WorldWideScience

Sample records for affects clinal variation

  1. 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.

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

    Science.gov (United States)

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

    2011-01-01

    • Understanding the adaptive basis of life history variation is a central goal in evolutionary 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 disciplines. • Here, we tested for clinal variation in life history and associated traits along an environmental and altitudinal gradient in the model species Arabidopsis thaliana. Seventeen natural populations of A. thaliana were geo-referenced in north-eastern Spain on a gradient in which precipitation increases but maximum spring temperature and minimum winter temperature decrease with altitude. • One hundred and eighty-nine genotypes from the 17 populations were grown under uniform controlled conditions. Variations in traits related to biomass allocation, fecundity, phenology and vegetative growth were tested for relationships with the altitude and climatic variables associated with the home sites. Above-ground mass, number of rosette leaves at bolting, developmental time and seed weight increased with the home site's altitude. Root allocation, vegetative growth during winter and number of seeds decreased with altitude. • We suggest that the differences among home sites provide clues to the variation in adaptive strategies associated with the climatic gradient. We compared these results with adaptations and clinal relationships reported for other species and with molecular mechanisms described in Arabidopsis.

  3. Maintenance of clinal variation for shell colour phenotype in the flat periwinkle Littorina obtusata.

    Science.gov (United States)

    Phifer-Rixey, M; Heckman, M; Trussell, G C; Schmidt, P S

    2008-07-01

    Clines can signal spatially varying selection and therefore have long been used to investigate the role of environmental heterogeneity in maintaining genetic variation. However, clinal patterns alone are not sufficient to reject neutrality or to establish the mechanism of selection. Indirect, inferential methods can be used to address neutrality and mechanism, but fully understanding the adaptive significance of clinal variation ultimately requires a direct approach. Ecological model systems such as the rocky intertidal provide a useful context for direct experimentation and can serve as a complement to studies in more traditional genetic model systems. In this study, we use indirect and direct approaches to investigate the role of environmental heterogeneity in the maintenance of shell colour polymorphism in the flat periwinkle snail, Littorina obtusata. We document replicated clines in shell colour morph frequencies over thermal gradients at two spatial scales, contrasting with patterns at previously reported microsatellite loci. In addition, experimental results demonstrate that that shell colour has predictable effects on shell temperature and that these differences in temperature, in turn, coincide with patterns of survivorship under episodic thermal stress. Direct manipulation of shell colour revealed that shell colour, and not a correlated character, was the target of selection. Our study provides evidence that spatially varying selection via thermal regime contributes to the maintenance of shell colour phenotype variation in L. obtusata in the sampled areas of the Gulf of Maine.

  4. 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.

  5. 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

  6. Clinal variation in a brown lemur (Eulemur spp.) hybrid zone: combining morphological, genetic and climatic data to examine stability.

    Science.gov (United States)

    Delmore, K E; Brenneman, R A; Lei, R; Bailey, C A; Brelsford, A; Louis, E E; Johnson, S E

    2013-08-01

    Studies of hybrid zones can inform our understanding of reproductive isolation and speciation. Two species of brown lemur (Eulemur rufifrons and E. cinereiceps) form an apparently stable hybrid zone in the Andringitra region of southeastern Madagascar. The aim of this study was to identify factors that contribute to this stability. We sampled animals at 11 sites along a 90-km transect through the hybrid zone and examined variation in 26 microsatellites, the D-loop region of mitochondrial DNA, six pelage and nine morphological traits; we also included samples collected in more distant allopatric sites. Clines in these traits were noncoincident, and there was no increase in either inbreeding coefficients or linkage disequilibrium at the centre of the zone. These results could suggest that the hybrid zone is maintained by weak selection against hybrids, conforming to either the tension zone or geographical selection-gradient model. However, a closer examination of clines in pelage and microsatellites indicates that these clines are not sigmoid or stepped in shape but instead plateau at their centre. Sites within the hybrid zone also occur in a distinct habitat, characterized by greater seasonality in precipitation and lower seasonality in temperature. Together, these findings suggest that the hybrid zone may follow the bounded superiority model, with exogenous selection favouring hybrids within the transitional zone. These findings are noteworthy, as examples supporting the bounded superiority model are rare and may indicate a process of ecologically driven speciation without geographical isolation.

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

    DEFF Research Database (Denmark)

    Sarup, Pernille Merete; Loeschcke, Volker

    2010-01-01

    -down resistance after development at either constant or fluctuating temperatures in nine Drosophila buzzatii populations collected along an altitudinal gradient in Tenerife, Spain. Flies that developed at fluctuating temperatures had higher stress resistance despite experiencing a slightly lower average...

  8. 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.

  9. Clinal adaptation and adaptive plasticity in Artemisia californica: implications for the response of a foundation species to predicted climate change.

    Science.gov (United States)

    Pratt, Jessica D; Mooney, Kailen A

    2013-08-01

    Local adaptation and plasticity pose significant obstacles to predicting plant responses to future climates. Although local adaptation and plasticity in plant functional traits have been documented for many species, less is known about population-level variation in plasticity and whether such variation is driven by adaptation to environmental variation. We examined clinal variation in traits and performance - and plastic responses to environmental change - for the shrub Artemisia californica along a 700 km gradient characterized (from south to north) by a fourfold increase in precipitation and a 61% decrease in interannual precipitation variation. Plants cloned from five populations along this gradient were grown for 3 years in treatments approximating the precipitation regimes of the north and south range margins. Most traits varying among populations did so clinally; northern populations (vs. southern) had higher water-use efficiencies and lower growth rates, C : N ratios and terpene concentrations. Notably, there was variation in plasticity for plant performance that was strongly correlated with source site interannual precipitation variability. The high-precipitation treatment (vs. low) increased growth and flower production more for plants from southern populations (181% and 279%, respectively) than northern populations (47% and 20%, respectively). Overall, precipitation variability at population source sites predicted 86% and 99% of variation in plasticity in growth and flowering, respectively. These striking, clinal patterns in plant traits and plasticity are indicative of adaptation to both the mean and variability of environmental conditions. Furthermore, our analysis of long-term coastal climate data in turn indicates an increase in interannual precipitation variation consistent with most global change models and, unexpectedly, this increased variation is especially pronounced at historically stable, northern sites. Our findings demonstrate the

  10. 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

  11. Does natural variation in diversity affect biotic resistance?

    Science.gov (United States)

    Harrison, Susan; Cornell, Howard; Grace, James B.

    2015-01-01

    Theories linking diversity to ecosystem function have been challenged by the widespread observation of more exotic species in more diverse native communities. Few studies have addressed the key underlying process by dissecting how community diversity is shaped by the same environmental gradients that determine biotic and abiotic resistance to new invaders. In grasslands on highly heterogeneous soils, we used addition of a recent invader, competitor removal and structural equation modelling (SEM) to analyse soil influences on community diversity, biotic and abiotic resistance and invader success. Biotic resistance, measured by reduction in invader success in the presence of the resident community, was negatively correlated with species richness and functional diversity. However, in the multivariate SEM framework, biotic resistance was independent of all forms of diversity and was positively affected by soil fertility via community biomass. Abiotic resistance, measured by invader success in the absence of the resident community, peaked on infertile soils with low biomass and high community diversity. Net invader success was determined by biotic resistance, consistent with this invader's better performance on infertile soils in unmanipulated conditions. Seed predation added slightly to biotic resistance without qualitatively changing the results. Soil-related genotypic variation in the invader also did not affect the results. Synthesis. In natural systems, diversity may be correlated with invasibility and yet have no effect on either biotic or abiotic resistance to invasion. More generally, the environmental causes of variation in diversity should not be overlooked when considering the potential functional consequences of diversity.

  12. Genetic variation in genes affecting milk composition and quality

    DEFF Research Database (Denmark)

    Bertelsen, Henriette Pasgaard

    In the past decade major advances in next generation sequencing technologies have provided new opportuneties for the detection of genetic variation. Combining the knowlegde of genetic variation with phenotypic distributions provides considerable possibilites for detection of candidate genes....... In addition, exploring genetic variation related to the major milk proteins of bovine milk indntified genetic variations with possitive effects on milk coagulation...

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

    Science.gov (United States)

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

    2013-12-01

    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 tested four landscape genomics methods on a simulated clinal population to determine their effectiveness at identifying a locus under varying selection strengths along an environmental gradient. We found all methods produced very low type I error rates across all selection strengths, but elevated type II error rates under "weak" selection. We then applied these methods to an AFLP genome scan of an alpine plant, Campanula barbata, and identified five highly supported candidate loci associated with precipitation variables. These loci also showed spatial autocorrelation and cline patterns indicative of selection along a precipitation gradient. Our results suggest that landscape genomics in combination with other spatial analyses provides a powerful approach for identifying loci potentially under selection and explaining spatially complex interactions between species and their environment.

  14. Clinal patterns in genetic variation for northern leopard frog (Rana pipiens): Conservation status and population histories

    Science.gov (United States)

    Stockwell, Craig A.; Fisher, Justin D.L.; McLean, Kyle I.

    2016-01-01

    The security of the northern leopard frog (Rana pipiens) varies spatially with populations east and west of North Dakota considered as secure and at risk, respectively. We used genetic markers to characterize the conservation status of northern leopard frog populations across North Dakota. We used multiple regression analyses and model selection to evaluate correlations of expected heterozygosity (HE) with the direct and additive effects of: i) geographic location,ii) wetland density and iii) average annual precipitation. There was lower genetic diversity in the western portion of the state due to lower levels of diversity for populations southwest of the Missouri River. This may reflect a refugial/colonization signature for the only non-glaciated area of North Dakota. Genetic diversity was also positively associated with wetland densities which is consistent with the reliance of this species on a mosaic of wetlands. Our findings suggest that populations in the southwestern part of North Dakota are of higher conservation concern, a finding consistent with the higher risk noted for northern leopard frog populations in most states west of North Dakota. Our findings also pose the hypothesis that climate change induced changes in wetland densities will reduce genetic diversity of northern leopard frog populations.

  15. Factors affecting yearly variations of indoor radon concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Steck, D.J.; Baynes, S.A. [John`s Univ., Collegeville, MN (United States)

    1996-06-01

    Since indoor radon exposures take place over many years while radon measurement periods are shorter, we are studying the yearly variation of indoor radon concentrations in approximately 100 houses located throughout Minnesota. Most houses were initially measured for one or more years in the late 1980`s and for 5 consecutive years starting in 1990. Two houses have been monitored for 12 y. Each year, two alpha track detectors were placed on the two lowest livable levels. The year-to-year variations averaged about 35% (corrected for instrumental uncertainties) in both basements and first floors. The minimum observed variation was 5% and the maximum was 130%. Some homes have shown substantial variation associated with Structural modifications. While most homes show no obvious systematic trends, a few houses have shown temporal trends that may be associated with aging or climate. We are studying possible correlation between year-to-year radon variation, climatic variables (yearly-average and seasonal such as heating/cooling degree days, precipitation, soil moisture), and structural changes.

  16. Listeners discern affective variation in computer-generated musical sounds.

    Science.gov (United States)

    Bailes, Freya; Dean, Roger T

    2009-01-01

    We carried out two experiments to test the relationship between real-time perception of structural change in stylistically unusual musical sounds, and perception of its affect (arousal and valence). Computer music was used because of its unfamiliarity and our capacity to control it in ecologically appropriate ways. In experiment 1, thirteen participants unselected for musical training participated in tasks to detect segmentation and changes in affect. Changes in affect occurred upon detection of segmentation; but not all algorithmically distinct segments conveyed distinct affect. Short segments followed by long segments led to greater changes in arousal and valence at the point of segmentation than vice versa. In experiment 2, intra-segment sound transitions were introduced. Sixteen musicians performed the same affect task as in experiment 1, and a novel change in sound task. Participants were slow to respond to a continuous transition, but quick to respond to instantaneous transitions. Contrary to literature on the perception of affect in more familiar music, the musician participants in experiment 2 differed more in their ratings of arousal than of valence, in spite of a strong correlation of arousal with the composition of the stimuli. These findings are discussed in relation to the positive valence attributed to the more familiar sounds in both experiments.

  17. 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....

  18. Copy number variations in affective disorders and meta-analysis

    DEFF Research Database (Denmark)

    Olsen, Line; Hansen, Thomas; Djurovic, Srdjan;

    2011-01-01

    in a combined analysis of three case-control samples from Denmark, Norway and Iceland. A total of 1897 cases (n=1223 unipolar and n=463 bipolar) and 11 231 controls were analyzed for CNVs at the 10 genomic loci, but we found no combined association between these CNVs and affective disorders....

  19. Variation in postsampling treatment of avian blood affects ecophysiological interpretations

    NARCIS (Netherlands)

    Hoye, B.J.

    2012-01-01

    1. The fluid component of blood is widely used in ecophysiological investigations, including measures of immune function and stable isotope ecology. After blood collection, delayed separation of blood extracellular fluids from red blood cells is known to affect the concentration of a wide range of b

  20. 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

  1. 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.

  2. Host plant affects morphometric variation of Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Paris, Thomson M; Allan, Sandra A; Hall, David G; Hentz, Matthew G; Hetesy, Gabriella; Stansly, Philip A

    2016-01-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is one of the most serious citrus pests worldwide due to its role as vector of huanglongbing or citrus greening disease. While some optimal plant species for ACP oviposition and development have been identified, little is known of the influence of host plants on ACP size and shape. Our goal was to determine how size and shape of ACP wing and body size varies when development occurs on different host plants in a controlled rearing environment. ACP were reared on six different rutaceous species; Bergera koenigii, Citrus aurantifolia, Citrus macrophylla, Citrus maxima, Citrus taiwanica and Murraya paniculata. Adults were examined for morphometric variation using traditional and geometric analysis based on 12 traits or landmarks. ACP reared on C. taiwanica were consistently smaller than those reared on the other plant species. Wing aspect ratio also differed between C. maxima and C. taiwanica. Significant differences in shape were detected with those reared on M. paniculata having narrower wings than those reared on C. macrophylla. This study provides evidence of wing size and shape differences of ACP based on host plant species which potentially may impact dispersal. Further study is needed to determine if behavioral and physiological differences are associated with the observed phenotypic differences.

  3. Host plant affects morphometric variation of Diaphorina citri (Hemiptera: Liviidae

    Directory of Open Access Journals (Sweden)

    Thomson M. Paris

    2016-11-01

    Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri Kuwayama, is one of the most serious citrus pests worldwide due to its role as vector of huanglongbing or citrus greening disease. While some optimal plant species for ACP oviposition and development have been identified, little is known of the influence of host plants on ACP size and shape. Our goal was to determine how size and shape of ACP wing and body size varies when development occurs on different host plants in a controlled rearing environment. ACP were reared on six different rutaceous species; Bergera koenigii, Citrus aurantifolia, Citrus macrophylla, Citrus maxima, Citrus taiwanica and Murraya paniculata. Adults were examined for morphometric variation using traditional and geometric analysis based on 12 traits or landmarks. ACP reared on C. taiwanica were consistently smaller than those reared on the other plant species. Wing aspect ratio also differed between C. maxima and C. taiwanica. Significant differences in shape were detected with those reared on M. paniculata having narrower wings than those reared on C. macrophylla. This study provides evidence of wing size and shape differences of ACP based on host plant species which potentially may impact dispersal. Further study is needed to determine if behavioral and physiological differences are associated with the observed phenotypic differences.

  4. 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.

  5. 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.

  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. 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

    2015-09-09

    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.

  8. 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.

  9. Sperm variation within a single ejaculate affects offspring development in Atlantic salmon

    Science.gov (United States)

    Immler, Simone; Hotzy, Cosima; Alavioon, Ghazal; Petersson, Erik; Arnqvist, Göran

    2014-01-01

    It is generally believed that variation in sperm phenotype within a single ejaculate has no consequences for offspring performance, because sperm phenotypes are thought not to reflect sperm genotypes. We show that variation in individual sperm function within an ejaculate affects the performance of the resulting offspring in the Atlantic salmon Salmo salar. We experimentally manipulated the time between sperm activation and fertilization in order to select for sperm cohorts differing in longevity within single ejaculates of wild caught male salmon. We found that within-ejaculate variation in sperm longevity significantly affected offspring development and hence time until hatching. Whether these effects have a genetic or epigenetic basis needs to be further evaluated. However, our results provide experimental evidence for transgenerational effects of individual sperm function. PMID:24522632

  10. A psycho-geography of crime areas: variations in the affective domain:

    OpenAIRE

    2004-01-01

    Ten dimensions from the affective domain are proposed as characterizing the major attitu-des and feelings found in areas of high crime in cities. These dimensions are related to a previously proposed model of community differentiation by the author, that tried to sum-marize the range of features that cause community or residential areas to differ from one another. It is suggested that these crime area dimensions are variations of the previously proposed dimensions rather than unique sources o...

  11. A psycho-geography of crime areas: variations in the affective domain

    Directory of Open Access Journals (Sweden)

    Wayne Davies

    2004-01-01

    Full Text Available Ten dimensions from the affective domain are proposed as characterizing the major attitudesand feelings found in areas of high crime in cities. These dimensions are related to apreviously proposed model of community differentiation by the author, that tried to summarizethe range of features that cause community or residential areas to differ from oneanother. It is suggested that these crime area dimensions are variations of the previouslyproposed dimensions rather than unique sources of differentiation.

  12. Variations in the Availability of Pollen Resources Affect Honey Bee Health

    Science.gov (United States)

    Di Pasquale, Garance; Alaux, Cédric; Le Conte, Yves; Odoux, Jean-François; Pioz, Maryline; Vaissière, Bernard E.; Belzunces, Luc P.; Decourtye, Axel

    2016-01-01

    Intensive agricultural systems often expose honey bees (Apis mellifera L.) to large temporal variations in the availability (quantity, quality and diversity) of nutritional resources. Such nutritional irregularity is expected to affect honey bee health. We therefore tested under laboratory conditions the effect of such variation in pollen availability on honey bee health (survival and nursing physiology—hypopharyngeal gland development and vitellogenin expression). We fed honey bees with different diets composed of pollen pellets collected by honey bees in an agricultural landscape of western France. Slight drops (5–10%) in the availability of oilseed rape (Brassica napus L.) pollen resulted in significant reductions of all tested variables. Despite some variations in taxonomic diversity and nutritional quality, the pollen mixes harvested over the season had a similar positive influence on honey bee health, except for the one collected in late July that induced poor survival and nursing physiology. This period coincided with the mass-flowering of maize (Zea mays L.), an anemophilous crop which produces poor-quality pollen. Therefore, changes in bee health were not connected to variations in pollen diversity but rather to variations in pollen depletion and quality, such as can be encountered in an intensive agricultural system of western France. Finally, even though pollen can be available ad libitum during the mass-flowering of some crops (e.g. maize), it can fail to provide bees with diet adequate for their development. PMID:27631605

  13. Inter-individual variation in vertebral kinematics affects predictions of neck musculoskeletal models.

    Science.gov (United States)

    Nevins, Derek D; Zheng, Liying; Vasavada, Anita N

    2014-10-17

    Experimental studies have found significant variation in cervical intervertebral kinematics (IVK) among healthy subjects, but the effect of this variation on biomechanical properties, such as neck strength, has not been explored. The goal of this study was to quantify variation in model predictions of extension strength, flexion strength and gravitational demand (the ratio of gravitational load from the weight of the head to neck muscle extension strength), due to inter-subject variation in IVK. IVK were measured from sagittal radiographs of 24 subjects (14F, 10M) in five postures: maximal extension, mid-extension, neutral, mid-flexion, and maximal flexion. IVK were defined by the position (anterior-posterior and superior-inferior) of each cervical vertebra with respect to T1 and its angle with respect to horizontal, and fit with a cubic polynomial over the range of motion. The IVK of each subject were scaled and incorporated into musculoskeletal models to create models that were identical in muscle force- and moment-generating properties but had subject-specific kinematics. The effect of inter-subject variation in IVK was quantified using the coefficient of variation (COV), the ratio of the standard deviation to the mean. COV of extension strength ranged from 8% to 15% over the range of motion, but COV of flexion strength was 20-80%. Moreover, the COV of gravitational demand was 80-90%, because the gravitational demand is affected by head position as well as neck strength. These results indicate that including inter-individual variation in models is important for evaluating neck musculoskeletal biomechanical properties.

  14. A psycho-geography of crime areas: variations in the affective domain

    Directory of Open Access Journals (Sweden)

    Wayne Kenneth David Davies

    2004-12-01

    Full Text Available Ten dimensions from the affective domain are proposed as characterizing the major attitu-des and feelings found in areas of high crime in cities. These dimensions are related to a previously proposed model of community differentiation by the author, that tried to sum-marize the range of features that cause community or residential areas to differ from one another. It is suggested that these crime area dimensions are variations of the previously proposed dimensions rather than unique sources of differentiation.

  15. 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

    these 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...... and 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....

  16. 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.

  17. 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

  18. Genetic variations in FSH action affect sex hormone levels and breast tissue size in infant girls

    DEFF Research Database (Denmark)

    Henriksen, Louise Scheutz; Hagen, Casper P; Assens, Maria

    2016-01-01

    , especially FSHR -29G>A and FSHR 2039A>G, affect female hormone profile and glandular breast tissue development already during minipuberty. Thus, genetic variations of FSH signaling appear to determine the individual set point of the hypothalamic-pituitary-gonadal axis already early in life.......Context: Single nucleotide polymorphisms altering FSH action (FSHB -211G>T, FSHR -29G>A, and FSHR 2039A>G) are associated with peripubertal and adult levels of reproductive hormones and age at pubertal onset in girls. Objective: To investigate whether genetic polymorphisms altering FSH action...... present in homozygotes. FSHB -211T carriers had smaller breast tissue size than girls who without a minor allele; GT+TT 10.5 (confidence interval 9.4 -11.5) mm vs GG 12.1 (confidence interval 11.4-12.8) mm, P = .014. Conclusions: Our study indicates that 3 genetic polymorphisms altering FSH action...

  19. 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.

  20. Region and site conditions affect phenotypic trait variation in five forest herbs

    Science.gov (United States)

    Lemke, Isgard Holle; Kolb, Annette; Diekmann, Martin Reemt

    2012-02-01

    Phenotypic plasticity is the ability of organisms to express different phenotypes under different environmental conditions. It may buffer individuals both against short-term environmental fluctuations and long-term effects of global change. A plastic behaviour in response to changes in the environment may be especially important in species with low migration rates and colonization capacities, such as in many forest plants in present-day fragmented landscapes. We compared the phenotypic trait variation (used as a proxy for the amount of phenotypic plasticity) of five forest herbs (Brachypodium sylvaticum, Circaea lutetiana, Impatiens noli-tangere, Sanicula europaea and Stachys sylvatica) between two regions in Germany that differ in their overall environmental conditions (Bremen in the northwest, Freiburg in the southwest; 5 species × 2 regions × 8-15 populations × 25-50 individuals). In addition, we measured light intensity and important soil parameters (soil pH, moisture, K, P and N) in all populations. We found consistent differences in trait variability between the two regions in several species. In Brachypodium and Stachys both vegetative and reproductive traits were more variable in Freiburg. Similarly, reproductive traits of Impatiens and Sanicula appeared to be more variable in Freiburg, while in both species at least one of the vegetative traits was more variable in Bremen. Mean local environmental conditions also affected trait variation; in most of the species both vegetative and reproductive traits were more variable in sites with higher nutrient contents and higher light availability. Across all traits and both regions, seed or fruit production was most variable. In summary, at least some of the studied forest herbs appear to respond strongly to large-scale environmental differences, showing a higher trait variability in the more southern region. Given the assumption that phenotypic trait variation is positively associated with phenotypic plasticity

  1. 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.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Dominiek Vangansbeke

    Full Text Available 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.

  4. How variation in head pitch could affect image matching algorithms for ant navigation.

    Science.gov (United States)

    Ardin, Paul; Mangan, Michael; Wystrach, Antoine; Webb, Barbara

    2015-06-01

    Desert ants are a model system for animal navigation, using visual memory to follow long routes across both sparse and cluttered environments. Most accounts of this behaviour assume retinotopic image matching, e.g. recovering heading direction by finding a minimum in the image difference function as the viewpoint rotates. But most models neglect the potential image distortion that could result from unstable head motion. We report that for ants running across a short section of natural substrate, the head pitch varies substantially: by over 20 degrees with no load; and 60 degrees when carrying a large food item. There is no evidence of head stabilisation. Using a realistic simulation of the ant's visual world, we demonstrate that this range of head pitch significantly degrades image matching. The effect of pitch variation can be ameliorated by a memory bank of densely sampled along a route so that an image sufficiently similar in pitch and location is available for comparison. However, with large pitch disturbance, inappropriate memories sampled at distant locations are often recalled and navigation along a route can be adversely affected. Ignoring images obtained at extreme pitches, or averaging images over several pitches, does not significantly improve performance.

  5. Variations in the chemical composition of cassava ( Manihot esculenta Crantz) leaves and roots as affected by genotypic and environmental variation.

    Science.gov (United States)

    Burns, Anna Elizabeth; Gleadow, Roslyn Margaret; Zacarias, Anabela M; Cuambe, Constantino Estevão; Miller, Rebecca Elizabeth; Cavagnaro, Timothy Richard

    2012-05-16

    The purpose of this study was to assess the quality of cassava cultivars, in terms of cyanogenic potential and composition of macro- and micronutrients, sampled from different locations in rural Mozambique. Total cyanide concentrations in fresh cassava tissues were measured using portable cyanide testing kits, and elemental nutrients were later analyzed from dried plant tissue. Variation in cyanogenic potential and nutrient composition occurred both among cultivars and across locations. The majority of cultivars contained >100 ppm total cyanide, fresh weight, and are therefore considered to be dangerously poisonous unless adequately processed before consumption. Leaf cyanogenic and nutrient content varied with plant water status, estimated using carbon isotope discrimination (δ(13)C). The colonization of roots of all cultivars by arbuscular mycorrhizal fungi was also quantified and found to be high, indicating that mycorrhizas could play a key role in plant nutrient acquisition in these low-input farming systems.

  6. 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

  7. 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.

  8. Nucleotide polymorphism affecting FLC expression underpins heading date variation in horticultural brassicas.

    Science.gov (United States)

    Irwin, Judith A; Soumpourou, Eleni; Lister, Clare; Ligthart, Jan-Dick; Kennedy, Sue; Dean, Caroline

    2016-09-01

    Variation in flowering time and response to overwintering has been exploited to breed brassica vegetables that can be harvested year-round. Our knowledge of flowering time control now enables the investigation of the molecular basis of this important variation. Here, we show that a major determinant of heading date variation in Brassica oleracea is from variation in vernalization response through allelic variation at FLOWERING LOCUS C.C2 (BoFLC4). We characterize two alleles of BoFLC.C2 that are both functional and confer a requirement for vernalization, but they show distinct expression dynamics in response to cold. Complementation experiments in Arabidopsis thaliana revealed that the allelic variation results from cis polymorphism at BoFLC.C2, which quantitatively influences the degree of cold-induced epigenetic silencing. This results in one allelic variant conferring consistently later heading under both glasshouse and field conditions through reduced environmental sensitivity. Our results suggest that breeding of brassica varieties for commercially valuable variation in heading date has been achieved through the selection of cis polymorphism at FLC, similar to that underpinning natural variation in A. thaliana. This understanding will allow for the selection of alleles with distinct sensitivities to cold and robust heading dates under variable climatic conditions, and will facilitate the breeding of varieties more resistant to climate change.

  9. Type 2 diabetes mellitus interacts with obesity and common variations in PLTP to affect plasma phospholipid transfer protein activity

    NARCIS (Netherlands)

    Dullaart, R. P. F.; Vergeer, M.; de Vries, R.; Kappelle, Paul J.W.H.; Dallinga-Thie, G. M.

    2012-01-01

    Dullaart RPF, Vergeer M, de Vries R, Kappelle PJWH, Dallinga-Thie GM (University Medical Center Groningen, University of Groningen, Groningen; and Academic Medical Center Amsterdam, Amsterdam; The Netherlands). Type 2 diabetes mellitus interacts with obesity and common variations in PLTP to affect p

  10. 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

    3918342 and rs1421292, were significantly associated with CSF HVA concentrations. Rs3918342 was found to be nominally associated with CSF 5-HIAA concentrations. None of the polymorphisms were significantly associated with MHPG concentrations. Our results indicate that DAOA gene variation affects dopamine...

  11. Quantitative trait loci affecting phenotypic variation in the vacuolated lens mouse mutant, a multigenic mouse model of neural tube defects

    NARCIS (Netherlands)

    Korstanje, Ron; Desai, Jigar; Lazar, Gloria; King, Benjamin; Rollins, Jarod; Spurr, Melissa; Joseph, Jamie; Kadambi, Sindhuja; Li, Yang; Cherry, Allison; Matteson, Paul G.; Paigen, Beverly; Millonig, James H.

    2008-01-01

    Korstanje R, Desai J, Lazar G, King B, Rollins J, Spurr M, Joseph J, Kadambi S, Li Y, Cherry A, Matteson PG, Paigen B, Millonig JH. Quantitative trait loci affecting phenotypic variation in the vacuolated lens mouse mutant, a multigenic mouse model of neural tube defects. Physiol Genomics 35: 296-30

  12. Type of frame dependence: variation in media frames affecting attitudes via audience frames

    NARCIS (Netherlands)

    van Drunen, A.S.; Boomgaarden, H.G.; Vliegenthart, R.

    2012-01-01

    In this paper two suggested processes of framing theory (Scheufele, 1999) are tested: frame setting (media affecting audience frames) and the individual effects process (audience frames affecting attitudes or behavior). Media frames may affect opinions and behavior, however these effects are not dir

  13. Does litter size variation affect models of terrestrial carnivore extinction risk and management?

    Directory of Open Access Journals (Sweden)

    Eleanor S Devenish-Nelson

    Full Text Available BACKGROUND: Individual variation in both survival and reproduction has the potential to influence extinction risk. Especially for rare or threatened species, reliable population models should adequately incorporate demographic uncertainty. Here, we focus on an important form of demographic stochasticity: variation in litter sizes. We use terrestrial carnivores as an example taxon, as they are frequently threatened or of economic importance. Since data on intraspecific litter size variation are often sparse, it is unclear what probability distribution should be used to describe the pattern of litter size variation for multiparous carnivores. METHODOLOGY/PRINCIPAL FINDINGS: We used litter size data on 32 terrestrial carnivore species to test the fit of 12 probability distributions. The influence of these distributions on quasi-extinction probabilities and the probability of successful disease control was then examined for three canid species - the island fox Urocyon littoralis, the red fox Vulpes vulpes, and the African wild dog Lycaon pictus. Best fitting probability distributions differed among the carnivores examined. However, the discretised normal distribution provided the best fit for the majority of species, because variation among litter-sizes was often small. Importantly, however, the outcomes of demographic models were generally robust to the distribution used. CONCLUSION/SIGNIFICANCE: These results provide reassurance for those using demographic modelling for the management of less studied carnivores in which litter size variation is estimated using data from species with similar reproductive attributes.

  14. Changes in pollinator fauna affect altitudinal variation of floral size in a bumblebee-pollinated herb.

    Science.gov (United States)

    Nagano, Yusuke; Abe, Kota; Kitazawa, Tomoaki; Hattori, Mitsuru; Hirao, Akira S; Itino, Takao

    2014-09-01

    Geographic trait variations are often caused by locally different selection regimes. As a steep environmental cline along altitude strongly influences adaptive traits, mountain ecosystems are ideal for exploring adaptive differentiation over short distances. We investigated altitudinal floral size variation of Campanula punctata var. hondoensis in 12 populations in three mountain regions of central Japan to test whether the altitudinal floral size variation was correlated with the size of the local bumblebee pollinator and to assess whether floral size was selected for by pollinator size. We found apparent geographic variations in pollinator assemblages along altitude, which consequently produced a geographic change in pollinator size. Similarly, we found altitudinal changes in floral size, which proved to be correlated with the local pollinator size, but not with altitude itself. Furthermore, pollen removal from flower styles onto bees (plant's male fitness) was strongly influenced by the size match between flower style length and pollinator mouthpart length. These results strongly suggest that C. punctata floral size is under pollinator-mediated selection and that a geographic mosaic of locally adapted C. punctata exists at fine spatial scale.

  15. Genetic variation in serotonin transporter function affects human fear expression indexed by fear-potentiated startle

    NARCIS (Netherlands)

    Klumpers, F.; Heitland, I.; Oosting, R.S.; Kenemans, J.L.; Baas, J.M.

    2012-01-01

    The serotonin transporter (SERT) plays a crucial role in anxiety. Accordingly, variance in SERT functioning appears to constitute an important pathway to individual differences in anxiety. The current study tested the hypothesis that genetic variation in SERT function is associated with variability

  16. Elevated CO2 affects plant responses to variation in boron availability

    Science.gov (United States)

    Effects of elevated CO2 on N relations are well studied, but effects on other nutrients, especially micronutrients, are not. We investigated effects of elevated CO2 on response to variation in boron (B) availability in three unrelated species: geranium (Pelargonium x hortorum), barley (Hordeum vulga...

  17. Technology Commercialization in Road Infrastructure: How Government Affects the Variation and Appropriability of Technology

    NARCIS (Netherlands)

    Caerteling, Jasper S.; Halman, Johannes I.M.; Dorée, André G.

    2008-01-01

    Successful technology commercialization is important for business profitability, and government policies can help or hinder firms' success. As a regulator, government affects standard setting and the nature and scope of property rights. As a sponsor, government can empower technology commercializati

  18. Natural selection affects multiple aspects of genetic variation at putatively peutral 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...... and that 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...... 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 whether positive selection acting on favorable alleles is also required. Here we attempt to address...

  19. Chronic Medical Conditions and Negative Affect; Racial Variation in Reciprocal Associations

    Directory of Open Access Journals (Sweden)

    Shervin Assari

    2016-08-01

    Full Text Available Background: Black-White health paradox can be defined as a lower frequency of depression despite a higher prevalence of economic and social adversities as well as chronic medical conditions (CMC among American Blacks compared to American Whites. Based on this paradox, the CMC - depressive symptoms link is expected to be weaker among Blacks and Whites. We conducted a 10 year longitudinal study to compare Blacks and Whites for bidirectional associations between number of CMC and negative affect.Methods: We used data from the MIDUS (Midlife in the United States, a nationally representative longitudinal study of American adults. A total number of 7,108 individuals with age range 25 to 75 (N = 7,108 were followed for 10 years from 1995 to 2004. Age, gender, and socioeconomic status (education and income measured at baseline were controls. Negative affect and chronic medical conditions were measured at baseline and end of follow up. Race was the moderator. Linear regression analysis was used to test the moderating effect of race on the reciprocal associations between CMC and negative affect, net of covariates.Results: In the pooled sample, while baseline CMC was predictive of an increase in negative affect over time, baseline negative affect was also predictive of an increase in CMC. We found interactions between race and baseline CMC on change in depressive symptoms, as well as race with negative affect on CMC change. Conclusion: Blacks and Whites differ in reciprocal links between CMC and negative affect over time. This finding replicates recent studies on differential links between psychosocial outcomes and physical health based on race. Findings may help us better understand how Black - White health paradox develops across mid and later life.

  20. Habitat variation and wing coloration affect wing shape evolution in dragonflies.

    Science.gov (United States)

    Outomuro, D; Dijkstra, K-D B; Johansson, F

    2013-09-01

    Habitats are spatially and temporally variable, and organisms must be able to track these changes. One potential mechanism for this is dispersal by flight. Therefore, we would expect flying animals to show adaptations in wing shape related to habitat variation. In this work, we explored variation in wing shape in relation to preferred water body (flowing water or standing water with tolerance for temporary conditions) and landscape (forested to open) using 32 species of dragonflies of the genus Trithemis (80% of the known species). We included a potential source of variation linked to sexual selection: the extent of wing coloration on hindwings. We used geometric morphometric methods for studying wing shape. We also explored the phenotypic correlation of wing shape between the sexes. We found that wing shape showed a phylogenetic structure and therefore also ran phylogenetic independent contrasts. After correcting for the phylogenetic effects, we found (i) no significant effect of water body on wing shape; (ii) male forewings and female hindwings differed with regard to landscape, being progressively broader from forested to open habitats; (iii) hindwings showed a wider base in wings with more coloration, especially in males; and (iv) evidence for phenotypic correlation of wing shape between the sexes across species. Hence, our results suggest that natural and sexual selection are acting partially independently on fore- and hindwings and with differences between the sexes, despite evidence for phenotypic correlation of wing shape between males and females.

  1. Genotypic variation in tetraploid wheat affecting homoeologous pairing in hybrids with Aegilops peregrina.

    Science.gov (United States)

    Ozkan, H; Feldman, M

    2001-12-01

    The Ph1 gene has long been considered the main factor responsible for the diploid-like meiotic behavior of polyploid wheat. This dominant gene, located on the long arm of chromosome 5B (5BL), suppresses pairing of homoeologous chromosomes in polyploid wheat and in their hybrids with related species. Here we report on the discovery of genotypic variation among tetraploid wheats in the control of homoeologous pairing. Compared with the level of homoeologous pairing in hybrids between Aegilops peregrina and the bread wheat cultivar Chinese Spring (CS), significantly higher levels of homoeologous pairing were obtained in hybrids between Ae. peregrina and CS substitution lines in which chromosome 5B of CS was replaced by either 5B of Triticum turgidum ssp. dicoccoides line 09 (TTD09) or 5G of Triticum timopheevii ssp. timopheevii line 01 (TIMO1). Similarly, a higher level of homoeologous pairing was found in the hybrid between Ae. peregrina and a substitution line of CS in which chromosome arm 5BL of line TTD140 substituted for 5BL of CS. It appears that the observed effect on the level of pairing is exerted by chromosome arm 5BL of T turgidum ssp. dicoccoides, most probably by an allele of Ph1. Searching for variation in the control of homoeologous pairing among lines of wild tetraploid wheat, either T turgidum ssp. dicoccoides or T timopheevii ssp. armeniacum, showed that hybrids between Ae. peregrina and lines of these two wild wheats exhibited three different levels of homoeologous pairing: low, low intermediate, and high intermediate. The low-intermediate and high-intermediate genotypes may possess weak alleles of Ph1. The three different T turgidum ssp. dicoccoides pairing genotypes were collected from different geographical regions in Israel, indicating that this trait may have an adaptive value. The availability of allelic variation at the Ph1 locus may facilitate the mapping, tagging, and eventually the isolation of this important gene.

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

    Science.gov (United States)

    Carlton, Elizabeth D.; Demas, Gregory E.

    2015-01-01

    ABSTRACT 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 seasonal changes in body mass, we food restricted long-day hamsters so that they exhibited body mass loss that mimicked the natural photoperiod-induced loss of body mass in short-day hamsters. We then experimentally induced sickness with lipopolysaccharide (LPS) and compared sickness responses among long-day food-restricted and long- and short-day ad libitum fed groups, predicting that long-day food-restricted hamsters would show sickness responses comparable to those of short-day ad libitum fed hamsters and attenuated in comparison to long-day ad libitum fed hamsters. We found that long-day food-restricted hamsters showed attenuated LPS-induced anorexia, loss of body mass and hypothermia compared with long-day ad libitum fed animals; however, anorexia remained elevated in long-day food-restricted animals compared with short-day ad libitum fed animals. Additionally, LPS-induced anhedonia and decreases in nest building were not influenced by body mass. Results of hormone assays suggest that cortisol levels could play a role in the attenuation of sickness in long-day food-restricted hamsters, indicating that future research should target the roles of glucocorticoids and natural variation in energy stores in seasonal sickness variation. PMID:25852068

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

    Institute of Scientific and Technical Information of China (English)

    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.

  4. 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

    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...... different stress paradigms: short-term confinement (STC) and long-term social (LTS) stress. Expression of proliferating cell nuclear antigen (PCNA), neurogenic differentiation factor (NeuroD) and doublecortin (DCX) was generally higher in HR compared to LR fish. STC stress led to increased expression...... of 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...

  5. Interannual variation in root production in grasslands affected by artificially modified amount of rainfall.

    Science.gov (United States)

    Fiala, Karel; Tůma, Ivan; Holub, Petr

    2012-01-01

    The effect of different amounts of rainfall on the below-ground plant biomass was studied in three grassland ecosystems. Responses of the lowland (dry Festuca grassland), highland (wet Cirsium grassland), and mountain (Nardus grassland) grasslands were studied during five years (2006-2010). A field experiment based on rainout shelters and gravity irrigation simulated three climate scenarios: rainfall reduced by 50% (dry), rainfall increased by 50% (wet), and the natural rainfall of the current growing season (ambient). The interannual variation in root increment and total below-ground biomass reflected the experimentally manipulated amount of precipitation and also the amount of current rainfall of individual years. The effect of year on these below-ground parameters was found significant in all studied grasslands. In comparison with dry Festuca grassland, better adapted to drought, submontane wet Cirsium grassland was more sensitive to the different water inputs forming rather lower amount of below-ground plant matter at reduced precipitation.

  6. Interannual Variation in Root Production in Grasslands Affected by Artificially Modified Amount of Rainfall

    Directory of Open Access Journals (Sweden)

    Karel Fiala

    2012-01-01

    Full Text Available The effect of different amounts of rainfall on the below-ground plant biomass was studied in three grassland ecosystems. Responses of the lowland (dry Festuca grassland, highland (wet Cirsium grassland, and mountain (Nardus grassland grasslands were studied during five years (2006–2010. A field experiment based on rainout shelters and gravity irrigation simulated three climate scenarios: rainfall reduced by 50% (dry, rainfall increased by 50% (wet, and the natural rainfall of the current growing season (ambient. The interannual variation in root increment and total below-ground biomass reflected the experimentally manipulated amount of precipitation and also the amount of current rainfall of individual years. The effect of year on these below-ground parameters was found significant in all studied grasslands. In comparison with dry Festuca grassland, better adapted to drought, submontane wet Cirsium grassland was more sensitive to the different water inputs forming rather lower amount of below-ground plant matter at reduced precipitation.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    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......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...... and that 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...

  8. Pubertal Onset in Girls is Strongly Influenced by Genetic Variation Affecting FSH Action

    Science.gov (United States)

    Hagen, Casper P.; Sørensen, Kaspar; Aksglaede, Lise; Mouritsen, Annette; Mieritz, Mikkel G.; Tinggaard, Jeanette; Wohlfart-Veje, Christine; Petersen, Jørgen Holm; Main, Katharina M.; Meyts, Ewa Rajpert-De; Almstrup, Kristian; Juul, Anders

    2014-01-01

    Age at pubertal onset varies substantially in healthy girls. Although genetic factors are responsible for more than half of the phenotypic variation, only a small part has been attributed to specific genetic polymorphisms identified so far. Follicle-stimulating hormone (FSH) stimulates ovarian follicle maturation and estradiol synthesis which is responsible for breast development. We assessed the effect of three polymorphisms influencing FSH action on age at breast deveopment in a population-based cohort of 964 healthy girls. Girls homozygous for FSHR -29AA (reduced FSH receptor expression) entered puberty 7.4 (2.5–12.4) months later than carriers of the common variants FSHR -29GG+GA, p = 0.003. To our knowledge, this is the strongest genetic effect on age at pubertal onset in girls published to date. PMID:25231187

  9. Affects of N-terminal variation in the SeM protein of Streptococcus equi on antibody and fibrinogen binding.

    Science.gov (United States)

    Timoney, John F; DeNegri, Rafaela; Sheoran, Abhineet; Forster, Nathalie

    2010-02-10

    The clonal Streptococcus equi causes equine strangles, a highly contagious suppurative lymphadenopathy and rhinopharyngitis. An important virulence factor and vaccine component, the antiphagocytic fibrinogen binding SeM of S. equi is a surface anchored fibrillar protein. Two recent studies of N. American, Japanese and European isolates have revealed a high frequency of N-terminal amino acid variation in SeM of S. equi CF32 that suggests this region of the protein is subject to immunologic selection pressure. The aims of the present study were firstly to map regions of SeM reactive with convalescent equine IgG and IgA and stimulatory for lymph node cells and secondly to determine effects of N-terminal variation on the functionality of SeM. Variation did not significantly affect fibrinogen binding or susceptibility of S. equi to an opsonic equine serum. Linear epitopes reactive with convalescent IgG and mucosal IgA were concentrated toward the conserved center of SeM. However, IgA but not IgG from every horse reacted with at least one peptide that contained variable sequence. Lymph node cells (CD4+) from horses immunized with SeM were strongly responsive to a peptide (alphaalpha36-138) encoding the entire variable region. SeM (CF32) specific mouse Mab 04D11 which reacted strongly with this larger peptide but not with shorter peptides within that sequence reacted strongly with whole cells of S. equi CF32 but only weakly with cells of any of 14 isolates of S. equi expressing different variants of SeM. These results in combination suggest that N-terminal variation alters a conformational epitope of significance in mucosal IgA and systemic T cell responses but does not affect antibody mediated phagocytosis and killing.

  10. Duration of fasting but not diurnal variation affects the response to glucagon in healthy cats.

    Science.gov (United States)

    Gilor, C; Glock, R; Gilor, S

    2015-10-01

    The role of glucagon disturbances in diabetes is increasingly recognized. Glucagon stimulation tests (GSTs) have been described in cats previously, but information is lacking on the response of cats to glucagon under specific conditions. The aim of this study was to assess a novel protocol for GST using human-recombinant glucagon and the effect of diurnal variation and duration of fasting using this protocol in healthy cats. All intravenous doses resulted in occasional vomiting and nausea, and eventually, a 20-μg/kg intramuscular dose was chosen. Five healthy cats were then used in a repeated-measures study. Cats were free-fed regularly at 7:30 AM and 5:30 PM for 30 min. In each cat, GST was performed at 7 PM after a 25-h fast (PM25), at 9 AM after a 25-h fast (AM25), and at 9 AM after a 15-h fast (AM15). Glucose and insulin concentrations were measured at -15, 0, 15, 25, 35, 45, and 60 min after stimulation. Baseline and peak concentrations were compared using the Friedman test. Baseline glucose and insulin did not differ significantly between treatment groups. Peak glucose concentrations occurred at 15 min and were significantly higher (P = 0.0085) at AM15 (mean ± standard deviation = 185.2 ± 43.0 mg/dL) vs AM25 (144.4 ± 10.5 mg/dL) and PM25 (128.0 ± 18.4 mg/dL). Similarly, peak insulin concentrations occurred at 15 min and were significantly higher (P = 0.04) at AM15 (1,911 ± 1,153 pg/mL) vs AM25 (739 ± 52 pg/mL) or PM25 (549 ± 366 pg/mL). In conclusion, prolonged fasting significantly blunted the glycemic response to glucagon compared with shorter fasting, but diurnal variation had no significant effect on glucose or insulin responses.

  11. Phenotypic variation of Pseudomonas putida and P. tolaasii affects attachment to Agaricus bisporus mycelium.

    Science.gov (United States)

    Rainey, P B

    1991-12-01

    The effect of phenotypic variation on attachment of Pseudomonas tolaasii and P. putida to Agaricus bisporus mycelium was investigated. Quantitative studies demonstrated the ability of each isolate to attach rapidly and firmly to A. bisporus mycelium and significant differences in attachment of wild-type and phenotypic variant strains were observed. This was most pronounced in P. tolaasii, where the percentage attachment of the wild-type form was always greater than that of the phenotypic variant. The medium upon which the bacteria were cultured, prior to conducting an attachment assay, had a significant effect on their ability to attach. Attachment of the wild-type form of P. putida was enhanced when the assay was performed in the presence of CaCl2, suggesting the involvement of electrostatic forces. No correlation was observed between bacterial hydrophobicity and ability to attach to A. bisporus mycelium. Scanning electron microscopy confirmed the results obtained from the quantitative studies and provided further evidence for marked differences in the ability of the pseudomonads to attach to mycelium. Fibrillar structures and amorphous material were frequently associated with attached cells and appeared to anchor bacteria to each other and to the hyphal surface. A time-course study of attachment using transmission electron microscopy revealed the presence of uneven fibrillar material on the surface of cells. This material stained positive for polysaccharide and may be involved in ensuring rapid, firm attachment of the cells.

  12. Genetic variation of the RASGRF1 regulatory region affects human hippocampus-dependent memory

    Directory of Open Access Journals (Sweden)

    Adriana eBarman

    2014-04-01

    Full Text Available The guanine nucleotide exchange factor RASGRF1 is an important regulator of intracellular signaling and neural plasticity in the brain. RASGRF1-deficient mice exhibit a complex phenotype with learning deficits and ocular abnormalities. Also in humans, a genome-wide association study has identified the single nucleotide polymorphism (SNP rs8027411 in the putative transcription regulatory region of RASGRF1 as a risk variant of myopia. Here we aimed to assess whether, in line with the RASGRF1 knockout mouse phenotype, rs8027411 might also be associated with human memory function. We performed computer-based neuropsychological learning experiments in two independent cohorts of young, healthy participants. Tests included the Verbal Learning and Memory Test (VLMT and the logical memory section of the Wechsler Memory Scale (WMS. Two sub-cohorts additionally participated in functional magnetic resonance imaging (fMRI studies of hippocampus function. 119 participants performed a novelty encoding task that had previously been shown to engage the hippocampus, and 63 subjects participated in a reward-related memory encoding study. RASGRF1 rs8027411 genotype was indeed associated with memory performance in an allele dosage-dependent manner, with carriers of the T allele (i.e. the myopia risk allele showing better memory performance in the early encoding phase of the VLMT and in the recall phase of the WMS logical memory section. In fMRI, T allele carriers exhibited increased hippocampal activation during presentation of novel images and during encoding of pictures associated with monetary reward. Taken together, our results provide evidence for a role of the RASGRF1 gene locus in hippocampus-dependent memory and, along with the previous association with myopia, point towards pleitropic effects of RASGRF1 genetic variations on complex neural function in humans.

  13. 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

  14. Flow variation and substrate type affect dislodgement of the freshwater polychaete, Manayunkia speciosa

    Science.gov (United States)

    Malakauskas, David M.; Wilson, Sarah J.; Wilzbach, Margaret A.; Som, Nicholas A.

    2013-01-01

    We quantified microscale flow forces and their ability to entrain the freshwater polychaete, Manayunkia speciosa, the intermediate host for 2 myxozoan parasites (Ceratomyxa shasta and Parvicapsula minibicornis) that cause substantial mortalities in salmonid fishes in the Pacific Northwest. In a laboratory flume, we measured the shear stress associated with 2 mean flow velocities and 3 substrates and quantified associated dislodgement of polychaetes, evaluated survivorship of dislodged polychaetes, and observed behavioral responses of the polychaetes in response to increased flow. We used a generalized linear mixed model to estimate the probability of polychaete dislodgement for treatment combinations of velocity (mean flow velocity  =  55 cm/s with a shear velocity  =  3 cm/s, mean flow velocity  =  140 cm/s with a shear velocity  =  5 cm/s) and substrate type (depositional sediments and analogs of rock faces and the filamentous alga, Cladophora). Few polychaetes were dislodged at shear velocities affected by both substrate type and velocity. After accounting for substrate, odds of dislodgement were 8× greater at the higher flow. After accounting for velocity, probability of dislodgement was greatest from fine sediments, intermediate from rock faces, and negligible from Cladophora. Survivorship of dislodged polychaetes was high. Polychaetes exhibited a variety of behaviors for avoiding increases in flow, including extrusion of mucus, burrowing into sediments, and movement to lower-flow microhabitats. Our findings suggest that polychaete populations probably exhibit high resilience to flow-mediated disturbances.

  15. 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.

  16. 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

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

    Science.gov (United States)

    Henden, John-André; Yoccoz, Nigel G; Ims, Rolf A; Langeland, Knut

    2013-01-01

    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 of willow thickets

  18. 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

  19. [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.

  20. 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.

  1. On the Nature of Extraversion: Variation in Conditioned Contextual Activation of Dopamine-Facilitated Affective, Cognitive, and Motor Processes

    Directory of Open Access Journals (Sweden)

    Richard allen Depue

    2013-06-01

    Full Text Available Research supports an association between extraversion and dopamine (DA functioning. DA facilitates incentive motivation and the conditioning and incentive encoding of contexts that predict reward. Therefore, we assessed whether extraversion is related to the efficacy of acquiring conditioned contextual facilitation of three processes that are dependent on DA: motor velocity, positive affect, and visuospatial working memory. We exposed high and low extraverts to three days of association of drug reward (methylphenidate, MP with a particular laboratory context (Paired group, a test day of conditioning, and three days of extinction in the same laboratory. A Placebo group and an Unpaired group (that had MP in a different laboratory context served as controls. Conditioned contextual facilitation was assessed by (i presenting video clips that varied in their pairing with drug and laboratory context and in inherent incentive value, and (ii measuring increases from day 1 to Test day on the three processes above. Results showed acquisition of conditioned contextual facilitation across all measures to video clips that had been paired with drug and laboratory context in the Paired high extraverts, but no conditioning in the Paired low extraverts (nor in either of the control groups. Increases in the Paired high extraverts were correlated across the three measures. Also, conditioned facilitation was evident on the first day of extinction in Paired high extraverts, despite the absence of the unconditioned effects of MP. By the last day of extinction, responding returned to day 1 levels. The findings suggest that extraversion is associated with variation in the acquisition of contexts that predict reward. Over time, this variation may lead to differences in the breadth of networks of conditioned contexts. Thus, individual differences in extraversion may be maintained by activation of differentially encoded central representations of incentive contexts that

  2. On the nature of extraversion: variation in conditioned contextual activation of dopamine-facilitated affective, cognitive, and motor processes.

    Science.gov (United States)

    Depue, Richard A; Fu, Yu

    2013-01-01

    Research supports an association between extraversion and dopamine (DA) functioning. DA facilitates incentive motivation and the conditioning and incentive encoding of contexts that predict reward. Therefore, we assessed whether extraversion is related to the efficacy of acquiring conditioned contextual facilitation of three processes that are dependent on DA: motor velocity, positive affect, and visuospatial working memory. We exposed high and low extraverts to three days of association of drug reward (methylphenidate, MP) with a particular laboratory context (Paired group), a test day of conditioning, and three days of extinction in the same laboratory. A Placebo group and an Unpaired group (that had MP in a different laboratory context) served as controls. Conditioned contextual facilitation was assessed by (i) presenting video clips that varied in their pairing with drug and laboratory context and in inherent incentive value, and (ii) measuring increases from day 1 to Test day on the three processes above. Results showed acquisition of conditioned contextual facilitation across all measures to video clips that had been paired with drug and laboratory context in the Paired high extraverts, but no conditioning in the Paired low extraverts (nor in either of the control groups). Increases in the Paired high extraverts were correlated across the three measures. Also, conditioned facilitation was evident on the first day of extinction in Paired high extraverts, despite the absence of the unconditioned effects of MP. By the last day of extinction, responding returned to day 1 levels. The findings suggest that extraversion is associated with variation in the acquisition of contexts that predict reward. Over time, this variation may lead to differences in the breadth of networks of conditioned contexts. Thus, individual differences in extraversion may be maintained by activation of differentially encoded central representations of incentive contexts that predict reward.

  3. 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).

  4. How do low/high height and weight variation affect upper limb movements during manual material handling of industrial boxes?

    Directory of Open Access Journals (Sweden)

    Ana B. Oliveira

    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.

  5. 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.

  6. Factors affecting the coefficient of variation of stride time of the elderly without falling history: a prospective study.

    Science.gov (United States)

    Matsuda, Kensuke; Ikeda, Shou; Nakahara, Masami; Ikeda, Takuro; Okamoto, Ryuji; Kurosawa, Kazuo; Horikawa, Etuo

    2015-04-01

    [Purpose] The purpose of this study was to investigate the factors affecting the coefficient of variation (CV) of stride time in an exercise intervention for the elderly without falling history. [Subjects and Methods] The subjects were 42 elderly women who had participated in a care prevention program for 12 weeks. Stride time CV, motor function, movement ability, balance, Modified Falls Efficacy Scale (MFES) score, and Life-space Assessment (LSA) score before and after the intervention were examined for significant differences using the paired t-test. Multiple regression analysis was used to determine the factors that changed in the stride time CV. [Results] There were significant differences in muscle strength, sit-and-reach flexibility, the one-leg standing time (eyes open), the maximum walking speed, local stability of trunk acceleration, The Timed Up and Go Test (TUG-T), the MFES score, and the LSA score between the pre-intervention and post-intervention. Stepwise multiple regression analysis revealed that improvement of quadriceps muscle strength, sit-and-reach flexibility, the one-leg standing time, TUG-T, local stability of trunk acceleration (vertical direction) and MFES score were independent variables explaining the reduction in stride time CV. [Conclusion] The results was suggested that it might be possible to reduce the stride time CV by improving strength, flexibility and dynamic balance, and reducing fear of falls through interventions.

  7. Factors affecting variations in the detailed fatty acid profile of Mediterranean buffalo milk determined by 2-dimensional gas chromatography.

    Science.gov (United States)

    Pegolo, S; Stocco, G; Mele, M; Schiavon, S; Bittante, G; Cecchinato, A

    2017-04-01

    Buffalo milk is the world's second most widely produced milk, and increasing attention is being paid to its composition, particularly the fatty acid profile. The objectives of the present study were (1) to characterize the fatty acid composition of Mediterranean buffalo milk, and (2) to investigate potential sources of variation in the buffalo milk fatty acid profile. We determined the profile of 69 fatty acid traits in 272 individual samples of Mediterranean buffalo milk using gas chromatography. In total, 51 individual fatty acids were identified: 24 saturated fatty acids, 13 monounsaturated fatty acids, and 14 polyunsaturated fatty acids. The major individual fatty acids in buffalo milk were in the order 16:0, 18:1 cis-9, 14:0, and 18:0. Saturated fatty acids were the predominant fraction in buffalo milk fat (70.49%); monounsaturated and polyunsaturated fatty acids were at 25.95 and 3.54%, respectively. Adopting a classification based on carbon-chain length, we found that medium-chain fatty acids (11-16 carbons) represented the greater part (53.7%) of the fatty acid fraction of buffalo milk, whereas long-chain fatty acids (17-24 carbons) and short-chain fatty acids (4-10 carbons) accounted for 32.73 and 9.72%, respectively. The n-3 and n-6 fatty acids were 0.46 and 1.77%, respectively. The main conjugated linoleic acid, rumenic acid, represented 0.45% of total milk fatty acids. Herd/test date and stage of lactation were confirmed as important sources of variation in the fatty acid profile of buffalo milk. The percentages of short-chain and medium-chain fatty acids in buffalo milk increased in early lactation (+0.6 and +3.5%, respectively), whereas long-chain fatty acids decreased (-4.2%). The only exception to this pattern was butyric acid, which linearly decreased from the beginning of lactation, confirmation that its synthesis is independent of malonyl-CoA. These results seem to suggest that in early lactation the mobilization of energy reserves may have less

  8. Accurately assessing the risk of schizophrenia conferred by rare copy-number variation affecting genes with brain function.

    Science.gov (United States)

    Raychaudhuri, Soumya; Korn, Joshua M; McCarroll, Steven A; Altshuler, David; Sklar, Pamela; Purcell, Shaun; Daly, Mark J

    2010-09-09

    Investigators have linked rare copy number variation (CNVs) to neuropsychiatric diseases, such as schizophrenia. One hypothesis is that CNV events cause disease by affecting genes with specific brain functions. Under these circumstances, we expect that CNV events in cases should impact brain-function genes more frequently than those events in controls. Previous publications have applied "pathway" analyses to genes within neuropsychiatric case CNVs to show enrichment for brain-functions. While such analyses have been suggestive, they often have not rigorously compared the rates of CNVs impacting genes with brain function in cases to controls, and therefore do not address important confounders such as the large size of brain genes and overall differences in rates and sizes of CNVs. To demonstrate the potential impact of confounders, we genotyped rare CNV events in 2,415 unaffected controls with Affymetrix 6.0; we then applied standard pathway analyses using four sets of brain-function genes and observed an apparently highly significant enrichment for each set. The enrichment is simply driven by the large size of brain-function genes. Instead, we propose a case-control statistical test, cnv-enrichment-test, to compare the rate of CNVs impacting specific gene sets in cases versus controls. With simulations, we demonstrate that cnv-enrichment-test is robust to case-control differences in CNV size, CNV rate, and systematic differences in gene size. Finally, we apply cnv-enrichment-test to rare CNV events published by the International Schizophrenia Consortium (ISC). This approach reveals nominal evidence of case-association in neuronal-activity and the learning gene sets, but not the other two examined gene sets. The neuronal-activity genes have been associated in a separate set of schizophrenia cases and controls; however, testing in independent samples is necessary to definitively confirm this association. Our method is implemented in the PLINK software package.

  9. Mosaics of gene variations in the Interleukin-10 gene promoter affect interleukin-10 production depending on the stimulation used.

    NARCIS (Netherlands)

    Mormann, M.; Rieth, H.; Hua, T.D.; Assohou-Luty, C.A.; Roupelieva, M.; Hu, S.L.; Kremsner, P.G.; Luty, J.F.; Kube, D.

    2004-01-01

    Interleukin-10 (IL-10), a cytokine involved in many aspects of the immune response shows interindividual variations in their expression. However, genetic variations of the 5'-flanking region of the IL-10 gene (PIL-10) are poorly characterised with respect to different stimuli. New extended haplo- an

  10. Do Intraindividual Variation in Disease Progression and the Ensuing Tight Window of Opportunity Affect Estimation of Screening Benefits?

    NARCIS (Netherlands)

    Koffijberg, Hendrik; Rinkel, Gabriel; Buskens, Erik

    2009-01-01

    Background. The effects of variation in disease progression between individuals on the effectiveness of screening have been assessed extensively in the literature. For several diseases, progression may also vary within individuals over time. The authors study the effects of intraindividual variation

  11. Stronger Association Between Valence- and Arousal Ratings of Affective Pictures with Older Age: Evidence for Variation Across Emotion Categories

    DEFF Research Database (Denmark)

    Mikkelsen, Mai Bjørnskov; Mehlsen, Mimi Yung; Lyby, Marlene Skovgaard;

    A sample of older and younger adults rated affective pictures according to valence, arousal and emotion category (happiness, sadness and disgust). Results indicate that older age is associated with a stronger linear association between ratings of arousal and valence. Further, the strength...... of the association vary according to emotion category....

  12. Does inter-plant variation in sprouting time affect the growth/reproduction trade-off and herbivory in a tropical tree species?

    Directory of Open Access Journals (Sweden)

    Marcilio Fagundes

    Full Text Available ABSTRACT The timing of phenological events varies within and among populations, affecting the performance of individual plants differently. We evaluated the effects of relative variation in sprouting time on the display of reproductive events, vegetative growth and herbivory in Copaifera langsdorffii (Fabaceae. A total of 93 trees of C. langsdorffii was monitored daily to determine their sprouting time. We collected ten terminal branches of each plant to evaluate vegetative growth, production of defense compounds and insect herbivore damage. The sprouting time for the studied population lasted 67 days. Variation in sprouting time did not affect the probability of plants to enter the reproductive stage. Plants that entered the reproductive stage showed greater vegetative biomass. Variation in sprouting time had a negative relationship with branch growth and a positive relationship with the number of leaflets. Leaf phenol concentration did not vary in relation to sprouting time or plant phenology, but herbivory was higher in plants that sprouted later. The relationships among plant sprouting time, vegetative development and display of reproductive stage in C. langsdorffii are discussed. The results of this study also suggest that early sprouting prior to the rainy season is a strategy used by C. langsdorffii to escape herbivores attacks.

  13. The erratic mitochondrial clock: variations of mutation rate, not population size, affect mtDNA diversity across birds and mammals

    Directory of Open Access Journals (Sweden)

    Galtier Nicolas

    2009-03-01

    Full Text Available Abstract Background During the last ten years, major advances have been made in characterizing and understanding the evolution of mitochondrial DNA, the most popular marker of molecular biodiversity. Several important results were recently reported using mammals as model organisms, including (i the absence of relationship between mitochondrial DNA diversity and life-history or ecological variables, (ii the absence of prominent adaptive selection, contrary to what was found in invertebrates, and (iii the unexpectedly large variation in neutral substitution rate among lineages, revealing a possible link with species maximal longevity. We propose to challenge these results thanks to the bird/mammal comparison. Direct estimates of population size are available in birds, and this group presents striking life-history trait differences with mammals (higher mass-specific metabolic rate and longevity. These properties make birds the ideal model to directly test for population size effects, and to discriminate between competing hypotheses about the causes of substitution rate variation. Results A phylogenetic analysis of cytochrome b third-codon position confirms that the mitochondrial DNA mutation rate is quite variable in birds, passerines being the fastest evolving order. On average, mitochondrial DNA evolves slower in birds than in mammals of similar body size. This result is in agreement with the longevity hypothesis, and contradicts the hypothesis of a metabolic rate-dependent mutation rate. Birds show no footprint of adaptive selection on cytochrome b evolutionary patterns, but no link between direct estimates of population size and cytochrome b diversity. The mutation rate is the best predictor we have of within-species mitochondrial diversity in birds. It partly explains the differences in mitochondrial DNA diversity patterns observed between mammals and birds, previously interpreted as reflecting Hill-Robertson interferences with the W

  14. 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.

  15. Strong differences in the clonal variation of two Daphnia species from mountain lakes affected by overwintering strategy

    Directory of Open Access Journals (Sweden)

    Mergeay Joachim

    2011-08-01

    Full Text Available Abstract Background The population structure of cyclical parthenogens such as water fleas is strongly influenced by the frequency of alternations between sexual and asexual (parthenogenetic reproduction, which may differ among populations and species. We studied genetic variation within six populations of two closely related species of water fleas of the genus Daphnia (Crustacea, Cladocera. D. galeata and D. longispina both occur in lakes in the Tatra Mountains (Central Europe, but their populations show distinct life history strategies in that region. In three studied lakes inhabited by D. galeata, daphnids overwinter under the ice as adult females. In contrast, in lakes inhabited by D. longispina, populations apparently disappear from the water column and overwinter as dormant eggs in lake sediments. We investigated to what extent these different strategies lead to differences in the clonal composition of late summer populations. Results Analysis of genetic variation at nine microsatellite loci revealed that clonal richness (expressed as the proportion of different multilocus genotypes, MLGs, in the whole analysed sample consistently differed between the two studied species. In the three D. longispina populations, very high clonal richness was found (MLG/N ranging from 0.97 to 1.00, whereas in D. galeata it was much lower (0.05 to 0.50. The dominant MLGs in all D. galeata populations were heterozygous at five or more loci, suggesting that such individuals all represented the same clonal lineages rather than insufficiently resolved groups of different clones. Conclusions The low clonal diversities and significant deviations from Hardy-Weinberg equilibrium in D. galeata populations were likely a consequence of strong clonal erosion over extended periods of time (several years or even decades and the limited influence of sexual reproduction. Our data reveal that populations of closely related Daphnia species living in relatively similar habitats

  16. 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.

  17. The thermal consequences of river-level variations in an urban groundwater body highly affected by groundwater heat pumps.

    Science.gov (United States)

    García-Gil, Alejandro; Vázquez-Suñe, Enric; Schneider, Eduardo Garrido; Sánchez-Navarro, José Ángel; Mateo-Lázaro, Jesús

    2014-07-01

    The extensive implementation of ground source heat pumps in urban aquifers is an important issue related to groundwater quality and the future economic feasibility of existent geothermal installations. Although many cities are in the immediate vicinity of large rivers, little is known about the thermal river-groundwater interaction at a kilometric-scale. The aim of this work is to evaluate the thermal impact of river water recharges induced by flood events into an urban alluvial aquifer anthropogenically influenced by geothermal exploitations. The present thermal state of an urban aquifer at a regional scale, including 27 groundwater heat pump installations, has been evaluated. The thermal impacts of these installations in the aquifer together with the thermal impacts from "cold" winter floods have also been spatially and temporally evaluated to ensure better geothermal management of the aquifer. The results showed a variable direct thermal impact from 0 to 6 °C depending on the groundwater-surface water interaction along the river trajectory. The thermal plumes far away from the riverbed also present minor indirect thermal impacts due to hydraulic gradient variations.

  18. Weather daily variation in winter and its effect on behavior and affective states in day-care children

    Science.gov (United States)

    Ciucci, Enrica; Calussi, Pamela; Menesini, Ersilia; Mattei, Alessandra; Petralli, Martina; Orlandini, Simone

    2011-05-01

    This study aimed to analyze the impact of winter weather conditions on young children's behavior and affective states by examining a group of 61 children attending day-care centers in Florence (Italy). Participants were 33 males, 28 females and their 11 teachers. The mean age of the children at the beginning of the observation period was 24.1 months. The day-care teachers observed the children's behavioral and emotional states during the morning before their sleeping time and filled in a questionnaire for each baby five times over a winter period of 3 weeks. Air temperature, relative humidity, air pressure and solar radiation data were collected every 15 min from a weather station located in the city center of Florence. At the same time, air temperature and relative humidity data were collected in the classroom and in the garden of each day-care center. We used multilevel linear models to evaluate the extent to which children's emotional and behavioral states could be predicted by weather conditions, controlling for child characteristics (gender and age). The data showed that relative humidity and solar radiation were the main predictors of the children's emotional and behavioral states. The outdoor humidity had a significant positive effect on frustration, sadness and aggression; solar radiation had a significant negative effect only on sadness, suggesting that a sunny winter day makes children more cheerful. The results are discussed in term of implications for parents and teachers to improve children's ecological environment.

  19. Attentional costs of walking are not affected by variations in lateral balance demands in young and older adults.

    Science.gov (United States)

    Mazaheri, Masood; Roerdink, Melvyn; Duysens, Jacques; Beek, Peter J; Peper, C Lieke E

    2016-05-01

    Increased attentional costs of walking in older adults have been attributed to age-related changes in visuomotor and/or balance control of walking. The present experiment was conducted to examine the hypothesis that attentional costs of walking vary with lateral balance demands during walking in young and older adults. Twenty young and twenty older adults walked on a treadmill at their preferred walking speed under five conditions: unconstrained normal walking, walking on projected visual lines corresponding to either the participant's preferred step width or 50% thereof (i.e. increased balance demand), and walking within low- and high-stiffness lateral stabilization frames (i.e. lower balance demands). Attentional costs were assessed using a probe reaction-time task during these five walking conditions, normalized to baseline performance as obtained during sitting. Both imposed step-width conditions were more attentionally demanding than the three other conditions, in the absence of any other significant differences between conditions. These effects were similar in the two groups. The results indicate that the attentional costs of walking were, in contrast to what has been postulated previously, not influenced by lateral balance demands. The observed difference in attentional costs between normal walking and both visual lines conditions suggests that visuomotor control processes, rather than balance control, strongly affect the attentional costs of walking. A tentative explanation of these results may be that visuomotor control processes are mainly governed by attention-demanding cortical processes, whereas balance is regulated predominantly subcortically.

  20. Systematic variation of prosthetic foot spring affects center-of-mass mechanics and metabolic cost during walking.

    Science.gov (United States)

    Zelik, Karl E; Collins, Steven H; Adamczyk, Peter G; Segal, Ava D; Klute, Glenn K; Morgenroth, David C; Hahn, Michael E; Orendurff, Michael S; Czerniecki, Joseph M; Kuo, Arthur D

    2011-08-01

    Lower-limb amputees expend more energy to walk than non-amputees and have an elevated risk of secondary disabilities. Insufficient push-off by the prosthetic foot may be a contributing factor. We aimed to systematically study the effect of prosthetic foot mechanics on gait, to gain insight into fundamental prosthetic design principles. We varied a single parameter in isolation, the energy-storing spring in a prototype prosthetic foot, the controlled energy storage and return (CESR) foot, and observed the effect on gait. Subjects walked on the CESR foot with three different springs. We performed parallel studies on amputees and on non-amputees wearing prosthetic simulators. In both groups, spring characteristics similarly affected ankle and body center-of-mass (COM) mechanics and metabolic cost. Softer springs led to greater energy storage, energy return, and prosthetic limb COM push-off work. But metabolic energy expenditure was lowest with a spring of intermediate stiffness, suggesting biomechanical disadvantages to the softest spring despite its greater push-off. Disadvantages of the softest spring may include excessive heel displacements and COM collision losses. We also observed some differences in joint kinetics between amputees and non-amputees walking on the prototype foot. During prosthetic push-off, amputees exhibited reduced energy transfer from the prosthesis to the COM along with increased hip work, perhaps due to greater energy dissipation at the knee. Nevertheless, the results indicate that spring compliance can contribute to push-off, but with biomechanical trade-offs that limit the degree to which greater push-off might improve walking economy.

  1. 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.

  2. Geographic variation in body size and sexual size dimorphism of a seed-feeding beetle.

    Science.gov (United States)

    Stillwell, R Craig; Morse, Geoffrey E; Fox, Charles W

    2007-09-01

    Body size of many animals varies with latitude: body size is either larger at higher latitudes (Bergmann's rule) or smaller at higher latitudes (converse Bergmann's rule). However, the causes underlying these patterns are poorly understood. Also, studies rarely explore how sexual size dimorphism varies with latitude. Here we investigate geographic variation in body size and sexual size dimorphism of the seed-feeding beetle Stator limbatus, collected from 95 locations along a 38 degrees range in latitude. We examine 14 variables to test whether clines in environmental factors are adequate to explain geographic patterns of body size. We found that body size and sexual size dimorphism of S. limbatus varied considerably with latitude; beetles were smaller but more dimorphic at lower latitudes. Body size was not correlated with a gradient in mean temperature, contrary to the commonly accepted hypothesis that clines are produced by latitudinal gradients in temperature. Instead, we found that three factors were adequate to explain the cline in body size: clinal variation in host plant seed size, moisture (humidity), and seasonality (variance in humidity, precipitation, and temperature). We also found that the cline in sexual size dimorphism was partially explainable by a gradient in moisture, though moisture alone was not sufficient to explain the cline. Other ecological or environmental variables must necessarily contribute to differences in selection on male versus female body size. The main implications of our study are that the sexes differ in the magnitude of clinal variation in body size, creating latitudinal variation in sexual size dimorphism, and that clines in body size of seed beetles are likely influenced by variation in host seed size, water availability, and seasonality.

  3. Factors Affecting Temporal and Spatial Variations of Microcystins in Gonghu Bay of Lake Taihu, with Potential Risk of Microcystin Contamination to Human Health

    Directory of Open Access Journals (Sweden)

    Qing Wang

    2010-01-01

    Full Text Available A field survey of the seasonal variation of microcystin (MC concentration was performed in Gonghu Bay (a total of 15 sampling sites of Lake Taihu from January to December 2008. Microcystis spp. biomass and intra-/extracellular MCs were significantly correlated with water temperature, suggesting the importance of temperature in cyanobacterial blooming in the lake. Higher MC concentration was found in summer and autumn, and peaks of Microcystis biomass and intra-/extracellular MC concentrations were all present in October. Spatially, risk of MCs was higher in littoral zones than in the pelagic area. There were significant correlations between N or P concentrations, and Microcystis biomass or MC content, suggesting that N and P levels affected MC production through influencing Microcystis biomass. Intra-/extracellular MCs and Microcystis biomass had negative exponential relationships with TN:TP, and the maximum values all occurred when TN:TP was <25. Multivariate analyses by pcca indicated that intra- and extracellular MC concentrations had better correlations with biological factors (such as Microcystis biomass and chl-a than physicochemical factors. The maximum concentration reached up to 17 µg/L MC-Lreq, considerably higher drinking water safety standard (1 µg/L recommended who. So it is necessary take measures reduce exposure risk of cyanobacterial toxins human beings.

  4. Spatiotemporal variations and factors affecting soil nitrogen in the purple hilly area of Southwest China during the 1980s and the 2010s.

    Science.gov (United States)

    Li, Qiquan; Luo, Youlin; Wang, Changquan; Li, Bing; Zhang, Xin; Yuan, Dagang; Gao, Xuesong; Zhang, Hao

    2016-03-15

    Determination of soil nitrogen distributions and the factors affecting them is critical for nitrogen fertilizer management and prevention of nitrogen pollution. In this paper, the spatiotemporal variations of soil nitrogen and the relative importance of their affecting factors were analysed at a county scale in the purple hilly area of the mid-Sichuan Basin in Southwest China based on soil data collected in 1981 and 2012. Statistical results showed that soil total nitrogen (TN) increased from 0.88 g kg(-1) in 1981 to 1.12 g kg(-1) in 2012, whereas available nitrogen (AN) decreased from 84.22 mg kg(-1) to 74.35 mg kg(-1). In particular, AN showed a significant decrease in agricultural ecosystems but remained stable in woodland and grassland. Correspondingly, most of the study area exhibited increased TN content and decreased AN content in space. The nugget/sill ratios of TN and AN increased from 0.419 to 0.608 and from 0.733 to 0.790, whereas spatial correlation distances decreased from 12.00 km to 9.50 km and from 9.50 km to 9.00 km, respectively, suggesting that the spatial dependence of soil nitrogen became weaker and that the extrinsic factors played increasingly important roles in affecting the soil nitrogen distribution. Soil group and land use type were the two dominant factors in 1981, followed by topographic factors, vegetation coverage and parent material, whereas land use type became the most important factor in 2012, and the relative contribution of topographic factors declined markedly. The results suggested that land use related to cultivation management and fertilizer application was the decisive factor for soil nitrogen change. The increase in TN content and the decrease in AN content over the study period also suggested improper use of nitrogen fertilizer, which can result in nitrogen loss through increasing nitrification rates. Thus, effective measures should be taken to increase the uptake rate of nitrogen and prevent nitrogen pollution.

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

    Directory of Open Access Journals (Sweden)

    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

  6. Small Variations in Early-Life Environment Can Affect Coping Behaviour in Response to Foraging Challenge in the Three-Spined Stickleback.

    Directory of Open Access Journals (Sweden)

    M Rohaa Langenhof

    Full Text Available An increasing concern in the face of human expansion throughout natural habitats is whether animal populations can respond adaptively when confronted with challenges like environmental change and novelty. Behavioural flexibility is an important factor in estimating the adaptive potential of both individuals and populations, and predicting the degree to which they can cope with change.This study on the three-spined stickleback (Gasterosteus aculeatus is an empiric illustration of the degree of behavioural variation that can emerge between semi-natural systems within only a single generation. Wild-caught adult sticklebacks (P, N = 400 were randomly distributed in equal densities over 20 standardized semi-natural environments (ponds, and one year later offspring (F1, N = 652 were presented with repeated behavioural assays. Individuals were challenged to reach a food source through a novel transparent obstacle, during which exploration, activity, foraging, sociability and wall-biting behaviours were recorded through video observation. We found that coping responses of individuals from the first generation to this unfamiliar foraging challenge were related to even relatively small, naturally diversified variation in developmental environment. All measured behaviours were correlated with each other. Especially exploration, sociability and wall-biting were found to differ significantly between ponds. These differences could not be explained by stickleback density or the turbidity of the water.Our findings show that a differences in early-life environment appear to affect stickleback feeding behaviour later in life; b this is the case even when the environmental differences are only small, within natural parameters and diversified gradually; and c effects are present despite semi-natural conditions that fluctuate during the year. Therefore, in behaviourally plastic animals like the stickleback, the adaptive response to human-induced habitat disturbance

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Phenotypic variation of the Mexican duck (Anas platyrhynchos diazi) in Mexico

    Science.gov (United States)

    Scott, N.J.; Reynolds, R.P.

    1984-01-01

    A collection of 98 breeding Mexican Ducks (Anas platyrhynchos diazi) was made in Mexico from six areas between the United States border with Chihuahua and Lake Chapala, Jalisco, in order to study geographic variation. Plumage indices showed a relatively smooth clinal change from north to south; northern populations were most influenced by the Northern Mallard (A. platyrhynchos) phenotype. Measurements of total, wing, and culmen lengths and bill width were usually significantly larger in males at any one site, but showed no regular geographic trends. Hybridization between platyrhynchos and diazi phenotypes may or may not be increasing in the middle Rio Grande and Rio Conchos valleys; available data are insufficient to decide. A spring 1978 aerial census yielded an estimate of 55,500 diazi -like birds in Mexico. Populations of diazi appear to be as large as the available habitat allows; management should be directed towards increasing and stabilizing the nesting habitat; and the stability of the zone of intergradation should be investigated.

  9. Factors affecting variation of different measures of cheese yield and milk nutrient recovery from an individual model cheese-manufacturing process.

    Science.gov (United States)

    Cipolat-Gotet, C; Cecchinato, A; De Marchi, M; Bittante, G

    2013-01-01

    procedure was used to process individual milk samples obtained from 1,167 Brown Swiss cows reared in 85 herds of the province of Trento (Italy). The assessed traits exhibited almost normal distributions, with the exception of REC(FAT). The average values (± SD) were as follows: %CY(CURD)=14.97±1.86, %CY(SOLIDS)=7.18±0.92, %CY(WATER)=7.77±1.27, dCY(CURD)=3.63±1.17, dCY(SOLIDS)=1.74±0.57, dCY(WATER)=1.88±0.63, REC(FAT)=89.79±3.55, REC(PROTEIN)=78.08±2.43, REC(SOLIDS)=51.88±3.52, and REC(ENERGY)=67.19±3.29. All traits were highly influenced by herd-test-date and days in milk of the cow, moderately influenced by parity, and weakly influenced by the utilized vat. Both %CY(CURD) and dCY(CURD) depended not only on the fat and protein (casein) contents of the milk, but also on their proportions retained in the curd; the water trapped in curd presented an higher variability than that of %CY(SOLIDS). All REC traits were variable and affected by days in milk and parity of the cows. The described model cheese-making procedure and the results obtained provided new insight into the phenotypic variation of cheese yield and recovery traits at the individual level.

  10. 情感障碍患者关联性负变实验观察%A contingent negative variation study in patients with affective disorder

    Institute of Scientific and Technical Information of China (English)

    路英智; 宗文斌; 任清涛; 蒲金玉

    2006-01-01

    .8±4.8)μV;(16.0±5.7)μV;P<0.01],抑郁相组患者指令信号前负相期待波面积较对照组小[(292.8±161.6)μV2;(412.8±159.9)μV2;p<0.01],抑郁相组患者关联性负变指令信号后负变化潜伏期延长[(261.9±79.3)ms;(211.9±36.3)ms;P<0.05],抑郁相单相组比双相组的关联性负变指令信号后负变化潜伏期显著延长[(344.5±66.9)ms;(230.4±83.8)ms;P<0.01].结论:关联性负变和指令信号后负变化等提示关联性负变潜伏期延长可能是抑郁相单相患者的素质标记,而关联性负变波幅的变化则可能是情感障碍患者的状态标记.%BACKGROUND: Contingent negative variation (CNV) is a kind of cerebral evoked potential, which is closely related with mental medicine and psychology.OBJECTIVE: To investigate the different manifestations between patients with affective disorder and normal adults in CNV detection.DESIGN: Case-control trial.SETTING: Department of Function, Psychiatric Hospital of Zibo, Shandong Province.PARTICIPANTS: Totally 29 inpatients and outpatients including 14 males and 15 females with affective disorder in the Fifth People's Hospital of Zibo between February 2005 and January 2006 were selected. The guardians were all informed and agreed the content; the diagnosed criteria of the patients were accorded wit h the criteria of DSM-Ⅳ. According to their mental status when hospitalized, the patients were divided into manic episode group and depressive episode group. There were 11 cases in the manic episode group, whose scores of Bech-Rataelson Mania Scale (BRMS)>16; there were 18 cases in the depressive episode group, including unipolar depression (without history of mania episode) and bipolar depression (with history of mania episode) whose Hamilton Depression Scale (HAMD)scores > 24. A total of 27 healthy hospital staff were selectedas control group including 14 males and 13 females aged 21-53 years and the mean age was (32.5±5.9) years. There was no significant

  11. Variation of milk urea in dairy cattle : a study on factors that affect the relationship between urea concentration in milk and urea excretion in urine

    NARCIS (Netherlands)

    Spek, J.W.

    2013-01-01

    The aim of this thesis was to increase the applicability of milk urea nitrogen concentration (MUN) as a predictor of urinary urea nitrogen excretion (UUN) by identifying and quantifying factors that can explain variation in MUN that is not related to UUN. A literature study was conducted in order to

  12. Pregnancy associated plasma protein A2 (PAPP-A2) affects bone size and shape and contributes to natural variation in postnatal growth in mice.

    Science.gov (United States)

    Christians, Julian Kenneth; de Zwaan, Devin Rhys; Fung, Sunny Ho Yeung

    2013-01-01

    Pregnancy associated plasma protein A2 (PAPP-A2) is a protease of insulin-like growth factor binding protein 5 and is receiving increasing attention for its roles in pregnancy and postnatal growth. The goals of the present study were to characterize the effects of PAPP-A2 deletion on bone size and shape in mice at 10 weeks of age, and to determine whether Pappa2 is the gene responsible for a previously-identified quantitative trait locus (QTL) contributing to natural variation in postnatal growth in mice. Mice homozygous for constitutive PAPP-A2 deletion were lighter than wild-type littermates, and had smaller mandible dimensions and shorter skull, humerus, femur, tibia, pelvic girdle, and tail bone. Furthermore, PAPP-A2 deletion reduced mandible dimensions and the lengths of the skull, femur, pelvic girdle, and tail bone more than would be expected due to the effect on body mass. In addition to its effects on bone size, PAPP-A2 deficiency also altered the shape of the mandible and pelvic girdle, as assessed by geometric morphometrics. Mice homozygous for the PAPP-A2 deletion had less deep mandibles, and pelvic girdles with a more feminine shape. Using a quantitative complementation test, we confirmed that Pappa2 is responsible for the effects of the previously-identified QTL, demonstrating that natural variation in the Pappa2 gene contributes to variation in postnatal growth in mice. If similar functional variation in the Pappa2 gene exists in other species, effects of this variation on the shape of the pelvic girdle might explain the previously-reported associations between Pappa2 SNPs and developmental dysplasia of the hip in humans, and birthing in cattle.

  13. Detection of QTL for metabolic and agronomic traits in wheat with adjustments for variation at genetic loci that affect plant phenology.

    Science.gov (United States)

    Hill, Camilla B; Taylor, Julian D; Edwards, James; Mather, Diane; Langridge, Peter; Bacic, Antony; Roessner, Ute

    2015-04-01

    Mapping of quantitative trait loci associated with levels of individual metabolites (mQTL) was combined with the mapping of agronomic traits to investigate the genetic basis of variation and co-variation in metabolites, agronomic traits, and plant phenology in a field-grown bread wheat population. Metabolome analysis was performed using liquid chromatography-mass spectrometry resulting in identification of mainly polar compounds, including secondary metabolites. A total of 558 metabolic features were obtained from the flag leaves of 179 doubled haploid lines, of which 197 features were putatively identified, mostly as alkaloids, flavonoids and phenylpropanoids. Coordinated genetic control was observed for several groups of metabolites, such as organic acids influenced by two loci on chromosome 7A. Five major phenology-related loci, which were introduced as cofactors in the analyses, differed in their impact upon metabolic and agronomic traits with QZad-aww-7A having more impact on the expression of both metabolite and agronomic QTL than Ppd-B1, Vrn-A1, Eps, and QZad-aww-7D. This QTL study validates the utility of combining agronomic and metabolomic traits as an approach to identify potential trait enhancement targets for breeding selection and reinforces previous results that demonstrate the importance of including plant phenology in the assessment of useful traits in this wheat mapping population.

  14. Evidence for small scale variation in the vertebrate brain: mating strategy and sex affect brain size and structure in wild brown trout (Salmo trutta).

    Science.gov (United States)

    Kolm, N; Gonzalez-Voyer, A; Brelin, D; Winberg, S

    2009-12-01

    The basis for our knowledge of brain evolution in vertebrates rests heavily on empirical evidence from comparative studies at the species level. However, little is still known about the natural levels of variation and the evolutionary causes of differences in brain size and brain structure within-species, even though selection at this level is an important initial generator of macroevolutionary patterns across species. Here, we examine how early life-history decisions and sex are related to brain size and brain structure in wild populations using the existing natural variation in mating strategies among wild brown trout (Salmo trutta). By comparing the brains of precocious fish that remain in the river and sexually mature at a small size with those of migratory fish that migrate to the sea and sexually mature at a much larger size, we show, for the first time in any vertebrate, strong differences in relative brain size and brain structure across mating strategies. Precocious fish have larger brain size (when controlling for body size) but migratory fish have a larger cerebellum, the structure in charge of motor coordination. Moreover, we demonstrate sex-specific differences in brain structure as female precocious fish have a larger brain than male precocious fish while males of both strategies have a larger telencephalon, the cognitive control centre, than females. The differences in brain size and structure across mating strategies and sexes thus suggest the possibility for fine scale adaptive evolution of the vertebrate brain in relation to different life histories.

  15. How Does Environmental Variation Affect the Distribution of Dragonfly Larvae (Odonata) in the Amazon-Cerrado Transition Zone in Central Brazil?

    Science.gov (United States)

    Mendes, T P; Luiza-Andrade, A; Cabette, H S R; Juen, L

    2017-03-11

    This study investigated the effects of environmental variation on assemblages of dragonfly larvae (Odonata). We hypothesize that there is a significant correlation between species richness, species composition, and abundance of Odonata individuals, and habitat integrity and abiotic variables. To test this hypothesis, we sampled odonate larvae at 12 streams in the Suiá-Miçú River basin in Mato Grosso, Brazil, during three different periods of the year. Local physical and chemical variables (temperature, pH, turbidity, electrical conductivity (EC), dissolved oxygen (DO), total dissolved solids (TDS), and oxidation reduction potential (ORP)) were measured at each site using a multi-parameter probe, and integrity was assessed using the Habitat Integrity Index (HII). The variation in richness, abundance, and composition of Odonata species was related to the environmental variables analyzed, primarily by the abiotic factors pH, electrical conductivity, dissolved oxygen, total dissolved solids, and oxidation reduction potential. Our hypothesis was corroborated for the suborder Anisoptera, which showed a significant relationship with these variables, whereas Zygoptera was only related to pH. Our results show the importance of physical and chemical conditions in ecological studies using Odonata larvae as tools for the management and conservation of freshwater ecosystems.

  16. Strontium and neodymium isotopic variations in early Archean gneisses affected by middle to late Archean high-grade metamorphic processes: West Greenland and Labrador

    Science.gov (United States)

    Collerson, K. D.; Mcculloch, M. T.; Bridgwater, D.; Mcgregor, V. R.; Nutman, A. P.

    1986-01-01

    Relicts of continental crust formed more than 3400 Ma ago are preserved fortuitously in most cratons. The cratons provide the most direct information about crust and mantle evolutionary processes during the first billion years of Earth history. In view of their polymetamorphic character, these terrains are commonly affected by subsequent tectonothermal events. Hence, their isotope systematics may be severely disturbed as a result of bulk chemical change or local isotopic homogenization. This leads to equivocal age and source information for different components within these terrains. The Sr and Nd isotopic data are presented for early Archean gneisses from the North Atlantic Craton in west Greenland and northern Labrador which were affected by younger metamorphic events.

  17. Modeling the two-locus architecture of divergent pollinator adaptation: how variation in SAD paralogs affects fitness and evolutionary divergence in sexually deceptive orchids

    Science.gov (United States)

    Xu, Shuqing; Schlüter, Philipp M

    2015-01-01

    Divergent selection by pollinators can bring about strong reproductive isolation via changes at few genes of large effect. This has recently been demonstrated in sexually deceptive orchids, where studies (1) quantified the strength of reproductive isolation in the field; (2) identified genes that appear to be causal for reproductive isolation; and (3) demonstrated selection by analysis of natural variation in gene sequence and expression. In a group of closely related Ophrys orchids, specific floral scent components, namely n-alkenes, are the key floral traits that control specific pollinator attraction by chemical mimicry of insect sex pheromones. The genetic basis of species-specific differences in alkene production mainly lies in two biosynthetic genes encoding stearoyl–acyl carrier protein desaturases (SAD) that are associated with floral scent variation and reproductive isolation between closely related species, and evolve under pollinator-mediated selection. However, the implications of this genetic architecture of key floral traits on the evolutionary processes of pollinator adaptation and speciation in this plant group remain unclear. Here, we expand on these recent findings to model scenarios of adaptive evolutionary change at SAD2 and SAD5, their effects on plant fitness (i.e., offspring number), and the dynamics of speciation. Our model suggests that the two-locus architecture of reproductive isolation allows for rapid sympatric speciation by pollinator shift; however, the likelihood of such pollinator-mediated speciation is asymmetric between the two orchid species O. sphegodes and O. exaltata due to different fitness effects of their predominant SAD2 and SAD5 alleles. Our study not only provides insight into pollinator adaptation and speciation mechanisms of sexually deceptive orchids but also demonstrates the power of applying a modeling approach to the study of pollinator-driven ecological speciation. PMID:25691974

  18. Factors affecting variation in the vase life response of waxflower cultivars (Myrtaceae: Chamelaucium Desf. and Verticordia spp. Desf. tested under various vase solutions

    Directory of Open Access Journals (Sweden)

    Dung Cao D.

    2016-06-01

    Full Text Available The effects of genotype and vase solutions on the vase lives of waxflower cultivars were studied. The vase life of 16 cultivars derived from different genetic backgrounds showed a variation. The vase life of Chamelaucium uncinatum cultivars held in deionised water was generally the shortest, with four cultivars averaging 9.5 and 8.9 days for flowers and leaves while the vase lives of C. uncinatum × megalopetalum hybrids were on average 16.0 and 25.0 days for flowers and leaves, respectively. The hybrid ‘Southern Stars’ with C. uncinatum × Verticordia plumosa as parents had the longest flower vase life of 24.9 days, although another Verticordia × Chamelaucium had a 9.5-day flower vase life and other hybrids of the cultivars of C. uncinatum and Verticordia grandis Desf. (‘WX73’, C. sp. Gingin Marchantii (‘WX97’ and C. floriferum (‘Lady Stephanie’ as a parent had intermediate to short vase lives of 11.4 to 15.5 days. The cultivars responded most to 8-hydroxyquniline sulphate (HQS + sucrose or HQS + sucrose + silver thiosulphate (STS, being 1.5- to 1.6-folds higher than in deionized water. The cultivars showed a varied response to a vase solution of sucrose + HQS + STS, with which C. uncinatum vase life increased 1.9-fold compared to 1.7-fold for C. megalopetalum. Waxflowers were found to be susceptible to water stress, causing flowers to close and shortening vase life. On average for the 80 cultivar-vase solution combinations tested, flower vase life ended when the stems reached 75.5 ± 5% fresh weigh. Longer vase life cultivars had a greater ability of maintaining a water balance at or above 75% for longer.

  19. Variations in the natural ¹⁵N abundance of Brassica chinensis grown in uncultivated soil affected by different nitrogen fertilizers.

    Science.gov (United States)

    Yuan, Yuwei; Hu, Guixian; Zhao, Ming; Chen, Tianjin; Zhang, Yongzhi; Zhu, Jiahong; Wang, Qiang

    2014-11-26

    To further investigate the method of using δ(15)N as a marker for organic vegetable discrimination, the effects of different fertilizers on the δ(15)N in different growing stages of Brassica chinensis (B. chinensis) grown in uncultivated soil were investigated with a pot experiment. B. chinensis was planted with uncultivated soil and different fertilizer treatments and then harvested three times in three seasons consecutively. For the spring experiments in the years of 2011 and 2012, the δ(15)N value of B. chinensis, which increased due to organic manure application and decreased due to chemical fertilizer application, was significantly different (p fertilizer urea treatment, and from +7.7‰ to +10.9‰ for the compost-chemical fertilizer treatment. However, the δ(15)N values observed in the autumn experiment of 2011 without any fertilizer application increased ranging from +13.4‰ to +15.4‰, + 11.2‰ to +17.7‰, +10.7‰ to +17.1‰, and +10.6‰ to +19.1‰, respectively, for the same treatments mentioned above. This result was not significantly different between manure treatment and chemical treatment. The δ(15)N values of soil obtained in the spring of 2011 during three growing stages were slightly affected by fertilizers and varied in the range of +1.6‰ to +2.5‰ for CK, +4.7‰ to +6.5‰ for compost treatment, +2.1‰ to +2.4‰ for chemical treatment, and +2.7‰ to +4.6‰ for chemical-compost treatment, respectively. High δ(15)N values of B. chinensis were observed in these experiments, which would be useful to supplement a δ(15)N database for discriminating organic vegetables. Although there was a significant difference between manure treatment and chemical treatment, it was still difficult to discriminate whether a labeled organic vegetable was really grown without chemical fertilizer just with a fixed high δ(15)N value, especially for the vegetables planted simultaneously with chemical and compost fertilizer.

  20. 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.

  1. 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.

  2. 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.

  3. Genotype-by-Environment Interactions and Adaptation to Local Temperature Affect Immunity and Fecundity in Drosophila melanogaster

    Science.gov (United States)

    Lazzaro, Brian P.; Flores, Heather A.; Lorigan, James G.; Yourth, Christopher P.

    2008-01-01

    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. PMID:18369474

  4. 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.

  5. Fimbrial phase variation

    DEFF Research Database (Denmark)

    Khandige, Surabhi; Møller-Jensen, Jakob

    2016-01-01

    if the fimbrial diversity seen at the population level is the product of random stochasticity or a concerted effort based on active communication. Here we discuss the possibility of a mechanism alternative to a stochastic fimbrial phase variation model affecting the dynamics of a heterogeneous population....

  6. Variation pattern and its affecting factors of three-dimensional landscape in urban residential community of Shenyang.%城市居住区三维景观变化规律与影响因素

    Institute of Scientific and Technical Information of China (English)

    张培峰; 胡远满; 熊在平; 刘淼

    2011-01-01

    基于1997年1:10000航片以及2002、2005和2008年QuickBird数据,应用Barista软件以及GIS、RS技术,提取了沈阳市铁西区居住区建筑物的三维信息,采用道路密度、绿化率、建筑平均高度、高度标准差、建筑覆盖率、容积率、建筑体形系数以及人口密度和人均GDP等指标,分析了1997-2008年铁西居住区改造过程中三维景观的变化规律与影响因素.结果表明:1997-2008年,铁西居住区工业建筑面积比重降低,商业与其他公共类建筑面积比重增加,居住、教育与医疗建筑面积比重基本保持稳定;研究区建筑数量减少,建筑覆盖率及体形系数降低,容积率、平均高度、高度标准差及道路密度、绿化率升高;在居住区有限的空间内,人口与经济活动容纳能力提高的同时环境质量也有所提高,建筑高度变异程度增大,建筑能耗降低.人口密度、人均GDP与容积率、道路密度和绿化率呈正相关,与建筑覆盖率呈负相关.%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 1997-2008and related affecting factors were analyzed with the indices. i e. road density, greening rate, aver-age 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

  7. Spatial Variations of Fundamental Constants

    CERN Document Server

    Barrow, John D; Barrow, John D.; Toole, Chris O'

    1999-01-01

    We show that observational limits on the possible time variation of constants of Nature are significantly affected by allowing for both space and time variation. Bekenstein's generalisation of Maxwell's equations to allow for cosmological variation of $alpha$ is investigated in a universe containing spherically symmetric inhomogeneities. The time variation of $alpha$ is determined by the local matter density and hence limits obtained in high-density geophysical enviroments are far more constraining than those obtained at high redshift. This new feature is expected to be a property of a wide class of theories for the variation of constants.

  8. 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

  9. 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

  10. Affective Urbanism

    DEFF Research Database (Denmark)

    Samson, Kristine

    Urban design and architecture are increasingly used as material and affective strategies for setting the scene, for manipulation and the production of urban life: The orchestration of atmospheres, the framing and staging of urban actions, the programming for contemplation, involvement, play, expe...... affects can be choreographed and designed intentionally or whether it arises from unpredictable circumstances within urbanity itself....

  11. Affective Maps

    DEFF Research Database (Denmark)

    Salovaara-Moring, Inka

    of environmental knowledge production. It uses InfoAmazonia, the databased platform on Amazon rainforests, as an example of affective geo-visualization within information mapping that enhances embodiment in the experience of the information. Amazonia is defined as a digitally created affective (map)space within...

  12. 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...

  13. Affective Networks

    Directory of Open Access Journals (Sweden)

    Jodi Dean

    2010-02-01

    Full Text Available This article sets out the idea of affective networks as a constitutive feature of communicative capitalism. It explores the circulation of intensities in contemporary information and communication networks, arguing that this circulation should be theorized in terms of the psychoanalytic notion of the drive. The article includes critical engagements with theorists such as Guy Debord, Jacques Lacan, Tiziana Terranova, and Slavoj Zizek.

  14. 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.

  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.

  16. Early life stress and serotonin transporter gene variation interact to affect the transcription of the glucocorticoid and mineralocorticoid receptors, and the co-chaperone FKBP5, in the adult rat brain.

    Directory of Open Access Journals (Sweden)

    Rick H. A. Van der Doelen

    2014-10-01

    Full Text Available The short allelic variant of the serotonin transporter (5-HTT promoter-linked polymorphic region (5-HTTLPR has been associated with the etiology of major depression by interaction with early life stress (ELS. A frequently observed endophenotype in depression is the abnormal regulation of levels of stress hormones such as glucocorticoids. It is hypothesized that altered central glucocorticoid influence on stress-related behavior and memory processes could underlie the depressogenic interaction of 5-HTTLPR and ELS. One possible mechanism could be the altered expression of the genes encoding the glucocorticoid and mineralocorticoid receptor (GR, MR and their inhibitory regulator FK506-binding protein 51 (FKBP5 in stress-related forebrain areas. To test this notion, we exposed heterozygous (5-HTT+/- and homozygous (5-HTT-/- serotonin transporter knockout rats and their wildtype littermates (5-HTT+/+ to daily 3 h maternal separations from postnatal day 2 to 14. In the medial prefrontal cortex (mPFC and hippocampus of the adult male offspring, we found that GR, MR and FKBP5 mRNA levels were affected by ELS x 5-HTT genotype interaction. Specifically, 5-HTT+/+ rats exposed to ELS showed decreased GR and FKBP5 mRNA in the dorsal and ventral mPFC, respectively. In contrast, 5-HTT+/- rats showed increased MR mRNA levels in the hippocampus and 5-HTT-/- rats showed increased FKBP5 mRNA in the ventral mPFC after ELS exposure. These findings indicate that 5-HTT genotype determines the specific adaptation of GR, MR and FKBP5 expression in response to early life adversity. Therefore, altered extra-hypothalamic glucocorticoid signaling should be considered to play a role in the depressogenic interaction of ELS and 5-HTTLPR.

  17. 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.

  18. 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

    2015-03-24

    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.

  19. Policies Affect Preferences: Evidence from Random Variation in Abortion Jurisprudence

    OpenAIRE

    2016-01-01

    Whether policies shift preferences is relevant to policy design. We exploit the random assignment of U.S. federal judges creating geographically local precedent and the fact that judges’ politics, religion, and race predict decision-making in abortion jurisprudence. Instrumenting for abortion jurisprudence with exogenous judicial characteristics, we estimate the impact of abortion jurisprudence on state laws, campaign donations, and abortion attitudes. We verify information transmission in th...

  20. 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.

  1. 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......Understanding genome to phenotype linkages has been greatly enabled by genomic sequencing. However, most genome analysis is typically confined to the nuclear genome. We conducted a metabolomic QTL analysis on a reciprocal RIL population structured to examine how variation in the organelle genomes...

  2. 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

  3. 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.

  4. Functions of bounded variation

    OpenAIRE

    Lind, Martin

    2006-01-01

    The paper begins with a short survey of monotone functions. The functions of bounded variation are introduced and some basic properties of these functions are given. Finally the jump function of a function of bounded variation is defined.

  5. 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

  6. 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

  7. 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...

  8. 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.

  9. Influence of Design Variations on Systems Performance

    Science.gov (United States)

    Tumer, Irem Y.; Stone, Robert B.; Huff, Edward M.; Norvig, Peter (Technical Monitor)

    2000-01-01

    High-risk aerospace components have to meet very stringent quality, performance, and safety requirements. Any source of variation is a concern, as it may result in scrap or rework. poor performance, and potentially unsafe flying conditions. The sources of variation during product development, including design, manufacturing, and assembly, and during operation are shown. Sources of static and dynamic variation during development need to be detected accurately in order to prevent failure when the components are placed in operation. The Systems' Health and Safety (SHAS) research at the NASA Ames Research Center addresses the problem of detecting and evaluating the statistical variation in helicopter transmissions. In this work, we focus on the variations caused by design, manufacturing, and assembly of these components, prior to being placed in operation (DMV). In particular, we aim to understand and represent the failure and variation information, and their correlation to performance and safety and feed this information back into the development cycle at an early stage. The feedback of such critical information will assure the development of more reliable components with less rework and scrap. Variations during design and manufacturing are a common source of concern in the development and production of such components. Accounting for these variations, especially those that have the potential to affect performance, is accomplished in a variety ways, including Taguchi methods, FMEA, quality control, statistical process control, and variation risk management. In this work, we start with the assumption that any of these variations can be represented mathematically, and accounted for by using analytical tools incorporating these mathematical representations. In this paper, we concentrate on variations that are introduced during design. Variations introduced during manufacturing are investigated in parallel work.

  10. 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.

  11. 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

  12. 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.

  13. Seasonal variation in pediatric dermatoses

    Directory of Open Access Journals (Sweden)

    Banerjee Sabyasachi

    2010-01-01

    Full Text Available Introduction: The under-five population is a unique and vulnerable component of our society that always demands special attention. Aims: Our present work aimed to study the seasonal variation, age-wise variation and distribution of lesions of common dermatoses of this age group. Materials and Methods: We clinically studied all fresh cases attending the skin OPD of our hospital for one month each from summer, rainy season and winter. Total number of patients was 879. Results: The top six skin diseases in our study were impetigo, miliaria, scabies, furunculosis, seborrheic dermatitis and papular urticaria. On statistical analysis, scabies and seborrheic dermatitis were more prevalent during winter while impetigo, furunculosis and miliaria were more during summer and rainy season. Papular urticaria was more frequent in the rainy season. Seborrheic dermatitis predominantly affected the infants while impetigo, furunculosis, miliaria and popular urticaria were commoner in older age groups. Conclusion: Distribution of lesions of common dermatoses will help diagnose difficult cases and extensive evaluation of the body parts which, by virtue of being commonly affected, are must-examine sites in under-five children.

  14. Ladder Variational Autoencoder

    DEFF Research Database (Denmark)

    Sønderby, Casper Kaae; Raiko, Tapani; Maaløe, Lars

    2016-01-01

    Variational autoencoders are powerful models for unsupervised learning. However deep models with several layers of dependent stochastic variables are difficult to train which limits the improvements obtained using these highly expressive models. We propose a new inference model, the Ladder Variat...

  15. Variation of Fundamental Constants

    Science.gov (United States)

    Flambaum, V. V.

    2006-11-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. The spatial variation can explain a fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are consistent with our existence. We present a review of recent works devoted to the variation of the fine structure constant α, 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 Feshbach resonance.

  16. Total variation regularization with bounded linear variations

    Science.gov (United States)

    Makovetskii, Artyom; Voronin, Sergei; Kober, Vitaly

    2016-09-01

    One of the most known techniques for signal denoising is based on total variation regularization (TV regularization). A better understanding of TV regularization is necessary to provide a stronger mathematical justification for using TV minimization in signal processing. In this work, we deal with an intermediate case between one- and two-dimensional cases; that is, a discrete function to be processed is two-dimensional radially symmetric piecewise constant. For this case, the exact solution to the problem can be obtained as follows: first, calculate the average values over rings of the noisy function; second, calculate the shift values and their directions using closed formulae depending on a regularization parameter and structure of rings. Despite the TV regularization is effective for noise removal; it often destroys fine details and thin structures of images. In order to overcome this drawback, we use the TV regularization for signal denoising subject to linear signal variations are bounded.

  17. Phasic Affective Modulation of Semantic Priming

    Science.gov (United States)

    Topolinski, Sascha; Deutsch, Roland

    2013-01-01

    The present research demonstrates that very brief variations in affect, being around 1 s in length and changing from trial to trial independently from semantic relatedness of primes and targets, modulate the amount of semantic priming. Implementing consonant and dissonant chords (Experiments 1 and 5), naturalistic sounds (Experiment 2), and visual…

  18. 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.

  19. Porosity variation in chalk

    DEFF Research Database (Denmark)

    Lind, Ida; Grøn, Peter

    1996-01-01

    Vertical porosity variations in chalk are generally assumed to result from either a vaguely defined combination of primary sedimentary and diagenetic processes or solely to diagenetic processes. In this study, image analysis of backscatter electron images of polished samples and geochemical...... microprobe mapping were applied to measure the porosity variation in a limited number of chalk samples. Microscope data indicate that in all cases the chalk has been subjected to diagenetic processes, but our data suggest that the variations in porosity originate in primary sedimentary differences....

  20. Variational Transition State Theory

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-29

    This is the final report on a project involving the development and applications of variational transition state theory. This project involved the development of variational transition state theory for gas-phase reactions, including optimized multidimensional tunneling contributions and the application of this theory to gas-phase reactions with a special emphasis on developing reaction rate theory in directions that are important for applications to combustion. The development of variational transition state theory with optimized multidimensional tunneling as a useful computational tool for combustion kinetics involved eight objectives.

  1. Drugs affecting the eye.

    Science.gov (United States)

    Taylor, F

    1985-08-01

    This discussion reviews drugs that affect the eye, including antihyperglycemic agents; corticosteroids; antirheumatic drugs (quinolines, indomethacin, and allopurinol); psychiatric drugs (phenothiazine, thioridazine, and chlorpromazine); drugs used in cardiology (practolol, amiodarone, and digitalis gylcosides); drugs implicated in optic neuritis and atrophy, drugs with an anticholinergic action; oral contraceptives (OCs); and topical drugs and systemic effects. Refractive changes, either myopic or hypermetropic, can occur as a result of hyperglycemia, and variation in vision is sometimes a presenting symptom in diabetes mellitus. If it causes a change in the refraction, treatment of hyperglycemia almost always produces a temporary hypermetropia. A return to the original refractive state often takes weeks, sometimes months. There is some evidence that patients adequately treated with insulin improve more rapidly than those taking oral medication. Such patients always should be referred for opthalmological evaluation as other factors might be responsible, but it might not be possible to order the appropriate spectacle correction for some time. The most important ocular side effect of the systemic adiministration of corticosteroids is the formation of a posterior subcapsular cataract. Glaucoma also can result from corticosteroids, most often when they are applied topically. Corticosteroids have been implicated in the production of benign intracranial hypertension, which is paradoxical because they also are used in its treatment. The most important side effect of drugs such as chloroquine and hydroxychloroquine is an almost always irreversible maculopathy with resultant loss of central vision. Corneal and retinal changes similar to those caused by the quinolines have been reported with indomethacin, but there is some question about a cause and effect relationship. The National Registry of Drug Induced Ocular Side Effects in the US published 30 case histories of

  2. 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...

  3. 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.

  4. The Schwinger Variational Method

    Science.gov (United States)

    Huo, Winifred M.

    1995-01-01

    Variational methods have proven invaluable in theoretical physics and chemistry, both for bound state problems and for the study of collision phenomena. For collisional problems they can be grouped into two types: those based on the Schroedinger equation and those based on the Lippmann-Schwinger equation. The application of the Schwinger variational (SV) method to e-molecule collisions and photoionization has been reviewed previously. The present chapter discusses the implementation of the SV method as applied to e-molecule collisions.

  5. 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.

  6. 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 effort....... Results show that variations in frequency content affect the perception of effort....

  7. Cognitive subtypes in non-affected siblings of schizophrenia patients : characteristics and profile congruency with affected family members

    NARCIS (Netherlands)

    Quee, P. J.; Alizadeh, B. Z.; Aleman, A.; van den Heuvel, E. R.

    2014-01-01

    Background Although cognitive subtypes have been suggested in schizophrenia patients, similar analyses have not been carried out in their non-affected siblings. Subtype classification may provide more insight into genetically driven variation in cognitive function. We investigated cognitive subtypes

  8. Cognitive subtypes in non-affected siblings of schizophrenia patients : characteristics and profile congruency with affected family members

    NARCIS (Netherlands)

    Quee, P J; Alizadeh, B Z; Aleman, A; van den Heuvel, E R

    2014-01-01

    BACKGROUND: Although cognitive subtypes have been suggested in schizophrenia patients, similar analyses have not been carried out in their non-affected siblings. Subtype classification may provide more insight into genetically driven variation in cognitive function. We investigated cognitive subtype

  9. Mammalian odorant receptors: functional evolution and variation.

    Science.gov (United States)

    Jiang, Yue; Matsunami, Hiroaki

    2015-10-01

    In mammals, the perception of smell starts with the activation of odorant receptors (ORs) by volatile molecules in the environment. The mammalian OR repertoire has been subject to rapid evolution, and is highly diverse within the human population. Recent advances in the functional expression and ligand identification of ORs allow for functional analysis of OR evolution, and reveal that changes in OR protein sequences translate into high degrees of functional variations. Moreover, in several cases the functional variation of a single OR affects the perception of its cognate odor ligand, providing clues as to how an odor is coded at the receptor level.

  10. Environmental Variation Generates Environmental Opportunist Pathogen Outbreaks.

    Directory of Open Access Journals (Sweden)

    Jani Anttila

    Full Text Available 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.

  11. Affectivity and race

    DEFF Research Database (Denmark)

    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 sheds light...... on the role of feelings in the formation of subjectivities, how race and whiteness are affectively circulated in public life and the ways in which emotions contribute to regimes of inclusion and exclusion. As such it will appeal to scholars across the social sciences, with interests in sociology, anthropology...

  12. Structural variations in pig genomes

    NARCIS (Netherlands)

    Paudel, Y.

    2015-01-01

    Abstract Paudel, Y. (2015). Structural variations in pig genomes. PhD thesis, Wageningen University, the Netherlands Structural variations are chromosomal rearrangements such as insertions-deletions (INDELs), duplications, inversions, translocations, and copy number variations (CNVs

  13. 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.

  14. Variation of fundamental constants: theory and observations

    CERN Document Server

    Flambaum, V V

    2007-01-01

    Review of recent works devoted to the variation of the fundamental constants is presented including atomic clocks, quasar absorption spectra, and Oklo natural nuclear reactor data. Assuming linear variation with time we can compare different results. From the quasar absorption spectra: $\\dot{\\mu}/\\mu=(1 \\pm 3) \\times 10^{-16}$ yr$^{-1}$. A combination of this result and the atomic clock results gives the best limt on variation of $\\alpha$: $\\dot{\\alpha}/\\alpha=(-0.8 \\pm 0.8) \\times 10^{-16}$ yr$^{-1}$. The Oklo natural reactor gives the best limit on the variation of $m_s/\\Lambda_{QCD}$ where $m_s$ is the strange quark mass. Huge enhancement of the relative variation effects happens in transitions between close atomic, molecular and nuclear energy levels. We suggest several new cases where the levels are very narrow. Large enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feshbach resonance. Massive bodies (stars or galaxies) can also affect physical constants....

  15. 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

  16. Variational electrodynamics of Atoms

    CERN Document Server

    De Luca, Jayme

    2013-01-01

    We study extrema with velocity discontinuities for the variational electromagnetic two-body problem. Along $C^2$ segments, these broken extrema satisfy the Euler-Lagrange equations of the variational principle, which are neutral differential delay equations with state-dependent deviating arguments. At points where accelerations are not defined and velocities are discontinuous, broken extrema satisfy Weierstrass-Erdmann corner conditions that energies and momenta are continuous. Here we construct periodic broken extrema near the $C^{\\infty}$ two-body circular orbits, using piecewise-defined $C^2$ solutions of the neutral differential delay equations along regular segments and a variational approximation for the boundary-layer segments. Broken periodic extrema with an integer number of corner points bifurcate from a discrete set of circular orbits, with scales defined by the Weierstrass-Erdmann corner conditions. We consider the three cases of hydrogen, muonium and positronium atoms. In each case the broken ext...

  17. 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.

  18. Discrete Variational Optimal Control

    CERN Document Server

    Jimenez, Fernando; de Diego, David Martin

    2012-01-01

    This paper develops numerical methods for optimal control of mechanical systems in the Lagrangian setting. It extends the theory of discrete mechanics to enable the solutions of optimal control problems through the discretization of variational principles. The key point is to solve the optimal control problem as a variational integrator of a specially constructed higher-dimensional system. The developed framework applies to systems on tangent bundles, Lie groups, underactuated and nonholonomic systems with symmetries, and can approximate either smooth or discontinuous control inputs. The resulting methods inherit the preservation properties of variational integrators and result in numerically robust and easily implementable algorithms. Several theoretical and a practical examples, e.g. the control of an underwater vehicle, will illustrate the application of the proposed approach.

  19. Discrete Variational Optimal Control

    Science.gov (United States)

    Jiménez, Fernando; Kobilarov, Marin; Martín de Diego, David

    2013-06-01

    This paper develops numerical methods for optimal control of mechanical systems in the Lagrangian setting. It extends the theory of discrete mechanics to enable the solutions of optimal control problems through the discretization of variational principles. The key point is to solve the optimal control problem as a variational integrator of a specially constructed higher dimensional system. The developed framework applies to systems on tangent bundles, Lie groups, and underactuated and nonholonomic systems with symmetries, and can approximate either smooth or discontinuous control inputs. The resulting methods inherit the preservation properties of variational integrators and result in numerically robust and easily implementable algorithms. Several theoretical examples and a practical one, the control of an underwater vehicle, illustrate the application of the proposed approach.

  20. Splines and variational methods

    CERN Document Server

    Prenter, P M

    2008-01-01

    One of the clearest available introductions to variational methods, this text requires only a minimal background in calculus and linear algebra. Its self-contained treatment explains the application of theoretic notions to the kinds of physical problems that engineers regularly encounter. The text's first half concerns approximation theoretic notions, exploring the theory and computation of one- and two-dimensional polynomial and other spline functions. Later chapters examine variational methods in the solution of operator equations, focusing on boundary value problems in one and two dimension

  1. 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…

  2. 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.

  3. 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…

  4. 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.

  5. Progress in variational methods

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The International Conference on Variational Methods (ICVAM) was held from May 20th to 26th in 2007 at the Chern Institute of Mathematics, Nankai University, Tianjin, China. Twenty eight invited speakers from ten countries and areas worldwide gave their lectures at the conference.

  6. Apparent surface curvature affects lightness perception.

    Science.gov (United States)

    Knill, D C; Kersten, D

    1991-05-16

    The human visual system has the remarkable capacity to perceive accurately the lightness, or relative reflectance, of surfaces, even though much of the variation in image luminance may be caused by other scene attributes, such as shape and illumination. Most physiological, and computational models of lightness perception invoke early sensory mechanisms that act independently of, or before, the estimation of other scene attributes. In contrast to the modularity of lightness perception assumed in these models are experiments that show that supposedly 'higher-order' percepts of planar surface attributes, such as orientation, depth and transparency, can influence perceived lightness. Here we show that perceived surface curvature can also affect perceived lightness. The results of the earlier experiments indicate that perceiving luminance edges as changes in surface attributes other than reflectance can influence lightness. These results suggest that the interpretation of smooth variations in luminance can also affect lightness percepts.

  7. Genetic variation and human longevity.

    Science.gov (United States)

    Soerensen, Mette

    2012-05-01

    The overall aim of the PhD project was to elucidate the association of human longevity with genetic variation in major candidate genes and pathways of longevity. Based on a thorough literature and database search we chose to apply a pathway approach; to explore variation in genes composing the DNA damage signaling, DNA repair, GH/IGF-1/insulin signaling and pro-/antioxidant pathways. In addition, 16 genes which did not belong to the core of either pathway, however recurrently regarded as candidate genes of longevity (e.g. APOE), were included. In this way a total of 168 genes were selected for investigation. We decided to explore the genetic variation in the form of single nucleotide polymorphisms (SNPs), a highly investigated type of genetic variation. SNPs having potential functional impact (e.g. affecting binding of transcription factors) were identified, so were specific SNPs in the candidate genes previously published to be associated with human longevity. To cover the majority of the common genetic variation in the 168 gene regions (encoding regions plus 5,000 bp upstream and 1,000 downstream) we applied the tagging SNP approach via the HapMap Consortium. Consequently 1,536 SNPs were selected. The majority of the previous publications on genetic variation and human longevity had employed a case-control study design, e.g. comparing centenarians to middle-aged controls. This type of study design is somehow prone to bias introduced by for instance cohort effects, i.e. differences in characteristics of cases and controls, a kind of bias which is avoided when a prospective cohort is under study. Therefore, we chose to investigate 1,200 individuals of the Danish 1905 birth cohort, which have been followed since 1998 when the members were 92-93 years old. The genetic contribution to human longevity has been estimated to be most profound during the late part of life, thus these oldest-old individuals are excellent for investigating such effect. The follow-up survival

  8. Environmental variation and population responses to global change

    NARCIS (Netherlands)

    Lawson, Callum R.; Vindenes, Yngvild; Bailey, Liam; van de Pol, Martijn

    2015-01-01

    Species' responses to environmental changes such as global warming are affected not only by trends in mean conditions, but also by natural and human-induced environmental fluctuations. Methods are needed to predict how such environmental variation affects ecological and evolutionary processes, in or

  9. 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

  10. Genetic analysis of environmental variation

    NARCIS (Netherlands)

    Hill, W.G.; Mulder, H.A.

    2010-01-01

    Environmental variation (VE) in a quantitative trait – variation in phenotype that cannot be explained by genetic variation or identifiable genetic differences – can be regarded as being under some degree of genetic control. Such variation may be either between repeated expressions of the same trait

  11. 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.

  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. On functions of bounded variation

    OpenAIRE

    Aistleitner, Christoph; Pausinger, Florian; Svane, Anne Marie; Tichy, Robert F.

    2015-01-01

    The recently introduced concept of $\\mathcal{D}$-variation unifies previous concepts of variation of multivariate functions. In this paper, we give an affirmative answer to the open question from Pausinger \\& Svane (J. Complexity, 2014) whether every function of bounded Hardy--Krause variation is Borel measurable and has bounded $\\mathcal{D}$-variation. Moreover, we show that the space of functions of bounded $\\mathcal{D}$-variation can be turned into a commutative Banach algebra.

  14. Genetic Variations Involved in Vitamin E Status

    Directory of Open Access Journals (Sweden)

    Patrick Borel

    2016-12-01

    Full Text Available Vitamin E (VE is the generic term for four tocopherols and four tocotrienols that exhibit the biological activity of α-tocopherol. VE status, which is usually estimated by measuring fasting blood VE concentration, is affected by numerous factors, such as dietary VE intake, VE absorption efficiency, and VE catabolism. Several of these factors are in turn modulated by genetic variations in genes encoding proteins involved in these factors. To identify these genetic variations, two strategies have been used: genome-wide association studies and candidate gene association studies. Each of these strategies has its advantages and its drawbacks, nevertheless they have allowed us to identify a list of single nucleotide polymorphisms associated with fasting blood VE concentration and α-tocopherol bioavailability. However, much work remains to be done to identify, and to replicate in different populations, all the single nucleotide polymorphisms involved, to assess the possible involvement of other kind of genetic variations, e.g., copy number variants and epigenetic modifications, in order to establish a reliable list of genetic variations that will allow us to predict the VE status of an individual by knowing their genotype in these genetic variations. Yet, the potential usefulness of this area of research is exciting with regard to personalized nutrition and for future clinical trials dedicated to assessing the biological effects of the various isoforms of VE.

  15. Intraseasonal variation of visibility in Hong Kong

    Science.gov (United States)

    Zhou, Wen; Li, Richard C. Y.; Chow, Eric C. H.

    2017-01-01

    Visibility is one of the parameters for indicating air pollution. In this study, visibility variation in Hong Kong during summer and winter is investigated. Visibility in Hong Kong has clear intraseasonal variation. Examination of different environmental parameters suggests that the intraseasonal component dominates the overall circulation anomalies in both summer and winter. Associated with the intraseasonal variation of environmental parameters, obvious variation in visibility impairment is found in both summer and winter. In summer, local visibility and air quality are found to be significantly affected by the (MJO) and the 10-30-day intraseasonal oscillation (ISO) through modulation of associated atmospheric circulations. In winter, the modulation effects appear to be weaker due to the southward shift of the associated convection. The results in this study highlight the importance of the ISO in contributing to the overall variation in visibility in Hong Kong, and provide useful implications for the development of possible mitigation strategies associated with visibility impairment and air pollution in Hong Kong.

  16. Human immune system variation.

    Science.gov (United States)

    Brodin, Petter; Davis, Mark M

    2017-01-01

    The human immune system is highly variable between individuals but relatively stable over time within a given person. Recent conceptual and technological advances have enabled systems immunology analyses, which reveal the composition of immune cells and proteins in populations of healthy individuals. The range of variation and some specific influences that shape an individual's immune system is now becoming clearer. Human immune systems vary as a consequence of heritable and non-heritable influences, but symbiotic and pathogenic microbes and other non-heritable influences explain most of this variation. Understanding when and how such influences shape the human immune system is key for defining metrics of immunological health and understanding the risk of immune-mediated and infectious diseases.

  17. Variation in community structure across vertical intertidal stress gradients: how does it compare with horizontal variation at different scales?

    Directory of Open Access Journals (Sweden)

    Nelson Valdivia

    Full Text Available In rocky intertidal habitats, the pronounced increase in environmental stress from low to high elevations greatly affects community structure, that is, the combined measure of species identity and their relative abundance. Recent studies have shown that ecological variation also occurs along the coastline at a variety of spatial scales. Little is known, however, on how vertical variation compares with horizontal variation measured at increasing spatial scales (in terms of sampling interval. Because broad-scale processes can generate geographical patterns in community structure, we tested the hypothesis that vertical ecological variation is higher than fine-scale horizontal variation but lower than broad-scale horizontal variation. To test this prediction, we compared the variation in community structure across intertidal elevations on rocky shores of Helgoland Island with independent estimates of horizontal variation measured at the scale of patches (quadrats separated by 10s of cm, sites (quadrats separated by a few m, and shores (quadrats separated by 100s to 1000s of m. The multivariate analyses done on community structure supported our prediction. Specifically, vertical variation was significantly higher than patch- and site-scale horizontal variation but lower than shore-scale horizontal variation. Similar patterns were found for the variation in abundance of foundation taxa such as Fucus spp. and Mastocarpus stellatus, suggesting that the effects of these canopy-forming algae, known to function as ecosystem engineers, may explain part of the observed variability in community structure. Our findings suggest that broad-scale processes affecting species performance increase ecological variability relative to the pervasive fine-scale patchiness already described for marine coasts and the well known variation caused by vertical stress gradients. Our results also indicate that experimental research aiming to understand community structure on

  18. Chronotype and diurnal patterns of positive affect and affective neural circuitry in primary insomnia.

    Science.gov (United States)

    Hasler, Brant P; Germain, Anne; Nofzinger, Eric A; Kupfer, David J; Krafty, Robert T; Rothenberger, Scott D; James, Jeffrey A; Bi, Wenzhu; Buysse, Daniel J

    2012-10-01

    While insomnia is a well-established risk factor for the initial onset, recurrence or relapse of affective disorders, the specific characteristics of insomnia that confer risk remain unclear. Patients with insomnia with an evening chronotype may be one particularly high-risk group, perhaps due to alterations in positive affect and its related affective circuitry. We explored this possibility by comparing diurnal patterns of positive affect and the activity of positive affect-related brain regions in morning- and evening-types with insomnia. We assessed diurnal variation in brain activity via the relative regional cerebral metabolic rate of glucose uptake by using [(18) F]fluorodeoxyglucose-positron emission tomography during morning and evening wakefulness. We focused on regions in the medial prefrontal cortex and striatum, which have been consistently linked with positive affect and reward processing. As predicted, chronotypes differed in their daily patterns in both self-reported positive affect and associated brain regions. Evening-types displayed diurnal patterns of positive affect characterized by phase delay and smaller amplitude compared with those of morning-types with insomnia. In parallel, evening-types showed a reduced degree of diurnal variation in the metabolism of both the medial prefrontal cortex and the striatum, as well as lower overall metabolism in these regions across both morning and evening wakefulness. Taken together, these preliminary findings suggest that alterations in the diurnal activity of positive affect-related neural structures may underlie differences in the phase and amplitude of self-reported positive affect between morning and evening chronotypes, and may constitute one mechanism for increased risk of mood disorders among evening-type insomniacs.

  19. 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

  20. Affects and assemblages

    DEFF Research Database (Denmark)

    Samson, Kristine

    and 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......Affects and assemblages are Deleuzian Guattarian notions related to aesthetics and spatial territories. In recent urban geography and urban studies these notions are increasingly gaining more impact (Amin & Thrift 2002, Pile 2008, Farías & Bender 2010, Andersen & Harrison 2010, Thrift 2008). What...... 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...

  1. 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.

  2. 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.

  3. An improved variational method

    Institute of Scientific and Technical Information of China (English)

    ZENG Zhuo-Quan; SHEN Peng-Nian; DING Yi-Bing

    2009-01-01

    In order to improve the unitarity of the S-matrix, an improved variational formulism is derived by proposing new generating functionals and adopting proper asymptotic boundary conditions for trial relative wave functions. The formulas with the weighted line-column balance for the single-channel and multi-channel scatterings, where the non-central interaction is implicitly considered, are presented. A numerical check is performed with a soluble model in a four coupled channel scattering problem. The result shows that the high accuracy and the unitarity of the S-matrix are reached.

  4. Factors affecting soil cohesion

    Science.gov (United States)

    Soil erodibility is a measure of a soil’s resistance against erosive forces and is affected by both intrinsic (or inherent) soil property and the extrinsic condition at the time erodibility measurement is made. Since soil erodibility is usually calculated from results obtained from erosion experimen...

  5. How Body Affects Brain.

    Science.gov (United States)

    Suzuki, Wendy A

    2016-08-09

    Studies show that physical exercise can affect a range of brain and cognitive functions. However, little is known about the peripheral signals that initiate these central changes. Moon et al. (2016) provide exciting new evidence that a novel myokine, cathepsin B (CTSB), released with exercise is associated with improved memory.

  6. Affective World Literature

    DEFF Research Database (Denmark)

    Vilslev, Annette Thorsen

    , 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...

  7. Affective Factors: Anxiety

    Science.gov (United States)

    Tasnimi, Mahshad

    2009-01-01

    Affective factors seem to play a crucial role in success or failure in second language acquisition. Negative attitudes can reduce learners' motivation and harm language learning, while positive attitudes can do the reverse. Discovering students' attitudes about language will help both teacher and student in teaching learning process. Anxiety is…

  8. Affective Tourism Ethnography

    NARCIS (Netherlands)

    Buda, Dorina; Tucker, Hazel

    2015-01-01

    In this paper we aim to advance the concept of affective tourism ethnography. We take ethnography to refer to a research strategy rather than simply a methodological tool. This is because ethnography entails methods (individual interviews, focus groups, participant observation amongst others) and co

  9. Individual Differences in Affect.

    Science.gov (United States)

    Haviland, Jeannette

    This paper argues that infants' affect patterns are innate and are meaningful indicators of individual differences in internal state. Videotapes of seven infants' faces were coded using an ethogram; the movement of the eyebrow, eye direction, eye openness, mouth shape, mouth position, lip position, and tongue protrusion were assessed…

  10. Multifunctions of bounded variation

    Science.gov (United States)

    Vinter, R. B.

    2016-02-01

    Consider control systems described by a differential equation with a control term or, more generally, by a differential inclusion with velocity set F (t , x). Certain properties of state trajectories can be derived when it is assumed that F (t , x) is merely measurable w.r.t. the time variable t. But sometimes a refined analysis requires the imposition of stronger hypotheses regarding the time dependence. Stronger forms of necessary conditions for minimizing state trajectories can be derived, for example, when F (t , x) is Lipschitz continuous w.r.t. time. It has recently become apparent that significant addition properties of state trajectories can still be derived, when the Lipschitz continuity hypothesis is replaced by the weaker requirement that F (t , x) has bounded variation w.r.t. time. This paper introduces a new concept of multifunctions F (t , x) that have bounded variation w.r.t. time near a given state trajectory, of special relevance to control. We provide an application to sensitivity analysis.

  11. Lexical Variation in Akokoid

    Directory of Open Access Journals (Sweden)

    Fádorò Jacob Oludare

    2014-07-01

    Full Text Available Language contact among Akokoid, Yoruboid and Edoid has resulted in extensive borrowing from Yoruboid and Edoid to Akokoid. Thus, the speech forms subsumed under Akokoid exhibit lexical items which are similar to Yoruboid and Edoid. To the best of our knowledge, no other scholarly work has addressed the concept ‘lexical variation in these speech forms, hence, the need for this present effort. Twenty lexical items were carefully selected for analysis in this paper. Data were elicited from 34 informants who are competent speakers of Akokoid. Apart from the linguistic data, these informants, including  traditional rulers, supplied us with historical facts about the migration patterns of the progenitors of Akokoid. The historical facts coupled with the linguistic data helped us to arrive at the conclusion that some of the words used in contemporary Akokoid found their way into Akokoid as a result of the contact between Akokoid and their neighbours, Yoruboid and Edoid.Keywords: Akokoid, Language Contact, Lexical Variation, Yoruboid, Edoid

  12. Variational Theory for Chandrasekharaiah Thermopizoelectricity

    Institute of Scientific and Technical Information of China (English)

    JiHuanHE

    1999-01-01

    Via the semi-inverse method of establishing generalized variational principle for physical problems,a classical variational model(non Gurtin-type and not involving convolutions) for Chandrasekharaiah thermopiezoelectricity is established directly from the governing equations.The present theory aims at providing a more complete theoretical basis for the variational-based finite element applications and variational-based meshless method(element-free method).

  13. Dynamic Synchronization of Teacher-Students Affection in Affective Instruction

    Science.gov (United States)

    Zhang, Wenhai; Lu, Jiamei

    2011-01-01

    Based on Bower's affective network theory, the article links the dynamic analysis of affective factors in affective instruction, and presents affective instruction strategic of dynamic synchronization between teacher and students to implement the best ideal mood that promotes students' cognition and affection together. In the process of teaching,…

  14. Regulatory focus affects physician risk tolerance.

    Science.gov (United States)

    Veazie, Peter J; McIntosh, Scott; Chapman, Benjamin P; Dolan, James G

    2014-01-01

    Risk tolerance is a source of variation in physician decision-making. This variation, if independent of clinical concerns, can result in mistaken utilization of health services. To address such problems, it will be helpful to identify nonclinical factors of risk tolerance, particularly those amendable to intervention-regulatory focus theory suggests such a factor. This study tested whether regulatory focus affects risk tolerance among primary care physicians. Twenty-seven primary care physicians were assigned to promotion-focused or prevention-focused manipulations and compared on the Risk Taking Attitudes in Medical Decision Making scale using a randomization test. Results provide evidence that physicians assigned to the promotion-focus manipulation adopted an attitude of greater risk tolerance than the physicians assigned to the prevention-focused manipulation (p = 0.01). The Cohen's d statistic was conventionally large at 0.92. Results imply that situational regulatory focus in primary care physicians affects risk tolerance and may thereby be a nonclinical source of practice variation. Results also provide marginal evidence that chronic regulatory focus is associated with risk tolerance (p = 0.05), but the mechanism remains unclear. Research and intervention targeting physician risk tolerance may benefit by considering situational regulatory focus as an explanatory factor.

  15. 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

  16. 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...... 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...... organizing good affective encounters based on limitations enhance and facilitate the performative dimension of self-management. Finally, the paper addresses the problem of critique confronting self-relation with Spinoza's ethics as an ethical difference of powe...

  17. 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.

  18. 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.

  19. Variations on tremor parameters

    Science.gov (United States)

    Boose, A.; Jentgens, Ch.; Spieker, S.; Dichgans, J.

    1995-03-01

    This paper describes our analysis procedure for long-term tremor EMG recordings, as well as three examples of applications. The description of the method focuses on how characteristics of the tremor (e.g. frequency, intensity, agonist-antagonist interaction) can be defined and calculated based on surface EMG data. The resulting quantitative characteristics are called ``tremor parameters.'' We discuss sinusoidally modulated, band-limited white noise as a model for pathological tremor-EMG, and show how the basic parameters can be extracted from this class of signals. The method is then applied to (1) estimate tremor severity in clinical studies, (2) quantify agonist-antagonist interaction, and (3) investigate the variations of the tremor parameters using simple methods from time-series analysis.

  20. Patient health causes substantial portion of geographic variation in Medicare costs.

    Science.gov (United States)

    Collado, Megan

    2013-10-01

    Key findings. (1) Substantial geographic variation exists in Medicare costs, but to determine the source and extent of this variation requires proper accounting for population health differences. (2) While physician practice patterns likely affect Medicare geographic cost variations, population health explains at least 75 to 85 percent of the variations—more than previously estimated. (3) Policy strategies should consider the magnitude of the impact of beneficiary health status on Medicare costs in order to address geographic variation.

  1. Epigenetic variation: origin and transgenerational inheritance.

    Science.gov (United States)

    Becker, Claude; Weigel, Detlef

    2012-11-01

    Recent studies have revealed that epigenetic variation in plant populations exceeds genetic diversity and that it is influenced by the environment. Nevertheless, epigenetic differences are not entirely independent of shared ancestry. Epigenetic modifications have gained increasing attention, because one can now study their patterns across the entire genome and in many different individuals. Not only do epigenetic phenomena modulate the activity of the genome in response to environmental stimuli, but they also constitute a potential source of natural variation. Understanding the emergence and heritability of epigenetic variants is critical for understanding how they might become subject to natural selection and thus affect genetic diversity. Here we review progress in characterizing natural epigenetic variants in model and nonmodel plant species and how this work is helping to delineate the role of epigenetic changes in evolution.

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

    Energy Technology Data Exchange (ETDEWEB)

    Guo Yongxin, E-mail: yxguo@lnu.edu.c [College of Physics, Liaoning University, Shenyang 110036 (China); Liu Shixing [College of Physics, Liaoning University, Shenyang 110036 (China); Liu Chang; Chang Peng [Department of Applied Mechanics, Beijing Institute of Technology, Beijing 100081 (China)

    2009-10-19

    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.

  3. Spatial and temporal small-scale variation in groundwater quality of a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Christensen, Thomas Højlund

    1992-01-01

    . 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...... limited correlation ranges (less than 10m) and large variations are found over a few metres. The temporal variations observed over a period of 15 months were modest. The observed large variations should be taken into account when designing groundwater sampling and monitoring....

  4. Risk, Affect and Emotion

    Directory of Open Access Journals (Sweden)

    Jens O. Zinn

    2006-01-01

    Full Text Available For a long time theorising has underestimated the importance of affect and emotion in decision making and the management of risk and uncertainty. In relatively one-sided interpretations emotions were often interpreted as threats for rational decision making, and could be triggered by uncertainties, which would go along with social change. Recent interdisciplinary research has shown the importance to acknowledge the more complex link between reasoning and emotions. The article outlines different perspectives on emotion in risk research of economics, psychology and sociology and argues for further research. URN: urn:nbn:de:0114-fqs0601293

  5. 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 '

  6. Geometric constrained variational calculus. II: The second variation (Part I)

    Science.gov (United States)

    Massa, Enrico; Bruno, Danilo; Luria, Gianvittorio; Pagani, Enrico

    2016-10-01

    Within the geometrical framework developed in [Geometric constrained variational calculus. I: Piecewise smooth extremals, Int. J. Geom. Methods Mod. Phys. 12 (2015) 1550061], the problem of minimality for constrained calculus of variations is analyzed among the class of differentiable curves. A fully covariant representation of the second variation of the action functional, based on a suitable gauge transformation of the Lagrangian, is explicitly worked out. Both necessary and sufficient conditions for minimality are proved, and reinterpreted in terms of Jacobi fields.

  7. 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.

  8. Adaptive introgression in animals: examples and comparison to new mutation and standing variation as sources of adaptive variation.

    Science.gov (United States)

    Hedrick, Philip W

    2013-09-01

    Adaptive genetic variation has been thought to originate primarily from either new mutation or standing variation. Another potential source of adaptive variation is adaptive variants from other (donor) species that are introgressed into the (recipient) species, termed adaptive introgression. Here, the various attributes of these three potential sources of adaptive variation are compared. For example, the rate of adaptive change is generally thought to be faster from standing variation, slower from mutation and potentially intermediate from adaptive introgression. Additionally, the higher initial frequency of adaptive variation from standing variation and lower initial frequency from mutation might result in a higher probability of fixation of the adaptive variants for standing variation. Adaptive variation from introgression might have higher initial frequency than new adaptive mutations but lower than that from standing variation, again making the impact of adaptive introgression variation potentially intermediate. Adaptive introgressive variants might have multiple changes within a gene and affect multiple loci, an advantage also potentially found for adaptive standing variation but not for new adaptive mutants. The processes that might produce a common variant in two taxa, convergence, trans-species polymorphism from incomplete lineage sorting or from balancing selection and adaptive introgression, are also compared. Finally, potential examples of adaptive introgression in animals, including balancing selection for multiple alleles for major histocompatibility complex (MHC), S and csd genes, pesticide resistance in mice, black colour in wolves and white colour in coyotes, Neanderthal or Denisovan ancestry in humans, mimicry genes in Heliconius butterflies, beak traits in Darwin's finches, yellow skin in chickens and non-native ancestry in an endangered native salamander, are examined.

  9. Spectral-collocation variational integrators

    Science.gov (United States)

    Li, Yiqun; Wu, Boying; Leok, Melvin

    2017-03-01

    Spectral methods are a popular choice for constructing numerical approximations for smooth problems, as they can achieve geometric rates of convergence and have a relatively small memory footprint. In this paper, we introduce a general framework to convert a spectral-collocation method into a shooting-based variational integrator for Hamiltonian systems. We also compare the proposed spectral-collocation variational integrators to spectral-collocation methods and Galerkin spectral variational integrators in terms of their ability to reproduce accurate trajectories in configuration and phase space, their ability to conserve momentum and energy, as well as the relative computational efficiency of these methods when applied to some classical Hamiltonian systems. In particular, we note that spectrally-accurate variational integrators, such as the Galerkin spectral variational integrators and the spectral-collocation variational integrators, combine the computational efficiency of spectral methods together with the geometric structure-preserving and long-time structural stability properties of symplectic integrators.

  10. 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.

  11. The Split Variational Inequality Problem

    CERN Document Server

    Censor, Yair; Reich, Simeon

    2010-01-01

    We propose a new variational problem which we call the Split Variational Inequality Problem (SVIP). It entails finding a solution of one Variational Inequality Problem (VIP), the image of which under a given bounded linear transformation is a solution of another VIP. We construct iterative algorithms that solve such problems, under reasonable conditions, in Hilbert space and then discuss special cases, some of which are new even in Euclidean space.

  12. Essential oil and bioactive compounds variation in myrtle (Myrtus communis L.) as affected by seasonal variation and salt stress.

    Science.gov (United States)

    Shoshtari, Zeinab Vafadar; Rahimmalek, Mehdi; Sabzalian, Mohammad Reza; Hosseini, Hossein

    2017-02-07

    The effect of different NaCl concentrations (control, 2, 4 and 6 dS m-1) and three harvesting times in different seasons including spring (9 April), summer (5 July) and fall (23 September) was evaluated on essential oil yield, composition, phenolic, flavonoid content and antioxidant activity of myrtle. Essential oil yield ranged from 0.2% in control and fall to 1.6% in moderate salinity (4 dS m-1) and spring season. The main constituents obtained from GC-MS analysis were α-pinene, 1,8-cineole, limonene, linalool, α-terpineol and linalyl acetate in which α-pinene ranged from 11.70% in moderate and fall to 30.99% in low salinity (2 dS m-1) and spring, while 1,8-cineole varied from 7.42% in high salinity (6 dS m-1) and summer to 15.45% in low salinity and spring, respectively. Salt stress also resulted in an increase in total phenolic, flavonoid content and antioxidant activity. The highest antioxidant activity based on DPPH radical scavenging activity, reducing power (FTC) and β-carotene-linoleic acid model systems was found in plants harvested in spring and summer in high stress condition. The lowest IC50 values obtained in 6 dS m-1 in spring (375.23 μg/ml) followed by summer (249.41 μg/ml) and fall (618.38 μg/ml). Eight major phenolic and flavonoid compounds were determined in three harvesting times using HPLC analysis. In overall, late harvesting time of myrtle in fall can lead to reduce the most of major essential oil components, while it can improve the amount of phenolic acids. This article is protected by copyright. All rights reserved.

  13. 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

    beta-oxidation of medium-chain fatty acids. We examined the functional basis for this association and identified linkage between rs211718 and the intragenic synonymous polymorphic variant c.1161A>G in ACADM exon 11 (rs1061337). Employing minigene studies we show that the c.1161A allele is associated...... proteins SRSF1 and hnRNP A1. Using publicly available pre-aligned RNA-seq data, we find that the ACADM c.1161G allele is expressed at significantly higher levels than the c.1161A allele across different tissues. This supports that c.1161A>G is a functional SNP, which leads to higher MCAD 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 sequence...

  14. Multisensory Perception of Affect

    Directory of Open Access Journals (Sweden)

    Beatrice de Gelder

    2011-10-01

    Full Text Available Multisensory integration must stand out among the fields of research that have witnessed a most impressive explosion of interest this last decade. One of these new areas of multisensory research concerns emotion. Since our first exploration of this phenomenon (de Gelder et al., 1999 a number of studies have appeared and they have used a wide variety of behavioral, neuropsychological and neuroscientifc methods. The goal of this presentation is threefold. First, we review the research on audiovisual perception of emotional signals from the face and the voice followed by a report or more recent studies on integrating emotional information provided by the voice and whole body expressions. We will also include some recent work on multisensory music perception. In the next section we discuss some methodological and theoretical issues. Finally, we will discuss findings about abnormal affective audiovisual integration in schizophrenia and in autism.

  15. Trauma-affected refugees

    DEFF Research Database (Denmark)

    Sonne, Charlotte Kærgaard

    2016-01-01

    . The aim of PTF3 was to examine differences in the effects of venlafaxine and sertraline on Post-traumatic Stress Disorder (PTSD), depression and functional impairments in trauma-affected refugees as well as research predictors for treatment outcome. The patients included were 207 adult refugees diagnosed......-reported depression and anxiety symptoms measured on Hopkins Symptom Check List-25 (HSCL-25), self-reported social functioning measured on the Social Adjustment Scale Self Report, short version (SAS-SR), and observer-rated depression and anxiety symptoms assessed on the Hamilton Depression and Anxiety Ratings Scales......=0.06). The only item from the rating scale that was significantly correlated to outcome on HTQ was job status, while a number of other items were significantly related to changes in depression and anxiety symptoms. The size of correlation coefficients was, however, modest. In addition, we found...

  16. Explorations in Regional Variation: A Variational Pragmatic Perspective

    Science.gov (United States)

    Barron, Anne

    2015-01-01

    The present article introduces the Special Issue entitled "A Variational Pragmatic Approach to Regional Variation in Language," a collection of papers which celebrates the work of Klaus P. Schneider (Rheinische Friedrich-Wilhelms-Universität Bonn, Germany) on the occasion of his 60th birthday.

  17. 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.

  18. Exploiting Natural Variation in Arabidopsis

    NARCIS (Netherlands)

    Molenaar, J.A.; Keurentjes, J.J.B.

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana . This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of

  19. Exploiting natural variation in Arabidopsis

    NARCIS (Netherlands)

    J.A. Molenaar; J.J.B. Keurentjes

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana. This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of g

  20. Robust Understanding of Statistical Variation

    Science.gov (United States)

    Peters, Susan A.

    2011-01-01

    This paper presents a framework that captures the complexity of reasoning about variation in ways that are indicative of robust understanding and describes reasoning as a blend of design, data-centric, and modeling perspectives. Robust understanding is indicated by integrated reasoning about variation within each perspective and across…

  1. Variational Bounds for Creeping Composites

    Science.gov (United States)

    Procházka, Petr

    2010-05-01

    In the paper time dependent variational bounds are derived based on Extended Hashin-Shtrikman variational principles. Direct calculation leads to explicit formulas to be presented in the text. For various mechanical properties easy coding in Excel, say, can be used and verification of accuracy for numerical procedures is available using the derived formulas.

  2. 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...

  3. [Genetic variations in alcohol dehydrogenase, drinking habits and alcoholism

    DEFF Research Database (Denmark)

    Tolstrup, J.S.; Rasmussen, S.; Tybjaerg-Hansen, A.

    2008-01-01

    Alcohol is degraded primarily by alcohol dehydrogenase (ADH), and genetic variation that affects the rate of alcohol degradation is found in ADH1B and ADH1C. By genotyping 9,080 white men and women from the general population, we found that men and women with ADH1B slow versus fast alcohol...

  4. 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.

  5. Comparing variation across European countries

    DEFF Research Database (Denmark)

    Thygesen, Lau C; Baixauli-Pérez, Cristobal; Librero-López, Julián;

    2015-01-01

    BACKGROUND: In geographical studies, population distribution is a key issue. An unequal distribution across units of analysis might entail extra-variation and produce misleading conclusions on healthcare performance variations. This article aims at assessing the impact of building more homogeneous...... 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...... of variation such as Extremal Quotient, Interquartile Interval ratio, Systematic Component of Variation and Empirical Bayes statistic. RESULTS: Ward's method reduced the number of areas, allowing a more homogeneous population distribution, yet 20% of the areas in Portugal exhibited less than 100 000...

  6. Fonetisk variation som social praksis

    DEFF Research Database (Denmark)

    Maegaard, Marie

    2010-01-01

    VARIATION I KØBENHAVNSK Sproglig variation kan betragtes på mange måder og ud fra mange forskellige perspektiver alt afhængig af erkendelsesinteresse og fagligt ståsted. I denne artikel vil jeg redegøre for et praksisperspektiv på sproglig variation, og jeg vil give eksempler på analyser af...... fonetisk variation blandt københavnske unge set som social praksis. Fonetisk variation i københavnsk er i de fleste kvantitative sociolingvistiske undersøgelser studeret med udgangspunkt i makrosociale kategorier baseret på alder, køn eller socialklasse (eks. Brink & Lund 1975, Jørgensen 1980, Gregersen...

  7. Exploring language variation across Europe

    DEFF Research Database (Denmark)

    Hovy, Dirk; Johannsen, Anders Trærup

    2016-01-01

    Language varies not only between countries, but also along regional and sociodemographic lines. This variation is one of the driving factors behind language change. However, investigating language variation is a complex undertaking: the more factors we want to consider, the more data we need...... training in both variational linguistics and computational methods, a combination that is still not common. We take a first step here to alleviate the problem by providing an interface to explore large-scale language variation along several socio-demographic factors without programming knowledge. It makes...... use of large amounts of data and provides statistical analyses, maps, and interactive features that enable scholars to explore language variation in a data-driven way....

  8. Walnut development affects chemical composition and codling moth performance

    NARCIS (Netherlands)

    Bezemer, T.M.; Mills, N.J.

    2001-01-01

    We investigated for early and late blooming walnut cultivars in California whether variation in nut phenology resulted in differences in nutritional quality and whether this, in turn, affected the performance of the codling moth, Cydia pomonella (L.), and the extent of nut damage. 2. Mid-season, dur

  9. Imprints of natural selection along environmental gradients in phenology-related genes of Quercus petraea.

    Science.gov (United States)

    Alberto, Florian J; Derory, Jérémy; Boury, Christophe; Frigerio, Jean-Marc; Zimmermann, Niklaus E; Kremer, Antoine

    2013-10-01

    We explored single nucleotide polymorphism (SNP) variation in candidate genes for bud burst from Quercus petraea populations sampled along gradients of latitude and altitude in Western Europe. SNP diversity was monitored for 106 candidate genes, in 758 individuals from 32 natural populations. We investigated whether SNP variation reflected the clinal pattern of bud burst observed in common garden experiments. We used different methods to detect imprints of natural selection (FST outlier, clinal variation at allelic frequencies, association tests) and compared the results obtained for the two gradients. FST outlier SNPs were found in 15 genes, 5 of which were common to both gradients. The type of selection differed between the two gradients (directional or balancing) for 3 of these 5. Clinal variations were observed for six SNPs, and one cline was conserved across both gradients. Association tests between the phenotypic or breeding values of trees and SNP genotypes identified 14 significant associations, involving 12 genes. The results of outlier detection on the basis of population differentiation or clinal variation were not very consistent with the results of association tests. The discrepancies between these approaches may reflect the different hierarchical levels of selection considered (inter- and intrapopulation selection). Finally, we obtained evidence for convergent selection (similar for gradients) and clinal variation for a few genes, suggesting that comparisons between parallel gradients could be used to screen for major candidate genes responding to natural selection in trees.

  10. Some Variations on Total Variation-Based Image Smoothing

    Science.gov (United States)

    2009-03-01

    influential paper, Rudin, Osher, and Fatemi [23] suggested using the bounded variation seminorm to smooth images. The functional proposed in their work has...unit square I = [0, 1]2, where the bounded variation seminorm is defined as |f |BV(I) := ∫ I |Df(x)| dx := sup {∫ I f ∇ · p ∣∣∣ p : I → R2,(1) p ∈ C1(I...approximation to the ROF functional. In Section 3, we propose a new formulation of an upwind finite-difference approximation to the bounded variation seminorm

  11. Encountering Science Education's Capacity to Affect and Be Affected

    Science.gov (United States)

    Alsop, Steve

    2016-01-01

    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…

  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. Transcriptomic variation in a coral reveals pathways of clonal organisation

    DEFF Research Database (Denmark)

    K Bay, Line; Nielsen, Henrik Bjørn; Jarmer, Hanne Østergaard

    2009-01-01

    A microarray study was undertaken to examine the potential for clonal gene expression variation in a branching reef building coral, Acropora millepora. The role of small-scale gradients in light and water flow was examined by comparing gene expression levels between branch elevation (tip and base...... metabolism, protein biosynthesis and cell-cell recognition representing either genotypic variation in gene expression or the effects of specific environmental conditions that affect patterns of energy acquisition, growth and pathogen encounters. Less variation was present between central and peripheral...... of mechanical stress and require greater levels of photo-protection associated with higher water flow and light levels. This study therefore confirms transcriptomic variation in response to small-scale environmental gradients consistent with differential resource allocation in clonal coral colonies. (C) 2009...

  14. Genetics of the dentofacial variation in human malocclusion.

    Science.gov (United States)

    Moreno Uribe, L M; Miller, S F

    2015-04-01

    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 genetic mechanisms underlying facial variation. Knowledge on the genetics of human malocclusion is limited even though results attained thus far are encouraging, with promising opportunities for future research. This review summarizes the most common dentofacial variations associated with malocclusions and reviews the current knowledge of the roles of genes in the development of malocclusions. Lastly, this review will describe ways to advance malocclusion research, following examples from the expanding fields of phenomics and genomic medicine, which aim to better patient outcomes.

  15. Cognitive subtypes in non-affected siblings of schizophrenia patients: characteristics and profile congruency with affected family members.

    NARCIS (Netherlands)

    Quee, P.J.; Alizadeh, B.Z.; Aleman, A.; van den Heuvel, E.R.; GROUP Investigators, [No Value

    2014-01-01

    Although cognitive subtypes have been suggested in schizophrenia patients, similar analyses have not been carried out in their non-affected siblings. Subtype classification may provide more insight into genetically driven variation in cognitive function. We investigated cognitive subtypes in sibling

  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. Modeling the effects of developmental variation on insect phenology.

    Science.gov (United States)

    Yurk, Brian P; Powell, James A

    2010-08-01

    Phenology, the timing of developmental events such as oviposition or pupation, is highly dependent on temperature; since insects are ectotherms, the time it takes them to complete a life stage (development time) depends on the temperatures they experience. This dependence varies within and between populations due to variation among individuals that is fixed within a life stage (giving rise to what we call persistent variation) and variation from random effects within a life stage (giving rise to what we call random variation). It is important to understand how both types of variation affect phenology if we are to predict the effects of climate change on insect populations.We present three nested phenology models incorporating increasing levels of variation. First, we derive an advection equation to describe the temperature-dependent development of a population with no variation in development time. This model is extended to incorporate persistent variation by introducing a developmental phenotype that varies within a population, yielding a phenotype-dependent advection equation. This is further extended by including a diffusion term describing random variation in a phenotype-dependent Fokker-Planck development equation. These models are also novel because they are formulated in terms of development time rather than developmental rate; development time can be measured directly in the laboratory, whereas developmental rate is calculated by transforming laboratory data. We fit the phenology models to development time data for mountain pine beetles (MPB) (Dendroctonus ponderosae Hopkins [Coleoptera: Scolytidae]) held at constant temperatures in laboratory experiments. The nested models are parameterized using a maximum likelihood approach. The results of the parameterization show that the phenotype-dependent advection model provides the best fit to laboratory data, suggesting that MPB phenology may be adequately described in terms of persistent variation alone. MPB

  18. 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...

  19. Variational formulation of high performance finite elements: Parametrized variational principles

    Science.gov (United States)

    Felippa, Carlos A.; Militello, Carmello

    1991-01-01

    High performance elements are simple finite elements constructed to deliver engineering accuracy with coarse arbitrary grids. This is part of a series on the variational basis of high-performance elements, with emphasis on those constructed with the free formulation (FF) and assumed natural strain (ANS) methods. Parametrized variational principles that provide a foundation for the FF and ANS methods, as well as for a combination of both are presented.

  20. Affective monitoring: A generic mechanism for affect elicitation

    Directory of Open Access Journals (Sweden)

    Hans ePhaf

    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.

  1. 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.

  2. Natural transformation and phase variation modulation in Neisseria meningitidis.

    Science.gov (United States)

    Alexander, Heather L; Richardson, Anthony R; Stojiljkovic, Igor

    2004-05-01

    Neisseria meningitidis has evolved the ability to control the expression-state of numerous genes by phase variation. It has been proposed that the process aids this human pathogen in coping with the diversity of microenvironments and host immune systems. Therefore, increased frequencies of phase variation may augment the organism's adaptability and virulence. In this study, we found that DNA derived from various neisserial co-colonizers of the human nasopharynx increased N. meningitidis switching frequencies, indicating that heterologous neisserial DNA modulates phase variation in a transformation-dependent manner. In order to determine whether the effect of heterologous DNA was specific to the Hb receptor, HmbR, we constructed a Universal Rates of Switching cassette (UROS). With this cassette, we demonstrated that heterologous DNA positively affects phase variation throughout the meningococcal genome, as UROS phase variation frequencies were also increased in the presence of neisserial DNA. Overexpressing components of the neisserial mismatch repair system partially alleviated DNA-induced changes in phase variation frequencies, thus implicating mismatch repair titration as a cause of these transformation-dependent increases in switching. The DNA-dependent effect on phase variation was transient and may serve as a mechanism for meningococcal genetic variability that avoids the fitness costs encountered by global mutators.

  3. Affective Productions of Mathematical Experience

    Science.gov (United States)

    Walshaw, Margaret; Brown, Tony

    2012-01-01

    In underscoring the affective elements of mathematics experience, we work with contemporary readings of the work of Spinoza on the politics of affect, to understand what is included in the cognitive repertoire of the Subject. We draw on those resources to tell a pedagogical tale about the relation between cognition and affect in settings of…

  4. 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.

  5. Social and Affective Robotics Tutorial

    NARCIS (Netherlands)

    Pantic, Maja; Evers, Vanessa; Deisenroth, Marc; Merino, Luis; Schuller, Björn

    2016-01-01

    Social and Affective Robotics is a growing multidisciplinary field encompassing computer science, engineering, psychology, education, and many other disciplines. It explores how social and affective factors influence interactions between humans and robots, and how affect and social signals can be se

  6. 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,…

  7. 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.

  8. Variational Integrators in Plasma Physics

    CERN Document Server

    Kraus, Michael

    2013-01-01

    Variational integrators are a special kind of geometric discretisation methods applicable to any system of differential equations that obeys a Lagrangian formulation. In this thesis, variational integrators are developed for several important models of plasma physics: guiding centre dynamics (particle dynamics), the Vlasov-Poisson system (kinetic theory), and ideal magnetohydrodynamics (plasma fluid theory). Special attention is given to physical conservation laws like conservation of energy and momentum. Most systems in plasma physics do not possess a Lagrangian formulation to which the variational integrator methodology is directly applicable. Therefore the theory is extended towards nonvariational differential equations by linking it to Ibragimov's theory of integrating factors and adjoint equations. It allows us to find a Lagrangian for all ordinary and partial differential equations and systems thereof. Consequently, the applicability of variational integrators is extended to a much larger family of syst...

  9. Variational Approach to Molecular Kinetics.

    Science.gov (United States)

    Nüske, Feliks; Keller, Bettina G; Pérez-Hernández, Guillermo; Mey, Antonia S J S; Noé, Frank

    2014-04-08

    The eigenvalues and eigenvectors of the molecular dynamics propagator (or transfer operator) contain the essential information about the molecular thermodynamics and kinetics. This includes the stationary distribution, the metastable states, and state-to-state transition rates. Here, we present a variational approach for computing these dominant eigenvalues and eigenvectors. This approach is analogous to the variational approach used for computing stationary states in quantum mechanics. A corresponding method of linear variation is formulated. It is shown that the matrices needed for the linear variation method are correlation matrices that can be estimated from simple MD simulations for a given basis set. The method proposed here is thus to first define a basis set able to capture the relevant conformational transitions, then compute the respective correlation matrices, and then to compute their dominant eigenvalues and eigenvectors, thus obtaining the key ingredients of the slow kinetics.

  10. Explaining variation in nascent entrepreneurship

    NARCIS (Netherlands)

    A.J. van Stel (André); A.R.M. Wennekers (Sander); P. Reynolds (Paul); A.R. Thurik (Roy)

    2004-01-01

    textabstractThis paper aims at explaining cross-country variation in nascent entrepreneurship. Regression analysis is applied using various explanatory variables derived from three different approaches. We make use of the Global Entrepreneurship Monitor database, including nascent entrepreneurship r

  11. Variation of fundamental constants: theory

    Science.gov (United States)

    Flambaum, Victor

    2008-05-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. There are some hints for the variation of different fundamental constants in quasar absorption spectra and Big Bang nucleosynthesis data. A large number of publications (including atomic clocks) report limits on the variations. We want to study the variation of the main dimensionless parameters of the Standard Model: 1. Fine structure constant alpha (combination of speed of light, electron charge and Plank constant). 2. Ratio of the strong interaction scale (LambdaQCD) to a fundamental mass like electron mass or quark mass which are proportional to Higgs vacuum expectation value. The proton mass is propotional to LambdaQCD, therefore, the proton-to-electron mass ratio comes into this second category. We performed necessary atomic, nuclear and QCD calculations needed to study variation of the fundamental constants using the Big Bang Nucleosynthsis, quasar spectra, Oklo natural nuclear reactor and atomic clock data. The relative effects of the variation may be enhanced in transitions between narrow close levels in atoms, molecules and nuclei. If one will study an enhanced effect, the relative value of systematic effects (which are not enhanced) may be much smaller. Note also that the absolute magnitude of the variation effects in nuclei (e.g. in very narrow 7 eV transition in 229Th) may be 5 orders of magnitude larger than in atoms. A different possibility of enhancement comes from the inversion transitions in molecules where splitting between the levels is due to the quantum tunneling amplitude which has strong, exponential dependence on the electron to proton mass ratio. Our study of NH3 quasar spectra has already given the best limit on the variation of electron to proton mass ratio.

  12. Temporal variation of diatom benthic propagules in a monsoon-influenced tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Patil, J.S.; Anil, A

    Temporal variations in the diatom benthic propagule (DBP) community and their role in the phytoplankton community in a monsoon-affected tropical estuary, Zuari estuary, Goa (India) are presented. The DBP from the sediments was enumerated using...

  13. Assistive Technology and Affective Mediation

    Directory of Open Access Journals (Sweden)

    Nestor Garay

    2006-01-01

    Full Text Available The lack of attention towards affective communication in assistive technology and disability research can be potentially overcome thanks to the development of affective computing and affective mediation areas. This document describes the main impairments and disorders that may involve affective communication deficits. We also present several affective mediation technologies that are being applied or may be integrated in assistive technologies in order to improve affective communication for a range of disabilities. Finally, we describe our experience with Gestele, an application that incorporates multimodal elements of affective mediation for people with mobility impairments, as well as the results of an empirical study conducted to evaluate the application’s validity in communication via telephone.

  14. Variational integrators for electric circuits

    Energy Technology Data Exchange (ETDEWEB)

    Ober-Blöbaum, Sina, E-mail: sinaob@math.upb.de [Computational Dynamics and Optimal Control, University of Paderborn (Germany); Tao, Molei [Courant Institute of Mathematical Sciences, New York University (United States); Cheng, Mulin [Applied and Computational Mathematics, California Institute of Technology (United States); Owhadi, Houman; Marsden, Jerrold E. [Control and Dynamical Systems, California Institute of Technology (United States); Applied and Computational Mathematics, California Institute of Technology (United States)

    2013-06-01

    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.

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

    Science.gov (United States)

    Alsop, Steve

    2016-09-01

    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.

  16. Effects of Wolbachia on mitochondrial DNA variation in populations of Athetis lepigone (Lepidoptera: Noctuidae) in China

    Science.gov (United States)

    Wolbachia are endosymbiotic bacteria that infect arthropods and incompatibility among strains can affect gene flow within host insect populations, that can result in significant host mitochondrial DNA (MtD) variation. The effects of Wolbachia infection on mtDNA variation was studied in Athetis lepi...

  17. Effects of intraspecific variation in white cabbage (Brassica oleracea var. capitata) on soil organisms

    NARCIS (Netherlands)

    Kabouw, P.; Van der Putten, W.H.; Van Dam, N.M.; Biere, A.

    2010-01-01

    Intraspecific variation in plants can affect soil organisms. However, little is known about whether the magnitude of the effect depends on the degree of interaction with the roots. We analyzed effects of plant intraspecific variation on root herbivores and other soil organisms that interact directly

  18. Effects of intraspecific variation in white cabbage (Brassica oleracea var. Capitata) on soil ogranisms

    NARCIS (Netherlands)

    Kabouw, P.; Putten, van der W.H.; Dam, van N.M.; Biere, A.

    2010-01-01

    Intraspecific variation in plants can affect soil organisms. However, little is known about whether the magnitude of the effect depends on the degree of interaction with the roots. We analyzed effects of plant intraspecific variation on root herbivores and other soil organisms that interact directly

  19. Affective and Behavioral Features of Jealousy Protest: Associations with Child Temperament, Maternal Interaction Style, and Attachment

    Science.gov (United States)

    Hart, Sybil L.; Behrens, Kazuko Y.

    2013-01-01

    This study explored variation in affective and behavioral components of infants' jealousy protests during an eliciting condition in which mother and an experimenter directed differential attention exclusively toward a rival. Variation was examined in relation to child temperamental emotionality, maternal interaction style, and attachment security.…

  20. 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.

  1. The influence of mitonuclear genetic variation on personality in seed beetles.

    Science.gov (United States)

    Løvlie, Hanne; Immonen, Elina; Gustavsson, Emil; Kazancioğlu, Erem; Arnqvist, Göran

    2014-12-07

    There is a growing awareness of the influence of mitochondrial genetic variation on life-history phenotypes, particularly via epistatic interactions with nuclear genes. Owing to their direct effect on traits such as metabolic and growth rates, mitonuclear interactions may also affect variation in behavioural types or personalities (i.e. behavioural variation that is consistent within individuals, but differs among individuals). However, this possibility is largely unexplored. We used mitonuclear introgression lines, where three mitochondrial genomes were introgressed into three nuclear genetic backgrounds, to disentangle genetic effects on behavioural variation in a seed beetle. We found within-individual consistency in a suite of activity-related behaviours, providing evidence for variation in personality. Composite measures of overall activity of individuals in behavioural assays were influenced by both nuclear genetic variation and by the interaction between nuclear and mitochondrial genomes. More importantly, the degree of expression of behavioural and life-history phenotypes was correlated and mitonuclear genetic variation affected expression of these concerted phenotypes. These results show that mitonuclear genetic variation affects both behavioural and life-history traits, and they provide novel insights into the maintenance of genetic variation in behaviour and personality.

  2. Planck intermediate results XXIV. Constraints on variations in fundamental constants

    DEFF Research Database (Denmark)

    Ade, P. A. R.; Aghanim, N.; Arnaud, M.;

    2015-01-01

    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...... of the electron, me, and in 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...

  3. Gillespie eco‐evolutionary models (GEMs) reveal the role of heritable trait variation in eco‐evolutionary dynamics

    OpenAIRE

    DeLong, John P.; Gibert, Jean P.

    2016-01-01

    Abstract Heritable trait variation is a central and necessary ingredient of evolution. Trait variation also directly affects ecological processes, generating a clear link between evolutionary and ecological dynamics. Despite the changes in variation that occur through selection, drift, mutation, and recombination, current eco‐evolutionary models usually fail to track how variation changes through time. Moreover, eco‐evolutionary models assume fitness functions for each trait and each ecologic...

  4. Climatic factors and bipolar affective disorder

    DEFF Research Database (Denmark)

    Christensen, Ellen Margrethe; Larsen, Jens Knud; Gjerris, Annette

    2008-01-01

    In bipolar disorder, the factors provoking a new episode are unknown. As a seasonal variation has been noticed, it has been suggested that weather conditions may play a role. The aim of the study was to elucidate whether meteorological parameters influence the development of new bipolar phases....... A group of patients with at least three previous hospitalizations for bipolar disorder was examined every 3 months for up to 3 years. At each examination an evaluation of the affective phase was made according to the Hamilton Depression Scale (HAM-D(17)), and the Bech-Rafaelsen Mania Rating Scale (MAS......). In the same period, daily recordings from the Danish Meteorological Institute were received. We found no correlations between onset of bipolar episodes [defined as MAS score of 11 or more (mania) and as HAM-D(17) score of 12 or more (depression)] and any meteorological parameters. We found a statistical...

  5. Systematic variation of rare earths in monazite

    Science.gov (United States)

    Murata, K.J.; Rose, H.J.; Carron, M.K.

    1953-01-01

    Ten monazites from widely scattered localities have been analyzed for La, Ce, Pr, Nd, Sm, Gd, Y and Th by means of a combined chemical and emission spectrographic method. The analytical results, calculated to atomic percent of total rare earths (thorium excluded), show a considerable variation in the proportions of every element except praseodymium, which is relatively constant. The general variation trends of the elements may be calculated by assuming that the monazites represent different stages in a fractional precipitation process, and by assuming that there is a gradational increase in the precipitability of rare earth elements with decreasing ionic radius. Fractional precipitation brings about an increase in lanthanum and cerium, little change in praseodymium, and a decrease in neodymium, samarium, gadolinium, and yttrium. Deviations from the calculated lines of variation consist of a simultaneous, abnormal increase or decrease in the proportions of cerium, praseodymium, and neodymium with antipathetic decrease or increase in the proportions of the other elements. These deviations are ascribed to abnormally high or low temperatures that affect the precipitability of the central trio of elements (Ce, Pr, Nd) relatively more than that of the other elements. The following semiquantitative rules have been found useful in describing the composition of rare earths from monazite: 1. 1. The sum of lanthanum and neodymium is very nearly a constant at 42 ?? 2 atomic percent. 2. 2. Praseodymium is very nearly constant at 5 ?? 1 atomic percent. 3. 3. The sum of Ce, Sm, Gd, and Y is very nearly a constant at 53 ?? 3 atomic percent. No correlation could be established between the content of Th and that of any of the rare earth elements. ?? 1953.

  6. The Role of Variation in Lexicography.

    Science.gov (United States)

    Lucas, Ceil

    2003-01-01

    Explores the relationship between lexicography and variation in both spoken languages and sign languages. Examines the function of dictionaries and discusses the nature of linguistic variation, using an example of lexical variation in American Sign Language. (Author/VWL)

  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...... the 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. Evolutionary response when selection and genetic variation covary across environments.

    Science.gov (United States)

    Wood, Corlett W; Brodie, Edmund D

    2016-10-01

    Although models of evolution usually assume that the strength of selection on a trait and the expression of genetic variation in that trait are independent, whenever the same ecological factor impacts both parameters, a correlation between the two may arise that accelerates trait evolution in some environments and slows it in others. Here, we address the evolutionary consequences and ecological causes of a correlation between selection and expressed genetic variation. Using a simple analytical model, we show that the correlation has a modest effect on the mean evolutionary response and a large effect on its variance, increasing among-population or among-generation variation in the response when positive, and diminishing variation when negative. We performed a literature review to identify the ecological factors that influence selection and expressed genetic variation across traits. We found that some factors - temperature and competition - are unlikely to generate the correlation because they affected one parameter more than the other, and identified others - most notably, environmental novelty - that merit further investigation because little is known about their impact on one of the two parameters. We argue that the correlation between selection and genetic variation deserves attention alongside other factors that promote or constrain evolution in heterogeneous landscapes.

  9. 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 ...

  10. Variational Methods for Biomolecular Modeling

    CERN Document Server

    Wei, Guo-Wei

    2016-01-01

    Structure, function and dynamics of many biomolecular systems can be characterized by the energetic variational principle and the corresponding systems of partial differential equations (PDEs). This principle allows us to focus on the identification of essential energetic components, the optimal parametrization of energies, and the efficient computational implementation of energy variation or minimization. Given the fact that complex biomolecular systems are structurally non-uniform and their interactions occur through contact interfaces, their free energies are associated with various interfaces as well, such as solute-solvent interface, molecular binding interface, lipid domain interface, and membrane surfaces. This fact motivates the inclusion of interface geometry, particular its curvatures, to the parametrization of free energies. Applications of such interface geometry based energetic variational principles are illustrated through three concrete topics: the multiscale modeling of biomolecular electrosta...

  11. Variational methods in molecular modeling

    CERN Document Server

    2017-01-01

    This book presents tutorial overviews for many applications of variational methods to molecular modeling. Topics discussed include the Gibbs-Bogoliubov-Feynman variational principle, square-gradient models, classical density functional theories, self-consistent-field theories, phase-field methods, Ginzburg-Landau and Helfrich-type phenomenological models, dynamical density functional theory, and variational Monte Carlo methods. Illustrative examples are given to facilitate understanding of the basic concepts and quantitative prediction of the properties and rich behavior of diverse many-body systems ranging from inhomogeneous fluids, electrolytes and ionic liquids in micropores, colloidal dispersions, liquid crystals, polymer blends, lipid membranes, microemulsions, magnetic materials and high-temperature superconductors. All chapters are written by leading experts in the field and illustrated with tutorial examples for their practical applications to specific subjects. With emphasis placed on physical unders...

  12. Antigenic Variation in Bacterial Pathogens.

    Science.gov (United States)

    Palmer, Guy H; Bankhead, Troy; Seifert, H Steven

    2016-02-01

    Antigenic variation is a strategy used by a broad diversity of microbial pathogens to persist within the mammalian host. Whereas viruses make use of a minimal proofreading capacity combined with large amounts of progeny to use random mutation for variant generation, antigenically variant bacteria have evolved mechanisms which use a stable genome, which aids in protecting the fitness of the progeny. Here, three well-characterized and highly antigenically variant bacterial pathogens are discussed: Anaplasma, Borrelia, and Neisseria. These three pathogens display a variety of mechanisms used to create the structural and antigenic variation needed for immune escape and long-term persistence. Intrahost antigenic variation is the focus; however, the role of these immune escape mechanisms at the population level is also presented.

  13. 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.

  14. Homotopy Method for Variational Inequalities

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Solving a finite-dimensional variational inequality is to find a vector x* ∈ X Rn such that where X is a nonempty, closed and convex subset of Rn and F is a mapping from Rn to itself,denoted by VI(X, F). The variational inequality problem (VIP) has had many successful practical applications in the last three decades. It has been used to formulate and investigate equilibrium models arising in economics, transportation, regional science and operations research. So far, a large number of existence conditions have been developed in the literature. Harker and Pang[1] gave excellent surveys of theories, methods and applications of VIPs.

  15. 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.

  16. A compiler for variational forms

    CERN Document Server

    Kirby, Robert C; 10.1145/1163641.1163644

    2011-01-01

    As a key step towards a complete automation of the finite element method, we present a new algorithm for automatic and efficient evaluation of multilinear variational forms. The algorithm has been implemented in the form of a compiler, the FEniCS Form Compiler FFC. We present benchmark results for a series of standard variational forms, including the incompressible Navier-Stokes equations and linear elasticity. The speedup compared to the standard quadrature-based approach is impressive; in some cases the speedup is as large as a factor 1000.

  17. Seasonal Affective Disorder: For Teens

    Science.gov (United States)

    ... can affect concentration, too, interfering with a person's school performance and grades. A student may have more trouble ... less motivated or is making less effort in school. Less time ... can affect self-esteem and leave a person feeling disappointed, isolated, and ...

  18. Novel sequence variation affects GPIb α in post-diarrheal hemolytic uremic syndrome

    NARCIS (Netherlands)

    Volokina, E.; Jakobi, A.J.; Urbanus, R.T; Huizinga, E.G.; Sluiter, H.; Middel, C.; Westra, D.; van Heerde, W.L.; van de Kar, N.; van den Heuvel, L.

    2014-01-01

    Background: Hemolytic uremic syndrome (HUS) is one of the major causes of renal failure in children. In most cases the disease is caused by infection with Shiga toxin- producing Escherichia coli (STEC) and preceded by diarrhea. Only in 15% of cases STEC infection leads to HUS. Genetic predisposition

  19. Variation in phosphorus content of milk from dairy cattle as affected by differences in milk composition

    NARCIS (Netherlands)

    Klop, G.; Ellis, J.L.; Blok, M.C.; Brandsma, G.G.; Bannink, A.; Dijkstra, J.

    2014-01-01

    In view of environmental concerns with regard to phosphorus (P) pollution and the expected global P scarcity, there is increasing interest in improving P utilization in dairy cattle. In high-producing dairy cows, P requirements for milk production comprise a significant fraction of total dietary P r

  20. Can environmental variation affect seedling survival of plants in northeastern Mexico?

    Directory of Open Access Journals (Sweden)

    García Jaime F.

    2011-01-01

    Full Text Available The effects of global warming increase the frequency and intensity of many climate events such as rainfall. We evaluated the effects of environmental conditions on early stage seedling survival of the native thorn scrub species Caesalpinia mexicana A. Gray, Celtis pallida Torr., Cordia boissieri A. DC., and Ebenopsis ebano (Berland. Barneby and J.W. Grimes, during the summer of 2009 and 2010. The experimental design had two factors, two levels of rainfall and three microhabitats of thorn scrub: (i open interspace, (ii thorn scrub edge and (iii under the canopy of dense thorn scrub. In dense thorn scrub, seedling survival was higher for Caesalpinia mexicana and Celtis pallida, and for Cordia boissieri and Ebenopsis ebano seedling survival was higher in dense thorn scrub and thorn scrub edge. The effect of rainfall on seedling survival depended on the year. Rainfall in 2010 and dense thorn scrub increased seedling survival of native species. For survival, the limiting factors of microhabitats appear to change across the years. Besides rainfall events, biological aspects like competition and mycorrhiza effects would need to be considered in models of plant establishment.

  1. Genetic variation of the serotonin 2a receptor affects hippocampal novelty processing in humans.

    Directory of Open Access Journals (Sweden)

    Björn H Schott

    Full Text Available 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 information. Here we investigated the relationship of 5-HTR2a His452Tyr and hippocampal novelty processing in 41 young, healthy subjects using functional magnetic resonance imaging (fMRI. Participants performed a novelty/familiarity task with complex scene stimuli, which was followed by a delayed recognition memory test 24 hours later. Compared to His homozygotes, Tyr carriers exhibited a diminished hippocampal response to novel stimuli and a higher tendency to judge novel stimuli as familiar during delayed recognition. Across the cohort, the false alarm rate during delayed recognition correlated negatively with the hippocampal novelty response. Our results suggest that previously reported effects of 5-HTR2a on explicit memory performance may, at least in part, be mediated by alterations of hippocampal novelty processing.

  2. Genetic variation of the serotonin 2a receptor affects hippocampal novelty processing in humans.

    Science.gov (United States)

    Schott, Björn H; Seidenbecher, Constanze I; Richter, Sylvia; Wüstenberg, Torsten; Debska-Vielhaber, Grazyna; Schubert, Heike; Heinze, Hans-Jochen; Richardson-Klavehn, Alan; Düzel, Emrah

    2011-01-18

    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 information. Here we investigated the relationship of 5-HTR2a His452Tyr and hippocampal novelty processing in 41 young, healthy subjects using functional magnetic resonance imaging (fMRI). Participants performed a novelty/familiarity task with complex scene stimuli, which was followed by a delayed recognition memory test 24 hours later. Compared to His homozygotes, Tyr carriers exhibited a diminished hippocampal response to novel stimuli and a higher tendency to judge novel stimuli as familiar during delayed recognition. Across the cohort, the false alarm rate during delayed recognition correlated negatively with the hippocampal novelty response. Our results suggest that previously reported effects of 5-HTR2a on explicit memory performance may, at least in part, be mediated by alterations of hippocampal novelty processing.

  3. 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.

  4. 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.

  5. 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

    strongyle type parasites (NC1, NC2). SYBR Green Real-Time PCRs were performed in triplicates. Results revealed a statistically significant increase in PCR yield after three days, which was statistically associated with beginning embryonation of the eggs. In conclusion, storage time and developmental stage...... of strongyle eggs are significant sources of error in studies based on quantitative real-time PCR analysis. This study suggests that for refrigerated storage of more than three days, eggs should be inactivated and preserved for further analysis....

  6. Cortisol variation in humans affects memory for emotionally laden and neutral information.

    Science.gov (United States)

    Abercrombie, Heather C; Kalin, Ned H; Thurow, Marchell E; Rosenkranz, Melissa A; Davidson, Richard J

    2003-06-01

    In a test of the effects of cortisol on emotional memory, 90 men were orally administered placebo or 20 or 40 mg cortisol and presented with emotionally arousing and neutral stimuli. On memory tests administered within 1 hr of stimulus presentation, cortisol elevations caused a reduction in the number of errors committed on free-recall tasks. Two evenings later, when cortisol levels were no longer manipulated, inverted-U quadratic trends were found for recognition memory tasks, reflecting memory facilitation in the 20-mg group for both negative and neutral information. Results suggest that the effects of cortisol on memory do not differ substantially for emotional and neutral information. The study provides evidence of beneficial effects of acute cortisol elevations on explicit memory in humans.

  7. Sugarcane genotype variation in leaf photosynthesis properties and yield as affected by mill mud application

    Science.gov (United States)

    Variability in yield among sugarcane (a complex hybrid of Saccharum spp.) genotypes grown with and without mill mud application on sand soils in Florida has been documented, but little is known about what causes yield differences and if there are any relationships between yield components and physio...

  8. Aggressive behavior, related conduct problems, and variation in genes affecting dopamine turnover.

    Science.gov (United States)

    Grigorenko, Elena L; De Young, Colin G; Eastman, Maria; Getchell, Marya; Haeffel, Gerald J; Klinteberg, Britt af; Koposov, Roman A; Oreland, Lars; Pakstis, Andrew J; Ponomarev, Oleg A; Ruchkin, Vladislav V; Singh, Jay P; Yrigollen, Carolyn M

    2010-01-01

    A number of dopamine-related genes have been implicated in the etiology of violent behavior and conduct problems. Of these genes, the ones that code for the enzymes that influence the turnover of dopamine (DA) have received the most attention. In this study, we investigated 12 genetic polymorphisms in four genes involved with DA functioning (COMT, MAOA and MAOB, and DbetaH) in 179 incarcerated male Russian adolescents and two groups of matched controls: boys without criminal records referred to by their teachers as (a) "troubled-behavior-free" boys, n=182; and (b) "troubled-behavior" boys, n=60. The participants were classified as (1) being incarcerated or not, (2) having the DSM-IV diagnosis of conduct disorder (CD) or not, and (3) having committed violent or nonviolent crimes (for the incarcerated individuals only). The findings indicate that, although no single genetic variant in any of the four genes differentiated individuals in the investigated groups, various linear combinations (i.e., haplotypes) and nonlinear combinations (i.e., interactions between variants within and across genes) of genetic variants resulted in informative and robust classifications for two of the three groupings. These combinations of genetic variants differentiated individuals in incarceration vs. nonincarcerated and CD vs. no-CD groups; no informative combinations were established consistently for the grouping by crime within the incarcerated individuals. This study underscores the importance of considering multiple rather than single markers within candidate genes and their additive and interactive combinations, both with themselves and with nongenetic indicators, while attempting to understand the genetic background of such complex behaviors as serious conduct problems.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    OBJECTIVES: Irregularities in cardiac repolarization are known to predispose for arrhythmias and sudden cardiac death in humans. The QT interval is a quantitative measurement of repolarization, and clinically, the QTc (QT interval corrected for heart rate) and Tpeak to Tend intervals (TpTe) are u...

  10. 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

    range, and a paraphyletic assembly of Trachymyrmex and Sericomyrmex species that cultivate more genetically diverse fungal symbionts. Leaf-decomposition productivity of colonies depends on the combined efforts of ant foragers collecting and macerating plant material and fungal enzymes excreted directly...... partners vary in metabolic performance, division of labour may not always be optimized and co-evolutionary trajectories become less predictable. The higher fungus-growing (attine) ants consist of the leafcutter ants (Acromyrmex and Atta), which rear a single fungal species throughout their Latin American...... or indirectly via ant fecal fluid. We determined the interaction specificity between ant species and fungal strains across sympatric populations of six Trachymyrmex and Sericomyrmex species in Panama, and established that these ants jointly reared eight fungal haplotype groups that differed significantly...

  11. Surface variations affecting human dental enamel studied using nanomechanical and chemical analysis

    Science.gov (United States)

    Dickinson, Michelle Emma

    The enamel surface is the interface between the tooth and its ever changing oral environment. Cavity (caries) formation and extrinsic tooth staining are due, respectively, to degradation of the enamel structure under low pH conditions and interactions between salivary pellicle and dietary elements. Both of these occur at the enamel surface and are caused by the local environment changing the chemistry of the surface. The results can be detrimental to the enamel's mechanical integrity and aesthetics. Incipient carious lesions are the precursor to caries and form due to demineralisation of enamel. These carious lesions are a reversible structure where ions (e.g. Ca2+, F -) can diffuse in (remineralisation) to preserve the tooth's structural integrity. This investigation used controlled in vitro demineralisation and remineralisation to study artificial carious lesion formation and repair. The carious lesions were cross-sectioned and characterised using nanoindentation, electron probe micro-analysis and time of flight secondary ion mass spectrometry. Mechanical and chemical maps showed the carious lesion had a significantly reduced hardness and elastic modulus, and the calcium and phosphate content was lower than in sound enamel. Fluoride based remineralisation treatments gave a new phase (possibly fluorohydroxyapatite) within the lesion with mechanical properties higher than sound enamel. The acquired salivary pellicle is a protein-rich film formed by the physisorption of organic molecules in saliva onto the enamel surface. Its functions include lubrication during mastication and chemical protection. However, pellicle proteins react with dietary elements such as polyphenols (tannins in tea) causing a brown stain. This study has used in vitro dynamic nanoindentation and atomic force microscopy to examine normal and stained pellicles formed in vivo. The effects of polyphenols on the pellicle's mechanical properties and morphology have been studied. It was found that the initial adsorption of proteins occurred within 30 seconds of exposure to the oral cavity; fully mature pellicles develop in 2 hours. Polyphenol staining resulted in substantial changes in the morphology and mechanical properties of the pellicle. Specifically, staining gives pellicles consisting of large globules with high surface adhesion and a high loss tangent. These changes help explain why extrinsic stains are difficult to remove abrasively.

  12. Flow, affect and visual creativity.

    Science.gov (United States)

    Cseh, Genevieve M; Phillips, Louise H; Pearson, David G

    2015-01-01

    Flow (being in the zone) is purported to have positive consequences in terms of affect and performance; however, there is no empirical evidence about these links in visual creativity. Positive affect often--but inconsistently--facilitates creativity, and both may be linked to experiencing flow. This study aimed to determine relationships between these variables within visual creativity. Participants performed the creative mental synthesis task to simulate the creative process. Affect change (pre- vs. post-task) and flow were measured via questionnaires. The creativity of synthesis drawings was rated objectively and subjectively by judges. Findings empirically demonstrate that flow is related to affect improvement during visual creativity. Affect change was linked to productivity and self-rated creativity, but no other objective or subjective performance measures. Flow was unrelated to all external performance measures but was highly correlated with self-rated creativity; flow may therefore motivate perseverance towards eventual excellence rather than provide direct cognitive enhancement.

  13. Affect intensity in voice recognized by tree shrews (Tupaia belangeri).

    Science.gov (United States)

    Schehka, Simone; Zimmermann, Elke

    2012-06-01

    Shared acoustic cues in speech, music, and nonverbal emotional expressions were postulated to code for emotion quality and intensity favoring the hypothesis of a prehuman origin of affective prosody in human emotional communication. To explore this hypothesis, we examined in playback experiments using a habituation-dishabituation paradigm whether a solitary foraging, highly vocal mammal, the tree shrew, is able to discriminate two behaviorally defined states of affect intensity (low vs. high) from the voice of conspecifics. Playback experiments with communication calls of two different types (chatter call and scream call) given in the state of low affect intensity revealed that habituated tree shrews dishabituated to one call type (the chatter call) and showed a tendency to do so for the other one (the scream call), both given in the state of high affect intensity. Findings suggest that listeners perceive the acoustic variation linked to defined states of affect intensity as different within the same call type. Our findings in tree shrews provide first evidence that acoustically conveyed affect intensity is biologically relevant without any other sensory cue, even for solitary foragers. Thus, the perception of affect intensity in voice conveyed in stressful contexts represents a shared trait of mammals, independent of the complexity of social systems. Findings support the hypothesis that affective prosody in human emotional communication has deep-reaching phylogenetic roots, deriving from precursors already present and relevant in the vocal communication system of early mammals.

  14. Leaf Length Variation in Perennial Forage Grasses

    Directory of Open Access Journals (Sweden)

    Philippe Barre

    2015-08-01

    Full Text Available Leaf length is a key factor in the economic value of different grass species and cultivars in forage production. It is also important for the survival of individual plants within a sward. The objective of this paper is to discuss the basis of within-species variation in leaf length. Selection for leaf length has been highly efficient, with moderate to high narrow sense heritability. Nevertheless, the genetic regulation of leaf length is complex because it involves many genes with small individual effects. This could explain the low stability of QTL found in different studies. Leaf length has a strong response to environmental conditions. However, when significant genotype × environment interactions have been identified, their effects have been smaller than the main effects. Recent modelling-based research suggests that many of the reported environmental effects on leaf length and genotype × environment interactions could be biased. Indeed, it has been shown that leaf length is an emergent property strongly affected by the architectural state of the plant during significant periods prior to leaf emergence. This approach could lead to improved understanding of the factors affecting leaf length, as well as better estimates of the main genetic effects.

  15. Patterns of genome size variation in snapping shrimp.

    Science.gov (United States)

    Jeffery, Nicholas W; Hultgren, Kristin; Chak, Solomon Tin Chi; Gregory, T Ryan; Rubenstein, Dustin R

    2016-06-01

    Although crustaceans vary extensively in genome size, little is known about how genome size may affect the ecology and evolution of species in this diverse group, in part due to the lack of large genome size datasets. Here we investigate interspecific, intraspecific, and intracolony variation in genome size in 39 species of Synalpheus shrimps, representing one of the largest genome size datasets for a single genus within crustaceans. We find that genome size ranges approximately 4-fold across Synalpheus with little phylogenetic signal, and is not related to body size. In a subset of these species, genome size is related to chromosome size, but not to chromosome number, suggesting that despite large genomes, these species are not polyploid. Interestingly, there appears to be 35% intraspecific genome size variation in Synalpheus idios among geographic regions, and up to 30% variation in Synalpheus duffyi genome size within the same colony.

  16. 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...

  17. Genetisk variation og langt liv

    DEFF Research Database (Denmark)

    Sørensen, Mette

    2013-01-01

    andre ikke gør. I dette ph.d.-projekt undersøgte vi sammenhængen mellem levetid og variation i tre biologiske skadesprocesser. De tre er: antioxidanter, væksthormon/insulin-signalering og DNA-reparation. Vi fandt nye genvariationer, hvoraf nogle har positiv indflydelse på chancen for at blive meget...

  18. Symmetries and variation of spectra

    OpenAIRE

    Bhatia, Rajendra; Elsner, Ludwig

    1992-01-01

    An interesting class of matrices is shown to have the property that the spectrum of each of its elements is invariant under multiplication by p-th roots of unity. For this class and tor a class of Hamiltonian matrices improved spectral variation bounds are obtained.

  19. The Dimensionality of Grammatical Variation

    Science.gov (United States)

    Sankoff, David; Cedergren, Henrietta J.

    1976-01-01

    Computer-based multidimensional scaling techniques are used to determine the dimensionality of grammatical variation in three large sets of data: Ross' (1973) Noun Phrase and fake Noun Phrase data; Sankoff's (1974) complementizer "que"-deletion (Montreal French) data; and Cedergren's (1973) syllable-final S-reduction (Panamanian Spanish) data. (DB)

  20. Creativity, depression, and circannual variation.

    Science.gov (United States)

    Sitton, S C; Hughes, R B

    1995-12-01

    Verbal creativity has been linked to personal and family histories of bipolar depression. The present studies investigated the relationship between creativity and atypical symptoms of bipolar depression such as seasonal mood variations. Although more creative individuals, as measured by scores on the Remote Associates Test and a writing sample, perceived seasonal fluctuations in their creativity, no significant differences in performance were found.

  1. Orbital variations, climate and paleoecology.

    Science.gov (United States)

    Bartlein, P J; Prentice, I C

    1989-07-01

    One of the most exciting discoveries in the earth sciences in recent decades has been the proof that ice ages are governed by deterministic variations in the earth's orbit. These variations modify the latitudinal and seasonal distribution of solar radiation at periods ranging from 103 to 10(5) years, and alternately produce conditions for building and melting continental ice. The same solar radiation variations also govern other aspects of world climate, including the temperatures of the midlatitude continental interiors, the intensity of upwelling in the tropical oceans, and the strength and extent of the monsoons. The interplay of solar radiation, seasonality and ice-sheet changes is responsible for the complex ecological history documented in the fossil record of the past 20 000 years. But the orbital variations have occurred throughout earth's history, and have caused periodic environmental changes in both terrestrial and marine environments even during times when there was no ice. Species have responded to these changes by range migration, an evolved ability that may maintain their genetic coherence in the face of a continually changing environment.

  2. Relevant principal factors affecting the reproducibility of insect primary culture.

    Science.gov (United States)

    Ogata, Norichika; Iwabuchi, Kikuo

    2017-02-22

    The primary culture of insect cells often suffers from problems with poor reproducibility in the quality of the final cell preparations. The cellular composition of the explants (cell number and cell types), surgical methods (surgical duration and surgical isolation), and physiological and genetic differences between donors may be critical factors affecting the reproducibility of culture. However, little is known about where biological variation (interindividual differences between donors) ends and technical variation (variance in replication of culture conditions) begins. In this study, we cultured larval fat bodies from the Japanese rhinoceros beetle, Allomyrina dichotoma, and evaluated, using linear mixed models, the effect of interindividual variation between donors on the reproducibility of the culture. We also performed transcriptome analysis of the hemocyte-like cells mainly seen in the cultures using RNA sequencing and ultrastructural analyses of hemocytes using a transmission electron microscope, revealing that the cultured cells have many characteristics of insect hemocytes.

  3. Variational integrators in plasma physics

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, Michael

    2013-07-01

    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

  4. Sensitivity of Solder Joint Fatigue to Sources of Variation in Advanced Vehicular Power Electronics Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Vlahinos, A.; O' Keefe, M.

    2010-06-01

    This paper demonstrates a methodology for taking variation into account in thermal and fatigue analyses of the die attach for an inverter of an electric traction drive vehicle. This method can be used to understand how variation and mission profile affect parameters of interest in a design. Three parameters are varied to represent manufacturing, material, and loading variation: solder joint voiding, aluminum nitride substrate thermal conductivity, and heat generation at the integrated gate bipolar transistor. The influence of these parameters on temperature and solder fatigue life is presented. The heat generation loading variation shows the largest influence on the results for the assumptions used in this problem setup.

  5. Immunodeficiency in Patients With 49,XXXXY Chromosomal Variation

    OpenAIRE

    Keller, Michael D; Sadeghin, Teresa; Samango-Sprouse, Carole; Orange, Jordan S.

    2013-01-01

    Boys affected with 49,XXXXY sex chromosomal variation have been described to have high incidence of recurrent otitis media and asthma, the cause of which is unknown. We hypothesized that primary immunodeficiency occurs in patients with XXXXY aneuploidy. To investigate this, 31 boys with known 49,XXXXY were evaluated through a multidisciplinary clinic. Screening history was performed using the “10 Warning Signs of primary immunodeficiency” (Jeffrey Modell Foundation), as well as by history of ...

  6. The variations in maize grain composition induced by different environments

    OpenAIRE

    Dragičević Vesna D.; Mladenović-Drinić Snežana D.; Babić Vojka B.; Filipović Milomir R.; Čamdžija Zoran F.; Kovačević Dragan R.

    2014-01-01

    Nine maize hybrids were grown with the aim to determine variations in chemical composition of the grain. Analyzed hybrids were grown in split-plot experimental design with tree replications in Sremska Mitrovica and Zemun Polje, during the summer of 2010 and 2011. Grain yield, protein, starch, oil, as well as, antioxidants like phytate, soluble phenolics and free sulfhydryl groups (PSH) were analyzed. Unfavorable meteorological conditions affected not only g...

  7. 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.  

  8. 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.

  9. Stress factors in affective diseases.

    Science.gov (United States)

    Bidzińska, E J

    1984-02-01

    An investigation carried out on 97 patients with affective disorders and on 100 healthy control subjects, revealed that acute and chronic stress factors occurred more in the group of patients with affective disorders than among healthy control over a similar time period. The frequency of stressful life situations was the same before the first affective episode in patients with unipolar and bipolar illness. The possible participation of such factors in triggering the first phase of illness is discussed. Similar factors appeared in both types of affective disorders. Significantly more frequent among patients than in the control group were: marital and family conflicts, health problems, emotional and ambitional failures, lack of success and work overload.

  10. 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.

  11. Exposing variation to aid climate change risk assessment

    Science.gov (United States)

    Smith, M. J.; Purves, D. W.; Joppa, L. N.; Emmott, S.; Lyutsarev, V.; Bishop, C. M.; Palmer, P. I.; Calderhead, B.; Vanderwel, M. C.

    2015-12-01

    Considerable efforts to quantify different sources of variation in climate change projections (some might say uncertainty) have led to a welcome set of additional information on which to base confidence about what and how different futures might unfold and how different types of mediating efforts might affect the future. Quantifying the impacts of these different sources of variation on key climate change projection metrics should be used in part to guide future model development efforts. I will report on several of my team's recent research projects to better quantify and assess the importance of different sources of variation. I will show how we use inference techniques to estimate parameter uncertainty in land and marine carbon components of earth system models by comparing them with observational evidence and show how we propagate such uncertainty to better assess how such systems might respond to climate change and quantify the impact of reducing uncertainty for different applications. I will also show how we use such techniques on simulation models themselves to identify key sources of variation in their predictions: helping to pinpoint important focal areas for model improvement. Lastly, I will show a new software prototype being designed to enable any user to view climate model projections alongside historical and recent observational evidence while, importantly, also exposing some of the variation / uncertainty in the reported information.

  12. 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...

  13. 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.

  14. Clinical Interpretation of Genomic Variations.

    Science.gov (United States)

    Sayitoğlu, Müge

    2016-09-05

    Novel high-throughput sequencing technologies generate large-scale genomic data and are used extensively for disease mapping of monogenic and/or complex disorders, personalized treatment, and pharmacogenomics. Next-generation sequencing is rapidly becoming routine tool for diagnosis and molecular monitoring of patients to evaluate therapeutic efficiency. The next-generation sequencing platforms generate huge amounts of genetic variation data and it remains a challenge to interpret the variations that are identified. Such data interpretation needs close collaboration among bioinformaticians, clinicians, and geneticists. There are several problems that must be addressed, such as the generation of new algorithms for mapping and annotation, harmonization of the terminology, correct use of nomenclature, reference genomes for different populations, rare disease variant databases, and clinical reports.

  15. 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...

  16. Variational Principle for Planetary Interiors

    Science.gov (United States)

    Zeng, Li; Jacobsen, Stein B.

    2016-09-01

    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. The 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 the variational principle to the planetary interior can beautifully summarize the set of differential equations into one, which provides us some insight into the problem. From this principle, a universal mass-radius relation, an estimate of the error propagation from the equation of state to the mass-radius relation, and a form of the virial theorem applicable to planetary interiors are derived.

  17. Variational principles for dissipative waves

    Science.gov (United States)

    Dodin, I. Y.; Ruiz, D. E.

    2016-10-01

    Variational methods are a powerful tool in plasma theory. However, their applications are typically restricted to conservative systems or require doubling of variables, which often contradicts the purpose of the variational approach altogether. We show that these restrictions can be relaxed for some classes of dynamical systems that are of practical interest in plasma physics, particularly including dissipative plasma waves. Applications will be discussed to calculating dispersion relations and modulational dynamics of individual plasma waves and wave ensembles. The work was supported by the NNSA SSAA Program through DOE Research Grant No. DE-NA0002948, by the U.S. DOE through Contract No. DE-AC02-09CH11466, and by the U.S. DOD NDSEG Fellowship through Contract No. 32-CFR-168a.

  18. Edge adaptive directional total variation

    Directory of Open Access Journals (Sweden)

    Hua Zhang

    2013-11-01

    Full Text Available The directional total variation (DTV model has been proposed very recently for image denoising. However, the DTV model works well when there is just one dominant direction in the image. In this Letter, the authors propose to make the DTV model adaptive to image edge direction so that the proposed model can handle images with several dominant directions. Experiment and comparison show the effectiveness of the proposed method.

  19. LGBTI Variations in Crime Reporting

    OpenAIRE

    Miles-Johnson, Toby

    2013-01-01

    Research shows that people vary in their willingness to report crime to police depending on the type of crime experienced, their gender, age, and their race or ethnicity. Whether or not lesbian, gay, bisexual, transgender, and intersex (LGBTI) and heterosexual people vary in their willingness to report crime to the police is not well understood in the extant literature. In this article, I examine variations in LGBTI re...

  20. Variational integrators for reduced magnetohydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, Michael, E-mail: michael.kraus@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching (Germany); Technische Universität München, Zentrum Mathematik, Boltzmannstraße 3, 85748 Garching (Germany); Tassi, Emanuele, E-mail: tassi@cpt.univ-mrs.fr [Aix-Marseille Université, Université de Toulon, CNRS, CPT, UMR 7332, 163 avenue de Luminy, case 907, 13288 cedex 9 Marseille (France); Grasso, Daniela, E-mail: daniela.grasso@infm.polito.it [ISC-CNR and Politecnico di Torino, Dipartimento Energia, C.so Duca degli Abruzzi 24, 10129 Torino (Italy)

    2016-09-15

    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 is described both at the continuous and discrete level. We verify the favourable properties of the variational integrator in particular with respect to the preservation of the invariants of the models under consideration and compare with results from the literature and those of a pseudo-spectral code.

  1. Variational integrators for reduced magnetohydrodynamics

    Science.gov (United States)

    Kraus, Michael; Tassi, Emanuele; Grasso, Daniela

    2016-09-01

    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 is described both at the continuous and discrete level. We verify the favourable properties of the variational integrator in particular with respect to the preservation of the invariants of the models under consideration and compare with results from the literature and those of a pseudo-spectral code.

  2. 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.

  3. Genetic variation in healthy oldest-old.

    Directory of Open Access Journals (Sweden)

    Julius Halaschek-Wiener

    Full Text Available Individuals who live to 85 and beyond without developing major age-related diseases may achieve this, in part, by lacking disease susceptibility factors, or by possessing resistance factors that enhance their ability to avoid disease and prolong lifespan. Healthy aging is a complex phenotype likely to be affected by both genetic and environmental factors. We sequenced 24 candidate healthy aging genes in DNA samples from 47 healthy individuals aged eighty-five years or older (the 'oldest-old', to characterize genetic variation that is present in this exceptional group. These healthy seniors were never diagnosed with cancer, cardiovascular disease, pulmonary disease, diabetes, or Alzheimer disease. We re-sequenced all exons, intron-exon boundaries and selected conserved non-coding sequences of candidate genes involved in aging-related processes, including dietary restriction (PPARG, PPARGC1A, SIRT1, SIRT3, UCP2, UCP3, metabolism (IGF1R, APOB, SCD, autophagy (BECN1, FRAP1, stem cell activation (NOTCH1, DLL1, tumor suppression (TP53, CDKN2A, ING1, DNA methylation (TRDMT1, DNMT3A, DNMT3B Progeria syndromes (LMNA, ZMPSTE24, KL and stress response (CRYAB, HSPB2. We detected 935 variants, including 848 single nucleotide polymorphisms (SNPs and 87 insertion or deletions; 41% (385 were not recorded in dbSNP. This study is the first to present a comprehensive analysis of genetic variation in aging-related candidate genes in healthy oldest-old. These variants and especially our novel polymorphisms are valuable resources to test for genetic association in models of disease susceptibility or resistance. In addition, we propose an innovative tagSNP selection strategy that combines variants identified through gene re-sequencing- and HapMap-derived SNPs.

  4. Genetic variation in healthy oldest-old.

    Science.gov (United States)

    Halaschek-Wiener, Julius; Amirabbasi-Beik, Mahsa; Monfared, Nasim; Pieczyk, Markus; Sailer, Christian; Kollar, Anita; Thomas, Ruth; Agalaridis, Georgios; Yamada, So; Oliveira, Lisa; Collins, Jennifer A; Meneilly, Graydon; Marra, Marco A; Madden, Kenneth M; Le, Nhu D; Connors, Joseph M; Brooks-Wilson, Angela R

    2009-08-14

    Individuals who live to 85 and beyond without developing major age-related diseases may achieve this, in part, by lacking disease susceptibility factors, or by possessing resistance factors that enhance their ability to avoid disease and prolong lifespan. Healthy aging is a complex phenotype likely to be affected by both genetic and environmental factors. We sequenced 24 candidate healthy aging genes in DNA samples from 47 healthy individuals aged eighty-five years or older (the 'oldest-old'), to characterize genetic variation that is present in this exceptional group. These healthy seniors were never diagnosed with cancer, cardiovascular disease, pulmonary disease, diabetes, or Alzheimer disease. We re-sequenced all exons, intron-exon boundaries and selected conserved non-coding sequences of candidate genes involved in aging-related processes, including dietary restriction (PPARG, PPARGC1A, SIRT1, SIRT3, UCP2, UCP3), metabolism (IGF1R, APOB, SCD), autophagy (BECN1, FRAP1), stem cell activation (NOTCH1, DLL1), tumor suppression (TP53, CDKN2A, ING1), DNA methylation (TRDMT1, DNMT3A, DNMT3B) Progeria syndromes (LMNA, ZMPSTE24, KL) and stress response (CRYAB, HSPB2). We detected 935 variants, including 848 single nucleotide polymorphisms (SNPs) and 87 insertion or deletions; 41% (385) were not recorded in dbSNP. This study is the first to present a comprehensive analysis of genetic variation in aging-related candidate genes in healthy oldest-old. These variants and especially our novel polymorphisms are valuable resources to test for genetic association in models of disease susceptibility or resistance. In addition, we propose an innovative tagSNP selection strategy that combines variants identified through gene re-sequencing- and HapMap-derived SNPs.

  5. [Affective disorders and eating disorders].

    Science.gov (United States)

    Fakra, Eric; Belzeaux, R; Azorin, J M; Adida, M

    2014-12-01

    Epidemiologic studies show a frequent co-occurence of affective and eating disorders. The incidence of one disorder in patients suffering from the other disorder is well over the incidence in the general population. Several causes could explain this increased comorbidity. First, the iatrogenic origin is detailed. Indeed, psychotropic drugs, and particularly mood stabilizers, often lead to modification in eating behaviors, generally inducing weight gain. These drugs can increase desire for food, reduce baseline metabolism or decrease motor activity. Also, affective and eating disorders share several characteristics in semiology. These similarities can not only obscure the differential diagnosis but may also attest of conjoint pathophysiological bases in the two conditions. However, genetic and biological findings so far are too sparse to corroborate this last hypothesis. Nonetheless, it is noteworthy that comorbidity of affective and eating disorders worsens patients'prognosis and is associated with more severe forms of affective disorders characterized by an earlier age of onset in the disease, higher number of mood episodes and a higher suicidality. Lastly, psychotropic drugs used in affective disorders (lithium, antiepileptic mood stabilizers, atypical antipsychotics, antidepressants) are reviewed in order to weigh their efficacy in eating disorders. This could help establish the best therapeutic option when confronted to comorbidity.

  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. 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.

  8. 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.

  9. Affect, Emotion and Similar Concepts

    Directory of Open Access Journals (Sweden)

    J.L. Pio Abreu

    2013-12-01

    Full Text Available The author begins by commenting on the difficulty of the semantic delimitation between concepts of affect, emotion, sentiment, feeling, mood, and passion. This difficulty becomes greater when the terms are translated into different languages. He then foccuses on the concept of emotion, which has benefited from recent research, and its distinction from mood, a concept which is at the base of the psychopathology of bipolar disorders. Much more complex is the Portuguese concept of affect (different from the English concept, which has an interpersonal dimension and can be developed from recent discoveries of “mirror neurons” and “theory of mind”.

  10. Trends affecting hospitals' human resources.

    Science.gov (United States)

    Neudeck, M M

    1985-01-01

    Hospital workers at every level--from administrators to housekeepers--will be affected by the interaction of changes already underway in the healthcare industry. Societal forces that will affect the hospital workforce include demographic change, the rise of the participatory ethic and decentralization, a growing philosophy of job entitlement, and new pressures for unionization. At the same time, the industry is faced with changing manpower requirements, cost containment, and the oversupply of physicians. This article identifies some of the likely effects of these changes on hospital human resources and suggests ways that administrators can prepare for them.

  11. 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

  12. 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

  13. Multiple weather factors affect apparent survival of European passerine birds.

    Science.gov (United States)

    Salewski, Volker; Hochachka, Wesley M; Fiedler, Wolfgang

    2013-01-01

    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 the potential for

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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...

  19. Variational collocation on finite intervals

    Energy Technology Data Exchange (ETDEWEB)

    Amore, Paolo [Facultad de Ciencias, Universidad de Colima, Bernal DIaz del Castillo 340, Colima, Colima (Mexico); Cervantes, Mayra [Facultad de Ciencias, Universidad de Colima, Bernal DIaz del Castillo 340, Colima, Colima (Mexico); Fernandez, Francisco M [INIFTA (Conicet, UNLP), Diag. 113 y 64 S/N, Sucursal 4, Casilla de Correo 16, 1900 La Plata (Argentina)

    2007-10-26

    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 Schroedinger equation, and we have compared the performance of the present approach with others.

  20. Early growth trajectories affect sexual responsiveness.

    Science.gov (United States)

    Lee, Who-Seung; Metcalfe, Neil B; Réale, Denis; Peres-Neto, Pedro R

    2014-02-22

    The trajectory of an animal's growth in early development has been shown to have long-term effects on a range of life-history traits. Although it is known that individual differences in behaviour may also be related to certain life-history traits, the linkage between early growth or development and individual variation in behaviour has received little attention. We used brief temperature manipulations, independent of food availability, to stimulate compensatory growth in juvenile three-spined sticklebacks Gasterosteus aculeatus. Here, we examine how these manipulated growth trajectories affected the sexual responsiveness of the male fish at the time of sexual maturation, explore associations between reproductive behaviour and investment and lifespan and test whether the perceived time stress (until the onset of the breeding season) influenced such trade-offs. We found a negative impact of growth rate on sexual responsiveness: fish induced (by temperature manipulation) to grow slowest prior to the breeding season were consistently quickest to respond to the presence of a gravid female. This speed of sexual responsiveness was also positively correlated with the rate of development of sexual ornaments and time taken to build a nest. However, after controlling for effects of growth rate, those males that had the greatest sexual responsiveness to females had the shortest lifespan. Moreover, the time available to compensate in size before the onset of the breeding season (time stress) affected the magnitude of these effects. Our results demonstrate that developmental perturbations in early life can influence mating behaviour, with long-term effects on longevity.

  1. Affecting Critical Thinking through Speech.

    Science.gov (United States)

    O'Keefe, Virginia P.

    Intended for teachers, this booklet shows how spoken language can affect student thinking and presents strategies for teaching critical thinking skills. The first section discusses the theoretical and research bases for promoting critical thinking through speech, defines critical thinking, explores critical thinking as abstract thinking, and tells…

  2. Urban Interaction and Affective Experience

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Brynskov, Martin

    2008-01-01

    in favor of three points in that direction: First we argue that interaction – and the definition of interaction – is central to unfold the potential of digital urban media, from big, shared screens and media facades to small pri-vate, networked mobile and embedded platforms. Then we argue that an affective...

  3. Intuition, affect, and peculiar beliefs

    NARCIS (Netherlands)

    Boden, M.T.; Berenbaum, H.; Topper, M.

    2012-01-01

    Research with college students has found that intuitive thinking (e.g., using hunches to ascribe meaning to experiences) and positive affect interactively predict ideas of reference and odd/magical beliefs. We investigated whether these results would generalize to a diverse community sample of adult

  4. Test Expectancy Affects Metacomprehension Accuracy

    Science.gov (United States)

    Thiede, Keith W.; Wiley, Jennifer; Griffin, Thomas D.

    2011-01-01

    Background: Theory suggests that the accuracy of metacognitive monitoring is affected by the cues used to judge learning. Researchers have improved monitoring accuracy by directing attention to more appropriate cues; however, this is the first study to more directly point students to more appropriate cues using instructions regarding tests and…

  5. Do recruitment ties affect wages?

    DEFF Research Database (Denmark)

    Larsen, Anna Folke; Rand, John; Torm, Nina Elisabeth

    This paper examines the extent to which recruitment ties affect individual wage outcomes in small and medium scale manufacturing firms. Based on a unique matched employer-employee dataset from Vietnam we find that there is a significant positive wage premium associated with obtaining a job through...

  6. Clinical Judgment and Affective Disorders.

    Science.gov (United States)

    Strohmer, Douglas C.; And Others

    1984-01-01

    Addressed the limitations of previous work on counselor clinical judgment in a study involving 20 counselors who were asked to make a series of judgments. Results suggested the judgment processes of experienced counselors making diagnoses of affective disorders differs depending on the type of judgment. (JAC)

  7. How indoor environment affects performance

    DEFF Research Database (Denmark)

    Wyon, David Peter; Wargocki, Pawel

    2013-01-01

    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...

  8. Aesthetics, Affect, and Educational Politics

    Science.gov (United States)

    Means, Alex

    2011-01-01

    This essay explores aesthetics, affect, and educational politics through the thought of Gilles Deleuze and Jacques Ranciere. It contextualizes and contrasts the theoretical valences of their ethical and democratic projects through their shared critique of Kant. It then puts Ranciere's notion of dissensus to work by exploring it in relation to a…

  9. Reclaiming hope: Affect, temporality, politics

    NARCIS (Netherlands)

    Taş, B.

    2016-01-01

    The critical task I take up in this research is to reconceptualize hope as an affective orientation in time, which requires remaining open to the risks that the unknowability of the future entails. I consider this opening a political contestation that is necessary to critique the current instrumenta

  10. A warm touch of affect?

    NARCIS (Netherlands)

    Willemse, Christian J.A.M.

    2015-01-01

    One of the research areas within affective Computer Mediated Communication currently under investigation is that of mediated social touch. A social touch is a complex composition of different physical parameters that can be simulated by haptic technologies. In this article we argue why we think it m

  11. Unconscious Affective Responses to Food

    Science.gov (United States)

    Sato, Wataru; Sawada, Reiko; Kubota, Yasutaka; Toichi, Motomi; Fushiki, Tohru

    2016-01-01

    Affective or hedonic responses to food are crucial for humans, both advantageously (e.g., enhancing survival) and disadvantageously (e.g., promoting overeating and lifestyle-related disease). Although previous psychological studies have reported evidence of unconscious cognitive and behavioral processing related to food, it remains unknown whether affective reactions to food can be triggered unconsciously and its relationship with daily eating behaviors. We investigated these issues by using the subliminal affective priming paradigm. Photographs of food or corresponding mosaic images were presented in the peripheral visual field for 33 ms. Target photos of faces with emotionally neutral expressions were then presented, and participants rated their preferences for the faces. Eating behaviors were also assessed using questionnaires. The food images, relative to the mosaics, increased participants’ preference for subsequent target faces. Furthermore, the difference in the preference induced by food versus mosaic images was positively correlated with the tendency to engage in external eating. These results suggest that unconscious affective reactions are elicited by the sight of food and that these responses contribute to daily eating behaviors related to overeating. PMID:27501443

  12. Variation of the Fundamental Constants:. Theory and Observations

    Science.gov (United States)

    Flambaum, V. V.

    2007-10-01

    Review of recent works devoted to the variation of the fine structure constant α, strong interaction and fundamental masses (Higgs vacuum) is presented. The results from Big Bang nucleosynthesis, quasar absorption spectra, and Oklo natural nuclear reactor data give us the space-time variation on the Universe lifetime scale. Comparison of different atomic clocks gives us the present time variation. Assuming linear variation with time we can compare different results. The best limit on the variation of the electron-to-proton mass ratio μ = me/Mp and Xe = me/ΛQCD follows from the quasar absorption spectra:1 ˙ {μ }/μ = ˙ {X}e/X_e = (1 ± 3) × 10-16 yr-1. A combination of this result and the atomic clock results2,3 gives the best limt on variation of α : ˙ {α }/α = (-0.8 ± 0.8) × 10-16 yr-1. The Oklo natural reactor gives the best limit on the variation of Xs = ms/ΛQCD where ms is the strange quark mass:4,5 ∣ ˙ {X}s/X_s∣ < 10-18 yr-1. Note that the Oklo data can not give us any limit on the variation of a since the effect of α there is much smaller than the effect of Xs and should be neglected. Huge enhancement of the relative variation effects happens in transitions between close atomic, molecular and nuclear energy levels. We suggest several new cases where the levels are very narrow. Large enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feshbach resonance. How changing physical constants and violation of local position invariance may occur? Light scalar fields very naturally appear in modern cosmological models, affecting parameters of the Standard Model (e.g. α). Cosmological variations of these scalar fields should occur because of drastic changes of matter composition in Universe: the latest such event is rather recent (about 5 billion years ago), from matter to dark energy domination. Massive bodies (stars or galaxies) can also affect physical constants. They have large scalar charge S

  13. 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.

  14. The impact of gene expression variation on the robustness and evolvability of a developmental gene regulatory network.

    Directory of Open Access Journals (Sweden)

    David A Garfield

    2013-10-01

    Full Text Available Regulatory interactions buffer development against genetic and environmental perturbations, but adaptation requires phenotypes to change. We investigated the relationship between robustness and evolvability within the gene regulatory network underlying development of the larval skeleton in the sea urchin Strongylocentrotus purpuratus. We find extensive variation in gene expression in this network throughout development in a natural population, some of which has a heritable genetic basis. Switch-like regulatory interactions predominate during early development, buffer expression variation, and may promote the accumulation of cryptic genetic variation affecting early stages. Regulatory interactions during later development are typically more sensitive (linear, allowing variation in expression to affect downstream target genes. Variation in skeletal morphology is associated primarily with expression variation of a few, primarily structural, genes at terminal positions within the network. These results indicate that the position and properties of gene interactions within a network can have important evolutionary consequences independent of their immediate regulatory role.

  15. Biological variation of cystatin C

    DEFF Research Database (Denmark)

    Reinhard, Mark; Erlandsen, Erland; Randers, Else

    2009-01-01

    Introduction: Cystatin C has been investigated as a marker of the glomerular filtration rate. However, previous studies have reported conflicting results concerning the biological variation of cystatin C. The aim of the present study was to evaluate the biological variation of cystatin C...... available for analysis. Serum cystatin C was measured using Dade Behring N Latex Cystatin C assay and serum creatinine by an enzymatic method (Roche). Results: The mean serum concentration of cystatin C was 0.70 mg/l (range 0.44-1.09) and the mean serum creatinine was 77 µmol/l (range 54......-100). The analytical variance (CVA) was 2.0% for cystatin C and 1.6% for creatinine. The intra-individual variance (CVI) was greater for cystatin C than for creatinine (8.6% vs. 4.7%). The inter-individual variance (CVG) was similar for both analytes (cystatin C 15.1% vs. creatinine 14.4%). Accordingly, the index...

  16. 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.

  17. 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

  18. Importance of Local Structural Variations on Recrystallization

    DEFF Research Database (Denmark)

    Juul Jensen, Dorte; Lin, Fengxiang; Zhang, Yubin

    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...... on the formation of protrusions on migrating boundaries. 2. Effects of an inhomogeneous spatial distribution of second phase particles on growth. 3. Effects of stored energy and orientation variations on recrystallization kinetics. © (2013) Trans Tech Publications, Switzerland....

  19. The Two Ignored Components of Random Variation

    OpenAIRE

    Shore, Haim

    2015-01-01

    A random phenomenon may have two sources of random variation: an unstable identity and a set of external variation-generating factors. When only a single source is active, two mutually exclusive extreme scenarios may ensue that result in the exponential or the normal, the only truly univariate distributions. All other supposedly univariate random variation observed in nature is truly bivariate. In this article, we elaborate on this new paradigm for random variation and develop a general bivar...

  20. 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.

  1. Dietary carbohydrate deprivation increases 24-hour nitrogen excretion without affecting postabsorptive hepatic or whole body protein metabolism in healthy men

    NARCIS (Netherlands)

    Bisschop, PH; de Sain-van der Velden, MGM; Stellaard, F; Kuipers, F; Meijer, AJ; Sauerwein, HP; Romijn, JA

    2003-01-01

    Because insulin is an important regulator of protein metabolism, we hypothesized that physiological modulation of insulin secretion, by means of extreme variations in dietary carbohydrate content, affects postabsorptive protein metabolism. Therefore, we studied the effects of three isocaloric diets

  2. Nutrition affects insect susceptibility to Bt toxins

    Science.gov (United States)

    Deans, Carrie A.; Behmer, Spencer T.; Tessnow, Ashley E.; Tamez-Guerra, Patricia; Pusztai-Carey, Marianne; Sword, Gregory A.

    2017-01-01

    Pesticide resistance represents a major challenge to global food production. The spread of resistance alleles is the primary explanation for observations of reduced pesticide efficacy over time, but the potential for gene-by-environment interactions (plasticity) to mediate susceptibility has largely been overlooked. Here we show that nutrition is an environmental factor that affects susceptibility to Bt toxins. Protein and carbohydrates are two key macronutrients for insect herbivores, and the polyphagous pest Helicoverpa zea self-selects and performs best on diets that are protein-biased relative to carbohydrates. Despite this, most Bt bioassays employ carbohydrate-biased rearing diets. This study explored the effect of diet protein-carbohydrate content on H. zea susceptibility to Cry1Ac, a common Bt endotoxin. We detected a 100-fold increase in LC50 for larvae on optimal versus carbohydrate-biased diets, and significant diet-mediated variation in survival and performance when challenged with Cry1Ac. Our results suggest that Bt resistance bioassays that use ecologically- and physiologically-mismatched diets over-estimate susceptibility and under-estimate resistance. PMID:28045087

  3. Nutrition affects insect susceptibility to Bt toxins

    Science.gov (United States)

    Deans, Carrie A.; Behmer, Spencer T.; Tessnow, Ashley E.; Tamez-Guerra, Patricia; Pusztai-Carey, Marianne; Sword, Gregory A.

    2017-01-01

    Pesticide resistance represents a major challenge to global food production. The spread of resistance alleles is the primary explanation for observations of reduced pesticide efficacy over time, but the potential for gene-by-environment interactions (plasticity) to mediate susceptibility has largely been overlooked. Here we show that nutrition is an environmental factor that affects susceptibility to Bt toxins. Protein and carbohydrates are two key macronutrients for insect herbivores, and the polyphagous pest Helicoverpa zea self-selects and performs best on diets that are protein-biased relative to carbohydrates. Despite this, most Bt bioassays employ carbohydrate-biased rearing diets. This study explored the effect of diet protein-carbohydrate content on H. zea susceptibility to Cry1Ac, a common Bt endotoxin. We detected a 100-fold increase in LC50 for larvae on optimal versus carbohydrate-biased diets, and significant diet-mediated variation in survival and performance when challenged with Cry1Ac. Our results suggest that Bt resistance bioassays that use ecologically- and physiologically-mismatched diets over-estimate susceptibility and under-estimate resistance.

  4. 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.

  5. Genetic sorting of subordinate species in grassland modulated by intraspecific variation in dominant species.

    Directory of Open Access Journals (Sweden)

    Danny J Gustafson

    Full Text Available Genetic variation in a single species can have predictable and heritable effects on associated communities and ecosystem processes, however little is known about how genetic variation of a dominant species affects plant community assembly. We characterized the genetic structure of a dominant grass (Sorghastrum nutans and two subordinate species (Chamaecrista fasciculata, Silphium integrifolium, during the third growing season in grassland communities established with genetically distinct (cultivated varieties or local ecotypes seed sources of the dominant grasses. There were genetic differences between subordinate species growing in the cultivar versus local ecotype communities, indicating that intraspecific genetic variation in the dominant grasses affected the genetic composition of subordinate species during community assembly. A positive association between genetic diversity of S. nutans, C. fasciculata, and S. integrifolium and species diversity established the role of an intraspecific biotic filter during community assembly. Our results show that intraspecific variation in dominant species can significantly modulate the genetic composition of subordinate species.

  6. Female mate preference explains countergradient variation in the sexual coloration of guppies (Poecilia reticulata).

    Science.gov (United States)

    Deere, Kerry A; Grether, Gregory F; Sun, Aida; Sinsheimer, Janet S

    2012-05-07

    We tested the hypothesis that mate choice is responsible for countergradient variation in the sexual coloration of Trinidadian guppies (Poecilia reticulata). The nature of the countergradient pattern is that geographical variation in the carotenoid content of the orange spots of males is counterbalanced by genetic variation in drosopterin production, resulting in a relatively uniform pigment ratio. A female hue preference could produce this pattern, because hue is the axis of colour variation most directly affected by the pigment ratio. To test this hypothesis, we crossed two populations differing in drosopterin production and produced an F(2) generation with variable drosopterin levels. When the carotenoid content of the orange spots was held constant, female guppies preferred males with intermediate drosopterin levels. This shows that females do not simply prefer males with greater orange spot pigment content; instead, the ratio of the pigments also affects male attractiveness. To our knowledge, this is the first direct evidence for a hypothesized agent of countergradient sexual selection.

  7. Crop responses to climatic variation

    DEFF Research Database (Denmark)

    Porter, John R.; Semenov, Mikhail A.

    2005-01-01

    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...... of adaptation possibilities for crops in response to drought and argues that characters that enable better exploration of the soil and slower leaf canopy expansion could lead to crop higher transpiration efficiency....

  8. The nature of quantitative genetic variation for Drosophila longevity.

    Science.gov (United States)

    Mackay, Trudy F C

    2002-01-01

    Longevity is a typical quantitative trait: the continuous variation in life span observed in natural populations is attributable to genetic variation at multiple quantitative trait loci (QTL), environmental sensitivity of QTL alleles, and truly continuous environmental variation. To begin to understand the genetic architecture of longevity at the level of individual QTL, we have mapped QTL for Drosophila life span that segregate between two inbred strains that were not selected for longevity. A mapping population of 98 recombinant inbred lines (RIL) was derived from these strains, and life span of virgin male and female flies measured under control culture conditions, chronic heat and cold stress, heat shock and starvation stress, and high and low density larval environments. The genotypes of the RIL were determined for polymorphic roo transposable element insertion sites, and life span QTL were mapped using composite interval mapping methods. A minimum of 19 life span QTL were detected by recombination mapping. The life span QTL exhibited strong genotype by sex, genotype by environment, and genotype by genotype (epistatic) interactions. These interactions complicate mapping efforts, but evolutionary theory predicts such properties of segregating QTL alleles. Quantitative deficiency mapping of four longevity QTL detected in the control environment by recombination mapping revealed a minimum of 11 QTL in these regions. Clearly, longevity is a complex quantitative trait. In the future, linkage disequilibrium mapping can be used to determine which candidate genes in a QTL region correspond to the genetic loci affecting variation in life span, and define the QTL alleles at the molecular level.

  9. 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.

  10. 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.

  11. 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.

  12. Salience-Affected Neural Networks

    CERN Document Server

    Remmelzwaal, Leendert A; Ellis, George F R

    2010-01-01

    We present a simple neural network model which combines a locally-connected feedforward structure, as is traditionally used to model inter-neuron connectivity, with a layer of undifferentiated connections which model the diffuse projections from the human limbic system to the cortex. This new layer makes it possible to model global effects such as salience, at the same time as the local network processes task-specific or local information. This simple combination network displays interactions between salience and regular processing which correspond to known effects in the developing brain, such as enhanced learning as a result of heightened affect. The cortex biases neuronal responses to affect both learning and memory, through the use of diffuse projections from the limbic system to the cortex. Standard ANNs do not model this non-local flow of information represented by the ascending systems, which are a significant feature of the structure of the brain, and although they do allow associational learning with...

  13. Variation in protein intake induces variation in spider silk expression.

    Directory of Open Access Journals (Sweden)

    Sean J Blamires

    Full Text Available BACKGROUND: It is energetically expensive to synthesize certain amino acids. The proteins (spidroins of spider major ampullate (MA silk, MaSp1 and MaSp2, differ in amino acid composition. Glutamine and proline are prevalent in MaSp2 and are expensive to synthesize. Since most orb web spiders express high proline silk they might preferentially attain the amino acids needed for silk from food and shift toward expressing more MaSp1 in their MA silk when starved. METHODOLOGY/PRINCIPAL FINDINGS: We fed three spiders; Argiope aetherea, Cyrtophora moluccensis and Leucauge blanda, high protein, low protein or no protein solutions. A. aetherea and L. blanda MA silks are high in proline, while C. moluccesnsis MA silks are low in proline. After 10 days of feeding we determined the amino acid compositions and mechanical properties of each species' MA silk and compared them between species and treatments with pre-treatment samples, accounting for ancestry. We found that the proline and glutamine of A. aetherea and L. blanda silks were affected by protein intake; significantly decreasing under the low and no protein intake treatments. Glutmaine composition in C. moluccensis silk was likewise affected by protein intake. However, the composition of proline in their MA silk was not significantly affected by protein intake. CONCLUSIONS: Our results suggest that protein limitation induces a shift toward different silk proteins with lower glutamine and/or proline content. Contradictions to the MaSp model lie in the findings that C. moluccensis MA silks did not experience a significant reduction in proline and A. aetherea did not experience a significant reduction in serine on low/no protein. The mechanical properties of the silks could not be explained by a MaSp1 expressional shift. Factors other than MaSp expression, such as the expression of spidroin-like orthologues, may impact on silk amino acid composition and spinning and glandular processes may impact

  14. 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.

  15. Rodent empathy and affective neuroscience.

    Science.gov (United States)

    Panksepp, Jules B; Lahvis, Garet P

    2011-10-01

    In the past few years, several experimental studies have suggested that empathy occurs in the social lives of rodents. Thus, rodent behavioral models can now be developed to elucidate the mechanistic substrates of empathy at levels that have heretofore been unavailable. For example, the finding that mice from certain inbred strains express behavioral and physiological responses to conspecific distress, while others do not, underscores that the genetic underpinnings of empathy are specifiable and that they could be harnessed to develop new therapies for human psychosocial impairments. However, the advent of rodent models of empathy is met at the outset with a number of theoretical and semantic problems that are similar to those previously confronted by studies of empathy in humans. The distinct underlying components of empathy must be differentiated from one another and from lay usage of the term. The primary goal of this paper is to review a set of seminal studies that are directly relevant to developing a concept of empathy in rodents. We first consider some of the psychological phenomena that have been associated with empathy, and within this context, we consider the component processes, or endophenotypes of rodent empathy. We then review a series of recent experimental studies that demonstrate the capability of rodents to detect and respond to the affective state of their social partners. We focus primarily on experiments that examine how rodents share affective experiences of fear, but we also highlight how similar types of experimental paradigms can be utilized to evaluate the possibility that rodents share positive affective experiences. Taken together, these studies were inspired by Jaak Panksepp's theory that all mammals are capable of felt affective experiences.

  16. The Affections of My Life

    Institute of Scientific and Technical Information of China (English)

    Zhang; Yan; Shi; Xiao; jing

    2013-01-01

    <正>When I look back over the 90 years of my life, through all the tumultuous events, highs and lows, joys and sorrows, I see that one bright, shining emotion has always warmed my heart: affection. The pillar supporting me throughout has been family love: the care of my parents, the love of my wife and children, and the close feelings between myself and my

  17. Emotional processing affects movement speed.

    Science.gov (United States)

    Hälbig, Thomas D; Borod, Joan C; Frisina, Pasquale G; Tse, Winona; Voustianiouk, Andrei; Olanow, C Warren; Gracies, Jean-Michel

    2011-09-01

    Emotions can affect various aspects of human behavior. The impact of emotions on behavior is traditionally thought to occur at central, cognitive and motor preparation stages. Using EMG to measure the effects of emotion on movement, we found that emotional stimuli differing in valence and arousal elicited highly specific effects on peripheral movement time. This result has conceptual implications for the emotion-motion link and potentially practical implications for neurorehabilitation and professional environments where fast motor reactions are critical.

  18. Affective robot for elderly assistance.

    Science.gov (United States)

    Carelli, Laura; Gaggioli, Andrea; Pioggia, Giovanni; De Rossi, Federico; Riva, Giuseppe

    2009-01-01

    Recently, several robotic solutions for the elderly have been proposed. However, to date, the diffusion of these devices has been limited: available robots are too cumbersome, awkward, and expensive to become widely adopted. Another key issue which reduces the appeal of assistive robots is the lack of socio-emotional interaction: affective interchanges represent key requirements to create sustainable relationships between elderly and robots. In this paper, we propose a new approach to enhance the acceptability of robotic systems, based on the introduction of affective dimensions in human-robot interaction. This strategy is aimed at designing a new generation of relational and cognitive robots fusing information from embodied unobtrusive sensory interfaces. The final objective is to develop embodied interfaces, which are able to learn and adapt their affective responses to the user's behavior. User and robot will engage in natural interactions, involving verbal and non-verbal communication, improving empathic exchange of moods and feelings. Relevant independent living and quality of life related issues will be addressed: on-going monitoring of health parameters, assistance in everyday's activities, social support and cognitive/physical exercises. We expect that the proposed strategy will enhance the user's acceptance and adoption of the assistive robotic system.

  19. 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.

  20. Hermite variational implicit surface reconstruction

    Institute of Scientific and Technical Information of China (English)

    PAN RongJiang; MENG XiangXu; WHANGBO TaegKeun

    2009-01-01

    We propose a new technique for reconstructing surfaces from a large set of unorganized 3D data points and their associated normal vectors. The surface is represented as the zero level set of an implicit vol-ume model which fits the data points and normal constraints. Compared with variational implicit sur-faces, we make use of surface normal vectors at data points directly in the implicit model and avoid of introducing manufactured off-surface points. Given n surface point/normal pairs, the proposed method only needs to solve an n×n positive definite linear system. It allows fitting large datasets effectively and robustly. We demonstrate the performance of the proposed method with both globally supported and compactly supported radial basis functions on several datasets.

  1. 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...

  2. Circadian Variation Of Stroke Onset

    Directory of Open Access Journals (Sweden)

    Kamath vasantha

    2003-01-01

    Full Text Available Diurnal variations in various physiological and biochemical functions and certain pathological events like myocardial infarction and stroke have been documented. We studied prospectively one hundred and seven patients of acute onset stroke confirmed by computed tomography for the exact time of onset, risk factors and type of stroke. Patients who were unclear of time of onset and with a diagnosis of cerebral venous thrombosis or sub-arachnoid hemorrhage were excluded. Infarction was detected in 71 patients and hemorrhage in 33 patients. Men out numbered women (1:6:1. Hypertension was more frequent in hemorrhage in the morning time (5 AM-12 noon and more infarction between 12-6 pm. However there was no relation between the time of onset of stroke and various risk-factors of stroke.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Variational principles in instanton problems

    Energy Technology Data Exchange (ETDEWEB)

    D' yakonov, D.I.; Petrov, V.Yu. (AN SSSR, Leningrad. Inst. Yadernoj Fiziki)

    1984-01-01

    The authors suggest a simple approximate method of evaluating path integrals for problems in which subbarrier transitions (instantons) play an important role. This method, based on Feyman's variational principle, is a generalization of the semi-classical approximation. When there is a quasiclassical parameter in a problem, the method is reduced to approximate calculations of Gauss' functional integrals (i.e. functional determinants). The authors derive general formulas for such integrals, which prove to be valid for a broad class of potentials, and verify the accuracy of the approximation using the examples of double-well and periodic potentials. In both cases the accuracy in determining the level splitting proves to be within several percent.

  8. Secular obliquity variations for Ceres

    Science.gov (United States)

    Bills, Bruce; Scott, Bryan R.; Nimmo, Francis

    2016-10-01

    We have constructed secular variation models for the orbit and spin poles of the asteroid (1) Ceres, and used them to examine how the obliquity, or angular separation between spin and orbit poles, varies over a time span of several million years. The current obliquity is 4.3 degrees, which means that there are some regions near the poles which do not receive any direct Sunlight. The Dawn mission has provided an improved estimate of the spin pole orientation, and of the low degree gravity field. That allows us to estimate the rate at which the spin pole precesses about the instantaneous orbit pole.The orbit of Ceres is secularly perturbed by the planets, with Jupiter's influence dominating. The current inclination of the orbit plane, relative to the ecliptic, is 10.6 degrees. However, it varies between 7.27 and 11.78 degrees, with dominant periods of 22.1 and 39.6 kyr. The spin pole precession rate parameter has a period of 205 kyr, with current uncertainty of 3%, dominated by uncertainty in the mean moment of inertia of Ceres.The obliquity varies, with a dominant period of 24.5 kyr, with maximum values near 26 degrees, and minimum values somewhat less than the present value. Ceres is currently near to a minimum of its secular obliquity variations.The near-surface thermal environment thus has at least 3 important time scales: diurnal (9.07 hours), annual (4.60 years), and obliquity cycle (24.5 kyr). The annual thermal wave likely only penetrates a few meters, but the much long thermal wave associated with the obliquity cycle has a skin depth larger by a factor of 70 or so, depending upon thermal properties in the subsurface.

  9. Variational methods for field theories

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Menahem, S.

    1986-09-01

    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.

  10. 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.

  11. 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.

  12. Genetic architecture of natural variation in cuticular hydrocarbon composition in Drosophila melanogaster.

    Science.gov (United States)

    Dembeck, Lauren M; Böröczky, Katalin; Huang, Wen; Schal, Coby; Anholt, Robert R H; Mackay, Trudy F C

    2015-11-14

    Insect cuticular hydrocarbons (CHCs) prevent desiccation and serve as chemical signals that mediate social interactions. Drosophila melanogaster CHCs have been studied extensively, but the genetic basis for individual variation in CHC composition is largely unknown. We quantified variation in CHC profiles in the D. melanogaster Genetic Reference Panel (DGRP) and identified novel CHCs. We used principal component (PC) analysis to extract PCs that explain the majority of CHC variation and identified polymorphisms in or near 305 and 173 genes in females and males, respectively, associated with variation in these PCs. In addition, 17 DGRP lines contain the functional Desat2 allele characteristic of African and Caribbean D. melanogaster females (more 5,9-C27:2 and less 7,11-C27:2, female sex pheromone isomers). Disruption of expression of 24 candidate genes affected CHC composition in at least one sex. These genes are associated with fatty acid metabolism and represent mechanistic targets for individual variation in CHC composition.

  13. An investigation of the potential causes for the seasonal and annual variations in indoor radon concentrations.

    Science.gov (United States)

    Barazza, F; Gfeller, W; Palacios, M; Murith, C

    2015-11-01

    Indoor radon concentrations exhibit strong variations on short and long timescales. Besides human influences, meteorological factors significantly affect the radon concentrations indoors as well as outdoors. In this article, long-term measurements showing strong annual variations are presented, which take a very similar course in different buildings located in largely separated regions in Switzerland. Also, seasonal variations can be very significant. In general, variations in indoor radon levels can primarily be attributed to human influences. On the other hand, specific weather conditions can have a significant impact on indoor radon levels. In order to further investigate the connection between indoor radon levels and meteorological factors, a measuring campaign has been started in two buildings located in two different regions in Switzerland exhibiting different climatic characteristics. Preliminary results of these investigations are presented, which provide evidence for correlations between indoor radon levels and in particular outdoor temperatures, contributing to seasonal and annual as well as short-term variations in indoor radon concentrations.

  14. 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.

  15. Geographic variation in acoustic communication in anurans and its neuroethological implications.

    Science.gov (United States)

    Velásquez, Nelson A

    2014-01-01

    Geographic variation of traits may represent the first step for evolutionary divergence potentially leading to speciation. Signals are behavioral traits of particular interest for the study of variation at a geographic scale. The anuran acoustic communication system represents an excellent model for studies of this kind, because their vocalizations play a main role in reproduction and the extant variation in this system may determine the evolution of this group. This review is committed to studies on geographic variation of acoustic communication systems in anurans, focusing on temporal and spectral characteristics of signals, environmental constraints affecting them and sound producing and receiving organs. In addition to the review of the literature on these topics, I highlight the deficit of investigation in some areas and propose alternative directions to overcome these drawbacks. Further, I propose the four-eyed frog, Pleurodema thaul, as an excellent model system to study geographic variation using a wide spectrum of approaches.

  16. The genetics of ray pattern variation in Caenorhabditis briggsae

    Directory of Open Access Journals (Sweden)

    Davidson Cynthia R

    2005-01-01

    Full Text Available Abstract Background How does intraspecific variation relate to macroevolutionary change in morphology? This question can be addressed in species in which derived characters are present but not fixed. In rhabditid nematodes, the arrangement of the nine bilateral pairs of peripheral sense organs (rays in tails of males is often the most highly divergent character between species. The development of ray pattern involves inputs from hometic gene expression patterns, TGFβ signalling, Wnt signalling, and other genetic pathways. In Caenorhabditis briggsae, strain-specific variation in ray pattern has provided an entrée into the evolution of ray pattern. Some strains were fixed for a derived pattern. Other strains were more plastic and exhibited derived and ancestral patterns at equal frequencies. Results Recombinant inbred lines (RILs constructed from crosses between the variant C. briggsae AF16 and HK104 strains exhibited a wide range of phenotypes including some that were more extreme than either parental strain. Transgressive segregation was significantly associated with allelic variation in the C. briggsae homolog of abdominal B, Cb-egl-5. At least two genes that affected different elements of ray pattern, ray position and ray fusion, were linked to a second gene, mip-1. Consistent with this, the segregation of ray position and ray fusion phenotypes were only partially correlated in the RILs. Conclusions The evolution of ray pattern has involved allelic variation at multiple loci. Some of these loci impact the specification of ray identities and simultaneously affect multiple ray pattern elements. Others impact individual characters and are not constrained by covariance with other ray pattern elements. Among the genetic pathways that may be involved in ray pattern evolution is specification of anteroposterior positional information by homeotic genes.

  17. Trends and Scales of Observed Soil Moisture Variations in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new soil moisture dataset from direct gravimetric measurements within the top 50-cm soil layers at 178 soil moisture stations in China covering the period 1981 1998 are used to study the long-term and seasonal trends of soil moisture variations, as well as estimate the temporal and spatial scales of soil moisture for different soil layers. Additional datasets of precipitation and temperature difference between land surface and air (TDSA) are analyzed to gain further insight into the changes of soil moisture. There are increasing trends for the top 10 cm, but decreasing trends for the top 50 cm of soil layers in most regions. Trends in precipitation appear to dominantly influence trends in soil moisture in both cases. Seasonal variation of soil moisture is mainly controlled by precipitation and evaporation, and in some regions can be affected by snow cover in winter. Timescales of soil moisture variation are roughly 1-3 months and increase with soil depth.Further influences of TDSA and precipitation on soil moisture in surface layers, rather than in deeper layers,cause this phenomenon. Seasonal variations of temporal scales for soil moisture are region-dependent and consistent in both layer depths. Spatial scales of soil moisture range from 200-600 km, with topography also having an affect on these. Spatial scales of soil moisture in plains are larger than in mountainous areas. In the former, the spatial scale of soil moisture follows the spatial patterns of precipitation and evaporation,whereas in the latter, the spatial scale is controlled by topography.

  18. 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

  19. Variants affecting exon skipping contribute to complex traits.

    Directory of Open Access Journals (Sweden)

    Younghee Lee

    Full Text Available DNA variants that affect alternative splicing and the relative quantities of different gene transcripts have been shown to be risk alleles for some Mendelian diseases. However, for complex traits characterized by a low odds ratio for any single contributing variant, very few studies have investigated the contribution of splicing variants. The overarching goal of this study is to discover and characterize the role that variants affecting alternative splicing may play in the genetic etiology of complex traits, which include a significant number of the common human diseases. Specifically, we hypothesize that single nucleotide polymorphisms (SNPs in splicing regulatory elements can be characterized in silico to identify variants affecting splicing, and that these variants may contribute to the etiology of complex diseases as well as the inter-individual variability in the ratios of alternative transcripts. We leverage high-throughput expression profiling to 1 experimentally validate our in silico predictions of skipped exons and 2 characterize the molecular role of intronic genetic variations in alternative splicing events in the context of complex human traits and diseases. We propose that intronic SNPs play a role as genetic regulators within splicing regulatory elements and show that their associated exon skipping events can affect protein domains and structure. We find that SNPs we would predict to affect exon skipping are enriched among the set of SNPs reported to be associated with complex human traits.

  20. Psychological Factors Affecting Infertile Women

    Directory of Open Access Journals (Sweden)

    Sati Unal

    2010-10-01

    Full Text Available AIM: This study was performed to determine the psychological factors affecting infertile women presenting at the infertility outpatients department. METHOD: The sample of this cross-sectional study consisted of 344 women who presented at the IVF center of a special branch hospital or a university hospital, March 2008 through September 2008, as determined by the non-random sampling method. All participating women gave their informed consent. The data were collected using the Data Form that consisted of questions on socio-demographic features and the Infertility Distress Scale (IDS. In the results, percentages were provided along with the Kruskal-Wallis H, Mann-Whitney U and Spearman correlation tests. RESULTS: The mean IDS was 39.01±9.6. There was a statistically significant linear relationship between the mean IDS score and age (r=0.106, p=0.048, marriage duration (r=0.232, p<0.001 and duration of desire to have a child (r=0.217, p<0.001. Women who were primary school graduates (X²=13.03, p=0.004, did not work (p=0.007, had no social security benefits (p=0.021 or from low socioeconomic status (X²=24.85, p<0.001 had significantly higher mean IDS scores. CONCLUSION: The results of this study show women become more adversely affected by infertility as their age, duration of marriage, and duration of desire to have a child increase. Women who are primary school graduates, do not work, have no social security benefits or have lower income are affected more negatively. We believe that taking these features into account when evaluating and planning supportive approaches for women presenting at the infertility treatment center and determining the psychological state of the women using the IDS will increase treatment success. [TAF Prev Med Bull 2010; 9(5.000: 481-486

  1. 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.

  2. 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.

  3. Climatic Versus Biotic Constraints on Carbon and Water Fluxes in Seasonally Drought-affected Ponderosa Pine Ecosystems. Chapter 2

    Science.gov (United States)

    Schwarz, P. A.; Law, B. E.; Williams, M.; Irvine, J.; Kurpius, M.; Moore, D.

    2005-01-01

    We investigated the relative importance of climatic versus biotic controls on gross primary production (GPP) and water vapor fluxes in seasonally drought-affected ponderosa pine forests. The study was conducted in young (YS), mature (MS), and old stands (OS) over 4 years at the AmeriFlux Metolius sites. Model simulations showed that interannual variation of GPP did not follow the same trends as precipitation, and effects of climatic variation were smallest at the OS (50%), and intermediate at the YS (<20%). In the young, developing stand, interannual variation in leaf area has larger effects on fluxes than climate, although leaf area is a function of climate in that climate can interact with age-related shifts in carbon allocation and affect whole-tree hydraulic conductance. Older forests, with well-established root systems, appear to be better buffered from effects of seasonal drought and interannual climatic variation. Interannual variation of net ecosystem exchange (NEE) was also lowest at the OS, where NEE is controlled more by interannual variation of ecosystem respiration, 70% of which is from soil, than by the variation of GPP, whereas variation in GPP is the primary reason for interannual changes in NEE at the YS and MS. Across spatially heterogeneous landscapes with high frequency of younger stands resulting from natural and anthropogenic disturbances, interannual climatic variation and change in leaf area are likely to result in large interannual variation in GPP and NEE.

  4. Genomic analysis reveals major determinants of cis-regulatory variation in Capsella grandiflora.

    Science.gov (United States)

    Steige, Kim A; Laenen, Benjamin; Reimegård, Johan; Scofield, Douglas G; Slotte, Tanja

    2017-01-31

    Understanding the causes of cis-regulatory variation is a long-standing aim in evolutionary biology. Although cis-regulatory variation has long been considered important for adaptation, we still have a limited understanding of the selective importance and genomic determinants of standing cis-regulatory variation. To address these questions, we studied the prevalence, genomic determinants, and selective forces shaping cis-regulatory variation in the outcrossing plant Capsella grandiflora We first identified a set of 1,010 genes with common cis-regulatory variation using analyses of allele-specific expression (ASE). Population genomic analyses of whole-genome sequences from 32 individuals showed that genes with common cis-regulatory variation (i) are under weaker purifying selection and (ii) undergo less frequent positive selection than other genes. We further identified genomic determinants of cis-regulatory variation. Gene body methylation (gbM) was a major factor constraining cis-regulatory variation, whereas presence of nearby transposable elements (TEs) and tissue specificity of expression increased the odds of ASE. Our results suggest that most common cis-regulatory variation in C. grandiflora is under weak purifying selection, and that gene-specific functional constraints are more important for the maintenance of cis-regulatory variation than genome-scale variation in the intensity of selection. Our results agree with previous findings that suggest TE silencing affects nearby gene expression, and provide evidence for a link between gbM and cis-regulatory constraint, possibly reflecting greater dosage sensitivity of body-methylated genes. Given the extensive conservation of gbM in flowering plants, this suggests that gbM could be an important predictor of cis-regulatory variation in a wide range of plant species.

  5. Dimension variation prediction and control for composites

    Science.gov (United States)

    Dong, Chensong

    This dissertation presents a systematic study on the dimension variation prediction and control for polymer matrix fiber reinforced composites. A dimension variation model was developed for process simulation based on thermal stress analysis and finite element analysis (FEA). This model was validated against the experimental data, the analytical solutions and the data from literature. Using the FEA-based dimension variation model, the deformations of typical composite structures were studied and the regression-based dimension variation model was developed. The regression-based dimension variation model can significantly reduce computation time and provide a quick design guide for composite products with reduced dimension variations. By introducing the material modification coefficient, this comprehensive model can handle various fiber/resin types and stacking sequences. It eliminates the complicated, time-consuming finite element meshing and material parameter defining process. The deformation compensation through tooling design was investigated using the FEA-based and the regression-based dimension variation models. The structural tree method (STM) was developed to compute the assembly deformation from the deformations of individual components, as well as the deformation of general shape composite components. The STM enables rapid dimension variation analysis/synthesis for complex composite assemblies with the regression-based dimension variation model. Using the STM and the regression-based dimension variation model, design optimization and tolerance analysis/synthesis were conducted. The exploring work presented in this research provides a foundation to develop practical and proactive dimension control techniques for composite products.

  6. 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.

  7. Genetisk variation i alkoholdehydrogenase, alkoholdrikkevaner og alkoholisme--sekundaerpublikation

    DEFF Research Database (Denmark)

    Tolstrup, J.S.; Nordestgaard, B.G.; Rasmussen, S.;

    2008-01-01

    Alcohol is degraded primarily by alcohol dehydrogenase (ADH), and genetic variation that affects the rate of alcohol degradation is found in ADH1B and ADH1C. By genotyping 9,080 white men and women from the general population, we found that men and women with ADH1B slow versus fast alcohol...... degradation drank approximately 30% more alcohol per week and had a higher risk of everyday and heavy drinking, and of alcoholism. Individuals with ADH1C slow versus fast alcohol degradation had a higher risk of heavy drinking Udgivelsesdato: 2008/8/25...

  8. Genetisk variation i alkoholdehydrogenase, alkoholdrikkevaner og alkoholisme-sekundaerpublikation

    DEFF Research Database (Denmark)

    Tolstrup, Janne S; Nordestgaard, Børge G; Rasmussen, Søren;

    2008-01-01

    Alcohol is degraded primarily by alcohol dehydrogenase (ADH), and genetic variation that affects the rate of alcohol degradation is found in ADH1B and ADH1C. By genotyping 9,080 white men and women from the general population, we found that men and women with ADH1B slow versus fast alcohol...... degradation drank approximately 30% more alcohol per week and had a higher risk of everyday and heavy drinking, and of alcoholism. Individuals with ADH1C slow versus fast alcohol degradation had a higher risk of heavy drinking. Udgivelsesdato: 2008-Aug-25...

  9. Environmental and biomedical applications of natural metal stable isotope variations

    Science.gov (United States)

    Bullen, T.D.; Walczyk, T.

    2009-01-01

    etal stable isotopes are now being used to trace metal contaminants in the environment and as indicators of human systemic function where metals play a role. Stable isotope abundance variations provide information about metal sources and the processes affecting metals in complex natural systems, complementing information gained from surrogate tracers, such as metal abundance ratios or biochemical markers of metal metabolism. The science is still in its infancy, but the results of initial studies confirm that metal stable isotopes can provide a powerful tool for forensic and biomedical investigations.

  10. Affect and technology acceptance: A test of two mechanisms

    DEFF Research Database (Denmark)

    Scholderer, Joachim; Grunert, Klaus G.; Søndergaard, Helle Alsted

    to strong changes in consumer attitudes (effect size d = .40). Furthermore, preferences for genetically modified products were found to be mainly dependent on the quality of the product participants had tried. Both effects were robust under contextual variations. Results are discussed in terms of theory...... GM organisms or their derivatives. In the absence of product experience, consumers tend to evaluate this technology by means of affective mechanisms, setting it in relation to other, even more abstract and general socio-political attitudes. Previous research has shown that these attitudes...

  11. Affective resonance in response to others' emotional faces varies with affective ratings and psychopathic traits in amygdala and anterior insula.

    Science.gov (United States)

    Seara-Cardoso, Ana; Sebastian, Catherine L; Viding, Essi; Roiser, Jonathan P

    2016-01-01

    Despite extensive research on the neural basis of empathic responses for pain and disgust, there is limited data about the brain regions that underpin affective response to other people's emotional facial expressions. Here, we addressed this question using event-related functional magnetic resonance imaging to assess neural responses to emotional faces, combined with online ratings of subjective state. When instructed to rate their own affective response to others' faces, participants recruited anterior insula, dorsal anterior cingulate, inferior frontal gyrus, and amygdala, regions consistently implicated in studies investigating empathy for disgust and pain, as well as emotional saliency. Importantly, responses in anterior insula and amygdala were modulated by trial-by-trial variations in subjective affective responses to the emotional facial stimuli. Furthermore, overall task-elicited activations in these regions were negatively associated with psychopathic personality traits, which are characterized by low affective empathy. Our findings suggest that anterior insula and amygdala play important roles in the generation of affective internal states in response to others' emotional cues and that attenuated function in these regions may underlie reduced empathy in individuals with high levels of psychopathic traits.

  12. 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

  13. Identification of common genetic variation that modulates alternative splicing.

    Directory of Open Access Journals (Sweden)

    Jeremy Hull

    2007-06-01

    Full Text Available Alternative splicing of genes is an efficient means of generating variation in protein function. Several disease states have been associated with rare genetic variants that affect splicing patterns. Conversely, splicing efficiency of some genes is known to vary between individuals without apparent ill effects. What is not clear is whether commonly observed phenotypic variation in splicing patterns, and hence potential variation in protein function, is to a significant extent determined by naturally occurring DNA sequence variation and in particular by single nucleotide polymorphisms (SNPs. In this study, we surveyed the splicing patterns of 250 exons in 22 individuals who had been previously genotyped by the International HapMap Project. We identified 70 simple cassette exon alternative splicing events in our experimental system; for six of these, we detected consistent differences in splicing pattern between individuals, with a highly significant association between splice phenotype and neighbouring SNPs. Remarkably, for five out of six of these events, the strongest correlation was found with the SNP closest to the intron-exon boundary, although the distance between these SNPs and the intron-exon boundary ranged from 2 bp to greater than 1,000 bp. Two of these SNPs were further investigated using a minigene splicing system, and in each case the SNPs were found to exert cis-acting effects on exon splicing efficiency in vitro. The functional consequences of these SNPs could not be predicted using bioinformatic algorithms. Our findings suggest that phenotypic variation in splicing patterns is determined by the presence of SNPs within flanking introns or exons. Effects on splicing may represent an important mechanism by which SNPs influence gene function.

  14. LGBTI Variations in Crime Reporting

    Directory of Open Access Journals (Sweden)

    Toby Miles-Johnson

    2013-05-01

    Full Text Available Research shows that people vary in their willingness to report crime to police depending on the type of crime experienced, their gender, age, and their race or ethnicity. Whether or not lesbian, gay, bisexual, transgender, and intersex (LGBTI and heterosexual people vary in their willingness to report crime to the police is not well understood in the extant literature. In this article, I examine variations in LGBTI respondents’ attitudes, subjective norms, and perceived behavioral control on their intentions to report crimes to the police. Drawing on a survey of LGBTI individuals sampled from a Gay Pride community event and online LGBTI community forums (N = 329, I use quantitative statistical methods to examine whether LGBTI people’s beliefs in police homophobia are also directly associated with the behavioral intention to report crime. Overall, the results indicate that LGBTI and heterosexual people differ significantly in their intention to report crime to the police, and that a belief in police homophobia strongly influences LGBTI people’s intention to underreport crime to the police.

  15. ON THE SINGULAR VARIATIONAL PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    谭经刚; 杨健夫

    2004-01-01

    The authors deal with the singular variational problem S(a,b,λ0):=infu∈E,u(≡/)0 ∫RN(||X|-a(△)u|m+∫|x|-(a+1)m|u|m)dx/(∫RN||X|-bU|P dx)m/p as well as (S)=(S)(a,b,λ1,λ2):=u,ν,E∈,u(u,ν)(≡/)(1,1) ∫RN J(u,ν)dx/(∫RN|x|-bp|u|α|ν|βdx)m/p, whereJ(u, v) = ||x|- au|m + λ1|x|- (a+1)m|u|m + ||x|- av|m + λ2|x|- (a+1)m|v|m,N ≥ m+ 1 > 2, 0 ≤ a < N-m/m, a ≤ b < a+ 1 and p = p(a,b) = α+β =Nm/N-m+m(b-a), α, β≥ 1, E = D1,mα(RN). The aim of this paper is to show the existence of minimizer for S(a, b, A0) and S(a, b, λ1, λ2).

  16. Variations in weight stigma concerns

    Directory of Open Access Journals (Sweden)

    Jessica E. Cornick

    2016-12-01

    Full Text Available Over the past 40 years, obesity rates in the United States have grown significantly; these rates have not grown uniformly across the United States (18 of the 20 counties with the highest obesity rates are located in the South. Obesity increases cardiovascular disease risk factors and new research has highlighted the negative psychological effects of obesity, known as weight stigma, including decreased selfcontrol resources, over eating, and exercise avoidance. The primary objective of this study was to determine if weight stigma concerns varied regionally and if social behaviors influenced this variation. In two studies, we collected cross-sectional data from participants in the United States including height and weight, weight stigma concerns, and perception of friends’ preoccupation with weight and dieting. We also collected each participant’s home zip code which was used to locate local obesity rate. We established differences in the relationship between body mass index and weight stigma concerns by local county obesity rate and showed that perceived friend preoccupation with weight and dieting mediated this relationship for individuals in low and medium obesity rate counties. For individuals living in United States counties with lower levels of obesity, increases in personal body mass index leads to increased weight stigma concerns due to an increase in perceived friend preoccupation with weight and dieting. These results indicate that relationships between body mass index, weight stigma concerns, and social networks vary significantly for subpopulations throughout the United States.

  17. PLURILINGUAL COMPETENCE, STYLES AND VARIATION

    Directory of Open Access Journals (Sweden)

    Jyrki Kalliokoski

    2011-01-01

    Full Text Available The paper explores plurilingual competence in respect to language proficiency, language education and pluri- and multilingualism. The notion of communicative competence was introduced by Hymes (1972 as a reaction to chomskyan view of language as an autonomous system. Hymes’ notion of communicative competence originally included plurilingualism. The concept of communicative competence was quickly adopted to applied linguistics but the idea of a linguistic repertoire consisting of the competencies of linguistic varieties was not imported to SLA or language testing. The Hymesian perspective to plurilingualism as an essential dimension of communicative competence was revived in the Common European Framework (CEFR. However,the practice of applying the CEFR has mostly neglected the dimension on plurilingualism and plurilingual competence. The focus in the use of the CEFR has been on the different areas of language skills within one single language at a time, while the application of plurilingual practices has gained very little attention. The Hymesian notion of communicative competence has lived on in the sociolinguistic research tradition, especially within interactional sociolinguistics. The present paper relates the notion of plurilingual competence to its hymesian origin, to recent trends in plurilingual and pluricultural education, and to the sociolinguistic study of style and linguistic variation in multilingual communities. The article uses Finnish L2 data to show how plurilingual competence is used as an interactional resource.From the perspective of language learning, plurilingual competence enables speakers with different linguistic backgrounds to use their shared linguistic repertoire in order to ensure smooth interaction and achieve mutual understanding.

  18. Genetic background of phenotypic variation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A noteworthy feature of the living world is its bewildering variability. A key issue in several biological disciplines is the achievement of an understanding of the hereditary basis of this variability. Two opposing, but not necessarily irreconcilable conceptions attempt to explain the underlying mechanism. The gene function paradigm postulates that phenotypic variance is generated by the polymorphism in the coding sequences of genes. However, comparisons of a great number of homologous gene and protein sequences have revealed that they predominantly remained functionally conserved even across distantly related phylogenic taxa. Alternatively, the gene regulation paradigm assumes that differences in the cis-regulatory region of genes do account for phenotype variation within species. An extension of this latter concept is that phenotypic variability is generated by the polyrnorphism in the overall gene expression profiles of gene networks.In other words, the activity of a particular gene is a system property determined both by the cis-regulatory sequences of the given genes and by the other genes of a gene network, whose expressions vary among individuals, too. Novel proponents of gene function paradigm claim that functional genetic variance within the coding sequences of regulatory genes is critical for the generation of morphological polymorphism. Note, however, that these developmental genes play direct regulatory roles in the control of gene expression.

  19. Genome size variation in Begonia.

    Science.gov (United States)

    Dewitte, Angelo; Leus, Leen; Eeckhaut, Tom; Vanstechelman, Ives; Van Huylenbroeck, Johan; Van Bockstaele, Erik

    2009-10-01

    The genome sizes of a Begonia collection comprising 37 species and 23 hybrids of African, Asiatic, Middle American, and South American origin were screened using flow cytometry. Within the collection, 1C values varied between 0.23 and 1.46 pg DNA. Genome sizes were, in most cases, not positively correlated with chromosome number, but with pollen size. A 12-fold difference in mean chromosome size was found between the genotypes with the largest and smallest chromosomes. In general, chromosomes from South American genotypes were smaller than chromosomes of African, Asian, or Middle American genotypes, except for B. boliviensis and B. pearcei. Cytological chromosome studies in different genotypes showed variable chromosome numbers, length, width, and total chromosome volume, which confirmed the diversity in genome size. Large secondary constrictions were present in several investigated genotypes. These data show that chromosome number and structure exhibit a great deal of variation within the genus Begonia, and likely help to explain the large number of taxa found within the genus.

  20. On Quadratic Variation of Martingales

    Indian Academy of Sciences (India)

    Rajeeva L Karandikar; B V Rao

    2014-08-01

    We give a construction of an explicit mapping $$\\Psi: D([0,∞),\\mathbb{R})→ D([0,∞),\\mathbb{R}),$$ where $D([0,∞), \\mathbb{R})$ denotes the class of real valued r.c.l.l. functions on $[0,∞)$ such that for a locally square integrable martingale $(M_t)$ with r.c.l.l. paths, $$\\Psi(M.())=A.()$$ gives the quadratic variation process (written usually as $[M,M]_t$) of $(M_t)$. We also show that this process $(A_t)$ is the unique increasing process $(B_t)$ such that $M_t^2-B_t$ is a local martingale, $B_0=0$ and $$\\mathbb{P}(( B)_t=[( M)_t]^2, 0 < ∞)=1.$$ Apart from elementary properties of martingales, the only result used is the Doob’s maximal inequality. This result can be the starting point of the development of the stochastic integral with respect to r.c.l.l. martingales.

  1. Temporal Variations in Jupiter's Atmosphere

    Science.gov (United States)

    Simon-Miller, Amy A.; Chanover, N. J.; Yanamandra-Fisher, P.; Hammel, H. B.; dePater, I.; Noll, K.; Wong, M.; Clarke, J.; Sanchez-Levega, A.; Orton, G. S.; Gonzaga, S.

    2009-01-01

    In recent years, Jupiter has undergone many atmospheric changes from storms turning red to global. cloud upheavals, and most recently, a cornet or asteroid impact. Yet, on top of these seemingly random changes events there are also periodic phenomena, analogous to observed Earth and Saturn atmospheric oscillations. We will present 15 years of Hubble data, from 1994 to 2009, to show how the equatorial tropospheric cloud deck and winds have varied over that time, focusing on the F953N, F41 ON and F255W filters. These filters give leverage on wind speeds plus cloud opacity, cloud height and tropospheric haze thickness, and stratospheric haze, respectively. The wind data consistently show a periodic oscillation near 7-8 S latitude. We will discuss the potential for variations with longitude and cloud height, within the calibration limits of those filters. Finally, we will discuss the role that large atmospheric events, such as the impacts in 1994 and 2009, and the global upheaval of 2007, have on temporal studies, This work was supported by a grant from the NASA Planetary Atmospheres Program. HST observational support was provided by NASA through grants from Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under contract NAS5-26555.

  2. Variational data assimilation with superparameterization

    Directory of Open Access Journals (Sweden)

    I. Grooms

    2015-03-01

    Full Text Available Superparameterization (SP is a multiscale computational approach wherein a large scale atmosphere or ocean model is coupled to an array of simulations of small scale dynamics on periodic domains embedded into the computational grid of the large scale model. SP has been successfully developed in global atmosphere and climate models, and is a promising approach for new applications. The authors develop a 3D-Var variational data assimilation framework for use with SP; the relatively low cost and simplicity of 3D-Var in comparison with ensemble approaches makes it a natural fit for relatively expensive multiscale SP models. To demonstrate the assimilation framework in a simple model, the authors develop a new system of ordinary differential equations similar to the two-scale Lorenz-'96 model. The system has one set of variables denoted {Yi}, with large and small scale parts, and the SP approximation to the system is straightforward. With the new assimilation framework the SP model approximates the large scale dynamics of the true system accurately.

  3. Dose variation during solar minimum

    Energy Technology Data Exchange (ETDEWEB)

    Gussenhoven, M.S.; Mullen, E.G.; Brautigam, D.H. (Phillips Lab., Geophysics Directorate, Hanscom Air Force Base, MA (US)); Holeman, E. (Boston Univ., MA (United States). Dept. of Physics)

    1991-12-01

    In this paper, the authors use direct measurement of dose to show the variation in inner and outer radiation belt populations at low altitude from 1984 to 1987. This period includes the recent solar minimum that occurred in September 1986. The dose is measured behind four thicknesses of aluminum shielding and for two thresholds of energy deposition, designated HILET and LOLET. The authors calculate an average dose per day for each month of satellite operation. The authors find that the average proton (HILET) dose per day (obtained primarily in the inner belt) increased systematically from 1984 to 1987, and has a high anticorrelation with sunspot number when offset by 13 months. The average LOLET dose per day behind the thinnest shielding is produced almost entirely by outer zone electrons and varies greatly over the period of interest. If any trend can be discerned over the 4 year period it is a decreasing one. For shielding of 1.55 gm/cm{sup 2} (227 mil) Al or more, the LOLET dose is complicated by contributions from {gt} 100 MeV protons and bremsstrahlung.

  4. Modeling of microscale variations in methane fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Kettunen, A.

    2002-07-01

    The current study analyzes the different modes of variation in methane fluxes from different microsites of a boreal mire. The results emphasize the importance of microsite characteristics, water table and vegetation cover for methane fluxes. Water level affects the moisture and oxygen profiles in peat matrix which are reflected to methane production and oxidation rates and the corresponding microbial populations. Vascular plants promote methane production by providing substrates in the form of root exudates and fine root litter, enhance methane oxidation by transporting oxygen to water saturated peat layers and accelerate methane transport by liberating methane from peat to the atmosphere via the aerenchymous tissue. The model presented in this study connects the methane fluxes to the seasonal photosynthetic cycle of plants at the microsite level while the thermal and hydrological conditions in peat are used as an operational framework. Overall, the model dynamically combines the microbial processes in peat to changing environmental factors in the level of peatland ecosystem. Sensitivity analysis of the model reveals the importance of substrate supply to methane fluxes. Furthermore, the model outcome is sensitive to increased capability of the vascular plants to transport oxygen downwards. Lack of oxygen and partly methane keep methane oxidation at a very low level. Any changes in model parameters or environmental conditions that compensate for these lacks have a remarkable decreasing effect on simulated flux. Simulated methane flux decreases considerably if the duration of simulated dry period increases, threshold for a dramatic change lying between 4 and 6 weeks of drought. Increase in air temperature enhances methane flux especially if the effect of increased temperature on gross primary production is taken into account. (orig.)

  5. Copy number variation in the horse genome.

    Science.gov (United States)

    Ghosh, Sharmila; Qu, Zhipeng; Das, Pranab J; Fang, Erica; Juras, Rytis; Cothran, E Gus; McDonell, Sue; Kenney, Daniel G; Lear, Teri L; Adelson, David L; Chowdhary, Bhanu P; Raudsepp, Terje

    2014-10-01

    We constructed a 400K WG tiling oligoarray for the horse and applied it for the discovery of copy number variations (CNVs) in 38 normal horses of 16 diverse breeds, and the Przewalski horse. Probes on the array represented 18,763 autosomal and X-linked genes, and intergenic, sub-telomeric and chrY sequences. We identified 258 CNV regions (CNVRs) across all autosomes, chrX and chrUn, but not in chrY. CNVs comprised 1.3% of the horse genome with chr12 being most enriched. American Miniature horses had the highest and American Quarter Horses the lowest number of CNVs in relation to Thoroughbred reference. The Przewalski horse was similar to native ponies and draft breeds. The majority of CNVRs involved genes, while 20% were located in intergenic regions. Similar to previous studies in horses and other mammals, molecular functions of CNV-associated genes were predominantly in sensory perception, immunity and reproduction. The findings were integrated with previous studies to generate a composite genome-wide dataset of 1476 CNVRs. Of these, 301 CNVRs were shared between studies, while 1174 were novel and require further validation. Integrated data revealed that to date, 41 out of over 400 breeds of the domestic horse have been analyzed for CNVs, of which 11 new breeds were added in this study. Finally, the composite CNV dataset was applied in a pilot study for the discovery of CNVs in 6 horses with XY disorders of sexual development. A homozygous deletion involving AKR1C gene cluster in chr29 in two affected horses was considered possibly causative because of the known role of AKR1C genes in testicular androgen synthesis and sexual development. While the findings improve and integrate the knowledge of CNVs in horses, they also show that for effective discovery of variants of biomedical importance, more breeds and individuals need to be analyzed using comparable methodological approaches.

  6. Sex reduces genetic variation: a multidisciplinary review.

    Science.gov (United States)

    Gorelick, Root; Heng, Henry H Q

    2011-04-01

    For over a century, the paradigm has been that sex invariably increases genetic variation, despite many renowned biologists asserting that sex decreases most genetic variation. Sex is usually perceived as the source of additive genetic variance that drives eukaryotic evolution vis-à-vis adaptation and Fisher's fundamental theorem. However, evidence for sex decreasing genetic variation appears in ecology, paleontology, population genetics, and cancer biology. The common thread among many of these disciplines is that sex acts like a coarse filter, weeding out major changes, such as chromosomal rearrangements (that are almost always deleterious), but letting minor variation, such as changes at the nucleotide or gene level (that are often neutral), flow through the sexual sieve. Sex acts as a constraint on genomic and epigenetic variation, thereby limiting adaptive evolution. The diverse reasons for sex reducing genetic variation (especially at the genome level) and slowing down evolution may provide a sufficient benefit to offset the famed costs of sex.

  7. Hidden Regular Variation: Detection and Estimation

    CERN Document Server

    Mitra, Abhimanyu

    2010-01-01

    Hidden regular variation defines a subfamily of distributions satisfying multivariate regular variation on $\\mathbb{E} = [0, \\infty]^d \\backslash \\{(0,0, ..., 0) \\} $ and models another regular variation on the sub-cone $\\mathbb{E}^{(2)} = \\mathbb{E} \\backslash \\cup_{i=1}^d \\mathbb{L}_i$, where $\\mathbb{L}_i$ is the $i$-th axis. We extend the concept of hidden regular variation to sub-cones of $\\mathbb{E}^{(2)}$ as well. We suggest a procedure of detecting the presence of hidden regular variation, and if it exists, propose a method of estimating the limit measure exploiting its semi-parametric structure. We exhibit examples where hidden regular variation yields better estimates of probabilities of risk sets.

  8. Synchronous Lagrangian variational principles in General Relativity

    CERN Document Server

    Cremaschini, Claudio

    2016-01-01

    The problem of formulating synchronous variational principles in the context of General Relativity is discussed. Based on the analogy with classical relativistic particle dynamics, the existence of variational principles is pointed out in relativistic classical field theory which are either asynchronous or synchronous. The historical Einstein-Hilbert and Palatini variational formulations are found to belong to the first category. Nevertheless, it is shown that an alternative route exists which permits one to cast these principles in terms of equivalent synchronous Lagrangian variational formulations. The advantage is twofold. First, synchronous approaches allow one to overcome the lack of gauge symmetry of the asynchronous principles. Second, the property of manifest covariance of the theory is also restored at all levels, including the symbolic Euler-Lagrange equations, with the variational Lagrangian density being now identified with a $4-$scalar. As an application, a joint synchronous variational principle...

  9. Procedural facade variations from a single layout

    KAUST Repository

    Bao, Fan

    2013-01-01

    We introduce a framework to generate many variations of a facade design that look similar to a given facade layout. Starting from an input image, the facade is hierarchically segmented and labeled with a collection of manual and automatic tools. The user can then model constraints that should be maintained in any variation of the input facade design. Subsequently, facade variations are generated for different facade sizes, where multiple variations can be produced for a certain size. Computing such new facade variations has many unique challenges, and we propose a new algorithm based on interleaving heuristic search and quadratic programming. In contrast to most previous work, we focus on the generation of new design variations and not on the automatic analysis of the input\\'s structure. Adding a modeling step with the user in the loop ensures that our results routinely are of high quality. © 2013 ACM.

  10. VARIATIONS IN REPRODUCTIVE TOXICANT IDENTIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, F

    2008-05-13

    Reproductive toxicants are a very important class of compounds. They present unique hazards to those of child bearing ages, perform their 'dirty work' using a wide variety of mechanisms on a number of different organs, and are regulatorily important. Because of all of this, properly identifying reproductive toxicants is important, but fraught with difficulty. In this paper we will describe types or reproductive toxicants, their importance, and both mistakes and good practices that people who are not experts in reproductive toxicology may use in their attempts to identify them. Additionally, this paper will focus on chemical reproductive toxicants and will not address biological agents that could affect reproductive toxicity although many principles outlined here could be applied to that endeavor.

  11. Models of Solar Irradiance Variations: Current Status

    Indian Academy of Sciences (India)

    Natalie A. Krivova; Sami K. Solanki

    2008-03-01

    Regular monitoring of solar irradiance has been carried out since 1978 to show that solar total and spectral irradiance varies at different time scales. Whereas variations on time scales of minutes to hours are due to solar oscillations and granulation, variations on longer time scales are driven by the evolution of the solar surface magnetic field. Here the most recent advances in modelling of solar irradiance variations on time scales longer than a day are briefly reviewed.

  12. Rheumatoid arthritis affecting temporomandibular joint.

    Science.gov (United States)

    Sodhi, Amandeep; Naik, Shobha; Pai, Anuradha; Anuradha, Ardra

    2015-01-01

    Rheumatoid arthritis (RA) is a chronic, systemic, autoimmune inflammatory disorder that is characterized by joint inflammation, erosive properties and symmetric multiple joint involvement. Temporomandibular joint (TMJ) is very rare to be affected in the early phase of the disease, thus posing diagnostic challenges for the dentist. Conventional radiographs fail to show the early lesions due to its limitations. More recently cone-beam computed tomography (CBCT) has been found to diagnose the early degenerative changes of TMJ and hence aid in the diagnosis of the lesions more accurately. Our case highlights the involvement of TMJ in RA and the role of advanced imaging (CBCT) in diagnosing the bony changes in the early phase of the disease.

  13. Bipolar Affective Disorder and Migraine

    Directory of Open Access Journals (Sweden)

    Birk Engmann

    2012-01-01

    Full Text Available This paper consists of a case history and an overview of the relationship, aetiology, and treatment of comorbid bipolar disorder migraine patients. A MEDLINE literature search was used. Terms for the search were bipolar disorder bipolar depression, mania, migraine, mood stabilizer. Bipolar disorder and migraine cooccur at a relatively high rate. Bipolar II patients seem to have a higher risk of comorbid migraine than bipolar I patients have. The literature on the common roots of migraine and bipolar disorder, including both genetic and neuropathological approaches, is broadly discussed. Moreover, bipolar disorder and migraine are often combined with a variety of other affective disorders, and, furthermore, behavioural factors also play a role in the origin and course of the diseases. Approach to treatment options is also difficult. Several papers point out possible remedies, for example, valproate, topiramate, which acts on both diseases, but no first-choice treatments have been agreed upon yet.

  14. 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...... particular political events or issues by means of media. To investigate how, when and why that happens, and to evaluate the long-term social impacts of mediating bodily vulnerability, the book offers a theoretical framework for understanding the role of bodily vulnerability in contemporary digital media...... 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....

  15. Rheumatoid arthritis affecting temporomandibular joint

    Directory of Open Access Journals (Sweden)

    Amandeep Sodhi

    2015-01-01

    Full Text Available Rheumatoid arthritis (RA is a chronic, systemic, autoimmune inflammatory disorder that is characterized by joint inflammation, erosive properties and symmetric multiple joint involvement. Temporomandibular joint (TMJ is very rare to be affected in the early phase of the disease, thus posing diagnostic challenges for the dentist. Conventional radiographs fail to show the early lesions due to its limitations. More recently cone-beam computed tomography (CBCT has been found to diagnose the early degenerative changes of TMJ and hence aid in the diagnosis of the lesions more accurately. Our case highlights the involvement of TMJ in RA and the role of advanced imaging (CBCT in diagnosing the bony changes in the early phase of the disease.

  16. Study on Somaclonal Variation of Spring Wheat

    Institute of Scientific and Technical Information of China (English)

    JIANG Shu-mei; HU Shang-lian; LI Wen-xiong

    2004-01-01

    Somaclonal variation of calli and regenerated plants of spring wheat ware detected by using technique RAPD in the study. Calli at different culture stages and regenerated plants derived from young spikes and immature embryos were used as materials. Molecular variation could be reflected from electrophoresis patternof RAPD fragments at different culture stage in calli, and in regenerated plants derived from different explants, even no phenotype variations were found. Somaclonal variation in calli and in regenerated plants appeared regularly: A higher frequency of variation in hybrids F2 was detected than that of the cultivar that is stable genetically. High variation frequency of RAPD fragments appeared in calli when cultured 75 days. The identical variations of RAPD fragments were observed in calli and in the regenerated plants induced from different genotype or explants. The variation frequency detected is higher in regenerated plants than that of in calli. RAPD could be applied easily and simply to determine variation in level of DNA at each stage cultured in vitro.

  17. Genetic variations in multiple myeloma I

    DEFF Research Database (Denmark)

    Vangsted, A.; Klausen, T.W.; Vogel, Ulla Birgitte

    2012-01-01

    Few risk factors have been established for the plasma cell disorder multiple myeloma, but some of these like African American ethnicity and a family history of B-cell lymphoproliferative diseases suggest a genetic component for the disease. Genetic variation represents the genetic basis...... of variability in a population. The complex interplay between environment and genes for the development of cancer may therefore be influenced by genetic variations. A genetic variation may change the function of the gene, and if the genetic variation is associated with the risk of disease, that particular gene...

  18. The circadian variation of premature atrial contractions

    DEFF Research Database (Denmark)

    Strøier Larsen, Bjørn; Kumarathurai, Preman; Wendelboe Nielsen, Olav;

    2016-01-01

    AIMS: The aim of the study was to assess a possible circadian variation of premature atrial contractions (PACs) in a community-based population and to determine if the daily variation could be used to assess a more vulnerable period of PACs in predicting later incidence of atrial fibrillation (AF...... variation in heart rate. After adjusting for relevant risk factors, the risk of AF was equal in all time intervals throughout the day. CONCLUSION: Premature atrial contractions showed a circadian variation in subjects with frequent PACs. No specific time interval of the day was more predictive of AF than...

  19. Non-contemporaneous variations and Holder's principle

    Institute of Scientific and Technical Information of China (English)

    LIANG; Lifu(梁立孚); HU; Haichang; (胡海昌); LIU; Shiquan; (刘石泉)

    2003-01-01

    In the process of deducing the Holder principle, a key step is to use the concept of non-contemporaneous variations. In this paper, whether starting from analytic method or from graphic solution method, the authors prove that the expression formula of non-contemporaneous variations is incorrect when the variable functions have zero-order nearness degree, and obtain a new expression. From the view of calculus of variations and differential calculus, the non-contemporaneous variations are studied. The study result shows that the concept of non-contemporaneous variations is a combination of the concept of variations and the concept of differentiation. The authors prove that the new expression is correct and obtain an equivalent expression of it. By means of this equivalent expression, this paper proves that the above expression formula of non-contemporaneous variations is correct when the variable functions have one-order nearness degree. Further study shows that, in the process of deducing Holder's principle, there is an implicit expression. Whether starting from analytic method or from graphic solution method, the authors discovered that the implicit expression of non-contemporaneous variations is incorrect when the variable functions have zero-order nearness degree and have one-order nearness degree. This paper proves that the implicit expression of non-contemporaneous variations is correct when the variable functions have two-order nearness degree. Further study shows that Holder's principle is tenable when the variable functions have two-order nearness degree.

  20. Equations of motion for variational electrodynamics

    Science.gov (United States)

    De Luca, Jayme

    2016-04-01

    We extend the variational problem of Wheeler-Feynman electrodynamics by generalizing the electromagnetic functional to a local space of absolutely continuous trajectories possessing a derivative (velocities) of bounded variation. We show here that the Gateaux derivative of the generalized functional defines two partial Lagrangians for variations in our generalized local space, one for each particle. We prove that the critical-point conditions of the generalized variational problem are: (i) the Euler-Lagrange equations must hold Lebesgue-almost-everywhere and (ii) the momentum of each partial Lagrangian and the Legendre transform of each partial Lagrangian must be absolutely continuous functions, generalizing the Weierstrass-Erdmann conditions.

  1. Extensive Variation in Chromatin States Across Humans

    KAUST Repository

    Kasowski, M.

    2013-10-17

    The majority of disease-associated variants lie outside protein-coding regions, suggesting a link between variation in regulatory regions and disease predisposition. We studied differences in chromatin states using five histone modifications, cohesin, and CTCF in lymphoblastoid lines from 19 individuals of diverse ancestry. We found extensive signal variation in regulatory regions, which often switch between active and repressed states across individuals. Enhancer activity is particularly diverse among individuals, whereas gene expression remains relatively stable. Chromatin variability shows genetic inheritance in trios, correlates with genetic variation and population divergence, and is associated with disruptions of transcription factor binding motifs. Overall, our results provide insights into chromatin variation among humans.

  2. Parkinson's disease and mitochondrial gene variations

    DEFF Research Database (Denmark)

    Andalib, Sasan; Vafaee, Manouchehr Seyedi; Gjedde, Albert

    2014-01-01

    Parkinson's disease (PD) is a common disorder of the central nervous system in the elderly. The pathogenesis of PD is a complex process, with genetics as an important contributing factor. This factor may stem from mitochondrial gene variations and mutations as well as from nuclear gene variations...... and mutations. More recently, a particular role of mitochondrial dysfunction has been suggested, arising from mitochondrial DNA variations or acquired mutations in PD pathogenesis. The present review summarizes and weighs the evidence in support of mitochondrial DNA (mtDNA) variations as important contributors...

  3. Spectrum characteristics of geoelectric field variation

    Institute of Scientific and Technical Information of China (English)

    YE Qing; DU Xue-bin; ZHOU Ke-chang; LI Ning; MA Zhan-hu

    2007-01-01

    The spectrum characteristics of geoelectric diurnal variation and geoelectric storm have been identified by maximum entropy method, based on geoelectric data from seven stations in the Chinese mainland, including Jiayuguan, Changli and Chongming. The study shows that, in geoelectric diurnal variation, the amplitude of the 12 h semidiurnal wave is the largest, followed in turn by the 24~25 h diurnal wave and the 8 h periodic wave; Geoelectric storm usually occurs in a large-scale space, whose spectrum values are higher than those of geoelectric diurnal variation by 2~3 orders of magnitude. A preliminary interpretation is presented for the generative mechanism of predominant waves in geoelectric field variation.

  4. Affective and Cognitive Aspects of Bilingualism.

    Science.gov (United States)

    Herrell, Ileana Collado; Herrell, James M.

    1980-01-01

    A study showing that lexically equivalent words in two languages have different affective meanings, that affective intensity of dominant language words is greater than for second language equivalents, and that the difference is greatest for words with high affective meaning demonstrates that affective meaning is an important component of…

  5. Giant wood spider Nephila pilipes alters silk protein in response to prey variation.

    Science.gov (United States)

    Tso, I-Min; Wu, Hsuan-Chen; Hwang, In-Ru

    2005-03-01

    Recent studies have demonstrated that orb-weaving spiders may alter web structures, foraging localities or silk output in response to prey variations. In this study we conducted field surveys and food manipulations to examine whether orb-weaving spiders may also adjust the protein of silk to prey variations. A comparison of dragline silks collected from nine giant wood spider Nephila pilipes populations in Taiwan showed a spatial variation. The percentage of all amino acids (except alanine and glycine) exhibited significant differences among populations. A survey of prey composition also revealed a significant spatial variation among N. pilipes populations. To determine whether prey variation was responsible for silk protein variation, we fed N. pilipes with different types of prey (dipteran vs orthopteran) then compared the percentage of five major dragline amino acids and secondary structures. The results showed that dragline of N. pilipes fed with orthopteran prey contained significantly higher proline and glutamine but lower alanine. Congruent with this result were those from FTIR spectroscopy, which showed that dragline of N. pilipes fed with crickets exhibited significantly higher percentage of proline- and glutamine-containing beta turns, and lower percentage of alanine-containing beta sheet structures. Since the results of feeding manipulations showed that diet significantly affected the compositions of dragline silks, the observed spatial variation seemed to reflect the different types of prey these spiders had consumed. Results of this study thus indicated that orb-weaving spiders can alter dragline protein in response to prey variations.

  6. Geographical Variation in Egg Mass and Egg Content in a Passerine Bird

    Science.gov (United States)

    Ruuskanen, Suvi; Siitari, Heli; Eeva, Tapio; Belskii, Eugen; Järvinen, Antero; Kerimov, Anvar; Krams, Indrikis; Moreno, Juan; Morosinotto, Chiara; Mänd, Raivo; Möstl, Erich; Orell, Markku; Qvarnström, Anna; Salminen, Juha-Pekka; Slater, Fred; Tilgar, Vallo; Visser, Marcel E.; Winkel, Wolfgang; Zang, Herwig; Laaksonen, Toni

    2011-01-01

    Reproductive, phenotypic and life-history traits in many animal and plant taxa show geographic variation, indicating spatial variation in selection regimes. Maternal deposition to avian eggs, such as hormones, antibodies and antioxidants, critically affect development of the offspring, with long-lasting effects on the phenotype and fitness. Little is however known about large-scale geographical patterns of variation in maternal deposition to eggs. We studied geographical variation in egg components of a passerine bird, the pied flycatcher (Ficedula hypoleuca), by collecting samples from 16 populations and measuring egg and yolk mass, albumen lysozyme activity, yolk immunoglobulins, yolk androgens and yolk total carotenoids. We found significant variation among populations in most egg components, but ca. 90% of the variation was among individuals within populations. Population however explained 40% of the variation in carotenoid levels. In contrast to our hypothesis, we found geographical trends only in carotenoids, but not in any of the other egg components. Our results thus suggest high within-population variation and leave little scope for local adaptation and genetic differentiation in deposition of different egg components. The role of these maternally-derived resources in evolutionary change should be further investigated. PMID:22110579

  7. The affective shift model of work engagement.

    Science.gov (United States)

    Bledow, Ronald; Schmitt, Antje; Frese, Michael; Kühnel, Jana

    2011-11-01

    On the basis of self-regulation theories, the authors develop an affective shift model of work engagement according to which work engagement emerges from the dynamic interplay of positive and negative affect. The affective shift model posits that negative affect is positively related to work engagement if negative affect is followed by positive affect. The authors applied experience sampling methodology to test the model. Data on affective events, mood, and work engagement was collected twice a day over 9 working days among 55 software developers. In support of the affective shift model, negative mood and negative events experienced in the morning of a working day were positively related to work engagement in the afternoon if positive mood in the time interval between morning and afternoon was high. Individual differences in positive affectivity moderated within-person relationships. The authors discuss how work engagement can be fostered through affect regulation.

  8. Maternal responses to adolescent positive affect are associated with adolescents' reward neuroanatomy.

    Science.gov (United States)

    Whittle, Sarah; Yap, Marie B H; Yücel, Murat; Sheeber, Lisa; Simmons, Julian G; Pantelis, Christos; Allen, Nicholas B

    2009-09-01

    The development of reward-based learning and decision-making, and the neural circuitry underlying these processes, appears to be influenced negatively by adverse child-rearing environments characterized by abuse and other forms of maltreatment. No research to-date has investigated whether normative variations in the child-rearing environment have effects on adolescent brain structure. We examined whether normative variations in maternal responses to adolescents' positive affective behavior were associated with morphometric measures of the adolescents' affective neural circuitry, namely the amygdala, orbitofrontal cortex (OFC), and anterior cingulate cortex (ACC). Healthy adolescents (N = 113) participated in laboratory-based interaction tasks with their mothers, and underwent high-resolution (3T) structural magnetic resonance imaging (MRI). The mother-adolescent interactions included a pleasant event-planning interaction (EPI) and a conflictual problem-solving interaction (PSI). Adolescents, whose mothers displayed more punishing responses to their positive affective behavior during both tasks, and only during the PSI, had larger left dorsal ACC and bilateral OFC volumes, respectively. In addition, boys whose mothers evidenced this pattern of behavior during the EPI had larger right amygdala volumes. These results suggest that normative variations in maternal responses to affective behavior are associated with the structural characteristics of adolescents' affective neural circuitry, which may have implications for the development of their social, cognitive and affective functioning.

  9. The Affective Regulation of Cognitive Priming

    OpenAIRE

    Storbeck, Justin; Clore, Gerald L.

    2008-01-01

    Semantic and affective priming are classic effects observed in cognitive and social psychology, respectively. We discovered that affect regulates such priming effects. In Experiment 1, positive and negative moods were induced prior to one of three priming tasks; evaluation, categorization, or lexical decision. As predicted, positive affect led to both affective priming (evaluation task) and semantic priming (category and lexical decision tasks). However, negative affect inhibited such effects...

  10. Twitter, Journalism and Affective Labour

    Directory of Open Access Journals (Sweden)

    Eugenia Siapera

    2015-03-01

    Full Text Available The rise of the network aspects of journalism in the context of social mediasuch as Twitter, and the increased importance accorded to community building and maintenance as well as to reciprocity, point to the need to take into account the affective part of journalistic labour. This refers to these aspects of journalistic work that are linked to the creation of networks and communities, to interactions with readers and the forming of bonds between journalists and their readers. An analysis of the affective labour of journalists on Twitter, we argue, is necessary in order to understand the potential and ambiguities of this part of their labour. Based on a set of in-depth interviews with Twitter journalists, this article found three main repertoires of affective labour: the organic relations repertoire, which points to the increasing importance of authenticity as a means of establishing credibility on Twitter; the temporal repertoire; and the repertoire of responsibility. The importance of the affective labour of journalism is found in its biopolitical productivity. The development of an organic relationship with followers, the emergence of stronger bonds between core groups that then become communities, the extension of care and help to the network, are all evidence of the importance of this biopolitical productivity and point to the construction of a new and potentially more radical sociopolitical role for journalism. However, this potential is ambiguous insofar as these elements contain unresolved tensions and ambiguities. These include the trade in selves and the associated commodification; the re-formulation of time, especially its diachronic dimension, as accumulation of social capital; the role of reciprocity and responsibility in reproducing inequalities; and care as care for only those deemed deserving. These ambiguities severely undermine and limit the potentials of affective labour, pointing to the need to develop a purposeful political

  11. Ash in fire affected ecosystems

    Science.gov (United States)

    Pereira, Paulo; Jordan, Antonio; Cerda, Artemi; Martin, Deborah

    2015-04-01

    Ash in fire affected ecosystems Ash lefts an important footprint in the ecosystems and has a key role in the immediate period after the fire (Bodi et al., 2014; Pereira et al., 2015). It is an important source of nutrients for plant recover (Pereira et al., 2014a), protects soil from erosion and controls soil hydrological process as runoff, infiltration and water repellency (Cerda and Doerr, 2008; Bodi et al., 2012, Pereira et al., 2014b). Despite the recognition of ash impact and contribution to ecosystems recuperation, it is assumed that we still have little knowledge about the implications of ash in fire affected areas. Regarding this situation we wanted to improve our knowledge in this field and understand the state of the research about fire ash around world. The special issue about "The role of ash in fire affected ecosystems" currently in publication in CATENA born from the necessity of joint efforts, identify research gaps, and discuss future cooperation in this interdisciplinary field. This is the first special issue about fire ash in the international literature. In total it will be published 10 papers focused in different aspects of the impacts of ash in fire affected ecosystems from several parts of the world: • Fire reconstruction using charcoal particles (Burjachs and Espositio, in press) • Ash slurries impact on rheological properties of Runoff (Burns and Gabet, in press) • Methods to analyse ash conductivity and sorbtivity in the laboratory and in the field (Balfour et al., in press) • Termogravimetric and hydrological properties of ash (Dlapa et al. in press) • Effects of ash cover in water infiltration (Leon et al., in press) • Impact of ash in volcanic soils (Dorta Almenar et al., in press; Escuday et al., in press) • Ash PAH and Chemical extracts (Silva et al., in press) • Microbiology (Barreiro et al., in press; Lombao et al., in press) We believe that this special issue will contribute importantly to the better understanding of

  12. Surveying of morphological variations in estuarine Nyband River

    Science.gov (United States)

    Ghobadi-Bistooni, S.; Ershadi, C.

    2009-04-01

    Rivers estuary in aspect of ecological and morphological is very sensitive in coastal zones. This area can affect from human activities and these activities have direct effective on natural state of these area. There for, overall aim of this work is steady on development of this coastal area and thus, it is investigated the morphological and sedimentation mechanism in estuarine area. For this case study, area is limited (27°11'NL ; 56°19'EL), begin from Genu mountains in southern parts of Iran and pass from mid of Bandar Abbas city and in final ends to north of Persian Gulf. There were some physical variations in this estuarine area of Nyband River due to human activities. These variations include: fixing the banks, Jetty break water in near of estuary and recently sealing the bed bottom of river and building of bridge. A numerical program was used for analysis this hydrodynamic and sediment condition. This result compares with field data for evaluation of the numerical analysis. Also, the aero photographical document in past decade was prepared for surveying morphological variations. For this purpose, the GIS (ARCVIEW) was used and finally, the effect of the human activities, such as building of new structure, on morphology of river was investigated.

  13. Hydrology Induced Gravity Variation Observed at Vienna and Conrad Observatory

    Science.gov (United States)

    Mikolaj, Michal; Meurers, Bruno

    2013-04-01

    Mass transport associated with hydrological processes induces gravity variations observed by superconducting gravimeter (SG) and thus can mask essential geodynamical signals. The presented study analyses time series acquired by superconducting gravimeter GWR C025 with a focus on hydrological effects. This gravimeter was transported from Vienna to Conrad Observatory in the end of year 2007. The gravimeter was in both cases installed in an underground laboratory, but Conrad Observatory is located in a mountain area, while Vienna represents an urbanized area. This affords an opportunity to study the hydrological gravity response for two different environments. Several global hydrological models are used to estimate the contribution of global hydrology to gravity variations. Local hydrology is analysed using in-situ meteorological measurements. Significant influence of heavy rain on gravity is observed for both underground stations. The gravity variation observed at Conrad Observatory is additionally strongly affected by snow accumulation and melting phase. The SG installation in an underground laboratory together with a specific topographic situation at the place of observation may lead to an interference of local and global hydrological effect.

  14. Seasonal variation of the barrier layer in the PN section

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yuan; WU Dexing; LIN Xiaopei; SHAN Feng

    2009-01-01

    In this paper, we use the conductivity-temperature-depth (CTD) observation data and a three-dimensional ocean model in a seasonally-varying forcing field to study the barrier layer (BL) in the PN section in the East China Sea (ECS). The BL can be found along the PN section with obviously seasonal variability. In winter, spring and autumn, the BL occurs around the slope where the cold shelf water meets with the warm Kuroshio water. In summer, the BL can also be found in the shelf area near salinity front of the Changjiang (Yangtze) River Dilution Water (YRDW). Seasonal variations of BL in the PN section are caused by local hydrological characteristics and seasonal variations of atmospheric forcing. Strong vertical convection caused by sea surface cooling thickens the BL in winter and spring in the slope area. Due to the large discharge of Changjiang River in summer, the BL occurs extensively in the shelf region where the fresh YRDW and the salty bottom water meet and form a strong halocline above the seasonal thermocline. The formation mechanism of BL in the PN section can be explained by the vertical shear of different water masses, which is called the advection mechanism. The interannual variation of BL in summer is greatly affected by the YRDW. In the larger YRDW year (such as 1998), a shallow but much thicker BL existed on the shelf area.

  15. Geomagnetic Secular Variation Prediction with Thermal Heterogeneous Boundary Conditions

    Science.gov (United States)

    Kuang, Weijia; Tangborn, Andrew; Jiang, Weiyuan

    2011-01-01

    It has long been conjectured that thermal heterogeneity at the core-mantle boundary (CMB) affects the geodynamo substantially. The observed two pairs of steady and strong magnetic flux lobes near the Polar Regions and the low secular variation in the Pacific over the past 400 years (and perhaps longer) are likely the consequences of this CMB thermal heterogeneity. There are several studies on the impact of the thermal heterogeneity with numerical geodynamo simulations. However, direct correlation between the numerical results and the observations is found very difficult, except qualitative comparisons of certain features in the radial component of the magnetic field at the CMB. This makes it difficult to assess accurately the impact of thermal heterogeneity on the geodynamo and the geomagnetic secular variation. We revisit this problem with our MoSST_DAS system in which geomagnetic data are assimilated with our geodynamo model to predict geomagnetic secular variations. In this study, we implement a heterogeneous heat flux across the CMB that is chosen based on the seismic tomography of the lowermost mantle. The amplitude of the heat flux (relative to the mean heat flux across the CMB) varies in the simulation. With these assimilation studies, we will examine the influences of the heterogeneity on the forecast accuracies, e.g. the accuracies as functions of the heterogeneity amplitude. With these, we could be able to assess the model errors to the true core state, and thus the thermal heterogeneity in geodynamo modeling.

  16. Disentangling the phylogenetic and ecological components of spider phenotypic variation.

    Science.gov (United States)

    Gonçalves-Souza, Thiago; Diniz-Filho, José Alexandre Felizola; Romero, Gustavo Quevedo

    2014-01-01

    An understanding of how the degree of phylogenetic relatedness influences the ecological similarity among species is crucial to inferring the mechanisms governing the assembly of communities. We evaluated the relative importance of spider phylogenetic relationships and ecological niche (plant morphological variables) to the variation in spider body size and shape by comparing spiders at different scales: (i) between bromeliads and dicot plants (i.e., habitat scale) and (ii) among bromeliads with distinct architectural features (i.e., microhabitat scale). We partitioned the interspecific variation in body size and shape into phylogenetic (that express trait values as expected by phylogenetic relationships among species) and ecological components (that express trait values independent of phylogenetic relationships). At the habitat scale, bromeliad spiders were larger and flatter than spiders associated with the surrounding dicots. At this scale, plant morphology sorted out close related spiders. Our results showed that spider flatness is phylogenetically clustered at the habitat scale, whereas it is phylogenetically overdispersed at the microhabitat scale, although phylogenic signal is present in both scales. Taken together, these results suggest that whereas at the habitat scale selective colonization affect spider body size and shape, at fine scales both selective colonization and adaptive evolution determine spider body shape. By partitioning the phylogenetic and ecological components of phenotypic variation, we were able to disentangle the evolutionary history of distinct spider traits and show that plant architecture plays a role in the evolution of spider body size and shape. We also discussed the relevance in considering multiple scales when studying phylogenetic community structure.

  17. Variational approaches to water wave simulations

    NARCIS (Netherlands)

    Gagarina, Elena Vitalyevna

    2014-01-01

    This thesis starts with the study the theoretical aspects of water wave modelling using a variational framework, which is directly associated with phase space and energy conservation laws. In particular, we focus on a new variational model based on the work of Cotter and Bokhove. The new model inclu

  18. The Needs of Students with Intersex Variations

    Science.gov (United States)

    Jones, Tiffany

    2016-01-01

    To date, people with intersex variations have been mainly studied via small-scale clinical research, with only a small amount of reflective commentary contributed by sociocultural scholars. This paper reports on findings from a 2015 online Australian survey of 272 people with intersex variations, which aimed to redress the gap in research on this…

  19. Accommodating Variation: Dialects, Idiolects, and Speech Processing

    Science.gov (United States)

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

    2008-01-01

    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…

  20. Anatomy, Medical Education, and Human Ancestral Variation

    Science.gov (United States)

    Strkalj, Goran; Spocter, Muhammad A.; Wilkinson, A. Tracey

    2011-01-01

    It is argued in this article that the human body both in health and disease cannot be fully understood without adequately accounting for the different levels of human variation. The article focuses on variation due to ancestry, arguing that the inclusion of information pertaining to ancestry in human anatomy teaching materials and courses should…

  1. Genetic variation in bovine milk fat composition

    NARCIS (Netherlands)

    Stoop, W.M.

    2009-01-01

    In her thesis, Stoop shows that there is considerable genetic variation in milk fat composition, which opens opportunities to improve milk fat composition by selective breeding. Short and medium chain fatty acids had high heritabilities, whereas variation due to herd (mainly feed effects) was modera

  2. Groupoids, Discrete Mechanics, and Discrete Variation

    Institute of Scientific and Technical Information of China (English)

    GUO Jia-Feng; JIA Xiao-Yu; WU Ke; ZHAO Wei-Zhong

    2008-01-01

    After introducing some of the basic definitions and results from the theory of groupoid and Lie algebroid,we investigate the discrete Lagrangian mechanics from the viewpoint of groupoid theory and give the connection between groupoids variation and the methods of the first and second discrete variational principles.

  3. Stochastic variational approach to minimum uncertainty states

    Energy Technology Data Exchange (ETDEWEB)

    Illuminati, F.; Viola, L. [Dipartimento di Fisica, Padova Univ. (Italy)

    1995-05-21

    We introduce a new variational characterization of Gaussian diffusion processes as minimum uncertainty states. We then define a variational method constrained by kinematics of diffusions and Schroedinger dynamics to seek states of local minimum uncertainty for general non-harmonic potentials. (author)

  4. Stochastic variational approach to minimum uncertainty states

    CERN Document Server

    Illuminati, F; Illuminati, F; Viola, L

    1995-01-01

    We introduce a new variational characterization of Gaussian diffusion processes as minimum uncertainty states. We then define a variational method constrained by kinematics of diffusions and Schr\\"{o}dinger dynamics to seek states of local minimum uncertainty for general non-harmonic potentials.

  5. Size variation in Middle Pleistocene humans.

    Science.gov (United States)

    Arsuaga, J L; Carretero, J M; Lorenzo, C; Gracia, A; Martínez, I; Bermúdez de Castro, J M; Carbonell, E

    1997-08-22

    It has been suggested that European Middle Pleistocene humans, Neandertals, and prehistoric modern humans had a greater sexual dimorphism than modern humans. Analysis of body size variation and cranial capacity variation in the large sample from the Sima de los Huesos site in Spain showed instead that the sexual dimorphism is comparable in Middle Pleistocene and modern populations.

  6. Circadian variation in the pharmacokinetics of verapamil

    DEFF Research Database (Denmark)

    Jespersen, C M; Frederiksen, M; Hansen, J F;

    1989-01-01

    Circadian variation in the metabolism of verapamil was investigated in 10 patients with stable angina pectoris during treatment with sustained-release verapamil 360 mg at 08.00 h or 22.0 h. No major difference in exercise parameters was found. During the evening dosage schedule a significantly gr...... or to circadian variation in hepatic microsomal metabolism....

  7. Geometric variations of the Boltzmann entropy

    OpenAIRE

    Kalogeropoulos, Nikos

    2008-01-01

    We perform a calculation of the first and second order infinitesimal variations, with respect to energy, of the Boltzmann entropy of constant energy hypersurfaces of a system with a finite number of degrees of freedom. We comment on the stability interpretation of the second variation in this framework.

  8. Variational bayesian method of estimating variance components.

    Science.gov (United States)

    Arakawa, Aisaku; Taniguchi, Masaaki; Hayashi, Takeshi; Mikawa, Satoshi

    2016-07-01

    We developed a Bayesian analysis approach by using a variational inference method, a so-called variational Bayesian method, to determine the posterior distributions of variance components. This variational Bayesian method and an alternative Bayesian method using Gibbs sampling were compared in estimating genetic and residual variance components from both simulated data and publically available real pig data. In the simulated data set, we observed strong bias toward overestimation of genetic variance for the variational Bayesian method in the case of low heritability and low population size, and less bias was detected with larger population sizes in both methods examined. The differences in the estimates of variance components between the variational Bayesian and the Gibbs sampling were not found in the real pig data. However, the posterior distributions of the variance components obtained with the variational Bayesian method had shorter tails than those obtained with the Gibbs sampling. Consequently, the posterior standard deviations of the genetic and residual variances of the variational Bayesian method were lower than those of the method using Gibbs sampling. The computing time required was much shorter with the variational Bayesian method than with the method using Gibbs sampling.

  9. A RARE VARIATION OF GREAT SAPHENOUS VEIN

    Directory of Open Access Journals (Sweden)

    Nakhate Manisha

    2014-11-01

    Full Text Available The venous system is more complex and variable than arterial system due to its frequent anatomical variations. This paper discusses the anatomy of the great saphenous vein and its variation observed in a male cadaver of around 60 years old.

  10. Size variation of fossil rodent populations

    NARCIS (Netherlands)

    Freudenthal, M.; Cuenca Bescos, G.

    1984-01-01

    Pearson's coefficient of variation is in general not applicable in palaeontology, due to the heterogeneity of samples. The heterogeneity may be due to the mixing of two species, mixture of material from various biotopes, or from a relatively large time span. A new coefficient of variation is propose

  11. Note on Methodology: The Coefficient of Variation.

    Science.gov (United States)

    Sheret, Michael

    1984-01-01

    Addresses applications of the coefficient of variation as a measure of educational inequality or as a means of measuring changes of inequality status. Suggests the Gini coefficient has many advantages over the coefficient of variation since it can be used with the Lorenz curve (Lorenz provides detail Gini omits). (BRR)

  12. Bilingualism affects audiovisual phoneme identification.

    Science.gov (United States)

    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 identification experiment with bilingual and monolingual adult participants. It was an ABX task involving a Bengali dental-retroflex contrast that does not exist in any of the participants' languages. The phonemes were presented in audiovisual (AV) and audio-only (A) conditions. The results revealed that in the audio-only condition monolinguals and bilinguals had difficulties in discriminating the retroflex non-native phoneme. They were phonologically "deaf" and assimilated it to the dental phoneme that exists in their native languages. In the audiovisual presentation instead, both groups could overcome the phonological deafness for the retroflex non-native phoneme and identify both Bengali phonemes. However, monolinguals were more accurate and responded quicker than bilinguals. This suggests that bilinguals do not use the same processes as monolinguals to decode visual speech.

  13. Affective Priming Caused by Lying

    Directory of Open Access Journals (Sweden)

    Megumi Sato

    2011-10-01

    Full Text Available Typically, arousal increases when telling a lie, as indicated in psychophysiological studies about lie detection. But the emotional valence induced by lying is unknown, though intuition indicates that it may be negative. Indeed, the Electrodermal Activity (EDA, used in such studies, only shows arousal changes during an emotional response. In this study, we examined the emotional valence induced by lying using two tasks. First, in the deceptive task, participants answered “no” to every question regarding the nature of displayed playing cards. Therefore, they told a lie about specific cards. During the task, their EDA was recorded. Secondly, in the figure estimation task, they assessed pictures by “like” or “dislike” after looking at playing cards visibly or subliminally as prime stimuli. We expected them to tend to estimate figures by “dislike” when cards relevant to deception were previously shown. This would mean that an affective priming effect due to telling a lie happened. Actually, this effect was found only when prime stimuli were displayed visibly. This result suggests that lying per se induces negative emotions even without motivation or punishment due to lying. Furthermore, we found that such effect was more blatant in participants whose EDA changes were salient while lying.

  14. Factors affecting forage stand establishment

    Directory of Open Access Journals (Sweden)

    Sulc R.M.

    1998-01-01

    Full Text Available 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 be expanded in the industry to enable matching seed lot performance to specific environmental conditions where performance can be maximized. Seed treatment and seed coating are used in the forage seed industry, and studies have shown they are of benefit in some environments. There is an increase in no-tillage seeding of forage crops, but improvements in the no-tillage planting equipment are needed to make them better suited to small seeds. Other recent developments in seeding techniques include broadcasting seed with dry granular and fluid fertilizers, which improves the efficiency of the seeding operation.

  15. Southwest ballot measures affecting healthcare

    Directory of Open Access Journals (Sweden)

    Robbins RA

    2016-11-01

    Full Text Available No abstract available. Article truncated after 150 words. Modern Healthcare (1 has published an article summarizing ballot measures affecting healthcare. Those from the Southwest are listed below: States: Arizona: 1. Recreational marijuana. Proposition 205: Legalizes recreational marijuana use for people 21 and older. Opponents of the measure include the Arizona Health and Hospital Association and Insys Therapeutics, a company that makes a cannabis-based pain medication. California : 1. Medi-Cal hospital fee program. Proposition 52: Requires the legislature to get voter approval to use fee revenue for purposes other than generating federal matching funds and funding enhanced Medicaid payments and grants for hospitals. The initiative, which was written by the California Hospital Association and is supported by most state lawmakers, would also make the program permanent, requiring a supermajority in the legislature to end it. 2. Tobacco tax. Proposition 56: Increases the state's cigarette tax by $2 a pack and impose an "equivalent increase on other tobacco products and ...

  16. Factors Affecting Radiologist's PACS Usage.

    Science.gov (United States)

    Forsberg, Daniel; Rosipko, Beverly; Sunshine, Jeffrey L

    2016-12-01

    The purpose of this study was to determine if any of the factors radiologist, examination category, time of week, and week effect PACS usage, with PACS usage defined as the sequential order of computer commands issued by a radiologist in a PACS during interpretation and dictation. We initially hypothesized that only radiologist and examination category would have significant effects on PACS usage. Command logs covering 8 weeks of PACS usage were analyzed. For each command trace (describing performed activities of an attending radiologist interpreting a single examination), the PACS usage variables number of commands, number of command classes, bigram repetitiveness, and time to read were extracted. Generalized linear models were used to determine the significance of the factors on the PACS usage variables. The statistical results confirmed the initial hypothesis that radiologist and examination category affect PACS usage and that the factors week and time of week to a large extent have no significant effect. As such, this work provides direction for continued efforts to analyze system data to better understand PACS utilization, which in turn can provide input to enable optimal utilization and configuration of corresponding systems. These continued efforts were, in this work, exemplified by a more detailed analysis using PACS usage profiles, which revealed insights directly applicable to improve PACS utilization through modified system configuration.

  17. Factors affecting tactile spatial acuity.

    Science.gov (United States)

    Craig, J C; Kisner, J M

    1998-01-01

    Tactile spatial acuity on the fingerpad was measured using a grating orientation task. In this task, subjects are required to identify the orientation of square-wave gratings placed on the skin. Previous studies have shown that performance varies as a function of the width of the grooves in the gratings. In the present study, both groove width and the overall size and configuration of the contactors were varied. Sensitivity improved with wider grooves and with larger contactors. Additional measurements showed that the improved sensitivity is not the result of the increase in total area contacted, but rather is due to two other factors associated with larger contactors. One is the greater linear extent of the larger contactors. The other appears to be due to the reduction in the interference produced by the outer edge of the contactor. Specifically, as the contactor increases in size, the distance between the outer edge and the center portion of the grooves also increases. It was also shown that subjects are more sensitive to a single, continuous groove as compared with two grooves of the same total length but spatially discontinuous. Similarly, subjects are more sensitive to a contactor with a continuous groove than to a contactor in which just the end points of the groove are presented. The results are generally consistent with the results of peripheral, neurophysiological recordings. The results are discussed in terms of the way in which both spatial and intensive factors may affect sensitivity to grating orientation.

  18. Quantum Tunneling Affects Engine Performance.

    Science.gov (United States)

    Som, Sibendu; Liu, Wei; Zhou, Dingyu D Y; Magnotti, Gina M; Sivaramakrishnan, Raghu; Longman, Douglas E; Skodje, Rex T; Davis, Michael J

    2013-06-20

    We study the role of individual reaction rates on engine performance, with an emphasis on the contribution of quantum tunneling. It is demonstrated that the effect of quantum tunneling corrections for the reaction HO2 + HO2 = H2O2 + O2 can have a noticeable impact on the performance of a high-fidelity model of a compression-ignition (e.g., diesel) engine, and that an accurate prediction of ignition delay time for the engine model requires an accurate estimation of the tunneling correction for this reaction. The three-dimensional model includes detailed descriptions of the chemistry of a surrogate for a biodiesel fuel, as well as all the features of the engine, such as the liquid fuel spray and turbulence. This study is part of a larger investigation of how the features of the dynamics and potential energy surfaces of key reactions, as well as their reaction rate uncertainties, affect engine performance, and results in these directions are also presented here.

  19. How feeling betrayed affects cooperation.

    Directory of Open Access Journals (Sweden)

    Pouria Ramazi

    Full Text Available For a population of interacting self-interested agents, we study how the average cooperation level is affected by some individuals' feelings of being betrayed and guilt. We quantify these feelings as adjusted payoffs in asymmetric games, where for different emotions, the payoff matrix takes the structure of that of either a prisoner's dilemma or a snowdrift game. Then we analyze the evolution of cooperation in a well-mixed population of agents, each of whom is associated with such a payoff matrix. At each time-step, an agent is randomly chosen from the population to update her strategy based on the myopic best-response update rule. According to the simulations, decreasing the feeling of being betrayed in a portion of agents does not necessarily increase the level of cooperation in the population. However, this resistance of the population against low-betrayal-level agents is effective only up to some extend that is explicitly determined by the payoff matrices and the number of agents associated with these matrices. Two other models are also considered where the betrayal factor of an agent fluctuates as a function of the number of cooperators and defectors that she encounters. Unstable behaviors are observed for the level of cooperation in these cases; however, we show that one can tune the parameters in the function to make the whole population become cooperative or defective.

  20. Bilingualism affects audiovisual phoneme identification

    Directory of Open Access Journals (Sweden)

    Sabine eBurfin

    2014-10-01

    Full Text Available 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 identification experiment with bilingual and monolingual adult participants. It was an ABX task involving a Bengali dental-retroflex contrast that does not exist in any of the participants’ languages. The phonemes were presented in audiovisual (AV and audio-only (A conditions. The results revealed that in the audio-only condition monolinguals and bilinguals had difficulties in discriminating the retroflex non-native phoneme. They were phonologically deaf and assimilated it to the dental phoneme that exists in their native languages. In the audiovisual presentation instead, both groups could overcome the phonological deafness for the retroflex non-native phoneme and identify both Bengali phonemes. However, monolinguals were more accurate and responded quicker than bilinguals. This suggests that bilinguals do not use the same processes as monolinguals to decode visual speech.