:00) (Wednesday 3rd February)BE auditorium, Salle Curie 40-S2-C01(Thursday 4th February)  Â
The science of computing - The evolution of parallel processing
NASA Technical Reports Server (NTRS)
Denning, P. J.
1985-01-01
The present paper is concerned with the approaches to be employed to overcome the set of limitations in software technology which impedes currently an effective use of parallel hardware technology. The process required to solve the arising problems is found to involve four different stages. At the present time, Stage One is nearly finished, while Stage Two is under way. Tentative explorations are beginning on Stage Three, and Stage Four is more distant. In Stage One, parallelism is introduced into the hardware of a single computer, which consists of one or more processors, a main storage system, a secondary storage system, and various peripheral devices. In Stage Two, parallel execution of cooperating programs on different machines becomes explicit, while in Stage Three, new languages will make parallelism implicit. In Stage Four, there will be very high level user interfaces capable of interacting with scientists at the same level of abstraction as scientists do with each other.
Phylogenetic analyses of mode of larval development.
Hart, M
2000-12-01
Phylogenies based on morphological or molecular characters have been used to provide an evolutionary context for analysis of larval evolution. Studies of gastropods, bivalves, tunicates, sea stars, sea urchins, and polychaetes have revealed massive parallel evolution of similar larval forms. Some of these studies were designed to test, and have rejected, the species selection hypothesis for evolutionary trends in the frequency of derived larvae or life history traits. However, the lack of well supported models of larval character evolution leave some doubt about the quality of inferences of larval evolution from phylogenies of living taxa. Better models based on maximum likelihood methods and known prior probabilities of larval character state changes will improve our understanding of the history of larval evolution. Copyright 2000 Academic Press.
Biogeography and climatic change as a context to human dispersal out of Africa and within Eurasia
NASA Astrophysics Data System (ADS)
van der Made, Jan
2011-06-01
The dispersal of the genus Homo occurred against a background of continuous environmental change. Here, dispersals of large mammals through the Levantine Corridor and into Western Europe and Java are studied and compared to existing records of climatic change and dispersals of early humans and lithic industry. The first human dispersal (with Oldowan lithic industry) out of Africa, around or shortly before 1.8 Ma may have been triggered by biological evolution and increased social organisation, rather than environmental change. After that event, increasing aridity led to decreased faunal exchange between Africa and Eurasia and may have isolated the human populations of Africa and Africa. Southern (Java) and Eastern Asia (China) also seem to have been isolated. Human dispersal into Western Europe may have been limited by closed environments in Central Europe until about 1.2 Ma ago, when faunal dispersal into Europe suggests the cyclic spread of open environments to the west. Acheulean technology originated in Africa, some 1.6-1.5 Ma ago, but its dispersal into Eurasia may have been obstructed by an arid Southwest Asia, until broadly about 0.9 Ma ago, when faunal exchange suggests that the area became temporarily less dry. By 0.6-0.5 Ma ago it reached Europe.
NASA Astrophysics Data System (ADS)
Georgiev, K.; Zlatev, Z.
2010-11-01
The Danish Eulerian Model (DEM) is an Eulerian model for studying the transport of air pollutants on large scale. Originally, the model was developed at the National Environmental Research Institute of Denmark. The model computational domain covers Europe and some neighbour parts belong to the Atlantic Ocean, Asia and Africa. If DEM model is to be applied by using fine grids, then its discretization leads to a huge computational problem. This implies that such a model as DEM must be run only on high-performance computer architectures. The implementation and tuning of such a complex large-scale model on each different computer is a non-trivial task. Here, some comparison results of running of this model on different kind of vector (CRAY C92A, Fujitsu, etc.), parallel computers with distributed memory (IBM SP, CRAY T3E, Beowulf clusters, Macintosh G4 clusters, etc.), parallel computers with shared memory (SGI Origin, SUN, etc.) and parallel computers with two levels of parallelism (IBM SMP, IBM BlueGene/P, clusters of multiprocessor nodes, etc.) will be presented. The main idea in the parallel version of DEM is domain partitioning approach. Discussions according to the effective use of the cache and hierarchical memories of the modern computers as well as the performance, speed-ups and efficiency achieved will be done. The parallel code of DEM, created by using MPI standard library, appears to be highly portable and shows good efficiency and scalability on different kind of vector and parallel computers. Some important applications of the computer model output are presented in short.
Local and nonlocal parallel heat transport in general magnetic fields
DOE Office of Scientific and Technical Information (OSTI.GOV)
Del-Castillo-Negrete, Diego B; Chacon, Luis
2011-01-01
A novel approach for the study of parallel transport in magnetized plasmas is presented. The method avoids numerical pollution issues of grid-based formulations and applies to integrable and chaotic magnetic fields with local or nonlocal parallel closures. In weakly chaotic fields, the method gives the fractal structure of the devil's staircase radial temperature profile. In fully chaotic fields, the temperature exhibits self-similar spatiotemporal evolution with a stretched-exponential scaling function for local closures and an algebraically decaying one for nonlocal closures. It is shown that, for both closures, the effective radial heat transport is incompatible with the quasilinear diffusion model.
Cortical organization in insectivora: the parallel evolution of the sensory periphery and the brain.
Catania, K C
2000-06-01
Insectivores are traditionally described as a primitive group that has not changed much in the course of mammalian evolution. In contrast, recent studies reveal a great diversity of sensorimotor specializations among insectivores adapted to a number of different ecological niches, indicating that there has been significant diversification and change in the course of their evolution. Here the organization of sensory cortex is compared in the African hedgehog (Atelerix albiventris), the masked shrew (Sorex cinereus), the eastern mole (Scalopus aquaticus), and the star-nosed mole (Condylura cristata). Each of these four closely related species lives in a unique ecological niche, exhibits a different repertoire of behaviors, and has a different configuration of peripheral sensory receptors. Corresponding specializations of cortical sensory areas reveal a number of ways in which the cortex has evolved in parallel with changes to the sensory periphery. These specializations include expansion of cortical representations (cortical magnification), the addition or loss of cortical areas in the processing network, and the subdivision of areas into modules (barrels and stripes). Copyright 2000 S. Karger AG, Basel
The tectonics of anorthosite massifs
NASA Technical Reports Server (NTRS)
Seyfert, C. K.
1981-01-01
Anorthosite massifs developed approximately 1.4 to 1.5 billion years ago along an arch which developed parallel to a zone of continental separation as a block which included North America, Europe, and probably Asia separated from a block which included parts of South America, Africa, India, and Australia. Anorthosite massifs also developed at the same time along a belt which runs through the continents which comprise Gondwanaland (South America), Africa, India, Australia, and Antarctica. This was a zone of continental separation which subsequently became a zone of continental collision about 1.2 billion years ago. The northern anorthosite belt also parallels an orogenic belt which was active between 1.8 and 1.7 billion years ago. Heat generated during this mountain building period helped in the formation of the anorthosites.
Carroll, Sean Michael; Chubiz, Lon M.; Agashe, Deepa; Marx, Christopher J.
2015-01-01
Bioengineering holds great promise to provide fast and efficient biocatalysts for methanol-based biotechnology, but necessitates proven methods to optimize physiology in engineered strains. Here, we highlight experimental evolution as an effective means for optimizing an engineered Methylobacterium extorquens AM1. Replacement of the native formaldehyde oxidation pathway with a functional analog substantially decreased growth in an engineered Methylobacterium, but growth rapidly recovered after six hundred generations of evolution on methanol. We used whole-genome sequencing to identify the basis of adaptation in eight replicate evolved strains, and examined genomic changes in light of other growth and physiological data. We observed great variety in the numbers and types of mutations that occurred, including instances of parallel mutations at targets that may have been “rationalized” by the bioengineer, plus other “illogical” mutations that demonstrate the ability of evolution to expose unforeseen optimization solutions. Notably, we investigated mutations to RNA polymerase, which provided a massive growth benefit but are linked to highly aberrant transcriptional profiles. Overall, we highlight the power of experimental evolution to present genetic and physiological solutions for strain optimization, particularly in systems where the challenges of engineering are too many or too difficult to overcome via traditional engineering methods. PMID:27682084
Cave men: stone tools, Victorian science, and the 'primitive mind' of deep time.
Pettitt, Paul B; White, Mark J
2011-03-20
Palaeoanthropology, the study of the evolution of humanity, arose in the nineteenth century. Excavations in Europe uncovered a series of archaeological sediments which provided proof that the antiquity of human life on Earth was far longer than the biblical six thousand years, and by the 1880s authors had constructed a basic paradigm of what 'primitive' human life was like. Here we examine the development of Victorian palaeoanthropology for what it reveals of the development of notions of cognitive evolution. It seems that Victorian specialists rarely addressed cognitive evolution explicitly, although several assumptions were generally made that arose from preconceptions derived from contemporary 'primitive' peoples. We identify three main phases of development of notions of the primitive mind in the period.
USSR and Eastern Europe Scientific Abstracts. Geophysics, Astronomy and Space, Number 387
1976-12-30
gives basis for assuming that the " greenhouse " effect hypothesis was completely confirmed. During the descent of the vehicle in the atmosphere the...conditions at the surface? On Venus the greenhouse effect was intensified in the initial stages of its geological evolution: an increase in temperature led
USDA-ARS?s Scientific Manuscript database
Feeding damage caused by the corn rootworm, Diabrotica virgifera virgifera, is destructive to corn plants in North America and Europe where control remains challenging due to evolution of resistance traits that allow survival when exposed to chemical and transgenic toxins. Genome sequencing of an i...
Hypercat: A Database for Extragalactic Astronomy
NASA Astrophysics Data System (ADS)
Prugniel, Ph.; Maubon, G.
The Hypercat Database is developed at Observatoire de Lyon and is distributed on the WEB(www-obs.univ-lyon1.fr/hypercat) through different mirrors in Europe. The goal of Hypercat is to gather data necessary for studying the evolution of galaxies (dynamics and stellar contains) and particularly for providing a z = 0 reference for these studies.
Recent Trends in Quality Assurance
ERIC Educational Resources Information Center
Amaral, Alberto; Rosa, Maria Joao
2010-01-01
In this paper we present a brief description of the evolution of quality assurance in Europe, paying particular attention to its relationship to the rising loss of trust in higher education institutions. We finalise by analysing the role of the European Commission in the setting up of new quality assurance mechanisms that tend to promote…
Impact of the eocene on the evolution of Pinus L.
Constance I. Millar
1993-01-01
Pinus evolved in middle latitudes of the Northern Hemisphere in the middle Mesozoic. By the late Cretaceous pines had spread east and west throughout Laurasia, attaining high diversity in eastern Asia, the eastern United States, and western Europe, but having little representation at high northern latitudes. Changing climates in the early Tertiary...
West nile virus: characteristics of an african virus adapting to the third millennium world.
Monini, Marina; Falcone, Emiliana; Busani, Luca; Romi, Roberto; Ruggeri, Franco Maria
2010-04-22
The emergence and spread of West Nile Virus (WNV) from North through South America during the last decade, and the recent outbreaks of disease in both humans and horses in Europe suggest that the epidemiology of this infection is evolving. WNV is now considered among the emerging threats for both human and veterinary public health in areas like Europe where it was previously regarded to as an exotic agent. Further knowledge has built up from studies investigating the characteristics of the virus and its genome evolution capacity, the adaptation to new avian host species, the changes in vector competence and biology, and the host-pathogen interactions, including the immune response. Also, the new needs for preparedness to future major outbursts of disease have stimulated research on virus detection and characterization, filling the gaps in both specialized diagnostic technology and the need for field rapid assays. This review will present an overview of WNV virology, remarking the impact of virus diversity and evolution on theoretical and practical aspects involved in both risk definition, detection and control of infection.
Yardang evolution from maturity to demise
NASA Astrophysics Data System (ADS)
Barchyn, Thomas E.; Hugenholtz, Chris H.
2015-07-01
Yardangs are enigmatic wind-parallel ridges sculpted by aeolian processes that are found extensively in arid environments on Earth and Mars. No general theory exists to explain the long-term evolution of yardangs, curtailing modeling of landscape evolution and dynamics of suspended sediment release. We present a hypothesis of yardang evolution using relative rates of sediment flux, interyardang corridor downcutting, yardang denudation, substrate erodibility, and substrate clast content. To develop and sustain yardangs, corridor downcutting must exceed yardang vertical denudation and deflation. However, erosion of substrate yields considerable quantities of sediment that shelters corridors, slowing downcutting. We model the evolution of yardangs through various combinations of rates and substrate compositions, demonstrating the life span, suspended sediment release, and resulting landscape evolution. We find that yardangs have a distinct and predictable evolution, with inevitable demise and unexpectedly dynamic and autogenic erosion rates driven by subtle differences in substrate clast composition.
Evolution of Kelvin-Helmholtz instability at Venus in the presence of the parallel magnetic field
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lu, H. Y.; Key Laboratory of Planetary Sciences, Chinese Academy of Sciences, Nanjing 210008; Cao, J. B.
2015-06-15
Two-dimensional MHD simulations were performed to study the evolution of the Kelvin-Helmholtz (KH) instability at the Venusian ionopause in response to the strong flow shear in presence of the in-plane magnetic field parallel to the flow direction. The physical behavior of the KH instability as well as the triggering and occurrence conditions for highly rolled-up vortices are characterized through several physical parameters, including Alfvén Mach number on the upper side of the layer, the density ratio, and the ratio of parallel magnetic fields between two sides of the layer. Using these parameters, the simulations show that both the high densitymore » ratio and the parallel magnetic field component across the boundary layer play a role of stabilizing the instability. In the high density ratio case, the amount of total magnetic energy in the final quasi-steady status is much more than that in the initial status, which is clearly different from the case with low density ratio. We particularly investigate the nonlinear development of the case that has a high density ratio and uniform magnetic field. Before the instability saturation, a single magnetic island is formed and evolves into two quasi-steady islands in the non-linear phase. A quasi-steady pattern eventually forms and is embedded within a uniform magnetic field and a broadened boundary layer. The estimation of loss rates of ions from Venus indicates that the stabilizing effect of the parallel magnetic field component on the KH instability becomes strong in the case of high density ratio.« less
Multicore: Fallout from a Computing Evolution
Yelick, Kathy [Director, NERSC
2017-12-09
July 22, 2008 Berkeley Lab lecture: Parallel computing used to be reserved for big science and engineering projects, but in two years that's all changed. Even laptops and hand-helds use parallel processors. Unfortunately, the software hasn't kept pace. Kathy Yelick, Director of the National Energy Research Scientific Computing Center at Berkeley Lab, describes the resulting chaos and the computing community's efforts to develop exciting applications that take advantage of tens or hundreds of processors on a single chip.
Hipp, Andrew L; Manos, Paul S; González-Rodríguez, Antonio; Hahn, Marlene; Kaproth, Matthew; McVay, John D; Avalos, Susana Valencia; Cavender-Bares, Jeannine
2018-01-01
Oaks (Quercus, Fagaceae) are the dominant tree genus of North America in species number and biomass, and Mexico is a global center of oak diversity. Understanding the origins of oak diversity is key to understanding biodiversity of northern temperate forests. A phylogenetic study of biogeography, niche evolution and diversification patterns in Quercus was performed using 300 samples, 146 species. Next-generation sequencing data were generated using the restriction-site associated DNA (RAD-seq) method. A time-calibrated maximum likelihood phylogeny was inferred and analyzed with bioclimatic, soils, and leaf habit data to reconstruct the biogeographic and evolutionary history of the American oaks. Our highly resolved phylogeny demonstrates sympatric parallel diversification in climatic niche, leaf habit, and diversification rates. The two major American oak clades arose in what is now the boreal zone and radiated, in parallel, from eastern North America into Mexico and Central America. Oaks adapted rapidly to niche transitions. The Mexican oaks are particularly numerous, not because Mexico is a center of origin, but because of high rates of lineage diversification associated with high rates of evolution along moisture gradients and between the evergreen and deciduous leaf habits. Sympatric parallel diversification in the oaks has shaped the diversity of North American forests. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.
Parallel Evolution of Copy-Number Variation across Continents in Drosophila melanogaster
Schrider, Daniel R.; Hahn, Matthew W.; Begun, David J.
2016-01-01
Genetic differentiation across populations that is maintained in the presence of gene flow is a hallmark of spatially varying selection. In Drosophila melanogaster, the latitudinal clines across the eastern coasts of Australia and North America appear to be examples of this type of selection, with recent studies showing that a substantial portion of the D. melanogaster genome exhibits allele frequency differentiation with respect to latitude on both continents. As of yet there has been no genome-wide examination of differentiated copy-number variants (CNVs) in these geographic regions, despite their potential importance for phenotypic variation in Drosophila and other taxa. Here, we present an analysis of geographic variation in CNVs in D. melanogaster. We also present the first genomic analysis of geographic variation for copy-number variation in the sister species, D. simulans, in order to investigate patterns of parallel evolution in these close relatives. In D. melanogaster we find hundreds of CNVs, many of which show parallel patterns of geographic variation on both continents, lending support to the idea that they are influenced by spatially varying selection. These findings support the idea that polymorphic CNVs contribute to local adaptation in D. melanogaster. In contrast, we find very few CNVs in D. simulans that are geographically differentiated in parallel on both continents, consistent with earlier work suggesting that clinal patterns are weaker in this species. PMID:26809315
ESA Earth Observation Ground Segment Evolution Strategy
NASA Astrophysics Data System (ADS)
Benveniste, J.; Albani, M.; Laur, H.
2016-12-01
One of the key elements driving the evolution of EO Ground Segments, in particular in Europe, has been to enable the creation of added value from EO data and products. This requires the ability to constantly adapt and improve the service to a user base expanding far beyond the `traditional' EO user community of remote sensing specialists. Citizen scientists, the general public, media and educational actors form another user group that is expected to grow. Technological advances, Open Data policies, including those implemented by ESA and the EU, as well as an increasing number of satellites in operations (e.g. Copernicus Sentinels) have led to an enormous increase in available data volumes. At the same time, even with modern network and data handling services, fewer users can afford to bulk-download and consider all potentially relevant data and associated knowledge. The "EO Innovation Europe" concept is being implemented in Europe in coordination between the European Commission, ESA and other European Space Agencies, and industry. This concept is encapsulated in the main ideas of "Bringing the User to the Data" and "Connecting the Users" to complement the traditional one-to-one "data delivery" approach of the past. Both ideas are aiming to better "empower the users" and to create a "sustainable system of interconnected EO Exploitation Platforms", with the objective to enable large scale exploitation of European EO data assets for stimulating innovation and to maximize their impact. These interoperable/interconnected platforms are virtual environments in which the users - individually or collaboratively - have access to the required data sources and processing tools, as opposed to downloading and handling the data `at home'. EO-Innovation Europe has been structured around three elements: an enabling element (acting as a back office), a stimulating element and an outreach element (acting as a front office). Within the enabling element, a "mutualisation" of efforts and funding between public institutions should prevent an unnecessary duplication of investments for enabling infrastructures in Europe and will stimulate the existence of many exploitation platforms or value-adding add-ons funded by different public and private entities in the outreach element (front office).
NASA Astrophysics Data System (ADS)
Marinou, Eleni; Amiridis, Vassilis; Binietoglou, Ioannis; Tsikerdekis, Athanasios; Solomos, Stavros; Proestakis, Emannouil; Konsta, Dimitra; Papagiannopoulos, Nikolaos; Tsekeri, Alexandra; Vlastou, Georgia; Zanis, Prodromos; Balis, Dimitrios; Wandinger, Ulla; Ansmann, Albert
2017-05-01
In this study we use a new dust product developed using CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) observations and EARLINET (European Aerosol Research Lidar Network) measurements and methods to provide a 3-D multiyear analysis on the evolution of Saharan dust over North Africa and Europe. The product uses a CALIPSO L2 backscatter product corrected with a depolarization-based method to separate pure dust in external aerosol mixtures and a Saharan dust lidar ratio (LR) based on long-term EARLINET measurements to calculate the dust extinction profiles. The methodology is applied on a 9-year CALIPSO dataset (2007-2015) and the results are analyzed here to reveal for the first time the 3-D dust evolution and the seasonal patterns of dust over its transportation paths from the Sahara towards the Mediterranean and Continental Europe. During spring, the spatial distribution of dust shows a uniform pattern over the Sahara desert. The dust transport over the Mediterranean Sea results in mean dust optical depth (DOD) values up to 0.1. During summer, the dust activity is mostly shifted to the western part of the desert where mean DOD near the source is up to 0.6. Elevated dust plumes with mean extinction values between 10 and 75 Mm-1 are observed throughout the year at various heights between 2 and 6 km, extending up to latitudes of 40° N. Dust advection is identified even at latitudes of about 60° N, but this is due to rare events of episodic nature. Dust plumes of high DOD are also observed above the Balkans during the winter period and above northwest Europe during autumn at heights between 2 and 4 km, reaching mean extinction values up to 50 Mm-1. The dataset is considered unique with respect to its potential applications, including the evaluation of dust transport models and the estimation of cloud condensation nuclei (CCN) and ice nuclei (IN) concentration profiles. Finally, the product can be used to study dust dynamics during transportation, since it is capable of revealing even fine dynamical features such as the particle uplifting and deposition on European mountainous ridges such as the Alps and Carpathian Mountains.
Molecular Epidemiology and Evolution of European Bat Lyssavirus 2
McElhinney, Lorraine M.; Zanoni, Reto; Kooi, Engbert A.; Neubauer-Juric, Antonie; Nokireki, Tiina; Müller, Thomas; Fooks, Anthony R.
2018-01-01
Bat rabies cases in Europe are mainly attributed to two lyssaviruses, namely European Bat Lyssavirus 1 (EBLV-1) and European Bat Lyssavirus 2 (EBLV-2). Prior to the death of a bat worker in Finland in 1985, very few bat rabies cases were reported. Enhanced surveillance in the two subsequent years (1986–1987) identified 263 cases (more than a fifth of all reported cases to date). Between 1977 and 2016, 1183 cases of bat rabies were reported, with the vast majority (>97%) being attributed to EBLV-1. In contrast, there have been only 39 suspected cases of EBLV-2, of which 34 have been confirmed by virus typing and presently restricted to just two bat species; Myotis daubentonii and Myotis dasycneme. The limited number of EBLV-2 cases in Europe prompted the establishment of a network of European reference laboratories to collate all available viruses and data. Despite the relatively low number of EBLV-2 cases, a large amount of anomalous data has been published in the scientific literature, which we have here reviewed and clarified. In this review, 29 EBLV-2 full genome sequences have been analysed to further our understanding of the diversity and molecular evolution of EBLV-2 in Europe. Analysis of the 29 complete EBLV-2 genome sequences clearly corroborated geographical relationships with all EBLV-2 sequences clustering at the country level irrespective of the gene studied. Further geographical clustering was also observed at a local level. There are high levels of homogeneity within the EBLV-2 species with nucleotide identities ranging from 95.5–100% and amino acid identities between 98.7% and 100%, despite the widespread distribution of the isolates both geographically and chronologically. The mean substitution rate for EBLV-2 across the five concatenated genes was 1.65 × 10−5, and evolutionary clock analysis confirms the slow evolution of EBLV-2 both between and within countries in Europe. This is further supported by the first detailed EBLV-2 intra-roost genomic analysis whereby a relatively high sequence homogeneity was found across the genomes of three EBLV-2 isolates obtained several years apart (2007, 2008, and 2014) from M. daubentonii at the same site (Stokesay Castle, Shropshire, UK). PMID:29303971
NASA Astrophysics Data System (ADS)
Lemaire, V. E. P.; Colette, A.; Menut, L.
2015-10-01
Because of its sensitivity to unfavorable weather patterns, air pollution is sensitive to climate change so that, in the future, a climate penalty could jeopardize the expected efficiency of air pollution mitigation measures. A common method to assess the impact of climate on air quality consists in implementing chemistry-transport models forced by climate projection. However, the computing cost of such method requires optimizing ensemble exploration techniques. By using a training dataset of deterministic projection of climate and air quality over Europe, we identified the main meteorological drivers of air quality for 8 regions in Europe and developed simple statistical models that could be used to predict air pollutant concentrations. The evolution of the key climate variables driving either particulate or gaseous pollution allows concluding on the robustness of the climate impact on air quality. The climate benefit for PM2.5 was confirmed -0.96 (±0.18), -1.00 (±0.37), -1.16 ± (0.23) μg m-3, for resp. Eastern Europe, Mid Europe and Northern Italy and for the Eastern Europe, France, Iberian Peninsula, Mid Europe and Northern Italy regions a climate penalty on ozone was identified 10.11 (±3.22), 8.23 (±2.06), 9.23 (±1.13), 6.41 (±2.14), 7.43 (±2.02) μg m-3. This technique also allows selecting a subset of relevant regional climate model members that should be used in priority for future deterministic projections.
Qian, W; Meng, J; Li, M; Frauen, M; Sass, O; Noack, J; Jung, C
2006-06-01
In spite of its short history of being an oil crop in China, the Chinese semi-winter rapeseed (Brassica napus L., 2n = 38, AACC) has been improved rapidly by intentional introgression of genomic components from Chinese B. rapa (2n = 20, AA). As a result, the Chinese semi-winter rapeseed has diversified genetically from the spring and winter rapeseed grown in the other regions such as Europe and North America. The objectives of this study were to investigate the roles of the introgression of the genomic components from the Chinese B. rapa in widening the genetic diversity of rapeseed and to verify the role of this introgression in the evolution of the Chinese rapeseed. Ten lines of the new type of rapeseed, which were produced by introgression of Chinese B. rapa to Chinese normal rapeseed, were compared for genetic diversity using amplified fragment length polymorphism (AFLP) with three groups of 35 lines of the normal rapeseed, including 9 semi-winter rapeseed lines from China, 9 winter rapeseed lines from Europe and 17 spring rapeseed lines from Northern Europe, Canada and Australia. Analysis of 799 polymorphic fragments revealed that within the groups, the new type rapeseed had the highest genetic diversity, followed by the semi-winter normal rapeseed from China. Spring and winter rapeseed had the lowest genetic diversity. Among the groups, the new type rapeseed group had the largest average genetic distance to the other three groups. Principal component analysis and cluster analysis, however, could not separate the new type rapeseed group from Chinese normal rapeseed group. Our data suggested that the introgression of Chinese B. rapa could significantly diversify the genetic basis of the rapeseed and play an important role in the evolution of Chinese rapeseed. The use of new genetic variation for the exploitation of heterosis in Brassica hybrid breeding is discussed.
Workshop "Physics for Health in Europe"
Boerman, Otto
2018-06-20
Presentation on Radioisotopes in diagnostics and therapy. 2-4 February 2010 at CERN This event will be will be available live via the Webcast Service and transmitted in parallel to: IT auditorium, Salle Anderssen 40-S2-A01(Tuesday 2nd February) BE auditorium (all day), Salle 40-S2-01 (only between 08:00- 14:00) (Wednesday 3rd February) BE auditorium, Salle Curie 40-S2-C01(Thursday 4th February). Â
Schmoll, Hans-Joachim; Arnold, Dirk; de Gramont, Aimery; Ducreux, Michel; Grothey, Axel; O'Dwyer, Peter J; Van Cutsem, Eric; Hermann, Frank; Bosanac, Ivan; Bendahmane, Belguendouz; Mancao, Christoph; Tabernero, Josep
2018-06-01
The old approach of one therapeutic for all patients with mCRC is evolving with a need to target specific molecular aberrations or cell-signalling pathways. Molecular screening approaches and new biomarkers are required to fully characterize tumours, identify patients most likely to benefit, and predict treatment response. MODUL is a signal-seeking trial with a design that is highly adaptable, permitting modification of different treatment cohorts and inclusion of further additional cohorts based on novel evidence on new compounds/combinations that emerge during the study. MODUL is ongoing and its adaptable nature permits timely and efficient recruitment of patients into the most appropriate cohort. Recruitment will take place over approximately 5 years in Europe, Asia, Africa, and South America. The design of MODUL with ongoing parallel/sequential treatment cohorts means that the overall size and duration of the trial can be modified/prolonged based on accumulation of new data. The early success of the current trial suggests that the design may provide definitive leads in a patient-friendly and relatively economical trial structure. Along with other biomarker-driven trials that are currently underway, it is hoped that MODUL will contribute to the continuing evolution of clinical trial design and permit a more 'tailored' approach to the treatment of patients with mCRC.
NASA Astrophysics Data System (ADS)
Beck, F. A.
2018-05-01
This article overviews a long period of an important evolution in the nuclear structure research in Strasbourg Laboratories, focussed on tracking of the weaker and weaker experimental signals carrying the more and more important physics messages. In particular we address the research of signatures of the collective behaviour of the nucleus as suggested in the early works of Bohr, Mottelson and Rainwater—at high and very high angular momenta—as well as the competition between the collective and non-collective excitation modes. These ambitious goals were possible to achieve only by constructing powerful spectrometers and developing related detectors, electronics and data acquisition systems. The theoretical modelling developed in parallel, provided essential guidance when choosing the right experiments and optimising their realisation. Theory calculations were equally helpful in interpreting the results of experiments leading to a more complete understanding of the underlying physics. Moreover, thanks to the development of heavy ion accelerators, the Strasbourg centre was the place where crossed the ways of many experimenters from European countries both from the Western and from the Central part of Europe, the place of the gradual development of more and more sophisticated European gamma-spectrometers in collaboration with more and more laboratories from the increasing number of countries allowing for the frontier-level studies of the nuclear behaviour at very high angular momenta.
NASA Astrophysics Data System (ADS)
Santabarbara, Ignacio; Haas, Edwin; Kraus, David; Herrera, Saul; Klatt, Steffen; Kiese, Ralf
2014-05-01
When using biogeochemical models to estimate greenhouse gas emissions at site to regional/national levels, the assessment and quantification of the uncertainties of simulation results are of significant importance. The uncertainties in simulation results of process-based ecosystem models may result from uncertainties of the process parameters that describe the processes of the model, model structure inadequacy as well as uncertainties in the observations. Data for development and testing of uncertainty analisys were corp yield observations, measurements of soil fluxes of nitrous oxide (N2O) and carbon dioxide (CO2) from 8 arable sites across Europe. Using the process-based biogeochemical model LandscapeDNDC for simulating crop yields, N2O and CO2 emissions, our aim is to assess the simulation uncertainty by setting up a Bayesian framework based on Metropolis-Hastings algorithm. Using Gelman statistics convergence criteria and parallel computing techniques, enable multi Markov Chains to run independently in parallel and create a random walk to estimate the joint model parameter distribution. Through means distribution we limit the parameter space, get probabilities of parameter values and find the complex dependencies among them. With this parameter distribution that determines soil-atmosphere C and N exchange, we are able to obtain the parameter-induced uncertainty of simulation results and compare them with the measurements data.
Hagenblad, Jenny; Hülskötter, Jennifer; Acharya, Kamal Prasad; Brunet, Jörg; Chabrerie, Olivier; Cousins, Sara A O; Dar, Pervaiz A; Diekmann, Martin; De Frenne, Pieter; Hermy, Martin; Jamoneau, Aurélien; Kolb, Annette; Lemke, Isgard; Plue, Jan; Reshi, Zafar A; Graae, Bente Jessen
2015-08-20
Invasive species can be a major threat to native biodiversity and the number of invasive plant species is increasing across the globe. Population genetic studies of invasive species can provide key insights into their invasion history and ensuing evolution, but also for their control. Here we genetically characterise populations of Impatiens glandulifera, an invasive plant in Europe that can have a major impact on native plant communities. We compared populations from the species' native range in Kashmir, India, to those in its invaded range, along a latitudinal gradient in Europe. For comparison, the results from 39 other studies of genetic diversity in invasive species were collated. Our results suggest that I. glandulifera was established in the wild in Europe at least twice, from an area outside of our Kashmir study area. Our results further revealed that the genetic diversity in invasive populations of I. glandulifera is unusually low compared to native populations, in particular when compared to other invasive species. Genetic drift rather than mutation seems to have played a role in differentiating populations in Europe. We find evidence of limitations to local gene flow after introduction to Europe, but somewhat less restrictions in the native range. I. glandulifera populations with significant inbreeding were only found in the species' native range and invasive species in general showed no increase in inbreeding upon leaving their native ranges. In Europe we detect cases of migration between distantly located populations. Human activities therefore seem to, at least partially, have facilitated not only introductions, but also further spread of I. glandulifera across Europe. Although multiple introductions will facilitate the retention of genetic diversity in invasive ranges, widespread invasive species can remain genetically relatively invariant also after multiple introductions. Phenotypic plasticity may therefore be an important component of the successful spread of Impatiens glandulifera across Europe.
Ruosch, Melanie; Spahni, Renato; Joos, Fortunat; Henne, Paul D; van der Knaap, Willem O; Tinner, Willy
2016-02-01
Information on how species distributions and ecosystem services are impacted by anthropogenic climate change is important for adaptation planning. Palaeo data suggest that Abies alba formed forests under significantly warmer-than-present conditions in Europe and might be a native substitute for widespread drought-sensitive temperate and boreal tree species such as beech (Fagus sylvatica) and spruce (Picea abies) under future global warming conditions. Here, we combine pollen and macrofossil data, modern observations, and results from transient simulations with the LPX-Bern dynamic global vegetation model to assess past and future distributions of A. alba in Europe. LPX-Bern is forced with climate anomalies from a run over the past 21 000 years with the Community Earth System Model, modern climatology, and with 21st-century multimodel ensemble results for the high-emission RCP8.5 and the stringent mitigation RCP2.6 pathway. The simulated distribution for present climate encompasses the modern range of A. alba, with the model exceeding the present distribution in north-western and southern Europe. Mid-Holocene pollen data and model results agree for southern Europe, suggesting that at present, human impacts suppress the distribution in southern Europe. Pollen and model results both show range expansion starting during the Bølling-Allerød warm period, interrupted by the Younger Dryas cold, and resuming during the Holocene. The distribution of A. alba expands to the north-east in all future scenarios, whereas the potential (currently unrealized) range would be substantially reduced in southern Europe under RCP8.5. A. alba maintains its current range in central Europe despite competition by other thermophilous tree species. Our combined palaeoecological and model evidence suggest that A. alba may ensure important ecosystem services including stand and slope stability, infrastructure protection, and carbon sequestration under significantly warmer-than-present conditions in central Europe. © 2015 John Wiley & Sons Ltd.
Evolution of the Arctic-North Atlantic and the Western Tethys
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ziegler, P.A.
1988-01-01
This volume provides an overview of the late Paleozoic to recent geological evolution of the continents and shelves bordering the North Atlantic Ocean, the Norwegian-Greenland Sea, the Arctic Ocean, and the Mediterranean Sea. The evolution of these seas has been the subject of many studies and compilations, which discuss the evolution of oceanic basins on the basis of their magnetic sea-floor anomalies. The volume presented combines this information with geological data from the adjacent shelf and onshore areas. It retraces the evolution of sedimentary basins developed during the rifting phases that preceded the opening of these oceans and highlights themore » scope of the associated intra-plate phenomena. The author presents a reconstruction of the late Paleozoic and early Mesozoic development of Europe, northernmost Africa and northeastern North America-Greenland and discusses the different orogenic cycles that accompanied the stepwise assembly of Pangea and the early rifting phases heralding its break-up.« less
Demotes-Mainard, Jacques
2010-12-01
Clinical research plays a key role both in the development of innovative health products and in the optimisation of medical strategies, leading to evidence-based practice and healthcare cost containment. ECRIN is a distributed ESFRI-roadmap pan-European infrastructure designed to support multinational clinical research, making Europe a single area for clinical studies, taking advantage of its population size to access patients, and unlocking latent scientific providing services to multinational. Servicing of multinational trials started during the preparatory phase, and ECRIN has applied for ERIC status in 2011. In parallel, ECRIN has also proposed an FP7 integrating activity project to further develop, upgrade and expand the ECRIN infrastructure built up during the past FP6 and FP7 projects, facilitating an efficient organization of clinical research in Europe, with ECRIN developing generic tools and providing generic services for multinational studies, and supporting the construction of pan-European disease-oriented networks that will in turn act as ECRIN users. This organization will improve Europe's attractiveness for industry trials, boost its scientific competitiveness, and result in better healthcare for European citizens. The three medical areas supported in this project (rare diseases, medical devices, and nutrition) will serve as pilots for other biomedical research fields. By creating a single area for clinical research in Europe, this structure will contribute to the implementation of the Europe flagship initiative 2020 'Innovation Union', whose objectives include defragmentation of research and educational capacities, tackling the major societal challenges (starting with healthy aging), and removing barriers to bringing ideas to the market.
Climate Impacts in Europe Under +1.5°C Global Warming
NASA Astrophysics Data System (ADS)
Jacob, Daniela; Kotova, Lola; Teichmann, Claas; Sobolowski, Stefan P.; Vautard, Robert; Donnelly, Chantal; Koutroulis, Aristeidis G.; Grillakis, Manolis G.; Tsanis, Ioannis K.; Damm, Andrea; Sakalli, Abdulla; van Vliet, Michelle T. H.
2018-02-01
The Paris Agreement of the United Nations Framework Convention on Climate Change aims not only at avoiding +2°C warming (and even limit the temperature increase further to +1.5°C), but also sets long-term goals to guide mitigation. Therefore, the best available science is required to inform policymakers on the importance of and the adaptation needs in a +1.5°C warmer world. Seven research institutes from Europe and Turkey integrated their competencies to provide a cross-sectoral assessment of the potential impacts at a pan-European scale. The initial findings of this initiative are presented and key messages communicated. The approach is to select periods based on global warming thresholds rather than the more typical approach of selecting time periods (e.g., end of century). The results indicate that the world is likely to pass the +1.5°C threshold in the coming decades. Cross-sectoral dimensions are taken into account to show the impacts of global warming that occur in parallel in more than one sector. Also, impacts differ across sectors and regions. Alongside the negative impacts for certain sectors and regions, some positive impacts are projected. Summer tourism in parts of Western Europe may be favored by climate change; electricity demand decreases outweigh increases over most of Europe and catchment yields in hydropower regions will increase. However, such positive findings should be interpreted carefully as we do not take into account exogenous factors that can and will influence Europe such as migration patterns, food production, and economic and political instability.
Host Genetic Variation Does Not Determine Spatio-Temporal Patterns of European Bat 1 Lyssavirus
Picard-Meyer, Evelyne; Dellicour, Simon; Casademont, Isabelle; Kergoat, Lauriane; Lepelletier, Anthony; Dacheux, Laurent; Baele, Guy; Monchâtre-Leroy, Elodie; Cliquet, Florence; Lemey, Philippe
2017-01-01
Abstract The majority of bat rabies cases in Europe are attributed to European bat 1 lyssavirus (EBLV-1), circulating mainly in serotine bats (Eptesicus serotinus). Two subtypes have been defined (EBLV-1a and EBLV-1b), each associated with a different geographical distribution. In this study, we undertake a comprehensive sequence analysis based on 80 newly obtained EBLV-1 nearly complete genome sequences from nine European countries over a 45-year period to infer selection pressures, rates of nucleotide substitution, and evolutionary time scale of these two subtypes in Europe. Our results suggest that the current lineage of EBLV-1 arose in Europe ∼600 years ago and the virus has evolved at an estimated average substitution rate of ∼4.19×10−5 subs/site/year, which is among the lowest recorded for RNA viruses. In parallel, we investigate the genetic structure of French serotine bats at both the nuclear and mitochondrial level and find that they constitute a single genetic cluster. Furthermore, Mantel tests based on interindividual distances reveal the absence of correlation between genetic distances estimated between viruses and between host individuals. Taken together, this indicates that the genetic diversity observed in our E. serotinus samples does not account for EBLV-1a and -1b segregation and dispersal in Europe. PMID:29165566
Ostrowski, Marie-France; Prosperi, Jean-Marie; David, Jacques
2016-01-01
Gene flow from crop to wild relatives is a common phenomenon which can lead to reduced adaptation of the wild relatives to natural ecosystems and/or increased adaptation to agrosystems (weediness). With global warming, wild relative distributions will likely change, thus modifying the width and/or location of co-occurrence zones where crop-wild hybridization events could occur (sympatry). This study investigates current and 2050 projected changes in sympatry levels between cultivated wheat and six of the most common Aegilops species in Europe. Projections were generated using MaxEnt on presence-only data, bioclimatic variables, and considering two migration hypotheses and two 2050 climate scenarios (RCP4.5 and RCP8.5). Overall, a general decline in suitable climatic conditions for Aegilops species outside the European zone and a parallel increase in Europe were predicted. If no migration could occur, the decline was predicted to be more acute outside than within the European zone. The potential sympatry level in Europe by 2050 was predicted to increase at a higher rate than species richness, and most expansions were predicted to occur in three countries, which are currently among the top four wheat producers in Europe: Russia, France and Ukraine. The results are also discussed with regard to conservation issues of these crop wild relatives.
Bertagnoli, S; Marchandeau, S
2015-08-01
Myxomatosis, a major disease of European rabbits (Oryctolagus cuniculus), is enzootic on several continents. The disease is infectious, virulent and contagious. The pathogen is a virus of the family Poxviridae, genus Leporipoxvirus. In its classic form the disease is often fatal, characterised by severe immunosuppression and the appearance of skin pseudotumours (myxomas); it is conducive to effective mechanical transmission by many biting arthropods. Atypical clinical forms, referred to as amyxomatous, of variable severity and with an apparent preference for direct transmission, have recently emerged in Europe. Virus-host interactions have been particularly well studied since the voluntary introduction of the myxoma virus into Australia and Europe, revealing a remarkable process of co-evolution. Molecular analysis has recently demonstrated the extraordinary evolutionary capacity of the myxoma virus.
ERIC Educational Resources Information Center
Lederman, Linda Costigan; Rogers, Don
The two papers in this document focus on general systems theory. In her paper, Linda Lederman discusses the emergence and evolution of general systems theory, defines its central concepts, and draws some conclusions regarding the nature of the theory and its value as an epistemology. Don Rogers, in his paper, relates some of the important features…
Gravitational field calculations on a dynamic lattice by distributed computing.
NASA Astrophysics Data System (ADS)
Mähönen, P.; Punkka, V.
A new method of calculating numerically time evolution of a gravitational field in general relativity is introduced. Vierbein (tetrad) formalism, dynamic lattice and massively parallelized computation are suggested as they are expected to speed up the calculations considerably and facilitate the solution of problems previously considered too hard to be solved, such as the time evolution of a system consisting of two or more black holes or the structure of worm holes.
Gravitation Field Calculations on a Dynamic Lattice by Distributed Computing
NASA Astrophysics Data System (ADS)
Mähönen, Petri; Punkka, Veikko
A new method of calculating numerically time evolution of a gravitational field in General Relatity is introduced. Vierbein (tetrad) formalism, dynamic lattice and massively parallelized computation are suggested as they are expected to speed up the calculations considerably and facilitate the solution of problems previously considered too hard to be solved, such as the time evolution of a system consisting of two or more black holes or the structure of worm holes.
On the consequences of bi-Maxwellian plasma distributions for parallel electric fields
NASA Technical Reports Server (NTRS)
Olsen, Richard C.
1992-01-01
The objective is to use the measurements of the equatorial particle distributions to obtain the parallel electric field structure and the evolution of the plasma distribution function along the field line. Appropriate uses of kinetic theory allows us to use the measured ( and inferred) particle distributions to obtain the electric field, and hence the variation on plasma density along the magnetic field line. The approach, here, is to utilize the adiabatic invariants, and assume the plasma distributions are in equilibrium.
Parallel ridge pattern on dermoscopy: observation in non-melanoma cases*
Fracaroli, Tainá Scalfoni; Lavorato, Fernanda Guedes; Maceira, Juan Piñeiro; Barcaui, Carlos
2013-01-01
The acral melanoma is the most prevalent type of melanoma in the non-Caucasian population, and dermoscopy is a useful tool for earlier diagnosis and differentiation from benign lesions. The dermoscopic pattern often associated with melanoma on the volar skin is the parallel ridge, with 99% specificity according to the literature. However, this pattern can also occur in several benign acral lesions, so it is important to make a good interpretation of this pattern, along with the clinical history and evolution. PMID:24068145
a Predator-Prey Model Based on the Fully Parallel Cellular Automata
NASA Astrophysics Data System (ADS)
He, Mingfeng; Ruan, Hongbo; Yu, Changliang
We presented a predator-prey lattice model containing moveable wolves and sheep, which are characterized by Penna double bit strings. Sexual reproduction and child-care strategies are considered. To implement this model in an efficient way, we build a fully parallel Cellular Automata based on a new definition of the neighborhood. We show the roles played by the initial densities of the populations, the mutation rate and the linear size of the lattice in the evolution of this model.
Multicore: Fallout From a Computing Evolution (LBNL Summer Lecture Series)
Yelick, Kathy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
2018-05-07
Summer Lecture Series 2008: Parallel computing used to be reserved for big science and engineering projects, but in two years that's all changed. Even laptops and hand-helds use parallel processors. Unfortunately, the software hasn't kept pace. Kathy Yelick, Director of the National Energy Research Scientific Computing Center at Berkeley Lab, describes the resulting chaos and the computing community's efforts to develop exciting applications that take advantage of tens or hundreds of processors on a single chip.
Payen, Celia; Di Rienzi, Sara C; Ong, Giang T; Pogachar, Jamie L; Sanchez, Joseph C; Sunshine, Anna B; Raghuraman, M K; Brewer, Bonita J; Dunham, Maitreya J
2014-03-20
Population adaptation to strong selection can occur through the sequential or parallel accumulation of competing beneficial mutations. The dynamics, diversity, and rate of fixation of beneficial mutations within and between populations are still poorly understood. To study how the mutational landscape varies across populations during adaptation, we performed experimental evolution on seven parallel populations of Saccharomyces cerevisiae continuously cultured in limiting sulfate medium. By combining quantitative polymerase chain reaction, array comparative genomic hybridization, restriction digestion and contour-clamped homogeneous electric field gel electrophoresis, and whole-genome sequencing, we followed the trajectory of evolution to determine the identity and fate of beneficial mutations. During a period of 200 generations, the yeast populations displayed parallel evolutionary dynamics that were driven by the coexistence of independent beneficial mutations. Selective amplifications rapidly evolved under this selection pressure, in particular common inverted amplifications containing the sulfate transporter gene SUL1. Compared with single clones, detailed analysis of the populations uncovers a greater complexity whereby multiple subpopulations arise and compete despite a strong selection. The most common evolutionary adaptation to strong selection in these populations grown in sulfate limitation is determined by clonal interference, with adaptive variants both persisting and replacing one another.
Payen, Celia; Di Rienzi, Sara C.; Ong, Giang T.; Pogachar, Jamie L.; Sanchez, Joseph C.; Sunshine, Anna B.; Raghuraman, M. K.; Brewer, Bonita J.; Dunham, Maitreya J.
2014-01-01
Population adaptation to strong selection can occur through the sequential or parallel accumulation of competing beneficial mutations. The dynamics, diversity, and rate of fixation of beneficial mutations within and between populations are still poorly understood. To study how the mutational landscape varies across populations during adaptation, we performed experimental evolution on seven parallel populations of Saccharomyces cerevisiae continuously cultured in limiting sulfate medium. By combining quantitative polymerase chain reaction, array comparative genomic hybridization, restriction digestion and contour-clamped homogeneous electric field gel electrophoresis, and whole-genome sequencing, we followed the trajectory of evolution to determine the identity and fate of beneficial mutations. During a period of 200 generations, the yeast populations displayed parallel evolutionary dynamics that were driven by the coexistence of independent beneficial mutations. Selective amplifications rapidly evolved under this selection pressure, in particular common inverted amplifications containing the sulfate transporter gene SUL1. Compared with single clones, detailed analysis of the populations uncovers a greater complexity whereby multiple subpopulations arise and compete despite a strong selection. The most common evolutionary adaptation to strong selection in these populations grown in sulfate limitation is determined by clonal interference, with adaptive variants both persisting and replacing one another. PMID:24368781
Discrete event performance prediction of speculatively parallel temperature-accelerated dynamics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zamora, Richard James; Voter, Arthur F.; Perez, Danny
Due to its unrivaled ability to predict the dynamical evolution of interacting atoms, molecular dynamics (MD) is a widely used computational method in theoretical chemistry, physics, biology, and engineering. Despite its success, MD is only capable of modeling time scales within several orders of magnitude of thermal vibrations, leaving out many important phenomena that occur at slower rates. The Temperature Accelerated Dynamics (TAD) method overcomes this limitation by thermally accelerating the state-to-state evolution captured by MD. Due to the algorithmically complex nature of the serial TAD procedure, implementations have yet to improve performance by parallelizing the concurrent exploration of multiplemore » states. Here we utilize a discrete event-based application simulator to introduce and explore a new Speculatively Parallel TAD (SpecTAD) method. We investigate the SpecTAD algorithm, without a full-scale implementation, by constructing an application simulator proxy (SpecTADSim). Finally, following this method, we discover that a nontrivial relationship exists between the optimal SpecTAD parameter set and the number of CPU cores available at run-time. Furthermore, we find that a majority of the available SpecTAD boost can be achieved within an existing TAD application using relatively simple algorithm modifications.« less
Discrete event performance prediction of speculatively parallel temperature-accelerated dynamics
Zamora, Richard James; Voter, Arthur F.; Perez, Danny; ...
2016-12-01
Due to its unrivaled ability to predict the dynamical evolution of interacting atoms, molecular dynamics (MD) is a widely used computational method in theoretical chemistry, physics, biology, and engineering. Despite its success, MD is only capable of modeling time scales within several orders of magnitude of thermal vibrations, leaving out many important phenomena that occur at slower rates. The Temperature Accelerated Dynamics (TAD) method overcomes this limitation by thermally accelerating the state-to-state evolution captured by MD. Due to the algorithmically complex nature of the serial TAD procedure, implementations have yet to improve performance by parallelizing the concurrent exploration of multiplemore » states. Here we utilize a discrete event-based application simulator to introduce and explore a new Speculatively Parallel TAD (SpecTAD) method. We investigate the SpecTAD algorithm, without a full-scale implementation, by constructing an application simulator proxy (SpecTADSim). Finally, following this method, we discover that a nontrivial relationship exists between the optimal SpecTAD parameter set and the number of CPU cores available at run-time. Furthermore, we find that a majority of the available SpecTAD boost can be achieved within an existing TAD application using relatively simple algorithm modifications.« less
NASA Astrophysics Data System (ADS)
Blasevski, D.; Del-Castillo-Negrete, D.
2012-10-01
Heat transport in magnetized plasmas is a problem of fundamental interest in controlled fusion. In Ref.footnotetext D. del-Castillo-Negrete, and L. Chac'on, Phys. Rev. Lett., 106, 195004 (2011); Phys. Plasmas 19, 056112 (2012). we proposed a Lagrangian-Green's function (LG) method to study this problem in the strongly anisotropic (χ=0) regime. The LG method bypasses the need to discretize the transport operators on a grid and it is applicable to general parallel flux closures and 3-D magnetic fields. Here we apply the LG method to parallel transport (with local and nonlocal parallel flux closures) in reversed shear magnetic field configurations known to exhibit robust transport barriers in the vicinity of the extrema of the q-profile. By shearless Cantori (SC) we mean the invariant Cantor sets remaining after the destruction of toroidal flux surfaces with zero magnetic shear, q^'=0. We provide numerical evidence of the role of SC in the anomalously slow relaxation of radial temperature gradients in chaotic magnetic fields with no transport barriers. The spatio-temporal evolution of temperature pulses localized in the reversed shear region exhibits non-diffusive self-similar evolution and nonlocal effective radial transport.
Construction and comparison of parallel implicit kinetic solvers in three spatial dimensions
NASA Astrophysics Data System (ADS)
Titarev, Vladimir; Dumbser, Michael; Utyuzhnikov, Sergey
2014-01-01
The paper is devoted to the further development and systematic performance evaluation of a recent deterministic framework Nesvetay-3D for modelling three-dimensional rarefied gas flows. Firstly, a review of the existing discretization and parallelization strategies for solving numerically the Boltzmann kinetic equation with various model collision integrals is carried out. Secondly, a new parallelization strategy for the implicit time evolution method is implemented which improves scaling on large CPU clusters. Accuracy and scalability of the methods are demonstrated on a pressure-driven rarefied gas flow through a finite-length circular pipe as well as an external supersonic flow over a three-dimensional re-entry geometry of complicated aerodynamic shape.
USDA-ARS?s Scientific Manuscript database
The Russian Territory covering a large part of Northern Eurasia is of special interest for influenza virus ecology and evolution, for it is situated in the center of Eurasia and covers three major migration routes, combining bird populations from Asia, Africa, and Europe. During surveillance for av...
The EU "Memorandum on Lifelong Learning". Old Wine in New Bottles?
ERIC Educational Resources Information Center
Borg, Carmel; Mayo, Peter
2005-01-01
This paper provides a critical analysis of the EU's "Memorandum on lifelong learning" in light of the evolution of the concepts of lifelong education and lifelong learning from the late sixties onward. It also analyses this document in light of the forces of globalisation that impinge on educational policy-making in Europe as well as the…
USDA-ARS?s Scientific Manuscript database
Background: The remarkable diversity and mobility of Newcastle disease viruses (NDV) includes virulent viruses of genotype VI. These viruses are often referred to as pigeon paramyxoviruses 1 because they are normally isolated and cause clinical disease in birds from the Columbidae family. Genotype V...
Evolution and biogeography of Pinus radiata, with a proposed revision of its quaternary history
Constance I. Millar
1999-01-01
The genus Pinus evolved about 100 million years ago, spreading from centres in eastern North America and western Europe throughout middle latitudes of the supercontinent Laurasia. Many early subsections of Pinus are recorded from fossil remains ofthis period, but it is not until the early Tertiary, when the genus was fragmented by...
The Future of Learning: From eLearning to mLearning.
ERIC Educational Resources Information Center
Keegan, Desmond
The future of electronic learning was explored in an analysis that viewed the provision of learning at a distance as a continuum and traced the evolution from distance learning to electronic learning to mobile learning in Europe and elsewhere. Special attention was paid to the following topics: (1) the impact of the industrial revolution, the…
ERIC Educational Resources Information Center
Case, Jennifer M.
2017-01-01
Recent times have seen significant realignment of engineering degrees globally, most notably in the Washington Accord, a system of mutual recognition of accreditation across much of the Anglophone world and beyond, and the Bologna Process, impacting significantly on the form of engineering degrees in Europe. This article, tracing the historical…
ERIC Educational Resources Information Center
Verger, Antoni; Hermo, Javier Pablo
2010-01-01
The article analyses two processes of higher education regionalisation, MERCOSUR-Educativo in Latin America and the Bologna Process in Europe, from a comparative perspective. The comparative analysis is centered on the content and the governance of both processes and, specifically, on the reasons of their uneven evolution and implementation. We…
A. Vercauteren; M. Larsen; E. Goss; N. Grunwald; M. Maes; K. Heungens
2011-01-01
Phytophthora ramorum is a recently introduced pathogen in Europe and North America consisting of three clonal lineages. Due to the limited intralineage genetic variation, only a few polymorphic markers are available for use in studies involving the epidemiology and evolution of P. ramorum. A total of 159 primer pairs for...
Population genetic analysis reveals ancient evolution and recent migration of P. ramorum
Erica M. Goss; Meg Larsen; Ignazio Carbone; Donald R. Givens; Gary A. Chastagner; Niklaus J. Gr& uuml; nwald
2010-01-01
Phytophthora ramorum populations in North America and Europe are comprised of three clonal lineages based on several different genetic marker systems (Ivors and others 2006, Martin 2008). Whether these lineages are ancient or a recent artifact of introduction has been unclear. We analyzed DNA sequence variation at five nuclear loci in order to...
ERIC Educational Resources Information Center
Schmitt, Catherine A.
2012-01-01
This dissertation examines the history of workforce education, corporate university development models in both literature and practice, and the evolution of the next generation of corporate universities. It traces workforce education from indentured servants in Europe during the Middle Ages, to the sophisticated corporate universities that…
Cunze, Sarah; Koch, Lisa K; Kochmann, Judith; Klimpel, Sven
2016-11-04
Aedes albopictus and Ae. japonicus are two of the most widespread invasive mosquito species that have recently become established in western Europe. Both species are associated with the transmission of a number of serious diseases and are projected to continue their spread in Europe. In the present study, we modelled the habitat suitability for both species under current and future climatic conditions by means of an Ensemble forecasting approach. We additionally compared the modelled MAXENT niches of Ae. albopictus and Ae. japonicus regarding temperature and precipitation requirements. Both species were modelled to find suitable habitat conditions in distinct areas within Europe: Ae. albopictus within the Mediterranean regions in southern Europe, Ae. japonicus within the more temperate regions of central Europe. Only in few regions, suitable habitat conditions were projected to overlap for both species. Whereas Ae. albopictus is projected to be generally promoted by climate change in Europe, the area modelled to be climatically suitable for Ae. japonicus is projected to decrease under climate change. This projection of range reduction under climate change relies on the assumption that Ae. japonicus is not able to adapt to warmer climatic conditions. The modelled MAXENT temperature niches of Ae. japonicus were found to be narrower with an optimum at lower temperatures compared to the niches of Ae. albopictus. Species distribution models identifying areas with high habitat suitability can help improving monitoring programmes for invasive species currently in place. However, as mosquito species are known to be able to adapt to new environmental conditions within the invasion range quickly, niche evolution of invasive mosquito species should be closely followed upon in future studies.
Minicozzi, Pamela; Cassetti, Tiziana; Vener, Claudia; Sant, Milena
2018-05-16
Pancreatic (PC) and biliary tract (BTC) cancers have higher incidence and mortality in Europe than elsewhere. We analysed time-trends in PC/BTC incidence, mortality, and survival across Europe. Since the European standard population (ESP) was recently revised to better represent European age structure, we also assessed the effect of adopting the revised ESP to age-standardise incidence and mortality data. We analysed PCs/BTCs (≥15 years) diagnosed in 2000-2007 and followed-up to end of 2008, in 29 European countries across five regions: UK/Ireland, and northern, central, southern, and eastern Europe. Incidence, mortality, and 5-year relative survival were compared between regions, by age, sex, and period of diagnosis. Variation in age-standardised incidence (PC 12-15/100,000; BTC 2-6) and mortality (PC 10-14; BTC 1-5) was modest. Eastern Europe had highest incidence and mortality, and lowest survival; northern and southern Europe had highest age-specific incidence (most age groups) for PC and BTC, respectively. Incidence and survival increased slightly from 2000 to 2007, particularly in elderly patients and women, but survival remained poor (≤8% for PC; 13-18% for BTC). Use of the revised ESP for age-standardisation did not impact European regional incidence and mortality rankings. Poor survival for PC and BTC, together with increasing incidence, indicate that action is required. Countries with higher incidence had higher risk factor frequency, suggesting that prevention initiatives targeting risk factors should be promoted. Improvements in diagnosis and treatment are also required. Our results provide a baseline from which to monitor evolution of the PC/BTC burden in Europe. Copyright © 2018 Elsevier Ltd. All rights reserved.
Direct write electron beam lithography: a historical overview
NASA Astrophysics Data System (ADS)
Pfeiffer, Hans C.
2010-09-01
Maskless pattern generation capability in combination with practically limitless resolution made probe-forming electron beam systems attractive tools in the semiconductor fabrication process. However, serial exposure of pattern elements with a scanning beam is a slow process and throughput presented a key challenge in electron beam lithography from the beginning. To meet this challenge imaging concepts with increasing exposure efficiency have been developed projecting ever larger number of pixels in parallel. This evolution started in the 1960s with the SEM-type Gaussian beam systems writing one pixel at a time directly on wafers. During the 1970s IBM pioneered the concept of shaped beams containing multiple pixels which led to higher throughput and an early success of e-beam direct write (EBDW) in large scale manufacturing of semiconductor chips. EBDW in a mix-and match approach with optical lithography provided unique flexibility in part number management and cycle time reduction and proved extremely cost effective in IBM's Quick-Turn-Around-Time (QTAT) facilities. But shaped beams did not keep pace with Moore's law because of limitations imposed by the physics of charged particles: Coulomb interactions between beam electrons cause image blur and consequently limit beam current and throughput. A new technology approach was needed. Physically separating beam electrons into multiple beamlets to reduce Coulomb interaction led to the development of massively parallel projection of pixels. Electron projection lithography (EPL) - a mask based imaging technique emulating optical steppers - was pursued during the 1990s by Bell Labs with SCALPEL and by IBM with PREVAIL in partnership with Nikon. In 2003 Nikon shipped the first NCR-EB1A e-beam stepper based on the PREVAIL technology to Selete. It exposed pattern segments containing 10 million pixels in single shot and represented the first successful demonstration of massively parallel pixel projection. However the window of opportunity for EPL had closed with the quick implementation of immersion lithography and the interest of the industry has since shifted back to maskless lithography (ML2). This historical overview of EBDW will highlight opportunities and limitation of the technology with particular focus on technical challenges facing the current ML2 development efforts in Europe and the US. A brief status report and risk assessment of the ML2 approaches will be provided.
Radiation-MHD Simulations of Pillars and Globules in HII Regions
NASA Astrophysics Data System (ADS)
Mackey, J.
2012-07-01
Implicit and explicit raytracing-photoionisation algorithms have been implemented in the author's radiation-magnetohydrodynamics code. The algorithms are described briefly and their efficiency and parallel scaling are investigated. The implicit algorithm is more efficient for calculations where ionisation fronts have very supersonic velocities, and the explicit algorithm is favoured in the opposite limit because of its better parallel scaling. The implicit method is used to investigate the effects of initially uniform magnetic fields on the formation and evolution of dense pillars and cometary globules at the boundaries of HII regions. It is shown that for weak and medium field strengths an initially perpendicular field is swept into alignment with the pillar during its dynamical evolution, matching magnetic field observations of the ‘Pillars of Creation’ in M16. A strong perpendicular magnetic field remains in its initial configuration and also confines the photoevaporation flow into a bar-shaped, dense, ionised ribbon which partially shields the ionisation front.
The evolution of dual meat and milk cattle husbandry in Linearbandkeramik societies
Kovačiková, Lenka; Bréhard, Stéphanie; Guthmann, Emilie; Vostrovská, Ivana; Nohálová, Hana; Arbogast, Rose-Marie; Domboróczki, László; Pechtl, Joachim; Anders, Alexander; Marciniak, Arkadiusz; Tresset, Anne; Vigne, Jean-Denis
2017-01-01
Cattle dominate archaeozoological assemblages from the north-central Europe between the sixth and fifth millennium BC and are frequently considered as exclusively used for their meat. Dairy products may have played a greater role than previously believed. Selective pressure on the lactase persistence mutation has been modelled to have begun between 6000 and 4000 years ago in central Europe. The discovery of milk lipids in late sixth millennium ceramic sieves in Poland may reflect an isolated regional peculiarity for cheese making or may signify more generalized milk exploitation in north-central Europe during the Early Neolithic. To investigate these issues, we analysed the mortality profiles based on age-at-death analysis of cattle tooth eruption, wear and replacement from 19 archaeological sites of the Linearbandkeramik (LBK) culture (sixth to fifth millennium BC). The results indicate that cattle husbandry was similar across time and space in the LBK culture with a degree of specialization for meat exploitation in some areas. Statistical comparison with reference age-at-death profiles indicate that mixed husbandry (milk and meat) was practised, with mature animals being kept. The analysis provides a unique insight into LBK cattle husbandry and how it evolved in later cultures in central and western Europe. It also opens a new perspective on how and why the Neolithic way of life developed through continental Europe and how dairy products became a part of the human diet. PMID:28768891
Improving allergy management in the primary care network--a holistic approach.
Jutel, M; Angier, L; Palkonen, S; Ryan, D; Sheikh, A; Smith, H; Valovirta, E; Yusuf, O; van Wijk, R G; Agache, I
2013-11-01
The incidence, prevalence and costs of allergy have increased substantially in recent decades in many parts of Europe. The dominant model of allergy care within Europe is at the moment specialist-based. This model will become unsustainable and undeliverable with increasing disease prevalence. One solution to increase provision of allergy services is to diversify the providers. A new model for the provision of allergy care in the community with the general practitioner at the forefront is proposed. Pre- and postgraduate allergy education and training, implementation of pathways of care, allergy specialization and political will to generate resources and support are essential to achieve this new model. In parallel the holistic view of allergic diseases should be maintained, including assessment of severity and risk, psychological factors and health-care related costs in the context of the patient-centered decision making process. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
IHE Europe: extending the IHE initiative to the European healthcare market
NASA Astrophysics Data System (ADS)
Eichelberg, Marco; Poiseau, Eric; Wein, Berthold B.; Riesmeier, Joerg
2003-05-01
The IHE (Integrating the Healthcare Enterprise) initiative has recently developed into a multi-national effort that addresses the specific needs of healthcare systems in North America, many European countries as well as Japan. The introduction of IHE in Europe is a particular challenge because the structure of the healthcare sector deviates significantly from country to country, with different legislation, language, medical and organizational procedures and, not the least, different vendors: HIS/RIS systems are typically tailored towards a specific market, and the majority of vendors is only present in one or a few countries. The first multi-national "European Connect-a-thon" was performed in April, 2002 with 57 participating systems from 33 companies, in preparation of four different public demonstrations in three countries. The systems were grouped into a French, German and Italian section (according to the national extensions supported by each system), with certain overlaps, i. e. systems participating in multiple sections in parallel. In conclusion, experiences in Europe show that IHE cannot simply be copied, but has to be adapted to the specificities of national healthcare systems. The good news is, however, that the specifics are only of minor nature compared to the overall complexity of the transactions involved.
Molecular epidemiology of HIV-1 infection in Europe: An overview.
Beloukas, Apostolos; Psarris, Alexandros; Giannelou, Polina; Kostaki, Evangelia; Hatzakis, Angelos; Paraskevis, Dimitrios
2016-12-01
Human Immunodeficiency Virus type 1 (HIV-1) is characterised by vast genetic diversity. Globally circulating HIV-1 viruses are classified into distinct phylogenetic strains (subtypes, sub-subtypes) and several recombinant forms. Here we describe the characteristics and evolution of European HIV-1 epidemic over time through a review of published literature and updated queries of existing HIV-1 sequence databases. HIV-1 in Western and Central Europe was introduced in the early-1980s in the form of subtype B, which is still the predominant clade. However, in Eastern Europe (Former Soviet Union (FSU) countries and Russia) the predominant strain, introduced into Ukraine in the mid-1990s, is subtype A (A FSU ) with transmission mostly occurring in People Who Inject Drugs (PWID). In recent years, the epidemic is evolving towards a complex tapestry with an increase in the prevalence of non-B subtypes and recombinants in Western and Central Europe. Non-B epidemics are mainly associated with immigrants, heterosexuals and females but more recently, non-B clades have also spread amongst groups where non-B strains were previously absent - non-immigrant European populations and amongst men having sex with men (MSM). In some countries, non-B clades have spread amongst the native population, for example subtype G in Portugal and subtype A in Greece, Albania and Cyprus. Romania provides a unique case where sub-subtype F1 has predominated throughout the epidemic. In contrast, HIV-1 epidemic in FSU countries remains more homogeneous with A FSU clade predominating in all countries. The differences between the evolution of the Western epidemic and the Eastern epidemic may be attributable to differences in transmission risk behaviours, lifestyle and the patterns of human mobility. The study of HIV-1 epidemic diversity provides a useful tool by which we can understand the history of the pandemic in addition to allowing us to monitor the spread and growth of the epidemic over time. Copyright © 2016 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Le Goff, Maxime; Gallet, Yves
2017-02-01
We present a new compilation and analysis of historical geomagnetic measurements made in Western Europe before AD 1750. The dataset in its ensemble provides a coherent evolution of magnetic field directions. Several data points excluded from previous analyses actually appear very consistent with most of the present compilation. A new average historical curve is computed for Paris, which is in very good agreement with the archeomagnetic data obtained in France, while significantly differing from the directional curve expected for Paris before AD 1675 based on the gufm1 model (Jackson et al. in Philos Trans R Soc Lond A 358:957-990, 2000). This finding suggests that the older segment of the gufm1 model lacks reliability and should be improved. Similarly, the historical part of the regional geomagnetic field model built for Europe by Pavón-Carrasco et al. (Geochem Geophys Geosyst 10:Q03013, 2009) should be revised because it erroneously incorporates directions derived from the gufm1 model.
Workshop âPhysics for Health in Europeâ
Battistoni, G.
2018-05-25
2nd part of the session. 2-4 February 2010 at CERN This event will be will be available live via the Webcast Service and transmitted in parallel to:IT auditorium, Salle Anderssen 40-S2-A01 (Tuesday 2nd February) BE auditorium (all day), Salle 40-S2-01 (only between 08:00- 14:00) (Wednesday 3rd February) BE auditorium, Salle Curie 40-S2-C01 (Thursday 4th February)  Â
Hierarchical fractional-step approximations and parallel kinetic Monte Carlo algorithms
DOE Office of Scientific and Technical Information (OSTI.GOV)
Arampatzis, Giorgos, E-mail: garab@math.uoc.gr; Katsoulakis, Markos A., E-mail: markos@math.umass.edu; Plechac, Petr, E-mail: plechac@math.udel.edu
2012-10-01
We present a mathematical framework for constructing and analyzing parallel algorithms for lattice kinetic Monte Carlo (KMC) simulations. The resulting algorithms have the capacity to simulate a wide range of spatio-temporal scales in spatially distributed, non-equilibrium physiochemical processes with complex chemistry and transport micro-mechanisms. Rather than focusing on constructing exactly the stochastic trajectories, our approach relies on approximating the evolution of observables, such as density, coverage, correlations and so on. More specifically, we develop a spatial domain decomposition of the Markov operator (generator) that describes the evolution of all observables according to the kinetic Monte Carlo algorithm. This domain decompositionmore » corresponds to a decomposition of the Markov generator into a hierarchy of operators and can be tailored to specific hierarchical parallel architectures such as multi-core processors or clusters of Graphical Processing Units (GPUs). Based on this operator decomposition, we formulate parallel Fractional step kinetic Monte Carlo algorithms by employing the Trotter Theorem and its randomized variants; these schemes, (a) are partially asynchronous on each fractional step time-window, and (b) are characterized by their communication schedule between processors. The proposed mathematical framework allows us to rigorously justify the numerical and statistical consistency of the proposed algorithms, showing the convergence of our approximating schemes to the original serial KMC. The approach also provides a systematic evaluation of different processor communicating schedules. We carry out a detailed benchmarking of the parallel KMC schemes using available exact solutions, for example, in Ising-type systems and we demonstrate the capabilities of the method to simulate complex spatially distributed reactions at very large scales on GPUs. Finally, we discuss work load balancing between processors and propose a re-balancing scheme based on probabilistic mass transport methods.« less
Darwinian perspectives on the evolution of human languages.
Pagel, Mark
2017-02-01
Human languages evolve by a process of descent with modification in which parent languages give rise to daughter languages over time and in a manner that mimics the evolution of biological species. Descent with modification is just one of many parallels between biological and linguistic evolution that, taken together, offer up a Darwinian perspective on how languages evolve. Combined with statistical methods borrowed from evolutionary biology, this Darwinian perspective has brought new opportunities to the study of the evolution of human languages. These include the statistical inference of phylogenetic trees of languages, the study of how linguistic traits evolve over thousands of years of language change, the reconstruction of ancestral or proto-languages, and using language change to date historical events.
Social Cognition and the Evolution of Language: Constructing Cognitive Phylogenies
Fitch, W. Tecumseh; Huber, Ludwig; Bugnyar, Thomas
2015-01-01
Human language and social cognition are closely linked: advanced social cognition is necessary for children to acquire language, and language allows forms of social understanding (and, more broadly, culture) that would otherwise be impossible. Both “language” and “social cognition” are complex constructs, involving many independent cognitive mechanisms, and the comparative approach provides a powerful route to understanding the evolution of such mechanisms. We provide a broad comparative review of mechanisms underlying social intelligence in vertebrates, with the goal of determining which human mechanisms are broadly shared, which have evolved in parallel in other clades, and which, potentially, are uniquely developed in our species. We emphasize the importance of convergent evolution for testing hypotheses about neural mechanisms and their evolution. PMID:20346756
Human tumors show a high level of genetic heterogeneity, but the processes that influence the timing and route of metastatic dissemination of the subclones are unknown. Here we have used whole-exome sequencing of 103 matched benign, malignant and metastatic skin tumors from genetically heterogeneous mice to demonstrate that most metastases disseminate synchronously from the primary tumor, supporting parallel rather than linear evolution as the predominant model of metastasis.
Diogo, Rui; Smith, Christopher M; Ziermann, Janine M
2015-11-01
We introduce a new subfield of the recently created field of Evolutionary-Developmental-Anthropology (Evo-Devo-Anth): Evolutionary-Developmental-Pathology-and-Anthropology (Evo-Devo-P'Anth). This subfield combines experimental and developmental studies of nonhuman model organisms, biological anthropology, chordate comparative anatomy and evolution, and the study of normal and pathological human development. Instead of focusing on other organisms to try to better understand human development, evolution, anatomy, and pathology, it places humans as the central case study, i.e., as truly model organism themselves. We summarize the results of our recent Evo-Devo-P'Anth studies and discuss long-standing questions in each of the broader biological fields combined in this subfield, paying special attention to the links between: (1) Human anomalies and variations, nonpentadactyly, homeotic transformations, and "nearest neighbor" vs. "find and seek" muscle-skeleton associations in limb+facial muscles vs. other head muscles; (2) Developmental constraints, the notion of "phylotypic stage," internalism vs. externalism, and the "logic of monsters" vs. "lack of homeostasis" views about human birth defects; (3) Human evolution, reversions, atavisms, paedomorphosis, and peromorphosis; (4) Scala naturae, Haeckelian recapitulation, von Baer's laws, and parallelism between phylogeny and development, here formally defined as "Phylo-Devo parallelism"; and (5) Patau, Edwards, and Down syndrome (trisomies 13, 18, 21), atavisms, apoptosis, heart malformations, and medical implications. © 2015 Wiley Periodicals, Inc.
Clonal origins and parallel evolution of regionally synchronous colorectal adenoma and carcinoma.
Kim, Tae-Min; An, Chang Hyeok; Rhee, Je-Keun; Jung, Seung-Hyun; Lee, Sung Hak; Baek, In-Pyo; Kim, Min Sung; Lee, Sug Hyung; Chung, Yeun-Jun
2015-09-29
Although the colorectal adenoma-to-carcinoma sequence represents a classical cancer progression model, the evolution of the mutational landscape underlying this model is not fully understood. In this study, we analyzed eight synchronous pairs of colorectal high-grade adenomas and carcinomas, four microsatellite-unstable (MSU) and four-stable (MSS) pairs, using whole-exome sequencing. In the MSU adenoma-carcinoma pairs, we observed no subclonal mutations in adenomas that became fixed in paired carcinomas, suggesting a 'parallel' evolution of synchronous adenoma-to-carcinoma, rather than a 'stepwise' evolution. The abundance of indel (in MSU and MSS pairs) and microsatellite instability (in MSU pairs) was noted in the later adenoma- or carcinoma-specific mutations, indicating that the mutational processes and functional constraints operative in early and late colorectal carcinogenesis are different. All MSU cases exhibited clonal, truncating mutations in ACVR2A, TGFBR2, and DNA mismatch repair genes, but none were present in APC or KRAS. In three MSS pairs, both APC and KRAS mutations were identified as both early and clonal events, often accompanying clonal copy number changes. An MSS case uniquely exhibited clonal ERBB2 amplification, followed by APC and TP53 mutations as carcinoma-specific events. Along with the previously unrecognized clonal origins of synchronous colorectal adenoma-carcinoma pairs, our study revealed that the preferred sequence of mutational events during colorectal carcinogenesis can be context-dependent.
Zúñiga-Reinoso, Álvaro; Méndez, Marco A
2018-04-24
The origin of cryptic species has traditionally been associated with events of recent speciation, genetic constraints, selection of an adaptive character, sexual selection and/or convergent evolution. Species of the genus Callyntra inhabit coastal terraces, mountain slopes, and peaks; their elytral designs are associated with each of these habitats. However, cryptic species have been described within each of these habitats; the taxonomy of this group has been problematic, thus establishing the phylogenetic relationships in this group is fundamental to clarify the systematics and evolutionary patterns of Callyntra. We reconstructed the phylogeny of this group using two mitochondrial genes (COI, 16S) and one nuclear gene (Mp20). We also performed species delimitation using PTP based methods (PTP, mlPTP, bPTP) and GMYC, and evaluated the evolution of the elytral design related to habitat preference. The results showed a tree with five clades, that together with the different methods of species delimitation recovered the described species and suggested at least five new species. The elytral design and habitat preference showed phylogenetic signals. We propose a new classification based on monophyletic groups recovered by phylogenetic analyses. We also suggest that parallel evolution in different habitats and later stasis in the elytral design would be the cause of the origin of cryptic species in this group from central Chile. Copyright © 2018 Elsevier Inc. All rights reserved.
Engel, Philipp; Salzburger, Walter; Liesch, Marius; Chang, Chao-Chin; Maruyama, Soichi; Lanz, Christa; Calteau, Alexandra; Lajus, Aurélie; Médigue, Claudine; Schuster, Stephan C; Dehio, Christoph
2011-02-10
Adaptive radiation is the rapid origination of multiple species from a single ancestor as the result of concurrent adaptation to disparate environments. This fundamental evolutionary process is considered to be responsible for the genesis of a great portion of the diversity of life. Bacteria have evolved enormous biological diversity by exploiting an exceptional range of environments, yet diversification of bacteria via adaptive radiation has been documented in a few cases only and the underlying molecular mechanisms are largely unknown. Here we show a compelling example of adaptive radiation in pathogenic bacteria and reveal their genetic basis. Our evolutionary genomic analyses of the α-proteobacterial genus Bartonella uncover two parallel adaptive radiations within these host-restricted mammalian pathogens. We identify a horizontally-acquired protein secretion system, which has evolved to target specific bacterial effector proteins into host cells as the evolutionary key innovation triggering these parallel adaptive radiations. We show that the functional versatility and adaptive potential of the VirB type IV secretion system (T4SS), and thereby translocated Bartonella effector proteins (Beps), evolved in parallel in the two lineages prior to their radiations. Independent chromosomal fixation of the virB operon and consecutive rounds of lineage-specific bep gene duplications followed by their functional diversification characterize these parallel evolutionary trajectories. Whereas most Beps maintained their ancestral domain constitution, strikingly, a novel type of effector protein emerged convergently in both lineages. This resulted in similar arrays of host cell-targeted effector proteins in the two lineages of Bartonella as the basis of their independent radiation. The parallel molecular evolution of the VirB/Bep system displays a striking example of a key innovation involved in independent adaptive processes and the emergence of bacterial pathogens. Furthermore, our study highlights the remarkable evolvability of T4SSs and their effector proteins, explaining their broad application in bacterial interactions with the environment.
Engel, Philipp; Salzburger, Walter; Liesch, Marius; Chang, Chao-Chin; Maruyama, Soichi; Lanz, Christa; Calteau, Alexandra; Lajus, Aurélie; Médigue, Claudine; Schuster, Stephan C.; Dehio, Christoph
2011-01-01
Adaptive radiation is the rapid origination of multiple species from a single ancestor as the result of concurrent adaptation to disparate environments. This fundamental evolutionary process is considered to be responsible for the genesis of a great portion of the diversity of life. Bacteria have evolved enormous biological diversity by exploiting an exceptional range of environments, yet diversification of bacteria via adaptive radiation has been documented in a few cases only and the underlying molecular mechanisms are largely unknown. Here we show a compelling example of adaptive radiation in pathogenic bacteria and reveal their genetic basis. Our evolutionary genomic analyses of the α-proteobacterial genus Bartonella uncover two parallel adaptive radiations within these host-restricted mammalian pathogens. We identify a horizontally-acquired protein secretion system, which has evolved to target specific bacterial effector proteins into host cells as the evolutionary key innovation triggering these parallel adaptive radiations. We show that the functional versatility and adaptive potential of the VirB type IV secretion system (T4SS), and thereby translocated Bartonella effector proteins (Beps), evolved in parallel in the two lineages prior to their radiations. Independent chromosomal fixation of the virB operon and consecutive rounds of lineage-specific bep gene duplications followed by their functional diversification characterize these parallel evolutionary trajectories. Whereas most Beps maintained their ancestral domain constitution, strikingly, a novel type of effector protein emerged convergently in both lineages. This resulted in similar arrays of host cell-targeted effector proteins in the two lineages of Bartonella as the basis of their independent radiation. The parallel molecular evolution of the VirB/Bep system displays a striking example of a key innovation involved in independent adaptive processes and the emergence of bacterial pathogens. Furthermore, our study highlights the remarkable evolvability of T4SSs and their effector proteins, explaining their broad application in bacterial interactions with the environment. PMID:21347280
Genomics of Parallel Ecological Speciation in Lake Victoria Cichlids.
Meier, Joana Isabel; Marques, David Alexander; Wagner, Catherine Elise; Excoffier, Laurent; Seehausen, Ole
2018-06-01
The genetic basis of parallel evolution of similar species is of great interest in evolutionary biology. In the adaptive radiation of Lake Victoria cichlid fishes, sister species with either blue or red-back male nuptial coloration have evolved repeatedly, often associated with shallower and deeper water, respectively. One such case is blue and red-backed Pundamilia species, for which we recently showed that a young species pair may have evolved through "hybrid parallel speciation". Coalescent simulations suggested that the older species P. pundamilia (blue) and P. nyererei (red-back) admixed in the Mwanza Gulf and that new "nyererei-like" and "pundamilia-like" species evolved from the admixed population. Here, we use genome scans to study the genomic architecture of differentiation, and assess the influence of hybridization on the evolution of the younger species pair. For each of the two species pairs, we find over 300 genomic regions, widespread across the genome, which are highly differentiated. A subset of the most strongly differentiated regions of the older pair are also differentiated in the younger pair. These shared differentiated regions often show parallel allele frequency differences, consistent with the hypothesis that admixture-derived alleles were targeted by divergent selection in the hybrid population. However, two-thirds of the genomic regions that are highly differentiated between the younger species are not highly differentiated between the older species, suggesting independent evolutionary responses to selection pressures. Our analyses reveal how divergent selection on admixture-derived genetic variation can facilitate new speciation events.
The oldest modern therian mammal from Europe and its bearing on stem marsupial paleobiogeography.
Vullo, Romain; Gheerbrant, Emmanuel; de Muizon, Christian; Néraudeau, Didier
2009-11-24
We report the discovery of mammalian tribosphenic teeth from the basal Cenomanian of southwestern France that we refer to a new primitive marsupial-like form identified as a basal taxon of Marsupialiformes, a new clade recognized here to include the crown group Marsupialia and primitive stem lineages more closely related to Marsupialia than to Deltatheroida. Arcantiodelphys marchandi gen et sp nov. shares several significant marsupial-like features (s.l.) with marsupialiform taxa known from the North American Mid-Cretaceous. Among marsupialiforms, it shows a closer resemblance to Dakotadens. This resemblance, which is plesiomorphic within "tribotherians," makes Arcantiodelphys one of the most archaic known Marsupialiformes. Moreover, Arcantiodelphys is characterized by an original and precocious crushing specialization. Both the plesiomorphic and autapomorphic characteristics of Arcantiodelphys among Marsupialiformes might be explained by an Eastern origin from Asian stem metatherians, with some in situ European evolution. In addition, the presence of a mammal with North American affinities in western Europe during the early Late Cretaceous provides further evidence of a large Euramerican biogeographical province at this age or slightly before. Concerning the paleobiogeographical history of the first stem marsupialiforms during the Albian-Cenomanian interval, 2 possible dispersal routes from an Asian metatherian ancestry can be proposed: Asia to Europe via North America and Asia to North America via Europe. The main significance of the Archingeay-Les Nouillers mammal discovery is that it indicates that the beginning of the stem marsupialiforms history involved not only North America but also Europe, and that this early history in Europe remains virtually unknown.
The oldest modern therian mammal from Europe and its bearing on stem marsupial paleobiogeography
Vullo, Romain; Gheerbrant, Emmanuel; de Muizon, Christian; Néraudeau, Didier
2009-01-01
We report the discovery of mammalian tribosphenic teeth from the basal Cenomanian of southwestern France that we refer to a new primitive marsupial-like form identified as a basal taxon of Marsupialiformes, a new clade recognized here to include the crown group Marsupialia and primitive stem lineages more closely related to Marsupialia than to Deltatheroida. Arcantiodelphys marchandi gen et sp nov. shares several significant marsupial-like features (s.l.) with marsupialiform taxa known from the North American Mid-Cretaceous. Among marsupialiforms, it shows a closer resemblance to Dakotadens. This resemblance, which is plesiomorphic within “tribotherians,” makes Arcantiodelphys one of the most archaic known Marsupialiformes. Moreover, Arcantiodelphys is characterized by an original and precocious crushing specialization. Both the plesiomorphic and autapomorphic characteristics of Arcantiodelphys among Marsupialiformes might be explained by an Eastern origin from Asian stem metatherians, with some in situ European evolution. In addition, the presence of a mammal with North American affinities in western Europe during the early Late Cretaceous provides further evidence of a large Euramerican biogeographical province at this age or slightly before. Concerning the paleobiogeographical history of the first stem marsupialiforms during the Albian–Cenomanian interval, 2 possible dispersal routes from an Asian metatherian ancestry can be proposed: Asia to Europe via North America and Asia to North America via Europe. The main significance of the Archingeay-Les Nouillers mammal discovery is that it indicates that the beginning of the stem marsupialiforms history involved not only North America but also Europe, and that this early history in Europe remains virtually unknown. PMID:19892730
Nuclear medicine technologist education and training in Europe: literature and web-based findings.
Matos, Ana C; Massa, Raquel C; Lucena, Filipa M; Vaz, Tânia R
2015-06-01
The education and training of a nuclear medicine technologist (NMT) is not homogeneous among European countries, which leads to different scope of practices and, therefore, different technical skills are assigned. The goal of this research was to characterize the education and training of NMT in Europe. This study was based on a literature research to characterize the education and training of NMT and support the historical evolution of this profession. It was divided into two different phases: the first phase included analysis of scientific articles and the second phase included research of curricula that allow health professionals to work as NMT in Europe. The majority of the countries [N=31 (89%)] offer the NMT curriculum integrated into the high education system and only in four (11%) countries the education is provided by professional schools. The duration in each education system is not equal, varying in professional schools (2-3 years) and high education level system (2-4 years), which means that different European Credit Transfer and Accumulation System, such as 240, 230, 222, 210 or 180 European Credit Transfer and Accumulation System, are attributed to the graduates. The professional title and scope of the practice of NMT are different in different countries in Europe. In most countries of Europe, nuclear medicine training is not specific and curriculum does not demonstrate the Nuclear Medicine competencies performed in clinical practice. The heterogeneity in education and training for NMT is an issue prevalent among European countries. For NMT professional development, there is a huge need to formalize and unify educational and training programmes in Europe.
Large-scale dynamics associated with clustering of extratropical cyclones affecting Western Europe
NASA Astrophysics Data System (ADS)
Pinto, Joaquim G.; Gómara, Iñigo; Masato, Giacomo; Dacre, Helen F.; Woollings, Tim; Caballero, Rodrigo
2015-04-01
Some recent winters in Western Europe have been characterized by the occurrence of multiple extratropical cyclones following a similar path. The occurrence of such cyclone clusters leads to large socio-economic impacts due to damaging winds, storm surges, and floods. Recent studies have statistically characterized the clustering of extratropical cyclones over the North Atlantic and Europe and hypothesized potential physical mechanisms responsible for their formation. Here we analyze 4 months characterized by multiple cyclones over Western Europe (February 1990, January 1993, December 1999, and January 2007). The evolution of the eddy driven jet stream, Rossby wave-breaking, and upstream/downstream cyclone development are investigated to infer the role of the large-scale flow and to determine if clustered cyclones are related to each other. Results suggest that optimal conditions for the occurrence of cyclone clusters are provided by a recurrent extension of an intensified eddy driven jet toward Western Europe lasting at least 1 week. Multiple Rossby wave-breaking occurrences on both the poleward and equatorward flanks of the jet contribute to the development of these anomalous large-scale conditions. The analysis of the daily weather charts reveals that upstream cyclone development (secondary cyclogenesis, where new cyclones are generated on the trailing fronts of mature cyclones) is strongly related to cyclone clustering, with multiple cyclones developing on a single jet streak. The present analysis permits a deeper understanding of the physical reasons leading to the occurrence of cyclone families over the North Atlantic, enabling a better estimation of the associated cumulative risk over Europe.
Vanadium Nitrogenase Reduces CO*
Lee, Chi Chung; Hu, Yilin; Ribbe, Markus W.
2011-01-01
Vanadium nitrogenase not only reduces dinitrogen to ammonia but also reduces carbon monoxide to ethylene, ethane, and propane. The parallelism between the two reactions suggests a potential link in mechanism and evolution between the carbon and nitrogen cycles on Earth. PMID:20689010
Parallel evolution of storage roots in morning glories (Convolvulaceae).
Eserman, Lauren A; Jarret, Robert L; Leebens-Mack, James H
2018-05-29
Storage roots are an ecologically and agriculturally important plant trait that have evolved numerous times in angiosperms. Storage roots primarily function to store carbohydrates underground as reserves for perennial species. In morning glories, storage roots are well characterized in the crop species sweetpotato, where starch accumulates in storage roots. This starch-storage tissue proliferates, and roots thicken to accommodate the additional tissue. In morning glories, storage roots have evolved numerous times. The primary goal of this study is to understand whether this was through parallel evolution, where species use a common genetic mechanism to achieve storage root formation, or through convergent evolution, where storage roots in distantly related species are formed using a different set of genes. Pairs of species where one forms storage roots and the other does not were sampled from two tribes in the morning glory family, the Ipomoeeae and Merremieae. Root anatomy in storage roots and fine roots was examined. Furthermore, we sequenced total mRNA from storage roots and fine roots in these species and analyzed differential gene expression. Anatomical results reveal that storage roots of species in the Ipomoeeae tribe, such as sweetpotato, accumulate starch similar to species in the Merremieae tribe but differ in vascular tissue organization. In both storage root forming species, more genes were found to be upregulated in storage roots compared to fine roots. Further, we find that fifty-seven orthologous genes were differentially expressed between storage roots and fine roots in both storage root forming species. These genes are primarily involved in starch biosynthesis, regulation of starch biosynthesis, and transcription factor activity. Taken together, these results demonstrate that storage roots of species from both morning glory tribes are anatomically different but utilize a common core set of genes in storage root formation. This is consistent with a pattern of parallel evolution, thus highlighting the importance of examining anatomy together with gene expression to understand the evolutionary origins of ecologically and economically important plant traits.
Mammalian bone palaeohistology: a survey and new data with emphasis on island forms
Scheyer, Torsten M.; Veitschegger, Kristof; Forasiepi, Analia M.; Amson, Eli; Van der Geer, Alexandra A.E.; Van den Hoek Ostende, Lars W.; Hayashi, Shoji; Sánchez-Villagra, Marcelo R.
2015-01-01
The interest in mammalian palaeohistology has increased dramatically in the last two decades. Starting in 1849 via descriptive approaches, it has been demonstrated that bone tissue and vascularisation types correlate with several biological variables such as ontogenetic stage, growth rate, and ecology. Mammalian bone displays a large variety of bone tissues and vascularisation patterns reaching from lamellar or parallel-fibred to fibrolamellar or woven-fibred bone, depending on taxon and individual age. Here we systematically review the knowledge and methods on cynodont and mammalian bone microstructure as well as palaeohistology and discuss potential future research fields and techniques. We present new data on the bone microstructure of two extant marsupial species and of several extinct continental and island placental mammals. Extant marsupials display mainly parallel-fibred primary bone with radial and oblique but mainly longitudinal vascular canals. Three juvenile specimens of the dwarf island hippopotamid Hippopotamus minor from the Late Pleistocene of Cyprus show reticular to plexiform fibrolamellar bone. The island murid Mikrotia magna from the Late Miocene of Gargano, Italy displays parallel-fibred primary bone with reticular vascularisation and strong remodelling in the middle part of the cortex. Leithia sp., the dormouse from the Pleistocene of Sicily, is characterised by a primary bone cortex consisting of lamellar bone and a high amount of compact coarse cancellous bone. The bone cortex of the fossil continental lagomorph Prolagus oeningensis and three fossil species of insular Prolagus displays mainly parallel-fibred primary bone and reticular, radial as well as longitudinal vascularisation. Typical for large mammals, secondary bone in the giant rhinocerotoid Paraceratherium sp. from the Late Oligocene of Turkey is represented by dense Haversian bone. The skeletochronological features of Sinomegaceros yabei, a large-sized deer from the Pleistocene of Japan closely related to Megaloceros, indicate a high growth rate. These examples and the synthesis of existing data show the potential of bone microstructure to reveal essential information on life history evolution. The bone tissue and the skeletochronological data of the sampled island species suggest the presence of various modes of bone histological modification and mammalian life history evolution on islands to depend on factors of island evolution such as island size, distance from mainland, climate, phylogeny, and time of evolution. PMID:26528418
NASA Astrophysics Data System (ADS)
Chen, Huayue; Gao, Xinliang; Lu, Quanming; Sun, Jicheng; Wang, Shui
2018-02-01
Nonlinear physical processes related to whistler mode waves are attracting more and more attention for their significant role in reshaping whistler mode spectra in the Earth's magnetosphere. Using a 1-D particle-in-cell simulation model, we have investigated the nonlinear evolution of parallel counter-propagating whistler mode waves excited by anisotropic electrons within the equatorial source region. In our simulations, after the linear phase of whistler mode instability, the strong electrostatic standing structures along the background magnetic field will be formed, resulting from the coupling between excited counter-propagating whistler mode waves. The wave numbers of electrostatic standing structures are about twice those of whistler mode waves generated by anisotropic hot electrons. Moreover, these electrostatic standing structures can further be coupled with either parallel or antiparallel propagating whistler mode waves to excite high-k modes in this plasma system. Compared with excited whistler mode waves, these high-k modes typically have 3 times wave number, same frequency, and about 2 orders of magnitude smaller amplitude. Our study may provide a fresh view on the evolution of whistler mode waves within their equatorial source regions in the Earth's magnetosphere.
Zhang, Xuejun; Lei, Jiaxing
2015-01-01
Considering reducing the airspace congestion and the flight delay simultaneously, this paper formulates the airway network flow assignment (ANFA) problem as a multiobjective optimization model and presents a new multiobjective optimization framework to solve it. Firstly, an effective multi-island parallel evolution algorithm with multiple evolution populations is employed to improve the optimization capability. Secondly, the nondominated sorting genetic algorithm II is applied for each population. In addition, a cooperative coevolution algorithm is adapted to divide the ANFA problem into several low-dimensional biobjective optimization problems which are easier to deal with. Finally, in order to maintain the diversity of solutions and to avoid prematurity, a dynamic adjustment operator based on solution congestion degree is specifically designed for the ANFA problem. Simulation results using the real traffic data from China air route network and daily flight plans demonstrate that the proposed approach can improve the solution quality effectively, showing superiority to the existing approaches such as the multiobjective genetic algorithm, the well-known multiobjective evolutionary algorithm based on decomposition, and a cooperative coevolution multiobjective algorithm as well as other parallel evolution algorithms with different migration topology. PMID:26180840
Duftner, Nina; Sefc, Kristina M; Koblmüller, Stephan; Salzburger, Walter; Taborsky, Michael; Sturmbauer, Christian
2007-11-01
Colour pattern diversity can be due to random processes or to natural or sexual selection. Consequently, similarities in colour patterns are not always correlated with common ancestry, but may result from convergent evolution under shared selection pressures or drift. Neolamprologus brichardi and Neolamprologus pulcher have been described as two distinct species based on differences in the arrangement of two dark bars on the operculum. Our study uses DNA sequences of the mitochondrial control region to show that relatedness of haplotypes disagrees with species assignment based on head colour pattern. This suggests repeated parallel evolution of particular stripe patterns. The complete lack of shared haplotypes between populations of the same or different phenotypes reflects strong philopatric behaviour, possibly induced by the cooperative breeding mode in which offspring remain in their natal territory and serve as helpers until they disperse to nearby territories or take over a breeding position. Concordant phylogeographic patterns between N. brichardi/N. pulcher populations and other rock-dwelling cichlids suggest that the same colonization routes have been taken by sympatric species and that these routes were affected by lake level fluctuations in the past.
Daane, Jacob M; Rohner, Nicolas; Konstantinidis, Peter; Djuranovic, Sergej; Harris, Matthew P
2016-01-01
The identification of genetic mechanisms underlying evolutionary change is critical to our understanding of natural diversity, but is presently limited by the lack of genetic and genomic resources for most species. Here, we present a new comparative genomic approach that can be applied to a broad taxonomic sampling of nonmodel species to investigate the genetic basis of evolutionary change. Using our analysis pipeline, we show that duplication and divergence of fgfr1a is correlated with the reduction of scales within fishes of the genus Phoxinellus. As a parallel genetic mechanism is observed in scale-reduction within independent lineages of cypriniforms, our finding exposes significant developmental constraint guiding morphological evolution. In addition, we identified fixed variation in fgf20a within Phoxinellus and demonstrated that combinatorial loss-of-function of fgfr1a and fgf20a within zebrafish phenocopies the evolved scalation pattern. Together, these findings reveal epistatic interactions between fgfr1a and fgf20a as a developmental mechanism regulating skeletal variation among fishes. © The Author 2015. 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.
Pan-European seasonal trends and recent changes of drought frequency and severity
NASA Astrophysics Data System (ADS)
Spinoni, Jonathan; Naumann, Gustavo; Vogt, Jürgen V.
2017-01-01
In the last decades drought has become one of the natural disasters with most relevant impacts in Europe and this not only in water scarce areas such as the Mediterranean that are inclined to such events. As a complex natural phenomenon, drought is characterized by many hydro-meteorological aspects, a large variety of possible impacts and definitions. This study focuses on meteorological drought, investigated by using indicators that include precipitation and potential evapotranspiration (PET), i.e. the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI). These indicators account for the lack of precipitation and the drying effects of hot temperatures and in this study have been computed for short-accumulation periods (3-month) to capture the seasonality of droughts. The input variables, monthly precipitation and temperature for 1950-2015, stem from daily gridded E-OBS data and indicators were computed on regular grids spanning over the whole of Europe. PET was calculated from minimum and maximum temperatures using the Hargreaves-Samani formulation. Monthly precipitation and PET have then been used to compute the SPI-3 and the SPEI-3 time series. From these series drought events were defined at seasonal scale and trends of frequency and severity of droughts and extreme droughts were analyzed for the periods 1950-2015 and 1981-2015. According to the SPI (driven by precipitation), results show a statistically significant tendency towards less frequent and severe drought events over North-Eastern Europe, especially in winter and spring, and a moderate opposite tendency over Southern Europe, especially in spring and summer. According to the SPEI (driven by precipitation and temperature), Northern Europe shows similar wetting patterns, while Southern and Eastern Europe show a more remarkable drying tendency, especially in summer and autumn. Both for frequency and severity, the evolution towards drier conditions is more relevant in the last three decades over Central Europe in spring, the Mediterranean area in summer, and Eastern Europe in autumn.
BARKER, BRITTANY S.; ANDONIAN, KRIKOR; SWOPE, SARAH M.; LUSTER, DOUGLAS G.; DLUGOSCH, KATRINA M.
2017-01-01
Identifying sources of genetic variation and reconstructing invasion routes for non-native introduced species is central to understanding the circumstances under which they may evolve increased invasiveness. In this study, we used genome-wide single nucleotide polymorphisms to study the colonization history of Centaurea solstitialis in its native range in Eurasia and invasions into the Americas. We leveraged this information to pinpoint key evolutionary shifts in plant size, a focal trait associated with invasiveness in this species. Our analyses revealed clear population genomic structure of potential source populations in Eurasia, including deep differentiation of a lineage found in the southern Apennine and Balkan Peninsulas and divergence among populations in Asia, eastern Europe, and western Europe. We found strongest support for an evolutionary scenario in which western European populations were derived from an ancient admixture event between populations from eastern Europe and Asia, and subsequently served as the main genetic ‘bridgehead’ for introductions to the Americas. Introductions to California appear to be from a single source region, and multiple, independent introductions of divergent genotypes likely occurred into the Pacific Northwest. Plant size has evolved significantly at three points during range expansion, including a large size increase in the lineage responsible for the aggressive invasion of California’s interior. These results reveal a long history of colonization, admixture, and trait evolution in C. solstitialis, and suggest routes for improving evidence-based management decisions for one of the most ecologically and economically damaging invasive species in the western United States. PMID:28029713
Forecasting the Northern African Dust Outbreak Towards Europe in April 2011: A Model Intercomparison
NASA Technical Reports Server (NTRS)
Huneeus, N.; Basart, S.; Fiedler, S.; Morcrette, J.-J.; Benedetti, A.; Mulcahy, J.; Terradellas, E.; Pérez García-Pando, C.; Pejanovic, G.; Nickovic, S.
2016-01-01
In the framework of the World Meteorological Organisation's Sand and Dust Storm Warning Advisory and Assessment System, we evaluated the predictions of five state-of-the-art dust forecast models during an intense Saharan dust outbreak affecting western and northern Europe in April 2011. We assessed the capacity of the models to predict the evolution of the dust cloud with lead times of up to 72 hours using observations of aerosol optical depth (AOD) from the AErosol RObotic NETwork (AERONET) and the Moderate Resolution Imaging Spectroradiometer (MODIS) and dust surface concentrations from a ground-based measurement network. In addition, the predicted vertical dust distribution was evaluated with vertical extinction profiles from the Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP). To assess the diversity in forecast capability among the models, the analysis was extended to wind field (both surface and profile), synoptic conditions, emissions and deposition fluxes. Models predict the onset and evolution of the AOD for all analysed lead times. On average, differences among the models are larger than differences among lead times for each individual model. In spite of large differences in emission and deposition, the models present comparable skill for AOD. In general, models are better in predicting AOD than near-surface dust concentration over the Iberian Peninsula. Models tend to underestimate the long-range transport towards northern Europe. Our analysis suggests that this is partly due to difficulties in simulating the vertical distribution dust and horizontal wind. Differences in the size distribution and wet scavenging efficiency may also account for model diversity in long-range transport.
Vaccinology capacity building in Europe for innovative platforms serving emerging markets.
Hendriks, Jan; Holleman, Marit; Hamidi, Ahd; Beurret, Michel; Boog, Claire
2013-04-01
The 2012 Terrapinn World Vaccine Congress held from 16 to 18 October in Lyon addressed in a dedicated session the transfer of innovative vaccine technologies from Europe to emerging markets. Past and recent transfers and experiences from Europe's public domain were summarized by the Netherlands' National Institute for Public Health and the Environment (RIVM) in Bilthoven. The role of capacity building through training courses for developing country partners was highlighted in several recent technology transfer programs developed in collaboration with the World Health Organisation (WHO). In another stream of the Congress, a case of human vaccine technology transfer from Europe's private sector to an emerging economy recipient in India was presented. The continuing globalization of vaccinology is further illustrated by the recent acquisition in 2012 of the Netherlands' public vaccine manufacturing capacity in Bilthoven by the Serum Institute of India Ltd, an emerging vaccine manufacturer. In a parallel development, the Netherlands' government decided to transform RIVM's vaccinology research and development capacity into a new not-for-profit entity: "the Institute for Translational Vaccinology" (see citation 1 in Note section for web address). Under a public private partnership structure, InTraVacc's mission will include the fostering of global health through international partnerships in innovative vaccinology. Projected activities will include training courses and curricula, capitalizing on various currently established platform technologies and the legacy of previous "producer -producer" collaborations between the RIVM and emerging manufacturers over the past 40 y. It is suggested to consider this as a basis for a common initiative from Europe to develop and implement a practical vaccinology course for emerging countries with particular focus to the African region.
NASA Astrophysics Data System (ADS)
Robinson, Keith
These days the story of stellar evolution could almost read like a Hollywood epic - and why not?! It is a story that probably began back at the time of the Renaissance in Europe, when the stars were first suspected as being distant suns. Over the centuries the "script" has been written by countless astronomers, both amateur and professional, some well-known and many unsung heroes. It now stands as one of the greatest of all astronomical tales, equaled probably only by the story of the origin and evolution of the universe itself, and just like that great story, the story of the river of starlight still has a long way to go before we can write "the end."
Kinnison, Michael T.
2017-01-01
Abstract Phenotypic plasticity is often an adaptation of organisms to cope with temporally or spatially heterogenous landscapes. Like other adaptations, one would predict that different species, populations, or sexes might thus show some degree of parallel evolution of plasticity, in the form of parallel reaction norms, when exposed to analogous environmental gradients. Indeed, one might even expect parallelism of plasticity to repeatedly evolve in multiple traits responding to the same gradient, resulting in integrated parallelism of plasticity. In this study, we experimentally tested for parallel patterns of predator-mediated plasticity of size, shape, and behavior of 2 species and sexes of mosquitofish. Examination of behavioral trials indicated that the 2 species showed unique patterns of behavioral plasticity, whereas the 2 sexes in each species showed parallel responses. Fish shape showed parallel patterns of plasticity for both sexes and species, albeit males showed evidence of unique plasticity related to reproductive anatomy. Moreover, patterns of shape plasticity due to predator exposure were broadly parallel to what has been depicted for predator-mediated population divergence in other studies (slender bodies, expanded caudal regions, ventrally located eyes, and reduced male gonopodia). We did not find evidence of phenotypic plasticity in fish size for either species or sex. Hence, our findings support broadly integrated parallelism of plasticity for sexes within species and less integrated parallelism for species. We interpret these findings with respect to their potential broader implications for the interacting roles of adaptation and constraint in the evolutionary origins of parallelism of plasticity in general. PMID:29491997
Creative Teaching and Learning in Europe: Promoting a New Paradigm
ERIC Educational Resources Information Center
Davies, Trevor
2006-01-01
The tides of globalization and the unsteady surges and distortions in the evolution of the European Union are causing identities and cultures to be in a state of flux. Education is used by politicians as a major lever for political and social change through micro-management, but it is a crude tool. There can, however, be opportunities within…
On Developing Content-Oriented Theories Taking Biological Evolution as an Example
ERIC Educational Resources Information Center
Andersson, Bjorn; Wallin, Anita
2006-01-01
Both in Europe and the United States there is a growing interest in design research. One example is the design and validation of topic-oriented teaching-learning sequences. This research may be said to have two objectives. One is to design and test "useful products", such as teachers guides and study material for students, which may be…
Teaching Mathematics and Astronomy in France: The "College Royal" (1550-1650)
ERIC Educational Resources Information Center
Pantin, Isabelle
2006-01-01
For a long time, the medieval university maintained relative consistency throughout Europe in teaching topics and methods. But between 1550 and 1650 this came to an end. The evolution concerned the content of the courses and, to a lesser extent, the way the field was taught. The impact of these changes varied greatly from place to place, and new…
Palaeolithic landscapes of Europe and environs, 150,000-25,000 years ago: An overview
NASA Astrophysics Data System (ADS)
Van Andel, T. H.; Tzedakis, P. C.
When considering the evolution and migrations of Neandertalers and early modem human beings, the harsh conditions of the last glacial maximum are often implicitly or explicitly assumed as their environmental background. This perception is false: the conditions of the high glacial apply to a small fraction of late Pleistocene time. Here we review the palaeoenvironmental history of Europe from 150,000 to 25,000 years ago with the aid of data from long cores of ice and marine and continental sediments. The results are displayed in four sketch maps that illustrate the landscapes of an interglacial-glacial cycle. The maps, connected by palaeoenvironmental histories, show that especially between 60,000 and 25,000 years ago, a critical part of the Palaeolithic, the glacial landscapes were for much of the time less barren than is generally assumed, but numerous climate changes on a scale of several millennia are evident, placing a premium on accurate dating of the co-evolution of humans and landscape. Moreover, during the glacial interval abrupt climatic changes lasting from a century to a few millennia were common. Their importance for landscape changes and their impact on human activity remain to be ascertained.
Utilization of PD modalities: evolution.
Venkataraman, Vijaya; Nolph, Karl D
2002-01-01
In the early 1960s, peritoneal dialysis (PD) was introduced as a form of long-term maintenance therapy in patients with end-stage renal disease (ESRD). We have come a long way since. Increasing understanding of peritoneal kinetic behavior, its innovative manipulation to meet patient needs, critical monitoring of clinical outcomes, and parallel development in technology have all contributed to the worldwide success of the therapy over the past four decades. In this article we review the evolution of the various PD modalities in the context of these factors.
Orliac, Maeva J; Ladevèze, Sandrine; Gingerich, Philip D; Lebrun, Renaud; Smith, Thierry
2014-04-22
Expansion of the brain is a key feature of primate evolution. The fossil record, although incomplete, allows a partial reconstruction of changes in primate brain size and morphology through time. Palaeogene plesiadapoids, closest relatives of Euprimates (or crown-group primates), are crucial for understanding early evolution of the primate brain. However, brain morphology of this group remains poorly documented, and major questions remain regarding the initial phase of euprimate brain evolution. Micro-CT investigation of the endocranial morphology of Plesiadapis tricuspidens from the Late Palaeocene of Europe--the most complete plesiadapoid cranium known--shows that plesiadapoids retained a very small and simple brain. Plesiadapis has midbrain exposure, and minimal encephalization and neocorticalization, making it comparable with that of stem rodents and lagomorphs. However, Plesiadapis shares a domed neocortex and downwardly shifted olfactory-bulb axis with Euprimates. If accepted phylogenetic relationships are correct, then this implies that the euprimate brain underwent drastic reorganization during the Palaeocene, and some changes in brain structure preceded brain size increase and neocortex expansion during evolution of the primate brain.
NASA Astrophysics Data System (ADS)
Rosin, M. S.; Schekochihin, A. A.; Rincon, F.; Cowley, S. C.
2011-05-01
Weakly collisional magnetized cosmic plasmas have a dynamical tendency to develop pressure anisotropies with respect to the local direction of the magnetic field. These anisotropies trigger plasma instabilities at scales just above the ion Larmor radius ρi and much below the mean free path λmfp. They have growth rates of a fraction of the ion cyclotron frequency, which is much faster than either the global dynamics or even local turbulence. Despite their microscopic nature, these instabilities dramatically modify the transport properties and, therefore, the macroscopic dynamics of the plasma. The non-linear evolution of these instabilities is expected to drive pressure anisotropies towards marginal stability values, controlled by the plasma beta βi. Here this non-linear evolution is worked out in an ab initio kinetic calculation for the simplest analytically tractable example - the parallel (k⊥= 0) firehose instability in a high-beta plasma. An asymptotic theory is constructed, based on a particular physical ordering and leading to a closed non-linear equation for the firehose turbulence. In the non-linear regime, both the analytical theory and the numerical solution predict secular (∝t) growth of magnetic fluctuations. The fluctuations develop a k-3∥ spectrum, extending from scales somewhat larger than ρi to the maximum scale that grows secularly with time (∝t1/2); the relative pressure anisotropy (p⊥-p∥)/p∥ tends to the marginal value -2/βi. The marginal state is achieved via changes in the magnetic field, not particle scattering. When a parallel ion heat flux is present, the parallel firehose mutates into the new gyrothermal instability (GTI), which continues to exist up to firehose-stable values of pressure anisotropy, which can be positive and are limited by the magnitude of the ion heat flux. The non-linear evolution of the GTI also features secular growth of magnetic fluctuations, but the fluctuation spectrum is eventually dominated by modes around a maximal scale ˜ρilT/λmfp, where lT is the scale of the parallel temperature variation. Implications for momentum and heat transport are speculated about. This study is motivated by our interest in the dynamics of galaxy cluster plasmas (which are used as the main astrophysical example), but its relevance to solar wind and accretion flow plasmas is also briefly discussed.
Moncel, Marie-Hélène; Despriée, Jackie; Voinchet, Pierre; Tissoux, Hélène; Moreno, Davinia; Bahain, Jean-Jacques; Courcimault, Gilles; Falguères, Christophe
2013-01-01
The human settlement of Europe during Pleistocene times was sporadic and several stages have been recognized, both from paleaoanthropological and archaeological records. If the first phase of hominin occupation (as early as 1.4 Ma) seems mainly restricted to the southern part of the continent, the second phase, characterized by specific lithic tools (handaxes), is linked to Acheulean settlements and to the emergence of Homo heidelbergensis, the ancestor of Neanderthals. This phase reached northwestern Europe and is documented in numerous sites in Germany, Great Britain and northern France, generally after 600 ka. At la Noira (Brinay, Central France), the Middle Pleistocene alluvial formation of the Cher River covers an archaeological level associated with a slope deposit (diamicton). The lithic assemblage from this level includes Large Cutting Tools (LCTs), flakes and cores, associated with numerous millstone slabs. The lithic series is classified as Acheulean on the basis of both technological and typological analyses. Cryoturbation features indicate that the slope deposits and associated archaeological level were strongly frozen and disturbed after hominin occupation and before fluvial deposition. Eight sediment samples were dated by the electron spin resonance (ESR) method and the weighted average age obtained for the fluvial sands overlying the slope deposits is 665±55 ka. This age is older than previous chronological data placing the first European Acheulean assemblages north of 45(th) parallel north at around 500 ka and modifies our current vision of the initial peopling of northern Europe. Acheulean settlements are older than previously assumed and the oldest evidences are not only located in southern Europe. La Noira is the oldest evidence of Acheulean presence in north-western Europe and attests to the possibility of pioneering phases of Acheulean settlement which would have taken place on a Mode 1-type substratum as early as 700 ka. The lithic assemblage from la Noira thus provides behavioral and technological data on early Acheulean occupation in Europe and contributes to our understanding of the diffusion of this tradition.
Moncel, Marie-Hélène; Despriée, Jackie; Voinchet, Pierre; Tissoux, Hélène; Moreno, Davinia; Bahain, Jean-Jacques; Courcimault, Gilles; Falguères, Christophe
2013-01-01
The human settlement of Europe during Pleistocene times was sporadic and several stages have been recognized, both from paleaoanthropological and archaeological records. If the first phase of hominin occupation (as early as 1.4 Ma) seems mainly restricted to the southern part of the continent, the second phase, characterized by specific lithic tools (handaxes), is linked to Acheulean settlements and to the emergence of Homo heidelbergensis, the ancestor of Neanderthals. This phase reached northwestern Europe and is documented in numerous sites in Germany, Great Britain and northern France, generally after 600 ka. At la Noira (Brinay, Central France), the Middle Pleistocene alluvial formation of the Cher River covers an archaeological level associated with a slope deposit (diamicton). The lithic assemblage from this level includes Large Cutting Tools (LCTs), flakes and cores, associated with numerous millstone slabs. The lithic series is classified as Acheulean on the basis of both technological and typological analyses. Cryoturbation features indicate that the slope deposits and associated archaeological level were strongly frozen and disturbed after hominin occupation and before fluvial deposition. Eight sediment samples were dated by the electron spin resonance (ESR) method and the weighted average age obtained for the fluvial sands overlying the slope deposits is 665±55 ka. This age is older than previous chronological data placing the first European Acheulean assemblages north of 45th parallel north at around 500 ka and modifies our current vision of the initial peopling of northern Europe. Acheulean settlements are older than previously assumed and the oldest evidences are not only located in southern Europe. La Noira is the oldest evidence of Acheulean presence in north-western Europe and attests to the possibility of pioneering phases of Acheulean settlement which would have taken place on a Mode 1-type substratum as early as 700 ka. The lithic assemblage from la Noira thus provides behavioral and technological data on early Acheulean occupation in Europe and contributes to our understanding of the diffusion of this tradition. PMID:24278105
Baroclinic wave configurations evolution at European scale in the period 1948-2013
NASA Astrophysics Data System (ADS)
Carbunaru, Daniel; Burcea, Sorin; Carbunaru, Felicia
2016-04-01
The main aim of the study was to investigate the dynamic characteristics of synoptic configurations at European scale and especially in south-eastern part of Europe for the period 1948-2013. Using the empirical orthogonal functions analysis, simultaneously applied to daily average geopotential field at different pressure levels (200 hPa, 300 hPa, 500 hPa and 850 hPa) during warm (April-September) and cold (October-March) seasons, on a synoptic spatial domain centered on Europe (-27.5o lon V to 45o lon E and 32.5o lat N to 72.5o lat N), the main mode of oscillation characteristic to vertical shift of mean baroclinic waves was obtained. The analysis independently applied on 66 years showed that the first eigenvectors in warms periods describe about 60% of the data and in cold season 40% of the data for each year. In comparison secondary eigenvectors describe up to 20% and 10% of the data. Thus, the analysis was focused on the complex evolution of the first eigenvector in 66 years, during the summer period. On average, this eigenvector describes a small vertical phase shift in the west part of the domain and a large one in the eastern part. Because the spatial extent of the considered synoptic domain incorporates in the west part AMO (Atlantic Multidecadal Oscillation) and NAO (North Atlantic Oscillation) oscillations, and in the north part being sensitive to AO (Arctic Oscillation) oscillation, these three oscillations were considered as modulating dynamic factors at hemispherical scale. The preliminary results show that in the summer seasons AMO and NAO oscillations modulated vertical phase shift of baroclinic wave in the west of the area (Northwestern Europe), and the relationship between AO and NAO oscillations modulated vertical phase shift in the southeast area (Southeast Europe). Second, it was shown the way in which this vertical phase shift modulates the overall behavior of cyclonic activity, particularly in Southeastern Europe. This work has been developed within the research project "Changes in climate extremes and associated impact in hydrological events in Romania" (CLIMHYDEX), code PN II-ID-2011-2-0073, financed by the Romanian Executive Agency for Higher Education Research, Development and Innovation Funding (UEFISCDI).
Modelling the risk of ecosystem disruption in Europe with a dynamic vegetation model
NASA Astrophysics Data System (ADS)
Dury, M.; Hambuckers, A.; Warnant, P.; Jacquemin, I.; Thuiller, W.; François, L.
2012-04-01
What will be the European ecosystem responses to future climate? With unprecedented speed and extent, the projected climate change might lead to a disruption of terrestrial plants functioning in many regions. In the framework of the EcoChange project, transient projections over the 1901-2100 period have been performed with a process-based dynamic vegetation model, CARAIB DVM (Dury et al., 2011, iForest 4: 82, 99). The vegetation model was driven by the outputs of four climate models under the SRES A1B scenario: the ARPEGE/Climate model and three regional climate models (KNMI-RACMO2, DMI-HIRHAM5 and HC-HadRM3Q0 RCMs) from the European Union project ENSEMBLES. DVMs are appropriate tools to apprehend potential climate change impacts on ecosystems and identify threatened regions over Europe. CARAIB outputs (soil moisture, runoff, net primary productivity, fire, etc.) were used to characterise the ecosystem evolution. To assess consequences on biodiversity, the evolution of 100 natural common European species (47 herbs, 12 shrubs and 41 trees) has been studied year-to-year over the 1901-2100 period. Under the combined effects of projected changes particularly in temperature and precipitations, CARAIB simulates important reductions in the annual soil water content. The species productivities vary strongly from year to year reaching during the driest years values much lower than present-day average productivities. According to CARAIB, a lot of species might go beyond their water tolerance very frequently, particularly after 2050, due to more intense summer droughts. In the northern part of Europe and in the Alps, with reduced temperature variability and positive soil water anomalies, NPP variability tends to decrease. Regions with more severe droughts might also be affected by an increase of the frequency and intensity of wildfires. With this background, the species distributions might be strongly modified at the end of the century. 15% of tree species and 30% of herb and shrub species (respectively 30% and 60% if the CO2 fertilization effect on species is not taken into account) might experience a loss of 30% or more of their current distribution. Proportions of new species appearance were also studied. Southern Europe might suffer important species extinction while the more suitable climate conditions in northern Europe might lead to a gain in species diversity.
Long-time dynamics through parallel trajectory splicing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Perez, Danny; Cubuk, Ekin D.; Waterland, Amos
2015-11-24
Simulating the atomistic evolution of materials over long time scales is a longstanding challenge, especially for complex systems where the distribution of barrier heights is very heterogeneous. Such systems are difficult to investigate using conventional long-time scale techniques, and the fact that they tend to remain trapped in small regions of configuration space for extended periods of time strongly limits the physical insights gained from short simulations. We introduce a novel simulation technique, Parallel Trajectory Splicing (ParSplice), that aims at addressing this problem through the timewise parallelization of long trajectories. The computational efficiency of ParSplice stems from a speculation strategymore » whereby predictions of the future evolution of the system are leveraged to increase the amount of work that can be concurrently performed at any one time, hence improving the scalability of the method. ParSplice is also able to accurately account for, and potentially reuse, a substantial fraction of the computational work invested in the simulation. We validate the method on a simple Ag surface system and demonstrate substantial increases in efficiency compared to previous methods. As a result, we then demonstrate the power of ParSplice through the study of topology changes in Ag 42Cu 13 core–shell nanoparticles.« less
Longitudinal trends in climate drive flowering time clines in North American Arabidopsis thaliana.
Samis, Karen E; Murren, Courtney J; Bossdorf, Oliver; Donohue, Kathleen; Fenster, Charles B; Malmberg, Russell L; Purugganan, Michael D; Stinchcombe, John R
2012-06-01
Introduced species frequently show geographic differentiation, and when differentiation mirrors the ancestral range, it is often taken as evidence of adaptive evolution. The mouse-ear cress (Arabidopsis thaliana) was introduced to North America from Eurasia 150-200 years ago, providing an opportunity to study parallel adaptation in a genetic model organism. Here, we test for clinal variation in flowering time using 199 North American (NA) accessions of A. thaliana, and evaluate the contributions of major flowering time genes FRI, FLC, and PHYC as well as potential ecological mechanisms underlying differentiation. We find evidence for substantial within population genetic variation in quantitative traits and flowering time, and putatively adaptive longitudinal differentiation, despite low levels of variation at FRI, FLC, and PHYC and genome-wide reductions in population structure relative to Eurasian (EA) samples. The observed longitudinal cline in flowering time in North America is parallel to an EA cline, robust to the effects of population structure, and associated with geographic variation in winter precipitation and temperature. We detected major effects of FRI on quantitative traits associated with reproductive fitness, although the haplotype associated with higher fitness remains rare in North America. Collectively, our results suggest the evolution of parallel flowering time clines through novel genetic mechanisms.
The evolution of dual meat and milk cattle husbandry in Linearbandkeramik societies.
Gillis, Rosalind E; Kovačiková, Lenka; Bréhard, Stéphanie; Guthmann, Emilie; Vostrovská, Ivana; Nohálová, Hana; Arbogast, Rose-Marie; Domboróczki, László; Pechtl, Joachim; Anders, Alexandra; Marciniak, Arkadiusz; Tresset, Anne; Vigne, Jean-Denis
2017-08-16
Cattle dominate archaeozoological assemblages from the north-central Europe between the sixth and fifth millennium BC and are frequently considered as exclusively used for their meat. Dairy products may have played a greater role than previously believed. Selective pressure on the lactase persistence mutation has been modelled to have begun between 6000 and 4000 years ago in central Europe. The discovery of milk lipids in late sixth millennium ceramic sieves in Poland may reflect an isolated regional peculiarity for cheese making or may signify more generalized milk exploitation in north-central Europe during the Early Neolithic. To investigate these issues, we analysed the mortality profiles based on age-at-death analysis of cattle tooth eruption, wear and replacement from 19 archaeological sites of the Linearbandkeramik (LBK) culture (sixth to fifth millennium BC). The results indicate that cattle husbandry was similar across time and space in the LBK culture with a degree of specialization for meat exploitation in some areas. Statistical comparison with reference age-at-death profiles indicate that mixed husbandry (milk and meat) was practised, with mature animals being kept. The analysis provides a unique insight into LBK cattle husbandry and how it evolved in later cultures in central and western Europe. It also opens a new perspective on how and why the Neolithic way of life developed through continental Europe and how dairy products became a part of the human diet. © 2017 The Authors.
Feau, Nicolas; Dutech, Cyril; Brusini, Jérémie; Rigling, Daniel; Robin, Cécile
2014-01-01
Cryphonectria hypovirus 1 (CHV1) is a mycovirus which decreases the virulence of its fungal host Cryphonectria parasitica, the causal agent of chestnut blight recently introduced in Europe. The understanding of the evolutionary processes which have shaped CHV1 populations in Europe is required to develop a sustainable biocontrol strategy targeting chestnut blight and effective in European chestnut forests. To retrace the evolutionary history of CHV1, we analyzed sequences from two genomic regions on a collection of 55 CHV1 strains from France and northern Spain, two countries where multiple introductions of C. parasitica occurred. Several recombination events and variable selection pressures contributed to CHV1 evolution, agreeing with a non-clock-like diversification rate. These two mechanisms may be at the origin of CHV1 population diversity observed in western Europe. Considering the actual prevalence of CHV1 and its association with host genotypes, multiple introductions of CHV1 may have occurred in Europe, some of them directly from Asia and some of them through North America. Although some viral strains remained with low frequency in their introduction area, multiple infections might have allowed homologous recombination within parental sequences. Some of these recombinant lineages are associated with the spread of CHV1 in European regions. PMID:24944571
A New Generation of Large Seismic Refraction Experiments in Central Europe (1997-2003)
NASA Astrophysics Data System (ADS)
Guterch, A.; Grad, M.; Spicak, A.; Brueckl, E.; Hegedus, E.; Keller, G. R.; Thybo, H.
2003-12-01
Beginning in 1997, Central Europe has been covered by an unprecedented network of seismic refraction experiments. These experiments (POLONAISE'97, CELEBRATION 2000, ALP 2002, SUDETES 2003) have only been possible due a massive international cooperative effort. The total length of all profiles is about 19,000 km, and over 300 explosive sources were employed. The result is a network of seismic refraction profiles that extends along the Trans-European Suture Zone region of Poland and the Bohemian massif, Pannonian basin, trough the Carpathians and Alps to the Adriatic Sea and the Dinarides. As reflected in structures within these areas, Central Europe has experienced a complex tectonic history that includes the Caledonian, Variscan, and Alpine orogenies. The related TESZ region is a broad zone of deformation that extends across Europe from British Isles to the Black Sea region that formed as Europe was assembled from a complex collage of terranes during the late Palaeozoic. For example, the Bohemian massif is mostly located in the Czech Republic and is a large, complex terrane whose origin can be traced to northern Gondwana (Africa). These terranes were accreted along the margin of Baltica that was formed during the break-up of Rodinia. The tectonic evolution of this region shares many attributes with the Appalachian/Ouachita origin and is certainly of global important to studies in terrane tectonics and continental evolution. In southern Poland, several structural blocks are located adjacent to Baltica and were probably transported laterally along it similar to the Cenozoic movement of terranes along the western margin of North America. The younger Carpathian arc and Pannonian back-arc basin were also targeted by these experiments. Thickness of the crust in the area of investigations changes from 22-25 km in the Pannonian basin to about 55 km in the Trans-European Suture Zone in SE Poland. Together, these experiments are providing an unprecedented 3-D image of the evolution and assembly of a continent. Experiment Working Group Members: K. Aric, S. Azevedo, I. Asudeh, M. Behm, A.A. Belinsky, T. Bodoky, R. Brinkmann, M. Broz, E. Brueckl, W. Chwatal, R. Clowes, W. Czuba, T. Fancsik, B. Forkmann, M. Fort, E. Gaczynski, H. Gebrande, H. Geissler, A. Gosar, M. Grad, H. Grassi, R. Greschke, A. Guterch, Z. Hajnal, S. Harder,E. Hegedus, A. Hemmann, S. Hock, V. Hoeck, P. Hrubcova, T. Janik, G. Jentzsch, P. Joergensen, G. Kaip, G.R. Keller, F. Kohlbeck, K. Komminaho, M. Korn, O. Korousova, S.L. Kostiuchenko, D. Kracke, C.-E. Lund, U. Luosto, M. Majdazski, M. Malinowski, K.C. Miller, A.F. Morozov, G. Motuza, V. Nasedkin, E.-M. Rumpfhuber, Ch. Schmid, A. Schulze, K. Schuster, O. Selvi, C. Snelson, A. Spicak, P. Sroda, F. Sumanovac, E. Tacasc, H. Thybo, T. Tiira, C. Tomek, J. Vozar, F. Weber, M. Wilde-Pierko, J. Yliniemi, A. Zelazniewicz
NASA Astrophysics Data System (ADS)
Eder, Erich; Turic, Katharina; Milasowszky, Norbert; van Adzin, Katherine; Hergovich, Andreas
2011-05-01
The present study is the first to investigate the relationships between a multiple set of paranormal beliefs and the acceptance of evolution, creationism, and intelligent design, respectively, in Europe. Using a questionnaire, 2,129 students at secondary schools in Vienna (Austria) answered the 26 statements of the Revised Paranormal Belief Scale (R-PBS) and three statements about naturalistic evolution, creationism and intelligent design (ID). The investigated Austrian students showed an average R-PBS score of 82.08, more than 50% of them agreed with naturalistic evolution, 28% with creationism, and more than a third agreed with ID, the latter two closely correlated with each other. Females generally showed higher belief scores in the paranormal, creationism and ID. The agreement with naturalistic evolution correlated negatively with religious belief, but not with other paranormal beliefs, whereas the two non-scientific alternatives to evolution significantly correlated with both traditional and paranormal beliefs. Religious belief showed a significant positive correlation with other paranormal beliefs. All subscales of paranormal belief decreased during the eight grades of secondary school, as did acceptance of creationism and ID. However, the acceptance of naturalistic evolution did not correlate with age or grade. Possible reasons and implications for science education and the biology curriculum at Austrian secondary schools are discussed.
NASA Technical Reports Server (NTRS)
Hinderer, J.; Lemoine, Frank G.; Crossley, D.; Boy, J.-P.
2004-01-01
We investigate the time-variable gravity changes in Europe retrieved from the initial GRACE monthly solutions spanning a 18 month duration from April 2002 to October 2003. Gravity anomaly maps are retrieved in Central Europe from the monthly satellite solutions we compare the fields according to various truncation levels (typically between degree 10 and 20) of the initial fields (expressed in spherical harmonics to degree 120). For these different degrees, an empirical orthogonal function (EOF) decomposition of the time-variable gravity field leads us to its main spatial and temporal characteristics. We show that the dominant signal is found to be annual with an amplitude and a phase both in agreement with predictions in Europe modeled using snow and soil-moisture variations from recent hydrology models. We compare these GRACE gravity field changes to surface gravity observations from 6 superconducting gravimeters of the GGP (Global Geodynamics Project) European sub-network, with a special attention to loading corrections. Initial results suggest that all 3 data sets (GRACE, hydrology and GGP) are responding to annual changes in near-surface water in Europe of a few microGal (at length scales of approx.1000 km) that show a high value in winter and a summer minimum. We also point out that the GRACE gravity field evolution seems to indicate that there is a trend in gravity between summer 2002 and summer 2003 which can be related to the 2003 heatwave in Europe and its hydrological consequences (drought). Despite the limited time span of our analysis and the uncertainties in retrieving a regional solution from the network of gravimeters, the calibration and validation aspects of the GRACE data processing based on the annual hydrology cycle in Europe are in progress.
An ethics training specific for European public health.
Camps, Victoria; Hernández-Aguado, Ildefonso; Puyol, Angel; Segura, Andreu
2015-01-01
Training in public health ethics is not at the core of public health programmes in Europe. The fruitful progress of the United States could stimulate the European schools of public health and other academic institutions to develop specifically European teaching programmes for ethics that embrace both transatlantic innovations and some adaptations based on the evolution of moral values in European societies. This paper reviews the arguments for a European public health ethics curriculum and recommends the main features of such a programme. Europe shares common values and, above all, the three major ethical principles that were socially and politically crystallized by the French Revolution: liberty, equality, and fraternity. Fraternity, otherwise known as solidarity, although rarely mentioned in the literature on ethical issues, is the moral value that best defines the European concept of public health expressed as a common good, mutual aid, and a collective or shared responsibility for health of the population. Specific political motivations were responsible for the origin of European health systems and for current policy proposals led by the European Union, such as Europe's commitments, at least in theory, to: reduce social inequities in health and to develop the health in all policies approach. These and other initiatives, albeit not exclusively European, have political and legal repercussions that pose unique ethical challenges. Europe combines homogeneity in social determinants of health with heterogeneity in public health approaches and interventions. It is therefore necessary to develop training in ethics and good government for all public health workers in Europe, especially since a large segment of the population's health depends on actions and decisions adopted by the European Commission and its regulatory agencies as well as for non EU European Region countries. Based on these arguments, the paper concludes with several recommendations for a common nucleus for the ethics curriculum in Europe.
The European Drought Observatory (EDO): Current State and Future Directions
NASA Astrophysics Data System (ADS)
Vogt, Jürgen; Sepulcre, Guadalupe; Magni, Diego; Valentini, Luana; Singleton, Andrew; Micale, Fabio; Barbosa, Paulo
2013-04-01
Europe has repeatedly been affected by droughts, resulting in considerable ecological and economic damage and climate change studies indicate a trend towards increasing climate variability most likely resulting in more frequent drought occurrences also in Europe. Against this background, the European Commission's Joint Research Centre (JRC) is developing methods and tools for assessing, monitoring and forecasting droughts in Europe and develops a European Drought Observatory (EDO) to complement and integrate national activities with a European view. At the core of the European Drought Observatory (EDO) is a portal, including a map server, a metadata catalogue, a media-monitor and analysis tools. The map server presents Europe-wide up-to-date information on the occurrence and severity of droughts, which is complemented by more detailed information provided by regional, national and local observatories through OGC compliant web mapping and web coverage services. In addition, time series of historical maps as well as graphs of the temporal evolution of drought indices for individual grid cells and administrative regions in Europe can be retrieved and analysed. Current work is focusing on validating the available products, developing combined indicators, improving the functionalities, extending the linkage to additional national and regional drought information systems and testing options for medium-range probabilistic drought forecasting across Europe. Longer-term goals include the development of long-range drought forecasting products, the analysis of drought hazard and risk, the monitoring of drought impact and the integration of EDO in a global drought information system. The talk will provide an overview on the development and state of EDO, the different products, and the ways to include a wide range of stakeholders (i.e. European, national river basin, and local authorities) in the development of the system as well as an outlook on the future developments.
In silico evolution of biochemical networks
NASA Astrophysics Data System (ADS)
Francois, Paul
2010-03-01
We use computational evolution to select models of genetic networks that can be built from a predefined set of parts to achieve a certain behavior. Selection is made with the help of a fitness defining biological functions in a quantitative way. This fitness has to be specific to a process, but general enough to find processes common to many species. Computational evolution favors models that can be built by incremental improvements in fitness rather than via multiple neutral steps or transitions through less fit intermediates. With the help of these simulations, we propose a kinetic view of evolution, where networks are rapidly selected along a fitness gradient. This mathematics recapitulates Darwin's original insight that small changes in fitness can rapidly lead to the evolution of complex structures such as the eye, and explain the phenomenon of convergent/parallel evolution of similar structures in independent lineages. We will illustrate these ideas with networks implicated in embryonic development and patterning of vertebrates and primitive insects.
Yaoqi Zhang; Bin Zheng; Ge Sun; Peilei Fan Fan
2015-01-01
Lawn has been used for landscaping, gardening, and beautification of homes and cities for a long time. The evolution of the lawn reflects important cultural and biophysical interactions between humans and nature. The American lawn, which was from Europe and has been a part of the American dream for home ownership and culture, has become an area going against nature for...
ERIC Educational Resources Information Center
Kováts, Gergely; Heidrich, Balázs; Chandler, Nick
2017-01-01
Higher education in Central Europe has been scrutinised from many different perspectives during the last 30 years. In our analysis, we focus solely on Hungary and specifically on two key areas: governance and organisational structure. Using an analytical model proposed by Leisyte (2014), we analyse how the governance and organisational structure…
N. Evangeliou; Y. Balkanski; A. Cozic; WeiMin Hao; F. Mouillot; K. Thonicke; R. Paugam; S. Zibtsev; T. A. Mousseau; R. Wang; B. Poulter; A. Petkov; C. Yue; P. Cadule; B. Koffi; J. W. Kaiser; A. P. Moller
2015-01-01
In this paper, we analyze the current and future status of forests in Ukraine and Belarus that were contaminated after the nuclear disaster in 1986. Using several models, together with remote-sensing data and observations, we studied how climate change in these forests may affect fire regimes. We investigated the possibility of 137Cs displacement over Europe...
ERIC Educational Resources Information Center
Bokaris, Efthymios P.; Koutalis, Vangelis
2008-01-01
The acceptance of new chemical ideas, before the Chemical Revolution of Lavoisier, in Greek-speaking communities in the 17th and 18th centuries did not create a discourse of chemical philosophy, as it did in Europe, but rather a "philosophy" of chemistry as it was formed through the evolution of didactic traditions of Chemistry. This…
US-Europe Workshop on Impact of Multifunctionality on Damage Evolution in Composite Materials
2015-09-01
Inventions (DD882) Scientific Progress See Attachment Technology Transfer Not applicable UNIVERSITY OF ILLINOIS AEROSPACE ENGINEERING...Composite Materials PI: Ioannis Chasiotis Aerospace Engineering University of Illinois at Urbana-Champaign Talbot Lab, 104 S. Wright Street, Urbana, IL...focused on the current state of corporate research in the aerospace industry which is a major potential adopter of multifunctional composites. The two
Alain Roques
1991-01-01
Patchy and ephemeral resources, such as the cones of conifers, can be very useful in the study of plant-insect relationships. Studies of such relationships in forest entomology are typically complicated by the spatial and temporal characteristics of the host plants, which occur over vast areas and have lifespans of decades or even centuries. The reproductive structures...
USSR and Eastern Europe Scientific Abstracts Geophysics, Astronomy and Space No. 404
1977-09-01
atmospheric circulation. A reliable linear correlation was established between the monthly fallout activity of 10^Ru + -^Rh and monthly precipitation and...therefore the washing out of this radionuclide from tropospheric air by precipitation is more important for its fallout. [153] ANALYTICAL...development of some methods for predicting definite weather phenomena (such as precipitation ), taking into account the evolution of the
NASA Astrophysics Data System (ADS)
Maneva, Y. G.; Poedts, S.
2018-05-01
The power spectra of magnetic field fluctuations in the solar wind typically follow a power-law dependence with respect to the observed frequencies and wave-numbers. The background magnetic field often influences the plasma properties, setting a preferential direction for plasma heating and acceleration. At the same time the evolution of the solar-wind turbulence at the ion and electron scales is influenced by the plasma properties through local micro-instabilities and wave-particle interactions. The solar-wind-plasma temperature and the solar-wind turbulence at sub- and sup-ion scales simultaneously show anisotropic features, with different components and fluctuation power in parallel with and perpendicular to the orientation of the background magnetic field. The ratio between the power of the magnetic field fluctuations in parallel and perpendicular direction at the ion scales may vary with the heliospheric distance and depends on various parameters, including the local wave properties and nonthermal plasma features, such as temperature anisotropies and relative drift speeds. In this work we have performed two-and-a-half-dimensional hybrid simulations to study the generation and evolution of anisotropic turbulence in a drifting multi-ion species plasma. We investigate the evolution of the turbulent spectral slopes along and across the background magnetic field for the cases of initially isotropic and anisotropic turbulence. Finally, we show the effect of the various turbulent spectra for the local ion heating in the solar wind.
Parallel Evolution of Cold Tolerance within Drosophila melanogaster
Braun, Dylan T.; Lack, Justin B.
2017-01-01
Drosophila melanogaster originated in tropical Africa before expanding into strikingly different temperate climates in Eurasia and beyond. Here, we find elevated cold tolerance in three distinct geographic regions: beyond the well-studied non-African case, we show that populations from the highlands of Ethiopia and South Africa have significantly increased cold tolerance as well. We observe greater cold tolerance in outbred versus inbred flies, but only in populations with higher inversion frequencies. Each cold-adapted population shows lower inversion frequencies than a closely-related warm-adapted population, suggesting that inversion frequencies may decrease with altitude in addition to latitude. Using the FST-based “Population Branch Excess” statistic (PBE), we found only limited evidence for parallel genetic differentiation at the scale of ∼4 kb windows, specifically between Ethiopian and South African cold-adapted populations. And yet, when we looked for single nucleotide polymorphisms (SNPs) with codirectional frequency change in two or three cold-adapted populations, strong genomic enrichments were observed from all comparisons. These findings could reflect an important role for selection on standing genetic variation leading to “soft sweeps”. One SNP showed sufficient codirectional frequency change in all cold-adapted populations to achieve experiment-wide significance: an intronic variant in the synaptic gene Prosap. Another codirectional outlier SNP, at senseless-2, had a strong association with our cold trait measurements, but in the opposite direction as predicted. More generally, proteins involved in neurotransmission were enriched as potential targets of parallel adaptation. The ability to study cold tolerance evolution in a parallel framework will enhance this classic study system for climate adaptation. PMID:27777283
Kan, Guangyuan; He, Xiaoyan; Ding, Liuqian; Li, Jiren; Liang, Ke; Hong, Yang
2017-10-01
The shuffled complex evolution optimization developed at the University of Arizona (SCE-UA) has been successfully applied in various kinds of scientific and engineering optimization applications, such as hydrological model parameter calibration, for many years. The algorithm possesses good global optimality, convergence stability and robustness. However, benchmark and real-world applications reveal the poor computational efficiency of the SCE-UA. This research aims at the parallelization and acceleration of the SCE-UA method based on powerful heterogeneous computing technology. The parallel SCE-UA is implemented on Intel Xeon multi-core CPU (by using OpenMP and OpenCL) and NVIDIA Tesla many-core GPU (by using OpenCL, CUDA, and OpenACC). The serial and parallel SCE-UA were tested based on the Griewank benchmark function. Comparison results indicate the parallel SCE-UA significantly improves computational efficiency compared to the original serial version. The OpenCL implementation obtains the best overall acceleration results however, with the most complex source code. The parallel SCE-UA has bright prospects to be applied in real-world applications.
Lai, Taavi; Habicht, Jarno
2011-01-01
To describe alcohol policy changes in parallel to consumption changes in 2005-2010 in Estonia, where alcohol consumption is among the highest in Europe. Review of pertinent legislation and literature. Alcohol consumption decreased since 2008, while alcohol excise tax, sales time restrictions and ad bans have increased since 2005. An economic downturn started in 2008. The precise roles of policy changes and the economic downturn in the decline of alcohol consumption, and whether the decrease will be sustained, are still unclear.
Experimental transmission of Zika virus by mosquitoes from central Europe.
Heitmann, Anna; Jansen, Stephanie; Lühken, Renke; Leggewie, Mayke; Badusche, Marlis; Pluskota, Björn; Becker, Norbert; Vapalahti, Olli; Schmidt-Chanasit, Jonas; Tannich, Egbert
2017-01-12
Mosquitoes collected in Germany in 2016, including Culex pipiens pipiens biotype pipiens, Culex torrentium and Aedes albopictus, as well as Culex pipiens pipiens biotype molestus (in colony since 2011) were experimentally infected with Zika virus (ZIKV) at 18 °C or 27 °C. None of the Culex taxa showed vector competence for ZIKV. In contrast, Aedes albopictus were susceptible for ZIKV but only at 27 °C, with transmission rates similar to an Aedes aegypti laboratory colony tested in parallel. This article is copyright of The Authors, 2017.
Parallel evolution of storage roots in Morning Glories (Convolvulaceae)
USDA-ARS?s Scientific Manuscript database
Storage roots are an ecologically and agriculturally important plant trait. In morning glories, storage roots are well characterized in the crop species sweetpotato. Storage roots have evolved numerous times across the morning glory family. This study aims to understand whether this was through para...
Drought evolution: greater and faster impacts on blue water than on green water
NASA Astrophysics Data System (ADS)
Destouni, G.; Orth, R.
2017-12-01
Drought propagates through the terrestrial water cycle, affecting different interlinked geospheres which have so far been mostly investigated separately and without direct comparison. By use of comprehensive multi-decadal data from >400 near-natural catchments along a steep climate gradient across Europe we here analyze drought propagation from precipitation (deficits) through soil moisture to runoff (blue water) and evapotranspiration (green water). We show that soil-moisture droughts reduce runoff stronger and faster than evapotranspiration. While runoff responds within weeks, evapotranspiration can be unaffected for months, or even entirely as in central and northern Europe. Understanding these different drought pathways towards blue and green water resources contributes to improve food and water security and offers early warning potential to mitigate (future) drought impacts on society and ecosystems.
Parallel and convergent evolution of the dim-light vision gene RH1 in bats (Order: Chiroptera).
Shen, Yong-Yi; Liu, Jie; Irwin, David M; Zhang, Ya-Ping
2010-01-21
Rhodopsin, encoded by the gene Rhodopsin (RH1), is extremely sensitive to light, and is responsible for dim-light vision. Bats are nocturnal mammals that inhabit poor light environments. Megabats (Old-World fruit bats) generally have well-developed eyes, while microbats (insectivorous bats) have developed echolocation and in general their eyes were degraded, however, dramatic differences in the eyes, and their reliance on vision, exist in this group. In this study, we examined the rod opsin gene (RH1), and compared its evolution to that of two cone opsin genes (SWS1 and M/LWS). While phylogenetic reconstruction with the cone opsin genes SWS1 and M/LWS generated a species tree in accord with expectations, the RH1 gene tree united Pteropodidae (Old-World fruit bats) and Yangochiroptera, with very high bootstrap values, suggesting the possibility of convergent evolution. The hypothesis of convergent evolution was further supported when nonsynonymous sites or amino acid sequences were used to construct phylogenies. Reconstructed RH1 sequences at internal nodes of the bat species phylogeny showed that: (1) Old-World fruit bats share an amino acid change (S270G) with the tomb bat; (2) Miniopterus share two amino acid changes (V104I, M183L) with Rhinolophoidea; (3) the amino acid replacement I123V occurred independently on four branches, and the replacements L99M, L266V and I286V occurred each on two branches. The multiple parallel amino acid replacements that occurred in the evolution of bat RH1 suggest the possibility of multiple convergences of their ecological specialization (i.e., various photic environments) during adaptation for the nocturnal lifestyle, and suggest that further attention is needed on the study of the ecology and behavior of bats.
Parallel and Convergent Evolution of the Dim-Light Vision Gene RH1 in Bats (Order: Chiroptera)
Shen, Yong-Yi; Liu, Jie; Irwin, David M.; Zhang, Ya-Ping
2010-01-01
Rhodopsin, encoded by the gene Rhodopsin (RH1), is extremely sensitive to light, and is responsible for dim-light vision. Bats are nocturnal mammals that inhabit poor light environments. Megabats (Old-World fruit bats) generally have well-developed eyes, while microbats (insectivorous bats) have developed echolocation and in general their eyes were degraded, however, dramatic differences in the eyes, and their reliance on vision, exist in this group. In this study, we examined the rod opsin gene (RH1), and compared its evolution to that of two cone opsin genes (SWS1 and M/LWS). While phylogenetic reconstruction with the cone opsin genes SWS1 and M/LWS generated a species tree in accord with expectations, the RH1 gene tree united Pteropodidae (Old-World fruit bats) and Yangochiroptera, with very high bootstrap values, suggesting the possibility of convergent evolution. The hypothesis of convergent evolution was further supported when nonsynonymous sites or amino acid sequences were used to construct phylogenies. Reconstructed RH1 sequences at internal nodes of the bat species phylogeny showed that: (1) Old-World fruit bats share an amino acid change (S270G) with the tomb bat; (2) Miniopterus share two amino acid changes (V104I, M183L) with Rhinolophoidea; (3) the amino acid replacement I123V occurred independently on four branches, and the replacements L99M, L266V and I286V occurred each on two branches. The multiple parallel amino acid replacements that occurred in the evolution of bat RH1 suggest the possibility of multiple convergences of their ecological specialization (i.e., various photic environments) during adaptation for the nocturnal lifestyle, and suggest that further attention is needed on the study of the ecology and behavior of bats. PMID:20098620
Efficient solution of parabolic equations by Krylov approximation methods
NASA Technical Reports Server (NTRS)
Gallopoulos, E.; Saad, Y.
1990-01-01
Numerical techniques for solving parabolic equations by the method of lines is addressed. The main motivation for the proposed approach is the possibility of exploiting a high degree of parallelism in a simple manner. The basic idea of the method is to approximate the action of the evolution operator on a given state vector by means of a projection process onto a Krylov subspace. Thus, the resulting approximation consists of applying an evolution operator of a very small dimension to a known vector which is, in turn, computed accurately by exploiting well-known rational approximations to the exponential. Because the rational approximation is only applied to a small matrix, the only operations required with the original large matrix are matrix-by-vector multiplications, and as a result the algorithm can easily be parallelized and vectorized. Some relevant approximation and stability issues are discussed. We present some numerical experiments with the method and compare its performance with a few explicit and implicit algorithms.
Moreno-Letelier, Alejandra; Olmedo, Gabriela; Eguiarte, Luis E.; Martinez-Castilla, Leon; Souza, Valeria
2011-01-01
The high affinity phosphate transport system (pst) is crucial for phosphate uptake in oligotrophic environments. Cuatro Cienegas Basin (CCB) has extremely low P levels and its endemic Bacillus are closely related to oligotrophic marine Firmicutes. Thus, we expected the pst operon of CCB to share the same evolutionary history and protein similarity to marine Firmicutes. Orthologs of the pst operon were searched in 55 genomes of Firmicutes and 13 outgroups. Phylogenetic reconstructions were performed for the pst operon and 14 concatenated housekeeping genes using maximum likelihood methods. Conserved domains and 3D structures of the phosphate-binding protein (PstS) were also analyzed. The pst operon of Firmicutes shows two highly divergent clades with no correlation to the type of habitat nor a phylogenetic congruence, suggesting horizontal gene transfer. Despite sequence divergence, the PstS protein had a similar 3D structure, which could be due to parallel evolution after horizontal gene transfer events. PMID:21461370
Daane, Jacob M.; Rohner, Nicolas; Konstantinidis, Peter; Djuranovic, Sergej; Harris, Matthew P.
2016-01-01
The identification of genetic mechanisms underlying evolutionary change is critical to our understanding of natural diversity, but is presently limited by the lack of genetic and genomic resources for most species. Here, we present a new comparative genomic approach that can be applied to a broad taxonomic sampling of nonmodel species to investigate the genetic basis of evolutionary change. Using our analysis pipeline, we show that duplication and divergence of fgfr1a is correlated with the reduction of scales within fishes of the genus Phoxinellus. As a parallel genetic mechanism is observed in scale-reduction within independent lineages of cypriniforms, our finding exposes significant developmental constraint guiding morphological evolution. In addition, we identified fixed variation in fgf20a within Phoxinellus and demonstrated that combinatorial loss-of-function of fgfr1a and fgf20a within zebrafish phenocopies the evolved scalation pattern. Together, these findings reveal epistatic interactions between fgfr1a and fgf20a as a developmental mechanism regulating skeletal variation among fishes. PMID:26452532
Huang, Yu; Guo, Feng; Li, Yongling; Liu, Yufeng
2015-01-01
Parameter estimation for fractional-order chaotic systems is an important issue in fractional-order chaotic control and synchronization and could be essentially formulated as a multidimensional optimization problem. A novel algorithm called quantum parallel particle swarm optimization (QPPSO) is proposed to solve the parameter estimation for fractional-order chaotic systems. The parallel characteristic of quantum computing is used in QPPSO. This characteristic increases the calculation of each generation exponentially. The behavior of particles in quantum space is restrained by the quantum evolution equation, which consists of the current rotation angle, individual optimal quantum rotation angle, and global optimal quantum rotation angle. Numerical simulation based on several typical fractional-order systems and comparisons with some typical existing algorithms show the effectiveness and efficiency of the proposed algorithm. PMID:25603158
EUPDF-II: An Eulerian Joint Scalar Monte Carlo PDF Module : User's Manual
NASA Technical Reports Server (NTRS)
Raju, M. S.; Liu, Nan-Suey (Technical Monitor)
2004-01-01
EUPDF-II provides the solution for the species and temperature fields based on an evolution equation for PDF (Probability Density Function) and it is developed mainly for application with sprays, combustion, parallel computing, and unstructured grids. It is designed to be massively parallel and could easily be coupled with any existing gas-phase CFD and spray solvers. The solver accommodates the use of an unstructured mesh with mixed elements of either triangular, quadrilateral, and/or tetrahedral type. The manual provides the user with an understanding of the various models involved in the PDF formulation, its code structure and solution algorithm, and various other issues related to parallelization and its coupling with other solvers. The source code of EUPDF-II will be available with National Combustion Code (NCC) as a complete package.
Parallel Grand Canonical Monte Carlo (ParaGrandMC) Simulation Code
NASA Technical Reports Server (NTRS)
Yamakov, Vesselin I.
2016-01-01
This report provides an overview of the Parallel Grand Canonical Monte Carlo (ParaGrandMC) simulation code. This is a highly scalable parallel FORTRAN code for simulating the thermodynamic evolution of metal alloy systems at the atomic level, and predicting the thermodynamic state, phase diagram, chemical composition and mechanical properties. The code is designed to simulate multi-component alloy systems, predict solid-state phase transformations such as austenite-martensite transformations, precipitate formation, recrystallization, capillary effects at interfaces, surface absorption, etc., which can aid the design of novel metallic alloys. While the software is mainly tailored for modeling metal alloys, it can also be used for other types of solid-state systems, and to some degree for liquid or gaseous systems, including multiphase systems forming solid-liquid-gas interfaces.
He, Wei-Ming; Feng, Yulong; Ridenour, Wendy M; Thelen, Giles C; Pollock, Jarrod L; Diaconu, Alecu; Callaway, Ragan M
2009-04-01
Recent studies suggest that the invasive success of Centaurea maculosa may be related to its stronger allelopathic effects on native North American species than on related European species, one component of the "novel weapons" hypothesis. Other research indicates that C. maculosa plants from the invasive range in North America have evolved to be larger and better competitors than conspecifics from the native range in Europe, a component of the "evolution of increased competitive ability" hypothesis. These hypotheses are not mutually exclusive, but this evidence sets the stage for comparing the relative importance of evolved competitive ability to inherent competitive traits. In a competition experiment with a large number of C. maculosa populations, we found no difference in the competitive effects of C. maculosa plants from North America and Europe on other species. However, both North American and European C. maculosa were much better competitors against plants native to North America than congeners native to Romania, collected in areas where C. maculosa is also native. These results are consistent with the novel weapons hypothesis. But, in a second experiment using just one population from North America and Europe, and where North American and European species were collected from a broader range of sites, competitive interactions were weaker overall, and the competitive effects of C. maculosa were slightly stronger against European species than against North American species. Also consistent with the novel weapons hypothesis, (+/-)-catechin had stronger effects on native North American species than on native European species in two experiments. Our results suggest that the regional composition of the plant communities being invaded by C. maculosa may be more important for invasive success than the evolution of increased size and competitive ability.
Forecasting the northern African dust outbreak towards Europe in April 2011: A model intercomparison
Huneeus, N.; Basart, S.; Fiedler, S.; ...
2016-04-21
In the framework of the World Meteorological Organisation's Sand and Dust Storm Warning Advisory and Assessment System, we evaluated the predictions of five state-of-the-art dust forecast models during an intense Saharan dust outbreak affecting western and northern Europe in April 2011. We assessed the capacity of the models to predict the evolution of the dust cloud with lead times of up to 72 h using observations of aerosol optical depth (AOD) from the AErosol RObotic NETwork (AERONET) and the Moderate Resolution Imaging Spectroradiometer (MODIS) and dust surface concentrations from a ground-based measurement network. In addition, the predicted vertical dust distributionmore » was evaluated with vertical extinction profiles from the Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP). To assess the diversity in forecast capability among the models, the analysis was extended to wind field (both surface and profile), synoptic conditions, emissions and deposition fluxes. Models predict the onset and evolution of the AOD for all analysed lead times. On average, differences among the models are larger than differences among lead times for each individual model. In spite of large differences in emission and deposition, the models present comparable skill for AOD. In general, models are better in predicting AOD than near-surface dust concentration over the Iberian Peninsula. Models tend to underestimate the long-range transport towards northern Europe. In this paper, our analysis suggests that this is partly due to difficulties in simulating the vertical distribution dust and horizontal wind. Differences in the size distribution and wet scavenging efficiency may also account for model diversity in long-range transport.« less
Tephra studies and the reconstruction of Middle-to-Upper Paleolithic cultural trajectories
NASA Astrophysics Data System (ADS)
d'Errico, Francesco; Banks, William E.
2015-06-01
This study describes an approach which combines tephra records with archaeological and contextual data in order to propose best fit scenarios for past cultural changes and population events. With this goal in mind, we critically examine the environmental, archaeological, anthropological, and chronometric records of the Middle-to-Upper Paleolithic (MUP) Transition (45-35 ka) in Europe and identify a number of shortcomings that make it difficult to correlate and interpret current evidence with respect to historical processes. The utility and limitations of tephra records are highlighted and an heuristic strategy, designed to merge evidence from tephra and other proxies, is described. Such a strategy is used to explore the stratigraphic and chronological relationship between the Campanian Ignimbrite (CI) eruption and the cultural changes that occurred during the MUP Transition in Southern Europe. Uncertainties pertaining to the timing of this volcanic event are discussed before summarizing the stratigraphic and cultural sequences of the eleven archaeological sites (Haua Fteah, Kozarnica, Franchthi Cave, Klissoura, Golema Pesht, Cavallo, Serino, Castelcivita, Tabula Traiana, Temnata, Kostenki 14) where the CI tephra has been reliably identified, along with three sites (Uluzzo, Uluzzo C, Bernardini) where such an identification remains tentative. We conclude that if one discards as inconclusive the recent attribution of the Uluzzian to modern humans, the best fit historical scenario that stems from a critical reading of the evidence identifies the Uluzzian as the result of in-situ cultural evolution of late Mousterian populations in this region of Southern Europe. Such evolution, which entails the independent development of cultural innovations typically found in subsequent cultures of the Upper Paleolithic, would have been truncated, before the CI event, by the arrival of modern or Neanderthal-modern hybrid populations bearing the Proto-Aurignacian material culture.
Nachman, M. W.; Boyer, S. N.; Searle, J. B.; Aquadro, C. F.
1994-01-01
The house mouse, Mus domesticus, includes many distinct Robertsonian (Rb) chromosomal races with diploid numbers from 2n = 22 to 2n = 38. Although these races are highly differentiated karyotypically, they are otherwise indistinguishable from standard karyotype (i.e., 2n = 40) mice, and consequently their evolutionary histories are not well understood. We have examined mitochondrial DNA (mtDNA) sequence variation from the control region and the ND3 gene region among 56 M. domesticus from Western Europe, including 15 Rb populations and 13 standard karyotype populations, and two individuals of the sister species, Mus musculus. mtDNA exhibited an average sequence divergence of 0.84% within M. domesticus and 3.4% between M. domesticus and M. musculus. The transition/transversion bias for the regions sequenced is 5.7:1, and the overall rate of sequence evolution is approximately 10% divergence per million years. The amount of mtDNA variation was as great among different Rb races as among different populations of standard karyotype mice, suggesting that different Rb races do not derive from a single recent maternal lineage. Phylogenetic analysis of the mtDNA sequences resulted in a parsimony tree which contained six major clades. Each of these clades contained both Rb and standard karyotype mice, consistent with the hypothesis that Rb races have arisen independently multiple times. Discordance between phylogeny and geography was attributable to ancestral polymorphism as a consequence of the recent colonization of Western Europe by mice. Two major mtDNA lineages were geographically localized and contained both Rb and standard karyotype mice. The age of these lineages suggests that mice have moved into Europe only within the last 10,000 years and that Rb populations in different geographic regions arose during this time. PMID:8005418
Kolář, Filip; Lučanová, Magdalena; Vít, Petr; Urfus, Tomáš; Chrtek, Jindřich; Fér, Tomáš; Ehrendorfer, Friedrich; Suda, Jan
2013-01-01
Background and Aims Plants endemic to areas covered by ice sheets during the last glaciation represent paradigmatic examples of rapid speciation in changing environments, yet very few systems outside the harsh arctic zone have been comprehensively investigated so far. The Galium pusillum aggregate (Rubiaceae) is a challenging species complex that exhibits a marked differentiation in boreal parts of Northern Europe. As a first step towards understanding its evolutionary history in deglaciated regions, this study assesses cytological variation and ecological preferences of the northern endemics and compares the results with corresponding data for species occurring in neighbouring unglaciated parts of Central and Western Europe. Methods DNA flow cytometry was used together with confirmatory chromosome counts to determine ploidy levels and relative genome sizes in 1158 individuals from 181 populations. A formalized analysis of habitat preferences was applied to explore niche differentiation among species and ploidy levels. Key Results The G. pusillum complex evolved at diploid and tetraploid levels in Northern Europe, in contrast to the high-polyploid evolution of most other northern endemics. A high level of eco-geographic segregation was observed between different species (particularly along gradients of soil pH and competition) which is unusual for plants in deglaciated areas and most probably contributes to maintaining species integrity. Relative monoploid DNA contents of the species from previously glaciated regions were significantly lower than those of their counterparts from mostly unglaciated Central Europe, suggesting independent evolutionary histories. Conclusions The aggregate of G. pusillum in Northern Europe represents an exceptional case with a geographically vicariant and ecologically distinct diploid/tetraploid species endemic to formerly glaciated areas. The high level of interspecific differentiation substantially widens our perception of the evolutionary dynamics and speciation rates in the dramatically changing environments of Northern Europe. PMID:23589633
A critical review of the German Paleolithic hominin record.
Street, Martin; Terberger, Thomas; Orschiedt, Jörg
2006-12-01
We review the hominin fossil record from western Central Europe in light of the recent major revisions of the geochronological context. The mandible from Mauer (Homo heidelbergensis), dated to circa 500,000 years ago, continues to represent the earliest German hominin and may coincide with the occupation of Europe north of the high alpine mountain chains. Only limited new evidence is available for the Middle Pleistocene, mostly in the form of skull fragments, a pattern that may relate to taphonomic processes. These finds and their ages suggest the gradual evolution of a suite of Neandertal features during this period. Despite new finds of classic Neandertals, there is no clear proof for Neandertal burial from Germany. Alternatively, cut marks on a skull fragment from the Neandertal type site suggest special treatment of that individual. New Accelerator Mass Spectrometry (AMS) radiocarbon dates of previous finds leave little reliably dated evidence for anatomically modern humans (AMH) in Europe before 30,000 BP; the remains from Hahnöfersand, Binshof-Speyer, Paderborn-Sande, and Vogelherd are now of Holocene age. Thus, a correlation of AMH with the Aurignacian remains to be proven, and the general idea of a long coexistence of Neandertals and AMH in Europe may be questioned. In western Central Europe, evidence of Gravettian human fossils is also very limited, although a new double grave from lower Austria may be relevant. The only dated burial from the German Upper Paleolithic (from Mittlere Klause) falls into a time period (circa 18,600 BP) represented by only a few occupation sites in western Central Europe. A number of human remains at Magdalenian sites appear to result from variable (secondary) burial practices. In contrast, the Final Paleolithic (circa 12,000-9600 cal. BC) yields an increase of hominin finds, including multiple burials (Bonn-Oberkassel, Neuwied-Irlich), similar to the situation in western and southern Europe.
Past climate changes, population dynamics and the origin of Bison in Europe.
Massilani, Diyendo; Guimaraes, Silvia; Brugal, Jean-Philip; Bennett, E Andrew; Tokarska, Malgorzata; Arbogast, Rose-Marie; Baryshnikov, Gennady; Boeskorov, Gennady; Castel, Jean-Christophe; Davydov, Sergey; Madelaine, Stéphane; Putelat, Olivier; Spasskaya, Natalia N; Uerpmann, Hans-Peter; Grange, Thierry; Geigl, Eva-Maria
2016-10-21
Climatic and environmental fluctuations as well as anthropogenic pressure have led to the extinction of much of Europe's megafauna. The European bison or wisent (Bison bonasus), one of the last wild European large mammals, narrowly escaped extinction at the onset of the 20th century owing to hunting and habitat fragmentation. Little is known, however, about its origin, evolutionary history and population dynamics during the Pleistocene. Through ancient DNA analysis we show that the emblematic European bison has experienced several waves of population expansion, contraction, and extinction during the last 50,000 years in Europe, culminating in a major reduction of genetic diversity during the Holocene. Fifty-seven complete and partial ancient mitogenomes from throughout Europe, the Caucasus, and Siberia reveal that three populations of wisent (Bison bonasus) and steppe bison (B. priscus) alternately occupied Western Europe, correlating with climate-induced environmental changes. The Late Pleistocene European steppe bison originated from northern Eurasia, whereas the modern wisent population emerged from a refuge in the southern Caucasus after the last glacial maximum. A population overlap during a transition period is reflected in ca. 36,000-year-old paintings in the French Chauvet cave. Bayesian analyses of these complete ancient mitogenomes yielded new dates of the various branching events during the evolution of Bison and its radiation with Bos, which lead us to propose that the genetic affiliation between the wisent and cattle mitogenomes result from incomplete lineage sorting rather than post-speciation gene flow. The paleogenetic analysis of bison remains from the last 50,000 years reveals the influence of climate changes on the dynamics of the various bison populations in Europe, only one of which survived into the Holocene, where it experienced severe reductions in its genetic diversity. The time depth and geographical scope of this study enables us to propose temperate Western Europe as a suitable biotope for the wisent compatible with its reintroduction.
A Parallel Genetic Algorithm for Automated Electronic Circuit Design
NASA Technical Reports Server (NTRS)
Long, Jason D.; Colombano, Silvano P.; Haith, Gary L.; Stassinopoulos, Dimitris
2000-01-01
Parallelized versions of genetic algorithms (GAs) are popular primarily for three reasons: the GA is an inherently parallel algorithm, typical GA applications are very compute intensive, and powerful computing platforms, especially Beowulf-style computing clusters, are becoming more affordable and easier to implement. In addition, the low communication bandwidth required allows the use of inexpensive networking hardware such as standard office ethernet. In this paper we describe a parallel GA and its use in automated high-level circuit design. Genetic algorithms are a type of trial-and-error search technique that are guided by principles of Darwinian evolution. Just as the genetic material of two living organisms can intermix to produce offspring that are better adapted to their environment, GAs expose genetic material, frequently strings of 1s and Os, to the forces of artificial evolution: selection, mutation, recombination, etc. GAs start with a pool of randomly-generated candidate solutions which are then tested and scored with respect to their utility. Solutions are then bred by probabilistically selecting high quality parents and recombining their genetic representations to produce offspring solutions. Offspring are typically subjected to a small amount of random mutation. After a pool of offspring is produced, this process iterates until a satisfactory solution is found or an iteration limit is reached. Genetic algorithms have been applied to a wide variety of problems in many fields, including chemistry, biology, and many engineering disciplines. There are many styles of parallelism used in implementing parallel GAs. One such method is called the master-slave or processor farm approach. In this technique, slave nodes are used solely to compute fitness evaluations (the most time consuming part). The master processor collects fitness scores from the nodes and performs the genetic operators (selection, reproduction, variation, etc.). Because of dependency issues in the GA, it is possible to have idle processors. However, as long as the load at each processing node is similar, the processors are kept busy nearly all of the time. In applying GAs to circuit design, a suitable genetic representation 'is that of a circuit-construction program. We discuss one such circuit-construction programming language and show how evolution can generate useful analog circuit designs. This language has the desirable property that virtually all sets of combinations of primitives result in valid circuit graphs. Our system allows circuit size (number of devices), circuit topology, and device values to be evolved. Using a parallel genetic algorithm and circuit simulation software, we present experimental results as applied to three analog filter and two amplifier design tasks. For example, a figure shows an 85 dB amplifier design evolved by our system, and another figure shows the performance of that circuit (gain and frequency response). In all tasks, our system is able to generate circuits that achieve the target specifications.
Ecological transition predictably associated with gene degeneration.
Wessinger, Carolyn A; Rausher, Mark D
2015-02-01
Gene degeneration or loss can significantly contribute to phenotypic diversification, but may generate genetic constraints on future evolutionary trajectories, potentially restricting phenotypic reversal. Such constraints may manifest as directional evolutionary trends when parallel phenotypic shifts consistently involve gene degeneration or loss. Here, we demonstrate that widespread parallel evolution in Penstemon from blue to red flowers predictably involves the functional inactivation and degeneration of the enzyme flavonoid 3',5'-hydroxylase (F3'5'H), an anthocyanin pathway enzyme required for the production of blue floral pigments. Other types of genetic mutations do not consistently accompany this phenotypic shift. This pattern may be driven by the relatively large mutational target size of degenerative mutations to this locus and the apparent lack of associated pleiotropic effects. The consistent degeneration of F3'5'H may provide a mechanistic explanation for the observed asymmetry in the direction of flower color evolution in Penstemon: Blue to red transitions are common, but reverse transitions have not been observed. Although phenotypic shifts in this system are likely driven by natural selection, internal constraints may generate predictable genetic outcomes and may restrict future evolutionary trajectories. © The Author 2014. 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.
Dawson, J C; Serpolay, E; Giuliano, S; Schermann, N; Galic, N; Chable, V; Goldringer, I
2012-03-01
Because of the lack of varieties for organic agriculture, associations of organic farmers in several European countries have begun cultivating landraces and historic varieties, effectively practicing in situ conservation of agricultural biodiversity. To promote agrobiodiversity conservation, a special list for "conservation varieties" was implemented in 2008 by the EU because for any exchange and marketing of seeds in the EU, a variety must be registered in an official catalog. Our study aimed at improving knowledge on the phenotypic diversity and evolution of such varieties when cultivated on organic farms in Europe, in order to better define their specific characteristics and the implications for the registration process. We assessed multi-trait phenotypic evolution in eight European landraces and historic varieties of bread wheat and in two pureline variety checks, each grown by eight organic farmers over 2 years and then evaluated in a common garden experiment at an organic research farm. Measurements on each farmer's version of each variety included several standard evaluation criteria for assessing distinctness, uniformity and stability for variety registration. Significant phenotypic differentiation was found among farmers' versions of each variety. Some varieties showed considerable variation among versions while others showed fewer phenotypic changes, even in comparison to the two checks. Although farmers' variety would not satisfy uniformity or stability criteria as defined in the catalog evaluation requirements, each variety remained distinct when assessed using multivariate analysis. The amount of differentiation may be related to the initial genetic diversity within landraces and historic varieties.
Engel, Dimitri; Jöst, Hanna; Wink, Michael; Börstler, Jessica; Bosch, Stefan; Garigliany, Mutien-Marie; Jöst, Artur; Czajka, Christina; Lühken, Renke; Ziegler, Ute; Groschup, Martin H.; Pfeffer, Martin; Becker, Norbert; Schmidt-Chanasit, Jonas
2016-01-01
ABSTRACT Usutu virus (USUV), one of the most neglected Old World encephalitic flaviviruses, causes epizootics among wild and captive birds and sporadic infection in humans. The dynamics of USUV spread and evolution in its natural hosts are unknown. Here, we present the phylogeny and evolutionary history of all available USUV strains, including 77 newly sequenced complete genomes from a variety of host species at a temporal and spatial scaled resolution. The results showed that USUV can be classified into six distinct lineages and that the most recent common ancestor of the recent European epizootics emerged in Africa at least 500 years ago. We demonstrated that USUV was introduced regularly from Africa into Europe in the last 50 years, and the genetic diversity of European lineages is shaped primarily by in situ evolution, while the African lineages have been driven by extensive gene flow. Most of the amino acid changes are deleterious polymorphisms removed by purifying selection, with adaptive evolution restricted to the NS5 gene and several others evolving under episodic directional selection, indicating that the ecological or immunological factors were mostly the key determinants of USUV dispersal and outbreaks. Host-specific mutations have been detected, while the host transition analysis identified mosquitoes as the most likely origin of the common ancestor and birds as the source of the recent European USUV lineages. Our results suggest that the major migratory bird flyways could predict the continental and intercontinental dispersal patterns of USUV and that migratory birds might act as potential long-distance dispersal vehicles. PMID:26838717
Neolithic dairy farming at the extreme of agriculture in northern Europe
Cramp, Lucy J. E.; Evershed, Richard P.; Lavento, Mika; Halinen, Petri; Mannermaa, Kristiina; Oinonen, Markku; Kettunen, Johannes; Perola, Markus; Onkamo, Päivi; Heyd, Volker
2014-01-01
The conventional ‘Neolithic package’ comprised animals and plants originally domesticated in the Near East. As farming spread on a generally northwest trajectory across Europe, early pastoralists would have been faced with the challenge of making farming viable in regions in which the organisms were poorly adapted to providing optimal yields or even surviving. Hence, it has long been debated whether Neolithic economies were ever established at the modern limits of agriculture. Here, we examine food residues in pottery, testing a hypothesis that Neolithic farming was practiced beyond the 60th parallel north. Our findings, based on diagnostic biomarker lipids and δ13C values of preserved fatty acids, reveal a transition at ca 2500 BC from the exploitation of aquatic organisms to processing of ruminant products, specifically milk, confirming farming was practiced at high latitudes. Combining this with genetic, environmental and archaeological information, we demonstrate the origins of dairying probably accompanied an incoming, genetically distinct, population successfully establishing this new subsistence ‘package’. PMID:25080345
Turbulence Evolution and Shock Acceleration of Solar Energetic Particles
NASA Technical Reports Server (NTRS)
Chee, Ng K.
2007-01-01
We model the effects of self-excitation/damping and shock transmission of Alfven waves on solar-energetic-particle (SEP) acceleration at a coronal-mass-ejection (CME) driven parallel shock. SEP-excited outward upstream waves speedily bootstrap acceleration. Shock transmission further raises the SEP-excited wave intensities at high wavenumbers but lowers them at low wavenumbers through wavenumber shift. Downstream, SEP excitation of inward waves and damping of outward waves tend to slow acceleration. Nevertheless, > 2000 km/s parallel shocks at approx. 3.5 solar radii can accelerate SEPs to 100 MeV in < 5 minutes.
Application of computational physics within Northrop
NASA Technical Reports Server (NTRS)
George, M. W.; Ling, R. T.; Mangus, J. F.; Thompkins, W. T.
1987-01-01
An overview of Northrop programs in computational physics is presented. These programs depend on access to today's supercomputers, such as the Numerical Aerodynamical Simulator (NAS), and future growth on the continuing evolution of computational engines. Descriptions here are concentrated on the following areas: computational fluid dynamics (CFD), computational electromagnetics (CEM), computer architectures, and expert systems. Current efforts and future directions in these areas are presented. The impact of advances in the CFD area is described, and parallels are drawn to analagous developments in CEM. The relationship between advances in these areas and the development of advances (parallel) architectures and expert systems is also presented.
Linguistic Ambiguity in a Connectionist Model for Grammatical Studies.
ERIC Educational Resources Information Center
Angelica, Julia; Ney, James W.
1995-01-01
Discusses the evolution of the connectionist model of language processing, focusing on the parallel distributed processing (PDP) model proposed by Rumelhart and others (1986) that explains the microstructure of cognition in terms of interactive activation between elementary input, output, and intermediate processing units linked by weighted…
Modern Science and Conservative Islam: An Uneasy Relationship
ERIC Educational Resources Information Center
Edis, Taner
2009-01-01
Familiar Western debates about religion, science, and science education have parallels in the Islamic world. There are difficulties reconciling conservative, traditional versions of Islam with modern science, particularly theories such as evolution. As a result, many conservative Muslim thinkers are drawn toward creationism, hopes of Islamizing…
Long waves in parallel flow in Hele-Shaw cells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zeybek, M.; Yortsos, Y.C.
During the past several years the flow of immiscible flow in Hele-Shaw cells and porous media has been investigated extensively. Of particular interest to most studies has been frontal displacement, specifically viscous fingering instabilities and finger growth. The practical ramifications regarding oil recovery, as well as many other industrial processes in porous media, have served as the primary driving force for most of these investigations. By contrast, little attention has been paid to the motion of lateral fluid interface, which are parallel to the main flow direction. Parallel flow is an often encountered, although much overlooked regime. The evolution ofmore » fluid interfaces in parallel flow in Hele-Shaw cells is studied both theoretically and experimentally in the large capillary number limit. It is shown that such interfaces support wave motion, the amplitude of which for long waves is governed by the KdV equation. Experiments are conducted in a long Hele-Shaw cell that validate the theory in the symmetric case. 35 refs., 16 figs.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Reimberg, Paulo; Bernardeau, Francis; Pitrou, Cyril, E-mail: paulo.flose-reimberg@cea.fr, E-mail: francis.bernardeau@cea.fr, E-mail: pitrou@iap.fr
Redshift-space distortions are generally considered in the plane parallel limit, where the angular separation between the two sources can be neglected. Given that galaxy catalogues now cover large fractions of the sky, it becomes necessary to consider them in a formalism which takes into account the wide angle separations. In this article we derive an operational formula for the matter correlators in the Newtonian limit to be used in actual data sets. In order to describe the geometrical nature of the wide angle RSD effect on Fourier space, we extend the formalism developed in configuration space to Fourier space withoutmore » relying on a plane-parallel approximation, but under the extra assumption of no bias evolution. We then recover the plane-parallel limit not only in configuration space where the geometry is simpler, but also in Fourier space, and we exhibit the first corrections that should be included in large surveys as a perturbative expansion over the plane-parallel results. We finally compare our results to existing literature, and show explicitly how they are related.« less
The spatial distribution and evolution characteristics of North Atlantic cyclones
NASA Astrophysics Data System (ADS)
Dacre, H.; Gray, S.
2009-09-01
Mid-latitude cyclones play a large role in determining the day-to-day weather conditions in western Europe through their associated wind and precipitation patterns. Thus, their typical spatial and evolution characteristics are of great interest to meteorologists, insurance and risk management companies. In this study a feature tracking algorithm is applied to a cyclone database produced using the Hewson-method of cyclone identification, based on low-level gradients of wet-bulb potential temperature, to produce a climatology of mid-latitude cyclones. The aim of this work is to compare the cyclone track and density statistics found in this study with previous climatologies and to determine reasons for any differences. This method is found to compare well with other cyclone identification methods; the north Atlantic storm track is reproduced along with the major regions of genesis. Differences are attributed to cyclone lifetime and strength thresholds, dataset resolution and cyclone identification and tracking methods. Previous work on cyclone development has been largely limited to case studies as opposed to analysis of climatological data, and does not distinguish between the different stages of cyclone evolution. The cyclone database used in this study allows cyclone characteristics to be tracked throughout the cyclone lifecycle. This enables the evaluation of the characteristics of cyclone evolution for systems forming in different genesis regions and a calculation of the spatial distribution and evolution of these characteristics in composite cyclones. It was found that most of the cyclones that cross western Europe originate in the east Atlantic where the baroclinicity and sea surface temperature gradients are weak compared to the west Atlantic. East Atlantic cyclones also have higher low-level relative vorticity and lower mean sea level pressure at their genesis point than west Atlantic cyclones. This is consistent with the hypothesis that they are secondary cyclones developing on the trailing fronts of pre-existing 'parent' cyclones. Furthermore, it was found that a higher proportion of east Atlantic cyclones are type C cyclones with strong upper-level forcing but weak low-level forcing suggesting that latent energy plays a more important role in their intensification than for west Atlantic cyclones.
The spatial distribution and evolution characteristics of North Atlantic cyclones
NASA Astrophysics Data System (ADS)
Dacre, H.; Gray, S.
2009-04-01
Mid-latitude cyclones play a large role in determining the day-to-day weather conditions in western Europe through their associated wind and precipitation patterns. Thus, their typical spatial and evolution characteristics are of great interest to meteorologists, insurance and risk management companies. In this study a feature tracking algorithm is applied to a cyclone database produced using the Hewson-method of cyclone identification, based on low-level gradients of wet-bulb potential temperature, to produce a climatology of mid-latitude cyclones. The aim of this work is to compare the cyclone track and density statistics found in this study with previous climatologies. This method is found to compare well with other cyclone identification methods; the north Atlantic storm track is reproduced along with the major regions of genesis. Differences are attributed to cyclone lifetime and strength thresholds, dataset resolution and cyclone identification and tracking methods. Previous work on cyclone development has been largely limited to case studies as opposed to analysis of climatological data, and does not distinguish between the different stages of cyclone evolution. The cyclone database used in this study allows cyclone characteristics to be tracked throughout the cyclone lifecycle. This enables the evaluation of the characteristics of cyclone evolution for systems forming in different genesis regions and a calculation of the spatial distribution and evolution of these characteristics in composite cyclones. It was found that most of the cyclones that cross western Europe originate in the east Atlantic where the baroclinicity and sea surface temperature gradients are weak compared to the west Atlantic. East Atlantic cyclones also have higher low-level relative vorticity and lower mean sea level pressure at their genesis point than west Atlantic cyclones. This is consistent with the hypothesis that they are secondary cyclones developing on the trailing fronts of pre-existing 'parent' cyclones. Furthermore, it was found that a higher proportion of east Atlantic cyclones are type C cyclones with strong upper-level forcing but weak low-level forcing suggesting that latent energy plays a more important role in their intensification than for west Atlantic cyclones.
The United States of Europe: The Evolution of European Unity, 1918-2001
2002-01-01
1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no...person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control...for reducing this burden, to Washington headquarters services, directorate for information operations and reports, 1215 Jefferson davis highway, suite
Recent evolution of antibiotic resistance in the anaerobes as compared to previous decades.
Boyanova, Lyudmila; Kolarov, Rossen; Mitov, Ivan
2015-02-01
Evolution of antibiotic resistance in the anaerobes was reviewed using recent data covering 2000-2013 as compared to previous years. All studies reported growing moxifloxacin resistance in Bacteroides/Parabacteroides spp. in Europe and USA and in Clostridium difficile in Europe. In half or more studies, the resistance rates in Bacteroides/Parabacteroides spp. to amoxicillin-clavulanate or ampicillin-sulbactam and clindamycin rose. In some studies, an increase in resistance was found in Bacteroides/Parabacteroides spp. to cefoxitin/cefotetan and carbapenems, in Prevotella spp. to penicillins, in anaerobic cocci to clindamycin and in Bacteroides/Parabacteroides spp. and C. difficile to metronidazole. Decreasing resistance was also observed, e.g. in Bacteroides/Parabacteroides spp. to cephalosporins, in Prevotella spp. and C. difficile to tetracyclines and in C. difficile to rifampin. No resistance changes were found to tigecycline, in Bacteroides/Parabacteroides spp. to chloramphenicol and in C. difficile to vancomycin. Factors influencing the resistance were the species, ribotype, country, hospital centre, antibiotic consumption and specimen type. In conclusion, the antibiotic resistance changes in the anaerobes are diverse and dynamic. Regular national surveys of resistance and both anaerobic microbiology and susceptibility testing of the isolates become more and more valuable. Copyright © 2014 Elsevier Ltd. All rights reserved.
Phylogeography of the European sturgeon (Acipenser sturio): A critically endangered species.
Chassaing, Olivier; Desse-Berset, Nathalie; Hänni, Catherine; Hughes, Sandrine; Berrebi, Patrick
2016-01-01
The European sturgeon (Acipenser sturio) was once a common species throughout Europe, but the sole remaining natural population presently inhabits the Gironde Estuary in France (Atlantic coast). The species was classified as 'Critically Endangered' in 1996, and the Gironde population is now on the verge of extinction. In this setting, and for the first time, we present the past phylogeographical features of this species throughout Europe along with an assessment of its former genetic diversity. This study was based on a molecular analysis (mtDNA CR sequencing) of 10 living specimens from the Gironde Estuary, 55 museum specimens that had been caught along 19th and 20th centuries, and 59 archaeological remains dating back to 260-5000years BP, from which mitochondrial DNA was extracted and amplified. Although discontinuous, the produced data provided a realistic image of the former structure of A. sturio in Europe. Reconstruction of the phylogenetic trees and haplotypes network led to the identification of several clades. The mitochondrial genetic diversity of this species was found to be much greater at the core (Iberian Peninsula, Mediterranean and Adriatic regions) than along the margins (Atlantic-Northern Europe, Black Sea) of its range. A series of hypotheses on the dates and causes of changes in the species' major structures are put forward on the basis of these data. Finally, competition with A. oxyrinchus, a sibling species whose presence in Northern Europe was recently reconsidered, is presented as a major factor in the evolution of this species. Copyright © 2015 Elsevier Inc. All rights reserved.
Paleomagnetic and geochronologic constraints on the geodynamic evolution of the Central Dinarides
de Leeuw, Arjan; Mandic, Oleg; Krijgsman, Wout; Kuiper, Klaudia; Hrvatović, Hazim
2012-01-01
The geodynamic evolution of the Dinaride Mountains of southeastern Europe is relatively poorly understood, especially in comparison with the neighboring Alps and Carpathians. Here, we construct a new chronostratigraphy for the post-orogenic intra-montane basins of the Central Dinarides based on paleomagnetic and 40Ar/39Ar age data. A first phase of basin formation occurred in the late Oligocene. A second phase of basin formation took place between 18 and 13 Ma, concurrent with profound extension in the neighboring Pannonian Basin. Our paleomagnetic results further indicate that the Dinarides have not experienced any significant tectonic rotation since the late Oligocene. This implies that the Dinarides were decoupled from the adjacent Adria and the Tisza–Dacia Mega-Units that both underwent major rotation during the Miocene. The Dinaride orogen must consequently have accommodated significant shortening. This is corroborated by our AMS data that indicate post-Middle Miocene shortening in the frontal zone, wrenching in the central part of the orogen, and compression in the hinterland. A review of paleomagnetic data from the Adria plate, which plays a major role in the evolution of the Dinarides as well as the Alps, constrains rotation since the Early Cretaceous to 48 ± 10° counterclockwise and indicates 20° of this rotation took place since the Miocene. It also shows that Adria behaved as an independent plate from the Late Jurassic to the Eocene. From the Eocene onwards, coupling between Adria and Africa was stronger than between Adria and Europe. Adria continued to behave as an independent plate. The amount of rotation within the Adria-Dinarides collision zone increases with age and proximity of the sampled sediments to undeformed Adria. These results significantly improve our insight in the post-orogenic evolution of the Dinarides and resolve an apparent controversy between structural geological and paleomagnetic rotation estimates for the Dinarides as well as Adria. PMID:27065500
NASA Astrophysics Data System (ADS)
Finsterbusch, Jürgen
2011-01-01
Experiments with two diffusion weightings applied in direct succession in a single acquisition, so-called double- or two-wave-vector diffusion-weighting (DWV) experiments at short mixing times, have been shown to be a promising tool to estimate cell or compartment sizes, e.g. in living tissue. The basic theory for such experiments predicts that the signal decays for parallel and antiparallel wave vector orientations differ by a factor of three for small wave vectors. This seems to be surprising because in standard, single-wave-vector experiments the polarity of the diffusion weighting has no influence on the signal attenuation. Thus, the question how this difference can be understood more pictorially is often raised. In this rather educational manuscript, the phase evolution during a DWV experiment for simple geometries, e.g. diffusion between parallel, impermeable planes oriented perpendicular to the wave vectors, is considered step-by-step and demonstrates how the signal difference develops. Considering the populations of the phase distributions obtained, the factor of three between the signal decays which is predicted by the theory can be reproduced. Furthermore, the intermediate signal decay for orthogonal wave vector orientations can be derived when investigating diffusion in a box. Thus, the presented “phase gymnastics” approach may help to understand the signal modulation observed in DWV experiments at short mixing times.
Efficient Parallel Algorithms for Landscape Evolution Modelling
NASA Astrophysics Data System (ADS)
Moresi, L. N.; Mather, B.; Beucher, R.
2017-12-01
Landscape erosion and the deposition of sediments by river systems are strongly controlled bytopography, rainfall patterns, and the susceptibility of the basement to the action ofrunning water. It is well understood that each of these processes depends on the other, for example:topography results from active tectonic processes; deformation, metamorphosis andexhumation alter the competence of the basement; rainfall patterns depend on topography;uplift and subsidence in response to tectonic stress can be amplified by erosionand sediment deposition. We typically gain understanding of such coupled systems through forward models which capture theessential interactions of the various components and attempt parameterise those parts of the individual systemthat are unresolvable at the scale of the interaction. Here we address the problem of predicting erosion and deposition rates at a continental scalewith a resolution of tens to hundreds of metres in a dynamic, Lagrangian framework. This isa typical requirement for a code to interface with a mantle / lithosphere dynamics model anddemands an efficient, unstructured, parallel implementation. We address this through a very general algorithm that treats all parts of the landscape evolution equationsin sparse-matrix form including those for stream-flow accumulation, dam-filling and catchment determination. This givesus considerable flexibility in developing unstructured, parallel code, and in creating a modular packagethat can be configured by users to work at different temporal and spatial scales, but is also has potential advantagesin treating the non-linear parts of the problem in a general manner.
The Development of the Mathematical Mind.
ERIC Educational Resources Information Center
Scott, Judith
1995-01-01
Draws parallels between Montessori's mathematical curriculum and the evolution of numbers and counting. Suggests that children share with ancient Sumerians a basic human tendency to develop "the mathematical mind." Argues that children do not need to be surrounded by math; rather, the classroom must supply them with the means to explore…
Educational preparation of black nurses: a historical perspective.
Carnegie, M Elizabeth
2005-01-01
To where minority nursing needs to proceed, the minority nursing community must understand where we have been. This historical perspective traces our roots through every level of nursing education. Parallels are drawn between minority nurse educational evolution and the historical events occurring in the greater society in the United States.
Using Coarrays to Parallelize Legacy Fortran Applications: Strategy and Case Study
Radhakrishnan, Hari; Rouson, Damian W. I.; Morris, Karla; ...
2015-01-01
This paper summarizes a strategy for parallelizing a legacy Fortran 77 program using the object-oriented (OO) and coarray features that entered Fortran in the 2003 and 2008 standards, respectively. OO programming (OOP) facilitates the construction of an extensible suite of model-verification and performance tests that drive the development. Coarray parallel programming facilitates a rapid evolution from a serial application to a parallel application capable of running on multicore processors and many-core accelerators in shared and distributed memory. We delineate 17 code modernization steps used to refactor and parallelize the program and study the resulting performance. Our initial studies were donemore » using the Intel Fortran compiler on a 32-core shared memory server. Scaling behavior was very poor, and profile analysis using TAU showed that the bottleneck in the performance was due to our implementation of a collective, sequential summation procedure. We were able to improve the scalability and achieve nearly linear speedup by replacing the sequential summation with a parallel, binary tree algorithm. We also tested the Cray compiler, which provides its own collective summation procedure. Intel provides no collective reductions. With Cray, the program shows linear speedup even in distributed-memory execution. We anticipate similar results with other compilers once they support the new collective procedures proposed for Fortran 2015.« less
Calderón, Luciano; Campagna, Leonardo; Wilke, Thomas; Lormee, Hervé; Eraud, Cyril; Dunn, Jenny C; Rocha, Gregorio; Zehtindjiev, Pavel; Bakaloudis, Dimitrios E; Metzger, Benjamin; Cecere, Jacopo G; Marx, Melanie; Quillfeldt, Petra
2016-11-07
Understanding how past climatic oscillations have affected organismic evolution will help predict the impact that current climate change has on living organisms. The European turtle dove, Streptopelia turtur, is a warm-temperature adapted species and a long distance migrant that uses multiple flyways to move between Europe and Africa. Despite being abundant, it is categorized as vulnerable because of a long-term demographic decline. We studied the demographic history and population genetic structure of the European turtle dove using genomic data and mitochondrial DNA sequences from individuals sampled across Europe, and performing paleoclimatic niche modelling simulations. Overall our data suggest that this species is panmictic across Europe, and is not genetically structured across flyways. We found the genetic signatures of demographic fluctuations, inferring an effective population size (Ne) expansion that occurred between the late Pleistocene and early Holocene, followed by a decrease in the Ne that started between the mid Holocene and the present. Our niche modelling analyses suggest that the variations in the Ne are coincident with recent changes in the availability of suitable habitat. We argue that the European turtle dove is prone to undergo demographic fluctuations, a trait that makes it sensitive to anthropogenic impacts, especially when its numbers are decreasing. Also, considering the lack of genetic structure, we suggest all populations across Europe are equally relevant for conservation.
Enzmann, P J; Kurath, G; Fichtner, D; Bergmann, S M
2005-09-23
Infectious hematopoietic necrosis virus (IHNV) was first detected in Europe in 1987 in France and Italy, and later, in 1992, in Germany. The source of the virus and the route of introduction are unknown. The present study investigates the molecular epidemiology of IHNV outbreaks in Germany since its first introduction. The complete nucleotide sequences of the glycoprotein (G) and non-virion (NV) genes from 9 IHNV isolates from Germany have been determined, and this has allowed the identification of characteristic differences between these isolates. Phylogenetic analysis of partial G gene sequences (mid-G, 303 nucleotides) from North American IHNV isolates (Kurath et al. 2003) has revealed 3 major genogroups, designated U, M and L. Using this gene region with 2 different North American IHNV data sets, it was possible to group the European IHNV strains within the M genogroup, but not in any previously defined subgroup. Analysis of the full length G gene sequences indicated that an independent evolution of IHN viruses had occurred in Europe. IHN viruses in Europe seem to be of a monophyletic origin, again most closely related to North American isolates in the M genogroup. Analysis of the NV gene sequences also showed the European isolates to be monophyletic, but resolution of the 3 genogroups was poor with this gene region. As a result of comparative sequence analyses, several different genotypes have been identified circulating in Europe.
What Pinnipeds Have to Say about Human Speech, Music, and the Evolution of Rhythm.
Ravignani, Andrea; Fitch, W Tecumseh; Hanke, Frederike D; Heinrich, Tamara; Hurgitsch, Bettina; Kotz, Sonja A; Scharff, Constance; Stoeger, Angela S; de Boer, Bart
2016-01-01
Research on the evolution of human speech and music benefits from hypotheses and data generated in a number of disciplines. The purpose of this article is to illustrate the high relevance of pinniped research for the study of speech, musical rhythm, and their origins, bridging and complementing current research on primates and birds. We briefly discuss speech, vocal learning, and rhythm from an evolutionary and comparative perspective. We review the current state of the art on pinniped communication and behavior relevant to the evolution of human speech and music, showing interesting parallels to hypotheses on rhythmic behavior in early hominids. We suggest future research directions in terms of species to test and empirical data needed.
What Pinnipeds Have to Say about Human Speech, Music, and the Evolution of Rhythm
Ravignani, Andrea; Fitch, W. Tecumseh; Hanke, Frederike D.; Heinrich, Tamara; Hurgitsch, Bettina; Kotz, Sonja A.; Scharff, Constance; Stoeger, Angela S.; de Boer, Bart
2016-01-01
Research on the evolution of human speech and music benefits from hypotheses and data generated in a number of disciplines. The purpose of this article is to illustrate the high relevance of pinniped research for the study of speech, musical rhythm, and their origins, bridging and complementing current research on primates and birds. We briefly discuss speech, vocal learning, and rhythm from an evolutionary and comparative perspective. We review the current state of the art on pinniped communication and behavior relevant to the evolution of human speech and music, showing interesting parallels to hypotheses on rhythmic behavior in early hominids. We suggest future research directions in terms of species to test and empirical data needed. PMID:27378843
Silencing, positive selection and parallel evolution: busy history of primate cytochromes C.
Pierron, Denis; Opazo, Juan C; Heiske, Margit; Papper, Zack; Uddin, Monica; Chand, Gopi; Wildman, Derek E; Romero, Roberto; Goodman, Morris; Grossman, Lawrence I
2011-01-01
Cytochrome c (cyt c) participates in two crucial cellular processes, energy production and apoptosis, and unsurprisingly is a highly conserved protein. However, previous studies have reported for the primate lineage (i) loss of the paralogous testis isoform, (ii) an acceleration and then a deceleration of the amino acid replacement rate of the cyt c somatic isoform, and (iii) atypical biochemical behavior of human cyt c. To gain insight into the cause of these major evolutionary events, we have retraced the history of cyt c loci among primates. For testis cyt c, all primate sequences examined carry the same nonsense mutation, which suggests that silencing occurred before the primates diversified. For somatic cyt c, maximum parsimony, maximum likelihood, and Bayesian phylogenetic analyses yielded the same tree topology. The evolutionary analyses show that a fast accumulation of non-synonymous mutations (suggesting positive selection) occurred specifically on the anthropoid lineage root and then continued in parallel on the early catarrhini and platyrrhini stems. Analysis of evolutionary changes using the 3D structure suggests they are focused on the respiratory chain rather than on apoptosis or other cyt c functions. In agreement with previous biochemical studies, our results suggest that silencing of the cyt c testis isoform could be linked with the decrease of primate reproduction rate. Finally, the evolution of cyt c in the two sister anthropoid groups leads us to propose that somatic cyt c evolution may be related both to COX evolution and to the convergent brain and body mass enlargement in these two anthropoid clades.
Silencing, Positive Selection and Parallel Evolution: Busy History of Primate Cytochromes c
Pierron, Denis; Opazo, Juan C.; Heiske, Margit; Papper, Zack; Uddin, Monica; Chand, Gopi; Wildman, Derek E.; Romero, Roberto; Goodman, Morris; Grossman, Lawrence I.
2011-01-01
Cytochrome c (cyt c) participates in two crucial cellular processes, energy production and apoptosis, and unsurprisingly is a highly conserved protein. However, previous studies have reported for the primate lineage (i) loss of the paralogous testis isoform, (ii) an acceleration and then a deceleration of the amino acid replacement rate of the cyt c somatic isoform, and (iii) atypical biochemical behavior of human cyt c. To gain insight into the cause of these major evolutionary events, we have retraced the history of cyt c loci among primates. For testis cyt c, all primate sequences examined carry the same nonsense mutation, which suggests that silencing occurred before the primates diversified. For somatic cyt c, maximum parsimony, maximum likelihood, and Bayesian phylogenetic analyses yielded the same tree topology. The evolutionary analyses show that a fast accumulation of non-synonymous mutations (suggesting positive selection) occurred specifically on the anthropoid lineage root and then continued in parallel on the early catarrhini and platyrrhini stems. Analysis of evolutionary changes using the 3D structure suggests they are focused on the respiratory chain rather than on apoptosis or other cyt c functions. In agreement with previous biochemical studies, our results suggest that silencing of the cyt c testis isoform could be linked with the decrease of primate reproduction rate. Finally, the evolution of cyt c in the two sister anthropoid groups leads us to propose that somatic cyt c evolution may be related both to COX evolution and to the convergent brain and body mass enlargement in these two anthropoid clades. PMID:22028846
Detecting regular sound changes in linguistics as events of concerted evolution
Hruschka, Daniel J.; Branford, Simon; Smith, Eric D.; ...
2014-12-18
Background: Concerted evolution is normally used to describe parallel changes at different sites in a genome, but it is also observed in languages where a specific phoneme changes to the same other phoneme in many words in the lexicon—a phenomenon known as regular sound change. We develop a general statistical model that can detect concerted changes in aligned sequence data and apply it to study regular sound changes in the Turkic language family. Results: Linguistic evolution, unlike the genetic substitutional process, is dominated by events of concerted evolutionary change. Our model identified more than 70 historical events of regular soundmore » change that occurred throughout the evolution of the Turkic language family, while simultaneously inferring a dated phylogenetic tree. Including regular sound changes yielded an approximately 4-fold improvement in the characterization of linguistic change over a simpler model of sporadic change, improved phylogenetic inference, and returned more reliable and plausible dates for events on the phylogenies. The historical timings of the concerted changes closely follow a Poisson process model, and the sound transition networks derived from our model mirror linguistic expectations. Conclusions: We demonstrate that a model with no prior knowledge of complex concerted or regular changes can nevertheless infer the historical timings and genealogical placements of events of concerted change from the signals left in contemporary data. Our model can be applied wherever discrete elements—such as genes, words, cultural trends, technologies, or morphological traits—can change in parallel within an organism or other evolving group.« less
Detecting regular sound changes in linguistics as events of concerted evolution.
Hruschka, Daniel J; Branford, Simon; Smith, Eric D; Wilkins, Jon; Meade, Andrew; Pagel, Mark; Bhattacharya, Tanmoy
2015-01-05
Concerted evolution is normally used to describe parallel changes at different sites in a genome, but it is also observed in languages where a specific phoneme changes to the same other phoneme in many words in the lexicon—a phenomenon known as regular sound change. We develop a general statistical model that can detect concerted changes in aligned sequence data and apply it to study regular sound changes in the Turkic language family. Linguistic evolution, unlike the genetic substitutional process, is dominated by events of concerted evolutionary change. Our model identified more than 70 historical events of regular sound change that occurred throughout the evolution of the Turkic language family, while simultaneously inferring a dated phylogenetic tree. Including regular sound changes yielded an approximately 4-fold improvement in the characterization of linguistic change over a simpler model of sporadic change, improved phylogenetic inference, and returned more reliable and plausible dates for events on the phylogenies. The historical timings of the concerted changes closely follow a Poisson process model, and the sound transition networks derived from our model mirror linguistic expectations. We demonstrate that a model with no prior knowledge of complex concerted or regular changes can nevertheless infer the historical timings and genealogical placements of events of concerted change from the signals left in contemporary data. Our model can be applied wherever discrete elements—such as genes, words, cultural trends, technologies, or morphological traits—can change in parallel within an organism or other evolving group. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
Why Africa matters: evolution of Old World Salvia (Lamiaceae) in Africa
Will, Maria; Claßen-Bockhoff, Regine
2014-01-01
Background and Aims Salvia is the largest genus in Lamiaceae and it has recently been found to be non-monophyletic. Molecular data on Old World Salvia are largely lacking. In this study, we present data concerning Salvia in Africa. The focus is on the colonization of the continent, character evolution and the switch of pollination systems in the genus. Methods Maximum likelihood and Bayesian inference were used for phylogenetic reconstruction. Analyses were based on two nuclear markers [internal transcribed spacer (ITS) and external transcribed spacer (ETS)] and one plastid marker (rpl32-trnL). Sequence data were generated for 41 of the 62 African taxa (66 %). Mesquite was used to reconstruct ancestral character states for distribution, life form, calyx shape, stamen type and pollination syndrome. Key Results Salvia in Africa is non-monophyletic. Each of the five major regions in Africa, except Madagascar, was colonized at least twice, and floristic links between North African, south-west Asian and European species are strongly supported. The large radiation in Sub-Saharan Africa (23 species) can be traced back to dispersal from North Africa via East Africa to the Cape Region. Adaptation to bird pollination in southern Africa and Madagascar reflects parallel evolution. Conclusions The phenotypic diversity in African Salvia is associated with repeated introductions to the continent. Many important evolutionary processes, such as colonization, adaptation, parallelism and character transformation, are reflected in this comparatively small group. The data presented in this study can help to understand the evolution of Salvia sensu lato and other large genera. PMID:24966353
Detecting regular sound changes in linguistics as events of concerted evolution
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hruschka, Daniel J.; Branford, Simon; Smith, Eric D.
Background: Concerted evolution is normally used to describe parallel changes at different sites in a genome, but it is also observed in languages where a specific phoneme changes to the same other phoneme in many words in the lexicon—a phenomenon known as regular sound change. We develop a general statistical model that can detect concerted changes in aligned sequence data and apply it to study regular sound changes in the Turkic language family. Results: Linguistic evolution, unlike the genetic substitutional process, is dominated by events of concerted evolutionary change. Our model identified more than 70 historical events of regular soundmore » change that occurred throughout the evolution of the Turkic language family, while simultaneously inferring a dated phylogenetic tree. Including regular sound changes yielded an approximately 4-fold improvement in the characterization of linguistic change over a simpler model of sporadic change, improved phylogenetic inference, and returned more reliable and plausible dates for events on the phylogenies. The historical timings of the concerted changes closely follow a Poisson process model, and the sound transition networks derived from our model mirror linguistic expectations. Conclusions: We demonstrate that a model with no prior knowledge of complex concerted or regular changes can nevertheless infer the historical timings and genealogical placements of events of concerted change from the signals left in contemporary data. Our model can be applied wherever discrete elements—such as genes, words, cultural trends, technologies, or morphological traits—can change in parallel within an organism or other evolving group.« less
Genome-wide comparison of medieval and modern Mycobacterium leprae.
Schuenemann, Verena J; Singh, Pushpendra; Mendum, Thomas A; Krause-Kyora, Ben; Jäger, Günter; Bos, Kirsten I; Herbig, Alexander; Economou, Christos; Benjak, Andrej; Busso, Philippe; Nebel, Almut; Boldsen, Jesper L; Kjellström, Anna; Wu, Huihai; Stewart, Graham R; Taylor, G Michael; Bauer, Peter; Lee, Oona Y-C; Wu, Houdini H T; Minnikin, David E; Besra, Gurdyal S; Tucker, Katie; Roffey, Simon; Sow, Samba O; Cole, Stewart T; Nieselt, Kay; Krause, Johannes
2013-07-12
Leprosy was endemic in Europe until the Middle Ages. Using DNA array capture, we have obtained genome sequences of Mycobacterium leprae from skeletons of five medieval leprosy cases from the United Kingdom, Sweden, and Denmark. In one case, the DNA was so well preserved that full de novo assembly of the ancient bacterial genome could be achieved through shotgun sequencing alone. The ancient M. leprae sequences were compared with those of 11 modern strains, representing diverse genotypes and geographic origins. The comparisons revealed remarkable genomic conservation during the past 1000 years, a European origin for leprosy in the Americas, and the presence of an M. leprae genotype in medieval Europe now commonly associated with the Middle East. The exceptional preservation of M. leprae biomarkers, both DNA and mycolic acids, in ancient skeletons has major implications for palaeomicrobiology and human pathogen evolution.
Rink, William J; Mercier, Norbert; Mihailović, Dušan; Morley, Mike W; Thompson, Jeroen W; Roksandic, Mirjana
2013-01-01
Newly obtained ages, based on electron spin resonance combined with uranium series isotopic analysis, and infrared/post-infrared luminescence dating, provide a minimum age that lies between 397 and 525 ka for the hominin mandible BH-1 from Mala Balanica cave, Serbia. This confirms it as the easternmost hominin specimen in Europe dated to the Middle Pleistocene. Inferences drawn from the morphology of the mandible BH-1 place it outside currently observed variation of European Homo heidelbergensis. The lack of derived Neandertal traits in BH-1 and its contemporary specimens in Southeast Europe, such as Kocabaş, Vasogliano and Ceprano, coupled with Middle Pleistocene synapomorphies, suggests different evolutionary forces acting in the east of the continent where isolation did not play such an important role during glaciations.
Commercial satellite broadcasting for Europe
NASA Astrophysics Data System (ADS)
Forrest, J. R.
1988-12-01
A review is presented of the current television broadcasting situation in European countries, which involves a varied mix of terrestrial VHF or UHF systems and cable networks. A small market has emerged in Europe for receivers using the low-power telecommunications satellite transmission between the program providers and cable network companies. This is expected to change with the launch of medium-power pan-European telecommunication satellites (e.g. ASTRA, EUTELSAT II), which are now directly addressing the market of home reception. DBS (direct broadcast satellite) in the UK, using the D-MAC transmission standard, will offer three additional television channels, data broadcasting services, and a planned evolution to compatible forms of wide-screen, high-definition television. Comments are given on receiver and conditional access system standardization. Some views are expressed on satellite broadcasting as part of an overall broadcasting framework for the future.
Antigenic Patterns and Evolution of the Human Influenza A (H1N1) Virus
Liu, Mi; Zhao, Xiang; Hua, Sha; Du, Xiangjun; Peng, Yousong; Li, Xiyan; Lan, Yu; Wang, Dayan; Wu, Aiping; Shu, Yuelong; Jiang, Taijiao
2015-01-01
The influenza A (H1N1) virus causes seasonal epidemics that result in severe illnesses and deaths almost every year. A deep understanding of the antigenic patterns and evolution of human influenza A (H1N1) virus is extremely important for its effective surveillance and prevention. Through development of antigenicity inference method for human influenza A (H1N1), named PREDAC-H1, we systematically mapped the antigenic patterns and evolution of the human influenza A (H1N1) virus. Eight dominant antigenic clusters have been inferred for seasonal H1N1 viruses since 1977, which demonstrated sequential replacements over time with a similar pattern in Asia, Europe and North America. Among them, six clusters emerged first in Asia. As for China, three of the eight antigenic clusters were detected in South China earlier than in North China, indicating the leading role of South China in H1N1 transmission. The comprehensive view of the antigenic evolution of human influenza A (H1N1) virus can help formulate better strategy for its prevention and control. PMID:26412348
Antigenic Patterns and Evolution of the Human Influenza A (H1N1) Virus.
Liu, Mi; Zhao, Xiang; Hua, Sha; Du, Xiangjun; Peng, Yousong; Li, Xiyan; Lan, Yu; Wang, Dayan; Wu, Aiping; Shu, Yuelong; Jiang, Taijiao
2015-09-28
The influenza A (H1N1) virus causes seasonal epidemics that result in severe illnesses and deaths almost every year. A deep understanding of the antigenic patterns and evolution of human influenza A (H1N1) virus is extremely important for its effective surveillance and prevention. Through development of antigenicity inference method for human influenza A (H1N1), named PREDAC-H1, we systematically mapped the antigenic patterns and evolution of the human influenza A (H1N1) virus. Eight dominant antigenic clusters have been inferred for seasonal H1N1 viruses since 1977, which demonstrated sequential replacements over time with a similar pattern in Asia, Europe and North America. Among them, six clusters emerged first in Asia. As for China, three of the eight antigenic clusters were detected in South China earlier than in North China, indicating the leading role of South China in H1N1 transmission. The comprehensive view of the antigenic evolution of human influenza A (H1N1) virus can help formulate better strategy for its prevention and control.
ZOONET: perspectives on the evolution of animal form. Meeting report.
Fischer, Antje H L; Arboleda, Enrique; Egger, Bernhard; Hilbrant, Maarten; McGregor, Alistair P; Cole, Alison G; Daley, Allison C
2009-11-15
What drives evolution? This was one of the main questions raised at the final ZOONET meeting in Budapest, Hungary, in November 2008. The meeting marked the conclusion of ZOONET, an EU-funded Marie-Curie Research Training Network comprising nine research groups from all over Europe (Max Telford, University College London; Michael Akam, University of Cambridge; Detlev Arendt, EMBL Heidelberg; Maria Ina Arnone, Stazione Zoologica Anton Dohrn Napoli; Michalis Averof, IMBB Heraklion; Graham Budd, Uppsala University; Richard Copley, University of Oxford; Wim Damen, University of Cologne; Ernst Wimmer, University of Göttingen). ZOONET meetings and practical courses held during the past four years provided researchers from diverse backgrounds--bioinformatics, phylogenetics, embryology, palaeontology, and developmental and molecular biology--the opportunity to discuss their work under a common umbrella of evolutionary developmental biology (Evo Devo). The Budapest meeting emphasized in-depth discussions of the key concepts defining Evo Devo, and bringing together ZOONET researchers with external speakers who were invited to present their views on the evolution of animal form. The discussion sessions addressed four main topics: the driving forces of evolution, segmentation, fossils and phylogeny, and the future of Evo Devo.
Experimental evolution in biofilm populations
Steenackers, Hans P.; Parijs, Ilse; Foster, Kevin R.; Vanderleyden, Jozef
2016-01-01
Biofilms are a major form of microbial life in which cells form dense surface associated communities that can persist for many generations. The long-life of biofilm communities means that they can be strongly shaped by evolutionary processes. Here, we review the experimental study of evolution in biofilm communities. We first provide an overview of the different experimental models used to study biofilm evolution and their associated advantages and disadvantages. We then illustrate the vast amount of diversification observed during biofilm evolution, and we discuss (i) potential ecological and evolutionary processes behind the observed diversification, (ii) recent insights into the genetics of adaptive diversification, (iii) the striking degree of parallelism between evolution experiments and real-life biofilms and (iv) potential consequences of diversification. In the second part, we discuss the insights provided by evolution experiments in how biofilm growth and structure can promote cooperative phenotypes. Overall, our analysis points to an important role of biofilm diversification and cooperation in bacterial survival and productivity. Deeper understanding of both processes is of key importance to design improved antimicrobial strategies and diagnostic techniques. PMID:26895713
Experimental evolution in biofilm populations.
Steenackers, Hans P; Parijs, Ilse; Dubey, Akanksha; Foster, Kevin R; Vanderleyden, Jozef
2016-05-01
Biofilms are a major form of microbial life in which cells form dense surface associated communities that can persist for many generations. The long-life of biofilm communities means that they can be strongly shaped by evolutionary processes. Here, we review the experimental study of evolution in biofilm communities. We first provide an overview of the different experimental models used to study biofilm evolution and their associated advantages and disadvantages. We then illustrate the vast amount of diversification observed during biofilm evolution, and we discuss (i) potential ecological and evolutionary processes behind the observed diversification, (ii) recent insights into the genetics of adaptive diversification, (iii) the striking degree of parallelism between evolution experiments and real-life biofilms and (iv) potential consequences of diversification. In the second part, we discuss the insights provided by evolution experiments in how biofilm growth and structure can promote cooperative phenotypes. Overall, our analysis points to an important role of biofilm diversification and cooperation in bacterial survival and productivity. Deeper understanding of both processes is of key importance to design improved antimicrobial strategies and diagnostic techniques. © FEMS 2016.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Weis, M. R.; Zhang, P.; Lau, Y. Y., E-mail: yylau@umich.edu
2014-12-15
Using the ideal magnetohydrodynamic model, we calculate the temporal evolution of initial ripples on the boundaries of a planar plasma slab that is subjected to the magneto-Rayleigh-Taylor instability. The plasma slab consists of three regions. We assume that in each region the plasma density is constant with an arbitrary value and the magnetic field is also constant with an arbitrary magnitude and an arbitrary direction parallel to the interfaces. Thus, the instability may be driven by a combination of magnetic pressure and kinetic pressure. The general dispersion relation is derived, together with the feedthrough factor between the two interfaces. Themore » temporal evolution is constructed from the superposition of the eigenmodes. Previously established results are recovered in the various limits. Numerical examples are given on the temporal evolution of ripples on the interfaces of the finite plasma slab.« less
Dynamically correlated mutations drive human Influenza A evolution.
Tria, F; Pompei, S; Loreto, V
2013-01-01
Human Influenza A virus undergoes recurrent changes in the hemagglutinin (HA) surface protein, primarily involved in the human antibody recognition. Relevant antigenic changes, enabling the virus to evade host immune response, have been recognized to occur in parallel to multiple mutations at antigenic sites in HA. Yet, the role of correlated mutations (epistasis) in driving the molecular evolution of the virus still represents a challenging puzzle. Further, though circulation at a global geographic level is key for the survival of Influenza A, its role in shaping the viral phylodynamics remains largely unexplored. Here we show, through a sequence based epidemiological model, that epistatic effects between amino acids substitutions, coupled with a reservoir that mimics worldwide circulating viruses, are key determinants that drive human Influenza A evolution. Our approach explains all the up-to-date observations characterizing the evolution of H3N2 subtype, including phylogenetic properties, nucleotide fixation patterns, and composition of antigenic clusters.
Giant hub Src and Syk tyrosine kinase thermodynamic profiles recapitulate evolution
NASA Astrophysics Data System (ADS)
Phillips, J. C.
2017-10-01
Thermodynamic scaling theory, previously applied mainly to small proteins, here analyzes quantitative evolution of the titled functional network giant hub enzymes. The broad domain structure identified homologically is confirmed hydropathically using amino acid sequences only. The most surprising results concern the evolution of the tyrosine kinase globular surface roughness from avians to mammals, which is first order, compared to the evolution within mammals from rodents to humans, which is second order. The mystery of the unique amide terminal region of proto oncogene tyrosine protein kinase is resolved by the discovery there of a rare hydroneutral septad targeting cluster, which is paralleled by an equally rare octad catalytic cluster in tyrosine kinase in humans and a few other species (cat and dog). These results, which go far towards explaining why these proteins are among the largest giant hubs in protein interaction networks, use no adjustable parameters.
Weis, Matthew Robert; Zhang, Peng; Lau, Yue Ying; ...
2014-12-17
Using the ideal magnetohydrodynamic model, we calculate the temporal evolution of initial ripples on the boundaries of a planar plasma slab that is subjected to the magneto-Rayleigh-Taylor instability. The plasma slab consists of three regions. We assume that in each region the plasma density is constant with an arbitrary value and the magnetic field is also constant with an arbitrary magnitude and an arbitrary direction parallel to the interfaces. Then, the instability may be driven by a combination of magnetic pressure and kinetic pressure. Thus the general dispersion relation is derived, together with the feedthrough factor between the two interfaces.more » The temporal evolution is constructed from the superposition of the eigenmodes. Those previously established results are recovered in the various limits. Numerical examples are given on the temporal evolution of ripples on the interfaces of the finite plasma slab.« less
Zammarchi, Lorenzo; Strohmeyer, Marianne; Bartalesi, Filippo; Bruno, Elisa; Muñoz, José; Buonfrate, Dora; Nicoletti, Alessandra; García, Héctor Hugo; Pozio, Edoardo; Bartoloni, Alessandro
2013-01-01
Background Cysticercosis is caused by the invasion of human or pig tissues by the metacestode larval stage of Taenia solium. In Europe, the disease was endemic in the past but the autochthonous natural life cycle of the parasite is currently completed very rarely. Recently, imported cases have increased in parallel to the increased number of migrations and international travels. The lack of specific surveillance systems for cysticercosis leads to underestimation of the epidemiological and clinical impacts. Objectives To review the available data on epidemiology and management of cysticercosis in Europe. Methods A review of literature on human cysticercosis and T. solium taeniasis in Europe published between 1990–2011 was conducted. Results Out of 846 cysticercosis cases described in the literature, 522 cases were autochthonous and 324 cases were imported. The majority (70.1%) of the autochthonous cases were diagnosed in Portugal from 1983 and 1994. Imported cases of which 242 (74.7%) diagnosed in migrants and 57 (17.6%) in European travellers, showed an increasing trend. Most of imported cases were acquired in Latin America (69.8% of migrants and 44.0% of travellers). The majority of imported cases were diagnosed in Spain (47.5%), France (16.7%) and Italy (8.3%). One third of neurosurgical procedures were performed because the suspected diagnosis was cerebral neoplasm. Sixty eight autochthonous and 5 imported T. solium taeniasis cases were reported. Conclusions Cysticercosis remains a challenge for European care providers, since they are often poorly aware of this infection and have little familiarity in managing this disease. Cysticercosis should be included among mandatory reportable diseases, in order to improve the accuracy of epidemiological information. European health care providers might benefit from a transfer of knowledge from colleagues working in endemic areas and the development of shared diagnostic and therapeutic processes would have impact on the quality of the European health systems. Key words: cysticercosis, neurocysticercosis, Taenia solium, taeniasis, Europe, travellers, migrants. PMID:23922733
A moral history of the evolution of a caste of workers.
Samuels, S W
1996-01-01
Using a dialectic method of philosophic inquiry, the actual ethical, legal, and social situation associated with genetic testing of beryllium-exposed workers in Department of Energy nuclear weapons facilities for markers of chronic beryllium disease is described. The cultural evolution of a caste system in a similar situation, and its social and biological implications, among uranium miners in the Erz Gebirge of Central Europe and on the Colorado Plateau of the United States, marked by suicide and lung disease, including cancer, is also described. The historically persistent social disease resulting from these situations. The Masada Syndrome, named from an analogous situation in biblical times, is characterized. Cultural intervention, a necessary condition for the ethical progression of the Human Genome Project, is outlined. PMID:8933047
The Evolution of U.S. Maritime Power in the Pacific
1991-11-01
POWER IN THE PACIFIC (E.A. Olsen) Before the Pacific was a gleam in the eye of American or other Western seafaring nations, bent on commercial or...country" and the preeminence of Europe in world affairs, that did not prevent the development of important commercial links between Americans and Asians...established American commercial interests. In other words, the flag followed trade. Following this sequence of events it is interesting to note that
Religious Justification for War in American History. A Savage Embrace: The Pequot War 1636-37
2008-06-13
and interacted with the local tribes. Their reports back to their fellow countrymen further illuminated some of the challenges and opportunities...commerce was subordinate to religion and required a moral underpinning. In Europe centuries of civic and commercial practice preceded the evolution and...was incubated in the minds of Kings, clergy, and colonists alike; and it set the conditions for the political and social interaction between the
1988-08-12
that first graders are the nicest, like all in one big family. Well-behaved and obedient. Maybe Matti teases Maija a little bit and Pekka pushes Kalle ...France as early as 1971 . The system designed for Finland is an all-weather ver- sion and it was originally intended to specifically destroy low-flying...ISTAT study covers principally the three years of 1984-86, but also examines the evolution of crime in Italy since 1971 . And this could not have
The Posture Triangle: A New Framework for U.S. Air Force Global Presence
2013-01-01
Air Forces in Europe, 1981, Declassified on July 20, 2011. Berry, William E. Jr ., U.S. Bases in the Philippines: The Evolution of the Special...The Battle for Grenada, Lexington, Mass.: Lexington Books, 1989; and Edward M. Flanagan, Jr ., Battle for Panama: Inside Operation Just Cause...distinctive culture and history—should have its own political state. Nationalist sentiment is anger at violations of this principle. Ernest Gellner and
Cultural evolutionary theory: How culture evolves and why it matters
Creanza, Nicole; Kolodny, Oren; Feldman, Marcus W.
2017-01-01
Human cultural traits—behaviors, ideas, and technologies that can be learned from other individuals—can exhibit complex patterns of transmission and evolution, and researchers have developed theoretical models, both verbal and mathematical, to facilitate our understanding of these patterns. Many of the first quantitative models of cultural evolution were modified from existing concepts in theoretical population genetics because cultural evolution has many parallels with, as well as clear differences from, genetic evolution. Furthermore, cultural and genetic evolution can interact with one another and influence both transmission and selection. This interaction requires theoretical treatments of gene–culture coevolution and dual inheritance, in addition to purely cultural evolution. In addition, cultural evolutionary theory is a natural component of studies in demography, human ecology, and many other disciplines. Here, we review the core concepts in cultural evolutionary theory as they pertain to the extension of biology through culture, focusing on cultural evolutionary applications in population genetics, ecology, and demography. For each of these disciplines, we review the theoretical literature and highlight relevant empirical studies. We also discuss the societal implications of the study of cultural evolution and of the interactions of humans with one another and with their environment. PMID:28739941
Cultural evolutionary theory: How culture evolves and why it matters.
Creanza, Nicole; Kolodny, Oren; Feldman, Marcus W
2017-07-24
Human cultural traits-behaviors, ideas, and technologies that can be learned from other individuals-can exhibit complex patterns of transmission and evolution, and researchers have developed theoretical models, both verbal and mathematical, to facilitate our understanding of these patterns. Many of the first quantitative models of cultural evolution were modified from existing concepts in theoretical population genetics because cultural evolution has many parallels with, as well as clear differences from, genetic evolution. Furthermore, cultural and genetic evolution can interact with one another and influence both transmission and selection. This interaction requires theoretical treatments of gene-culture coevolution and dual inheritance, in addition to purely cultural evolution. In addition, cultural evolutionary theory is a natural component of studies in demography, human ecology, and many other disciplines. Here, we review the core concepts in cultural evolutionary theory as they pertain to the extension of biology through culture, focusing on cultural evolutionary applications in population genetics, ecology, and demography. For each of these disciplines, we review the theoretical literature and highlight relevant empirical studies. We also discuss the societal implications of the study of cultural evolution and of the interactions of humans with one another and with their environment.
A case study in evolutionary contingency.
Blount, Zachary D
2016-08-01
Biological evolution is a fundamentally historical phenomenon in which intertwined stochastic and deterministic processes shape lineages with long, continuous histories that exist in a changing world that has a history of its own. The degree to which these characteristics render evolution historically contingent, and evolutionary outcomes thereby unpredictably sensitive to history has been the subject of considerable debate in recent decades. Microbial evolution experiments have proven among the most fruitful means of empirically investigating the issue of historical contingency in evolution. One such experiment is the Escherichia coli Long-Term Evolution Experiment (LTEE), in which twelve populations founded from the same clone of E. coli have evolved in parallel under identical conditions. Aerobic growth on citrate (Cit(+)), a novel trait for E. coli, evolved in one of these populations after more than 30,000 generations. Experimental replays of this population's evolution from various points in its history showed that the Cit(+) trait was historically contingent upon earlier mutations that potentiated the trait by rendering it mutationally accessible. Here I review this case of evolutionary contingency and discuss what it implies about the importance of historical contingency arising from the core processes of evolution. Copyright © 2015 Elsevier Ltd. All rights reserved.
Environmental impact of melting buried ice blocks (North Poland)
NASA Astrophysics Data System (ADS)
Ott, F.; Slowinski, M. M.; Blaszkiewicz, M.; Brauer, A.; Noryskiewicz, B.; Tyszkowski, S.
2013-12-01
The aim of the research was to decipher the impacts of the role of dead ice melting on landscape evolution in the Lateglacial and early Holocene Central Europe. Here, we present the paleoecological results from the middle section of the Wda river which is located in northern Poland (Central Europe), on the outwash plain formed during the Pomeranian phase of the last (Vistulian) glacial period ca 16,000 14C yrs BP. The Wda river has a typical polygenetic valley in young glacial areas of the northern central European lowlands. We reconstructed environmental changes using biotic proxies (plant macrofossil and pollen analyses) and geomorphological investigations. In this study we focused on a short terrestrial sediment core (48 cm) representing four phases of landscape evolution: telmatic, lacustrine, lacustrine-fluvial and alluvial. Abrupt changes in lithology and sediment structures show rapid changes and threshold processes in environmental conditions. The AMS 14C dating of terrestrial plant remains reveals an age for the basal sediments of 11 223 × 23 cal yr BP and thus falls within the Preboreal biozone. Our results showed that existence of buried ice blocks in northern Poland even at the beginning of the Holocene is clear evidence that locally discontinuous permafrost still was present at that time. The results of our study prove a strong influence of melting buried ice blocks on the geomorphological development, hydrological changes in the catchment, and the biotic environment even in the early Holocene. The research was supported by the National Science Centre Poland (grants No. NN 306085037 and NCN 2011/01/B/ST10/07367). This study is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution (ICLEA) of the Helmholtz Association. Financial support by the COST Action ES0907 INTIMATE is gratefully acknowledged.
NASA Astrophysics Data System (ADS)
Poulet, Thomas; Paesold, Martin; Veveakis, Manolis
2017-03-01
Faults play a major role in many economically and environmentally important geological systems, ranging from impermeable seals in petroleum reservoirs to fluid pathways in ore-forming hydrothermal systems. Their behavior is therefore widely studied and fault mechanics is particularly focused on the mechanisms explaining their transient evolution. Single faults can change in time from seals to open channels as they become seismically active and various models have recently been presented to explain the driving forces responsible for such transitions. A model of particular interest is the multi-physics oscillator of Alevizos et al. (J Geophys Res Solid Earth 119(6), 4558-4582, 2014) which extends the traditional rate and state friction approach to rate and temperature-dependent ductile rocks, and has been successfully applied to explain spatial features of exposed thrusts as well as temporal evolutions of current subduction zones. In this contribution we implement that model in REDBACK, a parallel open-source multi-physics simulator developed to solve such geological instabilities in three dimensions. The resolution of the underlying system of equations in a tightly coupled manner allows REDBACK to capture appropriately the various theoretical regimes of the system, including the periodic and non-periodic instabilities. REDBACK can then be used to simulate the drastic permeability evolution in time of such systems, where nominally impermeable faults can sporadically become fluid pathways, with permeability increases of several orders of magnitude.
NASA Astrophysics Data System (ADS)
Wittek, Peter; Calderaro, Luca
2015-12-01
We extended a parallel and distributed implementation of the Trotter-Suzuki algorithm for simulating quantum systems to study a wider range of physical problems and to make the library easier to use. The new release allows periodic boundary conditions, many-body simulations of non-interacting particles, arbitrary stationary potential functions, and imaginary time evolution to approximate the ground state energy. The new release is more resilient to the computational environment: a wider range of compiler chains and more platforms are supported. To ease development, we provide a more extensive command-line interface, an application programming interface, and wrappers from high-level languages.
nextPARS: parallel probing of RNA structures in Illumina
Saus, Ester; Willis, Jesse R.; Pryszcz, Leszek P.; Hafez, Ahmed; Llorens, Carlos; Himmelbauer, Heinz
2018-01-01
RNA molecules play important roles in virtually every cellular process. These functions are often mediated through the adoption of specific structures that enable RNAs to interact with other molecules. Thus, determining the secondary structures of RNAs is central to understanding their function and evolution. In recent years several sequencing-based approaches have been developed that allow probing structural features of thousands of RNA molecules present in a sample. Here, we describe nextPARS, a novel Illumina-based implementation of in vitro parallel probing of RNA structures. Our approach achieves comparable accuracy to previous implementations, while enabling higher throughput and sample multiplexing. PMID:29358234
Collisionless dissipation processes in quasi-parallel shocks. [in solar wind
NASA Technical Reports Server (NTRS)
Quest, K. B.; Forslund, D. W.; Brackbill, J. U.; Lee, K.
1983-01-01
The evolution of collisionless, quasi-parallel shocks (the angle between the shock normal and the upstream magnetic field being less than 45 deg) is examined using two dimensional particle simulations. Reflected ions upstream from the shock are observed with average guiding center velocity and gyrational energy which agree well with the prediction of simple specular reflection. Strong ion heating through the shock ramp is apparently caused by large amplitude whistler turbulence. A flux of suprathermal electrons is also the magnetic field direction. Much stronger ion heating occurs in the shock than electron heating. The relevance of this work to the earth's bow shock is discussed.
FBIS report. Science and technology: Europe/International, March 29, 1996
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1996-03-29
;Partial Contents: Advanced Materials (EU Project to Improve Production in Metal Matrix Compounds Noted, Germany: Extremely Hard Carbon Coating Development, Italy: Director of CNR Metallic Materials Institute Interviewed); Aerospace (ESA Considers Delays, Reductions as Result of Budget Cuts, Italy: Space Agency`s Director on Restructuring, Future Plans); Automotive, Transportation (EU: Clean Diesel Engine Technology Research Reviewed); Biotechnology (Germany`s Problems, Successes in Biotechnology Discussed); Computers (EU Europort Parallel Computing Project Concluded, Italy: PQE 2000 Project on Massively Parallel Systems Viewed); Defense R&D (France: Future Tasks of `Brevel` Military Intelligence Drone Noted); Energy, Environment (German Scientist Tests Elimination of Phosphates); Advanced Manufacturing (France:more » Advanced Rapid Prototyping System Presented); Lasers, Sensors, Optics (France: Strategy of Cilas Laser Company Detailed); Microelectronics (France: Simulation Company to Develop Microelectronic Manufacturing Application); Nuclear R&D (France: Megajoule Laser Plan, Cooperation with Livermore Lab Noted); S&T Policy (EU Efforts to Aid Small Companies` Research Viewed); Telecommunications (France Telecom`s Way to Internet).« less
NASA Astrophysics Data System (ADS)
Sheynin, Yuriy; Shutenko, Felix; Suvorova, Elena; Yablokov, Evgenej
2008-04-01
High rate interconnections are important subsystems in modern data processing and control systems of many classes. They are especially important in prospective embedded and on-board systems that used to be multicomponent systems with parallel or distributed architecture, [1]. Modular architecture systems of previous generations were based on parallel busses that were widely used and standardised: VME, PCI, CompactPCI, etc. Busses evolution went in improvement of bus protocol efficiency (burst transactions, split transactions, etc.) and increasing operation frequencies. However, due to multi-drop bus nature and multi-wire skew problems the parallel bussing speedup became more and more limited. For embedded and on-board systems additional reason for this trend was in weight, size and power constraints of an interconnection and its components. Parallel interfaces have become technologically more challenging as their respective clock frequencies have increased to keep pace with the bandwidth requirements of their attached storage devices. Since each interface uses a data clock to gate and validate the parallel data (which is normally 8 bits or 16 bits wide), the clock frequency need only be equivalent to the byte rate or word rate being transmitted. In other words, for a given transmission frequency, the wider the data bus, the slower the clock. As the clock frequency increases, more high frequency energy is available in each of the data lines, and a portion of this energy is dissipated in radiation. Each data line not only transmits this energy but also receives some from its neighbours. This form of mutual interference is commonly called "cross-talk," and the signal distortion it produces can become another major contributor to loss of data integrity unless compensated by appropriate cable designs. Other transmission problems such as frequency-dependent attenuation and signal reflections, while also applicable to serial interfaces, are more troublesome in parallel interfaces due to the number of additional cable conductors involved. In order to compensate for these drawbacks, higher quality cables, shorter cable runs and fewer devices on the bus have been the norm. Finally, the physical bulk of the parallel cables makes them more difficult to route inside an enclosure, hinders cooling airflow and is incompatible with the trend toward smaller form-factor devices. Parallel busses worked in systems during the past 20 years, but the accumulated problems dictate the need for change and the technology is available to spur the transition. The general trend in high-rate interconnections turned from parallel bussing to scalable interconnections with a network architecture and high-rate point-to-point links. Analysis showed that data links with serial information transfer could achieve higher throughput and efficiency and it was confirmed in various research and practical design. Serial interfaces offer an improvement over older parallel interfaces: better performance, better scalability, and also better reliability as the parallel interfaces are at their limits of speed with reliable data transfers and others. The trend was implemented in major standards' families evolution: e.g. from PCI/PCI-X parallel bussing to PCIExpress interconnection architecture with serial lines, from CompactPCI parallel bus to ATCA (Advanced Telecommunications Architecture) specification with serial links and network topologies of an interconnection, etc. In the article we consider a general set of characteristics and features of serial interconnections, give a brief overview of serial interconnections specifications. In more details we present the SpaceWire interconnection technology. Have been developed for space on-board systems applications the SpaceWire has important features and characteristics that make it a prospective interconnection for wide range of embedded systems.
Close Encounters of the Third Domain: The Emerging Genomic View of Archaeal Diversity and Evolution
Spang, Anja; Saw, Jimmy H.; Lind, Anders E.; Ettema, Thijs J. G.
2013-01-01
The Archaea represent the so-called Third Domain of life, which has evolved in parallel with the Bacteria and which is implicated to have played a pivotal role in the emergence of the eukaryotic domain of life. Recent progress in genomic sequencing technologies and cultivation-independent methods has started to unearth a plethora of data of novel, uncultivated archaeal lineages. Here, we review how the availability of such genomic data has revealed several important insights into the diversity, ecological relevance, metabolic capacity, and the origin and evolution of the archaeal domain of life. PMID:24348093
[The diffusion of the human evolution in Spain and the JAE (1907-1939)].
Pelayo, Francisco
2007-01-01
During the first decades of the 20th century important findings of hominids fossil remains were made, enlarging the knowledge on Human Evolution. This period runs parallel to the activity of the Junta para Ampliación de Estudios e Investigaciones Científicas (JAE), an institution that helped to spread the new paleontological facts in Spain by providing funds for further studies and research, by the foundation of the Comisión de Investigaciones Paleontológicas y Prehistóricas (CIPP) and the promotion of publications on Human Paleontology.
The petrographic microscope: Evolution of a mineralogical research instrument
Kile, D.E.
2003-01-01
The petrographic microscope, designed to observe and measure the optical properties of minerals as a means of identifying them, has provided a foundation for mineralogical and petrological research for more than 120 years. Much of what is known today in these fields is attributable to this instrument, the development of which paralleled an evolution of fundamental optical theory and its correlation with mineral structure and composition. This instrument and its related accessories have evolved through a range of models and designs, which are in themselves distinctive for their scientific function and elegant construction, and are today prized by collectors of scientific instruments.
Modeling evolution of crosstalk in noisy signal transduction networks
NASA Astrophysics Data System (ADS)
Tareen, Ammar; Wingreen, Ned S.; Mukhopadhyay, Ranjan
2018-02-01
Signal transduction networks can form highly interconnected systems within cells due to crosstalk between constituent pathways. To better understand the evolutionary design principles underlying such networks, we study the evolution of crosstalk for two parallel signaling pathways that arise via gene duplication. We use a sequence-based evolutionary algorithm and evolve the network based on two physically motivated fitness functions related to information transmission. We find that one fitness function leads to a high degree of crosstalk while the other leads to pathway specificity. Our results offer insights on the relationship between network architecture and information transmission for noisy biomolecular networks.
ERIC Educational Resources Information Center
Ha, Minsu; Nehm, Ross H.
2014-01-01
Although historical changes in scientific ideas sometimes display striking similarities with students' conceptual progressions, some scholars have cautioned that such similarities lack meaningful commonalities. In the history of evolution, while Darwin and his contemporaries often used natural selection to explain evolutionary trait gain or…
The "Three Doctrines Discussions" of Tang China: Religious Debate as a Rhetorical Strategy.
ERIC Educational Resources Information Center
Garrett, Mary M.
1994-01-01
Reports on the origins and importance of the "Three Doctrines Discussions" of the Chinese Tang dynasty (618-960). Shows how their evolution and decline parallel shifts in the balance of political power. Argues that these debates functioned rhetorically to enhance and legitimate the emperor's political power. (HB)
Experiences in Teaching a Graduate Course on Model-Driven Software Development
ERIC Educational Resources Information Center
Tekinerdogan, Bedir
2011-01-01
Model-driven software development (MDSD) aims to support the development and evolution of software intensive systems using the basic concepts of model, metamodel, and model transformation. In parallel with the ongoing academic research, MDSD is more and more applied in industrial practices. After being accepted both by a broad community of…
Interuniversal entanglement in a cyclic multiverse
NASA Astrophysics Data System (ADS)
Robles-Pérez, Salvador; Balcerzak, Adam; Dąbrowski, Mariusz P.; Krämer, Manuel
2017-04-01
We study scenarios of parallel cyclic multiverses which allow for a different evolution of the physical constants, while having the same geometry. These universes are classically disconnected, but quantum-mechanically entangled. Applying the thermodynamics of entanglement, we calculate the temperature and the entropy of entanglement. It emerges that the entropy of entanglement is large at big bang and big crunch singularities of the parallel universes as well as at the maxima of the expansion of these universes. The latter seems to confirm earlier studies that quantum effects are strong at turning points of the evolution of the universe performed in the context of the timeless nature of the Wheeler-DeWitt equation and decoherence. On the other hand, the entropy of entanglement at big rip singularities is going to zero despite its presumably quantum nature. This may be an effect of total dissociation of the universe structures into infinitely separated patches violating the null energy condition. However, the temperature of entanglement is large/infinite at every classically singular point and at maximum expansion and seems to be a better measure of quantumness.
Pulsating Magnetic Reconnection Driven by Three-Dimensional Flux-Rope Interactions.
Gekelman, W; De Haas, T; Daughton, W; Van Compernolle, B; Intrator, T; Vincena, S
2016-06-10
The dynamics of magnetic reconnection is investigated in a laboratory experiment consisting of two magnetic flux ropes, with currents slightly above the threshold for the kink instability. The evolution features periodic bursts of magnetic reconnection. To diagnose this complex evolution, volumetric three-dimensional data were acquired for both the magnetic and electric fields, allowing key field-line mapping quantities to be directly evaluated for the first time with experimental data. The ropes interact by rotating about each other and periodically bouncing at the kink frequency. During each reconnection event, the formation of a quasiseparatrix layer (QSL) is observed in the magnetic field between the flux ropes. Furthermore, a clear correlation is demonstrated between the quasiseparatrix layer and enhanced values of the quasipotential computed by integrating the parallel electric field along magnetic field lines. These results provide clear evidence that field lines passing through the quasiseparatrix layer are undergoing reconnection and give a direct measure of the nonlinear reconnection rate. The measurements suggest that the parallel electric field within the QSL is supported predominantly by electron pressure; however, resistivity may play a role.
Full-field drift Hamiltonian particle orbits in 3D geometry
NASA Astrophysics Data System (ADS)
Cooper, W. A.; Graves, J. P.; Brunner, S.; Isaev, M. Yu
2011-02-01
A Hamiltonian/Lagrangian theory to describe guiding centre orbit drift motion which is canonical in the Boozer coordinate frame has been extended to include full electromagnetic perturbed fields in anisotropic pressure 3D equilibria with nested magnetic flux surfaces. A redefinition of the guiding centre velocity to eliminate the motion due to finite equilibrium radial magnetic fields and the choice of a gauge condition that sets the radial component of the electromagnetic vector potential to zero are invoked to guarantee that the Boozer angular coordinates retain the canonical structure. The canonical momenta are identified and the guiding centre particle radial drift motion and parallel gyroradius evolution are derived. The particle coordinate position is linearly modified by wave-particle interactions. All the nonlinear wave-wave interactions appear explicitly only in the evolution of the parallel gyroradius. The radial variation of the electrostatic potential is related to the binormal component of the displacement vector for MHD-type perturbations. The electromagnetic vector potential projections can then be determined from the electrostatic potential and the radial component of the MHD displacement vector.
The effect of plastic strain on the evolution of crystallographic texture in Zircaloy-2
NASA Astrophysics Data System (ADS)
Ballinger, R. G.; Lucas, G. E.; Pelloux, R. M.
1984-09-01
The evolution of crystallographic texture during plastic deformation was investigated in Zircaloy-2 using X-ray and metallographic techniques. Inverse pole figures, the resolved fraction of basal poles, and the volume fraction of twinned material, were determined as a function of plastic strain for several strain paths and initial textures at 298 K and 623 K. Incremental transverse platic strain ratios ( R) were mesured as a function of plastic strain. Texture rotation occurs early in the deformation process, after as little as 1.5% plastic strain. For compressive plastic strains, the resolved fraction of basal poles increases in the direction parallel to the strain axis. For tensile plastic strains, the resolved fraction of basal poles decreases in the direction parallel to the strain axis. The rate of change of the resolved fraction of basal poles with plastic strain is a function of the initial resolved fraction of basal poles. The texture rotation can be explained by considering the operation of the principal tensile twinning systems, {101¯2}<1¯011>.
Parallel evolution of Nitric Oxide signaling: Diversity of synthesis & memory pathways
Moroz, Leonid L.; Kohn, Andrea B.
2014-01-01
The origin of NO signaling can be traceable back to the origin of life with the large scale of parallel evolution of NO synthases (NOSs). Inducible-like NOSs may be the most basal prototype of all NOSs and that neuronal-like NOS might have evolved several times from this prototype. Other enzymatic and non-enzymatic pathways for NO synthesis have been discovered using reduction of nitrites, an alternative source of NO. Diverse synthetic mechanisms can co-exist within the same cell providing a complex NO-oxygen microenvironment tightly coupled with cellular energetics. The dissection of multiple sources of NO formation is crucial in analysis of complex biological processes such as neuronal integration and learning mechanisms when NO can act as a volume transmitter within memory-forming circuits. In particular, the molecular analysis of learning mechanisms (most notably in insects and gastropod molluscs) opens conceptually different perspectives to understand the logic of recruiting evolutionarily conserved pathways for novel functions. Giant uniquely identified cells from Aplysia and related species precent unuque opportunities for integrative analysis of NO signaling at the single cell level. PMID:21622160
General trends of chromosomal evolution in Aphidococca (Insecta, Homoptera, Aphidinea + Coccinea)
Gavrilov-Zimin, Ilya A.; Stekolshchikov, Andrey V.; Gautam, D.C.
2015-01-01
Abstract Parallel trends of chromosomal evolution in Aphidococca are discussed, based on the catalogue of chromosomal numbers and genetic systems of scale insects by Gavrilov (2007) and the new catalogue for aphids provided in the present paper. To date chromosome numbers have been reported for 482 species of scale insects and for 1039 species of aphids, thus respectively comprising about 6% and 24% of the total number of species. Such characters as low modal numbers of chromosomes, heterochromatinization of part of chromosomes, production of only two sperm instead of four from each primary spermatocyte, physiological sex determination, "larval" meiosis, wide distribution of parthenogenesis and chromosomal races are considered as a result of homologous parallel changes of the initial genotype of Aphidococca ancestors. From a cytogenetic point of view, these characters separate Aphidococca from all other groups of Paraneoptera insects and in this sense can be considered as additional taxonomic characters. In contrast to available paleontological data the authors doubt that Coccinea with their very diverse (and partly primitive) genetic systems may have originated later then Aphidinea with their very specialised and unified genetic system. PMID:26312130
NASA Astrophysics Data System (ADS)
Voter, Arthur
Many important materials processes take place on time scales that far exceed the roughly one microsecond accessible to molecular dynamics simulation. Typically, this long-time evolution is characterized by a succession of thermally activated infrequent events involving defects in the material. In the accelerated molecular dynamics (AMD) methodology, known characteristics of infrequent-event systems are exploited to make reactive events take place more frequently, in a dynamically correct way. For certain processes, this approach has been remarkably successful, offering a view of complex dynamical evolution on time scales of microseconds, milliseconds, and sometimes beyond. We have recently made advances in all three of the basic AMD methods (hyperdynamics, parallel replica dynamics, and temperature accelerated dynamics (TAD)), exploiting both algorithmic advances and novel parallelization approaches. I will describe these advances, present some examples of our latest results, and discuss what should be possible when exascale computing arrives in roughly five years. Funded by the U.S. Department of Energy, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, and by the Los Alamos Laboratory Directed Research and Development program.
Terrane accumulation and collapse in central Europe: seismic and rheological constraints
NASA Astrophysics Data System (ADS)
Meissner, R.
1999-05-01
An attempt is made to compare the tectonic units and their evolution in central Europe with the deep seismic velocity structure and patterns of reflectivity. Caledonian and Variscan terrane accretion and orogenic collapse dominate the tectonic development in central and western Europe and have left their marks in a distinct velocity structure and crustal thickness as well as in the various reflectivity patterns. Whereas the memory of old collisional structures is still preserved in the rigid upper crust, collapse processes have formed and modified the lower crust. They have generally created rejuvenated, thin crusts with shallow Mohos. In the Variscan internides, the center of collision and post-orogenic heat pulses, the lower crust developed strong and thick seismic lamellae, the (cooler) externides show a thrust and shear pattern in the whole crust, and the North German Basin experienced large mafic intrusions in the lower crust and developed a high-velocity structure with only very thin lamellae on top of the Moho. The various kinds of reflectivity patterns in the lithosphere can be explained by a thermo-rheological model from terrane collision, with crustal thickening to collapse in a hot, post-orogenic setting.
Fleshy fruit characteristics in a temperate deciduous forest of Japan: how unique are they?
Masaki, Takashi; Takahashi, Kazuaki; Sawa, Ayako; Kado, Tomoyuki; Naoe, Shoji; Koike, Shinsuke; Shibata, Mitsue
2012-01-01
This study investigated the fleshy fruit characteristics of 28 woody species in a Japanese temperate forest where large sedentary seed-dispersing mammals are present. We tested whether the findings in previous studies in temperate forests of Europe and North America are universal or not. Results have suggested that fruits of all species were eaten both by birds and mammals except for four species with larger fruits, which were eaten only by mammals. A gradient was found from a syndrome characterized by small, oily, and large-seeded fruits to a syndrome characterized by large, succulent, non-oily, and small-seeded fruits. The sizes and colors of the fruits were not conspicuously different from previous findings in Europe and North America. On the other hand, nitrogen and lipids in the fleshy part did not show seasonally increasing trends, or even seasonally decreasing trends in terms of dry weight. This result, suggesting the absence of community-level adaptation of fruit traits to migratory bird dispersers, contrasted with findings in Europe and North America. Large sedentary arboreal or tree-climbing mammals may have a greater effect on the evolution of fruit-disperser relations than opportunistic migratory birds.
Fitzsimmons, Kathryn E.; Hambach, Ulrich; Veres, Daniel; Iovita, Radu
2013-01-01
The Campanian Ignimbrite (CI) volcanic eruption was the most explosive in Europe in the last 200,000 years. The event coincided with the onset of an extremely cold climatic phase known as Heinrich Event 4 (HE4) approximately 40,000 years ago. Their combined effect may have exacerbated the severity of the climate through positive feedbacks across Europe and possibly globally. The CI event is of particular interest not only to investigate the role of volcanism on climate forcing and palaeoenvironments, but also because its timing coincides with the arrival into Europe of anatomically modern humans, the demise of Neanderthals, and an associated major shift in lithic technology. At this stage, however, the degree of interaction between these factors is poorly known, based on fragmentary and widely dispersed data points. In this study we provide important new data from Eastern Europe which indicate that the magnitude of the CI eruption and impact of associated distal ash (tephra) deposits may have been substantially greater than existing models suggest. The scale of the eruption is modelled by tephra distribution and thickness, supported by local data points. CI ashfall extends as far as the Russian Plain, Eastern Mediterranean and northern Africa. However, modelling input is limited by very few data points in Eastern Europe. Here we investigate an unexpectedly thick CI tephra deposit in the southeast Romanian loess steppe, positively identified using geochemical and geochronological analyses. We establish the tephra as a widespread primary deposit, which blanketed the topography both thickly and rapidly, with potentially catastrophic impacts on local ecosystems. Our discovery not only highlights the need to reassess models for the magnitude of the eruption and its role in climatic transition, but also suggests that it may have substantially influenced hominin population and subsistence dynamics in a region strategic for human migration into Europe. PMID:23799050
Blonde, Lawrence; Marre, Michel; Vincent, Maya; Brette, Sandrine; Pilorget, Valerie; Danchin, Nicholas; Vespasiani, Giacomo; Home, Philip
2017-11-01
A number of insulin regimens are used in type 2 diabetes. This analysis aims to better understand the evolution of insulin therapy in different regions of Europe. Data from people starting any insulin were collected in eastern Europe (EEur: Croatia, Russia, Ukraine), northern Europe (NEur: Finland, Germany, UK) and southern Europe (SEur: France, Italy, Portugal, Spain). Retrospective data on starting insulin and prospective follow-up data were extracted from clinical records. At 4years, 1699 (76.0%) of 2236 eligible people had data. EEur participants were mostly female, younger and had shorter diabetes duration on starting insulin, yet had highest baseline HbA1c and more micro-/macrovascular disease. A majority (60%-64%) in all regions started on basal insulin alone, declining to 30%-38% at 4years, with most switching to basal+mealtime insulin regimen (24%-40%). Higher baseline (28%) and 4-year use (34%) of premix insulin was observed in NEur. Change in HbA1c (SD) ranged from -1.2 (2.1)% (-13 [23]mmol/mol) in NEur to -2.4 (2.0)% (-26 [22]mmol/mol) in EEur. Weight change ranged from +1.9 (8.3) kg in NEur to +3.2 (7.0) kg in SEur. Overall documented hypoglycemia ranged from 0.3 (1.3) to 1.3 (4.4) events/person/6-months (NEur vs. EEur, respectively) and was stable with time. Severe hypoglycemia rates remained low. When starting insulin, HbA1c and prevalence of complications were higher in EEur. Regional differences exist in choice of insulin regimens in Europe. However, people starting insulin improved and sustained their glycemic control regardless of regional differences or insulin regimens used. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
Fitzsimmons, Kathryn E; Hambach, Ulrich; Veres, Daniel; Iovita, Radu
2013-01-01
The Campanian Ignimbrite (CI) volcanic eruption was the most explosive in Europe in the last 200,000 years. The event coincided with the onset of an extremely cold climatic phase known as Heinrich Event 4 (HE4) approximately 40,000 years ago. Their combined effect may have exacerbated the severity of the climate through positive feedbacks across Europe and possibly globally. The CI event is of particular interest not only to investigate the role of volcanism on climate forcing and palaeoenvironments, but also because its timing coincides with the arrival into Europe of anatomically modern humans, the demise of Neanderthals, and an associated major shift in lithic technology. At this stage, however, the degree of interaction between these factors is poorly known, based on fragmentary and widely dispersed data points. In this study we provide important new data from Eastern Europe which indicate that the magnitude of the CI eruption and impact of associated distal ash (tephra) deposits may have been substantially greater than existing models suggest. The scale of the eruption is modelled by tephra distribution and thickness, supported by local data points. CI ashfall extends as far as the Russian Plain, Eastern Mediterranean and northern Africa. However, modelling input is limited by very few data points in Eastern Europe. Here we investigate an unexpectedly thick CI tephra deposit in the southeast Romanian loess steppe, positively identified using geochemical and geochronological analyses. We establish the tephra as a widespread primary deposit, which blanketed the topography both thickly and rapidly, with potentially catastrophic impacts on local ecosystems. Our discovery not only highlights the need to reassess models for the magnitude of the eruption and its role in climatic transition, but also suggests that it may have substantially influenced hominin population and subsistence dynamics in a region strategic for human migration into Europe.
Experiments with a Parallel Multi-Objective Evolutionary Algorithm for Scheduling
NASA Technical Reports Server (NTRS)
Brown, Matthew; Johnston, Mark D.
2013-01-01
Evolutionary multi-objective algorithms have great potential for scheduling in those situations where tradeoffs among competing objectives represent a key requirement. One challenge, however, is runtime performance, as a consequence of evolving not just a single schedule, but an entire population, while attempting to sample the Pareto frontier as accurately and uniformly as possible. The growing availability of multi-core processors in end user workstations, and even laptops, has raised the question of the extent to which such hardware can be used to speed up evolutionary algorithms. In this paper we report on early experiments in parallelizing a Generalized Differential Evolution (GDE) algorithm for scheduling long-range activities on NASA's Deep Space Network. Initial results show that significant speedups can be achieved, but that performance does not necessarily improve as more cores are utilized. We describe our preliminary results and some initial suggestions from parallelizing the GDE algorithm. Directions for future work are outlined.
Feynman’s clock, a new variational principle, and parallel-in-time quantum dynamics
McClean, Jarrod R.; Parkhill, John A.; Aspuru-Guzik, Alán
2013-01-01
We introduce a discrete-time variational principle inspired by the quantum clock originally proposed by Feynman and use it to write down quantum evolution as a ground-state eigenvalue problem. The construction allows one to apply ground-state quantum many-body theory to quantum dynamics, extending the reach of many highly developed tools from this fertile research area. Moreover, this formalism naturally leads to an algorithm to parallelize quantum simulation over time. We draw an explicit connection between previously known time-dependent variational principles and the time-embedded variational principle presented. Sample calculations are presented, applying the idea to a hydrogen molecule and the spin degrees of freedom of a model inorganic compound, demonstrating the parallel speedup of our method as well as its flexibility in applying ground-state methodologies. Finally, we take advantage of the unique perspective of this variational principle to examine the error of basis approximations in quantum dynamics. PMID:24062428
Quantum statistics and squeezing for a microwave-driven interacting magnon system.
Haghshenasfard, Zahra; Cottam, Michael G
2017-02-01
Theoretical studies are reported for the statistical properties of a microwave-driven interacting magnon system. Both the magnetic dipole-dipole and the exchange interactions are included and the theory is developed for the case of parallel pumping allowing for the inclusion of the nonlinear processes due to the four-magnon interactions. The method of second quantization is used to transform the total Hamiltonian from spin operators to boson creation and annihilation operators. By using the coherent magnon state representation we have studied the magnon occupation number and the statistical behavior of the system. In particular, it is shown that the nonlinearities introduced by the parallel pumping field and the four-magnon interactions lead to non-classical quantum statistical properties of the system, such as magnon squeezing. Also control of the collapse-and-revival phenomena for the time evolution of the average magnon number is demonstrated by varying the parallel pumping amplitude and the four-magnon coupling.
NASA Technical Reports Server (NTRS)
Cartier, S. L.; Dangelo, N.; Merlino, R. L.
1986-01-01
A laboratory study related to energetic upstreaming ions in the ionosphere-magnetosphere system is described. The experiment was carried out in a cesium Q machine plasma with a region of nonuniform magnetic field. Electrostatic ion cyclotron waves were excited by drawing an electron current to a small biased exciter electrode. In the presence of the instability, ions are heated in the direction perpendicular to B. Using a gridded retarding potential ion energy analyzer, the evolution of the ion velocity distribution was followed as the ions passed through the heating region and subsequently flowed out along the diverging B field lines. As expected, the heated ions transfer their energy from perpendicular to parallel motion as they move through the region of diverging B field. Both their parallel thermal energy and the parallel drift energy increase at the expense of the perpendicular energy.
Convergent evolution of marine mammals is associated with distinct substitutions in common genes
Zhou, Xuming; Seim, Inge; Gladyshev, Vadim N.
2015-01-01
Phenotypic convergence is thought to be driven by parallel substitutions coupled with natural selection at the sequence level. Multiple independent evolutionary transitions of mammals to an aquatic environment offer an opportunity to test this thesis. Here, whole genome alignment of coding sequences identified widespread parallel amino acid substitutions in marine mammals; however, the majority of these changes were not unique to these animals. Conversely, we report that candidate aquatic adaptation genes, identified by signatures of likelihood convergence and/or elevated ratio of nonsynonymous to synonymous nucleotide substitution rate, are characterized by very few parallel substitutions and exhibit distinct sequence changes in each group. Moreover, no significant positive correlation was found between likelihood convergence and positive selection in all three marine lineages. These results suggest that convergence in protein coding genes associated with aquatic lifestyle is mainly characterized by independent substitutions and relaxed negative selection. PMID:26549748
Bilgin, Raşit; Gürün, Kanat; Rebelo, Hugo; Puechmaille, Sebastien J; Maracı, Öncü; Presetnik, Primoz; Benda, Petr; Hulva, Pavel; Ibáñez, Carlos; Hamidovic, Daniela; Fressel, Norma; Horáček, Ivan; Karataş, Ayşegül; Karataş, Ahmet; Allegrini, Benjamin; Georgiakakis, Panagiotis; Gazaryan, Suren; Nagy, Zoltan L; Abi-Said, Mounir; Lučan, Radek K; Bartonička, Tomáš; Nicolaou, Haris; Scaravelli, Dino; Karapandža, Branko; Uhrin, Marcel; Paunović, Milan; Juste, Javier
2016-06-01
The isolation of populations in the Iberian, Italian and Balkan peninsulas during the ice ages define four main paradigms that explain much of the known distribution of intraspecific genetic diversity in Europe. In this study we investigated the phylogeography of a wide-spread bat species, the bent-winged bat, Miniopterus schreibersii around the Mediterranean basin and in the Caucasus. Environmental Niche Modeling (ENM) analysis was applied to predict both the current distribution of the species and its distribution during the last glacial maximum (LGM). The combination of genetics and ENM results suggest that the populations of M. schreibersii in Europe, the Caucasus and Anatolia went extinct during the LGM, and the refugium for the species was a relatively small area to the east of the Levantine Sea, corresponding to the Mediterranean coasts of present-day Syria, Lebanon, Israel, and northeastern and northwestern Egypt. Subsequently the species first repopulated Anatolia, diversified there, and afterwards expanded into the Caucasus, continental Europe and North Africa after the end of the LGM. The fossil record in Iberia and the ENM results indicate continuous presence of Miniopterus in this peninsula that most probably was related to the Maghrebian lineage during the LGM, which did not persist afterwards. Using our results combined with similar findings in previous studies, we propose a new paradigm explaining the general distribution of genetic diversity in Europe involving the recolonization of the continent, with the main contribution from refugial populations in Anatolia and the Middle East. The study shows how genetics and ENM approaches can complement each other in providing a more detailed picture of intraspecific evolution. Copyright © 2016 Elsevier Inc. All rights reserved.
Milestones in Software Engineering and Knowledge Engineering History: A Comparative Review
del Águila, Isabel M.; Palma, José; Túnez, Samuel
2014-01-01
We present a review of the historical evolution of software engineering, intertwining it with the history of knowledge engineering because “those who cannot remember the past are condemned to repeat it.” This retrospective represents a further step forward to understanding the current state of both types of engineerings; history has also positive experiences; some of them we would like to remember and to repeat. Two types of engineerings had parallel and divergent evolutions but following a similar pattern. We also define a set of milestones that represent a convergence or divergence of the software development methodologies. These milestones do not appear at the same time in software engineering and knowledge engineering, so lessons learned in one discipline can help in the evolution of the other one. PMID:24624046
Milestones in software engineering and knowledge engineering history: a comparative review.
del Águila, Isabel M; Palma, José; Túnez, Samuel
2014-01-01
We present a review of the historical evolution of software engineering, intertwining it with the history of knowledge engineering because "those who cannot remember the past are condemned to repeat it." This retrospective represents a further step forward to understanding the current state of both types of engineerings; history has also positive experiences; some of them we would like to remember and to repeat. Two types of engineerings had parallel and divergent evolutions but following a similar pattern. We also define a set of milestones that represent a convergence or divergence of the software development methodologies. These milestones do not appear at the same time in software engineering and knowledge engineering, so lessons learned in one discipline can help in the evolution of the other one.
de la Torre, Ignacio; Hirata, Satoshi
2015-11-19
Percussive technology is part of the behavioural suite of several fossil and living primates. Stone Age ancestors used lithic artefacts in pounding activities, which could have been most important in the earliest stages of stone working. This has relevant evolutionary implications, as other primates such as chimpanzees and some monkeys use stone hammer-and-anvil combinations to crack hard-shelled foodstuffs. Parallels between primate percussive technologies and early archaeological sites need to be further explored in order to assess the emergence of technological behaviour in our evolutionary line, and firmly establish bridges between Primatology and Archaeology. What are the anatomical, cognitive and ecological constraints of percussive technology? How common are percussive activities in the Stone Age and among living primates? What is their functional significance? How similar are archaeological percussive tools and those made by non-human primates? This issue of Phil. Trans. addresses some of these questions by presenting case studies with a wide chronological, geographical and disciplinary coverage. The studies presented here cover studies of Brazilian capuchins, captive chimpanzees and chimpanzees in the wild, research on the use of percussive technology among modern humans and recent hunter-gatherers in Australia, the Near East and Europe, and archaeological examples of this behaviour from a million years ago to the Holocene. In summary, the breadth and depth of research compiled here should make this issue of Philosophical Transactions of the Royal Society B, a landmark step forward towards a better understanding of percussive technology, a unique behaviour shared by some modern and fossil primates. © 2015 The Author(s).
Kato-Noguchi, Hisashi
2011-09-01
Plant second metabolites momilactone A and B, which act as potent phytoalexins and allelochemicals, have been found thus far only in rice and the moss Hypnum plumaeforme, although both plants are taxonomically quite distinct. The concentrations of momilactone A and B, respectively, in rice plants were 4.5-140 and 2.9-85μg/g, and those in H. plumaeforme were 8.4-58.7 and 4.2-23.4μg/g. Momilactone A and B concentrations in rice and H. plumaeforme plants were increased by UV irradiation, elicitor and jasmonic acid treatments. Rice and H. plumaeforme plants secrete momilactone A and B into the rhizosphere, and the secretion level was also increased by UV irradiation, elicitor and jasmonic acid treatments. In addition, although endogenous concentrations of momilactone A in rice and H. plumaeforme were greater than those of momilactone B, the secretion levels of momilactone B were greater than those of momilactone A in rice and H. plumaeforme, which suggests that momilactone B may be selectively secreted by both rice and H. plumaeforme. As momilactone A and B exert potent antifungal and growth inhibitory activities, momilactone A and B may play an important role in the defense responses in H. plumaeforme and rice against pathogen infections and in allelopathy. The secretion of momilactone A and B into the rhizosphere may also prevent bacterial and fungal infections and provide a competitive advantage for nutrients through the inhibition of invading root systems of neighboring plants as allelochemicals. Therefore, both plants, despite their evolutionary distance, may use same defense strategy with respect to the momilactone A and B production and secretion, which resulting from convergent or parallel evolutionary processes. In the case of parallel evolution, there may be plant species providing the missing link in molecular evolution of momilactones between H. plumaeforme and rice. Copyright © 2011 Elsevier GmbH. All rights reserved.
Chen, Tianju; Zhang, Jinzhi; Wu, Jinhu
2016-07-01
The kinetic and energy productions of pyrolysis of a lignocellulosic biomass were investigated using a three-parallel Gaussian distribution method in this work. The pyrolysis experiment of the pine sawdust was performed using a thermogravimetric-mass spectroscopy (TG-MS) analyzer. A three-parallel Gaussian distributed activation energy model (DAEM)-reaction model was used to describe thermal decomposition behaviors of the three components, hemicellulose, cellulose and lignin. The first, second and third pseudocomponents represent the fractions of hemicellulose, cellulose and lignin, respectively. It was found that the model is capable of predicting the pyrolysis behavior of the pine sawdust. The activation energy distribution peaks for the three pseudo-components were centered at 186.8, 197.5 and 203.9kJmol(-1) for the pine sawdust, respectively. The evolution profiles of H2, CH4, CO, and CO2 were well predicted using the three-parallel Gaussian distribution model. In addition, the chemical composition of bio-oil was also obtained by pyrolysis-gas chromatography/mass spectrometry instrument (Py-GC/MS). Copyright © 2016 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Fanton d'Andon, Odile; Martin-Lauzer, François-Regis; Mangin, Antoine; Barrot, Gilbert; Clouaire, Stephane; Sardou, Olivier; Demaria, Julien; Serra, Romain
2015-04-01
The GlobColour webservice provides a rich dataset of marine bio-geochemical information for research and education purposes. We report on recent evolutions to improve the functionalities of the service to access EO and in-situ data and check information quality. In addition, a new concept, the Collaborative Platform, support the processing of bespoke information for remote users. At the root of the service is an integrated and automated production chain, processing not only EO satellite data but also in-situ measurements from bio-Argo floats. This production chain provides daily updated bio-geochemical data and performs automated data analysis (merging of sensors, temporal and spatial binning). The GlobColour webservice has been recently upgraded to provide improved navigation and selection capabilities. These evolutions were necessary as the catalogue of EO products has been significantly increased, with many new parameters, new spatial resolution (1 km over Europe in addition to 4 km global products) and projections (rectangular grid in addition to sinus grid). The validation and quality control of the information is essential to demonstrate the fitness-for-purpose of the service. Match-ups between in-situ measurements and EO data are a key element to establish the validity of the information. The standard approach is to perform these match-ups off-line using a database of in-situ measurements, and report the results in a validation document. Two innovations are introduced which greatly increase the value for the user: • An interactive navigation tool allows a detailed analysis the results of the match-ups, with temporal and geographical selection capabilities. Background information for each match-up can be easily retrieved, both for in-situ (measurement identification) and for satellite data (context retrieval, providing information such as cloud coverage and spatial variability). This allows users to get a better insight into the validity of the retrieved data for their particular applications. • Match-ups using real-time EO data and data collected from bio-Argo floats are processed automatically on-the-fly. • This is possible because quality control of the bio-Argo float data is also automated. A dedicated interface has been set-up to monitor the whole fleet of Bio-Argo floats, and access detailed information from each acquired profile. Finally, a Collaborative Platform has been developed to support R&D activities in parallel to the standard production chain, enabling users to work remotely within a dedicated production environment in order to develop new algorithms and methods. The Collaborative Platform is based on a Collaborative Working Environment, a secured IT environment mixing hardware and software elements. It provides access to raw data, to processing and storage facilities, to specific applicative software (e.g. visualisation and post-processing tools). In addition, collaborative tools to exchange data, information and ideas between participants (through forums, web-conferencing…) contribute to create a "Virtual Research Centre" preparing future evolutions of the service. Acknowledgements: This research received funding from the following projects: • MCGS project funded by the Fonds Unique Interministériel, French regional funds PACA and Bretagne, the Fonds Européen de Développement Régional • FP7 Copernicus projects OSS2015 (grant n° 282723) and E-AIMS (grant n° 312642). • The French EQUIPEX project NAOS
Present status and future prospects of the JT-60SA project
NASA Astrophysics Data System (ADS)
Ishida, S.; Barabaschi, P.; Kamada, Y.
2014-10-01
The JT-60SA project has been implemented jointly by Europe and Japan since June 2007. After the disassembly of JT-60 from the torus hall had been completed in October 2012, the project achieved the major milestone of starting the tokamak's assembly at the JAEA Naka site in January 2013 following the completion of the cryostat base in Europe and its transport to Japan. Procurement and assembly activities for components such as the superconducting magnet, cryogenic system, power supply, vacuum vessel, divertor and cryostat are progressing on track towards the start of operation in March 2019. In preparation for exploitation, the JT-60SA Research Plan was issued in December 2011, and the research integration activities are addressing JT-60SA data management, validation and analysis tools. This paper overviews the latest evolution of the project in terms of construction and exploitation for JT-60SA.
ECS - The European Communication Satellite system
NASA Astrophysics Data System (ADS)
Wooster, C. B.
1981-09-01
The evolution of the European Communication Satellite system (ECS) is traced from feasibility studies in 1970 to the development and launch in 1978 of the Orbital Test Satellite (OTS) by the European Space Agency to prove the new satellite and radio transmission technology being used on ECS. This was followed by the establishment of 'Interim EUTELSAT' in 1979 as the organization to operate ECS. The satellite, which operates at 11/14 GHz, covers all the capitals in Europe via three spot beam antennas, supplemented by a 'Eurobeam' regional coverage antenna which extends the range to cover all of Europe and the Mediterranean basin. Telephony channels are transmitted digitally using time division multiple access (TDMA) with digital speech interpolation (DSI) to optimize satellite capacity. Television transmission is by analog FM over the Eurobeam antenna to North African as well as European capitals. System implications of TDMA operation are discussed, and the EUTELSAT policy for Special Services or satellite business systems is discussed.
Rink, William J.; Mercier, Norbert; Mihailović, Dušan; Morley, Mike W.; Thompson, Jeroen W.; Roksandic, Mirjana
2013-01-01
Newly obtained ages, based on electron spin resonance combined with uranium series isotopic analysis, and infrared/post-infrared luminescence dating, provide a minimum age that lies between 397 and 525 ka for the hominin mandible BH-1 from Mala Balanica cave, Serbia. This confirms it as the easternmost hominin specimen in Europe dated to the Middle Pleistocene. Inferences drawn from the morphology of the mandible BH-1 place it outside currently observed variation of European Homo heidelbergensis. The lack of derived Neandertal traits in BH-1 and its contemporary specimens in Southeast Europe, such as Kocabaş, Vasogliano and Ceprano, coupled with Middle Pleistocene synapomorphies, suggests different evolutionary forces acting in the east of the continent where isolation did not play such an important role during glaciations. PMID:23405085
The Variscan evolution in the External massifs of the Alps and place in their Variscan framework
NASA Astrophysics Data System (ADS)
von Raumer, Jürgen F.; Bussy, François; Stampfli, Gérard M.
2009-02-01
In the general discussion on the Variscan evolution of central Europe the pre-Mesozoic basement of the Alps is, in many cases, only included with hesitation. Relatively well-preserved from Alpine metamorphism, the Alpine External massifs can serve as an excellent example of evolution of the Variscan basement, including the earliest Gondwana-derived microcontinents with Cadomian relics. Testifying to the evolution at the Gondwana margin, at least since the Cambrian, such pieces took part in the birth of the Rheic Ocean. After the separation of Avalonia, the remaining Gondwana border was continuously transformed through crustal extension with contemporaneous separation of continental blocks composing future Pangea, but the opening of Palaeotethys had only a reduced significance since the Devonian. The Variscan evolution in the External domain is characterised by an early HP-evolution with subsequent granulitic decompression melts. During Visean crustal shortening, the areas of future formation of migmatites and intrusion of monzodioritic magmas in a general strike-slip regime, were probably in a lower plate situation, whereas the so called monometamorphic areas may have been in an upper plate position of the nappe pile. During the Latest Carboniferous, the emplacement of the youngest granites was associated with the strike-slip faulting and crustal extension at lower crustal levels, whereas, at the surface, detrital sediments accumulated in intramontaneous transtensional basins on a strongly eroded surface.
Age and Prematurity of the Alps Derived from Topography
NASA Astrophysics Data System (ADS)
Hergarten, S.; Wagner, T.; Stüwe, K.
2010-09-01
The European Alps are one of the best studied mountain ranges on Earth, but yet the age of their topography is almost unknown. Even their relative stage of evolution is unclear: Are the Alps still growing, in a steady state or already decaying, and is there a significant difference between Western and Eastern Alps? Using a new geomorphic parameter we analyze the topography of the Alps and provide one of the first quantitative constraints demonstrating that the range is still in its infancy: In contrast to several other mountain ranges, the Alps have still more than half of their evolution to a geomorphic steady state to go. Combining our results with sediment budget data from the surrounding basins we infer that the formation of the present topography began only 5-6 million years ago. Our results question the apparent consensus that the topographic evolution is distributed over much of the Miocene and might give new impulses to the reconstruction of paleoclimate in Central Europe.
Eldholm, Vegard; Pettersson, John H-O; Brynildsrud, Ola B; Kitchen, Andrew; Rasmussen, Erik Michael; Lillebaek, Troels; Rønning, Janne O; Crudu, Valeriu; Mengshoel, Anne Torunn; Debech, Nadia; Alfsnes, Kristian; Bohlin, Jon; Pepperell, Caitlin S; Balloux, Francois
2016-11-29
The "Beijing" Mycobacterium tuberculosis (Mtb) lineage 2 (L2) is spreading globally and has been associated with accelerated disease progression and increased antibiotic resistance. Here we performed a phylodynamic reconstruction of one of the L2 sublineages, the central Asian clade (CAC), which has recently spread to western Europe. We find that recent historical events have contributed to the evolution and dispersal of the CAC. Our timing estimates indicate that the clade was likely introduced to Afghanistan during the 1979-1989 Soviet-Afghan war and spread further after population displacement in the wake of the American invasion in 2001. We also find that drug resistance mutations accumulated on a massive scale in Mtb isolates from former Soviet republics after the fall of the Soviet Union, a pattern that was not observed in CAC isolates from Afghanistan. Our results underscore the detrimental effects of political instability and population displacement on tuberculosis control and demonstrate the power of phylodynamic methods in exploring bacterial evolution in space and time.
The Evolution of the Security Order in Europe: Importance of Multinational Forces
1992-02-25
facto-- prevented the economic self - sufficiency of the republics.1 Therefore, it would have been necessary to agree some form of common market and...Defense Identity", Survival (July/August 1991), 336. 32 Douglas T. Stuart, "Can NATO Trascend Its Europeans Borders? NATO Out of Area Disputes", Strategic...Overaio (Novembre 1990): 1-18. Stuart, Douglas T. "Can NATO Trascend Its European Borders?." Strateoic Studies Institute (USAWC): 1-21. 48 Taylor
The Future of NATO’s Mediterranean Initiative: Evolution and Next Steps
2000-01-01
the " guerra fria " between Spain and the Ottoman Empire, between Islam and the West. Views and Perspectives of the Dialogue Countries 29 Southern...crises in Asia , Russia, and Latin America place these questions in sharper relief around the Mediterranean, especially in relation to those...the Gulf, Turkey, and Israel. New pipelines from the Caucasus and central Asia may eventually provide gas to eastern and central Europe.5 As a result
JPRS Report, Soviet Union, World Economy & International Relations, No. 3, March 1987
1987-06-15
Efficiency Promotion in Industry (pp 28-40) (E. Vilkhovchenko) (not translated) •Star Wars ’ and Washington’s Allies Western Europe on SDI (pp 41-48) (G...sets of complex problems. The first is the problem S war and peace, pollution of environment and the socio-economic gap between industrially...developed capitalist countries and the developing world. The second -has taken shape as a result of the evolution of state-monopolistic capitalism and
2006-09-01
Postes des et Télécommunication . 19 GSM Global System for Mobile communications . . . . . . . . . 19 FDD Frequency Division Duplexing...entertainment centric in nature [84]. This evolution de - mands more from communication systems – improved quality of service (QoS), higher throughput...Spécial Mobile (GSM) emerged from the Conférence Européenne Postes des et Télécommunication (CEPT) and was commercially introduced in 1991 [103
ColDICE: A parallel Vlasov–Poisson solver using moving adaptive simplicial tessellation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sousbie, Thierry, E-mail: tsousbie@gmail.com; Department of Physics, The University of Tokyo, Tokyo 113-0033; Research Center for the Early Universe, School of Science, The University of Tokyo, Tokyo 113-0033
2016-09-15
Resolving numerically Vlasov–Poisson equations for initially cold systems can be reduced to following the evolution of a three-dimensional sheet evolving in six-dimensional phase-space. We describe a public parallel numerical algorithm consisting in representing the phase-space sheet with a conforming, self-adaptive simplicial tessellation of which the vertices follow the Lagrangian equations of motion. The algorithm is implemented both in six- and four-dimensional phase-space. Refinement of the tessellation mesh is performed using the bisection method and a local representation of the phase-space sheet at second order relying on additional tracers created when needed at runtime. In order to preserve in the bestmore » way the Hamiltonian nature of the system, refinement is anisotropic and constrained by measurements of local Poincaré invariants. Resolution of Poisson equation is performed using the fast Fourier method on a regular rectangular grid, similarly to particle in cells codes. To compute the density projected onto this grid, the intersection of the tessellation and the grid is calculated using the method of Franklin and Kankanhalli [65–67] generalised to linear order. As preliminary tests of the code, we study in four dimensional phase-space the evolution of an initially small patch in a chaotic potential and the cosmological collapse of a fluctuation composed of two sinusoidal waves. We also perform a “warm” dark matter simulation in six-dimensional phase-space that we use to check the parallel scaling of the code.« less
Extensive gene tree discordance and hemiplasy shaped the genomes of North American columnar cacti.
Copetti, Dario; Búrquez, Alberto; Bustamante, Enriquena; Charboneau, Joseph L M; Childs, Kevin L; Eguiarte, Luis E; Lee, Seunghee; Liu, Tiffany L; McMahon, Michelle M; Whiteman, Noah K; Wing, Rod A; Wojciechowski, Martin F; Sanderson, Michael J
2017-11-07
Few clades of plants have proven as difficult to classify as cacti. One explanation may be an unusually high level of convergent and parallel evolution (homoplasy). To evaluate support for this phylogenetic hypothesis at the molecular level, we sequenced the genomes of four cacti in the especially problematic tribe Pachycereeae, which contains most of the large columnar cacti of Mexico and adjacent areas, including the iconic saguaro cactus ( Carnegiea gigantea ) of the Sonoran Desert. We assembled a high-coverage draft genome for saguaro and lower coverage genomes for three other genera of tribe Pachycereeae ( Pachycereus , Lophocereus , and Stenocereus ) and a more distant outgroup cactus, Pereskia We used these to construct 4,436 orthologous gene alignments. Species tree inference consistently returned the same phylogeny, but gene tree discordance was high: 37% of gene trees having at least 90% bootstrap support conflicted with the species tree. Evidently, discordance is a product of long generation times and moderately large effective population sizes, leading to extensive incomplete lineage sorting (ILS). In the best supported gene trees, 58% of apparent homoplasy at amino sites in the species tree is due to gene tree-species tree discordance rather than parallel substitutions in the gene trees themselves, a phenomenon termed "hemiplasy." The high rate of genomic hemiplasy may contribute to apparent parallelisms in phenotypic traits, which could confound understanding of species relationships and character evolution in cacti. Published under the PNAS license.
Extensive gene tree discordance and hemiplasy shaped the genomes of North American columnar cacti
Búrquez, Alberto; Bustamante, Enriquena; Charboneau, Joseph L. M.; Childs, Kevin L.; Eguiarte, Luis E.; Lee, Seunghee; Liu, Tiffany L.; McMahon, Michelle M.; Whiteman, Noah K.; Wing, Rod A.; Wojciechowski, Martin F.; Sanderson, Michael J.
2017-01-01
Few clades of plants have proven as difficult to classify as cacti. One explanation may be an unusually high level of convergent and parallel evolution (homoplasy). To evaluate support for this phylogenetic hypothesis at the molecular level, we sequenced the genomes of four cacti in the especially problematic tribe Pachycereeae, which contains most of the large columnar cacti of Mexico and adjacent areas, including the iconic saguaro cactus (Carnegiea gigantea) of the Sonoran Desert. We assembled a high-coverage draft genome for saguaro and lower coverage genomes for three other genera of tribe Pachycereeae (Pachycereus, Lophocereus, and Stenocereus) and a more distant outgroup cactus, Pereskia. We used these to construct 4,436 orthologous gene alignments. Species tree inference consistently returned the same phylogeny, but gene tree discordance was high: 37% of gene trees having at least 90% bootstrap support conflicted with the species tree. Evidently, discordance is a product of long generation times and moderately large effective population sizes, leading to extensive incomplete lineage sorting (ILS). In the best supported gene trees, 58% of apparent homoplasy at amino sites in the species tree is due to gene tree-species tree discordance rather than parallel substitutions in the gene trees themselves, a phenomenon termed “hemiplasy.” The high rate of genomic hemiplasy may contribute to apparent parallelisms in phenotypic traits, which could confound understanding of species relationships and character evolution in cacti. PMID:29078296
Kierepko, Renata; Mietelski, Jerzy W; Ustrnul, Zbigniew; Anczkiewicz, Robert; Wershofen, Herbert; Holgye, Zoltan; Kapała, Jacek; Isajenko, Krzysztof
2016-11-01
This paper reports evidence of Pu isotopes in the lower part of the troposphere of Central Europe. The data were obtained based on atmospheric aerosol fraction samples collected from four places in three countries (participating in the informal European network known as the Ring of Five (Ro5)) forming a cell with a surface area of about 200,000km(2). We compared our original data sets from Krakow (Poland, 1990-2007) and Bialystok (Poland, 1991-2007) with the results from two other locations, Prague (Czech Republic; 1997-2004) and Braunschweig (Germany; 1990-2003) to find time evolution of the Pu isotopes. The levels of the activity concentration for (238)Pu and for ((239+240))Pu were estimated to be a few and some tens of nBqm(-3), respectively. However, we also noted some results were much higher (even about 70 times higher) than the average concentration of (238)Pu in the atmosphere. The achieved complex data sets were used to test a new approach to the problem of solving mixing isotopic traces from various sources (here up to three) in one sample. Results of our model, supported by mesoscale atmospheric circulation parameters, suggest that Pu from nuclear weapon accidents or tests and nuclear burnt-up fuel are present in the air. Copyright © 2016 Elsevier B.V. All rights reserved.
Phylogenomics of Colombian Helicobacter pylori isolates.
Gutiérrez-Escobar, Andrés Julián; Trujillo, Esperanza; Acevedo, Orlando; Bravo, María Mercedes
2017-01-01
During the Spanish colonisation of South America, African slaves and Europeans arrived in the continent with their corresponding load of pathogens, including Helicobacter pylori . Colombian strains have been clustered with the hpEurope population and with the hspWestAfrica subpopulation in multilocus sequence typing (MLST) studies. However, ancestry studies have revealed the presence of population components specific to H. pylori in Colombia. The aim of this study was to perform a thorough phylogenomic analysis to describe the evolution of the Colombian urban H. pylori isolates. A total of 115 genomes of H. pylori were sequenced with Illumina technology from H. pylori isolates obtained in Colombia in a region of high risk for gastric cancer. The genomes were assembled, annotated and underwent phylogenomic analysis with 36 reference strains. Additionally, population differentiation analyses were performed for two bacterial genes. The phylogenetic tree revealed clustering of the Colombian strains with hspWestAfrica and hpEurope, along with three clades formed exclusively by Colombian strains, suggesting the presence of independent evolutionary lines for Colombia. Additionally, the nucleotide diversity of horB and vacA genes from Colombian isolates was lower than in the reference strains and showed a significant genetic differentiation supporting the hypothesis of independent clades with recent evolution. The presence of specific lineages suggest the existence of an hspColombia subtype that emerged from a small and relatively isolated ancestral population that accompanied crossbreeding of human population in Colombia.
NASA Astrophysics Data System (ADS)
Denis, Gil; de Boissezon, Hélène; Hosford, Steven; Pasco, Xavier; Montfort, Bruno; Ranera, Franck
2016-10-01
The paper reviews the evolution of Earth Observation systems in Europe and Worldwide and analyses the potential impact of their performance in support of emergency response services. Earth Observation satellites play already a significant role in supporting the action of first responders in case of major disasters. The main principle is the coordinated use of satellites in order to ensure a rapid response and the timely delivery of images and geospatial information of the area affected by the event. The first part of the paper reviews the main instruments and evaluates their current performance. The International Charter ;Space and Major Disasters;, signed in October 2000, was the first international initiative aimed at establishing a unified system for the acquisition of space data. The charter is a cooperation agreement between space agencies and operators of space systems. At regional level, a similar instrument exists in Asia: Sentinel-Asia. In the frame of the European programme Copernicus, the emergency management service was launched in 2009. Geo-information products derived from space imagery are delivered during all phases of the emergency management cycle, in either rush or non-rush mode, free of charge for the users. In both cases, the capacities were historically drawn from national missions, funded with public money and directly operated by the space agencies or by national operators.
Different evolutionary pathways underlie the morphology of wrist bones in hominoids
2013-01-01
Background The hominoid wrist has been a focus of numerous morphological analyses that aim to better understand long-standing questions about the evolution of human and hominoid hand use. However, these same analyses also suggest various scenarios of complex and mosaic patterns of morphological evolution within the wrist and potentially multiple instances of homoplasy that would benefit from require formal analysis within a phylogenetic context. We identify morphological features that principally characterize primate – and, in particular, hominoid (apes, including humans) - wrist evolution and reveal the rate, process and evolutionary timing of patterns of morphological change on individual branches of the primate tree of life. Linear morphological variables of five wrist bones – the scaphoid, lunate, triquetrum, capitate and hamate – are analyzed in a diverse sample of extant hominoids (12 species, 332 specimens), Old World (8 species, 43 specimens) and New World (4 species, 26 specimens) monkeys, fossil Miocene apes (8 species, 20 specimens) and Plio-Pleistocene hominins (8 species, 18 specimens). Result Results reveal a combination of parallel and synapomorphic morphology within haplorrhines, and especially within hominoids, across individual wrist bones. Similar morphology of some wrist bones reflects locomotor behaviour shared between clades (scaphoid, triquetrum and capitate) while others (lunate and hamate) indicate clade-specific synapomorphic morphology. Overall, hominoids show increased variation in wrist bone morphology compared with other primate clades, supporting previous analyses, and demonstrate several occurrences of parallel evolution, particularly between orangutans and hylobatids, and among hominines (extant African apes, humans and fossil hominins). Conclusions Our analyses indicate that different evolutionary processes can underlie the evolution of a single anatomical unit (the wrist) to produce diversity in functional and morphological adaptations across individual wrist bones. These results exemplify a degree of evolutionary and functional independence across different wrist bones, the potential evolvability of skeletal morphology, and help to contextualize the postcranial mosaicism observed in the hominin fossil record. PMID:24148262
Harms, Alexander; Segers, Francisca H I D; Quebatte, Maxime; Mistl, Claudia; Manfredi, Pablo; Körner, Jonas; Chomel, Bruno B; Kosoy, Michael; Maruyama, Soichi; Engel, Philipp; Dehio, Christoph
2017-03-01
The α-proteobacterial genus Bartonella comprises a group of ubiquitous mammalian pathogens that are studied as a model for the evolution of bacterial pathogenesis. Vast abundance of two particular phylogenetic lineages of Bartonella had been linked to enhanced host adaptability enabled by lineage-specific acquisition of a VirB/D4 type IV secretion system (T4SS) and parallel evolution of complex effector repertoires. However, the limited availability of genome sequences from one of those lineages as well as other, remote branches of Bartonella has so far hampered comprehensive understanding of how the VirB/D4 T4SS and its effectors called Beps have shaped Bartonella evolution. Here, we report the discovery of a third repertoire of Beps associated with the VirB/D4 T4SS of B. ancashensis, a novel human pathogen that lacks any signs of host adaptability and is only distantly related to the two species-rich lineages encoding a VirB/D4 T4SS. Furthermore, sequencing of ten new Bartonella isolates from under-sampled lineages enabled combined in silico analyses and wet lab experiments that suggest several parallel layers of functional diversification during evolution of the three Bep repertoires from a single ancestral effector. Our analyses show that the Beps of B. ancashensis share many features with the two other repertoires, but may represent a more ancestral state that has not yet unleashed the adaptive potential of such an effector set. We anticipate that the effectors of B. ancashensis will enable future studies to dissect the evolutionary history of Bartonella effectors and help unraveling the evolutionary forces underlying bacterial host adaptation. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Ayuga, F; Briassoulis, D; Aguado, P; Farkas, I; Griepentrog, H; Lorencowicz, E
2010-01-01
The main objectives of European Thematic Network entitled 'Education and Research in Agricultural for Biosystems Engineering in Europe (ERABEE-TN)' is to initiate and contribute to the structural development and the assurance of the quality assessment of the emerging discipline of Biosystems Engineering in Europe. ERABEE is co-financed by the European Community in the framework of the LLP Programme. The partnership consists of 35 participants from 27 Erasmus countries, out of which 33 are Higher Education Area Institutions (EDU) and 2 are Student Associations (ASS). 13 Erasmus participants (e.g. Thematic Networks, Professional Associations, and Institutions from Brazil, Croatia, Russia and Serbia) are also involved in the Thematic Network through synergies. To date, very few Biosystems Engineering programs exist in Europe and those that are initiated are at a very primitive stage of development. The innovative and novel goal of the Thematic Network is to promote this critical transition, which requires major restructuring in Europe, exploiting along this direction the outcomes accomplished by its predecessor; the USAEE-TN (University Studies in Agricultural Engineering in Europe). It also aims at enhancing the compatibility among the new programmes of Biosystems Engineering, aiding their recognition and accreditation at European and International level and facilitating greater mobility of skilled personnel, researchers and students. One of the technical objectives of ERABEE is dealing with mapping and promoting the third cycle studies (including European PhDs) and supporting the integration of research at the 1st and 2nd cycle regarding European Biosystems Engineering university studies. During the winter 2008 - spring 2009 period, members of ERABEE conducted a survey on the contemporary status of doctoral studies in Europe, and on a possible scheme for promotion of cooperation and synergies in the framework of the third cycle of studies and the European Doctorate in Biosystems Engineering in Europe. This paper presents the results of the survey. The legal regulations and their extent on the different countries concerning the third cycle are presented, along with the current structure of third cycle studies. The evolution and adaptation to the new EHEA in each country is also considered. Information was also gathered on the emerging topics of the Biosystems Engineering field and how these topics could be addressed by the new doctoral programmes at the European level.
Why Africa matters: evolution of Old World Salvia (Lamiaceae) in Africa.
Will, Maria; Claßen-Bockhoff, Regine
2014-07-01
Salvia is the largest genus in Lamiaceae and it has recently been found to be non-monophyletic. Molecular data on Old World Salvia are largely lacking. In this study, we present data concerning Salvia in Africa. The focus is on the colonization of the continent, character evolution and the switch of pollination systems in the genus. Maximum likelihood and Bayesian inference were used for phylogenetic reconstruction. Analyses were based on two nuclear markers [internal transcribed spacer (ITS) and external transcribed spacer (ETS)] and one plastid marker (rpl32-trnL). Sequence data were generated for 41 of the 62 African taxa (66 %). Mesquite was used to reconstruct ancestral character states for distribution, life form, calyx shape, stamen type and pollination syndrome. Salvia in Africa is non-monophyletic. Each of the five major regions in Africa, except Madagascar, was colonized at least twice, and floristic links between North African, south-west Asian and European species are strongly supported. The large radiation in Sub-Saharan Africa (23 species) can be traced back to dispersal from North Africa via East Africa to the Cape Region. Adaptation to bird pollination in southern Africa and Madagascar reflects parallel evolution. The phenotypic diversity in African Salvia is associated with repeated introductions to the continent. Many important evolutionary processes, such as colonization, adaptation, parallelism and character transformation, are reflected in this comparatively small group. The data presented in this study can help to understand the evolution of Salvia sensu lato and other large genera. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
EON: software for long time simulations of atomic scale systems
NASA Astrophysics Data System (ADS)
Chill, Samuel T.; Welborn, Matthew; Terrell, Rye; Zhang, Liang; Berthet, Jean-Claude; Pedersen, Andreas; Jónsson, Hannes; Henkelman, Graeme
2014-07-01
The EON software is designed for simulations of the state-to-state evolution of atomic scale systems over timescales greatly exceeding that of direct classical dynamics. States are defined as collections of atomic configurations from which a minimization of the potential energy gives the same inherent structure. The time evolution is assumed to be governed by rare events, where transitions between states are uncorrelated and infrequent compared with the timescale of atomic vibrations. Several methods for calculating the state-to-state evolution have been implemented in EON, including parallel replica dynamics, hyperdynamics and adaptive kinetic Monte Carlo. Global optimization methods, including simulated annealing, basin hopping and minima hopping are also implemented. The software has a client/server architecture where the computationally intensive evaluations of the interatomic interactions are calculated on the client-side and the state-to-state evolution is managed by the server. The client supports optimization for different computer architectures to maximize computational efficiency. The server is written in Python so that developers have access to the high-level functionality without delving into the computationally intensive components. Communication between the server and clients is abstracted so that calculations can be deployed on a single machine, clusters using a queuing system, large parallel computers using a message passing interface, or within a distributed computing environment. A generic interface to the evaluation of the interatomic interactions is defined so that empirical potentials, such as in LAMMPS, and density functional theory as implemented in VASP and GPAW can be used interchangeably. Examples are given to demonstrate the range of systems that can be modeled, including surface diffusion and island ripening of adsorbed atoms on metal surfaces, molecular diffusion on the surface of ice and global structural optimization of nanoparticles.
Wu, Yi-Hsiu; Lo, Ting-Ya; She, Ming-Shiuan; Ho, Rong-Ming
2015-08-05
In this study, we aim to examine the morphological evolution of block copolymer (BCP) nanostructured thin films through solvent evaporation at different rates for solvent swollen polystyrene-block-poly(l-lactide) (PS-PLLA). Interesting phase transitions from disorder to perpendicular cylinder and then gyroid can be found while using a partially selective solvent for PS to swell PS-PLLA thin film followed by solvent evaporation. During the transitions, gyroid-forming BCP thin film with characteristic crystallographic planes of (111)G, (110)G, and (211)G parallel to air surface can be observed, and will gradually transform into coexisting (110)G and (211)G planes, and finally transforms to (211)G plane due to the preferential segregation of constituted block to the surface (i.e., the thermodynamic origin for self-assembly) that affects the relative amount of each component at the air surface. With the decrease on the evaporation rate, the disorder phase will transform to parallel cylinder and then directly to (211)G without transition to perpendicular cylinder phase. Most importantly, the morphological evolution of PS-PLLA thin films is strongly dependent upon the solvent removal rate only in the initial stage of the evaporation process due to the anisotropy of cylinder structure. Once the morphology is transformed back to the isotropic gyroid structure after long evaporation, the morphological evolution will only relate to the variation of the surface composition. Similar phase transitions at the substrate can also be obtained by controlling the ratio of PLLA-OH to PS-OH homopolymers to functionalize the substrate. As a result, the fabrication of well-defined nanostructured thin films with controlled orientation can be achieved by simple swelling and deswelling with controlled evaporation rate.
Harms, Alexander; Segers, Francisca H.I.D.; Quebatte, Maxime; Mistl, Claudia; Manfredi, Pablo; Körner, Jonas; Chomel, Bruno B.; Kosoy, Michael; Maruyama, Soichi; Engel, Philipp
2017-01-01
The α-proteobacterial genus Bartonella comprises a group of ubiquitous mammalian pathogens that are studied as a model for the evolution of bacterial pathogenesis. Vast abundance of two particular phylogenetic lineages of Bartonella had been linked to enhanced host adaptability enabled by lineage-specific acquisition of a VirB/D4 type IV secretion system (T4SS) and parallel evolution of complex effector repertoires. However, the limited availability of genome sequences from one of those lineages as well as other, remote branches of Bartonella has so far hampered comprehensive understanding of how the VirB/D4 T4SS and its effectors called Beps have shaped Bartonella evolution. Here, we report the discovery of a third repertoire of Beps associated with the VirB/D4 T4SS of B. ancashensis, a novel human pathogen that lacks any signs of host adaptability and is only distantly related to the two species-rich lineages encoding a VirB/D4 T4SS. Furthermore, sequencing of ten new Bartonella isolates from under-sampled lineages enabled combined in silico analyses and wet lab experiments that suggest several parallel layers of functional diversification during evolution of the three Bep repertoires from a single ancestral effector. Our analyses show that the Beps of B. ancashensis share many features with the two other repertoires, but may represent a more ancestral state that has not yet unleashed the adaptive potential of such an effector set. We anticipate that the effectors of B. ancashensis will enable future studies to dissect the evolutionary history of Bartonella effectors and help unraveling the evolutionary forces underlying bacterial host adaptation. PMID:28338931
Enzmann, P.-J.; Kurath, G.; Fichtner, D.; Bergmann, S.M.
2005-01-01
Infectious hematopoietic necrosis virus (IHNV) was first detected in Europe in 1987 in France and Italy, and later, in 1992, in Germany. The source of the virus and the route of introduction are unknown. The present study investigates the molecular epidemiology of IHNV outbreaks in Germany since its first introduction. The complete nucleotide sequences of the glycoprotein (G) and non-virion (NV) genes from 9 IHNV isolates from Germany have been determined, and this has allowed the identification of characteristic differences between these isolates. Phylogenetic analysis of partial G gene sequences (mid-G, 303 nucleotides) from North American IHNV isolates (Kurath et al. 2003) has revealed 3 major genogroups, designated U, M and L. Using this gene region with 2 different North American IHNV data sets, it was possible to group the European IHNV strains within the M genogroup, but not in any previously defined subgroup. Analysis of the full length G gene sequences indicated that an independent evolution of IHN viruses had occurred in Europe. IHN viruses in Europe seem to be of a monophyletic origin, again most closely related to North American isolates in the M genogroup. Analysis of the NV gene sequences also showed the European isolates to be monophyletic, but resolution of the 3 genogroups was poor with this gene region. As a result of comparative sequence analyses, several different genotypes have been identified circulating in Europe. ?? Inter-Research 2005.
Parasitism drives host genome evolution: Insights from the Pasteuria ramosa-Daphnia magna system.
Bourgeois, Yann; Roulin, Anne C; Müller, Kristina; Ebert, Dieter
2017-04-01
Because parasitism is thought to play a major role in shaping host genomes, it has been predicted that genomic regions associated with resistance to parasites should stand out in genome scans, revealing signals of selection above the genomic background. To test whether parasitism is indeed such a major factor in host evolution and to better understand host-parasite interaction at the molecular level, we studied genome-wide polymorphisms in 97 genotypes of the planktonic crustacean Daphnia magna originating from three localities across Europe. Daphnia magna is known to coevolve with the bacterial pathogen Pasteuria ramosa for which host genotypes (clonal lines) are either resistant or susceptible. Using association mapping, we identified two genomic regions involved in resistance to P. ramosa, one of which was already known from a previous QTL analysis. We then performed a naïve genome scan to test for signatures of positive selection and found that the two regions identified with the association mapping further stood out as outliers. Several other regions with evidence for selection were also found, but no link between these regions and phenotypic variation could be established. Our results are consistent with the hypothesis that parasitism is driving host genome evolution. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.
Luque, Cecilia; Cisternas, Felipe A; Araya, Magdalena
2006-06-01
During the twentieth century there was a change in the pattern of diseases in Europe, with an increase in the incidence of allergies and autoimmune disorders, that paralleled a decrease of infectious conditions. The Hygiene hypothesis proposes that these phenomena are causally related. To evaluate the epidemiological changes of allergic, autoimmune, and infectious diseases in Chile between 1950 and 2003. Search for the incidence and prevalence of these diseases in the national records published by the Ministry of Health, as well as through a systematic search of national literature using PubMed and Scielo as search engines. The annual incidence of tuberculosis, rheumatic fever, measles, and typhoid fever has progressively diminished in Chile since 1970. Figures for the national prevalence for asthma, rheumatoid arthritis, and type I diabetes are scarce and difficult to compare, but clearly show an increasing epidemiological trend in the last 20 years. The national figures suggest that, although the country has only recently gone through an epidemiological transition in health problems, there are detectable changes that show the same trends described in Europe.
Decadal changes in the distribution of common intertidal seaweeds in Galicia (NW Iberia).
Piñeiro-Corbeira, Cristina; Barreiro, Rodolfo; Cremades, Javier
2016-02-01
Seaweed assemblages in Atlantic Europe are been distorted by global change, but the intricate coastal profile of the area suggests that susceptibility may differ between regions. In particular, NW Iberia is an important omission because no study has systematically assessed long-term changes in a large number of species. Using intertidal surveys for 33 common perennial seaweeds, we show that the average number of species per site declined significantly from 1998-99 to 2014 in NW Iberia. The largest drops in site occupancy were detected in kelps, fucoids, and carrageenan-producing Rhodophyta. Parallel analyses revealed significant upward trends in SST, air temperature, and strong waves; meanwhile, nutrients decreased slightly except in areas affected by local inputs. Similar changes reported for subtidal assemblages in other parts of Atlantic Europe suggest that the drivers may be ubiquitous. Nonetheless, a more proper assessment of both global and local impacts, will require further surveys, and the regular monitoring of intertidal perennial seaweeds appears as a cost-effective alternative to discriminate genuine long-term trends from transitory fluctuations. Copyright © 2015 Elsevier Ltd. All rights reserved.
Molecular analysis of ancient caries
Simón, Marc; Montiel, Rafael; Smerling, Andrea; Solórzano, Eduvigis; Díaz, Nancy; Álvarez-Sandoval, Brenda A.; Jiménez-Marín, Andrea R.; Malgosa, Assumpció
2014-01-01
An 84 base pair sequence of the Streptococcus mutans virulence factor, known as dextranase, has been obtained from 10 individuals from the Bronze Age to the Modern Era in Europe and from before and after the colonization in America. Modern samples show four polymorphic sites that have not been found in the ancient samples studied so far. The nucleotide and haplotype diversity of this region have increased over time, which could be reflecting the footprint of a population expansion. While this segment has apparently evolved according to neutral evolution, we have been able to detect one site that is under positive selection pressure both in present and past populations. This study is a first step to study the evolution of this microorganism, analysed using direct evidence obtained from ancient remains. PMID:25056622
Dumchev, Kostyantyn; Varetska, Olga; Kuzin, Ihor
2017-07-01
Once facing the most severe HIV epidemic in Eastern Europe, Ukraine has built an elaborate Monitoring and Evaluation (M&E) system to track the response to AIDS. This system was developed using recommendations and input from multiple international expert organizations and donors and, at the current stage, serves as a best practice model in many areas. The present paper aims to provide a comprehensive overview of the evolution of the M&E system in Ukraine since its inception. Notable achievements and challenges are described and illustrated by epidemiological data and the recommendations for future development are discussed. Unique experiences and advances in M&E in Ukraine may be useful to other countries facing similar epidemiological, structural or methodological issues.
Technology transfer: The key to successful space engineering education
NASA Astrophysics Data System (ADS)
Fletcher, L. S.; Page, R. H.
The 1990s are the threshold of the space revolution for the next century. This space revolution was initiated by space pioneers like Tsiolkovsky, Goddard, and Oberth, who contributed a great deal to the evolution of space exploration, and more importantly, to space education. Recently, space engineering education programs for all ages have been advocated around the world, especially in Asia and Europe, as well as the U.S.A. and the Soviet Union. And yet, although space related technologies are developing rapidly, these technologies are not being incorporated successfully into space education programs. Timely technology transfer is essential to assure the continued education of professionals. This paper reviews the evolution of space engineering education and identifies a number of initiatives which could strengthen space engineering education for the next century.
Evolution of allowable stresses in shear for lumber
Robert L. Ethington; William L. Galligan; Henry M. Montrey; Alan D. Freas
1979-01-01
This paper surveys research leading to allowable shear stress parallel to grain for lumber. In early flexure tests of lumber, some pieces failed in shear. The estimated shear stress at time of failure was generally lower than shear strength measured on small, clear, straight-grained specimens. This and other engineering observations gave rise to adjustments that...
Parallel evolution of early and late feathering in turkey and chicken, same gene, different mutation
USDA-ARS?s Scientific Manuscript database
The sex-linked slow (SF) and fast (FF) feathering rate at hatch has been widely used in poultry breeding for autosexing at hatching. In chicken, the sex-linked K (SF), and k+ (FF) alleles are responsible for the feathering rate phenotype in chicken. The K allele is dominant and a partial duplication...
USDA-ARS?s Scientific Manuscript database
An infectious cDNA clone of Triticum mosaic virus (TriMV) (genus Poacevirus; family Potyviridae) was used to establish three independent lineages in wheat to examine intra-host population diversity levels within protein 1 (P1) and coat protein (CP) cistrons over time. Genetic variation was assessed ...
Monetizing French Distance Education: A Field Enquiry on Higher Education Value(s)
ERIC Educational Resources Information Center
Olivier, Marty
2014-01-01
A field enquiry in French distance education allows us to analyze the evolution of a specific institution towards new public management: Parallel to a trend of free courseware and open education, there is a paradoxical reality of distance education monetization. Whereas history shows how traditional French education is a state controlled public…
Parallel heat transport in integrable and chaotic magnetic fields
DOE Office of Scientific and Technical Information (OSTI.GOV)
Del-Castillo-Negrete, Diego B; Chacon, Luis
2012-01-01
The study of transport in magnetized plasmas is a problem of fundamental interest in controlled fusion, space plasmas, and astrophysics research. Three issues make this problem particularly chal- lenging: (i) The extreme anisotropy between the parallel (i.e., along the magnetic field), , and the perpendicular, , conductivities ( / may exceed 1010 in fusion plasmas); (ii) Magnetic field lines chaos which in general complicates (and may preclude) the construction of magnetic field line coordinates; and (iii) Nonlocal parallel transport in the limit of small collisionality. Motivated by these issues, we present a Lagrangian Green s function method to solve themore » local and non-local parallel transport equation applicable to integrable and chaotic magnetic fields in arbitrary geom- etry. The method avoids by construction the numerical pollution issues of grid-based algorithms. The potential of the approach is demonstrated with nontrivial applications to integrable (magnetic island chain), weakly chaotic (devil s staircase), and fully chaotic magnetic field configurations. For the latter, numerical solutions of the parallel heat transport equation show that the effective radial transport, with local and non-local closures, is non-diffusive, thus casting doubts on the appropriateness of the applicability of quasilinear diffusion descriptions. General conditions for the existence of non-diffusive, multivalued flux-gradient relations in the temperature evolution are derived.« less
Nishiguchi, Michele K.; Ruby, Edward G.; McFall-Ngai, Margaret J.
1998-01-01
One of the principal assumptions in symbiosis research is that associated partners have evolved in parallel. We report here experimental evidence for parallel speciation patterns among several partners of the sepiolid squid-luminous bacterial symbioses. Molecular phylogenies for 14 species of host squids were derived from sequences of both the nuclear internal transcribed spacer region and the mitochondrial cytochrome oxidase subunit I; the glyceraldehyde phosphate dehydrogenase locus was sequenced for phylogenetic determinations of 7 strains of bacterial symbionts. Comparisons of trees constructed for each of the three loci revealed a parallel phylogeny between the sepiolids and their respective symbionts. Because both the squids and their bacterial partners can be easily cultured independently in the laboratory, we were able to couple these phylogenetic analyses with experiments to examine the ability of the different symbiont strains to compete with each other during the colonization of one of the host species. Our results not only indicate a pronounced dominance of native symbiont strains over nonnative strains, but also reveal a hierarchy of symbiont competency that reflects the phylogenetic relationships of the partners. For the first time, molecular systematics has been coupled with experimental colonization assays to provide evidence for the existence of parallel speciation among a set of animal-bacterial associations. PMID:9726861
Parallel processing in the honeybee olfactory pathway: structure, function, and evolution.
Rössler, Wolfgang; Brill, Martin F
2013-11-01
Animals face highly complex and dynamic olfactory stimuli in their natural environments, which require fast and reliable olfactory processing. Parallel processing is a common principle of sensory systems supporting this task, for example in visual and auditory systems, but its role in olfaction remained unclear. Studies in the honeybee focused on a dual olfactory pathway. Two sets of projection neurons connect glomeruli in two antennal-lobe hemilobes via lateral and medial tracts in opposite sequence with the mushroom bodies and lateral horn. Comparative studies suggest that this dual-tract circuit represents a unique adaptation in Hymenoptera. Imaging studies indicate that glomeruli in both hemilobes receive redundant sensory input. Recent simultaneous multi-unit recordings from projection neurons of both tracts revealed widely overlapping response profiles strongly indicating parallel olfactory processing. Whereas lateral-tract neurons respond fast with broad (generalistic) profiles, medial-tract neurons are odorant specific and respond slower. In analogy to "what-" and "where" subsystems in visual pathways, this suggests two parallel olfactory subsystems providing "what-" (quality) and "when" (temporal) information. Temporal response properties may support across-tract coincidence coding in higher centers. Parallel olfactory processing likely enhances perception of complex odorant mixtures to decode the diverse and dynamic olfactory world of a social insect.
Origin and evolution of chromosomal sperm proteins.
Eirín-López, José M; Ausió, Juan
2009-10-01
In the eukaryotic cell, DNA compaction is achieved through its interaction with histones, constituting a nucleoprotein complex called chromatin. During metazoan evolution, the different structural and functional constraints imposed on the somatic and germinal cell lines led to a unique process of specialization of the sperm nuclear basic proteins (SNBPs) associated with chromatin in male germ cells. SNBPs encompass a heterogeneous group of proteins which, since their discovery in the nineteenth century, have been studied extensively in different organisms. However, the origin and controversial mechanisms driving the evolution of this group of proteins has only recently started to be understood. Here, we analyze in detail the histone hypothesis for the vertical parallel evolution of SNBPs, involving a "vertical" transition from a histone to a protamine-like and finally protamine types (H --> PL --> P), the last one of which is present in the sperm of organisms at the uppermost tips of the phylogenetic tree. In particular, the common ancestry shared by the protamine-like (PL)- and protamine (P)-types with histone H1 is discussed within the context of the diverse structural and functional constraints acting upon these proteins during bilaterian evolution.
Evolution of central pattern generators and rhythmic behaviours
Katz, Paul S.
2016-01-01
Comparisons of rhythmic movements and the central pattern generators (CPGs) that control them uncover principles about the evolution of behaviour and neural circuits. Over the course of evolutionary history, gradual evolution of behaviours and their neural circuitry within any lineage of animals has been a predominant occurrence. Small changes in gene regulation can lead to divergence of circuit organization and corresponding changes in behaviour. However, some behavioural divergence has resulted from large-scale rewiring of the neural network. Divergence of CPG circuits has also occurred without a corresponding change in behaviour. When analogous rhythmic behaviours have evolved independently, it has generally been with different neural mechanisms. Repeated evolution of particular rhythmic behaviours has occurred within some lineages due to parallel evolution or latent CPGs. Particular motor pattern generating mechanisms have also evolved independently in separate lineages. The evolution of CPGs and rhythmic behaviours shows that although most behaviours and neural circuits are highly conserved, the nature of the behaviour does not dictate the neural mechanism and that the presence of homologous neural components does not determine the behaviour. This suggests that although behaviour is generated by neural circuits, natural selection can act separately on these two levels of biological organization. PMID:26598733
Evolution of central pattern generators and rhythmic behaviours.
Katz, Paul S
2016-01-05
Comparisons of rhythmic movements and the central pattern generators (CPGs) that control them uncover principles about the evolution of behaviour and neural circuits. Over the course of evolutionary history, gradual evolution of behaviours and their neural circuitry within any lineage of animals has been a predominant occurrence. Small changes in gene regulation can lead to divergence of circuit organization and corresponding changes in behaviour. However, some behavioural divergence has resulted from large-scale rewiring of the neural network. Divergence of CPG circuits has also occurred without a corresponding change in behaviour. When analogous rhythmic behaviours have evolved independently, it has generally been with different neural mechanisms. Repeated evolution of particular rhythmic behaviours has occurred within some lineages due to parallel evolution or latent CPGs. Particular motor pattern generating mechanisms have also evolved independently in separate lineages. The evolution of CPGs and rhythmic behaviours shows that although most behaviours and neural circuits are highly conserved, the nature of the behaviour does not dictate the neural mechanism and that the presence of homologous neural components does not determine the behaviour. This suggests that although behaviour is generated by neural circuits, natural selection can act separately on these two levels of biological organization. © 2015 The Author(s).
Centeno, Carlos; Lynch, Thomas; Garralda, Eduardo; Carrasco, José Miguel; Guillen-Grima, Francisco; Clark, David
2016-04-01
The evolution of the provision of palliative care specialised services is important for planning and evaluation. To examine the development between 2005 and 2012 of three specialised palliative care services across the World Health Organization European Region - home care teams, hospital support teams and inpatient palliative care services. Data were extracted and analysed from two editions of the European Association for Palliative Care Atlas of Palliative Care in Europe. Significant development of each type of services was demonstrated by adjusted residual analysis, ratio of services per population and 2012 coverage (relationship between provision of available services and demand services estimated to meet the palliative care needs of a population). For the measurement of palliative care coverage, we used European Association for Palliative Care White Paper recommendations: one home care team per 100,000 inhabitants, one hospital support team per 200,000 inhabitants and one inpatient palliative care service per 200,000 inhabitants. To estimate evolution at the supranational level, mean comparison between years and European sub-regions is presented. Of 53 countries, 46 (87%) provided data. Europe has developed significant home care team, inpatient palliative care service and hospital support team in 2005-2012. The improvement was statistically significant for Western European countries, but not for Central and Eastern countries. Significant development in at least a type of services was in 21 of 46 (46%) countries. The estimations of 2012 coverage for inpatient palliative care service, home care team and hospital support team are 62%, 52% and 31% for Western European and 20%, 14% and 3% for Central and Eastern, respectively. Although there has been a positive development in overall palliative care coverage in Europe between 2005 and 2012, the services available in most countries are still insufficient to meet the palliative care needs of the population. © The Author(s) 2015.
NASA Astrophysics Data System (ADS)
Stecca, Guglielmo; Zolezzi, Guido; Surian, Nicola; Hicks, Murray
2017-04-01
Observations of morphological change in braided rivers, comprising narrowing of the total and active braidplain, degradation (at least in some reaches), increase in vegetation cover, and reduction of braiding complexity towards a transitional style, have been increasingly reported worldwide in the last decades. Most of the available literature concerns rivers in Europe, with particular reference to the Alpine and pre-Alpine region (e.g., Italy, France, Austria, Switzerland). This abundance reflects the magnitude of changes in Europe, where most of braided reaches have been heavily impacted. However, contributions from other regions of Europe (e.g., the Polish Carpathians, Spain, Scotland, Corsica) and of the Earth (e.g., the South Island of New Zealand) document similar stories. These morphodynamic changes have been related to the alteration of the fundamental physical processes in braided rivers driven by the flow and sediment supply regimes, due to anthropogenic changes in constraints and controls. Multiple and context-specific sources of impact on these controls have been identified, including damming, landuse change, gravel mining, torrent control works, channelisation, introduction of alien vegetation. Here, we focus on a comparative analysis of the relatively recent (multi-decadal) evolution of braided rivers located in different geographic regions on the Earth, with particular reference to the Waitaki (New Zealand), Piave (Italy) and Dunajec (Poland) rivers. These rivers display similar morphological trajectories, which nonetheless result from very different paths of causation, i.e., from different management causes and different alteration of physical processes. We focus on the role of different physical and human geographic contexts as drivers of the river evolution, highlighting the relations between the observed trajectories and the local conditions and characteristics. We discuss the relative role of dam construction and operation in contributing to the observed trajectories, and the prediction of future evolutionary trajectories through numerical morphodynamic modelling.
Kearney, Michael; Blacket, Mark J; Strasburg, Jared L; Moritz, Craig
2006-06-01
The rarity of parthenogenesis, reproduction without sex, is a major evolutionary puzzle. To understand why sexual genetic systems are so successful in nature, we must understand why parthenogenesis sometimes evolves and persists. Here we use DNA sequence data to test for similarities in the tempo and mode of the evolution of parthenogenesis in a grasshopper and a lizard from the Australian desert. We find spectacular congruence between genetic and geographic patterns of parthenogenesis in these distantly related organisms. In each species, parthenogenesis evolved twice and appears to have expanded in parallel waves across the desert, suggesting a highly general selective force against sex.
Matrix Product Operator Simulations of Quantum Algorithms
2015-02-01
parallel to the Grover subspace parametrically: (Zi|φ〉)‖ = s cos γ|α〉+ s sin γ|β〉, s = √ a(k)2 (N − 1)2 + b(k)2, γ = tan −1 ( b(k)(N − 1) a(k) ) (6.32) Each...of this vector parallel to the Grover subspace in parametric form: (XiZi|φ〉)‖ = s cos(γ)|α〉+ s sin(γ)|β〉, s = 1√ N − 1 , γ = tan −1 ( cot (( k + 1 2 ) θ...quant- ph/0001106, 2000. Bibliography 146 [30] Jérémie Roland and Nicolas J Cerf. Quantum search by local adiabatic evolution. Physical Review A, 65(4
Robust High-Resolution Cloth Using Parallelism, History-Based Collisions and Accurate Friction
Selle, Andrew; Su, Jonathan; Irving, Geoffrey; Fedkiw, Ronald
2015-01-01
In this paper we simulate high resolution cloth consisting of up to 2 million triangles which allows us to achieve highly detailed folds and wrinkles. Since the level of detail is also influenced by object collision and self collision, we propose a more accurate model for cloth-object friction. We also propose a robust history-based repulsion/collision framework where repulsions are treated accurately and efficiently on a per time step basis. Distributed memory parallelism is used for both time evolution and collisions and we specifically address Gauss-Seidel ordering of repulsion/collision response. This algorithm is demonstrated by several high-resolution and high-fidelity simulations. PMID:19147895
Assembly of the cnidarian camera-type eye from vertebrate-like components.
Kozmik, Zbynek; Ruzickova, Jana; Jonasova, Kristyna; Matsumoto, Yoshifumi; Vopalensky, Pavel; Kozmikova, Iryna; Strnad, Hynek; Kawamura, Shoji; Piatigorsky, Joram; Paces, Vaclav; Vlcek, Cestmir
2008-07-01
Animal eyes are morphologically diverse. Their assembly, however, always relies on the same basic principle, i.e., photoreceptors located in the vicinity of dark shielding pigment. Cnidaria as the likely sister group to the Bilateria are the earliest branching phylum with a well developed visual system. Here, we show that camera-type eyes of the cubozoan jellyfish, Tripedalia cystophora, use genetic building blocks typical of vertebrate eyes, namely, a ciliary phototransduction cascade and melanogenic pathway. Our findings indicative of parallelism provide an insight into eye evolution. Combined, the available data favor the possibility that vertebrate and cubozoan eyes arose by independent recruitment of orthologous genes during evolution.
On Borders: From Ancient to Postmodern Times
NASA Astrophysics Data System (ADS)
Bellezza, G.
2013-11-01
The article deals with the evolution of the concept of borders between human groups and with its slow evolution from the initial no men's land zones to the ideal single-dimension linear borders. In ancient times the first borders were natural, such as mountain ranges or large rivers until, with the development of Geodesy, astronomical borders based on meridians and parallels became a favourite natural base. Actually, Modern States adopted these to fix limits in unknown conquered territories. The postmodern thought led give more importance to cultural borders until, in the most recent times, is becoming rather impossible to fix borders in the virtual cyberspace.
Evolution, brain, and the nature of language.
Berwick, Robert C; Friederici, Angela D; Chomsky, Noam; Bolhuis, Johan J
2013-02-01
Language serves as a cornerstone for human cognition, yet much about its evolution remains puzzling. Recent research on this question parallels Darwin's attempt to explain both the unity of all species and their diversity. What has emerged from this research is that the unified nature of human language arises from a shared, species-specific computational ability. This ability has identifiable correlates in the brain and has remained fixed since the origin of language approximately 100 thousand years ago. Although songbirds share with humans a vocal imitation learning ability, with a similar underlying neural organization, language is uniquely human. Copyright © 2012 Elsevier Ltd. All rights reserved.
Evolution of Query Optimization Methods
NASA Astrophysics Data System (ADS)
Hameurlain, Abdelkader; Morvan, Franck
Query optimization is the most critical phase in query processing. In this paper, we try to describe synthetically the evolution of query optimization methods from uniprocessor relational database systems to data Grid systems through parallel, distributed and data integration systems. We point out a set of parameters to characterize and compare query optimization methods, mainly: (i) size of the search space, (ii) type of method (static or dynamic), (iii) modification types of execution plans (re-optimization or re-scheduling), (iv) level of modification (intra-operator and/or inter-operator), (v) type of event (estimation errors, delay, user preferences), and (vi) nature of decision-making (centralized or decentralized control).
NASA Astrophysics Data System (ADS)
Moskvin, A. S.; Panov, Yu. D.; Rybakov, F. N.; Borisov, A. B.
2017-11-01
We have used high-performance parallel computations by NVIDIA graphics cards applying the method of nonlinear conjugate gradients and Monte Carlo method to observe directly the developing ground state configuration of a two-dimensional hard-core boson system with decrease in temperature, and its evolution with deviation from a half-filling. This has allowed us to explore unconventional features of a charge order—superfluidity phase transition, specifically, formation of an irregular domain structure, emergence of a filamentary superfluid structure that condenses within of the charge-ordered phase domain antiphase boundaries, and formation and evolution of various topological structures.
Goedbloed, D J; Czypionka, T; Altmüller, J; Rodriguez, A; Küpfer, E; Segev, O; Blaustein, L; Templeton, A R; Nolte, A W; Steinfartz, S
2017-12-01
The utilization of similar habitats by different species provides an ideal opportunity to identify genes underlying adaptation and acclimatization. Here, we analysed the gene expression of two closely related salamander species: Salamandra salamandra in Central Europe and Salamandra infraimmaculata in the Near East. These species inhabit similar habitat types: 'temporary ponds' and 'permanent streams' during larval development. We developed two species-specific gene expression microarrays, each targeting over 12 000 transcripts, including an overlapping subset of 8331 orthologues. Gene expression was examined for systematic differences between temporary ponds and permanent streams in larvae from both salamander species to establish gene sets and functions associated with these two habitat types. Only 20 orthologues were associated with a habitat in both species, but these orthologues did not show parallel expression patterns across species more than expected by chance. Functional annotation of a set of 106 genes with the highest effect size for a habitat suggested four putative gene function categories associated with a habitat in both species: cell proliferation, neural development, oxygen responses and muscle capacity. Among these high effect size genes was a single orthologue (14-3-3 protein zeta/YWHAZ) that was downregulated in temporary ponds in both species. The emergence of four gene function categories combined with a lack of parallel expression of orthologues (except 14-3-3 protein zeta) suggests that parallel habitat adaptation or acclimatization by larvae from S. salamandra and S. infraimmaculata to temporary ponds and permanent streams is mainly realized by different genes with a converging functionality.
Integration Of Heat Transfer Coefficient In Glass Forming Modeling With Special Interface Element
NASA Astrophysics Data System (ADS)
Moreau, P.; César de Sá, J.; Grégoire, S.; Lochegnies, D.
2007-05-01
Numerical modeling of the glass forming processes requires the accurate knowledge of the heat exchange between the glass and the forming tools. A laboratory testing is developed to determine the evolution of the heat transfer coefficient in different glass/mould contact conditions (contact pressure, temperature, lubrication…). In this paper, trials are performed to determine heat transfer coefficient evolutions in experimental conditions close to the industrial blow-and-blow process conditions. In parallel of this work, a special interface element is implemented in a commercial Finite Element code in order to deal with heat transfer between glass and mould for non-meshing meshes and evolutive contact. This special interface element, implemented by using user subroutines, permits to introduce the previous heat transfer coefficient evolutions in the numerical modelings at the glass/mould interface in function of the local temperatures, contact pressures, contact time and kind of lubrication. The blow-and-blow forming simulation of a perfume bottle is finally performed to assess the special interface element performance.
Efficient Analysis of Simulations of the Sun's Magnetic Field
NASA Astrophysics Data System (ADS)
Scarborough, C. W.; Martínez-Sykora, J.
2014-12-01
Dynamics in the solar atmosphere, including solar flares, coronal mass ejections, micro-flares and different types of jets, are powered by the evolution of the sun's intense magnetic field. 3D Radiative Magnetohydrodnamics (MHD) computer simulations have furthered our understanding of the processes involved: When non aligned magnetic field lines reconnect, the alteration of the magnetic topology causes stored magnetic energy to be converted into thermal and kinetic energy. Detailed analysis of this evolution entails tracing magnetic field lines, an operation which is not time-efficient on a single processor. By utilizing a graphics card (GPU) to trace lines in parallel, conducting such analysis is made feasible. We applied our GPU implementation to the most advanced 3D Radiative-MHD simulations (Bifrost, Gudicksen et al. 2011) of the solar atmosphere in order to better understand the evolution of the modeled field lines.
NASA Astrophysics Data System (ADS)
Bettencourt, Luis; Kaiser, David
2004-03-01
Based on an a historically documented example of scientific discovery - Feynman diagrams as the main calculational tool of theoretical high energy Physics - we map the time evolution of the social network of early adopters through in the US, UK, Japan and the USSR. The spread of the technique for total number of users in each region is then modelled in terms of epidemic models, highlighting parallel and divergent aspects of this analogy. We also show that transient social arrangements develop as the idea is introduced and learned, which later disappear as the technique becomes common knowledge. Such early transient is characterized by abnormally low connectivity distribution powers and by high clustering. This interesting early non-equilibrium stage of network evolution is captured by a new dynamical model for network evolution, which coincides in its long time limit with familiar preferential aggregation dynamics.