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Sample records for affects clinal variation

  1.     Developmental acclimation affects clinal variation in stress resistance traits in Drosophila buzzatii

    DEFF Research Database (Denmark)

    Sarup, Pernille Merete; Loeschcke, Volker

    2010-01-01

      Patterns of clinal genetic variation in Drosophila are often characterized after rearing at constant temperatures. However, clinal patterns might change after acclimation if populations differ in their plastic response to fluctuating environments. We studied longevity, starvation and heat knock...... temperatures, especially in heat knock-down, for which clinal patterns disappeared when flies were reared at constant temperatures. This result emphasises the importance of determining whether populations originating from different environments differ in their plastic responses to stress....

  2. Thermal adaptation and clinal mitochondrial DNA variation of European anchovy

    OpenAIRE

    Silva, Gonçalo; Lima, Fernando P.; Martel, Paulo; Castilho, Rita

    2014-01-01

    Natural populations of widely distributed organisms often exhibit genetic clinal variation over their geographical ranges. The European anchovy, Engraulis encrasicolus, illustrates this by displaying a two-clade mitochondrial structure clinally arranged along the eastern Atlantic. One clade has low frequencies at higher latitudes, whereas the other has an anti-tropical distribution, with frequencies decreasing towards the tropics. The distribution pattern of these clades has been explained as...

  3. Genome-wide transcription analysis of clinal genetic variation in Drosophila

    NARCIS (Netherlands)

    Chen, Ying; Lee, Siu F.; Blanc, Eric; Reuter, Caroline; Wertheim, Bregje; Martinez-Diaz, Pedro; Hoffmann, Ary A.; Partridge, Linda

    2012-01-01

    Clinal variation in quantitative traits is widespread, but its genetic basis awaits identification. Drosophila melanogaster shows adaptive, clinal variation in traits such as body size along latitudinal gradients on multiple continents. To investigate genome wide transcription differentiation betwee

  4. Clinal variation of some mammals during the Holocene in Missouri

    Science.gov (United States)

    Purdue, James R.

    1980-03-01

    Eastern cottontail ( Sylvilagus floridanus), fox squirrel ( Sciurus niger), and gray squirrel ( Sciurus carolinensis) were examined for clinal variation during the Holocene. Modern samples of all three species displayed strong east-west patterns along the western edge of the eastern deciduous forest: S. floridanus and S. niger decrease and S. carolinensis increases in size. Archeological samples of S. carolinensis from Rodgers Shelter (23BE125), Benton County, Missouri, and Graham Cave (23MT2), Montgomery County, Missouri, indicated an increase in size from early to middle Holocene. Sylvilagus floridanus from Rodgers Shelter decreased in size from early to middle Holocene and then increased during the late Holocene to modern proportions. A literature survey reveals that clinal variation is a common phenomenon among modern homeotherms. In introduced species, clinal variation has developed after relatively few generations, indicating rapid adaptations to environmental conditions; often winter climatic variables are implicated. Morphological variation in the study species during the Holocene is interpreted as a response to changing climates. Studies of morphological clines may lead to another valuable data source for reconstructing past ecologies.

  5. Genome-Wide Transcription Analysis of Clinal Genetic Variation in Drosophila

    OpenAIRE

    Chen, Ying; Siu F Lee; Blanc, Eric; Reuter, Caroline; Wertheim, Bregje; Martinez-Diaz, Pedro; Hoffmann, Ary A.; Partridge, Linda

    2012-01-01

    Clinal variation in quantitative traits is widespread, but its genetic basis awaits identification. Drosophila melanogaster shows adaptive, clinal variation in traits such as body size along latitudinal gradients on multiple continents. To investigate genome wide transcription differentiation between North and South that might contribute to the clinal phenotypic variation, we compared RNA expression patterns during development of D. melanogaster from tropical northern and temperate southern p...

  6. Genome-wide transcription analysis of clinal genetic variation in Drosophila.

    OpenAIRE

    Chen, Y; Lee, S. F.; E. Blanc; C. Reuter; Wertheim, B.; Martinez-Diaz, P.; Hoffmann, A. A.; Partridge, L

    2012-01-01

    Clinal variation in quantitative traits is widespread, but its genetic basis awaits identification. Drosophila melanogaster shows adaptive, clinal variation in traits such as body size along latitudinal gradients on multiple continents. To investigate genome wide transcription differentiation between North and South that might contribute to the clinal phenotypic variation, we compared RNA expression patterns during development of D. melanogaster from tropical northern and temperate southern p...

  7. Thermal adaptation and clinal mitochondrial DNA variation of European anchovy.

    Science.gov (United States)

    Silva, Gonçalo; Lima, Fernando P; Martel, Paulo; Castilho, Rita

    2014-10-01

    Natural populations of widely distributed organisms often exhibit genetic clinal variation over their geographical ranges. The European anchovy, Engraulis encrasicolus, illustrates this by displaying a two-clade mitochondrial structure clinally arranged along the eastern Atlantic. One clade has low frequencies at higher latitudes, whereas the other has an anti-tropical distribution, with frequencies decreasing towards the tropics. The distribution pattern of these clades has been explained as a consequence of secondary contact after an ancient geographical isolation. However, it is not unlikely that selection acts on mitochondria whose genes are involved in relevant oxidative phosphorylation processes. In this study, we performed selection tests on a fragment of 1044 bp of the mitochondrial cytochrome b gene using 455 individuals from 18 locations. We also tested correlations of six environmental features: temperature, salinity, apparent oxygen utilization and nutrient concentrations of phosphate, nitrate and silicate, on a compilation of mitochondrial clade frequencies from 66 sampling sites comprising 2776 specimens from previously published studies. Positive selection in a single codon was detected predominantly (99%) in the anti-tropical clade and temperature was the most relevant environmental predictor, contributing with 59% of the variance in the geographical distribution of clade frequencies. These findings strongly suggest that temperature is shaping the contemporary distribution of mitochondrial DNA clade frequencies in the European anchovy. PMID:25143035

  8. Genome-wide transcription analysis of clinal genetic variation in Drosophila.

    Directory of Open Access Journals (Sweden)

    Ying Chen

    Full Text Available Clinal variation in quantitative traits is widespread, but its genetic basis awaits identification. Drosophila melanogaster shows adaptive, clinal variation in traits such as body size along latitudinal gradients on multiple continents. To investigate genome wide transcription differentiation between North and South that might contribute to the clinal phenotypic variation, we compared RNA expression patterns during development of D. melanogaster from tropical northern and temperate southern populations using whole genome tiling arrays. We found that genes that were differentially expressed between the cline ends were generally associated with metabolism and growth, and experimental alteration of expression of a sample of them generally resulted in altered body size in the predicted direction, sometimes significantly so. We further identified the serpent (srp transcription factor binding sites to be enriched near genes up-regulated in expression in the south. Analysis of clinal populations revealed a significant cline in the expression level of srp. Experimental over-expression of srp increased body size, as predicted from its clinal expression pattern, suggesting that it may be involved in regulating adaptive clinal variation in Drosophila. This study identified a handful of genes that contributed to clinal phenotypic variation through altered gene expression level, yet misexpression of individual gene led to modest body size change.

  9. Clinal variation for amino acid polymorphisms at the Pgm locus in Drosophila melanogaster.

    OpenAIRE

    Verrelli, B C; Eanes, W. F.

    2001-01-01

    Clinal variation is common for enzymes in the glycolytic pathway for Drosophila melanogaster and is generally accepted as an adaptive response to different climates. Although the enzyme phosphoglucomutase (PGM) possesses several allozyme polymorphisms, it is unique in that it had been reported to show no clinal variation. Our recent DNA sequence investigation of Pgm found extensive cryptic amino acid polymorphism segregating with the allozyme alleles. In this study, we characterize the geogra...

  10. Arabidopsis thaliana populations show clinal variation in a climatic gradient associated with altitude

    OpenAIRE

    Montesinos-Navarro, Alicia; Wig, Jennifer; Picó, F. Xavier; Tonsor, Stephen J.

    2011-01-01

    • Understanding the adaptive basis of life history variation is a central goal in evo- lutionary ecology. The use of model species enables the combination of molecular mechanistic knowledge with ecological and evolutionary questions, but the study of life history variation in natural environments is required to merge these disci- plines. • Here, we tested for clinal variation in life history and associated traits along an environmental and altitudinal gradient in the model species Arabid...

  11. Assortative mating and gene flow generate clinal phenological variation in trees

    OpenAIRE

    Soularue Jean-Paul; Kremer Antoine

    2012-01-01

    Abstract Background On-going climate change is shifting the timing of bud burst (TBB) of broad leaf and conifer trees in temperate areas, raising concerns about the abilities of natural populations to respond to these shifts. The level of expected evolutionary change depends on the level and distribution of genetic variation of TBB. While numerous experimental studies have highlighted the role of divergent selection in promoting clinal TBB differentiation, we explored whether the observed pat...

  12. Postponed reproduction as an adaptation to winter conditions in Drosophila melanogaster: evidence for clinal variation under semi-natural conditions.

    OpenAIRE

    Mitrovski, P.; Hoffmann, A. A.

    2001-01-01

    Patterns of climatic adaptation in drosophila and other insects have largely been inferred from laboratory comparisons of traits that vary clinally. Here, we extend this research to comparisons under semi-natural conditions. To test for clinal variation in reproductive patterns and survival over winter, Drosophila melanogaster populations were initiated from seven collection sites along the eastern coast of Australia, ranging from tropical to temperate regions. The fecundity and survival of t...

  13. Secondary contact and local adaptation contribute to genome-wide patterns of clinal variation in Drosophila melanogaster.

    Science.gov (United States)

    Bergland, Alan O; Tobler, Ray; González, Josefa; Schmidt, Paul; Petrov, Dmitri

    2016-03-01

    Populations arrayed along broad latitudinal gradients often show patterns of clinal variation in phenotype and genotype. Such population differentiation can be generated and maintained by both historical demographic events and local adaptation. These evolutionary forces are not mutually exclusive and can in some cases produce nearly identical patterns of genetic differentiation among populations. Here, we investigate the evolutionary forces that generated and maintain clinal variation genome-wide among populations of Drosophila melanogaster sampled in North America and Australia. We contrast patterns of clinal variation in these continents with patterns of differentiation among ancestral European and African populations. Using established and novel methods we derive here, we show that recently derived North America and Australia populations were likely founded by both European and African lineages and that this hybridization event likely contributed to genome-wide patterns of parallel clinal variation between continents. The pervasive effects of admixture mean that differentiation at only several hundred loci can be attributed to the operation of spatially varying selection using an FST outlier approach. Our results provide novel insight into the well-studied system of clinal differentiation in D. melanogaster and provide a context for future studies seeking to identify loci contributing to local adaptation in a wide variety of organisms, including other invasive species as well as temperate endemics. PMID:26547394

  14. Clinal variation at phenology-related genes in spruce: parallel evolution in FTL2 and Gigantea?

    Science.gov (United States)

    Chen, Jun; Tsuda, Yoshiaki; Stocks, Michael; Källman, Thomas; Xu, Nannan; Kärkkäinen, Katri; Huotari, Tea; Semerikov, Vladimir L; Vendramin, Giovanni G; Lascoux, Martin

    2014-07-01

    Parallel clines in different species, or in different geographical regions of the same species, are an important source of information on the genetic basis of local adaptation. We recently detected latitudinal clines in SNPs frequencies and gene expression of candidate genes for growth cessation in Scandinavian populations of Norway spruce (Picea abies). Here we test whether the same clines are also present in Siberian spruce (P. obovata), a close relative of Norway spruce with a different Quaternary history. We sequenced nine candidate genes and 27 control loci and genotyped 14 SSR loci in six populations of P. obovata located along the Yenisei river from latitude 56°N to latitude 67°N. In contrast to Scandinavian Norway spruce that both departs from the standard neutral model (SNM) and shows a clear population structure, Siberian spruce populations along the Yenisei do not depart from the SNM and are genetically unstructured. Nonetheless, as in Norway spruce, growth cessation is significantly clinal. Polymorphisms in photoperiodic (FTL2) and circadian clock (Gigantea, GI, PRR3) genes also show significant clinal variation and/or evidence of local selection. In GI, one of the variants is the same as in Norway spruce. Finally, a strong cline in gene expression is observed for FTL2, but not for GI. These results, together with recent physiological studies, confirm the key role played by FTL2 and circadian clock genes in the control of growth cessation in spruce species and suggest the presence of parallel adaptation in these two species. PMID:24814465

  15. Rapid Development of Adaptive, Climate-Driven Clinal Variation in Seed Mass in the Invasive Annual Forb Echium plantagineum L.

    OpenAIRE

    Konarzewski, Tara K.; Murray, Brad R.; Godfree, Robert C.

    2012-01-01

    We examined adaptive clinal variation in seed mass among populations of an invasive annual species, Echium plantagineum, in response to climatic selection. We collected seeds from 34 field populations from a 1,000 km long temperature and rainfall gradient across the species' introduced range in south-eastern Australia. Seeds were germinated, grown to reproductive age under common glasshouse conditions, and progeny seeds were harvested and weighed. Analyses showed that seed mass was significan...

  16. Genomics of clinal variation in Drosophila: disentangling the interactions of selection and demography.

    Science.gov (United States)

    Flatt, Thomas

    2016-03-01

    Clines in phenotypes and genotype frequencies across environmental gradients are commonly taken as evidence for spatially varying selection. Classical examples include the latitudinal clines in various species of Drosophila, which often occur in parallel fashion on multiple continents. Today, genomewide analysis of such clinal systems provides a fantastic opportunity for unravelling the genetics of adaptation, yet major challenges remain. A well-known but often neglected problem is that demographic processes can also generate clinality, independent of or coincident with selection. A closely related issue is how to identify true genic targets of clinal selection. In this issue of Molecular Ecology, three studies illustrate these challenges and how they might be met. Bergland et al. report evidence suggesting that the well-known parallel latitudinal clines in North American and Australian D. melanogaster are confounded by admixture from Africa and Europe, highlighting the importance of distinguishing demographic from adaptive clines. In a companion study, Machado et al. provide the first genomic comparison of latitudinal differentiation in D. melanogaster and its sister species D. simulans. While D. simulans is less clinal than D. melanogaster, a significant fraction of clinal genes is shared between both species, suggesting the existence of convergent adaptation to clinaly varying selection pressures. Finally, by drawing on several independent sources of evidence, Božičević et al. identify a functional network of eight clinal genes that are likely involved in cold adaptation. Together, these studies remind us that clinality does not necessarily imply selection and that separating adaptive signal from demographic noise requires great effort and care. PMID:26919307

  17. Assortative mating and gene flow generate clinal phenological variation in trees

    Directory of Open Access Journals (Sweden)

    Soularue Jean-Paul

    2012-06-01

    Full Text Available Abstract Background On-going climate change is shifting the timing of bud burst (TBB of broad leaf and conifer trees in temperate areas, raising concerns about the abilities of natural populations to respond to these shifts. The level of expected evolutionary change depends on the level and distribution of genetic variation of TBB. While numerous experimental studies have highlighted the role of divergent selection in promoting clinal TBB differentiation, we explored whether the observed patterns of variation could be generated by the joint effects of assortative mating for TBB and gene flow among natural populations. We tested this hypothesis using an in silico approach based on quantitative genetic models. Results Our simulations showed that genetic clines can develop even without divergent selection. Assortative mating in association with environmental gradients substantially shifted the mean genetic values of populations. Owing to assortative mating, immigrant alleles were screened for proximal or distant populations depending on the strength of the environmental cline. Furthermore, we confirmed that assortative mating increases the additive genetic variance within populations. However, we observed also a rapid decline of the additive genetic variance caused by restricted gene flow between neighboring populations resulting from preferential matings between phenologically-matching phenotypes. Conclusions We provided evidence that the patterns of genetic variation of phenological traits observed in forest trees can be generated solely by the effects of assortative mating and gene flow. We anticipate that predicted temperature increases due to climate change will further enhance genetic differentiation across the landscape. These trends are likely to be reinforced or counteracted by natural selection if phenological traits are correlated to fitness.

  18. Clinal variation or validation of a subspecies? A case study of the Graptemys nigrinoda complex (Testudines: Emydidae)

    Science.gov (United States)

    Ennen, Joshua R.; Kalis, Marley E.; Patterson, Adam L.; Kreiser, Brian R.; Lovich, Jeffrey E.; Godwin, James; Qualls, Carl P.

    2014-01-01

    Widely distributed species often display intraspecific morphological variation due to the abiotic and biotic gradients experienced across their ranges. Historically, in many vertebrate taxa, such as birds and reptiles, these morphological differences within a species were used to delimit subspecies. Graptemys nigrinoda is an aquatic turtle species endemic to the Mobile Bay Basin. Colour pattern and morphological variability were used to describe a subspecies (G. n. delticola) from the lower reaches of the system, although it and the nominate subspecies also reportedly intergrade over a large portion of the range. Other researchers have suggested that these morphological differences merely reflect clinal variation. Our molecular data (mtDNA) did not support the existence of the subspecies, as the haplotypes were differentiated by only a few base pairs and one haplotype was shared between the putative subspecies. While there were significant morphological and pattern differences among putative specimens of G. n. nigrinoda, G. n. delticola and G. n. nigrinoda × delticola, these differences probably represent clinal variation as they were also related to environmental variables [i.e. cumulative drainage area and drainage (categorical)]. Specimens occupying slow-current, high-turbidity river reaches (e.g. the Tensaw River) exhibited greater relative carapace heights and more dark pigmentation, while specimens occupying fast-current, clearer rivers (e.g. the upper Alabama, Cahaba and Tallapoosa rivers) exhibited lower carapace heights and more yellow pigmentation. Given the absence of clear molecular and morphological differences that are related to drainage characteristics, we suggest that there is not sufficient evidence for the recognition of G. n. delticola as a distinct subspecies.

  19. Rapid development of adaptive, climate-driven clinal variation in seed mass in the invasive annual Forb Echium plantagineum L.

    Science.gov (United States)

    Konarzewski, Tara K; Murray, Brad R; Godfree, Robert C

    2012-01-01

    We examined adaptive clinal variation in seed mass among populations of an invasive annual species, Echium plantagineum, in response to climatic selection. We collected seeds from 34 field populations from a 1,000 km long temperature and rainfall gradient across the species' introduced range in south-eastern Australia. Seeds were germinated, grown to reproductive age under common glasshouse conditions, and progeny seeds were harvested and weighed. Analyses showed that seed mass was significantly related to climatic factors, with populations sourced from hotter, more arid sites producing heavier seeds than populations from cooler and wetter sites. Seed mass was not related to edaphic factors. We also found that seed mass was significantly related to both longitude and latitude with each degree of longitude west and latitude north increasing seed mass by around 2.5% and 4% on average. There was little evidence that within-population or between-population variation in seed mass varied in a systematic manner across the study region. Our findings provide compelling evidence for development of a strong cline in seed mass across the geographic range of a widespread and highly successful invasive annual forb. Since large seed mass is known to provide reproductive assurance for plants in arid environments, our results support the hypothesis that the fitness and range potential of invasive species can increase as a result of genetic divergence of populations along broad climatic gradients. In E. plantagineum population-level differentiation has occurred in 150 years or less, indicating that the adaptation process can be rapid. PMID:23284621

  20. Rapid development of adaptive, climate-driven clinal variation in seed mass in the invasive annual Forb Echium plantagineum L.

    Directory of Open Access Journals (Sweden)

    Tara K Konarzewski

    Full Text Available We examined adaptive clinal variation in seed mass among populations of an invasive annual species, Echium plantagineum, in response to climatic selection. We collected seeds from 34 field populations from a 1,000 km long temperature and rainfall gradient across the species' introduced range in south-eastern Australia. Seeds were germinated, grown to reproductive age under common glasshouse conditions, and progeny seeds were harvested and weighed. Analyses showed that seed mass was significantly related to climatic factors, with populations sourced from hotter, more arid sites producing heavier seeds than populations from cooler and wetter sites. Seed mass was not related to edaphic factors. We also found that seed mass was significantly related to both longitude and latitude with each degree of longitude west and latitude north increasing seed mass by around 2.5% and 4% on average. There was little evidence that within-population or between-population variation in seed mass varied in a systematic manner across the study region. Our findings provide compelling evidence for development of a strong cline in seed mass across the geographic range of a widespread and highly successful invasive annual forb. Since large seed mass is known to provide reproductive assurance for plants in arid environments, our results support the hypothesis that the fitness and range potential of invasive species can increase as a result of genetic divergence of populations along broad climatic gradients. In E. plantagineum population-level differentiation has occurred in 150 years or less, indicating that the adaptation process can be rapid.

  1. Sympatric divergence and clinal variation in multiple coloration traits of Ficedula flycatchers

    NARCIS (Netherlands)

    Laaksonen, T.; Sirkia, P. M.; Calhim, S.; Brommer, J. E.; Leskinen, P. K.; Primmer, C. R.; Adamik, P.; Artemyev, A. V.; Belskii, E.; Both, C.; Bures, S.; Burgess, M. D.; Doligez, B.; Forsman, J. T.; Grinkov, V.; Hoffmann, U.; Ivankina, E.; Kral, M.; Krams, I.; Lampe, H. M.; Moreno, J.; Maegi, M.; Nord, A.; Potti, J.; Ravussin, P-A.; Sokolov, L.

    2015-01-01

    Geographic variation in phenotypes plays a key role in fundamental evolutionary processes such as local adaptation, population differentiation and speciation, but the selective forces behind it are rarely known. We found support for the hypothesis that geographic variation in plumage traits of the p

  2. Altitudinal Clinal Variation in Wing Size & Shape in African Drosophila melanogaster: One Cline or Many?

    OpenAIRE

    Pitchers, William; Pool, John E.; Dworkin, Ian

    2012-01-01

    Geographical patterns of morphological variation have been useful in addressing hypotheses about environmental adaptation. In particular, latitudinal clines in phenotypes have been studied in a number of Drosophila species. Some environmental conditions along latitudinal clines – e.g. temperature – also vary along altitudinal clines, but these have been studied infrequently and it remains unclear whether these environmental factors are similar enough for convergence or parallel evolution. Mos...

  3. Sympatric divergence and clinal variation in multiple coloration traits of Ficedula flycatchers.

    Science.gov (United States)

    Laaksonen, T; Sirkiä, P M; Calhim, S; Brommer, J E; Leskinen, P K; Primmer, C R; Adamík, P; Artemyev, A V; Belskii, E; Both, C; Bureš, S; Burgess, M D; Doligez, B; Forsman, J T; Grinkov, V; Hoffmann, U; Ivankina, E; Král, M; Krams, I; Lampe, H M; Moreno, J; Mägi, M; Nord, A; Potti, J; Ravussin, P-A; Sokolov, L

    2015-04-01

    Geographic variation in phenotypes plays a key role in fundamental evolutionary processes such as local adaptation, population differentiation and speciation, but the selective forces behind it are rarely known. We found support for the hypothesis that geographic variation in plumage traits of the pied flycatcher Ficedula hypoleuca is explained by character displacement with the collared flycatcher Ficedula albicollis in the contact zone. The plumage traits of the pied flycatcher differed strongly from the more conspicuous collared flycatcher in a sympatric area but increased in conspicuousness with increasing distance to there. Phenotypic differentiation (PST ) was higher than that in neutral genetic markers (FST ), and the effect of geographic distance remained when statistically controlling for neutral genetic differentiation. This suggests that a cline created by character displacement and gene flow explains phenotypic variation across the distribution of this species. The different plumage traits of the pied flycatcher are strongly to moderately correlated, indicating that they evolve non-independently from each other. The flycatchers provide an example of plumage patterns diverging in two species that differ in several aspects of appearance. The divergence in sympatry and convergence in allopatry in these birds provide a possibility to study the evolutionary mechanisms behind the highly divergent avian plumage patterns. PMID:25683091

  4. Recent ecological selection on regulatory divergence is shaping clinal variation in senecio on Mount Etna.

    Science.gov (United States)

    Muir, Graham; Osborne, Owen G; Sarasa, Jonas; Hiscock, Simon J; Filatov, Dmitry A

    2013-10-01

    The hybrid zone on Mount Etna (Sicily) between Senecio aethnensis and Senecio chrysanthemifolius (two morphologically and physiologically distinct species) is a classic example of an altitudinal cline. Hybridization at intermediate altitudes and gradients in phenotypic and life-history traits occur along altitudinal transects of the volcano. The cline is considered to be a good example of ecological selection with species differences arising by divergent selection opposing gene flow. However, the possibility that the cline formed from recent secondary contact following an allopatric phase is difficult to exclude. We demonstrate a recent split between S. aethnensis and S. chrysanthemifolius (as recent as ∼32,000 years ago) and sufficient gene flow (2Nm > 1) to have prevented divergence (implicating a role for diversifying selection in the maintenance of the cline). Differentially expressed genes between S. aethnensis and S. chrysanthemifolius exhibit significantly higher genetic divergence relative to "expression invariant" controls, suggesting that species differences may in part be mediated by divergent selection on differentially expressed genes involved with altitude-related adaptation. The recent split time and the absence of fixed differences between these two ecologically distinct species suggest the rapid evolution to an altitudinal cline involving selection on both sequence and expression variation. PMID:24094352

  5. The geographical variation of the Jay (Garrulus glandarius) in Europe: a study on individual and clinal variation

    NARCIS (Netherlands)

    Voous, K.H.

    1953-01-01

    Ever since it became apparent that terrestrial animals ranging over large continental areas generally showed a certain degree of gradual geographic variation, attention has been focused on the colour variation of the Jay, Garrulus glandarius, in Europe. Surely the Jays belong to those species of pal

  6. An Intronic Polymorphism in couch potato Is Not Distributed Clinally in European Drosophila melanogaster Populations nor Does It Affect Diapause Inducibility.

    Science.gov (United States)

    Zonato, Valeria; Fedele, Giorgio; Kyriacou, Charalambos P

    2016-01-01

    couch potato (cpo) encodes an RNA binding protein that has been reported to be expressed in the peripheral and central nervous system of embryos, larvae and adults, including the major endocrine organ, the ring gland. A polymorphism in the D. melanogaster cpo gene coding region displays a latitudinal cline in frequency in North American populations, but as cpo lies within the inversion In(3R)Payne, which is at high frequencies and itself shows a strong cline on this continent, interpretation of the cpo cline is not straightforward. A second downstream SNP in strong linkage disequilibrium with the first has been claimed to be primarily responsible for the latitudinal cline in diapause incidence in USA populations.Here, we investigate the frequencies of these two cpo SNPs in populations of Drosophila throughout continental Europe. The advantage of studying cpo variation in Europe is the very low frequency of In(3R)Payne, which we reveal here, does not appear to be clinally distributed. We observe a very different geographical scenario for cpo variation from the one in North America, suggesting that the downstream SNP does not play a role in diapause. In an attempt to verify whether the SNPs influence diapause we subsequently generated lines with different combinations of the two cpo SNPs on known timeless (tim) genetic backgrounds, because polymorphism in the clock gene tim plays a significant role in diapause inducibility. Our results reveal that the downstream cpo SNP does not seem to play any role in diapause induction in European populations in contrast to the upstream coding cpo SNP. Consequently, all future diapause studies on strains of D. melanogaster should initially determine their tim and cpo status. PMID:27598401

  7. Disentangling the Roles of History and Local Selection in Shaping Clinal Variation of Allele Frequencies and Gene Expression in Norway Spruce (Picea abies)

    OpenAIRE

    J. Chen; Kallman, T.; Ma, X.; Gyllenstrand, N; Zaina, G.; M. Morgante; Bousquet, J; Eckert, A; Wegrzyn, J.; Neale, D.; Lagercrantz, U.; Lascoux, M

    2012-01-01

    Understanding the genetic basis of local adaptation is challenging due to the subtle balance among conflicting evolutionary forces that are involved in its establishment and maintenance. One system with which to tease apart these difficulties is clines in adaptive characters. Here we analyzed genetic and phenotypic variation in bud set, a highly heritable and adaptive trait, among 18 populations of Norway spruce (Picea abies), arrayed along a latitudinal gradient ranging from 47°N to 68°N. We...

  8. Y-Chromosomal Diversity in Europe Is Clinal and Influenced Primarily by Geography, Rather than by Language

    OpenAIRE

    Rosser, Z H; Zerjal, T; Hurles, M. E.; Adojaan, M; Alavantic, D; Amorim, A.; Amos, W; Armenteros, M; E Arroyo; Barbujani, G; Beckman, G; Beckman, L.; Bertranpetit, J; Bosch, E.; Bradley, D.G

    2000-01-01

    Clinal patterns of autosomal genetic diversity within Europe have been interpreted in previous studies in terms of a Neolithic demic diffusion model for the spread of agriculture; in contrast, studies using mtDNA have traced many founding lineages to the Paleolithic and have not shown strongly clinal variation. We have used 11 human Y-chromosomal biallelic polymorphisms, defining 10 haplogroups, to analyze a sample of 3,616 Y chromosomes belonging to 47 European and circum-European population...

  9. Y chromosome genetic variation in the Italian peninsula is clinal and supports an admixture model for the Mesolithic-Neolithic encounter.

    Science.gov (United States)

    Capelli, Cristian; Brisighelli, Francesca; Scarnicci, Francesca; Arredi, Barbara; Caglia', Alessandra; Vetrugno, Giuseppe; Tofanelli, Sergio; Onofri, Valerio; Tagliabracci, Adriano; Paoli, Giorgio; Pascali, Vincenzo L

    2007-07-01

    The Italian peninsula, given its geographical location in the middle of the Mediterranean basin, was involved in the process of the peopling of Europe since the very beginning, with first settlements dating to the Upper Paleolithic. Later on, the Neolithic revolution left clear evidence in the archeological record, with findings going back to 7000 B.C. We have investigated the demographic consequences of the agriculture revolution in this area by genotyping Y chromosome markers for almost 700 individuals from 12 different regions. Data analysis showed a non-random distribution of the observed genetic variation, with more than 70% of the Y chromosome diversity distributed along a North-South axis. While the Greek colonisation during classical time appears to have left no significant contribution, the results support a male demic diffusion model, even if population replacement was not complete and the degree of Neolithic admixture with Mesolithic inhabitants was different in different areas of Italy. PMID:17275346

  10. The sampling scheme matters: Pan troglodytes troglodytes and P. t. schweinfurthii are characterized by clinal genetic variation rather than a strong subspecies break.

    Science.gov (United States)

    Fünfstück, Tillmann; Arandjelovic, Mimi; Morgan, David B; Sanz, Crickette; Reed, Patricia; Olson, Sarah H; Cameron, Ken; Ondzie, Alain; Peeters, Martine; Vigilant, Linda

    2015-02-01

    Populations of an organism living in marked geographical or evolutionary isolation from other populations of the same species are often termed subspecies and expected to show some degree of genetic distinctiveness. The common chimpanzee (Pan troglodytes) is currently described as four geographically delimited subspecies: the western (P. t. verus), the nigerian-cameroonian (P. t. ellioti), the central (P. t. troglodytes) and the eastern (P. t. schweinfurthii) chimpanzees. Although these taxa would be expected to be reciprocally monophyletic, studies have not always consistently resolved the central and eastern chimpanzee taxa. Most studies, however, used data from individuals of unknown or approximate geographic provenance. Thus, genetic data from samples of known origin may shed light on the evolutionary relationship of these subspecies. We generated microsatellite genotypes from noninvasively collected fecal samples of 185 central chimpanzees that were sampled across large parts of their range and analyzed them together with 283 published eastern chimpanzee genotypes from known localities. We observed a clear signal of isolation by distance across both subspecies. Further, we found that a large proportion of comparisons between groups taken from the same subspecies showed higher genetic differentiation than the least differentiated between-subspecies comparison. This proportion decreased substantially when we simulated a more clumped sampling scheme by including fewer groups. Our results support the general concept that the distribution of the sampled individuals can dramatically affect the inference of genetic population structure. With regard to chimpanzees, our results emphasize the close relationship of equatorial chimpanzees from central and eastern equatorial Africa and the difficult nature of subspecies definitions. PMID:25330245

  11. How variation between individuals affects species coexistence.

    Science.gov (United States)

    Hart, Simon P; Schreiber, Sebastian J; Levine, Jonathan M

    2016-08-01

    Although the effects of variation between individuals within species are traditionally ignored in studies of species coexistence, the magnitude of intraspecific variation in nature is forcing ecologists to reconsider. Compelling intuitive arguments suggest that individual variation may provide a previously unrecognised route to diversity maintenance by blurring species-level competitive differences or substituting for species-level niche differences. These arguments, which are motivating a large body of empirical work, have rarely been evaluated with quantitative theory. Here we incorporate intraspecific variation into a common model of competition and identify three pathways by which this variation affects coexistence: (1) changes in competitive dynamics because of nonlinear averaging, (2) changes in species' mean interaction strengths because of variation in underlying traits (also via nonlinear averaging) and (3) effects on stochastic demography. As a consequence of the first two mechanisms, we find that intraspecific variation in competitive ability increases the dominance of superior competitors, and intraspecific niche variation reduces species-level niche differentiation, both of which make coexistence more difficult. In addition, individual variation can exacerbate the effects of demographic stochasticity, and this further destabilises coexistence. Our work provides a theoretical foundation for emerging empirical interests in the effects of intraspecific variation on species diversity. PMID:27250037

  12. Small-scale clinal variation, genetic diversity and environmental heterogeneity in the marine gobies Pomatoschistus minutus and P. lozanoi (Gobiidae, Teleostei)

    OpenAIRE

    Gysels, E.S.; Leentjes, V.; Volckaert, F.A.M.J.

    2004-01-01

    Genetic variation was assayed at 14 allozyme loci in estuarine, coastal and offshore samples of Lozano's goby, Pomatoschistus lozanoi and the sand goby, P. minutus. Samples were taken from locations on the Belgian Continental Shelf and in the Schelde estuary with a range of environmental heterogeneity. We evaluate whether any differences in (1) the degree of genetic variation and (2) allele frequencies at the various loci exist within samples occurring in various habitats on the BCS and in th...

  13. Physical and Linkage Maps for Drosophila serrata, a Model Species for Studies of Clinal Adaptation and Sexual Selection

    OpenAIRE

    Stocker, Ann J.; Rusuwa, Bosco B.; Blacket, Mark J.; Frentiu, Francesca D; Sullivan, Mitchell; Foley, Bradley R.; Beatson, Scott; Hoffmann, Ary A.; Chenoweth, Stephen F.

    2012-01-01

    Drosophila serrata is a member of the montium group, which contains more than 98 species and until recently was considered a subgroup within the melanogaster group. This Drosophila species is an emerging model system for evolutionary quantitative genetics and has been used in studies of species borders, clinal variation and sexual selection. Despite the importance of D. serrata as a model for evolutionary research, our poor understanding of its genome remains a significant limitation. Here, w...

  14. Clinal Variation in phyB2, a Candidate Gene for Day-Length-Induced Growth Cessation and Bud Set, Across a Latitudinal Gradient in European Aspen (Populus tremula)

    OpenAIRE

    Ingvarsson, Pär K.; García, M. Victoria; Hall, David; Luquez, Virginia; Jansson, Stefan

    2006-01-01

    The initiation of growth cessation and dormancy represents a critical ecological and evolutionary trade-off between survival and growth in most forest trees. The most important environmental cue regulating the initiation of dormancy is a shortening of the photoperiod and phytochrome genes have been implicated in short-day-induced bud set and growth cessation in Populus. We characterized patterns of DNA sequence variation at the putative candidate gene phyB2 in 4 populations of European aspen ...

  15. Experimental Evolution under Fluctuating Thermal Conditions Does Not Reproduce Patterns of Adaptive Clinal Differentiation in Drosophila melanogaster.

    Science.gov (United States)

    Kellermann, Vanessa; Hoffmann, Ary A; Kristensen, Torsten Nygaard; Moghadam, Neda Nasiri; Loeschcke, Volker

    2015-11-01

    Experimental evolution can be a useful tool for testing the impact of environmental factors on adaptive changes in populations, and this approach is being increasingly used to understand the potential for evolutionary responses in populations under changing climates. However, selective factors will often be more complex in natural populations than in laboratory environments and produce different patterns of adaptive differentiation. Here we test the ability of laboratory experimental evolution under different temperature cycles to reproduce well-known patterns of clinal variation in Drosophila melanogaster. Six fluctuating thermal regimes mimicking the natural temperature conditions along the east coast of Australia were initiated. Contrary to expectations, on the basis of field patterns there was no evidence for adaptation to thermal regimes as reflected by changes in cold and heat resistance after 1-3 years of laboratory natural selection. While laboratory evolution led to changes in starvation resistance, development time, and body size, patterns were not consistent with those seen in natural populations. These findings highlight the complexity of factors affecting trait evolution in natural populations and indicate that caution is required when inferring likely evolutionary responses from the outcome of experimental evolution studies. PMID:26655772

  16. Clinal variation in the juvenal plumage of American kestrels

    Science.gov (United States)

    Smallwood, J.A.; Natale, C.; Steenhof, K.; Meetz, M.; Marti, C.D.; Melvin, R.J.; Bortolotti, G.R.; Robertson, R.; Robertson, S.; Shuford, W.R.; Lindemann, S.A.; Tornwall, B.

    1999-01-01

    The American Kestrel(Falco sparverius) is a sexually dichromatic falcon that exhibits considerable individual plumage variability. For example, the anterior extent of the black dorsal barring in juvenile males has been used throughout North America as one of several aging criteria, but recent data demonstrate that the variability among individual Southeastern American Kestrels(E S. paulus)exceeds that accounted for by age. The objective of this study was to search for geographic patterns in the variability of juvenal plumage, particularly those characteristics considered indicative of age. Nestling kestrels (n = 610) were examined prior to fledging during the 1997 breeding season at nest box programs across a large portion of the North American breeding range. From south to north (1) the crown patches of both males and females become more completely rufous, and (2) shaft streaks on forehead and crown feathers become more pronounced, especially in males. Male Southeastern American Kestrels differed from other males (E s. sparverius) in that the anterior extent of dorsal barring averaged less but was more variable. The variability observed in North America appears to be part of a cline extending across the species range in the Western Hemisphere, where tropical subspecies are small and have reduced dorsal barring. Both body size and, especially in males, dorsal barring increases with increasing north and south latitude. We suggest that this geographic pattern is adaptive in terms of thermoregulation, and that differences in the sex roles may explain why males become less barred with maturity while females do not.

  17. The affect of tissue depth variation on craniofacial reconstructions.

    Science.gov (United States)

    Starbuck, John M; Ward, Richard E

    2007-10-25

    We examined the affect of tissue depth variation on the reconstruction of facial form, through the application of the American method, utilizing published tissue depth measurements for emaciated, normal, and obese faces. In this preliminary study, three reconstructions were created on reproductions of the same skull for each set of tissue depth measurements. The resulting morphological variation was measured quantitatively using the anthropometric craniofacial variability index (CVI). This method employs 16 standard craniofacial anthropometric measurements and the results reflect "pattern variation" or facial harmony. We report no appreciable variation in the quantitative measure of the pattern facial form obtained from the three different sets of tissue depths. Facial similarity was assessed qualitatively utilizing surveys of photographs of the three reconstructions. Surveys indicated that subjects frequently perceived the reconstructions as representing different individuals. This disagreement indicates that size of the face may blind observers to similarities in facial form. This research is significant because it illustrates the confounding effect that normal human variation contributes in the successful recognition of individuals from a representational three-dimensional facial reconstruction. Research results suggest that successful identification could be increased if multiple reconstructions were created which reflect a wide range of possible outcomes for facial form. The creation of multiple facial images, from a single skull, will be facilitated as computerized versions of facial reconstruction are further developed and refined. PMID:17353107

  18. Plasticity of functional traits varies clinally along a rainfall gradient in Eucalyptus tricarpa.

    Science.gov (United States)

    McLean, Elizabeth H; Prober, Suzanne M; Stock, William D; Steane, Dorothy A; Potts, Brad M; Vaillancourt, René E; Byrne, Margaret

    2014-06-01

    Widespread species often occur across a range of climatic conditions, through a combination of local genetic adaptations and phenotypic plasticity. Species with greater phenotypic plasticity are likely to be better positioned to cope with rapid anthropogenic climate changes, while those displaying strong local adaptations might benefit from translocations to assist the movement of adaptive genes as the climate changes. Eucalyptus tricarpa occurs across a climatic gradient in south-eastern Australia, a region of increasing aridity, and we hypothesized that this species would display local adaptation to climate. We measured morphological and physiological traits reflecting climate responses in nine provenances from sites of 460 to 1040 mm annual rainfall, in their natural habitat and in common gardens near each end of the gradient. Local adaptation was evident in functional traits and differential growth rates in the common gardens. Some traits displayed complex combinations of plasticity and genetic divergence among provenances, including clinal variation in plasticity itself. Provenances from drier locations were more plastic in leaf thickness, whereas leaf size was more plastic in provenances from higher rainfall locations. Leaf density and stomatal physiology (as indicated by δ(13)C and δ(18)O) were highly and uniformly plastic. In addition to variation in mean trait values, genetic variation in trait plasticity may play a role in climate adaptation. PMID:24329726

  19. Stage-specific effects of candidate heterochronic genes on variation in developmental time along an altitudinal cline of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Julián Mensch

    Full Text Available BACKGROUND: Previously, we have shown there is clinal variation for egg-to-adult developmental time along geographic gradients in Drosophila melanogaster. Further, we also have identified mutations in genes involved in metabolic and neurogenic pathways that affect development time (heterochronic genes. However, we do not know whether these loci affect variation in developmental time in natural populations. METHODOLOGY/PRINCIPAL FINDINGS: Here, we constructed second chromosome substitution lines from natural populations of Drosophila melanogaster from an altitudinal cline, and measured egg-adult development time for each line. We found not only a large amount of genetic variation for developmental time, but also positive associations of the development time with thermal amplitude and altitude. We performed genetic complementation tests using substitution lines with the longest and shortest developmental times and heterochronic mutations. We identified segregating variation for neurogenic and metabolic genes that largely affected the duration of the larval stages but had no impact on the timing of metamorphosis. CONCLUSIONS/SIGNIFICANCE: Altitudinal clinal variation in developmental time for natural chromosome substitution lines provides a unique opportunity to dissect the response of heterochronic genes to environmental gradients. Ontogenetic stage-specific variation in invected, mastermind, cricklet and CG14591 may affect natural variation in development time and thermal evolution.

  20. Y-Chromosomal Diversity in Europe Is Clinal and Influenced Primarily by Geography, Rather than by Language

    Science.gov (United States)

    Rosser, Zoë H.; Zerjal, Tatiana; Hurles, Matthew E.; Adojaan, Maarja; Alavantic, Dragan; Amorim, António; Amos, William; Armenteros, Manuel; Arroyo, Eduardo; Barbujani, Guido; Beckman, Gunhild; Beckman, Lars; Bertranpetit, Jaume; Bosch, Elena; Bradley, Daniel G.; Brede, Gaute; Cooper, Gillian; Côrte-Real, Helena B. S. M.; de Knijff, Peter; Decorte, Ronny; Dubrova, Yuri E.; Evgrafov, Oleg; Gilissen, Anja; Glisic, Sanja; Gölge, Mukaddes; Hill, Emmeline W.; Jeziorowska, Anna; Kalaydjieva, Luba; Kayser, Manfred; Kivisild, Toomas; Kravchenko, Sergey A.; Krumina, Astrida; Kučinskas, Vaidutis; Lavinha, João; Livshits, Ludmila A.; Malaspina, Patrizia; Maria, Syrrou; McElreavey, Ken; Meitinger, Thomas A.; Mikelsaar, Aavo-Valdur; Mitchell, R. John; Nafa, Khedoudja; Nicholson, Jayne; Nørby, Søren; Pandya, Arpita; Parik, Jüri; Patsalis, Philippos C.; Pereira, Luísa; Peterlin, Borut; Pielberg, Gerli; Prata, Maria João; Previderé, Carlo; Roewer, Lutz; Rootsi, Siiri; Rubinsztein, D. C.; Saillard, Juliette; Santos, Fabrício R.; Stefanescu, Gheorghe; Sykes, Bryan C.; Tolun, Aslihan; Villems, Richard; Tyler-Smith, Chris; Jobling, Mark A.

    2000-01-01

    Clinal patterns of autosomal genetic diversity within Europe have been interpreted in previous studies in terms of a Neolithic demic diffusion model for the spread of agriculture; in contrast, studies using mtDNA have traced many founding lineages to the Paleolithic and have not shown strongly clinal variation. We have used 11 human Y-chromosomal biallelic polymorphisms, defining 10 haplogroups, to analyze a sample of 3,616 Y chromosomes belonging to 47 European and circum-European populations. Patterns of geographic differentiation are highly nonrandom, and, when they are assessed using spatial autocorrelation analysis, they show significant clines for five of six haplogroups analyzed. Clines for two haplogroups, representing 45% of the chromosomes, are continentwide and consistent with the demic diffusion hypothesis. Clines for three other haplogroups each have different foci and are more regionally restricted and are likely to reflect distinct population movements, including one from north of the Black Sea. Principal-components analysis suggests that populations are related primarily on the basis of geography, rather than on the basis of linguistic affinity. This is confirmed in Mantel tests, which show a strong and highly significant partial correlation between genetics and geography but a low, nonsignificant partial correlation between genetics and language. Genetic-barrier analysis also indicates the primacy of geography in the shaping of patterns of variation. These patterns retain a strong signal of expansion from the Near East but also suggest that the demographic history of Europe has been complex and influenced by other major population movements, as well as by linguistic and geographic heterogeneities and the effects of drift. PMID:11078479

  1. Variations in the Circumplex Model of Affect Across Contexts

    DEFF Research Database (Denmark)

    Mønster, Dan; Eskildsen, Jacob Kjær; Håkonsson, Dorthe Døjbak;

    2014-01-01

    Although Russell’s circumplex model of affect is one of the most widely used models for capturing self-reported emotions, few, if any, studies have examined whether this model is appropriate for measuring changes in emotions in different contexts. We construct an experiment which enables us to...... manipulate emotions and study the consequences of these manipulations over time. We find that self-report data at the end of our experiment match well with the circumplex model of affect, but that the model changes with experimental context over time. We suggest methods to determine when the circumplex model...... of affect is constant across different contexts and can be used to compare changes in emotions. Further we suggest a pragmatic solution when such comparisons cannot readily be made....

  2. Diurnal modulation and sources of variation affecting ventricular repolarization in Warmblood horses

    DEFF Research Database (Denmark)

    Pedersen, Philip Juul; Moeller, Sine B.; Madsen, Mette Flethøj;

    2014-01-01

    Te intervals were prolonged on day 0. Biphasic T waves shortened the TpTe interval approximately 10 ms. Age and BW did not appear to affect repolarization. CONCLUSIONS: Equine repolarization markers exhibit significant variation. Factors affecting repolarization measurements include horse-to-horse variation......, diurnal variation, the environment, and T wave conformation. These factors must be considered if markers of equine repolarization are used diagnostically....

  3. Insect prey characteristics affecting regional variation in chimpanzee tool use.

    Science.gov (United States)

    Sanz, Crickette M; Deblauwe, Isra; Tagg, Nikki; Morgan, David B

    2014-06-01

    It is an ongoing interdisciplinary pursuit to identify the factors shaping the emergence and maintenance of tool technology. Field studies of several primate taxa have shown that tool using behaviors vary within and between populations. While similarity in tools over spatial and temporal scales may be the product of socially learned skills, it may also reflect adoption of convergent strategies that are tailored to specific prey features. Much has been claimed about regional variation in chimpanzee tool use, with little attention to the ecological circumstances that may have shaped such differences. This study examines chimpanzee tool use in termite gathering to evaluate the extent to which the behavior of insect prey may dictate chimpanzee technology. More specifically, we conducted a systematic comparison of chimpanzee tool use and termite prey between the Goualougo Triangle in the Republic of Congo and the La Belgique research site in southeast Cameroon. Apes at both of these sites are known to use tool sets to gather several species of termites. We collected insect specimens and measured the characteristics of their nests. Associated chimpanzee tool assemblages were documented at both sites and video recordings were conducted in the Goualougo Triangle. Although Macrotermitinae assemblages were identical, we found differences in the tools used to gather these termites. Based on measurements of the chimpanzee tools and termite nests at each site, we concluded that some characteristics of chimpanzee tools were directly related to termite nest structure. While there is a certain degree of uniformity within approaches to particular tool tasks across the species range, some aspects of regional variation in hominoid technology are likely adaptations to subtle environmental differences between populations or groups. Such microecological differences between sites do not negate the possibility of cultural transmission, as social learning may be required to transmit

  4. Listening to music affects diurnal variation in muscle power output.

    Science.gov (United States)

    Chtourou, H; Chaouachi, A; Hammouda, O; Chamari, K; Souissi, N

    2012-01-01

    The purpose of this investigation was to assess the effects of listening to music while warming-up on the diurnal variations of power output during the Wingate test. 12 physical education students underwent four Wingate tests at 07:00 and 17:00 h, after 10 min of warm-up with and without listening to music. The warm-up consisted of 10 min of pedalling at a constant pace of 60 rpm against a light load of 1 kg. During the Wingate test, peak and mean power were measured. The main finding was that peak and mean power improved from morning to afternoon after no music warm-up (pmusic warm-up. Moreover, peak and mean power were significantly higher after music than no music warm-up during the two times of testing. Thus, as it is a legal method and an additional aid, music should be used during warm-up before performing activities requiring powerful lower limbs' muscles contractions, especially in the morning competitive events. PMID:22134883

  5. Interdecadal variation of Korea affecting tropical cyclone intensity

    Science.gov (United States)

    Choi, Ki-Seon; Cha, Yu-Mi; Kang, Sung-Dae; Kim, Hae-Dong

    2015-05-01

    This study analyzed a time series of average central pressure of tropical cyclone (TC) that affected Korea in summer season from 1965 to 2012. To determine whether climate regime shift exists in this time series, statistical change-point analysis was applied to this time series. The result showed that significant climate regime shift existed in 1989, that is, TC intensity from 1965 to 1988 (6588) was weaker than that from 1989 to 2012 (8912). Therefore, an average difference between former and latter periods was analyzed to study large-scale environments, which caused such difference. While TC genesis frequency showed a tendency that TCs in the 6588 period were originated from the northwest quadrant in the tropical and subtropical western North Pacific, TCs in the 8912 period were originated from the southeast quadrant. Thus, it was judged that TCs in the 6588 were generated at a higher latitude followed by moving to Korea, so their strength was weaker than those of TCs of 8912 due to lack of time to acquire sufficient energy from the sea. For TC passage frequency, TCs in the 6588 period showed a tendency to move a short distance from the sea far away from the southeast in Japan to the sea far away from the northeast in Japan or toward the East China Sea. On the other hand, TCs in the 8912 period moved a longer distance from the sea far away from the Philippines via Japan to the eastern sea of Kamchatka Peninsular or toward the east region in China. As such, an average difference of intensity between the former period and the latter period over the 500-hPa streamline was analyzed to determine why the intensity of TCs in the 6588 period was weaker than that of TCs in the 8912 period. As a result, anomalous cold northerlies from anomalous cyclones based on the northern territory of Japan were predominant, while these anomalous flows were originated from the tropical and subtropical western Pacific followed by moving to Korea, thereby affecting the weakening of the TC

  6. Do variations in leaf phenology affect radial growth variations in Fagus sylvatica?

    Science.gov (United States)

    Čufar, Katarina; De Luis, Martin; Prislan, Peter; Gričar, Jožica; Črepinšek, Zalika; Merela, Maks; Kajfež-Bogataj, Lučka

    2015-08-01

    We used a dendrochronological and leaf phenology network of European beech ( Fagus sylvatica) in Slovenia, a transitional area between Mediterranean, Alpine and continental climatic regimes, for the period 1955-2007 to test whether year to year variations in leaf unfolding and canopy duration (i.e. time between leaf unfolding and colouring) influence radial growth (annual xylem production and tree ring widths) and if such influences are more pronounced at higher altitudes. We showed that variability in leaf phenology has no significant effect on variations in radial growth. The results are consistent in the entire region, irrespective of the climatic regime or altitude, although previous studies have shown that leaf phenology and tree ring variation depend on altitude. The lack of relationship between year to year variability in leaf phenology and radial growth may suggest that earlier leaf unfolding—as observed in a previous study—probably does not cause increased tree growth rates in beech in Slovenia.

  7. Selective Pressure along a Latitudinal Gradient Affects Subindividual Variation in Plants

    OpenAIRE

    Sobral, Mar; Guitián, José; Guitián, Pablo; Larrinaga, Asier R.

    2013-01-01

    Individual plants produce repeated structures such as leaves, flowers or fruits, which, although belonging to the same genotype, are not phenotypically identical. Such subindividual variation reflects the potential of individual genotypes to vary with micro-environmental conditions. Furthermore, variation in organ traits imposes costs to foraging animals such as time, energy and increased predation risk. Therefore, animals that interact with plants may respond to this variation and affect pla...

  8. Selective pressure along a latitudinal gradient affects subindividual variation in plants.

    Science.gov (United States)

    Sobral, Mar; Guitián, José; Guitián, Pablo; Larrinaga, Asier R

    2013-01-01

    Individual plants produce repeated structures such as leaves, flowers or fruits, which, although belonging to the same genotype, are not phenotypically identical. Such subindividual variation reflects the potential of individual genotypes to vary with micro-environmental conditions. Furthermore, variation in organ traits imposes costs to foraging animals such as time, energy and increased predation risk. Therefore, animals that interact with plants may respond to this variation and affect plant fitness. Thus, phenotypic variation within an individual plant could be, in part, an adaptive trait. Here we investigated this idea and we found that subindividual variation of fruit size of Crataegus monogyna, in different populations throughout the latitudinal gradient in Europe, was explained at some extent by the selective pressures exerted by seed-dispersing birds. These findings support the hypothesis that within-individual variation in plants is an adaptive trait selected by interacting animals which may have important implications for plant evolution. PMID:24069297

  9. Integrating landscape genomics and spatially explicit approaches to detect loci under selection in clinal populations

    OpenAIRE

    Jones, Matthew R.; Forester, Brenna R.; Teufel, Ashley I.; Adams, Rachael V.; Anstett, Daniel N.; Goodrich, Betsy A.; Erin L. Landguth; Joost, Stéphane; Manel, Stéphanie

    2013-01-01

    Uncovering the genetic basis of adaptation hinges on the ability to detect loci under selection. However, population genomics outlier approaches to detect selected loci may be inappropriate for clinal populations or those with unclear population structure because they require that individuals be clustered into populations. An alternate approach, landscape genomics, uses individual-based approaches to detect loci under selection and reveal potential environmental drivers of selection. We teste...

  10. Population variation affects interactions between two California salt marsh plant species more than precipitation

    OpenAIRE

    Noto, AE; Shurin, JB

    2016-01-01

    © 2015 Springer-Verlag Berlin Heidelberg Species that occur along broad environmental gradients often vary in phenotypic traits that make them better adapted to local conditions. Variation in species interactions across gradients could therefore be due to either phenotypic differences among populations or environmental conditions that shift the balance between competition and facilitation. To understand how the environment (precipitation) and variation among populations affect species interac...

  11. Spatial and spatiotemporal variation in metapopulation structure affects population dynamics in a passively dispersing arthropod.

    Science.gov (United States)

    De Roissart, Annelies; Wang, Shaopeng; Bonte, Dries

    2015-11-01

    The spatial and temporal variation in the availability of suitable habitat within metapopulations determines colonization-extinction events, regulates local population sizes and eventually affects local population and metapopulation stability. Insights into the impact of such a spatiotemporal variation on the local population and metapopulation dynamics are principally derived from classical metapopulation theory and have not been experimentally validated. By manipulating spatial structure in artificial metapopulations of the spider mite Tetranychus urticae, we test to which degree spatial (mainland-island metapopulations) and spatiotemporal variation (classical metapopulations) in habitat availability affects the dynamics of the metapopulations relative to systems where habitat is constantly available in time and space (patchy metapopulations). Our experiment demonstrates that (i) spatial variation in habitat availability decreases variance in metapopulation size and decreases density-dependent dispersal at the metapopulation level, while (ii) spatiotemporal variation in habitat availability increases patch extinction rates, decreases local population and metapopulation sizes and decreases density dependence in population growth rates. We found dispersal to be negatively density dependent and overall low in the spatial variable mainland-island metapopulation. This demographic variation subsequently impacts local and regional population dynamics and determines patterns of metapopulation stability. Both local and metapopulation-level variabilities are minimized in mainland-island metapopulations relative to classical and patchy ones. PMID:25988264

  12. Variations in 5-HTTLPR: relation to familiar risk of affective disorder, life events, neuroticism and cortisol

    DEFF Research Database (Denmark)

    Vinberg, Maj; Mellerup, Erling; Andersen, Per Kragh;

    2009-01-01

    variations interact with life events in relation to depressive symptoms, neuroticism and salivary cortisol. METHOD: In a high-risk population study, healthy monozygotic and dizygotic twins with (high-risk twins) and without (low-risk twins) a co-twin history of affective disorder were identified through......BACKGROUND: Variations in the serotonin transporter gene (5-HTTLPR) and stressful life events are associated with affective disorders. AIM: To investigate whether the distribution of the alleles of the 5-HTTLPR is associated with a genetic predisposition to affective disorder and whether these...... the experience of SLE was associated with a higher neuroticism score, but not with depressive symptoms nor awakening or evening salivary cortisol. CONCLUSION: A combination of variants in 5-HTTLPR and environmental stress seems to increase neuroticism in healthy individuals....

  13. Similarities and differences in altitudinal versus latitudinal variation for morphological traits in Drosophila melanogaster.

    Science.gov (United States)

    Klepsatel, Peter; Gáliková, Martina; Huber, Christian D; Flatt, Thomas

    2014-05-01

    Understanding how natural environments shape phenotypic variation is a major aim in evolutionary biology. Here, we have examined clinal, likely genetically based variation in morphology among 19 populations of the fruit fly (Drosophila melanogaster) from Africa and Europe, spanning a range from sea level to 3000 m altitude and including locations approximating the southern and northern range limit. We were interested in testing whether latitude and altitude have similar phenotypic effects, as has often been postulated. Both latitude and altitude were positively correlated with wing area, ovariole number, and cell number. In contrast, latitude and altitude had opposite effects on the ratio between ovariole number and body size, which was negatively correlated with egg production rate per ovariole. We also used transgenic manipulation to examine how increased cell number affects morphology and found that larger transgenic flies, due to a higher number of cells, had more ovarioles, larger wings, and, unlike flies from natural populations, increased wing loading. Clinal patterns in morphology are thus not a simple function of changes in body size; instead, each trait might be subject to different selection pressures. Together, our results provide compelling evidence for profound similarities as well as differences between phenotypic effects of latitude and altitude. PMID:24410363

  14. Population variation affects interactions between two California salt marsh plant species more than precipitation.

    Science.gov (United States)

    Noto, Akana E; Shurin, Jonathan B

    2016-02-01

    Species that occur along broad environmental gradients often vary in phenotypic traits that make them better adapted to local conditions. Variation in species interactions across gradients could therefore be due to either phenotypic differences among populations or environmental conditions that shift the balance between competition and facilitation. To understand how the environment (precipitation) and variation among populations affect species interactions, we conducted a common garden experiment using two common salt marsh plant species, Salicornia pacifica and Jaumea carnosa, from six salt marshes along the California coast encompassing a large precipitation gradient. Plants were grown alone or with an individual of the opposite species from the same site and exposed to one of three precipitation regimes. J. carnosa was negatively affected in the presence of S. pacifica, while S. pacifica was facilitated by J. carnosa. The strength of these interactions varied by site of origin but not by precipitation treatment. These results suggest that phenotypic variation among populations can affect interaction strength more than environment, despite a threefold difference in precipitation. Geographic intraspecific variation may therefore play an important role in determining the strength of interactions in communities. PMID:26481794

  15. The genetic covariance among clinal environments after adaptation to an environmental gradient in Drosophila serrata.

    OpenAIRE

    Sgrò, Carla M.; Blows, Mark W.

    2004-01-01

    We examined the genetic basis of clinal adaptation by determining the evolutionary response of life-history traits to laboratory natural selection along a gradient of thermal stress in Drosophila serrata. A gradient of heat stress was created by exposing larvae to a heat stress of 36 degrees for 4 hr for 0, 1, 2, 3, 4, or 5 days of larval development, with the remainder of development taking place at 25 degrees. Replicated lines were exposed to each level of this stress every second generatio...

  16. Does School Duration Affect Student Performance? Findings from Canton-Based Variation in Swiss Educational Length

    OpenAIRE

    Skirbekk, V.

    2005-01-01

    This paper investigates Swiss canton-based regulations to determine the number of school years required to graduate from academic track secondary school. The results show that the variation (12, 12.5 or 13 years) does not affect human capital levels (TIMSS math and science performance). This suggests that one could decrease school length from 13 to 12 years without decreasing student performance levels. A younger school leaving age could extend the working life, soften the burden of populatio...

  17. Comparative population genomics of latitudinal variation in Drosophila simulans and Drosophila melanogaster.

    Science.gov (United States)

    Machado, Heather E; Bergland, Alan O; O'Brien, Katherine R; Behrman, Emily L; Schmidt, Paul S; Petrov, Dmitri A

    2016-02-01

    Examples of clinal variation in phenotypes and genotypes across latitudinal transects have served as important models for understanding how spatially varying selection and demographic forces shape variation within species. Here, we examine the selective and demographic contributions to latitudinal variation through the largest comparative genomic study to date of Drosophila simulans and Drosophila melanogaster, with genomic sequence data from 382 individual fruit flies, collected across a spatial transect of 19 degrees latitude and at multiple time points over 2 years. Consistent with phenotypic studies, we find less clinal variation in D. simulans than D. melanogaster, particularly for the autosomes. Moreover, we find that clinally varying loci in D. simulans are less stable over multiple years than comparable clines in D. melanogaster. D. simulans shows a significantly weaker pattern of isolation by distance than D. melanogaster and we find evidence for a stronger contribution of migration to D. simulans population genetic structure. While population bottlenecks and migration can plausibly explain the differences in stability of clinal variation between the two species, we also observe a significant enrichment of shared clinal genes, suggesting that the selective forces associated with climate are acting on the same genes and phenotypes in D. simulans and D. melanogaster. PMID:26523848

  18. COMT genetic variation confers risk for psychotic and affective disorders: a case control study

    Directory of Open Access Journals (Sweden)

    Lencz Todd

    2005-10-01

    Full Text Available Abstract Background Variation in the COMT gene has been implicated in a number of psychiatric disorders, including psychotic, affective and anxiety disorders. The majority of these studies have focused on the functional Val108/158Met polymorphism and yielded conflicting results, with limited studies examining the relationship between other polymorphisms, or haplotypes, and psychiatric illness. We hypothesized that COMT variation may confer a general risk for psychiatric disorders and have genotyped four COMT variants (Val158Met, rs737865, rs165599, and a SNP in the P2 promoter [-278A/G; rs2097603] in 394 Caucasian cases and 467 controls. Cases included patients with schizophrenia (n = 196, schizoaffective disorder (n = 62, bipolar disorder (n = 82, major depression (n = 30, and patients diagnosed with either psychotic disorder NOS or depressive disorder NOS (n = 24. Results SNP rs2097603, the Val/Met variant and SNP rs165599 were significantly associated (p = 0.004; p = 0.05; p = 0.035 with a broad "all affected" diagnosis. Haplotype analysis revealed a potentially protective G-A-A-A haplotype haplotype (-278A/G; rs737865; Val108/158Met; rs165599, which was significantly underrepresented in this group (p = 0.0033 and contained the opposite alleles of the risk haplotype previously described by Shifman et al. Analysis of diagnostic subgroups within the "all affecteds group" showed an association of COMT in patients with psychotic disorders as well as in cases with affective illness although the associated variants differed. The protective haplotype remained significantly underrepresented in most of these subgroups. Conclusion Our results support the view that COMT variation provides a weak general predisposition to neuropsychiatric disease including psychotic and affective disorders.

  19. Clinal variation in fitness related traits in tropical drosophilids of the Indian subcontinent

    Czech Academy of Sciences Publication Activity Database

    Rajpurohit, S.; Nedvěd, Oldřich

    2013-01-01

    Roč. 38, č. 6 (2013), s. 345-354. ISSN 0306-4565 Institutional support: RVO:60077344 Keywords : climatic adaption * Drosophila * geographic cline Subject RIV: ED - Physiology Impact factor: 1.544, year: 2013 http://www.sciencedirect.com/science/article/pii/S0306456513000569#

  20. Clinal Variation at Phenology-Related Genes in Spruce: Parallel Evolution in FTL2 and Gigantea?

    OpenAIRE

    Chen, Jun; Tsuda, Yoshiaki; Stocks, Michael; Källman, Thomas; Xu, Nannan; Kärkkäinen, Katri; Huotari, Tea; Semerikov, Vladimir L.; Vendramin, Giovanni G.; Lascoux, Martin

    2014-01-01

    Parallel clines in different species, or in different geographical regions of the same species, are an important source of information on the genetic basis of local adaptation. We recently detected latitudinal clines in SNPs frequencies and gene expression of candidate genes for growth cessation in Scandinavian populations of Norway spruce (Picea abies). Here we test whether the same clines are also present in Siberian spruce (P. obovata), a close relative of Norway spruce with a different Qu...

  1. A comparison of univariate and multivariate methods for analyzing clinal variation in an invasive species

    Czech Academy of Sciences Publication Activity Database

    Edwards, K.R.; Bastlová, D.; Edwards-Jonášová, Magda; Květ, J.

    2011-01-01

    Roč. 674, č. 1 (2011), s. 119-131. ISSN 0018-8158 Institutional research plan: CEZ:AV0Z60870520 Keywords : common garden * life history traits * local adaptation * principal components analysis * purple loosestrife * redundancy analysis Subject RIV: EH - Ecology, Behaviour Impact factor: 1.784, year: 2011 http://www.springerlink.com/content/71r10n3367m98jxl/

  2. B Chromosome Polymorphism in Maize Landraces: Adaptive vs. Demographic Hypothesis of Clinal Variation

    OpenAIRE

    Lia, Verónica V; Confalonieri, Viviana A.; Poggio, Lidia

    2007-01-01

    Cytogenetic analysis of maize landraces from northwestern Argentina has revealed an altitudinal cline in the mean number of B chromosomes (B's) per plant, with cultivars growing at higher altitudes exhibiting a higher number of B's. Altitudinal and longitudinal clines are frequently interpreted as evidence of selection, however, they can also be produced by the interplay between drift and spatially restricted gene flow or by admixture between previously isolated populations that have come int...

  3. Molecular-level variation affects population growth in a butterfly metapopulation.

    Directory of Open Access Journals (Sweden)

    Ilkka Hanski

    2006-05-01

    Full Text Available The dynamics of natural populations are thought to be dominated by demographic and environmental processes with little influence of intraspecific genetic variation and natural selection, apart from inbreeding depression possibly reducing population growth in small populations. Here we analyse hundreds of well-characterised local populations in a large metapopulation of the Glanville fritillary butterfly (Melitaea cinxia, which persists in a balance between stochastic local extinctions and recolonisations in a network of 4,000 discrete habitat patches. We show that the allelic composition of the glycolytic enzyme phosphoglucose isomerase (Pgi has a significant effect on the growth of local populations, consistent with previously reported effects of allelic variation on flight metabolic performance and fecundity in the Glanville fritillary and Colias butterflies. The strength and the sign of the molecular effect on population growth are sensitive to the ecological context (the area and spatial connectivity of the habitat patches, which affects genotype-specific gene flow and the influence of migration on the dynamics of local populations. The biological significance of the results for Pgi is underscored by lack of any association between population growth and allelic variation at six other loci typed in the same material. In demonstrating, to our knowledge for the first time, that molecular variation in a candidate gene affects population growth, this study challenges the perception that differential performance of individual genotypes, leading to differential fitness, is irrelevant to population dynamics. These results also demonstrate that the spatial configuration of habitat and spatial dynamics of populations contribute to maintenance of Pgi polymorphism in this species.

  4. Molecular-level variation affects population growth in a butterfly metapopulation.

    Science.gov (United States)

    Hanski, Ilkka; Saccheri, Ilik

    2006-05-01

    The dynamics of natural populations are thought to be dominated by demographic and environmental processes with little influence of intraspecific genetic variation and natural selection, apart from inbreeding depression possibly reducing population growth in small populations. Here we analyse hundreds of well-characterised local populations in a large metapopulation of the Glanville fritillary butterfly (Melitaea cinxia), which persists in a balance between stochastic local extinctions and recolonisations in a network of 4,000 discrete habitat patches. We show that the allelic composition of the glycolytic enzyme phosphoglucose isomerase (Pgi) has a significant effect on the growth of local populations, consistent with previously reported effects of allelic variation on flight metabolic performance and fecundity in the Glanville fritillary and Colias butterflies. The strength and the sign of the molecular effect on population growth are sensitive to the ecological context (the area and spatial connectivity of the habitat patches), which affects genotype-specific gene flow and the influence of migration on the dynamics of local populations. The biological significance of the results for Pgi is underscored by lack of any association between population growth and allelic variation at six other loci typed in the same material. In demonstrating, to our knowledge for the first time, that molecular variation in a candidate gene affects population growth, this study challenges the perception that differential performance of individual genotypes, leading to differential fitness, is irrelevant to population dynamics. These results also demonstrate that the spatial configuration of habitat and spatial dynamics of populations contribute to maintenance of Pgi polymorphism in this species. PMID:16620151

  5. Local divergence of thermal reaction norms among amphibian populations is affected by pond temperature variation.

    Science.gov (United States)

    Richter-Boix, Alex; Katzenberger, Marco; Duarte, Helder; Quintela, María; Tejedo, Miguel; Laurila, Anssi

    2015-08-01

    Although temperature variation is known to cause large-scale adaptive divergence, its potential role as a selective factor over microgeographic scales is less well-understood. Here, we investigated how variation in breeding pond temperature affects divergence in multiple physiological (thermal performance curve and critical thermal maximum [CTmax]) and life-history (thermal developmental reaction norms) traits in a network of Rana arvalis populations. The results supported adaptive responses to face two main constraints limiting the evolution of thermal adaptation. First, we found support for the faster-slower model, indicating an adaptive response to compensate for the thermodynamic constraint of low temperatures in colder environments. Second, we found evidence for the generalist-specialist trade-off with populations from colder and less thermally variable environments exhibiting a specialist phenotype performing at higher rates but over a narrower range of temperatures. By contrast, the local optimal temperature for locomotor performance and CTmax did not match either mean or maximum pond temperatures. These results highlight the complexity of the adaptive multiple-trait thermal responses in natural populations, and the role of local thermal variation as a selective force driving diversity in life-history and physiological traits in the presence of gene flow. PMID:26118477

  6. Variation in Cavolinia inflexa (Lesueur, 1813) (Gastropoda: Pteropoda: Euthecosomata)

    NARCIS (Netherlands)

    Spoel, van der S.; Pierrot-Bults, A.C.

    1998-01-01

    Cavolinia inflexa (Lesueur, 1813) proves not to be composed of subspecies or formae, or to show clinal variation. Maximum shell length varies between 4 and 7 mm, shell width between 2 and 4 mm, length/width ratio between 0.51 and 0.81. A geographic pattern in the occurrence of different length/width

  7. Latitudinal variation in Atlantic Salpa fusiformis Cuvier, 1804 (Tunicata, Thaliacea)

    NARCIS (Netherlands)

    Soest, van R.W.M.

    1972-01-01

    The existence of clinal variation in some morphological characters of Atlantic Salpa fusiformis Cuvier, 1804, is reported. The number of muscle fibres of both aggregate and solitary individuals is subjected to a decrease from higher to lower latitudes. Size and reproduction also seem to vary accordi

  8. Experimental parasite community ecology: intraspecific variation in a large tapeworm affects community assembly.

    Science.gov (United States)

    Benesh, Daniel P; Kalbe, Martin

    2016-07-01

    Non-random species associations occur in naturally sampled parasite communities. The processes resulting in predictable community structure (e.g. particular host behaviours, cross-immunity, interspecific competition) could be affected by traits that vary within a parasite species, like growth or antigenicity. We experimentally infected three-spined sticklebacks with a large tapeworm (Schistocephalus solidus) that impacts the energy needs, foraging behaviour and immune reactions of its host. The tapeworms came from two populations, characterized by high or low growth in sticklebacks. Our goal was to evaluate how this parasite, and variation in its growth, affects the acquisition of other parasites. Fish infected with S. solidus were placed into cages in a lake to expose them to the natural parasite community. We also performed a laboratory experiment in which infected fish were exposed to a fixed dose of a common trematode parasite. In the field experiment, infection with S. solidus affected the abundance of four parasite species, relative to controls. For two of the four species, changes occurred only in fish harbouring the high-growth S. solidus; one species increased in abundance and the other decreased. These changes did not appear to be directly linked to S. solidus growth though. The parasite exhibiting elevated abundance was the same trematode used in the laboratory infection. In that experiment, we found a similar infection pattern, suggesting that S. solidus affects the physiological susceptibility of fish to this trematode. Associations between S. solidus and other parasites occur and vary in direction. However, some of these associations were contingent on the S. solidus population, suggesting that intraspecific variability can affect the assembly of parasite communities. PMID:27061288

  9. Evolutionary factors affecting Lactate dehydrogenase A and B variation in the Daphnia pulex species complex

    Directory of Open Access Journals (Sweden)

    Cristescu Melania E

    2011-07-01

    Full Text Available Abstract Background Evidence for historical, demographic and selective factors affecting enzyme evolution can be obtained by examining nucleotide sequence variation in candidate genes such as Lactate dehydrogenase (Ldh. Two closely related Daphnia species can be distinguished by their electrophoretic Ldh genotype and habitat. Daphnia pulex populations are fixed for the S allele and inhabit temporary ponds, while D. pulicaria populations are fixed for the F allele and inhabit large stratified lakes. One locus is detected in most allozyme surveys, but genome sequencing has revealed two genes, LdhA and LdhB. Results We sequenced both Ldh genes from 70 isolates of these two species from North America to determine if the association between Ldh genotype and habitat shows evidence for selection, and to elucidate the evolutionary history of the two genes. We found that alleles in the pond-dwelling D. pulex and in the lake-dwelling D. pulicaria form distinct groups at both loci, and the substitution of Glutamine (S for Glutamic acid (F at amino acid 229 likely causes the electrophoretic mobility shift in the LDHA protein. Nucleotide diversity in both Ldh genes is much lower in D. pulicaria than in D. pulex. Moreover, the lack of spatial structuring of the variation in both genes over a wide geographic area is consistent with a recent demographic expansion of lake populations. Neutrality tests indicate that both genes are under purifying selection, but the intensity is much stronger on LdhA. Conclusions Although lake-dwelling D. pulicaria hybridizes with the other lineages in the pulex species complex, it remains distinct ecologically and genetically. This ecological divergence, coupled with the intensity of purifying selection on LdhA and the strong association between its genotype and habitat, suggests that experimental studies would be useful to determine if variation in molecular function provides evidence that LDHA variants are adaptive.

  10. Evaluation of variations and affecting factors of eco-environmental quality during urbanization.

    Science.gov (United States)

    Cui, Erqian; Ren, Lijun; Sun, Haoyu

    2015-03-01

    Regional eco-environmental quality is the foundation of economic sustainable development and rational utilization of resources. It is necessary to understand and evaluate the regional eco-environmental quality correctly. Based on national remote sensing land use data, normalized difference vegetation index (NDVI) data and some other statistical data, this paper established an eco-environmental quality index (EQI) model to evaluate the ecological status of Jinan from 2000 to 2011. The results of eco-environmental quality showed little variation, with EQI values ranged from 62.00 to 69.01. EQI of each region in Jinan firstly decreased sharply and then increased slowly with the development of local economy. Besides the spatial and temporal variations analysis, affecting factors of eco-environmental quality was also discussed in this article. According to the results of correlation and regression analysis, meteorological conditions (rainfall and sunshine duration) and industrial structure (the proportion of primary industry) had relatively high correlations with eco-environmental quality. To summarize, a better eco-environmental status is associated with increasing rainfall, shorter sunshine duration, and lower proportion of primary industry. This article aims to giving supporting data and decision-making bases to restore the ecological environment and promote the sustainable development of Jinan. PMID:25369921

  11. CES1 genetic variation affects the activation of angiotensin-converting enzyme inhibitors.

    Science.gov (United States)

    Wang, X; Wang, G; Shi, J; Aa, J; Comas, R; Liang, Y; Zhu, H-J

    2016-06-01

    The aim of the study was to determine the effect of carboxylesterase 1 (CES1) genetic variation on the activation of angiotensin-converting enzyme inhibitor (ACEI) prodrugs. In vitro incubation study of human liver, intestine and kidney s9 fractions demonstrated that the ACEI prodrugs enalapril, ramipril, perindopril, moexipril and fosinopril are selectively activated by CES1 in the liver. The impact of CES1/CES1VAR and CES1P1/CES1P1VAR genotypes and diplotypes on CES1 expression and activity on enalapril activation was investigated in 102 normal human liver samples. Neither the genotypes nor the diplotypes affected hepatic CES1 expression and activity. Moreover, among several CES1 nonsynonymous variants studied in transfected cell lines, the G143E (rs71647871) was a loss-of-function variant for the activation of all ACEIs tested. The CES1 activity on enalapril activation in human livers with the 143G/E genotype was approximately one-third of that carrying the 143G/G. Thus, some functional CES1 genetic variants (for example, G143E) may impair ACEI activation, and consequently affect therapeutic outcomes of ACEI prodrugs. PMID:26076923

  12. Revisiting the Clinal Concept of Evolution and Dispersal for the Tick-Borne Flaviviruses by Using Phylogenetic and Biogeographic Analyses

    OpenAIRE

    Heinze, D. M.; Gould, E A; Forrester, N. L.

    2012-01-01

    Tick-borne flaviviruses (TBF) are widely dispersed across Africa, Europe, Asia, Oceania, and North America, and some present a significant threat to human health. Seminal studies on tick-borne encephalitis viruses (TBEV), based on partial envelope gene sequences, predicted a westward clinal pattern of evolution and dispersal across northern Eurasia, terminating in the British Isles. We tested this hypothesis using all available full-length open reading frame (ORF) TBF sequences. Phylogenetic ...

  13. Genetic variation in a member of the laminin gene family affects variation in body composition in Drosophila and humans

    Directory of Open Access Journals (Sweden)

    Hunter Gary R

    2008-08-01

    Full Text Available Abstract Background The objective of the present study was to map candidate loci influencing naturally occurring variation in triacylglycerol (TAG storage using quantitative complementation procedures in Drosophila melanogaster. Based on our results from Drosophila, we performed a human population-based association study to investigate the effect of natural variation in LAMA5 gene on body composition in humans. Results We identified four candidate genes that contributed to differences in TAG storage between two strains of D. melanogaster, including Laminin A (LanA, which is a member of the α subfamily of laminin chains. We confirmed the effects of this gene using a viable LanA mutant and showed that female flies homozygous for the mutation had significantly lower TAG storage, body weight, and total protein content than control flies. Drosophila LanA is closely related to human LAMA5 gene, which maps to the well-replicated obesity-linkage region on chromosome 20q13.2-q13.3. We tested for association between three common single nucleotide polymorphisms (SNPs in the human LAMA5 gene and variation in body composition and lipid profile traits in a cohort of unrelated women of European American (EA and African American (AA descent. In both ethnic groups, we found that SNP rs659822 was associated with weight (EA: P = 0.008; AA: P = 0.05 and lean mass (EA: P= 0.003; AA: P = 0.03. We also found this SNP to be associated with height (P = 0.01, total fat mass (P = 0.01, and HDL-cholesterol (P = 0.003 but only in EA women. Finally, significant associations of SNP rs944895 with serum TAG levels (P = 0.02 and HDL-cholesterol (P = 0.03 were observed in AA women. Conclusion Our results suggest an evolutionarily conserved role of a member of the laminin gene family in contributing to variation in weight and body composition.

  14. Telomere length affects the frequency and mechanism of antigenic variation in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Galadriel A Hovel-Miner

    Full Text Available Trypanosoma brucei is a master of antigenic variation and immune response evasion. Utilizing a genomic repertoire of more than 1000 Variant Surface Glycoprotein-encoding genes (VSGs, T. brucei can change its protein coat by "switching" from the expression of one VSG to another. Each active VSG is monoallelically expressed from only one of approximately 15 subtelomeric sites. Switching VSG expression occurs by three predominant mechanisms, arguably the most significant of which is the non-reciprocal exchange of VSG containing DNA by duplicative gene conversion (GC. How T. brucei orchestrates its complex switching mechanisms remains to be elucidated. Recent work has demonstrated that an exogenous DNA break in the active site could initiate a GC based switch, yet the source of the switch-initiating DNA lesion under natural conditions is still unknown. Here we investigated the hypothesis that telomere length directly affects VSG switching. We demonstrate that telomerase deficient strains with short telomeres switch more frequently than genetically identical strains with long telomeres and that, when the telomere is short, switching preferentially occurs by GC. Our data supports the hypothesis that a short telomere at the active VSG expression site results in an increase in subtelomeric DNA breaks, which can initiate GC based switching. In addition to their significance for T. brucei and telomere biology, the findings presented here have implications for the many diverse pathogens that organize their antigenic genes in subtelomeric regions.

  15. Diurnal temperature variations affect development of a herbivorous arthropod pest and its predators.

    Science.gov (United States)

    Vangansbeke, Dominiek; Audenaert, Joachim; Nguyen, Duc Tung; Verhoeven, Ruth; Gobin, Bruno; Tirry, Luc; De Clercq, Patrick

    2015-01-01

    The impact of daily temperature variations on arthropod life history remains woefully understudied compared to the large body of research that has been carried out on the effects of constant temperatures. However, diurnal varying temperature regimes more commonly represent the environment in which most organisms thrive. Such varying temperature regimes have been demonstrated to substantially affect development and reproduction of ectothermic organisms, generally in accordance with Jensen's inequality. In the present study we evaluated the impact of temperature alternations at 4 amplitudes (DTR0, +5, +10 and +15°C) on the developmental rate of the predatory mites Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus McGregor (Acari: Phytoseiidae) and their natural prey, the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae). We have modelled their developmental rates as a function of temperature using both linear and nonlinear models. Diurnally alternating temperatures resulted in a faster development in the lower temperature range as compared to their corresponding mean constant temperatures, whereas the opposite was observed in the higher temperature range. Our results indicate that Jensen's inequality does not suffice to fully explain the differences in developmental rates at constant and alternating temperatures, suggesting additional physiological responses play a role. It is concluded that diurnal temperature range should not be ignored and should be incorporated in predictive models on the phenology of arthropod pests and their natural enemies and their performance in biological control programmes. PMID:25874697

  16. Anomalous ionospheric variations prior to major earthquakes during 2015 affecting Indian low latitude station Delhi

    Science.gov (United States)

    Gupta, Sumedha; Upadhayaya, Arun Kumar

    2016-07-01

    We have analyzed five major earthquakes (M>6) that occurred during the year 2015, affecting Indian ionosphere, using F2 layer critical frequency (foF2) data obtained using Digisonde from a low latitude station, Delhi (28.6°N, 77.2°E, 42.4°N dip). Normal day-to-day variability occurring in ionosphere is segregated by calculating F2 layer critical frequency variations (ΔfoF2) from the normal quiet time behavior apart from calculating interquartile range. We find that ionospheric F2 region across Delhi by and large shows some significant perturbations 3-4 days prior to these earthquake events. These observed perturbations indicate towards seismo-ionospheric coupling as solar and geomagnetic indices were normally quiet and stable during the period of these events. Further, it was also observed that the effect of earthquake was prominently observed even outside the earthquake preparation zone, calculated using Dobrovolsky et al. [1979].

  17. Social context-induced song variation affects female behavior and gene expression.

    Directory of Open Access Journals (Sweden)

    Sarah C Woolley

    2008-03-01

    Full Text Available Social cues modulate the performance of communicative behaviors in a range of species, including humans, and such changes can make the communication signal more salient. In songbirds, males use song to attract females, and song organization can differ depending on the audience to which a male sings. For example, male zebra finches (Taeniopygia guttata change their songs in subtle ways when singing to a female (directed song compared with when they sing in isolation (undirected song, and some of these changes depend on altered neural activity from a specialized forebrain-basal ganglia circuit, the anterior forebrain pathway (AFP. In particular, variable activity in the AFP during undirected song is thought to actively enable syllable variability, whereas the lower and less-variable AFP firing during directed singing is associated with more stereotyped song. Consequently, directed song has been suggested to reflect a "performance" state, and undirected song a form of vocal motor "exploration." However, this hypothesis predicts that directed-undirected song differences, despite their subtlety, should matter to female zebra finches, which is a question that has not been investigated. We tested female preferences for this natural variation in song in a behavioral approach assay, and we found that both mated and socially naive females could discriminate between directed and undirected song-and strongly preferred directed song. These preferences, which appeared to reflect attention especially to aspects of song variability controlled by the AFP, were enhanced by experience, as they were strongest for mated females responding to their mate's directed songs. We then measured neural activity using expression of the immediate early gene product ZENK, and found that social context and song familiarity differentially modulated the number of ZENK-expressing cells in telencephalic auditory areas. Specifically, the number of ZENK-expressing cells in the

  18. Spatial Variation and Resuscitation Process Affecting Survival after Out-of-Hospital Cardiac Arrests (OHCA.

    Directory of Open Access Journals (Sweden)

    Chien-Chou Chen

    Full Text Available Ambulance response times and resuscitation efforts are critical predictors of the survival rate after out-of-hospital cardiac arrests (OHCA. On the other hand, rural-urban differences in the OHCA survival rates are an important public health issue.We retrospectively reviewed the January 2011-December 2013 OHCA registry data of Kaohsiung City, Taiwan. With particular focus on geospatial variables, we aimed to unveil risk factors predicting the overall OHCA survival until hospital admission. Spatial analysis, network analysis, and the Kriging method by using geographic information systems were applied to analyze spatial variations and calculate the transport distance. Logistic regression was used to identify the risk factors for OHCA survival.Among the 4,957 patients, the overall OHCA survival to hospital admission was 16.5%. In the multivariate analysis, female sex (adjusted odds ratio:, AOR, 1.24 [1.06-1.45], events in public areas (AOR: 1.30 [1.05-1.61], exposure to automated external defibrillator (AED shock (AOR: 1.70 [1.30-2.23], use of laryngeal mask airway (LMA (AOR: 1.35 [1.16-1.58], non-trauma patients (AOR: 1.41 [1.04-1.90], ambulance bypassed the closest hospital (AOR: 1.28 [1.07-1.53], and OHCA within the high population density areas (AOR: 1.89 [1.55-2.32] were positively associated with improved OHCA survival. By contrast, a prolonged total emergency medical services (EMS time interval was negatively associated with OHCA survival (AOR: 0.98 [0.96-0.99].Resuscitative efforts, such as AED or LMA use, and a short total EMS time interval improved OHCA outcomes in emergency departments. The spatial heterogeneity of emergency medical resources between rural and urban areas might affect survival rate.

  19. Variation in honey bee gut microbial diversity affected by ontogenetic stage, age and geographic location.

    Directory of Open Access Journals (Sweden)

    Zuzana Hroncova

    Full Text Available Social honey bees, Apis mellifera, host a set of distinct microbiota, which is similar across the continents and various honey bee species. Some of these bacteria, such as lactobacilli, have been linked to immunity and defence against pathogens. Pathogen defence is crucial, particularly in larval stages, as many pathogens affect the brood. However, information on larval microbiota is conflicting. Seven developmental stages and drones were sampled from 3 colonies at each of the 4 geographic locations of A. mellifera carnica, and the samples were maintained separately for analysis. We analysed the variation and abundance of important bacterial groups and taxa in the collected bees. Major bacterial groups were evaluated over the entire life of honey bee individuals, where digestive tracts of same aged bees were sampled in the course of time. The results showed that the microbial tract of 6-day-old 5th instar larvae were nearly equally rich in total microbial counts per total digestive tract weight as foraging bees, showing a high percentage of various lactobacilli (Firmicutes and Gilliamella apicola (Gammaproteobacteria 1. However, during pupation, microbial counts were significantly reduced but recovered quickly by 6 days post-emergence. Between emergence and day 6, imago reached the highest counts of Firmicutes and Gammaproteobacteria, which then gradually declined with bee age. Redundancy analysis conducted using denaturing gradient gel electrophoresis identified bacterial species that were characteristic of each developmental stage. The results suggest that 3-day 4th instar larvae contain low microbial counts that increase 2-fold by day 6 and then decrease during pupation. Microbial succession of the imago begins soon after emergence. We found that bacterial counts do not show only yearly cycles within a colony, but vary on the individual level. Sampling and pooling adult bees or 6th day larvae may lead to high errors and variability, as both

  20. Variation in Biofilm Stability with Decreasing pH Affects Porous Medium Hydraulic Properties

    Science.gov (United States)

    Kirk, M. F.; Santillan, E. F.; McGrath, L. K.; Altman, S. J.

    2010-12-01

    Changes to microbial communities caused by subsurface CO2 injection may have many consequences, including possible impacts to CO2 transport. We used column experiments to examine how decreasing pH, a geochemical change associated with CO2 injection, will affect biofilm stability and ultimately the hydraulic properties of porous media. Columns consisted of 1 mm2 square capillary tubes filled with 105-150 µm diameter glass beads. Artificial groundwater medium containing 1 mM glucose was pumped through the columns at a rate of 0.01 mL/min (q = 14.4 m/day; Re = 0.03). Columns were inoculated with 3 × 10^8 CFU (avg.) of Pseudomonas fluorescens, a model biofilm former, transformed with a green fluorescent protein. Biomass distribution and transport was examined using scanning laser confocal microscopy and effluent plating. Variation in the bulk hydraulic properties of the columns was measured using manometers. In an initial experiment, biofilm growth was allowed to occur for seven days in medium with pH 7.3. Within this period, cells uniformly coated bead surfaces, effluent cell numbers stabilized at 1 × 10^9 CFU/mL, and hydraulic conductivity (K) decreased 77%. Next, medium with pH 4 was introduced. As a result, biomass within the reactor redistributed from bead surfaces to pores, effluent cell numbers decreased to 3 × 10^5 CFU/mL, and K decreased even further (>94% reduction). This decreased K was maintained until the experiment was terminated, seven days after introducing low pH medium. These results suggest that changes in biomass distribution as a result of decreased pH may initially limit transport of solubility-trapped CO2 following CO2 injection. Experiments in progress and planned will test this result in more detail and over longer periods of time. This material is based upon work supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office

  1. Natural Selection Affects Multiple Aspects of Genetic Variation at Putatively Neutral Sites across the Human Genome

    OpenAIRE

    Lohmueller, Kirk E.; Albrechtsen, Anders; Li, Yingrui; Kim, Su Yeon; Korneliussen, Thorfinn Sand; Vinckenbosch, Nicolas; Tian, Geng; Huerta-Sanchez, Emilia; Feder, Alison F.; Grarup, Niels; Jørgensen, Torben; Jiang, Tao; Witte, Daniel R.; Sandbæk, Annelli; Hellmann, Ines

    2011-01-01

    A major question in evolutionary biology is how natural selection has shaped patterns of genetic variation across the human genome. Previous work has documented a reduction in genetic diversity in regions of the genome with low recombination rates. However, it is unclear whether other summaries of genetic variation, like allele frequencies, are also correlated with recombination rate and whether these correlations can be explained solely by negative selection against deleterious mutations or ...

  2. eQTL Viewer: visualizing how sequence variation affects genome-wide transcription

    OpenAIRE

    Zeng Zhao-Bang; Aylor David L; Zou Wei

    2007-01-01

    Abstract Background Expression Quantitative Trait Locus (eQTL) mapping methods have been used to identify the genetic basis of gene expression variations. To map eQTL, thousands of expression profiles are related with sequence polymorphisms across the genome through their correlated variations. These eQTL distribute in many chromosomal regions, each of which can include many genes. The large number of mapping results produced makes it difficult to consider simultaneously the relationships bet...

  3. Distribution and clinal trends of the ABO and Rh genes in select Middle Eastern countries.

    Science.gov (United States)

    AlSuhaibani, E S; Kizilbash, N A; Afshan, K; Malik, S

    2015-01-01

    An understanding of the ABO and Rh blood group systems is important for blood transfusions and is also pertinent due to their potential association with certain morbidities and susceptibilities to infections. To investigate the diversity and differentiation of the ABO and Rh loci in Middle Eastern populations, data from twelve representative Middle Eastern populations were analyzed. Six populations were in conformity with Hardy-Weinberg equilibrium at the ABO locus. The pooled heterozygosity at both loci was calculated to be highest in the sample from Jordan and lowest in Bahrain. Heterogeneity was pronounced in the Northern compared to the Southern Middle Eastern populations. Overall, the absolute gene diversity was 0.0046 and gene differentiation was calculated to be 0.0100. Genetic diversity of the studied loci across all populations (HT) was estimated to be 0.4594, while the diversity within the populations (HS) was 0.4548. Nei's genetic distance analyses revealed highest affinities between the populations of Kuwait and Qatar, Oman and Yemen, and between Qatar and the United Arab Emirates. These results were displayed through a UGPMA dendrogram and principal component analyses, which established clustering of certain populations. Clinal trends of the allelic systems were observed by generating contour maps that allow a detailed appreciation of the distributions of alleles across the geography of the Arabian Peninsula and the Middle East. Taken together, these analyses are helpful in understanding the differentiation of blood group loci and for designing prospective studies for establishing the associations of these loci with health variables in the populations studied. PMID:26400302

  4. Allelic and copy-number variations of FcγRs affect granulocyte function and susceptibility for autoimmune blistering diseases.

    Science.gov (United States)

    Recke, Andreas; Vidarsson, Gestur; Ludwig, Ralf J; Freitag, Miriam; Möller, Steffen; Vonthein, Reinhard; Schellenberger, Julia; Haase, Ozan; Görg, Siegfried; Nebel, Almut; Flachsbart, Friederike; Schreiber, Stefan; Lieb, Wolfgang; Gläser, Regine; Benoit, Sandrine; Sárdy, Miklós; Eming, Rüdiger; Hertl, Michael; Zillikens, Detlef; König, Inke R; Schmidt, Enno; Ibrahim, Saleh

    2015-07-01

    Low-affinity Fcγ receptors (FcγR) bridge innate and adaptive immune responses. In many autoimmune diseases, these receptors act as key mediators of the pathogenic effects of autoantibodies. Genes encoding FcγR exhibit frequent variations in sequence and gene copy number that influence their functional properties. FcγR variations also affect the susceptibility to systemic autoimmunity, e.g. systemic lupus erythematosus and rheumatoid arthritis. This raises the question whether FcγR variations are also associated with organ-specific autoimmunity, particularly autoantibody-mediated diseases, such as subepidermal autoimmune blistering diseases (AIBD). A multitude of evidence suggests a pathogenic role of neutrophil granulocyte interaction with autoantibodies via FcγR. In a two-stage study, we analyzed whether the FcγR genotype affects neutrophil function and mRNA expression, and consequently, bullous pemphigoid (BP) disease risk. We compared this to findings in pemphigus vulgaris/foliaceus (PV/PF), two Fc-independent AIBDs. Our results indicate that both allele and copy number variation of FcγR genes affect FcγR mRNA expression and reactive oxygen species (ROS) release by granulocytes. Susceptibility of BP was associated with FcγR genotypes that led to a decreased ROS release by neutrophils, indicating an unexpected protective role for these cells. BP and PV/PF differed substantially regarding the FcγR genotype association patterns, pointing towards different disease etiologies. PMID:26032265

  5. Factors Affecting Spatial Variation of Annual Apparent Q10 of Soil Respiration in Two Warm Temperate Forests

    OpenAIRE

    Luan, Junwei; Liu, Shirong; Wang, Jingxin; Zhu, Xueling

    2013-01-01

    A range of factors has been identified that affect the temperature sensitivity (Q10 values) of the soil-to-atmosphere CO2 flux. However, the factors influencing the spatial distribution of Q10 values within warm temperate forests are poorly understood. In this study, we examined the spatial variation of Q10 values and its controlling factors in both a naturally regenerated oak forest (OF) and a pine plantation (PP). Q10 values were determined based on monthly soil respiration (RS) measurement...

  6. Social factors affecting seasonal variation in bovine trypanosomiasis on the Jos Plateau, Nigeria

    Science.gov (United States)

    2013-01-01

    Background African Animal Trypanosomiasis (AAT) is a widespread disease of livestock in Nigeria and presents a major constraint to rural economic development. The Jos Plateau was considered free from tsetse flies and the trypanosomes they transmit due to its high altitude and this trypanosomiasis free status attracted large numbers of cattle-keeping pastoralists to the area. The Jos Plateau now plays a major role in the national cattle industry in Nigeria, accommodating approximately 7% of the national herd, supporting 300,000 pastoralists and over one million cattle. During the past two decades tsetse flies have invaded the Jos Plateau and animal trypanosomiasis has become a significant problem for livestock keepers. Here we investigate the epidemiology of trypanosomiasis as a re-emerging disease on the Plateau, examining the social factors that influence prevalence and seasonal variation of bovine trypanosomiasis. Methods In 2008 a longitudinal two-stage cluster survey was undertaken on the Jos Plateau. Cattle were sampled in the dry, early wet and late wet seasons. Parasite identification was undertaken using species-specific polymerase chain reactions to determine the prevalence and distribution of bovine trypanosomiasis. Participatory rural appraisal was also conducted to determine knowledge, attitudes and practices concerning animal husbandry and disease control. Results Significant seasonal variation between the dry season and late wet season was recorded across the Jos Plateau, consistent with expected variation in tsetse populations. However, marked seasonal variations were also observed at village level to create 3 distinct groups: Group 1 in which 50% of villages followed the general pattern of low prevalence in the dry season and high prevalence in the wet season; Group 2 in which 16.7% of villages showed no seasonal variation and Group 3 in which 33.3% of villages showed greater disease prevalence in the dry season than in the wet season. Conclusions

  7. Phenotypic Variation in Mangrove Cuckoo (Coccyzus minor) across Its Geographic Range

    OpenAIRE

    Lloyd, John D.

    2016-01-01

    Mangrove Cuckoo (Coccyzus minor) exhibits substantial phenotypic variation across its geographic range, but the significance of this variation for taxonomy remains unresolved. Using measurements of bill size and ventral color recorded from 274 museum specimens, I found that variation in these traits was clinal. No named subspecies was reciprocally diagnosable from all others, and none was distinguishable from the nominate form, such that previously recognized subspecific distinctions are inva...

  8. Molecular-level variation affects population growth in a butterfly metapopulation.

    OpenAIRE

    Ilkka Hanski; Ilik Saccheri

    2006-01-01

    The dynamics of natural populations are thought to be dominated by demographic and environmental processes with little influence of intraspecific genetic variation and natural selection, apart from inbreeding depression possibly reducing population growth in small populations. Here we analyse hundreds of well-characterised local populations in a large metapopulation of the Glanville fritillary butterfly (Melitaea cinxia), which persists in a balance between stochastic local extinctions and re...

  9. Body mass affects seasonal variation in sickness intensity in a seasonally breeding rodent

    OpenAIRE

    Carlton, Elizabeth D.; Demas, Gregory E

    2015-01-01

    Species that display seasonal variation in sickness intensity show the most intense response in the season during which they have the highest body mass, suggesting that sickness intensity may be limited by an animal's energy stores. Siberian hamsters (Phodopus sungorus) display lower body masses and less intense sickness when housed in short, winter-like days as opposed to long, summer-like days. To determine whether reduced sickness intensity displayed by short-day hamsters is a product of s...

  10. Analysis of two single trait loci affecting flavonol glycoside accumulations in Arabidopsis thaliana natural variations

    OpenAIRE

    Ishihara, Hirofumi

    2007-01-01

    Various plant secondary metabolites, including flavonoids, are involved in plant adaptation to different environments. The needs of sessile lifestyle of plants may have increased the variation of enzymes which are required in the modification and/or accumulation of different flavonol derivatives. The probable mechanism for generating variants of the enzymes is by mutating the corresponding genes. Therefore, Arabidopsis thaliana wildtype accessions collected from different environments and loc...

  11. Factors affecting spatial variation of polycyclic aromatic hydrocarbons in surface soils in North China Plain.

    Science.gov (United States)

    Wang, Xilong; Zuo, Qian; Duan, Yonghong; Liu, Wenxin; Cao, Jun; Tao, Shu

    2012-10-01

    The spatial variation in concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in surface soils in the North China Plain and the influential factors were examined in the present study. High concentrations of the sum of 16 PAHs (∑PAH(16) ) appeared in cities and their surrounding areas. Emissions and soil organic carbon (SOC) content significantly regulated spatial differentiation of PAH contamination in soils in the study area. Compared with emissions, concentrations of individual and total PAHs in soils were more closely controlled by the SOC content. Furthermore, concentrations of PAH species with lower molecular weight (e.g., two- or three-ring) in surface soils were more strongly correlated with the SOC content in comparison with those of higher molecular weight (e.g., five- or six-ring), mainly because of their higher saturated vapor pressure, thus higher mobility. The spatial variation of PAH species in soils in the North China Plain tended to be larger with increasing benzene ring numbers, and the difference in physicochemical properties of PAH species determined their distinct spatial distribution characteristics. The present study highlights the relative importance of emissions and SOC content in spatial variation of PAHs and the dependence of the spatial distribution characteristics of PAH species in surface soils on their physicochemical properties at a regional scale. Results of the present work are helpful for regional risk assessment of the contaminants tested. PMID:22847656

  12. Morphological variation in two genetically distinct groups of the golden-striped salamander, Chioglossa lusitanica (Amphibia: Urodela)

    NARCIS (Netherlands)

    Alexandrino, J.; Ferrand, N.; Arntzen, J.W.

    2005-01-01

    Morphometric and colour pattern variation in the endemic Iberian salamander Chioglossa lusitanica is concordant with the genetic differentiation of two groups of populations separated by the Mondego river in Portugal. Salamanders from the south have shorter digits than those from the north. Clinal v

  13. Intraspecies variation in BMR does not affect estimates of early hominin total daily energy expenditure.

    Science.gov (United States)

    Froehle, Andrew W; Schoeninger, Margaret J

    2006-12-01

    We conducted a meta-analysis of 45 studies reporting basal metabolic rate (BMR) data for Homo sapiens and Pan troglodytes to determine the effects of sex, age, and latitude (a proxy for climate, in humans only). BMR was normalized for body size using fat-free mass in humans and body mass in chimpanzees. We found no effect of sex in either species and no age effect in chimpanzees. In humans, juveniles differed significantly from adults (ANCOVA: P interspecific comparisons. Comparisons of more closely related groups such as humans and Neandertals, however, may benefit from consideration of this variation. PMID:16941603

  14. Wind-wave affected phosphate loading variations and their relationship to redox condition in Lake Taihu

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Lu; ZHU; Guangwei; LUO; Liancong; GAO; Guang; ZHANG; Yunlin; QIN; Boqiang; FAN; Chengxin

    2006-01-01

    Variation of wind speed and the physico-chemical parameters, such as dissolved phosphate, ferrous and manganese in lake water were observed on site. Together with the chemistry analysis and simulated experiment in lab, the change of phosphate concentration in lake water was analyzed. The variation of ferrous/phosphate ratio explained that along with the enhancement of wind-wave effect and the oxidation ability of lake water, the effects of co-precipitation and removal of dissolved phosphate and iron in the lake water were reinforced. The ferrous/phosphate ratio in pore water was less than 2.0, demonstrating that the dissolved phosphate can be released into the overlying water. But, in the lake water, the stability of phosphate was controlled by the water dynamics.The phosphate release experiment showed that molecular release was only part of the whole and the direct discharge of phosphate in the pore water was also a part. The mineralization and biological process of suspended particulates in the water may be another important reason for the whole phosphate loadings.

  15. Genotypic variation in host response to infection affects parasite reproductive rate.

    Science.gov (United States)

    Tavalire, Hannah F; Blouin, Michael S; Steinauer, Michelle L

    2016-02-01

    Parasite fitness is largely influenced by a variation in host response due to the host's genetic background. Here we investigated the impact of host genotype on pathogen success in the snail vector of its castrating parasite, Schistosoma mansoni. We infected five inbred lines of Biomphalaria glabrata with two infection doses and followed their growth, reproductive output and parasite production throughout the course of infection. There was no difference in resistance to infection among inbred lines, but lines varied in their responses to infection and the numbers of parasites produced. Snails did not compensate for castration by increasing their fecundity during the early phase of infection (fecundity compensation). However, some lines were able to delay parasite shedding for up to 30 weeks, thus prolonging reproduction before the onset of castration. Here we propose this strategy as a novel defense against castrating pathogens in snails. Gigantism, a predicted outcome of castration due to energy reallocation, occurred early in infection (cercariae within a single 2h shedding period, resulting in a total production of 6981-29,509 cercariae over the lifetime of a single snail. Regardless of genetic background, snail size was a strong predictor of parasite reproduction: each millimetre increase in snail size at the time of the first shed resulted in up to 3500 more cercariae over the lifetime of the snail. The results of this study provide a detailed picture of variation in hosts' responses to infection and the resulting impacts on parasite fitness, further defining the intricacies of snail-schistosome compatibility. PMID:26552016

  16. Genetic variation in human NPY expression affects stress response and emotion.

    Science.gov (United States)

    Zhou, Zhifeng; Zhu, Guanshan; Hariri, Ahmad R; Enoch, Mary-Anne; Scott, David; Sinha, Rajita; Virkkunen, Matti; Mash, Deborah C; Lipsky, Robert H; Hu, Xian-Zhang; Hodgkinson, Colin A; Xu, Ke; Buzas, Beata; Yuan, Qiaoping; Shen, Pei-Hong; Ferrell, Robert E; Manuck, Stephen B; Brown, Sarah M; Hauger, Richard L; Stohler, Christian S; Zubieta, Jon-Kar; Goldman, David

    2008-04-24

    Understanding inter-individual differences in stress response requires the explanation of genetic influences at multiple phenotypic levels, including complex behaviours and the metabolic responses of brain regions to emotional stimuli. Neuropeptide Y (NPY) is anxiolytic and its release is induced by stress. NPY is abundantly expressed in regions of the limbic system that are implicated in arousal and in the assignment of emotional valences to stimuli and memories. Here we show that haplotype-driven NPY expression predicts brain responses to emotional and stress challenges and also inversely correlates with trait anxiety. NPY haplotypes predicted levels of NPY messenger RNA in post-mortem brain and lymphoblasts, and levels of plasma NPY. Lower haplotype-driven NPY expression predicted higher emotion-induced activation of the amygdala, as well as diminished resiliency as assessed by pain/stress-induced activations of endogenous opioid neurotransmission in various brain regions. A single nucleotide polymorphism (SNP rs16147) located in the promoter region alters NPY expression in vitro and seems to account for more than half of the variation in expression in vivo. These convergent findings are consistent with the function of NPY as an anxiolytic peptide and help to explain inter-individual variation in resiliency to stress, a risk factor for many diseases. PMID:18385673

  17. Genetic variation in human NPY expression affects stress response and emotion

    Science.gov (United States)

    Zhou, Zhifeng; Zhu, Guanshan; Hariri, Ahmad R.; Enoch, Mary-Anne; Scott, David; Sinha, Rajita; Virkkunen, Matti; Mash, Deborah C.; Lipsky, Robert H.; Hu, Xian-Zhang; Hodgkinson, Colin A.; Xu, Ke; Buzas, Beata; Yuan, Qiaoping; Shen, Pei-Hong; Ferrell, Robert E.; Manuck, Stephen B.; Brown, Sarah M.; Hauger, Richard L.; Stohler, Christian S.; Zubieta, Jon-Kar; Goldman, David

    2009-01-01

    Understanding inter-individual differences in stress response requires the explanation of genetic influences at multiple phenotypic levels, including complex behaviours and the metabolic responses of brain regions to emotional stimuli. Neuropeptide Y (NPY) is anxiolytic1,2 and its release is induced by stress3. NPY is abundantly expressed in regions of the limbic system that are implicated in arousal and in the assignment of emotional valences to stimuli and memories4–6. Here we show that haplotype-driven NPY expression predicts brain responses to emotional and stress challenges and also inversely correlates with trait anxiety. NPY haplotypes predicted levels of NPY messenger RNA in postmortem brain and lymphoblasts, and levels of plasma NPY. Lower haplotype-driven NPY expression predicted higher emotion-induced activation of the amygdala, as well as diminished resiliency as assessed by pain/stress-induced activations of endogenous opioid neurotransmission in various brain regions. A single nucleotide polymorphism (SNP rs16147) located in the promoter region alters NPY expression in vitro and seems to account for more than half of the variation in expression in vivo. These convergent findings are consistent with the function of NPY as an anxiolytic peptide and help to explain inter-individual variation in resiliency to stress, a risk factor for many diseases. PMID:18385673

  18. eQTL Viewer: visualizing how sequence variation affects genome-wide transcription

    Directory of Open Access Journals (Sweden)

    Zeng Zhao-Bang

    2007-01-01

    Full Text Available Abstract Background Expression Quantitative Trait Locus (eQTL mapping methods have been used to identify the genetic basis of gene expression variations. To map eQTL, thousands of expression profiles are related with sequence polymorphisms across the genome through their correlated variations. These eQTL distribute in many chromosomal regions, each of which can include many genes. The large number of mapping results produced makes it difficult to consider simultaneously the relationships between multiple genomic regions and multiple expressional profiles. There is a need for informative bioinformatics tools to assist the visualization and interpretation of these mapping results. Results We have developed a web-based tool, called eQTL Viewer, to visualize the relationships between the expression trait genes and the candidate genes in the eQTL regions using Scalable Vector Graphics. The plot generated by eQTL Viewer has the capacity to display mapping results with high resolutions at a variety of scales, and superimpose biological annotations onto the mapping results dynamically. Conclusion Our tool provides an efficient and intuitive way for biologists to explore transcriptional regulation patterns, and to generate hypotheses on the genetic basis of transcriptional regulations.

  19. Variation in orbitofrontal cortex volume: relation to sex, emotion regulation and affect

    OpenAIRE

    Welborn, B. Locke; Papademetris, Xenophon; Reis, Deidre L.; Rajeevan, Nallakkandi; Bloise, Suzanne M.; Gray, Jeremy R.

    2009-01-01

    Sex differences in brain structure have been examined extensively but are not completely understood, especially in relation to possible functional correlates. Our two aims in this study were to investigate sex differences in brain structure, and to investigate a possible relation between orbitofrontal cortex subregions and affective individual differences. We used tensor-based morphometry to estimate local brain volume from MPRAGE images in 117 healthy right-handed adults (58 female), age 18–...

  20. Natural selection affects multiple aspects of genetic variation at putatively neutral sites across the human genome

    DEFF Research Database (Denmark)

    Lohmueller, Kirk E; Albrechtsen, Anders; Li, Yingrui;

    2011-01-01

    A major question in evolutionary biology is how natural selection has shaped patterns of genetic variation across the human genome. Previous work has documented a reduction in genetic diversity in regions of the genome with low recombination rates. However, it is unclear whether other summaries of...... human diversity, human-chimp divergence, and average minor allele frequency are reduced near genes. Population genetic simulations show that either positive natural selection acting on favorable mutations or negative natural selection acting against deleterious mutations can explain these correlations...... throughout the genome. Further, we show that the widespread presence of weakly deleterious alleles, rather than a small number of strongly positively selected mutations, is responsible for the correlation between neutral genetic diversity and recombination rate. This work suggests that natural selection has...

  1. Neural plasticity is affected by stress and heritable variation in stress coping style

    DEFF Research Database (Denmark)

    Johansen, I.B.; Sørensen, C.; Sandvik, G.K.;

    2012-01-01

    behavioral flexibility in LR compared to HR fish and we hypothesize that this divergence is caused by differences in neural plasticity. Genes involved in neural plasticity and neurogenesis were investigated by quantitative PCR in brains of LR and HR fish at baseline conditions and in response to two......Here we use a comparative model to investigate how behavioral and physiological traits correlate with neural plasticity. Selection for divergent post-stress cortisol levels in rainbow trout (Oncorhynchus mykiss) has yielded low- (LR) and high responsive (HR) lines. Recent reports show low...... PCNA and brain-derived neurotrophic factor (BDNF) in both lines, whereas LTS stress generally suppressed PCNA and NeuroD expression while leaving BDNF expression unaltered. These results indicate that the transcription of neuroplasticity-related genes is associated with variation in coping style, while...

  2. Variation in Dube3a expression affects neurotransmission at the Drosophila neuromuscular junction

    Directory of Open Access Journals (Sweden)

    Colleen Valdez

    2015-07-01

    Full Text Available Changes in UBE3A expression levels in neurons can cause neurogenetic disorders ranging from Angelman syndrome (AS (decreased levels to autism (increased levels. Here we investigated the effects on neuronal function of varying UBE3A levels using the Drosophila neuromuscular junction as a model for both of these neurogenetic disorders. Stimulations that evoked excitatory junction potentials (EJPs at 1 Hz intermittently failed to evoke EJPs at 15 Hz in a significantly higher proportion of Dube3a over-expressors using the pan neuronal GAL4 driver C155-GAL4 (C155-GAL4>UAS-Dube3a relative to controls (C155>+ alone. However, in the Dube3a over-expressing larval neurons with no failures, there was no difference in EJP amplitude at the beginning of the train, or the rate of decrease in EJP amplitude over the course of the train compared to controls. In the absence of tetrodotoxin (TTX, spontaneous EJPs were observed in significantly more C155-GAL4>UAS-Dube3a larva compared to controls. In the presence of TTX, spontaneous and evoked EJPs were completely blocked and mEJP amplitude and frequency did not differ among genotypes. These data suggest that over-expression of wild type Dube3a, but not a ubiquitination defective Dube3a-C/A protein, compromises the ability of motor neuron axons to support closely spaced trains of action potentials, while at the same time increasing excitability. EJPs evoked at 15 Hz in the absence of Dube3a (Dube3a15b homozygous mutant larvae decayed more rapidly over the course of 30 stimulations compared to w1118 controls, and Dube3a15b larval muscles had significantly more negative resting membrane potentials (RMP. However, these results could not be recapitulated using RNAi knockdown of Dube3a in muscle or neurons alone, suggesting more global developmental defects contribute to this phenotype. These data suggest that reduced UBE3A expression levels may cause global changes that affect RMP and neurotransmitter release from

  3. Variation of Hydroxyapatite Content in Soft Gelatin Affects Mesenchymal Stem Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Fahsai Kantawong

    2016-01-01

    Full Text Available Gelatin is a common material used in tissue engineering and hydroxyapatite (HA has a composition and structure similar to natural bone mineral. HA is also used to increase the adhesion ability of scaffolds. The physical and mechanical properties of gelatin, together with the chemical properties of HA, can affect cell differentiation. The main purpose of this study is to investigate the gene expression of human mesenchymal stem cells (HMSCs upon culturing on gelatin composite with HA. Low amounts of HA were introduced into the gelatin in order to modulate properties of gelatin. Three types of hydrogel were fabricated by glutaraldehyde crosslinking before lyophilization to produce the porous 3D structure: (1 pure gelatin, (2 0.5 mg/ml HA in gelatin, and (3 1 mg/ml HA in gelatin. The fabricated hydrogels were used as scaffolds to cultivate HMSCs for two periods - 24 hours and 3 weeks. The results showed that all types of fabricated hydrogels could be used to cultivate HMSCs. Changes of gene expressions indicated that the HMSCs cultured on the 1 mg/ml HA in gelatin showed neuronal lineage-specific differentiation.

  4. Seasonal variation in affective and other clinical symptoms among high-risk families for bipolar disorders in an Arctic population

    Directory of Open Access Journals (Sweden)

    Sami Pirkola

    2015-11-01

    Full Text Available Background: In bipolar disorder (BD, seasonality of symptoms is common and disturbances in circadian rhythms have been reported. Objectives: We identified high-penetrance families in a geographically restricted area in Northern Fennoscandia and studied the seasonal variation of clinical symptoms among BD subjects and their healthy relatives. Design: We explored the clinical characteristics of subjects living in Northern Fennoscandia, with extreme annual variation in daylight. Among known indigenous high-risk families for BD, we compared the affected ones (N=16 with their healthy relatives (N=15, and also included 18 healthy non-related controls from the same geographical area. Seasonal fluctuation in clinical measures was followed up at the 4 most demarcated photoperiodic time points of the annual cycle: around the summer solstice and autumn equinox in 2013, the winter solstice in 2013/2014, and the spring equinox in 2014. In the baseline, lifetime manic symptoms [Mood Disorder Questionnaire (MDQ] and morningness–eveningness questionnaire type (MEQ were registered, whereas in the follow-up, depressive [Beck Depression Inventory (BDI] and distress [General Health Questionnaire (GHQ-12] symptoms and alcohol consumption and sleep were recorded. Results: Possibly indicative or statistically significant differences in symptoms between the affected subjects and their healthy relatives were the BDI winter (13.3 vs. 2.6, t=−2.51, p=0.022 and spring scores (12.6 vs. 3.2, t=−1.97, p=0.063 and GHQ winter (4.2 vs. 0.82, t=−2.08, p=0.052 and spring scores (3.8 vs. 0.82, t=−1.97, p=0.063. Scores were higher among the affected subjects, exceeding a possibly diagnostic threshold (10 and 3 at all the time points, and without the notable seasonality which was observed among the healthy relatives. In the overall population, MDQ and MEQ scores had an inverse correlation (−0.384, significant at 0.016, indicating increased lifetime manic behaviour among

  5. Does spatial variation in environmental conditions affect recruitment? A study using a 3-D model of Peruvian anchovy

    Science.gov (United States)

    Xu, Yi; Rose, Kenneth A.; Chai, Fei; Chavez, Francisco P.; Ayón, Patricia

    2015-11-01

    We used a 3-dimensional individual-based model (3-D IBM) of Peruvian anchovy to examine how spatial variation in environmental conditions affects larval and juvenile growth and survival, and recruitment. Temperature, velocity, and phytoplankton and zooplankton concentrations generated from a coupled hydrodynamic Nutrients-Phytoplankton-Zooplankton-Detritus (NPZD) model, mapped to a three dimensional rectangular grid, were used to simulate anchovy populations. The IBM simulated individuals as they progressed from eggs to recruitment at 10 cm. Eggs and yolk-sac larvae were followed hourly through the processes of development, mortality, and movement (advection), and larvae and juveniles were followed daily through the processes of growth, mortality, and movement (advection plus behavior). A bioenergetics model was used to grow larvae and juveniles. The NPZD model provided prey fields which influence both food consumption rate as well as behavior mediated movement with individuals going to grids cells having optimal growth conditions. We compared predicted recruitment for monthly cohorts for 1990 through 2004 between the full 3-D IBM and a point (0-D) model that used spatially-averaged environmental conditions. The 3-D and 0-D versions generated similar interannual patterns in monthly recruitment for 1991-2004, with the 3-D results yielding consistently higher survivorship. Both versions successfully captured the very poor recruitment during the 1997-1998 El Niño event. Higher recruitment in the 3-D simulations was due to higher survival during the larval stage resulting from individuals searching for more favorable temperatures that lead to faster growth rates. The strong effect of temperature was because both model versions provided saturating food conditions for larval and juvenile anchovies. We conclude with a discussion of how explicit treatment of spatial variation affected simulated recruitment, other examples of fisheries modeling analyses that have used a

  6. THREE SELECTIONS ARE BETTER THAN ONE: CLINAL VARIATION OF THERMAL QTL FROM INDEPENDENT SELECTION EXPERIMENTS IN DROSOPHILA

    OpenAIRE

    Rand, David M.; Weinreich, Daniel M.; Lerman, Daniel; Folk, Donna; Gilchrist, George W

    2010-01-01

    We report the results of two independent selection experiments that have exposed distinct populations of Drosophila melanogaster to different forms of thermal selection. A recombinant population derived from Arvin California and Zimbabwe isofemale lines was exposed to laboratory natural selection at two temperatures (TAZ: 18°C and 28°C). Microsatellite mapping identified quantitative trait loci (QTL) on the X-chromosome between the replicate “Hot” and “Cold” populations. In a separate experim...

  7. Evolution of insect life histories in relation to time constraints in seasonal environments:polymorphism and clinal variation

    OpenAIRE

    Kivelä, S. M. (Sami Mikael)

    2011-01-01

    Abstract Both the length of the season that is favourable for insect growth and reproduction and the number of generations emerging per season (voltinism) increase with decreasing latitude. Thus, time constraints on reproduction and juvenile development decrease with decreasing latitude, except where voltinism changes and time constraints suddenly increase as the season must be shared with one more generation. I studied the evolution of insect life histories in relation to time constrai...

  8. Clinal genetic variation and isolation by distance in the European eel Anguilla anguilla (L.)

    OpenAIRE

    Maes, G.E.; Volckaert, F.A.M.J.

    2002-01-01

    The genetic variability and structure of the European eel (Anguilla anguilla L.) in populations throughout Europe was reassessed using 15 allozymic loci, seven of which were polymorphic. Seven sites were sampled on a latitudinal gradient across the natural continental range, extending from southern France to southern Norway. Heterozygosity (He = 0.05) and level of polymorphism (P = 0.43) were comparable to other marine fish. Populations were poorly differentiated (GST = 0.014, FST = 0.002), w...

  9. Site variation in methane oxidation as affected by atmospheric deposition and type of temperate forest ecosystem

    Science.gov (United States)

    Brumme, Rainer; Borken, Werner

    1999-06-01

    Factors controlling methane oxidation were analyzed along a soil acidity gradient (pH(H2O) 3.9 to 5.2) under beech and spruce forests in Germany. Mean annual methane oxidation ranged from 0.1 to 2.5 kg CH4 ha-1 yr-1 and was correlated with base saturation (r2 = 0.88), soil pH (r2 = 0.77), total nitrogen (r2 = 0.71), amount of the organic surface horizon (r2 = 0.49) and bulk density of the mineral soil (r2 = 0.43). At lower pHs the formation of an organic surface horizon was promoted. This horizon did not have any methane oxidation capacity and acted like a gas diffusion barrier, which decreased the methane oxidation capacity of the soil. In contrast, on sites at the higher end of the pH range, higher burrowing activity of earthworms increased macroporosity and thereby gas diffusivity and methane oxidation. Gas diffusivity was also affected by litter shape: broad beech leaves reduced methane oxidation more than spruce needles. An increase in methane oxidation of most soil samples following sieving indicates that diffusion is the main limiting factor for methane oxidation. However, this "sieving effect" was less in soils with a pH below 5 than in soils with a pH above 5, which we attribute to a direct effect of soil acidity. We discuss our results using a hierarchical concept for the "short-term" and "long-term" controls on methane oxidation in forest ecosystems.

  10. Interannual variation of the Philippines affecting tropical cyclone intensity and its possible causes

    Science.gov (United States)

    Choi, Ki-Seon; Kim, Baek-Jo; Kang, Sung-Dae; Kim, Hae-Dong

    2015-10-01

    This study analyzed changes in tropical cyclone (TC) intensity for the past 62 years (1951-2012) by calculating annual average value of central pressure (CP) of TCs that affected the Philippines from July to September. Although TC intensity slightly weakened for the last 62 years, it was not statistically significant. In order to examine the causes of changes in intensity of TCs that influenced the Philippines, nine low CP years and nine high CP years among the 62 years were selected to analyze differences between the two groups. TCs largely occurred in the southeastern quadrant of tropical and subtropical western North Pacific during low CP years and tended to move to the Philippines from the far sea in the southeast of the nation. In differences in deep-layer-mean wind between the two groups, western North Pacific subtropical high (WNPSH) did not develop toward the middle latitudes of East Asia but toward the low latitudes of the region during low CP years. Therefore, TCs occurred in the southeastern quadrant of tropical and subtropical western North Pacific, triggering its movement of long distance westward toward the Philippines. As positive anomalies in precipitable water and at 600 hPa relative humidity, 850 hPa air temperature, and sea surface temperature continued to the Philippines from the southeastern quadrant, a favorable environment where intensity of TCs can be strengthened while they move to the Philippines during low CP years has been formed. In the end, because WNPSH developed toward the low latitudes during low CP years, anomalous easterlies that strengthened in the southern regions of WNPSH blew to the Philippines, and SST in the sea near the nation was heightened. Therefore, because TCs were able to obtain sufficient energy from the relatively warm sea while TCs moved a long distance to the Philippines, TC intensity was able to be strengthened.

  11. Variation in the Williams syndrome GTF2I gene and anxiety proneness interactively affect prefrontal cortical response to aversive stimuli.

    Science.gov (United States)

    Jabbi, M; Chen, Q; Turner, N; Kohn, P; White, M; Kippenhan, J S; Dickinson, D; Kolachana, B; Mattay, V; Weinberger, D R; Berman, K F

    2015-01-01

    Characterizing the molecular mechanisms underlying the heritability of complex behavioral traits such as human anxiety remains a challenging endeavor for behavioral neuroscience. Copy-number variation (CNV) in the general transcription factor gene, GTF2I, located in the 7q11.23 chromosomal region that is hemideleted in Williams syndrome and duplicated in the 7q11.23 duplication syndrome (Dup7), is associated with gene-dose-dependent anxiety in mouse models and in both Williams syndrome and Dup7. Because of this recent preclinical and clinical identification of a genetic influence on anxiety, we examined whether sequence variation in GTF2I, specifically the single-nucleotide polymorphism rs2527367, interacts with trait and state anxiety to collectively impact neural response to anxiety-laden social stimuli. Two hundred and sixty healthy adults completed the Tridimensional Personality Questionnaire Harm Avoidance (HA) subscale, a trait measure of anxiety proneness, and underwent functional magnetic resonance imaging (fMRI) while matching aversive (fearful or angry) facial identity. We found an interaction between GTF2I allelic variations and HA that affects brain response: in individuals homozygous for the major allele, there was no correlation between HA and whole-brain response to aversive cues, whereas in heterozygotes and individuals homozygous for the minor allele, there was a positive correlation between HA sub-scores and a selective dorsolateral prefrontal cortex (DLPFC) responsivity during the processing of aversive stimuli. These results demonstrate that sequence variation in the GTF2I gene influences the relationship between trait anxiety and brain response to aversive social cues in healthy individuals, supporting a role for this neurogenetic mechanism in anxiety. PMID:26285132

  12. How spatial variation in areal extent and configuration of labile vegetation states affect the riparian bird community in Arctic tundra.

    Directory of Open Access Journals (Sweden)

    John-André Henden

    Full Text Available The Arctic tundra is currently experiencing an unprecedented combination of climate change, change in grazing pressure by large herbivores and growing human activity. Thickets of tall shrubs represent a conspicuous vegetation state in northern and temperate ecosystems, where it serves important ecological functions, including habitat for wildlife. Thickets are however labile, as tall shrubs respond rapidly to both abiotic and biotic environmental drivers. Our aim was to assess how large-scale spatial variation in willow thicket areal extent, configuration and habitat structure affected bird abundance, occupancy rates and species richness so as to provide an empirical basis for predicting the outcome of environmental change for riparian tundra bird communities. Based on a 4-year count data series, obtained through a large-scale study design in low arctic tundra in northern Norway, statistical hierarchical community models were deployed to assess relations between habitat configuration and bird species occupancy and community richness. We found that species abundance, occupancy and richness were greatly affected by willow areal extent and configuration, habitat features likely to be affected by intense ungulate browsing as well as climate warming. In sum, total species richness was maximized in large and tall willow patches of small to intermediate degree of fragmentation. These community effects were mainly driven by responses in the occupancy rates of species depending on tall willows for foraging and breeding, while species favouring other vegetation states were not affected. In light of the predicted climate driven willow shrub encroachment in riparian tundra habitats, our study predicts that many bird species would increase in abundance, and that the bird community as a whole could become enriched. Conversely, in tundra regions where overabundance of large herbivores leads to decreased areal extent, reduced height and increased fragmentation

  13. Variations in DBTT and CTOD within weld heat-affected zone of API X65 pipeline steel

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Jang-Bog [Samsung Electronics Co. Ltd., Asan 336-841 (Korea, Republic of); Kim, Woo-sik [Research and Development Center, Korea Gas Corporation, Ansan 425-150 (Korea, Republic of); Jang, Jae-il, E-mail: jijang@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2012-06-01

    Highlights: Black-Right-Pointing-Pointer Fracture resistance of API X65 steel weld HAZ was systematically investigated. Black-Right-Pointing-Pointer Variations in DBTT and CTOD toughness within HAZ were explored. Black-Right-Pointing-Pointer Results were discussed with the additional data from simulated HAZ specimen tests. - Abstract: The fracture resistance of heat-affected zones (HAZs) in girth welded joint of API X65 steel pipeline was systematically investigated. While the change in Charpy impact energy has been typically evaluated in previous studies, here the variations in ductile-to-brittle temperature (DBTT) and crack-tip opening displacement (CTOD) within HAZ were explored. A series of experiments revealed that both values vary dramatically (i.e., DBTT increases and CTOD decreases) as the location approaches the fusion line (FL) and thus the region adjacent to FL exhibited the lowest CTOD and highest DBTT, possibly due to the increasing portion of coarse-grained HAZ. Interestingly, however, even the FL regions still showed moderate toughness at -40 Degree-Sign C {approx} room temperature. Microstructural analysis and additional impact tests using simulated HAZ specimens suggested a possibility that fine-grained HAZs with higher toughness may suppress the brittle fracture from neighboring coarse-grained region.

  14. [Variation pattern and its affecting factors of three-dimensional landscape in urban residential community of Shenyang].

    Science.gov (United States)

    Zhang, Pei-Feng; Hu, Yuan-Man; Xiong, Zai-Ping; Liu, Miao

    2011-02-01

    Based on the 1:10000 aerial photo in 1997 and the three QuickBird images in 2002, 2005, and 2008, and by using Barista software and GIS and RS techniques, the three-dimensional information of the residential community in Tiexi District of Shenyang was extracted, and the variation pattern of the three-dimensional landscape in the district during its reconstruction in 1997-2008 and related affecting factors were analyzed with the indices, ie. road density, greening rate, average building height, building height standard deviation, building coverage rate, floor area rate, building shape coefficient, population density, and per capita GDP. The results showed that in 1997-2008, the building area for industry decreased, that for commerce and other public affairs increased, and the area for residents, education, and medical cares basically remained stable. The building number, building coverage rate, and building shape coefficient decreased, while the floor area rate, average building height, height standard deviation, road density, and greening rate increased. Within the limited space of residential community, the containing capacity of population and economic activity increased, and the environment quality also improved to some extent. The variation degree of average building height increased, but the building energy consumption decreased. Population growth and economic development had positive correlations with floor area rate, road density, and greening rate, but negative correlation with building coverage rate. PMID:21608261

  15. Factors affecting spatial variation of annual apparent Q₁₀ of soil respiration in two warm temperate forests.

    Directory of Open Access Journals (Sweden)

    Junwei Luan

    Full Text Available A range of factors has been identified that affect the temperature sensitivity (Q₁₀ values of the soil-to-atmosphere CO₂ flux. However, the factors influencing the spatial distribution of Q₁₀ values within warm temperate forests are poorly understood. In this study, we examined the spatial variation of Q₁₀ values and its controlling factors in both a naturally regenerated oak forest (OF and a pine plantation (PP. Q₁₀ values were determined based on monthly soil respiration (R(S measurements at 35 subplots for each stand from Oct. 2008 to Oct. 2009. Large spatial variation of Q₁₀ values was found in both OF and PP, with their respective ranges from 1.7 to 5.12 and from 2.3 to 6.21. In PP, fine root biomass (FR (R = 0.50, P = 0.002, non-capillary porosity (NCP (R = 0.37, P = 0.03, and the coefficients of variation of soil temperature at 5 cm depth (CV of T₅ (R = -0.43, P = 0.01 well explained the spatial variance of Q₁₀. In OF, carbon pool lability reflected by light fractionation method (LLFOC well explained the spatial variance of Q₁₀ (R = -0.35, P = 0.04. Regardless of forest type, LLFOC and FR correlation with the Q₁₀ values were significant and marginally significant, respectively; suggesting a positive relationship between substrate availability and apparent Q₁₀ values. Parameters related to gas diffusion, such as average soil water content (SWC and NCP, negatively or positively explained the spatial variance of Q₁₀ values. Additionally, we observed significantly higher apparent Q₁₀ values in PP compared to OF, which might be partly attributed to the difference in soil moisture condition and diffusion ability, rather than different substrate availabilities between forests. Our results suggested that both soil chemical and physical characters contributed to the observed large Q₁₀ value variation.

  16. Factors affecting spatial variation of annual apparent Q₁₀ of soil respiration in two warm temperate forests.

    Science.gov (United States)

    Luan, Junwei; Liu, Shirong; Wang, Jingxin; Zhu, Xueling

    2013-01-01

    A range of factors has been identified that affect the temperature sensitivity (Q₁₀ values) of the soil-to-atmosphere CO₂ flux. However, the factors influencing the spatial distribution of Q₁₀ values within warm temperate forests are poorly understood. In this study, we examined the spatial variation of Q₁₀ values and its controlling factors in both a naturally regenerated oak forest (OF) and a pine plantation (PP). Q₁₀ values were determined based on monthly soil respiration (R(S)) measurements at 35 subplots for each stand from Oct. 2008 to Oct. 2009. Large spatial variation of Q₁₀ values was found in both OF and PP, with their respective ranges from 1.7 to 5.12 and from 2.3 to 6.21. In PP, fine root biomass (FR) (R = 0.50, P = 0.002), non-capillary porosity (NCP) (R = 0.37, P = 0.03), and the coefficients of variation of soil temperature at 5 cm depth (CV of T₅) (R = -0.43, P = 0.01) well explained the spatial variance of Q₁₀. In OF, carbon pool lability reflected by light fractionation method (LLFOC ) well explained the spatial variance of Q₁₀ (R = -0.35, P = 0.04). Regardless of forest type, LLFOC and FR correlation with the Q₁₀ values were significant and marginally significant, respectively; suggesting a positive relationship between substrate availability and apparent Q₁₀ values. Parameters related to gas diffusion, such as average soil water content (SWC) and NCP, negatively or positively explained the spatial variance of Q₁₀ values. Additionally, we observed significantly higher apparent Q₁₀ values in PP compared to OF, which might be partly attributed to the difference in soil moisture condition and diffusion ability, rather than different substrate availabilities between forests. Our results suggested that both soil chemical and physical characters contributed to the observed large Q₁₀ value variation. PMID:23717560

  17. Natural Genetic Variation and Candidate Genes for Morphological Traits in Drosophila melanogaster.

    Science.gov (United States)

    Carreira, Valeria Paula; Mensch, Julián; Hasson, Esteban; Fanara, Juan José

    2016-01-01

    Body size is a complex character associated to several fitness related traits that vary within and between species as a consequence of environmental and genetic factors. Latitudinal and altitudinal clines for different morphological traits have been described in several species of Drosophila and previous work identified genomic regions associated with such variation in D. melanogaster. However, the genetic factors that orchestrate morphological variation have been barely studied. Here, our main objective was to investigate genetic variation for different morphological traits associated to the second chromosome in natural populations of D. melanogaster along latitudinal and altitudinal gradients in Argentina. Our results revealed weak clinal signals and a strong population effect on morphological variation. Moreover, most pairwise comparisons between populations were significant. Our study also showed important within-population genetic variation, which must be associated to the second chromosome, as the lines are otherwise genetically identical. Next, we examined the contribution of different candidate genes to natural variation for these traits. We performed quantitative complementation tests using a battery of lines bearing mutated alleles at candidate genes located in the second chromosome and six second chromosome substitution lines derived from natural populations which exhibited divergent phenotypes. Results of complementation tests revealed that natural variation at all candidate genes studied, invected, Fasciclin 3, toucan, Reticulon-like1, jing and CG14478, affects the studied characters, suggesting that they are Quantitative Trait Genes for morphological traits. Finally, the phenotypic patterns observed suggest that different alleles of each gene might contribute to natural variation for morphological traits. However, non-additive effects cannot be ruled out, as wild-derived strains differ at myriads of second chromosome loci that may interact

  18. Biochemical systematics of the leaf mining moth family Nepticulidae (Lepidoptera). III. Allozyme variation patterns in the Ectoedemia subbimaculella group

    OpenAIRE

    Steph B J Menken

    1990-01-01

    Gel electrophoretic techniques were used to analyse patterns of variation at 12 genetic loci within and among species of the Ectoedemia subbimaculella group from western Europe. Geographically separated conspecific populations were similar to one another genetically, with the exception of E. subbimaculella where the malate dehydrogenase locus exhibited clinal variation. Genetic differences among species often concerned loci that were monomorphic or slightly polymorphic within populations. Thr...

  19. Simulation study for lifetime distribution of middle-of-line time-dependent dielectric breakdown affected by global and local spacing variations

    Science.gov (United States)

    Yokogawa, Shinji

    2016-06-01

    The impact of process fluctuations for the lifetime distribution of middle-of-line time-dependent dielectric breakdown was investigated by Monte-Carlo simulation. Global and local variations were simulated using a doubly truncated normal distribution. A goodness of fit to the generated data was determined statistically in terms of the Weibull distribution and clustering model. A change in the standard deviation of the global variation shows a large contribution to lifetime variation. However, it does not affect the average lifetime. A change in the standard deviation of the local variation contributes to both the average lifetime and the distribution variation. The upper limit of the process variation induces the convex upward shape of the lifetime distribution on the Weibull plot. The clustering model well explains the distribution shape.

  20. Variations in Concentration and Distribution of Health-Related Elements Affected by Environmental and Genotypic Differences in Rice Grains

    Institute of Scientific and Technical Information of China (English)

    REN Xue-liang; LIU Qing-long; WU Dian-xing; SHU Qing-yao

    2006-01-01

    A research work was conducted to investigate the variations in concentration and distribution of health-related elements affected by environmental and genotypic differences in rice grains. The grain of Xieqingzao B (indica rice variety) and Xiushui 110 (japonica rice variety) were divided into: hull, bran and milled rice, based on the conventional rice consumption and process. Xieqingzao B was grown at four different locations, and at one location, it was planted in the same field and season as Xiushui 110. In addition, another four indica and four japonica varieties were cultivated in the same field and time to analyze the elements in milled rice. The average concentrations of total P and phytic acid P were the highest in the bran, followed by milled rice and hull; Zn, K, Mg, and As concentrations were the highest in bran, followed by hull and milled rice, while Fe, Ca, and Cu concentrations were the highest in the hull, but similar in bran and milled rice. The result indicated that genotype and environment significantly affected the concentrations of all the tested elements, while the distribution of the above elements in grains was not in the same order as concentration. Moreover, all the elements except 97.7% of Cu and 93.2% of Fe was deposited in the hull on average, were mostly distributed either in the bran (37.3% and 57.7% for K and phytic acid P) or in milled rice (41.7%, 42.6%, 40.3%, 49.8% for Zn, Mg, As, total P, respectively).

  1. [Spatiotemporal variation characteristics and related affecting factors of actual evapotranspiration in the Hun-Taizi River Basin, Northeast China].

    Science.gov (United States)

    Feng, Xue; Cai, Yan-Cong; Guan, De-Xin; Jin, Chang-Jie; Wang, An-Zhi; Wu, Jia-Bing; Yuan, Feng-Hui

    2014-10-01

    Based on the meteorological and hydrological data from 1970 to 2006, the advection-aridity (AA) model with calibrated parameters was used to calculate evapotranspiration in the Hun-Taizi River Basin in Northeast China. The original parameter of the AA model was tuned according to the water balance method and then four subbasins were selected to validate. Spatiotemporal variation characteristics of evapotranspiration and related affecting factors were analyzed using the methods of linear trend analysis, moving average, kriging interpolation and sensitivity analysis. The results showed that the empirical parameter value of 0.75 of AA model was suitable for the Hun-Taizi River Basin with an error of 11.4%. In the Hun-Taizi River Basin, the average annual actual evapotranspiration was 347.4 mm, which had a slightly upward trend with a rate of 1.58 mm · (10 a(-1)), but did not change significantly. It also indicated that the annual actual evapotranspiration presented a single-peaked pattern and its peak value occurred in July; the evapotranspiration in summer was higher than in spring and autumn, and it was the smallest in winter. The annual average evapotranspiration showed a decreasing trend from the northwest to the southeast in the Hun-Taizi River Basin from 1970 to 2006 with minor differences. Net radiation was largely responsible for the change of actual evapotranspiration in the Hun-Taizi River Basin. PMID:25796880

  2. RNA Sequencing Analysis Reveals Transcriptomic Variations in Tobacco (Nicotiana tabacum Leaves Affected by Climate, Soil, and Tillage Factors

    Directory of Open Access Journals (Sweden)

    Bo Lei

    2014-04-01

    Full Text Available The growth and development of plants are sensitive to their surroundings. Although numerous studies have analyzed plant transcriptomic variation, few have quantified the effect of combinations of factors or identified factor-specific effects. In this study, we performed RNA sequencing (RNA-seq analysis on tobacco leaves derived from 10 treatment combinations of three groups of ecological factors, i.e., climate factors (CFs, soil factors (SFs, and tillage factors (TFs. We detected 4980, 2916, and 1605 differentially expressed genes (DEGs that were affected by CFs, SFs, and TFs, which included 2703, 768, and 507 specific and 703 common DEGs (simultaneously regulated by CFs, SFs, and TFs, respectively. GO and KEGG enrichment analyses showed that genes involved in abiotic stress responses and secondary metabolic pathways were overrepresented in the common and CF-specific DEGs. In addition, we noted enrichment in CF-specific DEGs related to the circadian rhythm, SF-specific DEGs involved in mineral nutrient absorption and transport, and SF- and TF-specific DEGs associated with photosynthesis. Based on these results, we propose a model that explains how plants adapt to various ecological factors at the transcriptomic level. Additionally, the identified DEGs lay the foundation for future investigations of stress resistance, circadian rhythm and photosynthesis in tobacco.

  3. Clinal patterns of desiccation and starvation resistance in ancestral and invading populations of Drosophila subobscura

    OpenAIRE

    Gilchrist, George W; Jeffers, Lisa M; West, Brianna; Folk, Donna G; Suess, Jeremy; Huey, Raymond B.

    2008-01-01

    As invading species expand, they eventually encounter physical and biotic stressors that limit their spread. We examine latitudinal and climatic variation in physiological tolerance in one native and two invading populations of Drosophila subobscura. These flies are native to the Palearctic region, but invaded both South and North America around 1980 and spread rapidly across 15° of latitude on each continent. Invading flies rapidly evolved latitudinal clines in chromosome inversion frequenci...

  4. Clinal differentiation during invasion: Senecio inaequidens (Asteraceae) along altitudinal gradients in Europe

    OpenAIRE

    Monty, Arnaud; Mahy, Grégory

    2009-01-01

    Plant population differentiation may play a role in decreasing the ability to predict whether, where, and when an introduced species will invade. However, few studies have addressed the level of genetic change an alien species may undergo during range expansion, e.g. in response to climatic variation with altitude. In the present study, we tested the hypothesis that invasive populations of Senecio inaequidens (Asteraceae) differentiated during migration from two independent introduction sites...

  5. Diferenciação clinal e correlação do polimorfismo cromossómico e tamanho do corpo em Drosophila subobscura

    OpenAIRE

    Lima, Margarida Rocha de, 1983-

    2011-01-01

    Tese de mestrado. Biologia (Biologia Evolutiva e do Desenvolvimento). Universidade de Lisboa, Faculdade de Ciências, 2011 A variação clinal permite a identificação de características e genes associados a condições ambientais, despertando um grande interesse ao nível da Biologia Evolutiva e da Conservação. A Drosophila subobscura apresenta um cline latitudinal quer no tamanho do corpo, quer no polimorfismo cromossómico no continente europeu. Mais recentemente, apresentou novamente esta vari...

  6. Rapid differentiation of sexual signals in invasive toads: call variation among populations.

    Science.gov (United States)

    Yasumiba, Kiyomi; Duffy, Richard L; Parsons, Scott A; Alford, Ross A; Schwarzkopf, Lin

    2016-01-01

    Advertisement calls tend to differ among populations, based on morphological and environmental factors, or simply geographic distance, in many taxa. Invasive cane toads (Rhinella marina) were introduced to Australia in 1935 and their distribution has expanded at increasing rates over time. Rapid evolution occurred in morphological and behavioural characters that accelerate dispersal, but the effects of rapid expansion on sexual signals have not been examined. We collected advertisement calls from four populations of different ages since invasion, and analysed the geographic differentiation of seven call parameters. Our comparisons indicate that the calls of R. marina differ among Australian populations. The signal variation was not simply clinal with respect to population age, climate, or morphological differentiation. We suggest that selection on signalling among populations has been idiosyncratic and may reflect local female preferences or adaptation to environmental factors that are not clinal such as energy availability. PMID:27328666

  7. Variations in heavy metal contamination of stream water and groundwater affected by an abandoned lead-zinc mine in Korea.

    Science.gov (United States)

    Lee, Jin-Yong; Choi, Jung-Chan; Lee, Kang-Kun

    2005-09-01

    This study evaluated variations in heavy metal contamination of stream waters and groundwaters affected by an abandoned lead-zinc mine, where a rockfill dam for water storage will be built 11 km downstream. For these purposes, a total of 10 rounds of stream and groundwater samplings and subsequent chemical analyses were performed during 2002-2003. Results of an exploratory investigation of stream waters in 2000 indicated substantial contamination with heavy metals including zinc (Zn), iron (Fe) and arsenic (As) for at least 6 km downstream from the mine. Stream waters near the mine showed metal contamination as high as arsenic (As) 8,923 microg L(-1), copper (Cu) 616 microg L(-1), cadmium (Cd) 223 microg L(-1) and lead (Pb) 10,590 microg L(-1), which greatly exceeded the Korean stream water guidelines. Remediation focused on the mine tailing piles largely improved the stream water qualities. However, there have still been quality problems for the waters containing relatively high concentrations of As (6-174 microg L(-1)), Cd (1-46 microg L(-1)) and Pb (2-26 microg L(-1)). Rainfall infiltration into the mine tailing piles resulted in an increase of heavy metals in the stream waters due to direct discharge of waste effluent, while dilution of the contaminated stream waters improved the water quality due to mixing with metal free rain waters. Levels of As, Cu and chromium (Cr) largely decreased after heavy rain but that of Pb was rather elevated. The stream waters were characterized by high concentrations of calcium (Ca) and sulfate (SO(4)), which were derived from dissolution and leaching of carbonate and sulfide minerals. It was observed that the proportions of Ca and SO(4) increased while those of bicarbonate (HCO(3)) and sodium and potassium (Na+K) decreased after a light rainfall event. Most interestingly, the reverse was generally detected for the groundwaters. The zinc, being the metal mined, was the most dominant heavy metal in the groundwaters (1758

  8. Seasonal water quality variations in a river affected by acid mine drainage: the Odiel River (South West Spain)

    International Nuclear Information System (INIS)

    This paper intends to analyse seasonal variations of the quality of the water of the Odiel River. This river, together with the Tinto River, drains the Iberian Pyrite Belt (IPB), a region containing an abundance of massive sulphide deposits. Because of mining activity dating back to prehistoric times, these two rivers are heavily contaminated. The Odiel and Tinto Rivers drain into a shared estuary known as the Ria of Huelva. This work studies dissolved contaminant data in water of the Odiel River collected by various organisations, between October 1980 and October 2002, close to the rivers entry into the estuary. Flow data for this location were also obtained. The most abundant metals in the water, in order of abundance, are zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu). Arsenic (As), cadmium (Cd) and lead (Pb) are also present but in much lower quantities. The quality of the river water is linked to precipitation; the maximum sulphate, Fe, Zn, Mn, Cd and Pb concentrations occur during the autumn rains, which dissolve the Fe hydroxysulphates that were precipitated during the summer months. In winter, the intense rains cause an increase in the river flow, producing a dilution of the contaminants and a slight increase in the pH. During spring and summer, the sulphate and metal concentration (except Fe) recover and once again increase. The Fe concentration pattern displays a low value during summer due to increased precipitation of ferric oxyhydroxides. The arsenic concentration displays a different evolution, with maximum values in winter, and minimum in spring and summer as they are strongly adsorbed and/or coprecipitated by the ferric oxyhydroxides. Mn and sulphates are the most conservative species in the water. Relative to sulphate, Mn, Zn and Cd, copper displays greater values in winter and lower ones in summer, probably due to its coprecipitation with hydroxysulphates during the spring and summer months. Cd and Zn also appear to be affected by the same

  9. Seasonal variation in affective and other clinical symptoms among high-risk families for bipolar disorders in an Arctic population

    OpenAIRE

    Pirkola, Sami; Eriksen, Heidi A.; Partonen, Timo; Kieseppä, Tuula; Veijola, Juha; Jääskeläinen, Erika; Mylläri-Figuerola, Eeva-Maija; Salo, Paula M.; Paunio, Tiina

    2015-01-01

    Background. In bipolar disorder (BD), seasonality of symptoms is common and disturbances in circadian rhythms have been reported.Objectives. We identified high-penetrance families in a geographically restricted area in Northern Fennoscandia and studied the seasonal variation of clinical symptoms among BD subjects and their healthy relatives.Design. We explored the clinical characteristics of subjects living in Northern Fennoscandia, with extreme annual variation in daylight. Among known indig...

  10. Does Intraspecific Size Variation in a Predator Affect Its Diet Diversity and Top-Down Control of Prey?

    OpenAIRE

    Travis Ingram; Stutz, William E.; Bolnick, Daniel I.

    2011-01-01

    It has long been known that intraspecific variation impacts evolutionary processes, but only recently have its potential ecological effects received much attention. Theoretical models predict that genetic or phenotypic variance within species can alter interspecific interactions, and experiments have shown that genotypic diversity in clonal species can impact a wide range of ecological processes. To extend these studies to quantitative trait variation within populations, we experimentally man...

  11. Does intraspecific size variation in a predator affect its diet diversity and top-down control of prey?

    Directory of Open Access Journals (Sweden)

    Travis Ingram

    Full Text Available It has long been known that intraspecific variation impacts evolutionary processes, but only recently have its potential ecological effects received much attention. Theoretical models predict that genetic or phenotypic variance within species can alter interspecific interactions, and experiments have shown that genotypic diversity in clonal species can impact a wide range of ecological processes. To extend these studies to quantitative trait variation within populations, we experimentally manipulated the variance in body size of threespine stickleback in enclosures in a natural lake environment. We found that body size of stickleback in the lake is correlated with prey size and (to a lesser extent composition, and that stickleback can exert top-down control on their benthic prey in enclosures. However, a six-fold contrast in body size variance had no effect on the degree of diet variation among individuals, or on the abundance or composition of benthic or pelagic prey. Interestingly, post-hoc analyses revealed suggestive correlations between the degree of diet variation and the strength of top-down control by stickleback. Our negative results indicate that, unless the correlation between morphology and diet is very strong, ecological variation among individuals may be largely decoupled from morphological variance. Consequently we should be cautious in our interpretation both of theoretical models that assume perfect correlations between morphology and diet, and of empirical studies that use morphological variation as a proxy for resource use diversity.

  12. Variation in Cavolinia inflexa (Lesueur, 1813) (Gastropoda: Pteropoda: Euthecosomata)

    OpenAIRE

    Spoel, van der, S.; Pierrot-Bults, A.C.

    1998-01-01

    Cavolinia inflexa (Lesueur, 1813) proves not to be composed of subspecies or formae, or to show clinal variation. Maximum shell length varies between 4 and 7 mm, shell width between 2 and 4 mm, length/width ratio between 0.51 and 0.81. A geographic pattern in the occurrence of different length/width ratios, on which the subdivision of this species was always based in literature, could not be found. Frequency analyses of length for all samples combined did not show subdivision in local populat...

  13. The role of awakening cortisol and psychological distress in diurnal variations in affect : a day reconstruction study

    OpenAIRE

    Daly, Michael; Delaney, Liam; Doran, Peter; MacLachlan, Malcolm

    2010-01-01

    People often feel unhappy in the morning but better later in the day, and this pattern may be amplified in the distressed. Past work suggests that one function of cortisol is to energize people in the mornings. In a study of 174 students we tested to see if daily affect patterns, psychological distress, and awakening cortisol levels were interlinked. Affect levels were assessed using the Day Reconstruction Method (Kahneman, Krueger, Schkade, Schwarz, & Stone, 2004) and psychological distress ...

  14. D-amino acid oxidase activator gene (DAOA) variation affects cerebrospinal fluid homovanillic acid concentrations in healthy Caucasians

    DEFF Research Database (Denmark)

    Andreou, Dimitrios; Saetre, Peter; Werge, Thomas;

    2012-01-01

    The D-amino acid oxidase activator (DAOA) protein regulates the function of D-amino oxidase (DAO), an enzyme that catalyzes the oxidative deamination of D-3,4-dihydroxyphenylalanine (D-DOPA) and D-serine. D-DOPA is converted to L-3,4-DOPA, a precursor of dopamine, whereas D-serine participates in...... dopamine turnover in healthy individuals, suggesting that disturbed dopamine turnover is a possible mechanism behind the observed associations between genetic variation in DAOA and behavioral phenotypes in humans....

  15. Genetic adaptation of the human circadian clock to day-length latitudinal variations and relevance for affective disorders

    OpenAIRE

    De Forni, D; Pozzoli, U; R. Cagliani; C. Tresoldi; G. Menozzi; Riva, S; F. Guerini; Comi, G; Bolognesi, E; Bresolin, N.; Clerici, M.; Sironi, M.

    2014-01-01

    Background The temporal coordination of biological processes into daily cycles is a common feature of most living organisms. In humans, disruption of circadian rhythms is commonly observed in psychiatric diseases, including schizophrenia, bipolar disorder, depression and autism. Light therapy is the most effective treatment for seasonal affective disorder and circadian-related treatments sustain antidepressant response in bipolar disorder patients. Day/night cycles represent a major circadian...

  16. The properties of NodD were affected by mere variation in length within its hinge region

    Institute of Scientific and Technical Information of China (English)

    Bihe Hou; Fengqing Li; Xiaoer Yang; Cruofan Hong

    2009-01-01

    In Rhizobium leguminosarum by. viciae, NodD, a member of the LysR-type transcriptional regulators, while auto-regulating, activates transcription of other nod genes in the presence of naringenin. A hinge region of NodD was previously identified in our lab-oratory as a functional region independent of its N-terminal DNA-binding and C-terminal regulatory domain. Further study was carried out to see the possible effect of the length variation in the hinge region on NodD's properties. To our surprise, as many as seven classes of phenotypes were observed. Class Ⅰ is deficient of activating nodA transcription and abolishes auto-regulation; class Ⅱ is able to acti-vate nodA transcription independently of naringenin and abolishes auto-regulation; class Ⅲ retains auto-regulating but partial activating ability; class Ⅳ is able to activate transcription independently of narin-genin and retains auto-regulation; in class Ⅴ, nod A is transcribed constitutively but the transcription level is drastically down-regulated in the presence of narin-genin; in class Ⅵ, nodA is transcribed constitutively with higher induction ratio; in class Ⅶ, nodA is tran-scribed constitutively with lower induction ratio. To learn more about the possible mechanism, circular permutation assays were done, which showed that the length variation of the hinge of NodD caused by mutation led to the change in bend angles of nod pro-moter. This finding should help to get an insight into how transcriptional regulation is mediated by NodD at the molecular level as well as to understand the regulatory system of this important family.

  17. Assessment of factors that may affect the moisture- and temperature variations in the concrete structures inside nuclear reactor containments

    International Nuclear Information System (INIS)

    Three factors that may affect the climatic conditions inside Swedish nuclear reactor containments are the outdoor climate, the cooling water temperature and the operational state of the reactor. Those factors that have a considerable affect on the climatic conditions will be identified through comparisons to actual conditions during operation inside reactor containments. Knowledge about the impact of the factors on the climatic conditions is essential when developing a model to determine the prevailing and to predict future conditions in the concrete structures. The comparison between a Pressurized Water Reactor and a Boiling Water Reactor showed that there is no clear similarity, with regard to fluctuation of the indoor climate conditions, between the two reactor types. The indoor climate at a Pressurized Water Reactor seemed not to be affected of changes in the operational state, but it follows the fluctuations of the outdoor temperature and to some extent the water temperature. The Boiling water Reactor did not follow the water or outdoor temperature fluctuations. However, at a full power outage during a short period of time during the operational year the temperature drastically decreased. An operational year of a Boiling water reactor can be divided into three periods, where the first represents the yearly power outage, the second represents the autumn-winter-spring period and the third represents the summer period. The operational year of a pressurized water reactor can't easily be divided into stable periods, since the indoor temperature fluctuation follows the outdoor temperature fluctuation. Based on these measurements a simplified model which includes outer factors is possible for a BWR but more difficult for a PWR. (authors)

  18. Seasonal Variations Affect the Physicochemical Composition of Bufallo Milk and Artisanal Cheeses Produced in Marajó Island (Pa, Brazil

    Directory of Open Access Journals (Sweden)

    M.G., Simões

    2014-01-01

    Full Text Available This research was carried out to evaluate the influence of seasonal variation in physicochemical composition and microbiological profile of buffalo milk and of the artisanal cream and butter types cheeses produced on Marajó Island. Eighteen farms located of the island were involved in the study. Milk and cheese quality were evaluated in two typical seasons. The rainy, from January to June and dry, from July to December. Samples were submitted to a detailed set of laboratorial analyses. Physicochemical composition of buffalo milk was influenced by the seasons. Compared to rainy, the dry period showed an increase in fat (5.53±0.71 to 6.74±1.19 and lactose (4.77±0.20 to 5.20±0.20 concentrations and reduction in total solids (16.89±0.92 to 15.77±1.54, nonfat dry matter (9.94±0.36 to 8.99±1.23 and minerals (0.84±0.12 to 0.62±0.09 concentrations (p<0.05. The season influence was observed in physicochemical composition of both cheese-types. Compared to rainy season, in the cream cheese type, higher values (p<0.05 were found for titratable acidity (0.63±0.02 to 0.78±0.15, fat (32.38±3.22 to 36.89±4.59, fat in the dry matter (55.06±3.26 to 63.92±2.49 but lower values for water activity (0.99±0.02 to 0.49±0.03, minerals (2.37±0.55 to 1.40±0.02 and calcium (0.28±0.08 to 0.18±0.07. For the butter cheese type, in the dry season, higher values were found only for titratable acidity (0.49±0.02 to 0.38±0.0 and lower values for water activity (0.18±0.07 to 0.45±0.08. The study have shown that some components of the buffalo milk and artisanal cheeses produced on Marajó Island are influenced by the dry and rainy typical seasons and therefore, some sensory variations are expected around the year.

  19. Daytime variation in ambient temperature affects skin temperatures and blood pressure: Ambulatory winter/summer comparison in healthy young women.

    Science.gov (United States)

    Martinez-Nicolas, Antonio; Meyer, Martin; Hunkler, Stefan; Madrid, Juan Antonio; Rol, Maria Angeles; Meyer, Andrea H; Schötzau, Andy; Orgül, Selim; Kräuchi, Kurt

    2015-10-01

    It is widely accepted that cold exposure increases peripheral vascular resistance and arterial blood pressure (BP) and, hence, increases cardiovascular risk primarily in the elderly. However, there is a lack of concomitantly longitudinal recordings at personal level of environmental temperature (PET) and cardiophysiological variables together with skin temperatures (STs, the “interface-variable” between the body core and ambient temperature). To investigate the intra-individual temporal relationships between PET, STs and BP 60 healthy young women (52 completed the entire study) were prospectively studied in a winter/summer design for 26 h under real life conditions. The main hypothesis was tested whether distal ST (Tdist)mediates the effect of PET-changes on mean arterial BP (MAP). Diurnal profiles of cardiophysiological variables (including BP), STs and PET were ambulatory recorded. Daytime variations between 0930 and 2030 h were analyzed in detail by intra-individual longitudinal path analysis. Additionally, time segments before, during and after outdoor exposure were separately analyzed. In both seasons short-term variations in PET were positively associated with short-term changes in Tdist (not proximal ST, Tprox) and negatively with those in MAP. However, long-term seasonal differences in daytime mean levels were observed in STs but not in BP leading to non-significant inter-individual correlation between STs and BP. Additionally, higher individual body mass index (BMI) was significantly associated with lower daytime mean levels of Tprox and higher MAP suggesting Tprox as potential mediator variable for the association of BMI with MAP. In healthy young women the thermoregulatory and BP-regulatory systems are closely linked with respect to short-term, but not long-term changes in PET. One hypothetical explanation could serve recent findings that thermogenesis in brown adipose tissue is activated in a cool environment, which could be responsible for the

  20. Temporally resolved intra-annual wood density variations in European beech (Fagus sylvatica L. as affected by climate and aspect

    Directory of Open Access Journals (Sweden)

    Ernst van der Maaten

    2012-05-01

    Full Text Available We investigated the temporal variability of intra-annual wood density variations in European beech (Fagus sylvatica L. in a valley in southwestern Germany. Samples were collected from 11 beech trees growing at north-west (NW and south-west (SW exposed slopes. High-frequency densitometry was used to obtain wood density profiles. We converted radial positions within these profiles to a seasonal time scale over automatic point dendrometer data for the period 2001–2006. Temporally resolved wood density data was analyzed both visually and statistically, using correlation analysis and multiple linear regressions. Water availability was found to be of major importance for wood formation. Further, our results suggest that climatic forcing of wood density is not necessarily restricted to the late growing season only, but that strong associations may exist during a major part of the growing season. Combining wood property data with point dendrometer measurements was demonstrated to be valuable for increasing the understanding on the effects of changing environmental conditions on wood formation

  1. Temporally resolved intra-annual wood density variations in European beech (Fagus sylvatica L. as affected by climate and aspect

    Directory of Open Access Journals (Sweden)

    Ernst van der Maaten

    2012-06-01

    Full Text Available We investigated the temporal variability of intra-annual wood density variations in European beech (Fagus sylvatica L. in a valley in southwestern Germany. Samples were collected from 11 beech trees growing at north-west (NW and south-west (SW exposed slopes. High-frequency densitometry was used to obtain wood density profiles. We converted radial positions within these profiles to a seasonal time scale over automatic point dendrometer data for the period 2001-2006. Temporally resolved wood density data was analyzed both visually and statistically, using correlation analysis and multiple linear regressions. Water availability was found to be of major importance for wood formation. Further, our results suggest that climatic forcing of wood density is not necessarily restricted to the late growing season only, but that strong associations may exist during a major part of the growing season. Combining wood property data with point dendrometer measurements was demonstrated to be valuable for increasing the understanding on the effects of changing environmental conditions on wood formation.

  2. Identification of toxicity variations in a stream affected by industrial effluents using Daphnia magna and Ulva pertusa.

    Science.gov (United States)

    Yoo, Jisu; Ahn, Byeongyong; Oh, Jeong-Ju; Han, Taejun; Kim, Woo-Keun; Kim, Sanghoon; Jung, Jinho

    2013-09-15

    A comprehensive toxicity monitoring study from August to October 2011 using Daphnia magna and Ulva pertusa was conducted to identify the cause of toxicity in a stream receiving industrial effluents (IEs) from a textile and leather products manufacturing complex. Acute toxicity toward both species was observed consistently in IE, which influenced toxicity of downstream (DS) water. A toxicity identification evaluation (TIE) confirmed that both Cu and Zn were key toxicants in the IE, and that the calculated toxicity based on Cu and Zn concentrations well simulated the variation in the observed toxicity (r(2)=0.9216 and 0.7256 for D. magna and U. pertusa, respectively). In particular, U. pertusa was sensitive enough to detect acute toxicity in DS and was useful to identify Zn as a key toxicant. Activities of catalase, superoxide dismutase, glutathione peroxidase, glutathione S-transferase, and malondialdehyde were induced significantly in D. magna, although acute toxicity was not observed. In addition, higher levels of antioxidant enzymes were expressed in DS than upstream waters, likely due to the Cu and Zn from IE. Overall, TIE procedures with a battery of bioassays were effective for identifying the cause of lethal and sub-lethal toxicity in effluent and stream water. PMID:23892313

  3. Distinguishing disease effects from environmental effects in a mountain ungulate: seasonal variation in body weight, hematology, and serum chemistry among Iberian ibex (Capra pyrenaica) affected by sarcoptic mange.

    Science.gov (United States)

    Pérez, Jesús M; Serrano, Emmanuel; Soriguer, Ramón C; González, Francisco J; Sarasa, Mathieu; Granados, José E; Cano-Manuel, Francisco J; Cuenca, Rafaela; Fandos, Paulino

    2015-01-01

    Our study focuses on the Iberian ibex (Capra pyrenaica) from the Sierra Nevada Natural Space (southern Spain), where sarcoptic mange is an endemic disease and animals are affected by a highly seasonal environment. Our aim was to distinguish between disease and environmental influences on seasonal variation in body weight, hematology, and serum biochemistry in Iberian ibex. We sampled 136 chemically immobilized male ibexes. The single effect of mange influenced hemoglobin, hematocrit, mean corpuscular volume, leukocytes, band neutrophils, monocytes, cholesterol, urea, creatine, and aspartate aminotransferase. Both mange and the period of the year also affected values of mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, neutrophils, glucose, and serum proteins. Scabietic animals showed a marked reduction in body weight (21.4 kg on average), which was more pronounced in winter. These results reveal that 1) infested animals are anemic, 2) secondary infections likely occur, and 3) sarcoptic mange is catabolic. PMID:25380360

  4. A 'cost-effective' probabilistic model to select the dominant factors affecting the variation of the component failure rate

    International Nuclear Information System (INIS)

    Within the framework of a Probabilistic Safety Assessment (PSA), the component failure rate λ is a key parameter in the sense that the study of its behavior gives the essential information for estimating the current values as well as the trends in the failure probabilities of interest. Since there is an infinite variety of possible underlying factors which might cause changes in λ (e.g. operating time, maintenance practices, component environment, etc.), an 'importance ranking' process of these factors is considered most desirable to prioritize research efforts. To be 'cost-effective', the modeling effort must be small, i.e. essentially involving no estimation of additional parameters other than λ. In this paper, using a multivariate data analysis technique and various statistical measures, such a 'cost-effective' screening process has been developed. Dominant factors affecting the failure rate of any components of interest can easily be identified and the appropriateness of current research plans (e.g. on the necessity of performing aging studies) can be validated. (author)

  5. Utilizing an early childhood science curriculum: Factors influencing implementation and how variations affect students' skills and attitudes

    Science.gov (United States)

    Shamas-Brandt, Ellen

    Early childhood is a ripe time for students to begin learning science, but due to certain constraints, this instruction is not happening as frequently as it should. This mixed-methods, multiple case study examined how two teachers implemented an early childhood science curriculum, the Young Scientist Series. The teacher participants were two early childhood teachers, and student participants were three groups of 4 to 6-year-olds they taught for eight weeks. The study investigated how the teachers' pedagogical decisions affected their students' process skills acquisition and attitudes toward science. It specifically examined how the teachers made choices about what to include, change, omit, and add to the lessons. It also analyzed the levels of inquiry present in the lessons (structured, guided, or open). Quantitative data were collected from the teachers through questionnaires, checklists, and observations, and qualitative data were gathered through interviews. Student data were quantitative. Their science process skills and attitudes towards science were assessed with two age-appropriate instruments, the Science Learning Assessment and the Puppet Interview Scale for Competence in and Enjoyment of Science. Findings showed that the students of the teacher who followed the curriculum more closely and employed more structured inquiry did not grow in their process skills, and their attitudes followed a normal distribution. The students of the teacher who followed the curriculum more leniently and employed more guided inquiry grew in their process skills in significant ways. Their attitudes followed a negatively skewed distribution, reflecting that a majority of the students scored very highly on the attitude assessment.

  6. Gene regulatory variation mediates flowering responses to vernalization along an altitudinal gradient in Arabidopsis.

    Science.gov (United States)

    Suter, Léonie; Rüegg, Marlene; Zemp, Niklaus; Hennig, Lars; Widmer, Alex

    2014-12-01

    Steep environmental gradients provide ideal settings for studies of potentially adaptive phenotypic and genetic variation in plants. The accurate timing of flowering is crucial for reproductive success and is regulated by several pathways, including the vernalization pathway. Among the numerous genes known to enable flowering in response to vernalization, the most prominent is FLOWERING LOCUS C (FLC). FLC and other genes of the vernalization pathway vary extensively among natural populations and are thus candidates for the adaptation of flowering time to environmental gradients such as altitude. We used 15 natural Arabidopsis (Arabidopsis thaliana) genotypes originating from an altitudinal gradient (800-2,700 m above sea level) in the Swiss Alps to test whether flowering time correlated with altitude under different vernalization scenarios. Additionally, we measured the expression of 12 genes of the vernalization pathway and its downstream targets. Flowering time correlated with altitude in a nonlinear manner for vernalized plants. Flowering time could be explained by the expression and regulation of the vernalization pathway, most notably by AGAMOUS LIKE19 (AGL19), FLOWERING LOCUS T (FT), and FLC. The expression of AGL19, FT, and VERNALIZATION INSENSITIVE3 was associated with altitude, and the regulation of MADS AFFECTING FLOWERING2 (MAF2) and MAF3 differed between low- and high-altitude genotypes. In conclusion, we found clinal variation across an altitudinal gradient both in flowering time and the expression and regulation of genes in the flowering time control network, often independent of FLC, suggesting that the timing of flowering may contribute to altitudinal adaptation. PMID:25339407

  7. Nature clinale de la fréquence des ovarioles et des spermathèques observée chez les ouvrières de l'abeille du Cap, Apis mellifera capensis

    OpenAIRE

    Phiancharoen, Mananya; Christian W W Pirk; Radloff, Sarah E.; Hepburn, Randall

    2010-01-01

    International audience It was determined that 300 Cape workers, Apis mellifera capensis (collected from each of 6 colonies at each of 5 localities about 200 km apart along an 800 km transect in the Western and Eastern Cape Provinces, South Africa) was the sample size required to statistically estimate the proportions of workers with spermathecae at each location at 95% confidence levels. Because of the extremely clinal nature of this honeybee population, we tested the hypotheses that (1) o...

  8. Allelic variation of the Tas1r3 taste receptor gene selectively affects taste responses to sweeteners: evidence from 129.B6-Tas1r3 congenic mice.

    Science.gov (United States)

    Inoue, Masashi; Glendinning, John I; Theodorides, Maria L; Harkness, Sarah; Li, Xia; Bosak, Natalia; Beauchamp, Gary K; Bachmanov, Alexander A

    2007-12-19

    The Tas1r3 gene encodes the T1R3 receptor protein, which is involved in sweet taste transduction. To characterize ligand specificity of the T1R3 receptor and the genetic architecture of sweet taste responsiveness, we analyzed taste responses of 129.B6-Tas1r3 congenic mice to a variety of chemically diverse sweeteners and glucose polymers with three different measures: consumption in 48-h two-bottle preference tests, initial licking responses, and responses of the chorda tympani nerve. The results were generally consistent across the three measures. Allelic variation of the Tas1r3 gene influenced taste responsiveness to nonnutritive sweeteners (saccharin, acesulfame-K, sucralose, SC-45647), sugars (sucrose, maltose, glucose, fructose), sugar alcohols (erythritol, sorbitol), and some amino acids (D-tryptophan, D-phenylalanine, L-proline). Tas1r3 genotype did not affect taste responses to several sweet-tasting amino acids (L-glutamine, L-threonine, L-alanine, glycine), glucose polymers (Polycose, maltooligosaccharide), and nonsweet NaCl, HCl, quinine, monosodium glutamate, and inosine 5'-monophosphate. Thus Tas1r3 polymorphisms affect taste responses to many nutritive and nonnutritive sweeteners (all of which must interact with a taste receptor involving T1R3), but not to all carbohydrates and amino acids. In addition, we found that the genetic architecture of sweet taste responsiveness changes depending on the measure of taste response and the intensity of the sweet taste stimulus. Variation in the T1R3 receptor influenced peripheral taste responsiveness over a wide range of sweetener concentrations, but behavioral responses to higher concentrations of some sweeteners increasingly depended on mechanisms that could override input from the peripheral taste system. PMID:17911381

  9. The Sampling Scheme Matters: Pan troglodytes troglodytes and P. t. schweinfurthii Are Characterized by Clinal Genetic Variation Rather Than a Strong Subspecies Break

    OpenAIRE

    FÜNFSTÜCK, TILLMANN; Arandjelovic, Mimi; MORGAN, DAVID B.; Sanz, Crickette; Reed, Patricia; Olson, Sarah H.; CAMERON, KEN; Ondzie, Alain; Peeters, Martine; Vigilant, Linda

    2014-01-01

    Populations of an organism living in marked geographical or evolutionary isolation from other populations of the same species are often termed subspecies and expected to show some degree of genetic distinctiveness. The common chimpanzee (Pan troglodytes) is currently described as four geographically delimited subspecies: the western (P. t. verus), the nigerian-cameroonian (P. t. ellioti), the central (P. t. troglodytes) and the eastern (P. t. schweinfurthii) chimpanzees. Although these taxa w...

  10. Detection of genetic variation affecting milk coagulation properties in Danish Holstein dairy cattle by analyses of pooled whole-genome sequences from phenotypically extreme samples (pool-seq).

    Science.gov (United States)

    Bertelsen, H P; Gregersen, V R; Poulsen, N; Nielsen, R O; Das, A; Madsen, L B; Buitenhuis, A J; Holm, L-E; Panitz, F; Larsen, L B; Bendixen, C

    2016-04-01

    Rennet-induced milk coagulation is an important trait for cheese production. Recent studies have reported an alarming frequency of cows producing poorly coagulating milk unsuitable for cheese production. Several genetic factors are known to affect milk coagulation, including variation in the major milk proteins; however, recent association studies indicate genetic effects from other genomic regions as well. The aim of this study was to detect genetic variation affecting milk coagulation properties, measured as curd-firming rate (CFR) and milk pH. This was achieved by examining allele frequency differences between pooled whole-genome sequences of phenotypically extreme samples (pool-seq).. Curd-firming rate and raw milk pH were measured for 415 Danish Holstein cows, and each animal was sequenced at low coverage. Pools were created containing whole genome sequence reads from samples with "extreme" values (high or low) for both phenotypic traits. A total of 6,992,186 and 5,295,501 SNP were assessed in relation to CFR and milk pH, respectively. Allele frequency differences were calculated between pools and 32 significantly different SNP were detected, 1 for milk pH and 31 for CFR, of which 19 are located on chromosome 6. A total of 9 significant SNP, which were selected based on the possible function of proximal candidate genes, were genotyped in the entire sample set ( = 415) to test for an association. The most significant SNP was located proximal to , explaining 33% of the phenotypic variance. , coding for κ-casein, is the most studied in relation to milk coagulation due to its position on the surface of the casein micelles and the direct involvement in milk coagulation. Three additional SNP located on chromosome 6 showed significant associations explaining 7, 3.6, and 1.3% of the phenotypic variance of CFR. The significant SNP on chromosome 6 were shown to be in linkage disequilibrium with the SNP peaking proximal to ; however, after accounting for the genotype of

  11. Expression conservation within the circadian clock of a monocot: natural variation at barley Ppd-H1 affects circadian expression of flowering time genes, but not clock orthologs

    Directory of Open Access Journals (Sweden)

    Campoli Chiara

    2012-06-01

    Full Text Available Abstract Background The circadian clock is an endogenous mechanism that coordinates biological processes with daily changes in the environment. In plants, circadian rhythms contribute to both agricultural productivity and evolutionary fitness. In barley, the photoperiod response regulator and flowering-time gene Ppd-H1 is orthologous to the Arabidopsis core-clock gene PRR7. However, relatively little is known about the role of Ppd-H1 and other components of the circadian clock in temperate crop species. In this study, we identified barley clock orthologs and tested the effects of natural genetic variation at Ppd-H1 on diurnal and circadian expression of clock and output genes from the photoperiod-response pathway. Results Barley clock orthologs HvCCA1, HvGI, HvPRR1, HvPRR37 (Ppd-H1, HvPRR73, HvPRR59 and HvPRR95 showed a high level of sequence similarity and conservation of diurnal and circadian expression patterns, when compared to Arabidopsis. The natural mutation at Ppd-H1 did not affect diurnal or circadian cycling of barley clock genes. However, the Ppd-H1 mutant was found to be arrhythmic under free-running conditions for the photoperiod-response genes HvCO1, HvCO2, and the MADS-box transcription factor and vernalization responsive gene Vrn-H1. Conclusion We suggest that the described eudicot clock is largely conserved in the monocot barley. However, genetic differentiation within gene families and differences in the function of Ppd-H1 suggest evolutionary modification in the angiosperm clock. Our data indicates that natural variation at Ppd-H1 does not affect the expression level of clock genes, but controls photoperiodic output genes. Circadian control of Vrn-H1 in barley suggests that this vernalization responsive gene is also controlled by the photoperiod-response pathway. Structural and functional characterization of the barley circadian clock will set the basis for future studies of the adaptive significance of the circadian clock in

  12. An explicit test for the contribution of environmental maternal effects to rapid clinal differentiation in an invasive plant

    OpenAIRE

    Monty, Arnaud; Lebeau, Julie; Meerts, Pierre; Mahy, Grégory

    2009-01-01

    Population differentiation of alien invasive plants within their non-native range has received increasingly more attention. Common gardens are typically used to assess the levels of genotypic differentiation among populations. However, in such experiments, environmental maternal effects can influence phenotypic variation among individuals if seed sources are collected from field populations under variable environmental regimes. In the present study, we investigated the causes of an altitudina...

  13. A haplotype variation affecting the mitochondrial transportation of hMYH protein could be a risk factor for colorectal cancer in Chinese

    International Nuclear Information System (INIS)

    The human MutY homolog (hMYH), a DNA glycolsylase involved in the excision repair of oxidative DNA damage, is currently studied in colorectal cancer (CRC). We previously demonstrated a haplotype variant c.53C>T/c.74G>A of hMYH (T/A) increasing the risk for gastric cancer in Chinese. However, most investigations on correlation between hMYH and CRC are conducted in Western countries and the underlying mechanism has been poorly understood. To determine whether the haplotype T/A variant of hMYH was related to colorectal carcinogenesis, we performed a case-control study in 138 colorectal cancer (CRC) patients and 343 healthy controls in a Chinese population. Furthermore, the C/G for wild-type, C/A or T/G for single base variant and T/A for haplotype variant hMYH cDNAs with a flag epitope tag were cloned into pcDNA3.1+ vector and transfected into cos-7 cell line. Their subcellular localizations were determined by immunofluorescence assay. It was found that the frequency of haplotype variant allele was statistically higher in CRC patients than that in controls (P = 0.02, odds ratio = 5.06, 95% confidence interval = 1.26 – 20.4). Similarly, significant difference of heterozygote frequency was indicated between the two groups (P = 0.019), while no homozygote was found. In addition, immunofluorescence analysis showed that hMYH protein with haplotype T/A variation presented in both nucleus and mitochondria, in contrast to the wild-type protein only converging in mitochondria. However, neither of the single missense mutations alone changed the protein subcelluar localization. Although preliminarily, these results suggest that: the haplotype variant allele of hMYH leads to a missense protein, which partly affects the protein mitochondrial transportation and results as nuclear localization. This observation might be responsible for the increased susceptibility to cancers, including CRC, in Chinese

  14. Geographic variation of floral traits in Nicotiana glauca : Relationships with biotic and abiotic factors

    Science.gov (United States)

    Nattero, Julieta; Sérsic, Alicia N.; Cocucci, Andrea A.

    2011-09-01

    Geographic pattern of phenotypic variation can appear in a clinal or a mosaic fashion and can evidence adaptive or non-adaptive variation. To shed light on the mechanisms underlying this variation, we studied the relationships between geographic variation of floral traits and both biotic and abiotic factors of the hummingbird-pollinated plant, Nicotiana glauca, across its natural range. We obtained floral measures of 38 populations from an area about 1600 km long and 1050 km wide and an altitude range from 7 to over 3400 m. We used a MANOVA to detect between-population differentiations in flower traits and a DFA to determine the traits that best discriminate between populations. To test for associations between floral traits and climatic variables we used correlation analysis. We explored any possible distance-based pattern of variation (either geographic or altitudinal) in floral traits or bill length of pollinators using Mantel tests. Finally, we used a multiple regression to analyze simultaneously the effects and relative importance of abiotic predictor variables and bill length on corolla length. We found a high variation in flower traits among populations. Morphometric traits were the ones that best discriminated across populations. There was a clinal pattern of floral phenotypic variation explained by climatic factors. Differences in floral phenotypic distances were structured by altitudinal distances but not by geographic distances. Bill length of the hummingbird pollinators was structured both by altitudinal and geographic distances. Differences in bill length of hummingbird pollinators explained differences in corolla length across populations. Our findings support the assumption of flower evolution at a broad geographic scale. Floral traits seem to be structured not only by altitude but also by climatic factors.

  15. Genetic variation in parthenogenetic Artemia from the Shandong Peninsula, P.R.C.

    Science.gov (United States)

    King, Charles E.; Zhao, Yuqi; Liu, Xin; Li, Mingren

    1988-06-01

    Results are presented of a survey of isozyme frequencies in parthenogenetic Artimia from six salterns in the Shandong Peninsula, P.R.C. Three of the eleven enzymes we scored using polyacryamide gel electrophoresis proved to be useful for analysis of electromorph frequency variation. These enzymes are tetrazolium oxidase (TO), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH). Each of these systems showed extensive isozyme variation both within and between salterns. In addition, we have examined the possibility that electromorph frequencies may vary as the result of natural selection for adaptation to specific salinity, or salinity-associated environmental conditions. An indication of clinal variation was found in two series of ponds differing in salinity, however more extensive data are needed before it is possible to conclude that these patterns are the result of natural selection. Finally, the use of isozyme analyses such as ours, for unraveling taxonomic problems in Artemia is discussed.

  16. Are there characteristic movement variations in the take-off technique and do they affect performance related kinetic variables? : Ski jumping - a principal component analysis of technique training

    OpenAIRE

    Gulbrandsen, Ådne Marlon

    2015-01-01

    Introduction. Part of technique training in ski jumping consists of land-based simulation jumps: athletes vary their sitting posture following instructions, such as “high”, “low”, “offensive”, or "defensive”, and evaluate the subsequent take-off motions with their coaches. This study addresses three research questions: (1) do different athletes interpret the different instructions in similar ways? (2) What characteristic variations are seen in the take-off kinematics? (3) Do changes in the si...

  17. Copy number variation of CCL3-like genes affects rate of progression to simian-AIDS in Rhesus Macaques (Macaca mulatta.

    Directory of Open Access Journals (Sweden)

    Jeremiah D Degenhardt

    2009-01-01

    Full Text Available Variation in genes underlying host immunity can lead to marked differences in susceptibility to HIV infection among humans. Despite heavy reliance on non-human primates as models for HIV/AIDS, little is known about which host factors are shared and which are unique to a given primate lineage. Here, we investigate whether copy number variation (CNV at CCL3-like genes (CCL3L, a key genetic host factor for HIV/AIDS susceptibility and cell-mediated immune response in humans, is also a determinant of time until onset of simian-AIDS in rhesus macaques. Using a retrospective study of 57 rhesus macaques experimentally infected with SIVmac, we find that CCL3L CNV explains approximately 18% of the variance in time to simian-AIDS (p<0.001 with lower CCL3L copy number associating with more rapid disease course. We also find that CCL3L copy number varies significantly (p<10(-6 among rhesus subpopulations, with Indian-origin macaques having, on average, half as many CCL3L gene copies as Chinese-origin macaques. Lastly, we confirm that CCL3L shows variable copy number in humans and chimpanzees and report on CCL3L CNV within and among three additional primate species. On the basis of our findings we suggest that (1 the difference in population level copy number may explain previously reported observations of longer post-infection survivorship of Chinese-origin rhesus macaques, (2 stratification by CCL3L copy number in rhesus SIV vaccine trials will increase power and reduce noise due to non-vaccine-related differences in survival, and (3 CCL3L CNV is an ancestral component of the primate immune response and, therefore, copy number variation has not been driven by HIV or SIV per se.

  18. Learned vocal variation is associated with abrupt cryptic genetic change in a parrot species complex.

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    Raoul F H Ribot

    Full Text Available Contact zones between subspecies or closely related species offer valuable insights into speciation processes. A typical feature of such zones is the presence of clinal variation in multiple traits. The nature of these traits and the concordance among clines are expected to influence whether and how quickly speciation will proceed. Learned signals, such as vocalizations in species having vocal learning (e.g. humans, many birds, bats and cetaceans, can exhibit rapid change and may accelerate reproductive isolation between populations. Therefore, particularly strong concordance among clines in learned signals and population genetic structure may be expected, even among continuous populations in the early stages of speciation. However, empirical evidence for this pattern is often limited because differences in vocalisations between populations are driven by habitat differences or have evolved in allopatry. We tested for this pattern in a unique system where we may be able to separate effects of habitat and evolutionary history. We studied geographic variation in the vocalizations of the crimson rosella (Platycercus elegans parrot species complex. Parrots are well known for their life-long vocal learning and cognitive abilities. We analysed contact calls across a ca 1300 km transect encompassing populations that differed in neutral genetic markers and plumage colour. We found steep clinal changes in two acoustic variables (fundamental frequency and peak frequency position. The positions of the two clines in vocal traits were concordant with a steep cline in microsatellite-based genetic variation, but were discordant with the steep clines in mtDNA, plumage and habitat. Our study provides new evidence that vocal variation, in a species with vocal learning, can coincide with areas of restricted gene flow across geographically continuous populations. Our results suggest that traits that evolve culturally can be strongly associated with reduced gene flow

  19. An Analysis of Factors Affecting Genotyping Success from Museum Specimens Reveals an Increase of Genetic and Morphological Variation during a Historical Range Expansion of a European Spider.

    Science.gov (United States)

    Krehenwinkel, Henrik; Pekar, Stano

    2015-01-01

    Natural history collections house an enormous amount of plant and animal specimens, which constitute a promising source for molecular analyses. Storage conditions differ among taxa and can have a dramatic effect on the success of DNA work. Here, we analyze the feasibility of DNA extraction from ethanol preserved spiders (Araneae). We tested genotyping success using several hundred specimens of the wasp spider, Argiope bruennichi, deposited in two large German natural history collections. We tested the influence of different factors on the utility of specimens for genotyping. Our results show that not the specimen's age, but the museum collection is a major predictor of genotyping success. These results indicate that long term storage conditions should be optimized in natural history museums to assure the utility of collections for DNA work. Using historical material, we also traced historical genetic and morphological variation in the course of a poleward range expansion of A. bruennichi by comparing contemporary and historical specimens from a native and an invasive population in Germany. We show that the invasion of A. bruennichi is tightly correlated with an historical increase of genetic and phenotypic variation in the invasive population. PMID:26309219

  20. An Analysis of Factors Affecting Genotyping Success from Museum Specimens Reveals an Increase of Genetic and Morphological Variation during a Historical Range Expansion of a European Spider.

    Directory of Open Access Journals (Sweden)

    Henrik Krehenwinkel

    Full Text Available Natural history collections house an enormous amount of plant and animal specimens, which constitute a promising source for molecular analyses. Storage conditions differ among taxa and can have a dramatic effect on the success of DNA work. Here, we analyze the feasibility of DNA extraction from ethanol preserved spiders (Araneae. We tested genotyping success using several hundred specimens of the wasp spider, Argiope bruennichi, deposited in two large German natural history collections. We tested the influence of different factors on the utility of specimens for genotyping. Our results show that not the specimen's age, but the museum collection is a major predictor of genotyping success. These results indicate that long term storage conditions should be optimized in natural history museums to assure the utility of collections for DNA work. Using historical material, we also traced historical genetic and morphological variation in the course of a poleward range expansion of A. bruennichi by comparing contemporary and historical specimens from a native and an invasive population in Germany. We show that the invasion of A. bruennichi is tightly correlated with an historical increase of genetic and phenotypic variation in the invasive population.

  1. Geographic variation in Caluromys derbianus and Caluromys lanatus (Didelphimorphia: Didelphidae

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    Raul Fonseca

    2015-04-01

    Full Text Available We analyzed the geographic variations in the shape and size of the cranium and mandible of two woolly opossums, Caluromys derbianus and Caluromys lanatus. Using geometric morphometrics we analyzed 202 specimens of C. derbianus and 123 specimens of C. lanatus, grouped in 7 and 9 populations, respectively. We found sexual dimorphism in shape variables only in the dorsal view of the cranium of Caluromys derbianus, which is not associated with geographical origin. We detected geographic variation in the size of the mandible in two populations (Nicaragua and Northern Panama, but no geographic variation in shape. The size of the cranium of C. lanatus varies significantly, with clinal variation in peri-Amazon populations, with a break between two populations, Bolivia and Paraguay. Shape analyses also revealed some separation between the Paraná population and all other populations. Our results suggest that the available name, Caluromys derbianus, should be maintained for all individuals throughout the geographic range of the species. The same is true for Caluromys lanatus, which can be separated into two distinct morphologic units, Caluromys lanatus ochropus, from the Amazon and Cerrado, and Caluromys lanatus lanatus, from the Atlantic forest.

  2. Thlaspi caerulescens (Brassicaceae) population genetics in western Switzerland: is the genetic structure affected by natural variation of soil heavy metal concentrations?

    Science.gov (United States)

    Besnard, Guillaume; Basic, Nevena; Christin, Pascal-Antoine; Savova-Bianchi, Dessislava; Galland, Nicole

    2009-03-01

    Thlaspi caerulescens (Brassicaceae) is a promising plant model with which to study heavy metal hyperaccumulation. Population genetics studies are necessary for a better understanding of its history, which will be useful for further genomic studies on the evolution of heavy metal hyperaccumulation.The genetic structure of 24 natural Swiss locations was investigated using nuclear and plastid loci. Population genetics parameters were estimated and genetic pools were identified using Bayesian inference on eight putatively neutral nuclear loci.Finally, the effect of cadmium (Cd) and zinc (Zn) soil concentrations on genetic differentiation at loci located in genes putatively involved in heavy metal responses was examined using partial Mantel tests in Jura, western Switzerland.Four main genetic clusters were recognized based on nuclear and plastid loci,which gave mostly congruent signals. In Jura, genetic differentiation linked to heavy metal concentrations in soil was shown at some candidate loci, particularly for genes encoding metal transporters. This suggests that natural selection limits gene flow between metalliferous and non metalliferous locations at such loci.Strong historical factors explain the present genetic structure of Swiss T. caerulescens populations, which has to be considered in studies testing for relationships between environmental and genetic variations. Linking of genetic differentiation at candidate genes with soil characteristics offers new perspectives in the study of heavy metal hyperaccumulation. PMID:19076982

  3. How switches and lags in biophysical regulators affect spatial-temporal variation of soil respiration in an oak-grass savanna

    Science.gov (United States)

    Baldocchi, Dennis; Tang, Jianwu; Xu, Liukang

    2006-06-01

    Complex behavior, associated with soil respiration of an oak-grass savanna ecosystem in California, was quantified with continuous measurements of CO2 exchange at two scales (soil and canopy) and with three methods (overstory and understory eddy covariance systems, soil respiration chambers, and a below-ground CO2 flux gradient system). To partition soil respiration into its autotrophic and heterotrophic components, we exploited spatial gradients in the landscape and seasonal variations in rainfall. During the dry summer, heterotrophic respiration was dominant in the senesced grassland area, whereas autotrophic respiration by roots and the feeding of microbes by root exudates was dominant under the trees. A temporal switch in soil respiration occurred in the spring. But the stimulation of root respiration lagged the timing of leaf-out by the trees. Another temporal switch in soil respiration occurred at the start of autumn rains. This switch was induced by the rapid germination of grass seed and new grass growth. Isolated summer rain storms caused a pulse in soil respiration. Such rain events stimulated microbial respiration only; the rain was not sufficient to replenish soil moisture in the root zone or to germinate grass seed. Soil respiration lagged photosynthetic activity on hourly scales. The likely mechanism is the slow translocation of photosynthate to the roots and associated microbes. Another lag occurred on daily scales because of modulations in photosynthesis and stomatal conductance by the passage of dry and humid air masses.

  4. Variations in grain lipophilic phytochemicals, proteins and resistance to Fusarium spp. growth during grain storage as affected by biological plant protection with Aureobasidium pullulans (de Bary).

    Science.gov (United States)

    Wachowska, Urszula; Tańska, Małgorzata; Konopka, Iwona

    2016-06-16

    Modern agriculture relies on an integrated approach, where chemical treatment is reduced to a minimum and replaced by biological control that involves the use of active microorganisms. The effect of the antagonistic yeast-like fungus Aureobasidium pullulans on proteins and bioactive compounds (alkylresorcinols, sterols, tocols and carotenoids) in winter wheat grain and on the colonization of wheat kernels by fungal microbiota, mainly Fusarium spp. pathogens, was investigated. Biological treatment contributed to a slight increase contents of tocols, alkylresorcinols and sterols in grain. At the same time, the variation of wheat grain proteins was low and not significant. Application of A. pullulans enhanced the natural yeast colonization after six months of grain storage and inhibited growth of F. culmorum pathogens penetrating wheat kernel. This study demonstrated that an integrated approach of wheat grain protection with the use of the yeast-like fungus A. pullulans reduced kernel colonization by Fusarium spp. pathogens and increased the content of nutritionally beneficial phytochemicals in wheat grain without a loss of gluten proteins responsible for baking value. PMID:27055191

  5. Seasonal and size-related variation of subcellular biomarkers in quagga mussels (Dreissena bugensis) inhabiting sites affected by moderate contamination with complex mixtures of pollutants.

    Science.gov (United States)

    Ács, A; Vehovszky, Á; Győri, J; Farkas, A

    2016-07-01

    The size-related differences in subcellular biomarker responses were assessed in Dreissena bugensis mussels inhabiting harbours moderately affected by pollution with complex mixtures of heavy metals and polycyclic aromatic hydrocarbons (PAHs). Adult D. bugensis samples were collected from three harbours of Lake Balaton (Hungary) characterized by moderate shipping activity, and as reference site, from a highly protected remote area of the lake. Biomarkers of exposure (metallothioneins (MTs), ethoxyresorufin-o-deethylase (EROD)), oxidative stress (lipid peroxidation (LPO), DNA strand breaks (DNAsb)) and possible endocrine disruption (vitellogenin-like proteins (VTG)) were analysed in whole-tissue homogenates of differently sized groups of mussels in relation to environmental parameters and priority pollutants (heavy metals and polycyclic aromatic hydrocarbons). Integrated biomarker response (IBR) indices were calculated for biomarker responses gained through in situ measurements to signalize critical sites and to better distinguish natural tendencies from biological effects of contaminants. Biomarker responses showed close positive correlation in case of MT, EROD, LPO, and DNAsb and negative correlation with VTG levels with mussel shell length in autumn, when higher levels of biomarkers appeared, possibly due to natural lifecycle changes of animals. PMID:27329477

  6. Small-scale variation in fuel loads differentially affects two co-dominant bunchgrasses in a species-rich pine savanna.

    Science.gov (United States)

    Gagnon, Paul R; Harms, Kyle E; Platt, William J; Passmore, Heather A; Myers, Jonathan A

    2012-01-01

    Ecological disturbances frequently control the occurrence and patterning of dominant plants in high-diversity communities like C(4) grasslands and savannas. In such ecosystems disturbance-related processes can have important implications for species, and for whole communities when those species are dominant, yet mechanistic understanding of such processes remains fragmentary. Multiple bunchgrass species commonly co-dominate disturbance-dependent and species-rich pine savannas, where small-scale fuel heterogeneity may influence bunchgrass survival and growth following fires. We quantified how fire in locally varying fuel loads influenced dynamics of dominant C(4) bunchgrasses in a species-rich pine savanna in southeastern Louisiana, USA. We focused on two congeneric, co-dominant species (Schizachyrium scoparium and S. tenerum) with similar growth forms, functional traits and reproductive strategies to highlight effects of fuel heterogeneity during fires. In experimental plots with either reduced or increased fuels versus controls with unmanipulated fuels, we compared: 1) bunchgrass damage and 2) mortality from fires; 3) subsequent growth and 4) flowering. Compared to controls, fire with increased fuels caused greater damage, mortality and subsequent flowering, but did not affect post-fire growth. Fire with reduced fuels had no effect on any of the four measures. The two species responded differently to fire with increased fuels--S. scoparium incurred measurably more damage and mortality than S. tenerum. Logistic regression indicated that the larger average size of S. tenerum tussocks made them resistant to more severe burning where fuels were increased. We speculate that locally increased fuel loading may be important in pine savannas for creating colonization sites because where fuels are light or moderate, dominant bunchgrasses persist through fires. Small-scale heterogeneity in fires, and differences in how species tolerate fire may together promote shared local

  7. Small-scale variation in fuel loads differentially affects two co-dominant bunchgrasses in a species-rich pine savanna.

    Directory of Open Access Journals (Sweden)

    Paul R Gagnon

    Full Text Available Ecological disturbances frequently control the occurrence and patterning of dominant plants in high-diversity communities like C(4 grasslands and savannas. In such ecosystems disturbance-related processes can have important implications for species, and for whole communities when those species are dominant, yet mechanistic understanding of such processes remains fragmentary. Multiple bunchgrass species commonly co-dominate disturbance-dependent and species-rich pine savannas, where small-scale fuel heterogeneity may influence bunchgrass survival and growth following fires. We quantified how fire in locally varying fuel loads influenced dynamics of dominant C(4 bunchgrasses in a species-rich pine savanna in southeastern Louisiana, USA. We focused on two congeneric, co-dominant species (Schizachyrium scoparium and S. tenerum with similar growth forms, functional traits and reproductive strategies to highlight effects of fuel heterogeneity during fires. In experimental plots with either reduced or increased fuels versus controls with unmanipulated fuels, we compared: 1 bunchgrass damage and 2 mortality from fires; 3 subsequent growth and 4 flowering. Compared to controls, fire with increased fuels caused greater damage, mortality and subsequent flowering, but did not affect post-fire growth. Fire with reduced fuels had no effect on any of the four measures. The two species responded differently to fire with increased fuels--S. scoparium incurred measurably more damage and mortality than S. tenerum. Logistic regression indicated that the larger average size of S. tenerum tussocks made them resistant to more severe burning where fuels were increased. We speculate that locally increased fuel loading may be important in pine savannas for creating colonization sites because where fuels are light or moderate, dominant bunchgrasses persist through fires. Small-scale heterogeneity in fires, and differences in how species tolerate fire may together promote

  8. Parallel Evolution of Copy-Number Variation across Continents in Drosophila melanogaster.

    Science.gov (United States)

    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. PMID:26809315

  9. Geographic variation in the morphology of Macrovipera lebetina (Linnaeus, 1758 (Ophidia: Viperidae in Iran

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    Naeim Moradi

    2014-12-01

    Full Text Available The Levantine viper, Macrovipera lebetina, has an extensive geographical range being distributed in central Asia and the Middle East. The species exhibits high levels of polymorphism, especially in colouration and pattern. Recent studies revealed significant morphological differences between the two subspecies from northeastern and western portions of Iran. However, considering limited geographic samplings, taxonomic status of Iranian Macrovipera are controversial. In this study, uni- and multivariate statistical techniques were used to analyze geographic variation in 31 morphological characters measured in 117 specimens of Macrovipera lebetina covering its entire range in Iran. Sexual dimorphism was obvious in number of scales across the head and subcaudals. Univariate analyses detected substantial geographic variation in several meristic characters. Pholidosis exhibits a general north-south pattern of variation and most scale counts averaged higher in southern regions. Colouration displayed a pattern of strong clinal variation among three broad areas consisting of the combined western and northwestern, northeastern, and southern highland regions. Also, morphometric characters exhibited a general north-south pattern of geographic variation and some characters averaged lower in southern regions. Populations from the southern regions remained clearly distinct in Principal Component, Cluster and Discriminant analyses. In the light of these differences, it is concluded that the southern Iranian populations should not be identified as belonging to Macrovipera lebetina obtusa (Dwigubsky, 1832, which occurs in northwestern and western regions of the Iranian Plateau.

  10. 1957-2004年影响我国的强热带气旋频数和强度变化%Variations in Frequency and Intensity of Strong Tropical Cyclones Affecting China During 1957-2004

    Institute of Scientific and Technical Information of China (English)

    王小玲; 任福民

    2008-01-01

    Based on tropical cyclone track dataset in the western North Pacific from China Meteorological Administration(CMA),variations in frequency and intensity of tropical cyclones(TCs)in the western North Pacific,affecting-China TCs(ACTCs)and landfall TCs(LTCs)achieving a typhoon intensity during 1957-2004 were studied.Frequencies of strong tropical cyclones showed significant decreasing trends from 1957 to 2004 and the linear trend was much greater when the intensity was stronger.There was no linear trend in the portion of strong tropical cyclones achieving a typhoon(TY)intensity,while those reaching a strong typhoon(STY)and a super typhoon(SuperTY)intensity showed decreasing trends during 1957-2004.The maximum intensities of TCs,ACTCs and LTCs all decreased during the period of 1957-2004.The mean intensities of TCs and ACTCs displayed decreasing trends and the mean intensity of LTCs achieving a TY intensity also showed a decreasing trend.

  11. Studies of ecomorphological variations of the European hare (Lepus europaeus in Turkey

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    Demirbaş Y.

    2013-01-01

    Full Text Available Hares (Lepus spp. are widely distributed across the globe and are adapted to diverse climatic conditions. In order to study the ecomorphological variations of hares from Turkey, the body and cranial measurements and body weight, as well as coat color types, of 138 hares collected from all over Turkey between 2006 and 2012, were examined. Statistically significant differences between regional samples (p <0.05, ANOVA only in terms of body weight and hindfoot length were found; however, there were a good number of external phenotypes, particularly in terms of coat color variants of the hare specimens. Furthermore, populations had similar variations in terms of morphometric measurement, body weight and coat coloration between different geographical regions. Turkish hares did not exhibit clinal variations from south to north in body and cranial measurements depending on the mean annual temperatures and precipitation. Therefore, it was assumed that all of these variations might be a polymorphism related to the local adaptations and high level of admixture of gene pools in Anatolia.

  12. Intra-population genetic variation in the temporal pattern of egg maturation in a parasitoid wasp.

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    Eric Wajnberg

    Full Text Available Parasitoid wasps are taxonomically and biologically extremely diverse. A conceptual framework has recently been developed for understanding life-history evolution and diversification in these animals, and it has confirmed that each of two linked life-history traits - the mode of larval development and the temporal pattern of egg maturation - acts as an organiser of life-history. The framework has been predicated on the assumption that there exists sufficient genetic variation in the latter trait to allow it to be shaped by natural selection. Focusing on the parasitoid wasp Trichogramma brassicae, our aim was to test the validity of that assumption, using established quantitative genetic methods. We demonstrate the existence of a statistically significant degree of intra-population polygenic variation in the temporal pattern of egg production within the wasp population we studied. Furthermore, our results, together with published data on clinal variation in the egg maturation pattern of another species, suggest that intra-specific evolutionary shifts in the temporal pattern of egg maturation of parasitoid wasps can result from a change in allocation to egg production either before, or very shortly after adult emergence, without there being an accompanying change in lifetime fecundity. As well as opening new avenues of research into the reproductive strategies, behaviour, community organisation and biological control potential of parasitoid wasps, this discovery also has implications for studies of life-history evolution and diversification in insects generally.

  13. Pattern and scale of geographic variation in environmental sex determination in the Atlantic silverside, Menidia menidia.

    Science.gov (United States)

    Duffy, Tara A; Hice, Lyndie A; Conover, David O

    2015-08-01

    The Atlantic silverside, Menidia menidia (Pisces: Atherinidae), exhibits an exceptionally high level of clinal variation in sex determination across its geographic range. Previous work suggested linear changes in the level of temperature-dependent sex determination (TSD) with increasing latitude. Based on comparisons at 31 sites encompassing the entire species' range, we find that the change in level of TSD with latitude is instead highly nonlinear. The level of TSD is uniformly high in the south (Florida to New Jersey), then declines rapidly into the northern Gulf of Maine where genotypic sex determination (GSD) predominates and then rebounds to moderate levels of TSD in the northern-most populations of the Gulf of St. Lawrence. Major latitudinal breakpoints occur in central New Jersey (40(o)N) and the northern Gulf of Maine (44(o)N). No populations display pure TSD or GSD. Length of the growing season is the likely agent of selection driving variation in TSD with a threshold at 210 days. Because gene flow among populations is high, such distinct patterns of geographic variation in TSD/GSD are likely maintained by contemporary selection thereby demonstrating the adaptive fine tuning of sex determining mechanisms. PMID:26177746

  14. Phenotypic Variation in Mangrove Cuckoo (Coccyzus minor) across Its Geographic Range.

    Science.gov (United States)

    Lloyd, John D

    2016-01-01

    Mangrove Cuckoo (Coccyzus minor) exhibits substantial phenotypic variation across its geographic range, but the significance of this variation for taxonomy remains unresolved. Using measurements of bill size and ventral color recorded from 274 museum specimens, I found that variation in these traits was clinal. No named subspecies was reciprocally diagnosable from all others, and none was distinguishable from the nominate form, such that previously recognized subspecific distinctions are invalid. Greatest differences in phenotype occurred between populations in Florida, the Bahamas, and the Greater Antilles--characteristically small-billed--and those in the Lesser Antilles, which had larger bills. Phenotypically intermediate individuals on the geographically intermediate islands of Barbuda and Antigua linked these two extremes. Individuals intermediate in bill size and color also characterized populations from throughout the remainder of the range in northern South America and Middle America. Mechanisms maintaining the fairly pronounced phenotypic differences between nearby populations of Greater and Lesser Antillean birds are unknown, yet the geographic proximity of these populations suggests that they probably persist despite occasional gene flow, and may be adaptive. PMID:27008380

  15. Phenotypic Variation in Mangrove Cuckoo (Coccyzus minor across Its Geographic Range.

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    John D Lloyd

    Full Text Available Mangrove Cuckoo (Coccyzus minor exhibits substantial phenotypic variation across its geographic range, but the significance of this variation for taxonomy remains unresolved. Using measurements of bill size and ventral color recorded from 274 museum specimens, I found that variation in these traits was clinal. No named subspecies was reciprocally diagnosable from all others, and none was distinguishable from the nominate form, such that previously recognized subspecific distinctions are invalid. Greatest differences in phenotype occurred between populations in Florida, the Bahamas, and the Greater Antilles--characteristically small-billed--and those in the Lesser Antilles, which had larger bills. Phenotypically intermediate individuals on the geographically intermediate islands of Barbuda and Antigua linked these two extremes. Individuals intermediate in bill size and color also characterized populations from throughout the remainder of the range in northern South America and Middle America. Mechanisms maintaining the fairly pronounced phenotypic differences between nearby populations of Greater and Lesser Antillean birds are unknown, yet the geographic proximity of these populations suggests that they probably persist despite occasional gene flow, and may be adaptive.

  16. Phenotypic Variation in Mangrove Cuckoo (Coccyzus minor) across Its Geographic Range

    Science.gov (United States)

    Lloyd, John D.

    2016-01-01

    Mangrove Cuckoo (Coccyzus minor) exhibits substantial phenotypic variation across its geographic range, but the significance of this variation for taxonomy remains unresolved. Using measurements of bill size and ventral color recorded from 274 museum specimens, I found that variation in these traits was clinal. No named subspecies was reciprocally diagnosable from all others, and none was distinguishable from the nominate form, such that previously recognized subspecific distinctions are invalid. Greatest differences in phenotype occurred between populations in Florida, the Bahamas, and the Greater Antilles–characteristically small-billed–and those in the Lesser Antilles, which had larger bills. Phenotypically intermediate individuals on the geographically intermediate islands of Barbuda and Antigua linked these two extremes. Individuals intermediate in bill size and color also characterized populations from throughout the remainder of the range in northern South America and Middle America. Mechanisms maintaining the fairly pronounced phenotypic differences between nearby populations of Greater and Lesser Antillean birds are unknown, yet the geographic proximity of these populations suggests that they probably persist despite occasional gene flow, and may be adaptive. PMID:27008380

  17. Genotype-by-environment interactions and adaptation to local temperature affect immunity and fecundity in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Brian P Lazzaro

    2008-03-01

    Full Text Available Natural populations of most organisms harbor substantial genetic variation for resistance to infection. The continued existence of such variation is unexpected under simple evolutionary models that either posit direct and continuous natural selection on the immune system or an evolved life history "balance" between immunity and other fitness traits in a constant environment. However, both local adaptation to heterogeneous environments and genotype-by-environment interactions can maintain genetic variation in a species. In this study, we test Drosophila melanogaster genotypes sampled from tropical Africa, temperate northeastern North America, and semi-tropical southeastern North America for resistance to bacterial infection and fecundity at three different environmental temperatures. Environmental temperature had absolute effects on all traits, but there were also marked genotype-by-environment interactions that may limit the global efficiency of natural selection on both traits. African flies performed more poorly than North American flies in both immunity and fecundity at the lowest temperature, but not at the higher temperatures, suggesting that the African population is maladapted to low temperature. In contrast, there was no evidence for clinal variation driven by thermal adaptation within North America for either trait. Resistance to infection and reproductive success were generally uncorrelated across genotypes, so this study finds no evidence for a fitness tradeoff between immunity and fecundity under the conditions tested. Both local adaptation to geographically heterogeneous environments and genotype-by-environment interactions may explain the persistence of genetic variation for resistance to infection in natural populations.

  18. Analysis on Variation Characteristics and Affecting Factors of Solar Radiation in Luoyang%洛阳地区太阳辐射变化特征及影响因子分析

    Institute of Scientific and Technical Information of China (English)

    朱学玲

    2015-01-01

    Based on the solar radiation and sunshine data from 1981 to 2010 of the radiation station in Zhengzhou and the sunshine duration,cloud cover,relative humidity,vapor pressure and visibility of the meteorological observation stations in Luoyang,variation characteristics and affecting factors of solar radiation in Luoyang were analyzed by means of climatology calculation,linear trend analysis method,Mann Kendall test,correlation analysis and Min-Max stan?dardized method. Results showed that:From 1981 to 2100,the average solar radiation was 4 842.36 MJ/m2 in Luoyang area,the maximum was 5 245.20 MJ/m2 in 1986,and the minimum was 4 548.60 MJ/m2 in 1989. There was a signifi?cantly decreasing trend in the solar radiation in 30 years,and the decreasing rate was 1.39 MJ/m2 a year. There was a turning point of the solar radiation variation in early 1990s. The average solar radiation from 1981 to 1993 was 4 812.23 MJ/m2,and 4 919.55MJ/m2 in 1994-2008. Annual solar radiation difference before and after the variation was 107.32MJ/m2 . The variation trend of the sunshine duration was similar to that of solar radiation. Low cloud cover,rela?tive humidity and visibility had marked drop trends in recent 30 years. There was a downward trend in total cloud cover and vapor pressure had the tendency of increase,but not significant. According to the related analysis,solar radiation was negatively correlated with the cloud cover,low cloud cover and relative humidity,vapor pressure,and positively correlated with visibility. Their correction coefficient was in the order:winter>spring and autumn>summer.%根据1981-2010年郑州气象站的太阳辐射和日照资料以及洛阳气象观测站日照、总云量、低云量、相对湿度、水汽压、能见度资料,采用气候学计算、线性趋势分析、M-K突变检验、相关分析、Min-max标准化等方法,对洛阳地区太阳辐射进行了计算,探讨了太阳辐射的变化特征,并分析了太阳辐射变化的

  19. A Preliminary Study of Genetic Variation in Populations of Monstera adansonii var. klotzschiana (Araceae) from North-East Brazil, Estimated with AFLP Molecular Markers

    Science.gov (United States)

    Andrade, I. M.; Mayo, S. J.; van den Berg, C.; Fay, M. F.; Chester, M.; Lexer, C.; Kirkup, D.

    2007-01-01

    Background and Aims This study sought genetic evidence of long-term isolation in populations of Monstera adansonii var. klotzschiana (Araceae), a herbaceous, probably outbreeding, humid forest hemi-epiphyte, in the brejo forests of Ceará (north-east Brazil), and clarification of their relationships with populations in Amazonia and the Atlantic forest of Brazil. Methods Within-population genetic diversity and between-population dissimilarity were estimated using AFLP molecular markers in 75 individuals from eight populations located in Ceará, the Brazilian Atlantic Forest and Amazonia. Key Results The populations showed a clinal pattern of weak genetic differentiation over a large geographical region (FST = 0·1896). A strong correlation between genetic and geographical distance (Mantel test: r = 0·6903, P = 0·002) suggests a historical pattern of isolation by distance. Genetic structure analysis revealed at least two distinct gene pools in the data. The two isolated Ceará populations are significantly different from each other (pairwise ΦPT = 0·137, P = 0·003) and as diverse (Nei's gene diversity, average He = 0·1832, 0·1706) as those in the Atlantic and Amazon forest regions. The population in southern Brazil is less diverse (Nei's gene diversity, average He = 0·127) than the rest. The Ceará populations are related to those of the Atlantic forest rather than those from Amazonia (AMOVA, among-groups variation = 11·95 %, P = 0·037). Conclusions The gene pools detected within an overall pattern of clinal variation suggest distinct episodes of gene flow, possibly correlated with past humid forest expansions. The Ceará populations show no evidence of erosion of genetic diversity, although this was expected because of their isolation. Their genetic differentiation and relatively high diversity reinforce the importance of conserving the endangered brejo forests. PMID:17823112

  20. 海南西部近岸浮游植物的周年变化及主要关联因素%ANNUAL VARIATION ON PHYTOPLANKTON IN COASTAL WATERS OF WESTERN HAINAN ISLAND AND RELATED AFFECTING FACTORS

    Institute of Scientific and Technical Information of China (English)

    王雨; 林茂; 陈兴群; 林更铭

    2012-01-01

    Annual variation of phytoplankton community in coastal waters at western Hainan Island and its related affecting factors were analyzed based on four cruise surveys of four seasons carried out in 2008 and 2009. A total of 155 species (including 5 forms and 2 varieties) belonging to 74 genera of 4 classes were identified in 165 samples, in which diatoms were predominant in the species composition and the cell abundance. Dinoflagellates contributed the second major group. Cyanobacteria abundance increased in July. The dominant species were Thalassionema nitzschioides, Ba-cillaria paradoxa, Paralia sulcata, Chaetoceros curvisetus, Rhizosolenia styliformis, Trichodesmium spp., Prorocentrum micans, etc. Among them, Thalassionema nitzschioides, Bacillaria paradoxa and Paralia sulcata were dominant in four seasons. The species composition showed a significant seasonal change while phytoplankton cell abundance did not. Phytoplankton species were lower in October than in January, while richer in April and July. The annual average cell abundance of phytoplankton was (6.36±4.75)×l03cells/L (n=165), and the peak cell abundance appeared in October. The phytoplankton abundance of each season reduced from near-shore waters to offshore. Patch distribution of Trichodesmium spp. were obvious in April and July. The diversity index was almost coincident with that of the Pielou evenness index. The high values of both index suggested that the phytoplankton community was in stability and the water quality was healthy in western Hainan Island. Pearson Correlate Analysis of phytoplankton cell abundance with environmental factors indicated that the phytoplankton abundance non-correlated to water temperature, correlated positively to the abio-notrogen in October, and negatively correlated to the salinity in January and to the abio-phosphate in July. The feeding stress from zooplankton directly affected annual variation of the cell abundance of phytoplankton along with influences of

  1. The association of white matter volume in psychotic disorders with genotypic variation in NRG1, MOG and CNP: a voxel-based analysis in affected individuals and their unaffected relatives

    OpenAIRE

    Cannon, D. M.; Walshe, M; Dempster, E.; Collier, D A; Marshall, N.; Bramon, E.; Murray, R. M.; C. McDonald

    2012-01-01

    We investigated the role of variation in putative psychosis genes coding for elements of the white matter system by examining the contribution of genotypic variation in three single-nucleotide polymorphisms (SNPs) neuregulin 1 (NRG1) SNP8NRG221533, myelin oligodendrocytes glycoprotein (MOG) rs2857766 and CNP (rs2070106) and one haplotype HAP(ICE) (deCODE) to white matter volume in patients with psychotic disorder and their unaffected relatives. Structural magnetic resonance imaging and blood ...

  2. Variational MCMC

    OpenAIRE

    De Freitas, Nando; Hojen-Sorensen, Pedro; Jordan, Michael I.; Russell, Stuart

    2013-01-01

    We propose a new class of learning algorithms that combines variational approximation and Markov chain Monte Carlo (MCMC) simulation. Naive algorithms that use the variational approximation as proposal distribution can perform poorly because this approximation tends to underestimate the true variance and other features of the data. We solve this problem by introducing more sophisticated MCMC algorithms. One of these algorithms is a mixture of two MCMC kernels: a random walk Metropolis kernel ...

  3. Numerical Simulation on Landslide Stability Affected by Seepage Field Variation Caused by Tunnel Excavation%隧洞开挖渗流场变化对滑坡稳定性的影响数值模拟分析

    Institute of Scientific and Technical Information of China (English)

    张凡; 韩爱果; 任光明; 杜飞; 吴龙科; 詹可

    2015-01-01

    The aim of this research is to investigate in landslide’s seepage field,slope deformation and stability af-fected by tunnel excavation.On the basis of analysing the physical and mechanical and water physical properties of a landslide slope,we simulated the variation of groundwater level and seepage field before and after tunnel excava-tion using 3D finite difference software Modflow.Furthermore,by employing Geo-Studio,we analyzed the stability and deformation of landslide after water level changed in natural and excavation conditions.Results reveal that the groundwater seepage field changed after tunnel excavation,and obvious water inflow was found at the excavation ar-ea.As a result,the groundwater level decreased about 20m and apparent “sinkholes”appeared in the excavation area.The change of groundwater level was mainly reflected in the front edge of landslide.The deformation of 2 #secondary sliding body,which caused the deformation of 1 #secondary sliding body,exacerbated under the com-bined actions of weakened sliding resistance and increased effective stress.The maximum slope deformation of sec-ondary landslide above the tunnel reached 1 2.42 cm,but the stability changed slightly.%为研究隧洞开挖对滑坡渗流场、坡体变形及稳定性的影响,在对某滑坡滑体物理力学及水理性质进行研究的基础上,采用 Modflow 有限元差分三维软件对隧洞开挖前后的地下水位进行数值模拟计算,分析隧洞开挖后渗流场的变化,并以此结合 Geo-Studio 软件对滑坡处于天然及开挖情况下水位变化后的稳定性及变形进行了分析研究。结果表明:隧洞开挖后地下水渗流场发生改变,隧洞开挖处产生明显涌水现象,开挖2 a 后地下水位降低约20 m,开挖区形成明显“落水洞”,地下水位变化主要体现在滑坡前缘;隧洞上部2#次级滑体在抗滑力减弱和有效应力增大的双重作用下变形加剧,其下滑带动1#

  4. Variational analysis

    CERN Document Server

    Rockafellar, R Tyrrell

    1998-01-01

    From its origins in the minimization of integral functionals, the notion of 'variations' has evolved greatly in connection with applications in optimization, equilibrium, and control. It refers not only to constrained movement away from a point, but also to modes of perturbation and approximation that are best describable by 'set convergence', variational convergence of functions and the like. This book develops a unified framework and, in finite dimension, provides a detailed exposition of variational geometry and subdifferential calculus in their current forms beyond classical and convex analysis. Also covered are set-convergence, set-valued mappings, epi-convergence, duality, maximal monotone mappings, second-order subderivatives, measurable selections and normal integrands. The changes in this 3rd printing mainly concern various typographical corrections, and reference omissions that came to light in the previous printings. Many of these reached the authors' notice through their own re-reading, that of th...

  5. Morphological and genetic variation in Cicindela lusitanica Mandl, 1935 (Coleoptera, Carabidae, Cicindelinae: implications for conservation

    Directory of Open Access Journals (Sweden)

    Serrano, A.

    2003-12-01

    Full Text Available The establishment of taxonomic and geographical boundaries is a common problem when analysing clinal distributions. This is of particular concern when the assessment of intraspecific groupings is required for conservation management. The tiger beetle Cicindela lusitanica Mandl, 1935 (Coleoptera, Carabidae is a typical case in which two recognised subspecies are distributed in a clinal latitudinal fashion in the dune systems along the Atlantic coast of Portugal. This habitat is increasingly under threat, and conservation measures are needed. We investigated the validity of the two named subspecies, based on a re-analysis of elytral and genitalic measurements using multivariate analysis. We also analysed variation in mitochondrial Cytochrome Oxidase I gene for a total of six populations along the cline. Multivariate analysis supported the idea of a morphological cline and revealed a clear distinction of the southernmost population and also some degree of distinctiveness of the most northern populations, partially supporting the recognised subspecific ranking. The mtDNA analysis identified two main groups corresponding to northern and southern populations. Both sets of markers showed that variation within the C. lusitanica assemblage is complex, with the boundaries between morphological and mtDNA groups not in agreement. However, populations at either end of the distributional range are clearly distinct from each other, and should be considered as provisional units for conservation programmes.El reconocimiento de límites taxonómicos y geográficos de la variabilidad observada es un problema habitual cuando se analizan distribuciones clinales. Esto es particularmente problemático cuando se requiere la determinación de agrupamientos intraespecíficos para tomar medidas de conservación. El cicindélido Cicindela lusitanica Mandl, 1935 (Coleoptera, Carabidae constituye un caso típico en el que dos subespecies reconocidas se hayan distribuidas a

  6. Variational principles

    CERN Document Server

    Moiseiwitsch, B L

    2004-01-01

    This graduate-level text's primary objective is to demonstrate the expression of the equations of the various branches of mathematical physics in the succinct and elegant form of variational principles (and thereby illuminate their interrelationship). Its related intentions are to show how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities (such as the phase shifts) that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mecha

  7. Dietary n-3 and n-6 polyunsaturated fatty acid intake interacts with FADS1 genetic variation to affect total and HDL-cholesterol concentrations in the Doetinchem Cohort Study

    OpenAIRE

    Y. Lu; Feskens, E.J.M.; Dollé, M.E.T.; Imholz, S.; Verschuren, W M M; Müller, M.R.; Boer, J.M.A.

    2010-01-01

    Background: The d-5 and d-6 desaturases, encoded by the FADS1 and FADS2 genes, are rate-limiting enzymes in polyunsaturated fatty acid (PUFA) biosynthesis. Single nucleotide polymorphisms in the FADS gene cluster region have been associated with both PUFA concentrations in plasma or erythrocyte membrane phospholipids and cholesterol concentrations in recent genome-wide association studies. Objective: We examined whether genetic variations in the FADS gene cluster region interact with dietary ...

  8. Cytoplasmic genetic variation and extensive cytonuclear interactions influence natural variation in the metabolome

    DEFF Research Database (Denmark)

    Joseph, Bindu; Corwin, Jason A.; Li, Baohua;

    2013-01-01

    affects phenotypic variation. This showed that the cytoplasmic variation had effects similar to, if not larger than, the largest individual nuclear locus. Inclusion of cytoplasmic variation into the genetic model greatly increased the explained phenotypic variation. Cytoplasmic genetic variation was a...... central hub in the epistatic network controlling the plant metabolome. This epistatic influence manifested such that the cytoplasmic background could alter or hide pairwise epistasis between nuclear loci. Thus, cytoplasmic genetic variation plays a central role in controlling natural variation in...... metabolomic networks. This suggests that cytoplasmic genomes must be included in any future analysis of natural variation....

  9. Affect Regulation

    DEFF Research Database (Denmark)

    Pedersen, Signe Holm; Poulsen, Stig Bernt; Lunn, Susanne

    2014-01-01

    Gergely and colleagues’ state that their Social Biofeedback Theory of Parental Affect Mirroring” can be seen as a kind of operationalization of the classical psychoanalytic concepts of holding, containing and mirroring. This article examines to what extent the social biofeedback theory of parenta...

  10. Individual Difference Variables, Affective Differentiation, and the Structures of Affect

    Science.gov (United States)

    Terracciano, Antonio; McCrae, Robert R.; Hagemann, Dirk; Costa, Paul T.

    2008-01-01

    Methodological arguments are usually invoked to explain variations in the structure of affect. Using self-rated affect from Italian samples (N = 600), we show that individual difference variables related to affective differentiation can moderate the observed structure. Indices of circumplexity (Browne, 1992) and congruence coefficients to the hypothesized target were used to quantify the observed structures. Results did not support the circumplex model as a universal structure. A circular structure with axes of activation and valence was approximated only among more affectively differentiated groups: students and respondents with high scores on Openness to Feelings and measures of negative emotionality. A different structure, with unipolar Positive Affect and Negative Affect factors, was observed among adults and respondents with low Openness to Feelings and negative emotionality. The observed structure of affect will depend in part on the nature of the sample studied. PMID:12932207

  11. Individual difference variables, affective differentiation, and the structures of affect.

    Science.gov (United States)

    Terracciano, Antonio; McCrae, Robert R; Hagemann, Dirk; Costa, Paul T

    2003-10-01

    Methodological arguments are usually invoked to explain variations in the structure of affect. Using self-rated affect from Italian samples (N=600), we show that individual difference variables related to affective differentiation can moderate the observed structure. Indices of circumplexity and congruence coefficients to the hypothesized target were used to quantify the observed structures. Results did not support the circumplex model as a universal structure. A circular structure with axes of activation and valence was approximated only among more affectively differentiated groups: students and respondents with high scores on Openness to Feelings and measures of negative emotionality. A different structure, with unipolar Positive Affect and Negative Affect factors, was observed among adults and respondents with low Openness to Feelings and negative emotionality. The observed structure of affect will depend in part on the nature of the sample studied. PMID:12932207

  12. Affective Urbanism

    DEFF Research Database (Denmark)

    Samson, Kristine

    , experience and consumption are all strategic design tools applied by planners and architects. Whereas urban design in former modernist planning served merely functional or political means, urban design has increasingly become an aesthetical mediator of ideologies embedded in the urban field of life forces...... capitalism not only changes urban life and its means of production, it specifically influences the way the city is designed and how it unfolds as events (Anderson & Harrison 2010) and affective, emotional production (Pile 2009). Through examples of urban design and events in the Carlsberg City in Copenhagen...... and The High Line in Chelsea, New York, the paper sets out to define and question these affective modes of production. Whether these productions are socio-material practices consisting of ludic designs (Stevens 2007), temporary architecture or art installations or evental practices consisting of...

  13. Meta-Analysis of Mitochondrial DNA Variation in the Iberian Peninsula.

    Science.gov (United States)

    Barral-Arca, Ruth; Pischedda, Sara; Gómez-Carballa, Alberto; Pastoriza, Ana; Mosquera-Miguel, Ana; López-Soto, Manuel; Martinón-Torres, Federico; Álvarez-Iglesias, Vanesa; Salas, Antonio

    2016-01-01

    The Iberian Peninsula has been the focus of attention of numerous studies dealing with mitochondrial DNA (mtDNA) variation, most of them targeting the control region segment. In the present study we sequenced the control region of 3,024 Spanish individuals from areas where available data were still limited. We also compiled mtDNA haplotypes from the literature involving 4,588 sequences and 28 population groups or small regions. We meta-analyzed all these data in order to shed further light on patterns of geographic variation, taking advantage of the large sample size and geographic coverage, in contrast with the atomized sampling strategy of previous work. The results indicate that the main mtDNA haplogroups show primarily clinal geographic patterns across the Iberian geography, roughly along a North-South axis. Haplogroup HV0 (where haplogroup U is nested) is more prevalent in the Franco Cantabrian region, in good agreement with previous findings that identified this area as a climate refuge during the Last Glacial Maximum (LGM), prior to a subsequent demographic re-expansion towards Central Europe and the Mediterranean. Typical sub-Saharan and North African lineages are slightly more prevalent in South Iberia, although at low frequencies; this pattern has been shaped mainly by the transatlantic slave trade and the Arab invasion of the Iberian Peninsula. The results also indicate that summary statistics that aim to measure molecular variation, or AMOVA, have limited sensitivity to detect population substructure, in contrast to patterns revealed by phylogeographic analysis. Overall, the results suggest that mtDNA variation in Iberia is substantially stratified. These patterns might be relevant in biomedical studies given that stratification is a common cause of false positives in case-control mtDNA association studies, and should be also considered when weighting the DNA evidence in forensic casework, which is strongly dependent on haplotype frequencies. PMID

  14. Affective Maps

    DEFF Research Database (Denmark)

    Salovaara-Moring, Inka

    Recently, in human geography there has been a considerable attention paid to retheorising maps; less as a product and more as practice. This refers to the notion that rather than reading maps as fixed representations, digital mapping is by nature a dynamic, performative, and participatory practice....... In particular, mapping environmental damage, endangered species, and human made disasters has become one of the focal point of affective knowledge production. These ‘more-than-humangeographies’ practices include notions of species, space and territory, and movement towards a new political ecology...

  15. [Affective dependency].

    Science.gov (United States)

    Scantamburlo, G; Pitchot, W; Ansseau, M

    2013-01-01

    Affective dependency is characterized by emotional distress (insecure attachment) and dependency to another person with a low self-esteem and reassurance need. The paper proposes a reflection on the definition of emotional dependency and the confusion caused by various denominations. Overprotective and authoritarian parenting, cultural and socio-environmental factors may contribute to the development of dependent personality. Psychological epigenetic factors, such as early socio-emotional trauma could on neuronal circuits in prefronto-limbic regions that are essential for emotional behaviour.We also focus on the interrelations between dependent personality, domestic violence and addictions. The objective for the clinician is to propose a restoration of self-esteem and therapeutic strategies focused on autonomy. PMID:23888587

  16. How does real affect affect affect recognition in speech?

    NARCIS (Netherlands)

    Truong, Khiet Phuong

    2009-01-01

    The aim of the research described in this thesis was to develop speech-based affect recognition systems that can deal with spontaneous (‘real’) affect instead of acted affect. Several affect recognition experiments with spontaneous affective speech data were carried out to investigate what combinati

  17. Morphometric and genetic variation of small dwarf honeybees Apis andreniformis Smith, 1858 in Thailand

    Institute of Scientific and Technical Information of China (English)

    ATSALEK RATTANAWANNEE; CHANPEN CHANCHAO; SIRIWAT WONGSIRI

    2007-01-01

    The small dwarf honey bee, Apis andreniformis, is a rare and patchily distributed Apis spp. and is one of the native Thai honey bees, yet little is known about its biodiversity. Thirty (27 Thai and 3 Malaysian) and 37 (32 Thai and 5 Malaysian) colonies of A.andreniformis were sampled for morphometric and genetic analysis, respectively. For morphometric analysis, 20 informative characters were used to determine the variation. After plotting the factor scores, A. andreniformis from across Thailand were found to belong to one group, a notion further supported by a cluster analysis generated dendrogram.However, clinal patterns in groups of bee morphometric characters were revealed by linear regression analysis. The body size of bees increases from South to North but decreases from West to East, although this may reflect altitude rather than longitude. Genetic variation was determined by sequence analysis of a 520 bp fragment of the mitochondrial cytochrome oxidase subunit b (cytb). DNA polymorphism among bees from the mainland of Thailand is lower than that from Phuket Island and Chiang Mai. Although two main different groups of bees were obtained from phylogenetic trees constructed by neighbor-joining and unweighted pair-group method using arithmetic averages programs, no clear geographic signal was present. Thus, while the minor group (B) contained all of the samples from the only island sampled (Phuket in the south), but not the southern mainland colonies, it also contained samples from the far northern inland region of Chiang Mai, other samples of which were firmly rooted in the major group (A).

  18. HLA variation reveals genetic continuity rather than population group structure in East Asia.

    Science.gov (United States)

    Di, Da; Sanchez-Mazas, Alicia

    2014-03-01

    Genetic differences between Northeast Asian (NEA) and Southeast Asian (SEA) populations have been observed in numerous studies. At the among-population level, despite a clear north-south differentiation observed for many genetic markers, debates were led between abrupt differences and a continuous pattern. At the within-population level, whether NEA or SEA populations have higher genetic diversity is also highly controversial. In this study, we analyzed a large set of HLA data from East Asia in order to map the genetic variation among and within populations in this continent and to clarify the distribution pattern of HLA lineages and alleles. We observed a genetic differentiation between NEA and SEA populations following a continuous pattern from north to south, and we show a significant and continuous decrease of HLA diversity by the same direction. This continuity is shaped by clinal distributions of many HLA lineages and alleles with increasing or decreasing frequencies along the latitude. These results bring new evidence in favor of the "overlapping model" proposed previously for East Asian peopling history, whereby modern humans migrated eastward from western Eurasia via two independent routes along each side of the Himalayas and, later, overlapped in East Asia across open land areas. Our study strongly suggests that intensive gene flow between NEA and SEA populations occurred and shaped the latitude-related continuous pattern of genetic variation and the peculiar HLA lineage and allele distributions observed in this continent. Probably for a very long period, the exact duration of these events remains to be estimated. PMID:24449274

  19. Accommodating variation: dialects, idiolects, and speech processing.

    Science.gov (United States)

    Kraljic, Tanya; Brennan, Susan E; Samuel, Arthur G

    2008-04-01

    Listeners are faced with enormous variation in pronunciation, yet they rarely have difficulty understanding speech. Although much research has been devoted to figuring out how listeners deal with variability, virtually none (outside of sociolinguistics) has focused on the source of the variation itself. The current experiments explore whether different kinds of variation lead to different cognitive and behavioral adjustments. Specifically, we compare adjustments to the same acoustic consequence when it is due to context-independent variation (resulting from articulatory properties unique to a speaker) versus context-conditioned variation (resulting from common articulatory properties of speakers who share a dialect). The contrasting results for these two cases show that the source of a particular acoustic-phonetic variation affects how that variation is handled by the perceptual system. We also show that changes in perceptual representations do not necessarily lead to changes in production. PMID:17803986

  20. Variations in Maternal 5-HTTLPR Affect Observed Sensitive Parenting

    Science.gov (United States)

    Cents, Rolieke A. M.; Kok, Rianne; Tiemeier, Henning; Lucassen, Nicole; Székely, Eszter; Bakermans-Kranenburg, Marian J.; Hofman, Albert; Jaddoe, Vincent W. V.; IJzendoorn, Marinus H.; Verhulst, Frank C.; Lambregtse-van den Berg, Mijke P.

    2014-01-01

    Background: Little is known about the genetic determinants of sensitive parenting. Two earlier studies examined the effect of the serotonin transporter polymorphism (5-HTTLPR) on sensitive parenting, but reported opposite results. In a large cohort we further examined whether 5-HTTLPR is a predictor of observed maternal sensitivity and whether…

  1. How the spatial variation of tree roots affects slope stability

    Science.gov (United States)

    Mao, Zhun; Stokes, A.; Jourdan, C.; Rey, H.; Courbaud, B.; Saint-André, L.

    2010-05-01

    It is now widely recognized that plant roots can reinforce soil against shallow mass movement. Although studies on the interactions between vegetation and slope stability have significantly augmented in recent years, a clear understanding of the spatial dynamics of root reinforcement (through additional cohesion by roots) in subalpine forest is still limited, especially with regard to the roles of different forest management strategies or ecological landscapes. The architecture of root systems is important for soil cohesion, but in reality it is not possible to measure the orientation of each root in a system. Therefore, knowledge on the effect of root orientation and anisotropy on root cohesion on the basis of in situ data is scanty. To determine the effect of root orientation in root cohesion models, we investigated root anisotropy in two mixed, mature, naturally regenerated, subalpine forests of Norway spruce (Picea abies), and Silver fir (Abies alba). Trees were clustered into islands, with open spaces between each group, resulting in strong mosaic heterogeneity within the forest stand. Trenches within and between clusters of trees were dug and root distribution was measured in three dimensions. We then simulated the influence of different values for a root anisotropy correction factor in forests with different ecological structures and soil depths. Using these data, we have carried out simulations of slope stability by calculating the slope factor of safety depending on stand structure. Results should enable us to better estimate the risk of shallow slope failure depending on the type of forest and species.

  2. Effects of body-size variation on flight-related traits in latitudinal populations of Drosophila melanogaster

    Indian Academy of Sciences (India)

    Veer Bhan; Ravi Parkash; Dau Dayal Aggarwal

    2014-04-01

    In the present study, we tested the hypothesis whether flight-related traits such as wing area, flight-muscle ratio, wing loading and dispersal yield evidence of geographical variation in nine wild-collected as well as laboratory-reared (at 21°C) latitudinal populations of Drosophila melanogaster from the Indian subcontinent. We observed positive clinal variation in the wing–thorax ratio, wing aspect ratio and wing area, along a latitudinal gradient for both the sexes. In contrast, geographical changes in three parameters of flight ability, i.e. flight-muscle ratio, wing loading and dispersal, showed negative correlation with latitude. On the basis of isofemale line variability, we observed positive correlation of wing loading with flight-muscle ratio as well as dispersal behaviour in both the sexes. We also found positive correlation between duration of development and wing area. Interestingly, southern populations of D. melanogaster from warm and humid habitats exhibited higher flight-muscle ratio as well as the higher wing loading than northern populations which occur in cooler and drier climatic conditions. Laboratory tests for dispersal-related walking behaviour showed significantly higher values for southern populations compared with northern populations of D. melanogaster. Multiple regression analysis of geographical changes in flight-muscle ratio, wing loading as well as walking behaviour as a function of average temperature and relative humidity of the origin of populations in wild-collected flies have suggested adaptive changes in flight-related traits in response to steeper gradients of climatic factors in the Indian subcontinent. Finally, adaptive latitudinal variations in flight-related traits in D. melanogaster are consistent with results of other studies from different continents despite differences due to specific climatic conditions in the Indian subcontinent.

  3. Effects of body-size variation on flight-related traits in latitudinal populations of Drosophila melanogaster.

    Science.gov (United States)

    Bhan, Veer; Parkash, Ravi; Aggarwal, Dau Dayal

    2014-04-01

    In the present study, we tested the hypothesis whether flight-related traits such as wing area, flight-muscle ratio, wing loading and dispersal yield evidence of geographical variation in nine wild-collected as well as laboratory-reared (at 21°C) latitudinal populations of Drosophila melanogaster from the Indian subcontinent. We observed positive clinal variation in the wing-thorax ratio, wing aspect ratio and wing area, along a latitudinal gradient for both the sexes. In contrast, geographical changes in three parameters of flight ability, i.e. flight-muscle ratio, wing loading and dispersal, showed negative correlation with latitude. On the basis of isofemale line variability, we observed positive correlation of wing loading with flight-muscle ratio as well as dispersal behaviour in both the sexes. We also found positive correlation between duration of development and wing area. Interestingly, southern populations of D. melanogaster from warm and humid habitats exhibited higher flight-muscle ratio as well as the higher wing loading than northern populations which occur in cooler and drier climatic conditions. Laboratory tests for dispersal-related walking behaviour showed significantly higher values for southern populations compared with northern populations of D. melanogaster. Multiple regression analysis of geographical changes in flight-muscle ratio, wing loading as well as walking behaviour as a function of average temperature and relative humidity of the origin of populations in wild-collected flies have suggested adaptive changes in flight-related traits in response to steeper gradients of climatic factors in the Indian subcontinent. Finally, adaptive latitudinal variations in flight-related traits in D. melanogaster are consistent with results of other studies from different continents despite differences due to specific climatic conditions in the Indian subcontinent. PMID:24840827

  4. Antimicrobial price variation: Conundrum of medical profession!

    Directory of Open Access Journals (Sweden)

    Rataboli P

    2007-01-01

    Full Text Available Pharmacoeconomics plays a pivotal role in clinical practice. High medicine prices can adversely affect a patient′s finances and compliance. The Indian pharmaceutical industry has become a cornucopia of medicines with wide variation in prices for the same medicine marketed under different brand names. Price list of available antimicrobial brands was procured from a commercial drug directory. Average price of widely prescribed oral antimicrobials was found and price variation between different brands was calculated. The variation in medicine prices was found to be from 95% lower to more than 350% higher than the average price. Implications of price variation in clinical practice are discussed and remedial measures suggested.

  5. Calculus of variations

    CERN Document Server

    Elsgolc, L E; Stark, M

    1961-01-01

    Calculus of Variations aims to provide an understanding of the basic notions and standard methods of the calculus of variations, including the direct methods of solution of the variational problems. The wide variety of applications of variational methods to different fields of mechanics and technology has made it essential for engineers to learn the fundamentals of the calculus of variations. The book begins with a discussion of the method of variation in problems with fixed boundaries. Subsequent chapters cover variational problems with movable boundaries and some other problems; sufficiency

  6. Environmental variation, stochastic extinction, and competitive coexistence.

    Science.gov (United States)

    Adler, Peter B; Drake, John M

    2008-11-01

    Understanding how environmental fluctuations affect population persistence is essential for predicting the ecological impacts of expected future increases in climate variability. However, two bodies of theory make opposite predictions about the effect of environmental variation on persistence. Single-species theory, common in conservation biology and population viability analyses, suggests that environmental variation increases the risk of stochastic extinction. By contrast, coexistence theory has shown that environmental variation can buffer inferior competitors against competitive exclusion through a storage effect. We reconcile these two perspectives by showing that in the presence of demographic stochasticity, environmental variation can increase the chance of extinction while simultaneously stabilizing coexistence. Our stochastic simulations of a two-species storage effect model reveal a unimodal relationship between environmental variation and coexistence time, implying maximum coexistence at intermediate levels of environmental variation. The unimodal pattern reflects the fact that the stabilizing influence of the storage effect accumulates rapidly at low levels of environmental variation, whereas the risk of extinction due to the combined effects of environmental variation and demographic stochasticity increases most rapidly at higher levels of variation. Future increases in environmental variation could either increase or decrease an inferior competitor's expected persistence time, depending on the distance between the present level of environmental variation and the optimal level anticipated by this theory. PMID:18817458

  7. Quantitative genetic variance and multivariate clines in the Ivyleaf morning glory, Ipomoea hederacea

    OpenAIRE

    Amanda J. Stock; Campitelli, Brandon E.; John R. Stinchcombe

    2014-01-01

    Clinal variation is commonly interpreted as evidence of adaptive differentiation, although clines can also be produced by stochastic forces. Understanding whether clines are adaptive therefore requires comparing clinal variation to background patterns of genetic differentiation at presumably neutral markers. Although this approach has frequently been applied to single traits at a time, we have comparatively fewer examples of how multiple correlated traits vary clinally. Here, we characterize ...

  8. Studying Variation in Tunes

    NARCIS (Netherlands)

    Janssen, B.; van Kranenburg, P.

    2014-01-01

    Variation in music can be caused by different phenomena: conscious, creative manipulation of musical ideas; but also unconscious variation during music recall. It is the latter phenomenon that we wish to study: variation which occurs in oral transmission, in which a melody is taught without the help

  9. Experiencing affective interactive art

    NARCIS (Netherlands)

    Bialoskorski, Leticia S.S.; Westerink, Joyce H.D.M.; Broek, van den Egon L.

    2010-01-01

    The progress in the field of affective computing enables the realization of affective art. This paper describes the affective interactive art system Mood Swings, which interprets and visualizes affect expressed by a person. Mood Swings is founded on the integration of a framework for affective move

  10. Population effects of increased climate variation

    OpenAIRE

    Drake, John M.

    2005-01-01

    Global circulation models predict and numerous observations confirm that anthropogenic climate change has altered high-frequency climate variability. However, it is not yet well understood how changing patterns of environmental variation will affect wildlife population dynamics and other ecological processes. Theory predicts that a population's long-run growth rate is diminished and the chance of population extinction is increased as environmental variation increases. This results from the fa...

  11. Cosmic Time Variation of the Gravitational Constant

    CERN Document Server

    Tomaschitz, R

    2000-01-01

    A pre-relativistic cosmological approach to electromagnetism and gravitation is explored that leads to a cosmic time variation of the fundamental constants. Space itself is supposed to have physical substance, which manifests by its permeability. The scale factors of the permeability tensor induce a time variation of the fundamental constants. Atomic radii, periods, and energy levels scale in cosmic time, which results in dispersionless redshifts without invoking a space expansion. Hubble constant and deceleration parameter are reviewed in this context. The time variation of the gravitational constant at the present epoch can be expressed in terms of these quantities. This provides a completely new way to restrain the deceleration parameter from laboratory bounds on the time variation of the gravitational constant. This variation also affects the redshift dependence of angular diameters and the surface brightness, and we study in some detail the redshift scaling of the linear sizes of radio sources. The effec...

  12. 脓毒症患儿血浆N-末端B型利钠肽原变化研究%Clinal study of plasma NH2 terminal pro-brain natriuretic peptide in patients with sepsis

    Institute of Scientific and Technical Information of China (English)

    叶辉; 刘喜; 李雪梅; 程美华

    2012-01-01

    Objective To observe the variation of NH2 terminal pro-brain natriuretic peptide(NT-proBNP) level in patients with sepsis and heart failure. Methods We recruited 36 patients whose diagnoses of sepsis were confirmed according to the diagnosis and treatment in 2002. The patients were divided into heart failure group (group A, n =25) and non-heart failure group (group B, n =11), meanwhile, twenty health subjects were enrolled as control group (group C, n =20). NT-proBNP in plasma in 36 patients and 20 health subjects were measured and then the differences among the three groups were analyzed. Meanwhile, the results of troponin KcTnI) were compared in three groups. Results There were significant differences in NT-proBNP levels among three groups, group A (4 876. 7± 1 934. 5) ng/L,group B (1 374. 7±256. 1) ng/L,and group C (456. 2 + 165.1) ng/L( P <0. 01). cTnI in three groups showed significance difference,group A (2. 56±0. 78)ng/L,group B (0. 09±0. 02) ng/L,group C (0. 03±0. 01) ng/L ( P < 0. 01) ,group A was the highest. Conclusion NT-proBNP in plasma is significantly higher in patients with sepsis,and the levels are different in sepsis combined with heart failure and without heart failure. The concentration of NT-proBNP can be used as the laboratory marker for detection of early heart failure and myorcardial functional lesion.%目的 观察N-末端B型利钠肽原(NT-proBNP)在脓毒症合并心力衰竭患儿中的水平变化.方法 本院儿科重症监护病房(PICU)住院的脓毒症患者36例,其中合并心力衰竭25例(A组),非心力衰竭11例(B组),健康对照者20例(C组).测定入院后24小时内血浆NT-proBNP及肌钙蛋白I(cTnI)的水平,比较各组之间血浆NT-proBNP及cTnI差异.结果 A、B、C组NT-proBNP水平入院后分别为(4 876.7±1 934.5) ng/L,(1 374.7±256.1) ng/L,(456.2±165.1) ng/L,对比各组入院后NT-proBNP的水平,差异有统计学意义(P<0.01).cTnI在A、B、C组分别为(2.56±0.78) ng/L,(0.09±0.02) ng/L,(0

  13. Variation of fundamental constants

    CERN Document Server

    Flambaum, V V

    2006-01-01

    We present a review of recent works devoted to the variation of the fine structure constant alpha, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feschbach resonance.

  14. Asynchronous Variational Integrators

    OpenAIRE

    Lew, A.; Marsden, J. E.; Ortiz, M.; West, M

    2003-01-01

    We describe a new class of asynchronous variational integrators (AVI) for nonlinear elastodynamics. The AVIs are distinguished by the following attributes: (i) The algorithms permit the selection of independent time steps in each element, and the local time steps need not bear an integral relation to each other; (ii) the algorithms derive from a spacetime form of a discrete version of Hamilton’s variational principle. As a consequence of this variational structure, the algorith...

  15. Morphological variation, advertisement call, and tadpoles of Bokermannohyla nanuzae (Bokermann, 1973), and taxonomic status of B. feioi (Napoli & Caramaschi, 2004) (Anura, Hylidae, Cophomantini).

    Science.gov (United States)

    Walker, Marina; Lourenço, Ana Carolina Calijorne; Pimenta, Bruno V S; Nascimento, Luciana Barreto

    2015-01-01

    Bokermannohyla nanuzae (Bokermann & Sazima 1973) and B. feioi (Napoli & Caramaschi 2004) belong to the B. cir-cumdata species group. The type locality of the former is Serra do Cipó, Espinhaço mountain range, and of the latter is Parque Estadual do Ibitipoca, Mantiqueira mountain range, both in Minas Gerais State, Brazil. Differences on dorsal draw-ing pattern of adults, oral disc morphology of tadpoles, and temporal properties of calls were proposed to distinguish these two species. However, several specimens found between the two type localities remain unidentified because diagnostic characters and states occur in all of these populations. Thus, in order to assess these characters variations, we performed an analysis of the morphology and morphometry of adults, vocalization, and morphology of tadpoles. Specimens were divided into three operational taxonomic units (OTUs): B. nanuzae (Serra do Cipó and northwards, Espinhaço mountain range), B. cf. nanuzae (Quadrilátero Ferrífero, Espinhaço mountain range, south of Serra do Cipó), and B. feioi (Serra do Ibitipoca, Mantiqueira mountain range). Drawing patterns of the dorsum and limbs show clinal variation and the three units are morphometrically very similar. Temporal and spectral properties of calls overlap in these three units. The diagnostic differences originally proposed for tadpoles are intrapopulational variations and occur in specimens from all of the locations analyzed. We found that these three units are morphologically indistinguishable. Therefore, we designate Bok-ermannohyla feioi (Napoli & Caramaschi 2004) as a junior synonym of Bokermannohyla nanuzae (Bokermann & Sazima 1973), extending its geographical distribution to the Mantiqueira mountain range. PMID:25947466

  16. Calculus of variations

    CERN Document Server

    Gelfand, I M

    2000-01-01

    Based on a series of lectures given by I. M. Gelfand at Moscow State University, this book actually goes considerably beyond the material presented in the lectures. The aim is to give a treatment of the elements of the calculus of variations in a form both easily understandable and sufficiently modern. Considerable attention is devoted to physical applications of variational methods, e.g., canonical equations, variational principles of mechanics, and conservation laws.The reader who merely wishes to become familiar with the most basic concepts and methods of the calculus of variations need on

  17. Geomagnetic Core Field Secular Variation Models

    DEFF Research Database (Denmark)

    Gillet, N.; Lesur, V.; Olsen, Nils

    2010-01-01

    (regularisation) affect the result of the ill-posed geomagnetic inverse problem. We show how data quality, frequency and selection procedures govern part of the temporal changes in the secular variation norms and spectra, which are sometimes difficult to dissociate from true changes of the core state. We...... assimilation) reduces the non-uniqueness of the geomagnetic inverse problem....

  18. The Variational Fair Autoencoder

    NARCIS (Netherlands)

    C. Louizos; K. Swersky; Y. Li; M. Welling; R. Zemel

    2016-01-01

    We investigate the problem of learning representations that are invariant to certain nuisance or sensitive factors of variation in the data while retaining as much of the remaining information as possible. Our model is based on a variational autoencoding architecture with priors that encourage indep

  19. Pulse pressure variation and systolic pressure variation in mechanically ventilated children

    OpenAIRE

    Johnny Nurman; Antonius H. Pudjiadi; Arwin AP. Akib

    2011-01-01

    Background In mechanically ventilated patients, changes in breathing patterns may affect the preload, causing stroke volume fluctuation. Pulse pressure variation (PPV) and systolic pressure variation (SPV) are dynamic means of the hemodynamic monitoring in ventilated patients. No study on PPV and SPV in children has been reported to date. Objective To study changes in PPV and SPV values in mechanically ventilated children. Method A descriptive cross-sectional study was done at the Pedia...

  20. Ensembl variation resources

    Directory of Open Access Journals (Sweden)

    Marin-Garcia Pablo

    2010-05-01

    Full Text Available Abstract Background The maturing field of genomics is rapidly increasing the number of sequenced genomes and producing more information from those previously sequenced. Much of this additional information is variation data derived from sampling multiple individuals of a given species with the goal of discovering new variants and characterising the population frequencies of the variants that are already known. These data have immense value for many studies, including those designed to understand evolution and connect genotype to phenotype. Maximising the utility of the data requires that it be stored in an accessible manner that facilitates the integration of variation data with other genome resources such as gene annotation and comparative genomics. Description The Ensembl project provides comprehensive and integrated variation resources for a wide variety of chordate genomes. This paper provides a detailed description of the sources of data and the methods for creating the Ensembl variation databases. It also explores the utility of the information by explaining the range of query options available, from using interactive web displays, to online data mining tools and connecting directly to the data servers programmatically. It gives a good overview of the variation resources and future plans for expanding the variation data within Ensembl. Conclusions Variation data is an important key to understanding the functional and phenotypic differences between individuals. The development of new sequencing and genotyping technologies is greatly increasing the amount of variation data known for almost all genomes. The Ensembl variation resources are integrated into the Ensembl genome browser and provide a comprehensive way to access this data in the context of a widely used genome bioinformatics system. All Ensembl data is freely available at http://www.ensembl.org and from the public MySQL database server at ensembldb.ensembl.org.

  1. Theory of conjectural variations

    CERN Document Server

    Jean-Marie, Alain

    2004-01-01

    We have witnessed in recent years a revival of Conjectural Variations in Game Theory. This reincarnation of an old idea, using a dynamic point of view, aims at combining the adequacy with facts to the requirements of a firmly grounded theory. This book presents, for the first time, a comprehensive account of conjectural variations equilibria in their static inceptions, featuring new comparative results of equilibria with regard to efficiency. It then describes several advances in Dynamic Game Theory, allowing to understand Conjectural Variations Equilibria as dynamic equilibria. The question o

  2. Quantum variational calculus

    CERN Document Server

    Malinowska, Agnieszka B

    2014-01-01

    This Brief puts together two subjects, quantum and variational calculi by considering variational problems involving Hahn quantum operators. The main advantage of its results is that they are able to deal with nondifferentiable (even discontinuous) functions, which are important in applications. Possible applications in economics are discussed. Economists model time as continuous or discrete. Although individual economic decisions are generally made at discrete time intervals, they may well be less than perfectly synchronized in ways discrete models postulate. On the other hand, the usual assumption that economic activity takes place continuously, is nothing else than a convenient abstraction that in many applications is far from reality. The Hahn quantum calculus helps to bridge the gap between the two families of models: continuous and discrete. Quantum Variational Calculus is self-contained and unified in presentation. It provides an opportunity for an introduction to the quantum calculus of variations fo...

  3. Variational Inequalities with Applications

    CERN Document Server

    Sofonea, Mircea

    2009-01-01

    Motivated by stimulating problems in contact mechanics, emphasizing antiplane frictional contact with linearly elastic and viscoelastic materials, this book focuses on the essentials with respect to the qualitative aspects of several classes of variational inequalities (VIs)

  4. Variational principles in physics

    CERN Document Server

    Basdevant, Jean-Louis

    2007-01-01

    Optimization under constraints is an essential part of everyday life. Indeed, we routinely solve problems by striking a balance between contradictory interests, individual desires and material contingencies. This notion of equilibrium was dear to thinkers of the enlightenment, as illustrated by Montesquieu’s famous formulation: "In all magistracies, the greatness of the power must be compensated by the brevity of the duration." Astonishingly, natural laws are guided by a similar principle. Variational principles have proven to be surprisingly fertile. For example, Fermat used variational methods to demonstrate that light follows the fastest route from one point to another, an idea which came to be known as Fermat’s principle, a cornerstone of geometrical optics. Variational Principles in Physics explains variational principles and charts their use throughout modern physics. The heart of the book is devoted to the analytical mechanics of Lagrange and Hamilton, the basic tools of any physicist. Prof. Basdev...

  5. Generalized quasi variational inequalities

    Energy Technology Data Exchange (ETDEWEB)

    Noor, M.A. [King Saud Univ., Riyadh (Saudi Arabia)

    1996-12-31

    In this paper, we establish the equivalence between the generalized quasi variational inequalities and the generalized implicit Wiener-Hopf equations using essentially the projection technique. This equivalence is used to suggest and analyze a number of new iterative algorithms for solving generalized quasi variational inequalities and the related complementarity problems. The convergence criteria is also considered. The results proved in this paper represent a significant improvement and refinement of the previously known results.

  6. Variational time integrators

    OpenAIRE

    Lew, A.; Marsden, J. E.; Ortiz, M.; West, M

    2004-01-01

    The purpose of this paper is to review and further develop the subject of variational integration algorithms as it applies to mechanical systems of engineering interest. In particular, the conservation properties of both synchronous and asynchronous variational integrators (AVIs) are discussed in detail. We present selected numerical examples which demonstrate the excellent accuracy, conservation and convergence characteristics of AVIs. In these tests, AVIs are found to result in substantial ...

  7. Revisiting the Iberian honey bee (Apis mellifera iberiensis) contact zone: maternal and genome-wide nuclear variations provide support for secondary contact from historical refugia.

    Science.gov (United States)

    Chávez-Galarza, Julio; Henriques, Dora; Johnston, J Spencer; Carneiro, Miguel; Rufino, José; Patton, John C; Pinto, M Alice

    2015-06-01

    Dissecting diversity patterns of organisms endemic to Iberia has been truly challenging for a variety of taxa, and the Iberian honey bee is no exception. Surveys of genetic variation in the Iberian honey bee are among the most extensive for any honey bee subspecies. From these, differential and complex patterns of diversity have emerged, which have yet to be fully resolved. Here, we used a genome-wide data set of 309 neutrally tested single nucleotide polymorphisms (SNPs), scattered across the 16 honey bee chromosomes, which were genotyped in 711 haploid males. These SNPs were analysed along with an intergenic locus of the mtDNA, to reveal historical patterns of population structure across the entire range of the Iberian honey bee. Overall, patterns of population structure inferred from nuclear loci by multiple clustering approaches and geographic cline analysis were consistent with two major clusters forming a well-defined cline that bisects Iberia along a northeastern-southwestern axis, a pattern that remarkably parallels that of the mtDNA. While a mechanism of primary intergradation or isolation by distance could explain the observed clinal variation, our results are more consistent with an alternative model of secondary contact between divergent populations previously isolated in glacial refugia, as proposed for a growing list of other Iberian taxa. Despite current intense honey bee management, human-mediated processes have seemingly played a minor role in shaping Iberian honey bee genetic structure. This study highlights the complexity of the Iberian honey bee patterns and reinforces the importance of Iberia as a reservoir of Apis mellifera diversity. PMID:25930679

  8. Annual variation in the atmospheric radon concentration in Japan

    International Nuclear Information System (INIS)

    Anomalous atmospheric variations in radon related to earthquakes have been observed in hourly exhaust-monitoring data from radioisotope institutes in Japan. The extraction of seismic anomalous radon variations would be greatly aided by understanding the normal pattern of variation in radon concentrations. Using atmospheric daily minimum radon concentration data from five sampling sites, we show that a sinusoidal regression curve can be fitted to the data. In addition, we identify areas where the atmospheric radon variation is significantly affected by the variation in atmospheric turbulence and the onshore-offshore pattern of Asian monsoons. Furthermore, by comparing the sinusoidal regression curve for the normal annual (seasonal) variations at the five sites to the sinusoidal regression curve for a previously published dataset of radon values at the five Japanese prefectures, we can estimate the normal annual variation pattern. By fitting sinusoidal regression curves to the previously published dataset containing sites in all Japanese prefectures, we find that 72% of the Japanese prefectures satisfy the requirements of the sinusoidal regression curve pattern. Using the normal annual variation pattern of atmospheric daily minimum radon concentration data, these prefectures are suitable areas for obtaining anomalous radon variations related to earthquakes. - Highlights: • Annual (seasonal) variation of atmospheric radon in Japan is determined. • The normal annual variation patterns are obtained by fitting a sinusoidal model. • Radon concentration is affected by atmospheric turbulence and Asian monsoons. • The normal radon pattern is estimated to relate radon and earthquake activity

  9. Chromatic variations suppress suprathreshold brightness variations.

    Science.gov (United States)

    Kingdom, Frederick A A; Bell, Jason; Gheorghiu, Elena; Malkoc, Gokhan

    2010-01-01

    Most objects in natural scenes are suprathreshold in both color (chromatic) and luminance contrast. How salient is each dimension? We have developed a novel method employing a stimulus similar to that used by B. C. Regan and J. D. Mollon (1997) who studied the relative saliencies of the two chromatic cardinal directions. Our stimuli consist of left- and right-oblique modulations of color and/or luminance defined within a lattice of circles. In the "separated" condition, the two modulations were presented separately as forced-choice pairs, and the task was to indicate which was more salient. In the "combined" condition, the two orthogonal-in-orientation modulations were added, and the task was to indicate the more salient orientation. The ratio of color to luminance contrast at the PSE was calculated for both conditions. Across color directions, 48% more luminance contrast relative to color contrast was required to achieve a PSE in the "combined" compared to the "separated" condition. A second experiment showed that the PSE difference was due to the luminance being masked by the color, rather than due to superior color grouping. We conclude that suprathreshold brightness variations are masked by suprathreshold color variations. PMID:20884478

  10. Variation in Metaphor Variation in Metaphor

    Directory of Open Access Journals (Sweden)

    Zóltan Kövecses

    2010-05-01

    Full Text Available

    Cognitive linguists have so far paid a great deal of attention to the emarkable universality of many conceptual metaphors. However, their theories fail to account for the equally impressive diversity of metaphorical conceptualization both across and within cultures. The present paper is an attempt to lay down the foundations of a theory of metaphor that is capable of simultaneously accounting for both universality and variation in metaphor.

     

    Cognitive linguists have so far paid a great deal of attention to the emarkable universality of many conceptual metaphors. However, their theories fail to account for the equally impressive diversity of metaphorical conceptualization both across and within cultures. The present paper is an attempt to lay down the foundations of a theory of metaphor that is capable of simultaneously accounting for both universality and variation in metaphor.

  11. Individual phenotypic variation reduces interaction strengths in a consumer–resource system

    OpenAIRE

    Gibert, Jean P.; Brassil, Chad E.

    2014-01-01

    Natural populations often show variation in traits that can affect the strength of interspecific interactions. Interaction strengths in turn influence the fate of pairwise interacting populations and the stability of food webs. Understanding the mechanisms relating individual phenotypic variation to interaction strengths is thus central to assess how trait variation affects population and community dynamics. We incorporated nonheritable variation in attack rates and handling times into a clas...

  12. Pain, Affect, and Attachment

    OpenAIRE

    Carl Eduard Scheidt; Elisabeth Waller

    2015-01-01

    Various psychodynamic processes may underlie the development of psychogenic pain disorder such as conversion, the displacement of affect, or narcissistic defenses. However, many of the processes suggested are related to a disorder of affect regulation. The term affect regulation in psychoanalytic literature refers to phenomena which are often described by the concept of alexithymia. Empirical observations suggest that alexithymia is correlated to insecure attachment, especially an insecure di...

  13. The affect structure revisited

    OpenAIRE

    Elefant-Yanni, Véronique Rica; Victoria-Feser, Maria-Pia

    2005-01-01

    In affective psychology, there is a persistent controversy about the number, the nature and the definition of the affect structure dimensions. Responding to the methodological criticisms addressed to the preceding studies, we conciliated the principal theories regarding the affect structure with the same experimental setting. In particular, using the semantic items all around the circumplex we found three bipolar independent dimensions and using only the PANAS semantic items, we found two uni...

  14. Environmental Variation Generates Environmental Opportunist Pathogen Outbreaks.

    Science.gov (United States)

    Anttila, Jani; Kaitala, Veijo; Laakso, Jouni; Ruokolainen, Lasse

    2015-01-01

    Many socio-economically important pathogens persist and grow in the outside host environment and opportunistically invade host individuals. The environmental growth and opportunistic nature of these pathogens has received only little attention in epidemiology. Environmental reservoirs are, however, an important source of novel diseases. Thus, attempts to control these diseases require different approaches than in traditional epidemiology focusing on obligatory parasites. Conditions in the outside-host environment are prone to fluctuate over time. This variation is a potentially important driver of epidemiological dynamics and affect the evolution of novel diseases. Using a modelling approach combining the traditional SIRS models to environmental opportunist pathogens and environmental variability, we show that epidemiological dynamics of opportunist diseases are profoundly driven by the quality of environmental variability, such as the long-term predictability and magnitude of fluctuations. When comparing periodic and stochastic environmental factors, for a given variance, stochastic variation is more likely to cause outbreaks than periodic variation. This is due to the extreme values being further away from the mean. Moreover, the effects of variability depend on the underlying biology of the epidemiological system, and which part of the system is being affected. Variation in host susceptibility leads to more severe pathogen outbreaks than variation in pathogen growth rate in the environment. Positive correlation in variation on both targets can cancel the effect of variation altogether. Moreover, the severity of outbreaks is significantly reduced by increase in the duration of immunity. Uncovering these issues helps in understanding and controlling diseases caused by environmental pathogens. PMID:26710238

  15. Consensus and stratification in the affective meaning of human sociality

    Science.gov (United States)

    Ambrasat, Jens; von Scheve, Christian; Conrad, Markus; Schauenburg, Gesche; Schröder, Tobias

    2014-01-01

    We investigate intrasocietal consensus and variation in affective meanings of concepts related to authority and community, two elementary forms of human sociality. Survey participants (n = 2,849) from different socioeconomic status (SES) groups in German society provided ratings of 909 social concepts along three basic dimensions of affective meaning. Results show widespread consensus on these meanings within society and demonstrate that a meaningful structure of socially shared knowledge emerges from organizing concepts according to their affective similarity. The consensus finding is further qualified by evidence for subtle systematic variation along SES differences. In relation to affectively neutral words, high-status individuals evaluate intimacy-related and socially desirable concepts as less positive and powerful than middle- or low-status individuals, while perceiving antisocial concepts as relatively more threatening. This systematic variation across SES groups suggests that the affective meaning of sociality is to some degree a function of social stratification. PMID:24843121

  16. How do low/high height and weight variation affect upper limb movements during manual material handling of industrial boxes? Como a variação de altura e massa da carga afetam os movimentos do membro superior durante o manuseio de caixas industriais?

    Directory of Open Access Journals (Sweden)

    Ana B. Oliveira

    2011-12-01

    Full Text Available OBJECTIVES: To evaluate the effect of surface height and load weight on upper limb movements and electromyographic (EMG recordings during manual handling performed by both experienced and inexperienced lifter subjects. METHODS: Sixteen experienced and sixteen inexperienced lifters handled a box (both 7 and 15 kg from an intermediate height (waist level to either a high or low surface. Electromyography and video images were recorded during the tasks. The 10th, 50th and 90th percentiles were calculated for the deltoid and biceps muscles, shoulder flexion, shoulder abduction, and elbow flexion movements. Groups, right/left sides, weights and heights were compared. There were no differences between either groups or sides. RESULTS: Weight and height variations affected EMG and posture, although weight had more impact on EMG. Shoulder abduction and flexion movements higher than 60º occurred, particularly for the higher surface. Shoulder flexion was also higher when the box was moved to the low height. This study provides new evidence as shoulder postures during boxes handling on low surfaces had not previously been evaluated. CONCLUSIONS: The high demand of upper limb in manual material handling tasks is clear, particularly for the shoulder. This knowledge can be used by physical therapists to plan better rehabilitation programs for manual material handling-related disorders, particularly focusing on return to work.OBJETIVOS: Avaliar o efeito da altura de superfície e massa da carga nos movimentos e na atividade eletromiográfica (EMG dos membros superiores durante o manuseio de carga realizado por sujeitos experientes e inexperientes. MÉTODOS: Dezesseis sujeitos experientes e 16 inexperientes manusearam uma caixa (7 e 15 kg de uma superfície com altura intermediária para uma superfície alta e/ou baixa. Durante as tarefas, foram registradas imagens de vídeo e EMG. Os dados foram processados para obtenção dos percentis 10, 50 e 90 referentes

  17. Exploring subdomain variation in biomedical language

    Directory of Open Access Journals (Sweden)

    Séaghdha Diarmuid Ó

    2011-05-01

    Full Text Available Abstract Background Applications of Natural Language Processing (NLP technology to biomedical texts have generated significant interest in recent years. In this paper we identify and investigate the phenomenon of linguistic subdomain variation within the biomedical domain, i.e., the extent to which different subject areas of biomedicine are characterised by different linguistic behaviour. While variation at a coarser domain level such as between newswire and biomedical text is well-studied and known to affect the portability of NLP systems, we are the first to conduct an extensive investigation into more fine-grained levels of variation. Results Using the large OpenPMC text corpus, which spans the many subdomains of biomedicine, we investigate variation across a number of lexical, syntactic, semantic and discourse-related dimensions. These dimensions are chosen for their relevance to the performance of NLP systems. We use clustering techniques to analyse commonalities and distinctions among the subdomains. Conclusions We find that while patterns of inter-subdomain variation differ somewhat from one feature set to another, robust clusters can be identified that correspond to intuitive distinctions such as that between clinical and laboratory subjects. In particular, subdomains relating to genetics and molecular biology, which are the most common sources of material for training and evaluating biomedical NLP tools, are not representative of all biomedical subdomains. We conclude that an awareness of subdomain variation is important when considering the practical use of language processing applications by biomedical researchers.

  18. Mediterranean sea level variations.

    Science.gov (United States)

    Vigo, I.; Sánchez Reales, J. M.; García, D.; Chao, B. F.

    2009-04-01

    In this work we report an updated study of the sea level variations for the Mediterranean sea for the period from October 1992 to January 2008. The study addresses two mayor issues: (i)The analysis of the spatial and temporal variability of sea surface height (SSH) from radar altimetry measurements (from TOPEX/Poseidon (T/P) + Jason-1, etc.). We use EOF analysis to explain most of its interannual variation, and how the different basins interact. (ii) The analysis of dynamics and balance of water mass transport for the whole period. We estimate the steric SSH by combining the steric SSH estimated from temperature and salt profiles simulated by the ECCO model with time-variable gravity (TVG) data (from GRACE) for the Mediterranean Sea. The estimated steric SSH together with the SSH obtained from altimetry allow for a more realistic estimation of the water mass variations in the Mediterranean for the whole period.

  19. Variation and Synthetic Speech

    CERN Document Server

    Miller, C; Massey, N; Miller, Corey; Karaali, Orhan; Massey, Noel

    1997-01-01

    We describe the approach to linguistic variation taken by the Motorola speech synthesizer. A pan-dialectal pronunciation dictionary is described, which serves as the training data for a neural network based letter-to-sound converter. Subsequent to dictionary retrieval or letter-to-sound generation, pronunciations are submitted a neural network based postlexical module. The postlexical module has been trained on aligned dictionary pronunciations and hand-labeled narrow phonetic transcriptions. This architecture permits the learning of individual postlexical variation, and can be retrained for each speaker whose voice is being modeled for synthesis. Learning variation in this way can result in greater naturalness for the synthetic speech that is produced by the system.

  20. Essential Variational Poisson Cohomology

    Science.gov (United States)

    De Sole, Alberto; Kac, Victor G.

    2012-08-01

    In our recent paper "The variational Poisson cohomology" (2011) we computed the dimension of the variational Poisson cohomology {{{H}^bullet_K({V})}} for any quasiconstant coefficient ℓ × ℓ matrix differential operator K of order N with invertible leading coefficient, provided that {{{V}}} is a normal algebra of differential functions over a linearly closed differential field. In the present paper we show that, for K skewadjoint, the {{{Z}}} -graded Lie superalgebra {{{H}^bullet_K({V})}} is isomorphic to the finite dimensional Lie superalgebra {{widetilde{H}(Nell,S)}} . We also prove that the subalgebra of "essential" variational Poisson cohomology, consisting of classes vanishing on the Casimirs of K, is zero. This vanishing result has applications to the theory of bi-Hamiltonian structures and their deformations. At the end of the paper we consider also the translation invariant case.

  1. Affectivity and race

    DEFF Research Database (Denmark)

    This book presents new empirical studies of social difference in the Nordic welfare states, in order to advance novel theoretical perspectives on the everyday practices and macro-politics of race and gender in multi-ethnic societies. With attention to the specific political and cultural landscapes...... of the Nordic countries, Affectivity and Race draws on a variety of sources, including television programmes, news media, fictional literature, interviews, ethnographic observations, teaching curricula and policy documents, to explore the ways in which ideas about affectivity and emotion afford new...... insights into the experience of racial difference and the unfolding of political discourses on race in various social spheres. Organised around the themes of the politicisation of race through affect, the way that race produces affect and the affective experience of race, this interdisciplinary collection...

  2. Affectivity in the Liminal

    DEFF Research Database (Denmark)

    Thomassen, Bjørn

    alternative interpretations of what liminality is, or could be, taking it to territories distant from its place of origin, quite the contrary: we are moving the concept back to its rightful place in intellectual history and back to the core of its significance, back to the centre of human emotions trembling......In this paper I propose a return to the work of Arnold van Gennep, in order to briefly discuss how the terms of liminality and affectivity were always already connected. By linking the concept of liminality that van Gennep made famous to affectivity, we are actually not proposing new and...... at the threshold. The paper contains three sections: a) liminality and affectivity in van Gennep’s life; b) liminality and affectivity as a theme in his work; c) liminality and affectivity as developed in the early reception of his work....

  3. Asynchronous Variational Contact Mechanics

    CERN Document Server

    Vouga, Etienne; Tamstorf, Rasmus; Grinspun, Eitan

    2010-01-01

    An asynchronous, variational method for simulating elastica in complex contact and impact scenarios is developed. Asynchronous Variational Integrators (AVIs) are extended to handle contact forces by associating different time steps to forces instead of to spatial elements. By discretizing a barrier potential by an infinite sum of nested quadratic potentials, these extended AVIs are used to resolve contact while obeying momentum- and energy-conservation laws. A series of two- and three-dimensional examples illustrate the robustness and good energy behavior of the method.

  4. Seasonal variation in leisure time physical activity.

    Science.gov (United States)

    Uitenbroek, D G

    1993-06-01

    In this paper seasonal variation in leisure time physical activity for exercise is studied and quantified with regard to several popular exercise activities and taking the respondents gender, occupational status, and age into consideration. The analysis concerns data collected by telephone in Scotland between January 1989 and March 1992. Data from 7,202 male and 9,284 female respondents is used in the analysis; cosinor analysis using GLIM is applied. Considerable seasonal variation was found affecting both outdoor and indoor activities. During the peak phase in July, 32% of the respondents reported exercising for at least 20 min three or more times during the previous week, in the winter period this decreased to 23%. Older respondents were found to exercise more later in the year and also showed seasonal variation to a larger extent than younger respondents. This is particularly so for those respondents who exercise at a relatively high frequency. PMID:8321115

  5. Natural 14C variations

    International Nuclear Information System (INIS)

    This thesis deals with the natural variations in the atmospheric 14C activity, their geophysical origin and their impact on radiocarbon dating. Studies confirm the idea that one is dealing with a mechanism of a certain regularity. The correlation between a 14C variation during the Little Ice Age and the absence of sunspots on the solar surface suggest the sun to be responsible for some kind of modulation of the galactic cosmic ray spectrum. The background of a changing natural 14C level is relevant when studying the antropogenic perturbation of the atmospheric 14C concentration by the addition of CO2 from fossil fuel combustion. The results presented point to a Suess effect over the past 150 years of about 20 per thousand, but also show a local dilution effect. If this local effect is present over large continental parts of the Northern Hemisphere this will put limits to the use of tree ring 14C measurements for testing carbon reservoir models. Finally the influence of 14C variations upon the interpretations of 14C dates for archaeological and geological purposes has been investigated. It is shown that care must be taken especially in the interpretation of highly accurate 14C data of material only covering a few years of growth. One geological example illustrates that 14C variations can easily be interpretated as alternating fast and slow rises of the sea level. (Auth.)

  6. Variational transition state theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, D.G. [Univ. of Minnesota, Minneapolis (United States)

    1993-12-01

    This research program involves the development of variational transition state theory (VTST) and semiclassical tunneling methods for the calculation of gas-phase reaction rates and selected applications. The applications are selected for their fundamental interest and/or their relevance to combustion.

  7. Seasonal Variation in Epidemiology

    Science.gov (United States)

    Marrero, Osvaldo

    2013-01-01

    Seasonality analyses are important in medical research. If the incidence of a disease shows a seasonal pattern, then an environmental factor must be considered in its etiology. We discuss a method for the simultaneous analysis of seasonal variation in multiple groups. The nuts and bolts are explained using simple trigonometry, an elementary…

  8. Bounded variation and around

    CERN Document Server

    Appell, Jürgen; Merentes Díaz, Nelson José

    2013-01-01

    This monographis a self-contained exposition of the definition and properties of functionsof bounded variation and their various generalizations; the analytical properties of nonlinear composition operators in spaces of such functions; applications to Fourier analysis, nonlinear integral equations, and boundary value problems. The book is written for non-specialists. Every chapter closes with a list of exercises and open problems.

  9. Variation and Linguistic Theory.

    Science.gov (United States)

    Bailey, Charles-James N.

    This volume presents principles and models for describing language variation, and introduces a time-based, dynamic framework for linguistic description. The book first summarizes some of the problems of grammatical description encountered from Saussure through the present and then outlines possibilities for new descriptions of language which take…

  10. Genetics in endocrinology: genetic variation in deiodinases: a systematic review of potential clinical effects in humans

    NARCIS (Netherlands)

    Verloop, H.; Dekkers, O.M.; Peeters, R.P.; Schoones, J.W.; Smit, J.W.

    2014-01-01

    Iodothyronine deiodinases represent a family of selenoproteins involved in peripheral and local homeostasis of thyroid hormone action. Deiodinases are expressed in multiple organs and thyroid hormone affects numerous biological systems, thus genetic variation in deiodinases may affect multiple clini

  11. Diurnal variations of Titan

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Mueller-Wodarg, I. C. F.; Kasprzak, W. T.; Waite, J. H.

    2009-04-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1,000 and 1,400 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from 8 close encounters of the Cassini spacecraft with Titan. Though there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ~700 cm-3 below ~1,300 km. Such a plateau is associated with the combination of distinct diurnal variations of light and heavy ions. Light ions (e.g. CH5+, HCNH+, C2H5+) show strong diurnal variation, with clear bite-outs in their nightside distributions. In contrast, heavy ions (e.g. c-C3H3+, C2H3CNH+, C6H7+) present modest diurnal variation, with significant densities observed on the nightside. We propose that the distinctions between light and heavy ions are associated with their different chemical loss pathways, with the former primarily through "fast" ion-neutral chemistry and the latter through "slow" electron dissociative recombination. The INMS data suggest day-to-night transport as an important source of ions on Titan's nightside, to be distinguished from the conventional scenario of auroral ionization by magnetospheric particles as the only ionizing source on the nightside. This is supported by the strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes. We construct a time-dependent ion chemistry model to investigate the effects of day-to-night transport on the ionospheric structures of Titan. The predicted diurnal variation has similar general characteristics to those observed, with some apparent discrepancies which could be reconciled by imposing fast horizontal thermal winds in Titan's upper atmosphere.

  12. Pain, Affect, and Attachment

    Directory of Open Access Journals (Sweden)

    Carl Eduard Scheidt

    2015-03-01

    Full Text Available Various psychodynamic processes may underlie the development of psychogenic pain disorder such as conversion, the displacement of affect, or narcissistic defenses. However, many of the processes suggested are related to a disorder of affect regulation. The term affect regulation in psychoanalytic literature refers to phenomena which are often described by the concept of alexithymia. Empirical observations suggest that alexithymia is correlated to insecure attachment, especially an insecure dismissing representation of attachment. Psychodynamic psychotherapy in psychogenic pain disorder should focus on the reintegration of split-off affects which may provoke intensive counter-transference and which in order to be used therapeutically must be linked to attachment experiences within and outside of the therapeutic relationship.

  13. Colors Can Affect Us!

    Institute of Scientific and Technical Information of China (English)

    张俊斌

    2006-01-01

    Different colors affect us differently.The following will show us how they work. Experiment proves that math problems worked on yellow paper have fewer mistakes than problems written on other colors of paper.

  14. Classifying Measures of Biological Variation

    OpenAIRE

    Gregorius, Hans-Rolf; Gillet, Elizabeth M

    2015-01-01

    Biological variation is commonly measured at two basic levels: variation within individual communities, and the distribution of variation over communities or within a metacommunity. We develop a classification for the measurement of biological variation on both levels: Within communities into the categories of dispersion and diversity, and within metacommunities into the categories of compositional differentiation and partitioning of variation. There are essentially two approaches to characte...

  15. Affective responses to dance.

    Science.gov (United States)

    Christensen, Julia F; Pollick, Frank E; Lambrechts, Anna; Gomila, Antoni

    2016-07-01

    The objective of the present work was the characterization of mechanisms by which affective experiences are elicited in observers when watching dance movements. A total of 203 dance stimuli from a normed stimuli library were used in a series of independent experiments. The following measures were obtained: (i) subjective measures of 97 dance-naïve participants' affective responses (Likert scale ratings, interviews); and (ii) objective measures of the physical parameters of the stimuli (motion energy, luminance), and of the movements represented in the stimuli (roundedness, impressiveness). Results showed that (i) participants' ratings of felt and perceived affect differed, (ii) felt and perceived valence but not arousal ratings correlated with physical parameters of the stimuli (motion energy and luminance), (iii) roundedness in posture shape was related to the experience of more positive emotion than edgy shapes (1 of 3 assessed rounded shapes showed a clear effect on positiveness ratings while a second reached trend level significance), (iv) more impressive movements resulted in more positive affective responses, (v) dance triggered affective experiences through the imagery and autobiographical memories it elicited in some people, and (vi) the physical parameters of the video stimuli correlated only weakly and negatively with the aesthetics ratings of beauty, liking and interest. The novelty of the present approach was twofold; (i) the assessment of multiple affect-inducing mechanisms, and (ii) the use of one single normed stimulus set. The results from this approach lend support to both previous and present findings. Results are discussed with regards to current literature in the field of empirical aesthetics and affective neuroscience. PMID:27235953

  16. The variational Poisson cohomolgy

    CERN Document Server

    De Sole, Alberto

    2011-01-01

    It is well known that the validity of the so called Lenard-Magri scheme of integrability of a bi-Hamiltonian PDE can be established if one has some precise information on the corresponding 1st variational Poisson cohomology for one of the two Hamiltonian operators. In the first part of the paper we explain how to introduce various cohomology complexes, including Lie superalgebra and Poisson cohomology complexes, and basic and reduced Lie conformal algebra and Poisson vertex algebra cohomology complexes, by making use of the corresponding universal Lie superalebra or Lie conformal superalgebra. The most relevant are certain subcomplexes of the basic and reduced Poisson vertex algebra cohomology complexes, which we identify (non-canonically) with the generalized de Rham complex and the generalized variational complex. In the second part of the paper we compute the cohomology of the generalized de Rham complex, and, via a detailed study of the long exact sequence, we compute the cohomology of the generalized var...

  17. Automatic Differentiation Variational Inference

    OpenAIRE

    Kucukelbir, Alp; Tran, Dustin; Ranganath, Rajesh; Gelman, Andrew; Blei, David M.

    2016-01-01

    Probabilistic modeling is iterative. A scientist posits a simple model, fits it to her data, refines it according to her analysis, and repeats. However, fitting complex models to large data is a bottleneck in this process. Deriving algorithms for new models can be both mathematically and computationally challenging, which makes it difficult to efficiently cycle through the steps. To this end, we develop automatic differentiation variational inference (ADVI). Using our method, the scientist on...

  18. Planar theory made variational

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, A.D.; Lande, A.; Smith, R.A.

    1985-04-08

    Within the framework of boson parquet-diagram summations in perturbation theory, we show analytically that several simple approximations lead inevitably to the radial distribution function g(r) which would be obtained with the Jastrow hypernetted-chain variational method. This is the first derivation of the Jastrow result from perturbation theory. Without mentioning pair correlation functions, we have a clear interpretation of g(r) and the structure function, S(k), in terms of diagram sums.

  19. Planar theory made variational

    International Nuclear Information System (INIS)

    Within the framework of boson parquet-diagram summations in perturbation theory, we show analytically that several simple approximations lead inevitably to the radial distribution function g(r) which would be obtained with the Jastrow hypernetted-chain variational method. This is the first derivation of the Jastrow result from perturbation theory. Without mentioning pair correlation functions, we have a clear interpretation of g(r) and the structure function, S(k), in terms of diagram sums

  20. Geographically Related Variation in Epicuticular Wax Traits of Pinus nigra Populations from Southern Carpathians and Central Balkans - Taxonomic Considerations.

    Science.gov (United States)

    Mitić, Zorica S; Zlatković, Bojan K; Jovanović, Snežana Č; Stojanović, Gordana S; Marin, Petar D

    2016-07-01

    The chemical composition of epicuticular waxes of nine populations from three Pinus nigra J. F. Arnold subspecies (namely subsp. nigra, subsp. banatica (Borbás) Novák, and subsp. pallasiana (Lamb.) Holmboe) from Southern Carpathians and central Balkan Peninsula were analyzed using GC/MS and GC/FID chromatography, and multivariate statistical techniques with respect to biogeography and taxonomy. In the needle waxes, four primary alcohols and 14 n-alkanes ranging from C21 to C33 were identified, and the most abundant compounds were the four odd-numbered n-alkanes C27 , C25 , C23 , and C29. Multivariate statistical analyses (CDA and CA) have shown existence of three P. nigra groups and suggested clinal differentiation as a mechanism of genetic variation across a geographic area: the first group consisted of the southernmost populations of subsp. pallasiana from Macedonia, the second consisted of the northernmost subsp. banatica populations from Romania, while all populations in Serbia described as three different subspecies (nigra, banatica, and pallasiana) formed the third group together with subsp. nigra population from Bosnia and Herzegovina. According to simple linear regression, geographic latitude and four bioclimatic parameters were moderately correlated with the contents of epicuticular wax compounds that are important in population discrimination, while stepwise multiple regression showed that latitude participated in most of the regression models for predicting the composition of the epicuticular waxes. These results agree with CDA and CA analysis, and confirmed the possibility of recognition of fine geographic differentiation of the analyzed P. nigra populations. PMID:27273147

  1. Canonical variate regression.

    Science.gov (United States)

    Luo, Chongliang; Liu, Jin; Dey, Dipak K; Chen, Kun

    2016-07-01

    In many fields, multi-view datasets, measuring multiple distinct but interrelated sets of characteristics on the same set of subjects, together with data on certain outcomes or phenotypes, are routinely collected. The objective in such a problem is often two-fold: both to explore the association structures of multiple sets of measurements and to develop a parsimonious model for predicting the future outcomes. We study a unified canonical variate regression framework to tackle the two problems simultaneously. The proposed criterion integrates multiple canonical correlation analysis with predictive modeling, balancing between the association strength of the canonical variates and their joint predictive power on the outcomes. Moreover, the proposed criterion seeks multiple sets of canonical variates simultaneously to enable the examination of their joint effects on the outcomes, and is able to handle multivariate and non-Gaussian outcomes. An efficient algorithm based on variable splitting and Lagrangian multipliers is proposed. Simulation studies show the superior performance of the proposed approach. We demonstrate the effectiveness of the proposed approach in an [Formula: see text] intercross mice study and an alcohol dependence study. PMID:26861909

  2. The Affective Turn

    Directory of Open Access Journals (Sweden)

    Alí Lara

    2013-11-01

    Full Text Available In the last decade studies on affect and emotions have become relevant in the social sciences. This is not just a fad guideline, but instead a simultaneous reader of public life changes and subjective experience, from which it is also being transformed the knowledge production. Such a trend has been known as ‘The Affective Turn’ within the Anglophone Academy. Here we will translate it as ‘El Giro Afectivo’. This turn, so far, has not dabbled in the social science literature that is written in Spanish. This paper draws on a singular panorama of discussions about contemporary social studies of affect and emotion, and it’s vertebrate by some of its expressions in the contemporary academy.

  3. The Affective Turn

    DEFF Research Database (Denmark)

    Carnera, Alexander

    2012-01-01

    This paper confronts biopolitics with modern labour addressing questions of ‘governmentality’, ‘self-management’ and ‘social innovation’. It argues that the new modes of production within immaterial labour involve a new complex relation between on the one hand the ‘Art of Governance......-management that human individuation ties together modes of productions with affects and emotions. Introducing Spinoza's concept of ‘affect’, and Gilles Deleuze's reading of Spinoza's ethics focusing on the ‘affective turn’ in relation to the new economy and society, the paper argues for a more positive notion of...... biopolitics that surpasses that of governmentality. The affective self-relation is used as a research tool to analyse the creation of social and economic values in our new modes of productions, for instance, within free labour of the cultural industry. The movie The Five Obstructions is used to show how...

  4. Affected in the nightclub

    DEFF Research Database (Denmark)

    Demant, Jakob Johan

    2013-01-01

    experiences within a club as a way of understanding the complexities of pleasure. The study does so by addressing experiences through the concept of affects, which is situated within a framework of a non-representational theory of space. Anxiety, pride, anger, shame and embarrassment are embodied...

  5. Life-history variation of drosophila subobscura under lead pollution depends on population history

    OpenAIRE

    Kenig Bojan; Patenković Aleksandra; Anđelković Marko; Stamenković-Rada Marina

    2014-01-01

    Contamination represents environmental stress that can affect genetic variability of populations, thus influencing the evolutionary processes. In this study, we evaluate the relationship between heavy metal contamination (Pb) and phenotypic variation, assessed by coefficients of variation (CV) of life-history traits. To investigate the consequences of population origin on variation of life history traits in Drosophila subobscura in response to different lab...

  6. An empirical model of the quiet daily geomagnetic field variation

    Science.gov (United States)

    Yamazaki, Y.; Yumoto, K.; Cardinal, M.G.; Fraser, B.J.; Hattori, P.; Kakinami, Y.; Liu, J.Y.; Lynn, K.J.W.; Marshall, R.; McNamara, D.; Nagatsuma, T.; Nikiforov, V.M.; Otadoy, R.E.; Ruhimat, M.; Shevtsov, B.M.; Shiokawa, K.; Abe, S.; Uozumi, T.; Yoshikawa, A.

    2011-01-01

    An empirical model of the quiet daily geomagnetic field variation has been constructed based on geomagnetic data obtained from 21 stations along the 210 Magnetic Meridian of the Circum-pan Pacific Magnetometer Network (CPMN) from 1996 to 2007. Using the least squares fitting method for geomagnetically quiet days (Kp ??? 2+), the quiet daily geomagnetic field variation at each station was described as a function of solar activity SA, day of year DOY, lunar age LA, and local time LT. After interpolation in latitude, the model can describe solar-activity dependence and seasonal dependence of solar quiet daily variations (S) and lunar quiet daily variations (L). We performed a spherical harmonic analysis (SHA) on these S and L variations to examine average characteristics of the equivalent external current systems. We found three particularly noteworthy results. First, the total current intensity of the S current system is largely controlled by solar activity while its focus position is not significantly affected by solar activity. Second, we found that seasonal variations of the S current intensity exhibit north-south asymmetry; the current intensity of the northern vortex shows a prominent annual variation while the southern vortex shows a clear semi-annual variation as well as annual variation. Thirdly, we found that the total intensity of the L current system changes depending on solar activity and season; seasonal variations of the L current intensity show an enhancement during the December solstice, independent of the level of solar activity. Copyright 2011 by the American Geophysical Union.

  7. Neurotransmitters affecting time perception

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND:It has been demonstrated that dopamine and acetylcholine are the main neurotransmitters that affect time perception,which is also affected by other neurotransmitters.OBJECTIVE:To summarize how the neurotransmitter affect the time perception,and put forward the perspectives for further study on time perception.RETRIEVE STRATEGY:An online search for related literatures published in English was conducted in Elsevier SDOL(ScienceDirect Online)database from May 1990 to March 2007 using key words of "timing neurotransmitter".Totally 69 literatures were collected,and they were primarily checked.Inclusive criteria:Reviews and experimental studies;correlative studies of timing neurotransmitter.Exclusive criteria:Repeated studies.LITERATURE EVALUATION:The literatures were mainly sourced from Cognitive Brain Research and Neuroscience,and they were analyzed according to the inclusive criteria.Nineteen of them were involved,and all were experimental studies and reviews.DATA SYNTHESIS:The studies on time perception are developed mainly concentrating on dopamine and acetylcholine.Dopamine D2 receptors mainly affect the speed of internal clock.Dopamine receptors play an important role in both timing excitation and inhibition,which suggests the bi-directional regulation of dopamine.Injection of dopamine agonist can affect the attention to timing information.Injection of BW813U(antagonist of acetylcholine) can induce memory disorder,which indicates the effect of acetylcholine on timing memory,and further study shows that it is the effect of acetylcholine in precentral medial area.In a word,the study on the neurotransmitters affecting time perception is still at the primary stage.CONCLUSION:Dopamine and acetylcholine are the neurotransmitters known to be related to time perception.Dopamine in the basal ganglia is related to internal-clock in the range of seconds and minutes;Acetylcholine in prefrontal cortex is related to the mechanisms of temporal memory and attention

  8. Introduction to global variational geometry

    CERN Document Server

    Krupka, Demeter

    2015-01-01

    The book is devoted to recent research in the global variational theory on smooth manifolds. Its main objective is an extension of the classical variational calculus on Euclidean spaces to (topologically nontrivial) finite-dimensional smooth manifolds; to this purpose the methods of global analysis of differential forms are used. Emphasis is placed on the foundations of the theory of variational functionals on fibered manifolds - relevant geometric structures for variational principles in geometry, physical field theory and higher-order fibered mechanics. The book chapters include: - foundations of jet bundles and analysis of differential forms and vector fields on jet bundles, - the theory of higher-order integral variational functionals for sections of a fibred space, the (global) first variational formula in infinitesimal and integral forms- extremal conditions and the discussion of Noether symmetries and generalizations,- the inverse problems of the calculus of variations of Helmholtz type- variational se...

  9. Harmonically excited orbital variations

    International Nuclear Information System (INIS)

    Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs

  10. Genetic variation of CHRNA4 does not modulate attention in Parkinson’s disease

    OpenAIRE

    Hudson, Gavin; Stutt, Andrea; Eccles, Martin; Robinson, Louise; Allcock, Liesl M.; Wesnes, Keith A.; Chinnery, Patrick F.; Burn, David J.

    2010-01-01

    Parkinson’s disease (PD) is a neurodegenerative disorder, characterised by cognitive decline and attentional impairment. Recently, variation in CHRNA4 (rs1044396) has been shown to affect visual and auditory function, affecting speed and attention, in healthy adults. An association between CHRNA4 variation and PD has not been shown. To determine the link between CHRNA4 variation and attentional deficit in PD. A genotype-phenotype correlation between the common CHRNA4:rs1044396 variant and sev...

  11. Social carry-over effects on non-social behavioral variation: mechanisms and consequences

    OpenAIRE

    Niemelä, Petri T.; Santostefano, Francesca

    2015-01-01

    The field of animal personality is interested in decomposing behaviors into different levels of variation, with its present focus on the ecological and evolutionary causes and consequences of expressed variation. Recently the role of the social environment, i.e., social partners, has been suggested to affect behavioral variation and induce selection on animal personality. Social partner effects exist because characters of social partners (e.g., size, behavior), affect the behavioral expressio...

  12. Affects and assemblages

    DEFF Research Database (Denmark)

    Samson, Kristine

    happens to aesthetics and how does it change the existing social and geographical understanding of urban space? The paper sets out to reintroduce aesthetical aspects of affects and assemblages in relation to urban space and urban planning. It presupposes urban space as a continuous state of becoming where...... ‘throwntogetherness’ (Massey 2005) or assemblage (Farias & Bender 2010) of perspectives bridging for instance the social and cultural experienced space investigated by the geographer and urban sociologist with the material and formal aesthetics of the architect and urban planner....... cultural geopgraphy. On this backdrop the paper states that affects and assemblages could serve as key notions for the reassembling the aesthetics of urban space. Thus, the paper suggest a less formal understanding of urban space and aesthetics, proposing an understanding of aesthetics as a...

  13. Comfortable bodies: sedentary affects

    OpenAIRE

    David Bissell

    2008-01-01

    Whilst to be comfortable is often equated with conservatism and complacency, this paper considers the various and often complex configurations of comfort as a desirable corporeal sensibility. Subsequently, this paper considers what corporeal comfort as an affective sensibility is and can do to theorisations of the sedentary body. The sensibility of corporeal comfort induced through the relationality between bodies and proximate objects is explored to trace through some of the affectual circul...

  14. Cytoplasm Affects Embryonic Development

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Recent studies by CAS researchers furnish strong evidence that a fertilized egg's nucleus isn't the sole site of control for an embryo's development. A research team headed by Prof. Zhu Zuoyan from the CAS Institute of Hydrobiology in Wuhan discovered that cytoplasm affects the number of vertebrae in cloned offspring created when nuclei from one fish genus were transplanted to enucleated eggs of another.

  15. Factors Affecting Wound Healing

    OpenAIRE

    Guo, S; DiPietro, L. A.

    2010-01-01

    Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutane...

  16. Affective Image Colorization

    Institute of Scientific and Technical Information of China (English)

    Xiao-Hui Wang; Jia Jia; Han-Yu Liao; Lian-Hong Cai

    2012-01-01

    Colorization of gray-scale images has attracted many attentions for a long time.An important role of image color is the conveyer of emotions (through color themes).The colorization with an undesired color theme is less useful,even it is semantically correct.However this has been rarely considered.Automatic colorization respecting both the semantics and the emotions is undoubtedly a challenge.In this paper,we propose a complete system for affective image colorization.We only need the user to assist object segmentation along with text labels and an affective word.First,the text labels along with other object characters are jointly used to filter the internet images to give each object a set of semantically correct reference images.Second,we select a set of color themes according to the affective word based on art theories.With these themes,a generic algorithm is used to select the best reference for each object,balancing various requirements.Finally,we propose a hybrid texture synthesis approach for colorization.To the best of our knowledge,it is the first system which is able to efficiently colorize a gray-scale image semantically by an emotionally controllable fashion.Our experiments show the effectiveness of our system,especially the benefit compared with the previous Markov random field (MRF) based method.

  17. Genetic by environment interactions affect plant–soil linkages

    OpenAIRE

    Pregitzer, Clara C; Joseph K Bailey; Schweitzer, Jennifer A.

    2013-01-01

    The role of plant intraspecific variation in plant–soil linkages is poorly understood, especially in the context of natural environmental variation, but has important implications in evolutionary ecology. We utilized three 18- to 21-year-old common gardens across an elevational gradient, planted with replicates of five Populus angustifolia genotypes each, to address the hypothesis that tree genotype (G), environment (E), and G × E interactions would affect soil carbon and nitrogen dynamics be...

  18. Terrestrial waters and sea level variations on interannual time scale

    OpenAIRE

    Llovel, W.; Becker, M.; Cazenave, A.; Jevrejeva, S.; R. Alkama; Decharme, B.; Douville, H.; Ablain, M.; Beckley, B

    2011-01-01

    On decadal to multidecadal time scales, thermal expansion of sea waters and land ice loss are the main contributors to sea level variations. However, modification of the terrestrial water cycle due to climate variability and direct anthropogenic forcing may also affect sea level. For the past decades, variations in land water storage and corresponding effects on sea level cannot be directly estimated from observations because these are almost unexistent at global continental scale. However, g...

  19. Variations in the Incidence of Schizophrenia: Data Versus Dogma

    OpenAIRE

    McGrath, John J.

    2006-01-01

    The schizophrenia research community has shared a belief that the incidence of schizophrenia shows little variation. This belief is related to the dogma that schizophrenia affects all individuals equally, regardless of sex, race, or nationality. However, there is now robust evidence that the incidence of schizophrenia is characterized by substantial variability. There is prominent variation in the incidence of schizophrenia between sites. The incidence of schizophrenia is significantly higher...

  20. Continuous radon measurements in schools: time variations and related parameters

    International Nuclear Information System (INIS)

    Some results are reported of observations made within a four-year survey, during different seasons and in different conditions of school building use. Natural radon variations (day-night cycles, seasonal and temperature dependent variations etc..) and artificial ones (opening of windows, weekends and vacations, deployment of air conditioning or heating systems. etc.) were investigated as parameters affecting time dependent radon concentrations. (P.A.)

  1. Bordetella bronchiseptica phase variation induced by crystal violet.

    OpenAIRE

    Ishikawa, H.; Isayama, Y

    1986-01-01

    A method for effective induction of phase variation in Bordetella bronchiseptica by treatment with crystal violet (CV) is presented. When grown in CV-broth, phase I cells dissociated into three serial phases. Appearance of variant cells was observed simultaneously with the beginning of cell multiplication. The maximum effect of CV was obtained at a concentration of 8 micrograms/ml, when the proportion of variants in the population reached 100%. The main factors which affected phase variation ...

  2. Genetics of the dentofacial variation in human malocclusion

    OpenAIRE

    Moreno Uribe, L. M.; Miller, S. F.

    2015-01-01

    Malocclusions affect individuals worldwide, resulting in compromised function and esthetics. Understanding the etiological factors contributing to the variation in dentofacial morphology associated with malocclusions is the key to develop novel treatment approaches. Advances in dentofacial phenotyping, which is the comprehensive characterization of hard and soft tissue variation in the craniofacial complex, together with the acquisition of large-scale genomic data have started to unravel gene...

  3. Intrafamilial variation of the phenotype in Bardet-Biedl syndrome

    OpenAIRE

    Riise, R.; Andreasson, S.; Borgstrom, M.; Wright, A; Tommerup, N.; Rosenberg, T; Tornqvist, K

    1997-01-01

    AIMS—To describe the variation of the phenotype within families with several individuals with Bardet-Biedl syndrome.
METHODS—The phenotypes of affected siblings in 11 Scandinavian families were compared with two or more members who had at least three of the features: retinal dystrophy, polydactyly, obesity, hypogenitalism, and mental retardation. Individuals without retinal dystrophy were excluded.
RESULTS—Intrafamilial variation of expressivity of the features obesity, polydactyly, abnormal ...

  4. Variation in content and composition of phenolic compounds in permanent pastures according to botanical variation

    OpenAIRE

    Reynaud, Aurélie; Fraisse, Didier; Cornu, Agnes; Farruggia, Anne; Pujos-Guillot, Estelle; Besle, Jean-Michel; Martin, Bruno; Lamaison, Jean-Louis; Paquet, Denis; Doreau, Michel; Graulet, Benoit

    2010-01-01

    Phenolic compounds contribute to the micronutrient composition of pasture, which in turn may affect animal product composition. To assess the importance and variations in content of these compounds, the polyphenolic and botanical compositions of 24 permanent pastures located in one lowland and two upland regions were studied at equivalent stages of growth. Phenolic fractions were characterized and quantified using HPLC-PDA-ESI-QToF, and the total content was determined by colorimetry over eac...

  5. Weather explains high annual variation in butterfly dispersal.

    Science.gov (United States)

    Kuussaari, Mikko; Rytteri, Susu; Heikkinen, Risto K; Heliölä, Janne; von Bagh, Peter

    2016-07-27

    Weather conditions fundamentally affect the activity of short-lived insects. Annual variation in weather is therefore likely to be an important determinant of their between-year variation in dispersal, but conclusive empirical studies are lacking. We studied whether the annual variation of dispersal can be explained by the flight season's weather conditions in a Clouded Apollo (Parnassius mnemosyne) metapopulation. This metapopulation was monitored using the mark-release-recapture method for 12 years. Dispersal was quantified for each monitoring year using three complementary measures: emigration rate (fraction of individuals moving between habitat patches), average residence time in the natal patch, and average distance moved. There was much variation both in dispersal and average weather conditions among the years. Weather variables significantly affected the three measures of dispersal and together with adjusting variables explained 79-91% of the variation observed in dispersal. Different weather variables became selected in the models explaining variation in three dispersal measures apparently because of the notable intercorrelations. In general, dispersal rate increased with increasing temperature, solar radiation, proportion of especially warm days, and butterfly density, and decreased with increasing cloudiness, rainfall, and wind speed. These results help to understand and model annually varying dispersal dynamics of species affected by global warming. PMID:27440662

  6. Variación morfológica del camarón café (Farfantepenaeus californiensis en el Pacífico mexicano Morphological variation of brown shrimp (Farfantepenaeus californiensis in Mexican Pacific

    Directory of Open Access Journals (Sweden)

    María de Lourdes Barbosa-Saldaña

    2012-03-01

    Nacional de la Pesca to monitoring the brown shrimp populations. The morphologic variation of each sample was estimated through the variation coefficient (CV% averaged over 18 measurements. A discriminant analysis was made using the standardized ratios for some of the measurements. Manhattan distances among samples were calculated to obtain a dendrogram with the UPGMA method where localities grouping showed a clinal pattern of morphological differentiation related to a geographical gradient. The low estimated morphologic variability within samples allowed us to conclude that each sampled locality conforms a phenotypically homogeneous group, with clear differences to the others. These differences could be explained on basis of the environmental characteristics of each locality in addition to possible genetic variations between populations. Thus, the morphological differentiation of the brown shrimp populations of the Mexican Pacific detected in this study provides additional elements to sustain the geographical division that the Instituto Nacional de la Pesca established to survey the shrimp fishery.

  7. Dynamics of nonholonomic systems from variational principles embedded variation identity

    International Nuclear Information System (INIS)

    Nondeterminacy of dynamics, i.e., the nonholonomic or the vakonomic, fundamental variational principles, e.g., the Lagrange-d'Alembert or Hamiltonian, and variational operators, etc., of nonholonomic mechanical systems can be attributed to the non-uniqueness of ways how to realize nonholonomic constraints. Making use of a variation identity of nonholonomic constraints embedded into the Hamilton's principle with the method of Lagrange undetermined multipliers, three kinds of dynamics for the nonholonomic systems including the vakonomic and nonholonomic ones and a new one are obtained if the variation is respectively reduced to three conditional variations: vakonomic variation, Hoelder's variation and Suslov's variation, defined by the identity. Therefore, different dynamics of nonholonomic systems can be derived from an integral variational principle, utilizing one way of embedding constraints into the principle, with different variations. It is verified that the similar embedding of the identity into the Lagrange-d'Alembert principle gives rise to the nonholonomic dynamics but fails to give the vakonomic one unless the constraints are integrable.

  8. The Affective Turn

    OpenAIRE

    Alí Lara; Giazú Enciso

    2013-01-01

    En la última década los estudios del afecto y las emociones han cobrado relevancia en las ciencias sociales. Esto no es simplemente una directriz de moda, es un indicador simultáneo de las modificaciones en la vida pública y de la experiencia subjetiva; a partir del cual se está transformando la producción de conocimiento. Tal tendencia ha sido conocida en la academia sajona como The Affective Turn, aquí traducido como “El giro afectivo” y que hasta el momento no ha incursionado como tal en l...

  9. Visual affect recognition

    CERN Document Server

    Stathopoulou, I-O

    2010-01-01

    It is generally known that human faces, as well as body motions and gestures, provide a wealth of information about a person, such as age, race, sex and emotional state. This monograph primarily studies the perception of facial expression of emotion, and secondarily of motion and gestures, with the purpose of developing a fully automated visual affect recognition system for use in modes of human/computer interaction. The book begins with a survey of the literature on emotion perception, followed by a description of empirical studies conducted with human participants and the construction of a '

  10. Néotectonique affectant les dépôts marins tyrrhéniens du littoral sud-est tunisien : implications pour les variations du niveau marinNeotectonics in the Tyrrhenian marine deposits of the southeastern Tunisian coast: implications for sea level changes

    Science.gov (United States)

    Bouaziz, Samir; Jedoui, Younes; Barrier, Éric; Angelier, Jacques

    2003-01-01

    Pleistocene marine deposits of so-called Tyrrhenian age in southeastern Tunisia include two lithostratigraphic units of Last Interglacial (marine isotopic substage 5e). The lower unit culminates at about +3 m above the sea level; the upper unit with Strombus bubonius culminates at +5 m. Brittle deformations affected the upper unit. The analysis of fault-slip data sets reveals a post-Tyrrhenian N020°E trending compression, consistent with joint patterns. This event induced limited vertical movements, showing that at the northeastern edge of the Saharan Platform, the coastal area of the southern Tunisia remained relatively stable since at least the Last Interglacial.

  11. Older age may offset genetic influence on affect: The COMT polymorphism and affective well-being across the life span.

    Science.gov (United States)

    Turan, Bulent; Sims, Tamara; Best, Sasha E; Carstensen, Laura L

    2016-05-01

    The catechol-O-methyltransferase (COMT_Val158Met) genetic polymorphism has been linked to variation in affective well-being. Compared with Val carriers, Met carriers experience lower affective well-being. In parallel, research on aging and affective experience finds that younger adults experience poorer affective well-being than older adults. This study examined how COMT and age may interact to shape daily affective experience across the life span. Results suggest that Met (vs. Val) carriers experience lower levels of affective well-being in younger but not in older ages. These findings suggest that age-related improvements in emotional functioning may offset genetic vulnerabilities to negative affective experience. (PsycINFO Database Record PMID:27111524

  12. Normal seasonal variations for atmospheric radon concentration: a sinusoidal model

    International Nuclear Information System (INIS)

    Anomalous radon readings in air have been reported before an earthquake activity. However, careful measurements of atmospheric radon concentrations during a normal period are required to identify anomalous variations in a precursor period. In this study, we obtained radon concentration data for 5 years (2003–2007) that can be considered a normal period and compared it with data from the precursory period of 2008 until March 2011, when the 2011 Tohoku-Oki Earthquake occurred. Then, we established a model for seasonal variation by fitting a sinusoidal model to the radon concentration data during the normal period, considering that the seasonal variation was affected by atmospheric turbulence. By determining the amplitude in the sinusoidal model, the normal variation of the radon concentration can be estimated. Thus, the results of this method can be applied to identify anomalous radon variations before an earthquake. - Highlights: • Normal seasonal variation of the atmospheric radon concentration was determined by accurately fitting with a sinusoidal model. • The seasonal variation in data was affected by atmospheric turbulence. • The normal radon pattern was used to extract precursory changes before earthquakes

  13. Genotypic richness predicts phenotypic variation in an endangered clonal plant

    Science.gov (United States)

    Sinclair, Elizabeth A.; Poore, Alistair G.B.; Bain, Keryn F.; Vergés, Adriana

    2016-01-01

    Declines in genetic diversity within a species can affect the stability and functioning of populations. The conservation of genetic diversity is thus a priority, especially for threatened or endangered species. The importance of genetic variation, however, is dependent on the degree to which it translates into phenotypic variation for traits that affect individual performance and ecological processes. This is especially important for predominantly clonal species, as no single clone is likely to maximise all aspects of performance. Here we show that intraspecific genotypic diversity as measured using microsatellites is a strong predictor of phenotypic variation in morphological traits and shoot productivity of the threatened, predominantly clonal seagrass Posidonia australis, on the east coast of Australia. Biomass and surface area variation was most strongly predicted by genotypic richness, while variation in leaf chemistry (phenolics and nitrogen) was unrelated to genotypic richness. Genotypic richness did not predict tissue loss to herbivores or epiphyte load, however we did find that increased herbivore damage was positively correlated with allelic richness. Although there was no clear relationship between higher primary productivity and genotypic richness, variation in shoot productivity within a meadow was significantly greater in more genotypically diverse meadows. The proportion of phenotypic variation explained by environmental conditions varied among different genotypes, and there was generally no variation in phenotypic traits among genotypes present in the same meadows. Our results show that genotypic richness as measured through the use of presumably neutral DNA markers does covary with phenotypic variation in functionally relevant traits such as leaf morphology and shoot productivity. The remarkably long lifespan of individual Posidonia plants suggests that plasticity within genotypes has played an important role in the longevity of the species

  14. Genotypic richness predicts phenotypic variation in an endangered clonal plant.

    Science.gov (United States)

    Evans, Suzanna M; Sinclair, Elizabeth A; Poore, Alistair G B; Bain, Keryn F; Vergés, Adriana

    2016-01-01

    Declines in genetic diversity within a species can affect the stability and functioning of populations. The conservation of genetic diversity is thus a priority, especially for threatened or endangered species. The importance of genetic variation, however, is dependent on the degree to which it translates into phenotypic variation for traits that affect individual performance and ecological processes. This is especially important for predominantly clonal species, as no single clone is likely to maximise all aspects of performance. Here we show that intraspecific genotypic diversity as measured using microsatellites is a strong predictor of phenotypic variation in morphological traits and shoot productivity of the threatened, predominantly clonal seagrass Posidonia australis, on the east coast of Australia. Biomass and surface area variation was most strongly predicted by genotypic richness, while variation in leaf chemistry (phenolics and nitrogen) was unrelated to genotypic richness. Genotypic richness did not predict tissue loss to herbivores or epiphyte load, however we did find that increased herbivore damage was positively correlated with allelic richness. Although there was no clear relationship between higher primary productivity and genotypic richness, variation in shoot productivity within a meadow was significantly greater in more genotypically diverse meadows. The proportion of phenotypic variation explained by environmental conditions varied among different genotypes, and there was generally no variation in phenotypic traits among genotypes present in the same meadows. Our results show that genotypic richness as measured through the use of presumably neutral DNA markers does covary with phenotypic variation in functionally relevant traits such as leaf morphology and shoot productivity. The remarkably long lifespan of individual Posidonia plants suggests that plasticity within genotypes has played an important role in the longevity of the species

  15. On the Variational Problems without Having Desired Variational Symmetries

    Directory of Open Access Journals (Sweden)

    Mehdi Nadjafikhah

    2013-01-01

    Full Text Available We will have an attempt to present a method for constructing variational problems without having a desired one-parameter transformation group as a variational symmetry. For this, we use the notation of μ-symmetry which was introduced by Giuseppe Gaeta and Paola Morando in 2004. Moreover, our given method enabled us to solve those constructed variational problems using μ-symmetries.

  16. FROG - Fingerprinting Genomic Variation Ontology.

    Directory of Open Access Journals (Sweden)

    E Abinaya

    Full Text Available Genetic variations play a crucial role in differential phenotypic outcomes. Given the complexity in establishing this correlation and the enormous data available today, it is imperative to design machine-readable, efficient methods to store, label, search and analyze this data. A semantic approach, FROG: "FingeRprinting Ontology of Genomic variations" is implemented to label variation data, based on its location, function and interactions. FROG has six levels to describe the variation annotation, namely, chromosome, DNA, RNA, protein, variations and interactions. Each level is a conceptual aggregation of logically connected attributes each of which comprises of various properties for the variant. For example, in chromosome level, one of the attributes is location of variation and which has two properties, allosomes or autosomes. Another attribute is variation kind which has four properties, namely, indel, deletion, insertion, substitution. Likewise, there are 48 attributes and 278 properties to capture the variation annotation across six levels. Each property is then assigned a bit score which in turn leads to generation of a binary fingerprint based on the combination of these properties (mostly taken from existing variation ontologies. FROG is a novel and unique method designed for the purpose of labeling the entire variation data generated till date for efficient storage, search and analysis. A web-based platform is designed as a test case for users to navigate sample datasets and generate fingerprints. The platform is available at http://ab-openlab.csir.res.in/frog.

  17. Polarizer reflectivity variations

    International Nuclear Information System (INIS)

    On Shiva the beam energy along the chain is monitored using available reflections and/or transmission through beam steering, splitting, and polarizing optics without the intrusion of any additional glass for diagnostics. On the preamp table the diagnostic signal is obtained from the signal transmitted through turning mirrors. At the input of each chain the signal is obtained from the transmission through one of the mirrors used for the chain input alignment sensor (CHIP). At the chain output the transmission through the final turning mirror is used. These diagnostics have proved stable and reliable. However, one of the prime diagnostic locations is at the output of the beta rod. The energy at this location is measured by collecting small reflections from the last polarizer surface of the beta Pockels cell polarizer package. Unfortunately, calibration of this diagnostic has varied randomly, seldom remaining stable for a week or more. The cause of this fluctuation has been investigated for the past year and'it has been discovered that polarizer reflectivity varies with humidity. This report will deal with the possible causes that were investigated, the evidence that humidity is causing the variation, and the associated mechanism

  18. Material and Affective Movements

    DEFF Research Database (Denmark)

    Rasmussen, Lisa Rosén

    2014-01-01

    This chapter offers a study of life at school as remembered by groups of people who finished secondary school in the 1950s, 1970s and 1990s. The article draws up three generational portraits based on in-depth interviews that demonstrate how school life is remembered in complex and textural ways....... The chapter traces the former pupil’s memories of physical and affective movements within the larger context of school and discovers surprisingly diverse modes of knowing, relating, and attending to things, teachers and classmates among and between the three generations. It thus taps into the rich...... demonstrates how the use of spoken memories is a rewarding source for the writing about school from the pupils’ perspective....

  19. Affective World Literature

    DEFF Research Database (Denmark)

    Vilslev, Annette Thorsen

    The PhD dissertation compares the literary theory and novels of modern Japanese writer Natsume Sōseki. It reads Sōseki’s Theory of Literature (2009, Bungakuron, 1907) as an inherently comparative and interdisciplinary approach to theorizing feelings in world literature. More broadly, the...... dissertation investigates the critical negotiation of the novel as a travelling genre in Japan in the beginning of the 20th century, and, more specifically, Sōseki’s work in relation to world literature and affect theory. Sōseki’s work is highly influential in Japan and East Asia, and his novels widely...... circulated beyond Japan. Using Sōseki’s theory as an example, and by comparing it to other theories, the dissertation argues that comparative literature needs to include not only more non-Western literature but also more non-Western literary theories in the ongoing debate of world literature. Close...

  20. Anticipated affect and behavioral choice.

    NARCIS (Netherlands)

    R. Richard; J. van der Pligt; N.K. de Vries

    1996-01-01

    Most research on the impact of affect on attitudes and behavior emphasizes the effect of past and present affective reactions. In this article we focus on anticipated, postbehavioral, affective reactions. The influence of anticipated affective reactions on a number of behaviors was investigated in t

  1. A synonymous polymorphic variation in ACADM exon 11 affects splicing efficiency and may affect fatty acid oxidation

    DEFF Research Database (Denmark)

    Bruun, Gitte Hoffmann; Doktor, Thomas Koed; Andresen, Brage Storstein

    2013-01-01

    In recent studies combining genome-wide association and tandem-MS based metabolic profiling, a single-nucleotide polymorphism (SNP), rs211718C>T, located far upstream of the MCAD gene (ACADM) was found to be associated with serum concentrations of medium-chain acylcarnitines indicating improved...... with exon 11 missplicing, and that the c.1161G allele corrects this missplicing. This may result in production of more full length MCAD protein from the c.1161G allele. Our analysis suggests that the improved splicing of the c.1161G allele is due to changes in the relative binding of splicing...... expression, perhaps due to improved splicing. This study is a proof of principle that synonymous SNPs are not neutral. By changing the binding sites for splicing regulatory proteins they can have significant effects on pre-mRNA splicing and thus protein function. In addition, this study shows that for a...

  2. Diurnal variation of mountain waves

    Directory of Open Access Journals (Sweden)

    R. M. Worthington

    2006-11-01

    Full Text Available Mountain waves could be modified as the boundary layer varies between stable and convective. However case studies show mountain waves day and night, and above e.g. convective rolls with precipitation lines over mountains. VHF radar measurements of vertical wind (1990–2006 confirm a seasonal variation of mountain-wave amplitude, yet there is little diurnal variation of amplitude. Mountain-wave azimuth shows possible diurnal variation compared to wind rotation across the boundary layer.

  3. The affective life of semiotics

    OpenAIRE

    J. S. Hutta

    2015-01-01

    The paper challenges writings on affect that locate affective dynamism in autonomic bodily responses while positing discourse and language as "capturing" affect. To move beyond such "verticalism", the paper seeks to further an understanding of language, and semiotics more broadly, as itself affective. Drawing on participatory research conducted in Rio de Janeiro, it uses poetic expression as a paradigmatic case of the affective life of semiotics. Conceptually, it builds on Guat...

  4. Security affects us all!

    CERN Multimedia

    SMB Department

    2016-01-01

    In the hope of minimising the number of thefts of the Organization’s property, which can lead to months of work going to waste on certain projects, you are reminded of the importance that CERN attaches to the rules concerning the protection of equipment for which we are responsible. If you see any unusual behaviour or if you are the victim of a theft, don’t hesitate to report it by submitting a ticket through the CERN Portal or calling the CSA. Security affects us all!   CERN is attractive in more ways than one, and it remains as attractive as ever to thieves. With the nice weather and with the holiday season in full swing, the number of thefts recorded at CERN is on the rise. Items stolen include money, computers, electronic equipment, cable drums and copper antennae.   There are a few basic precautions that you should take to protect both your own and the Organization’s property: lock your door, don’t leave valuable items in your office, st...

  5. Variations in measured computed tomography number values

    International Nuclear Information System (INIS)

    Computed Tomography (CT) scans of a water phantom have been performed on a number of different CT scanners, and variations in the measured mean pixel value for a central region have been observed. In addition, a positional variation of mean CT number was noted. In particular, the head rest on an EMI CT1010 scanner had a significant effect on the pixel values. To simulate head scanning, a phantom with a Teflon annulus surrounding a water bath was used. This annulus affected both the mean and standard deviation of the pixels in a central area of the scan. Both an mAS and beam width dependence on CT numbers was noted. The effect of calibration on the measured CT numbers for each reconstruction filter was examined on one machine. The variation of CT number with reconstruction matrix and compensation filter was also investigated. These measurements suggest caution must be exercised when interpreting actual CT number values. This will be particularly relevant when the numbers are used to differentiate between tissue types for diagnostic or therapeutic purposes. (author)

  6. Trace compounds affecting biogas energy utilisation - A review

    Energy Technology Data Exchange (ETDEWEB)

    Rasi, S., E-mail: saija.rasi@gmail.com [University of Jyvaeskylae, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 (Finland); Laentelae, J.; Rintala, J. [University of Jyvaeskylae, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 (Finland)

    2011-11-15

    Highlights: {yields} In regards to trace compounds, landfill gases are the most studied biogases. {yields} More strict requirements are set for biogas purity with new biogas applications. {yields} With traditional applications, small variations in biogas quality are acceptable. {yields} New requirements set challenges on raw material control and biogas quality. {yields} In this study, variations in analysing methods and biogas quality are discussed. - Abstract: This paper investigates the trace compounds affecting energy utilisation in biogas that come from different production sites. With biogas being more widely used in different energy applications more interest has arisen for the specific composition of biogas. In traditional energy applications, methane and hydrogen sulphide contents have had the most influence when energy utilisation application has been considered. With more advanced processes also the quantity and quality of trace compounds is more important. In regards to trace compounds, it was found that the concentrations and the variations of volatile organic compounds (VOCs) can be high in different landfills, especially, with compounds originating from the biological degradation process (like aromatics and terpenes) as seasonal variations affect the biological degradation. Trace compounds produced by direct volatilisation (halogenated and silicon compounds) show a smaller seasonal variation. Halogenated compounds are rarely present in high concentrations in waste water treatment plant (WWTP) biogas, but the concentrations of organic silicon compounds and their variation is high. Organic silicon compounds are usually detected only in low concentrations in co-digestion plant biogas, when no WWTP sludge is used as a raw material.

  7. Trace compounds affecting biogas energy utilisation - A review

    International Nuclear Information System (INIS)

    Highlights: → In regards to trace compounds, landfill gases are the most studied biogases. → More strict requirements are set for biogas purity with new biogas applications. → With traditional applications, small variations in biogas quality are acceptable. → New requirements set challenges on raw material control and biogas quality. → In this study, variations in analysing methods and biogas quality are discussed. - Abstract: This paper investigates the trace compounds affecting energy utilisation in biogas that come from different production sites. With biogas being more widely used in different energy applications more interest has arisen for the specific composition of biogas. In traditional energy applications, methane and hydrogen sulphide contents have had the most influence when energy utilisation application has been considered. With more advanced processes also the quantity and quality of trace compounds is more important. In regards to trace compounds, it was found that the concentrations and the variations of volatile organic compounds (VOCs) can be high in different landfills, especially, with compounds originating from the biological degradation process (like aromatics and terpenes) as seasonal variations affect the biological degradation. Trace compounds produced by direct volatilisation (halogenated and silicon compounds) show a smaller seasonal variation. Halogenated compounds are rarely present in high concentrations in waste water treatment plant (WWTP) biogas, but the concentrations of organic silicon compounds and their variation is high. Organic silicon compounds are usually detected only in low concentrations in co-digestion plant biogas, when no WWTP sludge is used as a raw material.

  8. Affective monitoring: A generic mechanism for affect elicitation

    OpenAIRE

    Phaf, R. Hans; Rotteveel, Mark

    2012-01-01

    In this paper we sketch a new framework for affect elicitation, which is based on previous evolutionary and connectionist modeling and experimental work from our group. Affective monitoring is considered a local match–mismatch process within a module of the neural network. Negative affect is raised instantly by mismatches, incongruency, disfluency, novelty, incoherence, and dissonance, whereas positive affect follows from matches, congruency, fluency, familiarity, coherence, and resonance, at...

  9. A Theory of Harmonic Variations

    OpenAIRE

    de Piro, Tristram

    2014-01-01

    We consider a class of "harmonic variations" for nonsingular curves, obtained as asymptotic degenerations along bitangents. On a geometric level, we obtain an attractive relationship between the class and the genus of $C$. The distribution of class points in pairs across nonsingular curves with such variations, further suggests applications to understanding covalent bonding in terms of shared electrons.

  10. Colony Variation in Staphylococcus lugdunensis

    OpenAIRE

    Leung, Michael J.; Nuttall, Nichalas; Pryce, Todd M.; Coombs, Geoffrey W; Pearman, John W.

    1998-01-01

    Staphylococcus lugdunensis is being increasingly reported as a pathogen with an outcome resembling that of S. aureus rather than coagulase-negative staphylococci. Recent local isolates exhibited colonial variation that delayed identification and interpretation of clinical significance. Until now previous descriptions have not emphasized colonial variation as an important identifying characteristic of S. lugdunensis.

  11. Variation in contour and cancer of stomach

    International Nuclear Information System (INIS)

    There were four types of stomach contour included eutonic, hypotonic, steerhorn, and cascade. The aim of this study is to clarify relationship between incidence of stomach cancer and contour variation of the stomach. Double- contrast upper gastrointestinal study was performed in 1,546 patients, who had dyspepsia or other gastrointestinal tract symptoms. The radiographs were classified into the four types including eutonic, hypotonic, steerhorn, and cascade according to stomach contour in relation to body build. We also reviewed pathologic reports on endoscopic biopsy or surgical specimen. We studied the presence of relationship between incidence of stomach cancer and variation of stomach contour. We also examined the incidence of gastritis and gastric ulcer to the stomach contour variation. Of total 1,546 patients, eutonic stomach were 438(28.3%), hypotonic 911(58.9%), steerhorn 102(6.5%) and cascade 95(6.2%). Stomach cancer was found in 139(31.7%) of 438 eutonic stomachs, in 135(14.8%) of 911 hypotonic, in 42(41.2%) of 102 steerhorn, and in 24(36.9%) of 95 cascade (P=0.001). In hypotonic stomach, the incidence of stomach cancer was lower compared to the other three types significantly (p<0.05). Gastritis or gastric ulcer was found in 146(33.3%) of eutonic stomach, in 293(32.1%) of hypotonic, in 36(35.2%) of steerhorn, and in 26(27.3%) of cascade (p=0.640). In conclusion, gastric contour variation seems to be a factor affecting development of stomach cancer. The patients with hypotonic stomach may have lower incidence of stomach cancer than that of the other types. There was no relationship between the contour and gastric ulcer

  12. Variation in contour and cancer of stomach

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Hong; Hwang, Seon Moon [Asan Medical Center, Asan (Korea, Republic of); Yoon, Kwon Ha [College of Medicine, Wonkwang Univ., Iksan (Korea, Republic of)

    1999-04-01

    There were four types of stomach contour included eutonic, hypotonic, steerhorn, and cascade. The aim of this study is to clarify relationship between incidence of stomach cancer and contour variation of the stomach. Double- contrast upper gastrointestinal study was performed in 1,546 patients, who had dyspepsia or other gastrointestinal tract symptoms. The radiographs were classified into the four types including eutonic, hypotonic, steerhorn, and cascade according to stomach contour in relation to body build. We also reviewed pathologic reports on endoscopic biopsy or surgical specimen. We studied the presence of relationship between incidence of stomach cancer and variation of stomach contour. We also examined the incidence of gastritis and gastric ulcer to the stomach contour variation. Of total 1,546 patients, eutonic stomach were 438(28.3%), hypotonic 911(58.9%), steerhorn 102(6.5%) and cascade 95(6.2%). Stomach cancer was found in 139(31.7%) of 438 eutonic stomachs, in 135(14.8%) of 911 hypotonic, in 42(41.2%) of 102 steerhorn, and in 24(36.9%) of 95 cascade (P=0.001). In hypotonic stomach, the incidence of stomach cancer was lower compared to the other three types significantly (p<0.05). Gastritis or gastric ulcer was found in 146(33.3%) of eutonic stomach, in 293(32.1%) of hypotonic, in 36(35.2%) of steerhorn, and in 26(27.3%) of cascade (p=0.640). In conclusion, gastric contour variation seems to be a factor affecting development of stomach cancer. The patients with hypotonic stomach may have lower incidence of stomach cancer than that of the other types. There was no relationship between the contour and gastric ulcer.

  13. Identifying Occupationally Specific Affective Behaviors.

    Science.gov (United States)

    Pucel, David J.

    1993-01-01

    Data from two groups of cosmetology instructors (n=15) and two groups of machinist instructors (n=17) validated the Occupational Affective Behavior Analysis instrument as capable of identifying affective behaviors viewed as important to success in a given occupation. (SK)

  14. Quantifying genetic variations and phenotypic plasticity of leaf phenology and growth for two temperate Fagaceae species (sessile oak and european beech)

    Science.gov (United States)

    Delzon, Sylvain; Vitasse, Yann; Alberto, Florian; Bresson, Caroline; Kremer, Antoine

    2010-05-01

    Under current climate change, research on inherent adaptive capacities of organisms is crucial to assess future evolutionary changes of natural populations. Genetic diversity and phenotypic plasticity constitute adaptative capacities that could allow populations to respond to new environmental conditions. The aim of the present study was (i) to determine whether there are genetic variations among populations from altitudinal gradients using a lowland common garden experiment and (ii) to assess the magnitude of phenotypic plasticity using a reciprocal transplant experiment (5 elevations from 100 to 1600 m asl.) for leaf phenology (flushing and senescence) and growth of two fagaceae species (Fagus sylvatica and Quercus petraea). We found significant differences in phenology among provenances for most species, and evidenced that these among-population differences in phenology were related to annual temperature of the provenance sites for both species. It's noteworthy that, along the same climatic gradient, the species exhibited opposite genetic clines: beech populations from high elevation flushed earlier than those of low elevation, whereas we observed an opposite trend for oak. Finally, we highlighted that both phenology timing and growth rate were highly consistent year to year. The results demonstrated that in spite of the proximity of the populations in their natural area, altitude led to genetic differentiations in their phenology and growth. Moreover, a high phenological plasticity was found for both species. We evidenced that reaction norms of flushing timing to temperature followed linear clinal trends for both species with an average shift of 5.7 days per degree increase. Timing of leaf senescence exhibited hyperbolic trends for beech and no or slight trends for oak. Furthermore, within species, there was no difference in magnitude of phenological plasticity among populations neither for flushing, nor for senescence. Consequently, for both species, the

  15. Affective monitoring: A generic mechanism for affect elicitation

    Directory of Open Access Journals (Sweden)

    MarkRotteveel

    2012-03-01

    Full Text Available In this paper we sketch a new framework for affect elicitation, which is based on previous evolutionary and connectionist modeling and experimental work from our group. Affective monitoring is considered a local match-mismatch process within a module of the neural network. Negative affect is raised instantly by mismatches, incongruency, disfluency, novelty, incoherence, and dissonance, whereas positive affect follows from matches, congruency, fluency, familiarity, coherence, and resonance, at least when an initial mismatch can be solved quickly. Affective monitoring is considered an evolutionary-early conflict and change detection process operating at the same level as, for instance, attentional selection. It runs in parallel and imparts affective flavour to emotional behavior systems, which involve evolutionary-prepared stimuli and action tendencies related to for instance defensive, exploratory, attachment, or appetitive behavior. Positive affect is represented in the networks by high-frequency oscillations, presumably in the gamma band. Negative affect corresponds to more incoherent lower-frequency oscillations, presumably in the theta band. For affect to become conscious, large-scale synchronization of the oscillations over the network and the construction of emotional experiences are required. These constructions involve perceptions of bodily states and action tendencies, but also appraisals as well as efforts to regulate the emotion. Importantly, affective monitoring accompanies every kind of information processing, but conscious emotions, which result from the later integration of affect in a cognitive context, are much rarer events.

  16. Three-Dimensional Models for Analyzing the Cyclic Variations in a Lean Burn CNG Engine

    Institute of Scientific and Technical Information of China (English)

    LI Guo-xiu; YU Yu-song; LIU Jian-ying

    2007-01-01

    Three-dimensional models, consisting of the flame kernel formation model, flame kernel development model and natural gas single step reaction model, are used to analyze the contribution of cyclic equivalence ratio variations to cyclic variations in the compressed natural gas (CNG) lean burn spark ignition engine. Computational results including the contributions of equivalence ratio cyclic variations to each combustion stage and effects of engine speed to the extent of combustion variations are discussed. It is concluded that the equivalence ratio variations affect mostly the main stage of combustion and hardly influence initial kernel development stage.

  17. Affective Induction and Creative Thinking

    Science.gov (United States)

    Fernández-Abascal, Enrique G.; Díaz, María D. Martín

    2013-01-01

    Three studies explored the relation between affect and production of creative divergent thinking, assessed with the Torrance Tests of Creative Thinking (Figural TTCT). In the first study, general, positive, and negative affect, assessed with the Positive and Negative Affect Scale (PANAS) were compared with creative production. In the second study,…

  18. Application of Affect to CALL

    Institute of Scientific and Technical Information of China (English)

    李露

    2006-01-01

    This essay mainly attempts to discuss some affective factors in CALL, with focus on affective influence on English (foreign language) learning and thus concludes that in the process of CALL related affect should be activated and made good use of to better foreign language teaching and learning.

  19. Impact of previous one-step variation in positively long-range correlated processes

    Science.gov (United States)

    Fu, Zuntao; Xie, Fenghua; Yuan, Naiming; Piao, Lin

    2016-04-01

    In a positively long-range correlated process, variations among consecutive steps are interdependent, especially the influence of previous one-step variation on next steps. How to quantify this kind of impact is of great importance to predict the future variations. In this paper, we demonstrate that this kind of impact depends on the memory strength of underlying processes from two aspects based on the theoretical and observational calculations. More precisely, the conditional calculations and the marginal distribution of the next step variation with given distribution of the previous one-step variation. Both the theoretical and observational calculations demonstrate that the previous one-step variation affect greatly the variation for the next one-step, and the expectation of next step variation will shift to larger value as the increase of memory strength but with a much smaller uncertainty. This is beneficial for our one-step ahead prediction, and will be especially beneficial for multi-step ahead prediction.

  20. Variational and quasi-variational inequalities in mechanics

    CERN Document Server

    Kravchuk, Alexander S

    2007-01-01

    The essential aim of the present book is to consider a wide set of problems arising in the mathematical modelling of mechanical systems under unilateral constraints. In these investigations elastic and non-elastic deformations, friction and adhesion phenomena are taken into account. All the necessary mathematical tools are given: local boundary value problem formulations, construction of variational equations and inequalities, and the transition to minimization problems, existence and uniqueness theorems, and variational transformations (Friedrichs and Young-Fenchel-Moreau) to dual and saddle-point search problems. Important new results concern contact problems with friction. The Coulomb friction law and some others are considered, in which relative sliding velocities appear. The corresponding quasi-variational inequality is constructed, as well as the appropriate iterative method for its solution. Outlines of the variational approach to non-stationary and dissipative systems and to the construction of the go...

  1. Theoretical and clinical overview of affective temperaments in mood disorders

    Directory of Open Access Journals (Sweden)

    Xenia Gonda

    2015-07-01

    Full Text Available Temperaments are imperturbable variations of personality, traits and ways of reacting to the environment that characterize individuals and remain constant throughout several different situations. Temperaments usually play a central role in determining emotional reactions, therefore several temperamental models have attempted to establish the potential relationship between temperaments and affective disorders. According to Hagop Akiskal, affective temperaments are subclinical and subaffective trait-like manifestations of affective disorders. Unlike several models of temperament which were exclusively developed theoretically in order to describe healthy human functioning, later extrapolated to capture the pathological domains of mental and behavioral features, the current model of affective temperaments was developed on classical traditions and mainly based on the observation of subjects with mood disorders and their healthy first degree relatives. There is accumulating evidence concerning the development of affective temperaments based on their adaptive evolutionary characteristics and genetic background, and normative data from large national studies on general and healthy samples indicate their universal characteristics. Studies in affective patient populations indicate that the relationship between affective temperaments and affective illness is more complex than a simple extrapolation from psychopathology and mental health, and affective temperaments may represent a latent state of the staging model, playing a pathoplastic role in mood disorders determining their evolution, clinical features, main characteristics and outcome. A large body of data on affective temperaments has been published during the last decade, deserving a critical analysis presented in this overview.

  2. Statistics, Uncertainty, and Transmitted Variation

    Energy Technology Data Exchange (ETDEWEB)

    Wendelberger, Joanne Roth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-05

    The field of Statistics provides methods for modeling and understanding data and making decisions in the presence of uncertainty. When examining response functions, variation present in the input variables will be transmitted via the response function to the output variables. This phenomenon can potentially have significant impacts on the uncertainty associated with results from subsequent analysis. This presentation will examine the concept of transmitted variation, its impact on designed experiments, and a method for identifying and estimating sources of transmitted variation in certain settings.

  3. Provenance Variation and Selection in Growth and Wood Quality of 34-year Pinus armandi Franch%34年生华山松生长和材性的种源变异与种源选择

    Institute of Scientific and Technical Information of China (English)

    王亚南; 王军辉; 麻文俊; 祁万宜; 高新章

    2013-01-01

    An experiment was conducted to study the genetic variation in growth traits among provenances and geographic varia-tion to select superior provenances, height, diameter, volume and amplitude of Pinus armandi Franch in provenance test forest established in 1982 .Variation of wood density in Pinus armandi Franch provenances was concluded based on the strong positive correlation between wood density and amplitude.Height, diameter, volume and amplitude among prove-nances were detected .There are significant differences in growth rate and wood quality among the provenances .A clinal variation pattern responding to the latitude of seed sources was found for DBH, height and volume, but not for density. There is a weak positive correlation between wood density and growth.Six superior provenances, Baoshan Yunnan, Qing-shui Gansu, Lianghe Yunnan, Weining Guizhou, Tongjiang Sichuan and Huizhe Yunnana, were selected by synthetical e-valuation.%利用1982年设置在湖北省宜昌市大老岭林场的34年生25个产地的华山松种源试验林,研究已达主伐年龄时华山松生长和材性的种源差异和地理变异模式,并采用阻力值的方法研究华山松种源木材密度的变异,最后挑选出优良种源。研究结果表明:华山松树高、胸径、材积和木材密度在种源间存在显著差异。种源胸径、树高和材积呈现出纬向倾群地理变异模式,而木材密度没有明显的地理变异模式;性状遗传相关分析结果显示:生长性状和阻力值呈微弱的正相关。利用多性状综合评价方法,选出云南保山、甘肃清水、云南梁河、贵州威宁、四川通江和云南会泽6个速生优质种源。

  4. Representing Term Variation in lemon

    OpenAIRE

    Montiel-Ponsoda, Elena; Aguado de Cea, G.; McCrae, J.

    2011-01-01

    In this contribution our objective is to define term variation, analyze the state of the art, and propose a new classification of term variants according to our representation purposes in lemon, a lexiconontology model to enrich ontologies with linguistic descriptions.

  5. Quality of Variational Trial States

    CERN Document Server

    Lucha, Wolfgang; Lucha, Wolfgang; Schoberl, Franz F.

    1999-01-01

    Besides perturbation theory (which clearly requires the knowledge of the exact unperturbed solution), variational techniques represent the main tool for any investigation of the eigenvalue problem of some semibounded operator H in quantum theory. For a reasonable choice of the employed trial subspace of the domain of H, the lowest eigenvalues of H usually can be located with acceptable precision whereas the trial-subspace vectors corresponding to these eigenvalues approximate, in general, the exact eigenstates of H with much less accuracy. Accordingly, various measures for the accuracy of the approximate eigenstates derived by variational techniques are scrutinized. In particular, the matrix elements of the commutator of the operator H and (suitably chosen) different operators with respect to degenerate approximate eigenstates of H obtained by variational methods are proposed as new criteria for the accuracy of variational eigenstates. These considerations are applied to precisely that Hamiltonian for which t...

  6. Encountering science education's capacity to affect and be affected

    Science.gov (United States)

    Alsop, Steve

    2015-12-01

    What might science education learn from the recent affective turn in the humanities and social sciences? Framed as a response to Michalinos Zembylas's article, this essay draws from selected theorizing in affect theory, science education and science and technology studies, in pursuit of diverse and productive ways to talk of affect within science education. These discussions are framed by desires to transcend traditional epistemic boundaries and practices. The article concludes offering some associated ambiguities and tensions involved.

  7. Magma rheology variation in sheet intrusions (Invited)

    Science.gov (United States)

    Magee, C.; O'Driscoll, B.; Petronis, M. S.; Stevenson, C.

    2013-12-01

    The rheology of magma fundamentally controls igneous intrusion style as well as the explosivity and type of volcanic eruptions. Importantly, the dynamic interplay between the viscosity of magma and other processes active during intrusion (e.g., crystallisation, magma mixing, assimilation of crystal mushes and/or xenolith entrainment) will likely bear an influence on the temporal variation of magma rheology. Constraining the timing of rheological changes during magma transit therefore plays an important role in understanding the nuances of volcanic systems. However, the rheological evolution of actively emplacing igneous intrusions cannot be directly studied. While significant advances have been made via experimental modelling and analysis of lava flows, how these findings relate to intruding magma remains unclear. This has led to an increasing number of studies that analyse various characteristics of fully crystallised intrusions in an attempt to ';back-out' the rheological conditions governing emplacement. For example, it has long been known that crystallinity affects the rheology and, consequently, the velocity of intruding magma. This means that quantitative textural analysis of crystal populations (e.g., crystal size distribution; CSD) used to elucidate crystallinity at different stages of emplacement can provide insights into magma rheology. Similarly, methods that measure flow-related fabrics (e.g., anisotropy of magnetic susceptibility; AMS) can be used to discern velocity profiles, a potential proxy for the magma rheology. To illustrate these ideas, we present an integrated AMS and petrological study of several sheet intrusions located within the Ardnamurchan Central Complex, NW Scotland. We focus on the entrainment and transport dynamics of gabbroic inclusions that were infiltrated by the host magma upon entrainment. Importantly, groundmass magnetic fabrics within and external to these inclusions are coaxial. This implies that a deviatoric stress was

  8. Stochastic Annealing for Variational Inference

    OpenAIRE

    Gultekin, San; Zhang, Aonan; Paisley, John

    2015-01-01

    We empirically evaluate a stochastic annealing strategy for Bayesian posterior optimization with variational inference. Variational inference is a deterministic approach to approximate posterior inference in Bayesian models in which a typically non-convex objective function is locally optimized over the parameters of the approximating distribution. We investigate an annealing method for optimizing this objective with the aim of finding a better local optimal solution and compare with determin...

  9. An Overview of Variational Integrators

    OpenAIRE

    Lew, Adrian; Marsden, Jerrold E.; Ortiz, Michael; West, Matthew

    2004-01-01

    The purpose of this paper is to survey some recent advances in variational integrators for both finite dimensional mechanical systems as well as continuum mechanics. These advances include the general development of discrete mechanics, applications to dissipative systems, collisions, spacetime integration algorithms, AVI’s (Asynchronous Variational Integrators), as well as reduction for discrete mechanical systems. To keep the article within the set limits, we will only trea...

  10. Variational Gaussian Process Dynamical Systems

    OpenAIRE

    Damianou, Andreas C.; Titsias, Michalis K.; Lawrence, Neil D.

    2011-01-01

    High dimensional time series are endemic in applications of machine learning such as robotics (sensor data), computational biology (gene expression data), vision (video sequences) and graphics (motion capture data). Practical nonlinear probabilistic approaches to this data are required. In this paper we introduce the variational Gaussian process dynamical system. Our work builds on recent variational approximations for Gaussian process latent variable models to allow for nonlinear dimensional...

  11. Coupled Dark Energy field variation

    OpenAIRE

    García-Zúñiga, Roberto Carlos; Izquierdo, Germán

    2014-01-01

    The variation of the dark energy field is found under the assumption that the dark energy is parametric and interacts with the cold dark matter. Considering that the variation of the field could not exceed the Planck mass, we obtain bounds on the coupling and adiabatic coefficients. Three parameterizations of the adiabatic coefficients are considered and two coupling terms where the energy flows from dark energy to dark matter, or the other way around.

  12. Variational integrators for electric circuits

    International Nuclear Information System (INIS)

    In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator

  13. Practitioner compression force variation in mammography: A 6-year study

    International Nuclear Information System (INIS)

    The application of breast compression in mammography may be more heavily influenced by the practitioner rather than the client. This could affect image quality and will affect client experience. This study builds on previous research to establish if mammography practitioners vary in the compression force they apply over a six-year period. This longitudinal study assessed 3 consecutive analogue screens of 500 clients within one screening centre in the UK. Recorded data included: practitioner code, applied compression force (daN), breast thickness (mm), BI-RADS® density category and breast dose. Exclusion criteria included: previous breast surgery, previous/ongoing assessment, breast implants. 344 met inclusion criteria. Data analysis: assessed variation of compression force (daN) and breast thickness (mm) over 3 sequential screens to determine whether compression force and breast thickness were affected by practitioner variations. Compression force over the 3 screens varied significantly; variation was highly dependent upon the practitioner who performed the mammogram. Significant thickness and compression force differences over the 3 screens were noted for the same client ( 0.31). When practitioners from different compression force groups performed 3 screens, maximum compression force variations were higher and significantly different (p < 0.0001). The amount of compression force used is highly dependent upon practitioner rather than client. This has implications for radiation dose, patient experience and image quality consistency

  14. Intraspecific genetic variation and species coexistence in plant communities.

    Science.gov (United States)

    Ehlers, Bodil K; Damgaard, Christian F; Laroche, Fabien

    2016-01-01

    Many studies report that intraspecific genetic variation in plants can affect community composition and coexistence. However, less is known about which traits are responsible and the mechanisms by which variation in these traits affect the associated community. Focusing on plant-plant interactions, we review empirical studies exemplifying how intraspecific genetic variation in functional traits impacts plant coexistence. Intraspecific variation in chemical and architectural traits promotes species coexistence, by both increasing habitat heterogeneity and altering competitive hierarchies. Decomposing species interactions into interactions between genotypes shows that genotype × genotype interactions are often intransitive. The outcome of plant-plant interactions varies with local adaptation to the environment and with dominant neighbour genotypes, and some plants can recognize the genetic identity of neighbour plants if they have a common history of coexistence. Taken together, this reveals a very dynamic nature of coexistence. We outline how more traits mediating plant-plant interactions may be identified, and how future studies could use population genetic surveys of genotype distribution in nature and methods from trait-based ecology to better quantify the impact of intraspecific genetic variation on plant coexistence. PMID:26790707

  15. A transcriptional network associated with natural variation in Drosophila aggressive behavior

    OpenAIRE

    Edwards, Alexis C.; Ayroles, Julien F.; STONE, ERIC A.; Carbone, Mary Anna; Lyman, Richard F.; Mackay, Trudy FC

    2009-01-01

    Background Aggressive behavior is an important component of fitness in most animals. Aggressive behavior is genetically complex, with natural variation attributable to multiple segregating loci with allelic effects that are sensitive to the physical and social environment. However, we know little about the genes and genetic networks affecting natural variation in aggressive behavior. Populations of Drosophila melanogaster harbor quantitative genetic variation in aggressive behavior, providing...

  16. Perception of head-position-dependent variations in interaural cross-correlation coefficient

    OpenAIRE

    Mason, R.; Kim, C.; Brookes, T

    2009-01-01

    Experiments were undertaken to elicit the perceived effects of head-position-dependent variations in the interaural cross-correlation coefficient of a range of signals. A graphical elicitation experiment showed that the variations in the IACC strongly affected the perceived width and depth of the reverberant environment, as well as the perceived width and distance of the sound source. A verbal experiment gave similar results, and also indicated that the head-position-dependent IACC variations...

  17. How does variation in the environment and individual cognition explain the existence of consistent behavioral differences?

    OpenAIRE

    Niemelä, Petri T.; Vainikka, Anssi; Forsman, Jukka T.; Loukola, Olli J; Kortet, Raine

    2012-01-01

    According to recent studies on animal personalities, the level of behavioral plasticity, which can be viewed as the slope of the behavioral reaction norm, varies among individuals, populations, and species. Still, it is conceptually unclear how the interaction between environmental variation and variation in animal cognition affect the evolution of behavioral plasticity and expression of animal personalities. Here, we (1) use literature to review how environmental variation and individual var...

  18. Life-history variation and age at maturity in Eurasian Perch (Perca fluviatilis L.)

    OpenAIRE

    Heibo,Erik

    2003-01-01

    This thesis deals with life-history variation in perch, with special focus on age at maturity. We conducted field studies to uncover the variation within short geographic distances and a literature review to study variation on a large geographic scale in order to reveal some factors affecting life-history. In two studies we discuss the relevance of predation risk and acidification, respectively, on age at maturity. With data from a large scale study (75 perch populations) covering a large ran...

  19. Analysis of variation factors of successful bid rate in public works tender

    Science.gov (United States)

    Matsumura, Yoshiaki; Kaneko, Yuichiro; Shimazaki, Toshikazu

    The aim of this study is to analyze the variation factors of successful bid rate in public works tender using data on MLIT (Ministry of Land, Infrastructure, Transport and Tourism), Kanto Regional Development Bureau. It was revealed that number of bidder and level of minimum price affect variation of successful bid rate based on multiple linear regression analysis.

  20. Extreme non-regular sea level variations in Cuba under the influence of intense tropical cyclones.

    OpenAIRE

    Hernández González, M.

    2011-01-01

    This paper aimed at analyzing non-regular sea level variations of meteorological origin under the influence of six major tropical cyclones that affected Cuba, from sea level hourly height series in twelve coastal localities. As a result, it was obtained a characterization of the magnitude and timing of extreme sea level variations under the influence of intense tropical cyclones.

  1. Is there much variation in variation? Revisiting statistics of small area variation in health services research

    Directory of Open Access Journals (Sweden)

    Ibáñez Berta

    2009-04-01

    Full Text Available Abstract Background The importance of Small Area Variation Analysis for policy-making contrasts with the scarcity of work on the validity of the statistics used in these studies. Our study aims at 1 determining whether variation in utilization rates between health areas is higher than would be expected by chance, 2 estimating the statistical power of the variation statistics; and 3 evaluating the ability of different statistics to compare the variability among different procedures regardless of their rates. Methods Parametric bootstrap techniques were used to derive the empirical distribution for each statistic under the hypothesis of homogeneity across areas. Non-parametric procedures were used to analyze the empirical distribution for the observed statistics and compare the results in six situations (low/medium/high utilization rates and low/high variability. A small scale simulation study was conducted to assess the capacity of each statistic to discriminate between different scenarios with different degrees of variation. Results Bootstrap techniques proved to be good at quantifying the difference between the null hypothesis and the variation observed in each situation, and to construct reliable tests and confidence intervals for each of the variation statistics analyzed. Although the good performance of Systematic Component of Variation (SCV, Empirical Bayes (EB statistic shows better behaviour under the null hypothesis, it is able to detect variability if present, it is not influenced by the procedure rate and it is best able to discriminate between different degrees of heterogeneity. Conclusion The EB statistics seems to be a good alternative to more conventional statistics used in small-area variation analysis in health service research because of its robustness.

  2. Analysis of parameters affecting beam gauge performance

    CERN Document Server

    Yadav, S; Ozelis, J P

    2000-01-01

    Beam gauges have been used in the last decade or so for measuring the internal azimuthal compressive coil stresses in superconducting magnets. In early model Large Hadron Collider Interaction Region (LHC IR) quadrupoles tested at Fermilab, the beam gauges indicated excessively high amounts of inner and outer coil prestress during the collaring process, inconsistent with the coil size and modulus data. In response to these measurements, a simple mechanics based quantitative understanding of different factors affecting beam gauges has been developed. A finite element model with contact elements and non-linear material behavior, confirmed with experimental results, was developed. The results indicate that a small plastic deformation of either the beam or the backing plate can cause significant errors in the measured stress values. The effect of variations in coil modulus and support boundary conditions on beam gauge performance are also discussed. (3 refs).

  3. Loads affecting the reflector of HTR-500

    International Nuclear Information System (INIS)

    A 1:6 true-to-scale model was built for the experimental study of the mechanical loads affecting the reactor core structure due to its proper weight, the weight of the pebbles, and the process of insertion of the core rods. A 120 -sector of the model was covered with sensing devices. The model was supported in the test bench by adjustable supporting elements held by a cylindrical steel panel. The supporting elements were provided with pre-stressed springs arranged so as to allow a free variation and adjustment of the spring forces and their effects on the model according to the test requirements, loads on the reflector, distribution and shifting of the loads were studied as a function of the depth of insertion of the core rods, by varying the support conditions. (orig.)

  4. Planck intermediate results. XXIV. Constraints on variation of fundamental constants

    OpenAIRE

    Ade, P. A. R.; Rachen, J. P.; Zonca, A.

    2014-01-01

    Any variation in the fundamental physical constants, more particularly in the fine structure constant, a, or in the mass of the electron, me, affects the recombination history of the Universe and cause an imprint on the cosmic microwave background angular power spectra. We show that the Planck data allow one to improve the constraint on the time variation of the fine structure constant at redshift z - 10(3) by about a factor of 5 compared to WMAP data, as well as to break the degeneracy with ...

  5. Whether Contexts Affecting TESOL Teachers

    Institute of Scientific and Technical Information of China (English)

    马炳军; 杨晓丽

    2013-01-01

    This article aims to verify whether contextual theories affect TESOL teachers in Chinese local classrooms via observing three different English teachers’classroom behaviors by using qualitative method. The findings indicate that three major aspects usually affect English teachers:(1) The teacher’s education context affects their TESOL classroom contexts;(2) The institution’s requirements affect the teacher’s classroom contexts; (3) The spirit of quality-oriented education from the New National Stan-dards for English influences the classroom contexts, which have proved the context theories.

  6. Weld metal toughness - sources of variation

    Energy Technology Data Exchange (ETDEWEB)

    Quintana, Marie; Major, Jeff; Dallam, Craig; James, Matt [Lincoln Electric, Cleveland, OH, (United States); Babu, S. S. [Ohia State University, Columbus, OH, (United States)

    2010-07-01

    The measurement of weld toughness is largely studied using Charpy V-notch (CVN), but the CVN toughness values can vary widely in the same weld. This study investigated the causes of such variations in CVN measurements. Several CVN tests, a microstructure analysis and nanohardness measurements were performed to identify the microstructural properties affecting the CNV toughness values. The results showed that the CVN toughness values are controlled by local microstructure conditions. The size of austenite grain and ferritic microstructures are conditioned by cooling conditions. It is shown that the highly localized regions of coarse-grained ferrite are associated with the lowest CVN toughness measurements. It is also shown that the transformation of austenite into martensite under the load and reduced temperature associated with coarse ferrite microstructure explain the magnitude in CVN results.

  7. Biological variation of thyroid autoantibodies and thyroglobulin

    DEFF Research Database (Denmark)

    Jensen, Esther; Petersen, Per Hyltoft; Blaabjerg, Ole;

    2007-01-01

    BACKGROUND: It has been shown that the level of serum thyroid antibodies affects serum thyrotropin (TSH) concentrations in men and women, and that these autoantibodies in combination with serum TSH are predictive of future thyroid disease. As the biological variation of these autoantibodies is...... unknown, we investigated this in fertile women during one complete regular menstrual cycle. METHODS: A total of 24 healthy women (23-46 years) were investigated twice a week between 07:30 and 11:00 h. Antibodies against thyroid peroxidase (TPOAb), thyroglobulin (TgAb), and thyrotropin receptor (TRAb) were...... upper reference limit of the laboratory (6 had TPOAb >10 kIU/L, 6 had TgAb >20 kIU/L and 1 had TRAb >0.75 IU/L). Eight women had Tg below the lower reference limit, five of whom had elevated TgAb. Variations in the thyroid antibodies were random and not related to the menstrual cycle. For TPOAb (2...

  8. Variational principle for quasibound states

    International Nuclear Information System (INIS)

    A minimum-variance principle for quasibound states is defined and utilized to investigate the corresponding energy resonances. The variational principle yields simultaneously a resonance energy E and a square-integrable wave function phi, such that minimum variance is obtained for arbitrary variations of a restricted class of square-integrable functions as well as with respect to variations of E. It is further shown that the optimum energy E0 obtained from this method can simultaneously be written as an expectation value of the actual Hamiltonian with respect to phi = phi (E0). The example of the Stark effect in the hydrogen atom is studied. It is shown that the variationally obtained resonance energy coincides with the real part of the complex pole of the m function of Weyl, related to the Green's function of the system under consideration. It is also shown that the corresponding numerical application of the Rayleigh-Ritz variational method only gives meaningful results for field intensities below 0.06 a.u., as compared with the ''exact'' results of Hehenberger, McIntosh, and Brandas

  9. Kernels and ranges in the variational formalism

    International Nuclear Information System (INIS)

    An extension of the concept of variational derivative is introduced which allows one to derive an integral identity in the variational formalism. It is applied to characterize the kernel and range of the variational derivative and the divergence operator. (Auth.)

  10. Human Technology and Human Affects

    DEFF Research Database (Denmark)

    Fausing, Bent

    2009-01-01

    Human Technology and Human Affects  This year Samsung introduced a mobile phone with "Soul". It was made with a human touch and included itself a magical touch. Which function does technology and affects get in everyday aesthetics like this, its images and interactions included this presentation...

  11. Current Research in Affective Development.

    Science.gov (United States)

    Strayer, Janet

    1985-01-01

    Current research concerning affective development in infants and children is selectively reviewed. The focus of findings and discussion is on three general and related topics: (1) expression of emotion and affective interaction in infancy; (2) socialization and regulation of emotion; (3) comprehension of emotions and empathy with others by…

  12. Affective modulation of recognition bias

    NARCIS (Netherlands)

    R.H. Phaf; M. Rotteveel

    2005-01-01

    A correspondence of processing on the familiarity-novelty and positive-negative dimensions, particularly in the earliest processing stages, is proposed. Familiarity manipulations should, therefore, not only influence affective evaluations (e.g., the mere exposure effect), but affective manipulations

  13. Variational Lie derivative and cohomology classes

    Science.gov (United States)

    Palese, Marcella; Winterroth, Ekkehart

    2011-07-01

    We relate cohomology defined by a system of local Lagrangian with the cohomology class of the system of local variational Lie derivative, which is in turn a local variational problem; we show that the latter cohomology class is zero, since the variational Lie derivative `trivializes' cohomology classes defined by variational forms. As a consequence, conservation laws associated with symmetries of the second variational derivative of a local variational problem are globally defined.

  14. Solid mechanics a variational approach

    CERN Document Server

    Dym, Clive L

    2013-01-01

    Solid Mechanics: A Variational Approach, Augmented Edition presents a lucid and thoroughly developed approach to solid mechanics for students engaged in the study of elastic structures not seen in other texts currently on the market. This work offers a clear and carefully prepared exposition of variational techniques as they are applied to solid mechanics. Unlike other books in this field, Dym and Shames treat all the necessary theory needed for the study of solid mechanics and include extensive applications. Of particular note is the variational approach used in developing consistent structural theories and in obtaining exact and approximate solutions for many problems.  Based on both semester and year-long courses taught to undergraduate seniors and graduate students, this text is geared for programs in aeronautical, civil, and mechanical engineering, and in engineering science. The authors’ objective is two-fold: first, to introduce the student to the theory of structures (one- and two-dimensional) as ...

  15. Affect intensity and cardiac arousal.

    Science.gov (United States)

    Blascovich, J; Brennan, K; Tomaka, J; Kelsey, R M; Hughes, P; Coad, M L; Adlin, R

    1992-07-01

    Relationships between affect intensity and basal, evoked, and perceived cardiac arousal were investigated in 3 experiments. Affect intensity was assessed using Larsen and Diener's (1987) Affect Intensity Measure (AIM). Cardiac arousal was evoked with exercise in the 1st study and with mental arithmetic in the 2nd and 3rd. Perceived cardiac arousal was measured under optimal conditions using a standard heartbeat discrimination procedure. Women as a group scored higher on the AIM. Affect intensity was unrelated to basal or evoked cardiac arousal and was negatively related to perceived cardiac arousal in all 3 studies. Data suggest that affect intensity, although unrelated to actual physiological arousal, is negatively related to the accuracy with which individuals perceive their own arousal. Results are discussed within the context of an expanded arousal-regulation model (Blascovich, 1990). PMID:1494983

  16. Constrained variational calculus: the second variation (part I)

    CERN Document Server

    Massa, Enrico; Pagani, Enrico; Luria, Gianvittorio

    2010-01-01

    This paper is a direct continuation of arXiv:0705.2362 . The Hamiltonian aspects of the theory are further developed. Within the framework provided by the first paper, the problem of minimality for constrained calculus of variations is analyzed among the class of differentiable curves. A necessary and sufficient condition for minimality is proved.

  17. Developmental stage of strongyle eggs affects the outcome variations of real-time PCR analysis

    DEFF Research Database (Denmark)

    Andersen, Ulla Vestergaard; Haakansson, I. T.; Roust, Tina;

    2013-01-01

    infected horse. Eggs were isolated and placed in microtiter plates with demineralized water. A total of 25 wells containing 100 eggs each were set up and kept refrigerated for up to five days. Once daily, five wells were examined on an inverted microscope at 100× magnification, where the developmental...

  18. Variation of Grain and Malt Qualities in Barley as Affected by Cultivars and Environments

    Institute of Scientific and Technical Information of China (English)

    WANG Jun-mei; ZHANG Guo-ping; CHEN Jin-xin; DING Shou-ren; ZHOU Ti-yao

    2003-01-01

    Inferior and unstable quality of malt barley in China has limited its wide use in malting and brewing industries. In this research, eight two-rowed barley cultivars were planted at 7 locations with different ecological conditions in southern China, to investigate the cultivar and environmental effect on grain and malt qualities. The results showed that grain protein content differed dramatically among locations, but there were no significant differences among cultivars. For four malt qualities including diastatic power, wort viscosity,Kolbach index and malt extract, significant differences were found among cultivars and locations, except for diastatic power among cultivars. Coefficients of variance (CV) caused by location were greater than those caused by cuitivar for each quality parameter, especially for diastatic power and Kolbach index, indicating the predominant influence of environment on malt quality. The analysis showed that grain protein content was positively related to diastatic power and wort viscosity, and negatively to malt extract. Kolbach index was positively related to malt extract, and negatively to diastatic power and wort viscosity. Diastatic power showed positive and negative correlation with wort viscosity and malt extract, respectively.

  19. Interannual variation in root production in grassland affected by artficially modified amount of rainfall

    Czech Academy of Sciences Publication Activity Database

    Fiala, Karel; Tůma, Ivan; Holub, Petr

    2012-01-01

    Roč. 2012, č. 805298 (2012). ISSN 1537-744X R&D Projects: GA ČR GAP504/10/1486; GA ČR(CZ) GA526/06/0556; GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z60870520 Institutional support: RVO:67985939 ; RVO:67179843 Keywords : root increment * below-ground plant mass * precipitation Subject RIV: EF - Botanics; EH - Ecology, Behaviour (UEK-B) Impact factor: 1.730, year: 2012

  20. How Do Revenue Variations Affect Expenditures within U.S. Research Universities?

    Science.gov (United States)

    Leslie, Larry L.; Slaughter, Sheila; Taylor, Barrett J.; Zhang, Liang

    2012-01-01

    Using Integrated Postsecondary Education Data System (IPEDS) figures on the 96 Research Extensive Institution in academic year 2007-2008, we employ panel data from academic year 1984-1985 to 2007-2008 to identify revenue-expenditure relationships. Although we consider a wide range of functional expenditure categories, we focus our analysis on…

  1. Variation in DISC1 affects hippocampal structure and function and increases risk for schizophrenia

    OpenAIRE

    Callicott, Joseph H.; Straub, Richard E.; Pezawas, Lukas; Egan, Michael F.; Mattay, Venkata S.; Hariri, Ahmad R.; Verchinski, Beth A.; Meyer-Lindenberg, Andreas; Balkissoon, Rishi; Kolachana, Bhaskar; Goldberg, Terry E.; Weinberger, Daniel R.

    2005-01-01

    Disrupted-in-schizophrenia 1 (DISC1) is a promising schizophrenia candidate gene expressed predominantly within the hippocampus. We typed 12 single-nucleotide polymorphisms (SNPs) that covered the DISC1 gene. A three-SNP haplotype [hCV219779 (C)-rs821597 (G)-rs821616 (A)] spanning 83 kb of the gene was associated with schizophrenia in a family-based sample (P = 0.002). A common nonconservative SNP (Ser704Cys) (rs821616) within this haplotype was associated with schizophrenia (P = 0.004). Base...

  2. The diversity of coral associated bacteria and the environmental factors affect their community variation.

    Science.gov (United States)

    Zhang, Yan-Ying; Ling, Juan; Yang, Qing-Song; Wang, You-Shao; Sun, Cui-Ci; Sun, Hong-Yan; Feng, Jing-Bin; Jiang, Yu-Feng; Zhang, Yuan-Zhou; Wu, Mei-Lin; Dong, Jun-De

    2015-10-01

    Coral associated bacterial community potentially has functions relating to coral health, nutrition and disease. Culture-free, 16S rRNA based techniques were used to compare the bacterial community of coral tissue, mucus and seawater around coral, and to investigate the relationship between the coral-associated bacterial communities and environmental variables. The diversity of coral associated bacterial communities was very high, and their composition different from seawater. Coral tissue and mucus had a coral associated bacterial community with higher abundances of Gammaproteobacteria. However, bacterial community in seawater had a higher abundance of Cyanobacteria. Different populations were also found in mucus and tissue from the same coral fragment, and the abundant bacterial species associated with coral tissue was very different from those found in coral mucus. The microbial diversity and OTUs of coral tissue were much higher than those of coral mucus. Bacterial communities of corals from more human activities site have higher diversity and evenness; and the structure of bacterial communities were significantly different from the corals collected from other sites. The composition of bacterial communities associated with same coral species varied with season's changes, geographic differences, and coastal pollution. Unique bacterial groups found in the coral samples from more human activities location were significant positively correlated to chemical oxygen demand. These coral specific bacteria lead to coral disease or adjust to form new function structure for the adaption of different surrounding needs further research. PMID:25833806

  3. Soil moisture variations affect short-term plant-microbial competition for ammonium, glycine, and glutamate

    OpenAIRE

    Månsson, Katarina F; Olsson, Magnus O; Falkengren-Grerup, Ursula; Bengtsson, Göran

    2014-01-01

    We tested whether the presence of plant roots would impair the uptake of ammonium ( ), glycine, and glutamate by microorganisms in a deciduous forest soil exposed to constant or variable moisture in a short-term (24-h) experiment. The uptake of 15NH4 and dual labeled amino acids by the grass Festuca gigantea L. and soil microorganisms was determined in planted and unplanted soils maintained at 60% WHC (water holding capacity) or subject to drying and rewetting. The experiment used a design by...

  4. Studies of genetical variation affecting grain protein type and amount in wheat

    International Nuclear Information System (INIS)

    Difficulties in improving protein content and optimizing amino acid ratios in wheat endosperm led to investigations of the genes controlling the endosperm proteins. In wild relatives of wheat different endosperm proteins have been discovered and attempts are described to transfer the genes to bread wheat. The generally negative correlation between grain yield and protein content stimulated further studies on genes of different origin and their effect on correlation, using monosomic techniques. Large grain size was found to be positively correlated with percentage protein. (author)

  5. Factors Affecting Diet Variation in the Pyrenean Rock Ptarmigan (Lagopus muta pyrenaica: Conservation Implications.

    Directory of Open Access Journals (Sweden)

    Ricardo García-González

    Full Text Available The Pyrenean rock ptarmigan (Lagopus muta pyrenaica lives at one of the southernmost limits of the ptarmigan range. Their small population sizes and the impacts of global changes are limiting factors in the conservation of this threatened subspecies. An effective conservation policy requires precise basic knowledge of a species' food and habitat requirements, information that is practically non-existent for this Pyrenean population. Here, we describe the diet of a ptarmigan population in the Eastern Pyrenees, the environmental factors influencing its variability and the relationship between diet floristic composition and quality. Diet composition was determined by microhistological analysis of faeces and diet quality was estimated from free-urate faecal N content. Our results show that grouse diet is based mainly on arctic-alpine shrubs of the Ericaceae family, as well as dwarf willows (Salix spp. and Dryas octopetala. The most frequently consumed plant species was Rhododendron ferrugineum, but its abundance in the diet was negatively related to the diet nitrogen content. Conversely, the abundance of Salix spp., grass leaves and arthropods increased the nitrogen content of the diet. Seasonality associated with snow-melting contributed the most to variability in the Pyrenean ptarmigan diet, differentiating winter from spring/summer diets. The latter was characterised by a high consumption of dwarf willows, flowers, arthropods and tender forb leaves. Geographic area and sex-age class influenced diet variability to a lesser extent. Current temperature increases in the Pyrenees due to global warming may reduce the persistence and surface area of snow-packs where preferred plants for rock ptarmigan usually grow, thus reducing food availability. The high consumption of Rh. ferrugineum characterised the diet of the Pyrenean population. Given the toxicity of this plant for most herbivores, its potential negative effect on Pyrenean ptarmigan populations should be evaluated.

  6. Genetic variation in human NPY expression affects stress response and emotion

    OpenAIRE

    Zhou, Zhifeng; Zhu, Guanshan; Hariri, Ahmad R; Enoch, Mary-Anne; Scott, David; Sinha, Rajita; Virkkunen, Matti; Mash, Deborah C.; Lipsky, Robert H; Hu, Xian-Zhang; Hodgkinson, Colin A.; Xu, Ke; Buzas, Beata; Yuan, Qiaoping; SHEN, PEI-HONG

    2008-01-01

    Understanding inter-individual differences in stress response requires the explanation of genetic influences at multiple phenotypic levels, including complex behaviours and the metabolic responses of brain regions to emotional stimuli. Neuropeptide Y (NPY) is anxiolytic1,2 and its release is induced by stress3. NPY is abundantly expressed in regions of the limbic system that are implicated in arousal and in the assignment of emotional valences to stimuli and memories4–6. Here we show that hap...

  7. Variations in the natural density of European oak wood affect thermal degradation during thermal modification

    OpenAIRE

    Hamada, Joël; Pétrissans, Anélie; Mothe, Frédéric; Ruelle, Julien; Pétrissans, Mathieu; Gérardin, Philippe

    2016-01-01

    International audience AbstractKey messageThermogravimetric analysis, performed on small samples of earlywood (EW) or latewood (LW), indicated that earlywood is more susceptible to thermal degradation than latewood. These results suggest a direct relationship between wood density (which depends on the EW/LW ratio and indirectly on silviculture) and the response of wood during thermo-modification processes.ContextOne of the main difficulties in developing thermo-modified wood products at an...

  8. Spatial trends and factors affecting variation of organochlorine contaminants levels in Canadian Arctic beluga (Delphinapterus leucas).

    Science.gov (United States)

    Stern, G A; Macdonald, C R; Armstrong, D; Dunn, B; Fuchs, C; Harwood, L; Muir, D C G; Rosenberg, B

    2005-12-01

    Organochlorine pesticides and PCBs were analysed in blubber from beluga (Delphinapterus leucas), or white whales, collected at 15 sites in the Canadian Arctic between 1993 and 2001. The objective of the study was to define and interpret the spatial trends of major organic contaminants in northern beluga in terms of sources and transport pathways, and the biological factors influencing accumulation. When compared on a lipid weight basis, the concentrations of beta-HCH, cis-CHL and SigmaCHL, cis-nonachlor, heptachlor epoxide and p,p'-DDT were significantly higher in males than females at all five sites in the eastern Arctic where the two sexes were harvested. The differences were attributed to losses from the females during fetal development and lactation as reported in previous studies. Major compounds increased with age in males at most sites, however the lack of a significant increase with age at some sites was in part due to high organochlorine concentrations in young year classes (2-5 years), particularly at eastern sites such as Iqaluit and Pangnirtung. Lower concentrations of SigmaHCH and SigmaDDT compounds in young males in 2001 relative to 1995 at Hendrickson Island could be due to declining levels in the environment, changes in the diet, or differences in organochlorine loads transferred from the female after birth. Age-corrected least square mean concentrations in males showed significantly higher levels of many compounds, such as p,p'-DDE and SigmaCHB, at south Baffin Island sites than those in the west. Two notable exceptions were HCBz and beta-HCH which were higher in the west. Methoxyclor was detected in males at Sanikiluaq (58 ng g-1) and in both sexes at Kimmirut, but at no other sites. Principal component analysis grouped the 16 sites into five major groupings based on the similarity of normalised organochlorine pesticide and PCB levels. Sites from the western Arctic were grouped by higher proportions of HCBz, beta-HCH and gamma-HCH and higher chlorinated PCBs. Endosulfan and alpha-HCH comprised a larger proportion of total organochlorine residues in the northern Hudson Bay sites, while methoxychlor, chlordane compounds and octachlorobiphenyls were enriched at Sanikiluaq in eastern Hudson Bay. The analysis showed that the relative amounts of several key compounds are similar in the beluga stocks over large spatial areas (i.e. eastern versus western sites), however, some stocks have distinct fingerprints which can be used to differentiate them from adjacent stocks. Ratios of major HCH isomers largely corresponded with air and surface water measurements conducted during the 1990s, but low alpha-/beta- and alpha-/gamma-HCH ratios in all three western Arctic collections indicate rapid losses of the alpha-isomer from the food web, proportionately higher beta- and gamma-isomers in the Beaufort Sea, or a combination of the two processes. Chlordane residue patterns generally correspond to those from previous studies, however, interpretation of spatial trends are difficult due to the aging of the probable sources in the south, possible atmospheric input from new sources and complex transport pathways. PMID:16154619

  9. Latitudinal Variation in Carbon Storage Can Help Predict Changes in Swamps Affected by Global Warming

    Science.gov (United States)

    Middleton, Beth A.; McKee, Karen

    2004-01-01

    Plants may offer our best hope of removing greenhouse gases (gases that contribute to global warming) emitted to the atmosphere from the burning of fossil fuels. At the same time, global warming could change environments so that natural plant communities will either need to shift into cooler climate zones, or become extirpated (Prasad and Iverson, 1999; Crumpacker and others, 2001; Davis and Shaw, 2001). It is impossible to know the future, but studies combining field observation of production and modeling can help us make predictions about what may happen to these wetland communities in the future. Widespread wetland types such as baldcypress (Taxodium distichum) swamps in the southeastern portion of the United States could be especially good at carbon sequestration (amount of CO2 stored by forests) from the atmosphere. They have high levels of production and sometimes store undecomposed dead plant material in wet conditions with low oxygen, thus keeping gases stored that would otherwise be released into the atmosphere (fig. 1). To study the ability of baldcypress swamps to store carbon, our project has taken two approaches. The first analysis looked at published data to develop an idea (hypothesis) of how production levels change across a temperature gradient in the baldcypress region (published data study). The second study tested this idea by comparing production levels across a latitudinal range by using swamps in similar field conditions (ongoing carbon storage study). These studies will help us make predictions about the future ability of baldcypress swamps to store carbon in soil and plant biomass, as well as the ability of these forests to shift northward with global warming.

  10. Genetic Variation of the Serotonin 2a Receptor Affects Hippocampal Novelty Processing in Humans

    OpenAIRE

    Schott, B. H.; Seidenbecher, C. I.; Richter, S.; Wustenberg, T.; Debska-Vielhaber, G.; Schubert, H.; Heinze, H J; Richardson-Klavehn, A; Duzel, E.

    2011-01-01

    Serotonin (5-hydroxytryptamine, 5-HT) is an important neuromodulator in learning and memory processes. A functional genetic polymorphism of the 5-HT 2a receptor (5-HTR2a His452Tyr), which leads to blunted intracellular signaling, has previously been associated with explicit memory performance in several independent cohorts, but the underlying neural mechanisms are thus far unclear. The human hippocampus plays a critical role in memory, particularly in the detection and encoding of novel infor...

  11. Variation in fungal enzyme spectra may affect mutualistic division of labour between ants and fungus gardens

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Boomsma, Jacobus Jan

    Partners in obligate mutualisms often contribute complementary elements to joint pathways for synthesizing or degrading metabolites. Their committed cooperation can make new niches accessible, with evolutionary diversification and speciation as possible consequences. However, when individual part...... appear to be analogous to a diverse array of subsistence farming practices at the mercy of local conditions, whereas the latter resemble large-scale, low-diversity “industrial” farming....

  12. A study on surveillance of environmental factors affecting the variation of indoor radon concentration

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Shin Ae; Kim, Ok Ja; Lee, Mi Kyeong; Cho, Eun Ok; Choi, Yun Sun; Choi, Jin Kyeong; Park, Seon Hye; Han, Hyeon Sun [Hankook Research, Seoul (Korea, Republic of)

    2000-03-15

    Before the main survey, a preliminary survey was carried out to decide the most suitable type of a radon detector the most appropriate places to install such a radon detector. To this end, three types of detectors were set up in 108 locations, approximately 3% of 3,000 to measure the radon levels, and 102 detectors(94%) were collected. As a result of the preliminary survey, Radtrack was chosen as a radon detector for the main survey, and bedrooms on the first floor of houses and the first floor of public buildings were decided to be the places for the first installment of detectors. It is most desirable to survey the radon concentrations in all houses nationwide. Considering the survey period and budgets, however, 3,000 spots were targeted for the main survey at the recommendation of the Korea Institute of Nuclear Safety in charge of this study. As it is important to maintain the same panels for a year to measure the radon concentrations at 3,000 locations, a total of 3,237 panels, 10% more than the target sample number, were surveyed considering the possible loss of panels during the survey period. The first radon detector was installed in each of 3,237 spots in December 1999, and collected three months later in March 2000, followed by the installment of the second detector.

  13. Storm surge variational assimilation model

    Directory of Open Access Journals (Sweden)

    Shi-li HUANG

    2010-06-01

    Full Text Available To eliminate errors caused by uncertainty of parameters and further improve capability of storm surge forecasting, the variational data assimilation method is applied to the storm surge model based on unstructured grid with high spatial resolution. The method can effectively improve the forecasting accuracy of storm surge induced by typhoon through controlling wind drag force coefficient parameter. The model is first theoretically validated with synthetic data. Then, the real storm surge process induced by the TC 0515 typhoon is forecasted by the variational data assimilation model, and results show the feasibility of practical application.

  14. A variational formulation of electrodynamics

    CERN Document Server

    De Nicola, Antonio

    2007-01-01

    We present a variational formulation of electrodynamics using de Rham even and odd differential forms. Our formulation relies on a variational principle more complete than the Hamilton principle and thus leads to field equations with external sources and permits the derivation of the constitutive relations. We interpret a domain in space-time as an odd de Rham 4-current. This permits a treatment of different types of boundary problems in an unified way. In particular we obtain a smooth transition to the infinitesimal version by using a current with a one point support.

  15. Structure variations of carbonizing lignin

    International Nuclear Information System (INIS)

    The studied lignin is a by-product of the process of ethanol production from eucaliptus. It was heat-treated under inert atmosphere conditions at increasing temperatures from 300C up to 2400C. The structural variations were studied by wide-angle X-ray diffraction, small-angle X-ray scattering and infrared absorption spectroscopy. The bulk and 'real' density of the compacted materials have also been determined as functions of the final temperature. These experimental results enabled us to establish a mechanism of structure variation based on the formation of a turbostratic graphite-like and porous structure within the initially amorphous lignin matrix. (Author)

  16. Variation

    OpenAIRE

    2001-01-01

    Veränderung (lat. variatio) einer melodisch oder harmonisch feststehenden Gestalt als epochen- und stilübergreifendes Kompositionsprinzip und im engeren Sinn als eigenständige, an ein (präexistentes) Thema gebundene Form.

  17. Urbanization Process and Variation of Energy Budget of Land Surfaces

    Directory of Open Access Journals (Sweden)

    Ciro Gardi

    Full Text Available Urban areas are increasing at a rate much higher than human population growth in many part of the world; actually more than 73 towns in the world are larger than 1000 km2. The European Environmental Agency indicates an urban area average growth rate, over the last 20 years, of 20%. The urbanization process, and the consequent soil sealing, determines not only the losses of the ecological functions of the soil, but also a variation of the energy budget of land surfaces, that affect the microclimatic conditions (heat islands. The alteration of the energy budget are determined by the variations of albedo and roughness of surfaces, but especially by the net losses of evapotranspirating areas. In the present research we have assessed the variation of Parma territory energy budget, induced by the change in land use over the last 122 years. The urban area increase between 1881 and 2003 was 535%.

  18. Seismic reflectivity effects from seasonal seafloor temperature variation

    Science.gov (United States)

    Wood, Warren T.; Martin, Kylara M.; Jung, Wooyeol; Sample, John

    2014-10-01

    The effects of seasonal temperature variation on sound speed contrasts at the seafloor are usually considered negligible in the analysis of seismic data but may be significant at large incidence angles (offsets) important for inversion of sediment elastic properties, or long-range acoustic transmission. In coastal areas, the maximum annual seafloor temperature variation can be several degrees Celsius or more, corresponding to a sound speed variation of 30 m/s or more. Thermal pulses propagate via conduction several meters into the seafloor resulting in a damped quasi-sinusoidal temperature profile with predictable wave number characteristics. The oscillating seasonal and spatial character of this signal creates a time- and frequency-dependent effect on the elastic seafloor reflectivity. Results of numerical simulations show that the expected temperature profile for most sediment types and porosities will have the strongest affect on frequencies between about 60 and 600 Hz, at incidence angles greater than about 50°.

  19. Auditory feedback affects perception of effort when exercising with a Pulley machine

    DEFF Research Database (Denmark)

    Bordegoni, Monica; Ferrise, Francesco; Grani, Francesco;

    2013-01-01

    In this paper we describe an experiment that investigates the role of auditory feedback in affecting the perception of effort when using a physical pulley machine. Specifically, we investigated whether variations in the amplitude and frequency content of the pulley sound affect perception of effo...

  20. Affective Computing and Intelligent Interaction

    CERN Document Server

    2012-01-01

    2012 International Conference on Affective Computing and Intelligent Interaction (ICACII 2012) was the most comprehensive conference focused on the various aspects of advances in Affective Computing and Intelligent Interaction. The conference provided a rare opportunity to bring together worldwide academic researchers and practitioners for exchanging the latest developments and applications in this field such as Intelligent Computing, Affective Computing, Machine Learning, Business Intelligence and HCI.   This volume is a collection of 119 papers selected from 410 submissions from universities and industries all over the world, based on their quality and relevancy to the conference. All of the papers have been peer-reviewed by selected experts.  

  1. The affective turn in ethnomusicology

    Directory of Open Access Journals (Sweden)

    Hofman Ana

    2015-01-01

    Full Text Available The affective turn, which has already questioned dominant paradigms in many disciplinary fields including cultural studies, philosophy, political theory, anthropology, psychology and neuroscience, has started to attract more attention in the field of ethnomusicology, becoming a particularly vibrant stream of thought. Drawing on the voices that call for the historicisation of and critical deliberation on the field of affect studies, the article strives to show how theories of affect might expand dominant paradigms in ethnomusicology and also points to their limitations.

  2. Variational approach for quarkonium potentials

    International Nuclear Information System (INIS)

    A variational method based on Coulomb and harmonic oscillator trial functions has been investigated in the context of single and superposition of power potentials which are commonly used for quarkonium systems. Ground state energies being upper bounds are calculated and emerge surprisingly close to their exact values considering the simplicity of the method

  3. Sea level and climate variations

    NARCIS (Netherlands)

    Oerlemans, J.

    1985-01-01

    Review paper, ESA Symposium on Application of Satellite Data to Climate Modelling. Alpbach (Austria) Sea level is an essential component of the climate system, on which many human activities in the coastal zone depend. Climate variations leading to changes in relative sea level are discussed, with

  4. Variational integrators in plasma physics

    International Nuclear Information System (INIS)

    To a large extent, research in plasma physics is concerned with the description and analysis of energy and momentum transfer between different scales and different kinds of waves. In the numerical modelling of such phenomena it appears to be crucial to describe the transfer processes preserving the underlying conservation laws in order to prevent physically spurious solutions. In this work, special numerical methods, so called variational integrators, are developed for several models of plasma physics. Special attention is given to conservation properties like conservation of energy and momentum. By design, variational integrators are applicable to all systems that have a Lagrangian formulation. Usually, equations of motion are derived by Hamilton's action principle and then discretised. In the application of the variational integrator theory, the order of these steps is reversed. At first, the Lagrangian and the accompanying variational principle are discretised, such that discrete equations of motion can be obtained directly by applying the discrete variational principle to the discrete Lagrangian. The advantage of this approach is that the resulting discretisation automatically retains the conservation properties of the continuous system. Following an overview of the geometric formulation of classical mechanics and field theory, which forms the basis of the variational integrator theory, variational integrators are introduced in a framework adapted to problems from plasma physics. The applicability of variational integrators is explored for several important models of plasma physics: particle dynamics (guiding centre dynamics), kinetic theory (the Vlasov-Poisson system) and fluid theory (magnetohydrodynamics). These systems, with the exception of guiding centre dynamics, do not possess a Lagrangian formulation to which the variational integrator methodology is directly applicable. Therefore the theory is extended by linking it to Ibragimov's theory of

  5. Mutations in many genes affect aggressive behavior in Drosophila melanogaster

    OpenAIRE

    Zwarts Liesbeth; Edwards Alexis C; Yamamoto Akihiko; Callaerts Patrick; Mackay Trudy FC

    2009-01-01

    Abstract Background Aggressive behavior in animals is important for survival and reproduction. Identifying the underlying genes and environmental contexts that affect aggressive behavior is important for understanding the evolutionary forces that maintain variation for aggressive behavior in natural populations, and to develop therapeutic interventions to modulate extreme levels of aggressive behavior in humans. While the role of neurotransmitters and a few other molecules in mediating and mo...

  6. Courting disaster: How diversification rate affects fitness under risk

    OpenAIRE

    Ratcliff, William C; Hawthorne, Peter; Libby, Eric

    2014-01-01

    Life is full of risk. To deal with this uncertainty, many organisms have evolved bet-hedging strategies that spread risk through phenotypic diversification. These rates of diversification can vary by orders of magnitude in different species. Here we examine how key characteristics of risk and organismal ecology affect the fitness consequences of variation in diversification rate. We find that rapid diversification is strongly favored when the risk faced has a wide spatial extent, with a singl...

  7. Spatial and temporal small-scale variation in groundwater quality of a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Christensen, Thomas Højlund

    The groundwater quality of a shallow unconfined sandy aquifer has been characterized for pH, alkalinity, chloride, nitrate, sulfate, calcium, magnesium, sodium and potassium in terms of vertical and horizontal variations (350 groundwater samples). The test area is located within a farmland lot. The...... geology of the area described on the basis of 31 sediment cores appears relatively homogeneous. Large vertical and horizontal variations were observed. The vertical variations are strongly affected by the deviating composition of the agricultural infiltration water. The horizontal variations show very...

  8. Retail Pricing Patterns and Driving Factors of Price Variation

    OpenAIRE

    Li,Chenguang; Volpe, Richard

    2013-01-01

    This study explores the strategic pricing behaviors across retail chains for produce products. We adopt a Panel-VAR model to identify the driving factors of retail price variation and find that retail price history, competition, product cost are among the key drivers of retail price change. Forecast Error Variance Decomposition (FEVD) is used to quantify the relative impact of driving factors to retail price changes and show how they affect prices differently across retail chains. We also fin...

  9. Inherited variation in immune genes and pathways and glioblastoma risk

    OpenAIRE

    Schwartzbaum, Judith A.; Xiao, Yuanyuan; Liu, Yanhong; Tsavachidis, Spyros; Berger, Mitchel S.; Bondy, Melissa L,; Chang, Jeffrey S.; Chang, Susan M.; Decker, Paul A.; Ding, Bo; Hepworth, Sarah J; Richard S. Houlston; Hosking, Fay J; Jenkins, Robert B.; Kosel, Matthew L.

    2010-01-01

    To determine whether inherited variations in immune function single-nucleotide polymorphisms (SNPs), genes or pathways affect glioblastoma risk, we analyzed data from recent genome-wide association studies in conjunction with predefined immune function genes and pathways. Gene and pathway analyses were conducted on two independent data sets using 6629 SNPs in 911 genes on 17 immune pathways from 525 glioblastoma cases and 602 controls from the University of California, San Francisco (UCSF) an...

  10. Geometric constrained variational calculus. III: The second variation (Part II)

    Science.gov (United States)

    Massa, Enrico; Luria, Gianvittorio; Pagani, Enrico

    2016-03-01

    The problem of minimality for constrained variational calculus is analyzed within the class of piecewise differentiable extremaloids. A fully covariant representation of the second variation of the action functional based on a family of local gauge transformations of the original Lagrangian is proposed. The necessity of pursuing a local adaptation process, rather than the global one described in [1] is seen to depend on the value of certain scalar attributes of the extremaloid, here called the corners’ strengths. On this basis, both the necessary and the sufficient conditions for minimality are worked out. In the discussion, a crucial role is played by an analysis of the prolongability of the Jacobi fields across the corners. Eventually, in the appendix, an alternative approach to the concept of strength of a corner, more closely related to Pontryagin’s maximum principle, is presented.

  11. Categorization in the Affective Domain

    DEFF Research Database (Denmark)

    Sauciuc, Gabriela-Alina

    2011-01-01

    Data collected in Romance and Scandinavian languages (N=474) in a superordinate category name production task indicate that a multiple-strategy approach would be more suitable for accounting of categorization in the affective domain instead of a prototype approach as suggested by previous studies....... This paper will highlight performance aspects which appear to be consistent with such an interpretation, as well as an important layman- expert knowledge asymmetry in affective categorization....

  12. A computational model of affects

    CERN Document Server

    Turkia, Mika

    2008-01-01

    This article provides a simple logical structure, in which affective concepts (i.e. concepts related to emotions and feelings) can be defined. The set of affects defined is similar to the set of emotions covered in the OCC model (Ortony A., Collins A., and Clore G. L.: The Cognitive Structure of Emotions. Cambridge University Press, 1988), but the model presented in this article is fully computationally defined.

  13. Rewards Affecting the Organizational Concerns

    OpenAIRE

    Doina I. POPESCU

    2011-01-01

    To obtain and maintain a high-performing workforce, an enterprise must develop a well-conceived compensation program. In addition to a salary, employees may be rewarded with benefit plans, bonuses, perquisites, stock options, and other long-term incentives. The main purpose of this article is to study how rewards affect employee perceptions, attitudes, and behavior in a variety of ways. Also, the purpose of this article is to analyze how organizational efficiency and effectiveness are affecte...

  14. Crop responses to climatic variation

    OpenAIRE

    Porter, John R; Semenov, Mikhail A.

    2005-01-01

    The yield and quality of food crops is central to the well being of humans and is directly affected by climate and weather. Initial studies of climate change on crops focussed on effects of increased carbon dioxide (CO2) level and/or global mean temperature and/or rainfall and nutrition on crop production. However, crops can respond nonlinearly to changes in their growing conditions, exhibit threshold responses and are subject to combinations of stress factors that affect their growth, develo...

  15. Variation of Parameters in Differential Equations (A Variation in Making Sense of Variation of Parameters)

    Science.gov (United States)

    Quinn, Terry; Rai, Sanjay

    2012-01-01

    The method of variation of parameters can be found in most undergraduate textbooks on differential equations. The method leads to solutions of the non-homogeneous equation of the form y = u[subscript 1]y[subscript 1] + u[subscript 2]y[subscript 2], a sum of function products using solutions to the homogeneous equation y[subscript 1] and…

  16. Influence of COMT genotype and affective distractors on the processing of self-generated thought

    OpenAIRE

    Kilford, E. J.; Dumontheil, I.; Wood, N. W.; Blakemore, S. J.

    2014-01-01

    The catechol-O-methyltransferase (COMT) enzyme is a major determinant of prefrontal dopamine levels. The Val158Met polymorphism affects COMT enzymatic activity and has been associated with variation in executive function and affective processing. This study investigated the effect of COMT genotype on the flexible modulation of the balance between processing self-generated and processing stimulus-oriented information, in the presence or absence of affective distractors. Analyses included 124 h...

  17. Planck intermediate results. XXIV. Constraints on variation of fundamental constants

    CERN Document Server

    Ade, P A R; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Battaner, E.; Benabed, K.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Burigana, C.; Butler, R.C.; Calabrese, E.; Chamballu, A.; Chiang, H.C.; Christensen, P.R.; Clements, D.L.; Colombo, L.P.L.; Couchot, F.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Diego, J.M.; Dole, H.; Dore, O.; Dupac, X.; Ensslin, T.A.; Eriksen, H.K.; Fabre, O.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gregorio, A.; Gruppuso, A.; Hansen, F.K.; Hanson, D.; Harrison, D.L.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Jaffe, A.H.; Jones, W.C.; Keihanen, E.; Keskitalo, R.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lamarre, J.M.; Lasenby, A.; Lawrence, C.R.; Leonardi, R.; Lesgourgues, J.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Mandolesi, N.; Maris, M.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Mazzotta, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Menegoni, E.; Mennella, A.; Migliaccio, M.; Miville-Deschenes, M.A.; Moneti, A.; Montier, L.; Morgante, G.; Moss, A.; Munshi, D.; Murphy, J.A.; Naselsky, P.; Nati, F.; Natoli, P.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C.A.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Pratt, G.W.; Prunet, S.; Rachen, J.P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Ristorcelli, I.; Rocha, G.; Roudier, G.; Rusholme, B.; Sandri, M.; Savini, G.; Scott, D.; Spencer, L.D.; Stolyarov, V.; Sudiwala, R.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Uzan, J.P.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L.A.; Yvon, D.; Zacchei, A.; Zonca, A.

    2015-01-01

    Any variation of the fundamental physical constants, and more particularly of the fine structure constant, $\\alpha$, or of the mass of the electron, $m_e$, would affect the recombination history of the Universe and cause an imprint on the cosmic microwave background angular power spectra. We show that the Planck data allow one to improve the constraint on the time variation of the fine structure constant at redshift $z\\sim 10^3$ by about a factor of 5 compared to WMAP data, as well as to break the degeneracy with the Hubble constant, $H_0$. In addition to $\\alpha$, we can set a constraint on the variation of the mass of the electron, $m_{\\rm e}$, and on the simultaneous variation of the two constants. We examine in detail the degeneracies between fundamental constants and the cosmological parameters, in order to compare the limits obtained from Planck and WMAP and to determine the constraining power gained by including other cosmological probes. We conclude that independent time variations of the fine structu...

  18. Developmental mechanisms underlying variation in craniofacial disease and evolution.

    Science.gov (United States)

    Fish, Jennifer L

    2016-07-15

    Craniofacial disease phenotypes exhibit significant variation in penetrance and severity. Although many genetic contributions to phenotypic variation have been identified, genotype-phenotype correlations remain imprecise. Recent work in evolutionary developmental biology has exposed intriguing developmental mechanisms that potentially explain incongruities in genotype-phenotype relationships. This review focuses on two observations from work in comparative and experimental animal model systems that highlight how development structures variation. First, multiple genetic inputs converge on relatively few developmental processes. Investigation of when and how variation in developmental processes occurs may therefore help predict potential genetic interactions and phenotypic outcomes. Second, genetic mutation is typically associated with an increase in phenotypic variance. Several models outlining developmental mechanisms underlying mutational increases in phenotypic variance are discussed using Satb2-mediated variation in jaw size as an example. These data highlight development as a critical mediator of genotype-phenotype correlations. Future research in evolutionary developmental biology focusing on tissue-level processes may help elucidate the "black box" between genotype and phenotype, potentially leading to novel treatment, earlier diagnoses, and better clinical consultations for individuals affected by craniofacial anomalies. PMID:26724698

  19. Multidimensional analysis of Drosophila wing variation in Evolution Canyon

    Indian Academy of Sciences (India)

    Vincent Debat; Raphael Cornette; Abraham B. Koral; Eviatar Nevo; David Soulet; Jean R. David

    2008-12-01

    Environmental stress has been suggested to be a major evolutionary force, both through inducing strong selection and because of its direct impact on developmental buffering processes that alter the evolvability of organisms. In particular, temperature has attracted much attention because of its importance as an ecological feature and the relative ease with which it can be experimentally manipulated in the lab. Evolution Canyon, Lower Nahal Oren, Israel, is a well studied natural site where ecological parameters are suspected to drive evolutionary differentiation. In this study, using Drosophila melanogaster isofemale lines derived from wild flies collected on both slopes of the canyon, we investigated the effect of developmental temperature upon the different components of phenotypic variation of a complex trait: the wing. Combining geometric and traditional morphometrics, we find only limited evidence for a differentiation among slopes. Investigating simultaneously phenotypic plasticity, genetic variation among isofemale lines, variation among individuals and fluctuating asymmetry, we could not identify a consistent effect of the stressful conditions encountered on the south facing slope. The prevailing structuring effect is that of the experimentally manipulated temperature which clearly influences wing mean size and shape. Variability, in contrast, is not consistently affected by temperature. Finally, we investigated the specific relationship between individual variation and fluctuating asymmetry. Using metric multi-dimensional scaling we show that the related patterns of wing shape variation are not identical, supporting the view that the underlying developmental processes are to a certain extent different.

  20. Comparing variation across European countries

    DEFF Research Database (Denmark)

    Thygesen, Lau C; Baixauli-Pérez, Cristobal; Librero-López, Julián;

    2015-01-01

    units of analysis in the estimation of systematic variation in three countries. METHODS: Hospital discharges for six conditions (congestive heart failure, short-term complications of diabetes, hip fracture, knee replacement, prostatectomy in prostate cancer and percutaneous coronary intervention......) produced in Denmark, England and Portugal in 2008 and 2009 were allocated to both original geographical units and new ad hoc areas. New areas were built using Ward's minimum variance methods. The impact of the new areas on variability was assessed using Kernel distribution curves and different statistic...... inhabitants vs. 7% in Denmark and 5% in England. Point estimates for Extremal Quotient and Interquartile Interval Ratio were lower in the three countries, particularly in less prevalent conditions. In turn, the Systematic Component of Variation and Empirical Bayes statistic were slightly lower in more...

  1. Variational Integrators for Reduced Magnetohydrodynamics

    CERN Document Server

    Kraus, Michael; Grasso, Daniela

    2015-01-01

    Reduced magnetohydrodynamics is a simplified set of magnetohydrodynamics equations with applications to both fusion and astrophysical plasmas, possessing a noncanonical Hamiltonian structure and consequently a number of conserved functionals. We propose a new discretisation strategy for these equations based on a discrete variational principle applied to a formal Lagrangian. The resulting integrator preserves important quantities like the total energy, magnetic helicity and cross helicity exactly (up to machine precision). As the integrator is free of numerical resistivity, spurious reconnection along current sheets is absent in the ideal case. If effects of electron inertia are added, reconnection of magnetic field lines is allowed, although the resulting model still possesses a noncanonical Hamiltonian structure. After reviewing the conservation laws of the model equations, the adopted variational principle with the related conservation laws are described both at the continuous and discrete level. We verify...

  2. Bernoulli Variational Problem and Beyond

    KAUST Repository

    Lorz, Alexander

    2013-12-17

    The question of \\'cutting the tail\\' of the solution of an elliptic equation arises naturally in several contexts and leads to a singular perturbation problem under the form of a strong cut-off. We consider both the PDE with a drift and the symmetric case where a variational problem can be stated. It is known that, in both cases, the same critical scale arises for the size of the singular perturbation. More interesting is that in both cases another critical parameter (of order one) arises that decides when the limiting behaviour is non-degenerate. We study both theoretically and numerically the values of this critical parameter and, in the symmetric case, ask if the variational solution leads to the same value as for the maximal solution of the PDE. Finally we propose a weak formulation of the limiting Bernoulli problem which incorporates both Dirichlet and Neumann boundary condition. © 2013 Springer-Verlag Berlin Heidelberg.

  3. Diurnal variation of depressive symptoms

    OpenAIRE

    Wirz-Justice, Anna

    2008-01-01

    Diurnal variation of depressive symptoms appears to be part of the core of depression. Yet longitudinal investigation of an individual's pattern regularity, relation to clinical state, and clinical improvement reveals little homogeneity. Morning lows, afternoon slump, evening worsening - all can occur during a single depressive episode. Mood variability, or the propensity to produce mood swings, appears to be the characteristic that most predicts capacity to respond to treatment. Laboratory s...

  4. Regular Variation and Smile Asymptotics

    OpenAIRE

    Benaim, Shalom; Friz, Peter

    2006-01-01

    We consider risk-neutral returns and show how their tail asymptotics translate directly to asymptotics of the implied volatility smile, thereby sharpening Roger Lee's celebrated moment formula. The theory of regular variation provides the ideal mathematical framework to formulate and prove such results. The practical value of our formulae comes from the vast literature on tail asymptotics and our conditions are often seen to be true by simple inspection of known results.

  5. Global Stress Variation over Time

    Science.gov (United States)

    Yi, H.; Lu, Z.; Wen, L.

    2015-12-01

    Understanding how stress changes over time is important as it is related to studies of earthquake triggering and mantle rheology. We calculate stress variation at the Earth's surface on the global scale from 2003 to 2014, resultant from several major physical forces acting on the Earth. The physical forces we considered include the surface loading due to terrestrial water storage (TWS), force associated with post-glacial rebound (PGR) and tidal loading (including solid tide and ocean tide). The stress change associated with TWS is calculated in this way: we infer TWS from monthly gravity field of the Gravity Recovery and Climate Experiment (GRACE), in which gravity variation associated with PGR has been removed; we then estimate stress change at the Earth's surface as the elastic response of the GRACE-inferred TWS change. The stress change associated with PGR is calculated as the rate of viscoelastic stress change responding to ice loading from ICE-5G model. And, tidal stress is calculated as the elastic response of the Earth to the traction forces of the Sun and the Moon (solid tide) and to the loading of ocean tide. The total stress change is the sum of the stress changes associated with these three types of forces. As first result, in the study period from 2003 to 2014, the radial normal stress variation exhibits a prominent decreasing trend in southern Africa and Queen Maud Land of Antarctica, an increasing trend in Alaska of the US (United States), Greenland and Marie Byrd Land of Antarctica, and strong annual cycles in southern Africa and Alaska of the US. We will present the geographical distribution of global stress variation from 2003 to 2014 and discuss its possible implications.

  6. Staging of unipolar affective illness

    Directory of Open Access Journals (Sweden)

    Ewa Ferensztajn

    2014-12-01

    Full Text Available In this article, a concept of staging of unipolar affective illness (recurrent depression is presented. In respective subchapters, three most important aspects of this issue have been discussed: 1 staging of unipolar affective illness; 2 staging of treatment-resistant depression; and 3 conversion of unipolar into bipolar affective illness. The evidence for so called neuroprogression of the illness, accumulated in recent years, has allowed for a classification of staging based on a concept of allostasis and allostatic load. In the course of illness, changes in neuroendocrine system (mainly hypothalamic pituitary-adrenal (HPA axis, immunological system, mechanisms of oxidative stress, neurotransmitters, neurotrophic factors as well as structural and functional changes of the brain occur. In their paper of 2007, Fava and Tossani elaborated a concept of staging of unipolar affective illness presenting a continuum model of five consecutive stages with specific clinical features. In the present paper, a concept of treatment-resistant depression and staging of treatment resistance is presented in the context of several models. An important determinant of treatment-resistant depression is so called subthreshold bipolarity which is connected with worse efficacy of antidepressant drugs. In the course of illness, there is a possibility of changing diagnosis from recurrent depression into bipolar affective illness. The studies on this issue show that frequency of such diagnostic conversion is 1,5% of depressed patients per year.

  7. Longitudinal Variations in Jupiter's Winds

    Science.gov (United States)

    Simon-Miller, Amy A.; Gierasch, P. J.; Tierney, G.

    2010-01-01

    Long-term studies of Jupiter's zonal wind field revealed temporal variations on the order of 20 to 40 m/s at many latitudes, greater than the typical data uncertainties of 1 to 10 m/s. No definitive periodicities were evident, however, though some latitudinally-confined signals did appear at periods relevant to the Quasi- Quadrennial Oscillation (Simon-Miller & Gierasch, Icarus, in press). As the QQO appears, from vertical temperature profiles, to propagate downward, it is unclear why a signal is not more obvious, unless other processes dominate over possibly weaker forcing from the QQO. An additional complication is that zonal wind profiles represent an average over some particular set of longitudes for an image pair and most data sets do not offer global wind coverage. Lien avoiding known features, such as the large anticyclonic vortices especially prevalent in the south, there can be distinct variations in longitude. We present results on the full wind field from Voyager and Cassini data, showing apparent longitudinal variations of up to 60 m/s or more. These are particularly obvious near disruptions such as the South Equatorial Disturbance, even when the feature itself is not clearly visible. These two dates represent very different states of the planet for comparison: Voyagers 1 & 2 flew by Jupiter shortly after a global upheaval, while many regions were in a disturbed state, while the Cassini view is typical of a more quiescent period present during much of the 1990s and early 2000s.

  8. Quantitative genetic variance and multivariate clines in the Ivyleaf morning glory, Ipomoea hederacea.

    Science.gov (United States)

    Stock, Amanda J; Campitelli, Brandon E; Stinchcombe, John R

    2014-08-19

    Clinal variation is commonly interpreted as evidence of adaptive differentiation, although clines can also be produced by stochastic forces. Understanding whether clines are adaptive therefore requires comparing clinal variation to background patterns of genetic differentiation at presumably neutral markers. Although this approach has frequently been applied to single traits at a time, we have comparatively fewer examples of how multiple correlated traits vary clinally. Here, we characterize multivariate clines in the Ivyleaf morning glory, examining how suites of traits vary with latitude, with the goal of testing for divergence in trait means that would indicate past evolutionary responses. We couple this with analysis of genetic variance in clinally varying traits in 20 populations to test whether past evolutionary responses have depleted genetic variance, or whether genetic variance declines approaching the range margin. We find evidence of clinal differentiation in five quantitative traits, with little evidence of isolation by distance at neutral loci that would suggest non-adaptive or stochastic mechanisms. Within and across populations, the traits that contribute most to population differentiation and clinal trends in the multivariate phenotype are genetically variable as well, suggesting that a lack of genetic variance will not cause absolute evolutionary constraints. Our data are broadly consistent theoretical predictions of polygenic clines in response to shallow environmental gradients. Ecologically, our results are consistent with past findings of natural selection on flowering phenology, presumably due to season-length variation across the range. PMID:25002704

  9. Family Intimacy and Affection: A Sociology of Positive Affect.

    Science.gov (United States)

    Martinson, Floyd M.

    This paper deals with aspects of positive family affect in intimate family relationships such as: (1) the nuclear family of orientation, including the child-parent subgroup and the sibling subgroup; (2) the nuclear family of procreation, including the marital subgroup and parent-child subgroup; and (3) the dating relationship. Interpersonal…

  10. Behavioral Management: An Affective Approach. (Affective Education Trainers Manual).

    Science.gov (United States)

    Heilman, John; Cole, Bob

    This manual provides a framework for training teachers who want to become more skilled in affective education. It is divided into three parts: teacher self-awareness, teacher-student interaction, and teacher-directed group activities. It is designed for use in a two-day workshop. Guidelines for discussions on expectations, responsibility,…

  11. Come, see and experience affective interactive art

    NARCIS (Netherlands)

    Bialoskorski, Leticia S.S.; Westerink, Joyce H.D.M.; Broek, van den Egon L.; Nijholt, Anton; Reidsma, Dennis; Hondorp, Hendri

    2009-01-01

    The progress in the field of affective computing enables the realization of affective consumer products, affective games, and affective art. This paper describes the affective interactive art system Mood Swings, which interprets and visualizes affect expressed by a person. Mood Swings is founded on

  12. Mood Swings: An Affective Interactive Art System

    NARCIS (Netherlands)

    Bialoskorski, Leticia S.S.; Westerink, Joyce H.D.M.; Broek, van den Egon L.; Nijholt, Anton; Reidsma, Dennis; Hondorp, Hendri

    2009-01-01

    The progress in the field of affective computing enables the realization of affective consumer products, affective games, and affective art. This paper describes the affective interactive art system Mood Swings, which interprets and visualizes affect expressed by a person. Mood Swings is founded on

  13. Come, See and Experience Affective Interactive Art

    NARCIS (Netherlands)

    Bialoskorski, Leticia S.S.; Westerink, Joyce H.D.M.; Broek, van den Egon L.; Nijholt, A.; Reidsma, D.; Hondorp, G.H.W.

    2009-01-01

    The progress in the field of affective computing enables the realization of affective consumer products, affective games, and affective art. This paper describes the affective interactive art system Mood Swings, which interprets and visualizes affect expressed by a person. Mood Swings is founded on

  14. Factors affecting chromatin stability of bovine spermatozoa.

    Science.gov (United States)

    Khalifa, T A A; Rekkas, C A; Lymberopoulos, A G; Sioga, A; Dimitriadis, I; Papanikolaou, Th

    2008-03-01

    . Individuality significantly influenced NCI. The variability of NCI within a frozen ejaculate affected efficiency of IVEP. Significant negative correlations were observed between incidence of NCI and both fertilization rate and developmental capacity of embryos after maturation of oocytes for 18 h. The significant variation in IVEP traits due to season was independent of the effect of sperm chromatin instability. PMID:17398042

  15. Industrial applications of affective engineering

    CERN Document Server

    Shiizuka, Hisao; Lee, Kun-Pyo; Otani, Tsuyoshi; Lim, Chee-Peng

    2014-01-01

    This book examines the industrial applications of affective engineering. The contributors cover new analytical methods such as fluctuation, fuzzy logic, fractals, and complex systems. These chapters also include interdisciplinary research that traverses a wide range of fields, including information engineering, human engineering, cognitive science, psychology, and design studies. The text is split into two parts: theory and applications. This work is a collection of the best papers from ISAE2013 (International Symposium of Affective Engineering) held at Kitakyushu, Japan and Japan Kansei Engineering Meeting on March 6-8, 2013.

  16. Affective Computing and Sentiment Analysis

    CERN Document Server

    Ahmad, Khurshid

    2011-01-01

    This volume maps the watershed areas between two 'holy grails' of computer science: the identification and interpretation of affect -- including sentiment and mood. The expression of sentiment and mood involves the use of metaphors, especially in emotive situations. Affect computing is rooted in hermeneutics, philosophy, political science and sociology, and is now a key area of research in computer science. The 24/7 news sites and blogs facilitate the expression and shaping of opinion locally and globally. Sentiment analysis, based on text and data mining, is being used in the looking at news

  17. On Factors Affecting Listening Comprehension

    Institute of Scientific and Technical Information of China (English)

    苗琴

    2014-01-01

    In English teaching and learning, listening ability is an important part of communicative competence, is a very practical integrated skill. It has been a difficult skill in second language acquisition for many students. Many Chinese students are skilled in reading, but often they tend to neglect the listening. However, owing to the higher requirements of many English tests and the great importance in communication, students begin to pay attention to develop their English listening skills. But there are many factors affecting listening, the paper mainly focuses on linguistic factors and non-linguistic factors that affect listening, to provide a theoretical basis to help exploring ways of improving listening and comprehension skills.

  18. Multiple weather factors affect apparent survival of European passerine birds.

    Directory of Open Access Journals (Sweden)

    Volker Salewski

    Full Text Available Weather affects the demography of animals and thus climate change will cause local changes in demographic rates. In birds numerous studies have correlated demographic factors with weather but few of those examined variation in the impacts of weather in different seasons and, in the case of migrants, in different regions. Using capture-recapture models we correlated weather with apparent survival of seven passerine bird species with different migration strategies to assess the importance of selected facets of weather throughout the year on apparent survival. Contrary to our expectations weather experienced during the breeding season did not affect apparent survival of the target species. However, measures for winter severity were associated with apparent survival of a resident species, two short-distance/partial migrants and a long-distance migrant. Apparent survival of two short distance migrants as well as two long-distance migrants was further correlated with conditions experienced during the non-breeding season in Spain. Conditions in Africa had statistically significant but relatively minor effects on the apparent survival of the two long-distance migrants but also of a presumably short-distance migrant and a short-distance/partial migrant. In general several weather effects independently explained similar amounts of variation in apparent survival for the majority of species and single factors explained only relatively low amounts of temporal variation of apparent survival. Although the directions of the effects on apparent survival mostly met our expectations and there are clear predictions for effects of future climate we caution against simple extrapolations of present conditions to predict future population dynamics. Not only did weather explains limited amounts of variation in apparent survival, but future demographics will likely be affected by changing interspecific interactions, opposing effects of weather in different seasons, and

  19. Ectomycorrhizal activity as affected by soil liming

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Solbritt

    1996-05-01

    Acidification of the forest soils in southern Sweden due to atmospheric deposition has become evident during recent decades. To counteract further acidification, liming of forests in the most affected areas has been proposed. Most forest trees in the temperate and boreal forest ecosystems live in symbiosis with ectomycorrhizal fungi, and their uptake of mineral nutrients from the soil is greatly influenced by the symbiosis. In this thesis effects of liming on ectomycorrhiza have been studied in relation to effects on root colonization, fungal growth and nitrogen uptake. In field experiments the effects of liming on ectomycorrhizal colonization of root tips were variable, possibly due to different soil types and climatic variations. However, a changed mycorrhizal community structure could be detected. Laboratory studies also showed that the substrate may influence the outcome of lime applications; the nutrient status of the substrate had a marked effect on how mycelial growth was affected by liming. Under the experimental conditions used in the studies presented in this thesis, liming reduced the uptake of nitrogen and phosphorus by both mycorrhizal and non-mycorrhizal plants. The amount of extractable nitrogen and phosphorus in the peat was also reduced by liming. The latter could be due to either microbial or chemical immobilization. The lime induced decrease in nitrogen uptake was stronger in non-mycorrhizal plants than in mycorrhizal plants. Thus, the mycorrhizal plants had a higher ability to deal with the negative effects of liming on nitrogen availability. This was not the case for phosphorus. The lime induced decrease in phosphorus uptake was stronger for mycorrhizal plants, and in the highest lime treatment there was no significant difference between the mycorrhizal and the non-mycorrhizal spruce plants. 76 refs, 2 figs, 1 tab

  20. On the Primacy of Affect.

    Science.gov (United States)

    Zajonc, R. B.

    1984-01-01

    Reasserts view that there can be emotional or affective arousal without prior cognitive appraisal. Criticizes Lazarus's rejection of this view on the grounds that it presents no empirical evidence, is based on an arbitrary definition of emotion, and obliterates all distinctions between cognition, sensation, and perception. (CMG)

  1. Affective temperament and personal identity.

    Science.gov (United States)

    Stanghellini, Giovanni; Rosfort, René

    2010-10-01

    The complex relationship between temperament and personal identity, and between these and mental disorders, is of critical interest to both philosophy and psychopathology. More than other living creatures, human beings are constituted and characterized by the interplay of their genotype and phenotype. There appears to be an explanatory gap between the almost perfect genetic identity and the individual differences among humans. One reason for this gap is that a human being is a person besides a physiological organism. We propose an outline of a theoretical model that might somewhat mitigate the explanatory discrepancies between physiological mechanisms and individual human emotional experience and behaviour. Arguing for the pervasive nature of human affectivity, i.e., for the assumption that human consciousness and behaviour is characterised by being permeated by affectivity; to envisage the dynamics of emotional experience, we make use of a three-levelled model of human personal identity that differentiates between factors that are simultaneously at work in the constitution of the individual human person: 1) core emotions, 2) affective temperament types/affective character traits, and 3) personhood. These levels are investigated separately in order to respect the methodological diversity among them (neuroscience, psychopathology, and philosophy), but they are eventually brought together in a hermeneutical account of human personhood. PMID:20236706

  2. Affective Development in University Education

    Science.gov (United States)

    Grootenboer, Peter

    2010-01-01

    There seems to be an increasing requirement for university courses and programs to develop students' affective qualities (beliefs, values, dispositions and attitudes). This study explored the ways academics determined what the desirable qualities were for their particular disciplines and the pedagogical strategies and approaches they used to…

  3. Do recruitment ties affect wages?

    DEFF Research Database (Denmark)

    Larsen, Anna Folke; Rand, John; Torm, Nina Elisabeth

    an informal contact, when controlling for standard determinants of wage compensation. Moreover, we show that the mechanism through which informal contacts affect wages depends on the type of recruitment tie used. The findings are robust across location, firm size categories and different worker types....

  4. Diurnal variations of Titan's ionosphere

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Müller-Wodarg, I. C. F.; Cravens, T. E.; Kasprzak, W. T.; Waite, J. H.

    2009-06-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1000 and 1300 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from eight close encounters of the Cassini spacecraft with Titan. Although there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ˜700 cm-3 below ˜1300 km. Such a plateau is a combined result of significant depletion of light ions and modest depletion of heavy ones on Titan's nightside. We propose that the distinctions between the diurnal variations of light and heavy ions are associated with their different chemical loss pathways, with the former primarily through “fast” ion-neutral chemistry and the latter through “slow” electron dissociative recombination. The strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes suggests a scenario in which the ions created on Titan's dayside may survive well to the nightside. The observed asymmetry between the dawn and dusk ion density profiles also supports such an interpretation. We construct a time-dependent ion chemistry model to investigate the effect of ion survival associated with solid body rotation alone as well as superrotating horizontal winds. For long-lived ions, the predicted diurnal variations have similar general characteristics to those observed. However, for short-lived ions, the model densities on the nightside are significantly lower than the observed values. This implies that electron precipitation from Saturn's magnetosphere may be an additional and important contributor to the densities of the short-lived ions observed on Titan's nightside.

  5. Genetic variation in dieback resistance

    DEFF Research Database (Denmark)

    Lobo, Albin; Hansen, Jon Kehlet; McKinney, Lea Vig;

    2014-01-01

    -eastern Zealand, Denmark, and confirmed the presence of substantial genetic variation in ash dieback susceptibility. The average crown damage increased in the trial from 61% in 2009 to 66% in 2012 and 72% in 2014, while the estimated heritability was 0.42 in both 2009 and 2012 but increased to 0.53 in 2014....... Genetic correlation between assessments was 0.88 between 2009 and 2012 and 0.91 between 2009 and 2014, suggesting fairly good possibilities for early selection of superior genotypes in the presence of high infection levels in the trial. The level of crown damage had strong negative effect on growth and...

  6. Quadratic Variation by Markov Chains

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Horel, Guillaume

    We introduce a novel estimator of the quadratic variation that is based on the the- ory of Markov chains. The estimator is motivated by some general results concerning filtering contaminated semimartingales. Specifically, we show that filtering can in prin- ciple remove the effects of market...... microstructure noise in a general framework where little is assumed about the noise. For the practical implementation, we adopt the dis- crete Markov chain model that is well suited for the analysis of financial high-frequency prices. The Markov chain framework facilitates simple expressions and elegant analyti...

  7. Induced polygenic variation in lentils

    International Nuclear Information System (INIS)

    In a study at the Himachal Pradesh Krishi Vishwa Vidyalay, India microsperma and macrosperma types of lentil seeds were irradiated with 5, 10, 15, 20 and 25 kR of gamma rays to study the nature and magnitude of induced variation in various polygenic traits in both lentil types. Data were recorded for seed yield, biological yield, harvest index, number of pods/plant, 100-seed weight, plant height, time to 50% flowering (days), and time to maturity (days). A sufficient genetic variability was induced for most polygenic traits in both lentil types. However, macrosperma type was found more radio-sensitive

  8. Systematic variations in divergence angle

    CERN Document Server

    Okabe, Takuya

    2012-01-01

    Practical methods for quantitative analysis of radial and angular coordinates of leafy organs of vascular plants are presented and applied to published phyllotactic patterns of various real systems from young leaves on a shoot tip to florets on a flower head. The constancy of divergence angle is borne out with accuracy of less than a degree. It is shown that apparent fluctuations in divergence angle are in large part systematic variations caused by the invalid assumption of a fixed center and/or by secondary deformations, while random fluctuations are of minor importance.

  9. Variational Recurrent Auto-Encoders

    OpenAIRE

    Fabius, Otto; van Amersfoort, Joost R.

    2014-01-01

    In this paper we propose a model that combines the strengths of RNNs and SGVB: the Variational Recurrent Auto-Encoder (VRAE). Such a model can be used for efficient, large scale unsupervised learning on time series data, mapping the time series data to a latent vector representation. The model is generative, such that data can be generated from samples of the latent space. An important contribution of this work is that the model can make use of unlabeled data in order to facilitate supervised...

  10. Variational collocation on finite intervals

    Science.gov (United States)

    Amore, Paolo; Cervantes, Mayra; Fernández, Francisco M.

    2007-10-01

    In this paper, we study a set of functions, defined on an interval of finite width, which are orthogonal and which reduce to the sinc functions when the appropriate limit is taken. We show that these functions can be used within a variational approach to obtain accurate results for a variety of problems. We have applied them to the interpolation of functions on finite domains and to the solution of the Schrödinger equation, and we have compared the performance of the present approach with others.

  11. Waterlogging and submergence stress: affects and acclimation.

    Science.gov (United States)

    Phukan, Ujjal J; Mishra, Sonal; Shukla, Rakesh Kumar

    2016-10-01

    Submergence, whether partial or complete, imparts some serious consequences on plants grown in flood prone ecosystems. Some plants can endure these conditions by embracing various survival strategies, including morphological adaptations and physiological adjustments. This review summarizes recent progress made in understanding of the stress and the acclimation responses of plants under waterlogged or submerged conditions. Waterlogging and submergence are often associated with hypoxia development, which may trigger various morphological traits and cellular acclimation responses. Ethylene, abscisic acid, gibberellic acid and other hormones play a crucial role in the survival process which is controlled genetically. Effects at the cellular level, including ATP management, starch metabolism, elemental toxicity, role of transporters and redox status have been explained. Transcriptional and hormonal interplay during this stress may provide some key aspects in understanding waterlogging and submergence tolerance. The level and degree of tolerance may vary depending on species or climatic variations which need to be studied for a proper understanding of waterlogging stress at the global level. The exploration of regulatory pathways and interplay in model organisms such as Arabidopsis and rice would provide valuable resources for improvement of economically and agriculturally important plants in waterlogging affected areas. PMID:26177332

  12. Factors Affecting Sugarcane Production in Pakistan

    Directory of Open Access Journals (Sweden)

    Adnan Nazir

    2013-05-01

    Full Text Available This study was undertaken to identify the factors affecting sugarcane production in Pakistan. Data were collected from 387 sugarcane growers from Sindh, Punjab and NWFP province. Data were collected during the period 2007-08. The study reveals that the costs of inputs of sugarcane i.e. urea, DAP, FYM, land preparation, seed and its application, weeding and cost of irrigation were the important factors which influenced on the returns of sugarcane growers. The effectiveness was examined by using the Cobb-Douglas production function; MVP and allocative efficiency were calculated. The coefficient of multiple determinations R2 was 0.9249, which indicated that 92% variation in the cost of inputs was explained by all explanatory variables and the adjusted R2 was 92%. The F-value was 666.94 and was highly significant at 5% level of significance, indicating that the regression model was well fitted. The high prices of inputs, low price of output, delay in payments and lack of scientific knowledge were the major problems in sugarcane production. In order to enhance the productivity of sugarcane in the country, government should solve the identified problems to increase the income of sugarcane growers.

  13. Interindividual variation in transdermal and oral drug deliveries.

    Science.gov (United States)

    Levin, Jacquelyn; Maibach, Howard

    2012-11-01

    It is generally assumed that the topical absorption of drugs is subject to more interindividual variation than the oral absorption of drugs. To date, we are unaware of any clinical studies or meta-analyses that compare the interindividual variation of transdermal and oral drug deliveries for a large number of medications. In this research article, the absorption data for 10 medications that can be used as an oral medication or a transdermal patch were compiled, and from the collected data, the interindividual variance was calculated for topical and oral absorption as an overall average and by drug. This research article also briefly reviews the pharmacokinetics and pharmacodynamics of transdermal and oral drug absorption. Our results indicate that there is considerable interindividual variation in topical and oral absorption for the 10 medications investigated. Yet, surprisingly, the calculated overall mean and median coefficient of variation (CV) for topical and oral absorption were comparable (within 10% of each other). Therefore, the interindividual variation in topical and oral absorption may not be as divergent as assumed previously. In a drug-by-drug comparison, certain medications demonstrated considerably more variation when absorbed orally versus topically and vice versa. It is unclear why certain drugs had less variation in absorption when delivered topically versus orally (or vice versa). However, patterns in drug molecular weight (MW) or octanol partition coefficient (log K(OCT) ) could not totally explain these findings. In our analysis, the previously reported correlation between MW or log K(OCT) and interindividual variation in absorption could only be replicated when plotting the topical absorption CV and MW. What became clear from our analysis is that the drug itself is an important variable when considering which route of delivery (oral or topical) will provide the least amount of interindividual variation. Our study had many limitations because

  14. SYSTEM OF GENERALIZED VECTOR VARIATIONAL INEQUALITIES

    Institute of Scientific and Technical Information of China (English)

    Fang Yaping; Huang Nanjing

    2005-01-01

    In this paper, the authors introduce and study system of generalized vector variational inequalities. Under suitable conditions, the existence of solutions for system of generalized vector variational inequalities is presented by Kakutani-Fan-Glicksberg fixed point theorem.

  15. Origins of variation in conducted vasomotor responses

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Welsh, Donald G.; Holstein-Rathlou, Niels-Henrik;

    2015-01-01

    variation. Using a computational approach that allows for introduction of structural and electrophysiological heterogeneity, we systematically tested variations in both arteriolar electrophysiology and modes of stimuli. Within the same vessel, our simulations show that conduction efficacy is influenced by...

  16. Canada: variations on a common theme

    Directory of Open Access Journals (Sweden)

    Raisa B. Deber

    2010-12-01

    Full Text Available Canada faces health care challenges common to all industrialized countries – how to ensure timely access to high quality care, close to home, at an affordable cost. Addressing these challenges is complicated by interjurisdictional variation in both how health care is managed and delivered, and in health outcomes. Canada can be described as a non-system of 10 provincial and three territorial health insurance plans which mandate publicly-funded coverage for medically necessary hospital and physician services, based upon common principles and shaped by a federal governance structure that affords substantial power and autonomy to the provinces/territories over matters of health and health care. This article first examines the structural context of the health care system in Canada, including the range of services publicly funded, the public-private mix, and the complexities of current governance arrangements. It then discusses several issues affecting health policy reform: costs versus access; questions of sustainability, quality, and performance; human resources capacity; and the provision of public and population health services.

  17. Racial variations in obstetric practice.

    Science.gov (United States)

    Cauchi, M N

    1986-05-01

    This study involves a retrospective analysis of 453 pregnant persons, with the aim of comparing certain disorders of pregnancy as well as infant and placental parameters in various racial groups within the same community. Significant variations were seen in the mean age of the patients, age at first pregnancy, frequency distribution of first pregnancy, infant weight as well as gravida: parity ratio. There was a 3-fold increase in incidence of preeclampsia in the Australian-born population compared to other racial groups. Mild anaemias (haemoglobin less than 11.5 g/dl) were found in up to 61% of the Australian-born population compared to 32% of the other racial groups; however, more significant degrees of anaemia were more commonly found in certain ethnic groups (e.g. Greek 16%, Italian 15%, Australian-born 6%). These studies emphasize that overall incidence studies in a polyglot population can have very limited meaning, and that greater attention must be paid to the actual racial variations within a population. PMID:3464247

  18. On polar daily geomagnetic variation

    Directory of Open Access Journals (Sweden)

    Paola De Michelis

    2015-11-01

    Full Text Available The aim of this work is to investigate the nature of the daily magnetic field perturbations produced by ionospheric and magnetospheric currents at high latitudes. We analyse the hourly means of the X and Y geomagnetic field components recorded by a meridian chain of permanent geomagnetic observatories in the polar region of the Northern Hemisphere during a period of four years (1995-1998 around the solar minimum. We apply a mathematical method, known as natural orthogonal component (NOC, which is capable of characterizing the dominant modes of the geomagnetic field daily variability through a set of empirical orthogonal functions (EOFs. Using the first two modes we reconstruct a two-dimensional equivalent current representation of the ionospheric electric currents, which contribute substantially to the geomagnetic daily variations. The obtained current structures resemble the equivalent current patterns of DP2 and DP1. We characterize these currents by studying their evolution with the geomagnetic activity level and by analysing their dependence on the interplanetary magnetic field. The obtained results support the idea of a coexistence of two main processes during all analysed period although one of them, the directly driven process, represents the dominant component of the geomagnetic daily variation.

  19. Accommodating environmental variation in population models: metaphysiological biomass loss accounting.

    Science.gov (United States)

    Owen-Smith, Norman

    2011-07-01

    1. There is a pressing need for population models that can reliably predict responses to changing environmental conditions and diagnose the causes of variation in abundance in space as well as through time. In this 'how to' article, it is outlined how standard population models can be modified to accommodate environmental variation in a heuristically conducive way. This approach is based on metaphysiological modelling concepts linking populations within food web contexts and underlying behaviour governing resource selection. Using population biomass as the currency, population changes can be considered at fine temporal scales taking into account seasonal variation. Density feedbacks are generated through the seasonal depression of resources even in the absence of interference competition. 2. Examples described include (i) metaphysiological modifications of Lotka-Volterra equations for coupled consumer-resource dynamics, accommodating seasonal variation in resource quality as well as availability, resource-dependent mortality and additive predation, (ii) spatial variation in habitat suitability evident from the population abundance attained, taking into account resource heterogeneity and consumer choice using empirical data, (iii) accommodating population structure through the variable sensitivity of life-history stages to resource deficiencies, affecting susceptibility to oscillatory dynamics and (iv) expansion of density-dependent equations to accommodate various biomass losses reducing population growth rate below its potential, including reductions in reproductive outputs. Supporting computational code and parameter values are provided. 3. The essential features of metaphysiological population models include (i) the biomass currency enabling within-year dynamics to be represented appropriately, (ii) distinguishing various processes reducing population growth below its potential, (iii) structural consistency in the representation of interacting populations and

  20. Variations of images to increase their visibility

    OpenAIRE

    Sparavigna, Amelia Carolina

    2012-01-01

    The calculus of variations applied to the image processing requires some numerical models able to perform the variations of images and the extremization of appropriate actions. To produce the variations of images, there are several possibilities based on the brightness maps. Before a numerical model, I propose an experimental approach, based on a tool of Gimp, GNU Image Manipulation Program, in order to visualize how the image variations can be. After the discussion of this tool, which is abl...

  1. Psychological factors affecting equine performance

    Directory of Open Access Journals (Sweden)

    McBride Sebastian D

    2012-09-01

    Full Text Available Abstract For optimal individual performance within any equestrian discipline horses must be in peak physical condition and have the correct psychological state. This review discusses the psychological factors that affect the performance of the horse and, in turn, identifies areas within the competition horse industry where current behavioral research and established behavioral modification techniques could be applied to further enhance the performance of animals. In particular, the role of affective processes underpinning temperament, mood and emotional reaction in determining discipline-specific performance is discussed. A comparison is then made between the training and the competition environment and the review completes with a discussion on how behavioral modification techniques and general husbandry can be used advantageously from a performance perspective.

  2. Global Media, Biopolitics and Affect

    DEFF Research Database (Denmark)

    Knudsen, Britta Timm; Stage, Carsten

    Global Media, Biopolitics and Affect shows how mediations of bodily vulnerability have become a strong political force in contemporary societies. In discussions and struggles concerning war involvement, healthcare issues, charity, democracy movements, contested national pasts, and climate change...... culture. Likewise, it presents a range of close empirical case studies in the areas of illness blogging, global protests after the killing of Neda Agda Soltan in Iran, charity communication, green media activism, online war commemoration and digital witnessing related to conflicts in Sarajevo and Ukraine......., performances of bodily vulnerability is increasingly used by citizens to raise awareness, create sympathy, encourage political action, and to circulate information in global media networks. The book thus argues that bodily vulnerability can serve as a catalyst for affectively charging and disseminating...

  3. Food aroma affects bite size

    Directory of Open Access Journals (Sweden)

    de Wijk René A

    2012-03-01

    Full Text Available Abstract Background To evaluate the effect of food aroma on bite size, a semisolid vanilla custard dessert was delivered repeatedly into the mouth of test subjects using a pump while various concentrations of cream aroma were presented retronasally to the nose. Termination of the pump, which determined bite size, was controlled by the subject via a push button. Over 30 trials with 10 subjects, the custard was presented randomly either without an aroma, or with aromas presented below or near the detection threshold. Results Results for ten subjects (four females and six males, aged between 26 and 50 years, indicated that aroma intensity affected the size of the corresponding bite as well as that of subsequent bites. Higher aroma intensities resulted in significantly smaller sizes. Conclusions These results suggest that bite size control during eating is a highly dynamic process affected by the sensations experienced during the current and previous bites.

  4. Spatial variation of temperature and precipitation in Bhutan and links to vegetation and land cover

    DEFF Research Database (Denmark)

    Dorji, Ugyen; Olesen, Jørgen E; Bøcher, Peder Klith;

    2016-01-01

    Bhutan. It assesses the spatial variation of temperature and precipitation across the country and evaluates the causes for this variation based on daily data from 70 meteorological stations that have been recording data for time spans ranging from 3 to 21 years. Temperature and precipitation show...... contrasting spatial variation, with temperature primarily affected by elevation and precipitation by latitude. Models were developed using mixed linear regression models to predict seasonal and annual mean temperature and precipitation based on geographical location. Using linear regression we found that...... spatial distribution of precipitation was mainly controlled by latitude, having a quadratic relationship, with the highest rates in the southern foothills of the Himalayan range and the lowest at midlatitudes. The land cover is affected by topography and local climate, with variations in temperature being...

  5. Herbivory Differentially Affects Plant Fitness in Three Populations of the Perennial Herb Lythrum salicaria along a Latitudinal Gradient

    OpenAIRE

    Lina Lehndal; Jon Ågren

    2015-01-01

    Herbivory can negatively and selectively affect plant fitness by reducing growth, survival and reproductive output, thereby influencing plant population dynamics and evolution. Latitudinal variation in intensity of herbivory is common, but the extent to which it translates into corresponding variation in effects on plant performance is still poorly known. We tested the hypothesis that variation in the fitness-consequences of herbivory mirror differences in intensity of herbivory among three n...

  6. Pseudobulbar affect: prevalence and management

    OpenAIRE

    Ahmed A; Simmons Z

    2013-01-01

    Aiesha Ahmed, Zachary SimmonsDepartment of Neurology, Penn State Hershey Medical Center, Hershey, PA, USAAbstract: Pseudobulbar affect (PBA) may occur in association with a variety of neurological diseases, and so may be encountered in the setting of amyotrophic lateral sclerosis, extrapyramidal and cerebellar disorders, multiple sclerosis, traumatic brain injury, Alzheimer's disease, stroke, and brain tumors. The psychological consequences and the impact on social interactions may be...

  7. Trade Finance Affects Trade Dynamics

    OpenAIRE

    ARESPA CASTELLÓ, Marta; Gruber, Diego

    2016-01-01

    Existent literature is by no means conclusive on the effects of trade finance on trade and the economy. We propose a suitable framework to explore the linkages between international trade and finance based on an international real business cycle model where firms require external finance to import and can be financially constrained. We find that credit shocks do affect the dynamic properties of the economy and they have the potential to cause significant deviations in trade and economic perfo...

  8. Bilingualism affects audiovisual phoneme identification

    OpenAIRE

    Burfin, Sabine; Pascalis, Olivier; Ruiz Tada, Elisa; Costa, Albert; Savariaux, Christophe; Kandel, Sonia

    2014-01-01

    We all go through a process of perceptual narrowing for phoneme identification. As we become experts in the languages we hear in our environment we lose the ability to identify phonemes that do not exist in our native phonological inventory. This research examined how linguistic experience—i.e., the exposure to a double phonological code during childhood—affects the visual processes involved in non-native phoneme identification in audiovisual speech perception. We conducted a phoneme identifi...

  9. Factors affecting forage stand establishment

    OpenAIRE

    Sulc R.M.

    1998-01-01

    Significant advances have been made in our knowledge of forage seed physiology, technology, and stand establishment practices; however, stand establishment continues to be one of the most common production problems affecting forage crops in the USA. There is a need for research on stand establishment of forage crops under abiotic and biotic stress. Although the forage seed industry produces and markets seed of high quality, new methods of assessing seed vigor are needed and their use should b...

  10. How competition affects evolutionary rescue

    OpenAIRE

    Osmond, Matthew Miles; de Mazancourt, Claire

    2013-01-01

    Populations facing novel environments can persist by adapting. In nature, the ability to adapt and persist will depend on interactions between coexisting individuals. Here we use an adaptive dynamic model to assess how the potential for evolutionary rescue is affected by intra- and interspecific competition. Intraspecific competition (negative density-dependence) lowers abundance, which decreases the supply rate of beneficial mutations, hindering evolutionary rescue. On the other hand, inters...

  11. Internal factors affecting brand performance

    OpenAIRE

    Harris, Fiona J.

    2002-01-01

    In terms of effective branding, several recent trends have indicated the need for greater attention within the organisation than has traditionally been the case. With increased emphasis on corporate branding, the team responsible for managing a brand is becoming larger and more diverse and all staff, as the corporate brand's representatives, affect consumers' perceptions of the corporate brand. Furthermore, the shift in emphasis in the literature from the externally perceived brand image to t...

  12. Environmental issues affecting CCT development

    Energy Technology Data Exchange (ETDEWEB)

    Reidy, M. [U.S. House of Representatives, Washington, DC (United States)

    1997-12-31

    While no final legislative schedule has been set for the new Congress, two issues with strong environmental ramifications which are likely to affect the coal industry seem to top the list of closely watched debates in Washington -- the Environmental Protection Agency`s proposed new ozone and particulate matter standards and utility restructuring. The paper discusses the background of the proposed standards, public comment, the Congressional review of regulations, other legislative options, and utility restructuring.

  13. Quantum Annealing for Variational Bayes Inference

    OpenAIRE

    Sato, Issei; Kurihara, Kenichi; Tanaka, Shu; Nakagawa, Hiroshi; Miyashita, Seiji

    2014-01-01

    This paper presents studies on a deterministic annealing algorithm based on quantum annealing for variational Bayes (QAVB) inference, which can be seen as an extension of the simulated annealing for variational Bayes (SAVB) inference. QAVB is as easy as SAVB to implement. Experiments revealed QAVB finds a better local optimum than SAVB in terms of the variational free energy in latent Dirichlet allocation (LDA).

  14. Importance of Local Structural Variations on Recrystallization

    DEFF Research Database (Denmark)

    Juul Jensen, Dorte; Lin, Fengxiang; Zhang, Yubin; Zhang, Y.H.

    2013-01-01

    Effects of local variations in the deformation microstructure on subsequent recrystallization are discussed and illustrated by three examples. The three examples consider local variations on different length scales and are: 1. Effects of local variations in the deformation microstructure on the f...

  15. Crop responses to climatic variation

    DEFF Research Database (Denmark)

    Porter, John R.; Semenov, Mikhail A.

    2005-01-01

    The yield and quality of food crops is central to the well being of humans and is directly affected by climate and weather. Initial studies of climate change on crops focussed on effects of increased carbon dioxide (CO2) level and/or global mean temperature and/or rainfall and nutrition on crop...... production. However, crops can respond nonlinearly to changes in their growing conditions, exhibit threshold responses and are subject to combinations of stress factors that affect their growth, development and yield. Thus, climate variability and changes in the frequency of extreme events are important for...... resolution. This paper demonstrates the impacts of climate variability for crop production in a number of crops. Increasing temperature and precipitation variability increases the risks to yield, as shown via computer simulation and experimental studies. The issue of food quality has not been given...

  16. Musical affect regulation in infancy.

    Science.gov (United States)

    Trehub, Sandra E; Ghazban, Niusha; Corbeil, Mariève

    2015-03-01

    Adolescents and adults commonly use music for various forms of affect regulation, including relaxation, revitalization, distraction, and elicitation of pleasant memories. Mothers throughout the world also sing to their infants, with affect regulation as the principal goal. To date, the study of maternal singing has focused largely on its acoustic features and its consequences for infant attention. We describe recent laboratory research that explores the consequences of singing for infant affect regulation. Such work reveals that listening to recordings of play songs can maintain 6- to 9-month-old infants in a relatively contented or neutral state considerably longer than recordings of infant-directed or adult-directed speech. When 10-month-old infants fuss or cry and are highly aroused, mothers' multimodal singing is more effective than maternal speech at inducing recovery from such distress. Moreover, play songs are more effective than lullabies at reducing arousal in Western infants. We explore the implications of these findings along with possible practical applications. PMID:25773634

  17. Oculometric variations during mind wandering

    OpenAIRE

    Grandchamp, Romain; Braboszcz, Claire; Delorme, Arnaud

    2014-01-01

    A significant body of literature supports the contention that pupil size varies depending on cognitive load, affective state, and level of drowsiness. Here we assessed whether oculometric measures such as gaze position, blink frequency and pupil size were correlated with the occurrence and time course of self-reported mind-wandering episodes. We recorded the pupil size of two subjects engaged in a monotonous breath counting task while keeping their eyes on a fixation cross. This task is condu...

  18. Oculometric variations during mind wandering

    OpenAIRE

    RomainGrandchamp; ArnaudDelorme

    2014-01-01

    A significant body of literature supports the contention that pupil size varies depending on cognitive load, affective state, and level of drowsiness. Here we assessed whether oculometric measures such as gaze position, blink frequency and pupil size were correlated with the occurrence and time course of self-reported mind-wandering episodes. We recorded the pupil size of two subjects engaged in a monotonous breath counting task while keeping their eyes on a fixation cross. Each subject perfo...

  19. DEMAND AND SUPPLY SIDE VIEW ON THE FACTORS AFFECTING SIZE OF THE NON-PROFIT ECONOMY

    OpenAIRE

    Pevcin, Primož

    2012-01-01

    This paper empirically investigates various factors affecting variations in the size of the non-profit sector by using cross-country data in the sample of selected countries. Namely, the available data on sector employment (workforce) indicate substantial variations in the size of the sector among countries, although certain problems exist with the measurement of the sector size, whicha are mostly related to its diversity. The existing literature can provide several theories, hypotheses and c...

  20. Non-differentiable variational principles

    Science.gov (United States)

    Cresson, Jacky

    2005-07-01

    We develop a calculus of variations for functionals which are defined on a set of non-differentiable curves. We first extend the classical differential calculus in a quantum calculus, which allows us to define a complex operator, called the scale derivative, which is the non-differentiable analogue of the classical derivative. We then define the notion of extremals for our functionals and obtain a characterization in term of a generalized Euler-Lagrange equation. We finally prove that solutions of the Schrödinger equation can be obtained as extremals of a non-differentiable variational principle, leading to an extended Hamilton's principle of least action for quantum mechanics. We compare this approach with the scale relativity theory of Nottale, which assumes a fractal structure of space-time.Résumé (Principes variationnels non différentiable). Nous développons un calcul des variations pour des fonctionnelles définies sur un ensemble de courbes non différentiables. Pour cela, nous étendons le calcul différentiel classique, en calcul appelé calcul quantique, qui nous permet de définir un opérateur à valeur complexes, appelé dérivée d'échelle, qui est l'analogue non différentiable de la dérivée usuelle. On définit alors la notion d'extremale pour ces fonctionnelles pour lesquelles nous obtenons une caractérisation via une équation d'Euler-Lagrange généralisée. On prouve enfin que les solutions de l'équation de Schrödinger peuvent s'obtenir comme solution d'un problème variationnel non différentiable, étendant ainsi le principe de moindre action de Hamilton au cadre de la mécanique quantique. On discute enfin la connexion entre ce travail et la théorie de la relativité d'échelle développée par Nottale, et qui suppose une structure fractale de l'espace-temps.

  1. Both male and female identity influence variation in male signalling effort

    OpenAIRE

    Svensson P Andreas; Lehtonen Topi K; Wong Bob BM

    2011-01-01

    Abstract Background Male sexual displays play an important role in sexual selection by affecting reproductive success. However, for such displays to be useful for female mate choice, courtship should vary more among than within individual males. In this regard, a potentially important source of within male variation is adjustment of male courtship effort in response to female traits. Accordingly, we set out to dissect sources of variation in male courtship effort in a fish, the desert goby (C...

  2. Seasonal variations in physicochemical profiles of Guduchi Satva (starchy substance from Tinospora cordifolia [Willd.] Miers)

    OpenAIRE

    Rohit Sharma; Hetal Amin; Galib R; P K Prajapati

    2013-01-01

    Guduchi Satva (GS), the starchy material extracted from the Guduchi stem is well-known Ayurvedic single drug formulation having a wide range of therapeutic utility. Species of the plant, stem size, collection time, season and maturity of the plant may affect the yield and physico-chemical profile of GS. However, published data on such variations is lacking. Considering this, present study is planned to screen seasonal variations in physico-chemical profile of GS. 18 batches of GS were prepare...

  3. Seasonal variations of the humoral immune parameters of European sea bass (Dicentrarchus labrax L.)

    OpenAIRE

    Valero, Y. (Yulema)

    2014-01-01

    Seasonal cycles, mainly due to great variations in the light duration and temperature, are important and modulate several aspects of the animal behavior. In the case of poikilotherms animals such as fish this is very relevant. Thus, temperature changes fish immunity and affects disease resistance. We evaluate in this work the season variations of the European sea bass (Dicentrarchus labrax) humoral innate parameters focusing on winter months, at which the culture of this specie is more diffic...

  4. Effects of the variation of fundamental constants on Pop III stellar evolution

    OpenAIRE

    Ekstrom, Sylvia; Coc, Alain; Descouvemont, Pierre; Meynet, Georges; Olive, Keith A.; Uzan, Jean-Philippe; Vangioni, Elisabeth

    2009-01-01

    A variation of the fundamental constants is expected to affect the thermonuclear rates important for stellar nucleosynthesis. In particular, because of the very small resonant energies of Be8 and C12, the triple $\\alpha$ process is extremely sensitive to any such variations. Using a microscopic model for these nuclei, we derive the sensitivity of the Hoyle state to the nucleon-nucleon potential allowing for a change in the magnitude of the nuclear interaction. We follow the evolution of 15 an...

  5. The effects of coefficient of restitution variations on long fly balls

    Science.gov (United States)

    Kagan, David T.

    1990-02-01

    The coefficient of restitution of major league baseballs is required to be 0.546±0.032. These allowed variations affect the launch velocity and ultimately the range of fly balls. The variations in the range for well-hit balls are calculated here to be on the order of 15 ft. These calculations provide an interesting collection of mechanics problems that might be of interest for undergraduate students.

  6. Analysis of mitochondrial DNA variations in Indian patients with congenital cataract

    OpenAIRE

    Roshan, Mascarenhas; Kabekkodu, Shama Prasada; Vijaya, Pai H.; Manjunath, Kamath; Graw, Jochen; Gopinath, PM.; Satyamoorthy, Kapeattu

    2012-01-01

    Purpose Identification of mitochondrial DNA (mtDNA) variations in the inherited cataract patients from south India. Methods Three families with inherited cataract of maternal origin were evaluated. Clinical and ophthalmologic examinations were performed on available affected as well as unaffected family members. Samples of mtDNA were amplified using 24 pairs of overlapping primers to analyze the entire mitochondrial genome to screen for variations and analyzed for both coding and non-coding r...

  7. Geographical distribution of fish catches and temperature variations in the Northeast Atlantic since 1945

    OpenAIRE

    Hannesson, Rögnvaldur

    2006-01-01

    Warming of the northeast Atlantic is expected to affect the location and productivity of fish stocks. It is examined whether variations in catches of cod, herring, mackerel, anchovy and sardines in the ICES statistical areas are related to variations in ocean temperature. Temperatures at certain locations along the Norwegian coast are taken as proxies for temperatures in the Norwegian Sea and the North Sea. It is found that the catches of cod in the North Sea are inversely correlated with tem...

  8. Variations in COMT Gene Interact With Parenting to Influence Attention in Early Development1

    OpenAIRE

    Voelker, Pascale; Sheese, Brad E.; Rothbart, Mary K.; Posner, Michael I.

    2009-01-01

    Attention influences many aspects of cognitive development. Variations in the COMT gene, known to affect dopamine neurotransmission, have frequently been found to influence attention in adults and older children. In this paper we examined 2 year old children and found that variation in the COMT gene influenced attention in a task involving looking to a sequence of visual stimuli. Because the influence of another dopamine related gene (DRD4) has been shown to interact with parenting quality at...

  9. Comparison of Genome Wide Variation between Malawians and African Ancestry HapMap Populations

    OpenAIRE

    Joubert, Bonnie R.; North, Kari E.; Wang, Yunfei; Mwapasa, Victor; Franceschini, Nora; Meshnick, Steven R; Lange, Ethan M.

    2010-01-01

    Understanding genetic variation between populations is important because it affects the portability of human genome wide analytical methods. We compared genetic variation and substructure between Malawians and other African and non-African HapMap populations. Allele frequencies and adjacent linkage disequilibrium (LD) were measured for 617,715 single nucleotide polymorphisms (SNPs) across subject genomes. Allele frequencies in the Malawian population (N = 226) were highly correlated with alle...

  10. Variation of the latissimus dorsi

    Directory of Open Access Journals (Sweden)

    Ishani P Shah

    2014-01-01

    Full Text Available A typical muscle variation of latissimus dorsi - the axillary arch is represented by the muscular or fibromuscular slip detached from the anteroinferior border of the musculus latissimus dorsi passing over the axilla under the axillary fascia crossing the medial side of the brachial plexus to continue as a septum intermusculare mediale brachii distally to the medial epicondyle of humerus. The full extent of the muscle is rarely present. Slips of muscle extend from the latissimus dorsi at the inferior angle of scapula to insert into pectoralis major (Langer, coracobrachilis, biceps or coracoid process forming what is described as a common variant - the muscular axillary arch. We report three cases of variants of latissimus dorsi, one of which has not been reported in the literature before.

  11. Reasoning about Variation: Student Voice

    Directory of Open Access Journals (Sweden)

    Jackie Reid

    2007-10-01

    Full Text Available This paper reports one recent study that was part of a project investigating tertiary students’ understanding of variation. These students completed a questionnaire prior to, and at the end of, an introductory statistics course and this paper focuses on interviews of selected students designed to determine whether more information could have been gathered about the students’ reasoning. Clarification during interviews reinforced researcher interpretation of responses. Prompting assisted students to develop better quality responses but probing was mostly useful for assisting students to re-express reasoning already presented. Cognitive conflict situations proved challenging. The diversity of activities identified by students as assisting the development of their understanding provides a challenge for educators in planning teaching sequences. Both educators and researchers need to listen to students to better understand the development of reasoning.

  12. Equilibrium models and variational inequalities

    CERN Document Server

    Konnov, Igor

    2007-01-01

    The concept of equilibrium plays a central role in various applied sciences, such as physics (especially, mechanics), economics, engineering, transportation, sociology, chemistry, biology and other fields. If one can formulate the equilibrium problem in the form of a mathematical model, solutions of the corresponding problem can be used for forecasting the future behavior of very complex systems and, also, for correcting the the current state of the system under control. This book presents a unifying look on different equilibrium concepts in economics, including several models from related sciences.- Presents a unifying look on different equilibrium concepts and also the present state of investigations in this field- Describes static and dynamic input-output models, Walras, Cassel-Wald, spatial price, auction market, oligopolistic equilibrium models, transportation and migration equilibrium models- Covers the basics of theory and solution methods both for the complementarity and variational inequality probl...

  13. Variational Principle for Planetary Interiors

    CERN Document Server

    Zeng, Li

    2016-01-01

    In the past few years, the number of confirmed planets has grown above 2000. It is clear that they represent a diversity of structures not seen in our own solar system. In addition to very detailed interior modeling, it is valuable to have a simple analytical framework for describing planetary structures. Variational principle is a fundamental principle in physics, entailing that a physical system follows the trajectory which minimizes its action. It is alternative to the differential equation formulation of a physical system. Applying this principle to planetary interior can beautifully summarize the set of differential equations into one, which provides us some insight into the problem. From it, a universal mass-radius relation, an estimate of error propagation from equation of state to mass-radius relation, and a form of virial theorem applicable to planetary interiors are derived.

  14. Variational Approach and Deformed Derivatives

    CERN Document Server

    Weberszpil, José

    2015-01-01

    Recently, we have demonstrated that there exists a possible relationship between q-deformed algebras in two different contexts of Statistical Mechanics, namely, the Tsallis' framework and the Kaniadakis' scenario, with a local form of fractional-derivative operators for fractal media, the so-called Hausdorff derivatives, mapped into a continuous medium with a fractal measure. Here, in this paper, we present an extension of the traditional calculus of variations for systems containing deformed-derivatives embedded into the Lagrangian and the Lagrangian densities for classical and field systems. The results extend the classical Euler-Lagrange equations and the Hamiltonian formalism. The resulting dynamical equations seem to be compatible with those found in the literature, specially with mass-dependent and with nonlinear equations for systems in classical and quantum mechanics. Examples are presented to illustrate applications of the formulation. Also, the conserved Nether current, are worked out.

  15. Some Variations on Maxwell's Equations

    CERN Document Server

    Ascoli, G A; Ascoli, Giorgio A.; Goldin, Gerald A.

    2006-01-01

    In the first sections of this article, we discuss two variations on Maxwell's equations that have been introduced in earlier work---a class of nonlinear Maxwell theories with well-defined Galilean limits (and correspondingly generalized Yang-Mills equations), and a linear modification motivated by the coupling of the electromagnetic potential with a certain nonlinear Schroedinger equation. In the final section, revisiting an old idea of Lorentz, we write Maxwell's equations for a theory in which the electrostatic force of repulsion between like charges differs fundamentally in magnitude from the electrostatic force of attraction between unlike charges. We elaborate on Lorentz' description by means of electric and magnetic field strengths, whose governing equations separate into two fully relativistic Maxwell systems---one describing ordinary electromagnetism, and the other describing a universally attractive or repulsive long-range force. If such a force cannot be ruled out {\\it a priori\\/} by known physical ...

  16. Fisher Algorithm: Variations And Applications

    Directory of Open Access Journals (Sweden)

    Adegoke

    2013-12-01

    Full Text Available This paper examines Fisherface (Linear Discriminant Analysis methods, its different modifications as applied to feature extraction in face recognition. Researchers showed that Fisher algorithm, though it performs better than PCA, Eigenface and some other fundamental methods, computational complexity, enormous hardware resources usage are inhibitors to its implementation. Different versions or adaptations of Fisher algorithm had been developed, and applied to face recognition and validated using some of the available public face databases. If fisher algorithm and its various variations had so marvelously helped in face recognition, application of this effective dimensionality reduction method can be applied to research area of iris recognition system. This will in return enhance performance of biometric systems in its application to computer security and surveillance.

  17. Flux Variation of Cosmic Muons

    CERN Document Server

    Ramesh, Nepal; Martin, Clayton; Bachri, Abdel

    2012-01-01

    In the current paper, we analyzed the variation of cosmic radiation flux with elevation, time of the year and ambient temperature with the help of a portable cosmic muon detector, the construction of which was completed by a team from Southern Arkansas University (SAU) at Lawrence Berkeley National Laboratory (LBNL). Cosmic muons and gamma rays traverse two synchronized scintillators connected to two photomultiplier tubes (PMT) via light guides, and generate electronic pulses which we counted using a Data Acquisition Board (DAQ). Because muons are the product of collisions between high-energy cosmic rays and atmospheric nuclei, and therefore shower onto earth, the scintillators were arranged horizontally for detection. The elevation measurements were recorded at different locations, starting from 60 feet below sea-level at the Underground Radiation Counting Laboratory at Johnson Space Center, TX, to 4200 feet at Mt. Hamilton, CA. Intermediate locations included sea-level Galveston Bay, TX, and Mt. Magazine, A...

  18. Variational approach and deformed derivatives

    Science.gov (United States)

    Weberszpil, J.; Helayël-Neto, J. A.

    2016-05-01

    Recently, we have demonstrated that there exists a possible relationship between q-deformed algebras in two different contexts of Statistical Mechanics, namely, the Tsallis' framework and the Kaniadakis' scenario, with a local form of fractional-derivative operators for fractal media, the so-called Hausdorff derivatives, mapped into a continuous medium with a fractal measure. Here, in this paper, we present an extension of the traditional calculus of variations for systems containing deformed-derivatives embedded into the Lagrangian and the Lagrangian densities for classical and field systems. The results extend the classical Euler-Lagrange equations and the Hamiltonian formalism. The resulting dynamical equations seem to be compatible with those found in the literature, specially with mass-dependent and with nonlinear equations for systems in classical and quantum mechanics. Examples are presented to illustrate applications of the formulation. Also, the conserved ​Noether current is worked out.

  19. Turbidity variations at Hanford since July 1974

    International Nuclear Information System (INIS)

    Spectral turbidity coefficients derived from multiwavelength sunphotometer measurements obtained from July 1974 to December 1976 have been analyzed for seasonal and weekly variations. Weak biannual variations in turbidity are apparent in the data. Day-to-day variations, however, can be much larger than the coefficients for the fitted biannual terms. Consequently, it now appears that observed variations in turbidity at Hanford are related to the synoptic meteorology with a smaller, superimposed seasonality of dust and smoke sources. Turbidity variations are also independent of the day of the week

  20. Some Variational Principles for Coupled Thermoelasticity

    Directory of Open Access Journals (Sweden)

    Francesco Marotti de Sciarra

    2013-01-01

    Full Text Available The nonlinear thermoelasticity of type II proposed by Green and Naghdi is considered. The thermoelastic structural model is formulated in a quasistatic range, and the related thermoelastic variational formulation in the complete set of state variables is recovered. Hence a consistent framework to derive all the variational formulations with different combinations of the state variables is provided, and a family of mixed variational formulations, with different combinations of state variables, is provided starting from the general variational formulation. A uniqueness condition is provided on the basis of a suitable variational formulation.

  1. Opsin clines in butterflies suggest novel roles for insect photopigments.

    Science.gov (United States)

    Frentiu, Francesca D; Yuan, Furong; Savage, Wesley K; Bernard, Gary D; Mullen, Sean P; Briscoe, Adriana D

    2015-02-01

    Opsins are ancient molecules that enable animal vision by coupling to a vitamin-derived chromophore to form light-sensitive photopigments. The primary drivers of evolutionary diversification in opsins are thought to be visual tasks related to spectral sensitivity and color vision. Typically, only a few opsin amino acid sites affect photopigment spectral sensitivity. We show that opsin genes of the North American butterfly Limenitis arthemis have diversified along a latitudinal cline, consistent with natural selection due to environmental factors. We sequenced single nucleotide (SNP) polymorphisms in the coding regions of the ultraviolet (UVRh), blue (BRh), and long-wavelength (LWRh) opsin genes from ten butterfly populations along the eastern United States and found that a majority of opsin SNPs showed significant clinal variation. Outlier detection and analysis of molecular variance indicated that many SNPs are under balancing selection and show significant population structure. This contrasts with what we found by analysing SNPs in the wingless and EF-1 alpha loci, and from neutral amplified fragment length polymorphisms, which show no evidence of significant locus-specific or genome-wide structure among populations. Using a combination of functional genetic and physiological approaches, including expression in cell culture, transgenic Drosophila, UV-visible spectroscopy, and optophysiology, we show that key BRh opsin SNPs that vary clinally have almost no effect on spectral sensitivity. Our results suggest that opsin diversification in this butterfly is more consistent with natural selection unrelated to spectral tuning. Some of the clinally varying SNPs may instead play a role in regulating opsin gene expression levels or the thermostability of the opsin protein. Lastly, we discuss the possibility that insect opsins might have important, yet-to-be elucidated, adaptive functions in mediating animal responses to abiotic factors, such as temperature or photoperiod

  2. Variational methods for field theories

    International Nuclear Information System (INIS)

    Four field theory models are studied: Periodic Quantum Electrodynamics (PQED) in (2 + 1) dimensions, free scalar field theory in (1 + 1) dimensions, the Quantum XY model in (1 + 1) dimensions, and the (1 + 1) dimensional Ising model in a transverse magnetic field. The last three parts deal exclusively with variational methods; the PQED part involves mainly the path-integral approach. The PQED calculation results in a better understanding of the connection between electric confinement through monopole screening, and confinement through tunneling between degenerate vacua. This includes a better quantitative agreement for the string tensions in the two approaches. Free field theory is used as a laboratory for a new variational blocking-truncation approximation, in which the high-frequency modes in a block are truncated to wave functions that depend on the slower background modes (Boron-Oppenheimer approximation). This ''adiabatic truncation'' method gives very accurate results for ground-state energy density and correlation functions. Various adiabatic schemes, with one variable kept per site and then two variables per site, are used. For the XY model, several trial wave functions for the ground state are explored, with an emphasis on the periodic Gaussian. A connection is established with the vortex Coulomb gas of the Euclidean path integral approach. The approximations used are taken from the realms of statistical mechanics (mean field approximation, transfer-matrix methods) and of quantum mechanics (iterative blocking schemes). In developing blocking schemes based on continuous variables, problems due to the periodicity of the model were solved. Our results exhibit an order-disorder phase transition. The transfer-matrix method is used to find a good (non-blocking) trial ground state for the Ising model in a transverse magnetic field in (1 + 1) dimensions

  3. Variation in Students' Conceptions of Self-Assessment and Standards

    Directory of Open Access Journals (Sweden)

    Heng Kiat Kelvin Tan

    2011-01-01

    Full Text Available This paper reports the results of a phenomenographic study on the different ways that secondary students understood and utilized student self-assessment and how various ego types could affect the accuracy of self-assessment. The study sought to contribute to the growing literature which recognizes the critical role that students play in assessment processes, and in particular the different roles that they assume in student self-assessment. The results of the study provide insights into how different students experience self-assessment by articulating the variation in the perception and purposes of assessing one's own learning. This variation is depicted as a hierarchy of logically related students' conceptions of self-assessment.

  4. Single nucleotide variations: biological impact and theoretical interpretation.

    Science.gov (United States)

    Katsonis, Panagiotis; Koire, Amanda; Wilson, Stephen Joseph; Hsu, Teng-Kuei; Lua, Rhonald C; Wilkins, Angela Dawn; Lichtarge, Olivier

    2014-12-01

    Genome-wide association studies (GWAS) and whole-exome sequencing (WES) generate massive amounts of genomic variant information, and a major challenge is to identify which variations drive disease or contribute to phenotypic traits. Because the majority of known disease-causing mutations are exonic non-synonymous single nucleotide variations (nsSNVs), most studies focus on whether these nsSNVs affect protein function. Computational studies show that the impact of nsSNVs on protein function reflects sequence homology and structural information and predict the impact through statistical methods, machine learning techniques, or models of protein evolution. Here, we review impact prediction methods and discuss their underlying principles, their advantages and limitations, and how they compare to and complement one another. Finally, we present current applications and future directions for these methods in biological research and medical genetics. PMID:25234433

  5. Daily Variations of the Geomagnetic Field in the Brazilian zone

    CERN Document Server

    Oliva, David; Papa, Andrés R R

    2014-01-01

    The solar quiet daily variation (Sq) was investigated with respect to the longitudinal and seasonal variations at the Brazilian geomagnetic ground stations of Tatuoca (TTB), Vassouras (VSS ) and S\\~ao Martinho da Serra (SMS). The data utilized was collected during the time interval from January to May 2010. We employed the continuous wavelet transforms and cross wavelet coherence to study the spectral content and correlations of the time series in the time-frequency domain. We identified possible phenomena of regional or global scope that could be affecting the magnetic response measured at TTB, VSS and SMS observatories. As a result some signatures of planetary waves and semidiurnal tides in the Sq variability were obtained.

  6. Social carry-over effects on non-social behavioral variation: mechanisms and consequences

    Directory of Open Access Journals (Sweden)

    Petri Toivo Niemelä

    2015-05-01

    Full Text Available The field of animal personality is interested in decomposing behaviors into different levels of variation, with its present focus on the ecological and evolutionary causes and consequences of expressed variation. Recently the role of the social environment, i.e. social partners, has been suggested to affect behavioral variation and induce selection on animal personality. Social partner effects exist because characters of social partners (e.g. size, behavior, affect the behavioral expression of a focal individual. Here, we 1 first review the proximate mechanisms underlying the social partner effects on behavioral expression and the timescales at which such effects might take place. We then 2 discuss how within- and among-individual variation in single behaviors and covariation between multiple behaviors, caused by social partners, can carry-over to non-social behaviors expressed outside the social context. Finally, we 3 highlight evolutionary consequences of social carry-over effects to non-social behaviors and 4 suggest study designs and statistical approaches which can be applied to study the nature and evolutionary consequences of social carry-over effects on non-social behaviors. Understanding the proximate mechanisms underpinning the social partner effects is important since it opens a door for deeper understanding of how social environments can affect behavioral variation and covariation at multiple levels, and the evolution of non-social behaviors (i.e. exploration, activity, boldness that are affected by social interactions.

  7. Seed predators exert selection on the subindividual variation of seed size.

    Science.gov (United States)

    Sobral, M; Guitián, J; Guitián, P; Larrinaga, A R

    2014-07-01

    Subindividual variation among repeated organs in plants constitutes an overlooked level of variation in phenotypic selection studies, despite being a major component of phenotypic variation. Animals that interact with plants could be selective agents on subindividual variation. This study examines selective pressures exerted during post-dispersal seed predation and germination on the subindividual variation of seed size in hawthorn (Crataegus monogyna). With a seed offering experiment and a germination test, we estimated phenotypic selection differentials for average and subindividual variation of seed size due to seed predation and germination. Seed size affects germination, growth rate and the probability of an individual seed of escaping predation. Longer seeds showed higher germination rates, but this did not result in significant selection on phenotypes of the maternal trees. On the other hand, seed predators avoided wider seeds, and by doing so exerted phenotypic selection on adult average and subindividual variation of seed size. The detected selection on subindividual variation suggests that the levels of phenotypic variation within individual plants may be, at least partly, the adaptive consequence of animal-mediated selection. PMID:24176051

  8. Diet affects spawning in zebrafish.

    Science.gov (United States)

    Markovich, Michelle L; Rizzuto, Noel V; Brown, Paul B

    2007-01-01

    Seven-month-old zebrafish (Danio rerio) were fed four different diets to test the hypothesis that diet affects spawning success and resulting characteristics of eggs and offspring. The diets were: the recommended feeding regime for zebrafish (a mixture of Artemia, flake feed, and liver paste); Artemia; a flake feed; and a commercially available trout diet. The number of eggs laid and average egg diameter were significantly different as functions of male, female, and individual matings. Fish fed the flake diet produced significantly fewer eggs (mean, 116) than fish fed all other diets (means, 166-187). However, the percent hatch of eggs from fish fed the flake diet (62.5%) was significantly higher than from fish fed the trout diet (19.5%). The percentages of hatched eggs from fish fed the control diet (36.2%) or Artemia (35.6%) were not significantly different from each other or from fish fed the other two diets. Wet weight and diameter of eggs were not significantly affected by diet. Larval length was significantly higher from parents fed the flake diet (14.5 mm) compared to larvae from parents fed Artemia (13.7 mm). Length of larvae from fish fed the control or trout diets was intermediate and not significantly different from fish fed the flake diet or Artemia. Larval weight was not significantly affected by dietary treatment, but offspring from fish fed the flake diet were heavier than larvae from adults fed any of the other diets. Feeding adult zebrafish the flake diet alone resulted in more viable offspring and larger larvae and is a simpler feeding regime than the current recommendation. The authors recommend feeding adult zebrafish flake diets to satiation three times daily for maximum production of viable offspring. PMID:18041944

  9. Diurnal variations in water vapor over Central and South America

    Science.gov (United States)

    Meza, Amalia; Mendoza, Luciano; Bianchi, Clara

    2016-07-01

    Diurnal variations in atmospheric integrated water vapor (IWV) are studied employing IWV estimates, with a 30 minutes sampling rate, derived from Global Navigation Satellite Systems (GNSS) observations during the period 2007-2013. The analysis was performed in 73 GNSS tracking sites (GPS + GLONASS) which have more than 5 years of data. The selected area involves different climate types, from polar to tropical, with different diurnal variations of the integrated total humidity content. There are many processes that could induce diurnal variations in atmospheric water vapor (Dai et al, 1999 a,b), the most relevant causes are: surface evapotranspiration, atmospheric large-scale vertical motion, atmospheric low-level moisture convergence and precipitation and vertical mixing (which affects the vertical distribution of water vapor but does not affect the IWV). The numerical tools, Singular Value Decomposition and classical Multidimensional Scaling methods, are used to study these variations, considering the measurements made at each stations, as sample in the analysis. The aim of this investigation is to identify the IWV variability with respect to the local time associated to the different climate regions. In order to improve our analysis, all available weather information, such as radiosondes measurements (which are few), measurements of pressure and temperature and Numerical Weather Models reanalysis data, are used. Reference: Dai, A., K. E. Trenberth, and T. R. Karl, 1999 a: Effects of clouds, soil moisture, precipitation and water vapor on diurnal temperature range. J. Climate, 12, 2451-2473. Dai, A., F. Giorgi, and K. E. Trenberth, 1999 b: Observed and model simulated precipitation diurnal cycle over the contiguous United States.J. Geophys. Res., 104, 6377-6402. KEYWORDS: water vapor, diurnal cycle, GNSS

  10. Analysis of Interannual Variations of Inorganic Nitrogen in the Bohai Sea

    Institute of Scientific and Technical Information of China (English)

    Shi Qiang; Gao Zhenhui; Yang Jianqiang

    2002-01-01

    According to the Bohai Sea cross-section data during 1985~1998, the high concentration inorganic nitrogen in the Bohai Sea section bottom layer water nearshore diffused and transferred to the middle of the Bohai Sea year after year. The interannual variations of the concentration of inorganic nitrogen in the Bohai Sea section bottom layer water may reflect the degree of eutrophication more steadily. The nitrate nitrogen and nitrite nitrogen are used to show quasi-equilibrium state interannual variations, but with the aggravation of seawater pollution, the quasi-equilibrium state of interannual variations has been broken and the marine biological-chemical processes can only maintain the secondary part of the interannual variations in a quasi-equilibrium state, but are not sufficient to prevent the main pan of interannual variations from deviating from the quasi-equilibrium state. The spatial distributions of inorganic nitrogen would be affected by the reproduction and swarming of marine life.

  11. affective variables of language learning

    Institute of Scientific and Technical Information of China (English)

    李文敬

    2011-01-01

    why people enjoy different degrees of success in second language learning,given similar opportunities.in the presence of overly negative emotions such as anxiety,fear,stress,anger or depression,our optimal learning potential maybe compromised.the affective domain refers to the emotional domain that has to do with the emotional behavior of human beings.it includes such factors as self-confidence,extroversion,anxiety,attitudes and motivation.three major factors are introduced here:self-confidence,anxiety and motivation.

  12. How indoor environment affects performance

    DEFF Research Database (Denmark)

    Wyon, David Peter; Wargocki, Pawel

    2013-01-01

    , in the form of answers to 40 frequently asked questions. Our answers are based on the results of behavioral experiments conducted to date. We offer no opinions on long-term health effects of indoor environmental quality. We provide some references to relevant sources, but there is not enough space......As experienced researchers in the effects of thermal comfort and indoor air quality on performance, we are often asked to give our best estimate of how, and to what extent, performance is affected by different aspects of indoor climate. This article provides a brief summary of our personal opinions...

  13. Does trade affect child health?

    Science.gov (United States)

    Levine, David I; Rothman, Dov

    2006-05-01

    Frankel and Romer [Frankel, J., Romer, D., 1999. Does trade cause growth? American Economic Review 89 (3), 379-399] documented positive effects of geographically determined trade openness on economic growth. At the same time, critics fear that openness can lead to a "race to the bottom" that increases pollution and reduces government resources for investments in health and education. We use Frankel and Romer's gravity model of trade to examine how openness to trade affects children. Overall, we find little harm from trade, and potential benefits largely through slightly faster GDP growth. PMID:16303196

  14. Analysing the behaviour of LED module driver under variation of ambient temperature

    Science.gov (United States)

    Bürger, A.; Sanchez, O.

    2015-01-01

    Temperature variations affect the operation of electronic devices. In this article we analyze effects that temperature variation entails a LED lamp commonly used in Brazil. We simulated temperature variations through the use of an oven of 1 m3. Then obtained emission spectrum in the visible, CRI, Correlated Color Temperature, harmonic distortion on the current, supply current, and CIE Chromatic Coordinates x and y in two situations: first with the LED module and controller inside the oven and second with the controller outside. The temperature was monitored in different part of this set. Interesting correlations for specifiers and developers were found.

  15. Analysing the behaviour of LED module driver under variation of ambient temperature

    International Nuclear Information System (INIS)

    Temperature variations affect the operation of electronic devices. In this article we analyze effects that temperature variation entails a LED lamp commonly used in Brazil. We simulated temperature variations through the use of an oven of 1 m3. Then obtained emission spectrum in the visible, CRI, Correlated Color Temperature, harmonic distortion on the current, supply current, and CIE Chromatic Coordinates x and y in two situations: first with the LED module and controller inside the oven and second with the controller outside. The temperature was monitored in different part of this set. Interesting correlations for specifiers and developers were found

  16. Mood Swings: An Affective Interactive Art System

    Science.gov (United States)

    Bialoskorski, Leticia S. S.; Westerink, Joyce H. D. M.; van den Broek, Egon L.

    The progress in the field of affective computing enables the realization of affective consumer products, affective games, and affective art. This paper describes the affective interactive art system Mood Swings, which interprets and visualizes affect expressed by a person. Mood Swings is founded on the integration of a framework for affective movements and a color model. This enables Mood Swings to recognize affective movement characteristics as expressed by a person and display a color that matches the expressed emotion. With that, a unique interactive system is introduced, which can be considered as art, a game, or a combination of both.

  17. Pseudobulbar affect: prevalence and management

    Directory of Open Access Journals (Sweden)

    Ahmed A

    2013-11-01

    Full Text Available Aiesha Ahmed, Zachary SimmonsDepartment of Neurology, Penn State Hershey Medical Center, Hershey, PA, USAAbstract: Pseudobulbar affect (PBA may occur in association with a variety of neurological diseases, and so may be encountered in the setting of amyotrophic lateral sclerosis, extrapyramidal and cerebellar disorders, multiple sclerosis, traumatic brain injury, Alzheimer's disease, stroke, and brain tumors. The psychological consequences and the impact on social interactions may be substantial. Although it is most commonly misidentified as a mood disorder, particularly depression or a bipolar disorder, there are characteristic features that can be recognized clinically or assessed by validated scales, resulting in accurate identification of PBA, and thus permitting proper management and treatment. Mechanistically, PBA is a disinhibition syndrome in which pathways involving serotonin and glutamate are disrupted. This knowledge has permitted effective treatment for many years with antidepressants, particularly tricyclic antidepressants and selective serotonin reuptake inhibitors. A recent therapeutic breakthrough occurred with the approval by the Food and Drug Administration of a dextromethorphan/quinidine combination as being safe and effective for treatment of PBA. Side effect profiles and contraindications differ for the various treatment options, and the clinician must be familiar with these when choosing the best therapy for an individual, particularly elderly patients and those with multiple comorbidities and concomitant medications.Keywords: pseudobulbar affect, emotional lability, depression, amyotrophic lateral sclerosis, multiple sclerosis

  18. Factors Affecting Medical Service Quality.

    Directory of Open Access Journals (Sweden)

    Ali Mohammad Mosadeghrad

    2014-02-01

    Full Text Available A better understanding of factors influencing quality of medical service can pinpoint better strategies for quality assurance in medical services. This study aimed to identify factors affecting the quality of medical services provided by Iranian physicians.Exploratory in-depth individual interviews were conducted with sixty-four physicians working in various medical institutions in Iran.Individual, organizational and environmental factors enhance or inhibit the quality of medical services. Quality of medical services depends on the personal factors of the physician and patient, and factors pertaining to the healthcare setting and the broader environment.Differences in internal and external factors such as availability of resources, patient cooperation and collaboration among providers affect the quality of medical services and patient outcomes. Supportive leadership, proper planning, education and training and effective management of resources and processes improve the quality of medical services. This article contributes to healthcare theory and practice by developing a conceptual framework for understanding factors that influence medical services quality.

  19. Trees to treehoppers: genetic variation in host plants contributes to variation in the mating signals of a plant-feeding insect.

    Science.gov (United States)

    Rebar, Darren; Rodríguez, Rafael L

    2014-02-01

    Community genetics research has demonstrated 'bottom-up' effects of genetic variation within a plant species in shaping the larger community with which it interacts, such as compositions of arthropod faunas. We demonstrate that such cross-trophic interactions also influence sexually selected traits. We used a member of the Enchenopa binotata species complex of treehoppers (Hemiptera: Membracidae) to ask whether male mating signals are influenced by host plant genetic variation. We reared a random sample of the treehoppers on potted replicates of a sample of host plant clone lines. We found that treehopper male signals varied according to the clone line on which they developed, showing that genetic variation in host plants affects male treehoppers' behavioural phenotypes. This is the first demonstration of cross-trophic indirect genetic effects on a sexually selected trait. We discuss how such effects may play an important role in the maintenance of variation and within-population phenotypic differentiation, thereby promoting evolutionary divergence. PMID:24350855

  20. Dispositional affectivity and work outcomes of expatriates

    DEFF Research Database (Denmark)

    Selmer, Jan; Lauring, Jakob

    2013-01-01

    How the two components of dispositional affectivity, positive affectivity, representing the predisposition to respond positively to environmental stimuli, and negative affectivity, depicting the opposite reaction, influence work has been the focus of much research. Although dispositional affectiv......How the two components of dispositional affectivity, positive affectivity, representing the predisposition to respond positively to environmental stimuli, and negative affectivity, depicting the opposite reaction, influence work has been the focus of much research. Although dispositional...... affectivity appears to be a promising construct to explain and predict many attitudinal and behavioral outcomes in the workplace, few studies have empirically investigated dispositional affectivity and the work of expatriates. Hence, data from a net-based survey including 350 expatriates in Denmark were used...... to examine the relationship between dispositional affectivity and their work outcomes. Results showed consistent positive associations between positive affectivity and all the studied work outcomes and the opposite relationships for negative affectivity. Implications and suggestions for future...