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Sample records for influence fitness variation

  1. Seasonal temperature variations influence tapetum mitosis patterns associated with reproductive fitness.

    PubMed

    Lavania, Umesh C; Basu, Surochita; Kushwaha, Jyotsana Singh; Lavania, Seshu

    2014-09-01

    Environmental stress in plants impacts many biological processes, including male gametogenesis, and affects several cytological mechanisms that are strongly interrelated. To understand the likely impact of rising temperature on reproductive fitness in the climate change regime, a study of tapetal mitosis and its accompanying meiosis over seasons was made to elucidate the influence of temperature change on the cytological events occurring during microsporogenesis. For this we used two species of an environmentally sensitive plant system, i.e., genus Cymbopogon Sprengel (Poaceae), namely Cymbopogon nardus (L.) Rendle var. confertiflorus (Steud.) Bor (2n = 20) and Cymbopogon jwaruncusha (Jones) Schult. (2n = 20). Both species flower profusely during extreme summer (48 °C) and mild winter (15 °C) but support low and high seed fertility, respectively, in the two seasons. We have shown that tapetal mitotic patterns over seasons entail differential behavior for tapetal mitosis. During the process of tapetum development there are episodes of endomitosis that form either (i) an endopolyploid genomically imbalanced uninucleate and multinucleate tapetum, and (or) (ii) an acytokinetic multinucleate genomically balanced tapetum, with the progression of meiosis in the accompanying sporogenous tissue. The relative frequency of occurrence of the two types of tapetum mitosis patterns is significantly different in the two seasons, and it is found to be correlated with the temperature conditions. Whereas, the former (genomically imbalanced tapetum) are prevalent during the hot summer, the latter (genomically balanced tapetum) are frequent under optimal conditions. Such a differential behaviour in tapetal mitosis vis-à-vis temperature change is also correspondingly accompanied by substantial disturbances or regularity in meiotic anaphase disjunction. Both species show similar patterns. The study underpins that tapetal mitotic behaviour per se could be a reasonable indicator to

  2. Fitness implications of seasonal climate variation in Columbian ground squirrels.

    PubMed

    Dobson, F Stephen; Lane, Jeffrey E; Low, Matthew; Murie, Jan O

    2016-08-01

    The influence of climate change on the fitness of wild populations is often studied in the context of the spring onset of the reproductive season. This focus is relevant for climate influences on reproductive success, but neglects other fitness-relevant periods (e.g., autumn preparation for overwintering). We examined variation in climate variables (temperature, rainfall, snowfall, and snowpack) across the full annual cycle of Columbian ground squirrels (Urocitellus columbianus) for 21 years. We investigated seasonal climate variables that were associated with fitness variables, climate variables that exhibited directional changes across the study period, and finally observed declines in fitness (-0.03 units/year; total decline = 37%) that were associated with directional changes in climate variables. Annual fitness of adult female ground squirrels was positively associated with spring temperature (r = 0.69) and early summer rainfall (r = 0.56) and negatively associated with spring snow conditions (r = -0.44 to -0.66). Across the 21 years, spring snowmelt has become significantly delayed (r = 0.48) and summer rainfall became significantly reduced (r = -0.53). Using a standardized partial regression model, we found that directional changes in the timing of spring snowmelt and early summer rainfall (i.e., progressively drier summers) had moderate influences on annual fitness, with the latter statistically significant (ρ = -0.314 and 0.437, respectively). The summer period corresponds to prehibernation fattening of young and adult ground squirrels. Had we focused on a single point in time (viz. the onset of the breeding season), we would have underestimated the influences of climate change on our population. Rather, we obtained a comprehensive understanding of the influences of climate change on individual fitness by investigating the full lifecycle.

  3. Factors Influencing Physical Fitness Evaluation.

    ERIC Educational Resources Information Center

    Haarer, Barbara G.

    This annotated bibliography focuses on works that examine areas in which the physical educator can improve the administration of physical fitness tests in the elementary and secondary schools. The first part contains annotations that examine modifications of existing components which measure aspects of muscular and cardiovascular endurance. The…

  4. Assortative mating by fitness and sexually antagonistic genetic variation.

    PubMed

    Arnqvist, Göran

    2011-07-01

    Recent documentations of sexually antagonistic genetic variation in fitness have spurred an interest in the mechanisms that may act to maintain such variation in natural populations. Using individual-based simulations, I show that positive assortative mating by fitness increases the amount of sexually antagonistic genetic variance in fitness, primarily by elevating the equilibrium frequency of heterozygotes, over most of the range of sex-specific selection and dominance. Further, although the effects of assortative mating by fitness on the protection conditions of polymorphism in sexually antagonistic loci were relatively minor, it widens the protection conditions under most reasonable scenarios (e.g., under heterozygote superiority when fitness is averaged across the sexes) but can also somewhat narrow the protection conditions under other circumstances. The near-ubiquity of assortative mating in nature suggests that it may contribute to upholding standing sexually antagonistic genetic variation in fitness.

  5. Social and genetic interactions drive fitness variation in a free-living dolphin population

    PubMed Central

    Frère, Celine H.; Krützen, Michael; Mann, Janet; Connor, Richard C.; Bejder, Lars; Sherwin, William B.

    2010-01-01

    The evolutionary forces that drive fitness variation in species are of considerable interest. Despite this, the relative importance and interactions of genetic and social factors involved in the evolution of fitness traits in wild mammalian populations are largely unknown. To date, a few studies have demonstrated that fitness might be influenced by either social factors or genes in natural populations, but none have explored how the combined effect of social and genetic parameters might interact to influence fitness. Drawing from a long-term study of wild bottlenose dolphins in the eastern gulf of Shark Bay, Western Australia, we present a unique approach to understanding these interactions. Our study shows that female calving success depends on both genetic inheritance and social bonds. Moreover, we demonstrate that interactions between social and genetic factors also influence female fitness. Therefore, our study represents a major methodological advance, and provides critical insights into the interplay of genetic and social parameters of fitness. PMID:21041638

  6. Social and genetic interactions drive fitness variation in a free-living dolphin population.

    PubMed

    Frère, Celine H; Krützen, Michael; Mann, Janet; Connor, Richard C; Bejder, Lars; Sherwin, William B

    2010-11-16

    The evolutionary forces that drive fitness variation in species are of considerable interest. Despite this, the relative importance and interactions of genetic and social factors involved in the evolution of fitness traits in wild mammalian populations are largely unknown. To date, a few studies have demonstrated that fitness might be influenced by either social factors or genes in natural populations, but none have explored how the combined effect of social and genetic parameters might interact to influence fitness. Drawing from a long-term study of wild bottlenose dolphins in the eastern gulf of Shark Bay, Western Australia, we present a unique approach to understanding these interactions. Our study shows that female calving success depends on both genetic inheritance and social bonds. Moreover, we demonstrate that interactions between social and genetic factors also influence female fitness. Therefore, our study represents a major methodological advance, and provides critical insights into the interplay of genetic and social parameters of fitness.

  7. Variation in the post-mating fitness landscape in fruitflies.

    PubMed

    Fricke, Claudia; Chapman, Tracey

    2017-04-09

    Sperm competition is pervasive and fundamental to determining a male's overall fitness. Sperm traits and seminal fluid proteins (Sfps) are key factors. However, studies of sperm competition may often exclude females that fail to remate during a defined period. Hence, the resulting datasets contain fewer data from the potentially fittest males that have most success in preventing female remating. It is also important to consider a male's reproductive success before entering sperm competition, which is a major contributor to fitness. The exclusion of these data can both hinder our understanding of the complete fitness landscapes of competing males and lessen our ability to assess the contribution of different determinants of reproductive success to male fitness. We addressed this here, using the Drosophila melanogaster model system, by (i) capturing a comprehensive range of intermating intervals that define the fitness of interacting wild type males, and (ii) analysing outcomes of sperm competition using selection analyses. We conducted additional tests using males lacking the sex peptide (SP) ejaculate component versus genetically matched (SP(+) ) controls. This allowed us to assess the comprehensive fitness effects of this important Sfp on sperm competition. The results showed a signature of positive, linear selection in wild type and SP(+) control males on the length of the intermating interval and on male sperm competition defense. However, the fitness surface for males lacking SP was distinct, with local fitness peaks depending on contrasting combinations of remating intervals and offspring numbers. The results suggest that there are alternative routes to success in sperm competition and provide an explanation for the maintenance of variation in sperm competition traits. This article is protected by copyright. All rights reserved.

  8. Variation in the fitness effects of mutations with population density and size in Escherichia coli.

    PubMed

    Cao, Huansheng; Butler, Kevin; Hossain, Mithi; Lewis, James D

    2014-01-01

    The fitness effects of mutations are context specific and depend on both external (e.g., environment) and internal (e.g., cellular stress, genetic background) factors. The influence of population size and density on fitness effects are unknown, despite the central role population size plays in the supply and fixation of mutations. We addressed this issue by comparing the fitness of 92 Keio strains (Escherichia coli K12 single gene knockouts) at comparatively high (1.2×10(7) CFUs/mL) and low (2.5×10(2) CFUs/mL) densities, which also differed in population size (high: 1.2×10(8); low: 1.25×10(3)). Twenty-eight gene deletions (30%) exhibited a fitness difference, ranging from 5 to 174% (median: 35%), between the high and low densities. Our analyses suggest this variation among gene deletions in fitness responses reflected in part both gene orientation and function, of the gene properties we examined (genomic position, length, orientation, and function). Although we could not determine the relative effects of population density and size, our results suggest fitness effects of mutations vary with these two factors, and this variation is gene-specific. Besides being a mechanism for density-dependent selection (r-K selection), the dependence of fitness effects on population density and size has implications for any population that varies in size over time, including populations undergoing evolutionary rescue, species invasions into novel habitats, and cancer progression and metastasis. Further, combined with recent advances in understanding the roles of other context-specific factors in the fitness effects of mutations, our results will help address theoretical and applied biological questions more realistically.

  9. Longitudinal variations in fitting parameters for adult cochlear implant recipients.

    PubMed

    Mosca, F; Grassia, R; Leone, C A

    2014-04-01

    In patients with a cochlear implant (CI), the first critical point in processing auditory information from sound stimuli that leads to comprehension is the interface between the electrode and the cochlear nerve, which is dependent on providing appropriate current input. The purpose of this work was to evaluate the longitudinal differences in psychoacoustic fitting parameters in CI users. We studied 26 profoundly deaf adults, aged between 18 and 58 years, who had been implanted in our department between 2009 and 2011. The lowest current levels that evoked an auditory sensation (T-level) and the highest current levels that did not elicit an uncomfortable loud sensation (C-level) were recorded at the time of activation, approximately 30 days after implantation (mean 28.5 days) (T0), after one month (T1), 3 months (T3), 6 months (T6) and one year (T12). Impedance values were calculated for electrode groups: basal, middle and apical. In all cases, the same model of perimodiolar implant (Cochlear™ Nucleus(®) CI24RE) and the same surgical technique (cochleostomy) were used. The values of T-level and C-level showed significant incremental changes between T0 and T1 and between T1 and T3. T-levels in the basal regions of the cochlea were higher than in other sites. T-levels in the basal turn exhibited higher values consistent with a greater amount of fibrosis, as reported in other studies. Our findings suggest that fitting sessions should be scheduled more frequently during the first three months as indicated by the greater slope of T- and C- level variations during that time frame.

  10. Environmental variation alters the fitness effects of rifampicin resistance mutations in Pseudomonas aeruginosa.

    PubMed

    Gifford, Danna R; Moss, Ethan; MacLean, R Craig

    2016-03-01

    The fitness effects of antibiotic resistance mutations in antibiotic-free conditions play a key role in determining the long-term maintenance of resistance. Although resistance is usually associated with a cost, the impact of environmental variation on the cost of resistance is poorly understood. Here, we test the impact of heterogeneity in temperature and resource availability on the fitness effects of antibiotic resistance using strains of the pathogenic bacterium Pseudomonas aeruginosa carrying clinically important rifampicin resistance mutations. Although the rank order of fitness was generally maintained across environments, fitness effects relative to the wild type differed significantly. Changes in temperature had a profound impact on the fitness effects of resistance, whereas changes in carbon substrate had only a weak impact. This suggests that environmental heterogeneity may influence whether the costs of resistance are likely to be ameliorated by second-site compensatory mutations or by reversion to wild-type rpoB. Our results highlight the need to consider environmental heterogeneity and genotype-by-environment interactions for fitness in models of resistance evolution.

  11. Eat fit. Get big? How fitness cues influence food consumption volumes.

    PubMed

    Koenigstorfer, Joerg; Groeppel-Klein, Andrea; Kettenbaum, Myriam; Klicker, Kristina

    2013-06-01

    Fitness cues on food packages are a common marketing practice in the food sector. This study aims to find out whether and how fitness cues influence food consumption. The results of two field studies show that, even though eating fitness-cued food does not help consumers become more fit, the claims on the packaging increase both serving size and actual food consumption. This effect is mediated by serving size inferences. Also, consumers feel less guilty and perceive themselves closer to desired fitness levels after having consumed the food. The findings show that packaging cues relating to energy expenditure can increase energy intake despite the fact that consumers are not engaged in any actual physical activity while eating the food.

  12. Ecological Influences on Teachers' Well-Being and "Fitness"

    ERIC Educational Resources Information Center

    Price, Deborah; McCallum, Faye

    2015-01-01

    The complex and ever-changing nature of teachers' work challenges their well-being. Teacher well-being and "fitness" includes versatility, mental strength, and commitment to promote effective teaching and learning. In framing this notion, we seek to understand the ecological influences impacting on teacher well-being and…

  13. The X chromosome is a hot spot for sexually antagonistic fitness variation.

    PubMed Central

    Gibson, Jonathan R; Chippindale, Adam K; Rice, William R

    2002-01-01

    Sexually antagonistic alleles are selected discordantly between the sexes. Experimental evidence indicates that sexually antagonistic fitness variation is abundant in the genome of Drosophila melanogaster. Theory predicts that the X chromosome will be enriched with this type of variation. To test this prediction in D. melanogaster, we sampled, and cytogenetically cloned, 20 X chromosomes and compared their fitness variation to genome-wide levels. At the juvenile stage, in which gender roles are most similar, the X chromosome made no detectable contribution to genome-wide fitness variation. At the adult stage, in which gender roles diverge, the X chromosome was estimated to harbour 45% of the genome-wide fitness variation and 97% of the genome-wide sexually antagonistic variation. This genomic structure has important implications for the process of sexual selection because X-linked sexually antagonistic variation contributes to negative intersexual heritability for fitness, i.e. high-fitness males (females) produce, on average, low-fitness daughters (sons). PMID:11886642

  14. Influence of Coronal Abundance Variations

    NASA Technical Reports Server (NTRS)

    Gurman, Joseph (Technical Monitor); DeLuca, Edward

    2005-01-01

    During the final year of this program we concentrated on understanding the how to constrain the models with the best available observations. Work on developing accurate temperature and density diagnostics fkom TRACE and CDS together with constrained fits of non-potential force free fields will be extremely useful in the guiding the next generation of coronal models. The program has produced three fully operation numerical codes that model multi-species of ions in coronal loops: Static models and constant flow models. The time dependent numerical models have not been completed. We have extended the steady flow investigations to study the effect these flows have on coronal structure as observed with TRACE. Coronal observations derive from heavy-ion emission; thus, we focus on the extent to which flow may modify coronal abundances by examining the heavy-ion abundance stratification within long-lived loops. We discuss the magnitudes of the physical effects modeled and compare simulated results with TRACE observations. These results can have a profound effect on the interpretation of TRACE observations.

  15. Sesquiterpene lactone stereochemistry influences herbivore resistance and plant fitness in the field

    PubMed Central

    Ahern, Jeffrey R.; Whitney, Kenneth D.

    2014-01-01

    Background and Aims Stereochemical variation is widely known to influence the bioactivity of compounds in the context of pharmacology and pesticide science, but our understanding of its importance in mediating plant–herbivore interactions is limited, particularly in field settings. Similarly, sesquiterpene lactones are a broadly distributed class of putative defensive compounds, but little is known about their activities in the field. Methods Natural variation in sesquiterpene lactones of the common cocklebur, Xanthium strumarium (Asteraceae), was used in conjunction with a series of common garden experiments to examine relationships between stereochemical variation, herbivore damage and plant fitness. Key Results The stereochemistry of sesquiterpene lactone ring junctions helped to explain variation in plant herbivore resistance. Plants producing cis-fused sesquiterpene lactones experienced significantly higher damage than plants producing trans-fused sesquiterpene lactones. Experiments manipulating herbivore damage above and below ambient levels found that herbivore damage was negatively correlated with plant fitness. This pattern translated into significant fitness differences between chemotypes under ambient levels of herbivore attack, but not when attack was experimentally reduced via pesticide. Conclusions To our knowledge, this work represents only the second study to examine sesquiterpene lactones as defensive compounds in the field, the first to document herbivore-mediated natural selection on sesquiterpene lactone variation and the first to investigate the ecological significance of the stereochemistry of the lactone ring junction. The results indicate that subtle differences in stereochemistry may be a major determinant of the protective role of secondary metabolites and thus of plant fitness. As stereochemical variation is widespread in many groups of secondary metabolites, these findings suggest the possibility of dynamic evolutionary histories

  16. Differential responses to thermal variation between fitness metrics

    PubMed Central

    Clavijo-Baquet, Sabrina; Boher, Francisca; Ziegler, Lucia; Martel, Sebastián I.; Estay, Sergio A.; Bozinovic, Francisco

    2014-01-01

    Temperature is a major factor affecting population abundance and individual performance. Net reproductive rate (R0) and intrinsic rate of increase (r) differ in their response to different temperature regimes, and much of the difference is mediated by generation time (Tg). Here, we evaluate the effects of thermal mean and variability on R0, r and Tg, at four population densities in Drosophila melanogaster. The results show that R0, r and Tg present differential responses to thermal variation. Although temperature effects on R0 and Tg are non-linear, r response was negligible. R0 and Tg comprise a generational time scale, while r is at a chronological time scale. Thus, we argue that individuals growing under different thermal environments perform similarly on a chronological scale, but differently on a generational scale. PMID:24954717

  17. Differential responses to thermal variation between fitness metrics.

    PubMed

    Clavijo-Baquet, Sabrina; Boher, Francisca; Ziegler, Lucia; Martel, Sebastián I; Estay, Sergio A; Bozinovic, Francisco

    2014-06-23

    Temperature is a major factor affecting population abundance and individual performance. Net reproductive rate (R0) and intrinsic rate of increase (r) differ in their response to different temperature regimes, and much of the difference is mediated by generation time (Tg). Here, we evaluate the effects of thermal mean and variability on R0, r and Tg, at four population densities in Drosophila melanogaster. The results show that R0, r and Tg present differential responses to thermal variation. Although temperature effects on R0 and Tg are non-linear, r response was negligible. R0 and Tg comprise a generational time scale, while r is at a chronological time scale. Thus, we argue that individuals growing under different thermal environments perform similarly on a chronological scale, but differently on a generational scale.

  18. Low Demographic Variability in Wild Primate Populations: Fitness Impacts of Variation, Covariation, and Serial Correlation in Vital Rates

    PubMed Central

    Morris, William F.; Altmann, Jeanne; Brockman, Diane K.; Cords, Marina; Fedigan, Linda M.; Pusey, Anne E.; Stoinski, Tara S.; Bronikowski, Anne M.; Alberts, Susan C.; Strier, Karen B.

    2013-01-01

    In a stochastic environment, long-term fitness can be influenced by variation, covariation, and serial correlation in vital rates (survival and fertility). Yet no study of an animal population has parsed the contributions of these three aspects of variability to long-term fitness. We do so using a unique database that includes complete life-history information for wild-living individuals of seven primate species that have been the subjects of long-term (22–45 years) behavioral studies. Overall, the estimated levels of vital rate variation had only minor effects on long-term fitness, and the effects of vital rate covariation and serial correlation were even weaker. To explore why, we compared estimated variances of adult survival in primates with values for other vertebrates in the literature and found that adult survival is significantly less variable in primates than it is in the other vertebrates. Finally, we tested the prediction that adult survival, because it more strongly influences fitness in a constant environment, will be less variable than newborn survival, and we found only mixed support for the prediction. Our results suggest that wild primates may be buffered against detrimental fitness effects of environmental stochasticity by their highly developed cognitive abilities, social networks, and broad, flexible diets. PMID:21117962

  19. Motivational Influences on Cognitive Performance in Children: Focus Over Fit.

    PubMed

    Worthy, Darrell A; Brez, Caitlin C; Markman, Arthur B; Maddox, W Todd

    2011-01-01

    Cognitive psychologists have begun to address how motivational factors influence adults' performance on cognitive tasks. However, little research has examined how different motivational factors interact with one another to affect behavior across the lifespan. The current study examined how children perform on a classification task when placed in a regulatory fit or mismatch. Nine-year-old children performed a classification task in which they either gained or lost points for each response. Additionally, children were given either a global promotion focus (trying to earn a gift card) or a prevention focus (trying to avoid losing a gift card). Previous work indicates that adults in this task tend to perform better when there is a match (or fit) between the overall incentive to earn or avoid losing the incentive and the task reward structure to maximize points gained or minimize points lost. Unlike adults, nine-year-olds perform better in the promotion condition than in the prevention condition regardless of task reward structure. Possible explanations for the differences between adults' and children's performance are discussed as well as possible applications for academic settings.

  20. Dietary Intake Influences Adult Fertility and Offspring Fitness in Zebrafish

    PubMed Central

    Jhinku, Noel; Meier, Michael; Horsfield, Julia

    2016-01-01

    The burden of malnutrition, including both over- and undernutrition, is a major public health concern. Here we used a zebrafish model of diet-induced obesity to analyze the impact of dietary intake on fertility and the phenotype of the next generation. Over an eight-week period, one group received 60 mg of food each day (60 mg arm), while another received 5 mg (5 mg arm). At the end of the diet, the body mass index of the 60 mg arm was 1.5 fold greater than the 5 mg arm. The intervention also had a marked impact on fertility; breeding success and egg production in the 60 mg arm were increased 2.1- and 6.2-fold compared to the 5 mg arm, respectively. Transcriptome analysis of eggs revealed that transcripts involved in metabolic biological processes differed according to dietary intake. The progeny from the differentially fed fish were more likely to survive when the parents had access to more food. An intergenerational crossover study revealed that while parental diet did not influence weight gain in the offspring, the progeny of well-fed parents had increased levels of physical activity when exposed again to high nutrient availability. We conclude that dietary intake has an important influence on fertility and the subsequent fitness of offspring, even prior to breeding. PMID:27870856

  1. Eurofit Special: European Fitness Battery Score Variation among Individuals with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Skowronski, Waldemar; Horvat, Michael; Nocera, Joe; Roswal, Glenn; Croce, Ron

    2009-01-01

    The Eurofit Special Test is a battery of motor fitness tests resulting from a 10-year project of the Committee of Experts for Sports Research and is comprised of strength, speed, flexibility, and balance. The purpose of this study was to investigate whether the Eurofit Special was able to distinguish variations in functioning among individuals…

  2. A Segregating Inversion Generates Fitness Variation in Yellow Monkeyflower (Mimulus guttatus)

    PubMed Central

    Fishman, Lila; Kelly, John K.; Willis, John H.

    2016-01-01

    Polymorphic chromosomal rearrangements can bind hundreds of genes into single genetic loci with diverse effects. Rearrangements are often associated with local adaptation and speciation and may also be an important component of genetic variation within populations. We genetically and phenotypically characterize a segregating inversion (inv6) in the Iron Mountain (IM) population of Mimulus guttatus (yellow monkeyflower). We initially mapped inv6 as a region of recombination suppression in three F2 populations resulting from crosses among IM plants. In each case, the F1 parent was heterozygous for a derived haplotype, homogenous across markers spanning over 5 Mb of chromsome 6. In the three F2 populations, inv6 reduced male and female fitness components. In addition, inv6 carriers suffered an ∼30% loss of pollen viability in the field. Despite these costs, inv6 exists at moderate frequency (∼8%) in the natural population, suggesting counterbalancing fitness benefits that maintain the polymorphism. Across 4 years of monitoring in the field, inv6 had an overall significant positive effect on seed production (lifetime female fitness) of carriers. This benefit was particularly strong in harsh years and may be mediated (in part) by strong positive effects on flower production. These data suggest that opposing fitness effects maintain an intermediate frequency, and as a consequence, inv6 generates inbreeding depression and high genetic variance. We discuss these findings in relation to the theory of inbreeding depression and the maintenance of fitness variation. PMID:26868767

  3. Variation in sport participation, fitness and motor coordination with socioeconomic status among Flemish children.

    PubMed

    Vandendriessche, Joric B; Vandorpe, Barbara F R; Vaeyens, Roel; Malina, Robert M; Lefevre, Johan; Lenoir, Matthieu; Philippaerts, Renaat M

    2012-02-01

    Socioeconomic status (SES) is often indicated as a factor that influences physical activity and associated health outcomes. This study examined the relationship between SES and sport participation, morphology, fitness and motor coordination in a sample of 1955 Flemish children 6-11 years of age. Gender, age and SES-specific values for morphologic dimensions, amount and type of sport participation and fitness and motor coordination tests were compared. SES was positively and significantly associated with sport participation and sports club membership in both sexes. Although differences were not consistently significant, morphologic dimensions and tests of fitness and motor coordination showed a trend in favor of children from higher SES. The results suggest that public and local authorities should consider providing equal opportunities for children in all social strata and especially those in the lower SES to experience the beneficial effects of sport participation through which they can enhance levels of physical fitness and motor coordination.

  4. Fitness consequences of maternal and embryonic responses to environmental variation: using reptiles as models for studies of developmental plasticity.

    PubMed

    Warner, Daniel A

    2014-11-01

    Environmental factors strongly influence phenotypic variation within populations. The environment contributes to this variation in two ways: (1) by acting as a determinant of phenotypic variation (i.e., plastic responses) and (2) as an agent of selection that "chooses" among existing phenotypes. Understanding how these two environmental forces contribute to phenotypic variation is a major goal in the field of evolutionary biology and a primary objective of my research program. The objective of this article is to provide a framework to guide studies of environmental sources of phenotypic variation (specifically, developmental plasticity and maternal effects, and their adaptive significance). Two case studies from my research on reptiles are used to illustrate the general approaches I have taken to address these conceptual topics. Some key points for advancing our understanding of environmental influences on phenotypic variation include (1) merging laboratory-based research that identifies specific environmental effects with field studies to validate ecological relevance; (2) using controlled experimental approaches that mimic complex environments found in nature; (3) integrating data across biological fields (e.g., genetics, morphology, physiology, behavior, and ecology) under an evolutionary framework to provide novel insights into the underlying mechanisms that generate phenotypic variation; (4) assessing fitness consequences using measurements of survival and/or reproductive success across ontogeny (from embryos to adults) and under multiple ecologically-meaningful contexts; and (5) quantifying the strength and form of natural selection in multiple populations over multiple periods of time to understand the spatial and temporal consistency of phenotypic selection. Research programs that focus on organisms that are amenable to these approaches will provide the most promise for advancing our understanding of the environmental factors that generate the remarkable

  5. Ontogenic behavioral consistency, individual variation and fitness consequences among lady beetles.

    PubMed

    Rodrigues, Alice S; Botina, Lisbetd; Nascimento, Carolina P; Gontijo, Lessando M; Torres, Jorge B; Guedes, Raul Narciso C

    2016-10-01

    The potential relevance of complete metamorphosis for the individual variation in sets of behavioral traits and their fitness consequences in predatory species led to the present study. A set of nine behavioral traits were assessed for the larvae and adults of a pyrethroid-resistant and a susceptible population of the lady beetle Eriopis connexa. The aim was to assess: 1) the average individual behavioral (pheno)types and their within-population variation, 2) their ontogenic behavioral consistency from larva to adult, and 3) whether the observed correlated sets of behavioral traits can impact fitness. The average behavioral type differed between populations. The pyrethroid-resistant population consistently exhibited lower aggressiveness (as larvae) and exploration, but showed higher activity, as well as larva sociality, and sometimes boldness than the susceptible population. Behavioral trait variation was higher among pyrethroid-resistant individuals, particularly during the larval stage, but there was significant behavior correlation between larvae and adults, regardless of the insect population. Reduced aggressiveness, and to a lesser extent intermediate levels of boldness against heterospecific individuals were associated with higher population growth. Besides shedding light on the ontogenic consistency of behavioral traits and their fitness impact, our results also suggest that reduced aggressiveness is associated with predator population increase, but may compromise its effectiveness as a biocontrol agent.

  6. Flower and cotyledon asymmetry in Brassica cretica: genetic variation and relationships with fitness.

    PubMed

    Rao, Guang-Yuan; Andersson, Stefan; Widén, Björn

    2002-04-01

    Plants of the partially self-incompatible perennial herb Brassica cretica, derived from controlled cross- and self-pollinations within each of seven populations, were raised under uniform conditions and scored for two measures of developmental stability, flower asymmetry (quantified as the difference in length and width between opposite petals) and cotyledon asymmetry (quantified as the difference in the area of the two lobes of each cotyledon). The primary goals were to assess the level of heritable variation in asymmetry, the effect of selfing on mean asymmetry, and the relationship between asymmetry and components of fitness. A paternal half-sibling analysis of data on flower asymmetry failed to detect significant levels of genetic variation at the within-population level, whereas the between-population component reached significance for all measures of asymmetry. Analysis of family-structured data from another crossing experiment revealed significant between-population variation in cotyledon asymmetry and a tendency for inbred progeny to produce more asymmetric cotyledons than outbred progeny. However, the response to inbreeding was weak and differed in magnitude between populations. Judging from the ranking of populations, we found no support for the hypothesis that the mean expression of developmental stability is controlled by genomewide characteristics such as the level of inbreeding. Correlations between measures of asymmetry and fitness were too low to be declared statistically or biologically significant. The present study provides little evidence that flower and cotyledon asymmetry serve as more appropriate predictors of genetic health than conventional (direct) measures of fitness.

  7. Preservice Physical Education Teacher Attitudes toward Fitness Tests and the Factors Influencing Their Attitudes.

    ERIC Educational Resources Information Center

    Keating, Xiaofen Deng; Silverman, Stephen; Kulinna, Pamela Hodges

    2002-01-01

    Examined preservice teachers' attitudes toward fitness tests in schools. Respondents had only slightly positive attitudes toward fitness tests and did not consider them very important or useful. These responses persisted as students' professional preparation increased. Previous experience with fitness tests influenced their attitudes, while age,…

  8. Physical Fitness Influences Stress Reactions to Extreme Military Training

    DTIC Science & Technology

    2007-08-09

    Research Center, 140 Sylvester Road, San Diego, CA 92106. tJohns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205...examining individual differences in buman perfor- 738 MILITARY MEDICINE, Vol. 173, August 2008 Physical Fitness and Military Stress manee and stress

  9. Is death-feigning adaptive? Heritable variation in fitness difference of death-feigning behaviour.

    PubMed

    Miyatake, Takahisa; Katayama, Kohji; Takeda, Yukari; Nakashima, Akiko; Sugita, Atsushi; Mizumoto, Makoto

    2004-11-07

    The adaptation of death-feigning (thanatosis), a subject that has been overlooked in evolutionary biology, was inferred in a model prey-and-predator system. We studied phenotypic variation among individuals, fitness differences, and the inheritance of death-feigning behaviour in the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). Two-way artificial selections for the duration of death-feigning, over 10 generations, showed a clear direct response in the trait and a correlated response in the frequency of death-feigning, thus indicating variation and inheritance of death-feigning behaviour. A comparison of the two selected strains with divergent frequencies of death-feigning showed a significant difference in the fitness for survival when a model predator, a female Adanson jumper spider, Hasarius adansoni Audouin (Araneomophae: Salticidae), was presented to the beetles. The frequency of predation was lower among beetles from strains selected for long-duration than among those for short-duration death-feigning. The results indicate the possibility of the evolution of death-feigning under natural selection.

  10. Influence of Design Variations on Systems Performance

    NASA Technical Reports Server (NTRS)

    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.

  11. Socio-Cultural Influences in Eating Disorders: Focus on Sports/Fitness Program.

    ERIC Educational Resources Information Center

    Moriarty, Dick; Moriarty, Mary

    This report notes that eating disorders are frequently described as a diet and fitness program gone wild. It outlines and describes five sociocultural influences which have been identified for eating disorders: (1) emphasis on thinness; (2) glorification of youth; (3) changing roles of women; (4) emphasis on fitness and sport programs; and (5) the…

  12. Could Sport Specialization Influence Fitness and Health of Adults with Mental Retardation?

    ERIC Educational Resources Information Center

    Guidetti, Laura; Franciosi, Emanuele; Gallotta, Maria Chiara; Emerenziani, Gian Pietro; Baldari, Carlo

    2010-01-01

    Although several studies showed the positive effects of exercise and physical activity on health and well-being for individuals with ID, there is a lack of information about the influence of sport specialization on fitness and health components. Therefore, the aims of this study were to assess: (a) physical fitness of athletes with intellectual…

  13. Motivational Influences on Cognitive Performance in Children: Focus over Fit

    ERIC Educational Resources Information Center

    Worthy, Darrell A.; Brez, Caitlin C.; Markman, Arthur B.; Maddox, W. Todd

    2011-01-01

    Cognitive psychologists have begun to address how motivational factors influence adults' performance on cognitive tasks. However, little research has examined how different motivational factors interact with one another to affect behavior across the life span. In the current study, the authors examined how children perform on a classification task…

  14. A gamma variate model that includes stretched exponential is a better fit for gastric emptying data from mice

    PubMed Central

    Bajzer, Željko; Gibbons, Simon J.; Coleman, Heidi D.; Linden, David R.

    2015-01-01

    Noninvasive breath tests for gastric emptying are important techniques for understanding the changes in gastric motility that occur in disease or in response to drugs. Mice are often used as an animal model; however, the gamma variate model currently used for data analysis does not always fit the data appropriately. The aim of this study was to determine appropriate mathematical models to better fit mouse gastric emptying data including when two peaks are present in the gastric emptying curve. We fitted 175 gastric emptying data sets with two standard models (gamma variate and power exponential), with a gamma variate model that includes stretched exponential and with a proposed two-component model. The appropriateness of the fit was assessed by the Akaike Information Criterion. We found that extension of the gamma variate model to include a stretched exponential improves the fit, which allows for a better estimation of T1/2 and Tlag. When two distinct peaks in gastric emptying are present, a two-component model is required for the most appropriate fit. We conclude that use of a stretched exponential gamma variate model and when appropriate a two-component model will result in a better estimate of physiologically relevant parameters when analyzing mouse gastric emptying data. PMID:26045615

  15. Sex-specific fitness variation in gynodioecious Beta vulgaris ssp. maritima: do empirical observations fit theoretical predictions?

    PubMed

    De Cauwer, I; Arnaud, J-F; Courseaux, A; Dufay, M

    2011-11-01

    In gynodioecious species, in which hermaphroditic and female plants co-occur, the maintenance of sexual polymorphism relies on the genetic determination of sex and on the relative fitness of the different phenotypes. Flower production, components of male fitness (pollen quantity and pollen quality) and female fitness (fruit and seed set) were measured in gynodioecious Beta vulgaris spp. maritima, in which sex is determined by interactions between cytoplasmic male sterility (CMS) genes and nuclear restorers of male fertility. The results suggested that (i) female had a marginal advantage over hermaphrodites in terms of flower production only, (ii) restored CMS hermaphrodites (carrying both CMS genes and nuclear restorers) suffered a slight decrease in fruit production compared to non-CMS hermaphrodites and (iii) restored CMS hermaphrodites were poor pollen producers compared to non-CMS hermaphrodites, probably as a consequence of complex determination of restoration. These observations potentially have important consequences for the conditions of maintenance of sexual polymorphism in B. vulgaris and are discussed in the light of existing theory on evolutionary dynamics of gynodioecy.

  16. Cardiorespiratory fitness attenuates the influence of amyloid on cognition

    PubMed Central

    Schultz, Stephanie A.; Boots, Elizabeth A.; Almeida, Rodrigo P.; Oh, Jennifer M.; Einerson, Jean; Korcarz, Claudia E.; Edwards, Dorothy F.; Koscik, Rebecca L.; Dowling, Maritza N.; Gallagher, Catherine L.; Bendlin, Barbara B.; Christian, Bradley T.; Zetterberg, Henrik; Blennow, Kaj; Carlsson, Cynthia M.; Asthana, Sanjay; Hermann, Bruce P.; Sager, Mark A.; Johnson, Sterling C.; Stein, James H.; Okonkwo, Ozioma C.

    2015-01-01

    Objective To examine cross-sectionally whether higher cardiorespiratory fitness (CRF) might favorably modify amyloid-β (Aβ)-related decrements in cognition in a cohort of late-middle-aged adults at risk for Alzheimer's disease (AD). Methods Sixty-nine enrollees in the Wisconsin Registry for Alzheimer's Prevention participated in this study. They completed a comprehensive neuropsychological exam, underwent 11C Pittsburgh Compound B (PiB)-PET imaging, and performed a graded treadmill exercise test to volitional exhaustion. Peak oxygen consumption (VO2peak) during the exercise test was used as the index of CRF. Forty-five participants also underwent lumbar puncture for collection of cerebrospinal fluid (CSF) samples, from which Aβ42 was immunoassayed. Covariate-adjusted regression analyses were used to test whether the association between Aβ and cognition was modified by CRF. Results There were significant VO2peak*PiB-PET interactions for Immediate Memory (p= .041) and Verbal Learning & Memory (p= .025). There were also significant VO2peak*CSF Aβ42 interactions for Immediate Memory (p<.001) and Verbal Learning & Memory (p <.001). Specifically, in the context of high Aβ burden—i.e., increased PiB-PET binding or reduced CSF Aβ42—individuals with higher CRF exhibited significantly better cognition compared with individuals with lower CRF. Conclusion In a late-middle-aged, at-risk cohort, higher CRF is associated with a diminution of Aβ-related effects on cognition. These findings suggest that exercise might play an important role in the prevention of AD. PMID:26581795

  17. Cardiorespiratory Fitness Attenuates the Influence of Amyloid on Cognition.

    PubMed

    Schultz, Stephanie A; Boots, Elizabeth A; Almeida, Rodrigo P; Oh, Jennifer M; Einerson, Jean; Korcarz, Claudia E; Edwards, Dorothy F; Koscik, Rebecca L; Dowling, Maritza N; Gallagher, Catherine L; Bendlin, Barbara B; Christian, Bradley T; Zetterberg, Henrik; Blennow, Kaj; Carlsson, Cynthia M; Asthana, Sanjay; Hermann, Bruce P; Sager, Mark A; Johnson, Sterling C; Stein, James H; Okonkwo, Ozioma C

    2015-11-01

    The aim of this study was to examine cross-sectionally whether higher cardiorespiratory fitness (CRF) might favorably modify amyloid-β (Aβ)-related decrements in cognition in a cohort of late-middle-aged adults at risk for Alzheimer's disease (AD). Sixty-nine enrollees in the Wisconsin Registry for Alzheimer's Prevention participated in this study. They completed a comprehensive neuropsychological exam, underwent 11C Pittsburgh Compound B (PiB)-PET imaging, and performed a graded treadmill exercise test to volitional exhaustion. Peak oxygen consumption (VO2peak) during the exercise test was used as the index of CRF. Forty-five participants also underwent lumbar puncture for collection of cerebrospinal fluid (CSF) samples, from which Aβ42 was immunoassayed. Covariate-adjusted regression analyses were used to test whether the association between Aβ and cognition was modified by CRF. There were significant VO2peak*PiB-PET interactions for Immediate Memory (p=.041) and Verbal Learning & Memory (p=.025). There were also significant VO2peak*CSF Aβ42 interactions for Immediate Memory (p<.001) and Verbal Learning & Memory (p<.001). Specifically, in the context of high Aβ burden, that is, increased PiB-PET binding or reduced CSF Aβ42, individuals with higher CRF exhibited significantly better cognition compared with individuals with lower CRF. In a late-middle-aged, at-risk cohort, higher CRF is associated with a diminution of Aβ-related effects on cognition. These findings suggest that exercise might play an important role in the prevention of AD.

  18. The influence of acute intense exercise on exogenous spatial attention depends on physical fitness level.

    PubMed

    Llorens, Francesc; Sanabria, Daniel; Huertas, Florentino

    2015-01-01

    We investigated the effect of a previous bout of intense exercise on exogenous spatial attention. In Experiment 1, a group of participants performed an exogenous spatial task at rest (without prior effort), immediately after intense exercise, and after recovering from an intense exercise. The analyses revealed that the typical "facilitation effect" (i.e., faster reaction times on cued than on uncued trials) immediately after exercise was positively correlated with participants' fitness level. In Experiment 2, a high-fit and a low-fit group performed the same task at rest (without prior effort) and immediately after an intense exercise. Results revealed that, after the bout of exercise, only low-fit participants showed reduced attentional effects compared to the rest condition. We argue that the normal functioning of exogenous attention was influenced by intense effort, affecting low-fit participants to a larger extent than to high-fit participants. As a consequence, target processing was prioritized over irrelevant stimuli.

  19. Longitudinal influence of musculo-skeletal injuries and extra physical education on physical fitness in schoolchildren.

    PubMed

    Rexen, C T; Ersbøll, A K; Wedderkopp, N; Andersen, L B

    2016-12-01

    The aims of this study were to investigate if (A) injuries and (B) increased physical education (PE) influenced the development of physical fitness in schoolchildren. Simultaneously, to investigate if a possible PE effect was modified by sport participation outside school hours. This was a longitudinal controlled school-based study. Six schools with 270 min of PE (extra PE) and four schools with 90 min of PE were followed up for 2.5 years. In total, 1054 children were included for analysis (normal PE = 443, extra PE = 611). Development in fitness was analyzed using composite z-scores from six fitness tests measured four times. Information of injury and sport was derived from weekly automated mobile phone text messages surveying the presence of musculo-skeletal pain and organized sport participation. Injury and extra PE both influenced the development of physical fitness. Injury decreased development of physical fitness with -1.01 composite z-score units (95% CI: -1.57; -0.45). Extra PE increased physical fitness development with 0.80 (95% CI: 0.49; 1.10) composite z-score units. The influence of injury was not dependent on extra PE. No modifying effect was found by mean weekly sport participation outside school hours. In conclusion, extra PE had a positive effect, whereas injuries had a negative effect on physical fitness development in schoolchildren.

  20. Parent influences on physical activity participation and physical fitness of deaf children.

    PubMed

    Ellis, M Kathleen; Lieberman, Lauren J; Dummer, Gail M

    2014-04-01

    Research has consistently demonstrated that parents' values toward physical activity and fitness have strongly influenced the physical activity habits of hearing children (Welk, G. J., Wood, K., & Morss, G. [2003]. Parental influences on physical activity in children: An exploration of potential mechanisms. Pediatric Exercise Science, 15, 19-33). The primary purpose of this study was to determine whether similar findings are obtained for deaf (1) children. The influence of parents' hearing status and parents' involvement in Deaf sport (2) was assessed in addition to their values toward sports participation and physical fitness for their deaf children. Deaf children's physical activity habits were determined by the number of activities participated per week, and fitness levels by the number of scores within the Healthy Fitness Zone from the Fitnessgram test. Parents demonstrated positive values toward physical fitness regardless of hearing status; this finding was strongest among deaf parents of deaf children. Significant positive relationships were found among parents' values toward physical fitness and sport participation and children's physical activity and fitness levels, as well as between Deaf sport involvement by deaf parents and children's physical activity levels.

  1. Reproductive Fitness and Random Amplified Polymorphic DNA Variation among Isolates of Pratylenchus vulnus

    PubMed Central

    Pinochet, P.; Cenis, J. L.; Fernández, C.; Doucet, M.; Maruli, J.

    1994-01-01

    The reproductive fitness of seven isolates of Pratylenchus vulnus from different geographical areas and hosts was assessed in monoxenic cultures (carrot), and greenhouse cultures (plum, sour orange, and quince). The genetic makeup of the different isolates was compared by Random Amplified Polymorphic DNA (RAPD-PCR). The apple (PvAP-S) and apricot (PvAT-F) isolates reproduced less in monoxenic cultures than the rose (PvRO-S) and walnut (PvWA-A and PvWA-U) isolates. On plum, the rose isolate (PvRO-S) reproduced better than the apple (PvAP-S) and walnut isolate from the United States (PvWA-U). On sour orange, the apple (PvAP-S), unknown origin (PvU-UK), and walnut isolate from Argentina (PvWA-A) multiplied well, whereas the walnut isolate from the United States (PvWA-U), apricot (PvAT-F), and rose (PvRO-S) did not. On quince, the apple (PvAP-S) and walnut (PvWA-U) isolates showed a higher reproduction than the one from unknown origin (PvU-UK). RAPD-PCR patterns among the seven P. vulnus isolates were similar, although high intraspecific varibility was detected. Very few bands of P. neglectus were shared by any population of P. vulnus. A high degree of similarity was found among the patterns corresponding to the rose (PvRO-S), apple (PvAP-S), walnut from the United States (PvWA-U), and unknown origin (PvUK-U) isolates. The apricot isolate (PvAT-F) was the most dissimilar among the seven isolates. No correlation could be established between the genetic variation of P. vulnus detected by RAPD-PCR and reproductive fitness. Results demonstrate high genetic varibility between geographically separated populations of P. vulnus. PMID:19279892

  2. Resolution Influence on 3D Anthropometric Data Clustering for Fitting Design.

    PubMed

    Niu, Jianwei; Li, Zhizhong; Salvendy, Gavriel

    2009-10-01

    Sizing based on 3D anthropometric data may lead to significant improvement in fitting comfort of wearing products. However, the required computational load is a common problem in 3D data processing. In a previous study, wavelet analysis was adopted to establish a multi-resolution description of 3D anthropometric data to reduce computational load and modeling complexity. K-means clustering was subsequently performed on the decomposed 3D samples. This study further examines the influence of decomposition level on clustering results. As a case study, 378 face samples, 447 head samples and 432 upper head samples were analyzed. Cluster membership variation on five different resolution levels was examined by using Cluster Membership Accuracy Rate (CMAR), which denotes the clustering consistency on the decomposed levels compared with the clustering results on the original data sets. For the face data sets, the CMAR values on the five decomposition levels are 100, 99.21, 97.88, 93.92 and 93.39%, respectively; for upper heads, the CMAR values are 99.3, 99.1, 98.4, 92.1 and 84.3%, respectively; while for whole heads, the CMAR values are 99.3, 98.2, 95.1, 85.5 and 77.9%, respectively. These results indicate that clustering on the third decomposition level is proper for face and head scans in reducing computational load while maintaining at least 95% clustering accuracy.

  3. Influence of physical fitness, age, experience, and weekly training load on match performance in elite Australian football.

    PubMed

    Gastin, Paul B; Fahrner, Brendan; Meyer, Denny; Robinson, Dean; Cook, Jill L

    2013-05-01

    Season long competition schedules in football create unique challenges for coaches in balancing the requirements of recovery, developing and maintaining physical fitness, and adjusting the training load before each match. The aim of this study was to investigate the influence of player characteristics (physical fitness, age, and playing experience) and weekly in-season training load on elite match performance across an Australian football season. Twenty-five players (age: 24.1 ± 3.0 years; height: 188.3 ± 7.3 cm; weight: 90.4 ± 8.3 kg) from one elite team participated in this study. Before the season, player's age, experience, height, and weight along with measures of aerobic (6-minute run) and anaerobic (6 × 40 m repeated sprints) physical fitness were recorded. Individual player training load during the season was measured using global positioning system technology for the main training session of the week. Player match performance was calculated weekly from 33 individual playing statistics. Multilevel modeling was used to investigate the relationship between weekly training load and match performance and to explore the influence of player characteristics on this relationship. Playing experience (p < 0.01) and aerobic fitness (p < 0.05) displayed positive relationships with performance, whereas player age (p < 0.01) showed a negative relationship. Most players coped well with weekly variations in training load; however, the relationship was moderated by the results of the preseason repeated sprint test (p < 0.05). The adverse effect on playing performance in selected players after a more intense training session suggests that recovery from the session may be delayed in players who exhibit a better anaerobic fitness profile.

  4. Genetic variation in fitness within a clonal population of a plant RNA virus.

    PubMed

    Cervera, Héctor; Elena, Santiago F

    2016-01-01

    A long-standing observation in evolutionary virology is that RNA virus populations are highly polymorphic, composed by a mixture of genotypes whose abundances in the population depend on complex interaction between fitness differences, mutational coupling and genetic drift. It was shown long ago, though in cell cultures, that most of these genotypes had lower fitness than the population they belong, an observation that explained why single-virion passages turned on Muller's ratchet while very large population passages resulted in fitness increases in novel environments. Here we report the results of an experiment specifically designed to evaluate in vivo the fitness differences among the subclonal components of a clonal population of the plant RNA virus tobacco etch potyvirus (TEV). Over 100 individual biological subclones from a TEV clonal population well adapted to the natural tobacco host were obtained by infectivity assays on a local lesion host. The replicative fitness of these subclones was then evaluated during infection of tobacco relative to the fitness of large random samples taken from the starting clonal population. Fitness was evaluated at increasing number of days post-inoculation. We found that at early days, the average fitness of subclones was significantly lower than the fitness of the clonal population, thus confirming previous observations that most subclones contained deleterious mutations. However, as the number of days of viral replication increases, population size expands exponentially, more beneficial and compensatory mutations are produced, and selection becomes more effective in optimizing fitness, the differences between subclones and the population disappeared.

  5. Cognitive Performance and Heart Rate Variability: The Influence of Fitness Level

    PubMed Central

    Luque-Casado, Antonio; Zabala, Mikel; Morales, Esther; Mateo-March, Manuel; Sanabria, Daniel

    2013-01-01

    In the present study, we investigated the relation between cognitive performance and heart rate variability as a function of fitness level. We measured the effect of three cognitive tasks (the psychomotor vigilance task, a temporal orienting task, and a duration discrimination task) on the heart rate variability of two groups of participants: a high-fit group and a low-fit group. Two major novel findings emerged from this study. First, the lowest values of heart rate variability were found during performance of the duration discrimination task, compared to the other two tasks. Second, the results showed a decrement in heart rate variability as a function of the time on task, although only in the low-fit group. Moreover, the high-fit group showed overall faster reaction times than the low-fit group in the psychomotor vigilance task, while there were not significant differences in performance between the two groups of participants in the other two cognitive tasks. In sum, our results highlighted the influence of cognitive processing on heart rate variability. Importantly, both behavioral and physiological results suggested that the main benefit obtained as a result of fitness level appeared to be associated with processes involving sustained attention. PMID:23437276

  6. Phenotypic Variation in Fitness Traits of a Managed Solitary Bee, Osmia ribifloris (Hymenoptera: Megachilidae).

    PubMed

    Sampson, B J; Rinehart, T A; Kirker, G T; Stringer, S J; Werle, C T

    2015-12-01

    We investigated fitness in natural populations of a managed solitary bee Osmia ribifloris Cockerell (Hymenoptera: Megachilidae) from sites separated from 400 to 2,700 km. Parental wild bees originated in central Texas (TX), central-northern Utah (UT), and central California (CA). They were then intercrossed and raised inside a mesh enclosure in southern Mississippi (MS). Females from all possible mated pairs of O. ribifloris produced F1 broods with 30-40% female cocoons and outcrossed progeny were 30% heavier. Mitochondrial (COI) genomes of the four populations revealed three distinct clades, a TX-CA clade, a UT clade, and an MS clade, the latter (MS) representing captive progeny of CA and UT bees. Although classified as separate subspecies, TX and CA populations from 30° N to 38° N latitude shared 98% similarity in COI genomes and the greatest brood biomass per nest straw (600- to 700-mg brood). Thus, TX and CA bees show greater adaptation for southern U.S. sites. In contrast, UT-sourced bees were more distantly related to TX and CA bees and also produced ∼50% fewer brood. These results, taken together, confirm that adult O. ribifloris from all trap-nest sites are genetically compatible, but some phenotypic variation exists that could affect this species performance as a commercial blueberry pollinator. Males, their sperm, or perhaps a substance in their sperm helped stabilize our captive bee population by promoting legitimate nesting over nest usurpation. Otherwise, without insemination, 50% fewer females nested (they nested 14 d late) and 20% usurped nests, killing 33-67% of brood in affected nests.

  7. Individual Variation in Life History Characteristics Can Influence Extinction Risk

    SciTech Connect

    Jager, H I

    2001-01-01

    The white sturgeon (Acipenser transmontanus) shows great individual variation in the age at maturation. This study examines the consequences of model assumptions about individual variation in the age at maturation on predicted population viability. I considered: (1) the effects of variation in age at maturation alone; (2) the effects of heritability; and (3) the influence of a stable and an altered selective regime. Two selective regimes represented conditions before and after the impoundment of a river, blocking access of anadromous white sturgeon populations to the ocean. In contrast to previous simulation studies, I found that increased individual variation in the age at maturity did not necessarily lead to a higher likelihood of persistence. Individual variation increased the simulated likelihood of persistence when the variation was heritable and the selective regime had changed such that the mean age at maturity was no longer optimal.

  8. Fitting the Rasch Model to Account for Variation in Item Discrimination

    ERIC Educational Resources Information Center

    Weitzman, R. A.

    2009-01-01

    Building on the Kelley and Gulliksen versions of classical test theory, this article shows that a logistic model having only a single item parameter can account for varying item discrimination, as well as difficulty, by using item-test correlations to adjust incorrect-correct (0-1) item responses prior to an initial model fit. The fit occurs…

  9. Genetic variation in fitness within a clonal population of a plant RNA virus

    PubMed Central

    Cervera, Héctor; Elena, Santiago F.

    2016-01-01

    A long-standing observation in evolutionary virology is that RNA virus populations are highly polymorphic, composed by a mixture of genotypes whose abundances in the population depend on complex interaction between fitness differences, mutational coupling and genetic drift. It was shown long ago, though in cell cultures, that most of these genotypes had lower fitness than the population they belong, an observation that explained why single-virion passages turned on Muller’s ratchet while very large population passages resulted in fitness increases in novel environments. Here we report the results of an experiment specifically designed to evaluate in vivo the fitness differences among the subclonal components of a clonal population of the plant RNA virus tobacco etch potyvirus (TEV). Over 100 individual biological subclones from a TEV clonal population well adapted to the natural tobacco host were obtained by infectivity assays on a local lesion host. The replicative fitness of these subclones was then evaluated during infection of tobacco relative to the fitness of large random samples taken from the starting clonal population. Fitness was evaluated at increasing number of days post-inoculation. We found that at early days, the average fitness of subclones was significantly lower than the fitness of the clonal population, thus confirming previous observations that most subclones contained deleterious mutations. However, as the number of days of viral replication increases, population size expands exponentially, more beneficial and compensatory mutations are produced, and selection becomes more effective in optimizing fitness, the differences between subclones and the population disappeared. PMID:27774299

  10. Regional brain activation as a biological marker of affective responsivity to acute exercise: influence of fitness.

    PubMed

    Petruzzello, S J; Hall, E E; Ekkekakis, P

    2001-01-01

    Previous research has shown that regional brain activation, assessed via frontal electroencephalographic (EEG) asymmetry, predicts affective responsivity to aerobic exercise. To replicate and extend this work, in the present study we examined whether resting brain activation was associated with affective responses to an acute bout of aerobic exercise and the extent to which aerobic fitness mediated this relationship. Participants (high-fit, n = 22; low/moderate-fit, n = 45) ran on a treadmill for 30 min at 75% VO2max. EEG and affect were assessed pre- and 0-, 10-, 20-, and 30-min postexercise. Resting EEG asymmetry predicted positive affect (as measured by the energetic arousal subscale of the Activation Deactivation Adjective Check List) postexercise. Furthermore, resting frontal EEG asymmetry predicted affect only in the high-fit group, suggesting the effect might be mediated by some factor related to fitness. It was also shown that subjects with relatively greater left frontal activation had significantly more energy (i.e., activated pleasant affect) following exercise than subjects with relatively greater right frontal activation. In conclusion, aerobic fitness influenced the relationship between resting frontal asymmetry and exercise-related affective responsivity.

  11. Pedigree-based inbreeding coefficient explains more variation in fitness than heterozygosity at 160 microsatellites in a wild bird population.

    PubMed

    Nietlisbach, Pirmin; Keller, Lukas F; Camenisch, Glauco; Guillaume, Frédéric; Arcese, Peter; Reid, Jane M; Postma, Erik

    2017-03-15

    Although the pedigree-based inbreeding coefficient F predicts the expected proportion of an individual's genome that is identical-by-descent (IBD), heterozygosity at genetic markers captures Mendelian sampling variation and thereby provides an estimate of realized IBD. Realized IBD should hence explain more variation in fitness than their pedigree-based expectations, but how many markers are required to achieve this in practice remains poorly understood. We use extensive pedigree and life-history data from an island population of song sparrows (Melospiza melodia) to show that the number of genetic markers and pedigree depth affected the explanatory power of heterozygosity and F, respectively, but that heterozygosity measured at 160 microsatellites did not explain more variation in fitness than F This is in contrast with other studies that found heterozygosity based on far fewer markers to explain more variation in fitness than F Thus, the relative performance of marker- and pedigree-based estimates of IBD depends on the quality of the pedigree, the number, variability and location of the markers employed, and the species-specific recombination landscape, and expectations based on detailed and deep pedigrees remain valuable until we can routinely afford genotyping hundreds of phenotyped wild individuals of genetic non-model species for thousands of genetic markers.

  12. [Variation of the judgment of the fitness to specific work in a cohort study in construction industry].

    PubMed

    Riva, M M; Pavesi, G; Papageorgiou, C; Mosconi, G

    2005-01-01

    This work shows the results of a study about variation of the judgement of the fitness to specific work in the construction industry in a year. In the 8.6% of the cases, after a year from the previous examination, it was necessary to express new limitations to the job activity mainly because of the presence of illness of the musculoskeletal or cardiovascular system. Considering only workers aged over 35 years, the percentage of variation after a year grows to 12.3%.

  13. Does Plant Origin Influence the Fitness Impact of Flower Damage? A Meta-Analysis

    PubMed Central

    González-Browne, Catalina; Murúa, Maureen M.; Navarro, Luis; Medel, Rodrigo

    2016-01-01

    Herbivory has been long considered an important component of plant-animal interactions that influences the success of invasive species in novel habitats. One of the most important hypotheses linking herbivory and invasion processes is the enemy-release hypothesis, in which exotic plants are hypothesized to suffer less herbivory and fitness-costs in their novel ranges as they leave behind their enemies in the original range. Most evidence, however, comes from studies on leaf herbivory, and the importance of flower herbivory for the invasion process remains largely unknown. Here we present the results of a meta-analysis of the impact of flower herbivory on plant reproductive success, using as moderators the type of damage caused by floral herbivores and the residence status of the plant species. We found 51 papers that fulfilled our criteria. We also included 60 records from unpublished data of the laboratory, gathering a total of 143 case studies. The effects of florivory and nectar robbing were both negative on plant fitness. The methodology employed in studies of flower herbivory influenced substantially the outcome of flower damage. Experiments using natural herbivory imposed a higher fitness cost than simulated herbivory, such as clipping and petal removal, indicating that studies using artificial herbivory as surrogates of natural herbivory underestimate the real fitness impact of flower herbivory. Although the fitness cost of floral herbivory was high both in native and exotic plant species, floral herbivores had a three-fold stronger fitness impact on exotic than native plants, contravening a critical element of the enemy-release hypothesis. Our results suggest a critical but largely unrecognized role of floral herbivores in preventing the spread of introduced species into newly colonized areas. PMID:26785039

  14. The fitness of dispersing spotted hyaena sons is influenced by maternal social status

    PubMed Central

    Höner, Oliver P.; Wachter, Bettina; Hofer, Heribert; Wilhelm, Kerstin; Thierer, Dagmar; Trillmich, Fritz; Burke, Terry; East, Marion L.

    2010-01-01

    Life history theory predicts that mothers should provide their offspring with a privileged upbringing if this enhances their offspring's and their own fitness. In many mammals, high-ranking mothers provide their offspring with a privileged upbringing. Whether dispersing sons gain fitness benefits during adulthood from such privileges (a 'silver spoon' effect) has rarely been examined. In this paper, we show that in the complex, female-dominated society of spotted hyaenas, high-born sons grew at higher rates, were more likely to disperse to clans offering the best fitness prospects, started reproducing earlier and had a higher reproductive value than did lower-born sons. This illustrates the evolutionary importance of maternal effects even in societies in which male size or fighting ability does not influence fitness. By demonstrating for the first time in a non-human mammal that maternal status influences immigration patterns, the study also advances our understanding of two key ecological and evolutionary processes, dispersal and habitat selection. PMID:20975715

  15. The Influence of Body Mass Index on Long-Term Fitness from Physical Education in Adolescent Girls

    ERIC Educational Resources Information Center

    Camhi, Sarah M.; Phillips, Jennie; Young, Deborah R.

    2011-01-01

    Background: Physical education (PE) can improve physical fitness; however, little research has evaluated PE's long-term influence. The purpose is to determine PE's longitudinal effects on fitness in a group of adolescent girls and to determine whether body mass index (BMI) status influenced any potential effects. Methods: Participants were…

  16. The influence of age, playing position, anthropometry and fitness on career attainment outcomes in rugby league.

    PubMed

    Till, Kevin; Cobley, Steve; Morley, David; O'hara, John; Chapman, Chris; Cooke, Carlton

    2016-01-01

    This study evaluated the influence of annual-age category, relative age, playing position, anthropometry and fitness on the career attainment outcomes of junior rugby league players originally selected for a talent identification and development (TID) programme. Junior rugby league players (N = 580) were grouped retrospectively according to their career attainment level (i.e., amateur, academy and professional). Anthropometric (height, sitting height, body mass, sum of four skinfolds), maturational (age at peak height velocity; PHV) and fitness (power, speed, change of direction speed, estimated[Formula: see text]) characteristics were assessed at the Under 13s, 14s and 15s annual-age categories. Relative age (Q2 = 8.5% vs. Q4 = 25.5%) and playing position (Pivots = 19.5% vs. Props = 5.8%) influenced the percentage of players attaining professional status. Anthropometry and fitness had a significant effect on career attainment at the Under 14 (P = 0.002, η(2) = 0.16) and 15 (P = 0.01, η(2) = 0.12) annual-age categories. Findings at the Under 14s showed future professional players were significantly later maturing compared to academy and amateur players. Findings suggest that relative age, playing position, anthropometry and fitness can influence the career attainment of junior rugby league players. TID programmes within rugby league, and other related team sports, should be aware and acknowledge the factors influencing long-term career attainment, and not delimit development opportunities during early adolescence.

  17. Variation in Mutational Robustness between Different Proteins and the Predictability of Fitness Effects.

    PubMed

    Lind, Peter A; Arvidsson, Lars; Berg, Otto G; Andersson, Dan I

    2016-11-08

    Random mutations in genes from disparate protein classes may have different distributions of fitness effects (DFEs) depending on different structural, functional, and evolutionary constraints. We measured the fitness effects of 156 single mutations in the genes encoding AraC (transcription factor), AraD (enzyme), and AraE (transporter) used for bacterial growth on l-arabinose. Despite their different molecular functions these genes all had bimodal DFEs with most mutations either being neutral or strongly deleterious, providing a general expectation for the DFE. This contrasts with the unimodal DFEs previously obtained for ribosomal protein genes where most mutations were slightly deleterious. Based on theoretical considerations, we suggest that the 33-fold higher average mutational robustness of ribosomal proteins is due to stronger selection for reduced costs of translational and transcriptional errors. Whereas the large majority of synonymous mutations were deleterious for ribosomal proteins genes, no fitness effects could be detected for the AraCDE genes. Four mutations in AraC and AraE increased fitness, suggesting that slightly advantageous mutations make up a significant fraction of the DFE, but that they often escape detection due to the limited sensitivity of commonly used fitness assays. We show that the fitness effects of amino acid substitutions can be predicted based on evolutionary conservation, but those weakly deleterious mutations are less reliably detected. This suggests that large-effect mutations and the fraction of highly deleterious mutations can be computationally predicted, but that experiments are required to characterize the DFE close to neutrality, where many mutations ultimately fixed in a population will occur.

  18. Emergence timing and fitness consequences of variation in seed oil composition in Arabidopsis thaliana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early seedling emergence can increase plant fitness under competition. Seed oil composition (the types and relative amounts of fatty acids in the oils) may play an important role in determining emergence timing in oilseeds. Saturated fatty acids provide more energy per carbon atom than unsaturated...

  19. Could sport specialization influence fitness and health of adults with mental retardation?

    PubMed

    Guidetti, Laura; Franciosi, Emanuele; Gallotta, Maria Chiara; Emerenziani, Gian Pietro; Baldari, Carlo

    2010-01-01

    Although several studies showed the positive effects of exercise and physical activity on health and well-being for individuals with ID, there is a lack of information about the influence of sport specialization on fitness and health components. Therefore, the aims of this study were to assess: (a) physical fitness of athletes with intellectual disability (ID) compared with individuals included in recreational and leisure activity programs (non-athletic people); (b) contribution of sport specialization on athletes' fitness; and c) correlation of each fitness variable with subjects' ID levels. Twenty-two track and field, 19 basketball, and 23 non-athletic adults were recruited. Before and after a 9-month period, all participants performed fitness tests assessing body composition, flexibility (SR), arm muscular strength (HG), lower and upper-body muscular strength and endurance (SUP and PUP), explosive leg power (SLJ), cardiovascular endurance (ST), balance ability (FT), motor coordination (TUGT). The results showed that participants' weight, BMI and FT were significantly affected by time; SLJ by activity; ST, HG, PUP, SUP, and TUGT by both time and activity. Only track and field athletes increased significantly ST. All athletes improved significantly HG, PUP and SUP, instead non-athletic people decreased significantly SUP (p<0.01). TUGT improved significantly in track and field athletes (p<0.05), and decreased significantly in non-athletic people. ID level was positively correlated to TUGT. Findings of this study showed that physical activity improved fitness in adult athletes with ID, decreasing health risks. Athletes with lower ID obtained higher performance scores in motor coordination test.

  20. Influence of aerobic fitness and body fatness on tolerance to uncompensable heat stress.

    PubMed

    Selkirk, G A; McLellan, T M

    2001-11-01

    This study examined the independent and combined importance of aerobic fitness and body fatness on physiological tolerance and exercise time during weight-bearing exercise while wearing a semipermeable protective ensemble. Twenty-four men and women were matched for aerobic fitness and body fatness in one of four groups (4 men and 2 women in each group). Aerobic fitness was expressed per kilogram of lean body mass (LBM) to eliminate the influence of body fatness on the expression of fitness. Subjects were defined as trained (T; regularly active with a peak aerobic power of 65 ml x kg LBM(-1) x min(-1)) or untrained (UT; sedentary with a peak aerobic power of 53 ml x kg LBM(-1) x min(-1)) with high (High; 20%) or low (Low; 11%) body fatness. Subjects exercised until exhaustion or until rectal temperature reached 39.5 degrees C or heart rate reached 95% of maximum. Exercise times were significantly greater in T(Low) (116 +/- 6.5 min) compared with their matched sedentary (UT(Low); 70 +/- 3.6 min) or fatness (T(High); 82 +/- 3.9 min) counterparts, indicating an advantage for both a high aerobic fitness and low body fatness. However, similar effects were not evident between T(High) and UT(High) (74 +/- 4.1 min) or between the UT groups (UT(Low) and UT(High)). The major advantage attributed to a higher aerobic fitness was the ability to tolerate a higher core temperature at exhaustion (the difference being as great as 0.9 degrees C), whereas both body fatness and rate of heat storage affected the exercise time as independent factors.

  1. Does Male Care, Provided to Immature Individuals, Influence Immature Fitness in Rhesus Macaques?

    PubMed Central

    Langos, Doreen; Kulik, Lars; Ruiz-Lambides, Angelina; Widdig, Anja

    2015-01-01

    Among many mammals, maternal care strongly impacts infant survival; however, less is known about whether adult males also affect infant fitness. Paternal care is expected when providing care enhances offspring survival and reproduction, which likewise increases fathers’ fitness. Males might also care for unrelated immature individuals to increase their mating probability with the immature individuals’ mothers. Studies in multimale primate groups showed that sires enhance food access for offspring and provide protection in conflicts. Furthermore, fathers’ presence during infancy has been suggested to accelerate offspring sexual maturation. However, no study has yet directly linked the degree of father-offspring bonds to offspring fitness in primates. We previously reported father-offspring affiliation in rhesus macaques, pronounced during early infancy and independent of mothers’ presence. The present study aims at investigating whether affiliation with fathers or other males affects proxies of immature fitness (body mass gain, body fat and testis size). First, we combined behavioral, genetic and morphometric data from 55 subjects of one group. Second, using demographic and genetic data, we investigated for 92 individuals of the population whether mother- and father-offspring co-residence during immaturity influenced offspring lifetime reproductive success (LRS). Our results show that focal rank and higher amounts of affiliation with high-ranking males during infancy tend to positively impact body mass gain of female, but not male focal animals. In contrast, body mass gain of male focal individuals, but not females’, appeared to be higher when affiliation of male immature individuals was evenly distributed across their adult male partners. Moreover, we found mothers’, but not fathers’, presence during immaturity to predict offspring LRS. Our results suggest that male-immature affiliation, but not father-offspring co-residence, potentially impacts

  2. Identification of quantitative genetic components of fitness variation in farmed, hybrid and native salmon in the wild

    PubMed Central

    Besnier, F; Glover, K A; Lien, S; Kent, M; Hansen, M M; Shen, X; Skaala, Ø

    2015-01-01

    Feral animals represent an important problem in many ecosystems due to interbreeding with wild conspecifics. Hybrid offspring from wild and domestic parents are often less adapted to local environment and ultimately, can reduce the fitness of the native population. This problem is an important concern in Norway, where each year, hundreds of thousands of farm Atlantic salmon escape from fish farms. Feral fish outnumber wild populations, leading to a possible loss of local adaptive genetic variation and erosion of genetic structure in wild populations. Studying the genetic factors underlying relative performance between wild and domesticated conspecific can help to better understand how domestication modifies the genetic background of populations, and how it may alter their ability to adapt to the natural environment. Here, based upon a large-scale release of wild, farm and wild x farm salmon crosses into a natural river system, a genome-wide quantitative trait locus (QTL) scan was performed on the offspring of 50 full-sib families, for traits related to fitness (length, weight, condition factor and survival). Six QTLs were detected as significant contributors to the phenotypic variation of the first three traits, explaining collectively between 9.8 and 14.8% of the phenotypic variation. The seventh QTL had a significant contribution to the variation in survival, and is regarded as a key factor to understand the fitness variability observed among salmon in the river. Interestingly, strong allelic correlation within one of the QTL regions in farmed salmon might reflect a recent selective sweep due to artificial selection. PMID:26059968

  3. Emergence timing and fitness consequences of variation in seed oil composition in Arabidopsis thaliana

    PubMed Central

    Pelc, Sandra E; Linder, C Randal

    2015-01-01

    Early seedling emergence can increase plant fitness under competition. Seed oil composition (the types and relative amounts of fatty acids in the oils) may play an important role in determining emergence timing and early growth rate in oilseeds. Saturated fatty acids provide more energy per carbon atom than unsaturated fatty acids but have substantially higher melting points (when chain length is held constant). This characteristic forms the basis of an adaptive hypothesis that lower melting point seeds (lower proportion of saturated fatty acids) should be favored under colder germination temperatures due to earlier germination and faster growth before photosynthesis, while at warmer germination temperatures, seeds with a higher amount of energy (higher proportion of saturated fatty acids) should be favored. To assess the effects of seed oil melting point on timing of seedling emergence and fitness, high- and low-melting point lines from a recombinant inbred cross of Arabidopsis thaliana were competed in a fully factorial experiment at warm and cold temperatures with two different density treatments. Emergence timing between these lines was not significantly different at either temperature, which aligned with warm temperature predictions, but not cold temperature predictions. Under all conditions, plants competing against high-melting point lines had lower fitness relative to those against low-melting point lines, which matched expectations for undifferentiated emergence times. PMID:25628873

  4. Emergence timing and fitness consequences of variation in seed oil composition in Arabidopsis thaliana.

    PubMed

    Pelc, Sandra E; Linder, C Randal

    2015-01-01

    Early seedling emergence can increase plant fitness under competition. Seed oil composition (the types and relative amounts of fatty acids in the oils) may play an important role in determining emergence timing and early growth rate in oilseeds. Saturated fatty acids provide more energy per carbon atom than unsaturated fatty acids but have substantially higher melting points (when chain length is held constant). This characteristic forms the basis of an adaptive hypothesis that lower melting point seeds (lower proportion of saturated fatty acids) should be favored under colder germination temperatures due to earlier germination and faster growth before photosynthesis, while at warmer germination temperatures, seeds with a higher amount of energy (higher proportion of saturated fatty acids) should be favored. To assess the effects of seed oil melting point on timing of seedling emergence and fitness, high- and low-melting point lines from a recombinant inbred cross of Arabidopsis thaliana were competed in a fully factorial experiment at warm and cold temperatures with two different density treatments. Emergence timing between these lines was not significantly different at either temperature, which aligned with warm temperature predictions, but not cold temperature predictions. Under all conditions, plants competing against high-melting point lines had lower fitness relative to those against low-melting point lines, which matched expectations for undifferentiated emergence times.

  5. Inbreeding influences within-brood heterozygosity-fitness correlations (HFCS) in an isolated passerine population.

    PubMed

    Townsend, Sheena M; Jamieson, Ian G

    2013-08-01

    Molecular estimates of inbreeding may be made using genetic markers such as microsatellites, however the interpretation of resulting heterozygosity-fitness correlations (HFCs) with respect to inbreeding depression is not straightforward. We investigated the relationship between pedigree-determined inbreeding coefficients (f) and HFCs in a closely monitored, reintroduced population of Stewart Island robins (Petroica australis rakiura) on Ulva Island, New Zealand. Using a full sibling design, we focused on differences in juvenile survival associated specifically with individual sibling variation in standardized multilocus heterozygosity (SH) when expected f was identical. We found that within broods, siblings with higher SH at microsatellite loci experienced a higher probability of juvenile survival. This effect, however, was detected primarily within broods that experienced inbreeding or when inbreeding had occurred in their pedigree histories (i.e., at the parents' level). Thus we show, for the first time in a wild population, that the strength of an HFC is partially dependent on the presence of inbreeding events in the recent pedigree history. Our results illustrate the importance of realized effects of inbreeding on genetic variation and fitness and the value of full-sibling designs for the study of HFCs in the context of small, inbred populations.

  6. Cognitive ability influences reproductive life history variation in the wild.

    PubMed

    Cole, Ella F; Morand-Ferron, Julie; Hinks, Amy E; Quinn, John L

    2012-10-09

    Cognition has been studied intensively for several decades, but the evolutionary processes that shape individual variation in cognitive traits remain elusive [1-3]. For instance, the strength of selection on a cognitive trait has never been estimated in a natural population, and the possibility that positive links with life history variation [1-5] are mitigated by costs [6] or confounded by ecological factors remains unexplored in the wild. We assessed novel problem-solving performance in 468 wild great tits Parus major temporarily taken into captivity and subsequently followed up their reproductive performance in the wild. Problem-solver females produced larger clutches than nonsolvers. This benefit did not arise because solvers timed their breeding better, occupied better habitats, or compromised offspring quality or their own survival. Instead, foraging range size and day length were relatively small and short, respectively, for solvers, suggesting that they were more efficient at exploiting their environment. In contrast to the positive effect on clutch size, problem solvers deserted their nests more often, leading to little or no overall selection on problem-solving performance. Our results are consistent with the idea that variation in cognitive ability is shaped by contrasting effects on different life history traits directly linked to fitness [1, 3].

  7. Type of fitness cost influences the rate of evolution of resistance to transgenic Bt crops.

    PubMed

    Hackett, Sean C; Bonsall, Michael B

    2016-10-01

    The evolution of resistance to pesticides by insect pests is a significant challenge for sustainable agriculture. For transgenic crops expressing Bacillus thuringiensis (Bt), crystalline (Cry) toxins resistance evolution may be delayed by the high-dose/refuge strategy in which a non-toxic refuge is planted to promote the survival of susceptible insects. The high-dose/refuge strategy may interact with fitness costs associated with resistance alleles to further delay resistance. However, while a diverse range of fitness costs are reported in the field, they are typically represented as a fixed reduction in survival or viability which is insensitive to ecological conditions such as competition. Furthermore, the potential dynamic consequences of restricting susceptible insects to a refuge which represents only a fraction of the available space have rarely been considered.We present a generalized discrete time model which utilizes dynamic programming methods to derive the optimal management decisions for the control of a theoretical insect pest population exposed to Bt crops. We consider three genotypes (susceptible homozygotes, resistant homozygotes and heterozygotes) and implement fitness costs of resistance to Bt toxins as either a decrease in the relative competitive ability of resistant insects or as a penalty on fecundity. Model analysis is repeated and contrasted for two types of density dependence: uniform density dependence which operates equally across the landscape and heterogeneous density dependence where the intensity of competition scales inversely with patch size and is determined separately for the refuge and Bt crop.When the planting of Bt is decided optimally, fitness costs to fecundity allow for the planting of larger areas of Bt crops than equivalent fitness costs that reduce the competitive ability of resistant insects.Heterogeneous competition only influenced model predictions when the proportional area of Bt planted in each season was decided

  8. Indy gene variation in natural populations confers fitness advantage and life span extension through transposon insertion.

    PubMed

    Zhu, Chen-Tseh; Chang, Chengyi; Reenan, Robert A; Helfand, Stephen L

    2014-01-01

    Natural selection acts to maximize reproductive fitness. However, antagonism between life span and reproductive success frequently poses a dilemma pitting the cost of fecundity against longevity. Here, we show that natural populations of Drosophila melanogaster harbor a Hoppel transposon insertion variant in the longevity gene Indy (I'm not dead yet), which confers both increased reproduction and longevity through metabolic changes. Heterozygosity for this natural long-lived variant has been maintained in isolates despite long-term inbreeding under laboratory conditions and advantageously confers increased fecundity. DNA sequences of variant chromosome isolates show evidence of selective sweep acting on the advantageous allele, suggesting that natural selection acts to maintain this variant. The transposon insertion also regulates Indy expression level, which has experimentally been shown to affect life span and fecundity. Thus, in the wild, evolution reaffirms that the mechanism of heterozygote advantage has acted upon the Indy gene to assure increased reproductive fitness and, coincidentally, longer life span through regulatory transposon mutagenesis.

  9. Dissimilar Fitness Associated with Resistance to Fluoroquinolones Influences Clonal Dynamics of Various Multiresistant Bacteria

    PubMed Central

    Fuzi, Miklos

    2016-01-01

    Fitness cost associated with resistance to fluoroquinolones was recently shown to vary across clones of methicillin-resistant Staphylococcus aureus and extended-spectrum β-lactamase-producing Klebsiella pneumoniae. The resulting dissimilar fitness should have influenced the clonal dynamics and thereby the rates of resistance for these pathogens. Moreover, a similar mechanism was recently proposed for the emergence of the H30 and H30R lineages of ESBL-producing E. coli and the major international clone (ribotype 027) of Clostridium difficile. Furthermore, several additional international clones of various multiresistant bacteria are suspect to have been selected by an analogous process. An ability to develop favorable mutations in the gyrase and topoisomerase IV genes seems to be a prerequisite for pathogens to retain fitness while showing high-level resistance to fluoroquinolones. Since, the consumption of other “non-fluoroquinolone” groups of antibiotics have also contributed to the rise in resistance rates a more judicious use of antibiotics in general and of fluoroquinolones in particular could ameliorate the international resistance situation. PMID:27458434

  10. Consumer trait variation influences tritrophic interactions in salt marsh communities.

    PubMed

    Hughes, Anne Randall; Hanley, Torrance C; Orozco, Nohelia P; Zerebecki, Robyn A

    2015-07-01

    The importance of intraspecific variation has emerged as a key question in community ecology, helping to bridge the gap between ecology and evolution. Although much of this work has focused on plant species, recent syntheses have highlighted the prevalence and potential importance of morphological, behavioral, and life history variation within animals for ecological and evolutionary processes. Many small-bodied consumers live on the plant that they consume, often resulting in host plant-associated trait variation within and across consumer species. Given the central position of consumer species within tritrophic food webs, such consumer trait variation may play a particularly important role in mediating trophic dynamics, including trophic cascades. In this study, we used a series of field surveys and laboratory experiments to document intraspecific trait variation in a key consumer species, the marsh periwinkle Littoraria irrorata, based on its host plant species (Spartina alterniflora or Juncus roemerianus) in a mixed species assemblage. We then conducted a 12-week mesocosm experiment to examine the effects of Littoraria trait variation on plant community structure and dynamics in a tritrophic salt marsh food web. Littoraria from different host plant species varied across a suite of morphological and behavioral traits. These consumer trait differences interacted with plant community composition and predator presence to affect overall plant stem height, as well as differentially alter the density and biomass of the two key plant species in this system. Whether due to genetic differences or phenotypic plasticity, trait differences between consumer types had significant ecological consequences for the tritrophic marsh food web over seasonal time scales. By altering the cascading effects of the top predator on plant community structure and dynamics, consumer differences may generate a feedback over longer time scales, which in turn influences the degree of trait

  11. Consumer trait variation influences tritrophic interactions in salt marsh communities

    PubMed Central

    Hughes, Anne Randall; Hanley, Torrance C; Orozco, Nohelia P; Zerebecki, Robyn A

    2015-01-01

    The importance of intraspecific variation has emerged as a key question in community ecology, helping to bridge the gap between ecology and evolution. Although much of this work has focused on plant species, recent syntheses have highlighted the prevalence and potential importance of morphological, behavioral, and life history variation within animals for ecological and evolutionary processes. Many small-bodied consumers live on the plant that they consume, often resulting in host plant-associated trait variation within and across consumer species. Given the central position of consumer species within tritrophic food webs, such consumer trait variation may play a particularly important role in mediating trophic dynamics, including trophic cascades. In this study, we used a series of field surveys and laboratory experiments to document intraspecific trait variation in a key consumer species, the marsh periwinkle Littoraria irrorata, based on its host plant species (Spartina alterniflora or Juncus roemerianus) in a mixed species assemblage. We then conducted a 12-week mesocosm experiment to examine the effects of Littoraria trait variation on plant community structure and dynamics in a tritrophic salt marsh food web. Littoraria from different host plant species varied across a suite of morphological and behavioral traits. These consumer trait differences interacted with plant community composition and predator presence to affect overall plant stem height, as well as differentially alter the density and biomass of the two key plant species in this system. Whether due to genetic differences or phenotypic plasticity, trait differences between consumer types had significant ecological consequences for the tritrophic marsh food web over seasonal time scales. By altering the cascading effects of the top predator on plant community structure and dynamics, consumer differences may generate a feedback over longer time scales, which in turn influences the degree of trait

  12. One Size Does Not Fit All: Understanding the Variation in Charter Management Scale-Up

    ERIC Educational Resources Information Center

    Farrell, Caitlin; Nayfack, Michelle B.; Smith, Joanna; Wohlstetter, Priscilla

    2014-01-01

    The prevalence of charter management organizations (CMOs)--networks of charter schools overseen by a home office--has exploded in recent years but there is a paucity of research into how CMOs approach growth and the factors that influence their growth plans. In this qualitative study, we examine how a set of 25 older, more established CMOs…

  13. Phenotypic variation and fitness in a metapopulation of tubeworms (Ridgeia piscesae Jones) at hydrothermal vents.

    PubMed

    Tunnicliffe, Verena; St Germain, Candice; Hilário, Ana

    2014-01-01

    We examine the nature of variation in a hot vent tubeworm, Ridgeia piscesae, to determine how phenotypes are maintained and how reproductive potential is dictated by habitat. This foundation species at northeast Pacific hydrothermal sites occupies a wide habitat range in a highly heterogeneous environment. Where fluids supply high levels of dissolved sulphide for symbionts, the worm grows rapidly in a "short-fat" phenotype characterized by lush gill plumes; when plumes are healthy, sperm package capture is higher. This form can mature within months and has a high fecundity with continuous gamete output and a lifespan of about three years in unstable conditions. Other phenotypes occupy low fluid flux habitats that are more stable and individuals grow very slowly; however, they have low reproductive readiness that is hampered further by small, predator cropped branchiae, thus reducing fertilization and metabolite uptake. Although only the largest worms were measured, only 17% of low flux worms were reproductively competent compared to 91% of high flux worms. A model of reproductive readiness illustrates that tube diameter is a good predictor of reproductive output and that few low flux worms reached critical reproductive size. We postulate that most of the propagules for the vent fields originate from the larger tubeworms that live in small, unstable habitat patches. The large expanses of worms in more stable low flux habitat sustain a small, but long-term, reproductive output. Phenotypic variation is an adaptation that fosters both morphological and physiological responses to differences in chemical milieu and predator pressure. This foundation species forms a metapopulation with variable growth characteristics in a heterogeneous environment where a strategy of phenotypic variation bestows an advantage over specialization.

  14. Phenotypic Variation and Fitness in a Metapopulation of Tubeworms (Ridgeia piscesae Jones) at Hydrothermal Vents

    PubMed Central

    Tunnicliffe, Verena; St. Germain, Candice; Hilário, Ana

    2014-01-01

    We examine the nature of variation in a hot vent tubeworm, Ridgeia piscesae, to determine how phenotypes are maintained and how reproductive potential is dictated by habitat. This foundation species at northeast Pacific hydrothermal sites occupies a wide habitat range in a highly heterogeneous environment. Where fluids supply high levels of dissolved sulphide for symbionts, the worm grows rapidly in a “short-fat” phenotype characterized by lush gill plumes; when plumes are healthy, sperm package capture is higher. This form can mature within months and has a high fecundity with continuous gamete output and a lifespan of about three years in unstable conditions. Other phenotypes occupy low fluid flux habitats that are more stable and individuals grow very slowly; however, they have low reproductive readiness that is hampered further by small, predator cropped branchiae, thus reducing fertilization and metabolite uptake. Although only the largest worms were measured, only 17% of low flux worms were reproductively competent compared to 91% of high flux worms. A model of reproductive readiness illustrates that tube diameter is a good predictor of reproductive output and that few low flux worms reached critical reproductive size. We postulate that most of the propagules for the vent fields originate from the larger tubeworms that live in small, unstable habitat patches. The large expanses of worms in more stable low flux habitat sustain a small, but long-term, reproductive output. Phenotypic variation is an adaptation that fosters both morphological and physiological responses to differences in chemical milieu and predator pressure. This foundation species forms a metapopulation with variable growth characteristics in a heterogeneous environment where a strategy of phenotypic variation bestows an advantage over specialization. PMID:25337895

  15. Between-school variation in physical activity, aerobic fitness, and organized sports participation: a multi-level analysis.

    PubMed

    Kristensen, Peter L; Olesen, Line G; Ried-Larsen, Mathias; Grøntved, Anders; Wedderkopp, Niels; Froberg, Karsten; Andersen, Lars B

    2013-01-01

    A large proportion of a child's day is spent at school interacting with certain physical surroundings, teachers, and school friends. Thus, schools could have a marked impact on establishing physical activity habits. The aim of the present study was to assess between-school variation in physical activity, aerobic fitness, and organized sports participation. Altogether, we tested 1766 nine- and fifteen-year-old children attending 242 school classes at 35 different schools in Denmark in 1997-2003. The intra-class correlation coefficient (ICC) for objectively assessed physical activity ranged between 0.06 and 0.18 depending on the dimension of physical activity and the time considered (i.e. school time vs. leisure time). For aerobic fitness, an ICC of 0.10 was observed, whereas that for organized sports participation ranged between 0.01 and 0.10 depending on the age group. Studying between-school variation in physical activity provides information about the extent to which children adjust their physical activity habits according to the social and environmental circumstances that they share, and helps to plan future school-based physical activity studies, especially in terms of sample size and power calculation.

  16. The Influence of Diet Composition on Fitness of the Blue Crab, Callinectes sapidus

    PubMed Central

    Belgrad, Benjamin A.; Griffen, Blaine D.

    2016-01-01

    The physiological condition and fecundity of an organism is frequently controlled by diet. As changes in environmental conditions often cause organisms to alter their foraging behavior, a comprehensive understanding of how diet influences the fitness of an individual is central to predicting the effect of environmental change on population dynamics. We experimentally manipulated the diet of the economically and ecologically important blue crab, Callinectes sapidus, to approximate the effects of a dietary shift from primarily animal to plant tissue, a phenomenon commonly documented in crabs. Crabs whose diet consisted exclusively of animal tissue had markedly lower mortality and consumed substantially more food than crabs whose diet consisted exclusively of seaweed. The quantity of food consumed had a significant positive influence on reproductive effort and long-term energy stores. Additionally, seaweed diets produced a three-fold decrease in hepatopancreas lipid content and a simultaneous two-fold increase in crab aggression when compared to an animal diet. Our results reveal that the consumption of animal tissue substantially enhanced C. sapidus fitness, and suggest that a dietary shift to plant tissue may reduce crab population growth by decreasing fecundity as well as increasing mortality. This study has implications for C. sapidus fisheries. PMID:26784581

  17. The Influence of Diet Composition on Fitness of the Blue Crab, Callinectes sapidus.

    PubMed

    Belgrad, Benjamin A; Griffen, Blaine D

    2016-01-01

    The physiological condition and fecundity of an organism is frequently controlled by diet. As changes in environmental conditions often cause organisms to alter their foraging behavior, a comprehensive understanding of how diet influences the fitness of an individual is central to predicting the effect of environmental change on population dynamics. We experimentally manipulated the diet of the economically and ecologically important blue crab, Callinectes sapidus, to approximate the effects of a dietary shift from primarily animal to plant tissue, a phenomenon commonly documented in crabs. Crabs whose diet consisted exclusively of animal tissue had markedly lower mortality and consumed substantially more food than crabs whose diet consisted exclusively of seaweed. The quantity of food consumed had a significant positive influence on reproductive effort and long-term energy stores. Additionally, seaweed diets produced a three-fold decrease in hepatopancreas lipid content and a simultaneous two-fold increase in crab aggression when compared to an animal diet. Our results reveal that the consumption of animal tissue substantially enhanced C. sapidus fitness, and suggest that a dietary shift to plant tissue may reduce crab population growth by decreasing fecundity as well as increasing mortality. This study has implications for C. sapidus fisheries.

  18. Parasite fitness traits under environmental variation: disentangling the roles of a chytrid's immediate host and external environment.

    PubMed

    Van den Wyngaert, Silke; Vanholsbeeck, Olivier; Spaak, Piet; Ibelings, Bas W

    2014-10-01

    Parasite environments are heterogeneous at different levels. The first level of variability is the host itself. The second level represents the external environment for the hosts, to which parasites may be exposed during part of their life cycle. Both levels are expected to affect parasite fitness traits. We disentangle the main and interaction effects of variation in the immediate host environment, here the diatom Asterionella formosa (variables host cell volume and host condition through herbicide pre-exposure) and variation in the external environment (variables host density and acute herbicide exposure) on three fitness traits (infection success, development time and reproductive output) of a chytrid parasite. Herbicide exposure only decreased infection success in a low host density environment. This result reinforces the hypothesis that chytrid zoospores use photosynthesis-dependent chemical cues to locate its host. At high host densities, chemotaxis becomes less relevant due to increasing chance contact rates between host and parasite, thereby following the mass-action principle in epidemiology. Theoretical support for this finding is provided by an agent-based simulation model. The immediate host environment (cell volume) substantially affected parasite reproductive output and also interacted with the external herbicide exposed environment. On the contrary, changes in the immediate host environment through herbicide pre-exposure did not increase infection success, though it had subtle effects on zoospore development time and reproductive output. This study shows that both immediate host and external environment as well as their interaction have significant effects on parasite fitness. Disentangling these effects improves our understanding of the processes underlying parasite spread and disease dynamics.

  19. Fitness consequences of natural variation in flooding-induced shoot elongation in Rumex palustris.

    PubMed

    Chen, Xin; Visser, Eric J W; de Kroon, Hans; Pierik, Ronald; Voesenek, Laurentius A C J; Huber, Heidrun

    2011-04-01

    • Plants can respond to their environment by morphological plasticity. Generally, the potential benefits of adaptive plastic responses are beyond doubt under predictable environmental changes. However, the net benefits may be less straightforward when plants encounter temporal stresses, such as flooding in river flood plains. • Here, we tested whether the balance of costs and benefits associated with flooding-induced shoot elongation depends on the flooding regime, by subjecting Rumex palustris plants with different elongation capacity to submergence of different frequency and duration. • Our results showed that reaching the surface by shoot elongation is associated with fitness benefits, as under less frequent, but longer, flooding episodes plants emerging above the floodwater had greater biomass production than plants that were kept below the surface. As we predicted, slow-elongating plants had clear advantages over fast-elongating ones if submergence was frequent but of short duration, indicating that elongation also incurs costs. • Our data suggest that high costs select for weak plasticity under frequent environmental change. In contrast to our predictions, however, fast-elongating plants did not have an overall advantage over slow-elongating plants when floods lasted longer. This indicates that the delicate balance between benefits and costs of flooding-induced elongation depends on the specific characteristics of the flooding regime.

  20. Better stay together: pair bond duration increases individual fitness independent of age-related variation

    PubMed Central

    Sánchez-Macouzet, Oscar; Rodríguez, Cristina; Drummond, Hugh

    2014-01-01

    Prolonged pair bonds have the potential to improve reproductive performance of socially monogamous animals by increasing pair familiarity and enhancing coordination and cooperation between pair members. However, this has proved very difficult to test robustly because of important confounds such as age and reproductive experience. Here, we address limitations of previous studies and provide a rigorous test of the mate familiarity effect in the socially monogamous blue-footed booby, Sula nebouxii, a long-lived marine bird with a high divorce rate. Taking advantage of a natural disassociation between age and pair bond duration in this species, and applying a novel analytical approach to a 24 year database, we found that those pairs which have been together for longer establish their clutches five weeks earlier in the season, hatch more of their eggs and produce 35% more fledglings, regardless of age and reproductive experience. Our results demonstrate that pair bond duration increases individual fitness and further suggest that synergistic effects between a male and female's behaviour are likely to be involved in generating a mate familiarity effect. These findings help to explain the age- and experience-independent benefits of remating and their role in life-history evolution. PMID:24827435

  1. Spatiotemporal Variation in Distance Dependent Animal Movement Contacts: One Size Doesn’t Fit All

    PubMed Central

    Brommesson, Peter; Wennergren, Uno; Lindström, Tom

    2016-01-01

    The structure of contacts that mediate transmission has a pronounced effect on the outbreak dynamics of infectious disease and simulation models are powerful tools to inform policy decisions. Most simulation models of livestock disease spread rely to some degree on predictions of animal movement between holdings. Typically, movements are more common between nearby farms than between those located far away from each other. Here, we assessed spatiotemporal variation in such distance dependence of animal movement contacts from an epidemiological perspective. We evaluated and compared nine statistical models, applied to Swedish movement data from 2008. The models differed in at what level (if at all), they accounted for regional and/or seasonal heterogeneities in the distance dependence of the contacts. Using a kernel approach to describe how probability of contacts between farms changes with distance, we developed a hierarchical Bayesian framework and estimated parameters by using Markov Chain Monte Carlo techniques. We evaluated models by three different approaches of model selection. First, we used Deviance Information Criterion to evaluate their performance relative to each other. Secondly, we estimated the log predictive posterior distribution, this was also used to evaluate their relative performance. Thirdly, we performed posterior predictive checks by simulating movements with each of the parameterized models and evaluated their ability to recapture relevant summary statistics. Independent of selection criteria, we found that accounting for regional heterogeneity improved model accuracy. We also found that accounting for seasonal heterogeneity was beneficial, in terms of model accuracy, according to two of three methods used for model selection. Our results have important implications for livestock disease spread models where movement is an important risk factor for between farm transmission. We argue that modelers should refrain from using methods to simulate

  2. Spatiotemporal Variation in Distance Dependent Animal Movement Contacts: One Size Doesn't Fit All.

    PubMed

    Brommesson, Peter; Wennergren, Uno; Lindström, Tom

    2016-01-01

    The structure of contacts that mediate transmission has a pronounced effect on the outbreak dynamics of infectious disease and simulation models are powerful tools to inform policy decisions. Most simulation models of livestock disease spread rely to some degree on predictions of animal movement between holdings. Typically, movements are more common between nearby farms than between those located far away from each other. Here, we assessed spatiotemporal variation in such distance dependence of animal movement contacts from an epidemiological perspective. We evaluated and compared nine statistical models, applied to Swedish movement data from 2008. The models differed in at what level (if at all), they accounted for regional and/or seasonal heterogeneities in the distance dependence of the contacts. Using a kernel approach to describe how probability of contacts between farms changes with distance, we developed a hierarchical Bayesian framework and estimated parameters by using Markov Chain Monte Carlo techniques. We evaluated models by three different approaches of model selection. First, we used Deviance Information Criterion to evaluate their performance relative to each other. Secondly, we estimated the log predictive posterior distribution, this was also used to evaluate their relative performance. Thirdly, we performed posterior predictive checks by simulating movements with each of the parameterized models and evaluated their ability to recapture relevant summary statistics. Independent of selection criteria, we found that accounting for regional heterogeneity improved model accuracy. We also found that accounting for seasonal heterogeneity was beneficial, in terms of model accuracy, according to two of three methods used for model selection. Our results have important implications for livestock disease spread models where movement is an important risk factor for between farm transmission. We argue that modelers should refrain from using methods to simulate

  3. Variation potential influence on photosynthetic cyclic electron flow in pea

    PubMed Central

    Sukhov, Vladimir; Surova, Lyubov; Sherstneva, Oksana; Katicheva, Lyubov; Vodeneev, Vladimir

    2015-01-01

    Cyclic electron flow is an important component of the total photosynthetic electron flow and participates in adaptation to the action of stressors. Local leaf stimulation induces electrical signals, including variation potential (VP), which inactivate photosynthesis; however, their influence on cyclic electron flow has not been investigated. The aim of this study was to investigate VP's influence on cyclic electron flow in pea (Pisum sativum L.). VP was induced in pea seedling leaves by local heating and measured in an adjacent, undamaged leaf by extracellular electrodes. CO2 assimilation was measured using a portable gas exchange measuring system. Photosystem I and II parameters were investigated using a measuring system for simultaneous assessment of P700 oxidation and chlorophyll fluorescence. Heating-induced VP reduced CO2 assimilation and electron flow through photosystem II. In response, cyclic electron flow rapidly decreased and subsequently slowly increased. Slow increases in cyclic flow were caused by decreased electron flow through photosystem II, which was mainly connected with VP-induced photosynthetic dark stage inactivation. However, direct influence by VP on photosystem I also participated in activation of cyclic electron flow. Thus, VP, induced by local leaf-heating, activated cyclic electron flow in undamaged leaves. This response was similar to photosynthetic changes observed under the direct action of stressors. Possible mechanisms of VP's influence on cyclic flow were discussed. PMID:25610447

  4. Genetic Variations Strongly Influence Phenotypic Outcome in the Mouse Retina

    PubMed Central

    Jelcick, Austin S.; Yuan, Yang; Leehy, Barrett D.; Cox, Lakeisha C.; Silveira, Alexandra C.; Qiu, Fang; Schenk, Sarah; Sachs, Andrew J.; Morrison, Margaux A.; Nystuen, Arne M.; DeAngelis, Margaret M.; Haider, Neena B.

    2011-01-01

    Variation in genetic background can significantly influence the phenotypic outcome of both disease and non-disease associated traits. Additionally, differences in temporal and strain specific gene expression can also contribute to phenotypes in the mammalian retina. This is the first report of microarray based cross-strain analysis of gene expression in the retina investigating genetic background effects. Microarray analyses were performed on retinas from the following mouse strains: C57BL6/J, AKR/J, CAST/EiJ, and NOD.NON-H2-nb1 at embryonic day 18.5 (E18.5) and postnatal day 30.5 (P30.5). Over 3000 differentially expressed genes were identified between strains and developmental stages. Differential gene expression was confirmed by qRT-PCR, Western blot, and immunohistochemistry. Three major gene networks were identified that function to regulate retinal or photoreceptor development, visual perception, cellular transport, and signal transduction. Many of the genes in these networks are implicated in retinal diseases such as bradyopsia, night-blindness, and cone-rod dystrophy. Our analysis revealed strain specific variations in cone photoreceptor cell patterning and retinal function. This study highlights the substantial impact of genetic background on both development and function of the retina and the level of gene expression differences tolerated for normal retinal function. These strain specific genetic variations may also be present in other tissues. In addition, this study will provide valuable insight for the development of more accurate models for human retinal diseases. PMID:21779340

  5. Preseason variations in aerobic fitness and performance in elite-standard soccer players: a team study.

    PubMed

    Castagna, Carlo; Impellizzeri, Franco M; Chaouachi, Anis; Manzi, Vincenzo

    2013-11-01

    The aim of this study was to examine the effects of individual training loads considered as permanent in selected heart-rate (HR) zones on aerobic fitness and performance in elite professional soccer players. Eighteen professional soccer players were observed during the prechampionship training period (8 weeks). Speeds and HR at 2 and 4 mmol · L blood-lactate concentrations (S2, S4, respectively), VO2max, and Yo-Yo intermittent recovery test level 1 performance (Yo-Yo IR1) were assessed pretraining and posttraining. Training intensities were categorized using 3 HR zones: low intensity (


    HR 4 mmol · L). Training-session HRs (n = 900) showed a polarized distribution with 73.6 ± 3.7 (2,945 ± 148 minutes), 19.1 ± 3.5 (763 ± 141 minutes), and 7.3 ± 2.9% (292 ± 116 minutes) of the total training time spent at low, moderate, and high intensities, respectively (p < 0.001). The S2 and S4 significantly improved posttraining (+10 and 7%, respectively, p < 0.001). The VO2max and Yo-Yo IR1 values were 6 and 19.5% higher posttraining, respectively (p < 0.01). Training performed at high intensity was significantly related to relative improvement in S2 (r = 0.78, p = 0.002), S4 (r = 0.60, p = 0.03), VO2max (r = 0.65, p = 0.02), and Yo-Yo IR1 (r = 0.66, p = 0.01). The results of this study provided further evidence for HR longitudinal validity and effectiveness of the high-intensity training (i.e., >90% HRmax) in men's professional soccer. In this regard, the time spent at high intensity should be in the range of 7-8% of the total training time during preseason.

  6. The Influence of Functional Fitness and Cognitive Training of Physical Disabilities of Institutions

    PubMed Central

    Yeh, I-Chen; Chang, Chia-Ming; Chen, Ko-Chia; Hong, Wei-Chin; Lu, Yu-Hsiung

    2015-01-01

    According to an investigation done by Taiwan Ministry of the Interior in 2013, there was more than 90% of the disability care institutions mainly based on life care. Previous studies have shown that individuals can effectively improve physical and cognitive training, improved in independent living and everyday competence. The purpose of the study was to investigate influence of the intervention program applying functional fitness and cognitive training to disabled residents in the institution. The subjects were disabled persons of a care institution in southern Taiwan and were randomly divided into training and control groups, both having 17 subjects. The age of the subjects was between 56 and 98 years with a mean age of 79.08 ± 10.04 years; the subjects of training group implemented 12 weeks of training on physical and cognitive training, while the control group subjects did not have any training program. The results revealed that subjects of the training group have significantly improved their functional shoulder rotation flexibility of left and right anterior hip muscle group flexibility of right, sitting functional balance of left and right, naming, attention, delayed recall, orientation, and Montreal cognitive assessment (MOCA). The study suggested developing physical fitness programs and physical and cognitive prescriptions for the disabled people of the institutions. PMID:25756064

  7. The influence of active components of Eleutherococcus senticosus on cellular defence and physical fitness in man.

    PubMed

    Szołomicki, J; Samochowiec, L; Wójcicki, J; Droździk, M; Szołomicki, S

    2000-02-01

    The influence of active components of Eleutherococcus senticosus, contained in Taiga Wurzel preparation, were studied on cellular defence and physical fitness in man. 50 healthy volunteers of both sexes were selected, and basic clinical examination and laboratory tests were performed in all subjects. All were randomly subdivided into two study groups: group A with 35 subjects receiving Taiga Wurzel and group B with 15 subjects receiving Echinacea. 20 healthy males were randomly selected from both groups and underwent an ergospirometric study. The preparations were administered for 30 days as follows: Taiga Wurzel 25 drops three times daily, Echinacea 40 drops three times daily. After 1 month blood was drawn for control tests. Changes in the following blood parameters were observed in comparison to initial values in group A: total and LDL cholesterol, triglycerides and glucose. No alterations were seen in group B. The ergospirometric test revealed a higher oxygen plateau in group A (Taiga Wurzel). On the basis of the present study the following conclusions were drawn: active components in Eleutherococcus senticosus contained in Taiga Wurzel preparation affect cellular defence and physical fitness, as well as lipid metabolism.

  8. The influence of motivation on stress: is it stressful not to fit?

    PubMed

    Schwab, Sebastian; Wolf, Oliver T; Memmert, Daniel

    2015-01-01

    The present research elaborates on the regulatory fit hypothesis by investigating a biological stress marker in a motivational fit- and non-fit-situation. Recent stress theories lead to the assumption that the participants' stress level in fit-situations remains constant or rather decreases, whereas under non-fit-conditions an increase of the stress activity is observed. We tested this hypothesis by assessment of salivary α-amylase (sAA), a saliva-based stress marker presumed to reflect noradrenergic activity. The results indicated that participants in a fit-situation show a decrease in sAA, whereas participants in a non-fit-situation demonstrate a contrary effect with an increase in sAA. These findings extend the concept of regulatory fit by illustrating that there are differences in sAA activity depending on whether participants are in a fit-situation. The experience of regulatory fit appears to be associated with a reduction of stress.

  9. Extreme variation in migration strategies between and within wandering albatross populations during their sabbatical year, and their fitness consequences.

    PubMed

    Weimerskirch, Henri; Delord, Karine; Guitteaud, Audrey; Phillips, Richard A; Pinet, Patrick

    2015-03-09

    Migratory behavior, routes and zones used during the non-breeding season are assumed to have been selected to maximize fitness, and can lead to genetic differentiation. Yet, here we show that migration strategies differ markedly between and within two genetically similar populations of wandering albatross Diomedea exulans from the Crozet and Kerguelen archipelagos in the Indian Ocean. Wandering albatrosses usually breed biennially if successful, and during the sabbatical year, all birds from Kerguelen migrate to the Pacific Ocean, whereas most from Crozet are sedentary. Instead of taking the shortest routes, which would involve a return against headwinds, migratory birds fly with the westerly winds, requiring detours of 10,000 s km. In total, migrants circumnavigate Antarctica 2 to 3 times, covering more than 120,000 km in a single sabbatical year. Our results indicate strong links between migratory behavior and fitness; all birds from Kerguelen breed biennially, whereas a significant proportion of those from Crozet, especially females, are sedentary and breed in consecutive calendar years. To breed annually, these females temporarily change mate, but return to their original partner in the following year. This extreme variation in migratory behavior has important consequences in term of life history evolution and susceptibility to climate change and fisheries.

  10. Extreme variation in migration strategies between and within wandering albatross populations during their sabbatical year, and their fitness consequences

    PubMed Central

    Weimerskirch, Henri; Delord, Karine; Guitteaud, Audrey; Phillips, Richard A.; Pinet, Patrick

    2015-01-01

    Migratory behavior, routes and zones used during the non-breeding season are assumed to have been selected to maximize fitness, and can lead to genetic differentiation. Yet, here we show that migration strategies differ markedly between and within two genetically similar populations of wandering albatross Diomedea exulans from the Crozet and Kerguelen archipelagos in the Indian Ocean. Wandering albatrosses usually breed biennially if successful, and during the sabbatical year, all birds from Kerguelen migrate to the Pacific Ocean, whereas most from Crozet are sedentary. Instead of taking the shortest routes, which would involve a return against headwinds, migratory birds fly with the westerly winds, requiring detours of 10,000 s km. In total, migrants circumnavigate Antarctica 2 to 3 times, covering more than 120,000 km in a single sabbatical year. Our results indicate strong links between migratory behavior and fitness; all birds from Kerguelen breed biennially, whereas a significant proportion of those from Crozet, especially females, are sedentary and breed in consecutive calendar years. To breed annually, these females temporarily change mate, but return to their original partner in the following year. This extreme variation in migratory behavior has important consequences in term of life history evolution and susceptibility to climate change and fisheries. PMID:25747757

  11. Mitochondrial sequence variation suggests an African influence in Portuguese cattle.

    PubMed Central

    Cymbron, T; Loftus, R T; Malheiro, M I; Bradley, D G

    1999-01-01

    A total of 49 samples from indigenous Portuguese cattle breeds were analysed for sequence variation in the hypervariable region of the mitochondrial DNA D-loop. Sequence comparison and phylogenetic analyses revealed that haplotypes fell into two distinct groups. These corresponded with two separate haplotype clusters into which, respectively, all African, or alternatively all sequences of European origin, have previously been shown to fall. Here, the majority of sequences of African type were encountered in three southern, as compared to three northern breeds. This pattern of African influence may reflect an intercontinental admixture in the initial origins of Iberian breeds, or it is perhaps an introgression dating from the long and influential Moorish occupation of the south of the Iberian peninsula. PMID:10212450

  12. Interspecific competition influences fitness benefits of assortative mating for territorial aggression in eastern bluebirds (Sialia sialis).

    PubMed

    Harris, Morgan R; Siefferman, Lynn

    2014-01-01

    Territorial aggression influences fitness and, in monogamous pairs, the behavior of both individuals could impact reproductive success. Moreover, territorial aggression is particularly important in the context of interspecific competition. Tree swallows and eastern bluebirds are highly aggressive, secondary cavity-nesting birds that compete for limited nesting sites. We studied eastern bluebirds at a field site in the southern Appalachian Mountains that has been recently colonized (<40 yr) by tree swallows undergoing a natural range expansion. The field site is composed of distinct areas where bluebirds compete regularly with tree swallows and areas where there is little interaction between the two species. Once birds had settled, we measured how interspecific competition affects the relationship between assortative mating (paired individuals that behave similarly) and reproductive success in eastern bluebirds. We found a strong tendency toward assortative mating throughout the field site. In areas of high interspecific competition, pairs that behaved the most similarly and displayed either extremely aggressive or extremely non-aggressive phenotypes experienced higher reproductive success. Our data suggest that interspecific competition with tree swallows may select for bluebirds that express similar behavior to that of their mate. Furthermore, animal personality may be an important factor influencing the outcome of interactions between native and aggressive, invasive species.

  13. Interspecific Competition Influences Fitness Benefits of Assortative Mating for Territorial Aggression in Eastern Bluebirds (Sialia sialis)

    PubMed Central

    Harris, Morgan R.; Siefferman, Lynn

    2014-01-01

    Territorial aggression influences fitness and, in monogamous pairs, the behavior of both individuals could impact reproductive success. Moreover, territorial aggression is particularly important in the context of interspecific competition. Tree swallows and eastern bluebirds are highly aggressive, secondary cavity-nesting birds that compete for limited nesting sites. We studied eastern bluebirds at a field site in the southern Appalachian Mountains that has been recently colonized (<40 yr) by tree swallows undergoing a natural range expansion. The field site is composed of distinct areas where bluebirds compete regularly with tree swallows and areas where there is little interaction between the two species. Once birds had settled, we measured how interspecific competition affects the relationship between assortative mating (paired individuals that behave similarly) and reproductive success in eastern bluebirds. We found a strong tendency toward assortative mating throughout the field site. In areas of high interspecific competition, pairs that behaved the most similarly and displayed either extremely aggressive or extremely non-aggressive phenotypes experienced higher reproductive success. Our data suggest that interspecific competition with tree swallows may select for bluebirds that express similar behavior to that of their mate. Furthermore, animal personality may be an important factor influencing the outcome of interactions between native and aggressive, invasive species. PMID:24516672

  14. Aerobic fitness influences cerebral oxygenation response to maximal exercise in healthy subjects.

    PubMed

    Oussaidene, Kahina; Prieur, Fabrice; Tagougui, Semah; Abaidia, Abdelbasset; Matran, Regis; Mucci, Patrick

    2015-01-01

    The study examined whether the aerobic fitness level modifies the cerebral oxygenation response to incremental ramp exercise, and more specifically the decline in cerebral oxygenation from heavy exercise up to maximal intensities. 11 untrained (VO2max 47.3±4.0 mL min(-1) kg(-1)) and 13 endurance-trained (VO2max 61.2±8.0 mL min(-1) kg(-1)) healthy men performed a maximal ramp cycle exercise. Left prefrontal cortex oxygenation (ΔHbO2) was monitored by near-infrared spectroscopy. A cerebral oxygenation threshold decline (ThCOx) during exercise was determined. ThCox occurred in all subjects but for higher VO2 (mL min(-1) kg(-1)) in endurance-trained than in untrained subjects (P<0.01). At submaximal exercise intensity corresponding to ThCOx, ΔHbO2 was higher in endurance-trained than in untrained subjects (P<0.05). VO2 at ThCox was related to VO2 at respiratory compensation point (n=24, r=0.93, P<0.001) and to VO2max (n=24, r=0.92, P<0.001). These findings indicate that above the respiratory compensation point the prefrontal O2 demand exceeds the supply in untrained and in endurance-trained subjects. In addition, the occurrence of ThCOx was delayed to higher absolute exercise intensities in endurance-trained in relation with their higher VO2max than untrained men. These results demonstrated that aerobic fitness influences cerebral oxygenation during exercise.

  15. Influence of megapolis on the physical field variations

    NASA Astrophysics Data System (ADS)

    Riabova, Svetlana; Loktev, Dmitry; Spivak, Alexander

    2016-04-01

    The research of geophysical fields in the conditions of megapolis attracts particular interest not only in terms of their influence on the operation of precision equipment and technological processes associated with nanotechnology, but also it is perhaps the most important in terms of the formation of a special human and other biological objects' habitat. Indeed, the megapolis causes significant changes in regime of the physical fields both directly and indirectly. Negative factors of megapolis associated with elevated vibrations of soil as a result of traffic, acoustic load in the construction of infrastructure and transport communications, etc. are complemented by another negative factor, which until quite recently wasn't known much. It is a variation of physical fields (primarily electric and magnetic) induced by anthropogenic activities. As a result of the evolution a man has adapted to the natural regime of physical fields. Therefore, any, even the short-term changes of physical fields in the environment, their deviations from the natural rate can have a significant influence on human health including changes in the psycho-emotional state. In the present work we have evaluated the influence of the megapolis (in our case, Moscow) on the nature and regime of microseismic, electric and acoustic field in the surface atmosphere. We have analyzed data obtained as a result of continuous simultaneous registration of physical fields and meteorological parameters at the Center for geophysical monitoring of Moscow of Institute of Geosphere Dynamics of Russian Academy of Sciences. For determination of the characteristics of physical fields in the megapolis obtained data were compared with the results of the registration carried out at the Geophysical Observatory "Mikhnevo" of IDG RAS (located 85 km south from Moscow). The work is shown that the influence of the megapolis appears to increase the amplitude of physical fields, change of their spectral composition

  16. Different CAD/CAM-processing routes for zirconia restorations: influence on fitting accuracy.

    PubMed

    Kohorst, Philipp; Junghanns, Janet; Dittmer, Marc P; Borchers, Lothar; Stiesch, Meike

    2011-08-01

    The aim of the present in vitro study was to evaluate the influence of different processing routes on the fitting accuracy of four-unit zirconia fixed dental prostheses (FDPs) fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM). Three groups of zirconia frameworks with ten specimens each were fabricated. Frameworks of one group (CerconCAM) were produced by means of a laboratory CAM-only system. The other frameworks were made with different CAD/CAM systems; on the one hand by in-laboratory production (CerconCAD/CAM) and on the other hand by centralized production in a milling center (Compartis) after forwarding geometrical data. Frameworks were then veneered with the recommended ceramics, and marginal accuracy was determined using a replica technique. Horizontal marginal discrepancy, vertical marginal discrepancy, absolute marginal discrepancy, and marginal gap were evaluated. Statistical analyses were performed by one-way analysis of variance (ANOVA), with the level of significance chosen at 0.05. Mean horizontal discrepancies ranged between 22 μm (CerconCAM) and 58 μm (Compartis), vertical discrepancies ranged between 63 μm (CerconCAD/CAM) and 162 μm (CerconCAM), and absolute marginal discrepancies ranged between 94 μm (CerconCAD/CAM) and 181 μm (CerconCAM). The marginal gap varied between 72 μm (CerconCAD/CAM) and 112 μm (CerconCAM, Compartis). Statistical analysis revealed that, with all measurements, the marginal accuracy of the zirconia FDPs was significantly influenced by the processing route used (p < 0.05). Within the limitations of this study, all restorations showed a clinically acceptable marginal accuracy; however, the results suggest that the CAD/CAM systems are more precise than the CAM-only system for the manufacture of four-unit FDPs.

  17. Relationship between ambulatory capacity and cardiorespiratory fitness in chronic stroke: Influence of stroke-specific impairments

    PubMed Central

    Pang, Marco YC; Eng, Janice J; Dawson, Andrew S

    2016-01-01

    Study Objectives To identify in individuals with chronic stroke (1) the relationship between the maximal oxygen uptake (VO2max) during cycle ergometry and the distance covered in the Six Minute Walk Test (6MWT), and (2) the stroke-specific impairments which are important determinants for the 6MWT distance. Design Cross-sectional study using a convenience sample. Setting Exercise testing laboratory in a tertiary rehabilitation center. Participants Sixty-three older adults (mean age ± standard deviation, 65.3 ± 8.7) with an average post-stroke interval of 5.5 ± 4.9 years. Intervention Not applicable Main Outcome Measures Each subject underwent a maximal cycle ergometer test and a 6MWT. Oxygen consumption (VO2) was measured during both tests. Subjects were also evaluated for Berg Balance Scale, Modified Ashworth Scale of Spasticity, isometric knee extension strength and percent body fat. Results The 6MW distance had a low correlation with the VO2max (r=0.402). Balance, knee extension strength and spasticity were all significant determinants for the 6MWT distance, with balance being the major contributor for the 6MWT distance, accounting for 66.5% of its variance. Conclusions Factors other than the cardiorespiratory status considerably influenced the ambulatory capacity as measured by the 6MWT. The 6MWT distance alone should not be used to indicate cardiorespiratory fitness in individuals with chronic stroke. PMID:15705987

  18. How Transformational Leadership Influences Work Engagement Among Nurses: Does Person-Job Fit Matter?

    PubMed

    Enwereuzor, Ibeawuchi K; Ugwu, Leonard I; Eze, Onyinyechi A

    2016-12-05

    The current study examines whether person-job fit moderates the relationship between transformational leadership and work engagement. Data were collected using cross-sectional design from 224 (15 male and 209 female) hospital nurses. Participants completed measures of transformational leadership, person-job fit, and work engagement. Moderated multiple regression results showed that transformational leadership had a significant positive predictive relationship with work engagement, and person-job fit had a significant positive predictive relationship with work engagement. Simple slope analysis showed that person-job fit moderated the relationship between transformational leadership and work engagement such that transformational leadership was more positively related to work engagement for nurses with high person-job fit compared with those with low person-job fit. Thus, all the hypotheses were confirmed. The findings were discussed, and suggestions for future research were offered.

  19. Influence of mutation and recombination on HIV-1 in vitro fitness recovery.

    PubMed

    Arenas, Miguel; Lorenzo-Redondo, Ramon; Lopez-Galindez, Cecilio

    2016-01-01

    The understanding of the evolutionary processes underlying HIV-1 fitness recovery is fundamental for HIV-1 pathogenesis, antiretroviral treatment and vaccine design. It is known that HIV-1 can present very high mutation and recombination rates, however the specific contribution of these evolutionary forces in the "in vitro" viral fitness recovery has not been simultaneously quantified. To this aim, we analyzed substitution, recombination and molecular adaptation rates in a variety of HIV-1 biological clones derived from a viral isolate after severe population bottlenecks and a number of large population cell culture passages. These clones presented an overall but uneven fitness gain, mean of 3-fold, respect to the initial passage values. We found a significant relationship between the fitness increase and the appearance and fixation of mutations. In addition, these fixed mutations presented molecular signatures of positive selection through the accumulation of non-synonymous substitutions. Interestingly, viral recombination correlated with fitness recovery in most of studied viral quasispecies. The genetic diversity generated by these evolutionary processes was positively correlated with the viral fitness. We conclude that HIV-1 fitness recovery can be derived from the genetic heterogeneity generated through both mutation and recombination, and under diversifying molecular adaptation. The findings also suggest nonrandom evolutionary pathways for in vitro fitness recovery.

  20. Influence of physical fitness on antioxidant activity and malondialdehyde level in healthy older adults.

    PubMed

    Bouzid, Mohamed Amine; Hammouda, Omar; Matran, Régis; Robin, Sophie; Fabre, Claudine

    2015-06-01

    The aim of this study was to investigate how physical fitness level could affect antioxidant activity and malondialdehyde (MDA) level at rest and in response to exhaustive exercise in healthy older adults. Fifty older adults (average age: 66.1 ± 3.8 years) were divided according to their physical fitness level into an unfit group (UG) (n = 15), a low fitness level group (LFG) (n = 18), and a high fitness level group (HFG) (n = 17). Fitness status was classified based on answers to a questionnaire about physical activity in the previous 12 months. Before and after an incremental cycle ergometer test to exhaustion, the following markers were assessed: superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione reductase, ascorbic acid, α-tocopherol, and MDA. At rest, SOD, GPX, and α-tocopherol activities were higher in the HFG (p < 0.05), whereas MDA level was lower in the LFG in comparison with the 2 other groups (p < 0.05). During the postexercise period, antioxidant activity increased only in the LFG and the HFG (GPX, SOD, and α-tocopherol). MDA level increased in all groups after the exercise (p < 0.05). In addition, MDA level was higher during the recovery period in the HFG as compared with the others groups. This study concluded that both low and high physical fitness levels help maintain better antioxidant defenses in older adults. However, a higher physical fitness level, rather than a lower physical fitness level, could increase lipid peroxidation.

  1. A flexible method for estimating the fraction of fitness influencing mutations from large sequencing data sets

    PubMed Central

    Moon, Sunjin; Akey, Joshua M.

    2016-01-01

    A continuing challenge in the analysis of massively large sequencing data sets is quantifying and interpreting non-neutrally evolving mutations. Here, we describe a flexible and robust approach based on the site frequency spectrum to estimate the fraction of deleterious and adaptive variants from large-scale sequencing data sets. We applied our method to approximately 1 million single nucleotide variants (SNVs) identified in high-coverage exome sequences of 6515 individuals. We estimate that the fraction of deleterious nonsynonymous SNVs is higher than previously reported; quantify the effects of genomic context, codon bias, chromatin accessibility, and number of protein–protein interactions on deleterious protein-coding SNVs; and identify pathways and networks that have likely been influenced by positive selection. Furthermore, we show that the fraction of deleterious nonsynonymous SNVs is significantly higher for Mendelian versus complex disease loci and in exons harboring dominant versus recessive Mendelian mutations. In summary, as genome-scale sequencing data accumulate in progressively larger sample sizes, our method will enable increasingly high-resolution inferences into the characteristics and determinants of non-neutral variation. PMID:27197222

  2. The Influences on Teaching Perspectives of Australian Physical Education Teacher Education Students: The First-Year Influences on Teaching Perspectives Exploratory (FIT-PE) Study

    ERIC Educational Resources Information Center

    Hyndman, Brendon P.; Pill, Shane

    2016-01-01

    There has been a paucity of literature investigating the teaching beliefs and intentions of Australian physical education teacher education (PETE) students that enter teacher training. The First-year Influences on Teaching Perspectives Exploratory (FIT-PE) study explores the teaching perspectives of first year PETE students; including teaching…

  3. Influence of variations in methodology on populations of Listeria monocytogenes recovered from lettuce treated with sanitizers.

    PubMed

    Burnett, Andrea B; Iturriaga, Montserrat H; Escartin, Eduardo F; Pettigrew, Charles A; Beuchat, Larry R

    2004-04-01

    The elimination of Listeria monocytogenes inoculated onto a piece of cut iceberg lettuce (3.8 by 3.8 cm) by treatment with chlorinated water (200 micrograms/ml free chlorine) and a 0.5% (wt/vol) solution of FIT Professional Line Antibacterial Cleaner (FIT) was investigated. The efficacy of the two sanitizers was not influenced by the composition of the medium used to culture the L. monocytogenes used in the inocula, the number of strains in the inoculum, or the recovery medium used to enumerate the pathogen on lettuce after treatment. Drying inoculum on lettuce for 45 min at 37 degrees C caused more cells to die or not be retrieved compared with drying inoculum for 30 min at 25 degrees C. However, the percentage of cells in the inoculum recovered from lettuce treated with chlorine or FIT was not significantly different, regardless of the drying method. Stomaching, homogenizing, or stomaching followed by homogenizing lettuce treated with sanitizers resulted in recovery of similar numbers of L. monocytogenes, indicating that stomaching and homogenizing are equivalent in extracting cells; the sequential use of both processing methods did not substantially increase the efficiency of recovery. Washing lettuce with water or treating lettuce with 200 micrograms/ml chlorine or FIT resulted in decreases in populations of 0.60, 1.76, and 1.51 log CFU per lettuce piece, respectively, regardless of variations in test parameters. Reductions caused by sanitizers were significantly greater (alpha = 0.05) than that observed for water but not significantly different from each other. It is concluded that evaluation of sanitizers for their efficacy in killing L. monocytogenes on lettuce can be determined by spot inoculating 50 microliters of a five-strain mixture of cells from 24-h cultures suspended in 5% horse serum albumen, followed by drying the inoculum for 45 min at 37 degrees C, treatment by submerging in 50 ml of sanitizer for 5 min, stomaching samples in 50 ml of Dey

  4. Effect of Rickettsia felis Strain Variation on Infection, Transmission, and Fitness in the Cat Flea (Siphonaptera: Pulicidae).

    PubMed

    Healy, Sean P; Brown, Lisa D; Hagstrom, Melena R; Foil, Lane D; Macaluso, Kevin R

    2017-03-02

    Rickettsia felis is a human pathogen transmitted by the cat flea, Ctenocephalides felis (Bouché) (str. LSU), as well as an obligate symbiont of the parthenogenic booklouse Liposcelis bostrychophila (Badonnel) (str. LSU-Lb). The influence of genetic variability in these two strains of R. felis on host specialization and fitness and possible resulting differences on infection and transmission kinetics in C. felis is unknown. Utilizing an artificial host system, cat fleas were exposed to a R. felis str. LSU-Lb-infected bloodmeal and monitored for infection at 7-d intervals for 28 d. Quantitative real-time PCR was used to determine rickettsial load and infection density in newly exposed cat fleas, and transmission frequency between cat fleas. The effect of persistent R. felis infection on cat flea F1 progeny was also assessed. At 7 d postexposure 76.7% of the cat fleas successfully acquired R. felis str. LSU-Lb. In R. felis str. LSU-Lb-exposed cat fleas, the mean infection load (6.15 × 106), infection density (0.76), and infection prevalence (91/114) were significantly greater than R. felis str. LSU infection load (3.09 × 106), infection density (0.68), and infection prevalence (76/113). A persistent R. felis str. LSU-Lb infection was detected for 28 d in adult cat fleas but neither female:male ratio distortion nor vertical transmission was observed in F1 progeny. While infection kinetics differed, with higher intensity associated with R. felis str. LSU-Lb, no distinct phenotype was observed in the F1 progeny.

  5. Influence of cardiorespiratory fitness and physical activity levels on cardiometabolic risk factors during menopause transition: A MONET study.

    PubMed

    Abdulnour, Joseph; Razmjou, Sahar; Doucet, Éric; Boulay, Pierre; Brochu, Martin; Rabasa-Lhoret, Rémi; Lavoie, Jean-Marc; Prud'homme, Denis

    2016-12-01

    To determine the influence of cardiorespiratory fitness (hereafter "fitness") and physical activity levels on cardiometabolic risk factors in premenopausal women going through the menopause transition. An ancillary study including 66 premenopausal women who participated to a 5-year observational, longitudinal study (2004 to 2009 in Ottawa) on the effects of menopause transition on body composition and cardiometabolic risk factors. Women underwent a graded exercise test on treadmill to measure peak oxygen uptake (VO2 peak) at year 1 and 5 and physical activity levels were measured using accelerometers. Cardiometabolic risk factors included: waist circumference, fasting plasma lipids, glucose and insulin levels, HOMA-IR score, c-reactive protein, apolipoprotein B (apoB) and resting systolic and diastolic blood pressure. Change in fitness was not associated with changes in cardiometabolic risk factors. The changes in total physical activity levels on the other hand showed a significant negative association with apoB levels. Three-way linear mixed model repeated measures, showed lower values of waist circumference, fasting triglycerides, insulin levels, HOMA-IR score, apoB and diastolic blood pressure in women with a fitness ≥ 30.0 mlO2 kg(- 1) min(- 1) compared to women with a fitness < 30.0 mlO2 kg(- 1) min(- 1) (P < 0.05). However, only fasting triglycerides was lower in women with physical activity levels ≥ 770.0 Kcal/day (P < 0.05). Between fitness and physical activity levels, fitness was associated with more favorable values of cardiometabolic risk factors in women followed for 5 years during the menopause transition.

  6. Geographical Variation in Health-Related Physical Fitness and Body Composition among Chilean 8th Graders: A Nationally Representative Cross-Sectional Study

    PubMed Central

    Garber, Michael D.; Sajuria, Marcelo; Lobelo, Felipe

    2014-01-01

    Purpose In addition to excess adiposity, low cardiorespiratory fitness (CRF) and low musculoskeletal fitness (MSF) are important independent risk factors for future cardio-metabolic disease in adolescents, yet global fitness surveillance in adolescents is poor. The objective of this study was to describe and investigate geographical variation in levels of health-related physical fitness, including CRF, MSF, body mass index (BMI), and waist circumference (WC) in Chilean 8th graders. Methods This cross-sectional study was based on a population-based, representative sample of 19,929 8th graders (median age = 14 years) in the 2011 National Physical Education Survey from Chile. CRF was assessed with the 20-meter shuttle run test, MSF with standing broad jump, and body composition with BMI and WC. Data were classified according to health-related standards. Prevalence of levels of health-related physical fitness was mapped for each of the four variables, and geographical variation was explored at the country level by region and in the Santiago Metropolitan Area by municipality. Results Girls had significantly higher prevalence of unhealthy CRF, MSF, and BMI than boys (p<0.05). Overall, 26% of boys and 55% of girls had unhealthy CRF, 29% of boys and 35% of girls had unhealthy MSF, 29% of boys and 44% of girls had unhealthy BMI, and 31% of adolescents had unhealthy WC. High prevalence of unhealthy fitness levels concentrates in the northern and middle regions of the country and in the North and Southwest sectors for the Santiago Metropolitan Area. Conclusion Prevalence of unhealthy CRF, MSF, and BMI is relatively high among Chilean 8th graders, especially in girls, when compared with global estimates. Identification of geographical regions and municipalities with high prevalence of unhealthy physical fitness presents opportunity for targeted intervention. PMID:25255442

  7. The Factors Influencing Teaching (FIT)-Choice Scale in a Dutch Teacher Education Program

    ERIC Educational Resources Information Center

    Fokkens-Bruinsma, Marjon; Canrinus, Esther T.

    2012-01-01

    This study examined the suitability of the FIT-Choice scale in a Dutch educational context among two cohorts of preservice teachers (Ns = 62, 89), surveyed at the end and the beginning of their one-year program respectively. The relationships between the motivations for becoming a teacher and concurrent commitment were examined, as well as the…

  8. Accuracy of Person-Fit Statistics: A Monte Carlo Study of the Influence of Aberrance Rates

    ERIC Educational Resources Information Center

    St-Onge, Christina; Valois, Pierre; Abdous, Belkacem; Germain, Stephane

    2011-01-01

    Using a Monte Carlo experimental design, this research examined the relationship between answer patterns' aberrance rates and person-fit statistics (PFS) accuracy. It was observed that as the aberrance rate increased, the detection rates of PFS also increased until, in some situations, a peak was reached and then the detection rates of PFS…

  9. Influences of physical fitness on bone mass in women with fibromyalgia.

    PubMed

    Gómez-Cabello, Alba; Vicente-Rodríguez, Germán; Navarro-Vera, Isabel; Martinez-Redondo, Diana; Díez-Sánchez, Carmen; Casajús, José Antonio

    2015-04-01

    The aim of this study was to provide information about the relationship of bone mineral content (BMC) and density (BMD) with some physical-fitness-related variables in a sample of women with fibromyalgia (FM) and age-matched women without FM. Twenty-eight women clinically diagnosed with FM (age 51.1 ± 8.4 yr, M ± SD) and 22 age-matched controls participated in the study. Whole-body BMC and BMD, lean mass, handgrip strength, quadriceps strength, and cardiovascular fitness were measured in all participants. The association between physical-fitness variables and bone-related variables was tested by linear regression controlling for body weight as a possible confounder. There were no differences in BMC or BMD between groups. Women with FM had lower values of handgrip strength, quadriceps strength, and VO2peak than the control group. Handgrip strength and aerobic capacity were associated with BMC and BMD and quadriceps strength was associated with BMD in women with FM; however, only VO2peak was associated with BMC in the group of women without FM. Bone mass of women with FM may be more susceptible to changes in physical fitness than that of the women without fibromyalgia.

  10. Predation risk influences adaptive morphological variation in fish populations.

    PubMed

    Eklöv, Peter; Svanbäck, Richard

    2006-03-01

    Predators can cause a shift in both density and frequency of a prey phenotype that may lead to phenotypic divergence through natural selection. What is less investigated is that predators have a variety of indirect effects on prey that could potentially have large evolutionary responses. We conducted a pond experiment to test whether differences in predation risk in different habitats caused shifts in behavior of prey that, in turn, would affect their morphology. We also tested whether the experimental data could explain the morphological variation of perch in the natural environment. In the experiment, predators caused the prey fish to shift to the habitat with the lower predation risk. The prey specialized on habitat-specific resources, and there was a strong correlation between diet of the prey fish and morphological variation, suggesting that resource specialization ultimately affected the morphology. The lack of differences in competition and mortality suggest that the morphological variation among prey was induced by differences in predation risk among habitats. The field study demonstrated that there are differences in growth related to morphology of perch in two different habitats. Thus, a trade-off between foraging and predator avoidance could be responsible for adaptive morphological variation of young perch.

  11. Fitness drivers in the threatened Dianthus guliae Janka (Caryophyllaceae): disentangling effects of growth context, maternal influence and inbreeding depression.

    PubMed

    Gargano, D; Gullo, T; Bernardo, L

    2011-01-01

    We studied inbreeding depression, growth context and maternal influence as constraints to fitness in the self-compatible, protandrous Dianthus guliae Janka, a threatened Italian endemic. We performed hand-pollinations to verify outcomes of self- and cross-fertilisation over two generations, and grew inbred and outbred D. guliae offspring under different conditions - in pots, a common garden and field conditions (with/without nutrient addition). The environment influenced juvenile growth and flowering likelihood/rate, but had little effect on inbreeding depression. Significant interactions among genetic and environmental factors influenced female fertility. Overall, genetic factors strongly affected both early (seed mass, seed germination, early survival) and late (seed/ovule ratio) life-history traits. After the first pollination experiment, we detected higher mortality in the selfed progeny, which is possibly a consequence of inbreeding depression caused by over-expression of early-acting deleterious alleles. The second pollination induced a strong loss of reproductive fitness (seed production, seed mass) in inbred D. guliae offspring, regardless of the pollination treatment (selfing/crossing); hence, a strong (genetic) maternal influence constrained early life-history traits of the second generation. Based on current knowledge, we conclude that self-compatibility does not prevent the detrimental effects of inbreeding in D. guliae populations, and may increase the severe extinction risk if out-crossing rates decrease.

  12. Influence of Hatha yoga on physical activity constraints, physical fitness, and body image of breast cancer survivors: a pilot study.

    PubMed

    Van Puymbroeck, Marieke; Schmid, Arlene; Shinew, Kimberly J; Hsieh, Pei-Chun

    2011-01-01

    Breast cancer survivors often experience changes in their perception of their bodies following surgical treatment. These changes in body image may increase self-consciousness and perceptions of physical activity constraints and reduce participation in physical activity. While the number of studies examining different types of yoga targeting women with breast cancer has increased, studies thus far have not studied the influence that Hatha yoga has on body image and physical activity constraints. The objective of this study was to explore the changes that occur in breast cancer survivors in terms of body image, perceived constraints, and physical fitness following an 8-week Hatha yoga intervention. This study used a nonrandomized two-group pilot study, comparing an 8-week Hatha yoga intervention with a light exercise group, both designed for women who were at least nine months post-treatment for breast cancer. Both quantitative and qualitative data were collected in the areas of body image, physical activity constraints, and physical fitness. Findings indicated that quantitatively, yoga participants experienced reductions in physical activity constraints and improvements in lower- and upper-body strength and flexibility, while control participants experienced improvements in abdominal strength and lower-body strength. Qualitative findings support changes in body image, physical activity constraints, and physical fitness for the participants in the yoga group. In conclusion, Hatha yoga may reduce constraints to physical activity and improve fitness in breast cancer survivors. More research is needed to explore the relationship between Hatha yoga and improvements in body image.

  13. Getting what you want: How fit between desired and received leader sensitivity influences emotion and counterproductive work behavior.

    PubMed

    Rupprecht, Elizabeth A; Kueny, Clair Reynolds; Shoss, Mindy K; Metzger, Andrew J

    2016-10-01

    We challenge the intuitive belief that greater leader sensitivity is always associated with desirable outcomes for employees and organizations. Specifically, we argue that followers' idiosyncratic desires for, and perceptions of, leader sensitivity behaviors play a key role in how followers react to their leader's sensitivity. Moreover, these resulting affective experiences are likely to have important consequences for organizations, specifically as they relate to employee counterproductive work behavior (CWB). Drawing from supplies-values (S-V) fit theory and the stressor-emotion model of CWB, the current study focuses on the affective and behavioral consequences of fit between subordinates' ideal leader sensitivity behavior preferences and subordinates' perceptions of their actual leader's sensitivity behaviors. Polynomial regression analyses reveal that congruence between ideal and actual leader sensitivity influences employee negative affect and, consequently, engagement in counterproductive work behavior. (PsycINFO Database Record

  14. Fatness mediates the influence of muscular fitness on metabolic syndrome in Colombian collegiate students

    PubMed Central

    Carrillo, Hugo Alejandro; González-Ruíz, Katherine; Vivas, Andrés; Triana-Reina, Héctor Reynaldo; Martínez-Torres, Javier; Prieto-Benavidez, Daniel Humberto; Ramos-Sepúlveda, Jeison Alexander; Villa-González, Emilio

    2017-01-01

    The purpose of this study was two-fold: to analyze the association between muscular fitness (MF) and clustering of metabolic syndrome (MetS) components, and to determine if fatness parameters mediate the association between MF and MetS clustering in Colombian collegiate students. This cross-sectional study included a total of 886 (51.9% women) healthy collegiate students (21.4 ± 3.3 years old). Standing broad jump and isometric handgrip dynamometry were used as indicators of lower and upper body MF, respectively. Also, a MF score was computed by summing the standardized values of both tests, and used to classify adults as fit or unfit. We also assessed fat mass, body mass index, waist-to-height ratio, and abdominal visceral fat, and categorized individuals as low and high fat using international cut-offs. A MetS cluster score was derived by calculating the sum of the sample-specific z-scores from the triglycerides, HDL cholesterol, fasting glucose, waist circumference, and arterial blood pressure. Linear regression models were used to examine whether the association between MF and MetS cluster was mediated by the fatness parameters. Data were collected from 2013 to 2016 and the analysis was done in 2016. Findings revealed that the best profiles (fit + low fat) were associated with lower levels of the MetS clustering (p <0.001 in the four fatness parameters), compared with unfit and fat (unfit + high fat) counterparts. Linear regression models indicated a partial mediating effect for fatness parameters in the association of MF with MetS clustering. Our findings indicate that efforts to improve MF in young adults may decrease MetS risk partially through an indirect effect on improvements to adiposity levels. Thus, weight reduction should be taken into account as a complementary goal to improvements in MF within exercise programs. PMID:28296952

  15. Fatness mediates the influence of muscular fitness on metabolic syndrome in Colombian collegiate students.

    PubMed

    García-Hermoso, Antonio; Carrillo, Hugo Alejandro; González-Ruíz, Katherine; Vivas, Andrés; Triana-Reina, Héctor Reynaldo; Martínez-Torres, Javier; Prieto-Benavidez, Daniel Humberto; Correa-Bautista, Jorge Enrique; Ramos-Sepúlveda, Jeison Alexander; Villa-González, Emilio; Peterson, Mark D; Ramírez-Vélez, Robinson

    2017-01-01

    The purpose of this study was two-fold: to analyze the association between muscular fitness (MF) and clustering of metabolic syndrome (MetS) components, and to determine if fatness parameters mediate the association between MF and MetS clustering in Colombian collegiate students. This cross-sectional study included a total of 886 (51.9% women) healthy collegiate students (21.4 ± 3.3 years old). Standing broad jump and isometric handgrip dynamometry were used as indicators of lower and upper body MF, respectively. Also, a MF score was computed by summing the standardized values of both tests, and used to classify adults as fit or unfit. We also assessed fat mass, body mass index, waist-to-height ratio, and abdominal visceral fat, and categorized individuals as low and high fat using international cut-offs. A MetS cluster score was derived by calculating the sum of the sample-specific z-scores from the triglycerides, HDL cholesterol, fasting glucose, waist circumference, and arterial blood pressure. Linear regression models were used to examine whether the association between MF and MetS cluster was mediated by the fatness parameters. Data were collected from 2013 to 2016 and the analysis was done in 2016. Findings revealed that the best profiles (fit + low fat) were associated with lower levels of the MetS clustering (p <0.001 in the four fatness parameters), compared with unfit and fat (unfit + high fat) counterparts. Linear regression models indicated a partial mediating effect for fatness parameters in the association of MF with MetS clustering. Our findings indicate that efforts to improve MF in young adults may decrease MetS risk partially through an indirect effect on improvements to adiposity levels. Thus, weight reduction should be taken into account as a complementary goal to improvements in MF within exercise programs.

  16. Direct fitness of group living mammals varies with breeding strategy, climate and fitness estimates.

    PubMed

    Ebensperger, Luis A; Rivera, Daniela S; Hayes, Loren D

    2012-09-01

    1. Understanding how variation in fitness relates to variation in group living remains critical to determine whether this major aspect of social behaviour is currently adaptive. 2. Available evidence in social mammals aimed to examine this issue remains controversial. Studies show positive (i.e. potentially adaptive), neutral or even negative fitness effects of group living. 3. Attempts to explain this variation rely on intrinsic and extrinsic factors to social groups. Thus, relatively more positive fitness effects are predicted in singularly breeding as opposed to plural breeding species. Fitness effects of sociality in turn may depend on ecological conditions (i.e. extrinsic factors) that influence associated benefits and costs. 4. We used meta-analytic tools to review how breeding strategy or ecological conditions influence the effect size associated with direct fitness-sociality relationships reported in the mammalian literature. Additionally, we determined how taxonomic affiliation of species studied, different fitness and sociality measures used, and major climatic conditions of study sites explained any variation in direct fitness effect size. 5. We found group living had modest, yet positive effects on direct fitness. This generally adaptive scenario was contingent not only upon breeding strategy and climate of study sites, but also on fitness measures examined. Thus, positive and significant effects characterized singular as opposed to plural breeding strategies. 6. We found more positive fitness effects on studies conducted in tropical as opposed to temperate or arid climates. More positive and significant effects were noted on studies that relied on group fecundity, male fecundity and offspring survival as measures of fitness. 7. To conclude, direct fitness consequences of mammalian group living are driven by interspecific differences in breeding strategy and climate conditions. Other factors not examined in this study, namely individual variation in

  17. Influence of the 11-Year Solar Cycle on Variations of Cosmic Ray Intensity

    NASA Astrophysics Data System (ADS)

    Ma, L. H.; Han, Y. B.; Yin, Z. Q.

    2009-03-01

    The monthly cosmic ray intensity (CRI) time series from Climax, Huancayo, Moscow, Kiel, and Calgary are used to investigate the presence of the 11-year periodic component with special attention paid to the solar influence on these variations. The results show obvious 11-year temporal characteristics in CRI variations. We also find a close anticorrelation between the 11-year solar cycle and CRI variations and time delays of the CRI relative to solar activity.

  18. The Influence of Daily Variation in Teacher Performance on the Reliability and Validity of Assessment Data.

    ERIC Educational Resources Information Center

    Cronin, Linda; Capie, William

    The influence of day-to-day variation in teacher performance on the reliability and validity of teacher assessment was examined. An attempt was made to identify and quantify sources of score variation attributable to differences in teacher performance, day of observation, observers, and test subscales; and to determine their effects on reliability…

  19. For Fit's Sake: A Norms-Based Approach to Healthy Behaviors Through Influence of Presumed Media Influence.

    PubMed

    Ho, Shirley S; Lee, Edmund W J; Ng, Kaijie; Leong, Grace S H; Tham, Tiffany H M

    2016-09-01

    Based on the influence of presumed media influence (IPMI) model as the theoretical framework, this study examines how injunctive norms and personal norms mediate the influence of healthy lifestyle media messages on public intentions to engage in two types of healthy lifestyle behaviors-physical activity and healthy diet. Nationally representative data collected from 1,055 adults in Singapore demonstrate partial support for the key hypotheses that make up the extended IPMI model, highlighting the importance of a norms-based approach in health communication. Our results indicate that perceived media influence on others indirectly shaped public intentions to engage in healthy lifestyle behaviors through personal norms and attitude, providing partial theoretical support for the extended IPMI model. Practical implications for health communicators in designing health campaigns media messages to motivate the public to engage in healthy lifestyle are discussed.

  20. Variation in Extrafloral Nectary Productivity Influences the Ant Foraging.

    PubMed

    Lange, Denise; Calixto, Eduardo Soares; Del-Claro, Kleber

    2017-01-01

    Extrafloral nectar is the main food source offered by plants to predatory ants in most land environments. Although many studies have demonstrated the importance of extrafloral nectaries (EFNs) to plant defense against herbivores, the influence of EFNs secretory activity pattern on predatory ants remains yet not fully understood. Here, we verified the relation between the extrafloral nectar production of a plant community in Cerrado in different times of the day, and its attractiveness to ants. The extrafloral nectaries (EFNs) of seven plant species showed higher productivity overnight. Ant abundance was higher in times of large extrafloral nectar production, however, there was no positive relation between ant richness on plants and EFNs productivity. There was temporal resource partitioning among ant species, and it indicates strong resource competition. The nectar productivity varied among plant species and time of the day, and it influenced the visitation patterns of ants. Therefore, EFNs are a key ant-plant interaction driver in the studied system.

  1. Variation in Extrafloral Nectary Productivity Influences the Ant Foraging

    PubMed Central

    2017-01-01

    Extrafloral nectar is the main food source offered by plants to predatory ants in most land environments. Although many studies have demonstrated the importance of extrafloral nectaries (EFNs) to plant defense against herbivores, the influence of EFNs secretory activity pattern on predatory ants remains yet not fully understood. Here, we verified the relation between the extrafloral nectar production of a plant community in Cerrado in different times of the day, and its attractiveness to ants. The extrafloral nectaries (EFNs) of seven plant species showed higher productivity overnight. Ant abundance was higher in times of large extrafloral nectar production, however, there was no positive relation between ant richness on plants and EFNs productivity. There was temporal resource partitioning among ant species, and it indicates strong resource competition. The nectar productivity varied among plant species and time of the day, and it influenced the visitation patterns of ants. Therefore, EFNs are a key ant-plant interaction driver in the studied system. PMID:28046069

  2. Possibility to explain global climate variations by earthquakes influence

    NASA Astrophysics Data System (ADS)

    Molchanov, O.

    2009-12-01

    An additional natural source of the global warming could be heat flux from seismicity. Estimated earthquakes energy release in the near-equatorial Pacific area during a year ≈ 1020 J that is equivalent to the energy released in the detonation about one million atomic bombs of Hiroshima class and produce average power flux due to seismicity ≈ 0.3-1 W/m2 . We have analyzed together the slow climate temperature variations in the near-equatorial Pacific Ocean area (SSTOI indices) and crustal seismic activity in the same region during 1973-2008 time period using correlation analysis and found similarity in seismic and ENSO periodicities (the latter with time lag about 1.5 years). Trends of the processes are also similar showing about 2 times increase in average seismic energy release during the whole period of analysis and conventional 0.10C/(10 years) increase in SSTOI index anomalies. Our main conclusion is on real possibility of climate-seismicity coupling. It is rather probable that at least partially climate ENSO oscillations and temperature anomaly trends are induced by similar variation in seismicity. A mechanism of several years periodicity in the seismic activity is unclear at present. Probably it is initiated in the upper mantle of the Earth (depth 600-700 km) and then penetrates in the crust as so-called deformation (or stress) wave with time delay from 3 to 10 years [1] [1] O.A. Molchanov and S. Uyeda, Upward migration of earthquake hypocenters in Japan,Kurile- Kamchatka and Sunda subduction zones, Physics and Chemistry of the Earth, 34, 423-430, 2009; doi:10.1016/j.pce.2008.09.011.

  3. Bringing the frame into focus: the influence of regulatory fit on processing fluency and persuasion.

    PubMed

    Lee, Angela Y; Aaker, Jennifer L

    2004-02-01

    This research demonstrates that people's goals associated with regulatory focus moderate the effect of message framing on persuasion. The results of 6 experiments show that appeals presented in gain frames are more persuasive when the message is promotion focused, whereas loss-framed appeals are more persuasive when the message is prevention focused. These regulatory focus effects suggesting heightened vigilance against negative outcomes and heightened eagerness toward positive outcomes are replicated when perceived risk is manipulated. Enhanced processing fluency leading to more favorable evaluations in conditions of compatibility appears to underlie these effects. The findings underscore the regulatory fit principle that accounts for the persuasiveness of message framing effects and highlight how processing fluency may contribute to the "feeling right" experience when the strategy of goal pursuit matches one's goal.

  4. Fitness versus Fatness: Which Influences Health and Mortality Risk the Most?

    PubMed

    Gaesser, Glenn A; Tucker, Wesley J; Jarrett, Catherine L; Angadi, Siddhartha S

    2015-01-01

    Cardiorespiratory fitness (CRF) is a more powerful predictor of mortality than body mass index or adiposity, and improving CRF is more important than losing body fat for reducing risk of cardiovascular disease and all-cause mortality. Data on reduced morbidity and mortality associated with increased CRF are strong and consistent. By contrast, data on intentional weight loss and mortality are uncertain, and weight loss-induced risk factor modification may be largely transient. Because weight loss maintenance is poor and considering the health risks associated with chronic weight instability ( "yo-yo" dieting), we propose an alternative paradigm that focuses on improving CRF rather than reducing body weight. We contend that this is a safer alternative for management of obesity and the associated comorbidities. Exercise adherence may improve if clinicians emphasized to their patients the importance of CRF compared with weight loss in improving health and reducing the risk of chronic diseases.

  5. Genotoxic effects of cadmium and influence on fitness components of Lymantria dispar caterpillars.

    PubMed

    Matić, Dragana; Vlahović, Milena; Kolarević, Stoimir; Perić Mataruga, Vesna; Ilijin, Larisa; Mrdaković, Marija; Vuković Gačić, Branka

    2016-11-01

    The current study extends our previous findings concerning the sensitivity of Lymantria dispar larvae to cadmium in light of ecotoxicological risk assessment. Here we report the results of the comet assay performed for the first time on this species. We examined the chronic effects of two cadmium concentrations (50 and 100 μg Cd/g dry food) on DNA integrity and haemocyte viability, as well as on fitness-related traits (larval mass and development duration parameters). All parameters were assessed individually and then used to calculate the integrated biomarker response (IBR) index. Egg-masses of L. dispar were collected from two locations in Serbia - the uncontaminated Homolje mountains and a metal-polluted area near Bor copper mines, smelter and refinery. Distinctive patterns in the response of these populations to cadmium exposure were noticed. In haemocytes of larvae from the pollution-free location both cadmium treatments increased the level of DNA damage, although in a similar range. Haemocyte viability and larval mass were reduced, while duration of the fourth instar and total development time were prolonged in a concentration-dependent manner. Cadmium tolerance was noticeable in the population from the metal-contaminated site at all organizational levels. Nevertheless, haemocyte viability in that population was reduced by the stronger treatment. Haemocyte viability was recognized as a promising biomarker due to the evident response of both populations to dietary cadmium. Genotoxicity, fitness-related traits and the IBR index could be used for biomonitoring of sensitive populations not previously exposed to metals.

  6. Planetary Wave Influence on Wintertime OH Meinel Longitudinal Variation?

    NASA Astrophysics Data System (ADS)

    Winick, J. R.; Picard, R. H.; Wintersteiner, P. P.; Mlynczak, M. G.; Russell, J. M.; Gordley, L.

    2009-05-01

    We report on very unusual conditions in the upper mesosphere during the boreal winters of 2004 and 2006. Unusually bright OH volume emissions, as measured by TIMED/SABER, occurred in the region north of 60N. These emissions also occurred at unusually low altitudes, while at the same time very high temperatures characterized the upper mesosphere. These large perturbations allowed us to see more clearly longitudinal spatial and temporal variations that were present in the emissions. The affected areas varied in size and location on time scales of a few days and had a distinct planetary-wave wave-1 structure. We present data demonstrating the variability in the emissions and temperatures throughout the polar region and the correlations among them, and we contrast their behavior with that in normal years. The underlying cause of the correlations and longitudinal structure appears to be greatly enhanced downwelling in the upper mesosphere, which in turn was produced by unusual dynamical conditions in the lower atmosphere, consisting of stratospheric warmings and perturbations of wave structures within the polar vortex.

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

    PubMed Central

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

    2014-01-01

    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. PMID:25320161

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

    PubMed

    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.

  9. Influence of fitness on the integrated neuroendocrine response to aerobic exercise until exhaustion.

    PubMed

    de Diego Acosta, A M; García, J C; Fernández-Pastor, V J; Perán, S; Ruiz, M; Guirado, F

    2001-12-01

    A group of trained and sedentary men performed an incremental graded exercise-test to exhaustion in order to assess the organic response of the two main stress-activated systems: the sympathetic nervous system with its endocrine component (the adrenal medulla), and the hypothalamic-pituitary-adrenal (HPA) axis. Maximal plasma concentrations of ACTH, cortisol and endogenous opioids (beta-endorphins) were obtained at the end of the exercise-test in the trained group. Thus ACTH increased from basal value of 21.25 +/- 2.5 pg/ml to 88.78 +/- 11.8 pg/ml at the end of the exercise (p<0.01); cortisol, from 16.56 microg/dl +/- 4.94 microg/dl to 23.80 +/- 4.57 microg/dl in min 15 of the recovery period (p<0.001); and beta-endorphin from 21.80 +/- 8.33 pmol/ml to 64.36 +/- 9.8 pmol/ml in min 3 of the recovery period (p<0.05). Catecholamine levels were increased from initial values at the end of the effort test in both control and trained groups. Control subjects exhibited a higher responsiveness compared to trained and showed superior intrinsic stimulation of the sympathetic nervous system. These results reveal a different response according to fitness in a physical stress situation.

  10. Gut microbes influence fitness and malaria transmission potential of Asian malaria vector Anopheles stephensi.

    PubMed

    Sharma, Anil; Dhayal, Devender; Singh, O P; Adak, T; Bhatnagar, Raj K

    2013-10-01

    The midgut of parasite transmitting vector, Anopheles stephensi is a physiologically dynamic ecological niche of resident microbes. The gut resident microbes of anisomorphic and physiologically variable male and female A. stephensi mosquitoes were different (Rani et al., 2009). To understand the possible interaction of gut microbes and mosquito host, we examined the contribution of the microbe community on the fitness of the adult mosquitoes and their ability to permit development of the malaria parasite. A. stephensi mosquitoes were fed with antibiotic to sterilize their gut to study longevity, blood meal digestion, egg laying and maturation capacity, and consequently ability to support malaria parasite development. The sterilization of gut imparted reduction in longevity by a median of 5 days in male and 2 days in female mosquitoes. Similarly, the sterilization also diminished the reproductive potential probably due to increased rate of the resorption of follicles in ovaries coupled with abated blood meal digestion in gut-sterilized females. Additionally, gut sterilization also led to increased susceptibility to oocyst development upon feeding on malaria infected blood. The susceptibility to malaria parasite introduced upon gut sterilization of A. stephensi was restored completely upon re-colonization of gut by native microbes. The information provided in the study provides insights into the role of the gut-resident microbial community in various life events of the mosquito that may be used to develop alternate malaria control strategies, such as paratransgenesis.

  11. Influence of Atmospheric CO2 Variation on Strom Track Behavior

    NASA Astrophysics Data System (ADS)

    Martynova, Yuliya; Krupchatnikov, Vladimir

    2015-04-01

    The storm tracks are the regions of strong baroclinicity where surface cyclones occur. The effect of increase with following decrease of anthropogenic load on storm tracks activity in the Northern Hemisphere was studied. The global climate system model of intermediate complexity ('Planet Simulator', Fraedrich K. et al., 2005) was used in this study. Anthropogenic forcing was set according to climatic scenario RCP8.5 continued till 4000 AD with fixed CO2 concentration till 3000 AD and linear decrease of anthropogenic load to preindustrial value at two different rates: for 100 and 1000 years. Modeling data analysis showed meridional shift of storm tracks due to atmospheric CO2 concentration variation. When CO2 concentration increases storm tracks demonstrate poleward shifting. When CO2 concentration decreases to preindustrial value storm tracks demonstrate a tendency to equator-ward shifting. Storm tracks, however, don't recover their original activity and location to the full. This manifests itself particularly for 'fast' CO2 concentration decrease. Heat and moisture fluxes demonstrate the same behavior. In addition, analysis of eddy length scale (Kidston J. Et al., 2011) showed their increase at mid-latitudes and decrease at tropic latitudes due to intensive CO2 concentration increase. This might cause poleward shift of mid-latitude jets. Acknowledgements. This work is partially supported by SB RAS project VIII.80.2.1, RFBR grant 13-05-12034, 13-05-00480, 14-05-00502 and grant of the President of the Russian Federation. Fraedrich K., Jansen H., Kirk E., Luksch U., and Lunkeit F. The Planet Simulator: Towards a user friendly model // Meteorol. Zeitschrift. 2005, 14, 299-304. Kidston J., Vallis G.K., Dean S.M., Renwick J.A. Can the increase in the eddy length scale ander global warming cause the poleward shift of the jet streams? // J. Climate. 2011, V.24. P. 3764-3780.

  12. Variation in resource limitation of plant reproduction influences natural selection on floral traits of Asclepias syriaca.

    PubMed

    Caruso, Christina M; Remington, Davin L D; Ostergren, Kate E

    2005-11-01

    The availability of both pollen and resources can influence natural selection on floral traits, but their relative importance in shaping floral evolution is unclear. We experimentally manipulated pollinator and resource (fertilizer and water) availability in the perennial wildflower Asclepias syriaca L. Nine floral traits, one male fitness component (number of pollinia removed), and two female fitness components (number of pollinia inserted and number of fruits initiated) were measured for plants in each of three treatments (unmanipulated control, decreased pollinator access, and resource supplementation). Although decreasing pollinators' access to flowers did result in fewer pollinia inserted and removed, fruit set and phenotypic selection on floral traits via female and male fitness did not differ from the control. In contrast, resource supplementation increased fruit set, and phenotypic selection on seven out of nine floral traits was stronger via female than male fitness, consistent with the prediction that selection via female fitness would be greater when reproduction was less resource-limited. Our results support the hypothesis that abiotic resource availability can influence floral evolution by altering gender-specific selection.

  13. How Rainfall Variation Influences Reproductive Patterns of African Savanna Ungulates in an Equatorial Region Where Photoperiod Variation Is Absent.

    PubMed

    Ogutu, Joseph O; Owen-Smith, Norman; Piepho, Hans-Peter; Dublin, Holly T

    2015-01-01

    In high temperate latitudes, ungulates generally give birth within a narrow time window when conditions are optimal for offspring survival in spring or early summer, and use changing photoperiod to time conceptions so as to anticipate these conditions. However, in low tropical latitudes day length variation is minimal, and rainfall variation makes the seasonal cycle less predictable. Nevertheless, several ungulate species retain narrow birth peaks under such conditions, while others show births spread quite widely through the year. We investigated how within-year and between-year variation in rainfall influenced the reproductive timing of four ungulate species showing these contrasting patterns in the Masai Mara region of Kenya. All four species exhibited birth peaks during the putative optimal period in the early wet season. For hartebeest and impala, the birth peak was diffuse and offspring were born throughout the year. In contrast, topi and warthog showed a narrow seasonal concentration of births, with conceptions suppressed once monthly rainfall fell below a threshold level. High rainfall in the previous season and high early rains in the current year enhanced survival into the juvenile stage for all the species except impala. Our findings reveal how rainfall variation affecting grass growth and hence herbivore nutrition can govern the reproductive phenology of ungulates in tropical latitudes where day length variation is minimal. The underlying mechanism seems to be the suppression of conceptions once nutritional gains become insufficient. Through responding proximally to within-year variation in rainfall, tropical savanna ungulates are less likely to be affected adversely by the consequences of global warming for vegetation phenology than northern ungulates showing more rigid photoperiodic control over reproductive timing.

  14. How Rainfall Variation Influences Reproductive Patterns of African Savanna Ungulates in an Equatorial Region Where Photoperiod Variation Is Absent

    PubMed Central

    Ogutu, Joseph O.; Owen-Smith, Norman; Piepho, Hans-Peter; Dublin, Holly T.

    2015-01-01

    In high temperate latitudes, ungulates generally give birth within a narrow time window when conditions are optimal for offspring survival in spring or early summer, and use changing photoperiod to time conceptions so as to anticipate these conditions. However, in low tropical latitudes day length variation is minimal, and rainfall variation makes the seasonal cycle less predictable. Nevertheless, several ungulate species retain narrow birth peaks under such conditions, while others show births spread quite widely through the year. We investigated how within-year and between-year variation in rainfall influenced the reproductive timing of four ungulate species showing these contrasting patterns in the Masai Mara region of Kenya. All four species exhibited birth peaks during the putative optimal period in the early wet season. For hartebeest and impala, the birth peak was diffuse and offspring were born throughout the year. In contrast, topi and warthog showed a narrow seasonal concentration of births, with conceptions suppressed once monthly rainfall fell below a threshold level. High rainfall in the previous season and high early rains in the current year enhanced survival into the juvenile stage for all the species except impala. Our findings reveal how rainfall variation affecting grass growth and hence herbivore nutrition can govern the reproductive phenology of ungulates in tropical latitudes where day length variation is minimal. The underlying mechanism seems to be the suppression of conceptions once nutritional gains become insufficient. Through responding proximally to within-year variation in rainfall, tropical savanna ungulates are less likely to be affected adversely by the consequences of global warming for vegetation phenology than northern ungulates showing more rigid photoperiodic control over reproductive timing. PMID:26295154

  15. Individual variation in life history characteristics can influence extinction risk (vol 144, pg 61, 2001) Correction

    SciTech Connect

    Jager, Yetta

    2009-01-01

    The white sturgeon (Acipenser transmontanus) shows great individual variation in the age at maturation. This study examines the consequences of model assumptions about individual variation in the age at maturation on predicted population viability. I considered: (1) the effects of variation in age at maturation alone; (2) the effects of heritability; and (3) the influence of a stable and an altered selective regime. Two selective regimes represented conditions before and after the impoundment of a river, blocking access of anadromous white sturgeon populations to the ocean. In contrast to previous simulation studies, I found that increased individual variation in the age at maturity did not necessarily lead to a higher likelihood of persistence. Individual variation increased the simulated likelihood of persistence when the variation was heritable and the selective regime had changed such that the mean age at maturity was no longer optimal.

  16. Influence of space use on fitness and the reintroduction success of the Laysan teal

    USGS Publications Warehouse

    Reynolds, M.H.; Hatfield, J.S.; Laniawe, L.P.; Vekasy, M.S.; Klavitter, J.L.; Berkowitz, P.; Crampton, L.H.; Walters, J.R.

    2012-01-01

    Translocation is an important tool for wildlife conservation and biodiversity restoration, but an inefficient one because of the unpredictability of success. Predictors of success such as habitat quality of the release site and number of individuals released have been identified, but the dynamics of successful translocations remain poorly understood. In particular, little is known about the relationship of individual post-release movements to population establishment. In 2004, Laysan teal Anas laysanensis were reintroduced by translocating 20 wild birds from Laysan Island to Midway Atoll. Twenty-two additional wild founders were brought the next year. We monitored the survival, reproductive success and movements of the 42 translocated individuals and their offspring for 4 years. Additionally, we monitored population size from 2004 to 2010. Unlike most translocations, we did not observe elevated post-release mortality despite flight-feather trimming to prevent immediate dispersal off-island: first year survival was > 90% and survival rates until 2009 were 0.65±0.08 for founding adults. Laysan teal flew between the two main islands of Midway Atoll, and offspring had significantly larger maximum movement distances than founders. We monitored 84 nests and observed a significant, negative relationship of home range size to productivity for founding females. Flightless founders did not show fidelity to their release sites, but had strong fidelity to annual home ranges after attaining flight. Although we observed a component Allee effect on mate-finding, this did not translate into a demographic Allee effect, and generally, the high fitness of founders contributed substantially to successful population establishment. Laysan teal abundance increased linearly until 2009, but showed evidence of population regulation afterwards. The population estimate was 473 (95% confidence interval 439–508) in 2010. On the much larger main Hawaiian Islands, we expect greater post

  17. Influence of marginal fit and cement types on microleakage of all-ceramic crown systems.

    PubMed

    Yüksel, Ece; Zaimoğlu, Ali

    2011-01-01

    The purpose of this study was to evaluate the effects of both marginal fit and cementing with different luting agents on the microleakage of all-ceramic crown systems. Thirty-six extracted upper central incisors were prepared for full-coverage crowns and were divided into three groups. Group 1: CAD/CAM-fabricated ZrO2, Group 2: Heat-pressed lithium-disilicate, and Group 3: Cast Cr-Co copings as the control group. Copings were made following standard techniques, and groups were assigned cementation with either self-adhesive resin cement (A) or glass-ionomer luting cement (B). The specimens were subjected to thermocycling, immersed in basic fuchsin solution, sectioned mesiodistally and buccolingually. The surface of each section was digitally photographed under a stereomicroscope. Microleakage was scored using a five-point scale, and the marginal gap was measured using image analysis software. Data were statistically analyzed using 2-way ANOVA, Kruskal-Wallis, and Mann-Whitney U tests (α: 0.05). The marginal discrepancy of each group was 82.7 ± 7 µm, 92.6 ± 4 µm and 96.5 ± 7 µm respectively. Group 1 showed significantly smaller gaps than Group 3 (P = 0.042). Self-adhesive resin cement (A) showed a lower level of microleakage than glass-ionomer luting cement (B) in all groups (P = 0.029). Microleakage scores of '0' were 83% for 1A, 50% for 1B, 50% for 2A, 16% for 2B, 33% for 3A and none for 3B. Marginal discrepancy and cement type both had significant effects on microleakage. Lower levels of microleakage were recorded with self-adhesive resin cement, while CAD/CAM-fabricated ZrO2 copings showed smaller marginal discrepancy and less microleakage in comparison to cast Cr-Co.

  18. Influence of the bank vegetation on the river bed variations

    NASA Astrophysics Data System (ADS)

    Ruei Ke, Bo; Chan, Hsun-Chuan; Chen, You-Cheng

    2014-05-01

    In the natural rivers, woody vegetation commonly grows along the riverbank. When flood flows run through the woody vegetation zones, the stream processes are markedly affected. This study experimentally discusses the characteristics of flow fields and the changes of river bedform while water flows through woody vegetation zones. The experiments were produced in a flume with 20m long, 1m wide, and a fixed slope of 0.001. The woody vegetation was set in 10 square centimeters at one side of the flume. Experimental vegetation was simulated by the steel columns due to the stem of emergent woody vegetation near bed is rigid. The experimental flow was steady and flow velocity was adopted to near the critical flow for the initiation of sediment motion. Uniform sand with a median size of 0.88 mm was used as the bed sediment. The three dimensional flow fields of time-averaged velocity distributions and turbulent characteristics were measured by an Acoustic Doppler Velocimeter(ADV). The bed morphology of equilibrium scour condition was measured by a Laser Distance Meter. The interactions between water flows and river bed with vegetation ware investigated by observing the scour and deposition processes around the vegetation zone. In addition, the flow fields at flat bed and equilibrium scour conditions are measured separately. Furthermore, the influence of vegetation density on the flow and bedform was investigated by using the present experiment. When the flows passed through the vegetation zones, the approaching flow was retarded by the vegetation zone along the vegetation-bank side and accelerated in the main channel. The flow velocities also reduced downstream of the vegetation zones and the water depths dropped significantly in the streamwise direction. It was observed that the levels of the sediment deposition decreased at downstream of the vegetation zones as the vegetation density increased. Near the vegetation zone, the size of the scour hole increased as the

  19. Variations on hormone replacement therapy: an answer to the 'one dose fits all' Women's Health Initiative study.

    PubMed

    Studd, John

    2007-11-01

    The Women's Health Initiative study worked on the assumption that one dose would fit all asymptomatic postmenopausal women. The investigators therefore often used the wrong dose, of the wrong hormones, on the wrong patients and therefore came to many wrong conclusions. Different combinations of different hormones are necessary for different symptoms and different age groups. Hormone replacement therapy may be commenced in the perimenopausal phase, the early postmenopause, the late postmenopause or after hysterectomy and bilateral salpingo-oophorectomy or a premature menopause. These all require different treatments. Similarly, various indications such as vasomotor symptoms, sexual problems, depression or the treatment/prevention of osteoporosis all need different combinations of estradiol and possibly progestogen and testosterone, according to the specific requirements of the patient.

  20. Influence of muscle fitness test performance on metabolic risk factors among adolescent girls

    PubMed Central

    2010-01-01

    Background The purpose of this study was to examine the association between muscular fitness (MF), assessed by 2 components of Fitnessgram test battery, the Curl-Up and Push-Ups tests and the metabolic risk score among adolescent girls. Methods A total of 229 girls (aged 12-15 years old) comprised the sample of this study. Anthropometric data (height, body mass, waist circumference) were collected. Body mass index (BMI) was also calculated. Muscular strength was assessed taking into account the tests that comprised the FITNESSGRAM test battery, i.e. the curl-up and the push-up. Participants were then categorized in one of 3 categories according the number of tests in which they accomplished the scores that allow them to be classified in health or above health zone. The blood pressure [BP], fasting total cholesterol [TC], low density lipoprotein-cholesterol [LDL-C], high density lipoprotein-cholesterol [HDL-C], triglycerides [TG], glucose, and a metabolic risk score (MRS) were also examined. Physical Activity Index (PAI) was obtained by questionnaire. Results Higher compliance with health-zone criteria (good in the 2 tests), adjusted for age and maturation, were positive and significantly (p ≤ 0.05) associated with height (r = 0.19) and PAI (r = 0.21), while a significant but negative association was found for BMI (r = -0.12); WC (r = -0.19); TC (r = -0.16); TG (r = -0.16); LDL (r = -0.16) and MRS (r = -0.16). Logistic regression showed that who were assigned to MF fittest group were less likely (OR = 0.27; p = 0.003) to be classified overweight/obese and less likely (OR = 0.26; p = 0.03) to be classified as having MRS. This last association was also found for those whom only performed 1 test under the health zone (OR = 0.23; p = 0.02). Conclusions Our data showed that low strength test performance was associated with increased risk for obesity and metabolic risk in adolescent girls even after adjustment for age and maturation. PMID:20573222

  1. Influence of Excess Adiposity on Exercise Fitness and Performance in Overweight Children and Adolescents

    PubMed Central

    Norman, Anne-Caroline; Drinkard, Bart; McDuffie, Jennifer R.; Ghorbani, Samareh; Yanoff, Lisa B.; Yanovski, Jack A.

    2005-01-01

    Objective Relatively little is known about how excess body mass affects adolescents’ capacity to perform sustained exercise. We hypothesized that most of the difficulty that severely overweight adolescents have with sustained exercise occurs because the metabolic costs of moving excess mass result in use of a high proportion of their total oxygen reserve. Methods We compared results from a maximal cycle ergometry fitness test in 129 severely overweight adolescents who had BMIs of 41.5 ± 9.7 kg/m2 and ages of 14.5 ± 1.8 years (range: 12.1–17.8 years) and 34 nonoverweight adolescents who had BMIs of 20.1 ± 2.9 kg/m2 and ages of 14.5 ± 1.5 years (range: 12.0–18.1 years). Oxygen uptake (V̇o2) was compared at 3 times: during a 4-minute period of unloaded cycling (ULV̇o2), at the lactate thresh-old estimated by gas exchange (LTV̇o2), and at maximal exertion (V̇o2 max). Heart rate was obtained at rest and at V̇o2 max. Participants also completed a 12-minute walk/run performance test to obtain distance traveled (D12) and heart rate. Results Absolute LTV̇o2 and V̇o2 max and LTV̇o2 as a percentage of V̇o2 max were not different in overweight and nonoverweight adolescents during the cycle test. However, absolute ULV̇o2 was significantly greater in overweight adolescents: ULV̇o2 accounted for 35 ± 8% of V̇o2 max (and 63 ± 15% of LTV̇o2) in overweight adolescents but only 20 ± 5% of V̇o2 max (and 39 ± 12% of LTV̇o2) in nonoverweight adolescents. Resting heart rate before initiating the cycle test was significantly greater in overweight than nonoverweight adolescents (94 ± 14 vs 82 ± 15 beats per minute). However, maximal heart rate during the cycle test was significantly lower in overweight adolescents (186 ± 13 vs 196 ± 11 beats per minute). During the walk/run test, mean D12 was significantly shorter for overweight than for nonoverweight adolescents (1983 ± 323 vs 1159 ± 194 m). D12 was negatively related to BMI SDS (r = −0.81) and to ULV

  2. The Candida albicans Pho4 Transcription Factor Mediates Susceptibility to Stress and Influences Fitness in a Mouse Commensalism Model

    PubMed Central

    Urrialde, Verónica; Prieto, Daniel; Pla, Jesús; Alonso-Monge, Rebeca

    2016-01-01

    The Pho4 transcription factor is required for growth under low environmental phosphate concentrations in Saccharomyces cerevisiae. A characterization of Candida albicans pho4 mutants revealed that these cells are more susceptible to both osmotic and oxidative stress and that this effect is diminished in the presence of 5% CO2 or anaerobiosis, reflecting the relevance of oxygen metabolism in the Pho4-mediated response. A pho4 mutant was as virulent as wild type strain when assayed in the Galleria mellonella infection model and was even more resistant to murine macrophages in ex vivo killing assays. The lack of Pho4 neither impairs the ability to colonize the murine gut nor alters the localization in the gastrointestinal tract. However, we found that Pho4 influenced the colonization of C. albicans in the mouse gut in competition assays; pho4 mutants were unable to attain high colonization levels when inoculated simultaneously with an isogenic wild type strain. Moreover, pho4 mutants displayed a reduced adherence to the intestinal mucosa in a competitive ex vivo assays with wild type cells. In vitro competitive assays also revealed defects in fitness for this mutant compared to the wild type strain. Thus, Pho4, a transcription factor involved in phosphate metabolism, is required for adaptation to stress and fitness in C. albicans. PMID:27458452

  3. The influence of active and passive smoking on the cardiorespiratory fitness of adults

    PubMed Central

    2014-01-01

    Background The aim of this study was to analyze the influence of active and passive smoking on cardiorespiratory responses in asymptomatic adults during a sub-maximal-exertion incremental test. Methods The participants (n = 43) were divided into three different groups: active smokers (n = 14; aged 36.5 ± 8 years), passive smokers (n = 14; aged 34.6 ± 11.9 years) and non-smokers (n = 15; aged 30 ± 8.1 years). They all answered the Test for Nicotine Dependence and underwent anthropometric evaluation, spirometry and ergospirometry according to the Bruce Treadmill Protocol. Results VO2max differed statistically between active and non-smokers groups (p < 0.001) and between non-smokers and passive group (p=0.022). However, there was no difference between the passive and active smokers groups (p=0.053). Negative and significant correlations occurred between VO2max and age (r = - 0.401, p = 0.044), percentage of body fat (r = - 0.429, p = 0.011), and waist circumference (WC) (r = - 0.382, p = 0.025). Conclusion VO2max was significantly higher in non-smokers compared to active smokers and passive smokers. However, the VO2max of passive smokers did not differ from active smokers. PMID:25009739

  4. [Influence of a variation potential on photosynthesis in pumpkin seedlings (Cucurbita pepo L.)].

    PubMed

    Sukhov, V S; Shesterneva, O N; Surova, L M; Rumiantsev, E A; Vodeneev, V A

    2013-01-01

    The influence of a variation potential on photosynthesis in pumpkin seedlings (Cucurbita pepo L.) was investigated in our work. It was shown that the variation potential induced by cotyledon burning propagates into a leaf. It decreases CO2 assimilation and transpiration as well as increases nonphotochemical quenching. Investigation of isolated chloroplasts showed that lowering of the pH in incubation medium from 6.9-7.2 to 6.5 increases nonphotochemical quenching. It was proposed that lowering of the cytoplasmic pH induced by the variation potential takes place in the photosynthetic response development.

  5. The influence of fine-scale habitat features on regional variation in population performance of alpine White-tailed Ptarmigan

    USGS Publications Warehouse

    Fedy, B.; Martin, K.

    2011-01-01

    It is often assumed (explicitly or implicitly) that animals select habitat features to maximize fitness. However, there is often a mismatch between preferred habitats and indices of individual and population measures of performance. We examined the influence of fine-scale habitat selection on the overall population performance of the White-tailed Ptarmigan (Lagopus leucura), an alpine specialist, in two subdivided populations whose habitat patches are configured differently. The central region of Vancouver Island, Canada, has more continuous and larger habitat patches than the southern region. In 2003 and 2004, using paired logistic regression between used (n = 176) and available (n = 324) sites, we identified food availability, distance to standing water, and predator cover as preferred habitat components . We then quantified variation in population performance in the two regions in terms of sex ratio, age structure (n = 182 adults and yearlings), and reproductive success (n = 98 females) on the basis of 8 years of data (1995-1999, 2002-2004). Region strongly influenced females' breeding success, which, unsuccessful hens included, was consistently higher in the central region (n = 77 females) of the island than in the south (n = 21 females, P = 0.01). The central region also had a much higher proportion of successful hens (87%) than did the south (55%, P < 0.001). In light of our findings, we suggest that population performance is influenced by a combination of fine-scale habitat features and coarse-scale habitat configuration. ?? The Cooper Ornithological Society 2011.

  6. Variation.

    ERIC Educational Resources Information Center

    Hamilton City Board of Education (Ontario).

    Suggestions for studying the topic of variation of individuals and objects (balls) to help develop elementary school students' measurement, comparison, classification, evaluation, and data collection and recording skills are made. General suggestions of variables that can be investigated are made for the study of human variation. Twelve specific…

  7. Explaining Racial/Ethnic Variation in Partnered Women’s and Men’s Housework: Does One Size Fit All?

    PubMed Central

    Wight, Vanessa R.; Bianchi, Suzanne M.; Hunt, Bijou R.

    2014-01-01

    Using a national sample of 12,424 partnered women and 10,721 partnered men from the 2003–2006 American Time Use Survey, this article examines racial/ethnic variation in women’s and men’s housework time and its covariates. The ratio of women’s to men’s housework hours is greatest for Hispanics and Asians and smallest for Whites and Blacks. White and Hispanic women’s housework hours are associated with household composition and employment suggesting that the time availability perspective is a good predictor for these women, but may have less explanatory power for other race/ ethnic groups of women. Relative resources also have explanatory power for White women’s housework time but are weak predictors for women of Other race/ethnicities. Time availability and relative resource measures show some association with White men’s housework time but are generally poor predictors among other race/ethnic groups of men, suggesting that traditional models of housework allocation do not “fit” all groups equally. PMID:25429170

  8. Synonymous Co-Variation across the E1/E2 Gene Junction of Hepatitis C Virus Defines Virion Fitness

    PubMed Central

    Fanning, Liam J.

    2016-01-01

    Hepatitis C virus is a positive-sense single-stranded RNA virus. The gene junction partitioning the viral glycoproteins E1 and E2 displays concurrent sequence evolution with the 3′-end of E1 highly conserved and the 5′-end of E2 highly heterogeneous. This gene junction is also believed to contain structured RNA elements, with a growing body of evidence suggesting that such structures can act as an additional level of viral replication and transcriptional control. We have previously used ultradeep pyrosequencing to analyze an amplicon library spanning the E1/E2 gene junction from a treatment naïve patient where samples were collected over 10 years of chronic HCV infection. During this timeframe maintenance of an in-frame insertion, recombination and humoral immune targeting of discrete virus sub-populations was reported. In the current study, we present evidence of epistatic evolution across the E1/E2 gene junction and observe the development of co-varying networks of codons set against a background of a complex virome with periodic shifts in population dominance. Overtime, the number of codons actively mutating decreases for all virus groupings. We identify strong synonymous co-variation between codon sites in a group of sequences harbouring a 3 bp in-frame insertion and propose that synonymous mutation acts to stabilize the RNA structural backbone. PMID:27880830

  9. Heterozygosity at a single locus explains a large proportion of variation in two fitness-related traits in great tits: a general or a local effect?

    PubMed

    García-Navas, V; Cáliz-Campal, C; Ferrer, E S; Sanz, J J; Ortego, J

    2014-12-01

    In natural populations, mating between relatives can have important fitness consequences due to the negative effects of reduced heterozygosity. Parental level of inbreeding or heterozygosity has been also found to influence the performance of offspring, via direct and indirect parental effects that are independent of the progeny own level of genetic diversity. In this study, we first analysed the effects of parental heterozygosity and relatedness (i.e. an estimate of offspring genetic diversity) on four traits related to offspring viability in great tits (Parus major) using 15 microsatellite markers. Second, we tested whether significant heterozygosity-fitness correlations (HFCs) were due to 'local' (i.e. linkage to genes influencing fitness) and/or 'general' (genome-wide heterozygosity) effects. We found a significant negative relationship between parental genetic relatedness and hatching success, and maternal heterozygosity was positively associated with offspring body size. The characteristics of the studied populations (recent admixture, polygynous matings) together with the fact that we found evidence for identity disequilibrium across our set of neutral markers suggest that HFCs may have resulted from genome-wide inbreeding depression. However, one locus (Ase18) had disproportionately large effects on the observed HFCs: heterozygosity at this locus had significant positive effects on hatching success and offspring size. It suggests that this marker may lie near to a functional locus under selection (i.e. a local effect) or, alternatively, heterozygosity at this locus might be correlated to heterozygosity across the genome due to the extensive ID found in our populations (i.e. a general effect). Collectively, our results lend support to both the general and local effect hypotheses and reinforce the view that HFCs lie on a continuum from inbreeding depression to those strictly due to linkage between marker loci and genes under selection.

  10. Genetic composition of social groups influences male aggressive behaviour and fitness in natural genotypes of Drosophila melanogaster

    PubMed Central

    Saltz, Julia B.

    2013-01-01

    Indirect genetic effects (IGEs) describe how an individual's behaviour—which is influenced by his or her genotype—can affect the behaviours of interacting individuals. IGE research has focused on dyads. However, insights from social networks research, and other studies of group behaviour, suggest that dyadic interactions are affected by the behaviour of other individuals in the group. To extend IGE inferences to groups of three or more, IGEs must be considered from a group perspective. Here, I introduce the ‘focal interaction’ approach to study IGEs in groups. I illustrate the utility of this approach by studying aggression among natural genotypes of Drosophila melanogaster. I chose two natural genotypes as ‘focal interactants’: the behavioural interaction between them was the ‘focal interaction’. One male from each focal interactant genotype was present in every group, and I varied the genotype of the third male—the ‘treatment male’. Genetic variation in the treatment male's aggressive behaviour influenced the focal interaction, demonstrating that IGEs in groups are not a straightforward extension of IGEs measured in dyads. Further, the focal interaction influenced male mating success, illustrating the role of IGEs in behavioural evolution. These results represent the first manipulative evidence for IGEs at the group level. PMID:24068359

  11. Influence of Military Training and Standardized Nutrition in Military Unit on Soldiers' Nutritional Status and Physical Fitness.

    PubMed

    Tomczak, Andrzej; Bertrandt, Jerzy; Kłos, Anna; Kłos, Krzysztof

    2016-10-01

    Tomczak, A, Bertrandt, J, Kłos, A, and Kłos, K. Influence of military training and standardized nutrition in military unit on soldiers' nutritional status and physical fitness. J Strength Cond Res 30(10): 2774-2780, 2016-Despite suspension of conscription in Polish Army, trainings of soldiers are still carried out. It is expected that they will be effective and will contribute to obtaining optimum level of psychophysical efficiency that enables fulfillment of military tasks. Total of 60 soldiers took part in the study. During the 9-month military service, soldiers had 200 hours of physical training and basic military training (shooting, drill, anti-chemical training, topography, general tactics, and military equipment operation). The training lasted 8 hours everyday. To assess fitness level, 4 trials were done: long jump, pull-ups, sit-ups, and 1,000 m run. Evaluation of food was based on the analysis of full board menus using the "Tables of composition and nutritional value of food products." Energy value was assessed, and content of basic nutrients was calculated. Assessment of nutritional status was based on anthropometric measurements, such as body height, body mass, and thickness of 4 selected skinfolds. Body height and body mass were the basis for the body mass index calculation. Soldiers serving in the mechanized infantry unit, after completing the training, got better results only in 1,000 m run (from 250.3 to 233.61 seconds). During the research, an average energy value of a daily food ration planned for consumption was 4,504 kcal. This value consisted of 13.2% of energy from protein, 31.9% of energy from fat, and 54.9% from carbohydrates. In the course of military service, percentage of subjects indicating overweight increased from 10.2 to 25.4%.

  12. Influence of taekwondo as security martial arts training on anaerobic threshold, cardiorespiratory fitness, and blood lactate recovery.

    PubMed

    Kim, Dae-Young; Seo, Byoung-Do; Choi, Pan-Am

    2014-04-01

    [Purpose] This study was conducted to determine the influence of Taekwondo as security martial arts training on anaerobic threshold, cardiorespiratory fitness, and blood lactate recovery. [Subjects and Methods] Fourteen healthy university students were recruited and divided into an exercise group and a control group (n = 7 in each group). The subjects who participated in the experiment were subjected to an exercise loading test in which anaerobic threshold, value of ventilation, oxygen uptake, maximal oxygen uptake, heart rate, and maximal values of ventilation / heart rate were measured during the exercise, immediately after maximum exercise loading, and at 1, 3, 5, 10, and 15 min of recovery. [Results] At the anaerobic threshold time point, the exercise group showed a significantly longer time to reach anaerobic threshold. The exercise group showed significantly higher values for the time to reach VO2max, maximal values of ventilation, maximal oxygen uptake and maximal values of ventilation / heart rate. Significant changes were observed in the value of ventilation volumes at the 1- and 5-min recovery time points within the exercise group; oxygen uptake and maximal oxygen uptake were significantly different at the 5- and 10-min time points; heart rate was significantly different at the 1- and 3-min time points; and maximal values of ventilation / heart rate was significantly different at the 5-min time point. The exercise group showed significant decreases in blood lactate levels at the 15- and 30-min recovery time points. [Conclusion] The study results revealed that Taekwondo as a security martial arts training increases the maximal oxygen uptake and anaerobic threshold and accelerates an individual's recovery to the normal state of cardiorespiratory fitness and blood lactate level. These results are expected to contribute to the execution of more effective security services in emergencies in which violence can occur.

  13. The interrelationship between muscle oxygenation, muscle activation, and pulmonary oxygen uptake to incremental ramp exercise: influence of aerobic fitness.

    PubMed

    Boone, Jan; Barstow, Thomas J; Celie, Bert; Prieur, Fabrice; Bourgois, Jan

    2016-01-01

    We investigated whether muscle and ventilatory responses to incremental ramp exercise would be influenced by aerobic fitness status by means of a cross-sectional study with a large subject population. Sixty-four male students (age: 21.2 ± 3.2 years) with a heterogeneous peak oxygen uptake (51.9 ± 6.3 mL·min(-1)·kg(-1), range 39.7-66.2 mL·min(-1)·kg(-1)) performed an incremental ramp cycle test (20-35 W·min(-1)) to exhaustion. Breath-by-breath gas exchange was recorded, and muscle activation and oxygenation were measured with surface electromyography and near-infrared spectroscopy, respectively. The integrated electromyography (iEMG), mean power frequency (MPF), deoxygenated [hemoglobin and myoglobin] (deoxy[Hb+Mb]), and total[Hb+Mb] responses were set out as functions of work rate and fitted with a double linear function. The respiratory compensation point (RCP) was compared and correlated with the breakpoints (BPs) (as percentage of peak oxygen uptake) in muscle activation and oxygenation. The BP in total[Hb+Mb] (83.2% ± 3.0% peak oxygen uptake) preceded (P < 0.001) the BP in iEMG (86.7% ± 4.0% peak oxygen uptake) and MPF (86.3% ± 4.1% peak oxygen uptake), which in turn preceded (P < 0.01) the BP in deoxy[Hb+Mb] (88.2% ± 4.5% peak oxygen uptake) and RCP (87.4% ± 4.5% peak oxygen uptake). Furthermore, the peak oxygen uptake was significantly (P < 0.001) positively correlated to the BPs and RCP, indicating that the BPs in total[Hb+Mb] (r = 0.66; P < 0.001), deoxy[Hb+Mb] (r = 0.76; P < 0.001), iEMG (r = 0.61; P < 0.001), MPF (r = 0.63; P < 0.001), and RCP (r = 0.75; P < 0.001) occurred at a higher percentage of peak oxygen uptake in subjects with a higher peak oxygen uptake. In this study a close relationship between muscle oxygenation, activation, and pulmonary oxygen uptake was found, occurring in a cascade of events. In subjects with a higher aerobic fitness level this cascade occurred at a higher relative intensity.

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

    PubMed Central

    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

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

    PubMed

    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.

  16. Regional variation of climatic influences on West Nile virus outbreaks in the United States.

    PubMed

    Wimberly, Michael C; Lamsal, Aashis; Giacomo, Paolla; Chuang, Ting-Wu

    2014-10-01

    The national resurgence of human West Nile virus (WNV) disease in 2012 raised questions about the factors responsible for WNV outbreaks. Interannual climatic variations may influence WNV amplification and transmission to humans through multiple pathways, including mosquito breeding habitats, gonotrophic cycles, extrinsic incubation, avian communities, and human behavior. We examined the influences of temperature and precipitation anomalies on interannual variation in human WNV cases in three regions of the United States. There were consistent positive influences of winter temperatures, weaker and more variable positive effects of spring and summer temperatures, and highly variable precipitation effects that ranged from positive to negative. The overwintering period may be a particularly important climatic constraint on the dynamics of WNV in cold-temperate regions of North America. Geographic differences in the seasonal timing and relative importance of climatic drivers of WNV risk likely reflect underlying variability in key ecological and social characteristics.

  17. Regional Variation of Climatic Influences on West Nile Virus Outbreaks in the United States

    PubMed Central

    Wimberly, Michael C.; Lamsal, Aashis; Giacomo, Paolla; Chuang, Ting-Wu

    2014-01-01

    The national resurgence of human West Nile virus (WNV) disease in 2012 raised questions about the factors responsible for WNV outbreaks. Interannual climatic variations may influence WNV amplification and transmission to humans through multiple pathways, including mosquito breeding habitats, gonotrophic cycles, extrinsic incubation, avian communities, and human behavior. We examined the influences of temperature and precipitation anomalies on interannual variation in human WNV cases in three regions of the United States. There were consistent positive influences of winter temperatures, weaker and more variable positive effects of spring and summer temperatures, and highly variable precipitation effects that ranged from positive to negative. The overwintering period may be a particularly important climatic constraint on the dynamics of WNV in cold-temperate regions of North America. Geographic differences in the seasonal timing and relative importance of climatic drivers of WNV risk likely reflect underlying variability in key ecological and social characteristics. PMID:25092814

  18. Daily variations in pathogenic bacterial populations in a monsoon influenced tropical environment.

    PubMed

    Khandeparker, Lidita; Anil, Arga Chandrashekar; Naik, Sneha D; Gaonkar, Chetan C

    2015-07-15

    Changing climatic conditions have influenced the monsoon pattern in recent years. Variations in bacterial population in one such tropical environment were observed everyday over two years and point out intra and inter annual changes driven by the intensity of rainfall. Vibrio spp. were abundant during the monsoon and so were faecal coliforms. Vibrio alginolyticus were negatively influenced by nitrate, whereas, silicate and rainfall positively influenced Vibrio parahaemolyticus numbers. It is also known that pathogenic bacteria are associated with the plankton. Changes in the abundance of plankton, which are governed mainly by environmental changes, could be responsible for variation in pathogenic bacterial abundance during monsoon, other than the land runoff due to precipitation and influx of fresh water.

  19. Variations and Defects: Influence on Performance and Safety of Aerospace Missions

    NASA Technical Reports Server (NTRS)

    Turner, Irem Y.; Koga, Dennis (Technical Monitor)

    2001-01-01

    The overall goal of this project is to determine sources of normal and abnormal statistical variation for helicopter transmission vibrations. One current application is HUMS technology for helicopters. The design and manufacturing research hypothesis is that statistical variation due to design and manufacturing is a significant source of unreliability and eventual failures of systems. The Systems Health and Safety group research objectives include the following: (1) to develop empirical database for modeling and evaluation; (2) to identify and model factors that influence vibrations; (3) to develop algorithms for damage detection; (4) to determine 'hit' and 'false alarm' rates; and (5) to understand the fundamentals of transmission vibrations.

  20. Lean mass as a total mediator of the influence of muscular fitness on bone health in schoolchildren: a mediation analysis.

    PubMed

    Torres-Costoso, Ana; Gracia-Marco, Luis; Sánchez-López, Mairena; García-Prieto, Jorge Cañete; García-Hermoso, Antonio; Díez-Fernández, Ana; Martínez-Vizcaíno, Vicente

    2015-01-01

    This report aims to analyse the independent association of lean mass and muscle fitness with bone mineral content (BMC) and bone mineral density (BMD), and to examine whether the relationship between muscle fitness and bone health is mediated by lean mass. Body composition (by dual energy X-ray absorptiometry (DXA)), muscle fitness, physical activity, age and height were measured in 132 schoolchildren (62 boys, aged 8-11 years). Analysis of covariance tested differences in bone-related variables by lean mass and muscle fitness, controlling for different sets of confounders. Linear regression models fitted for mediation analyses examined whether the association between muscle fitness and bone mass was mediated by lean mass. Children with good performance in handgrip and standing long jump had better and worse bone health, respectively. These differences disappeared after controlling for lean mass. Children with high lean mass had higher values in all bone-related variables. In addition, the relationship between muscle fitness and bone mass was fully mediated by lean mass. In conclusion, the relationship between upper-limbs muscle fitness and bone health seems to be dependent on lean mass but not on muscle fitness. Schoolchildren with high lean mass have more BMC and BMD in all regions. Lean mass mediates the association between muscle fitness and bone mass.

  1. The influence of regulatory fit and interactivity on brand satisfaction and trust in E-health marketing inside 3D virtual worlds (Second Life).

    PubMed

    Jin, Seung-A Annie; Lee, Kwan Min

    2010-12-01

    Interactive three-dimensional (3D) virtual environments like Second Life have great potential as venues for effective e-health marketing and e-brand management. Drawing from regulatory focus and interactivity literatures, this study examined the effects of the regulatory fit that consumers experience in interactive e-health marketing on their brand satisfaction and brand trust. The results of a two-group comparison experiment conducted within Second Life revealed that consumers in the regulatory fit condition show greater brand satisfaction and brand trust than those in the regulatory misfit condition, thus confirming the persuasive influence of regulatory fit in e-brand management inside 3D virtual worlds. In addition, a structural equation modeling analysis demonstrated the mediating role of consumers' perceived interactivity in explaining the processional link between regulatory fit and brand evaluation. Theoretical contributions and managerial implications of these findings are discussed.

  2. Intrapersonal variation in consumer susceptibility to normative influence: toward a better understanding of brand choice decisions.

    PubMed

    Orth, Ulrich R; Kahle, Lynn R

    2008-08-01

    The authors examined intrapersonal variation in consumer susceptibility to normative influence as a key mediator of wine brand choice. On the basis of a consumer sample, the authors found that individual values and social identity complexity affect consumer susceptibility to normative influence with downstream effects on (a) which brand benefits consumers desire in wine and (b) choice. Individuals higher on internal values and with more complex social identities were less susceptible to normative influence and placed less emphasis on social brand benefits. Separate examinations of consumption scenarios with and without salient reference groups showed that reference group salience interacts with personal values and social identity complexity in affecting consumer susceptibility to normative influence, which in turn affects which brand benefits consumers desire and consequently choice.

  3. Genetic variation in offspring indirectly influences the quality of maternal behaviour in mice.

    PubMed

    Ashbrook, David George; Gini, Beatrice; Hager, Reinmar

    2015-12-23

    Conflict over parental investment between parent and offspring is predicted to lead to selection on genes expressed in offspring for traits influencing maternal investment, and on parentally expressed genes affecting offspring behaviour. However, the specific genetic variants that indirectly modify maternal or offspring behaviour remain largely unknown. Using a cross-fostered population of mice, we map maternal behaviour in genetically uniform mothers as a function of genetic variation in offspring and identify loci on offspring chromosomes 5 and 7 that modify maternal behaviour. Conversely, we found that genetic variation among mothers influences offspring development, independent of offspring genotype. Offspring solicitation and maternal behaviour show signs of coadaptation as they are negatively correlated between mothers and their biological offspring, which may be linked to costs of increased solicitation on growth found in our study. Overall, our results show levels of parental provisioning and offspring solicitation are unique to specific genotypes.

  4. Spacebased Observations of Oceanic Influence on the Annual Variation of South American Water Balance

    NASA Technical Reports Server (NTRS)

    Liu, W. Timothy; Xie, Xiaosu; Tang, Wenqing; Zlotnicki, Victor

    2006-01-01

    The mass change of South America (SA) continent measured by the Gravity Recovery and Climate Experiment (GRACE) imposes a constraint on the uncertainties in estimating the annual variation of rainfall measured by Tropical Rain Measuring Mission (TRMM) and ocean moisture influx derived from QuikSCAT data. The approximate balance of the mass change rate with the moisture influx less climatological river discharge, in agreement with the conservation principle, bolsters not only the credibility of the spacebased measurements, but supports the characterization of ocean's influence on the annual variation of continental water balance. The annual variation of rainfall is found to be in phase with the mass change rate in the Amazon and the La Plata basins, and the moisture advection across relevant segments of the Pacific and Atlantic coasts agrees with the annual cycle of rainfall in the two basins and the Andes mountains.

  5. Factors influencing the variations of PM10 aerosol dust in Klang Valley, Malaysia during the summer

    NASA Astrophysics Data System (ADS)

    Juneng, Liew; Latif, Mohd Talib; Tangang, Fredolin

    2011-08-01

    The associations between the variations of PM10 concentration during summer monsoon dry seasons over the Klang Valley, Malaysia and the local meteorological factors, synoptic weather conditions as well as the regional hotspots number were examined based on simple multiple linear regression analysis. The regressive relationships established, suggest that the variation of PM10 in Klang Valley was governed significantly by all of the examined factors. Local meteorological conditions are among those factors which governed the largest day-to-day variations of PM10 concentration in the Klang Valley areas during the dry season. When augmented by synoptic meteorological variables and foreign emission sources, a remarkable increase in the explained variance was apparent. On the other hand, domestic burning sources only had a minimal impact on PM10 fluctuations. Important synoptic weather patterns which influence the air pollution variations were also identified. These synoptic conditions include the strengthening of the summer monsoon southwesterly winds over the equatorial area. In addition, the formation of cyclonic circulation, associated with typhoon formation over the north-west Pacific and the South China Sea as well as over the Bay of Bengal, are found to have had a profound impact on PM10 variations over the Malaysian region through the modulation of regional moisture distributions.

  6. Quantifying heritable variation in fitness-related traits of wild, farmed and hybrid Atlantic salmon families in a wild river environment.

    PubMed

    Reed, T E; Prodöhl, P; Hynes, R; Cross, T; Ferguson, A; McGinnity, P

    2015-08-01

    Farmed fish are typically genetically different from wild conspecifics. Escapees from fish farms may contribute one-way gene flow from farm to wild gene pools, which can depress population productivity, dilute local adaptations and disrupt coadapted gene complexes. Here, we reanalyse data from two experiments (McGinnity et al., 1997, 2003) where performance of Atlantic salmon (Salmo salar) progeny originating from experimental crosses between farm and wild parents (in three different cohorts) were measured in a natural stream under common garden conditions. Previous published analyses focussed on group-level differences but did not account for pedigree structure, as we do here using modern mixed-effect models. Offspring with one or two farm parents exhibited poorer survival in their first and second year of life compared with those with two wild parents and these group-level inferences were robust to excluding outlier families. Variation in performance among farm, hybrid and wild families was generally similar in magnitude. Farm offspring were generally larger at all life stages examined than wild offspring, but the differences were moderate (5-20%) and similar in magnitude in the wild versus hatchery environments. Quantitative genetic analyses conducted using a Bayesian framework revealed moderate heritability in juvenile fork length and mass and positive genetic correlations (>0.85) between these morphological traits. Our study confirms (using more rigorous statistical techniques) previous studies showing that offspring of wild fish invariably have higher fitness and contributes fresh insights into family-level variation in performance of farm, wild and hybrid Atlantic salmon families in the wild. It also adds to a small, but growing, number of studies that estimate key evolutionary parameters in wild salmonid populations. Such information is vital in modelling the impacts of introgression by escaped farm salmon.

  7. Genetic variations in TCF7L2 influence therapeutic response to sulfonylureas in Indian diabetics.

    PubMed

    Dhawan, Dipali; Padh, Harish

    2016-11-01

    Sulfonylureas are widely used to treat type 2 diabetes, with considerable inter-individual variation in the hypoglycaemic response to sulfonylureas. Genetic variants in the gene encoding for transcription factor-7-like 2 (TCF7L2) have been associated with type 2 diabetes. This study aimed to study the effect of variations in TCF7L2 on therapeutic response to sulfonylureas in Type 2 diabetes mellitus patients. The effect of TCF7L2 rs12255372, rs7903146 and rs4506565 genotypes on glycaemic response was observed in 250 diabetic patients treated with sulfonylureas and sulfonylureas along with metformin. The genotyping tests were done by allele-specific multiplex PCR. Glycated haemoglobin (HbA1c) levels were used as phenotypic marker. 60% of sulfonylurea users did not achieve a target HbA1c levels of ⩽6.5% (48mmol/mol) (which denotes good control in diabetics). Genotype influenced response to sulfonylureas, with more treatment failure in the TT homozygotes in case of rs12255372 and rs4506565. The GG genotype at rs12255372 favourably influences treatment success with sulfonylurea therapy in patients with type 2 diabetes (p⩽0.05). At rs12255372, 70.5% GT or TT genotype failed to achieve therapeutic target, an absolute difference of 19% compared to GG homozygotes. Our preliminary data show that genetic variation at rs12255372 has a direct correlation with therapeutic success with sulfonylureas in type 2 diabetes, hence paving the way for better treatment outcomes in diabetics.

  8. Local sweating on the forehead, but not forearm, is influenced by aerobic fitness independently of heat balance requirements during exercise.

    PubMed

    Cramer, Matthew N; Bain, Anthony R; Jay, Ollie

    2012-05-01

    The present study investigated the influence of maximal oxygen uptake (V(O2 max)) on local steady-state sudomotor responses to exercise, independently of evaporative requirements for heat balance (E(req)). Eleven fit (F; (V(O2 max))61.9 ± 6.0 ml kg(-1) min(-1)) and 10 unfit men (UF; (V(O2 max)) 40.4 ± 3.8 ml kg(-1) min(-1)) cycled for 60 min at an air temperature of 24.5 ± 0.8°C and ambient humidity of 0.9 ± 0.3 kPa at a set metabolic heat production per unit surface area, producing the same E(req) in all participants (BAL trial) and, in a second trial, at 60% of (V(O2 max)). During the BAL trial, absolute power (F 107 ± 2 and UF 102 ± 2 W; P = 0.126), E(req) (F 175 ± 5 and UF 176 ± 9 W m(-2); P = 0.855), steady-state whole-body sweat rate (F 0.44 ± 0.02 and UF 0.47 ± 0.02 mg cm(-2) min(-1); P = 0.385) and local sweat rate on the arm (F 0.29 ± 0.03 and UF 0.35 ± 0.03 mg cm(-2) min(-1); P = 0.129) were not different between groups; however, local sweat rate on the forehead in UF (1.67 ± 0.20 mg cm(-2) min(-1)) was almost double (P = 0.002) that of F (0.87 ± 0.11 mg cm(-2) min(-1)). Heart rate, ratings of perceived exertion and relative exercise intensity were also significantly greater in UF (P < 0.05). There was a trend towards an elevated minute ventilation in UF (P = 0.052), while end-tidal P(CO2) was significantly lower in UF (P = 0.028). At 60% (V(O2 max)), absolute power (F 174 ± 6 and UF 110 ± 5 W; P < 0.001), E(req) (F 291 ± 14 and UF 190 ± 17 W m(-2); P < 0.001), steady-state whole-body sweat rate (F 0.84 ± 0.05 and UF 0.53 ± 0.03 mg cm(-2) min(-1); P < 0.001) and local sweat rate on the arm (F 0.75 ± 0.04 and UF 0.35 ± 0.03 mg cm(-2) min(-1); P < 0.001) and on the forehead (F 2.92 ± 0.42 and UF 1.68 ± 0.23 mg cm(-2) min(-1); P = 0.022) were all significantly greater in F compared with UF. Heart rate and ratings of perceived exertion were similar at all time points (P > 0.05). Significantly greater minute ventilation (P < 0.001) and

  9. Genetic variation in social environment construction influences the development of aggressive behavior in Drosophila melanogaster.

    PubMed

    Saltz, J B

    2017-04-01

    Individuals are not merely subject to their social environments; they choose and create them, through a process called social environment (or social niche) construction. When genotypes differ in social environment-constructing behaviors, different genotypes are expected to experience different social environments. As social experience often affects behavioral development, quantitative genetics and psychology theories predict that genetic variation in social environment construction should have an important role in determining phenotypic variation; however, this hypothesis has not been tested directly. I identify multiple mechanisms of social environment construction that differ among natural genotypes of Drosophila melanogaster and investigate their consequences for the development of aggressive behavior. Male genotypes differed in the group sizes that they preferred and in their aggressive behavior; both of these behaviors influenced social experience, demonstrating that these behaviors function as social environment-constructing traits. Further, the effects of social experience-as determined in part by social environment construction-carried over to affect focal male aggression at a later time and with a new opponent. These results provide manipulative experimental support for longstanding hypotheses in psychology, that genetic variation in social environment construction has a causal role in behavioral development. More broadly, these results imply that studies of the genetic basis of complex traits should be expanded to include mechanisms by which genetic variation shapes the environments that individuals experience.

  10. Provincial variation of carbon emissions from bituminous coal: Influence of inertinite and other factors

    USGS Publications Warehouse

    Quick, J.C.; Brill, T.

    2002-01-01

    We observe a 1.3 kg C/net GJ variation of carbon emissions due to inertinite abundance in some commercially available bituminous coal. An additional 0.9 kg C/net GJ variation of carbon emissions is expected due to the extent of coalification through the bituminous rank stages. Each percentage of sulfur in bituminous coal reduces carbon emissions by about 0.08 kg C/net GJ. Other factors, such as mineral content, liptinite abundance and individual macerals, also influence carbon emissions, but their quantitative effect is less certain. The large range of carbon emissions within the bituminous rank class suggests that rank- specific carbon emission factors are provincial rather than global. Although carbon emission factors that better account for this provincial variation might be calculated, we show that the data used for this calculation may vary according to the methods used to sample and analyze coal. Provincial variation of carbon emissions and the use of different coal sampling and analytical methods complicate the verification of national greenhouse gas inventories. Published by Elsevier Science B.V.

  11. Phase variable DNA repeats in Neisseria gonorrhoeae influence transcription, translation, and protein sequence variation

    PubMed Central

    Zelewska, Marta A.; Pulijala, Madhuri; Spencer-Smith, Russell; Mahmood, Hiba-Tun-Noor A.; Norman, Billie; Churchward, Colin P.; Calder, Alan

    2016-01-01

    There are many types of repeated DNA sequences in the genomes of the species of the genus Neisseria, from homopolymeric tracts to tandem repeats of hundreds of bases. Some of these have roles in the phase-variable expression of genes. When a repeat mediates phase variation, reversible switching between tract lengths occurs, which in the species of the genus Neisseria most often causes the gene to switch between on and off states through frame shifting of the open reading frame. Changes in repeat tract lengths may also influence the strength of transcription from a promoter. For phenotypes that can be readily observed, such as expression of the surface-expressed Opa proteins or pili, verification that repeats are mediating phase variation is relatively straightforward. For other genes, particularly those where the function has not been identified, gathering evidence of repeat tract changes can be more difficult. Here we present analysis of the repetitive sequences that could mediate phase variation in the Neisseria gonorrhoeae strain NCCP11945 genome sequence and compare these results with other gonococcal genome sequences. Evidence is presented for an updated phase-variable gene repertoire in this species, including a class of phase variation that causes amino acid changes at the C-terminus of the protein, not previously described in N. gonorrhoeae. PMID:28348872

  12. The influence of fixatives and other variations in tissue processing on nuclear morphometric features.

    PubMed

    Baak, J P; Noteboom, E; Koevoets, J J

    1989-08-01

    The influence on the area and numerical density of nuclei was investigated in 5-mm-thick slices of guinea pig liver for different fixatives and variations in tissue processing: delay in fixation, air drying, degree of acidity of 10% formalin (= 4% formaldehyde), Bouin and mercury-formalin fixatives, acetone and ethanol dehydration and understretching and overstretching of the paraffin-embedded sections. Air drying (either forced or as a result of delayed fixation), the type of fixative and the degree of acidity affected the nuclear area. Regarding the latter, nuclear area was approximately 25% lower for pH less than or equal to 3 as compared with pH greater than 5. In comparison with the standard tissue processing used, the nuclear density was higher after all of the variations studied (air drying, acetone dehydration and fixation). These findings indicate that nuclear area, in contrast to other tissue components, is relatively insensitive to variations in tissue processing. However, it is essential to regularly measure the pH of the fixative: deviations from pH = 7 should be carefully avoided in order to keep nuclear area variations as a result of tissue processing within acceptable limits.

  13. THE INFLUENCE OF SCREW TYPE, ALLOY AND CYLINDER POSITION ON THE MARGINAL FIT OF IMPLANT FRAMEWORKS BEFORE AND AFTER LASER WELDING

    PubMed Central

    Castilio, Daniela; Pedreira, Ana Paula Ribeiro do Vale; Rossetti, Paulo Henrique Orlato; Rossetti, Leylha Maria Nunes; Bonachela, Wellington Cardoso

    2006-01-01

    Misfit at the abutment-prosthetic cylinder interface can cause loss of preload, leading to loosening or fracture of gold and titanium screws. Objectives: To evaluate the influence of screw type, alloy, and cylinder position on marginal fit of implant frameworks before and after laser welding. Methods: After Estheticone-like abutments were screwed to the implants, thirty plastic prosthetic cylinders were mounted and waxed-up to fifteen cylindrical bars. Each specimen had three interconnected prosthetic components. Five specimens were one-piece cast in titanium and five in cobalt-chromium alloy. On each specimen, tests were conducted with hexagonal titanium and slotted gold screws separately, performing a total of thirty tested screws. Measurements at the interfaces were performed using an optical microscope with 5 μm accuracy. After sectioning, specimens were laser welded and new measurements were obtained. Data were submitted to a four-way ANOVA and Tukey's multiple comparisons test (α =0.05). Results: Slotted and hexagonal screws did not present significant differences regarding to the fit of cylinders cast in titanium, either in one-piece casting framework or after laser welding. When slotted and hexagonal screws were tested on the cobalt-chromium specimens, statistically significant differences were found for the one-piece casting condition, with the slotted screws presenting better fit (24.13μm) than the hexagonal screws (27.93 μm). Besides, no statistically significant differences were found after laser welding. Conclusions: 1) The use of different metal alloys do exert influence on the marginal fit, 2) The slotted and hexagonal screws play the exclusive role of fixing the prosthesis, and did not improve the fit of cylinders, and 3) cylinder position did not affect marginal fit values. PMID:19089035

  14. Influence of pre- and post-usage flushing frequencies on bacterial water quality of non-touch water fittings

    PubMed Central

    2013-01-01

    Background Non-touch fittings have been reported to be susceptible for Pseudomonas aeruginosa accumulation. A number of factors may contribute to this, including the frequency of usage, duration of water stagnation, or presence of plastic materials. Programmable non-touch fittings are appearing which allow regular automated post-flushing with cold water to prevent water stagnation. However, the ideal duration of post-flushing is unknown as well as the effect of pre-rinsing with cold water before use. Methods Eight non-touch fittings with brass valve blocks were mounted on a mobile test sink and connected to the same central water pipe source, differing only in presence or absence of water connection pipes, length of connection pipe, frequency of usage, and time intervals for pre- and post-usage water flush. The total bacteria colony-forming unit (cfu) counts were obtained by the spread plate technique. Results Low frequency of water use in combination with a long stagnating water column resulted in high bacterial cfu counts. Post-usage flushing for 2 seconds did not differ from no flushing. Flushing for 10 seconds with cold water after use or 30 seconds flush before use were both the most effective measures to prevent non-touch fittings from biofilm formation over a period of 20 weeks. Conclusion Further improvements in water fitting technology could possibly solve the problem of bacterial water contamination in health care settings. PMID:24000790

  15. Marine and terrestrial influences on interannual CO{sub 2} variations at Mauna Loa and the South Pole

    SciTech Connect

    Dettinger, M.D.; Ghil, M.

    1997-11-01

    Data are presented and very briefly discussed regarding interannual variations of atmospheric carbon dioxide (CO{sub 2}) concentrations. Interannual variations are isolated from monthly concentrations by using singular-spectrum analysis of CO{sub 2} and atmospheric carbon isotopic ratios at Mauna Loa, Hawaii, United States and at the South Pole. Interannual variations are shared at the two sites, and can be used to differentiate between marine and land-surface responses to different interannual climate variations on global scales. Two time-scales are compared: (1) quasi-quadrennial (QQ) and (2) 3-year. Phase relations indicate that QQ variations are dominated by terrestrial influences, whereas the 3-year variations reflect marine (upwelling) influences in the eastern Pacific. The contrasting CO{sub 2} responses on these two time scales thus provide a useful measure of differences in global climate responses, and especially in terrestrial-ecosystem responses to different tropical forcings. 1 fig.

  16. Intention to be Physically Active is Influenced by Physical Activity and Fitness, Sedentary Behaviours, and Life Satisfaction in Adolescents.

    PubMed

    Grao-Cruces, Alberto; Fernández-Martínez, Antonio; Nuviala, Alberto; Pérez-Turpin, José A

    2015-09-01

    The aim of this study was to determine the association of levels of physical activity (PA), physical fitness (PF), sedentary lifestyle and life satisfaction with the intention to be physically active after secondary school graduation, in teenagers of both genders. A total of 1986 Spanish adolescents (12-16 years) participated in this cross-sectional study. PA, sedentary lifestyle, life satisfaction and intention to be physically active were assessed through validated questionnaires, and PF was evaluated objectively with the ALPHA battery tests. In both genders, adolescents who had significantly higher odds ratios (OR) of showing low intention to be physically active had low level of PA, cardiorespiratory fitness and muscular fitness in the lower body, and they were more sedentary in front of the computer. The girls that spent a lot of time watching TV and the boys with low life satisfaction also showed higher OR of having low intention to be physically active.

  17. Reduced Fitness of Virulent Aphis glycines (Hemiptera: Aphididae) Biotypes May Influence the Longevity of Resistance Genes in Soybean.

    PubMed

    Varenhorst, Adam J; McCarville, Michael T; O'Neal, Matthew E

    2015-01-01

    Sustainable use of insect resistance in crops require insect resistance management plans that may include a refuge to limit the spread of virulence to this resistance. However, without a loss of fitness associated with virulence, a refuge may not prevent virulence from becoming fixed within a population of parthenogenetically reproducing insects like aphids. Aphid-resistance in soybeans (i.e., Rag genes) prevent outbreaks of soybean aphid (Aphis glycines), yet four biotypes defined by their capacity to survive on aphid-resistant soybeans (e.g., biotype-2 survives on Rag1 soybean) are found in North America. Although fitness costs are reported for biotype-3 on aphid susceptible and Rag1 soybean, it is not clear if virulence to aphid resistance in general is associated with a decrease in fitness on aphid susceptible soybeans. In laboratory assays, we measured fitness costs for biotype 2, 3 and 4 on an aphid-susceptible soybean cultivar. In addition, we also observed negative cross-resistance for biotype-2 on Rag3, and biotype-3 on Rag1 soybean. We utilized a simple deterministic, single-locus, four compartment genetic model to account for the impact of these findings on the frequency of virulence alleles. When a refuge of aphid susceptible was included within this model, fitness costs and negative cross-resistance delayed the increase of virulence alleles when virulence was inherited recessively or additively. If virulence were inherited additively, fitness costs decreased the frequency of virulence. Combined, these results suggest that a refuge may prevent virulent A. glycines biotypes from overcoming Rag genes if this aphid-resistance were used commercially in North America.

  18. Behavioral adjustments of African herbivores to predation risk by lions: spatiotemporal variations influence habitat use.

    PubMed

    Valeix, M; Loveridge, A J; Chamaillé-Jammes, S; Davidson, Z; Murindagomo, F; Fritz, H; Macdonald, D W

    2009-01-01

    Predators may influence their prey populations not only through direct lethal effects, but also through indirect behavioral changes. Here, we combined spatiotemporal fine-scale data from GPS radio collars on lions with habitat use information on 11 African herbivores in Hwange National Park (Zimbabwe) to test whether the risk of predation by lions influenced the distribution of herbivores in the landscape. Effects of long-term risk of predation (likelihood of lion presence calculated over four months) and short-term risk of predation (actual presence of lions in the vicinity in the preceding 24 hours) were contrasted. The long-term risk of predation by lions appeared to influence the distributions of all browsers across the landscape, but not of grazers. This result strongly suggests that browsers and grazers, which face different ecological constraints, are influenced at different spatial and temporal scales in the variation of the risk of predation by lions. The results also show that all herbivores tend to use more open habitats preferentially when lions are in their vicinity, probably an effective anti-predator behavior against such an ambush predator. Behaviorally induced effects of lions may therefore contribute significantly to structuring African herbivore communities, and hence possibly their effects on savanna ecosystems.

  19. Proton cellular influx as a probable mechanism of variation potential influence on photosynthesis in pea.

    PubMed

    Sukhov, Vladimir; Sherstneva, Oksana; Surova, Lyubov; Katicheva, Lyubov; Vodeneev, Vladimir

    2014-11-01

    Electrical signals (action potential and variation potential, VP) caused by environmental stimuli are known to induce various physiological responses in plants, including changes in photosynthesis; however, their functional mechanisms remain unclear. In this study, the influence of VP on photosynthesis in pea (Pisum sativum L.) was investigated and the proton participation in this process analysed. VP, induced by local heating, inactivated photosynthesis and activated respiration, with the initiation of the photosynthetic response connected with inactivation of the photosynthetic dark stage; however, direct VP influence on the light stage was also probable. VP generation was accompanied with pH increases in apoplasts (0.17-0.30 pH unit) and decreases in cytoplasm (0.18-0.60 pH unit), which probably reflected H(+) -ATPase inactivation and H(+) influx during this electrical event. Imitation of H(+) influx using the protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP) induced a photosynthetic response that was similar with a VP-induced response. Experiments on chloroplast suspensions showed that decreased external pH also induced an analogous response and that its magnitude depended on the magnitude of pH change. Thus, the present results showed that proton cellular influx was the probable mechanism of VP's influence on photosynthesis in pea. Potential means of action for this influence are discussed.

  20. The nature of nurture in a wild mammal's fitness.

    PubMed

    McFarlane, S Eryn; Gorrell, Jamieson C; Coltman, David W; Humphries, Murray M; Boutin, Stan; McAdam, Andrew G

    2015-05-07

    Genetic variation in fitness is required for the adaptive evolution of any trait but natural selection is thought to erode genetic variance in fitness. This paradox has motivated the search for mechanisms that might maintain a population's adaptive potential. Mothers make many contributions to the attributes of their developing offspring and these maternal effects can influence responses to natural selection if maternal effects are themselves heritable. Maternal genetic effects (MGEs) on fitness might, therefore, represent an underappreciated source of adaptive potential in wild populations. Here we used two decades of data from a pedigreed wild population of North American red squirrels to show that MGEs on offspring fitness increased the population's evolvability by over two orders of magnitude relative to expectations from direct genetic effects alone. MGEs are predicted to maintain more variation than direct genetic effects in the face of selection, but we also found evidence of maternal effect trade-offs. Mothers that raised high-fitness offspring in one environment raised low-fitness offspring in another environment. Such a fitness trade-off is expected to maintain maternal genetic variation in fitness, which provided additional capacity for adaptive evolution beyond that provided by direct genetic effects on fitness.

  1. The Influence of Word Retrieval and Planning on Phonetic Variation: Implications for Exemplar Models

    PubMed Central

    Fink, Angela; Goldrick, Matthew

    2015-01-01

    Over the past several decades, an increasing number of empirical studies have documented the interaction of information across the traditional linguistic modules of phonetics, phonology, and lexicon. For example, the frequency with which a word occurs influences its phonetic properties of its sounds; high frequency words tend to be reduced relative to low frequency words. Lexicalist Exemplar Models have been successful in accounting for this body of results through a single mechanism, exemplars— memory representations that integrate lexical, phonological, and phonetic information into a single structure. We review recent studies that suggest there are critical limitations to assuming that phonetic variation solely reflects the storage of word labels and sound structure in exemplars. Specifically, these studies show that factors related to the on-line retrieval and planning of lexical items also influence phonetic variation. The implications of these findings for exemplar models are discussed; the relationship of exemplar storage to the broader cognitive system is examined, as well as alternative theoretical frameworks incorporating gradience at all levels of linguistic representation. PMID:26756024

  2. Heritable influences on amygdala and orbitofrontal cortex contribute to genetic variation in core dimensions of personality.

    PubMed

    Lewis, G J; Panizzon, M S; Eyler, L; Fennema-Notestine, C; Chen, C-H; Neale, M C; Jernigan, T L; Lyons, M J; Dale, A M; Kremen, W S; Franz, C E

    2014-12-01

    While many studies have reported that individual differences in personality traits are genetically influenced, the neurobiological bases mediating these influences have not yet been well characterized. To advance understanding concerning the pathway from genetic variation to personality, here we examined whether measures of heritable variation in neuroanatomical size in candidate regions (amygdala and medial orbitofrontal cortex) were associated with heritable effects on personality. A sample of 486 middle-aged (mean=55 years) male twins (complete MZ pairs=120; complete DZ pairs=84) underwent structural brain scans and also completed measures of two core domains of personality: positive and negative emotionality. After adjusting for estimated intracranial volume, significant phenotypic (r(p)) and genetic (r(g)) correlations were observed between left amygdala volume and positive emotionality (r(p)=.16, p<.01; r(g)=.23, p<.05, respectively). In addition, after adjusting for mean cortical thickness, genetic and nonshared-environmental correlations (r(e)) between left medial orbitofrontal cortex thickness and negative emotionality were also observed (r(g)=.34, p<.01; r(e)=-.19, p<.05, respectively). These findings support a model positing that heritable bases of personality are, at least in part, mediated through individual differences in the size of brain structures, although further work is still required to confirm this causal interpretation.

  3. The influence of population characteristics on variation in general practice based morbidity estimations

    PubMed Central

    2011-01-01

    Background General practice based registration networks (GPRNs) provide information on morbidity rates in the population. Morbidity rate estimates from different GPRNs, however, reveal considerable, unexplained differences. We studied the range and variation in morbidity estimates, as well as the extent to which the differences in morbidity rates between general practices and networks change if socio-demographic characteristics of the listed patient populations are taken into account. Methods The variation in incidence and prevalence rates of thirteen diseases among six Dutch GPRNs and the influence of age, gender, socio economic status (SES), urbanization level, and ethnicity are analyzed using multilevel logistic regression analysis. Results are expressed in median odds ratios (MOR). Results We observed large differences in morbidity rate estimates both on the level of general practices as on the level of networks. The differences in SES, urbanization level and ethnicity distribution among the networks' practice populations are substantial. The variation in morbidity rate estimates among networks did not decrease after adjusting for these socio-demographic characteristics. Conclusion Socio-demographic characteristics of populations do not explain the differences in morbidity estimations among GPRNs. PMID:22111707

  4. Natural Genetic Variation Influences Protein Abundances in C. elegans Developmental Signalling Pathways

    PubMed Central

    Singh, Kapil Dev; Roschitzki, Bernd; Snoek, L. Basten; Grossmann, Jonas; Zheng, Xue; Elvin, Mark; Kamkina, Polina; Schrimpf, Sabine P.; Poulin, Gino B.; Kammenga, Jan E.; Hengartner, Michael O.

    2016-01-01

    Complex traits, including common disease-related traits, are affected by many different genes that function in multiple pathways and networks. The apoptosis, MAPK, Notch, and Wnt signalling pathways play important roles in development and disease progression. At the moment we have a poor understanding of how allelic variation affects gene expression in these pathways at the level of translation. Here we report the effect of natural genetic variation on transcript and protein abundance involved in developmental signalling pathways in Caenorhabditis elegans. We used selected reaction monitoring to analyse proteins from the abovementioned four pathways in a set of recombinant inbred lines (RILs) generated from the wild-type strains N2 (Bristol) and CB4856 (Hawaii) to enable quantitative trait locus (QTL) mapping. About half of the cases from the 44 genes tested showed a statistically significant change in protein abundance between various strains, most of these were however very weak (below 1.3-fold change). We detected a distant QTL on the left arm of chromosome II that affected protein abundance of the phosphatidylserine receptor protein PSR-1, and two separate QTLs that influenced embryonic and ionizing radiation-induced apoptosis on chromosome IV. Our results demonstrate that natural variation in C. elegans is sufficient to cause significant changes in signalling pathways both at the gene expression (transcript and protein abundance) and phenotypic levels. PMID:26985669

  5. Adverse influence on reproduction and potential fitness cost in survivors of orthene-treated tarnished plant bug, Lygus lineolaris

    Technology Transfer Automated Retrieval System (TEKTRAN)

    By using dose response to Orthene at 80 mg/L (LC50 of the laboratory susceptible colony), a relative resistant population (71% survival rate) of the tarnished plant bug, Lygus lineolaris, was located near Tillar, Arkansas. This population was used in this study to evaluate potential fitness cost in ...

  6. TSPY1 Copy Number Variation Influences Spermatogenesis and Shows Differences among Y Lineages

    PubMed Central

    Giachini, Claudia; Nuti, Francesca; Turner, Daniel J.; Laface, Ilaria; Xue, Yali; Daguin, Fabrice; Forti, Gianni; Tyler-Smith, Chris; Krausz, Csilla

    2012-01-01

    Context TSPY1 is a tandemly-repeated gene on the human Y chromosome forming an array of approximately 21–35 copies. The testicular expression pattern and the inferred function of the TSPY1 protein suggest possible involvement in spermatogenesis. However, data are scarce on TSPY1 copy number variation in different Y lineages and its role in spermatogenesis. Objectives We sought to define: 1) the extent of TSPY1 copy number variation within and among Y chromosome haplogroups; and 2) the role of TSPY1 dosage in spermatogenic efficiency. Materials and Methods A total of 154 idiopathic infertile men and 130 normozoospermic controls from Central Italy were analyzed. We used a quantitative PCR assay to measure TSPY1 copy number and also defined Y haplogroups in all subjects. Results We provide evidence that TSPY1 copy number shows substantial variation among Y haplogroups and thus that population stratification does represent a potential bias in case-control association studies. We also found: 1) a significant positive correlation between TSPY1 copy number and sperm count (P < 0.001); 2) a significant difference in mean TSPY1 copy number between patients and controls (28.4 ± 8.3 vs. 33.9 ± 10.7; P < 0.001); and 3) a 1.5-fold increased risk of abnormal sperm parameters in men with less than 33 copies (P < 0.001). Conclusions TSPY copy number variation significantly influences spermatogenic efficiency. Low TSPY1 copy number is a new risk factor for male infertility with potential clinical consequences. PMID:19773397

  7. Flowering phenology in subalpine meadows: does climate variation influence community co-flowering patterns?

    PubMed

    Forrest, Jessica; Inouye, David W; Thomson, James D

    2010-02-01

    Climate change is expected to alter patterns of species co-occurrence, in both space and time. Species-specific shifts in reproductive phenology may alter the assemblages of plant species in flower at any given time during the growing season. Temporal overlap in the flowering periods (co-flowering) of animal-pollinated species may influence reproductive success if competitive or facilitative interactions between plant species affect pollinator services. We used a 33-year data set on flowering phenology in subalpine meadows in Colorado, USA, to determine whether interannual variation in snowmelt date, which marks the start of the growing season, affected co-flowering patterns. For two of four species considered, we found a significant relationship between snowmelt timing and composition of the assemblage of co-flowering plants. In years of early snowmelt, Lathyrus lanszwertii var. leucanthus (Fabaceae), the species we investigated in most detail, tended to overlap with earlier-flowering species and with fewer species overall. In particular, overlap with the flowering period of Lupinus polyphyllus var. prunophilus, with which Lathyrus leucanthus shares pollinators, was significantly reduced in early-snowmelt years. The observed association between timing of snowmelt and patterns of flowering overlap could not have been predicted simply by examining temporal trends in the dates of peak flowering of the dominant species in the community, as peak flowering dates have largely shifted in parallel with respect to snowmelt date. However, subtle interspecific differences in responsiveness of flowering time, duration, and intensity to interannual climate variation have likely contributed to the observed relationship. Although much of the year-to-year variation in flowering overlap remains unexplained by snowmelt date, our finding of a measurable signal of climate variation suggests that future climate change may lead to altered competitive environments for these wildflower

  8. Spatial variation in springtime food resources influences the winter body mass of roe deer fawns.

    PubMed

    Pettorelli, Nathalie; Dray, Stephane; Gaillard, Jean-Michel; Chessel, Daniel; Duncan, Patrick; Illius, Andrew; Guillon, Nadine; Klein, Francois; Van Laere, Guy

    2003-11-01

    It is well established that the dynamics of mammalian populations vary in time, in relation to density and weather, and often in interaction with phenotypic differences (sex, age and social status). Habitat quality has recently been identified as another significant source of individual variability in vital rates of deer, including roe deer where spatial variations in fawn body mass were found to be only about a tenth of temporal variations. The approach used was to classify the habitat into blocks a priori, and to analyse variation in animal performance among the predefined areas. In a fine-grained approach, here we use data collected over 24 years on 1,235 roe deer fawns captured at known locations and the plant species composition sampled in 2001 at 578 sites in the Chizé forest to determine the spatial structure at a fine scale of both vegetation and winter body mass of fawns, and then to determine links between the two. Space and time played a nearly equal role in determining fawn body masses of both sexes, each accounting for about 20% of variance and without any interaction between them. The spatial distribution of fawn body mass was perennial over the 24 years considered and predicted values showed a 2 kg range according to location in the reserve, which is much greater than suggested in previous work and is enough to have strong effects on fawn survival. The spatial distribution and the range of predicted body masses were closely similar in males and females. The result of this study is therefore consistent with the view that the life history traits of roe deer are only weakly influenced by sexual selection. The occurrence of three plant species that are known to be important food items in spring/summer roe deer diets, hornbeam ( Carpinus betulus), bluebell ( Hyacinthoides sp.) and Star of Bethlehem ( Ornithogalum sp.) was positively related to winter fawn body mass. The occurrence of species known to be avoided in spring/summer roe deer diets [e

  9. Evaluating influences of seasonal variations and anthropogenic activities on alluvial groundwater hydrochemistry using ensemble learning approaches

    NASA Astrophysics Data System (ADS)

    Singh, Kunwar P.; Gupta, Shikha; Mohan, Dinesh

    2014-04-01

    Chemical composition and hydrochemistry of groundwater is influenced by the seasonal variations and anthropogenic activities in a region. Understanding of such influences and responsible factors is vital for the effective management of groundwater. In this study, ensemble learning based classification and regression models are constructed and applied to the groundwater hydrochemistry data of Unnao and Ghaziabad regions of northern India. Accordingly, single decision tree (SDT), decision tree forest (DTF), and decision treeboost (DTB) models were constructed. Predictive and generalization abilities of the proposed models were investigated using several statistical parameters and compared with the support vector machines (SVM) method. The DT and SVM models discriminated the groundwater in shallow and deep aquifers, industrial and non-industrial areas, and pre- and post-monsoon seasons rendering misclassification rate (MR) between 1.52-14.92% (SDT); 0.91-6.52% (DTF); 0.61-5.27% (DTB), and 1.52-11.69% (SVM), respectively. The respective regression models yielded a correlation between measured and predicted values of COD and root mean squared error of 0.874, 0.66 (SDT); 0.952, 0.48 (DTF); 0.943, 0.52 (DTB); and 0.785, 0.85 (SVR) in complete data array of Ghaziabad. The DTF and DTB models outperformed the SVM both in classification and regression. It may be noted that incorporation of the bagging and stochastic gradient boosting algorithms in DTF and DTB models, respectively resulted in their enhanced predictive ability. The proposed ensemble models successfully delineated the influences of seasonal variations and anthropogenic activities on groundwater hydrochemistry and can be used as effective tools for forecasting the chemical composition of groundwater for its management.

  10. Influence of porcelain veneering on the marginal fit of Digident and Lava CAD/CAM zirconia ceramic crowns

    PubMed Central

    Pak, Hyun-Soon; Han, Jung-Suk; Lee, Jai-Bong; Kim, Sung-Hun

    2010-01-01

    PURPOSE Marginal fit is a very important factor considering the restoration's long-term success. However, adding porcelain to copings can cause distortion and lead to an inadequate fit which exposes more luting material to the oral environment and causes secondary caries. The purpose of this study was to compare the marginal fit of 2 different all-ceramic crown systems before and after porcelain veneering. This study was also intended to verify the marginal fit of crowns originated from green machining of partially sintered blocks of zirconia (Lava CAD/CAM system) and that of crowns obtained through machining of fully sintered blocks of zirconia (Digident CAD/CAM system). MATERIALS AND METHODS 20 crowns were made per each system and the marginal fit was evaluated through a light microscope with image processing (Accura 2000) at 50 points that were randomly selected. Each crown was measured twice: the first measurement was done after obtaining a 0.5 mm coping and the second measurement was done after porcelain veneering. The means and standard deviations were calculated and statistical inferences among the 2 groups were made using independent t-test and within the same group through paired t-test. RESULTS The means and standard deviations of the marginal fit were 61.52 ± 2.88 µm for the Digident CAD/CAM zirconia ceramic crowns before porcelain veneering and 83.15 ± 3.51 µm after porcelain veneering. Lava CAD/CAM zirconia ceramic crowns showed means and standard deviations of 62.22 ± 1.78 µm before porcelain veneering and 82.03 ± 1.85 µm after porcelain veneering. Both groups showed significant differences when analyzing the marginal gaps before and after porcelain veneering within each group. However, no significant differences were found when comparing the marginal gaps of each group before porcelain veneering and after porcelain veneering as well. CONCLUSION The 2 all-ceramic crown systems showed marginal gaps that were within a reported clinically

  11. Variation Within Dialects: A Case of Cajun/Creole Influence Within Child SAAE and SWE

    PubMed Central

    Oetting, Janna B.; Garrity, April Wimberly

    2012-01-01

    Purpose This study examined whether child speakers of Southern African American English (SAAE) and Southern White English (SWE) who were also perceived by some listeners to present a Cajun/Creole English (CE) influence within their dialects produced elevated rates of 6 phonological and 5 morphological patterns of vernacular relative to other SAAE- and SWE-speaking children. Method A group comparison design was followed. The data were listener judgments, 1-min audiotaped excerpts of conversational speech, and transcribed language samples from 93 children (31 classified as specifically language impaired while the others were classified as either aged-matched or language-matched controls; 13 classified as SWE with CE, 40 classified as SWE only, 18 classified as SAAE with CE, and 22 classified as SAAE only). Results Results indicated that children with a CE influence produced elevated rates of vernacular phonology relative to the others, with 2 patterns (nonaspirated stops and glide reduction) showing statistically significant group differences. In contrast, the children’s use of vernacular morphology was unrelated to their CE status, but was instead related to their primary dialect (SWE vs. SAAE) and language ability classification (impaired vs. normal). Conclusions The findings highlight the role of phonology in listeners’ perceptions of dialect variation within 2 nonmainstream dialects (SWE and SAAE). The findings also demonstrate the ways phonological and morphological forms of vernacular can be independently influenced by different types of child variables. PMID:16533070

  12. Variation in habitat soundscape characteristics influences settlement of a reef-building coral

    PubMed Central

    Bohnenstiehl, DelWayne; Peters, Jason W.; Eggleston, David

    2016-01-01

    Coral populations, and the productive reef ecosystems they support, rely on successful recruitment of reef-building species, beginning with settlement of dispersing larvae into habitat favourable to survival. Many substrate cues have been identified as contributors to coral larval habitat selection; however, the potential for ambient acoustic cues to influence coral settlement responses is unknown. Using in situ settlement chambers that excluded other habitat cues, larval settlement of a dominant Caribbean reef-building coral, Orbicella faveolata, was compared in response to three local soundscapes, with differing acoustic and habitat properties. Differences between reef sites in the number of larvae settled in chambers isolating acoustic cues corresponded to differences in sound levels and reef characteristics, with sounds at the loudest reef generating significantly higher settlement during trials compared to the quietest site (a 29.5 % increase). These results suggest that soundscapes could be an important influence on coral settlement patterns and that acoustic cues associated with reef habitat may be related to larval settlement. This study reports an effect of soundscape variation on larval settlement for a key coral species, and adds to the growing evidence that soundscapes affect marine ecosystems by influencing early life history processes of foundational species. PMID:27761342

  13. Variation in habitat soundscape characteristics influences settlement of a reef-building coral.

    PubMed

    Lillis, Ashlee; Bohnenstiehl, DelWayne; Peters, Jason W; Eggleston, David

    2016-01-01

    Coral populations, and the productive reef ecosystems they support, rely on successful recruitment of reef-building species, beginning with settlement of dispersing larvae into habitat favourable to survival. Many substrate cues have been identified as contributors to coral larval habitat selection; however, the potential for ambient acoustic cues to influence coral settlement responses is unknown. Using in situ settlement chambers that excluded other habitat cues, larval settlement of a dominant Caribbean reef-building coral, Orbicella faveolata, was compared in response to three local soundscapes, with differing acoustic and habitat properties. Differences between reef sites in the number of larvae settled in chambers isolating acoustic cues corresponded to differences in sound levels and reef characteristics, with sounds at the loudest reef generating significantly higher settlement during trials compared to the quietest site (a 29.5 % increase). These results suggest that soundscapes could be an important influence on coral settlement patterns and that acoustic cues associated with reef habitat may be related to larval settlement. This study reports an effect of soundscape variation on larval settlement for a key coral species, and adds to the growing evidence that soundscapes affect marine ecosystems by influencing early life history processes of foundational species.

  14. The influence of friction and interference on the seating of a hemispherical press-fit cup: a finite element investigation.

    PubMed

    Spears, I R; Morlock, M M; Pfleiderer, M; Schneider, E; Hille, E

    1999-11-01

    The formation of gaps in the polar region of acetabular cups is seen as a drawback of press-fit fixation of non-cemented acetabular cups. Recent findings indicate a link between long-term polar gaps and the gaps present directly after implantation. In this study the process of press-fitting is simulated with a linear-elastic two-dimensional axisymmetric finite-element model. The aim of this paper is to investigate the possible importance of friction and interference on the formation of these gaps. A range of cup-bone friction coefficients (mu = 0.1-0.5) is assigned to the cup-bone interface in order to represent the unknown amount of friction occurring during press-fitting. The cup is modeled with a radius of 27 mm, whereas the radius of the cavity is varied between 26.50 and 26.75 mm, thus, creating 0.50 and 0.25 mm radial interference fits. The difference in cavity radius represents the discrepancy between the radius of the last-reamer-used and radius of the cavity it creates. The subchondral plate is considered as being completely removed during reaming. The effects of impact blows via the surgeon's mallet during surgery are modeled as a series of four load pulses, in which peak force is gradually increased from 0.5 to 4.0 kN. The effects of load removal as well as those of load application are investigated. On load application, the cup penetrates into the cavity, and on load removal, the cup rebounds. Depending on the friction, interference and load applied, the position of the cup after the load pulse is somewhere between its position at peak force and its position at the beginning of the pulse. Although the simplifications and conditions involved in the creation of the model necessitate caution when interpreting the results for all clinical cases, it is found that the seating of hemispherical cups in trabecular bone could be more satisfactory for intermediate values of friction (mu = 0.2-0.3) and smaller interference fits (0.25 mm).

  15. Influence of the Earth s Corotation Field on the Atmospheric Electricity: Latitudinal Variation and Response to the Solar Activity

    NASA Astrophysics Data System (ADS)

    Dumin, Y.

    Influence of the magnetospheric convection field on the atmospheric electricity is widely studied, both theoretically and experimentally, from the early 1970s. On the other hand, a considerably less attention was paid to the effects of plasmaspheric corotation field, since it was usually believed that the electric field of corotation of the solid Earth is fitted smoothly to the corotation field of plasmasphere, so that no potential difference is formed between them in the lower atmosphere. A conjecture on the important role of corotation field in the global atmospheric-electric circuit was done a few years ago in [P.A. Bespalov, Yu.V. Chugunov, J. Atmos. Terr. Phys., 1996, v.58, p.601] and several subsequent works. Unfortunately, because of using an oversimplified model of plasmasphere (in the form of a spherically-symmetric envelope with isotropic conductivity and rigid-body rotation), no reliable numerical estimates were derived, and no comparison with experimental distributions of the atmospheric electric field could be conducted. The main aim of the present report is to study the corotation effects in the framework of a considerably more realistic analytical model, where conductivity of the plasmasphere is strongly anisotropic, and the magnetic field lines are substantially distorted (stretched to "infinity") in the polar regions. Escape of polarization electric charges along the distorted field lines results in appreciable decrease (by 10-15 V/m) in the average atmospheric electric field at high latitudes. Such phenomenon was experimentally discovered as early as the International Geophysical Year (1957-1958) but was not quantitatively explained by now. Yet another interesting effect following from our model is changing the high-latitude electric field due to variations in the degree of distortion of the magnetic field lines at different levels of the solar activity. These transient changes in the atmospheric electricity should be symmetric about the noon

  16. Spatial variation in fish assemblages across a beaver-influenced successional landscape

    USGS Publications Warehouse

    Schlosser, I.J.; Kallemeyn, L.W.

    2000-01-01

    Beavers are increasingly viewed as 'ecological engineers,' having broad effects on physical, chemical, and biological attributes of north-temperate landscapes. We examine the influence of both local successional processes associated with beaver activity and regional geomorphic boundaries on spatial variation in fish assemblages along the Kabetogama Peninsula in Voyageurs National Park, northern Minnesota, USA. Fish abundance and species richness exhibited considerable variation among drainages along the peninsula. Geological barriers to fish dispersal at outlets of some drainages has reduced fish abundance and species richness. Fish abundance and species richness also varied within drainages among local environments associated with beaver pond succession. Fish abundance was higher in upland ponds than in lowland ponds, collapsed ponds, or streams, whereas species richness was highest in collapsed ponds and streams. Cluster analyses based on fish abundance at sites classified according to successional environment indicated that four species (northern redbelly dace, Phoxinus eos; brook stickleback, Culaea inconstans; finescale dace, P. neogaeus; and fathead minnow, Pimephales promelas), were predominant in all successional environments. Several less abundant species were added in collapsed ponds and streams, with smaller size classes of large lake species (e.g., black crappie, Pomoxis nigromaculatus; smallmouth bass, Micropertus dolomieui; yellow perch, Perca flavescens; and burbot, Lota lota) being a component of these less abundant species. The addition of smaller size classes of large lake species indicates that dispersal of early life-history stages from Kabetogama Lake played a role in determining the species richness and composition of less abundant species in successional environments on the peninsula. Furthermore, collapsed-pond and stream environments closer to Kabetogama Lake had higher species richness than similar successional sites located farther from

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

    PubMed Central

    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

  18. Influence of the inner core geopotential variations on the rotation of the Earth

    NASA Astrophysics Data System (ADS)

    Escapa, A.; Getino, J.; Miguel, D.; Ferrándiz, J. M.

    2011-10-01

    In this investigation we determine a new contribution to the rotation of a three layer Earth model composed by an axial-symmetric mantle, a fluid core, and an axial-symmetric inner core. This contribution emerges as a consequence of the variation of the geopotential induced by the differential rotation of the solid inner core. Within the framework of the Hamiltonian theory of the rotation of the non-rigid Earth, and following the same guidelines as those described in Escapa et al. (2001, 2008), we discuss the influence of this effect on the motion of the Earth figure axis. We also provide numerical estimations for the amplitudes of the nutational motion of this axis.

  19. The influence of geographic variations on the muscular activity in selected sports movements.

    PubMed

    Clarys, J P; Alewaeters, K; Zinzen, E

    2001-12-01

    Surface EMG (SEMG) has been used frequently to study motion techniques or skills, body positions, material or equipment used, training-methodology and learning processes in sports and ergonomics. Little if any information is available on the effect of the geographical environment on the neuromuscular control of an athlete or workman during his/her performance or effort. Motions were chosen in Alpine skiing and cycling. Thirty-one certified ski instructors and twelve professional road cyclists participated in the study of geographical variance and its impact on muscle activity. SEMG was measured from the agonists and antagonists of the upper- and lower limb. Skiers were measured on downhill slopes ranging from 19 to 51% while the cyclists performed with different saddle positions on 2, 7 and 12% slope inclinations, respectively. Verification of the variation of muscular intensity (IEMG) over the slope inclination during a simulated giant slalom indicated that the muscular activity increased with increasing slope angle and decreased with decreasing slope angle, while heart rate measured with short-range radio telemetry increased at a constant rate between start and finish independent of the geographical variations. In a direct descent on different slopes % levels the integrated EMG is well related to the inclination (r=0.82) confirming the findings of the giant slalom. In cycling we found that, regardless of the pelvis position, the muscular intensity of lower limb muscles increased with increasing slope inclination, while the muscular intensity of the arms decreased with the same increasing slope inclination. In addition the decreased intensity of the arm muscles remained significantly higher with the pelvis (saddle) fully forward. The geography of the terrain did influence the neuromuscular work and therewith probably the performance also. The influence however, varies with specific circumstances and is coupled with items of variability of the equipment used and

  20. Common variations in the pretest environment influence genotypic comparisons in models of anxiety.

    PubMed

    Izídio, G S; Lopes, D M; Spricigo, L; Ramos, A

    2005-10-01

    The behavioral characterization of rodent strains in different studies and laboratories can provide unreplicable results even when genotypes are kept constant and environmental control is maximized. In the present study, the influence of common laboratory environmental variables and their interaction with genotype on the results of behavioral tests of anxiety/emotionality were investigated. To this end, the inbred rat strains Lewis (LEW) and spontaneously hypertensive rats (SHR), which are known to differ for numerous emotionality-related behaviors, were tested in the open field (OF), elevated plus maze (EPM) and black/white box (BWB), while three environmental factors were systematically controlled and analyzed: (1) the experimenter handling the animal (familiar or unfamiliar); (2) the position of the home cage (top or bottom shelf of the rack) and (3) the behavioral state of the animal immediately before the test (arousal or rest). Experimenter familiarity did not alter the behavior of rats in the OF. Cage position, on the other hand, influenced the behavior in the OF and BWB, with rats housed in top cages appearing less anxious than those housed in the bottom. In the BWB (but not in the OF), these effects were genotype dependent. Finally, the behavioral state of the animals prior to testing altered the results of the EPM in a strain-dependent manner, with some anxiety-related genotypic differences being found only among rats that were aroused in their home cages. This study showed that common variations in the laboratory environment interact with genotype in behavioral tests of anxiety/emotionality. Recognizing and understanding such variations can help in the design of more effective experiments.

  1. Influences of vowel and tone variation on emergent word knowledge: a cross-linguistic investigation.

    PubMed

    Singh, Leher; Hui, Tam Jun; Chan, Calista; Golinkoff, Roberta Michnick

    2014-01-01

    To learn words, infants must be sensitive to native phonological contrast. While lexical tone predominates as a source of phonemic contrast in human languages, there has been little investigation of the influences of lexical tone on word learning. The present study investigates infants' sensitivity to tone mispronunciations in two groups of infants. For one group (Chinese learners), tone is phonemic in their native language, and for the second group (English learners), tone is non-phonemic and constituted suprasegmental variation. In Experiment 1, English learners were trained on novel word-object pairings and tested on their recognition of correct pronunciations, tone and vowel mispronunciations of these words at 18 and 24 months. In Experiment 2a, bilingual English-Chinese learners were tested on a similar task translated into Chinese at the same age intervals. Results demonstrate that non-tonal learners treated tonal and vowel substitutions alike as mispronunciations at 18 months but only treated vowel substitutions as mispronunciations at 24 months. Tonal learners treated both tonal and vowel substitutions as mispronunciations at both ages. In Experiment 2b, bilingual non-tone language learners were tested on the same set of tasks replicating a similar set of results as monolingual non-tone language learners (Experiment 1). Findings point to an early predisposition to treat tone as a defining characteristic of words regardless of its lexical relevance at 18 months. Between 18 and 24 months, learners appear to ascribe lexical relevance to tone in a language-specific manner. The current study identifies the influences of tone variation on memories for newly learned words and the time period during which lexical tone - a highly frequent constituent of human languages - actually becomes lexical for early learners. Findings are contextualized with prevailing models of the developing lexicon.

  2. The environmental magnetic record of palaeoenvironmental variations during the past 3100 years: A possible solar influence?

    NASA Astrophysics Data System (ADS)

    Sandeep, K.; Shankar, R.; Warrier, Anish K.; Weijian, Z.; Xuefeng, Lu

    2015-07-01

    Sediments from Pookot Lake (PK) in southern India have provided a record of local environmental changes and catchment processes during the past 3100 cal. years B.P. Variations in the rock magnetic parameters (χlf, χfd, χARM and IRM's at different field strengths) of sediments from two AMS 14C-dated cores reflect climate-induced changes in the catchment of Pookot Lake. Assuming that rainfall is most likely the dominant driving mechanism behind the rock magnetic variations of PK sediments, the environmental history of the site has been reconstructed. Rock magnetic parameters exhibit significant variations during the past 3100 years. The palaeoenvironmental history of the Pookot Lake region may be divided into three phases. During the first phase (~ 3100 to 2500 cal. years B.P.), catchment erosion and detrital influx were high, indicating a strong monsoon. The second phase, which lasted from 2500 to 1000 cal. years B.P., was characterised by low and steady rainfall, resulting in a low and uniform catchment erosion and detrital influx. Phase 2 was interspersed with brief intervals of strong monsoon and characterised by frequent drying up of the lake. During Phase 3 (~ 1000 cal. years B.P. to the present), catchment erosion was high, indicating a shift to strong monsoonal conditions. It appears that monsoonal rainfall in the region is influenced by solar activity, with periods of high total solar irradiance being characterised by high rainfall and vice versa; it was relatively low during the Little Ice Age and high during the Medieval Warm Period. The magnetic susceptibility (χlf) data exhibit a number of periodicities which might have a solar origin. The χlf record exhibits similarities with other continental and marine palaeoclimatic records from the region, indicating that regional trends in the monsoon during the Late Holocene are broadly similar.

  3. Influence of ambient temperature variations on the performance of Lyot depolarizers

    NASA Astrophysics Data System (ADS)

    Redek, M.; Makowski, P. L.; Domanski, A. W.

    2013-10-01

    The influence of temperature on the efficiency of Lyot depolarizers is analysed. It is a commonly used idealization that if the birefringent sections forming the depolarizer are made long enough with respect to the coherence time of the lightwave then strictly complete depolarization is always assured. This can lead to a false conclusion that in a real-world system the residual degree of polarization (DoP) will reach a certain value, slightly higher than zero, and remain independent of the initial polarization state (SoP) and insensitive for small variations of material parameters. We point out that Lyot depolarizers are always inhomogeneous in general and, thus, a precise estimation of the maximum possible DoP of an emerging lighwave is not trivial. Using a system made of two sections of lithium niobate we examine and explain how environmental temperature variations within the range of 1 ° C can significantly affect the depolarization efficiency. The numerical predictions of the effect have been verified qualitatively in experiments.

  4. [Variation characteristic in soil respiration of apple orchard and its biotic and abiotic influencing factors].

    PubMed

    Wang, Rui; Guo, Sheng-Li; Liu, Qing-Fang; Zhang, Yan-Jun; Jiang, Ji-Shao; Guo, Hui-Min; Li, Ru-Jian

    2014-05-01

    To evaluate the orchard variability of soil respiration and the response of soil respiration to its influencing factors is helpful for a deep understanding about the effects of converting cropland to apple orchard. A field experiment was conducted in the Changwu State Key Agro-Ecological Station. Soil respiration, soil temperature, soil moisture and roots biomasses were periodically measured in a mature apple orchard during 2011 and 2012. Soil respiration decreased as the distance from the trunk increased. The cumulative soil respiration in the 0.5 m-distance from the trunk was 20% and 31% higher than that in the 2 m-distance from the trunk, respectively in 2011 and 2012. The temperature sensitivity of soil respiration (Q10) was relatively lower in the 2 m-distance than that in the 0. 5 m-distance in both years. Soil temperature and soil moisture were slightly higher in the 2 m-distance, but there was no significant difference between the 2 m-distance and the 0. 5 m-distance. Soil respiration and soil temperature showed a significant exponential relationship, but there was no positive correlation between soil moisture and soil respiration. Soil temperature changes can explain seasonal variation of soil respiration well, but it could not explain its spatial variability. Root density was an important factor for the spatial variability of soil respiration and Q15. Variation of soil respiration coefficient was 23% -31%. Therefore, the distance from the trunk should be considered when estimating orchards soil respiration.

  5. Chemotypic variation in terpenes emitted from storage pools influences early aphid colonisation on tansy

    PubMed Central

    Clancy, Mary V.; Zytynska, Sharon E.; Senft, Matthias; Weisser, Wolfgang W.; Schnitzler, Jörg-Peter

    2016-01-01

    Tansy plants (Tanacetum vulgare L.) exhibit high chemical variation, particularly in mono- and sesquiterpenes that are stored in specialised glands on the plant surface. In the present work we investigated the effects of terpene chemotypes on Metopeurum fuscoviride, an aphid species specialised on tansy, and their tending ants, at the field scale. Previous studies have chemotyped tansy by assessing dominant compounds; here we propose a method of chemotyping using all volatile compounds that are likely emitted from the storage glands. The analysis is based on two extraction methods: GC-MS analysis of leaf hexane extracts and SBSE analysis of headspace emissions. In an initial screening we identified the subset of compounds present in both chemical patterns, labelled as ‘compounds likely emitted from storage’. In a large field survey we could show that the putative chemotypic emission pattern from storage pools significantly affected the early aphid colonisation of tansy. Moreover, the statistical analyses revealed that minor compounds exerted a stronger influence on aphid and tending-ant presence than dominant compounds. Overall we demonstrated that within the enormous chemotypic variation of terpenes in tansy plants, chemical signatures of volatile terpenes can be related to the occurrence of insects on individual plants in the field. PMID:27892539

  6. PRDM9 variation strongly influences recombination hot-spot activity and meiotic instability in humans.

    PubMed

    Berg, Ingrid L; Neumann, Rita; Lam, Kwan-Wood G; Sarbajna, Shriparna; Odenthal-Hesse, Linda; May, Celia A; Jeffreys, Alec J

    2010-10-01

    PRDM9 has recently been identified as a likely trans regulator of meiotic recombination hot spots in humans and mice. PRDM9 contains a zinc finger array that, in humans, can recognize a short sequence motif associated with hot spots, with binding to this motif possibly triggering hot-spot activity via chromatin remodeling. We now report that human genetic variation at the PRDM9 locus has a strong effect on sperm hot-spot activity, even at hot spots lacking the sequence motif. Subtle changes within the zinc finger array can create hot-spot nonactivating or enhancing variants and can even trigger the appearance of a new hot spot, suggesting that PRDM9 is a major global regulator of hot spots in humans. Variation at the PRDM9 locus also influences aspects of genome instability-specifically, a megabase-scale rearrangement underlying two genomic disorders as well as minisatellite instability-implicating PRDM9 as a risk factor for some pathological genome rearrangements.

  7. Influence of seasonal variation on the phenology and liriodenine content of Annona lutescens (Annonaceae).

    PubMed

    Castro-Moreno, Marisol; Tinoco-Ojangurén, Clara Leonor; Cruz-Ortega, Ma Del Rocío; González-Esquinca, Alma Rosa

    2013-07-01

    Annona lutescens Saff. (Annonaceae) grows as a native tree in Chiapas, Mexico in Tropical Dry Forest habitat. Like most Annonaceae, it biosynthesizes benzylisoquinoline alkaloids, mostly liriodenine. To determine the influence of seasonal changes in the accumulation of liriodenine, the monthly variation of liriodenine content in roots, stems and leaves of mature and young trees was observed. These parts of young and mature A. lutescens trees were collected monthly over a 1 year period and the alkaloids were extracted; the liriodenine was quantified by high-resolution liquid chromatography. The phenological stages of the species were also assessed (leaf development, flowering and fruiting) using the Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH) scale. The analysis of both young and mature trees showed a significant increase in the liriodenine concentration occurs within roots during the dry season, which coincides with leaf fall. A significant decrease also occurred at the beginning of the rainy season (the period of leaf growth); the liriodenine content for the next rainy season did not reach the levels of the previous dry season. The climatic variation induced phenological and physiological changes in this species.

  8. Decadal variation of the Northern Hemisphere Annular Mode and its influence on the East Asian trough

    NASA Astrophysics Data System (ADS)

    Lu, Chunhui; Zhou, Botao; Ding, Yihui

    2016-06-01

    We analyze the decadal variation of the stratosphere-troposphere coupled system around the year 2000 by using the NCEP reanalysis-2 data. Specifically, the relationship between the Northern Hemisphere Annular Mode (NAM) and the tropospheric East Asian trough is investigated in order to find the effective stratospheric signals during cold air outbreaks in China. Statistical analyses and dynamic diagnoses both indicate that after 2000, increased stratospheric polar vortex disturbances occur and the NAM is mainly in negative phase. The tropospheric polar areas are directly affected by the polar vortex, and in the midlatitudes, the Ural blocking high and East Asian trough are more active, which lead to enhanced cold air activities in eastern and northern China. Further investigation reveals that under this circulation pattern, downward propagations of negative NAM index are closely related to the intensity variation of the East Asian trough. When negative NAM anomalies propagate down to the upper troposphere and reach a certain intensity (standardized NAM index less than-1), they result in apparent reinforcement of the East Asian trough, which reaches its maximum intensity about one week later. The northerly wind behind the trough transports cold air southward and eastward, and the range of influence and the intensity are closely associated with the trough location. Therefore, the NAM index can be used as a measure of the signals from the disturbed stratosphere to give some indication of cold air activities in China.

  9. CFD investigation of the influence of volute geometrical variations on hydrodynamic characteristics of circulator pump

    NASA Astrophysics Data System (ADS)

    Wu, Denghao; Yuan, Shouqi; Ren, Yun; Mu, Jiegang; Yang, Youdong; Liu, Jian

    2016-03-01

    Improper design of volute geometry can be the main cause that leads to unsteady pressure pulsation and radial force in pumps. Therefore, it is important to understand the influence of volute geometrical parameters on hydrodynamic characteristics of pump and the mechanism. However, the existing studies are limited to investigate the influence of only one or two volute geometrical parameters each time, and a systematic study of the influence of the combinations of different volute geometrical parameters on the pump's hydrodynamic characteristics is missing. In this paper, a study on the understanding of the influence of volute geometrical variations on hydrodynamic characteristics of a high speed circulator pump by using computational fluid dynamics(CFD) technology is presented. Five main volute geometrical parameters D 3, A 8, α 0, φ 0 and R t are selected and 25 different volute configurations are generated by using design of experiments(DOE) method. The 3D unsteady flow numerical simulations, which are based on the SST k- w turbulence model and sliding mesh technique provided by CFX, are executed on the 25 different volute configurations. The hydraulic performance, pressure pulsation and unsteady radial force inside the pump at design condition are obtained and analyzed. It has been found that volute geometrical parameters D 3 and A 8 are major influence factors on hydrodynamic characteristics of the pump, while α 0, φ 0 and R t are minor influence factors. The minimum contribution from both D 3 and A 8 is 58% on head, and maximum contribution from both D 3 and A 8 is 90% on pressure pulsation. Regarding the pressure pulsation intensity, two peaks can be found. One is in the tongue area and the other is in the diffusor area. The contributions are around 60% from tongue and 25% from diffusor, respectively. The amplitude of pressure pulsation has a quadratic polynomial functional relationship with respect to D 3/ D 2 and A 8/ A 10, and fluctuating level of

  10. Influence of long-term variation in storage on hydrological drought characteristics

    NASA Astrophysics Data System (ADS)

    van Huijgevoort, Marjolein; van Lanen, Henny; Teuling, Adriaan; Uijlenhoet, Remko

    2014-05-01

    Characteristics of drought events in streamflow, like drought duration and deficit, are largely determined by catchment processes. Understanding and identification of these processes that affect drought development is important to ensure water availability in the future, especially because drought severity is projected to increase in many regions of the world. In this study, we analysed the influence of storage processes on drought characteristics to quantify the relationship between long-term variation in storage and drought characteristics. For this analysis, a large dataset with discharge observations from 1737 catchments (made available by GRDC and MOPEX) was used. The catchments are situated in Europe and the United States. The discharge time series were divided in three components with a Seasonal-Trend decomposition procedure based on Loess (STL). The long-term trend component derived with the STL method was used as a proxy for the long-term variation in storage. Hydrological drought events were identified from the observations with the variable threshold level method. The contribution of the trend component to the total discharge indicates the importance of the long-term storage variation for drought development in the catchment. A high contribution of the trend component was found in slowly-responding catchments compared to fast-responding catchments. Features of drought propagation (pooling, lag, lengthening and attenuation) were identified in slowly-responding catchments. The contribution of the trend component was linked to the mean drought duration. As expected the catchments with a high contribution experienced relatively long drought events as compared to catchments with a low contribution of the trend component. This relation was less clear for the mean standardized deficit volume. A high contribution of the trend component was only found in smaller catchments, which reflects the importance of storage processes in these catchments. With the STL

  11. Influence of ice load variations on shallow magma storage zones: Application to Katla volcano, Iceland

    NASA Astrophysics Data System (ADS)

    Albino, F.; Pinel, V.; Sigmundsson, F.

    2009-12-01

    As a consequence of climate warming, many volcanoes are currently located under retreating ice caps. The resulting unloading can modify the eruptive activity as proven by observed correlation between deglaciation periods and eruptive activity in the past. Unloading can modify melt generation in the mantle, or modify magma storage conditions at shallow depth. Here we investigate how ice load variations at the Earth's surface act on shallow magma chambers. Numerical calculations are carried out in axisymmetric geometry for an elliptical chamber embedded in an elastic medium, taking magma compressibility into account. For variable chamber shape, size and depth, we quantify how unloading events induce magmatic pressure change as well as variation of the threshold pressure required for dyke initiation at the chamber wall. Influence on eruption likelihood is determined by the interplay between these two parameters. We evaluate the triggering effect of these surface events on onset of eruptions and find it depends strongly on the surface load location and magnitude, and the shape, depth and size of the magma chamber. We apply this model to Katla volcano, Iceland, which is covered by the Mýrdalsjökull ice cap. Ice load variations include long term thinning, as well as an annual load cycle, with up to 6 meters change in snow thickness from winter to summer. As the seasonal snow load is reduced, a pressure decrease of the same order of magnitude as the load is induced within the magma storage zone. The threshold pressure for failure is modified at the same time. Our model predicts that, in case of a spherical or horizontally elongated magma chamber, eruptions are more likely when the seasonal snow cover is smallest. This triggering effect is small, around few kPa, but appears consistent with the fact that all the nine last major historical eruptions at Katla occurred during the summer period. A long-term ice thinning due to global warming is also occurring, mainly at the

  12. Influence of rice black streaked dwarf virus on the ecological fitness of non-vector planthopper Nilaparvata lugens (Hemiptera: Delphacidae).

    PubMed

    Xu, Hong-Xing; He, Xiao-Chan; Zheng, Xu-Song; Yang, Ya-Jun; Lu, Zhong-Xian

    2014-08-01

    Rice black streak dwarf virus (RBSDV) is transmitted by the small brown planthopper (SBPH), Laodelphax striatellus (Fallen). Non-vector rice brown planthopper (BPH), Nilaparvata lugens (Stål), shares the same host rice plants with SBPH in paddy fields. The changes in nutritional composition of rice plants infected by RBSDV and the ecological fitness of BPH feeding on the infected plants were studied under both artificial climate chamber and field conditions. Contents of 16 detected amino acids and soluble sugar in RBSDV infected rice plants were higher than those in the healthy ones. On the diseased plants BPH had significantly higher nymphal survival rates, nymphal duration of the males, weight of the female adults, as well as egg hatchability compared to BPH being fed on healthy plants. However, there was no obvious difference in female nymph duration, longevity and fecundity. Defense enzymes (superoxidase dismutase, SOD and catalase, CAT) and detoxifying enzymes (carboxylesterase, CAE and glutathione S-transferase, GST) in BPH adults fed on diseased plants had markedly higher activities. The results indicate rice plants infected by RBSDV improved the ecological fitness of the brown planthopper, a serious pest but not a transmitter of the RBSDV virus.

  13. Influence of shoes increasing dorsiflexion and decreasing metatarsus flexion on lower limb muscular activity during fitness exercises, walking, and running.

    PubMed

    Bourgit, David; Millet, Guillaume Y; Fuchslocher, Jörg

    2008-05-01

    The aim of the present study was to compare electromyographic activity during fitness exercises, walking, and running among 3 different dorsiflexion shoes (+2 degrees , +4 degrees , and +10 degrees ) and standard shoes (-4 degrees ). The 3 different dorsiflexion shoes tested in this study have a curvature placed in the middle of the sole. This design was specially projected to decrease the metatarsus flexion. Electromyographic activity of 9 lower limb muscles was measured on 12 healthy female subjects during 5 fitness exercises (unload squat, side and front step, submaximal ballistic plantar flexion, and lunge exercise), and during running (10 km x h(-1)) and walking (4.5 km x h(-1)) on a treadmill. EMG signal was analyzed with the root mean square (RMS) and integrated EMG. All RMS data measured during these exercises were expressed as percentages of maximum voluntary isometric contraction. The results show that dorsiflexion affects muscle recruitment and reorganizes the motor pattern. The general tendency was that the tibialis anterior activity increased with dorsiflexion. However, an optimal dorsiflexion existed for various exercises. It is concluded that shoes with moderate dorsiflexion can activate lower limb muscles differently compared with both standard shoes and shoes with large dorsiflexion during submaximal exercises and locomotion.

  14. [Influence of an 8-week exercise intervention on body composition, physical fitness, and mental health in female nursing students].

    PubMed

    Yamazaki, Fumio; Yamada, Hisao; Morikawa, Sachiko

    2013-03-01

    To determine the effectiveness of habitual exercise on the health promotion of college students, we measured the body composition and physical fitness of female nursing students before (Pre) and after (Post) an 8-week low-intensity exercise intervention. We also conducted a questionnaire survey of their mental health condition before and at every 4 weeks during the intervention. The quantity of physical exercise increased (P < 0.0001) from 0.9 ± 0.2 METs・hr/week in the pre-intervention period to 6.6 ± 0.7 METs・hr /week during the intervention period. The exercise intervention did not alter the body weight, but decreased the body fat (Pre, 26.8 ± 0.5%; Post, 24.9 ± 0.5%, P < 0.01) and increased the whole-body muscle mass (Pre, 69.1 ± 0.5%; Post, 70.8 ± 0.4%, P < 0.01). The results of physical fitness tests showed that the intervention promoted muscular strength, muscular endurance, flexibility, agility, and muscular power. The scores for mental health were significantly raised by the intervention. These results suggest that habitual exercise for 8 weeks was effective for the promotion of physical and mental health in female nursing students.

  15. Patient-specific factors influence somatic variation patterns in von Hippel–Lindau disease renal tumours

    PubMed Central

    Fei, Suzanne S.; Mitchell, Asia D.; Heskett, Michael B.; Vocke, Cathy D.; Ricketts, Christopher J.; Peto, Myron; Wang, Nicholas J.; Sönmez, Kemal; Linehan, W. Marston; Spellman, Paul T.

    2016-01-01

    Cancer development is presumed to be an evolutionary process that is influenced by genetic background and environment. In laboratory animals, genetics and environment are variables that can largely be held constant. In humans, it is possible to compare independent tumours that have developed in the same patient, effectively constraining genetic and environmental variation and leaving only stochastic processes. Patients affected with von Hippel–Lindau disease are at risk of developing multiple independent clear cell renal carcinomas. Here we perform whole-genome sequencing on 40 tumours from six von Hippel-Lindau patients. We confirm that the tumours are clonally independent, having distinct somatic single-nucleotide variants. Although tumours from the same patient show many differences, within-patient patterns are discernible. Single-nucleotide substitution type rates are significantly different between patients and show biases in trinucleotide mutation context. We also observe biases in chromosome copy number aberrations. These results show that genetic background and/or environment can influence the types of mutations that occur. PMID:27174753

  16. Influence of Reservoir Operation on River Eco-hydrological Regime Variation

    NASA Astrophysics Data System (ADS)

    Chang, J.; Wang, Y.; Li, Y.

    2013-12-01

    With the development of reservoir, river hydrological situation has undergone great changes. Liujiaxia and Longyangxia reservoir which all have great regulation ability were constructed in the upper reaches above Lanzhou station of the Yellow River. In view of the Indicator of Hydrologic Alteration (IHA), the Range of Variability Approach ( RVA ) is used to calculate the eco- hydrological characteristic values and analyze the influence of different reservoir operating modes on the variation of eco-hydrological characteristics of the Yellow River upstream. On the whole, the hydrologic regime at each station downstream of the Liujiaxia reservoir has changed obviously, especially that at Lanzhou station. The overall degree of hydrologic alteration with single reservoir (Liujiaxia) was 72. 64%, and the hydrologic alteration degree with two reservoirs joint operation was 78. 90%. Both of them were belong to high change. Also, after joint operation of Liujiaxia and Longyangxia reservoir, the flow in flood season significantly reduce and the number of high and low flow reversals increase, which would influence the living condition of aquatic organism in the Yellow River, and greatly endanger the aquatic species' reproduction.

  17. Influence of variation potential on resistance of the photosynthetic machinery to heating in pea.

    PubMed

    Sukhov, Vladimir; Surova, Lyubov; Sherstneva, Oksana; Vodeneev, Vladimir

    2014-12-01

    Electrical signals [action potentials (APs) and variation potentials (VPs)] induced by local stimuli are a mechanism that underlies rapid plant response to environmental factors. Such signals induce a number of functional responses, including changes in photosynthesis. Ultimately, these responses are considered to increase plant resistance to stress factors, but this question has been poorly investigated. We studied the influence of VP on photosynthesis and resistance of the photosynthetic machinery to heating in leaves of pea (Pisum sativum). Localized burning induced a VP that decreased photosynthesis parameters [CO(2) assimilation rate and quantum yields of photosystem I (PSI) and photosystem II (PSII)]. The photosynthetic response was initiated by a decrease in photosynthesis dark-stage activity, which in turn increased resistance of PSI to heating. Three results supported this hypothesized mechanism: (1) the magnitude of VP-induced decrease in CO(2) assimilation and enhanced PSI resistance to heating were highly correlated; (2) the VP influence on PSI resistance to heating was suppressed under a low external CO(2) concentration and (3) decreasing external CO(2) concentration imitated the VP-induced photosynthetic response and increased PSI resistance to heating.

  18. Influence of Arabidopsis thaliana accessions on rhizobacterial communities and natural variation in root exudates

    PubMed Central

    Micallef, Shirley A.; Shiaris, Michael P.; Colón-Carmona, Adán

    2009-01-01

    Plant species is considered to be one of the most important factors in shaping rhizobacterial communities, but specific plant–microbe interactions in the rhizosphere are still not fully understood. Arabidopsis thaliana, for which a large number of naturally occurring ecotype accessions exist, lacks mycorrhizal associations and is hence an ideal model for rhizobacterial studies. Eight Arabidopsis accessions were found to exert a marked selective influence on bacteria associated with their roots, as determined by terminal-restriction fragment length polymorphism (T-RFLP) and ribosomal intergenic spacer analysis (RISA). Community differences in species composition and relative abundance were both significant (P <0.001). The eight distinct and reproducible accession-dependent community profiles also differed from control bulk soil. Root exudates of these variants were analysed by high performance liquid chromatography (HPLC) to try to establish whether the unique rhizobacterial assemblages among accessions could be attributed to plant-regulated chemical changes in the rhizosphere. Natural variation in root exudation patterns was clearly exhibited, suggesting that differences in exudation patterns among accessions could be influencing bacterial assemblages. Other factors such as root system architecture are also probably involved. Finally, to investigate the Arabidopsis rhizosphere further, the phylogenetic diversity of rhizobacteria from accession Cvi-0 is described. PMID:19342429

  19. Retraction notice to: influence of post fit and post length on fracture resistance: an in vitro study. J Contemp Dent Pract 2013;14(3):496-500.

    PubMed

    2013-09-01

    It has been notified to the Editorial Board, The Journal of Contemporary Dental Practice (JCDP), that considerable script of the aforementioned article has been plagiarized from the article: Büttel L, Krastl G, Lorch H, Naumann M, Zitzmann NU, Weiger R. Influence of Post Fit and Post Length on Fracture Resistance. Int Endod J 2009;42(1):47-53. The same was confirmed after thorough evaluation and interpretation. In accordance to observe serious view in case of plagiarism, the Editorial Board, JCDP decided to take appropriate action against the act. Thus, it is herewith decided by the Editorial Board, JCDP to retract the title as addressed from the assigned issue.

  20. Atomic force microscopy of crystalline insulins: the influence of sequence variation on crystallization and interfacial structure.

    PubMed Central

    Yip, C M; Brader, M L; DeFelippis, M R; Ward, M D

    1998-01-01

    The self-association of proteins is influenced by amino acid sequence, molecular conformation, and the presence of molecular additives. In the presence of phenolic additives, LysB28ProB29 insulin, in which the C-terminal prolyl and lysyl residues of wild-type human insulin have been inverted, can be crystallized into forms resembling those of wild-type insulins in which the protein exists as zinc-complexed hexamers organized into well-defined layers. We describe herein tapping-mode atomic force microscopy (TMAFM) studies of single crystals of rhombohedral (R3) LysB28ProB29 that reveal the influence of sequence variation on hexamer-hexamer association at the surface of actively growing crystals. Molecular scale lattice images of these crystals were acquired in situ under growth conditions, enabling simultaneous identification of the rhombohedral LysB28ProB29 crystal form, its orientation, and its dynamic growth characteristics. The ability to obtain crystallographic parameters on multiple crystal faces with TMAFM confirmed that bovine and porcine insulins grown under these conditions crystallized into the same space group as LysB28ProB29 (R3), enabling direct comparison of crystal growth behavior and the influence of sequence variation. Real-time TMAFM revealed hexamer vacancies on the (001) terraces of LysB28ProB29, and more rounded dislocation noses and larger terrace widths for actively growing screw dislocations compared to wild-type bovine and porcine insulin crystals under identical conditions. This behavior is consistent with weaker interhexamer attachment energies for LysB28ProB29 at active growth sites. Comparison of the single crystal x-ray structures of wild-type insulins and LysB28ProB29 suggests that differences in protein conformation at the hexamer-hexamer interface and accompanying changes in interhexamer bonding are responsible for this behavior. These studies demonstrate that subtle changes in molecular conformation due to a single sequence

  1. Influence of linear and undulating strength periodization on physical fitness, physiological, and performance responses to simulated judo matches.

    PubMed

    Franchini, Emerson; Branco, Braulio M; Agostinho, Marcus F; Calmet, Michel; Candau, Robin

    2015-02-01

    To determine the most effective strength periodization model is important to improve judo athletes' performance. Thus, the aim of this study was to compare the effects of linear and daily undulating periodized resistance training on anthropometrical, strength, and judo-specific performance. For this, 13 adult male judo athletes (LP = 6 and DUP = 7) completed a 8-week training program concomitantly to a typical judo training program. Athletes were submitted to a physical fitness test battery, before and after 8 weeks of training, consisting of: (a) maximal strength evaluation: bench press, squat, and row exercises 1 repetition maximum (1RM) tests, and handgrip maximal isometric strength; (b) power evaluation: standing long jump test; (c) strength endurance evaluation: dynamic and isometric chin-up tests gripping the judogi; (d) anthropometry measurements: body mass, height, skinfold thickness and circumferences; (e) judo-specific fitness: performance during the Special Judo Fitness Test (SJFT); (f) match simulation: three 5-minute judo match simulations separated by 15-minute passive recovery. Eight weeks of linear and undulating strength training protocols induced similar significant (P ≤ 0.05) decreases in skinfold thicknesses (-6.5%) and increases in flexed arm (2.0%) and forearm (1.8%) circumferences, maximal isometric handgrip strength (4.6% and 6.1% for right and left hands, respectively), isometric strength endurance chin-up performance gripping the judogi (18.9%), maximal dynamic strength for row (11.5%), bench press (11.6%) and squat exercises (7.1%), total weight lifted at 70% 1RM for bench press (15.1%) and squat (9.6%) exercises, number of throws during sets B (3.1%) and C (9.5%) of the SJFT (resulting in increased total number of throws, 5.5%), and decreased index in this test, -4.2%). However, no changes were observed in the physiological, rating of perceived exertion, or technical actions during 3 match simulations. Thus, it seems that the short

  2. Thermal variation and factors influencing vertical migration behavior in Daphnia populations.

    PubMed

    Glaholt, Stephen P; Kennedy, Meghan L; Turner, Elizabeth; Colbourne, John K; Shaw, Joseph R

    2016-08-01

    The antipredator behavior diel vertical migration (DVM), common in aquatic keystone species Daphnia, involves daily migration from warmer surface waters before dawn to cooler deeper waters after dusk. Plasticity in Daphnia DVM behavior optimizes fitness via trade-offs between growth, reproduction, and predator avoidance. Migration behavior is affected by co-varying biotic and abiotic factors, including light, predator cues, and anthropogenic stressors making it difficult to determine each factor's individual contribution to the variation in this behavior. This study aims to better understand this ecologically significant behavior in Daphnia by: (1) determining how Daphnia pulicaria thermal preferences vary within and among natural populations; (2) distinguishing the role of temperature verses depth in Daphnia vertical migration; and (3) defining how two anthropogenic stressors (copper and nickel) impact Daphnia migratory behavior. Simulated natural lake stratification were constructed in 8L (0.5m tall, 14.5cm wide) water columns to monitor under controlled laboratory conditions the individual effects of temperature gradients, depth, and metal stressors on Daphnia vertical migration. Three major findings are reported. First, while no difference in thermal preference was found among the four populations studied, within lake populations variability among isolates was high. Second, decoupling temperature and depth revealed that depth was a better predictor of Daphnia migratory patterns over temperature. Third, exposure to environmentally relevant concentrations of copper or nickel inhibited classic DVM behavior. These findings revealed the high variability in thermal preference found within Daphnia populations, elucidated the individual roles that depth and temperature have on migratory behavior, and showed how copper and nickel can interfere with the natural response of Daphnia to fish predator cues. Thus contributing to the body of knowledge necessary to predict how

  3. Integrin-mediated interactions between B cells and follicular dendritic cells influence germinal center B cell fitness1

    PubMed Central

    Wang, Xiaoming; Rodda, Lauren; Bannard, Oliver; Cyster, Jason G.

    2014-01-01

    Integrin-ligand interactions between germinal center (GC) B cells and antigen-presenting follicular dendritic cells (FDCs) have been suggested to play central roles during GC responses but their in vivo requirement has not been directly tested. Here we show that while integrins αLβ2 and α4β1 are highly expressed and functional on mouse GC B cells, removal of single integrins or their ligands had little effect on B cell participation in the GC response. Combined β2-integrin deficiency and α4-integrin blockade also did not affect the GC response against a particulate antigen. However, the combined integrin deficiency did cause B cells to be outcompeted in splenic GC responses against a soluble protein antigen and in mesenteric lymph node GC responses against gut-derived antigens. Similar findings were made for β2-deficient B cells in mice lacking VCAM1 on FDCs. The reduced fitness of the GC B cells did not appear to be due to decreased antigen acquisition, proliferation rates or pAKT levels. In summary, our findings provide evidence that αLβ2 and α4β1 play overlapping and context-dependent roles in supporting interactions with FDCs that can augment the fitness of responding GC B cells. We also find that mouse GC B cells upregulate αvβ3 and adhere to vitronectin and milk fat globule EGF-factor-8 protein. Integrin β3-deficient B cells contributed in a slightly exaggerated manner to GC responses suggesting this integrin has a regulatory function in GC B cells. PMID:24740506

  4. Dynamical influences on the moment of inertia tensor from lateral viscosity variations inferred from seismic tomographic models

    NASA Technical Reports Server (NTRS)

    Zhang, Shuxia; Yuen, David A.

    1994-01-01

    We have investigated the influences of lateral variations of viscosity on the moment of inertia tensor from viscous flows due to the density anomalies in the mantle inferred from seismic tomographic models. The scaling relations between the density and the seismic anomalies is taken as either a constant or a function increasing with depth in accord with the recent high-pressure experimental studies. The viscosity is taken as an exponential function of the 3D density anomaly. In models with an isoviscous background, the effects on the perturbed moment of inertia tensor from the lateral viscosity variations are smaller than those due to variations in the radial viscosity profiles. In mantle models with a background viscosity increasing with depth, the influences of the lateral viscosity variations are significant. The most striking feature in the latter case is that the two off-diagonal elements delta I(sub xz) and delta I(sub yz) in the inertia tensor exhibit greatest sensitivity to lateral variations of the viscosity. While the other elements of the inertia change by only about a few tens of percent in the range of lateral viscosity contrast considered (less than 300), delta I(sub xz) and delta I(sub yz) can vary up to 40 times even with a change in sign, depending on the radial viscosity stratification and the location of the strongest lateral variations. The increase in the velocity-density scaling relation with depth can reduce the influences of the lateral viscosity variations, but it does not change the overall sensitive nature of delta I(sub xz) and delta I(sub yz). This study demonstrates clearly that the lateral viscosity variations, especially in the upper mantle, must be considered in the determination of long-term polar wander, since the variations in the delta I(sub xz) and delta I(sub yz) terms are directly responsible for exciting rotational movements.

  5. Latitudinal Range Influences the Seasonal Variation in the Foraging Behavior of Marine Top Predators

    PubMed Central

    Villegas-Amtmann, Stella; Simmons, Samantha E.; Kuhn, Carey E.; Huckstadt, Luis A.; Costa, Daniel P.

    2011-01-01

    Non-migratory resident species should be capable of modifying their foraging behavior to accommodate changes in prey abundance and availability associated with a changing environment. Populations that are better adapted to change will have higher foraging success and greater potential for survival in the face of climate change. We studied two species of resident central place foragers from temperate and equatorial regions with differing population trends and prey availability associated to season, the California sea lion (Zalophus californianus) (CSL) whose population is increasing and the endangered Galapagos sea lion (Zalophus wollebaeki) (GSL) whose population is declining. To determine their response to environmental change, we studied and compared their diving behavior using time-depth recorders and satellite location tags and their diet by measuring C and N isotope ratios during a warm and a cold season. Based on latitudinal differences in oceanographic productivity, we hypothesized that the seasonal variation in foraging behavior would differ for these two species. CSL exhibited greater seasonal variability in their foraging behavior as seen in changes to their diving behavior, foraging areas and diet between seasons. Conversely, GSL did not change their diving behavior between seasons, presenting three foraging strategies (shallow, deep and bottom divers) during both. GSL exhibited greater dive and foraging effort than CSL. We suggest that during the warm and less productive season a greater range of foraging behaviors in CSL was associated with greater competition for prey, which relaxed during the cold season when resource availability was greater. GSL foraging specialization suggests that resources are limited throughout the year due to lower primary production and lower seasonal variation in productivity compared to CSL. These latitudinal differences influence their foraging success, pup survival and population growth reflected in contrasting population

  6. Factors influencing variation in physician adenoma detection rates: a theory-based approach

    PubMed Central

    Atkins, Louise; Hunkeler, Enid M.; Jensen, Christopher D.; Michie, Susan; Lee, Jeffrey K.; Doubeni, Chyke A.; Zauber, Ann G.; Levin, Theodore R.; Quinn, Virginia P.; Corley, Douglas A.

    2015-01-01

    Background & Aims Interventions to improve physician adenoma detection rates for colonoscopy have generally not been successful and there are little data on the factors contributing to variation that may be appropriate targets for intervention. We sought to identify factors that may influence variation in detection rates using theory-based tools for understanding behavior. Methods We separately studied gastroenterologists and endoscopy nurses at three Kaiser Permanente Northern California medical centers to identify potentially modifiable factors relevant to physician adenoma detection rate variability using structured group interviews (focus groups) and theory-based tools for understanding behavior and eliciting behavior change: the Capability, Opportunity, and Motivation behavior model; the Theoretical Domains Framework; and the Behavior Change Wheel. Results Nine factors potentially associated with detection rate variability were identified, including six related to capability (uncertainty about which types of polyps to remove; style of endoscopy team leadership; compromised ability to focus during an examination due to distractions; examination technique during withdrawal; difficulty detecting certain types of adenomas; and examiner fatigue and pain), two related to opportunity (perceived pressure due to the number of examinations expected per shift and social pressure to finish examinations before scheduled breaks or the end of a shift), and one related to motivation (valuing a meticulous examination as the top priority). Examples of potential intervention strategies are provided. Conclusions Using theory-based tools, this study identified several novel and potentially modifiable factors relating to capability, opportunity, and motivation that may contribute to adenoma detection rate variability and be appropriate targets for future intervention trials. PMID:26366787

  7. The influence from synoptic weather on the variation of air pollution and pollen exposure

    NASA Astrophysics Data System (ADS)

    Grundström, Maria; Dahl, Åslög; Chen, Deliang; Pleijel, Håkan

    2014-05-01

    Exposure to elevated air pollution levels can make people more susceptible to allergies or result in more severe allergic reactions for people with an already pronounced sensitivity to pollen. The aim of this study was to investigate the relationships between urban air pollution (nitrogen oxides, ozone and particles) and airborne Betula pollen in Gothenburg, Sweden, during the pollen seasons for the years 2001-2012. Further, the influence from atmospheric weather pattern on pollen/pollution related risk, using Lamb Weather Types (LWT), was also considered. Daily LWTs were obtained by comparing the variation in atmospheric pressure from a 16 point grid over a given region on earth (scale ~1000km) and essentially describe the air mass movement for the region. They include two non-directional types, cyclonic (C) and anticyclonic (A) and eight directional types depending on the wind direction (N, NE, E... etc.). LWTs with dry and calm meteorological character e.g. limited precipitation and low to moderate wind speeds (A, NE, E, SE) were associated with strongly elevated air pollution and pollen levels where Betula was exceptionally high in LWTs NE and E. The co-variation between Betula pollen and ozone was strong and significant during situations with LWTs A, NE, E and SE. The most important conclusion from this study was that LWTs A, NE, E and SE were associated with high pollen and air pollution levels and can therefore be classified as high risk weather situations for combined air pollution and pollen exposure. Our study shows that LWTs have the potential to be developed into an objective tool for integrated air quality forecasting and a warning system for risk of high exposure situations.

  8. Annual variations of carbonaceous PM2.5 in Malaysia: influence by Indonesian peatland fires

    NASA Astrophysics Data System (ADS)

    Fujii, Y.; Tohno, S.; Amil, N.; Latif, M. T.; Oda, M.; Matsumoto, J.; Mizohata, A.

    2015-12-01

    In this study, we quantified carbonaceous PM2.5 in Malaysia through annual observations of PM2.5, focusing on organic compounds derived from biomass burning. We determined organic carbon (OC), elemental carbon and concentrations of solvent-extractable organic compounds (biomarkers derived from biomass burning sources and n-alkanes). We observed seasonal variations in the concentrations of pyrolyzed OC (OP), levoglucosan (LG), mannosan (MN), galactosan, syringaldehyde, vanillic acid (VA) and cholesterol. The average concentrations of OP, LG, MN, galactosan, VA and cholesterol were higher during the southwestern monsoon season (June-September) than during the northeastern monsoon season (December-March), and these differences were statistically significant. Conversely, the syringaldehyde concentration during the southwestern monsoon season was lower. The PM2.5 OP / OC4 mass ratio allowed distinguishing the seven samples, which have been affected by the Indonesian peatland fires (IPFs). In addition, we observed significant differences in the concentrations between the Indonesian peatland fire (IPF) and other samples of many chemical species. Thus, the chemical characteristics of PM2.5 in Malaysia appeared to be significantly influenced by IPFs during the southwestern monsoon season. Furthermore, we evaluated two indicators, the vanillic acid / syringic acid (VA / SA) and LG / MN mass ratios, which have been suggested as indicators of IPFs. The LG / MN mass ratio ranged from 14 to 22 in the IPF samples and from 11 to 31 in the other samples. Thus, the respective variation ranges partially overlapped. Consequently, this ratio did not satisfactorily reflect the effects of IPFs in Malaysia. In contrast, the VA / SA mass ratio may serve as a good indicator, since it significantly differed between the IPF and other samples. However, the OP / OC4 mass ratio provided more remarkable differences than the VA / SA mass ratio, offering an even better indicator. Finally, we

  9. Genetic variation in the serotonin transporter gene influences ERP old/new effects during recognition memory

    PubMed Central

    Ross, Robert S.; Medrano, Paolo; Boyle, Kaitlin; Smolen, Andrew; Curran, Tim; Nyhus, Erika

    2015-01-01

    Recognition memory is defined as the ability to recognize a previously encountered stimulus and has been associated with spatially and temporally distinct event related potentials (ERPs). Allelic variations of the serotonin transporter gene (SLC6A4) have recently been shown to impact memory performance. Common variants of the serotonin transporter-linked polymorphic region (5HTTLPR) of the SLC6A4 gene result in long (l) and short (s) allelic variants with carriers of the s allele having lowered transcriptional efficiency. Thus, the current study examines the effects polymorphisms of the SLC6A4 gene have on performance and ERP amplitudes commonly associated with recognition memory. Electroencephalogram (EEG), genetic, and behavioral data were collected from sixty participants as they performed an item and source memory recognition task. In both tasks, participants studied and encoded 200 words, which were then mixed with 200 new words during retrieval. Participants were monitored with EEG during the retrieval portion of each memory task. EEG electrodes were grouped into four ROIs, left anterior superior, right anterior superior, left posterior superior, and right posterior superior. ERP mean amplitudes during hits in the item and source memory task were compared to correctly recognizing new items (correct rejections). Results show that s-carriers have decreased mean hit amplitudes in both the right anterior superior ROI 1000–1500 ms post stimulus during the source memory task and the left anterior superior ROI 300–500 ms post stimulus during the item memory task. These results suggest that individual differences due to genetic variation of the serotonin transporter gene influences recognition memory. PMID:26423665

  10. Composite resin's adhesive resistance to dentin: influence of Er:YAG laser focal distance variation.

    PubMed

    Corona, Silmara Aparecida Milori; Atoui, Juliana Abdallah; Chimello, Daniela Thomazatti; Borsatto, Maria Cristina; Pecora, Jesus Djalma; Dibb, Regina Guenka Palma

    2005-04-01

    The aim of this study was to analyze in vitro the influence of Er:YAG laser focal distance variation on tensile bond strength of a composite resin to dentin. Although there are several studies using the Er:YAG laser for dentin treatment, there is a lack of available literature related to the Er:YAG laser focal distance variation. Sixty vestibular and lingual dentin surfaces from extracted human third molars, kept in a 0.4% azide sodium solution, were ground and assigned to six groups. The control group was conditioned with 35% phosphoric acid (CA). In the lased groups, the dentin surface treatment was performed by irradiation with Er:YAG laser (80 mJ/2 Hz), varying the focal distance (11, 12, 14, 16, and 17 mm), followed by acid etching. The Single Bond/Filtek Z250 (3M) resinous system was used for the specimen manufacture. The tensile bond strength tests were performed in a Universal Testing Machine with 50 kgf load cell and 0.5 mm/min cross head speed. The averages in MPa were: CA: 18.03 (+/-2.09); 11 mm; 9.92 (+/-3.34); 12 mm: 9.49 (+/-2.29); 14 mm: 10.99 (+/-3.45); 16 mm: 10.56 (+/-1.93); and 17 mm: 17.05 (+/-2.31). It was concluded that the application of Er:YAG laser in a defocused mode (17 mm) associated with acid etching was similar to the treatment of acid solely. Er:YAG laser irradiation in a focused (12 mm) and a defocused (11, 14, and 16 mm) mode coupled with acid conditioning produced the lowest values of adhesion.

  11. Monitoring water storage variations in the vadose zone with gravimeters - quantifying the influence of observatory buildings

    NASA Astrophysics Data System (ADS)

    Reich, Marvin; Güntner, Andreas; Mikolaj, Michal; Blume, Theresa

    2016-04-01

    Time-lapse ground-based measurements of gravity have been shown to be sensitive to water storage variations in the surroundings of the gravimeter. They thus have the potential to serve as an integrative observation of storage changes in the vadose zone. However, in almost all cases of continuous gravity measurements, the gravimeter is located within a building which seals the soil beneath it from natural hydrological processes like infiltration and evapotranspiration. As water storage changes in close vicinity of the gravimeter have the strongest influence on the measured signal, it is important to understand the hydrology in the unsaturated soil zone just beneath the impervious building. For this reason, TDR soil moisture sensors were installed in several vertical profiles up to a depth of 2 m underneath the planned new gravimeter building at the Geodetic Observatory Wettzell (southeast Germany). In this study, we assess the influence of the observatory building on infiltration and subsurface flow patterns and thus the damping effect on gravimeter data in a two-way approach. Firstly, soil moisture time series of sensors outside of the building area are correlated with corresponding sensors of the same depth beneath the building. The resulting correlation coefficients, time lags and signal to noise relationships are used to find out how and where infiltrating water moves laterally beneath the building and towards its centre. Secondly, a physically based hydrological model (HYDRUS) with high discretization in space and time is set up for the 20 by 20 m area around and beneath the gravimeter building. The simulated spatial distribution of soil moisture in combination with the observed point data help to identify where and to what extent water storage changes and thus mass transport occurs beneath the building and how much this differs to the dynamics of the surroundings. This allows to define the umbrella space, i.e., the volume of the vadose zone where no mass

  12. Understanding Host-Switching by Ecological Fitting

    PubMed Central

    Araujo, Sabrina B. L.; Braga, Mariana Pires; Brooks, Daniel R.; Agosta, Salvatore J.; Hoberg, Eric P.; von Hartenthal, Francisco W.; Boeger, Walter A.

    2015-01-01

    Despite the fact that parasites are highly specialized with respect to their hosts, empirical evidence demonstrates that host switching rather than co-speciation is the dominant factor influencing the diversification of host-parasite associations. Ecological fitting in sloppy fitness space has been proposed as a mechanism allowing ecological specialists to host-switch readily. That proposal is tested herein using an individual-based model of host switching. The model considers a parasite species exposed to multiple host resources. Through time host range expansion can occur readily without the prior evolution of novel genetic capacities. It also produces non-linear variation in the size of the fitness space. The capacity for host colonization is strongly influenced by propagule pressure early in the process and by the size of the fitness space later. The simulations suggest that co-adaptation may be initiated by the temporary loss of less fit phenotypes. Further, parasites can persist for extended periods in sub-optimal hosts, and thus may colonize distantly related hosts by a "stepping-stone" process. PMID:26431199

  13. Wolbachia effects on host fitness and the influence of male aging on cytoplasmic incompatibility in Aedes polynesiensis (Diptera: Culicidae).

    PubMed

    Brelsfoard, C L; Dobson, S L

    2011-09-01

    The endosymbiotic bacteria Wolbachia manipulate host reproduction by inducing a form of sterility known as cytoplasmic incompatibility (CI), promoting the invasion of infection into natural host populations. CI has received attention for use in applied strategies to control insect vectors of disease. Thus, to understand both naturally occurring Wolbachia invasions and evaluate potential applied strategies, it is important to understand Wolbachia interactions with its host, including impacts on fitness and the CI level. In this study, we examined for an effect of Wolbachia on survivorship, developmental time, sex ratio, longevity, fecundity, and egg hatch of Aedes polynesiensis Marks, which is the primary vector of Wuchereria bancrofti in the South Pacific. In this study, we have compared strains of A. polynesiensis that are naturally and artificially infected with Wolbachia and additional strains that are aposymbiotic (Wolbachia removed to generate an uninfected strain). Artificially infected strains were observed to have increased larval mortality and decreased adult longevity when compared with aposymbiotic strains. Naturally infected strains were observed to have decreased larval mortality, pupal mortality, increased adult longevity, and a larger adult size when compared with aposymbiotic strains. Artificially infected males that were 4 wk old were able to induce high rates of CI, similar to young males. We discuss the results in relation to the natural spread of Wolbachia and Wolbachia-based applied strategies to modify A. polynesiensis populations.

  14. Pollinator visitation patterns strongly influence among-flower variation in selfing rate

    PubMed Central

    Karron, Jeffrey D.; Holmquist, Karsten G.; Flanagan, Rebecca J.; Mitchell, Randall J.

    2009-01-01

    Background and Aims Adjacent flowers on Mimulus ringens floral displays often vary markedly in selfing rate. We hypothesized that this fine-scale variation in mating system reflects the tendency of bumble-bee pollinators to probe several flowers consecutively on multiflower displays. When a pollinator approaches a display, the first flower probed is likely to receive substantial outcross pollen. However, since pollen carryover in this species is limited, receipt of self pollen should increase rapidly for later flowers. Here the first direct experimental test of this hypothesis is described. Methods In order to link floral visitation sequences with selfing rates of individual flowers, replicate linear arrays were established, each composed of plants with unique genetic markers. This facilitated unambiguous assignment of paternity to all sampled progeny. A single wild bumble-bee was permitted to forage on each linear array, recording the order of floral visits on each display. Once fruits had matured, 120 fruits were harvested (four flowers from each of five floral displays in each of six arrays). Twenty-five seedlings from each fruit were genotyped and paternity was unambiguously assigned to all 3000 genotyped progeny. Key Results The order of pollinator probes on Mimulus floral displays strongly and significantly influenced selfing rates of individual fruits. Mean selfing rates increased from 21 % for initial probes to 78 % for the fourth flower probed on each display. Conclusions Striking among-flower differences in selfing rate result from increased deposition of geitonogamous (among-flower, within-display) self pollen as bumble-bees probe consecutive flowers on each floral display. The resulting heterogeneity in the genetic composition of sibships may influence seedling competition and the expression of inbreeding depression. PMID:19218584

  15. Affiliative Behavior, Ultrasonic Communication and Social Reward Are Influenced by Genetic Variation in Adolescent Mice

    PubMed Central

    Panksepp, Jules B.; Jochman, Kimberly A.; Kim, Joseph U.; Koy, Jamie J.; Wilson, Ellie D.; Chen, QiLiang; Wilson, Clarinda R.; Lahvis, Garet P.

    2007-01-01

    Social approach is crucial for establishing relationships among individuals. In rodents, social approach has been studied primarily within the context of behavioral phenomena related to sexual reproduction, such as mating, territory defense and parental care. However, many forms of social interaction occur before the onset of reproductive maturity, which suggests that some processes underlying social approach among juvenile animals are probably distinct from those in adults. We conducted a longitudinal study of social investigation (SI) in mice from two inbred strains to assess the extent to which genetic factors influence the motivation for young mice to approach one another. Early-adolescent C57BL/6J (B6) mice, tested 4–6 days after weaning, investigated former cage mates to a greater degree than BALB/cJ (BALB) mice, irrespective of the sex composition within an interacting pair. This strain difference was not due to variation in maternal care, the phenotypic characteristics of stimulus mice or sensitivity to the length of isolation prior to testing, nor was it attributable to a general difference in appetitive motivation. Ultrasonic vocalization (USV) production was positively correlated with the SI responses of mice from both strains. Interestingly, several USV characteristics segregated with the genetic background of young mice, including a higher average frequency and shorter duration for the USVs emitted by B6 mice. An assessment of conditioned place preference responses indicated that there was a strain-dependent difference in the rewarding nature of social contact. As adolescent mice aged, SI responses gradually became less sensitive to genetic background and more responsive to the particular sex of individuals within an interacting pair. We have thus identified a specific, genetic influence on the motivation of early-adolescent mice to approach one another. Consistent with classical theories of motivation, which propose a functional relationship between

  16. Influence of the vertical structure of the atmosphere on the seasonal variation of precipitable water and greenhouse effect

    SciTech Connect

    Bony, S.; Duvel, J.P.

    1994-06-01

    By using satellite observations and European Centre for Medium Range Weather Forecasts (ECMWF) analyses, we study the seasonal variations of the precipitable water and the greenhouse effect, defined as the normalized difference between the longwave flux emitted at the surface and that emergent at the top of the atmosphere. Results show a strong systematic influence of the vertical structure of the atmosphere on geographical and seasonal variations of both precipitable water and greenhouse effect. Over ocean, in middle and high latitudes, the seasonal variation of the mean temperature lapse rate in the troposphere leads to large seasonal phase lags between greenhouse effect and precipitable water. By contrast, the seasonal variation of the clear-sky greenhouse effect over tropical oceans is mainly driven by the total atmospheric transmittance and thus by precipitable water variations. Over land, the seasonal variations of the tropospheric lapse rate acts to amplify the radiative impact of water vapor changes, giving a strong seasonal variation of the greenhouse effect. Over tropical land regions, monsoon activity generates a seasonal phase lag between surface temperature and relative humidity variations that gives a seasonal lag of about 2 months between the surface temperature and the clear-sky greenhouse effect. Generally, the cloudiness amplifies clear-sky tendencies. Finally, as an illustration, obtained results are used to evaluate the general circulation model of the Laboratoire de Meteorologie Dynamique.

  17. Variations in phytoplankton community in a monsoon-influenced tropical estuary.

    PubMed

    Patil, Jagadish S; Anil, Arga Chandrashekar

    2011-11-01

    In a monsoon-affected tropical estuary, oscillations in freshwater discharge during monsoon shifted the phytoplankton blooms from those adapted to low salinities to high salinities and vice versa. Salinity stratification during monsoon (onset and restart after an intermittent break) favored diatom (Skeletonema) bloom in low-saline surface waters. In high-saline, nutrient-rich bottom waters, Fragilariopsis (diatom) bloom was observed during onset of monsoon and persisted till the end of monsoon. The break period in monsoon altered the phytoplankton community leading to mixed species bloom of large-sized diatoms and harmful dinoflagellates (Gymnodinium catenatum and Cochlodinium polykrikoides) under high-saline, nutrient-poor, non-stratified, and transparent water column. Such variations in community should be considered for better understanding the biogeochemistry of monsoon-influenced tropical estuaries. The dominance of Skeletonema is determined positively by the extent of low-saline stratified condition whereas most of the observed taxa were favored by high-saline, nutrient-poor, and transparent waters.

  18. The influence of variations in biophysical conditions on hemolysis near ultrasonically activated gas-filled micropores

    SciTech Connect

    Miller, D.L.; Thomas, R.M. )

    1990-05-01

    Hemolysis induced by 1.9-MHz ultrasound in 0.5% suspensions of canine erythrocytes with 3.7-{mu}m-diam micropore-trapped gas bodies was investigated for a variety of biophysical conditions. For isotonic media, hemolysis increased with exposure duration but did not greatly change with exposure temperature, or prior heat treatment. The temperature results were especially interesting because increased temperatures might have been expected to increase the sensitivity of the cells to the ultrasonically activated gas bodies. Variations in osmolarity had little influence on the results. Increasing the viscosity of the medium decreased the effect, and this did not seem to depend on the molecular weight of the dextran additive. A medium with elevated mass density seemed to increase the effectiveness of the exposures. This condition eliminated the density difference between the cells and the medium, and might have been expected to reduce the effectiveness of the exposures, because the radiation force, which theoretically gathers cells to the gas bodies, is minimized for such conditions. This information should aid in developing refinements to the theoretical understanding of low-intensity ultrasonic bioeffects.

  19. Day and night trophic variations of dominant fish species in a lagoon influenced by freshwater seeps.

    PubMed

    Arceo-Carranza, D; Vega-Cendejas, M E; Hernández de Santillana, M

    2013-01-01

    The aim of this study was to determine the trophic structure and nycthemeral variations in the diet of dominant fish species (Ariopsis felis, Bairdiella chrysoura, Micropogonias undulatus, Eucinostomus gula, Eucinostomus argenteus, Lagodon rhomboides and Sphoeroides testudineus) in Celestun Lagoon, a biosphere reserve located in the southern Gulf of Mexico, and influenced by freshwater seeps. A total of 1473 stomachs were analysed and nine trophic groups were recorded. Bray-Curtis analyses with analyses of similarity (ANOSIM) statistical tests were used to determine two groups of feeding guilds: zoobenthivores and omnivores, with significant differences between time and habitat. The relationships between fish feeding habits, size class and environmental variables were investigated using canonical correspondence analysis (CCA). Most of the species showed a low niche breadth with high specialization towards amphipod consumption, with the exception of L. rhomboides (0·60), which indicated generalist feeding. This study in a protected area is an important source of information for drawing up conservation policies in relation to the management of aquatic resources, and will aid in the establishment of priority areas for conservation.

  20. Influence of fluid-property variation on turbulent convective heat transfer in vertical annular channel flows.

    SciTech Connect

    D. M. McEligot; J. H. Bae; J. Y. Yoo; H. Choi; James R. Wolf

    2005-10-01

    Influence of strongly-varying properties of supercritical-pressure fluids on turbulent convective heat transfer is investigated using direct numerical simulation. We consider thermally-developing upward flows in a vertical annular channel where the inner wall is heated with a constant heat flux and the outer wall is insulated. CO2 is chosen as the working fluid at a pressure to 8 Mpa, and the inlet Reynolds number based on the channel hydraulic diameter and the bulk velocity is Re0 = 8900. It is shown that turbulent convective heat transfer characteristics of supercritical flow are significantly different from those of constant-property flow mainly due to spatial and temporal variations of fluid density. Non-uniform density distribution causes fluid particles to be accelerated either by expansion or buoyancy force near the heated wall, while temporal density fluctuations change the transport characteristics of turbulent heat and momentum via the buoyancy production terms arising from the correlations such as p1u1x, p1u1r and p1h1. Among various turbulence statistics, the streamwise turbulent heat flux shows a very peculiar transitional behavior due to the buoyancy effect, changing both in sign and magnitude. Consequently, a non-monotonic temperature distribution is developed in the flow direction, causing severe impairment of heat transfer in supercritical flows.

  1. Protocol variations in arm position influence the magnitude of waist girth.

    PubMed

    Lennie, Susan C; Amofa-Diatuo, Tracy; Nevill, Alan; Stewart, Arthur D

    2013-01-01

    Waist girth is recognised as a better predictor of obesity, particularly abdominal obesity, compared to other measures. Although several protocols for waist girth exist, arm position is either ignored, or not specified in unambiguous terms. Therefore, the purpose of this study was to determine if arm position influenced anthropometric waist girth measurement. Waist girth was measured in 92 adults (19 males, 73 females) with arms relaxed, abducted, horizontal, folded across the chest (three variations) and raised vertically. Duplicate measures, in all positions, were recorded by a single International Society for the Advancement of Kinanthropometry (ISAK)-trained technician to a precision of 0.2% technical error of measurement (TEM). Arm position had a significant effect (P < 0.001) on waist girth. Male participants had greater waist girth than females (P < 0.001) and the waist girth differences across the varying arm positions exhibited a significant position-by-gender interaction (P < 0.001). The arm position-by-body mass index (BMI) category interaction was also significant (P = 0.016) with greater differences observed at higher BMI. These findings suggest caution in comparing results of different studies where arm position is not specified and indicate that the arm position corresponding to the ISAK protocol has the lowest error and is therefore recommended.

  2. Common variation at 2q22.3 (ZEB2) influences the risk of renal cancer

    PubMed Central

    Henrion, Marc; Frampton, Matthew; Scelo, Ghislaine; Purdue, Mark; Ye, Yuanqing; Broderick, Peter; Ritchie, Alastair; Kaplan, Richard; Meade, Angela; McKay, James; Johansson, Mattias; Lathrop, Mark; Larkin, James; Rothman, Nathaniel; Wang, Zhaoming; Chow, Wong-Ho; Stevens, Victoria L.; Ryan Diver, W.; Gapstur, Susan M.; Albanes, Demetrius; Virtamo, Jarmo; Wu, Xifeng; Brennan, Paul; Chanock, Stephen; Eisen, Timothy; Houlston, Richard S.

    2013-01-01

    Genome-wide association studies (GWASs) of renal cell cancer (RCC) have identified four susceptibility loci thus far. To identify an additional RCC common susceptibility locus, we conducted a GWAS and performed a meta-analysis with published GWASs (totalling 2215 cases and 8566 controls of European background) and followed up the most significant association signals [nine single nucleotide polymorphisms (SNPs) in eight genomic regions] in 3739 cases and 8786 controls. A combined analysis identified a novel susceptibility locus mapping to 2q22.3 marked by rs12105918 (P = 1.80 × 10−8; odds ratio 1.29, 95% CI: 1.18–1.41). The signal localizes to intron 2 of the ZEB2 gene (zinc finger E box-binding homeobox 2). Our findings suggest that genetic variation in ZEB2 influences the risk of RCC. This finding provides further insights into the genetic and biological basis of inherited genetic susceptibility to RCC. PMID:23184150

  3. Influence of barriers to movement on within-watershed genetic variation of coastal cutthroat trout

    USGS Publications Warehouse

    Wofford, John E.B.; Gresswell, Robert E.; Banks, Michael A.

    2005-01-01

    Because human land use activities often result in increased fragmentation of aquatic and terrestrial habitats, a better understanding of the effects of fragmentation on the genetic heterogeneity of animal populations may be useful for effective management. We used eight microsatellites to examine the genetic structure of coastal cutthroat trout (Oncorhynchus clarki clarki) in Camp Creek, an isolated headwater stream in western Oregon. Our objectives were to determine if coastal cutthroat trout were genetically structured within streams and to assess the effects of natural and anthropogenic barriers on coastal cutthroat trout genetic variation. Fish sampling occurred at 10 locations, and allele frequencies differed significantly among all sampling sections. Dispersal barriers strongly influenced coastal cutthroat trout genetic structure and were associated with reduced genetic diversity and increased genetic differentiation. Results indicate that Camp Creek coastal cutthroat trout exist as many small, partially independent populations that are strongly affected by genetic drift. In headwater streams, barriers to movement can result in genetic and demographic isolation leading to reduced coastal cutthroat trout genetic diversity, and potentially compromising long-term population persistence. When habitat fragmentation eliminates gene flow among small populations, similar results may occur in other species.

  4. Differences in Muscle Activity During Cable Resistance Training Are Influenced by Variations in Handle Types.

    PubMed

    Rendos, Nicole K; Heredia Vargas, Héctor M; Alipio, Taislaine C; Regis, Rebeca C; Romero, Matthew A; Signorile, Joseph F

    2016-07-01

    Rendos, NK, Heredia Vargas, HM, Alipio, TC, Regis, RC, Romero, MA, and Signorile, JF. Differences in muscle activity during cable resistance training are influenced by variations in handle types. J Strength Cond Res 30(7): 2001-2009, 2016-There has been a recent resurgence in the use of cable machines for resistance training allowing movements that more effectively simulate daily activities and sports-specific movements. By necessity, these devices require a machine/human interface through some type of handle. Considerable data from material handling, industrial engineering, and exercise training studies indicate that handle qualities, especially size and shape, can significantly influence force production and muscular activity, particularly of the forearm muscles, which affect the critical link in activities that require object manipulation. The purpose for this study was to examine the influence of three different handle conditions: standard handle (StandH), ball handle with the cable between the index and middle fingers (BallIM), and ball handle with the cable between the middle and ring fingers (BallMR), on activity levels (rmsEMG) of the triceps brachii lateral and long heads (TriHLat, TriHLong), brachioradialis (BR), flexor carpi radialis (FCR), extensor carpi ulnaris, and extensor digitorum (ED) during eight repetitions of standing triceps pushdown performed from 90° to 0° elbow flexion at 1.5 s per contractile stage. Handle order was randomized. No significant differences were seen for triceps or BR rmsEMG across handle conditions; however, relative patterns of activation did vary for the forearm muscles by handle condition, with more coordinated activation levels for the FCR and ED during the ball handle conditions. In addition, the rmsEMG for the ED was significantly higher during the BallIM than any other condition and during the BallMR than the StandH. These results indicate that the use of ball handles with the cable passing between different fingers

  5. Ozone reaction with interior building materials: Influence of diurnal ozone variation, temperature and humidity

    NASA Astrophysics Data System (ADS)

    Rim, Donghyun; Gall, Elliott T.; Maddalena, Randy L.; Nazaroff, William W.

    2016-01-01

    Elevated tropospheric ozone concentrations are associated with increased morbidity and mortality. Indoor ozone chemistry affects human exposure to ozone and reaction products that also may adversely affect health and comfort. Reactive uptake of ozone has been characterized for many building materials; however, scant information is available on how diurnal variation of ambient ozone influences ozone reaction with indoor surfaces. The primary objective of this study is to investigate ozone-surface reactions in response to a diurnally varying ozone exposure for three common building materials: ceiling tile, painted drywall, and carpet tile. A secondary objective is to examine the effects of air temperature and humidity. A third goal is to explore how conditioning of materials in an occupied office building might influence subsequent ozone-surface reactions. Experiments were performed at bench-scale with inlet ozone concentrations varied to simulate daytime (ozone elevated) and nighttime (ozone-free in these experiments) periods. To simulate office conditions, experiments were conducted at two temperatures (22 °C and 28 °C) and three relative humidity values (25%, 50%, 75%). Effects of indoor surface exposures were examined by placing material samples in an occupied office and repeating bench-scale characterization after exposure periods of 1 and 2 months. Deposition velocities were observed to be highest during the initial hour of ozone exposure with slow decrease in the subsequent hours of simulated daytime conditions. Daily-average ozone reaction probabilities for fresh materials are in the respective ranges of (1.7-2.7) × 10-5, (2.8-4.7) × 10-5, and (3.0-4.5) × 10-5 for ceiling tile, painted drywall, and carpet tile. The reaction probability decreases by 7%-47% across the three test materials after two 8-h periods of ozone exposure. Measurements with the samples from an occupied office reveal that deposition velocity can decrease or increase with time

  6. Invasion fitness, inclusive fitness, and reproductive numbers in heterogeneous populations.

    PubMed

    Lehmann, Laurent; Mullon, Charles; Akçay, Erol; Van Cleve, Jeremy

    2016-08-01

    How should fitness be measured to determine which phenotype or "strategy" is uninvadable when evolution occurs in a group-structured population subject to local demographic and environmental heterogeneity? Several fitness measures, such as basic reproductive number, lifetime dispersal success of a local lineage, or inclusive fitness have been proposed to address this question, but the relationships between them and their generality remains unclear. Here, we ascertain uninvadability (all mutant strategies always go extinct) in terms of the asymptotic per capita number of mutant copies produced by a mutant lineage arising as a single copy in a resident population ("invasion fitness"). We show that from invasion fitness uninvadability is equivalently characterized by at least three conceptually distinct fitness measures: (i) lineage fitness, giving the average individual fitness of a randomly sampled mutant lineage member; (ii) inclusive fitness, giving a reproductive value weighted average of the direct fitness costs and relatedness weighted indirect fitness benefits accruing to a randomly sampled mutant lineage member; and (iii) basic reproductive number (and variations thereof) giving lifetime success of a lineage in a single group, and which is an invasion fitness proxy. Our analysis connects approaches that have been deemed different, generalizes the exact version of inclusive fitness to class-structured populations, and provides a biological interpretation of natural selection on a mutant allele under arbitrary strength of selection.

  7. Variations in leopard cat (Prionailurus bengalensis) skull morphology and body size: sexual and geographic influences

    PubMed Central

    Oliveira, Luiz Flamarion B.

    2015-01-01

    The leopard cat, Prionailurus bengalensis (Kerr, 1792), is one of the most widespread Asian cats, occurring in continental eastern and southeastern Asia. Since 1929, several studies have focused on the morphology, ecology, and taxonomy of leopard cats. Nevertheless, hitherto there has been no agreement on basic aspects of leopard cat biology, such as the presence or absence of sexual dimorphism, morphological skull and body differences between the eleven recognized subspecies, and the biogeography of the different morphotypes. Twenty measurements on 25 adult leopard cat skulls from different Asian localities were analyzed through univariate and multivariate statistical approaches. Skull and external body measurements from studies over the last 77 years were assembled and organized in two categories: full data and summary data. Most of this database comprises small samples, which have never been statistically tested and compared with each other. Full data sets were tested with univariate and multivariate statistical analyses; summary data sets (i.e., means, SDs, and ranges) were analyzed through suitable univariate approaches. The independent analyses of the data from these works confirmed our original results and improved the overview of sexual dimorphism and geographical morphological variation among subspecies. Continental leopard cats have larger skulls and body dimensions. Skulls of Indochinese morphotypes have broader and higher features than those of continental morphotypes, while individuals from the Sunda Islands have skulls with comparatively narrow and low profiles. Cranial sexual dimorphism is present in different degrees among subspecies. Most display subtle sex-related variations in a few skull features. However, in some cases, sexual dimorphism in skull morphology is absent, such as in P. b. sumatranus and P. b. borneoensis. External body measurement comparisons also indicate the low degree of sexual dimorphism. Apart from the gonads, the longer hind

  8. Annual variations of carbonaceous PM2.5 in Malaysia: influence by Indonesian peatland fires

    NASA Astrophysics Data System (ADS)

    Fujii, Y.; Tohno, S.; Amil, N.; Latif, M. T.; Oda, M.; Matsumoto, J.; Mizohata, A.

    2015-08-01

    In this study, we quantified carbonaceous PM2.5 in Malaysia through annual observations of PM2.5, focusing on organic compounds derived from biomass burning. We determined organic carbon (OC), elemental carbon (EC) and concentrations of solvent-extractable organic compounds (biomarkers derived from biomass burning sources and n-alkanes). We observed seasonal variations in the concentrations of pyrolyzed OC (OP), levoglucosan (LG), mannosan (MN), galactosan, syringaldehyde, vanillic acid (VA) and cholesterol. The average concentrations of OP, LG, MN, galactosan, VA and cholesterol were higher during the southwest monsoon season (June-September) than during the northeast monsoon season (December-March), and these differences were statistically significant. Conversely, the syringaldehyde concentration during the southwest monsoon season was lower. The PM2.5 OP/OC4 mass ratio allowed distinguishing the seven samples, which have been affected by the Indonesian peatland fires (IPFs). In addition, we observed significant differences in the concentrations between the IPF and other samples of many chemical species. Thus, the chemical characteristics of PM2.5 in Malaysia appeared to be significantly influenced by IPFs during the southwest monsoon season. Furthermore, we evaluated two indicators, the vanillic acid/syringic acid (VA/SA) and LG/MN mass ratios, which have been suggested as indicators of IPFs. The LG/MN mass ratio ranged from 14 to 22 in the IPF samples and from 11 to 31 in the other samples. Thus, the respective variation ranges partially overlapped. Consequently, this ratio did not satisfactorily reflect the effects of IPFs in Malaysia. In contrast, the VA/SA mass ratio may serve as a good indicator, since it significantly differed between the IPF and other samples. However, the OP/OC4 mass ratio provided more remarkable differences than the VA/SA mass ratio, offering an even better indicator. Finally, we extracted biomass burning emissions' sources such as IPF

  9. Dengue virus genomic variation associated with mosquito adaptation defines the pattern of viral non-coding RNAs and fitness in human cells.

    PubMed

    Filomatori, Claudia V; Carballeda, Juan M; Villordo, Sergio M; Aguirre, Sebastian; Pallarés, Horacio M; Maestre, Ana M; Sánchez-Vargas, Irma; Blair, Carol D; Fabri, Cintia; Morales, Maria A; Fernandez-Sesma, Ana; Gamarnik, Andrea V

    2017-03-01

    The Flavivirus genus includes a large number of medically relevant pathogens that cycle between humans and arthropods. This host alternation imposes a selective pressure on the viral population. Here, we found that dengue virus, the most important viral human pathogen transmitted by insects, evolved a mechanism to differentially regulate the production of viral non-coding RNAs in mosquitos and humans, with a significant impact on viral fitness in each host. Flavivirus infections accumulate non-coding RNAs derived from the viral 3'UTRs (known as sfRNAs), relevant in viral pathogenesis and immune evasion. We found that dengue virus host adaptation leads to the accumulation of different species of sfRNAs in vertebrate and invertebrate cells. This process does not depend on differences in the host machinery; but it was found to be dependent on the selection of specific mutations in the viral 3'UTR. Dissecting the viral population and studying phenotypes of cloned variants, the molecular determinants for the switch in the sfRNA pattern during host change were mapped to a single RNA structure. Point mutations selected in mosquito cells were sufficient to change the pattern of sfRNAs, induce higher type I interferon responses and reduce viral fitness in human cells, explaining the rapid clearance of certain viral variants after host change. In addition, using epidemic and pre-epidemic Zika viruses, similar patterns of sfRNAs were observed in mosquito and human infected cells, but they were different from those observed during dengue virus infections, indicating that distinct selective pressures act on the 3'UTR of these closely related viruses. In summary, we present a novel mechanism by which dengue virus evolved an RNA structure that is under strong selective pressure in the two hosts, as regulator of non-coding RNA accumulation and viral fitness. This work provides new ideas about the impact of host adaptation on the variability and evolution of flavivirus 3'UTRs with

  10. Young patients with cystic fibrosis: attitude toward physical activity and influence on physical fitness and spirometric values of a 2-week training course.

    PubMed

    Stanghelle, J K; Winnem, M; Roaldsen, K; de Wit, S; Notgewitch, J H; Nilsen, B R

    1988-02-01

    The purpose of this investigation was to study the attitude toward physical activity in young patients with cystic fibrosis (CF) and the influence of 2 weeks of training on physical fitness and spirometric values. Two groups of CF patients with mean ages of 11 and 15 years, respectively (total of 13 patients, range 9-21 years), participated in the study. Two healthy control groups with mean ages of 11 and 14 years, respectively, performed the same tests as the CF patients. The CF patients answered questionnaires regarding their attitude toward the activities both during the camp and at home and accomplished spirometric and exercise tests. The CF childrens' parents were interviewed concerning their children's attitude toward physical activity. The attitude toward physical activity of the CF children was very positive both during the camps and at home. The CF patients had at least as good a motivation for exercise as the healthy controls. The physical fitness of the CF patients was reduced, but improved during the training period. The spirometric tests were unchanged during the first course, but increased significantly during the other camp, even if lung physiotherapy was stopped during the training period. The study indicates that CF patients can be motivated for physical exercise, even for training for endurance and at a high enough level to replace lung physiotherapy, at least for shorter periods.

  11. Influences of Salinity Variations on Pore-water Flow in Salt Marshes

    NASA Astrophysics Data System (ADS)

    Shen, C.; Jin, G.; Xin, P.; Li, L.

    2013-12-01

    Salt marshes are important wetlands at the ocean-land interface with various ecological functions, serving as essential habitats for intertidal fauna, affecting the productivity of coastal waters through nutrient exchange, moderating the greenhouse gas emission and global warming. They are influenced by various physical and biogeochemical processes, among which the pore-water flow and associated solute transport processes play an important role in determining the material exchange between marsh soils and coastal water. Previous studies have examined such processes under the solo or combined effects of tidal fluctuation, evapotranspiration, stratigraphy, inland freshwater input, and topography. However, these investigations have neglected the spatial and temporal salinity variations in surface water and pore-water, which commonly exist in salt marshes due to the impacts of tidal inundation, precipitation and evapotranspiration. The density contrast between the surface water and pore-water may lead to significant modifications of the pore-water flow. Based on results from laboratory experiments and numerical simulations, we will demonstrate that: (1) under upward salinity gradients, flow instabilities in the form of fingers occur once the salinity contrast reaches a certain level, whereas under downward salinity gradients the system is stable; (2) because of the strong tidally-induced advective process occurring near the creek, both the number and size of fingers change gradually from the near-creek zone to the marsh interior; and (3) both upward and downward salinity gradients enhance the exchange between the surface water and pore-water in the marsh sediments. Keywords: Salt marshes; density effect; salinity gradient; pore-water flow; fingers. Instabilities under upward salinity gradient Stable system under downward salinity gradient

  12. Influence of in situ stress variations on acoustic emissions: a numerical study

    NASA Astrophysics Data System (ADS)

    Zhao, Qi; Tisato, Nicola; Grasselli, Giovanni; Mahabadi, Omid K.; Lisjak, Andrea; Liu, Qinya

    2015-11-01

    The study of acoustic emissions (AEs) is of paramount importance to understand rock deformation processes. AE recorded during laboratory experiments mimics, in a controlled geometry and environment, natural and induced seismicity. However, these experiments are destructive, time consuming and require a significant amount of resources. Lately, significant progresses have been made in numerical simulations of rock failure processes, providing detailed insights into AE. We utilized the 2-D combined finite-discrete element method to simulate the deformation of Stanstead Granite under varying confining pressure (Pc) and demonstrated that the increase of confining pressure, Pc, (i) shifts failures from tensile towards shear dominated and (ii) enhance the macroscopic ductility. We quantitatively describe the AE activity associated with the fracturing process by assessing the spatial fractal dimension (D-value), the temporal distribution (AE rate) and the slope of the frequency-magnitude distribution (b-value). Based on the evaluation of D-value and AE rate, we defined two distinct deformation phases: Phase I and Phase II. The influence of Pc on the spatial distribution of AE varies according to the deformation phase: for increasing Pc, D-value decreases and increases during Phases I and II, respectively. In addition, b-value decreases with increasing Pc during the entire experiment. Our numerical results show for the first time that variations of D- and b-values as a function of in situ stress can be simulated using the combined finite-discrete element approach. We demonstrate that the examination of seismicity should be carried out carefully, taking into consideration the deformation phase and in situ stress conditions.

  13. Variation in annual runoff of the Jinghe River as influenced by climate change

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Chang, J.

    2014-12-01

    Variation in annual runoff of the Jinghe River as influenced by climate change Jian-xia Chang , Yimin WangInstitute of Water Resources and Hydroelectric Power, Xi'an University of Technology, Xi'an Shaanxi, China The characteristics of hydro-climatic changes in the Jinghe River Basin were analysed based on data collected at hydro-meteorological stations for the period 1960-2010. The analytical results revealed an increasing trend of the air temperature in the last several decades, but decreasing trends for streamflow and precipitation. This paper demonstrates the application of TOPMODEL, a rainfall-runoff model to simulate runoff of the Jinghe River Basin. Global climate model participating in Phase 5 of the Coupled Model Inter-comparison Project (CMIP5) has been used to project climate change of the Jinghe River Basin, by the year 2050. The projected temperature and precipitation were integrated into TOPMODEL to simulate runoff under future climate conditions. The projections show that the Jinghe River Basin tends to become warmer. Annual average maximum and minimum temperature would rise by 4.2℃ and 3.8 ℃ under RCP8.5 in the 2040s. Annual precipitation would also increase by 32 mm-68 mm under both scenarios, notably by 68 mm in 2030s under RCP8.5. The change in spring precipitation is most significant with an increase by 8%-29%. Annual average runoff is likely to increase about by -3%, -1% and 1% in the 2020s, 2030s and the 2040s under RCP 8.5 and by 2%, -8% and 15% under RCP 4.5 relative to the baseline (1990-2010).

  14. Cognitive fitness.

    PubMed

    Gilkey, Roderick; Kilts, Clint

    2007-11-01

    Recent neuroscientific research shows that the health of your brain isn't, as experts once thought, just the product of childhood experiences and genetics; it reflects your adult choices and experiences as well. Professors Gilkey and Kilts of Emory University's medical and business schools explain how you can strengthen your brain's anatomy, neural networks, and cognitive abilities, and prevent functions such as memory from deteriorating as you age. The brain's alertness is the result of what the authors call cognitive fitness -a state of optimized ability to reason, remember, learn, plan, and adapt. Certain attitudes, lifestyle choices, and exercises enhance cognitive fitness. Mental workouts are the key. Brain-imaging studies indicate that acquiring expertise in areas as diverse as playing a cello, juggling, speaking a foreign language, and driving a taxicab expands your neural systems and makes them more communicative. In other words, you can alter the physical makeup of your brain by learning new skills. The more cognitively fit you are, the better equipped you are to make decisions, solve problems, and deal with stress and change. Cognitive fitness will help you be more open to new ideas and alternative perspectives. It will give you the capacity to change your behavior and realize your goals. You can delay senescence for years and even enjoy a second career. Drawing from the rapidly expanding body of neuroscience research as well as from well-established research in psychology and other mental health fields, the authors have identified four steps you can take to become cognitively fit: understand how experience makes the brain grow, work hard at play, search for patterns, and seek novelty and innovation. Together these steps capture some of the key opportunities for maintaining an engaged, creative brain.

  15. Dengue virus genomic variation associated with mosquito adaptation defines the pattern of viral non-coding RNAs and fitness in human cells

    PubMed Central

    Aguirre, Sebastian; Pallarés, Horacio M.; Blair, Carol D.; Fabri, Cintia; Morales, Maria A.; Fernandez-Sesma, Ana; Gamarnik, Andrea V.

    2017-01-01

    The Flavivirus genus includes a large number of medically relevant pathogens that cycle between humans and arthropods. This host alternation imposes a selective pressure on the viral population. Here, we found that dengue virus, the most important viral human pathogen transmitted by insects, evolved a mechanism to differentially regulate the production of viral non-coding RNAs in mosquitos and humans, with a significant impact on viral fitness in each host. Flavivirus infections accumulate non-coding RNAs derived from the viral 3’UTRs (known as sfRNAs), relevant in viral pathogenesis and immune evasion. We found that dengue virus host adaptation leads to the accumulation of different species of sfRNAs in vertebrate and invertebrate cells. This process does not depend on differences in the host machinery; but it was found to be dependent on the selection of specific mutations in the viral 3’UTR. Dissecting the viral population and studying phenotypes of cloned variants, the molecular determinants for the switch in the sfRNA pattern during host change were mapped to a single RNA structure. Point mutations selected in mosquito cells were sufficient to change the pattern of sfRNAs, induce higher type I interferon responses and reduce viral fitness in human cells, explaining the rapid clearance of certain viral variants after host change. In addition, using epidemic and pre-epidemic Zika viruses, similar patterns of sfRNAs were observed in mosquito and human infected cells, but they were different from those observed during dengue virus infections, indicating that distinct selective pressures act on the 3’UTR of these closely related viruses. In summary, we present a novel mechanism by which dengue virus evolved an RNA structure that is under strong selective pressure in the two hosts, as regulator of non-coding RNA accumulation and viral fitness. This work provides new ideas about the impact of host adaptation on the variability and evolution of flavivirus 3

  16. Male reproductive fitness and queen polyandry are linked to variation in the supergene Gp-9 in the fire ant Solenopsis invicta

    PubMed Central

    Lawson, Lucinda P.; Vander Meer, Robert K.; Shoemaker, DeWayne

    2012-01-01

    Supergenes are clusters of tightly linked loci maintained in specific allelic combinations to facilitate co-segregation of genes governing adaptive phenotypes. In species where strong selection potentially operates at different levels (e.g. eusocial Hymenoptera), positive selection acting within a population to maintain specific allelic combinations in supergenes may have unexpected consequences for some individuals, including the preservation of disadvantageous traits. The nuclear gene Gp-9 in the invasive fire ant Solenopsis invicta is part of a non-recombining, polymorphic supergene region associated with polymorphism in social organization as well as traits affecting physiology, fecundity and behaviour. We show that both male reproductive success and facultative polyandry in queens have a simple genetic basis and are dependent on male Gp-9 genotype. Gp-9b males are unable to maintain exclusive reproductive control over their mates such that queens mated to Gp-9b males remain highly receptive to remating. Queens mated to multiple Gp-9B males are rare. This difference appears to be independent of mating plug production in fertile males of each Gp-9 genotype. However, Gp-9b males have significantly lower sperm counts than Gp-9B males, which could be a cue to females to seek additional mates. Despite the reduced fitness of Gp-9b males, polygyne worker-induced selective mortality of sexuals lacking b-like alleles coupled with the overall success of the polygyne social form act to maintain the Gp-9b allele within nature. Our findings highlight how strong worker-induced selection acting to maintain the Gp-9b allele in the polygyne social form may simultaneously result in reduced reproductive fitness for individual sexual offspring. PMID:22535783

  17. Influence of seasonal variations in sea level on the salinity regime of a coastal groundwater-fed wetland.

    PubMed

    Wood, Cameron; Harrington, Glenn A

    2015-01-01

    Seasonal variations in sea level are often neglected in studies of coastal aquifers; however, they may have important controls on processes such as submarine groundwater discharge, sea water intrusion, and groundwater discharge to coastal springs and wetlands. We investigated seasonal variations in salinity in a groundwater-fed coastal wetland (the RAMSAR listed Piccaninnie Ponds in South Australia) and found that salinity peaked during winter, coincident with seasonal sea level peaks. Closer examination of salinity variations revealed a relationship between changes in sea level and changes in salinity, indicating that sea level-driven movement of the fresh water-sea water interface influences the salinity of discharging groundwater in the wetland. Moreover, the seasonal control of sea level on wetland salinity seems to override the influence of seasonal recharge. A two-dimensional variable density model helped validate this conceptual model of coastal groundwater discharge by showing that fluctuations in groundwater salinity in a coastal aquifer can be driven by a seasonal coastal boundary condition in spite of seasonal recharge/discharge dynamics. Because seasonal variations in sea level and coastal wetlands are ubiquitous throughout the world, these findings have important implications for monitoring and management of coastal groundwater-dependent ecosystems.

  18. Interannaul variations of the vertical and their possible influence on the star catalogs derived from ground-based astrometric observations

    NASA Astrophysics Data System (ADS)

    Li, Z. X.

    The efforts at Shanghai Observatory since 1991, in response to the Resolution of IAU Comm.19: "Applications of optical astrometry time and latitude programs", is described in the paper, especially the studies concerned with the interannual variations of the vertical and their influence on the astronomical studies. It is clear now that there is a component of the order 0.01 - 0.02" on an interannual time scale in latitude residuals which is correlated with geophysical phenomena on the Earth. A recent study has confirmed that the component discovered is actually the variation of the vertical, related to ground-based observation in astronomy. So, it should be emphasized now that the variation of the vertical is significant enough to be considered in astronomy from now on. Its influence on the past studies, including the star catalogs already published and the ERP before 1980 when optical astrometry observations were still used, should be studied in the future. In comparing the HIPPARCOS catalog with those derived by the past observations, we should keep in mind the existence of this error in an astrometric observation and its influence on the star catalogs and other results derived from ground-based astrometric observations.

  19. Variations in the Free Chlorine Content of the Stratosphere (1991-1997): Anthropogenic an Volcanic Influences

    NASA Technical Reports Server (NTRS)

    Froidevaux, L.; Waters, J.; Read, W.; Connell, P.; Kinnison, D.; Russell, J.

    1999-01-01

    Remote sensing of chlorine monoxide (CIO) by the Microwave Limb Sounder (MLS) experiment aboard the Upper Atmosphere Research Satellite (UARS) has provided global measurements of variations in stratospheric free chlorine (for 1991 to 1997).

  20. Influence of respirometry methods on intraspecific variation in standard metabolic rates in newts.

    PubMed

    Kristín, Peter; Gvoždík, Lumír

    2012-09-01

    Standard metabolic rate (SMR) is both a highly informative and variable trait. Variation in SMR stems not only from diverse intrinsic and extrinsic factors, but also from the use of diverse methods for metabolic measurements. We measured CO(2) production (VCO(2)) and oxygen consumption rates (VO(2)) using two flow-through respirometry modes, continuous and intermittent (stop-flow), to evaluate their potential contribution to SMR variation in Alpine newts, Ichthyosaura alpestris. Both respirometry modes yielded similar and repeatable VCO(2) values. Although VO(2) was highly repeatable, continuous respirometry produced lower VO(2) than the intermittent method. During intermittent measurements, the total number of activity bouts was higher than during continuous respirometry trials. Statistical correction for disparate activity levels minimized variation in oxygen consumption between respirometry modes. We conclude that use of either method of flow-through respirometry, if properly applied, introduced less noise to SMR estimates than a variation in activity levels.

  1. Understanding the relative influence of climatic variations and agricultural management practices on crop yields at the US county level

    NASA Astrophysics Data System (ADS)

    Leng, G.; Zhang, X.; Huang, M.; Yang, Q.; Rafique, R.; Asrar, G.; Leung, L. R.

    2015-12-01

    Crop yields are largely determined by climate variations and agricultural management practices, such as irrigation, fertilization and residue management. Understanding the role of these factors in regulating crop yield variations is not only important for improved crop yield production, but also equally valuable for future crop yield prediction and food security assessments. Recently, the Community Land Model (CLM) has been augmented and evaluated for simulating corn, soybean and cereals at coarse aerial resolutions of 2 degrees (2000x2000 km). To better understand the underlying mechanisms controlling yield variations, we implemented and validated the agricultural version of CLM (CLM-crop) at a 0.125 degree resolution over the Conterminous United States (CONUS). We conducted a suite of numerical experiments to untangle the relative influence of climatic variations (temperature, precipitation, and radiation) and agricultural management practices on yield variations for the past 30 years at the US county level. Preliminary results show that the model with default parameter settings captures well the temporal variations in crop yields, as compared with the actual yield reported by the US Department of Agriculture (USDA). However, the magnitude of simulated crop yields is substantially higher, especially in the Mid-western US. We find that improved characterization of fertilizers and irrigation practices is key to model performance. Retrospectively (1979-2012), crop yields are more sensitive to changes in climate factors (such as temperature) than to changes in crop management practices. The results of this study advances understanding of the dominant factors in regulating the crop yield variations at the county level, which is essential for credible prediction of crop yields in a changing climate, under different agricultural management practices.

  2. Darwinian fitness.

    PubMed

    Demetrius, Lloyd; Ziehe, Martin

    2007-11-01

    The term Darwinian fitness refers to the capacity of a variant type to invade and displace the resident population in competition for available resources. Classical models of this dynamical process claim that competitive outcome is a deterministic event which is regulated by the population growth rate, called the Malthusian parameter. Recent analytic studies of the dynamics of competition in terms of diffusion processes show that growth rate predicts invasion success only in populations of infinite size. In populations of finite size, competitive outcome is a stochastic process--contingent on resource constraints--which is determined by the rate at which a population returns to its steady state condition after a random perturbation in the individual birth and death rates. This return rate, a measure of robustness or population stability, is analytically characterized by the demographic parameter, evolutionary entropy, a measure of the uncertainty in the age of the mother of a randomly chosen newborn. This article appeals to computational and numerical methods to contrast the predictive power of the Malthusian and the entropic principles. The computational analysis rejects the Malthusian model and is consistent with of the entropic principle. These studies thus provide support for the general claim that entropy is the appropriate measure of Darwinian fitness and constitutes an evolutionary parameter with broad predictive and explanatory powers.

  3. Influence of topography on the temperature variation around the tropical tropopause layer

    NASA Astrophysics Data System (ADS)

    Kubokawa, H.; Masaki, S.; Fujiwara, M.; Suzuki, J.

    2015-12-01

    Temperature variations in the Tropical Tropopause Layer (TTL) are an important factor for dehydration in the UTLS region. It is known that Kelvin waves induce large temperature variations in the TTL. We investigated the temperature variations in the TTL using both numerical data produced by the Nonhydrostatic Icosahedral Atmospheric Model (NICAM) and various observational data including satellite data (the Constellation Observing System for Meteorology, Ionosphere, and Climate; COSMIC), the reanalysis data of different resolution (ERA-40-interim, NCEP-CFSR, MERRA, YOTC-ECMWF), and radiosonde data for the Cooperative Indian Ocean experiment on intra-seasonal variability in the Year 2011 (CINDY). We found that all the data shows that the temperature variations become larger over the mountainous regions of the Indonesian maritime continent than over the oceanic regions and that the large temperature variations are associated with Kelvin waves. As, the horizontal resolution of the reanalysis becomes higher, the standard deviations of the TTL temperature near the mountains became larger. When Kelvin waves passed over the Indonesian maritime continent, the amplitude of temperature becomes about 2 K larger over the mountainous regions. The power spectrum for the periods between 7 days and 12 days was larger over the mountainous regions compared with that over the ocean. The sensitivity study using the stretch-NICAM shows that the height of mountains clearly affect the amplitude of temperature near the TTL.

  4. Variations in critical morphine biosynthesis genes and their potential to influence human health.

    PubMed

    Mantione, Kirk; Kream, Richard M; Stefano, George B

    2010-01-01

    Endogenous morphine has been detected in human tissues from the vascular, immune and nervous systems. The genes/enzymes (CYP2D6, COMT and PNMT) that are involved in the biosynthesis of morphine have variations that affect their functionality. Some of these variations are the result of single nucleotide polymorphisms of DNA sequences. This review highlights some of the functional differences in the critical enzymes required for the biosynthesis of morphine that may affect human health. These variations have been shown to change the way animals react to stressors, perceive pain and behave. The presence of morphine signaling in almost all organ systems suggests that it is most likely playing a role in maintaining the health and promoting the normal functioning of these physiological systems.

  5. Exercise Prescription for Physical Fitness.

    ERIC Educational Resources Information Center

    Pollock, Michael L.; And Others

    1995-01-01

    Examines current guidelines for physical fitness, noting issues that may influence the updating of the American College of Sports Medicine exercise statement. Differences between exercise prescription for fitness and physical activity for health are discussed, noting the importance of designing individualized programs with appropriate levels of…

  6. Factors that influence the occurrence of response variations in Parkinson's disease.

    PubMed

    de Jong, G J; Meerwaldt, J D; Schmitz, P I

    1987-07-01

    Retrospective study of 129 patients treated with dopamine substitution showed that the occurrence of response variations is related to the duration of therapy and not to the nature of the predominant symptom (tremor or hypokinesia and rigidity) or the age of onset of the disease. A relationship was found between the occurrence of response variations and the severity of the disease when levodopa therapy was started. Patients fared worst who were in Hoehn and Yahr stages I and II when levodopa therapy was begun.

  7. Influence of Analogy Instruction for Pitch Variation on Perceptual Ratings of Other Speech Parameters

    ERIC Educational Resources Information Center

    Tse, Andy C. Y.; Wong, Andus W-K.; Ma, Estella P-M.; Whitehill, Tara L.; Masters, Rich S. W.

    2013-01-01

    Purpose: "Analogy" is the similarity of different concepts on which a comparison can be based. Recently, an analogy of "waves at sea" was shown to be effective in modulating fundamental frequency (F[subscript 0]) variation. Perceptions of intonation were not examined, as the primary aim of the work was to determine whether…

  8. Influence of Stuttering Variation on Talker Group Classification in Preschool Children: Preliminary Findings

    ERIC Educational Resources Information Center

    Johnson, Kia N.; Karrass, Jan; Conture, Edward G.; Walden, Tedra

    2009-01-01

    The purpose of this study was to investigate whether variations in disfluencies of young children who do (CWS) and do not stutter (CWNS) significantly change their talker group classification or diagnosis from stutterer to nonstutterer, and vice versa. Participants consisted of seventeen 3- to 5-year-old CWS and nine 3- to 5-year-old CWNS, with no…

  9. Factors influencing the variation in capture rates of shrews in southern California, USA

    USGS Publications Warehouse

    Laakkonen, Juha; Fisher, Robert N.; Case, Ted J.

    2003-01-01

    We examined the temporal variation in capture rates of shrewsNotiosorex crawfordi (Coues, 1877) and Sorex ornatus (Merriam, 1895) in 20 sites representing fragmented and continuous habitats in southern California, USA. InN. crawfordi, the temporal variation was significantly correlated with the mean capture rates. Of the 6 landscape variables analyzed (size of the landscape, size of the sample area, altitude, edge, longitude and latitude), sample area was positively correlated with variation in capture rates ofN. crawfordi. InS. ornatus, longitude was negatively correlated with variation in capture rates. Analysis of the effect of precipitation on the short- and long-term capture rates at 2 of the sites showed no correlation between rainfall and capture rates of shrews even though peak number of shrews at both sites were reached during the year of highest amount of rainfall. A key problem confounding capture rates of shrews in southern California is the low overall abundance of both shrew species in all habitats and seasons.

  10. Influence of antenatal care, placental weight and genetic variation on low birth weight, Makassar Indonesia.

    PubMed

    Amiruddin, Ridwan; Yusuf, Irawan

    2008-10-01

    Inadequate antenatal care and nutrition, gene variation (CYP2A6), and poor placental growth are associated with low birthweight (LBW). The objective for this study was to analyze risk factors for LBW, including antenatal care, gene variation CYP2A6 and placental weight. A case control of infants with a birthweight less than 2500 gm, compared to a control group of infants with a birthweight > 2500 gm. There were 57 cases and a similar number of controls. In the analysis odds ratios (OR) were calculated for each risk factor. Low placental weight was strongly related to low birth weight (OR 43.9 CI 14.7-129.8). Mothers who had inadequate antenatal care had increased risk of LBW (OR 2.7, 95% CI. 1.2-6.1). The gene variation CYP2A6 was found to be risk factor for a lighter placenta weight (OR 9.5 95% CI. 4.0-22.3). Programs to improve antenatal care and monitoring for the gene variation CYP2A6 would reduce the incidence of LBW.

  11. Influence of Agricultural Practices on Micrometerological Spatial Variations at Local and Regional Scales

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil-vegetation-atmosphere transfers significantly influence interactions and feedbacks between vegetation and boundary layer in relation with plant phenology and water status. The current study focused on linking micrometeorological conditions to cultural practices at the local and regional scales ...

  12. INFLUENCE OF AGRICULTURAL PRACTICES ON MICROMETEOROLOGICAL SPATIAL VARIATIONS AT THE LOCAL AND REGIONAL SCALES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil - vegetation - atmosphere transfers significantly influence interactions and feedbacks between vegetation and boundary layer, in relation with plant phenology and water status. The current study focused on linking micrometeorological conditions to cultural practices at the local and regional sc...

  13. The influence of life history trade-offs and the size of the incubation gravels on egg size variation in sockeye salmon Onchorhynchus nerka

    USGS Publications Warehouse

    Quinn, Thomas P; Hendry , Andrew P.; Wetzel, Lisa A.

    1995-01-01

    Egg size is a critical life history trait, reflecting female investment and affecting off- spring fitness. We investigated several factors which may influence variation in egg weight for sockeye salmon (Oncorhynchus nerka). Comparisons were based on col- lections from 18 Alaskan populations, among which adult migration distance and ju- venile rearing habitat were similar but the size composition of incubation gravels was different. Among populations, most of the variation in egg weight could be explained by a positive correlation with different measures of the size composition of incubation gravels (Pearson's r = 0.45-0.91). In contrast, egg weight was poorly correlated with female body length and with female snout length, a morphological feature used during intra-sexual competition. Within each of the Alaskan populations, however, egg weight and snout length were positively correlated with female body length and hence with each other. A positive association between snout length and egg weight was still evident even after the effects of covariance with body size were removed using resid- uals analysis: for all of the fish pooled and within 6 of the 16 populations. A signifi- cant relationship was not detected in the other populations but the trend was neverthe- less positive in 8 of the other 10. Examination of reproductive traits (gonad weight, egg weight, egg number, snout length and hump size) within another population iden- tified a trade-off between egg weight and egg number for females of a given body length. In contrast, positive correlations between reproductive traits were more com- mon, suggesting that energy-rich individuals produce large eggs and large secondary sexual characteristics rather than sacrificing one for the other.

  14. Influence of Sub-Daily Variation on Multi-Fractal Detrended Fluctuation Analysis of Wind Speed Time Series

    PubMed Central

    Li, Weinan; Kong, Yanjun; Cong, Xiangyu

    2016-01-01

    Using multi-fractal detrended fluctuation analysis (MF-DFA), the scaling features of wind speed time series (WSTS) could be explored. In this paper, we discuss the influence of sub-daily variation, which is a natural feature of wind, in MF-DFA of WSTS. First, the choice of the lower bound of the segment length, a significant parameter of MF-DFA, was studied. The results of expanding the lower bound into sub-daily scope shows that an abrupt declination and discrepancy of scaling exponents is caused by the inability to keep the whole diel process of wind in one single segment. Additionally, the specific value, which is effected by the sub-daily feature of local meteo-climatic, might be different. Second, the intra-day temporal order of wind was shuffled to determine the impact of diel variation on scaling exponents of MF-DFA. The results illustrate that disregarding diel variation leads to errors in scaling. We propose that during the MF-DFA of WSTS, the segment length should be longer than 1 day and the diel variation of wind should be maintained to avoid abnormal phenomena and discrepancy in scaling exponents. PMID:26741491

  15. Influence of Sub-Daily Variation on Multi-Fractal Detrended Fluctuation Analysis of Wind Speed Time Series.

    PubMed

    Wang, Xianxun; Mei, Yadong; Li, Weinan; Kong, Yanjun; Cong, Xiangyu

    2016-01-01

    Using multi-fractal detrended fluctuation analysis (MF-DFA), the scaling features of wind speed time series (WSTS) could be explored. In this paper, we discuss the influence of sub-daily variation, which is a natural feature of wind, in MF-DFA of WSTS. First, the choice of the lower bound of the segment length, a significant parameter of MF-DFA, was studied. The results of expanding the lower bound into sub-daily scope shows that an abrupt declination and discrepancy of scaling exponents is caused by the inability to keep the whole diel process of wind in one single segment. Additionally, the specific value, which is effected by the sub-daily feature of local meteo-climatic, might be different. Second, the intra-day temporal order of wind was shuffled to determine the impact of diel variation on scaling exponents of MF-DFA. The results illustrate that disregarding diel variation leads to errors in scaling. We propose that during the MF-DFA of WSTS, the segment length should be longer than 1 day and the diel variation of wind should be maintained to avoid abnormal phenomena and discrepancy in scaling exponents.

  16. Friendship networks and achievement goals: an examination of selection and influence processes and variations by gender.

    PubMed

    Shin, Huiyoung; Ryan, Allison M

    2014-09-01

    Interactions with friends are a salient part of students' experience at school. Thus, friends are likely to be an important source of influence on achievement goals. This study investigated processes within early adolescent friendships (selection and influence) with regard to achievement goals (mastery, performance-approach, and performance-avoidance goals) among sixth graders (N = 587, 50% girls at wave 1, N = 576, 52% girls at wave 2) followed from fall to spring within one academic year. Students' gender was examined as a moderator in these processes. Longitudinal social network analysis found that friends were similar to each other in mastery goals and that this similarity was due to both selection and influence effects. Influence but not selection effects were found for performance-approach goals. Influence effects for performance-approach goals were stronger for boys compared to girls in the classroom. Neither selection, nor influence, effects were found in relation to performance-avoidance goals. However, the higher a student was in performance-avoidance goals, the less likely they were to be named as a friend by classmates. Implications for early adolescents' classroom adjustment are discussed.

  17. Measuring Your Fitness Level

    MedlinePlus

    Healthy Lifestyle Fitness Ready to start a fitness program? Measure your fitness level with a few simple tests. ... 14, 2017 Original article: http://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/fitness/art-20046433 . Mayo Clinic ...

  18. Sequence variations at the HLA-linked olfactory receptor cluster do not influence female preferences for male odors

    PubMed Central

    Thompson, Emma E; Haller, Gabe; Pinto, Jayant M; Sun, Ying; Zelano, Bethanne; Jacob, Suma; McClintock, Martha K.; Nicolae, Dan L.; Ober, Carole

    2013-01-01

    We previously reported that paternally-inherited human leukocyte antigen (HLA) alleles are a template for women's preference for male odors (P = 0.0007). However, it has been suggested that sequence variation in a nearby olfactory receptor (OR) cluster on chromosome 6p influences smell preference. To determine if the HLA-linked OR genes contribute to previously observed HLA-mediated behaviors, we use the odor preference data from our earlier study in combination with a new resequencing study of four functional HLA-linked OR genes in the same subjects. Our results indicate that OR alleles in the genes surveyed are not in linkage disequilibrium (LD) with HLA variation and do not explain the previous findings of HLA-associated odor preference. PMID:19833159

  19. Exploring Neighborhood Influences on Small-Area Variations in Intimate Partner Violence Risk: A Bayesian Random-Effects Modeling Approach

    PubMed Central

    Gracia, Enrique; López-Quílez, Antonio; Marco, Miriam; Lladosa, Silvia; Lila, Marisol

    2014-01-01

    This paper uses spatial data of cases of intimate partner violence against women (IPVAW) to examine neighborhood-level influences on small-area variations in IPVAW risk in a police district of the city of Valencia (Spain). To analyze area variations in IPVAW risk and its association with neighborhood-level explanatory variables we use a Bayesian spatial random-effects modeling approach, as well as disease mapping methods to represent risk probabilities in each area. Analyses show that IPVAW cases are more likely in areas of high immigrant concentration, high public disorder and crime, and high physical disorder. Results also show a spatial component indicating remaining variability attributable to spatially structured random effects. Bayesian spatial modeling offers a new perspective to identify IPVAW high and low risk areas, and provides a new avenue for the design of better-informed prevention and intervention strategies. PMID:24413701

  20. Spatial Variation of Leaf Optical Properties in a Boreal Forest Is Influenced by Species and Light Environment.

    PubMed

    Atherton, Jon; Olascoaga, Beñat; Alonso, Luis; Porcar-Castell, Albert

    2017-01-01

    Leaf Optical Properties (LOPs) convey information relating to temporally dynamic photosynthetic activity and biochemistry. LOPs are also sensitive to variability in anatomically related traits such as Specific Leaf Area (SLA), via the interplay of intra-leaf light scattering and absorption processes. Therefore, variability in such traits, which may demonstrate little plasticity over time, potentially disrupts remote sensing estimates of photosynthesis or biochemistry across space. To help to disentangle the various factors that contribute to the variability of LOPs, we defined baseline variation as variation in LOPs that occurs across space, but not time. Next we hypothesized that there were two main controls of potentially disruptive baseline spatial variability of photosynthetically-related LOPs at our boreal forest site: light environment and species. We measured photosynthetically-related LOPs in conjunction with morphological, biochemical, and photosynthetic leaf traits during summer and across selected boreal tree species and vertical gradients in light environment. We then conducted a detailed correlation analysis to disentangle the spatial factors that control baseline variability of leaf traits and, resultantly, LOPs. Baseline spatial variability of the Photochemical Reflectance Index (PRI) was strongly influenced by species and to a lesser extent light environment. Baseline variability of spectral fluorescence derived LOPs was less influenced by species; however at longer near-infrared wavelengths, light environment was an important control. In summary, remote sensing of chlorophyll fluorescence has good potential to detect variation in photosynthetic performance across space in boreal forests given reduced sensitivity to species related baseline variability in comparison to the PRI. Our results also imply that spatially coarse remote sensing observations are potentially unrepresentative of the full scope of natural variation that occurs within a boreal

  1. Spatial Variation of Leaf Optical Properties in a Boreal Forest Is Influenced by Species and Light Environment

    PubMed Central

    Atherton, Jon; Olascoaga, Beñat; Alonso, Luis; Porcar-Castell, Albert

    2017-01-01

    Leaf Optical Properties (LOPs) convey information relating to temporally dynamic photosynthetic activity and biochemistry. LOPs are also sensitive to variability in anatomically related traits such as Specific Leaf Area (SLA), via the interplay of intra-leaf light scattering and absorption processes. Therefore, variability in such traits, which may demonstrate little plasticity over time, potentially disrupts remote sensing estimates of photosynthesis or biochemistry across space. To help to disentangle the various factors that contribute to the variability of LOPs, we defined baseline variation as variation in LOPs that occurs across space, but not time. Next we hypothesized that there were two main controls of potentially disruptive baseline spatial variability of photosynthetically-related LOPs at our boreal forest site: light environment and species. We measured photosynthetically-related LOPs in conjunction with morphological, biochemical, and photosynthetic leaf traits during summer and across selected boreal tree species and vertical gradients in light environment. We then conducted a detailed correlation analysis to disentangle the spatial factors that control baseline variability of leaf traits and, resultantly, LOPs. Baseline spatial variability of the Photochemical Reflectance Index (PRI) was strongly influenced by species and to a lesser extent light environment. Baseline variability of spectral fluorescence derived LOPs was less influenced by species; however at longer near-infrared wavelengths, light environment was an important control. In summary, remote sensing of chlorophyll fluorescence has good potential to detect variation in photosynthetic performance across space in boreal forests given reduced sensitivity to species related baseline variability in comparison to the PRI. Our results also imply that spatially coarse remote sensing observations are potentially unrepresentative of the full scope of natural variation that occurs within a boreal

  2. The influence of weather and lemmings on spatiotemporal variation in the abundance of multiple avian guilds in the arctic.

    PubMed

    Robinson, Barry G; Franke, Alastair; Derocher, Andrew E

    2014-01-01

    Climate change is occurring more rapidly in the Arctic than other places in the world, which is likely to alter the distribution and abundance of migratory birds breeding there. A warming climate can provide benefits to birds by decreasing spring snow cover, but increases in the frequency of summer rainstorms, another product of climate change, may reduce foraging opportunities for insectivorous birds. Cyclic lemming populations in the Arctic also influence bird abundance because Arctic foxes begin consuming bird eggs when lemmings decline. The complex interaction between summer temperature, precipitation, and the lemming cycle hinder our ability to predict how Arctic-breeding birds will respond to climate change. The main objective of this study was to investigate the relationship between annual variation in weather, spring snow cover, lemming abundance and spatiotemporal variation in the abundance of multiple avian guilds in a tundra ecosystem in central Nunavut, Canada: songbirds, shorebirds, gulls, loons, and geese. We spatially stratified our study area based on vegetation productivity, terrain ruggedness, and freshwater abundance, and conducted distance sampling to estimate strata-specific densities of each guild during the summers of 2010-2012. We also monitored temperature, rainfall, spring snow cover, and lemming abundance each year. Spatial variation in bird abundance matched what was expected based on previous ecological knowledge, but weather and lemming abundance also significantly influenced the abundance of some guilds. In particular, songbirds were less abundant during the cool, wet summer with moderate snow cover, and shorebirds and gulls declined with lemming abundance. The abundance of geese did not vary over time, possibly because benefits created by moderate spring snow cover were offset by increased fox predation when lemmings were scarce. Our study provides an example of a simple way to monitor the correlation between weather, spring snow

  3. The influence of temperature variations on ultrasonic guided waves in anisotropic CFRP plates.

    PubMed

    Putkis, O; Dalton, R P; Croxford, A J

    2015-07-01

    Carbon Fibre Reinforced Polymer (CFRP) materials are lightweight and corrosion-resistant and therefore are increasingly used in aerospace, automotive and construction industries. In Structural Health Monitoring (SHM) applications of CFRP materials, ultrasonic guided waves potentially offer large area inspection or inspection from a remote location. This paper addresses the effect of temperature variation on guided wave propagation in highly anisotropic CFRP materials. Temperature variations cause changes in guided wave velocity that can in turn compromise the baseline subtraction procedures employed by many SHM systems for damage detection. A simple model that describes the dependence of elastic properties of the CFRP plates on temperature is presented in this paper. The model can be used to predict anisotropic velocity changes and baseline subtraction performance under varying thermal conditions. The results produced by the model for unidirectional and 0/90 CFRP plates are compared with experimental measurements.

  4. Influence of paleo-heat flow variations on estimates of exhumation rates

    NASA Astrophysics Data System (ADS)

    von Hagke, Christoph; Luijendijk, Elco

    2016-04-01

    Deriving exhumation estimates from thermochronological data requires assumptions on the paleo-thermal field of the Earth's crust. Existing thermal models take into account heat transfer by diffusion and advection caused by the movement of the crust and erosion as well as changes in geothermal gradient over time caused by changes in structure or thermal properties of the crust, surface temperature and elevation. However, temperature field of mountain belts and basins may vary not only due to tectonic activity or landscape evolution. We present a high-resolution thermochronology data set from the foreland fold-and-thrust belt of the European Alps that shows substantial variation of cooling rates probably caused by hydrothermal flow in the subsurface in the past. Tectonic blocks with uniform exhumation history show variations in cooling of up to 50°C. In addition, changes in cooling between two different fault blocks show opposite trend than expected by models of their tectonic history. The observed historic changes in paleo-geothermal gradients are equal in magnitude to a present-day thermal anomaly caused by the upward flow of warm fluids in the distal part of the foreland basin. The strong variations in geothermal gradients by fluid flow imply that straightforward interpretation of landscape evolution rates using thermochronology is not possible, unless the thermal effects of fluid flow are taken into account. This is of particular importance to studies where the amount of thermochronology data is limited and local hydrothermal anomalies could easily be interpreted as regional exhumation signals. On the other hand, our findings suggest that thermochronology offers new opportunities to constrain magnitude and timing of paleo-heat flow variations in the upper crust.

  5. The Influence of Social Class on Academic Outcomes: A Structural Equation Model Examining the Relationships between Student Dependency Style, Student-Academic Environment Fit, and Satisfaction on Academic Outcomes

    ERIC Educational Resources Information Center

    Nadler, Dustin R.

    2013-01-01

    The purpose of this study was to investigate the relationship between college students' social class and their academic outcomes. A structural equation model was proposed, hypothesizing that a student's socioeconomic status (SES) is related to their motives for attending college, thus influencing their perception of fit at the university, their…

  6. Mismatch repair regulates homologous recombination, but has little influence on antigenic variation, in Trypanosoma brucei.

    PubMed

    Bell, Joanna S; McCulloch, Richard

    2003-11-14

    Antigenic variation is critical in the life of the African trypanosome, as it allows the parasite to survive in the face of host immunity and enhance its transmission to other hosts. Much of trypanosome antigenic variation uses homologous recombination of variant surface glycoprotein (VSG)-encoding genes into specialized transcription sites, but little is known about the processes that regulate it. Here we describe the effects on VSG switching when two central mismatch repair genes, MSH2 and MLH1, are mutated. We show that disruption of the parasite mismatch repair system causes an increased frequency of homologous recombination, both between perfectly matched DNA molecules and between DNA molecules with divergent sequences. Mismatch repair therefore provides an important regulatory role in homologous recombination in this ancient eukaryote. Despite this, the mismatch repair system has no detectable role in regulating antigenic variation, meaning that VSG switching is either immune to mismatch selection or that mismatch repair acts in a subtle manner, undetectable by current assays.

  7. Variations of deep soil moisture under different vegetation types and influencing factors in a watershed of the Loess Plateau, China

    NASA Astrophysics Data System (ADS)

    Fang, Xuening; Zhao, Wenwu; Wang, Lixin; Feng, Qiang; Ding, Jingyi; Liu, Yuanxin; Zhang, Xiao

    2016-08-01

    Soil moisture in deep soil layers is a relatively stable water resource for vegetation growth in the semi-arid Loess Plateau of China. Characterizing the variations in deep soil moisture and its influencing factors at a moderate watershed scale is important to ensure the sustainability of vegetation restoration efforts. In this study, we focus on analyzing the variations and factors that influence the deep soil moisture (DSM) in 80-500 cm soil layers based on a soil moisture survey of the Ansai watershed in Yan'an in Shanxi Province. Our results can be divided into four main findings. (1) At the watershed scale, higher variations in the DSM occurred at 120-140 and 480-500 cm in the vertical direction. At the comparable depths, the variation in the DSM under native vegetation was much lower than that in human-managed vegetation and introduced vegetation. (2) The DSM in native vegetation and human-managed vegetation was significantly higher than that in introduced vegetation, and different degrees of soil desiccation occurred under all the introduced vegetation types. Caragana korshinskii and black locust caused the most serious desiccation. (3) Taking the DSM conditions of native vegetation as a reference, the DSM in this watershed could be divided into three layers: (i) a rainfall transpiration layer (80-220 cm); (ii) a transition layer (220-400 cm); and (iii) a stable layer (400-500 cm). (4) The factors influencing DSM at the watershed scale varied with vegetation types. The main local controls of the DSM variations were the soil particle composition and mean annual rainfall; human agricultural management measures can alter the soil bulk density, which contributes to higher DSM in farmland and apple orchards. The plant growth conditions, planting density, and litter water holding capacity of introduced vegetation showed significant relationships with the DSM. The results of this study are of practical significance for vegetation restoration strategies, especially

  8. Neighbouring populations, opposite dynamics: influence of body size and environmental variation on the demography of stream-resident brown trout (Salmo trutta).

    PubMed

    Fernández-Chacón, Albert; Genovart, Meritxell; Álvarez, David; Cano, José M; Ojanguren, Alfredo F; Rodriguez-Muñoz, Rolando; Nicieza, Alfredo G

    2015-06-01

    In organisms such as fish, where body size is considered an important state variable for the study of their population dynamics, size-specific growth and survival rates can be influenced by local variation in both biotic and abiotic factors, but few studies have evaluated the complex relationships between environmental variability and size-dependent processes. We analysed a 6-year capture-recapture dataset of brown trout (Salmo trutta) collected at 3 neighbouring but heterogeneous mountain streams in northern Spain with the aim of investigating the factors shaping the dynamics of local populations. The influence of body size and water temperature on survival and individual growth was assessed under a multi-state modelling framework, an extension of classical capture-recapture models that considers the state (i.e. body size) of the individual in each capture occasion and allows us to obtain state-specific demographic rates and link them to continuous environmental variables. Individual survival and growth patterns varied over space and time, and evidence of size-dependent survival was found in all but the smallest stream. At this stream, the probability of reaching larger sizes was lower compared to the other wider and deeper streams. Water temperature variables performed better in the modelling of the highest-altitude population, explaining over a 99 % of the variability in maturation transitions and survival of large fish. The relationships between body size, temperature and fitness components found in this study highlight the utility of multi-state approaches to investigate small-scale demographic processes in heterogeneous environments, and to provide reliable ecological knowledge for management purposes.

  9. Influence of small temperature variations on the ultrasonic velocity in concrete

    NASA Astrophysics Data System (ADS)

    Niederleithinger, E.; Wunderlich, C.

    2013-01-01

    Ultrasonic methods are valuable tools for quality assessment and structural imaging of concrete. In such applications, accurate and reliable determination of ultrasonic wave velocities is essential, as they are affected by various experimental and environmental factors. In this research coda wave interferometry (CWI) was used to determine the influence of temperature (0 to 50 °C) on ultrasonic wave velocity in concrete samples. A resolution of better than 10-4 was achieved in the measurement of relative velocity changes. Reversibility and repeatability as well as the influence of moisture were taken into account. In addition the influence of sensor (transmitter and receiver) positioning errors on the results of the interferometric algorithm was evaluated as well as the benefit of newly developed, permanently embedded sensors. The presented results can be used to evaluate and refine data from ultrasonic monitoring systems.

  10. A three-dimensional finite element analysis of a passive and friction fit implant abutment interface and the influence of occlusal table dimension on the stress distribution pattern on the implant and surrounding bone

    PubMed Central

    Sarfaraz, Hasan; Paulose, Anoopa; Shenoy, K. Kamalakanth; Hussain, Akhter

    2015-01-01

    Aims: The aim of the study was to evaluate the stress distribution pattern in the implant and the surrounding bone for a passive and a friction fit implant abutment interface and to analyze the influence of occlusal table dimension on the stress generated. Materials and Methods: CAD models of two different types of implant abutment connections, the passive fit or the slip-fit represented by the Nobel Replace Tri-lobe connection and the friction fit or active fit represented by the Nobel active conical connection were made. The stress distribution pattern was studied at different occlusal dimension. Six models were constructed in PRO-ENGINEER 05 of the two implant abutment connection for three different occlusal dimensions each. The implant and abutment complex was placed in cortical and cancellous bone modeled using a computed tomography scan. This complex was subjected to a force of 100 N in the axial and oblique direction. The amount of stress and the pattern of stress generated were recorded on a color scale using ANSYS 13 software. Results: The results showed that overall maximum Von Misses stress on the bone is significantly less for friction fit than the passive fit in any loading conditions stresses on the implant were significantly higher for the friction fit than the passive fit. The narrow occlusal table models generated the least amount of stress on the implant abutment interface. Conclusion: It can thus be concluded that the conical connection distributes more stress to the implant body and dissipates less stress to the surrounding bone. A narrow occlusal table considerably reduces the occlusal overload. PMID:26929518

  11. Four-year change in cardiorespiratory fitness and influence on glycemic control in adults with Type 2 diabetes in a randomized trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    OBJECTIVE To examine an intensive lifestyle intervention (ILI) compared with diabetes support and education (DSE) on 4-year change in fitness and physical activity (PA), and to examine the effect of change in fitness and PA, adjusting for potential confounders, on glycemic control in the Look AHEAD ...

  12. Long-term influence of normal variation in neonatal characteristics on human brain development

    PubMed Central

    Walhovd, Kristine B.; Fjell, Anders M.; Brown, Timothy T.; Kuperman, Joshua M.; Chung, Yoonho; Hagler, Donald J.; Roddey, J. Cooper; Erhart, Matthew; McCabe, Connor; Akshoomoff, Natacha; Amaral, David G.; Bloss, Cinnamon S.; Libiger, Ondrej; Schork, Nicholas J.; Darst, Burcu F.; Casey, B. J.; Chang, Linda; Ernst, Thomas M.; Frazier, Jean; Gruen, Jeffrey R.; Kaufmann, Walter E.; Murray, Sarah S.; van Zijl, Peter; Mostofsky, Stewart; Dale, Anders M.; Jernigan, Terry L.; McCabe, Connor; Chang, Linda; Akshoomoff, Natacha; Newman, Erik; Dale, Anders M.; Ernst, Thomas; Dale, Anders M.; Van Zijl, Peter; Kuperman, Joshua; Murray, Sarah; Bloss, Cinnamon; Schork, Nicholas J.; Appelbaum, Mark; Gamst, Anthony; Thompson, Wesley; Bartsch, Hauke; Jernigan, Terry L.; Dale, Anders M.; Akshoomoff, Natacha; Chang, Linda; Ernst, Thomas; Keating, Brian; Amaral, David; Sowell, Elizabeth; Kaufmann, Walter; Van Zijl, Peter; Mostofsky, Stewart; Casey, B.J.; Ruberry, Erika J.; Powers, Alisa; Rosen, Bruce; Kenet, Tal; Frazier, Jean; Kennedy, David; Gruen, Jeffrey

    2012-01-01

    It is now recognized that a number of cognitive, behavioral, and mental health outcomes across the lifespan can be traced to fetal development. Although the direct mediation is unknown, the substantial variance in fetal growth, most commonly indexed by birth weight, may affect lifespan brain development. We investigated effects of normal variance in birth weight on MRI-derived measures of brain development in 628 healthy children, adolescents, and young adults in the large-scale multicenter Pediatric Imaging, Neurocognition, and Genetics study. This heterogeneous sample was recruited through geographically dispersed sites in the United States. The influence of birth weight on cortical thickness, surface area, and striatal and total brain volumes was investigated, controlling for variance in age, sex, household income, and genetic ancestry factors. Birth weight was found to exert robust positive effects on regional cortical surface area in multiple regions as well as total brain and caudate volumes. These effects were continuous across birth weight ranges and ages and were not confined to subsets of the sample. The findings show that (i) aspects of later child and adolescent brain development are influenced at birth and (ii) relatively small differences in birth weight across groups and conditions typically compared in neuropsychiatric research (e.g., Attention Deficit Hyperactivity Disorder, schizophrenia, and personality disorders) may influence group differences observed in brain parameters of interest at a later stage in life. These findings should serve to increase our attention to early influences. PMID:23169628

  13. Herbivore attack in Casearia nitida influenced by plant ontogenetic variation in foliage quality and plant architecture.

    PubMed

    Boege, Karina

    2005-03-01

    Traits influencing plant quality as food and/or shelter for herbivores may change during plant ontogeny, and as a consequence, influence the amount of herbivory that plants receive as they develop. In this study, differences in herbivore density and herbivory were evaluated for two ontogenetic stages of the tropical tree Casearia nitida. To assess plant ontogenetic differences in foliage quality as food for herbivores, nutritional and defensive traits were evaluated in saplings and reproductive trees. Predatory arthropods were quantified and the foraging preferences of a parasitoid wasp of the genus Zacremnops were assessed. In addition, survival rates of lepidopteran herbivores (Geometridae) were evaluated experimentally. Herbivore density was three times higher and herbivory was 66% greater in saplings than in reproductive trees. Accordingly, concentrations of total foliar phenolics were higher in reproductive trees than in saplings, whereas leaf toughness, water and nitrogen concentration did not vary between ontogenetic stages. Survival rates of lepidopteran larvae exposed to natural enemies were equivalent in reproductive trees and saplings. Given the greater herbivore density on saplings, equal survival rates implied a greater foraging effort of predators on reproductive trees. Furthermore, observed foraging of parasitoid wasps was restricted to reproductive trees. I propose that herbivore density, and as a consequence, leaf damage were lower in reproductive trees than in saplings due to both traits influencing food quality, and architectural or unmeasured indirect defensive traits influencing foraging preference of natural enemies of herbivores.

  14. Influences of Vowel and Tone Variation on Emergent Word Knowledge: A Cross-Linguistic Investigation

    ERIC Educational Resources Information Center

    Singh, Leher; Hui, Tam Jun; Chan, Calista; Golinkoff, Roberta Michnick

    2014-01-01

    To learn words, infants must be sensitive to native phonological contrast. While lexical tone predominates as a source of phonemic contrast in human languages, there has been little investigation of the influences of lexical tone on word learning. The present study investigates infants' sensitivity to tone mispronunciations in two groups of…

  15. Saltwater wedge variation in a non-anthropogenic coastal karst aquifer influenced by a strong tidal range (Burren, Ireland)

    NASA Astrophysics Data System (ADS)

    Perriquet, Marie; Leonardi, Véronique; Henry, Tiernan; Jourde, Hervé

    2014-11-01

    Spatial and temporal changes in saltwater wedges in coastal karst aquifers are still poorly understood, largely due to complex mixing processes in these heterogeneous environments, but also due to anthropogenic forcing such as pumping, which commonly affect natural variations in wedges. The purpose of this study was first to characterize the hydrodynamic functioning of a karst aquifer in an oceanic temperate climate with little anthropogenic pressure but strongly influenced by a high tidal range and second, to evaluate the extent and movements of a saltwater wedge influenced by both the tide and the natural recharge of the aquifer. Variations in specific conductivity combined with water chemistry results from six boreholes and two lakes located in the Bell Harbour catchment (western Ireland) enabled us to assess the extent of the intrusion of the saltwater wedge into the aquifer as a function of both karst recharge and tidal movements at high/low and neap/spring tidal cycles. The marked spatial disparity of the saltwater wedge was analysed as a function of both the hydrodynamic and the structural properties of the karst aquifer. Results showed that the extent of the saltwater wedge depended not only on the intrinsic properties of the aquifer but also on the relative influence of the recharge and the tide on groundwater levels, which have opposite effects. Recharge in the Burren area throughout the year is large enough to prevent saltwater intruding more than about one kilometre from the shore. A strong tidal amplitude seems to be the motor of sudden saltwater intrusion observed in the aquifer near the shore while the position of the groundwater level seems to influence the intensity of the salinity increase. Competition between recharge and the tide thus controls the seawater inputs, hence explaining temporal and spatial changes in the saltwater wedge in this coastal karst aquifer.

  16. Influence of daily variations in baseline ozone on urban air quality in the United States Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Wigder, Nicole L.; Jaffe, Daniel A.; Herron-Thorpe, Farren L.; Vaughan, Joseph K.

    2013-04-01

    We examine the influence of daily variations in baseline ozone (O3) on urban air quality in the U.S. Pacific Northwest (PNW) during 2004 to 2010 through two analyses: (1) transport of free tropospheric (FT) O3 from Mount Bachelor Observatory (MBO) to Boise, Idaho; and (2) transport of marine boundary layer (MBL) O3 from Cheeka Peak (CP) to Enumclaw, Washington. Both Boise and Enumclaw experience days with maximum daily 8 hour averages of O3 (MDA8) exceeding U.S. standards. Backward trajectory cluster analyses identify days when FT and MBL O3 strongly influence MDA8 in Boise and Enumclaw. On these days, MBO and CP O3 observations explain 40% and 69% of the variations in Boise and Enumclaw MDA8, respectively. Bivariate regressions for Boise/MBO and Enumclaw/CP have slopes of 0.52 ± 0.16 and 1.04 ± 0.08, respectively, representing the differing interplay of O3 dilution, production, and loss during FT to boundary layer transport (Boise/MBO) and fast boundary layer transport (Enumclaw/CP). AIRPACT-3/CMAQ (Air Indicator Report for Public Access and Community Tracking version 3/Community Multi-scale Air Quality model) high-resolution air-quality simulation results demonstrate how transport of O3 from the FT above MBO contributes to elevated O3 at Boise. Average MDA8 O3 in Boise is higher than in Enumclaw due to site elevation and greater entrainment of FT air masses, a finding likely applicable to other PNW sites. Days with high baseline influence at Boise and Enumclaw have lower average MDA8 O3 than other days; however, some of these days would still exceed the U.S. standard if it is substantially tightened in 2013, highlighting the increasing importance of FT O3 influence on urban MDA8.

  17. Chemical variation in Jacobaea vulgaris is influenced by the interaction of season and vegetation successional stage.

    PubMed

    Carvalho, Sabrina; Macel, Mirka; Mulder, Patrick P J; Skidmore, Andrew; van der Putten, Wim H

    2014-03-01

    Knowledge on spatio-temporal dynamics of plant primary and secondary chemistry under natural conditions is important to assess how plant defence varies in real field conditions. Plant primary and secondary chemistry is known to vary with both season and vegetation successional stage, however, in few studies these two sources of variation have been examined in combination. Here we examine variations in primary and secondary chemistry of Jacobaea vulgaris (Asteraceae) throughout the growing season in early, mid, and late stages of secondary succession following land abandonment using a well-established chronosequence in The Netherlands. We investigated primary and secondary chemistry of both leaves and flowers, in order to determine if patterns during seasonal (phenological) development may differ among successional stages. The chemical concentration of primary and secondary chemistry compounds in J. vulgaris varied throughout the season and was affected by vegetation succession stage. Concentrations of pyrrolizidine alkaloid (PA) tertiary-amines were highest in flowers during early Summer and in fields that had been abandoned ten to twenty years ago. PA N-oxide concentrations of both leaves and flowers, on the other hand increased with the progression of both season and succession. In Spring and early Summer chlorophyll concentrations were highest, especially in the oldest fields of the chronosequence. During phenological development, nitrogen concentration increased in flowers and decreased in leaves revealing allocation of nutrients from vegetative to reproductive plant parts throughout the growing season. The highest concentrations of N-oxides and chlorophylls were detected in older fields. Thus, our results suggest that variations in plant patterns of nutritional and defence compounds throughout the growing season are depending on successional context.

  18. Genotypic variation influences reproductive success and thermal stress tolerance in the reef building coral, Acropora palmata

    NASA Astrophysics Data System (ADS)

    Baums, I. B.; Devlin-Durante, M. K.; Polato, N. R.; Xu, D.; Giri, S.; Altman, N. S.; Ruiz, D.; Parkinson, J. E.; Boulay, J. N.

    2013-09-01

    The branching coral Acropora palmata is a foundation species of Caribbean reefs that has been decimated in recent decades by anthropogenic and natural stressors. Declines in population density and genotypic diversity likely reduce successful sexual reproduction in this self-incompatible hermaphrodite and might impede recovery. We investigated variation among genotypes in larval development under thermally stressful conditions. Six two-parent crosses and three four-parent batches were reared under three temperatures and sampled over time. Fertilization rates differed widely with two-parent crosses having lower fertilization rates (5-56 %, mean 22 % ± 22 SD) than batches (from 31 to 87 %, mean 59 % ± 28 SD). Parentage analysis of larvae in batch cultures showed differences in gamete compatibility among parents, coinciding with significant variation in both sperm morphology and egg size. While all larval batches developed more rapidly at increased water temperatures, rate of progression through developmental stages varied among batches, as did swimming speed. Together, these results indicate that loss of genotypic diversity exacerbates already severe limitations in sexual reproductive success of A. palmata. Nevertheless, surviving parental genotypes produce larvae that do vary in their phenotypic response to thermal stress, with implications for adaptation, larval dispersal and population connectivity in the face of warming sea surface temperatures.

  19. Long-term global temperature variations under the influence of different cosmophysical factors

    NASA Astrophysics Data System (ADS)

    Biktash, Lilia

    2016-07-01

    We have analyzed different cosmophysical factors which have effect on long-term global temperature variations during solar cycles 20-24. A detailed analysis of total solar irradiance (TSI), the spectral solar ultraviolet emission (UV), space weather and cosmic rays (CRs) have effects on the atmosphere processes. We have shown that increasing of global temperature is likely affected by TSI and UV during solar maxima. During the descending phases of these solar cycles the interplanetary magnetic field and long-lasting solar wind high speed streams occurred frequently and were the primary contributors to minimize of CRs effect on the Earth's atmosphere. In this case global temperature is increased extra as result of increase in the atmosphere's transparency. We show that there are a few effective physical mechanisms of the action of solar activity and space weather on the global temperature. TSI and CRs play essential role in climate change and main part of climate variations can be explained by the mechanism of action TSI and CRs modulated by the solar activity on the state of lower atmosphere and meteorological parameters.

  20. Influence of variations in extratropical wintertime teleconnections on Northern Hemisphere temperature

    SciTech Connect

    Hurrell, J.W.

    1996-03-15

    Pronounced changes in the wintertime atmospheric circulation have occurred since the mid-1970s over the ocean basins of the Northern Hemisphere, and these changes have had a profound effect on surface temperatures. The variations over the North Atlantic are related to changes in the North Atlantic Oscillation (NAO), while the changes over the North Pacific are linked to the tropics and involve variations in the Aleutian low with teleconnections downstream over North America. Multivariate linear regression is used to show that nearly all of the cooling in the northwest Atlantic and the warming across Europe and downstream over Eurasia since the mid-1970s results from the changes in the NAO, and the NAO accounts for 31% of the hemispheric interannual variance over the past 60 winters. Over the Pacific basin and North America, the temperature anomalies result in part from tropical forcing associated with the El Nino-Southern Oscillation phenomenon but with important feedbacks in the extratropics. The changes in circulation over the past two decades have resulted in a surface temperature anomaly pattern of warmth over the continents and coolness over the oceans. This pattern of temperature change has amplified the observed hemispheric-averaged warming because of it interaction with land and ocean; temperature changes are larger over land compared to the oceans because of the small heat capacity of the former. 13 refs., 5 fig., 2 tab.

  1. The Influence of Variation in Time and HCl Concentration to the Glucose Produced from Kepok Banana

    NASA Astrophysics Data System (ADS)

    Widodo M, Rohman; Noviyanto, Denny; RM, Faisal

    2016-01-01

    Kepok banana (Musa paradisiaca) is a plant that has many advantagesfrom its fruit, stems, leaves, flowers and cob. However, we just tend to take benefit from the fruit. We grow and harvest the fruit without taking advantages from other parts. So they would be a waste or detrimental to animal nest if not used. The idea to take the benefit from the banana crop yields, especially cob is rarely explored. This study is an introduction to the use of banana weevil especially from the glucose it contains. This study uses current methods of hydrolysis using HCl as a catalyst with the concentration variation of 0.4 N, 0.6 N and 0.8 N and hydrolysis times variation of 20 minutes, 25 minutes and 30 minutes. The stages in the hydrolysis include preparation of materials, the process of hydrolysis and analysis of test results using Fehling and titrate with standard glucose solution. HCl is used as a catalyst because it is cheaper than the enzyme that has the same function. NaOH 60% is used for neutralizing the pH of the filtrate result of hydrolysis. From the results of analysis, known thatthe biggest yield of glucose is at concentration 0.8 N and at 30 minutes reaction, it contains 6.25 gram glucose / 20 gram dry sampel, and the convertion is 27.22% at 20 gram dry sampel.

  2. Influence of ocean tides on the diurnal and semidiurnal earth rotation variations from VLBI observations

    NASA Astrophysics Data System (ADS)

    Gubanov, V. S.; Kurdubov, S. L.

    2015-05-01

    The International astrogeodetic standard IERS Conventions (2010) contains a model of the diurnal and semidiurnal variations in Earth rotation parameters (ERPs), the pole coordinates and the Universal Time, arising from lunisolar tides in the world ocean. This model was constructed in the mid-1990s through a global analysis of Topex/Poseidon altimetry. The goal of this study is to try to estimate the parameters of this model by processing all the available VLBI observations on a global network of stations over the last 35 years performed within the framework of IVS (International VLBI Service) geodetic programs. The complexity of the problemlies in the fact that the sought-for corrections to the parameters of this model lie within 1 mm and, thus, are at the limit of their detectability by all currently available methods of ground-based positional measurements. This requires applying universal software packages with a high accuracy of reduction calculations and a well-developed system of controlling the simultaneous adjustment of observational data to analyze long series of VLBI observations. This study has been performed with the QUASAR software package developed at the Institute of Applied Astronomy of the Russian Academy of Sciences. Although the results obtained, on the whole, confirm a high accuracy of the basic model in the IERS Conventions (2010), statistically significant corrections that allow this model to be refined have been detected for some harmonics of the ERP variations.

  3. Modeling the interdecadal eurasian snow cover variations influenced by large-scale atmospheric modes

    NASA Astrophysics Data System (ADS)

    Shmakin, A. B.; Popova, V. V.

    2003-04-01

    The variations of snow water equivalent (SWE) in Eurasia during the last 100 years have been evaluated using a simplified model of heat/water exchange at the land surface. The model is designed for monthly time step, and its equations are written in deviations from average climatic regime. The forcing anomalies of meteorological parameters for 20th century at each grid cell were specified according to large-scale atmospheric indices (such as NAO, PNA, etc.) and regressions between the indices and the meteorological variables. The results were tested against the data observed in Russia during several decades at regular stations and in their vicinity in typical environment. The observed data, Former Soviet Union Hydrological Snow Surveys, were obtained from the National Snow and Ice Data Center (NSIDC), University of Colorado at Boulder. The main features of SWE spatial distribution and its interdecadal variance were reproduced satisfactorily, but the errors were greater in the regions with poorer correlation between atmospheric variables and circulation indices. The regions located closer to Atlantic and, to lesser extent, Pacific coast, demonstrated better agreement with observed data. The large-scale atmospheric modes most responsible for the Eurasian SWE variations at decadal time scale are NAO and intensity of Aleutian low. The study was supported by the Russian Foundation for Basic Research (grants 01-05-64707 and 01-05-64395).

  4. Investigation of the spatiotemporal variation and influencing factors on fine particulate matter and carbon monoxide concentrations near a road intersection

    NASA Astrophysics Data System (ADS)

    Wang, Zhanyong; Lu, Qing-Chang; He, Hong-Di; Wang, Dongsheng; Gao, Ya; Peng, Zhong-Ren

    2017-03-01

    The minute-scale variations of fine particulate matter (PM2.5) and carbon monoxide (CO) concentrations near a road intersection in Shanghai, China were investigated to identify the influencing factors at three traffic periods. Measurement results demonstrate a synchronous variation of pollutant concentrations at the roadside and setbacks, and the average concentration of PM2.5 at the roadside is 7% (44% for CO) higher than that of setbacks within 500 m of the intersection. The pollution level at traffic peak periods is found to be higher than that of off-peak periods, and the morning peak period is found to be the most polluted due to a large amount of diesel vehicles and unfavorable dispersion conditions. Partial least square regressions were constructed for influencing factors and setback pollutant concentrations, and results indicate that meteorological factors are the most significant, followed by setback distance from the intersection and traffic factors. CO is found to be sensitive to distance from the traffic source and vehicle type, and highly dependent on local traffic conditions, whereas PM2.5 originates more from other sources and background levels. These findings demonstrate the importance of localized factors in understanding spatiotemporal patterns of air pollution at intersections, and support decision makers in roadside pollution management and control.

  5. Comparative multilocus phylogeography of two Palaearctic spruce bark beetles: influence of contrasting ecological strategies on genetic variation.

    PubMed

    Mayer, François; Piel, Frédéric B; Cassel-Lundhagen, Anna; Kirichenko, Natalia; Grumiau, Laurent; Økland, Bjørn; Bertheau, Coralie; Grégoire, Jean-Claude; Mardulyn, Patrick

    2015-03-01

    While phylogeographic patterns of organisms are often interpreted through past environmental disturbances, mediated by climate changes, and geographic barriers, they may also be strongly influenced by species-specific traits. To investigate the impact of such traits, we focused on two Eurasian spruce bark beetles that share a similar geographic distribution, but differ in their ecology and reproduction. Ips typographus is an aggressive tree-killing species characterized by strong dispersal, whereas Dendroctonus micans is a discrete inbreeding species (sib mating is the rule), parasite of living trees and a poor disperser. We compared genetic variation between the two species over both beetles' entire range in Eurasia with five independent gene fragments, to evaluate whether their intrinsic differences could have an influence over their phylogeographic patterns. We highlighted widely divergent patterns of genetic variation for the two species and argue that the difference is indeed largely compatible with their contrasting dispersal strategies and modes of reproduction. In addition, genetic structure in I. typographus divides European populations in a northern and a southern group, as was previously observed for its host plant, and suggests past allopatric divergence. A long divergence time was estimated between East Asian and other populations of both species, indicating their long-standing presence in Eurasia, prior to the last glacial maximum. Finally, the strong population structure observed in D. micans for the mitochondrial locus provides insights into the recent colonization history of this species, from its native European range to regions where it was recently introduced.

  6. Variation in chromosome copy number influences the virulence of Cryptococcus neoformans and occurs in isolates from AIDS patients

    PubMed Central

    2011-01-01

    Background The adaptation of pathogenic fungi to the host environment via large-scale genomic changes is a poorly characterized phenomenon. Cryptococcus neoformans is the leading cause of fungal meningoencephalitis in HIV/AIDS patients, and we recently discovered clinical strains of the fungus that are disomic for chromosome 13. Here, we examined the genome plasticity and phenotypes of monosomic and disomic strains, and compared their virulence in a mouse model of cryptococcosis Results In an initial set of strains, melanin production was correlated with monosomy at chromosome 13, and disomic variants were less melanized and attenuated for virulence in mice. After growth in culture or passage through mice, subsequent strains were identified that varied in melanin formation and exhibited copy number changes for other chromosomes. The correlation between melanin and disomy at chromosome 13 was observed for some but not all strains. A survey of environmental and clinical isolates maintained in culture revealed few occurrences of disomic chromosomes. However, an examination of isolates that were freshly collected from the cerebrospinal fluid of AIDS patients and minimally cultured provided evidence for infections with multiple strains and copy number variation. Conclusions Overall, these results suggest that the genome of C. neoformans exhibits a greater degree of plasticity than previously appreciated. Furthermore, the expression of an essential virulence factor and the severity of disease are associated with genome variation. The occurrence of chromosomal variation in isolates from AIDS patients, combined with the observed influence of disomy on virulence, indicates that genome plasticity may have clinical relevance. PMID:22032296

  7. Porous gravity currents: A survey to determine the joint influence of fluid rheology and variations of medium properties

    NASA Astrophysics Data System (ADS)

    Ciriello, Valentina; Longo, Sandro; Chiapponi, Luca; Di Federico, Vittorio

    2016-06-01

    We develop a model to grasp the combined effect of rheology and spatial stratifications on two-dimensional non-Newtonian gravity-driven flow in porous media. We consider a power-law constitutive equation for the fluid, and a monomial variation of permeability and porosity along the vertical direction (transverse to the flow) or horizontal direction (parallel to the flow). Under these assumptions, similarity solutions are derived in semi-analytical form for thin gravity currents injected into a two-dimensional porous medium and having constant or time-varying volume. The extent and shape of the porous domain affected by the injection is significantly influenced by the interplay of model parameters. These describe the fluid (flow behaviour index n), the spatial heterogeneity (coefficients β, γ, δ, ω for variations of permeability and porosity in the horizontal or vertical direction), and the type of release (volume exponent α). Theoretical results are validated against two sets of experiments with α = 1 (constant inflow) conducted with a stratified porous medium (simulated by superimposing layers of glass beads of different diameter) and a Hele-Shaw analogue for power-law fluid flow, respectively. In the latter case, a recently established Hele-Shaw analogy is extended to the variation of properties parallel to the flow direction. Comparison with experimental results shows that the proposed model is able to capture the propagation of the current front and the current profile.

  8. On the influence of dynamic stress variations on strain accumulation in fault zones

    NASA Astrophysics Data System (ADS)

    Grigoriev, A. S.; Shilko, E. V.; Astafurov, S. V.; Dimaki, A. V.; Vysotsky, E. M.; Psakhie, S. G.

    2015-10-01

    In this paper, a numerical study of the influence of the stress state of interface of the block medium structural elements on the deformation response of interface to the dynamic impacts. It is shown that the basic characteristics of the stress state determining the deformation response of the interface are the values of shear stress and mean stress. It is found that the dependence of the irreversible displacement at the interface zone initiated by dynamic impact on the reduced shear stress is described by the logistic function. Herewith, the influence of the mean stress and dynamic impact energy on the value of displacement initiated by dynamic impact can be taken into account by dependence of the logistic function numerator on these parameters.

  9. Variation in the human immune system is largely driven by non-heritable influences

    PubMed Central

    Brodin, Petter; Jojic, Vladimir; Gao, Tianxiang; Bhattacharya, Sanchita; Angel, Cesar J Lopez; Furman, David; Shen-Orr, Shai; Dekker, Cornelia L; Swan, Gary E.; Butte, Atul J; Maecker, Holden T; Davis, Mark M

    2015-01-01

    SUMMARY There is considerable heterogeneity in immunological parameters between individuals, but its sources are largely unknown. To assess the relative contribution of heritable versus non-heritable factors, we have performed a systems-level analysis of 210 healthy twins between 8–82 years of age. We measured 204 different parameters, including cell population frequencies, cytokine responses, and serum proteins, and found that 77% of these are dominated (> 50% of variance) and 58% almost completely determined (> 80% of variance) by non-heritable influences. In addition, some of these parameters become more variable with age, suggesting the cumulative influence of environmental exposure. Similarly, the serological responses to seasonal influenza vaccination are also determined largely by non-heritable factors, likely due to repeated exposure to different strains. Lastly, in MZ twins discordant for cytomegalovirus infection, over half of all parameters are affected. These results highlight the largely reactive and adaptive nature of the immune system in healthy individuals. PMID:25594173

  10. Influences on Tobacco Control Funding Decisions: Explaining State Variation in Appropriations

    DTIC Science & Technology

    2003-01-01

    OMB control number. 1. REPORT DATE 2003 2 . REPORT TYPE 3. DATES COVERED - 4. TITLE AND SUBTITLE Influences on Tobacco Control Funding...hypertension, diabetes , emphysema, angina, and dental problems (CDC, 2001). Annual death rates from smoking vary by state with a high of 414 per 100,000 in...New Mexico 1.338259 3.8124 0 1 50.78128 3.3 0 32. New York .8958431 2.4494 2 1

  11. The influence of aerobic fitness on cerebral white matter integrity and cognitive function in older adults: results of a one-year exercise intervention.

    PubMed

    Voss, Michelle W; Heo, Susie; Prakash, Ruchika S; Erickson, Kirk I; Alves, Heloisa; Chaddock, Laura; Szabo, Amanda N; Mailey, Emily L; Wójcicki, Thomas R; White, Siobhan M; Gothe, Neha; McAuley, Edward; Sutton, Bradley P; Kramer, Arthur F

    2013-11-01

    Cerebral white matter (WM) degeneration occurs with increasing age and is associated with declining cognitive function. Research has shown that cardiorespiratory fitness and exercise are effective as protective, even restorative, agents against cognitive and neurobiological impairments in older adults. In this study, we investigated whether the beneficial impact of aerobic fitness would extend to WM integrity in the context of a one-year exercise intervention. Further, we examined the pattern of diffusivity changes to better understand the underlying biological mechanisms. Finally, we assessed whether training-induced changes in WM integrity would be associated with improvements in cognitive performance independent of aerobic fitness gains. Results showed that aerobic fitness training did not affect group-level change in WM integrity, executive function, or short-term memory, but that greater aerobic fitness derived from the walking program was associated with greater change in WM integrity in the frontal and temporal lobes, and greater improvement in short-term memory. Increases in WM integrity, however, were not associated with short-term memory improvement, independent of fitness improvements. Therefore, while not all findings are consistent with previous research, we provide novel evidence for correlated change in training-induced aerobic fitness, WM integrity, and cognition among healthy older adults.

  12. Clinical influences on antibiotic prescribing decisions for lower respiratory tract infection: a nine country qualitative study of variation in care

    PubMed Central

    Hood, Kerenza; Cooper, Lucy; Coenen, Samuel; Little, Paul; Verheij, Theo; Godycki-Cwirko, Maciek; Melbye, Hasse; Krawczyk, Jaroslaw; Borras-Santos, Alicia; Jakobsen, Kristin; Worby, Patricia; Goossens, Herman; Butler, Christopher C

    2012-01-01

    Objectives There is variation in antibiotic prescribing for lower respiratory tract infections (LRTI) in primary care that does not benefit patients. This study aims to investigate clinicians' accounts of clinical influences on antibiotic prescribing decisions for LRTI to better understand variation and identify opportunities for improvement. Design Multi country qualitative interview study. Semi-structured interviews using open-ended questions and a patient scenario. Data were subjected to five-stage analytic framework approach (familiarisation, developing a thematic framework from the interview questions and emerging themes, indexing, charting and mapping to search for interpretations), with interviewers commenting on preliminary reports. Setting Primary care. Participants 80 primary care clinicians randomly selected from primary care research networks based in nine European cities. Results Clinicians reported four main individual clinical factors that guided their antibiotic prescribing decision: auscultation, fever, discoloured sputum and breathlessness. These were considered alongside a general impression of the patient derived from building a picture of the illness course, using intuition and familiarity with the patient. Comorbidity and older age were considered main risk factors for poor outcomes. Clinical factors were similar across networks, apart from C reactive protein near patient testing in Tromsø. Clinicians developed ways to handle diagnostic and management uncertainty through their own clinical routines. Conclusions Clinicians emphasised the importance of auscultation, fever, discoloured sputum and breathlessness, general impression of the illness course, familiarity with the patient, comorbidity, and age in informing their antibiotic prescribing decisions for LRTI. As some of these factors may be overemphasised given the evolving evidence base, greater standardisation of assessment and integration of findings may help reduce unhelpful variation

  13. Influence of diurnal variations in stream temperature on streamflow loss and groundwater recharge

    USGS Publications Warehouse

    Constantz, Jim; Thomas, Carole L.; Zellweger, Gary W.

    1994-01-01

    We demonstrate that for losing reaches with significant diurnal variations in stream temperature, the effect of stream temperature on streambed seepage is a major factor contributing to reduced afternoon streamflows. An explanation is based on the effect of stream temperature on the hydraulic conductivity of the streambed, which can be expected to double in the 0° to 25°C temperature range. Results are presented for field experiments in which stream discharge and temperature were continuously measured for several days over losing reaches at St. Kevin Gulch, Colorado, and Tijeras Arroyo, New Mexico. At St. Kevin Gulch in July 1991, the diurnal stream temperature in the 160-m study reach ranged from about 4° to 18°C, discharges ranged from 10 to 18 L/s, and streamflow loss in the study reach ranged from 2.7 to 3.7 L/s. On the basis of measured stream temperature variations, the predicted change in conductivity was about 38%; the measured change in stream loss was about 26%, suggesting that streambed temperature varied less than the stream temperature. At Tijeras Arroyo in May 1992, diurnal stream temperature in the 655-m study reach ranged from about 10° to 25°C and discharge ranged from 25 to 55 L/s. Streamflow loss was converted to infiltration rates by factoring in the changing stream reach surface area and streamflow losses due to evaporation rates as measured in a hemispherical evaporation chamber. Infiltration rates ranged from about 0.7 to 2.0 m/d, depending on time and location. Based on measured stream temperature variations, the predicted change in conductivity was 29%; the measured change in infiltration was also about 27%. This suggests that high infiltration rates cause rapid convection of heat to the streambed. Evapotranspiration losses were estimated for the reach and adjacent flood plain within the arroyo. On the basis of these estimates, only about 5% of flow loss was consumed via stream evaporation and stream-side evapotranspiration

  14. A kinematic eddy viscosity model including the influence of density variations and preturbulence

    NASA Technical Reports Server (NTRS)

    Cohen, L. S.

    1973-01-01

    A model for the kinematic eddy viscosity was developed which accounts for the turbulence produced as a result of jet interactions between adjacent streams as well as the turbulence initially present in the streams. In order to describe the turbulence contribution from jet interaction, the eddy viscosity suggested by Prandtl was adopted, and a modification was introduced to account for the effect of density variation through the mixing layer. The form of the modification was ascertained from a study of the compressible turbulent boundary layer on a flat plate. A kinematic eddy viscosity relation which corresponds to the initial turbulence contribution was derived by employing arguments used by Prandtl in his mixing length hypothesis. The resulting expression for self-preserving flow is similar to that which describes the mixing of a submerged jet. Application of the model has led to analytical predictions which are in good agreement with available turbulent mixing experimental data.

  15. Influence of quaternary sea-level variations on a land bird endemic to Pacific atolls.

    PubMed

    Cibois, Alice; Thibault, Jean-Claude; Pasquet, Eric

    2010-11-22

    Little is known about the effect of quaternary climate variations on organisms that inhabited carbonate islands of the Pacific Ocean, although it has been suggested that one or several uplifted islands provided shelter for terrestrial birds when sea-level reached its highest. To test this hypothesis, we investigated the history of colonization of the Tuamotu reed-warbler (Acrocephalus atyphus) in southeastern Polynesia, and found high genetic structure between the populations of three elevated carbonate islands. Estimates of time since divergence support the hypothesis that these islands acted as refugia during the last interglacial maximum. These findings are particularly important for defining conservation priorities on atolls that endure the current trend of sea-level rise owing to global warming.

  16. Variations in the influence of parental socialization of anxiety among clinic referred children.

    PubMed

    Holly, Lindsay E; Pina, Armando A

    2015-06-01

    This study examined the relations between parental socialization of child anxious behaviors (i.e., reinforcement, punishment, modeling, transmission of information) and child anxiety and related problems at varying child sensitivity levels. Data corresponding to 70 clinic-referred children (M age = 9.86 years; 50% girls; 49% Hispanic/Latino, 51% Caucasian) showed that for children with low (but not high) anxiety sensitivity, anxiety-related parental socialization behaviors were associated with more child anxiety and depression symptoms. Findings also indicated that parental socialization of anxious behaviors and anxiety sensitivity functioned similarly in the prediction of anxiety and depression across Caucasian and Hispanic/Latino children. There were no significant mean level variations across child sociodemographic characteristics in general, but anxiety-promoting parenting behaviors were twice as high in Hispanic/Latino compared to Caucasian families.

  17. Variation at the fragile X locus does not influence susceptibility to bipolar disorder

    SciTech Connect

    Craddock, N.; Daniels, J.; McGuffin, P.

    1994-06-15

    Over the last 20 years several pedigrees have been reported which are suggestive of linkage between susceptibility to bipolar disorder and markers on chromosome Xq28. Other workers have failed to replicate these reports and the methodology of the positive reports has been criticized. Recently there have been several reports of an association between fragile X (FRA(X)) and affective disorder within families and in unrelated individuals compared with controls. Such reports could be consistent with the Xq28 marker reports because FRA(X) maps to Xq27.3. We report a study at the FRA(X) CGG repeat locus in 79 unrelated Caucasian bipolar probands without fragile X syndrome and 77 unrelated controls. We found no evidence that variation at this locus confers susceptibility to bipolar disorder. 28 refs., 1 fig.

  18. Variation in complex olfactory stimuli and its influence on odour recognition.

    PubMed Central

    Wrigh, Geraldine A.; Smith, Brian H.

    2004-01-01

    Natural olfactory stimuli are often complex and highly variable. The olfactory systems of animals are likely to have evolved to use specific features of olfactory stimuli for identification and discrimination. Here, we train honeybees to learn chemically defined odorant mixtures that systematically vary from trial to trial and then examine how they generalize to each odorant present in the mixture. An odorant that was present at a constant concentration in a mixture becomes more representative of the mixture than other variable odorants. We also show that both variation and intensity of a complex olfactory stimulus affect the rate of generalization by honeybees to subsequent olfactory stimuli. These results have implications for the way that all animals perceive and attend to features of olfactory stimuli. PMID:15058390

  19. Geographic variation in avian incubation periods and parental influences on embryonic temperature

    USGS Publications Warehouse

    Martin, T.E.; Auer, S.K.; Bassar, R.D.; Niklison, Alina M.; Lloyd, P.

    2007-01-01

    Theory predicts shorter embryonic periods in species with greater embryo mortality risk and smaller body size. Field studies of 80 passerine species on three continents yielded data that largely conflicted with theory; incubation (embryonic) periods were longer rather than shorter in smaller species, and egg (embryo) mortality risk explained some variation within regions, but did not explain larger differences in incubation periods among geographic regions. Incubation behavior of parents seems to explain these discrepancies. Bird embryos are effectively ectothermic and depend on warmth provided by parents sitting on the eggs to attain proper temperatures for development. Parents of smaller species, plus tropical and southern hemisphere species, commonly exhibited lower nest attentiveness (percent of time spent on the nest incubating) than larger and northern hemisphere species. Lower nest attentiveness produced cooler minimum and average embryonic temperatures that were correlated with longer incubation periods independent of nest predation risk or body size. We experimentally tested this correlation by swapping eggs of species with cool incubation temperatures with eggs of species with warm incubation temperatures and similar egg mass. Incubation periods changed (shortened or lengthened) as expected and verified the importance of egg temperature on development rate. Slower development resulting from cooler temperatures may simply be a cost imposed on embryos by parents and may not enhance offspring quality. At the same time, incubation periods of transferred eggs did not match host species and reflect intrinsic differences among species that may result from nest predation and other selection pressures. Thus, geographic variation in embryonic development may reflect more complex interactions than previously recognized. ?? 2007 The Author(s).

  20. Geographic variation in avian incubation periods and parental influences on embryonic temperature.

    PubMed

    Martin, Thomas E; Auer, Sonya K; Bassar, Ronald D; Niklison, Alina M; Lloyd, Penn

    2007-11-01

    Theory predicts shorter embryonic periods in species with greater embryo mortality risk and smaller body size. Field studies of 80 passerine species on three continents yielded data that largely conflicted with theory; incubation (embryonic) periods were longer rather than shorter in smaller species, and egg (embryo) mortality risk explained some variation within regions, but did not explain larger differences in incubation periods among geographic regions. Incubation behavior of parents seems to explain these discrepancies. Bird embryos are effectively ectothermic and depend on warmth provided by parents sitting on the eggs to attain proper temperatures for development. Parents of smaller species, plus tropical and southern hemisphere species, commonly exhibited lower nest attentiveness (percent of time spent on the nest incubating) than larger and northern hemisphere species. Lower nest attentiveness produced cooler minimum and average embryonic temperatures that were correlated with longer incubation periods independent of nest predation risk or body size. We experimentally tested this correlation by swapping eggs of species with cool incubation temperatures with eggs of species with warm incubation temperatures and similar egg mass. Incubation periods changed (shortened or lengthened) as expected and verified the importance of egg temperature on development rate. Slower development resulting from cooler temperatures may simply be a cost imposed on embryos by parents and may not enhance offspring quality. At the same time, incubation periods of transferred eggs did not match host species and reflect intrinsic differences among species that may result from nest predation and other selection pressures. Thus, geographic variation in embryonic development may reflect more complex interactions than previously recognized.

  1. Can the Tibetan Plateau snow cover influence the interannual variations of Eurasian heat wave frequency?

    NASA Astrophysics Data System (ADS)

    Wu, Zhiwei; Zhang, Peng; Chen, Hua; Li, Yun

    2016-06-01

    The Eurasian continent has experienced significant year-to-year variations of summer heat waves during the past decades. Several possible factors, such as ocean temperature, soil moisture, and changes in land use and greenhouse gases, have been identified in previous studies, but the mechanisms are still unclear. In this study, it is found that the Tibetan Plateau snow cover (TPSC) is closely linked to the interannual variations of summer heat waves over Eurasia. The TPSC variability explains more than 30 % of the total variances of heat wave variability in the southern Europe and northeastern Asia (SENA) region. A set of numerical experiments reveal that the reduced TPSC may induce a distinct teleconnection pattern across the Eurasian continent, with two anomalous high pressure centers in the upper troposphere over the SENA region, which may lead to a reduction of the cloud formation near the surface. The less cloud cover tends to increase the net shortwave radiation and favor a stronger surface sensible heat flux in the dry surface condition over the SENA region, resulting in a deeper, warmer and drier atmospheric boundary layer that would further inhibit the local cloud formation. Such a positive land-atmosphere feedback may dry the surface even further, heat the near-surface atmosphere and thereby intensify the local heat waves. The above dynamical processes also operate on interdecadal time scales. Given the reduction of the TPSC could become more pronounced with increasing levels of greenhouse gases in a warming climate, we infer that the TPSC may play an increasingly important role in shaping the summer heat waves over the SENA region in next decades.

  2. Vegetation structure and fire weather influence variation in burn severity and fuel consumption during peatland wildfires

    NASA Astrophysics Data System (ADS)

    Davies, G. M.; Domènech, R.; Gray, A.; Johnson, P. C. D.

    2015-09-01

    Temperate peatland wildfires are of significant environmental concern but information on their environmental effects is lacking. We assessed variation in burn severity and fuel consumption within and between wildfires that burnt British moorlands in 2011 and 2012. We adapted the Composite Burn Index (pCBI) to provide semi-quantitative estimates of burn severity. Pre- and post-fire surface (shrubs and graminoids) and ground (litter, moss, duff) fuel loads associated with large wildfires were assessed using destructive sampling and analysed using a Generalised Linear Mixed Model (GLMM). Consumption during wildfires was compared with published estimates of consumption during prescribed burns. Burn severity and fuel consumption were related to fire weather, assessed using the Canadian Fire Weather Index System (FWI System), and pre-fire fuel structure. pCBI varied 1.6 fold between, and up to 1.7 fold within, wildfires. pCBI was higher where moisture codes of the FWI System indicated drier fuels. Spatial variation in pre- and post-fire fuel load accounted for a substantial proportion of the variance in fuel loads. Average surface fuel consumption was a linear function of pre-fire fuel load. Average ground fuel combustion completeness could be predicted by the Buildup Index. Carbon release ranged between 0.36 and 1.00 kg C m-2. The flammability of ground fuel layers may explain the higher C release-rates seen for wildfires in comparison to prescribed burns. Drier moorland community types appear to be at greater risk of severe burns than blanket-bog communities.

  3. Vegetation structure and fire weather influence variation in burn severity and fuel consumption during peatland wildfires

    NASA Astrophysics Data System (ADS)

    Davies, G. M.; Domènech, R.; Gray, A.; Johnson, P. C. D.

    2016-01-01

    Temperate peatland wildfires are of significant environmental concern but information on their environmental effects is lacking. We assessed variation in burn severity and fuel consumption within and between wildfires that burnt British moorlands in 2011 and 2012. We adapted the composite burn index (pCBI) to provide semi-quantitative estimates of burn severity. Pre- and post-fire surface (shrubs and graminoids) and ground (litter, moss, duff) fuel loads associated with large wildfires were assessed using destructive sampling and analysed using a generalised linear mixed model (GLMM). Consumption during wildfires was compared with published estimates of consumption during prescribed burns. Burn severity and fuel consumption were related to fire weather, assessed using the Canadian Fire Weather Index System (FWI System), and pre-fire vegetation type. pCBI varied 1.6 fold between, and up to 1.7 fold within, wildfires. pCBI was higher where moisture codes of the FWI System indicated drier fuels. Spatial variation in pre- and post-fire fuel load accounted for a substantial proportion of the variance in fuel loads. Average surface fuel consumption was a linear function of pre-fire fuel load. Average ground fuel combustion completeness could be predicted by the Buildup Index. Carbon release ranged between 0.36 and 1.00 kg C m-2. The flammability of ground fuel layers may explain the higher C release-rates seen for wildfires in comparison to prescribed burns. Drier moorland community types appear to be at greater risk of severe burns than blanket-bog communities.

  4. Influence of interannual rainfall anomalies on sea level variations in the tropical Indian Ocean

    NASA Astrophysics Data System (ADS)

    Perigaud, Claire; McCreary, Julian P.

    2003-10-01

    A halo-thermal, reduced-gravity model with four active layers is used to investigate how interannual rainfall anomalies affect sea surface height (SSH) variability in the Indian Ocean. The model is forced by monthly varying winds observed over the period 1980-2000 in two experiments that differ by their rainfall forcing, Run FSU and Run Arkin, forced by climatological and interannually varying rainfall, respectively. Compared to the large impact of wind on SSH (about 30 cm), the impact of rain is much smaller. Its maximum (found in the southeastern Indian Ocean during the rainfall deficits of 1994 and 1997) is only 2 cm. Because rainfall significantly affects model salinity and temperature, the deficits make the layers of Run Arkin colder and saltier than in Run FSU, causing a -5 cm change in sea level. Baroclinic adjustments also occur such that the top (bottom) two layers are thicker (thinner), increasing sea level by 3 cm and hence significantly reducing the SSH change due to steric effects alone. SSH variability in either Run Arkin or Run FSU compares very well with TOPEX data. Although the impact of rainfall on SSH is negligible, salinity variations significantly affect dynamic-height calculations of SSH. In the model, the neglect of salinity variations leads to an error of 5 to 10 cm along the eastern boundary, in the Bay of Bengal, and in the interior ocean south of 8°S. This error is validated by the difference between TOPEX data and SSH derived from observed temperature profiles.

  5. Intraclonal Variations Among Streptococcus pneumoniae Isolates Influence the Likelihood of Invasive Disease in Children

    PubMed Central

    Browall, Sarah; Norman, Martin; Tångrot, Jeanette; Galanis, Ilias; Sjöström, Karin; Dagerhamn, Jessica; Hellberg, Christel; Pathak, Anuj; Spadafina, Tiziana; Sandgren, Andreas; Bättig, Patrick; Franzén, Oscar; Andersson, Björn; Örtqvist, Åke; Normark, Staffan; Henriques-Normark, Birgitta

    2014-01-01

    Background. Pneumococcal serotypes are represented by a varying number of clonal lineages with different genetic contents, potentially affecting invasiveness. However, genetic variation within the same genetic lineage may be larger than anticipated. Methods. A total of 715 invasive and carriage isolates from children in the same region and during the same period were compared using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Bacterial genome sequencing, functional assays, and in vivo virulence mice studies were performed. Results. Clonal types of the same serotype but also intraclonal variants within clonal complexes (CCs) showed differences in invasive-disease potential. CC138, a common CC, was divided into several PFGE patterns, partly explained by number, location, and type of temperate bacteriophages. Whole-genome sequencing of 4 CC138 isolates representing PFGE clones with different invasive-disease potentials revealed intraclonal sequence variations of the virulence-associated proteins pneumococcal surface protein A (PspA) and pneumococcal choline-binding protein C (PspC). A carrier isolate lacking PcpA exhibited decreased virulence in mice, and there was a differential binding of human factor H, depending on invasiveness. Conclusions. Pneumococcal clonal types but also intraclonal variants exhibited different invasive-disease potentials in children. Intraclonal variants, reflecting different prophage contents, showed differences in major surface antigens. This suggests ongoing immune selection, such as that due to PspC-mediated complement resistance through varied human factor H binding, that may affect invasiveness in children. PMID:24009156

  6. Variation in the TLR4 gene influences the risk of organ failure and shock post-trauma: a cohort study

    PubMed Central

    Shalhub, Sherene; Junker, Christopher E.; Imahara, Scott D.; Mindrinos, Michael N.; Dissanaike, Sharmila; O’Keefe, Grant E.

    2009-01-01

    Background Genetic variation contributes to risk and outcomes of sepsis. We sought to determine if variation in inflammation related genes is associated with severity of sepsis in trauma patients. Methods A cohort of severely injured Caucasian patients was studied and genotyped for candidate single nucleotide polymorphisms (SNPs). These were toll-like receptor 4 (TLR4) A896G, tumor necrosis factor-α G-308A, interleukin-6 G-174C, interleukin-1β C-31T, and cluster of differentiation marker-14 C-159T. SNP genotypes among patients with sepsis and complicated sepsis were analyzed by chi-square and logistic regression. Six haplotype-tagging SNPs in the TLR4 gene were subsequently examined to determine their influence on TLR4 A896G SNP’s relationship to sepsis severity. Results We enrolled 598 patients. Complicated sepsis developed in 147 (25%). Adjusting for independent risk factors, carriage of the variant TLR4 896 G allele was associated with decreased risk of complicated sepsis (OR = 0.3, 95%CI = 0.1–0.7, p = 0.008). Furthermore, two haplotypes seemed to better characterize this risk than the variant TLR4 896 G allele. The variant TLR4 896G allele is linked to one common haplotype, which seems to confer a considerably reduced risk of complicated sepsis. (aOR = 0.2 95% CI = 0.05–0.7, p = 0.01) Conclusions Variation within TLR4 gene is associated with severity of post-traumatic sepsis. This risk may not be solely related to TLR4 A896G SNP. It is likely that other, uncharacterized variations in the TLR4 gene contribute to sepsis severity. A thorough evaluation of variability within the TLR4 gene is needed to characterize sepsis risk. PMID:19131814

  7. Characterization of a Novel Antisense RNA in the Major Pilin Locus of Neisseria meningitidis Influencing Antigenic Variation

    PubMed Central

    Tan, Felicia Y. Y.; Wörmann, Mirka E.; Tang, Christoph M.

    2015-01-01

    ABSTRACT Expression of type four pili (Tfp) is essential for virulence in Neisseria meningitidis. Pili mediate adhesion, bacterial aggregation, and DNA uptake. In N. meningitidis, the major pilin subunit is encoded by the pilE gene. In some strains, PilE is subject to phase and antigenic variation, which can alter Tfp properties and together offer a possible mechanism of immune escape. Pilin expression and antigenic variation can be modulated in response to environmental cues; however, the precise mechanisms of such regulation remain unclear. We identified a promoter in the pilE locus, 3′ of the pilE coding sequence, on the antisense (AS) strand which is conserved in meningococci. We show that this promoter directs transcription of an AS RNA that is expressed during specific growth phases and in response to salt stress. Furthermore, we demonstrate that the transcript encompasses sequences complementary to the entire pilE coding sequence and 5′ untranslated region. AS RNAs can regulate the gene on the sense strand by altering transcript stability or translation. However, by using Northern blotting, quantitative reverse transcription-PCR (RT-PCR), and Western blotting, we found no significant AS RNA-dependent changes in pilE transcript or protein level. Instead, our data indicate that the AS RNA influences pilin antigenic variation. This work provides further insights into the complex regulation of pilin expression and variation in pathogenic Neisseria. IMPORTANCE Pathogenic Neisseria spp. express type four pili (Tfp) which are important for adhesion, aggregation and transformation. Some strains of N. meningitidis are able to vary the sequence of the major subunit (PilE) of the Tfp. The mechanisms underlying this variation are not fully defined, but the process requires several noncoding elements that are found adjacent to the pilE gene. In this work, we identified a cis-encoded RNA antisense to pilE in N. meningitidis. By using Northern blotting and RT

  8. The influence of climatically-driven surface loading variations on continental strain and seismicity

    NASA Astrophysics Data System (ADS)

    Craig, Tim; Calais, Eric; Fleitout, Luce; Bollinger, Laurent; Scotti, Oona

    2016-04-01

    In slowly deforming regions of plate interiors, secondary sources of stress and strain can result in transient deformation rates comparable to, or greater than, the background tectonic rates. Highly variable in space and time, these transients have the potential to influence the spatio-temporal distribution of seismicity, interfering with any background tectonic effects to either promote or inhibit the failure of pre-existing faults, and potentially leading to a clustered, or 'pulse-like', seismic history. Here, we investigate the ways in which the large-scale deformation field resulting from climatically-controlled changes in surface ice mass over the Pleistocene and Holocene may have influenced not only the seismicity of glaciated regions, but also the wider seismicity around the ice periphery. We first use a set of geodynamic models to demonstrate that a major pulse of seismic activity occurring in Fennoscandia, coincident with the time of end-glaciation, occurred in a setting where the contemporaneous horizontal strain-rate resulting from the changing ice mass, was extensional - opposite to the reverse sense of coseismic displacement accommodated on these faults. Therefore, faulting did not release extensional elastic strain that was building up at the time of failure, but compressional elastic strain that had accumulated in the lithosphere on timescales longer than the glacial cycle, illustrating the potential for a non-tectonic trigger to tap in to the background tectonic stress-state. We then move on to investigate the more distal influence that changing ice (and ocean) volumes may have had on the evolving strain field across intraplate Europe, how this is reflected in the seismicity across intraplate Europe, and what impact this might have on the paleoseismic record.

  9. Influence of estrogen and variations at the BRCA1 promoter region on transcription and translation.

    PubMed

    Fernandes, Lívia R; Costa, Emmerson C B; Vargas, Fernando R; Moreira, Miguel A M

    2014-01-01

    We analyzed wild-type (WT) and four sequence variants of the BRCA1 promoter region-found in patients selected for hereditary breast and ovarian cancer syndrome-in respect to their influence on transcription and translation efficiencies in transient transfection assays in the presence or absence of estrogen. Five types of plasmids containing the EGFP reporter gene proceeded by WT 5'UTR-a, WT 5'UTR-b, and the three 5'UTR-b variants were constructed to evaluate their influence on translation. Plasmids containing the firefly luciferase reporter gene were constructed with the WT BRCA1 promoter region (containing promoter α, 5'UTR-a, promoter β, and 5'UTR-b) and with the four promoter variants for evaluating their influence on transcription and translation. All constructs were transfected in MCF7 cells maintained with and without estrogen. Expression of EGFP plasmids with WT 5'UTR-a was six to sevenfold higher than of plasmids with WT 5'UTR-b, expression of WT and the three variant 5'UTR-b plasmids showed slight differences in EGFP expression, and the presence or absence of estrogen result in non-significant changes in expression. Promoter's constructs that carry the variants WT or g.3988C showed a higher firefly luciferase activity when estrogen is present; conversely, no significant differences were found in the transcription efficiency of the reporter gene indicating that estrogen affect the translation rather than transcription. The presence or absence of estrogen did not affect the activity of firefly luciferase for constructs with the other promoter variants, being the transcription efficiencies equivalent in both conditions.

  10. The influences of fluorine and process variations on polysilicon film stress and MOSFET hot carrier effects

    NASA Technical Reports Server (NTRS)

    Lowry, Lynn E.; Macwilliams, Kenneth P.; Isaac, Mary

    1991-01-01

    The use of fluorinated gate oxides may provide an improvement in nMOSFET reliability by enhancing hot carrier resistance. In order to clarify the mechanisms by which polysilicon processing and fluorination influence the oxide behavior, a matrix of nMOSFET structures was prepared using various processing, doping, and implantation strategies. These structures were evaluated for crystalline morphology and chemical element distribution. Mechanical stress measurements were taken on the polysilicon films from room temperature to cryogenic temperature. These examinations showed that fluorination of a structure with randomly oriented polysilicon can reduce residual mechanical stress and improve hot carrier resistance at room temperature.

  11. Physical fitness of children and adolescents in the United States: status and secular change.

    PubMed

    Malina, Robert M

    2007-01-01

    The physical fitness of school-age children in the United States is considered from two perspectives--status and secular change. This chapter principally examines health-related fitness, including the BMI, though performance-related fitness is briefly considered. Concepts of reference data and standards and factors that may influence secular change are initially discussed. National data on the physical fitness status of school children in the continental United States are limited to the 1980s. Ethnic variation in physical fitness is not considered except for the prevalence of overweight and obesity. More recent physical fitness data, including examination of ethnic variation, are based on several statewide and more local surveys. Although results vary by test, the majority of American school children meet or exceed criterion-referenced standards, although sex differences are not consistent. Poor morphological fitness manifest in obesity is an exception. The prevalence of overweight and obesity has increased since the early 1980s. Secular data for specific fitness items are less extensive. Regression analyses suggest a recent decline in maximal aerobic power in girls, but fairly stable levels between the 1930s and today in boys. However, the highest values for boys occur in the 1960s and 1970s and more recent values are somewhat lower. The general trend may be consistent with the decline since the 1980s in aerobic performance assessed with the 20 m shuttle run. These trends highlight the need for updated national physical fitness data for American youth.

  12. fits2hdf: FITS to HDFITS conversion

    NASA Astrophysics Data System (ADS)

    Price, D. C.; Barsdell, B. R.; Greenhill, L. J.

    2015-05-01

    fits2hdf ports FITS files to Hierarchical Data Format (HDF5) files in the HDFITS format. HDFITS allows faster reading of data, higher compression ratios, and higher throughput. HDFITS formatted data can be presented transparently as an in-memory FITS equivalent by changing the import lines in Python-based FITS utilities. fits2hdf includes a utility to port MeasurementSets (MS) to HDF5 files.

  13. Influence of filtration velocity on DON variation in BAF for micropolluted surface water treatment.

    PubMed

    Ma, Teng-Fei; Chen, You-Peng; Kang, Jia; Gao, Xu; Guo, Jin-Song; Fang, Fang; Zhang, Xiao-Tian

    2016-12-01

    Biological aerated filters (BAFs) are widely used for the treatment of micropolluted surface water. However, the biological process produces dissolved organic nitrogen (DON), which, as precursors of nitrogenous disinfection by-products, pose potential threats to drinking water safety. Therefore, to control DON in BAF effluent, it is necessary to study the influence of BAF operation parameters on DON production. In this study, the influence of filtration velocity in a BAF on DON production was investigated. Under different filtration velocity (0.5, 2, and 4 m/h) conditions, profiles of DON concentrations along the media layer were measured. The profile at a filtration velocity of 0.5 m/h showed a decreasing trend, and the ones under filtration velocities of 2 and 4 m/h fluctuated in a small range (from 0.1 to 0.4 mg/L). Moreover, the relatively high filtration velocities of 2 and 4 m/h resulted in a lower level of DON concentration. Additionally, 3D excitation-emission matrix fluorescence spectroscopy was used to characterize DON. It is found that the patterns of DON at a relatively high filtration velocity condition (4 m/h) were obviously different from the ones under low filtration velocity conditions (0.5 and 2 m/h).

  14. Influences of recent climate change and human activities on water storage variations in Central Asia

    NASA Astrophysics Data System (ADS)

    Deng, Haijun; Chen, Yaning

    2017-01-01

    Terrestrial water storage (TWS) change is an indicator of climate change. Therefore, it is helpful to understand how climate change impacts water systems. In this study, the influence of climate change on TWS in Central Asia over the past decade was analyzed using the Gravity Recovery and Climate Experiment satellites and Climatic Research Unit datasets. Results indicate that TWS experienced a decreasing trend in Central Asia from 2003 to 2013 at a rate of -4.44 ± 2.2 mm/a, and that the maximum positive anomaly for TWS (46 mm) occurred in July 2005, while the minimum negative anomaly (-32.5 mm) occurred in March 2008-August 2009. The decreasing trend of TWS in northern Central Asia (-3.86 ± 0.63 mm/a) is mainly attributed to soil moisture storage depletion, which is driven primarily by the increase in evapotranspiration. In the mountainous regions, climate change exerted an influence on TWS by affecting glaciers and snow cover change. However, human activities are now the dominant factor driving the decline of TWS in the Aral Sea region and the northern Tarim River Basin.

  15. The influence of diurnal temperature variation on degree-day accumulation and insect life history.

    PubMed

    Chen, Shi; Fleischer, Shelby J; Saunders, Michael C; Thomas, Matthew B

    2015-01-01

    Ectotherms, such as insects, experience non-constant temperatures in nature. Daily mean temperatures can be derived from the daily maximum and minimum temperatures. However, the converse is not true and environments with the same mean temperature can exhibit very different diurnal temperate ranges. Here we apply a degree-day model for development of the grape berry moth (Paralobesia viteana, a significant vineyard pest in the northeastern USA) to investigate how different diurnal temperature range conditions can influence degree-day accumulation and, hence, insect life history. We first consider changes in diurnal temperature range independent of changes in mean temperatures. We then investigate grape berry moth life history under potential climate change conditions, increasing mean temperature via variable patterns of change to diurnal temperature range. We predict that diurnal temperature range change can substantially alter insect life history. Altering diurnal temperature range independent of the mean temperature can affect development rate and voltinism, with the magnitude of the effects dependent on whether changes occur to the daily minimum temperature (Tmin), daily maximum temperature (Tmax), or both. Allowing for an increase in mean temperature produces more marked effects on life history but, again, the patterns and magnitude depend on the nature of the change to diurnal temperature range together with the starting conditions in the local environment. The study highlights the importance of characterizing the influence of diurnal temperature range in addition to mean temperature alone.

  16. [Variation characteristics and influencing factors of air pollution index in China].

    PubMed

    Li, Xiao-Fei; Zhang, Ming-Jun; Wang, Sheng-Jie; Zhao, Ai-Fang; Ma, Qian

    2012-06-01

    Based on the daily air pollution index (API), primary pollutant, air quality level and status of 42 cities in China during 2001-2010, the characteristics of air quality were analyzed. The results showed that the atmosphere was significantly influenced by consumption of coal. The primary pollutant was PM10, and the air quality status was excellent (0 < API < 50), good (50 < API <100) and slightly polluted (100 < API < 150) in the majority. The air pollution status varied seasonally, which was the most serious in winter, and slightest in summer. The air quality was better and better in the observed period generally; The spatial distribution of urban air environment displayed a worsening trend from the south to the north and from the coasts to the inland; The local emission and natural dust transmission from the Northwest China was the main sources of urban air pollution; The air pollutants were impacted by the meteorological elements, and the air pollution index correlated linearly with precipitation, wind speed and temperature inversion; The distribution of weather conditions, which was affected by the terrain, also could influence the air quality; In addition, the human activities had both positive and negative functions on the urban air quality.

  17. Influence of Different Patellofemoral Design Variations Based on Genesis II Total Knee Endoprosthesis on Patellofemoral Pressure and Kinematics

    PubMed Central

    Lange, Barbara; Herzog, Yvonne; Schnauffer, Peter; Leichtle, Carmen I.; Wülker, Nikolaus

    2017-01-01

    In total knee arthroplasty (TKA), patellofemoral groove design varies greatly and likely has a distinct influence on patellofemoral biomechanics. To analyse the selective influence, five patellofemoral design variations were developed based on Genesis II total knee endoprosthesis (original design, being completely flat, being laterally elevated, being medially elevated, and both sides elevated) and made from polyamide using rapid prototyping. Muscle-loaded knee flexion was simulated on 10 human knee specimens using a custom-made knee simulator, measuring the patellofemoral pressure distribution and tibiofemoral and patellofemoral kinematics. The measurements were carried out in the native knee as well as after TKA with the 5 design prototypes. The overall influence of the different designs on the patellofemoral kinematics was small, but we found detectable effects for mediolateral tilt (p < 0.05 for 35°–80° flexion) and translation of the patella (p < 0.045 for 20°–65° and 75°–90°), especially for the completely flat design. Considering patellofemoral pressures, major interindividual differences were seen between the designs, which, on average, largely cancelled each other out. These results suggest that the elevation of the lateral margin of the patellofemoral groove is essential for providing mediolateral guidance, but smooth contouring as with original Genesis II design seems to be sufficient. The pronounced interindividual differences identify a need for more patellofemoral design options in TKA. PMID:28255225

  18. Influence of Different Patellofemoral Design Variations Based on Genesis II Total Knee Endoprosthesis on Patellofemoral Pressure and Kinematics.

    PubMed

    Leichtle, Ulf G; Lange, Barbara; Herzog, Yvonne; Schnauffer, Peter; Leichtle, Carmen I; Wülker, Nikolaus; Lorenz, Andrea

    2017-01-01

    In total knee arthroplasty (TKA), patellofemoral groove design varies greatly and likely has a distinct influence on patellofemoral biomechanics. To analyse the selective influence, five patellofemoral design variations were developed based on Genesis II total knee endoprosthesis (original design, being completely flat, being laterally elevated, being medially elevated, and both sides elevated) and made from polyamide using rapid prototyping. Muscle-loaded knee flexion was simulated on 10 human knee specimens using a custom-made knee simulator, measuring the patellofemoral pressure distribution and tibiofemoral and patellofemoral kinematics. The measurements were carried out in the native knee as well as after TKA with the 5 design prototypes. The overall influence of the different designs on the patellofemoral kinematics was small, but we found detectable effects for mediolateral tilt (p < 0.05 for 35°-80° flexion) and translation of the patella (p < 0.045 for 20°-65° and 75°-90°), especially for the completely flat design. Considering patellofemoral pressures, major interindividual differences were seen between the designs, which, on average, largely cancelled each other out. These results suggest that the elevation of the lateral margin of the patellofemoral groove is essential for providing mediolateral guidance, but smooth contouring as with original Genesis II design seems to be sufficient. The pronounced interindividual differences identify a need for more patellofemoral design options in TKA.

  19. Sources of Variation Influencing Concordance between Functional MRI and Direct Cortical Stimulation in Brain Tumor Surgery

    PubMed Central

    Morrison, Melanie A.; Tam, Fred; Garavaglia, Marco M.; Hare, Gregory M. T.; Cusimano, Michael D.; Schweizer, Tom A.; Das, Sunit; Graham, Simon J.

    2016-01-01

    Object: Preoperative functional magnetic resonance imaging (fMRI) remains a promising method to aid in the surgical management of patients diagnosed with brain tumors. For patients that are candidates for awake craniotomies, surgical decisions can potentially be improved by fMRI but this depends on the level of concordance between preoperative brain maps and the maps provided by the gold standard intraoperative method, direct cortical stimulation (DCS). There have been numerous studies of the concordance between fMRI and DCS using sensitivity and specificity measures, however the results are variable across studies and the key factors influencing variability are not well understood. Thus, the present work addresses the influence of technical factors on fMRI and DCS concordance. Methods: Motor and language mapping data were collected for a group of glioma patients (n = 14) who underwent both preoperative fMRI and intraoperative DCS in an awake craniotomy procedure for tumor removal. Normative fMRI data were also acquired in a healthy control group (n = 12). The fMRI and DCS mapping data were co-registered; true positive (TP), true negative (TN), false positive (FP), and false negative (FN) occurrences were tabulated over the exposed brain surface. Sensitivity and specificity were measured for the total group, and for the motor and language sub-groups. The influence of grid placement, fMRI statistical thresholding, and task standardization were assessed. Correlations between proportions of agreement and error were also carefully scrutinized to evaluate concordance in more detail. Results: Concordance was significantly better for motor vs. language mapping. There was an inverse relationship between TP and TN with increasing statistical threshold, and FP dominated the total error. Sensitivity and specificity were reduced when tasks were not standardized across fMRI and DCS. Conclusions: Although the agreement between fMRI and DCS is good, variability is introduced by

  20. No influence of chromosome Y haplogroup variation in acute graft-versus-host disease in sardinia.

    PubMed

    Orofino, Maria Grazia; Contu, Daniela; Argiolu, Francesca; Sanna, Maria Adele; Gaziev, Javid; La Nasa, Giorgio; Vacca, Adriana; Cao, Antonio; Cucca, Francesco

    2006-12-15

    The donor-recipient sex-related mismatch has been reported as a risk factor for acute graft-versus-host disease (GVHD). However, the results obtained in previous studies appear to be contradictory. Here we evaluate the impact of donor-recipient sex-related mismatch in a series of 204 Sardinian individuals (92.1% of them affected by Beta- Thalassemia major) who underwent bone marrow transplantation (BMT) from human leukocyte antigen (HLA) identical siblings. In all, 78 of these patients had acute GVHD (aGVHD). We found that also in this homogenous group of patients from a homogenous population, the donor-female/recipient-male pair provided an increased risk for aGVHD when compared with a reference donor-male/recipient-male pair (POR=2.3, P=0.042). This data could be consistent with a role of variation in the male-specific portion of the Y chromosome in aGVHD. To assess this, we compared the distribution of the main Y-chromosome haplogroups in 28 male patients, who had aGVHD and underwent BMT from HLA-identical sisters, and 366 ethnically-matched controls. No significant differences were observed. These findings do not support the presence of Y chromosome founder variants contributing significantly to aGVHD in the Sardinian population.

  1. Genetic variation at the TPH2 gene influences impulsivity in addition to eating disorders.

    PubMed

    Slof-Op't Landt, Margarita C T; Bartels, Meike; Middeldorp, Christel M; van Beijsterveldt, Catherina E M; Slagboom, P Eline; Boomsma, Dorret I; van Furth, Eric F; Meulenbelt, Ingrid

    2013-01-01

    Genes are involved in eating disorders (EDs) and self-induced vomiting (SV), a key symptom of different types of EDs. Perfectionism and impulsivity are potential risk factors for EDs. TPH2 (tryptophan hydroxylase 2) SNP rs1473473 was previously associated with anorexia nervosa and EDs characterized by SV. Could perfectionism or impulsivity be underlying the association between rs1473473 and EDs? Genetic association between TPH2 SNP rs1473473 and perfectionism or impulsivity was first evaluated in a random control group (N = 512). The associations obtained in this control group were subsequently tested in a group of patients with an ED (N = 267). The minor allele of rs1473473 (OR = 1.49) was more frequent in impulsive controls, but also in impulsive patients with an ED (OR = 1.83). The largest effect was found in the patients with an ED characterized by SV (OR = 2.51, p = 0.02). Genetic variation at the TPH2 gene appeared to affect impulsivity which, in turn, might predispose to the SV phenotype.

  2. Influence of soil consolidation and thermal expansion effects on height and gravity variations

    NASA Astrophysics Data System (ADS)

    Romagnoli, C.; Zerbini, S.; Lago, L.; Richter, B.; Simon, D.; Domenichini, F.; Elmi, C.; Ghirotti, M.

    2003-07-01

    The daily GPS height series of the Medicina station were analyzed for the period July 1996-September 2001. The station is located in the middle Po Plain on fine-grained alluvial deposits. A seasonal oscillation in the order of 18 mm (peak-to-peak amplitude) is present in the data. This crustal deformation has been modeled by including variations in the atmospheric, oceanic and hydrologic mass. The vertical positions can also be affected significantly by soil consolidation. Geotechnical parameters derived by in situ tests and laboratory analyses of the clayey soil collected at Medicina allowed the estimate of the soil settlement relevant to the seasonal oscillation of the surficial water table. Thermal expansion of the geodetic monument has to be taken into account in the case of high-precision vertical positioning. In this work models both for the soil consolidation and the thermal expansion effects are provided. The continuous gravity observations collected at Medicina by means of a superconducting gravimeter also exhibit a marked seasonal oscillation, which has been interpreted as the sum of loading and Newtonian attraction effects, as well as of the contribution due to soil consolidation. Especially the study concerning the soil consolidation effect has allowed a better insight on the seasonal vertical movements occurring at the Medicina station by providing quantitative information on soil behavior due to change of effective pressures. The results can be applied to those stations characterized by similar fine-grained soils and surficial hydrogeology.

  3. Influence of complex childhood diseases on variation in growth and skeletal development.

    PubMed

    Zemel, Babette S

    2017-03-01

    The study of human growth and skeletal development by human biologists is framed by the larger theoretical concerns regarding the underpinnings of population variation and human evolution. This unique perspective is directly relevant to the assessment of child health and well-being at the individual and group level, as well as the construction of growth charts. Environmental, behavioral (nutrition and physical activity), and disease-related factors can prevent attainment of full genetic potential for growth. Undernutrition is most often the cause of growth faltering and poor skeletal development. Disease related factors, such as malabsorption, inflammation, and immobility also have profound effects. These effects will be illustrated with examples from diseases such as cystic fibrosis, inflammatory bowel disease, and Down syndrome. The need for separate growth charts for children with genetic disorders is often controversial because of potential medical and/or nutritional complications associated with some disorders. Children with Alagille syndrome and Down syndrome will be used to illustrate the advantages and limitations of syndrome-specific charts. This overview of health and disease effects on growth and skeletal development provides insights into the plasticity of human growth and its sensitivity to overall health and well-being.

  4. Influence of isentropic transport on seasonal ozone variations in the lower stratosphere and subtropical upper troposphere

    NASA Technical Reports Server (NTRS)

    Jing, P.; Cunnold, D. M.; Yang, E.-S.; Wang, H.-J.

    2005-01-01

    The isentropic cross-tropopause ozone transport has been estimated in both hemispheres in 1999 based on the potential vorticity mapping of Stratospheric Aerosol and Gas Experiment 11 ozone measurements and contour advection calculations using the NASA Goddard Space Flight Center Global and Modeling Assimilation Office analysis. The estimated net isentropic stratosphere-to-troposphere ozone flux is approx.118 +/- 61 x 10(exp9)kg/yr globally within the layer between 330 and 370 K in 1999; 60% of it is found in the Northern Hemisphere, and 40% is found in the Southern Hemisphere. The monthly average ozone fluxes are strongest in summer and weakest in winter in both hemispheres. The seasonal variations of ozone in the lower stratosphere (LS) and upper troposphere (UT) have been analyzed using ozonesonde observations from ozonesonde stations in the extratropics and subtropics, respectively. It is shown that observed ozone levels increase in the UT over subtropical ozonesonde stations and decrease in the LS over extratropical stations in late spring/early summer and that the ozone increases in the summertime subtropical UT are unlikely to be explained by photochemical ozone production and diabatic transport alone. We conclude that isentropic transport is a significant contributor to ozone levels in the subtropical upper troposphere, especially in summer.

  5. Regional Variations of Public Perception on Contaminated Industrial Sites in China and Its Influencing Factors

    PubMed Central

    Li, Xiaonuo; Jiao, Wentao; Xiao, Rongbo; Chen, Weiping; Bai, Yanying

    2016-01-01

    Public involvement is critical in sustainable contaminated site management. It is important for China to improve public knowledge and participation, foster dialogue between urban managers and laypeople, and accelerate the remediation and redevelopment processes in contaminated site management. In this study, we collected 1812 questionnaires from nine cities around China through face-to-face interviews and statistically analyzed the perception of residents concerning contaminated sites. The results show that respondents’ concern about soil pollution was lower than for other environmental issues and their knowledge of soil contamination was limited. The risks posed by contaminated industrial sites were well recognized by respondents, but they were unsatisfied with the performance of local agencies regarding information disclosure, publicity and education and public participation. Respondents believed that local governments and polluters should take the primary responsibility for contaminated site remediation. Most of them were unwilling to pay for contaminated site remediation and preferred recreational or public service redevelopment. Moreover, our research indicated that public perception varied among different cities. This variation was mainly determined by implementations of policy instruments and additionally affected by remediation technology, pollutant type, regional policy response and living distance. PMID:27070632

  6. Regional Variations of Public Perception on Contaminated Industrial Sites in China and Its Influencing Factors.

    PubMed

    Li, Xiaonuo; Jiao, Wentao; Xiao, Rongbo; Chen, Weiping; Bai, Yanying

    2016-04-08

    Public involvement is critical in sustainable contaminated site management. It is important for China to improve public knowledge and participation, foster dialogue between urban managers and laypeople, and accelerate the remediation and redevelopment processes in contaminated site management. In this study, we collected 1812 questionnaires from nine cities around China through face-to-face interviews and statistically analyzed the perception of residents concerning contaminated sites. The results show that respondents' concern about soil pollution was lower than for other environmental issues and their knowledge of soil contamination was limited. The risks posed by contaminated industrial sites were well recognized by respondents, but they were unsatisfied with the performance of local agencies regarding information disclosure, publicity and education and public participation. Respondents believed that local governments and polluters should take the primary responsibility for contaminated site remediation. Most of them were unwilling to pay for contaminated site remediation and preferred recreational or public service redevelopment. Moreover, our research indicated that public perception varied among different cities. This variation was mainly determined by implementations of policy instruments and additionally affected by remediation technology, pollutant type, regional policy response and living distance.

  7. Influence of Chemical Composition Variations on Densification During the Sintering of MOX Materials

    NASA Astrophysics Data System (ADS)

    Vaudez, S.; Marlot, C.; Lechelle, J.

    2016-06-01

    The mixed uranium-plutonium oxide (MOX) fabrication process is based on the preparation of UO2 and PuO2 powders. The mixture is pelletized before being sintered at 1973 K (1700 °C) in a reducing atmosphere of Ar/4pctH2/H2O. This paper shows how the densification of MOX fuel is affected during sintering by the moisture content of the gas, the plutonium content of the fuel, and the carbon impurity content in the raw materials. MOX densification can be monitored through dilatometric measurements and gas releases can be continuously analyzed during sintering in terms of their quantity and quality. Variations in the oxygen content in the fuel can be continuously recorded by coupling the dilatometer furnace with an oxygen measurement at the gas outlet. Any carbon-bearing species released, such as CO, can be also linked to densification phenomena when a gas chromatograph is installed at the outlet of the dilatometer. Recommendations on the choice of sintering atmosphere that best optimizes the fuel characteristics have been given on the basis of the results reported in this paper.

  8. Common variation near CDKN1A, POLD3 and SHROOM2 influences colorectal cancer risk.

    PubMed

    Dunlop, Malcolm G; Dobbins, Sara E; Farrington, Susan Mary; Jones, Angela M; Palles, Claire; Whiffin, Nicola; Tenesa, Albert; Spain, Sarah; Broderick, Peter; Ooi, Li-Yin; Domingo, Enric; Smillie, Claire; Henrion, Marc; Frampton, Matthew; Martin, Lynn; Grimes, Graeme; Gorman, Maggie; Semple, Colin; Ma, Yusanne P; Barclay, Ella; Prendergast, James; Cazier, Jean-Baptiste; Olver, Bianca; Penegar, Steven; Lubbe, Steven; Chander, Ian; Carvajal-Carmona, Luis G; Ballereau, Stephane; Lloyd, Amy; Vijayakrishnan, Jayaram; Zgaga, Lina; Rudan, Igor; Theodoratou, Evropi; Starr, John M; Deary, Ian; Kirac, Iva; Kovacević, Dujo; Aaltonen, Lauri A; Renkonen-Sinisalo, Laura; Mecklin, Jukka-Pekka; Matsuda, Koichi; Nakamura, Yusuke; Okada, Yukinori; Gallinger, Steven; Duggan, David J; Conti, David; Newcomb, Polly; Hopper, John; Jenkins, Mark A; Schumacher, Fredrick; Casey, Graham; Easton, Douglas; Shah, Mitul; Pharoah, Paul; Lindblom, Annika; Liu, Tao; Smith, Christopher G; West, Hannah; Cheadle, Jeremy P; Midgley, Rachel; Kerr, David J; Campbell, Harry; Tomlinson, Ian P; Houlston, Richard S

    2012-05-27

    We performed a meta-analysis of five genome-wide association studies to identify common variants influencing colorectal cancer (CRC) risk comprising 8,682 cases and 9,649 controls. Replication analysis was performed in case-control sets totaling 21,096 cases and 19,555 controls. We identified three new CRC risk loci at 6p21 (rs1321311, near CDKN1A; P = 1.14 × 10(-10)), 11q13.4 (rs3824999, intronic to POLD3; P = 3.65 × 10(-10)) and Xp22.2 (rs5934683, near SHROOM2; P = 7.30 × 10(-10)) This brings the number of independent loci associated with CRC risk to 20 and provides further insight into the genetic architecture of inherited susceptibility to CRC.

  9. Common variation near CDKN1A, POLD3 and SHROOM2 influences colorectal cancer risk

    PubMed Central

    Dunlop, Malcolm G; Dobbins, Sara E; Farrington, Susan Mary; Jones, Angela M; Palles, Claire; Whiffin, Nicola; Tenesa, Albert; Spain, Sarah; Broderick, Peter; Ooi, Li-Yin; Domingo, Enric; Smillie, Claire; Henrion, Marc; Frampton, Matthew; Martin, Lynn; Grimes, Graeme; Gorman, Maggie; Semple, Colin; Ma, Yussanne; Barclay, Ella; Prendergast, James; Cazier, Jean-Baptiste; Olver, Bianca; Carvajal-Carmona, Luis G; Ballereau, Stephane; Lloyd, Amy; Vijayakrishnan, Jayaram; Zgaga, Lina; Rudan, Igor; Theodoratou, Evropi; Starr, John M; Deary, Ian; Kirac, Iva; Kovačević, Dujo; Aaltonen, Lauri A; Renkonen-Sinisalo, Laura; Mecklin, Jukka-Pekka; Matsuda, Koichi; Nakamura, Yusuke; Okada, Yukinori; Gallinger, Steven; Duggan, David J; Conti, David; Newcomb, Polly; Hopper, John; Jenkins, Mark A.; Schumacher, Fredrick; Casey, Graham; Easton, Douglas; Shah, Mitul; Pharoah, Paul; Lindblom, Annika; Liu, Tao; Smith, Christopher G; West, Hannah; Cheadle, Jeremy P.; Midgley, Rachel; Kerr, David J; Campbell, Harry; Tomlinson, Ian P; Houlston, Richard S

    2015-01-01

    We performed a meta-analysis of five genome-wide association studies to identify common variants influencing colorectal cancer (CRC) risk comprising 8,682 cases and 9,649 controls. Replication analysis was performed in case-control sets totalling 21,096 cases and 19,555 controls. We identified three novel CRC risk loci at 6p21 (rs1321311, near CDKN1A; P=1.14×10−10), 11q13.4 (rs3824999, intronic to POLD3; P=3.65×10−10) and Xp22.2 (rs5934683, near SHROOM2; P=7.30×10−10) This brings to 20 the number of independent loci associated with CRC risk, and provides further insight into the genetic architecture of inherited susceptibility to CRC. PMID:22634755

  10. Monsoonal influence on variation of hydrochemistry and isotopic signatures: Implications for associated arsenic release in groundwater

    NASA Astrophysics Data System (ADS)

    Majumder, Santanu; Datta, Saugata; Nath, Bibhash; Neidhardt, Harald; Sarkar, Simita; Roman-Ross, Gabriela; Berner, Zsolt; Hidalgo, Manuela; Chatterjee, Debankur; Chatterjee, Debashis

    2016-04-01

    The present study examines the groundwater and surface water geochemistry of two different geomorphic domains within the Chakdaha block, West Bengal, in an attempt to decipher potential influences of groundwater abstraction on the hydrochemical evolution of the aquifer, the effect of different water inputs (monsoon rain, irrigation and downward percolation from surface water impoundments) to the groundwater system and concomitant As release. A low-land flood plain and a natural levee have been selected for this purpose. Although the stable isotopic signatures of oxygen (δ18O) and hydrogen (δ2H) are largely controlled by local precipitation, the isotopic composition falls sub-parallel to the Global Meteoric Water Line (GMWL). The Cl/Br molar ratio indicates vertical recharge into the wells within the flood plain area, especially during the post-monsoon season, while influences of both evaporation and vertical mixing are visible within the natural levee wells. Increase in mean DOC concentrations (from 1.33 to 6.29 mg/L), from pre- to post-monsoon season, indicates possible inflow of organic carbon to the aquifer during the monsoonal recharge. Concomitant increase in AsT, Fe(II) and HCO3- highlights a possible initial episode of reductive dissolution of As-rich Fe-oxyhydroxides. The subsequent sharp increase in the mean As(III) proportions (by 223%), particularly in the flood plain samples during the post-monsoon season, which is accompanied by a slight increase in mean AsT (7%) may refer to anaerobic microbial degradation of DOC coupled with the reduction of As(V) to As(III) without triggering additional As release from the aquifer sediments.

  11. Hamiltonian inclusive fitness: a fitter fitness concept

    PubMed Central

    Costa, James T.

    2013-01-01

    In 1963–1964 W. D. Hamilton introduced the concept of inclusive fitness, the only significant elaboration of Darwinian fitness since the nineteenth century. I discuss the origin of the modern fitness concept, providing context for Hamilton's discovery of inclusive fitness in relation to the puzzle of altruism. While fitness conceptually originates with Darwin, the term itself stems from Spencer and crystallized quantitatively in the early twentieth century. Hamiltonian inclusive fitness, with Price's reformulation, provided the solution to Darwin's ‘special difficulty’—the evolution of caste polymorphism and sterility in social insects. Hamilton further explored the roles of inclusive fitness and reciprocation to tackle Darwin's other difficulty, the evolution of human altruism. The heuristically powerful inclusive fitness concept ramified over the past 50 years: the number and diversity of ‘offspring ideas’ that it has engendered render it a fitter fitness concept, one that Darwin would have appreciated. PMID:24132089

  12. Factors influencing variation of bulk milk antibiotic residue occurrence, somatic cell count, and total bacterial count in dairy sheep flocks.

    PubMed

    Gonzalo, C; Carriedo, J A; García-Jimeno, M C; Pérez-Bilbao, M; de la Fuente, L F

    2010-04-01

    To study the variations of bulk tank milk variables in dairy ewe flocks and to identify the main target practices and flock groups to improve milk quality and safety, a total of 71,228 records of antibiotic residue (AR) and milk yield and 68,781 records of somatic cell count (SCC) and total bacterial count (TBC) were obtained over 5 yr from the same 209 dairy ewe flocks of the Assaf breed belonging to the Consortium for Ovine Promotion of Castilla-León (Spain). Based on a logistic regression model, year, month, semester, SCC, TBC, dry therapy, and milk yield significantly contributed to AR variation. High SCC was associated with increased AR violations. When antibiotic dry therapy was implemented, AR occurrence was higher than when this practice was not used. A polynomial monthly distribution throughout the year was observed for AR occurrence; the highest values were in autumn, coinciding with low milk yields per flock. Yearly occurrences drastically diminished from 2004 (1.36%) to 2008 (0.30%), probably as a result of effective educational programs. The mixed-model ANOVA of factors influencing variation in SCC and TBC indicated that year, month, AR, dry therapy group, milking type, and year interactions were significant variation factors for SCC and TBC; mathematical model accounted for 74.1 and 35.4% of total variance for each variable, respectively. Differences in management and hygiene practice caused significant SCC and TBC variations among flocks and within flocks throughout the 5-yr study. Over time, continuously dry treated flocks showed lower logSCC (5.80) and logTBC (4.92) than untreated (6.10 and 5.18, respectively) or discontinuously dry treated (6.01 and 5.05, respectively) flocks. Continuously dry treated flocks had lower AR occurrences than did discontinuously dry treated flocks. As a whole, AR occurrence and SCC and TBC bulk tank milk variables can be used for monitoring mammary health and milk hygiene and safety in dairy sheep throughout time.

  13. Factors influencing temporal variation of scrapie incidence within a closed Suffolk sheep flock.

    PubMed

    González, Lorenzo; Dagleish, Mark P; Martin, Stuart; Finlayson, Jeanie; Sisó, Sílvia; Eaton, Samantha L; Goldmann, Wilfred; Witz, Janey; Hamilton, Scott; Stewart, Paula; Pang, Yvonne; Steele, Philip; Reid, Hugh W; Chianini, Francesca; Jeffrey, Martin

    2012-01-01

    Several studies have shown that transmission of natural scrapie can occur vertically and horizontally, and that variations in scrapie incidence between and within infected flocks are mostly due to differences in the proportion of sheep with susceptible and resistant PRNP genotypes. This report presents the results of a 12-year period of scrapie monitoring in a closed flock of Suffolk sheep, in which only animals of the ARQ/ARQ genotype developed disease. Among a total of 120 of these, scrapie attack rates varied between birth cohorts from 62.5 % (5/8) to 100 % (9/9), and the incidence of clinical disease among infected sheep from 88.9 % (8/9) to 100 % (in five birth cohorts). Susceptible sheep born to scrapie-infected ewes showed a slightly higher risk of becoming infected (97.2 %), produced earlier biopsy-positive results (mean 354 days) and developed disease at a younger age (median 736 days) than those born to non-infected dams (80.3 %, 451 and 782 days, respectively). Taken together, this was interpreted as evidence of maternal transmission. However, it was also observed that, for the birth cohorts with the highest incidence of scrapie (90-100 %), sheep born to infected and non-infected dams had a similar risk of developing scrapie (97.1 and 95.3 %, respectively). Compared with moderate-attack-rate cohorts (62.5-66.7 %), high-incidence cohorts had greater numbers of susceptible lambs born to infected ewes, suggesting that increased rates of horizontal transmission in these cohorts could have been due to high levels of environmental contamination caused by infected placentas.

  14. Identification of inherited genetic variations influencing prognosis in early-onset breast cancer.

    PubMed

    Rafiq, Sajjad; Tapper, William; Collins, Andrew; Khan, Sofia; Politopoulos, Ioannis; Gerty, Sue; Blomqvist, Carl; Couch, Fergus J; Nevanlinna, Heli; Liu, Jianjun; Eccles, Diana

    2013-03-15

    Genome-Wide Association Studies (GWAS) have begun to investigate associations between inherited genetic variations and breast cancer prognosis. Here, we report our findings from a GWAS conducted in 536 patients with early-onset breast cancer aged 40 or less at diagnosis and with a mean follow-up period of 4.1 years (SD = 1.96). Patients were selected from the Prospective Study of Outcomes in Sporadic versus Hereditary breast cancer. A Bonferroni correction for multiple testing determined that a P value of 1.0 × 10(-7) was a statistically significant association signal. Following quality control, we identified 487,496 single nucleotide polymorphisms (SNP) for association tests in stage 1. In stage 2, 35 SNPs with the most significant associations were genotyped in 1,516 independent cases from the same early-onset cohort. In stage 2, 11 SNPs remained associated in the same direction (P ≤ 0.05). Fixed effects meta-analysis models identified one SNP associated at close to genome wide level of significance 556 kb upstream of the ARRDC3 locus [HR = 1.61; 95% confidence interval (CI), 1.33-1.96; P = 9.5 × 10(-7)]. Four further associations at or close to the PBX1, RORα, NTN1, and SYT6 loci also came close to genome-wide significance levels (P = 10(-6)). In the first ever GWAS for the identification of SNPs associated with prognosis in patients with early-onset breast cancer, we report a SNP upstream of the ARRDC3 locus as potentially associated with prognosis (median follow-up time for genotypes: CC = 4 years, CT = 3 years, and TT = 2.7 years; Wilcoxon rank-sum test CC vs. CT, P = 4 × 10(-4) and CT vs. TT, P = 0.76). Four further loci may also be associated with prognosis.

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

    NASA Astrophysics Data System (ADS)

    Patil, Jagadish S.; Anil, Arga Chandrashekar

    2008-10-01

    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 an extinction dilution method (most probable number method), which allows estimation of resting stages through examination of germinated vegetative cells in culture. The DBP community was dominated by planktonic species belonging to the genera Skeletonema, Fragilariopsis, Thalassiosira, and Chaetoceros. Benthic propagules (BPs) of Skeletonema costatum and Fragilariopsis sp. were dominant throughout the year. Between these two species, only S. costatum showed a linear relationship between the BP and planktonic cells, indicating that this species is particularly important in coupling of pelagic and benthic ecosystems. During the onset and restart of monsoon after an intermittent break, water column was stratified, with a low-salinity layer arising from riverine discharge and precipitation at the surface and relatively cold, saline, low-oxygen waters at the bottom. Stratification favored blooming of S. costatum and Fragilariopsis sp. in nutrient-rich surface and bottom waters, respectively. The decline in these blooms ensuing nitrate depletion and salinity change resulted in an increased abundance of BP. Chaetoceros bloom was observed during the monsoon break as well as during non-monsoon period and on both the occasions the decline in bloom was coupled with freshwater discharge. During the non-monsoon season, Thalassiosira blooms were encountered subsequent to high nitrate inputs. These findings suggest that in such shallow tropical regions, physical processes during monsoon (freshwater discharge) and non-monsoon seasons (currents, waves and tides) cause resuspension of diatom BP. Since light is not a limiting factor for germination in such regions, the blooming of resuspended BP depends on nutrient availability.

  16. Tryptophan hydroxylase-2 gene variation influences personality traits and disorders related to emotional dysregulation.

    PubMed

    Gutknecht, Lise; Jacob, Christian; Strobel, Alexander; Kriegebaum, Claudia; Müller, Johannes; Zeng, Yong; Markert, Christoph; Escher, Andrea; Wendland, Jens; Reif, Andreas; Mössner, Rainald; Gross, Cornelius; Brocke, Burkhard; Lesch, Klaus-Peter

    2007-06-01

    Variation in the tryptophan hydroxylase-2 gene (TPH2) coding for the rate-limiting enzyme of serotonin (5-HT) synthesis in the brain modulates responses of limbic circuits to emotional stimuli and has been linked to a spectrum of clinical populations characterized by emotional dysregulation. Here, we tested a set of common single nucleotide polymorphisms (SNPs) in and downstream of the transcriptional control region of TPH2 for association with personality traits and with risk for personality disorders in two cohorts comprising of 336 healthy individuals and 420 patients with personality disorders. Personality dimensions were assessed by the Tridimensional Personality Questionnaire (TPQ) and the revised NEO Personality Inventory (NEO-PI-R). Personality disorders were diagnosed with the Structured Clinical Interview of DSM-IV and were allocated to clusters A, B, and C. Individual SNP and haplotype analyses revealed significant differences in genotype frequencies between controls and cluster B as well as cluster C patients, respectively. In both patient groups, we observed overrepresentation of T allele carriers of a functional polymorphism in the upstream regulatory region of TPH2 (SNP G-703T, rs4570625) which was previously shown to bias responsiveness of the amygdala, a structure critically involved in emotionality. Furthermore, significant effects of TPH2 variants on anxiety-related traits defined primarily by the TPQ Harm Avoidance were found in healthy individuals. The results link potentially functional TPH2 variants to personality traits related to emotional instability as well as to cluster B and cluster C personality disorders. These findings implicate alterations of 5-HT synthesis in emotion regulation and confirm TPH2 as a susceptibility and/or modifier gene of affective spectrum disorders.

  17. Influence of the mechanical coupling and inherited strength variations on the geometry of continental rifts.

    NASA Astrophysics Data System (ADS)

    Philippon, Melody; van Delft, Pim; van Winden, Matthijs; Zamuroviç, Dejan; Sokoutis, Dimitrios; Willingshofer, Ernst; Cloetingh, Sierd

    2013-04-01

    The geometry of continental rifts is strongly controlled by the rheology of the lithosphere at the onset of rifting. This initial geometry will further control the development of ocean spreading centers and the structure of adjacent passive margins. Therefore, understanding the influence of coupling between the different layers of the lithosphere with and without laterally variable strength in the crust is key when investigating continental rifts. In this study we infer the influence of coupling in the crust on the rift geometry by means of crustal scale analogue experiments, where we characterize the response of the crust to deformation in terms of the strength ratio between brittle and ductile crust. The degree of coupling has been varied for setups containing or not a pre-existing weak zone. To allow a better description of the geometry obtained in our models, some key observations such as: a) the degree of tilting of the blocks, b) the total width of the graben, c) the displacement along the main fault and d) the distribution of thinning in the lower crust are monitored. Models containing a weak zone are compared to natural examples of the inherited Mozambique Ocean suture zones (MOSZ) in the Red Sea rift. The modelling results suggest that deformation is not a-priori localized within pre-existing weak zones unless the coupling between the brittle and the ductile crust is high. With respect to the MOSZ, we infer that: (1) Jurassic NW-SE trending grabens developed parallel to but not within the MOSZ and hence reflect a low degree of coupling whereas (2) Eocene rifting in the Red Sea occurred under coupled conditions as deformation strongly focused within the MOSZ. Models without weak zone shows that large-scale detachment faults can also form within a highly coupled crust, which is at variance to the common perception that detachment faulting demands strong decoupling. Our findings shed light on natural rift systems, which show a wide range of geometries that

  18. Jet mixing into a heated cross flow in a cylindrical duct: Influence of geometry and flow variations

    NASA Technical Reports Server (NTRS)

    Hatch, M. S.; Sowa, W. A.; Samuelsen, G. S.; Holdeman, J. D.

    1992-01-01

    To examine the mixing characteristics of jets in an axi-symmetric can geometry, temperature measurements were obtained downstream of a row of cold jets injected into a heated cross stream. Parametric, non-reacting experiments were conducted to determine the influence of geometry and flow variations on mixing patterns in a cylindrical configuration. Results show that jet to mainstream momentum flux ratio and orifice geometry significantly impact the mixing characteristics of jets in a can geometry. For a fixed number of orifices, the coupling between momentum flux ratio and injector determines (1) the degree of jet penetration at the injection plane, and (2) the extent of circumferential mixing downstream of the injection plane. The results also show that, at a fixed momentum flux ratio, jet penetration decreases with (1) an increase in slanted slot aspect ratio, and (2) an increase in the angle of the slots with respect to the mainstream direction.

  19. Political disagreement in intergroup terms: contextual variation and the influence of power.

    PubMed

    OBrien, Léan V; McGarty, Craig

    2009-03-01

    In two studies we examined justified attributions made in the face of political disagreement. Study 1 showed that Australian supporters and opponents of Australian involvement in the 2003 invasion of Iraq made stereotypical attributions that justified the superiority of the in-group over the out-group. Stereotypical attributions were consistent with the justification that the supporters of the war had been misled by dishonest political leaders. Study 2 replicated this pattern with supporters and opponents of Australia's policy of mandatory detention of asylum seekers. It also identified pragmatism as a dimension that dominant, government-aligned, groups may use to justify the superiority of the in-group over the out-group. In both studies political leaders were seen as more competent than members of the public. The results show the influence of intergroup power and within-group leader/supporter distinctions on people's attributions about political disagreement. They point to the power of social psychological theory to help analyse important contemporary political concerns.

  20. Polymorphisms at Amino Acid Residues 141 and 154 Influence Conformational Variation in Ovine PrP

    PubMed Central

    Yang, Sujeong; Thackray, Alana M.; Hopkins, Lee; Monie, Tom P.; Burke, David F.; Bujdoso, Raymond

    2014-01-01

    Polymorphisms in ovine PrP at amino acid residues 141 and 154 are associated with susceptibility to ovine prion disease: Leu141Arg154 with classical scrapie and Phe141Arg154 and Leu141His154 with atypical scrapie. Classical scrapie is naturally transmissible between sheep, whereas this may not be the case with atypical scrapie. Critical amino acid residues will determine the range or stability of structural changes within the ovine prion protein or its functional interaction with potential cofactors, during conversion of PrPC to PrPSc in these different forms of scrapie disease. Here we computationally identified that regions of ovine PrP, including those near amino acid residues 141 and 154, displayed more conservation than expected based on local structural environment. Molecular dynamics simulations showed these conserved regions of ovine PrP displayed genotypic differences in conformational repertoire and amino acid side-chain interactions. Significantly, Leu141Arg154 PrP adopted an extended beta sheet arrangement in the N-terminal palindromic region more frequently than the Phe141Arg154 and Leu141His154 variants. We supported these computational observations experimentally using circular dichroism spectroscopy and immunobiochemical studies on ovine recombinant PrP. Collectively, our observations show amino acid residues 141 and 154 influence secondary structure and conformational change in ovine PrP that may correlate with different forms of scrapie. PMID:25126555

  1. Genetic, environmental and epigenetic influences on variation in human tooth number, size and shape.

    PubMed

    Townsend, Grant; Bockmann, Michelle; Hughes, Toby; Brook, Alan

    2012-01-01

    The aim of this review is to highlight some key recent developments in studies of tooth number, size and shape that are providing better insights into the roles of genetic, environmental and epigenetic factors in the process of dental development. Advances in molecular genetics are helping to clarify how epigenetic factors influence the spatial and temporal regulation of the complex processes involved in odontogenesis. At the phenotypic level, the development of sophisticated systems for image analysis is enabling new dental phenotypes to be defined. The 2D and 3D data that are generated by these imaging systems can then be analysed with mathematical approaches, such as geometric morphometric analysis. By gathering phenotypic data and DNA from twins, it is now possible to use 'genome-wide' association studies and the monozygotic co-twin design to identify important genes in odontogenesis and also to clarify how epigenetic and environmental factors can affect this process. Given that many of the common dental anomalies affecting the human dentition are interrelated, apparently reflecting pleiotropic genetic effects, the discoveries and new directions described in this paper should have important implications for clinical dental practice in the future.

  2. Influence of tropical seasonal variations on landfill leachate characteristics--results from lysimeter studies.

    PubMed

    Tränkler, J; Visvanathan, C; Kuruparan, P; Tubtimthai, O

    2005-01-01

    Considering the quality of design and construction of landfills in developing countries, little information can be derived from randomly taken leachate samples. Leachate generation and composition under monsoon conditions have been studied using lysimeters to simulate sanitary landfills and open cell settings. In this study, lysimeters were filled with domestic waste, highly organic market waste and pre-treated waste. Results over two subsequent dry and rainy seasons indicate that the open cell lysimeter simulation showed the highest leachate generation throughout the rainy season, with leachate flow in all lysimeters coming to a halt during the dry periods. More than 60% of the precipitation was found in the form of leachate. The specific COD and TKN load discharged from the open cell was 20% and 180% more than that of the sanitary landfill lysimeters. Types of waste material and kind of pre-treatment prior to landfilling strongly influenced the pollutant load. Compared to the sanitary landfill lysimeter filled with domestic waste, the specific COD and TKN load discharged from the pre-treated waste lysimeter accounted for only 4% and 16%, respectively. Considering the local settings of tropical landfills, these results suggest that landfill design and operation has to be adjusted. Leachate can be collected and stored during the rainy season, and recirculation of leachate is recommended to maintain a steady and even accelerated degradation during the prolonged dry season. The open cell approach in combination with leachate recirculation is suggested as an option for interim landfill operations.

  3. Climate effects on volcanism: Influence of ice load variations on magma storage zones with application to Icelandic volcanoes.

    NASA Astrophysics Data System (ADS)

    Albino, F.; Pinel, V.; Sigmundsson, F.

    2011-12-01

    Correlations between deglaciation periods and eruptive activity in the past have been strongly suggested, especially in Iceland, where the end of the last glaciation was characterised by a large pulse in volcanic production. Present-day reduction in ice load on subglacial volcanoes due to global warming is modifying pressure conditions in magmatic systems with a potential to influence magma production as well as shallow storage. Here, we model stress induced by variation in surface loads and evaluate how the resulting pressure conditions can modulate magmatic activity. We focus on the effect on shallow storage zones and show that ice loading can modify their failure conditions in a manner that depends critically on ice retreat timing and spatial distribution, the shape and depth of magma chambers as well the compressibility of the magma. We study in particular two subglacial volcanoes in Iceland: the Katla volcano under the Mýrdalsjökull ice cap and Grímsvötn at the Vatnajökull ice cap. Numerical calculations have been carried out in axisymmetric geometry for elliptical magma chambers. An elastic model is first used to evaluate the effects of the annual load cycle, due to seasonal variation of ice mass, which indicates an annual modulation of failure conditions on magma chambers at subglacial volcanoes. Our model predicts that, in case of a spherical or horizontally elongated magma chamber, eruptions are more likely when the seasonal snow cover is smallest. This triggering effect is small, around few kPa, but appears consistent with the fact that all the nine last major historical eruptions of Katla volcano occurred in period from May - October when the annual snow load is minimum. Viscous effects are then introduced to evaluate the influence of long term ice thinning on the shallow magma storage zones.

  4. Corticotropin-releasing hormone receptor type 1 (CRHR1) genetic variation and stress interact to influence reward learning.

    PubMed

    Bogdan, Ryan; Santesso, Diane L; Fagerness, Jesen; Perlis, Roy H; Pizzagalli, Diego A

    2011-09-14

    Stress is a general risk factor for psychopathology, but the mechanisms underlying this relationship remain largely unknown. Animal studies and limited human research suggest that stress can induce anhedonic behavior. Moreover, emerging data indicate that genetic variation within the corticotropin-releasing hormone type 1 receptor gene (CRHR1) at rs12938031 may promote psychopathology, particularly in the context of stress. Using an intermediate phenotypic neurogenetics approach, we assessed how stress and CRHR1 genetic variation (rs12938031) influence reward learning, an important component of anhedonia. Psychiatrically healthy female participants (n = 75) completed a probabilistic reward learning task during stress and no-stress conditions while 128-channel event-related potentials were recorded. Fifty-six participants were also genotyped across CRHR1. Response bias, an individual's ability to modulate behavior as a function of reward, was the primary behavioral variable of interest. The feedback-related positivity (FRP) in response to reward feedback was used as a neural index of reward learning. Relative to the no-stress condition, acute stress was associated with blunted response bias as well as a smaller and delayed FRP (indicative of disrupted reward learning) and reduced anterior cingulate and orbitofrontal cortex activation to reward. Critically, rs12938031 interacted with stress to influence reward learning: both behaviorally and neurally, A homozygotes showed stress-induced reward learning abnormalities. These findings indicate that acute, uncontrollable stressors reduce participants' ability to modulate behavior as a function of reward, and that such effects are modulated by CRHR1 genotype. Homozygosity for the A allele at rs12938031 may increase risk for psychopathology via stress-induced reward learning deficits.

  5. Temporal Variations of Water Productivity in Irrigated Corn: An Analysis of Factors Influencing Yield and Water Use across Central Nebraska.

    PubMed

    Carr, Tony; Yang, Haishun; Ray, Chittaranjan

    2016-01-01

    Water Productivity (WP) of a crop defines the relationship between the economic or physical yield of the crop and its water use. With this concept it is possible to identify disproportionate water use or water-limited yield gaps and thereby support improvements in agricultural water management. However, too often important qualitative and quantitative environmental factors are not part of a WP analysis and therefore neglect the aspect of maintaining a sustainable agricultural system. In this study, we examine both the physical and economic WP in perspective with temporally changing environmental conditions. The physical WP analysis was performed by comparing simulated maximum attainable corn yields per unit of water using the crop model Hybrid-Maize with observed data from 2005 through 2013 from 108 farm plots in the Central Platte and the Tri Basin Natural Resource Districts of Nebraska. In order to expand the WP analysis on external factors influencing yields, a second model, Maize-N, was used to estimate optimal nitrogen (N)-fertilizer rate for specific fields in the study area. Finally, a vadose zone flow and transport model, HYDRUS-1D for simulating vertical nutrient transport in the soil, was used to estimate locations of nitrogen pulses in the soil profile. The comparison of simulated and observed data revealed that WP was not on an optimal level, mainly due to large amounts of irrigation used in the study area. The further analysis illustrated year-to-year variations of WP during the nine consecutive years, as well as the need to improve fertilizer management to favor WP and environmental quality. In addition, we addressed the negative influence of groundwater depletion on the economic WP through increasing pumping costs. In summary, this study demonstrated that involving temporal variations of WP as well as associated environmental and economic issues can represent a bigger picture of WP that can help to create incentives to sustainably improve

  6. Temporal Variations of Water Productivity in Irrigated Corn: An Analysis of Factors Influencing Yield and Water Use across Central Nebraska

    PubMed Central

    Carr, Tony; Yang, Haishun; Ray, Chittaranjan

    2016-01-01

    Water Productivity (WP) of a crop defines the relationship between the economic or physical yield of the crop and its water use. With this concept it is possible to identify disproportionate water use or water-limited yield gaps and thereby support improvements in agricultural water management. However, too often important qualitative and quantitative environmental factors are not part of a WP analysis and therefore neglect the aspect of maintaining a sustainable agricultural system. In this study, we examine both the physical and economic WP in perspective with temporally changing environmental conditions. The physical WP analysis was performed by comparing simulated maximum attainable corn yields per unit of water using the crop model Hybrid-Maize with observed data from 2005 through 2013 from 108 farm plots in the Central Platte and the Tri Basin Natural Resource Districts of Nebraska. In order to expand the WP analysis on external factors influencing yields, a second model, Maize-N, was used to estimate optimal nitrogen (N)–fertilizer rate for specific fields in the study area. Finally, a vadose zone flow and transport model, HYDRUS-1D for simulating vertical nutrient transport in the soil, was used to estimate locations of nitrogen pulses in the soil profile. The comparison of simulated and observed data revealed that WP was not on an optimal level, mainly due to large amounts of irrigation used in the study area. The further analysis illustrated year-to-year variations of WP during the nine consecutive years, as well as the need to improve fertilizer management to favor WP and environmental quality. In addition, we addressed the negative influence of groundwater depletion on the economic WP through increasing pumping costs. In summary, this study demonstrated that involving temporal variations of WP as well as associated environmental and economic issues can represent a bigger picture of WP that can help to create incentives to sustainably improve

  7. R-R interval variations influence the degree of mitral regurgitation in dogs with myxomatous mitral valve disease.

    PubMed

    Reimann, M J; Møller, J E; Häggström, J; Markussen, B; Holen, A E W; Falk, T; Olsen, L H

    2014-03-01

    Mitral regurgitation (MR) due to myxomatous mitral valve disease (MMVD) is a frequent finding in Cavalier King Charles Spaniels (CKCSs). Sinus arrhythmia and atrial premature complexes leading to R-R interval variations occur in dogs. The aim of the study was to evaluate whether the duration of the R-R interval immediately influences the degree of MR assessed by echocardiography in dogs. Clinical examination including echocardiography was performed in 103 privately-owned dogs: 16 control Beagles, 70 CKCSs with different degree of MR and 17 dogs of different breeds with clinical signs of congestive heart failure due to MMVD. The severity of MR was evaluated in apical four-chamber view using colour Doppler flow mapping (maximum % of the left atrium area) and colour Doppler M-mode (duration in ms). The influence of the ratio between present and preceding R-R interval on MR severity was evaluated in 10 consecutive R-R intervals using a linear mixed model for repeated measurements. MR severity was increased when a short R-R interval was followed by a long R-R interval in CKCSs with different degrees of MR (P<0.005 when adjusted for multiple testing). The relationship was not significant in control dogs with minimal MR and in dogs with severe MR and clinical signs of heart failure. In conclusion, MR severity increases in long R-R intervals when these follow a short R-R interval in CKCSs with different degrees of MR due to asymptomatic MMVD. Thus, R-R interval variations may affect the echocardiographic grading of MR in CKCSs.

  8. Environmental variation and macrofauna response in a coastal area influenced by land runoff

    NASA Astrophysics Data System (ADS)

    Akoumianaki, Ioanna; Papaspyrou, Sokratis; Kormas, Konstantinos Ar.; Nicolaidou, Artemis

    2013-11-01

    Macrofauna community interactions with environmental variables in the water column (salinity, temperature, turbidity, transparency, suspended particulate matter, particulate organic matter, choloroplastic pigments) and in the sediment (granulometric variables, organic carbon and pigments) were investigated in a coastal area with high land runoff due to riverine and temporary stream discharges (Greece, Aegean Sea, Maliakos Gulf). Samples were taken along a distance-depositional gradient from the river mouth to the open sea at eight stations, at times of different precipitation regime from August 2000 to May 2001. The physical variables, such as transparency and median grain size, generally increased seawards, and parallelled the depositional gradient as opposed to measures of food inputs and hydrodynamic regime. High environmental heterogeneity was observed during peak precipitation. The total number of species increased seawards and from August (122 species) to May (170 species). Maximum abundance also increased from August (4953 m-2) to May (10,220 individuals m-2), irrespective of distance from river mouth. Species belonging to different functional groups, as to recolonization, feeding, motility and substrate preferences, coexisted at all times indicating high functional diversity. Non-parametric multivariate regression showed that at times of low, rising and falling precipitation 78-81% of community variation was explained by environmental variables, indicating that macrofauna distribution and species composition respond to food inputs and sediment characteristics. During peak land runoff the community-environment relationship weakened (57% of the variability explained). The diversity of functional traits of the most abundant species indicates that the macrofauna community can absorb the impact of increased turbidity, sedimentation and current-driven dispersion. The study offers baseline information for the integrated coastal zone management in microtidal areas

  9. Influence of Curve Number variation on peak discharge of small catchment

    NASA Astrophysics Data System (ADS)

    Banasik, Kazimierz; Hejduk, Leszek; Banasik, Jerzy; Rutkowska, Agnieszka

    2014-05-01

    In this study, we have examined the impact of Curve Number variability on peak discharge, estimated with the use of lumped parametric model SEGMO. Analysis has been conducted for a small (82 km2) agro-forested lowland catchment, located in the center of Poland. Both, the curve number, which is determining runoff depth from rainfall depth, and the IUH characteristics (such as lag time, time to peak, maximum ordinate), which are used to transform the runoff depth into direct runoff hydrograph, have been estimated on the base of recorded in the catchment rainfall-runoff events (Banasik et al. 2011, Banasik et al. 2013). All of them include some stochastic variables, however IUH has been approximated, and used in computation as deterministic. A big variability in CNs has been found, when they were computed from recorded rainfall-runoff data. Next, using the 40 rainfall-runoff data set, the curve numbers were computed again, for each of the ordered pairs, and finally plotted against rainfall depth. Curve numbers were found to approximate an exponential function, varying with storm depth (i.e. decreasing with rainfall increase), and approaches a constant value (CN∞=69.8, which was very close to that value estimated on the base of soil type and land use) at higher rainfalls, what is call a standard behavior (Van Mullem et al. 2002). Standard error of estimation of CN was 1.54. The examination indicated high sensitivity of the flood discharge, estimated as catchment response to 100-year rainfall, to CN changes. Banasik K., Hejduk L. & Oygarden L., 2011. Prediction and reduction of diffuse pollution, solid emission and extreme flows from rural areas - case study of small agricultural catchments. Warsaw University of Life Sciences Press, Warsaw. Banasik K., Hejduk L., Banasik J., 2013. Variation of IUH shapes with size of rainfall-runoff events in a small agricultural catchment. EGU General Assembly, Abstract & Poster. Van Mullem J.A., Woodward D.E., Hawkins R

  10. Influence of late Quaternary climate change on present patterns of genetic variation in valley oak, Quercus lobata Née.

    PubMed

    Gugger, Paul F; Ikegami, Makihiko; Sork, Victoria L

    2013-07-01

    Phylogeography and ecological niche models (ENMs) suggest that late Quaternary glacial cycles have played a prominent role in shaping present population genetic structure and diversity, but have not applied quantitative methods to dissect the relative contribution of past and present climate vs. other forces. We integrate multilocus phylogeography, climate-based ENMs and multivariate statistical approaches to infer the effects of late Quaternary climate change on contemporary genetic variation of valley oak (Quercus lobata Née). ENMs indicated that valley oak maintained a stable distribution with local migration from the last interglacial period (~120 ka) to the Last Glacial Maximum (~21 ka, LGM) to the present compared with large-scale range shifts for an eastern North American white oak (Quercus alba L.). Coast Range and Sierra Nevada foothill populations diverged in the late Pleistocene before the LGM [104 ka (28-1622)] and have occupied somewhat distinct climate niches, according to ENMs and coalescent analyses of divergence time. In accordance with neutral expectations for stable populations, nuclear microsatellite diversity positively correlated with niche stability from the LGM to present. Most strikingly, nuclear and chloroplast microsatellite variation significantly correlated with LGM climate, even after controlling for associations with geographic location and present climate using partial redundancy analyses. Variance partitioning showed that LGM climate uniquely explains a similar proportion of genetic variance as present climate (16% vs. 11-18%), and together, past and present climate explains more than geography (19%). Climate can influence local expansion-contraction dynamics, flowering phenology and thus gene flow, and/or impose selective pressures. These results highlight the lingering effect of past climate on genetic variation in species with stable distributions.

  11. Influence of Atmospheric Variations on Photovoltaic Performance and Modeling Their Effects for Days with Clear Skies: Preprint

    SciTech Connect

    Marion, B.

    2012-06-01

    Although variation in photovoltaic (PV) performance is predominantly influenced by clouds, performance variations also exist for days with clear skies with different amounts of atmospheric constituents that absorb and reflect different amounts of radiation as it passes through the earth's atmosphere. The extent of the attenuation is determined by the mass of air and the amounts of water vapor, aerosols, and ozone that constitute the atmosphere for a particular day and location. Because these constituents selectively absorb radiation of particular wavelengths, their impact on PV performance is sensitive to the spectral response of the PV device. The impact may be assessed by calculating the spectral mismatch correction. This approach was validated using PV module performance data at the National Renewable Energy Laboratory (NREL) for summer, fall, and winter days with clear skies. The standard deviation of daily efficiencies for single-crystal Si, a-Si/a-Si/a-Si:Ge, CdTe, and CIGS PV modules were reduced to 0.4% to 1.0% (relative) by correcting for spectral mismatch, temperature, and angle-of-incidence effects.

  12. Genetic variation in South Asia: assessing the influences of geography, language and ethnicity for understanding history and disease risk.

    PubMed

    Ayub, Qasim; Tyler-Smith, Chris

    2009-09-01

    South Asia is home to more than 1.5 billion humans representing many diverse ethnicities, linguistic and religious groups and representing almost one-quarter of humanity. Modern humans arrived here soon after their departure from Africa approximately 50,000-70,000 years before present (YBP) and several subsequent human migrations and invasions, as well as the unique social structure of the region, have helped shape the pattern of genetic diversity currently observed in these populations. Over the last few decades population geneticists and molecular anthropologists have analyzed DNA variation in indigenous populations from this region in order to catalog their genetic relationships and histories. The emphasis is gradually shifting from the study of population origins to high resolution surveys of DNA variation to address issues of population stratification and genetic susceptibility or resistance to diseases in genome-wide association surveys. We present a historical overview of the genetic studies carried out on populations from this region in order to understand the influence of geographic, linguistic and religious factors on population diversity in this region, and discuss future prospects in light of developments in high throughput genotyping and next generation sequencing technologies.

  13. Long-term diffuse phosphorus pollution dynamics under the combined influence of land use and soil property variations.

    PubMed

    Huang, Haobo; Ouyang, Wei; Wu, Haotian; Liu, Hongbin; Andrea, Critto

    2017-02-01

    Analyses of the spatial-temporal distribution of diffuse pollution in agricultural regions are essential to the sustained management of water resources. Although nutrients, such as phosphorus fertilizers, can promote crop growth while improving soil fertility, excessive nutrient inputs can produce diffuse pollution, which may results in water quality degradation. The objective of this paper is to employ the SWAT (Soil and Water Assessment Tool) to estimate diffuse P effects on temporal and spatial distributions for a typical agricultural watershed and to identify the conjunct and independent influences of long-term land use and soil properties variation on diffuse P. With the validated model, the four-period simulation results (from 1979 to 2009) indicate that land use changes from agricultural development increased diffuse P yields. However, regarding updated soil properties, no significant differences of P yield were found between 1979 and 2009, demonstrating that impact of the cropland expansion were naturalized with soil property variations. An F-test was employed to assess the essentiality of all of the variables examined during the simulation period, and the test results indicated that diffuse P loading was more sensitive to soil properties than to land use. Before the P pollution control project about the land use optimization planning, it is more effective to distinguish the impacts of land use and soil properties.

  14. Using DRS during breast conserving surgery: identifying robust optical parameters and influence of inter-patient variation

    PubMed Central

    de Boer, Lisanne L.; Hendriks, Benno H. W.; van Duijnhoven, Frederieke; Peeters-Baas, Marie-Jeanne T. F. D. Vrancken; Van de Vijver, Koen; Loo, Claudette E.; Jóźwiak, Katarzyna; Sterenborg, Henricus J. C. M.; Ruers, Theo J. M.

    2016-01-01

    Successful breast conserving surgery consists of complete removal of the tumor while sparing healthy surrounding tissue. Despite currently available imaging and margin assessment tools, recognizing tumor tissue at a resection margin during surgery is challenging. Diffuse reflectance spectroscopy (DRS), which uses light for tissue characterization, can potentially guide surgeons to prevent tumor positive margins. However, inter-patient variation and changes in tissue physiology occurring during the resection might hamper this light-based technology. Here we investigate how inter-patient variation and tissue status (in vivo vs ex vivo) affect the performance of the DRS optical parameters. In vivo and ex vivo measurements of 45 breast cancer patients were obtained and quantified with an analytical model to acquire the optical parameters. The optical parameter representing the ratio between fat and water provided the best discrimination between normal and tumor tissue, with an area under the receiver operating characteristic curve of 0.94. There was no substantial influence of other patient factors such as menopausal status on optical measurements. Contrary to expectations, normalization of the optical parameters did not improve the discriminative power. Furthermore, measurements taken in vivo were not significantly different from the measurements taken ex vivo. These findings indicate that DRS is a robust technology for the detection of tumor tissue during breast conserving surgery. PMID:28018735

  15. Influence of Egr-1 in cardiac tissue-derived mesenchymal stem cells in response to glucose variations.

    PubMed

    Bastianelli, Daniela; Siciliano, Camilla; Puca, Rosa; Coccia, Andrea; Murdoch, Colin; Bordin, Antonella; Mangino, Giorgio; Pompilio, Giulio; Calogero, Antonella; De Falco, Elena

    2014-01-01

    Mesenchymal stem cells (MSCs) represent a promising cell population for cell therapy and regenerative medicine applications. However, how variations in glucose are perceived by MSC pool is still unclear. Since, glucose metabolism is cell type and tissue dependent, this must be considered when MSCs are derived from alternative sources such as the heart. The zinc finger transcription factor Egr-1 is an important early response gene, likely to play a key role in the glucose-induced response. Our aim was to investigate how short-term changes in in vitro glucose concentrations affect multipotent cardiac tissue-derived MSCs (cMSCs) in a mouse model of Egr-1 KO (Egr-1(-/-)). Results showed that loss of Egr-1 does not significantly influence cMSC proliferation. In contrast, responses to glucose variations were observed in wt but not in Egr-1(-/-) cMSCs by clonogenic assay. Phenotype analysis by RT-PCR showed that cMSCs Egr-1(-/-) lost the ability to regulate the glucose transporters GLUT-1 and GLUT-4 and, as expected, the Egr-1 target genes VEGF, TGF β -1, and p300. Acetylated protein levels of H3 histone were impaired in Egr-1(-/-) compared to wt cMSCs. We propose that Egr-1 acts as immediate glucose biological sensor in cMSCs after a short period of stimuli, likely inducing epigenetic modifications.

  16. A Model of the Influence of Neutral Air Dynamics on the Seasonal Variation in the Low Ionosphere

    NASA Technical Reports Server (NTRS)

    Nestorov, G.; Velinov, P. J.; Pancheva, T.

    1984-01-01

    Recently it has become clear that the phenomena in the ionospheric D-region are determined to a great extent by dynamical processes in the strato-mesosphere D-region. In this respect much attention is paid to the study of the winter anomaly (WA) phenomenon on medium and short radiowaves, in which the meteorological character of the lower ionosphere is most prominent. Significant experimental data about the variations of the electron concentration, N, ion composition, temperature and dynamic regime during WA permit a better understanding of the character of the physical processes in the middle atmosphere. The influence of the neutral wind on the seasonal variation of the electron concentration N for the altitude interval 90 or = z or = 120 km, where the ratio upsilon sub in/omega sub i, of the ion-neutral collision frequency, upsilon sub in and the ion gyrofrequency, omega sub i decreases from 40 to 1 was evaluated. CIRA-72 is used as a model of the zonal wind.

  17. Are South Texas Streamflow Variations Influenced by Sea Surface Temperature Changes in Pacific and Atlantic Oceans?

    NASA Astrophysics Data System (ADS)

    Murgulet, V.; Hay, R.; Ard, R.

    2013-12-01

    The impact of sea surface temperature (SST) anomalies of the Pacific and Atlantic Oceans on several major river basins in the continental U. S. has recently become well documented. Clear relationships have been identified between El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO) and continental U. S. streamflow. Because these relationships can be potentially used to predict streamflow variability, it would also be of great importance to evaluate whether these climate phenomena affect river basins at the sub-regional and/or local scale, objectives that are not usually addressed in previous studies. Therefore, this study is focused on the basin river system of South Texas, an area that encompasses approximately 30,000 km2 and is climatologically defined as subtropical subhumid. Streamflow data (1940-2011) from sixteen unimpaired U.S. Geological Survey gage stations were normalized into a South Texas streamflow data set and evaluated with respect to ENSO, PDO and AMO index time series. The comparison of South Texas annual streamflow with Pacific Decadal Oscillation and El Niño Southern Oscillation Indices shows that the warm phases of ENSO and PDO are generally associated with increased streamflow, whereas cold phases of ENSO and PDO result in lower streamflow volumes. In addition, cross-correlation analyses show a 7-8 month delayed streamflow response to sea surface temperature signals. Furthermore, annual streamflow variability in the South Texas river basins can be also due to sea surface temperature anomalies in the Atlantic Ocean. Higher streamflow values are shown during the cold phase of AMO, while relatively low streamflow values are illustrated during the warm phase of AMO. Thus, preliminary results show that SST anomalies in both Pacific and Atlantic Oceans influence the streamflow variability in the South Texas area. Current research is also focused on evaluating if these climate phenomena

  18. Variations in the stimulus salience of cocaine reward influences drug-associated contextual memory.

    PubMed

    Liddie, Shervin; Itzhak, Yossef

    2016-03-01

    Drugs of abuse act as reinforcers because they influence learning and memory processes resulting in long-term memory of drug reward. We have previously shown that mice conditioned by fixed daily dose of cocaine (Fix-C) or daily escalating doses of cocaine (Esc-C) resulted in short- and long-term persistence of drug memory, respectively, suggesting different mechanisms in acquisition of cocaine memory. The present study was undertaken to investigate the differential contribution of N-methyl-D-aspartate receptor (NMDAR) subunits in the formation of Fix-C and Esc-C memory in C57BL/6J mice. Training by Esc-C resulted in marked elevation in hippocampal expression of Grin2b mRNA and NR2B protein levels compared with training by Fix-C. The NR2B-containing NMDAR antagonist ifenprodil had similar attenuating effects on acquisition and reconsolidation of Fix-C and Esc-C memory. However, the NMDAR antagonist MK-801 had differential effects: (1) higher doses of MK-801 were required for post-retrieval disruption of reconsolidation of Esc-C memory than Fix-C memory; and (2) pre-retrieval MK-801 inhibited extinction of Fix-C memory but it had no effect on Esc-C memory. In addition, blockade of NMDAR downstream signaling pathways also showed differential regulation of Fix-C and Esc-C memory. Inhibition of neuronal nitric oxide synthase attenuated acquisition and disrupted reconsolidation of Fix-C but not Esc-C memory. In contrast, the mitogen-activating extracellular kinase inhibitor SL327 attenuated reconsolidation of Esc-C but not Fix-C memory. These results suggest that NMDAR downstream signaling molecules associated with consolidation and reconsolidation of cocaine-associated memory may vary upon changes in the salience of cocaine reward during conditioning.

  19. Genetic Variation in Autophagy-Related Genes Influences the Risk and Phenotype of Buruli Ulcer

    PubMed Central

    Capela, Carlos; Dossou, Ange Dodji; Silva-Gomes, Rita; Sopoh, Ghislain Emmanuel; Makoutode, Michel; Menino, João Filipe; Fraga, Alexandra Gabriel; Cunha, Cristina; Carvalho, Agostinho; Rodrigues, Fernando; Pedrosa, Jorge

    2016-01-01

    Introduction Buruli ulcer (BU) is a severe necrotizing human skin disease caused by Mycobacterium ulcerans. Clinically, presentation is a sum of these diverse pathogenic hits subjected to critical immune-regulatory mechanisms. Among them, autophagy has been demonstrated as a cellular process of critical importance. Since microtubules and dynein are affected by mycolactone, the critical pathogenic exotoxin produced by M. ulcerans, cytoskeleton-related changes might potentially impair the autophagic process and impact the risk and progression of infection. Objective Genetic variants in the autophagy-related genes NOD2, PARK2 and ATG16L1 has been associated with susceptibility to mycobacterial diseases. Here, we investigated their association with BU risk, its severe phenotypes and its progression to an ulcerative form. Methods Genetic variants were genotyped using KASPar chemistry in 208 BU patients (70.2% with an ulcerative form and 28% in severe WHO category 3 phenotype) and 300 healthy endemic controls. Results The rs1333955 SNP in PARK2 was significantly associated with increased susceptibility to BU [odds ratio (OR), 1.43; P = 0.05]. In addition, both the rs9302752 and rs2066842 SNPs in NOD2 gee significantly increased the predisposition of patients to develop category 3 (OR, 2.23; P = 0.02; and OR 12.7; P = 0.03, respectively, whereas the rs2241880 SNP in ATG16L1 was found to significantly protect patients from presenting the ulcer phenotype (OR, 0.35; P = 0.02). Conclusion Our findings indicate that specific genetic variants in autophagy-related genes influence susceptibility to the development of BU and its progression to severe phenotypes. PMID:27128681

  20. Do aerosols influence the diurnal variation of H2O2 in the atmosphere?

    NASA Astrophysics Data System (ADS)

    Liang, H.; Chen, Z.; Wu, Q.; Huang, D.; Zhao, Y.

    2013-12-01

    Hydrogen peroxide (H2O2) and organic peroxides are crucial reactive species that are involved in the cycling of HOx (OH and HO2) radicals and the formation of secondary inorganic and organic aerosols in the atmosphere. Despite the importance of peroxides, their formation and removal mechanisms with the coexistence of aerosols are as yet less well known. From June 10 to July 15 2013, summertime surface measurements for atmospheric peroxides were simultaneously obtained in urban Beijing (UB) and Gucheng (GC). The UB site is located in the northern downtown of Beijing city, while the GC site is a rural site located in the North China Plain and ~100 km southwest of Beijing. In both sites, the major peroxides were determined to be H2O2, methyl hydroperoxide (MHP), peroxyformic acid (PFA) and peroxyacetic acid (PAA). By comparing the concentrations of PFA and PAA in the gas phase and rainwater, for the first time, we estimated the Henry's law constant for PFA as ~210 M atm-1 at 298 K, a quarter of that for PAA. Interestingly, we observed different H2O2 profiles in the two sites as follows: (i) the average concentration of H2O2 in UB was 50% higher than that in GC; (ii) H2O2 in GC reached its peak concentration at around 15:30, whereas the peak concentration in UB appeared at as late as 21:00; and (iii) the daily variation of H2O2 in GC generally kept consistent with that of O3 and organic peroxides while it was not always the case in UB. These differences indicate a hitherto unrecognized storage-release mechanism for H2O2 in UB, that is, an extra sink in the noontime and an extra source in the early evening. The extra source of H2O2 would enhance the aerosol phase OH radical in the early evening by the Fenton reaction. A box model analysis shows that the impacts of aerosols were majorly responsible to this unrecognized mechanism, although NOx, regional transport and planet boundary layer height also contributed a minor part. Aerosols participated in the storage

  1. Genetic Variation of the Alpha Subunit of the Epithelial Na+ Channels Influences Exhaled Na+ in Healthy Humans

    PubMed Central

    Foxx-Lupo, William T.; Wheatley, Courtney M.; Baker, Sarah E.; Cassuto, Nicholas A.; Delamere, Nicholas A.; Snyder, Eric M.

    2011-01-01

    Epithelial Na+ Channels (ENaC) are located on alveolar cells and are important in β2-adrenergic receptor-mediated lung fluid clearance through the removal of Na+ from the alveolar airspace. Previous work has demonstrated that genetic variation of the alpha subunit of ENaC at amino acid 663 is important in channel function: cells with the genotype resulting in alanine at amino acid 663 (A663) demonstrate attenuated function when compared to genotypes with at least one allele encoding threonine (T663, AT/TT). We sought to determine the influence of genetic variation at position 663 of ENaC on exhaled Na+ in healthy humans. Exhaled Na+ was measured in 18 AA and 13 AT/TT subjects (age=27±8 vs. 30±10yrs., ht.=174±12 vs. 171±10cm., wt=68±12 vs. 73±14kg., BMI=22±3 vs. 25±4kg/m2, mean±SD, for AA and AT/TT, respectively). Measurements were made at baseline and at 30, 60 and 90 minutes following the administration of a nebulized β2-agonist (albuterol sulfate, 2.5mg diluted in 3ml normal saline). The AA group had a higher baseline level of exhaled Na+ and a greater response to β2-agonist stimulation (baseline= 3.1±1.8 vs. 2.3±1.5mmol/l; 30min-post= 2.1±0.7 vs. 2.2±0.8mmol/l; 60min-post= 2.0±0.5 vs. 2.3±1.0mmol/l; 90min-post= 1.8±0.8 vs. 2.6±1.5mmol/l, mean±SD, for AA and AT/TT, respectively, p<0.05). The results are consistent with the notion that genetic variation of ENaC influences β2-adrenergic receptor stimulated Na+ clearance in the lungs, as there was a significant reduction in exhaled Na+ over time in the AA group. PMID:21889619

  2. [Distribution, seasonal variation and influence factors of dissolved inorganic arsenic in the Sanggou Bay].

    PubMed

    Li, Lei; Ren, Jing-Ling; Liu, Su-Mei; Jiang, Zeng-Jie; Du, Jin-Zhou; Fang, Jian-Guang

    2014-07-01

    The biogeochemical behavior of arsenic in the aquatic environment has already captured the attentions of scientists due to its complex forms and toxicity. Four cruises were carried out in April, August, October 2011 and January 2012 in the Sanggou Bay. The concentrations of total dissolved inorganic arsenic (TDIAs, TDIAs = [ As(5+] + [As(3+)]) and arsenite (As(3+)) were measured by Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS). The concentrations of TDIAs ranged from 3.4-12.4 nmol x L(-1) in April, 8.9-16.9 nmol x L(-1) in August, 14.7-21.3 nmol x L(-1) in October and 13.8-21.9 nmol x L(-1) in January. The concentrations of arsenite ranged from 0.3-2.1 nmol x L(-1), 0.4-3.8 nmol x L(-1), 1.8-4.0 nmol x L(-1) and 0.3-2.9 nmol x L(-1) during four cruises, respectively. The concentrations of TDIAs in spring and summer were lower than those in autumn and winter, and high values of TDIAs appeared in the bay-mouth and the coastal estuary. The concentrations of arsenite in spring and winter were lower than those in summer and autumn. The maximum As(3+)/TDIAs ratios appeared in summer. The mean value of TDIAs in the Sanggou Bay was (13.9 +/- 4.7) nmol x L(-1), which was lower than the national primary drinking in water Standards from USEPA and met the first grade water quality based on the environmental quality standards for surface water of China. It indicates that there is no obvious anthropogenic pollution. The concentrations of TDIAs in the Sanggou Bay were lower than those in the Ailian Bay and the Lidao Bay in spring and summer due to the different hydrological environments and terrestrial inputs. Riverine input, incursion of Yellow Sea and biological activities were the three main factors impacting the distribution of TDIAs in the Sanggou Bay, and the influence of aquaculture activities was particularly significant. The enrichment of arsenic by aquaculture may lead to potential ecological crisis and food safety problems, and need to be paid more

  3. Influence of hydrography of Central Mexican Pacific in the spatial variation of inorganic nutrients during 2010

    NASA Astrophysics Data System (ADS)

    Olivos-Ortiz, A.; Gaviño-Rodríguez, J. H.; Quijano-Scheggia, S.; Pelayo-Martinez, G.; Torres-Orozco, E.; Calva-Chavez, M.

    2014-12-01

    The Mexican Central Pacific (MCP) is considered an oligotrophic area that holds important populations of different species with ecological and economic importance like marine mammals, billfish and tunas. Hydrographic mechanisms are responsible to interplay with the biogeochemical cycles of nutrients to support primary productivity for these food webs. It is argued that seasonal upwelling of bottom waters rich in nutrients generates distributed in patches of high-productivity, which are also linked to topographic continental forcing. The goal of this study is determine the presence of water masses, depth of the mixed layer, temperature, salinity, patterns of geostrophic currents and their influence on the spatiotemporal variability of inorganic nutrients. For that pupose, three oceanographic cruises were conducted in January, May-June, and October of 2010 off the coast of the MCP. Each campaign consisted of 15 stations in five perpendicular transects with stations at 2, 50 and 100 nm offshore. At each station samples were taken to determine the concentration of NO3-+ NO2-, NH4+, PO43- and SiO2 at 0, 10, 25, 50, 75, 100, 150 and 200 m depth. CTD casts were made up to 500m to obtain profiles of salinity, temperature, water masses, and identify geostrophic currents (direction and intensity). Identified water masses were: Pacific Tropical Surface Water (PTSW), Pacific Equatorial Surface Water (PESW), Equatorial Pacific Water (EPW), California Current Water (CCW), Subtropical Subsurface Water (STSsW), and Pacific Intermediate Water (PIT); these water masses were present in all three seasons being more clear the presence of CCW during autumn and PTSW in winter. The interaction between coastal topography, geostrophic circulation, and the depth of the mixed layer (55m oceanic part in January and 10m coastal area in October) were the factors that determined the location of areas of high concentration of nutrients. The distribution of nutrients was heterogeneous

  4. Do Variations in Detrital Inputs Influence Stable Soil Organic Matter? - An Experimental Approach

    NASA Astrophysics Data System (ADS)

    Lajtha, K.; Townsend, K.; Brewer, E.; Caldwell, B.; Kalbitz, K.; Plante, A.

    2007-12-01

    Recognition of the importance of feedbacks from plants in determining soil nutrient dynamics and C storage led to a large number of litter decomposition studies. Despite growing knowledge of short-term litter dynamics, we know relatively little about the fate of plant litter and its role in determining SOM content and nutrient cycling over time scales ranging from decades and centuries. To address this gap, we established long-term studies of controls on soil organic matter formation in an old-growth forest at the H.J. Andrews Experimental Forest, OR. This study complements a network of recently established similar experiments that pan climatic and soil gradients, as well as the original DIRT experiment established in the Wisconsin Arboretum in 1956 in both grassland and forested sites. The central goal of the DIRT project is to assess how rates and sources of plant litter inputs control the accumulation and dynamics of organic matter and nutrients in forest soils over decadal time scales. Treatment plots include doubled litter (needle) inputs , doubled wood, no above ground litter (screened) inputs, no root inputs (trenched), and no inputs (screened and trenched). For the 50th anniversary of the Wisconsin sites and the 10th anniversary of the H.J. Andrews site, we used sequential density fractionation of soils from all treatments to determine if adding or removing either below- or above-ground litter inputs influenced carbon stabilization as soil organic matter. After 50 years, double litter plots in both prairie and forested soils had higher %C in the 0-10 cm horizon. In the forested site, plots showed increased C content of the lightest fraction, which represents relatively young SOM with a short turnover time. However, the first two heavy fractions also showed increases in C with added aboveground litter, suggesting the importance of aboveground litter inputs to SOM in the forest. No such pattern existed for the prairie soil, and we hypothesize that this is

  5. Variations of surface ozone at Ieodo Ocean Research Station in the East China Sea and influence of Asian outflows

    NASA Astrophysics Data System (ADS)

    Han, J.; Shin, B.; Lee, M.; Hwang, G.; Kim, J.; Shim, J.; Lee, G.; Shim, C.

    2015-06-01

    Ieodo Ocean Research Station (IORS), a research tower (~ 40 m a.s.l.) for atmospheric and oceanographic observations, is located in the East China Sea (32.07° N, 125.10° E). The IORS is almost equidistant from South Korea, China, and Japan and, therefore, it is an ideal place to observe Asian outflows without local emission effects. The average ozone concentrations were 51.8 ± 15.9 ppbv during June 2003-December 2010. The seasonal variation of ozone was distinct, with a summer minimum (37.8 ppbv) and a spring maximum (61.1 ppbv), and was largely affected by seasonal wind pattern over East Asia. The fractional contribution of ozone at IORS could be attributed to six well distinguished air masses that were classified by the cluster analysis of backward trajectories. Marine air from the Pacific Ocean represents a relatively clean background air with a lowest ozone level of 32.2 ppbv in summer. In spring and winter the influence of Chinese outflows was dominant with higher ozone concentrations of 61.6 and 49.3 ppbv, respectively. This study confirms that the influence of Chinese outflows was the main factor determining O3 levels at IORS, of which extent was apt to be changed by meteorological state, particularly at a long-term scale.

  6. Variations of surface ozone at Ieodo Ocean Research Station in the East China Sea and the influence of Asian outflows

    NASA Astrophysics Data System (ADS)

    Han, J.; Shin, B.; Lee, M.; Hwang, G.; Kim, J.; Shim, J.; Lee, G.; Shim, C.

    2015-11-01

    Ieodo Ocean Research Station (IORS), a research tower (~ 40 m a.s.l.) for atmospheric and oceanographic observations, is located in the East China Sea (32.07° N, 125.10° E). The IORS is almost equidistant from South Korea, China, and Japan and, therefore, it is an ideal place to observe Asian outflows without local emission effects. The seasonal variation of ozone was distinct, with a minimum in August (37 ppbv) and two peaks in April and October (62 ppbv), and was largely affected by the seasonal wind pattern over east Asia. At IORS, six types of air masses were distinguished with different levels of O3 concentrations by the cluster analysis of backward trajectories. Marine air masses from the Pacific Ocean represent a relatively clean background air with a lowest ozone level of 32 ppbv, which was most frequently observed in summer (July-August). In spring (March-April) and winter (December-February), the influence of Chinese outflows was dominant with higher ozone concentrations of 62 and 49 ppbv, respectively. This study confirms that the influence of Chinese outflows was the main factor determining O3 levels at IORS and its extent was dependent on meteorological state, particularly at a long-term scale.

  7. Climate effects on volcanism: influence on magmatic systems of loading and unloading from ice mass variations, with examples from Iceland.

    PubMed

    Sigmundsson, Freysteinn; Pinel, Virginie; Lund, Björn; Albino, Fabien; Pagli, Carolina; Geirsson, Halldór; Sturkell, Erik

    2010-05-28

    Pressure influences both magma production and the failure of magma chambers. Changes in pressure interact with the local tectonic settings and can affect magmatic activity. Present-day reduction in ice load on subglacial volcanoes due to global warming is modifying pressure conditions in magmatic systems. The large pulse in volcanic production at the end of the last glaciation in Iceland suggests a link between unloading and volcanism, and models of that process can help to evaluate future scenarios. A viscoelastic model of glacio-isostatic adjustment that considers melt generation demonstrates how surface unloading may lead to a pulse in magmatic activity. Iceland's ice caps have been thinning since 1890 and glacial rebound at rates exceeding 20 mm yr(-1) is ongoing. Modelling predicts a significant amount of 'additional' magma generation under Iceland due to ice retreat. The unloading also influences stress conditions in shallow magma chambers, modifying their failure conditions in a manner that depends critically on ice retreat, the shape and depth of magma chambers as well as the compressibility of the magma. An annual cycle of land elevation in Iceland, due to seasonal variation of ice mass, indicates an annual modulation of failure conditions in subglacial magma chambers.

  8. Physical Fitness at Camp.

    ERIC Educational Resources Information Center

    Steen, Thomas B.; And Others

    1990-01-01

    Describes decline in youth fitness, emphasizing role of camping programs in youth fitness education. Describes Michigan camp's fitness program, consisting of daily workouts, fitness education, and record keeping. Describes fitness consultants' role in program. Discusses program's highlights and problems, suggesting changes for future use. Shows…

  9. Fit for purpose: Australia's National Fitness Campaign.

    PubMed

    Collins, Julie A; Lekkas, Peter

    2011-12-19

    During a time of war, the federal government passed the National Fitness Act 1941 to improve the fitness of the youth of Australia and better prepare them for roles in the armed services and industry. Implementation of the National Fitness Act made federal funds available at a local level through state-based national fitness councils, which coordinated promotional campaigns, programs, education and infrastructure for physical fitness, with volunteers undertaking most of the work. Specifically focused on children and youth, national fitness councils supported the provision of children's playgrounds, youth clubs and school camping programs, as well as the development of physical education in schools and its teaching and research in universities. By the time the Act was repealed in 1994, fitness had become associated with leisure and recreation rather than being seen as equipping people for everyday life and work. The emergence of the Australian National Preventive Health Agency Act 2010 offers the opportunity to reflect on synergies with its historic precedent.

  10. Belled end fittings: A recently qualified, high strength, low cost, and production friendly welded fitting design

    SciTech Connect

    Bayard, R.R.; Oakes, F.D. Jr.

    1996-07-01

    This paper presents an overview of the design development, fatigue testing, MSS Standard Practice development and Navy shipboard use of light wall (Schedule 10) socket welded cold formed fittings designed to replace B16.9 type butt welded fittings in sizes 1/4 through 12 NPS. Variations of the belled end fitting design have been successfully used -- thus proven in service -- for almost 40 years. This Government-sponsored program has legitimized the fittings by laboratory testing, has standardized the fittings by Standard Practice publication and has given the fittings a market presence by acceptance on Navy ship new construction and repair.

  11. Herbivory strongly influences among-population variation in reproductive output of Lythrum salicaria in its native range.

    PubMed

    Lehndal, Lina; Hambäck, Peter A; Ericson, Lars; Ågren, Jon

    2016-04-01

    Herbivory can negatively affect several components of plant reproduction. Yet, because of a lack of experimental studies involving multiple populations, the extent to which differences in herbivory contribute to among-population variation in plant reproductive success is poorly known. We experimentally determined the effects of insect herbivory on reproductive output in nine natural populations of the perennial herb Lythrum salicaria along a disturbance gradient in an archipelago in northern Sweden, and we quantified among-population differentiation in resistance to herbivory in a common-garden experiment in the same area. The intensity of leaf herbivory varied >500-fold and mean female reproductive success >400-fold among the study populations. The intensity of herbivory was lowest in populations subject to strong disturbance from ice and wave action. Experimental removal of insect herbivores showed that the effect of herbivory on female reproductive success was correlated with the intensity of herbivory and that differences in insect herbivory could explain much of the among-population variation in the proportion of plants flowering and seed production. Population differentiation in resistance to herbivory was limited. The results demonstrate that the intensity of herbivory is a major determinant of flowering and seed output in L. salicaria, but that differences in herbivory are not associated with differences in plant resistance at the spatial scale examined. They further suggest that the physical disturbance regime may strongly influence the performance and abundance of perennial herbs and patterns of selection not only because of its effect on interspecific competition, but also because of effects on interactions with specialized herbivores.

  12. The influence of the internalization of emotional regulation on mental health among the Taiwanese people: the moderating effect of cultural fit.

    PubMed

    Chu, Li-Chuan

    2015-03-01

    This study used a 2-stage questionnaire survey to explore whether self-regulation by withholding negative emotions (SRWNE) affects mental health and examines further whether cultural fit can moderate the relationship between SRWNE and mental health. The 2-stage studies used data collected from 405 (time 1) and 313 (time 2) full-time staff employed by private and public enterprises in Taiwan. The author tested hypotheses through the use of hierarchical multiple regression. The results showed that controlled SRWNE through external regulation and introjected regulation is significantly associated positively with somatic symptoms, anxiety and insomnia, social dysfunction, and severe depression, whereas autonomous SRWNE through identified regulation is significantly associated negatively with anxiety and insomnia, and social dysfunction. In addition, this study also found that cultural fit may moderate the relationship between SRWNE or introjected regulation and identified regulation and the mental health indicators.

  13. Sweat lactate response between males with high and low aerobic fitness.

    PubMed

    Green, J M; Pritchett, R C; Crews, T R; McLester, J R; Tucker, D C

    2004-01-01

    Sweat lactate indirectly reflects eccrine gland metabolism. However the potential influence of aerobic fitness on sweat lactate is not well-understood. Six males with high aerobic fitness [peak oxygen consumption ( VO(2)peak): 61.6 (2.5) ml.kg(-1).min(-1)] and seven males with low aerobic fitness [ VO(2)peak: 41.8 (6.4) ml.kg(-1).min(-1)] completed a maximal exertion cycling trial followed on a different day by 60 min of cycling (60 rev.min(-1)) in a 30 degrees C wet bulb globe temperature environment. Intensity was individualized at 90% of the ventilatory threshold ( V(E)/ VO(2) increase with no concurrent V(E)/ VCO(2) increase). Sweat samples were collected from the lumbar region every 10 min and analyzed for lactate concentration. Sweat rate (SR) was significantly greater ( p<0.05) for subjects with a high [1445 (254) ml.h(-1)] versus a low [1056 (261) ml.h(-1)] fitness level. Also, estimated total lactate excretion (SRxmean sweat lactate concentration) was marginally greater ( p=0.2) in highly fit males. However, repeated measures ANOVA showed no significant differences ( p>0.05) between groups for sweat lactate concentration at any time point. Current results show highly fit (vs. low fitness level) males have a greater sweat rate which is consistent with previous literature. However aerobic fitness and subsequent variations in SR do not appear to influence sweat lactate concentrations in males.

  14. The role of remote versus local climatic influences in shaping seasonal to interannual rainfall isotopic variations in northern Borneo

    NASA Astrophysics Data System (ADS)

    Moerman, J. W.; Cobb, K. M.; Konecky, B. L.; Noone, D. C.

    2014-12-01

    While interannual and intraseasonal variability are the dominant influences on modern rainfall water isotopes (δ18O and δD) in northern Borneo (Moerman et al., 2013), the strong resemblance between stalagmite δ18O and equatorial boreal fall insolation over the Holocene and late Pleistocene suggests that seasonal δ18O variability is an important control on Borneo stalagmite δ18O over glacial/interglacial timescales (Carolin et al., 2013). A weak, bimodal seasonal cycle of 2-3‰ exists in northern Borneo rainfall δ18O, with relative minima during winter/summer and relative maxima during spring/fall. The seasonal cycle in rainfall δ18O, however, is poorly correlated to seasonal variations in precipitation amount. As a result, the processes driving rainfall δ18O seasonality at Borneo remain unclear. To better constrain the controlling mechanisms, we compare a 7-yr-long timeseries of daily Borneo rainfall δ18O to overlapping satellite-based measurements of GOSAT and TES tropospheric water vapor δD. To investigate the role of moist processes such as evaporation, condensation, and convection, we explore the relationship between seasonal composites of water vapor δD and specific humidity in the Borneo region. We also use HYSPLIT air mass back-trajectories to differentiate local (e.g. moisture recycling, local convection/evaporation) versus regional (e.g. moisture source region, trajectory, and convective activity) controls on the seasonal isotopic composition of Borneo rainfall. Given the sensitivity of Borneo rainfall δ18O to interannual shifts in the zonal location of deep convection in the western Pacific - which drive rainfall δ18O variations of up to 6-8‰ - we perform similar investigations during the weak-to-moderate and moderate-to-strong ENSO cycles of 2006-2008 and 2009-2011 respectively. With this study, we identify the relative influence of local moist processes as well as meridional and zonal shifts in regional hydrology on past western Pacific

  15. Genetic Variation in the Human Brain Dopamine System Influences Motor Learning and Its Modulation by L-Dopa

    PubMed Central

    Pearson-Fuhrhop, Kristin M.; Minton, Brian; Acevedo, Daniel; Shahbaba, Babak; Cramer, Steven C.

    2013-01-01

    Dopamine is important to learning and plasticity. Dopaminergic drugs are the focus of many therapies targeting the motor system, where high inter-individual differences in response are common. The current study examined the hypothesis that genetic variation in the dopamine system is associated with significant differences in motor learning, brain plasticity, and the effects of the dopamine precursor L-Dopa. Skilled motor learning and motor cortex plasticity were assessed using a randomized, double-blind, placebo-controlled, crossover design in 50 healthy adults during two study weeks, one with placebo and one with L-Dopa. The influence of five polymorphisms with established effects on dopamine neurotransmission was summed using a gene score, with higher scores corresponding to higher dopaminergic neurotransmission. Secondary hypotheses examined each polymorphism individually. While training on placebo, higher gene scores were associated with greater motor learning (p = .03). The effect of L-Dopa on learning varied with the gene score (gene score*drug interaction, p = .008): participants with lower gene scores, and thus lower endogenous dopaminergic neurotransmission, showed the largest learning improvement with L-Dopa relative to placebo (p<.0001), while L-Dopa had a detrimental effect in participants with higher gene scores (p = .01). Motor cortex plasticity, assessed via transcranial magnetic stimulation (TMS), also showed a gene score*drug interaction (p = .02). Individually, DRD2/ANKK1 genotype was significantly associated with motor learning (p = .02) and its modulation by L-Dopa (p<.0001), but not with any TMS measures. However, none of the individual polymorphisms explained the full constellation of findings associated with the gene score. These results suggest that genetic variation in the dopamine system influences learning and its modulation by L-Dopa. A polygene score explains differences in L-Dopa effects on learning and plasticity

  16. Variation trends and influencing factors of total gaseous mercury in the Pearl River Delta-A highly industrialised region in South China influenced by seasonal monsoons

    NASA Astrophysics Data System (ADS)

    Chen, Laiguo; Liu, Ming; Xu, Zhencheng; Fan, Ruifang; Tao, Jun; Chen, Duohong; Zhang, Deqiang; Xie, Donghai; Sun, Jiaren

    2013-10-01

    Studies on atmospheric mercury in the Pearl River Delta (PRD) region are important because of the economic relevance of this region to China, because of its economic developmental pattern and because it is a highly industrialised area influenced by the strong seasonal monsoons. Total gaseous mercury (TGM), meteorological parameters and criteria pollutant concentrations were measured at Mt. Dinghu (DH, a regional monitoring site) and Guangzhou (GZ, an urban monitoring site) in the PRD region from October 2009 to April 2010 and from November 2010 to November 2011, respectively. The ranges of daily average TGM concentrations at the DH and GZ sites were 1.87-29.9 ng m-3 (5.07 ± 2.89 ng m-3) and 2.66-11.1 ng m-3 (4.60 ± 1.36 ng m-3), respectively, which were far more significant than the background values in the Northern Hemisphere (1.5-1.7 ng m-3), suggesting that the atmosphere in the PRD has suffered from mercury pollution. Similar TGM seasonal distributions at the two sites were observed, with a descending order of spring, winter, autumn and summer. The different seasonal monsoons were the dominant factor controlling the seasonal variability of the TGM, with variations in the boundary layer and oxidation also possibly partially contributing. Different diurnal patterns of the TGM at two sites were observed. TGM levels during the daytime were higher than those during the nighttime and were predominantly influenced by mountain and valley winds at the DH site, whereas the opposite trend was evident at the GZ site, which was primarily influenced by the boundary-layer height and O3 concentration. During the monitoring period, the correlations between the daily TGM levels and the SO2 and NO2 levels at the DH site were significant (r = 0.36, p < 0.001; r = 0.29, p < 0.001), suggesting that coal-fired emission is an important source of mercury for this regional monitoring site. At the GZ site, the correlations between the daily TGM level and the NO, NO2, CO levels were

  17. Variations in labeling protocol influence incorporation, distribution and retention of iron oxide nanoparticles into human umbilical vein endothelial cells.

    PubMed

    van Tiel, Sandra T; Wielopolski, Piotr A; Houston, Gavin C; Krestin, Gabriel P; Bernsen, Monique R

    2010-01-01

    Various studies have shown that various cell types can be labeled with iron oxide particles and visualized by magnetic resonance imaging (MRI). However, reported protocols for cell labeling show a large variation in terms of labeling dose and incubation time. It is therefore not clear how different labeling protocols may influence labeling efficiency. Systematic assessment of the effects of various labeling protocols on labeling efficiency of human umbilical vein endothelial cells (HUVEC) using two different types of iron oxide nanoparticles, i.e. super paramagnetic iron oxide particles (SPIOs) and microparticles of iron oxide (MPIOs), demonstrated that probe concentration, incubation time and particle characteristics all influence the efficiency of label incorporation, label distribution, label retention and cell behavior. For SPIO the optimal labeling protocol consisted of a dose of 12.5 µg iron/2 ml/9.5 cm(2) and an incubation time of 24 h, resulting in an average iron load of 12.0 pg iron/per cell (uptake efficiency of 9.6%). At 4 h many SPIOs are seen sticking to the outside of the cell instead of being taken up by the cell. For MPIO optimal labeling was obtained with a dose of 50 µg iron/2 ml/9.5 cm(2). Incubation time was of less importance since most of the particles were already incorporated within 4 h with a 100% labeling efficiency, resulting in an intracellular iron load of 626 pg/cell. MPIO were taken up more efficiently than SPIO and were also better tolerated. HUVEC could be exposed to and contain higher amounts of iron without causing significant cell death, even though MPIO had a much more pronounced effect on cell appearance. Using optimal labeling conditions as found for HUVEC on other cell lines, we observed that different cell types react differently to identical labeling conditions. Consequently, for each cell type separately an optimal protocol has to be established.

  18. ProFit: Bayesian galaxy fitting tool

    NASA Astrophysics Data System (ADS)

    Robotham, A. S. G.; Taranu, D.; Tobar, R.

    2016-12-01

    ProFit is a Bayesian galaxy fitting tool that uses the fast C++ image generation library libprofit (ascl:1612.003) and a flexible R interface to a large number of likelihood samplers. It offers a fully featured Bayesian interface to galaxy model fitting (also called profiling), using mostly the same standard inputs as other popular codes (e.g. GALFIT ascl:1104.010), but it is also able to use complex priors and a number of likelihoods.

  19. Potential Influence of Arctic Sea Ice to the Inter-annual Variations of East Asian Spring Precipitation

    NASA Astrophysics Data System (ADS)

    Li, Xinxin; Wu, Zhiwei; Li, Yanjie

    2016-04-01

    Arctic sea ice (ASI) and its potential climatic impacts have received increasing attention during the past decades, yet the relevant mechanisms are far from being understood, particularly on how anomalous ASI affects climate in midlatitudes. The spring precipitation takes up as much as 30% of the annual total and has significant influences to agriculture in East Asia. Here, observed evidence and numerical experiment results manifest that the ASI variability in the Norwegian Sea and the Barents Sea in preceding winter is intimately connected with interannual variations of the East Asian spring precipitation (EAP). The former can explain about 14% of the total variances of the latter. The ASI anomalies persist from winter through the ensuing spring and excite downstream tele-connections of a distinct Rossby wave train prevailing over the Eurasian continent. For the reduced ASI, such a wave train pattern is usually associated with an anomalous low pressure center over Mongolian Plateau, which accelerates the East Asian subtropical westerly jet. The intensified subtropical westerly jet, concurrent with lower-level convergence and upper-level divergence, enhances the local convection and consequently favors rich spring precipitation over East Asia. For the excessive ASI, the situation tends to be opposite. Given that seasonal prediction of the EAP remains a challenging issue, the winter ASI variability may provide another potential predictability source besides El Niño-Southern Oscillation.

  20. Influences of Variations of Characteristic Parameters of Protein Molecules on States of Soliton Transported Bio-Energy

    NASA Astrophysics Data System (ADS)

    Pang, Xiao-Feng; Zhang, Huai-Wu; Yu, Jia-Feng; Luo, Yu-Hui

    We simulate numerically the dynamic properties of new soliton with quasi-coherent two quanta in the improved model by fourth-order Runge-Kutta way. We observed that the window of formation of new soliton is shifted toward smaller values of coupling constants when compared with the Davydov's soliton with one quantum and Förner's soliton with two quantum model. The new soliton formation starts at (χ1+χ2)=20 PN, and pinning starts from (χ1+χ2)=86 PN. The pinned solitons are also observed if both quanta are on the same end of the chain in the initial state. The behaviors of new soliton are varied under influences for variations of characteristic parameters arising from the structure nonuniformity of protein molecules. Although the new soliton is also sensitive to the dipole-dipole interaction and diagonal disorder, the sensitivity to the impurity is weaker than that of the Davydov's and Förner's solitons. Therefore, the new soliton is robust against the fluctuations of coupled constant, dipole-dipole interaction and diagonal disorder arising from the impurity or structure nonuniformity, when compared with that of the Davydov's and Förner's solitons.

  1. Influence of carbon and lipid sources on variation of mercury and other trace elements in polar bears (Ursus maritimus).

    PubMed

    Routti, Heli; Letcher, Robert J; Born, Erik W; Branigan, Marsha; Dietz, Rune; Evans, Thomas J; McKinney, Melissa A; Peacock, Elizabeth; Sonne, Christian

    2012-12-01

    In the present study, the authors investigated the influence of carbon and lipid sources on regional differences in liver trace element (As, Cd, Cu, total Hg, Mn, Pb, Rb, Se, and Zn) concentrations measured in polar bears (Ursus maritimus) (n = 121) from 10 Alaskan, Canadian Arctic, and East Greenland subpopulations. Carbon and lipid sources were assessed using δ(13) C in muscle tissue and fatty acid (FA) profiles in subcutaneous adipose tissue as chemical tracers. A negative relationship between total Hg and δ(13) C suggested that polar bears feeding in areas with higher riverine inputs of terrestrial carbon accumulate more Hg than bears feeding in areas with lower freshwater input. Mercury concentrations were also positively related to the FA 20:1n-9, which is biosynthesized in large amounts in Calanus copepods. This result raises the hypothesis that Calanus glacialis are an important link in the uptake of Hg in the marine food web and ultimately in polar bears. Unadjusted total Hg, Se, and As concentrations showed greater geographical variation among polar bear subpopulations compared with concentrations adjusted for carbon and lipid sources. The Hg concentrations adjusted for carbon and lipid sources in Bering-Chukchi Sea polar bear liver tissue remained the lowest among subpopulations. Based on these findings, the authors suggest that carbon and lipid sources for polar bears should be taken into account when one is assessing spatial and temporal trends of long-range transported trace elements.

  2. Variations and factors that influence the formation of polychlorinated naphthalenes in cement kilns co-processing solid waste.

    PubMed

    Jin, Rong; Zhan, Jiayu; Liu, Guorui; Zhao, Yuyang; Zheng, Minghui

    2016-09-05

    Pilot studies of unintentionally produced pollutants should be performed before waste being co-processed in cement kilns. Polychlorinated naphthalene (PCN) formation and emission from cement kilns co-processing sorted municipal solid waste, sewage sludge, and waste acid, however, have not previously been studied. Here, PCNs were analyzed in stack gas samples and solid samples from different stages of three cement production runs. PCN destruction efficiencies were higher when waste was co-processed (93.1% and 88.7% in two tests) than when waste was not co-processed (39.1%), so co-processing waste would not increase PCN outputs. The PCN concentrations were higher in particle samples from the C1 preheater and stages at back end of kiln than in particle samples from other stages, suggesting that cyclone preheater and back end of kiln should be focused for controlling PCN emissions. Besides that, based on the variation of PCN concentrations and corresponding operating conditions in different stages, the temperature, feeding materials, and chlorine content were suggested as the main factors influencing PCN formation. The PCN homologue and congener profiles suggested chlorination and dechlorination were the main PCN formation and decomposition pathways, and congeners CN-23, CN-46, and CN-59 appear to be appropriate indicators of PCNs emitted from coal-burning sources.

  3. TAA repeat variation in the GRIK2 gene does not influence age at onset in Huntington's disease

    PubMed Central

    Lee, Ji-Hyun; Lee, Jong-Min; Ramos, Eliana Marisa; Gillis, Tammy; Mysore, Jayalakshmi S.; Kishikawa, Shotaro; Hadzi, Tiffany; Hendricks, Audrey E.; Hayden, Michael R.; Morrison, Patrick J.; Nance, Martha; Ross, Christopher A.; Margolis, Russell L.; Squitieri, Ferdinando; Gellera, Cinzia; Gomez-Tortosa, Estrella; Ayuso, Carmen; Suchowersky, Oksana; Trent, Ronald J.; McCusker, Elizabeth; Novelletto, Andrea; Frontali, Marina; Jones, Randi; Ashizawa, Tetsuo; Frank, Samuel; Saint-Hilaire, Marie-Helene; Hersch, Steven M.; Rosas, Herminia D.; Lucente, Diane; Harrison, Madaline B.; Zanko, Andrea; Abramson, Ruth K.; Marder, Karen; Sequeiros, Jorge; Landwehrmeyer, G. Bernhard; Network, Ira Shoulson; Myers, Richard H.; MacDonald, Marcy E.; Gusella, James F.

    2013-01-01

    Huntington's disease is a neurodegenerative disorder caused by an expanded CAG trinucleotide repeat whose length is the major determinant of age at onset but remaining variation appears to be due in part to the effect of genetic modifiers. GRIK2, which encodes GluR6, a mediator of excitatory neurotransmission in the brain, has been suggested in several studies to be a modifier gene based upon a 3′ untranslated region TAA trinucleotide repeat polymorphism. Prior to investing in detailed studies of the functional impact of this polymorphism, we sought to confirm its effect on age at onset in a much larger dataset than in previous investigations. We genotyped the HD CAG repeat and the GRIK2 TAA repeat in DNA samples from 2,911 Huntington's disease subjects with known age at onset, and tested for a potential modifier effect of GRIK2 using a variety of statistical approaches. Unlike previous reports, we detected no evidence of an influence of the GRIK2 TAA repeat polymorphism on age at motor onset. Similarly, the GRIK2 polymorphism did not show significant modifier effect on psychiatric and cognitive age at onset in HD. Comprehensive analytical methods applied to a much larger sample than in previous studies do not support a role for GRIK2 as a genetic modifier of age at onset of clinical symptoms in Huntington's disease. PMID:22771793

  4. Influence of Two Different Exercise Programs on Physical Fitness and Cognitive Performance in Active Older Adults: Functional Resistance-Band Exercises vs. Recreational Oriented Exercises

    PubMed Central

    Ponce-Bravo, Hernán; Ponce, Christian; Feriche, Belén; Padial, Paulino

    2015-01-01

    This study examines the impact of a resistance-band functional exercise program, compared with a recreational exercise program, on physical fitness and reaction times in persons older than 60 years. Fifty-four community-dwelling volunteers (71.76 ± 6.02 years) were assigned to a specific exercise program: Functional activity program (focused on resistance-band multi-joint activities; experimental group, EG), or recreational physical activity program (with gross motor activities of ludic content; control group, CG). Before and after the intervention, we determined cognitive capacity in terms of simple reaction time (S-RT), choice reaction time (C-RT) and fitness. In both groups physical performance improved, though this improvement was more marked in the EG for grip strength, arm strength and gross motor abilities (p < 0.05). Reaction times were better only in EG (S-RT = 10.70%, C-RT = 14.34%; p < 0.05) after the corresponding physical training intervention. The training period showed no effect on the moderate relationship between both RT and gross motor abilities in the CG, whereas the EG displayed an enhanced relationship between S-RT and grip-strength as well as the C-RT with arm strength and aerobic capacity (r ~ 0.457; p < 0.05). Our findings indicate that a functional exercise program using a resistance band improves fitness and cognitive performance in healthy older adults. Key points Better cognitive processes can be achieved as physical condition improves Exercise sessions of a more recreational type do not seem to constitute a stimulus able to improve both physical and cognitive performance in healthy active older adults The improvement of cognitive function, as assessed through reaction times, seems more linked to the workload and strength component of the training program. PMID:26664267

  5. An Evaluation of the Significance of Work-Related Influence Factors on Fitness and the Development of Medical and Orthopaedic Conditions in Military Executives

    PubMed Central

    Becker, Michael; Finze, Susanne; Holtherm, Christoph; Hinder, Jens; Lison, Andreas

    2016-01-01

    Occupational health promotion is an effective tool to improve the state of health of employees. As part of occupational health promotion in the German Bundeswehr, top-ranking military executives are offered a medical examination and training programme. Health-related data is collected as a basis for training and lifestyle counselling. This data was subjected to a retrospective evaluation in order to identify occupational risk factors and their correlation with cardiovascular resilience, trunk strength, and the development of orthopaedic and internal disorders. A total of 122 military executives (all male, age 54.6 ± 4.2 years) answered a questionnaire aimed at evaluating private and occupational stress factors. The medical history was followed by a medical and orthopaedic examination involving a lactate performance test (treadmill or bicycle ergometry) and an isometric trunk strength measurement. The data obtained was then statistically evaluated. For military executives, work-related travelling and commuting involve a high risk of medical and orthopaedic conditions. Regular exercise leads to improved fitness levels. In order to prevent medical problems, military executives working long hours should regularly take part in fitness and weight training under professional instructions. PMID:27774505

  6. An ethnographic exploration of influences on prescribing in general practice: why is there variation in prescribing practices?

    PubMed Central

    2013-01-01

    Background Prescribing is a core activity for general practitioners, yet significant variation in the quality of prescribing has been reported. This suggests there may be room for improvement in the application of the current best research evidence. There has been substantial investment in technologies and interventions to address this issue, but effect sizes so far have been small to moderate. This suggests that prescribing is a decision-making process that is not sufficiently understood. By understanding more about prescribing processes and the implementation of research evidence, variation may more easily be understood and more effective interventions proposed. Methods An ethnographic study in three Scottish general practices with diverse organizational characteristics. Practices were ranked by their performance against Audit Scotland prescribing quality indicators, incorporating established best research evidence. Two practices of high prescribing quality and one practice of low prescribing quality were recruited. Participant observation, formal and informal interviews, and a review of practice documentation were employed. Results Practices ranked as high prescribing quality consistently made and applied macro and micro prescribing decisions, whereas the low-ranking practice only made micro prescribing decisions. Macro prescribing decisions were collective, policy decisions made considering research evidence in light of the average patient, one disease, condition, or drug. Micro prescribing decisions were made in consultation with the patient considering their views, preferences, circumstances and other conditions (if necessary). Although micro prescribing can operate independently, the implementation of evidence-based, quality prescribing was attributable to an interdependent relationship. Macro prescribing policy enabled prescribing decisions to be based on scientific evidence and applied consistently where possible. Ultimately, this influenced prescribing

  7. SU-E-I-96: A Study About the Influence of ROI Variation On Tumor Segmentation in PET

    SciTech Connect

    Li, L; Tan, S; Lu, W; D'Souza, W

    2014-06-01

    Purpose: To study the influence of different regions of interest (ROI) on tumor segmentation in PET. Methods: The experiments were conducted on a cylindrical phantom. Six spheres with different volumes (0.5ml, 1ml, 6ml, 12ml, 16ml and 20 ml) were placed inside a cylindrical container to mimic tumors of different sizes. The spheres were filled with 11C solution as sources and the cylindrical container was filled with 18F-FDG solution as the background. The phantom was continuously scanned in a Biograph-40 True Point/True View PET/CT scanner, and 42 images were reconstructed with source-to-background ratio (SBR) ranging from 16:1 to 1.8:1. We took a large and a small ROI for each sphere, both of which contain the whole sphere and does not contain any other spheres. Six other ROIs of different sizes were then taken between the large and the small ROI. For each ROI, all images were segmented by eitht thresholding methods and eight advanced methods, respectively. The segmentation results were evaluated by dice similarity index (DSI), classification error (CE) and volume error (VE). The robustness of different methods to ROI variation was quantified using the interrun variation and a generalized Cohen's kappa. Results: With the change of ROI, the segmentation results of all tested methods changed more or less. Compared with all advanced methods, thresholding methods were less affected by the ROI change. In addition, most of the thresholding methods got more accurate segmentation results for all sphere sizes. Conclusion: The results showed that the segmentation performance of all tested methods was affected by the change of ROI. Thresholding methods were more robust to this change and they can segment the PET image more accurately. This work was supported in part by National Natural Science Foundation of China (NNSFC), under Grant Nos. 60971112 and 61375018, and Fundamental Research Funds for the Central Universities, under Grant No. 2012QN086. Wei Lu was supported in

  8. Fitting in or opting out: A review of key social-psychological factors influencing a sense of belonging for women in physics

    NASA Astrophysics Data System (ADS)

    Lewis, Karyn L.; Stout, Jane G.; Pollock, Steven J.; Finkelstein, Noah D.; Ito, Tiffany A.

    2016-12-01

    [This paper is part of the Focused Collection on Gender in Physics.] A number of cultural, social, environmental, and biological factors have been suggested to explain women's relatively lower representation in physics and other science, technology, engineering, and math (STEM) fields. Given its persistence, the causes of gender disparities are likely to be complex and multiply determined. In this review paper, we discuss how a sense of belonging relates to women's interest, persistence, and achievement in physics. We explore what it means to "fit in" and belong in academic contexts, the situational and interpersonal antecedents to belonging, and the consequences of a lack of belonging. We review the empirical evidence for the efficacy of interventions designed to bolster a sense of belonging. Based on these interventions we conclude the paper with a number of practical recommendations to affirm women's sense of belonging and create more welcoming and inclusive physics environments for all students.

  9. [Diurnal and Seasonal Dynamic Variation of Soil Respiration and Its Influencing Factors of Different Fenced Enclosure Years in Desert Steppec].

    PubMed

    Cui, Hai; Zhang, Ya-hong

    2016-04-15

    The fenced measures could improve the ecological environment of degraded grassland, it's a main measure for restoration of degraded grassland vegetation in China. Soil respiration (Rs) is an important component of an ecosystem's carbon cycle and the main pathway for carbon moving from the ecosystem to the atmosphere. In order to explore soil respiration characteristics and influencing factors of the different fenced years in arid desert grassland, we continuously observed Rs rate and environmental factors in the growing season of fenced enclosure 11a, 7a and no fenced (CK) desert steppe in Ningxia. The results showed that: (1) Both the diurnal andseasonal variations of Rs rate showed a single asymmetric peak changing in fenced enclosure of 11 years, 7 years, CK desert steppe. On the daily scale, the maximum and minimum values of Rs rate were found in the periods of 12:00-16:00 and 00:00-06:00,respectively. On the seasonal variation scale, the maximum value of Rs rate occurred in August with suitable precipitation and temperature conditions. And the Rs rate of the growing season of different fenced enclosure years was in the order of 11a [0.143 g · (m² · h)⁻¹] > 7a [0.138 g · (m² · h)⁻¹] > CK [0.106 g · (m2 - h)⁻¹]. (2) According to statistical analysis, it indicated that R² rate had a significant exponential positive relationship with air and soil temperature in fenced enclosure of 11 years, 7 years, CK desert steppe (P < 0.01). The order of the correlation of Rs rate and temperature was shown as soil surface temperature (R²: 0.408-0.413) > air temperature (R2: 0.355-0.376) > 5-20 cm soil temperature (R2: 0.263-0.394). The temperature sensitivity coefficient Q, increased gradually with the soil depth, and Q1, of different fenced enclosure years was showed as 11 a (2.728) > 7a (2.436) > CK (2.086). (3) A significant quadratic function model (P < 0.05) was observed for the relationship between Rs rate and relative air humidity, soil moisture content

  10. Variation in migratory behavior influences regional genetic diversity and structure among American kestrel populations (Falco sparverius) in North America

    USGS Publications Warehouse

    Miller, Mark P.; Mullins, Thomas D.; Parrish, John G.; Walters, Jeffrey R.; Haig, Susan M.

    2012-01-01

    Birds employ numerous strategies to cope with seasonal fluctuations in high-quality habitat availability. Long distance migration is a common tactic; however, partial migration is especially common among broadly distributed species. Under partial migration systems, a portion of a species migrates, whereas the remainder inhabits breeding grounds year round. In this study, we identified effects of migratory behavior variation on genetic structure and diversity of American Kestrels (Falco sparverius), a widespread partial migrant in North America. American Kestrels generally migrate; however, a resident group inhabits the southeastern United States year round. The southeastern group is designated as a separate subspecies (F. s. paulus) from the migratory group (F. s. sparverius). Using mitochondrial DNA and microsatellites from 183 and 211 individuals, respectively, we illustrate that genetic structure is stronger among nonmigratory populations, with differentiation measures ranging from 0.060 to 0.189 depending on genetic marker and analysis approach. In contrast, measures from western North American populations ranged from 0 to 0.032. These findings suggest that seasonal migratory behavior is also associated with natal and breeding dispersal tendencies. We likewise detected significantly lower genetic diversity within nonmigratory populations, reflecting the greater influence of genetic drift in small populations. We identified the signal of population expansion among nonmigratory populations, consistent with the recent establishment of higher latitude breeding locations following Pleistocene glacial retreat. Differentiation of F. s. paulus and F. s. sparverius reflected subtle differences in allele frequencies. Because migratory behavior can evolve quickly, our analyses suggest recent origins of migratory American Kestrel populations in North America.

  11. The condition dependency of fitness in males and females: the fitness consequences of juvenile diet assessed in environments differing in key adult resources.

    PubMed

    Zikovitz, Andrea E; Agrawal, Aneil F

    2013-10-01

    Variation in environmental or genetic quality leads to phenotypic variation in condition, but how much variation in fitness is created by this variation in condition? Using Drosophila melanogaster, we manipulated condition via alternative larval diets and then tested several key factors predicted to influence how much variation in fitness results from differences in condition. Specifically, we were interested in whether male and female fitness are affected equally by condition and whether the strength of selection on condition depends on the abundance of key resources limiting the reproductive output of each sex. We measured selection on condition in alternative assay contexts that varied in the abundance of adult food (a key resource for females) or in the abundance of females (a key resource for males). Overall, selection tended to be stronger on males than females. However, selection on males was weakened when the abundance of their key resource (females) was elevated. Increasing the abundance of the key resource for females (live yeast) elevated their reproductive output as expected but did not change the strength of selection in this sex. Instead, this manipulation increased selection on males, suggesting that this environmental factor indirectly affects selection on males via their interaction with females.

  12. Social personality trait and fitness.

    PubMed

    Cote, J; Dreiss, A; Clobert, J

    2008-12-22

    Several recent studies have explored various aspects of animal personality and their ecological consequences. However, the processes responsible for the maintenance of personality variability within a population are still largely unknown. We have recently demonstrated that social personality traits exist in the common lizard (Lacerta vivipara) and that the variation in sociability provides an explanation for variable dispersal responses within a given species. However, we need to know the fitness consequences of variation in sociability across environmental contexts in order to better understand the maintenance of such variation. In order to achieve this, we investigated the relationship between sociability and survival, body growth and fecundity, in one-year-old individuals in semi-natural populations with varying density. 'Asocial' and 'social' lizards displayed different fitness outcomes in populations of different densities. Asocial lizards survived better in low-density populations, while social females reproduced better. Spatiotemporal variation in environmental conditions might thus be the process underlying the maintenance of these personality traits within a population. Finally, we also discuss the position of sociability in a more general individual behavioural pattern including boldness, exploration and aggressiveness.

  13. Influence of a Medium-Impact Exercise Program on Health-Related Quality of Life and Cardiorespiratory Fitness in Females with Subclinical Hypothyroidism: An Open-Label Pilot Study

    PubMed Central

    Garces-Arteaga, Andrea; Nieto-Garcia, Nataly; Suarez-Sanchez, Freddy; Triana-Reina, Héctor Reynaldo; Ramírez-Vélez, Robinson

    2013-01-01

    Objective. To examine the influence of a medium-impact exercise program (MIEP) on health-related quality of life (HRQoL) and cardiorespiratory fitness (VO2max) in females with subclinical hypothyroidism (sHT). Materials and Methods. We selected 17 sedentary women with sHT (mean age: 43.1 (standard deviation: 9.7) years). Participants carried out an MIEP consisting of 3 weekly sessions of 60 minutes during 12 weeks. Before and after the exercise program HRQoL was assessed by the SF-12v2 questionnaire, and VO2max was evaluated by Rockport walk test. Results. After the 12-week intervention, the participants that performed an MIEP showed improvements in HRQoL in most domains, particularly the vitality domain by 7 points, the social functioning domain by 10 points, the mental health domain by 7 points, and the mental component summary by 7 points. One of the four domains within the physical component summary (general health domain) showed significant effect of the exercise intervention: 6 points. Moreover, the participants that performed exercise showed a higher VO2max (28%; P < 0.01). Conclusion. After 12 weeks of medium-impact exercise program, there were remarkable improvements in HRQoL in most domains. Moreover, this exercise program proved to have a positive influence on cardiorespiratory fitness. PMID:24490101

  14. Influence of a medium-impact exercise program on health-related quality of life and cardiorespiratory fitness in females with subclinical hypothyroidism: an open-label pilot study.

    PubMed

    Garces-Arteaga, Andrea; Nieto-Garcia, Nataly; Suarez-Sanchez, Freddy; Triana-Reina, Héctor Reynaldo; Ramírez-Vélez, Robinson

    2013-01-01

    Objective. To examine the influence of a medium-impact exercise program (MIEP) on health-related quality of life (HRQoL) and cardiorespiratory fitness (VO2max) in females with subclinical hypothyroidism (sHT). Materials and Methods. We selected 17 sedentary women with sHT (mean age: 43.1 (standard deviation: 9.7) years). Participants carried out an MIEP consisting of 3 weekly sessions of 60 minutes during 12 weeks. Before and after the exercise program HRQoL was assessed by the SF-12v2 questionnaire, and VO2max was evaluated by Rockport walk test. Results. After the 12-week intervention, the participants that performed an MIEP showed improvements in HRQoL in most domains, particularly the vitality domain by 7 points, the social functioning domain by 10 points, the mental health domain by 7 points, and the mental component summary by 7 points. One of the four domains within the physical component summary (general health domain) showed significant effect of the exercise intervention: 6 points. Moreover, the participants that performed exercise showed a higher VO2max (28%; P < 0.01). Conclusion. After 12 weeks of medium-impact exercise program, there were remarkable improvements in HRQoL in most domains. Moreover, this exercise program proved to have a positive influence on cardiorespiratory fitness.

  15. Family Activities for Fitness

    ERIC Educational Resources Information Center

    Grosse, Susan J.

    2009-01-01

    This article discusses how families can increase family togetherness and improve physical fitness. The author provides easy ways to implement family friendly activities for improving and maintaining physical health. These activities include: walking, backyard games, and fitness challenges.

  16. Outdoor fitness routine

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000891.htm Outdoor fitness routine To use the sharing features on this ... you and is right for your level of fitness. Here are some ideas: Warm up first. Get ...

  17. Understanding host switching through ecological fitting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite the fact that parasites are highly specialized to their hosts, extensive empirical evidence demonstrates that host switching rather than co-speciation is the most important factor influencing the origin of host-parasite associations. Ecological fitting in sloppy fitness space has been propos...

  18. Children's Physical Fitness and Academic Performance

    ERIC Educational Resources Information Center

    Wittberg, Richard A.; Northrup, Karen L.; Cottrel, Lesley

    2009-01-01

    Background: Childhood obesity is a major public health threat. Increased fitness may have a positive influence on cognitive performance in both adults and children. Purpose: To examine which aspects of children's fitness assessment are associated with their performance on four different academic areas. Methods: FITNESSGRAM measures aerobic…

  19. Influence of anthropogenic alterations on geomorphic response to climate variations and change in San Francisco Bay-Delta and watershed

    USGS Publications Warehouse

    Florsheim, J.L.; Dettinger, M.D.

    2004-01-01

    Global warming and attendant sea-level rise may soon impact geomorphic processes in the Sacramento-San Joaquin River and San Francisco Bay Delta systems. During the past two centuries, dramatic anthropogenic changes in sediment supply and pervasive structural controls on rivers and floodplains have altered geomorphic responses to floods throughout a zone that extends upstream from tidally influenced areas to dams that regulate flow. Current geomorphic responses to floods differ from natural responses due to historical actions that concentrated the pre-disturbance multiple-channel and flood-basin system into single channels isolated by levees from increasingly developed floodplains and flood bypass channels, altered flow and sediment regimes, and caused subsidence of leveed Delta Islands. A review of historic and current geomorphic responses to floods illustrates the dominance of structural controls on geomorphic changes in the lowland part of the Sacramento-San Joaquin system. Current climate-change projections for CA suggest that the total volume of snowmelt runoff that may be shifted from spring and added to winter flows is roughly 5 maf/yr, similar to the volume currently available for flood storage in Sierra Nevadan reservoirs. Changes in timing of reservoir releases to accommodate these changes could add to either the magnitude or duration of winter flood peaks, each causing different geomorphic responses. Increased wintertime flows that accompany already large floods could increase overbank flood extent, erosion, and sedimentation, or alternatively increase the depth and strength of confined flows and increase the risk of levee failures. Runoff released from reservoirs as a relatively constant addition to winter baseflow would increase the duration of bankfull or possibly "levee-full" flows. This scenario could lead to bank and levee failure through increased saturation and seepage erosion. Projected sea level rise of 1-2 m would compound vulnerability of

  20. Physical characteristics related to bra fit.

    PubMed

    Chen, Chin-Man; LaBat, Karen; Bye, Elizabeth

    2010-04-01

    Producing well-fitting garments has been a challenge for retailers and manufacturers since mass production began. Poorly fitted bras can cause discomfort or pain and result in lost sales for retailers. Because body contours are important factors affecting bra fit, this study analyses the relationship of physical characteristics to bra-fit problems. This study has used 3-D body-scanning technology to extract upper body angles from a sample of 103 college women; these data were used to categorise physical characteristics into shoulder slope, bust prominence, back curvature and acromion placement. Relationships between these physical categories and bra-fit problems were then analysed. Results show that significant main effects and two-way interactions of the physical categories exist in the fit problems of poor bra support and bra-motion restriction. The findings are valuable in helping the apparel industry create better-fitting bras. STATEMENT OF RELEVANCE: Poorly fitted bras can cause discomfort or pain and result in lost sales for retailers. The findings regarding body-shape classification provide researchers with a statistics method to quantify physical characteristics and the findings regarding the relationship analysis between physical characteristics and bra fit offer bra companies valuable information about bra-fit perceptions attributable to women with figure variations.

  1. Quasispecies on Fitness Landscapes.

    PubMed

    Schuster, Peter

    2016-01-01

    Selection-mutation dynamics is studied as adaptation and neutral drift on abstract fitness landscapes. Various models of fitness landscapes are introduced and analyzed with respect to the stationary mutant distributions adopted by populations upon them. The concept of quasispecies is introduced, and the error threshold phenomenon is analyzed. Complex fitness landscapes with large scatter of fitness values are shown to sustain error thresholds. The phenomenological theory of the quasispecies introduced in 1971 by Eigen is compared to approximation-free numerical computations. The concept of strong quasispecies understood as mutant distributions, which are especially stable against changes in mutations rates, is presented. The role of fitness neutral genotypes in quasispecies is discussed.

  2. Potential environmental influences on variation in body size and sexual size dimorphism among Arizona populations of the western diamond-backed rattlesnake (Crotalus atrox)

    USGS Publications Warehouse

    Amarello, Melissa; Nowak, Erica M.; Taylor, Emily N.; Schuett, Gordon W.; Repp, Roger A.; Rosen, Philip C.; Hardy, David L.

    2010-01-01

    Differences in resource availability and quality along environmental gradients are important influences contributing to intraspecific variation in body size, which influences numerous life-history traits. Here, we examined variation in body size and sexual size dimorphism (SSD) in relation to temperature, seasonality, and precipitation among 10 populations located throughout Arizona of the western diamond-backed rattlesnake (Crotalus atrox). Specifically, in our analyses we addressed the following questions: (i) Are adult males larger in cooler, wetter areas? (ii) Does female body size respond differently to environmental variation? (iii) Is seasonality a better predictor of body size variation? (iv) Is SSD positively correlated with increased resources? We demonstrate that male and female C. atrox are larger in body size in cooler (i.e., lower average annual maximum, minimum, and mean temperature) and wetter areas (i.e., higher average annual precipitation, more variable precipitation, and available surface water). Although SSD in C. atrox appeared to be more pronounced in cooler, wetter areas, this relationship did not achieve statistical significance.

  3. Methods for quantifying the influences of pressure and temperature variation on metal hydride reaction rates measured under isochoric conditions.

    PubMed

    Voskuilen, Tyler G; Pourpoint, Timothée L

    2013-11-01

    Analysis techniques for determining gas-solid reaction rates from gas sorption measurements obtained under non-constant pressure and temperature conditions often neglect temporal variations in these quantities. Depending on the materials in question, this can lead to significant variations in the measured reaction rates. In this work, we present two new analysis techniques for comparison between various kinetic models and isochoric gas measurement data obtained under varying temperature and pressure conditions in a high pressure Sievert system. We introduce the integral pressure dependence method and the temperature dependence factor as means of correcting for experimental variations, improving model-measurement fidelity, and quantifying the effect that such variations can have on measured reaction rates. We use measurements of hydrogen absorption in LaNi5 and TiCrMn to demonstrate the effect of each of these methods and show that their use can provide quantitative improvements in interpretation of kinetics measurements.

  4. Influence of the aerobic fitness on time spent at high percentage of maximal oxygen uptake during a high-intensity intermittent running.

    PubMed

    Panissa, V L; Julio, U F; Pinto-E-Silva, C M; Andreato, L V; Schwartz, J; Franchini, E

    2014-12-01

    This study aimed to evaluate absolute and relative (%V.O2max) oxygen uptake (total, during effort and pause), and time spent above 90% of V.O2max during high-intensity intermittent running in subjects with different training status. Fourteen males were evaluated and divided (moderate and high aerobic power) according to their V.O2max obtained in an incremental treadmill test to volitional exhaustion. They were then submitted to high-intensity intermittent aerobic exercise (1 min:1 min at maximum velocity attained during the treadmill test, totalling 4 km). A Student's t test for independent data was conducted to identify differences between groups. The moderate aerobic power group spent more time above 90% V.O2max compared to the high aerobic power group (30.2 ±9.1%; 7.3±6%, respectively, P=0.001). Moreover, the moderate aerobic power group presented lower V.O2total (P=0.011), V.O2effort (P=0.007), higher V.O2total (%V.O2), V.O2effort (P<0.001), V.O2pause (V.O2max%) (P=0.006) compared with the high aerobic power group. There was no difference in V.O2pause between groups (P=0.091), the difference between V.O2 effort and pause was greater for the high aerobic power group compared with the moderate group (4.4±2.1; 7.8±2 mL.kg-1.min-1; P=0.009) and the difference between V.O2 effort and pause (%V.O2max) was not different between groups. To conclude, these results demonstrated that individuals with better aerobic fitness spent less time above 90% of the V.O2max and that this response can be due to better capacity to recover during the pause.

  5. Mapping the genetic basis of symbiotic variation in legume-rhizobium interactions in Medicago truncatula.

    PubMed

    Gorton, Amanda J; Heath, Katy D; Pilet-Nayel, Marie-Laure; Baranger, Alain; Stinchcombe, John R

    2012-11-01

    Mutualisms are known to be genetically variable, where the genotypes differ in the fitness benefits they gain from the interaction. To date, little is known about the loci that underlie such genetic variation in fitness or whether the loci influencing fitness are partner specific, and depend on the genotype of the interaction partner. In the legume-rhizobium mutualism, one set of potential candidate genes that may influence the fitness benefits of the symbiosis are the plant genes involved in the initiation of the signaling pathway between the two partners. Here we performed quantitative trait loci (QTL) mapping in Medicago truncatula in two different rhizobium strain treatments to locate regions of the genome influencing plant traits, assess whether such regions are dependent on the genotype of the rhizobial mutualist (QTL × rhizobium strain), and evaluate the contribution of sequence variation at known symbiosis signaling genes. Two of the symbiotic signaling genes, NFP and DMI3, colocalized with two QTL affecting average fruit weight and leaf number, suggesting that natural variation in nodulation genes may potentially influence plant fitness. In both rhizobium strain treatments, there were QTL that influenced multiple traits, indicative of either tight linkage between loci or pleiotropy, including one QTL with opposing effects on growth and reproduction. There was no evidence for QTL × rhizobium strain or genotype × genotype interactions, suggesting either that such interactions are due to small-effect loci or that more genotype-genotype combinations need to be tested in future mapping studies.

  6. Improving NEC Fit

    DTIC Science & Technology

    2015-09-01

    requirements and in managing personnel by tracking sailors who have acquired these skills. NEC Fit is one of two primary metrics that Navy leadership...with a rating. They are used in defining manpower requirements and in personnel management to track sailors who have acquired these skills. NEC Fit...of the new NEC requirements in the Total Force Manpower Management System (TFMMS) for Fit levels to reach their steady state. The primary reason for

  7. Leak test fitting

    DOEpatents

    Pickett, P.T.

    A hollow fitting for use in gas spectrometry leak testing of conduit joints is divided into two generally symmetrical halves along the axis of the conduit. A clip may quickly and easily fasten and unfasten the halves around the conduit joint under test. Each end of the fitting is sealable with a yieldable material, such as a piece of foam rubber. An orifice is provided in a wall of the fitting for the insertion or detection of helium during testing. One half of the fitting also may be employed to test joints mounted against a surface.

  8. Leak test fitting

    DOEpatents

    Pickett, Patrick T.

    1981-01-01

    A hollow fitting for use in gas spectrometry leak testing of conduit joints is divided into two generally symmetrical halves along the axis of the conduit. A clip may quickly and easily fasten and unfasten the halves around the conduit joint under test. Each end of the fitting is sealable with a yieldable material, such as a piece of foam rubber. An orifice is provided in a wall of the fitting for the insertion or detection of helium during testing. One half of the fitting also may be employed to test joints mounted against a surface.

  9. Both leaf properties and microbe-microbe interactions influence within-species variation in bacterial population diversity and structure in the lettuce (Lactuca Species) phyllosphere.

    PubMed

    Hunter, Paul J; Hand, Paul; Pink, David; Whipps, John M; Bending, Gary D

    2010-12-01

    Morphological and chemical differences between plant genera influence phyllosphere microbial populations, but the factors driving within-species variation in phyllosphere populations are poorly understood. Twenty-six lettuce accessions were used to investigate factors controlling within-species variation in phyllosphere bacterial populations. Morphological and physiochemical characteristics of the plants were compared, and bacterial community structure and diversity were investigated using terminal restriction fragment length polymorphism (T-RFLP) profiling and 16S rRNA gene clone libraries. Plant morphology and levels of soluble carbohydrates, calcium, and phenolic compounds (which have long been associated with plant responses to biotic stress) were found to significantly influence bacterial community structure. Clone libraries from three representative accessions were found to be significantly different in terms of both sequence differences and the bacterial genera represented. All three libraries were dominated by Pseudomonas species and the Enterobacteriaceae family. Significant differences in the relative proportions of genera in the Enterobacteriaceae were detected between lettuce accessions. Two such genera (Erwinia and Enterobacter) showed significant variation between the accessions and revealed microbe-microbe interactions. We conclude that both leaf surface properties and microbial interactions are important in determining the structure and diversity of the phyllosphere bacterial community.

  10. Both Leaf Properties and Microbe-Microbe Interactions Influence Within-Species Variation in Bacterial Population Diversity and Structure in the Lettuce (Lactuca Species) Phyllosphere▿

    PubMed Central

    Hunter, Paul J.; Hand, Paul; Pink, David; Whipps, John M.; Bending, Gary D.

    2010-01-01

    Morphological and chemical differences between plant genera influence phyllosphere microbial populations, but the factors driving within-species variation in phyllosphere populations are poorly understood. Twenty-six lettuce accessions were used to investigate factors controlling within-species variation in phyllosphere bacterial populations. Morphological and physiochemical characteristics of the plants were compared, and bacterial community structure and diversity were investigated using terminal restriction fragment length polymorphism (T-RFLP) profiling and 16S rRNA gene clone libraries. Plant morphology and levels of soluble carbohydrates, calcium, and phenolic compounds (which have long been associated with plant responses to biotic stress) were found to significantly influence bacterial community structure. Clone libraries from three representative accessions were found to be significantly different in terms of both sequence differences and the bacterial genera represented. All three libraries were dominated by Pseudomonas species and the Enterobacteriaceae family. Significant differences in the relative proportions of genera in the Enterobacteriaceae were detected between lettuce accessions. Two such genera (Erwinia and Enterobacter) showed significant variation between the accessions and revealed microbe-microbe interactions. We conclude that both leaf surface properties and microbial interactions are important in determining the structure and diversity of the phyllosphere bacterial community. PMID:20952648

  11. Seasonal and diel variations of ammonia and methane emissions from a naturally ventilated dairy building and the associated factors influencing emissions.

    PubMed

    Saha, C K; Ammon, C; Berg, W; Fiedler, M; Loebsin, C; Sanftleben, P; Brunsch, R; Amon, T

    2014-01-15

    Understanding seasonal and diel variations of ammonia (NH3) and methane (CH4) emissions from a naturally ventilated dairy (NVD) building may lead to develop successful control strategies for reducing emissions throughout the year. The main objective of this study was to quantify seasonal and diel variations of NH3 and CH4 emissions together with associated factors influencing emissions. Measurements were carried out with identical experimental set-up to cover three winter, spring and summer seasons, and two autumn seasons in the years 2010, 2011, and 2012. The data from 2010 and 2011 were used for developing emission prediction models and the data from 2012 were used for model validation. The results showed that NH3 emission varied seasonally following outside temperature whereas CH4 emission did not show clear seasonal trend. Diel variation of CH4 emission was less pronounced than NH3. The average NH3 and CH4 emissions between 6a.m. and 6p.m. were 66% and 33% higher than the average NH3 and CH4 emissions between 6p.m. and 6a.m., respectively for all seasons. The significant relationships (P<0.0001) between NH3 and influencing factors were found including outside temperature, humidity, wind speed and direction, hour of the day and day of the year. The significant effect (P<0.0001) of climate factors, hours of the day and days of the year on CH4 emission might be directly related to activities of the cows.

  12. The influence of ecology and genetics on behavioral variation in salamander populations across the Eastern Continental Divide.

    PubMed

    Rissler, Leslie J; Wilbur, Henry M; Taylor, Douglas R

    2004-08-01

    Understanding the unique contributions of ecology and history to the distribution of species within communities requires an integrative approach. The Eastern Continental Divide in southwestern Virginia separates river drainages that differ in species composition: the more aquatic, predatory Desmognathus quadramaculatus is present only in the New River drainage (which drains to the Gulf of Mexico), while Desmognathus monticola is present in both the New River drainage and the James River drainage (which drains to the Atlantic Ocean). We investigated natural distributions, behavioral variation in experimental mesocosms, population genetic, and phylogenetic implications of community structure. The presence of D. quadramaculatus increased the terrestriality of D. monticola in natural and experimental situations but to different degrees in allopatric and sympatric populations. Our ecological data suggest that the degree of terrestriality in D. monticola is a result of a balance between the optimal aquatic habitat and risks of predation. Our genetic analyses suggest that D. monticola has experienced a recent range expansion and has only a recent history of association with D. quadramaculatus in Virginia. This is surprising given the strong behavioral variation that exists in populations experiencing unique community compositions over a scale of meters. This study demonstrates the need to combine both ecology and genetics toward an understanding of the factors affecting species distributions, behavioral variation between populations, and patterns of genetic variation across a landscape.

  13. Why Does Working Memory Capacity Predict Variation in Reading Comprehension? On the Influence of Mind Wandering and Executive Attention

    ERIC Educational Resources Information Center

    McVay, Jennifer C.; Kane, Michael J.

    2012-01-01

    Some people are better readers than others, and this variation in comprehension ability is predicted by measures of working memory capacity (WMC). The primary goal of this study was to investigate the mediating role of mind-wandering experiences in the association between WMC and normal individual differences in reading comprehension, as predicted…

  14. Temporal variation of genetic composition in Atlantic salmon populations from the Western White Sea Basin: influence of anthropogenic factors?

    PubMed Central

    2013-01-01

    Background Studies of the temporal patterns of population genetic structure assist in evaluating the consequences of demographic and environmental changes on population stability and persistence. In this study, we evaluated the level of temporal genetic variation in 16 anadromous and 2 freshwater salmon populations from the Western White Sea Basin (Russia) using samples collected between 1995 and 2008. To assess whether the genetic stability was affected by human activity, we also evaluated the effect of fishing pressure on the temporal genetic variation in this region. Results We found that the genetic structure of salmon populations in this region was relatively stable over a period of 1.5 to 2.5 generations. However, the level of temporal variation varied among geographical regions: anadromous salmon of the Kola Peninsula exhibited a higher stability compared to that of the anadromous and freshwater salmon from the Karelian White Sea coast. This discrepancy was most likely attributed to the higher census, and therefore effective, population sizes of the populations inhabiting the rivers of the Kola Peninsula compared to salmon of the Karelian White Sea coast. Importantly, changes in the genetic diversity observed in a few anadromous populations were best explained by the increased level of fishing pressure in these populations rather than environmental variation or the negative effects of hatchery escapees. The observed population genetic patterns of isolation by distance remained consistent among earlier and more recent samples, which support the stability of the genetic structure over the period studied. Conclusions Given the increasing level of fishing pressure in the Western White Sea Basin and the higher level of temporal variation in populations exhibiting small census and effective population sizes, further genetic monitoring in this region is recommended, particularly on populations from the Karelian rivers. PMID:24053319

  15. Influence of conventional and organic agricultural practices on the phenolic content in eggplant pulp: Plant-to-plant variation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumer awareness, pesticide and fertilizer contaminations, and environmental concerns have resulted in increased demand for organically grown farm products. The present study evaluates the influence that organic versus conventional farming practices exert on the total phenolic content in eggplant...

  16. Soccer players' fitting perception of different upper boot materials.

    PubMed

    Olaso Melis, J C; Priego Quesada, J I; Lucas-Cuevas, A G; González García, J C; Puigcerver Palau, S

    2016-07-01

    The present study assessed the influence of upper boot materials on fitting perception. Twenty players tested three soccer boots only differing in the upper boot material (natural calf leather, natural kangaroo leather and synthetic leather). Players reported fitting perception and preference on specific foot areas using a perceived fitting scale. Ratings were averaged for every foot area. Repeated measures ANOVA was used to analyze the differences between boots. The kangaroo leather boots were perceived tighter and closer to the preferred fitting in general fitting, metatarsals area and instep area. The synthetic leather boots were perceived as the loosest and as the most distant boot from the preferred fitting in medial front area and instep area. In conclusion, the type of upper boot material influences the fitting perception of soccer players. The kangaroo leather was the material whose fitting was perceived closest to the players fitting preference.

  17. Atmospheric Fossil Fuel CO2 Traced by Δ(14)C in Beijing and Xiamen, China: Temporal Variations, Inland/Coastal Differences and Influencing Factors.

    PubMed

    Niu, Zhenchuan; Zhou, Weijian; Wu, Shugang; Cheng, Peng; Lu, Xuefeng; Xiong, Xiaohu; Du, Hua; Fu, Yunchong; Wang, Gehui

    2016-06-07

    One year of atmospheric Δ(14)CO2 were observed in 2014 in the inland city of Beijing and coastal city of Xiamen, China, to trace temporal CO2ff variations and to determine the factors influencing them. The average CO2ff concentrations at the sampling sites in Beijing and Xiamen were 39.7 ± 36.1 ppm and 13.6 ± 12.3 ppm, respectively. These contributed 75.2 ± 14.6% and 59.1 ± 26.8% to their respective annual ΔCO2 offsets over background CO2 concentrations. Significantly (p < 0.05) high CO2ff values were observed in winter in Beijing. We did not find any significant differences in CO2ff values between weekdays and weekends. Diurnal CO2ff variations were plainly evident, with high values between midnight and 4:00, and during morning and afternoon rush hours. The sampling site in the inland city of Beijing displayed much higher CO2ff inputs and overall temporal variations than the site in the coastal city of Xiamen. The variations of CO2ff at both sites were controlled by a combination of emission sources, topography, and atmospheric dispersion. In particular, diurnal observations at the urban site in Beijing showed that CO2ff was easily accumulated under the southeast wind conditions.

  18. Fitness and Americans.

    ERIC Educational Resources Information Center

    Nordholm, Catherine R.

    This document makes a number of observations about physical fitness in America. Among them are: (1) the symptoms of aging (fat accumulation, lowered basal metabolic rate, loss of muscular strength, reduction in motor fitness, reduction in work capacity, etc.) are not the result of disease but disuse; (2) society conditions the individual to…

  19. Physical Fitness and Counseling.

    ERIC Educational Resources Information Center

    Helmkamp, Jill M.

    Human beings are a delicate balance of mind, body, and spirit, so an imbalance in one domain affects all others. The purpose of this paper is to examine the effects that physical fitness may have on such human characteristics as personality and behavior. A review of the literature reveals that physical fitness is related to, and can affect,…

  20. Fitness in Special Populations.

    ERIC Educational Resources Information Center

    Shephard, Roy J.

    This book examines fitness research among special populations, including research on fitness assessment, programming, and performance for persons with various forms of physical disabilities. The book covers such topics as diseases that complicate life in a wheelchair, disability classifications, physiological responses to training, positive…

  1. Fitness Day. Lesson Plan.

    ERIC Educational Resources Information Center

    McNamara, Jeanne

    This lesson plan introduces students to the concept of supply and demand by appealing to bodily/kinesthetic intelligences. Students participate in a fitness class and then analyze the economic motives behind making an individual feel better after a fitness activity; i.e., analyzing how much an individual would pay for a drink and snack after a…

  2. Outfitting Campus Fitness Centers.

    ERIC Educational Resources Information Center

    Fickes, Michael

    1999-01-01

    Explains how universities and colleges, both private and public, are including fitness centers as ways of increasing their student enrollment levels. Comments are provided on school experiences in fitness-center design, equipment purchasing, and maintenance and operating-costs issues. (GR)

  3. Fun & Fitness with Balloons

    ERIC Educational Resources Information Center

    Farrell, Anne; Faigenbaum, Avery; Radler, Tracy

    2010-01-01

    The urgency to improve fitness levels and decrease the rate of childhood obesity has been at the forefront of physical education philosophy and praxis. Few would dispute that school-age youth need to participate regularly in physical activities that enhance and maintain both skill- and health-related physical fitness. Regular physical activity…

  4. Fit for Life.

    ERIC Educational Resources Information Center

    Klahr, Gary Peter

    1992-01-01

    Although the 1980's fitness craze is wearing off and adults are again becoming "couch potatoes," this trend does not justify expansion of high school compulsory physical education requirements. To encourage commitment to lifetime physical fitness, the Phoenix (Arizona) Union High School District offers students private showers, relaxed…

  5. Influence of sea level change on sediment provenance variations since the last glaciation in the southern South China Sea

    NASA Astrophysics Data System (ADS)

    Jiwarungrueangkul, T.; Liu, Z.; Zhao, Y.

    2015-12-01

    Clay mineralogy and grain size of 170 sediment samples from Core MD05-2893 located near the Molengraaff paleo-river mouth on the upper Sunda slope in the southern South China Sea were investigated to assess the effect of sea level change on sediment provenance variations. The clay mineral results show high contents of smectite (35-55%), moderate contents of illite (16-31%), kaolinite (11-29%), and chlorite (8-15%). Due to distinction of clay mineral assemblages from each sediment provenance, the Indonesian Archipelago is the majority of smectite source, whereas North Boneo mainly provides illite to the southern South China Sea. Therefore, the smectite/illite ratio is applied to determine the sediment provenance variations. Both the mineralogical ratio and median grain size show consistent sediment source and dynamic variations since the last glaciation, in which case the response of sediment provenance change due to the sea level rise is expected. Our study suggests a three-stage evolution of the sediment provenance variation on the Sunda slope in the southern South China Sea: (1) during the low sea level stand of the last glaciation, the high content of smectite implies that the Indonesian Archipelago provided the majority of sediments to this area through the Molengraaff paleo-river system; (2) during the sea level rise of the deglaciation, the decreasing of smectite content but the increasing of illite indicates that the Indonesian Archipelago reduced in sediments supply due to regression of coastline, whereas North Boneo increased sediment supply; (3) during the high sea level stand of Holocene, the smectite content increases again, implying that the Indonesian Archipelago provides sediments to this area again through the ocean circulation. Consequently, the sea level rise mainly results in sediment provenance change in the southern South China Sea since the last deglaciation.

  6. Investigating the use of liquisolid compacts technique to minimize the influence of pH variations on loratadine release.

    PubMed

    El-Hammadi, Mazen; Awad, Nisrine

    2012-03-01

    Loratadine is a class II water-insoluble drug and its dissolution rate and, consequently, absorption are dependent on the gastrointestinal pH. The resulting very high variability in bioavailability and related inter- and intra-subject absorption variations present a major challenge that hinders the realization of an effective and uniform therapy. Among the several techniques that have been used to minimize pH dependency of dissolution rate, liquisolid compacts technique can be suggested as a promising solution. In this study, it was hypothesized that the formulation of loratadine using liquisolid compacts technique may reduce the effect of pH variation on the drug dissolution rate. Solubilities of loratadine in propylene glycol, Tween 80, and polyethylene glycol 400 were first measured and propylene glycol was selected as for producing the highest solubility among the tested solvents. Several liquisolid tablet formulations containing various ratios of drug: propylene glycol (5%, 10%, and 20% w/w) were prepared. The ratio of microcrystalline cellulose (carrier) to silica (coating powder material) was kept constant in all formulations. The dissolution behavior of loratadine from liquisolid compacts was investigated in several buffered media with different pH values (pH 1.2, 2.5, and 5). The results showed that the drug release rates produced by liquisolid compacts were significantly higher and less affected by pH variation compared with conventionally made (direct compression) and commercial (Clarityn) tablets. In conclusion, liquisolid compacts technique may be used as a tool to minimize the effects of pH variation on the dissolution rate of drugs with poor water solubility.

  7. The influence of thermal inertia on Mars' seasonal pressure variation and the effect of the weather component

    NASA Technical Reports Server (NTRS)

    Wood, S. E.; Paige, D. A.

    1993-01-01

    Using a Leighton-Murray type diurnal and seasonal Mars thermal model, we found that it is possible to reproduce the seasonal variation in daily-averaged pressures (approximately 680-890 Pa) measured by Viking Lander 1 (VL1), during years without global dust storms, with a standard deviation of less than 5 Pa. In this simple model, surface CO2, frost condensation, and sublimation rates at each latitude are determined by the net effects of radiation, latent heat, and heat conduction in subsurface soil layers. An inherent assumption of our model is that the seasonal pressure variation is due entirely to the exchange of mass between the atmosphere and polar caps. However, the results of recent Mars GCM modeling have made it clear that there is a significant dynamical contribution to the seasonal pressure variation. This 'weather' component is primarily due to large-scale changes in atmospheric circulation, and its magnitude depends somewhat on the dust content of the atmosphere. The overall form of the theoretical weather component at the location of VL1, as calculated by the AMES GCM, remains the same over the typical range of Mars dust opacities.

  8. AN Fitting Reconditioning Tool

    NASA Technical Reports Server (NTRS)

    Lopez, Jason

    2011-01-01

    A tool was developed to repair or replace AN fittings on the shuttle external tank (ET). (The AN thread is a type of fitting used to connect flexible hoses and rigid metal tubing that carry fluid. It is a U.S. military-derived specification agreed upon by the Army and Navy, hence AN.) The tool is used on a drill and is guided by a pilot shaft that follows the inside bore. The cutting edge of the tool is a standard-size replaceable insert. In the typical Post Launch Maintenance/Repair process for the AN fittings, the six fittings are removed from the ET's GUCP (ground umbilical carrier plate) for reconditioning. The fittings are inspected for damage to the sealing surface per standard operations maintenance instructions. When damage is found on the sealing surface, the condition is documented. A new AN reconditioning tool is set up to cut and remove the surface damage. It is then inspected to verify the fitting still meets drawing requirements. The tool features a cone-shaped interior at 36.5 , and may be adjusted at a precise angle with go-no-go gauges to insure that the cutting edge could be adjusted as it wore down. One tool, one setting block, and one go-no-go gauge were fabricated. At the time of this reporting, the tool has reconditioned/returned to spec 36 AN fittings with 100-percent success of no leakage. This tool provides a quick solution to repair a leaky AN fitting. The tool could easily be modified with different-sized pilot shafts to different-sized fittings.

  9. The genetic architecture of fitness in a seed beetle: assessing the potential for indirect genetic benefits of female choice

    PubMed Central

    2008-01-01

    Background Quantifying the amount of standing genetic variation in fitness represents an empirical challenge. Unfortunately, the shortage of detailed studies of the genetic architecture of fitness has hampered progress in several domains of evolutionary biology. One such area is the study of sexual selection. In particular, the evolution of adaptive female choice by indirect genetic benefits relies on the presence of genetic variation for fitness. Female choice by genetic benefits fall broadly into good genes (additive) models and compatibility (non-additive) models where the strength of selection is dictated by the genetic architecture of fitness. To characterize the genetic architecture of fitness, we employed a quantitative genetic design (the diallel cross) in a population of the seed beetle Callosobruchus maculatus, which is known to exhibit post-copulatory female choice. From reciprocal crosses of inbred lines, we assayed egg production, egg-to-adult survival, and lifetime offspring production of the outbred F1 daughters (F1 productivity). Results We used the bio model to estimate six components of genetic and environmental variance in fitness. We found sizeable additive and non-additive genetic variance in F1 productivity, but lower genetic variance in egg-to-adult survival, which was strongly influenced by maternal and paternal effects. Conclusion Our results show that, in order to gain a relevant understanding of the genetic architecture of fitness, measures of offspring fitness should be inclusive and should include quantifications of offspring reproductive success. We note that our estimate of additive genetic variance in F1 productivity (CVA = 14%) is sufficient to generate indirect selection on female choice. However, our results also show that the major determinant of offspring fitness is the genetic interaction between parental genomes, as indicated by large amounts of non-additive genetic variance (dominance and/or epistasis) for F1 productivity. We

  10. Assessing Differential Effects: Applying Regression Mixture Models to Identify Variations in the Influence of Family Resources on Academic Achievement

    ERIC Educational Resources Information Center

    Van Horn, M. Lee; Jaki, Thomas; Masyn, Katherine; Ramey, Sharon Landesman; Smith, Jessalyn A.; Antaramian, Susan

    2009-01-01

    Developmental scientists frequently seek to understand effects of environmental contexts on development. Traditional analytic strategies assume similar environmental effects for all children, sometimes exploring possible moderating influences or exceptions (e.g., outliers) as a secondary step. These strategies are poorly matched to ecological…

  11. Spatial Variations In The Fate And Transport Of Metals In A Mining-Influenced Stream, North Fork Clear Creek, Colorado

    EPA Science Inventory

    North Fork Clear Creek (NFCC) receives acid-mine drainage (AMD) from multiple abandoned mines in the Clear Creek Watershed. Point sources of AMD originate In the Black Hawk/Central City region of the stream. Water chemistry also is influenced by several non-point sources of AMD,...

  12. Identifying the loci that influence quantitative trait variation in oats: Lessons from human population-based GWAS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, the resources have become available to enable genome-wide genotype-phenotype association analyses in cereal crops using thousands of genetic markers measured on hundreds of lines. One open question is whether these resources are sufficient to identify the loci influencing quantitati...

  13. Kids in Action. Fitness for Children.

    ERIC Educational Resources Information Center

    President's Council on Physical Fitness and Sports, Washington, DC.

    This booklet contains ideas for parents to encourage their children to be physically active. Twenty-one activities--incorporating such skills as jumping, balancing, and stretching--are described and illustrated, and variations are provided to accommodate children's different abilities. A "Physical Activity Pyramid" shows how to fit activity into…

  14. Integrating the Levels of Person-Environment Fit: The Roles of Vocational Fit and Group Fit

    ERIC Educational Resources Information Center

    Vogel, Ryan M.; Feldman, Daniel C.

    2009-01-01

    Previous research on fit has largely focused on person-organization (P-O) fit and person-job (P-J) fit. However, little research has examined the interplay of person-vocation (P-V) fit and person-group (P-G) fit with P-O fit and P-J fit in the same study. This article advances the fit literature by examining these relationships with data collected…

  15. Flow cytometric characterization of hemocytes of the sunray venus clam Macrocallista nimbosa and influence of salinity variation.

    PubMed

    Jauzein, Cécile; Donaghy, Ludovic; Volety, Aswani K

    2013-09-01

    Sunray venus clam Macrocallista nimbosa is a native bivalve mollusc of Florida, USA, currently evaluated as a potential new aquaculture species. Very little is known about the physiology and hemocyte characteristics of this species. Bivalve hemocytes are generally involved in various physiological functions including nutrition, tissue repair, detoxification and immune defense. Understanding hemocytes of M. nimbosa and their response to environmental variations is crucial. In estuarine Florida areas, salinity is probably the most important factor potentially affecting clams physiology since wide variations can occur within few days. In the present work, using flow cytometry, hemocyte types and cellular parameters (oxidative activity, lysosomal content, phagocytosis capacity) were first characterized in sunray venus clams, in relation with endogenous variables (i.e., size, body weight, gender). Clams were then transferred from salinity 30 psu to 18, 21, 25, 30, 35 and 38 psu. After 7 days, impact of salinity variations was determined on hemocyte parameters, along with estimation of physiological status of clams (mortality, valve closure, filtration activity). Hemocytes of sunray venus clam appeared as a unique population, both in terms of morphology (FSC vs. SSC) and intracellular parameters, but displayed high inter-individual variability. Allometric relationship was only described for intracellular oxidative activity. Transfer of clams to 18 psu and, at lower extent, 21 psu resulted in valve closure, mortality and decreased filtration activity. Low salinities resulted in reduction of the number of circulating hemocytes, potentially reflecting infiltration in tissues as part of an inflammatory response or to optimize nutrient distribution. Low salinities also highly impacted hemocytes as depicted by increased cell and lysosomal compartment volumes, decreased phagocytosis capacity as well as increased oxidative stress and mortality. Salinity drops depress physiology

  16. Influence of Forest Structure on the Sentinel-1 Backscatter Variation- Analysis with Full-Waveform LiDAR Data

    NASA Astrophysics Data System (ADS)

    Dostalova, A.; Milenkovic, M.; Hollaus, M.; Wagner, W.

    2016-08-01

    The availability of Sentinel-1 sensor provided the former unprecedented availability of high resolution dual-polarization Synthetic Aperture Radar (SAR) data over European continent. Dense time-series enables the study of the seasonal variability of C-Band SAR backscatter over forested areas. In this study, the Sentinel-1 backscatter and its annual variation is analysed with respect to forest type and structural parameters provided from the external dataset and airborne laser scanning acquisition. Different seasonal patterns are observed for coniferous and deciduous tree species. Less pronounced backscatter differences are also attributed to forest structure and vegetation cover fraction.

  17. Finding Time for Fitness

    MedlinePlus

    ... exercise strategy to improve health and fitness? Applied Physiology Nutrition and Metabolism. 2014;39:409. Gibala MJ, ... interval training in health and disease. Journal of Physiology. 2012;590:1077. Aug. 06, 2016 Original article: ...

  18. Exponentially fitted symplectic integrator

    NASA Astrophysics Data System (ADS)

    Simos, T. E.; Vigo-Aguiar, Jesus

    2003-01-01

    In this paper a procedure for constructing efficient symplectic integrators for Hamiltonian problems is introduced. This procedure is based on the combination of the exponential fitting technique and symplecticness conditions. Based on this procedure, a simple modified Runge-Kutta-Nyström second-order algebraic exponentially fitted method is developed. We give explicitly the symplecticness conditions for the modified Runge-Kutta-Nyström method. We also give the exponential fitting and trigonometric fitting conditions. Numerical results indicate that the present method is much more efficient than the “classical” symplectic Runge-Kutta-Nyström second-order algebraic method introduced by M.P. Calvo and J.M. Sanz-Serna [J. Sci. Comput. (USA) 14, 1237 (1993)]. We note that the present procedure is appropriate for all near-unimodal systems.